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1

Denton, PH, DM Fowlkes, ST Lord y HM Reisner. "Hemophilia B Durham: a mutation in the first EGF-like domain of factor IX that is characterized by polymerase chain reaction". Blood 72, n.º 4 (1 de octubre de 1988): 1407–11. http://dx.doi.org/10.1182/blood.v72.4.1407.bloodjournal7241407.

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Two men with factor IX (FIX)antigen-positive (CRM+) hemophilia B were selected for study because of their abnormal expression of an immunologically defined epitope previously localized to the EGF-like domains of the molecule. Exons IV and V (coding for the first and second EGF-like domains) of FIX were amplified 10(7) times from the patients' genomic DNA by using polymerase chain reaction (PCR) technology and sequenced. Both patients had identical mutations which resulted in the highly conserved Gly 60 residue being changed to Ser. PCR-amplified exon IV from six normal males had the previously defined canonic sequence. The correlation between the mutation and defective epitope expression in the two patients suggests that a change in the tertiary structure of the EGF-like domain is likely to cause the mild hemophilia B.
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2

Denton, PH, DM Fowlkes, ST Lord y HM Reisner. "Hemophilia B Durham: a mutation in the first EGF-like domain of factor IX that is characterized by polymerase chain reaction". Blood 72, n.º 4 (1 de octubre de 1988): 1407–11. http://dx.doi.org/10.1182/blood.v72.4.1407.1407.

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Abstract Two men with factor IX (FIX)antigen-positive (CRM+) hemophilia B were selected for study because of their abnormal expression of an immunologically defined epitope previously localized to the EGF-like domains of the molecule. Exons IV and V (coding for the first and second EGF-like domains) of FIX were amplified 10(7) times from the patients' genomic DNA by using polymerase chain reaction (PCR) technology and sequenced. Both patients had identical mutations which resulted in the highly conserved Gly 60 residue being changed to Ser. PCR-amplified exon IV from six normal males had the previously defined canonic sequence. The correlation between the mutation and defective epitope expression in the two patients suggests that a change in the tertiary structure of the EGF-like domain is likely to cause the mild hemophilia B.
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3

Hennessy, Bryan T. J., Kirsten M. Timms, Mark S. Carey, Alexander Gutin, Larissa A. Meyer, Darl D. Flake, Victor Abkevich et al. "Somatic Mutations in BRCA1 and BRCA2 Could Expand the Number of Patients That Benefit From Poly (ADP Ribose) Polymerase Inhibitors in Ovarian Cancer". Journal of Clinical Oncology 28, n.º 22 (1 de agosto de 2010): 3570–76. http://dx.doi.org/10.1200/jco.2009.27.2997.

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Purpose The prevalence of BRCA½ mutations in germline DNA from unselected ovarian cancer patients is 11% to 15.3%. It is important to determine the frequency of somatic BRCA½ changes, given the sensitivity of BRCA-mutated cancers to poly (ADP ribose) polymerase-1 (PARP1) inhibitors and platinum analogs. Patients and Methods In 235 unselected ovarian cancers, BRCA½ was sequenced in 235, assessed by copy number analysis in 95, and tiling arrays in 65. 113 tumors were sequenced for TP53. BRCA½ transcript levels were assessed by quantitative polymerase chain reaction in 220. When available for tumors with BRCA½ mutations, germline DNA was sequenced. Results Forty-four mutations (19%) in BRCA1 (n = 31)/BRCA2 (n = 13) were detected, including one homozygous BRCA1 intragenic deletion. BRCA½ mutations were particularly common (23%) in high-grade serous cancers. In 28 patients with available germline DNA, nine (42.9%) of 21 and two (28.6%) of seven BRCA1 and BRCA2 mutations were demonstrated to be somatic, respectively. Five mutations not previously identified in germline DNA were more commonly somatic than germline (four of 11 v one of 17; P = .062). There was a positive association between BRCA1 and TP53 mutations (P = .012). BRCA½ mutations were associated with improved progression-free survival (PFS) after platinum-based chemotherapy in univariate (P = .032; hazard ratio [HR] = 0.65; 95% CI, 0.43 to 0.98) and multivariate (P = .019) analyses. BRCA½ deficiency, defined as BRCA½ mutations or expression loss (in 24 [13.3%] BRCA½–wild-type cancers), was present in 67 ovarian cancers (30%) and was also significantly associated with PFS in univariate (P = .026; HR = 0.67; 95% CI, 0.47 to 0.96) and multivariate (P = .008) analyses. Conclusion BRCA½ somatic and germline mutations and expression loss are sufficiently common in ovarian cancer to warrant assessment for prediction of benefit in clinical trials of PARP1 inhibitors.
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4

Flores, R., J. A. Navarro, M. de la Peña, B. Navarro, S. Ambrós y A. Vera. "Viroids with Hammerhead Ribozymes: Some Unique Structural and Functional Aspects with Respect to Other Members of the Group". Biological Chemistry 380, n.º 7-8 (1 de julio de 1999): 849–54. http://dx.doi.org/10.1515/bc.1999.104.

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AbstractViroids, subviral pathogens of plants, are composed of a single-stranded circular RNA of 246–399 nucleotides. Within the 27 viroids sequenced, avocado sunblotch, peach latent mosaic and chrysanthemum chlorotic mottle viroids (ASBVd, PLMVd and CChMVd, respectively) can form hammerhead structures in both of their polarity strands. These ribozymes mediate self-cleavage of the oligomeric RNAs generated in the replication through a rolling circle mechanism, whose two other steps are catalyzed by an RNA polymerase and an RNA ligase. ASBVd, and presumably PLMVd and CChMVd, replicate and accumulate in the chloroplast, whereas typical viroids replicate and accumulate in the nucleus. PLMVd and CChMVd do not adopt a rod-like or quasi rod-like secondary structure as typical viroids do but have a highly branched conformation. A pathogenicity determinant has been mapped in a defined region of the CChMVd molecule.
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5

Baum, Bernard R. y D. A. Johnson. "The molecular diversity of the 5S rRNA gene in barley (Hordeum vulgare)". Genome 37, n.º 6 (1 de diciembre de 1994): 992–98. http://dx.doi.org/10.1139/g94-140.

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The 5S rDNA genes from several accessions of cultivated barley, Hordeum vulgare L., were amplified by the polymerase chain reaction, cloned, and sequenced. Analysis of the aligned sequences, followed by principal coordinate analysis, support the recognition of at least two distinct classes of 5S rDNA genes. The short repeat class corresponds to the 300-bp tandem repeat defined by E.V. Ananiev as containing several TAG repeating units. The long repeat class contains long tandem repeats and lacks the TAG repeating unit. Sequences in each class can be further subdivided, with the long repeat class containing two groups and the short repeat class containing two and possibly three groups. These results suggest that in cultivated barley the sequence diversity found within the 5S rDNA non-transcribed spacer region may be encoded by three or more loci and may be useful for phylogenetic analyses provided that orthology can be established.Key words: 5S rDNA, sequence diversity, barley, phylogenetic analysis.
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6

Puel, O., F. Galgani, C. Dalet y P. Lassus. "Partial sequence of the 24S rRNA and polymerase chain reaction based assay for the toxic dinoflagellateDinophysis acuminata". Canadian Journal of Fisheries and Aquatic Sciences 55, n.º 3 (1 de marzo de 1998): 597–604. http://dx.doi.org/10.1139/f97-288.

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We describe the polymerase chain reaction (PCR) amplification of an 805 base pair fragment of 24S rRNA from the toxic dinoflagellate Dinophysis acuminata and the sequence of this fragment. We also describe a PCR-based assay for the specific detection of D. acuminata in seawater samples. Conserved primers, starting at positions 711 and 1489 of the 24S rRNA from the dinoflagellate Prorocentrum micans, were used for the PCR. The PCR product was cloned and sequenced. The fragment was aligned with rRNA sequences from other protists. Two oligonucleotides in variable domains of the sequence from D. acuminata were chosen and a protocol was defined for PCR-based detection of D. acuminata (30 cycles, 50°C). Experiments conducted with seawater samples led to the detection of D. acuminata in naturally contaminated samples. The PCR enabled us to detect down to 30 cells/L seawater. The problem of interference from large concentrations of other phytoplankton species may be solved using nested PCR.
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7

Bagasra, Omar. "Application on in situ PCR methods in histochemistry". Proceedings, annual meeting, Electron Microscopy Society of America 53 (13 de agosto de 1995): 754–55. http://dx.doi.org/10.1017/s0424820100140142.

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Since the publication of the first report regarding the in situ amplification of HIV-1 gag gene in a HIV-l infected cell line in 1990, there has been an explosion of research in the area of in situ PCR. There are over 200 publications describing various forms of in situ gene, identifying various infectious agents, tumor marker genes and other genetic elements of interest, in peer reviewed journals (reviewed in 2-15). The polymerase chain reaction (PCR) method for amplification of defined gene sequences has proved a valuable tool not only for basic researchers but also for clinical scientists. Using even a minute amount of DNA or RNA and choosing a thermostable enzyme from a large variety of sources, one can enlarge the amount of the gene of interest, which can be analyzed and/or sequenced. Thus genes or portions of gene sequences present only in a small sample of cells or small fraction of mixed cellular populations can be examined.
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8

Grünberg, Sebastian, Michael S. Bartlett, Souad Naji y Michael Thomm. "Transcription Factor E Is a Part of Transcription Elongation Complexes". Journal of Biological Chemistry 282, n.º 49 (5 de octubre de 2007): 35482–90. http://dx.doi.org/10.1074/jbc.m707371200.

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A homologue of the N-terminal domain of the α subunit of the general eukaryotic transcription factor TFE is encoded in the genomes of all sequenced archaea, but the position of archaeal TFE in transcription complexes has not yet been defined. We show here that TFE binds nonspecifically to single-stranded DNA, and photochemical cross-linking revealed TFE binding to a preformed open transcription bubble. In preinitiation complexes, the N-terminal part of TFE containing a winged helix-turn-helix motif is cross-linked specifically to DNA of the nontemplate DNA strand at positions –9 and –11. In complexes stalled at +20, TFE cross-linked specifically to positions +9, +11, and +16 of the non-template strand. Analyses of transcription complexes stalled at position +20 revealed a TFE-dependent increase of the resumption efficiency of stalled RNA polymerase and a TFE-induced enhanced permanganate sensitivity of thymine residues in the transcription bubble. These results demonstrate the presence of TFE in early elongation complexes and suggest a role of TFE in stabilization of the transcription bubble during elongation.
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9

Clark, M. R., S. B. Clarkson, P. A. Ory, N. Stollman y I. M. Goldstein. "Molecular basis for a polymorphism involving Fc receptor II on human monocytes." Journal of Immunology 143, n.º 5 (1 de septiembre de 1989): 1731–34. http://dx.doi.org/10.4049/jimmunol.143.5.1731.

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Abstract IgG Fc receptor II (Fc gamma RII) on human monocytes is polymorphic with respect to its appearance on gels after isoelectric focusing and with respect to its ability to mediate T lymphocyte proliferation induced by murine anti-CD3 mAb of the IgG1 isotype (i.e., its ability to bind murine IgG1). To determine the molecular basis for this polymorphism, we isolated total cellular RNA from PBMC of responders and nonresponders (defined by Leu-4-induced [3H] thymidine incorporation) and synthesized corresponding cDNA. Sequences encoding the extracellular domain of Fc gamma RII were then amplified using the Taq polymerase chain reaction. Amplified DNA fragments were cloned into pUC vectors, and sequenced. Analysis of clones from two nonresponders revealed a single base change (G for A) at position 519, which would result in the substitution of a histidine for an arginine at residue 133 in the mature Fc gamma RII protein. These findings suggest that the polymorphism involving human monocyte Fc gamma RII results from allelic variation of a single gene.
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10

Hong, Soo Jong, Do Hyun Kim, Da Jin Sol Jung, Md Najmul Haque y Myunggi Baik. "PSII-7 Complete genome analysis of a novel mucolytic bacterium, Prevotella mucinisolvens sp. nov., isolated from bovine rumen epithelium". Journal of Animal Science 98, Supplement_4 (3 de noviembre de 2020): 406. http://dx.doi.org/10.1093/jas/skaa278.711.

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Abstract We report the complete genome sequence of a novel mucolytic bacterium, Prevotella mucinisolvens sp. nov. Mucolytic bacteria were isolated from rumen epithelium of the dorsal sac of Korean cattle steer using a targeted cultivation on a mucin defined medium as a sole carbon source in anaerobic conditions. The genome of P. mucinisolvens was sequenced by means of both the Illumina HiSeq™ X and PacBio RSII platforms. The genome (2,730,135 bp) was found to contain 2,445 genes, 2,374 coding sequences, 61 transfer RNA, 1 transfer-messenger RNA, and 9 ribosomal RNA. The P. mucinisolvens had a total 51 glycoside hydrolases (GHs), of which 14 GHs, including β-galactosidases (GH2, GH20), α-N-acetylgalactosaminidases (GH101), α-N-acetylglucosaminidase (GH89), sialidase (GH33), and fucosidases (GH29, GH95), were identified as enzymes involved in mucin degradation. Following the KEGG pathways, the putative mucolytic pathway was constructed, including the metabolism of carbon sources such as galactose, N-acetylglucosamine, sialic acid (N-acetylneuraminic acid), and mannose. The presence of putative extracellular polysaccharide biosynthesis pathways, including Wzx/Wzy-dependent pathway (4 putative glycosyltransferases, 3 acetyltransferases, 1 flippase, 1 polymerase, 1 polysaccharide co-polymerase, and 1 outer membrane transport protein) and synthase-dependent pathway (1 putative synthase, 3 precursors of synthesis), was confirmed in P. mucinisolvens. Twelve putative virulence factors associated with adherence (hasB, KpsF, and htpB), stress reactions (clpP and clpC), antiphagocytosis (hasB and bcs1), O-antigen (gmd, fcl, and galE), and metabolic adaption (panD) were identified. This study contributes to a better understanding of epimural bacteria in putative mucin-degrading ability.
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11

DeMartini, Daniel G., John M. Errico, Sebastian Sjoestroem, April Fenster y J. Herbert Waite. "A cohort of new adhesive proteins identified from transcriptomic analysis of mussel foot glands". Journal of The Royal Society Interface 14, n.º 131 (junio de 2017): 20170151. http://dx.doi.org/10.1098/rsif.2017.0151.

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The adaptive attachment of marine mussels to a wide range of substrates in a high-energy, saline environment has been explored for decades and is a significant driver of bioinspired wet adhesion research. Mussel attachment relies on a fibrous holdfast known as the byssus, which is made by a specialized appendage called the foot. Multiple adhesive and structural proteins are rapidly synthesized, secreted and moulded by the foot into holdfast threads. About 10 well-characterized proteins, namely the mussel foot proteins (Mfps), the preCols and the thread matrix proteins, are reported as representing the bulk of these structures. To explore how robust this proposition is, we sequenced the transcriptome of the glandular tissues that produce and secrete the various holdfast components using next-generation sequencing methods. Surprisingly, we found around 15 highly expressed genes that have not previously been characterized, but bear key similarities to the previously defined mussel foot proteins, suggesting additional contribution to byssal function. We verified the validity of these transcripts by polymerase chain reaction, cloning and Sanger sequencing as well as confirming their presence as proteins in the byssus. These newly identified proteins greatly expand the palette of mussel holdfast biochemistry and provide new targets for investigation into bioinspired wet adhesion.
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12

Phyu, Wint Wint, Reiko Saito, Yadanar Kyaw, Nay Lin, Su Mon Kyaw Win, Nay Chi Win, Lasham Di Ja et al. "Evolutionary Dynamics of Whole-Genome Influenza A/H3N2 Viruses Isolated in Myanmar from 2015 to 2019". Viruses 14, n.º 11 (31 de octubre de 2022): 2414. http://dx.doi.org/10.3390/v14112414.

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This study aimed to analyze the genetic and evolutionary characteristics of the influenza A/H3N2 viruses circulating in Myanmar from 2015 to 2019. Whole genomes from 79 virus isolates were amplified using real-time polymerase chain reaction and successfully sequenced using the Illumina iSeq100 platforms. Eight individual phylogenetic trees were retrieved for each segment along with those of the World Health Organization (WHO)-recommended Southern Hemisphere vaccine strains for the respective years. Based on the WHO clades classification, the A/H3N2 strains in Myanmar from 2015 to 2019 collectively belonged to clade 3c.2. These strains were further defined based on hemagglutinin substitutions as follows: clade 3C.2a (n = 39), 3C.2a1 (n = 2), and 3C.2a1b (n = 38). Genetic analysis revealed that the Myanmar strains differed from the Southern Hemisphere vaccine strains each year, indicating that the vaccine strains did not match the circulating strains. The highest rates of nucleotide substitution were estimated for hemagglutinin (3.37 × 10−3 substitutions/site/year) and neuraminidase (2.89 × 10−3 substitutions/site/year). The lowest rate was for non-structural protein segments (4.19 × 10−5 substitutions/site/year). The substantial genetic diversity that was revealed improved phylogenetic classification. This information will be particularly relevant for improving vaccine strain selection.
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13

Caporali, E. H. G., T. Kuykendall y M. C. Stewart. "Complete sequencing and characterization of equine aggrecan". Veterinary and Comparative Orthopaedics and Traumatology 28, n.º 02 (2015): 79–87. http://dx.doi.org/10.3415/vcot-14-05-0069.

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SummaryObjectives: To fully sequence and characterize equine aggrecan and confirm conservation of major aggrecanase, calpain and matrix metalloproteinase (MMP) cleavage sites.Methods: Reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends were used to generate clones that encompassed the complete equine aggrecan sequence. Clones were sequenced and compared with the equine genome database to determine intron-exon boundaries.Results: The aggrecan gene spans over 61 kb on chromosome 1 and is encoded by 17 exons. Two major variants of aggrecan were cloned; one containing 8187 bp (2728 amino acids) and a second sequence of 8061 nucleotides (2686 amino acids). The variation was due to a CS1 domain polymorphism. Both sequences are substantially larger than predicted by the genomic database; 11 CS1 repeat elements are absent in the database sequence. The equine amino acid sequence was compared with human, bovine and murine sequences. Globular domains 1, 2 and 3 are highly conserved (overall identity over 80%). Equine CS1 is considerably larger than in other species and, therefore, is the least conserved domain (an overall amino acid identity of 22%). Previously defined aggrecanase, calpain and MMP cleavage sites were identified. Western blotting of chondrocyte culture samples showed complex post-secretion processing.Clinical significance: The complete equine aggrecan sequence will support more in-depth research on aggrecan processing and degradation in equine articular cartilage and other musculoskeletal tissues.
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14

Sricharern, Wanat, Supakarn Kaewchot, Sarawan Kaewmongkol, Natnaree Inthong, Thitichai Jarudecha, Rucksak Rucksaken, Bandid Mangkit, Sakulchit Wichianchot y Tawin Inpankaew. "Detection and genetic characterization of "Candidatus Mycoplasma haemomacaque" infection among long-tailed macaques (Macaca fascicularis) in Thailand using broad-range nested polymerase chain reaction assay". Veterinary World 14, n.º 4 (19 de abril de 2021): 943–48. http://dx.doi.org/10.14202/vetworld.2021.943-948.

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Background and Aim: Hemoplasmas are defined as small, epicellular parasitic bacteria that can infect the red blood cells of several mammalian species. Diseases caused by these bacteria range from asymptomatic infections to acute hemolytic anemia. However, data on hemoplasmas in non-human primates in Thailand remain to be limited. Therefore, this study aims to determine the occurrence and genetic diversity of hemoplasmas among long-tailed macaques in Thailand. Materials and Methods: Blood samples were collected from 339 long-tailed macaques in three provinces of Thailand. DNA was then extracted from the blood samples and tested for hemoplasma using broad-range nested polymerase chain reaction (PCR) based on the 16S rRNA gene. PCR-positive samples were sequenced, and phylogenetic analysis for species identification was conducted. Results: In total, 38 (11.2%) out of the 339 samples were found to be positive for hemoplasmas, based on the broad-range nested PCR assay of the 16S rRNA gene. The 16S rRNA sequences of Mycoplasma spp. were highly similar (98-99% identity) to "Candidatus Mycoplasma haemomacaque." Furthermore, phylogenetic analysis using maximum likelihood demonstrated that the sequences were located in the same cluster of "Ca. M. haemomacaque." Conclusion: The detection of hemoplasmas among long-tailed macaques in Thailand is reported. Genetic characterization confirmed that these hemoplasmas are closely related to "Ca. M. haemomacaque." These results indicate that long-tailed macaques in several locations in Thailand may be infected and serve as reservoirs for this parasite.
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15

Lapointe, Hope R., Weiyan Dong, Winnie W. Y. Dong, Don Kirkby, Conan Woods, Art F. Y. Poon, Anita Y. M. Howe, P. Richard Harrigan y Chanson J. Brumme. "Validation of a Genotype-Independent Hepatitis C Virus Near-Whole Genome Sequencing Assay". Viruses 13, n.º 9 (30 de agosto de 2021): 1721. http://dx.doi.org/10.3390/v13091721.

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Despite the effectiveness of direct-acting antiviral agents in treating hepatitis C virus (HCV), cases of treatment failure have been associated with the emergence of resistance-associated substitutions. To better guide clinical decision-making, we developed and validated a near-whole-genome HCV genotype-independent next-generation sequencing strategy. HCV genotype 1–6 samples from direct-acting antiviral agent treatment-naïve and -treated HCV-infected individuals were included. Viral RNA was extracted using a NucliSens easyMAG and amplified using nested reverse transcription-polymerase chain reaction. Libraries were prepared using Nextera XT and sequenced on the Illumina MiSeq sequencing platform. Data were processed by an in-house pipeline (MiCall). Nucleotide consensus sequences were aligned to reference strain sequences for resistance-associated substitution identification and compared to NS3, NS5a, and NS5b sequence data obtained from a validated in-house assay optimized for HCV genotype 1. Sequencing success rates (defined as achieving >100-fold read coverage) approaching 90% were observed for most genotypes in samples with a viral load >5 log10 IU/mL. This genotype-independent sequencing method resulted in >99.8% nucleotide concordance with the genotype 1-optimized method, and 100% agreement in genotype assignment with paired line probe assay-based genotypes. The assay demonstrated high intra-run repeatability and inter-run reproducibility at detecting substitutions above 2% prevalence. This study highlights the performance of a freely available laboratory and bioinformatic approach for reliable HCV genotyping and resistance-associated substitution detection regardless of genotype.
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16

Gaarenstroom, K. N., P. Melkert, J. M. M. Walboomers, A. J. C. Van Den Brule, P. F. J. Van Bommel, C. J. L. M. Meyer, F. J. Voorhorst, P. Kenemans y Th J. M. Helmerhorst. "Human papillomavirus DNA and genotypes: prognostic factors for progression of cervical intraepithelial neoplasia". International Journal of Gynecologic Cancer 4, n.º 2 (1994): 73–78. http://dx.doi.org/10.1046/j.1525-1438.1994.04020073.x.

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A retrospective study of 227 patients presenting with abnormal cervical cytology was conducted to investigate the relationship between human papillomavirus (HPV) and progression of untreated cervical intraepithelial neoplasia (CIN) lesions. All patients had colposcopically directed biopsies for histologic diagnosis. The patients were followed cytologically and colposcopically for a mean of 19 months (range 6–42 months). Progression of a cervical lesion was defined as progression to a higher CIN grade confirmed histologically by directed biopsy. HPV DNA detection was done on material remaining from the cervical swabs by the general primer polymerase chain reaction (PCR) and type-specific PCR method, which made the detection of HPV types 6, 11, 16, 18, 31, 33 and not yet sequenced DNA types (X) possible. The presence of HPV DNA increased with the severity of the lesion (P< 0.001). In CIN III, a 100% HPV DNA prevalence was found, with HPV type 16 being the most prevalent type in 75%. Progression was significantly related to the presence of HPV DNA, in particular HPV type 16. The percentage of progressive disease was 21% in the case of HPV DNA positive lesions (n= 130) and 29% in the presence of HPV type 16, whereas HPV DNA negative lesions (n= 97) showed no progression. The detection of HPV DNA and HPV genotype can be used to identify patients with high-risk cervical lesions, since the presence of HPV DNA and genotype 16 in particular are closely related to CIN progression.
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17

Robinson, W. H., H. Ying, M. C. Miceli y J. R. Parnes. "Extensive polymorphism in the extracellular domain of the mouse B cell differentiation antigen Lyb-2/CD72." Journal of Immunology 149, n.º 3 (1 de agosto de 1992): 880–86. http://dx.doi.org/10.4049/jimmunol.149.3.880.

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Abstract Lyb-2/CD72 is a 45-kDa mouse B cell surface protein that binds CD5 and has been shown to play a role in B cell proliferation and differentiation. Using the polymerase chain reaction we have isolated and sequenced cDNA clones encoding the serologically defined mouse Lyb-2a, Lyb-2b, and Lyb-2c alleles. We confirmed that our full length cDNA clones encode the Lyb-2a, -2b, and -2c alleles, respectively, by transfecting the isolated Lyb-2/CD72 cDNA clones into L cells and demonstrating that the transfectants bind only the appropriate allele specific anti-Lyb-2/CD72 antibodies. Sequence comparisons demonstrate that the Lyb-2/CD72 allels are highly conserved in their cytoplasmic and transmembrane domains but exhibit a high degree of polymorphism in their extracellular domains. This polymorphism in the extracellular region involves amino acid substitutions at a minimum of 20 residues and is concentrated primarily in the membrane distal region. cDNA sequence comparisons also demonstrate two distinct seven amino acid insertion/deletions among these allelic variants. A form of Lyb-2b cDNA lacking the sequence encoding the transmembrane region was isolated from a C57B1/6 mouse and a CH12.LX subline. The Lyb-2/CD72 PCR products from mRNA of mice expressing Lyb-2a and Lyb-2c contain a DNA fragment that corresponds in size to the transmembraneless form, suggesting that these mouse strains also express this mRNA.
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18

Temam, Stéphane, Antoine Flahault, Sophie Périé, Guy Monceaux, Florence Coulet, Patrice Callard, Jean-François Bernaudin, Jean Lacau St Guily y Pierre Fouret. "p53 Gene Status as a Predictor of Tumor Response to Induction Chemotherapy of Patients With Locoregionally Advanced Squamous Cell Carcinomas of the Head and Neck". Journal of Clinical Oncology 18, n.º 2 (1 de enero de 2000): 385. http://dx.doi.org/10.1200/jco.2000.18.2.385.

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PURPOSE: To determine whether p53 gene status predicts tumor responses to platinum- and fluorouracil-based induction chemotherapy in locoregionally advanced squamous cell carcinomas of the head and neck. PATIENTS AND METHODS: Tumor responses of 105 patients were measured at the primary tumor site. Objective response and major response were defined by a 50% and 80% reduction in tumor size, respectively. All coding parts of p53 gene were directly sequenced. p53 expression in tumor cells was determined by immunohistochemistry. Human papillomavirus infection was detected by polymerase chain reaction. Odd ratios were adjusted by stepwise logistic regression analysis. RESULTS: p53 mutations, p53 expression, and tumor stage were sufficient to explain the variation in tumor responses to chemotherapy in multivariate models. p53 mutation was the only variable to significantly predict objective response (odds ratio, 0.23; 95% confidence interval, 0.10 to 0.57; P = .002) and was the strongest predictor of major response (odds ratio, 0.29; 95% confidence interval, 0.11 to 0.74; P = .006). p53 expression (odds ratio, 0.39; 95% confidence interval, 0.16 to 0.98) and tumor stage (odds ratio, 0.31; 95% confidence interval, 0.10 to 0.96) also predicted major response. Specific mutations (contact mutations) accounted for much of the reduction in the risk of major response associated with overall mutations. In complementary analyses, p53 expression was weakly predictive of major response in the subgroup with wild-type p53, and p53 mutations also predicted histologic response. CONCLUSION: p53 gene mutations are strongly associated with a poor risk of both objective and major responses to chemotherapy. Contact mutations are associated with the lowest risk of major response to chemotherapy.
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Mohamad Yadzir, Zailatul Hani, Brenda Leecyous y Amelia Suhana Zamri. "Isolation and Cloning of Tropomyosin and Arginine Kinase from Tiger Prawn Penaeus monodon and Blue Swimming Crab Portunus trituberculatus". Journal of Science and Mathematics Letters 8, n.º 2 (24 de marzo de 2020): 36–38. http://dx.doi.org/10.37134/jsml.vol8.2.5.2020.

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Shellfish is an important source of food and plays a significant role in human nutrition and health. However, shellfish allergy is a long-lasting disorder which mostly persists throughout life and is often associated with severe reactions [1]. Among the various consumed shellfish, prawns and crabs are the most widely consumed and can lead to the most severe reactions. At present, allergies to shellfish are diagnosed similarly to other food allergies. The diagnosis relies upon careful evaluation of history, the presence of appropriate clinical signs and confirmation with in vivo or in vitro tests to demonstrate the presence of allergen-specific immunoglobulin E (IgE) [2]. However, both in vivo or in vitro diagnostic approaches are mainly based on the use of crude allergen extracts. Crude allergen extracts are obtained from biological sources and consist of mixture of allergenic components with high amounts of undesirable products that can interfere with diagnosis. In many cases, only few of the several proteins found in crude allergen extracts act as the essential allergens in the majority of patients that are allergic to the substance. The most important ones are called major allergens. Problems associated with using crude allergen extracts for allergy diagnosis may be overcome with recombinant allergens. Recombinant allergens with high purity can be produced by using controlled production procedures that yield defined molecules with known molecular, immunologic and biological characteristics [1]. Tiger prawn Penaeus monodon and blue swimming crab Portunus trituberculatus, are among the widely consumed shellfish in Malaysia. Our earlier study involving 131 atopic patients in Allergy Clinic, Kuala Lumpur Hospital demonstrated that patients in Malaysia suffering from allergic responses to shellfish including tiger prawn Penaeus monodon and blue swimming crab Portunus trituberculatus. Amongst the shellfish extracts tested, prawn elicited the highest frequency of positive reactivity in 39% of the patients. Further, crab was the second most common shellfish to elicit a positive reaction in 24% of the patients [3]. Our first phase study has successfully identified tropomyosin and arginine kinase as the major allergens in both species of shellfish. However, more information about the individual allergenic species-specific components is needed. Therefore, we continued our study to isolate and clone the tropomyosin and arginine kinase from these two species of shellfish, tiger prawn Penaeus monodon and blue swimming crab Portunus trituberculatus. Tropomyosin and arginine kinase were isolated from the total RNA (Ribonucleic Acid) obtained from both prawn and crab muscles followed by RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction). The RT-PCR products were then cloned into the cloning vector, pJET 1.2 and transformed into Escherichia coli host. Transformants were screened for positive clones by PCR (Polymerase Chain Reaction) colony and sequenced. The 855 bp tropomyosins have been isolated and sequenced from both prawn and crab. Arginine kinases isolated and sequenced from prawn and crab were 1071 bp and 1074 bp, respectively (Figure 1). The GenBank BLAST search for the sequences showed high homology to the targeted proteins as shown in Table 1. Tropomyosin is a 34 to 38 kDa heat-stable protein that belongs to a highly conserved family of actin filament binding proteins, which plays a functional role in contractile activities in muscle cells [4]. Arginine kinase is a 40 to 42 kDa heat-labile protein that plays an important role in regenerating adenosine triphosphate (ATP) during bursts of cellular activity [5]. Tropomyosin and arginine kinase from the prawn and crab have been isolated and the full-length sequences were obtained. Current ongoing study focuses on sub-cloning and full-length expression of tropomyosin and arginine kinase in order to produce respective recombinant proteins, and subsequently investigate their physicochemical and allergenic characteristics.
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20

Alabi, Olufemi J., Maher Al Rwahnih, Gandhi Karthikeyan, Sudarsana Poojari, Marc Fuchs, Adib Rowhani y Rayapati A. Naidu. "Grapevine leafroll-associated virus 1 Occurs as Genetically Diverse Populations". Phytopathology® 101, n.º 12 (diciembre de 2011): 1446–56. http://dx.doi.org/10.1094/phyto-04-11-0114.

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The genetic diversity of 34 isolates of Grapevine leafroll-associated virus 1 (GLRaV-1) from different wine, table, and ornamental grape cultivars in California, New York, and Washington States in the United States was investigated. Segments of the heat-shock protein 70 homolog (HSP70h) gene, coat protein (CP) gene, coat protein duplicate 2 (CPd2) gene, and open reading frame 9 (p24) were amplified by reverse-transcription polymerase chain reaction, cloned, and sequenced. A pairwise comparison of nucleotide sequences revealed intra- and interisolate sequence diversity, with CPd2 and HSP70h being the most and the least divergent, respectively, among the four genomic regions studied. The normalized values for the ratio of nonsynonymous substitutions per nonsynonymous site to synonymous substitutions per synonymous site indicated different purifying selection pressures acting on each of the four genomic regions, with the CP and CPd2 being subjected to the strongest and weakest functional constraints, respectively. A global phylogenetic analysis of sequences from the four genomic regions revealed segregation of GLRaV-1 isolates into three major clades and a lack of clearly defined clustering by geographical origin. In contrast, only two lineages were apparent when the CP and CPd2 gene sequences were used in phylogenetic analyses. Putative recombination events were revealed among the HSP70h, CP, and p24 sequences. The genetic landscape of GLRaV-1 populations presented in this study provides a foundation for better understanding of the epidemiology of grapevine leafroll disease across grape-growing regions in the United States. In addition, this study will benefit grape clean plant programs across the country in improving the sanitary status of planting materials provided to nurseries and grape growers.
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21

Christen, Friederike, Kaja Hoyer, Kenichi Yoshida, Hsin-An Hou, Nils Waldhueter, Michael Heuser, Robert K. Hills et al. "Genomic landscape and clonal evolution of acute myeloid leukemia with t(8;21): an international study on 331 patients". Blood 133, n.º 10 (7 de marzo de 2019): 1140–51. http://dx.doi.org/10.1182/blood-2018-05-852822.

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Abstract Acute myeloid leukemia with t(8;21)(q22;q22) is characterized by considerable clinical and biological heterogeneity leading to relapse in up to 40% of patients. We sequenced coding regions or hotspot areas of 66 recurrently mutated genes in a cohort of 331 t(8;21) patients. At least 1 mutation, in addition to t(8;21), was identified in 95%, with a mean of 2.2 driver mutations per patient. Recurrent mutations occurred in genes related to RAS/RTK signaling (63.4%), epigenetic regulators (45%), cohesin complex (13.6%), MYC signaling (10.3%), and the spliceosome (7.9%). Our study identified mutations in previously unappreciated genes: GIGYF2, DHX15, and G2E3. Based on high mutant levels, pairwise precedence, and stability at relapse, epigenetic regulator mutations were likely to occur before signaling mutations. In 34% of RAS/RTKmutated patients, we identified multiple mutations in the same pathway. Deep sequencing (∼42 000×) of 126 mutations in 62 complete remission samples from 56 patients identified 16 persisting mutations in 12 patients, of whom 5 lacked RUNX1-RUNX1T1 in quantitative polymerase chain reaction analysis. KIThigh mutations defined by a mutant level ≥25% were associated with inferior relapse-free survival (hazard ratio, 1.96; 95% confidence interval, 1.22-3.15; P = .005). Together with age and white blood cell counts, JAK2, FLT3-internal tandem duplicationhigh, and KIThigh mutations were identified as significant prognostic factors for overall survival in multivariate analysis. Whole-exome sequencing was performed on 19 paired diagnosis, remission, and relapse trios. Exome-wide analysis showed an average of 16 mutations with signs of substantial clonal evolution. Based on the resemblance of diagnosis and relapse pairs, genetically stable (n = 13) and unstable (n = 6) subgroups could be identified.
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22

Alhussona, Ali Jumaah, Ali Habeeb Al-Musawi, Hayder Hussein Jalood y Sawsan S. Hamzah. "A study of ATPase gene variants of mitochondrial DNA in patients with Type 2 diabetes mellitus". Biomedicine 43, n.º 1 (26 de febrero de 2023): 225–29. http://dx.doi.org/10.51248/.v43i1.2432.

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Introduction and Aim: Diabetes mellitus is a complex disease that is a major global health problem. It is defined as a chronic metabolic disease characterized by high blood glucose levels. Diabetes risk has been linked to genetic variations within mitochondrial DNA. The current study sought to identify and compare genetic variation (mutations) in ATPase genes in diabetic patients and healthy individuals. Materials and Methods: This study included 100 individuals (50 T2DM patients and 50 healthy volunteers). Peripheral blood samples were collected from each individual and DNA extracted. The mitochondrial mtATPase genes were amplified using specific primers by polymerase chain reaction. The amplified products were sequenced, and the sequences obtained analyzed for nucleotide changes. Results: The ATPase gene sequence analysis revealed nine nucleotide changes, three of which (A9039G, G9092A, and G9100T) are classified as polymorphisms in the human mitochondrial genome database. Furthermore, we presented the first description of mutations in ATPase genes such as (A8586G, C8637T, G8813A, A8953G, C8981T and T9024G). The A9039G mutation changed the amino acid isoleucine to glycine, the G9100T mutation changed the amino acid serine to isoleucine, and the C8981G mutation changed the amino acid threonine to isoleucine. Most patients were found to predict haplogroup H2a (H2a2), in addition to having H1c (H1c3) and L1c(L1c2). The presence of genetic variations in mtATPase genes may be an inheritable risk factor for type 2 diabetes mellitus pathogenesis. Conclusion: Variants in ATPase mitochondrial genes may be one of the risk factors associated with type 2 diabetes. Hence, documenting these mutations is clinically important in the possibility of diagnosing diabetes, as well as the likelihood that these mutations could be pathogenic.
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23

Xu, De-Qi, John Thompson y John O. Cisar. "Genetic Loci for Coaggregation Receptor Polysaccharide Biosynthesis in Streptococcus gordonii 38". Journal of Bacteriology 185, n.º 18 (15 de septiembre de 2003): 5419–30. http://dx.doi.org/10.1128/jb.185.18.5419-5430.2003.

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ABSTRACT The cell wall polysaccharide of Streptococcus gordonii 38 functions as a coaggregation receptor for surface adhesins on other members of the oral biofilm community. The structure of this receptor polysaccharide (RPS) is defined by a heptasaccharide repeat that includes a GalNAcβ1→3Gal-containing recognition motif. The same RPS has now been identified from S. gordonii AT, a partially sequenced strain. PCR primers designed from sequences in the genomic database of strain AT were used to identify and partially characterize the S. gordonii 38 RPS gene cluster. This cluster includes genes for seven putative glycosyltransferases, a polysaccharide polymerase (Wzy), an oligosaccharide repeating unit transporter (Wzx), and a galactofuranose mutase, the enzyme that promotes synthesis of UDP-Galf, one of five predicted RPS precursors. Genes outside this region were identified for the other four nucleotide-linked sugar precursors of RPS biosynthesis, namely, those for formation of UDP-Glc, UDP-Gal, UDP-GalNAc, and dTDP-Rha. Two genes for putative galactose 4-epimerases were identified. The first, designated galE1, was identified as a pseudogene in the galactose operon, and the second, designated galE2, was transcribed with three of the four genes for dTDP-Rha biosynthesis (i.e., rmlA, rmlC, and rmlB). Insertional inactivation of galE2 abolished (i) RPS production, (ii) growth on galactose, and (iii) both UDP-Gal and UDP-GalNAc 4-epimerase activities in cell extracts. Repair of the galE1 pseudogene in this galE2 mutant restored growth on galactose but not RPS production. Cell extracts containing functional GalE1 but not GalE2 contained UDP-Gal 4-epimerase but not UDP-GalNAc 4-epimerase activity. Thus, provision of both UDP-Gal and UDP-GalNAc for RPS production by S. gordonii 38 depends on the dual specificity of the epimerase encoded by galE2.
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24

Spiegelman, Dan, Gavin Whissell y Charles W. Greer. "A survey of the methods for the characterization of microbial consortia and communities". Canadian Journal of Microbiology 51, n.º 5 (1 de mayo de 2005): 355–86. http://dx.doi.org/10.1139/w05-003.

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A survey of the available literature on methods most frequently used for the identification and characterization of microbial strains, communities, or consortia is presented. The advantages and disadvantages of the various methodologies were examined from several perspectives including technical, economic (time and cost), and regulatory. The methods fall into 3 broad categories: molecular biological, biochemical, and microbiological. Molecular biological methods comprise a broad range of techniques that are based on the analysis and differentiation of microbial DNA. This class of methods possesses several distinct advantages. Unlike most other commonly used methods, which require the production of secondary materials via the manipulation of microbial growth, molecular biological methods recover and test their source materials (DNA) directly from the microbial cells themselves, without the requirement for culturing. This eliminates both the time required for growth and the biases associated with cultured growth, which is unavoidably and artificially selective. The recovered nucleic acid can be cloned and sequenced directly or subpopulations can be specifically amplified using polymerase chain reaction (PCR), and subsequently cloned and sequenced. PCR technology, used extensively in forensic science, provides researchers with the unique ability to detect nucleic acids (DNA and RNA) in minute amounts, by amplifying a single target molecule by more than a million-fold. Molecular methods are highly sensitive and allow for a high degree of specificity, which, coupled with the ability to separate similar but distinct DNA molecules, means that a great deal of information can be gleaned from even very complex microbial communities. Biochemical methods are composed of a more varied set of methodologies. These techniques share a reliance on gas chromatography and mass spectrometry to separate and precisely identify a range of biomolecules, or else investigate biochemical properties of key cellular biomolecules. Like the molecular biological methods, some biochemical methods such as lipid analyses are also independent of cultured growth. However, many of these techniques are only capable of producing a profile that is characteristic of the microbial community as a whole, providing no information about individual members of the community. A subset of these methodologies are used to derive taxonomic information from a community sample; these rely on the identification of key subspecies of biomolecules that differ slightly but characteristically between species, genera, and higher biological groupings. However, when the consortium is already growing in chemically defined media (as is often the case with commercial products), the rapidity and relatively low costs of these procedures can mitigate concerns related to culturing biases. Microbiological methods are the most varied and the least useful for characterizing microbial consortia. These methods rely on traditional tools (cell counting, selective growth, and microscopic examination) to provide more general characteristics of the community as a whole, or else to narrow down and identify only a small subset of the members of that community. As with many of the biochemical methods, some of the microbiological methods can fairly rapidly and inexpensively create a community profile, which can be used to compare 2 or more entire consortia. However, for taxonomic identification of individual members, microbiological methods are useful only to screen for the presence of a few key predetermined species, whose preferred growth conditions and morphological characteristics are well defined and reproducible.Key words: microbial communities, microbial consortia, characterization methods, taxonomic identification.
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25

Kim, Soo-Hyun, Soo Young Choi, Sung-Eun Lee, Yun Jeong Oh, Jin-Eok Park, Hae Lyun Yoo, Hye-Rim Jeon, Eun-Jung Jang y Dong-Wook Kim. "Kinetics Of Low-Level Mutant Clones Detected By Subcloning and Sequencing In Tyrosine Kinase Inhibitor Resistant CML". Blood 122, n.º 21 (15 de noviembre de 2013): 2720. http://dx.doi.org/10.1182/blood.v122.21.2720.2720.

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Abstract Background BCR-ABL1 kinase domain (KD) point mutation causes resistance to tyrosine kinase inhibitors (TKI) in chronic myeloid leukemia (CML) patients through impaired binding of TKI to the target site. Recent studies have reported that multiple mutations detected in 2-9% of patients with imatinib (IM)-resistant CML were associated with poor response rate and survival outcomes. However, biological characteristics and dynamics of multiple low-level mutations are still not assessed with a quantitative serial follow-up data in the same populations. Aims The aim of this study was to investigate biological characteristics and dynamics of low-level mutations in the serial samples from the patients carrying multiple mutations using subcloning and sequencing. Methods Since 2002, 414 CML patients were screened for mutation analysis due to sign of resistance to TKIs including imatinib (IM), nilotinib (NIL), dasatinib (DAS), bosutinib (BOS), radotinib (RAD) or ponatinib (PON) at Seoul St Mary’s Hospital using direct sequencing and allele specific oligonucleotide-polymerase chain reaction (ASO-PCR). Among them, 31 patients carried ≥ 2 BCR-ABL1 kinase domain mutations. We analyzed 137 samples from these 31 patients using subcloning and sequencing (in total, 2737 colonies were sequenced). By cloning and sequencing, two or more missense mutations present in the same clone were defined as compound mutation and co-existence of single missense mutations in the separated clones was defined as polyclonal mutation. Co-existence of single missense mutation and compound mutation harboring two or more missense mutations in the same clone was defined as mixed mutation. Missense mutations detected by direct sequencing are defined as predominant mutations. Missense mutations detected by cloning and sequencing but not by direct sequencing are defined as low-level mutations. Results In a total of 2737 colonies from 137 samples, 1596 (58%) colonies harbored ≥ 2 missense mutations with a median 2 (range, 2 – 7) mutations, and 905 (33%) colonies with a single mutation and 236 (9%) colonies with wild type were observed. In 2737 colonies, 692 different low-level mutations were detected by cloning and sequencing but not by direct sequencing. Among them, M244V, G250E, Y253H, E279K, T315I, F317L, M351T, E355A, F359I, and F359V were detected by direct sequencing in the followed-up samples, and the others remain undetectable by direct sequencing. To address whether these low-level mutations were distinct in the patients with TKI resistance, we applied the cloning and sequencing to samples from 3 healthy controls and 3 patients with optimal response to IM. 38 different mutations were detected healthy controls. 52 different mutations were detected in optimal responders. S349P, N374S, E450G, and S485P were detected in both healthy controls and optimal responders. All mutations detected in optimal responders except 3 missense mutations (V335A, F382V, and A395S) were detected as low-level mutations in the 31 patients’ cohort with TKI resistance. Of 38 different mutations detected in healthy control, 31 mutations except 7 missense mutations (Y264H, M343R, A350V, E373G, G298R, E462K, and T495K) were also detected as low-level mutations in the 31 patients’ cohort. Conclusions We showed basic characteristics and dynamics of low-level mutations by subcloning and sequencing. Some of the low-level mutant clones harboring previously known (clinically common) TKI resistant mutations changes to the predominant in the followed-up samples. Except them, most low-level mutant clones were not detected repeatly and did not increase gradually in the serial samples, implying that they may not have clinical significance. Disclosures: No relevant conflicts of interest to declare.
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26

Lv, Fang, Yiqian Liu, Yaxi Zhang, Xiaoli Liu, Pei Zhihua, Jianing Yu, Weizhi Chen y Ji He. "Accurately estimating the homologous recombination deficiency based on low-pass whole-genome sequencing and target sequencing." Journal of Clinical Oncology 39, n.º 15_suppl (20 de mayo de 2021): e15077-e15077. http://dx.doi.org/10.1200/jco.2021.39.15_suppl.e15077.

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e15077 Background: Homologous recombination deficiency (HRD) is a promising biomarker for poly ADP-ribose polymerase (PARP) inhibitors. In the past, the HRD status was mainly estimated by summing the loss of heterozygosity (LOH), telomeric allelic imbalance (TAI), and large-scale state transition (LST) based on target sequencing. However, the heterozygous loci coverage and probe number are closely correlated to B allele frequency and copy number variations (CNVs). Here we developed a novel method to combine the data from low-pass whole-genome sequencing (WGS) and target sequencing to accurately estimate the genome-wide CNVs and allelic imbalance. Methods: We first performed low-pass WGS and target sequencing on 30 healthy controls, formalin-fixed and paraffin-embedded (FFPE) samples, and matched blood cell samples for 29 patients with breast cancer or ovarian cancer. Two HRD positive samples were diluted to 40%, 30%, 20%, and 10% tumor purity with matched blood cell samples, respectively. Each diluted sample was sequenced 20 times. The baseline for CNVs was built based on the sequencing data of healthy donors. To eliminate the artifacts resulted from the sequencing platform, models for each candidate single nucleotide polymorphism (SNP) in target regions were trained using the data from healthy donors. The mutations of BRCA1/BRCA2 of 29 patients were used to define the threshold of the HRD score. The numbers of LOH, LST, and TAI were evaluated by CNVs and B allele frequency. Results: We defined a cutoff of 42 for the HRD status based on the low-pass WGS and target sequencing data of 29 patients. Specifically, the original HRD scores for two selected HRD positive samples were 68 and 89. The median HRD scores for 40%, 30%, 20%, and 10% tumor purity samples were 69 and 88, 66.5 and 90, 61 and 68, 52 and 34.5, respectively. Conclusions: We developed a novel method for robustly inferring the HRD status using low-pass WGS and target sequencing with a limit of detection of 20%.
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27

Scott, Emily, Jane Kuypers, Michael L. Jackson y Helen Chu. "716. Molecular Epidemiology of Respiratory Syncytial Virus in Children and Adults in Seattle, WA". Open Forum Infectious Diseases 5, suppl_1 (noviembre de 2018): S257. http://dx.doi.org/10.1093/ofid/ofy210.723.

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Abstract Background Respiratory syncytial virus (RSV) is the most important cause of pneumonia in children &lt;5 years worldwide and may cause severe disease in elderly and high-risk adults. Multiple RSV strains co-circulate and evolve over seasons. We seek to describe the evolution of RSV over five seasons in Seattle, WA, USA with two seasons reported here. Methods From 2014 to 2016, subjects 6 months and older seeking outpatient care for acute respiratory illness at Kaiser Permanente Washington were enrolled in the Influenza Vaccine Efficacy Network (Flu VE Network) and a respiratory swab was collected. Real-time polymerase chain reaction (RT-PCR) was performed to test and quantify RSV and subtype positive samples. A subset of RSV samples with cycle threshold (CT) value &lt;30 will be sequenced using a metagenomic next-generation sequencing (NGS) approach. Specific RSV genotypes will be associated with severe disease, defined as requiring emergency department care or hospitalization, or chest radiographic findings. Results A total of 8,730 patients were enrolled in the Flu VE Network and PCR testing of seasons 2014/2015 and 2015/2016 resulted in 562 of 4,137 (13.6%) RSV-positive specimens. Of patients with RSV-positive specimens, 204 (36.5%) were adults 18–64 years and 112 (20.0%) were 65+ years. RSV-B predominated in the 2014/2015 season (n = 298; 83.7%), whereas RSV-A was more common in the 2015/2016 season (n = 154; 79.8%) (Figure 1). The median (IQR) CT value for RSV-A specimens was 26.7 (23.3–29.9) compared with 27.9 (25.2–31.3) for RSV-B. Conclusion One RSV subtype predominated within each season. Similar RSV subtype distributions were seen across age categories. With multiple RSV vaccine candidates in development, understanding the genetic diversity and circulation of RSV various viruses within a population is important for analyzing the effects of a vaccine on the evolution of RSV. Figure 1, Total counts (A) and proportions (B) of RSV-A and RSV-B specimens collected from study patients in Seattle, WA during 2014/2015 and 2015/2016 seasons, by age category. Disclosures M. L. Jackson, sanofi pasteur: Grant Investigator, Research support. H. Chu, Sanofi-Pasteur: Grant Investigator, Grant recipient.
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28

Dorai, T., J. B. Levy, L. Kang, J. S. Brugge y L. H. Wang. "Analysis of cDNAs of the proto-oncogene c-src: heterogeneity in 5' exons and possible mechanism for the genesis of the 3' end of v-src". Molecular and Cellular Biology 11, n.º 8 (agosto de 1991): 4165–76. http://dx.doi.org/10.1128/mcb.11.8.4165-4176.1991.

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To further characterize the gene structure of the proto-oncogene c-src and the mechanism for the genesis of the v-src sequence in Rous sarcoma virus, we have analyzed genomic and cDNA copies of the chicken c-src gene. From a cDNA library of chicken embryo fibroblasts, we isolated and sequenced several overlapping cDNA clones covering the full length of the 4-kb c-src mRNA. The cDNA sequence contains a 1.84-kb sequence downstream from the 1.6-kb pp60c-src coding region. An open reading frame of 217 amino acids, called sdr (src downstream region), was found 105 nucleotides from the termination codon for pp60c-src. Within the 3' noncoding region, a 39-bp sequence corresponding to the 3' end of the RSV v-src was detected 660 bases downstream of the pp60c-src termination codon. The presence of this sequence in the c-src mRNA exon supports a model involving an RNA intermediate during transduction of the c-src sequence. The 5' region of the c-src cDNA was determined by analyzing several cDNA clones generated by conventional cloning methods and by polymerase chain reaction. Sequences of these chicken embryo fibroblast clones plus two c-src cDNA clones isolated from a brain cDNA library show that there is considerable heterogeneity in sequences upstream from the c-src coding sequence. Within this region, which contains at least 300 nucleotides upstream of the translational initiation site in exon 2, there exist at least two exons in each cDNA which fall into five cDNA classes. Four unique 5' exon sequences, designated exons UE1, UE2, UEX, and UEY, were observed. All of them are spliced to the previously characterized c-src exons 1 and 2 with the exception of type 2 cDNA. In type 2, the exon 1 is spliced to a novel downstream exon, designated exon 1a, which maps in the region of the c-src DNA defined previously as intron 1. Exon UE1 is rich in G+C content and is mapped at 7.8 kb upstream from exon 1. This exon is also present in the two cDNA clones from the brain cDNA library. Exon UE2 is located at 8.5 kb upstream from exon 1. The precise locations of exons UEX and UEY have not been determined, but both are more than 12 kb upstream from exon 1. The existence and exon arrangements of these 5' cDNAs were further confirmed by RNase protection assays and polymerase chain reactions using specific primers. Our findings indicate that the heterogeneity in the 5' sequences of the c-src mRNAs results from differential splicing and perhaps use of distinct initiation sites. All of these RNAs have the potential of coding for pp60c-src, since their 5' exons are all eventually joined to exon 2.
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29

Dorai, T., J. B. Levy, L. Kang, J. S. Brugge y L. H. Wang. "Analysis of cDNAs of the proto-oncogene c-src: heterogeneity in 5' exons and possible mechanism for the genesis of the 3' end of v-src." Molecular and Cellular Biology 11, n.º 8 (agosto de 1991): 4165–76. http://dx.doi.org/10.1128/mcb.11.8.4165.

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To further characterize the gene structure of the proto-oncogene c-src and the mechanism for the genesis of the v-src sequence in Rous sarcoma virus, we have analyzed genomic and cDNA copies of the chicken c-src gene. From a cDNA library of chicken embryo fibroblasts, we isolated and sequenced several overlapping cDNA clones covering the full length of the 4-kb c-src mRNA. The cDNA sequence contains a 1.84-kb sequence downstream from the 1.6-kb pp60c-src coding region. An open reading frame of 217 amino acids, called sdr (src downstream region), was found 105 nucleotides from the termination codon for pp60c-src. Within the 3' noncoding region, a 39-bp sequence corresponding to the 3' end of the RSV v-src was detected 660 bases downstream of the pp60c-src termination codon. The presence of this sequence in the c-src mRNA exon supports a model involving an RNA intermediate during transduction of the c-src sequence. The 5' region of the c-src cDNA was determined by analyzing several cDNA clones generated by conventional cloning methods and by polymerase chain reaction. Sequences of these chicken embryo fibroblast clones plus two c-src cDNA clones isolated from a brain cDNA library show that there is considerable heterogeneity in sequences upstream from the c-src coding sequence. Within this region, which contains at least 300 nucleotides upstream of the translational initiation site in exon 2, there exist at least two exons in each cDNA which fall into five cDNA classes. Four unique 5' exon sequences, designated exons UE1, UE2, UEX, and UEY, were observed. All of them are spliced to the previously characterized c-src exons 1 and 2 with the exception of type 2 cDNA. In type 2, the exon 1 is spliced to a novel downstream exon, designated exon 1a, which maps in the region of the c-src DNA defined previously as intron 1. Exon UE1 is rich in G+C content and is mapped at 7.8 kb upstream from exon 1. This exon is also present in the two cDNA clones from the brain cDNA library. Exon UE2 is located at 8.5 kb upstream from exon 1. The precise locations of exons UEX and UEY have not been determined, but both are more than 12 kb upstream from exon 1. The existence and exon arrangements of these 5' cDNAs were further confirmed by RNase protection assays and polymerase chain reactions using specific primers. Our findings indicate that the heterogeneity in the 5' sequences of the c-src mRNAs results from differential splicing and perhaps use of distinct initiation sites. All of these RNAs have the potential of coding for pp60c-src, since their 5' exons are all eventually joined to exon 2.
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30

Zhang, A. W., L. Riccioni, W. L. Pedersen, K. P. Kollipara y G. L. Hartman. "Molecular Identification and Phylogenetic Grouping of Diaporthe phaseolorum and Phomopsis longicolla Isolates from Soybean". Phytopathology® 88, n.º 12 (diciembre de 1998): 1306–14. http://dx.doi.org/10.1094/phyto.1998.88.12.1306.

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Diaporthe phaseolorum and Phomopsis longicolla isolates from soybean were examined using traditional mycological characteristics and molecular methods. Cultural characteristics including types of fruiting bodies and conidia were assessed for isolates collected from soybean stems and seeds. Cultures were identified as P. longicolla, D. phaseolorum var. caulivora, D. phaseolorum var. meridionalis, or D. phaseolorum var. sojae. Molecular markers for these groups were developed and analyzed using polymerase chain reaction restriction fragment length polymorphisms (PCR-RFLP) and DNA sequencing in the internal transcribed spacer (ITS) and the 5.8S ribosomal DNA. The ITS4 and ITS5 primers amplified PCR products for all isolates studied. Gel electrophoresis of undigested PCR products and DNA sequencing produced various fragment lengths including 604 bp for P. longicolla, 602 and 603 bp for D. phaseolorum var. caulivora, 603 bp for D. phaseolorum var. meridionalis, and from 597 to 609 bp for D. phaseolorum var. sojae. Digestion of these PCR products with enzymes AluI, HhaI, MseI, RsaI, and ScrFI resulted in distinct bands for identification of P. longicolla and the varieties of D. phaseolorum I. All P. longicolla, D. phaseolorum var. caulivora, and D. phaseolorum var. meridionalis isolates were distinguished using AluI and HhaI with RsaI or ScrFI. The banding patterns of D. phaseolorum var. sojae isolates were complex and were separated into 11 subgroups after digestion with AluI, HhaI, MseI, RsaI, and ScrFI. Phylogenetic analysis of 20 isolates of D. phaseolorum and P. longicolla based on the DNA sequence of the ITS region resolved six clades termed A, B, C, D, E, and F. Clade A included all sequenced D. phaseolorum var. caulivora isolates, two from Italy and one from the United States. Isolates in clade B were exclusively associated with D. phaseolorum var. meridionalis. Clades A and B formed a well-supported monophyletic group. Isolates in clades C, D, E, and F were morphologically defined as isolates of P. longicolla, D. phaseolorum var. sojae, and Diaporthe spp. The ITS sequences similarity of seven geographically diverse P. longi-colla isolates illustrated that P. longicolla isolates have a similar genetic background, with some affiliations to some D. phaseolorum var. sojae isolates. Morphological characteristics of the isolates along with the terminal clades of the ITS phylogeny suggest that P. longicolla is an individual species, D. phaseolorum var. caulivora and D. phaseolorum var. meridionalis are varieties of D. phaseolorum, and D. phaseolorum var. sojae is either several varieties of D. phaseolorum or possibly several distinct species.
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31

Liu, A. H., P. K. Jena y L. J. Wysocki. "Tracing the development of single memory-lineage B cells in a highly defined immune response." Journal of Experimental Medicine 183, n.º 5 (1 de mayo de 1996): 2053–63. http://dx.doi.org/10.1084/jem.183.5.2053.

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To study the development of B lymphocyte memory, we identified and isolated splenic B cells expressing a highly defined antibody variable region that constitutes a reproducible and predominant component of the memory antibody response to p-azophenylarsonate (Ars). Isolation was achieved during the primary immune response by surface staining and flow cytometry using a specific anti-idiotypic antibody called E4, which recognizes this canonical V region, encoded by one set of V gene segments. The isolated E4+ cells displayed all of the phenotypic characteristics of germinal center centrocytes, including a low level of surface Ig, a lack of surface IgD, a high level of receptor for peanut agglutinin, and expression of mutated antibody V genes. E4+ B cells were first detected in the spleen 7-8 d after primary immunization, reached peak numbers from days 10-13, and waned by day 16. Surprisingly, at their peak, E4+ cells comprised only 40,000 of all splenocytes, and half of these failed to bind Ars. Using this number, we estimate the total number of Ars-specific memory-lineage cells in the spleen to be no more than 50,000 (0.1%) at any one time, and presumably far fewer that are committed to the memory pool. Chromosomal copies of rearranged V genes from single E4+ cells were amplified by nested PCR, and the amplified products were sequenced directly without cloning, using standardized conditions that disclose virtually no Taq polymerase errors. V gene sequence analyses of E4+ cells isolated from single mice confirmed their canonical nature and revealed that they were derived from few precursors. In the average mouse, the E4+ pool was derived from fewer than five canonical precursors. Somatic mutations were found within the V genes of almost all cell isolates. At day 13, a significant fraction of E4+ cells had mutations known to increase antibody affinity for Ars, suggesting they were products of at least one cycle of post-mutational antigen-driven selection. However, the lack of shared mutations by clonally related cells indicated that the selective expansion of mutant subclones typical of memory responses had not yet taken place. This was supported by the observation that half of the E4+ cells failed to bind Ars. Collectively, our results indicate that the memory compartment is a highly selected entity, even at relatively early stages of the primary immune response when somatic mutation and clonal selection are still in progress. If germinal centers are the source of memory B cells, our data suggest that B cell memory may be derived from only a small fraction of all germinal centers.
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32

Shao, Changxia, Yixin Ren, Heng Zhou, Cai Chen, Elisha Dettman, Razvan Cristescu, Alexander Gozman, Fan Jin y Wei Zhou. "Prevalence and prognosis of BRCAm, homologous recombination repair mutation (HRRm) or HR deficiency positive (HRD+) across tumor types." Journal of Clinical Oncology 40, n.º 16_suppl (1 de junio de 2022): e18802-e18802. http://dx.doi.org/10.1200/jco.2022.40.16_suppl.e18802.

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e18802 Background: BRCAm, HRRm, or HRD+ may be predictive of response to poly (ADP-ribose) polymerase inhibitors (PARPi) with/without immunotherapy (IO). However, there is limited data on the prevalence of these biomarkers and their impact on overall survival (OS) among patients who are not treated with PARPi or IO. Methods: This is a retrospective observational study across 15 available tumor types, using data from the de-identified Flatiron Health - Foundation Medicine (FMI) clinicogenomic database collected up to Dec 31, 2020. The de-identified data originated from ̃280 US cancer clinics (̃800 sites of care). Eligible patients were aged ≥ 18 years, diagnosed with advanced/metastatic solid tumors in 2018-2019. BRCAm, HRRm, and HRD were assessed by FMI F1CDx. HRD+ was defined as genomic loss of heterozygosity (gLOH) ≥16. OS analysis from second line therapy initiation (2L, primary index date) was performed as primary analysis since this population had high unmet medical need, and most patients were sequenced after 1L. Patients were excluded if PARPi/IO started on the index date or earlier or if patients died before the index date; and patients were censored as of PARPi/IO initiation if PARPi/IO was started later than the index date. OS was analyzed using the Kaplan-Meier method and Cox proportional hazards model, adjusted for age, sex, and tumor type. Results: A total of 9,462 patients with advanced/metastatic solid tumors were included, with 52% women and mean age of 66 years. The top five tumor types represented more than 75% of the patients, including non-small cell lung cancer (27%), colorectal (19%), breast (13%), pancreatic (8%) and gastric (8%) cancers. Known or suspected deleterious BRCAm was observed in 4.6% of patients across tumors and varied by tumor type, with the highest prevalence in ovarian cancer (13.0%). Total HRRm prevalence was 13.2% across tumor types with prostate cancer (25.9%) as the highest, and the prevalence of HRD+ was 20.6% cross tumor types with breast cancer (34.4%) as the highest. The adjusted hazard ratio (aHR) for OS from initiation of 2L therapy for patients with BRCAm vs BRCA wild type (BRCAwt) was 0.81 (95%CI, 0.61-1.07). Comparable results were observed when calculating OS from 1L or 3L therapy. The aHR of OS from 2L therapy with HRRm vs HRRwt was 0.92 (0.78-1.09) and 1.20 (1.01-1.43) for patients with HRD+ vs HRD negative (HRD-). Conclusions: The prevalence of BRCAm, HRRm, and HRD+ varies widely by tumor type. There was no association between BRCA/HRRm status and OS, yet HRD+ might be associated with shorter OS among patients who were not treated with PARPi or IO across the evaluated tumor types.[Table: see text]
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33

Passamonti, Francesco, Kate Burbury, Tarec Christoffer El-Galaly, Aaron T. Gerds, Vikas Gupta, Brian Higgins, Ling-Yuh Huw et al. "Molecular Response Patterns in Hydroxyurea (HU)-Resistant or Intolerant Polycythemia Vera (PV) during Treatment with Idasanutlin: Results of an Open-Label, Single-Arm Phase 2 Study". Blood 136, Supplement 1 (5 de noviembre de 2020): 38–40. http://dx.doi.org/10.1182/blood-2020-136135.

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Background Activating mutations in JAK2 are the molecular hallmark of PV. However, achieving molecular remission is not a validated endpoint in PV, as its correlation with patient-relevant endpoints, such as thrombotic events or disease progression, is not well established. The expression of MDM2, a negative regulator of wild-type p53, is significantly higher in CD34+ cells from patients with PV vs those from healthy controls. Therefore, MDM2 antagonists such as idasanutlin (idasa) may have selective and potentially disease-modifying effects in PV. This exploratory analysis reports baseline mutational profiling and serial measurements of JAK2 V617F variant allele frequency (VAF) from patients treated with idasa in the Phase II NP39761 study (NCT03287245). Methods Patients with PV, as defined by the 2016 World Health Organization criteria, were eligible for inclusion if their disease was HU resistant/intolerant according to European LeukemiaNet criteria and they were phlebotomy dependent (≥ 1 phlebotomy in the 16-wk period prior to screening). Prior PV therapy with ruxolitinib and/or interferon was allowed. Idasa was given orally once daily on days 1-5 of 28-day cycles for up to 24 mo. The starting dose was 150 mg, but dose increase (to 200 mg) or decrease (to 100 mg) was allowed per protocol-defined criteria. The primary efficacy endpoints were hematocrit control (HTC), defined as maintaining acceptable hematocrit levels with ≤ 1 phlebotomy between cycle 1, day 1 (C1D1) and wk 8 and no phlebotomy after wk 8, and complete hematologic remission (CHR), defined as HTC together with platelets &lt; 400 × 109/L and white blood cell count &lt; 109/L on the day of response assessment (or most recent test). JAK2 V617F VAF was analyzed at screening and at C3D28, C5D28 and wk 32. The JAK2 V617F VAF was determined using quantitative polymerase chain reaction. Baseline blood samples were sequenced using the Foundation Medicine FoundationOne Heme next-generation sequencing panel, which interrogates &gt; 400 DNA-sequenced genes, to explore the genetic landscape of PV beyond JAK2 V617F. Results All 27 patients enrolled in the study harbored JAK2 V617F. Baseline and ≥ 1 later JAK2 VAF measurements were available in 23 patients, allowing for analysis. The median age was 56 y (range, 34-74), and 7 patients (26%) had been previously treated with ruxolitinib. Median treatment duration was 257 days (range, 5-677), and the median number of treatment cycles was 8 (range, 1-22). JAK2 V617F VAFs at baseline were highly variable, ranging from 7% to 96% (median, 66%). A reduction in JAK2 V617F VAF was observed as early as after 3 cycles (median reduction, 39%; n = 19) and was sustained in patients receiving treatment, with a median reduction of 58% at C5D28 (n = 17) and of 76% at wk 32 (n = 13). The median reductions in JAK2 V617F VAF were significantly higher for patients with CHR and HTC than in nonresponders on C3D28 (CHR, P &lt; 0.01; HTC, P = 0.04) and C5D28 (CHR, P &lt; 0.01; HTC, P = 0.03), with a similar trend also at wk 32 (CHR, P = 0.06; HTC, P = 0.19) (Figures). Baseline targeted sequencing (n = 16) identified several additional subclonal mutations. However, no TP53 mutations were detected. Variants in TET2 and ASXL1 were detected in 37% (6 of 16) and 20% (3 of 16) of patients, with VAFs of 2%-51% and 38%-50%, respectively. Notably, 68% of the patients had variants detected in 1 to 3 DNA repair genes, including ATM (VAF, 47%-52%), ATR (VAF, 49%), BRCA2 (VAF, 47%-51%), PARP1 (VAF, 52%), PARP3 (VAF, 48%), FANCM (VAF, 47%-50%), BLM (VAF, 48%) and MSH3 (VAF, 49%). In the absence of sequencing of patient-matched non-hematologic tissue and the VAFs being ≈50%, it is possible some of these variants are germline. Whether such variants predispose to PV is unknown. Conclusions Idasa has relevant clinical activity in patients with PV who are resistant to or intolerant of HU and showed rapid JAK2 V617F VAF reduction in a subset of patients as early as after 3 treatment cycles. The median JAK2 VAF reduction was significantly greater in patients who achieved CHR and HTC after 3 and 5 cycles of idasa treatment, suggesting that early molecular response was associated with higher likelihood of clinical response. Baseline mutations were seen in several genes commonly mutated in PV. A high frequency of variants in DNA repair genes has not previously been reported in PV and may contribute to genomic instability in this disease. Figure Disclosures Passamonti: Roche: Other: Support of parent study and funding of editorial support; BMS: Speakers Bureau; Novartis: Speakers Bureau. El-Galaly:F. Hoffmann-La Roche: Current Employment, Other: Support of parent study and funding of editorial support. Gerds:Celgene: Consultancy, Research Funding; Gilead Sciences: Research Funding; CTI Biopharma: Consultancy, Research Funding; Imago Biosciences: Research Funding; AstraZeneca/MedImmune: Consultancy; Roche/Genentech: Research Funding; Incyte Corporation: Consultancy, Research Funding; Pfizer: Research Funding; Apexx Oncology: Consultancy; Sierra Oncology: Research Funding. Gupta:Incyte: Honoraria, Research Funding; Bristol MyersSquibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sierra Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy. Higgins:Roche: Current Employment, Current equity holder in publicly-traded company, Other: Support of parent study and funding of editorial support. Huw:Roche: Current Employment, Other: Support of parent study and funding of editorial support. Maffioli:Roche: Other: Support of parent study and funding of editorial support. Mesa:Sierra Oncology: Consultancy; Incyte: Research Funding; Samus Therapeutics: Research Funding; Promedior: Research Funding; Genentech: Research Funding; Novartis: Consultancy; CTI BioPharma: Research Funding; LaJolla Pharmaceutical Company: Consultancy; AbbVie: Research Funding; Bristol Myers Squibb: Research Funding. Rambaldi:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support of parent study and funding of editorial support. Received travel support., Research Funding; Sanofi: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Astellas: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support from Gilead.; BMS/Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Advisory board and speaker fees from Pfizer.; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Research grant from Amgen Inc.; Omeros: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); University of Milan: Current Employment. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Blueprint: Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Yacoub:Incyte: Speakers Bureau; Hylapharm: Current equity holder in private company; Cara Therapeutics: Current equity holder in publicly-traded company; Dynavax: Current equity holder in publicly-traded company; Agios: Honoraria, Speakers Bureau; Novartis: Speakers Bureau; Roche: Other: Support of parent study and funding of editorial support; Ardelyx: Current equity holder in publicly-traded company. Mascarenhas:Celgene, Prelude, Galecto, Promedior, Geron, Constellation, and Incyte: Consultancy; Incyte, Kartos, Roche, Promedior, Merck, Merus, Arog, CTI Biopharma, Janssen, and PharmaEssentia: Other: Research funding (institution).
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34

Ricard, L., P. Hirsch, M. Mohty, O. Fain, B. Gaugler, J. Rossignol, F. Delhommeau y A. Mekinian. "AB0161 CLONAL HEMATOPOIESIS IS INCREASED AND NOT RELATED TO AGING IN SYSTEMIC SCLEROSIS". Annals of the Rheumatic Diseases 79, Suppl 1 (junio de 2020): 1381.3–1381. http://dx.doi.org/10.1136/annrheumdis-2020-eular.5489.

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Background:Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis, microangiopathy and immune dysfunctions including dysregulation of proinflammatory cytokines. Clonal hematopoiesis of indeterminate potential (CHIP) is defined by the acquisition of somatic mutations in hematopoietic stem cells leading to detectable clones in the blood. Recent data have shown a higher risk of cardiovascular disease in patients with CHIP resulting from increased production of proinflammatory cytokines and accelerated atherosclerosis. Eventual links between CHIP and autoimmune diseases are undetermined.Objectives:The aim of our study was to evaluate the prevalence of CHIP in SSc patients and its association with clinical phenotype.Methods:Forty-one genes frequently mutated in myeloid malignancies were sequenced in peripheral blood mononuclear cells from 90 SSc patients and from 44 healthy donors.Results:A total of 15 somatic variants was detected in 13/90 SSc patients (14%) and 4 somatic variants in 4/44 (9%) HD (p=0.58). The prevalence of CHIP was significantly higher in younger SSc patients than in HD: 25% (6/24) vs 4% (1/26) (p=0.045) under 50 years and 17% (7/42) vs 3% (1/38) (p=0.065) under 60 years. The prevalence of CHIP in patients over 70 years was similar in SSc patients and healthy donorsFor SSc patients the most common mutations occurred inDNMT3A(7 variants). Other variants involvedATM,SF3B1, SETBP1, TET2,TP53,NF1orCBL. The distribution of gene mutations was overall comparable in SSc patients and in previously described CHIP series (3)In most SSc patients, we identified a single CHIP mutation. Several mutations were detected in two SSc patients:SETBP1andNF1in one and,TET2andATMin the other Clonal mutations included missense (n=10), nonsense (n=3), frameshift (n=1) and a single splice site mutation. In all HD we detected a single CHIP mutation which occurred inDNMT3A, TP53 and CSF3RVariant allele frequencies (VAF) of CHIP mutations ranged from 2 to 18.6% and did not differ between genes (DNMT3Aor others). Mean age was the same in patients withDNMT3Amutations or with other mutations. However, C>T transversions, that have been associated with ageing were more frequent inDNMT3Avariants than in other genes, suggesting distinct mechanisms for mutation acquisition or clonal selection No major differences in clinical and laboratory data were observed between SSc patients with or without CHIP. SSc subtypes, disease duration, different organ involvements and the prevalence of ischemic events were not associated with the presence of CHIP, except less frequent pyrosis in patients with CHIP than those without. SSc patients with CHIP had significantly more anti-RNA polymerase III antibodies than those without CHIP (p=0.045) At the time of analysis, 45 SSc patients had received a treatment for SSc which consisted in low-dose steroids, hydroxychloroquine, mycophenolate mofetil, cyclophosphamide or methotrexate. SSc patients with CHIP were significantly more exposed to cyclophosphamide (3/13 vs. 3/77) (p=0.04) (5, 6.5 and 11 gram respectively between 5 years to 8 years before the NGS sequencing analysis), but among these cyclophosphamide-exposed SSc the age was over 65 in 2/3 of them. When considering all immunosuppressive drugs (cyclophosphamide, methotrexate and mycophenolate mofetil) SSc patients with CHIP were not more exposed than those without CHIP (p=0.75) No patient developed any hematologic malignancy and no cytopenia during the median follow-up of 13 months (0-24 months). One SSc patients with CHIP developed a small lung cancer few months after NGS testing.Conclusion:Whether CHIP increases the risk to develop SSc or is a consequence of a SSc-derived modified bone marrow micro-environment remains to be explored.Acknowledgments:naDisclosure of Interests:None declared
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35

Peter, K. A., I. Vico, V. Gaskins, W. J. Janisiewicz, R. A. Saftner y W. M. Jurick. "First Report of Penicillium carneum Causing Blue Mold on Stored Apples in Pennsylvania". Plant Disease 96, n.º 12 (diciembre de 2012): 1823. http://dx.doi.org/10.1094/pdis-06-12-0541-pdn.

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Blue mold decay occurs during long term storage of apples and is predominantly caused by Penicillium expansum Link. Apples harvested in 2010 were stored in a controlled atmosphere at a commercial Pennsylvania apple packing and storage facility, and were examined for occurrence of decay in May 2011. Several decayed apples from different cultivars, exhibiting blue mold symptoms with a sporulating fungus were collected. One isolate recovered from a decayed ‘Golden Delicious’ apple fruit was identified as P. carneum Frisvad. Genomic DNA was isolated, 800 bp of the 3′ end of the β-tubulin locus was amplified using gene specific primers and sequenced (4). The recovered nucleotide sequence (GenBank Accession No. JX127312) indicated 99% sequence identity with P. carneum strain IBT 3472 (GenBank Accession No. JF302650) (3). The P. carneum colonies strongly sporulated and had a blue green color on potato dextrose agar (PDA), Czapek yeast autolysate agar (CYA), malt extract agar (MEA), and yeast extract sucrose agar (YES) media at 25°C after 7 days. The colonies also had a beige color on plate reverse on CYA and YES media. The species tested positive for the production of alkaloids, as indicated by a violet reaction for the Ehrlich test, and grew on CYA at 30°C and on Czapek with 1,000 ppm propionic acid agar at 25°C; all of which are diagnostic characters of this species (2). The conidiophores were hyaline and tetraverticillate with a finely rough stipe. Conida were produced in long columns, blue green, globose, and averaged 2.9 μm in diameter. To prove pathogenicity, Koch's postulates were conducted using 20 ‘Golden Delicious’ apple fruits. Fruits were washed, surface sterilized with 70% ethanol, and placed onto fruit trays. Using a nail, 3-mm wounds were created and inoculated with 50 μl of a 106/ml conidial suspension or water only as a negative control. The fruit trays were placed into boxes and were stored in the laboratory at 20°C for 7 days. The inoculated fruit developed soft watery lesions, with hard defined edges 37 ± 4 mm in diameter. The sporulating fungus was reisolated from infected tissue of all conidia inoculated apples and confirmed to be P. carneum by polymerase chain reaction (PCR) using the β-tubulin locus as described. Water inoculated control apples were symptomless. Originally grouped with P. roqueforti, P. carneum was reclassified in 1996 as a separate species (1). P. carneum is typically associated with meat products, beverages, and bread spoilage and produces patulin, which is not produced by P. roqueforti (1,2). Our isolate of P. carneum was susceptible to the thiabendazole (TBZ) fungicide at 250 ppm, which is below the recommended labeled application rate of 600 ppm. The susceptibility to TBZ suggests that this P. carneum isolate has been recently introduced because resistance to TBZ has evolved rapidly in P. expansum (4). To the best of our knowledge, P. carneum has not previously been described on apple, and this is the first report of P. carneum causing postharvest decay on apple fruits obtained from storage in Pennsylvania. References: (1) M. Boyson et al. Microbiology 142:541, 1996. (2) J. C. Frisvad and R. A. Samson. Stud. Mycol. 49:1, 2004. (3) B. G. Hansen et al. BMC Microbiology 11:202, 2011. (4) P. L. Sholberg et al. Postharvest Biol. Technol. 36:41, 2005.
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Saitoh, Takayuki, Chiaki Ushie, Atsushi Iwasaki, Norihiko Moriyama, Tomonori Takani, Hattori Hikaru, Hiroshi Handa et al. "The Cytokine Polymorphisms Affect the Severity of Thrombocytopenia at Diagnosis in Chronic Immune Thrombocytopenia." Blood 120, n.º 21 (16 de noviembre de 2012): 2194. http://dx.doi.org/10.1182/blood.v120.21.2194.2194.

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Abstract Abstract 2194 Introduction: The severity of immune thrombocytopenia (ITP) depends on the degree of the thrombocytopenia and the extent of bleeding. Some investigators have reported the association between the thrombocytopenia and cytokine dysregulation in ITP. We investigated the association between the severity of thrombocytopenia at diagnosis in ITP patients and several cytokine polymorphisms, including IL-10-1082A/G, -819T/C, -592A/C, IL-17F-7488T/C and IL-18-607A/C, −137G/C. Patients and methods: We examined 102 patients (male/female, 24/78; median age, 42) diagnosed with chronic ITP. The definition, response criteria, including complete response (CR)and response (R), loss of CR,and “corticosteroid-dependence” were assessed according to the criteria of the ITP International Working Group. ITP with severe thrombocytopenia (ST group)was defined as thrombocytopenia (platelet count < 10×109/L) at the initial diagnosis of ITP. Genotyping of IL-10 (rs1800870 − 1082 A/G, rs1800871 − 819 T/C, and rs1800872 − 592 A/C) and IL-17F (rs763780, 7488 T/C) polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the genotyping of the IL-18 polymorphism (rs187238 −137G/C and rs1946518−607 A/C) was determined by the allelic specific polymerase chain reaction technique. To confirm the accuracy of the assay, amplification products of several individuals were sequenced using an ABI Prism Genetic Analyzer. Genotype and allele frequencies were compared between the study groups using χ2-test. The characteristics and laboratory features of ITP patients with each polymorphisms were compared using χ2-tests and student t-tests. Odds ratios (OR) and 95% confidence intervals (CIs) were estimated for each study. All patients were provided written information about the study. This study was approved by the Institutional Research Board of Gunma University Hospital. Results: Clinical features of chronic ITP: The platelet count ranged from 1×109/L to 98×109/L with a mean of platelet count of 32×109/L at the initial diagnosis. Fifty seven patients (49%) had bleeding tendency. Steroid treatment was given to 68 patients (66.7%) and eradication of Helicobacter pylori (H. pylori) was performed in 32 patients (31.4%), while splenectomy was performed in only 11 patients (10.8%). Clinical features of ST group vs. non-ST group in chronic ITP: Of these 102 patients, 17 (16.7%) had severe thrombocytopenia (platelet count < 10×109/L) (ST group). ST group were significantly older (ST group: median 59 years vs. non-ST group: 41 years, p<0.01) and had more severe bleeding tendency (ST group: 100% vs. non-ST group: 54%, p<0.0001). Steroid treatment was frequently given to ST group than to non-ST group (ST group: 100% vs. non-ST group: 59.5%, p<0.001). Though the response to corticosteroids treatment was not significantly different between ST group and non-ST group (CR rate, ST group: 50% vs. non-ST group: 51.0%, p=0.94), corticosteroid-dependent patients in ST group was significantly higher than in non-ST group (76.9% vs. 25.3%, p<0.005). Polymorphism study of ST group vs. non-ST group in chronic ITP: The frequencies of genotypes of cytokines in patients with chronic ITP according to the definition of criteria of ST were as follows: AA (93.3% vs. 97.1%) and AG (6.7% vs. 2.9%, p=0.48) for IL-10–1082; TT (46.7% vs. 33.3%), TC (33.3% vs.55 %) and CC (20% vs. 11.7%) for IL-10–819; AA (46.7% vs. 33.3%), AC (33.3% vs.55 %) and CC (12.2% vs. 11.5%) for IL-10–592; TT (100% vs. 81%) and TC (0% vs. 19%) for IL-17F; GG (82.4% vs. 74.4%), GC (17.6% vs. 23.2%) and CC (0% vs. 2.4%) for IL-18–137; AA (35.3% vs. 34.1%), AC (58.8% vs. 53.7%) and CC (5.9% vs 12.2%) for IL-18–607 loci (ST group vs. non-ST group, respectively). No significant difference was observed between ST group and non-ST group according to IL-10–1082A/G, −819T/C, −592A/C, and IL-18–607A/C, −137G/C polymorphism. However, the numbers of IL-17F 7488TT genotype (higher function type) in ST group were significantly higher than in non-ST group (ST group: 100% vs. non-ST group: 81% p<0.05). Conclusion: These findings suggest that severe thrombocytopenia at diagnosis have an impact of bleeding tendency and corticosteroid-dependency of chronic ITP. Furthermore, IL-17F polymorphism may affect the severity of thrombocytopenia of chronic ITP. Disclosures: No relevant conflicts of interest to declare.
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37

Oliva, Stefania, Manuela Gambella, Alessandra Larocca, Stefano Spada, Eleonora Marzanati, Barbara Mantoan, Sara Grammatico et al. "Prognostic Impact of Minimal Residual Disease By ASO-RQ-PCR in Multiple Myeloma: A Pooled Analysis of 2 Phase III Studies in Patients Treated with Lenalidomide after Front-Line Therapy". Blood 128, n.º 22 (2 de diciembre de 2016): 4409. http://dx.doi.org/10.1182/blood.v128.22.4409.4409.

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Abstract Background: The prognostic utility of minimal residual disease (MRD) analysis in multiple myeloma (MM) patients has been well described in the last few years. The role of prolonged maintenance therapy even in persistent MRD negative patients is still unclear. The aim of this study is to evaluate the role of MRD by allelic-specific oligonucleotide real-time quantitative polymerase chain reaction (ASO-RQ-PCR) as predictor of progression-free survival (PFS) in newly diagnosed MM (NDMM) patients receiving Lenalidomide maintenance after frontline treatment. Patients and Methods: NDMM patients enrolled in the RV-MM-EMN-441 (NCT01091831) and the RV-MM-COOP-0556 (EMN02/HO95 MM) phase III trials achieving ≥ very good partial response (VGPR) after consolidation/intensification were included in the pooled MRD molecular analysis. After induction therapy, patients in the RV-MM-EMN-441 study were randomized to Cyclophosphamide-Lenalidomide-Dexamethasone (CRD) or Autologous Stem Cell Transplantation (ASCT); patients in the RV-MM-COOP-0556 were randomized to Bortezomib-Melphalan-Prednisone (VMP) vs ASCT (Gay F et al Lancet Oncol 2016, Cavo M et al J Clin Oncol 34, 2016 abstr 8000). All patients received Lenalidomide maintenance until progression or intolerance. MRD analysis was performed on bone marrow (BM) aspirates after intensification/consolidation, after 6 courses of maintenance and then every 6 months until clinical relapse. Patient-specific IgH rearrangements were amplified and directly sequenced from genomic DNA at diagnosis. IgH-based MRD detection by ASO-RQ-PCR was performed using an AbiPrism7900HT.MRD analysis was interpreted following the Euro-MRD guidelines(van der Velden VH et al. Leukemia 2007). Molecular-CR (m-CR) was defined as two consecutive negative MRD results by ASO-RQ-PCR with minimal sensitivity of 10−5. PFS was analyzed using the Kaplan-Meier method, curves were compared with the log-rank test. Multivariate Cox model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: a total of 105 patients entered the molecular MRD pooled study: a specific IgH molecular marker was identified in 73 patients (70%), 32 (30%) did not obtain a successful sequencing. Median age was 57 years (37-65); 30 (41%) patients had International Staging System (ISS) stage I, 33 (45%) stage II and 10 (14%) stage III. FISH risk profile was standard in 43 (59%) patients, high in 24 (33%) and not available in 6 (8%). Thirty-eight (52%) patients did not receive ASCT consolidation and 35 (48%) underwent ASCT. After consolidation/intensification 33/73 (45%) patients achieved m-CR: 19/35 (54%) ASCT patients and 14/38 (37%) no ASCT patients. The impact of m-CR on outcome after consolidation was explored: after a median follow-up of 44 months, median PFS was 48.8 months versus not reached in no m-CR vs m-CR patients, respectively (p=0.01). Lenalidomide maintenance further improved depth of MRD response: 11/40 (27%) MRD positive patients after consolidation obtained a m-CR during maintenance and a median of 2 natural logarithms of tumor burden reduction was recorded. In multivariable Cox analysis the risk of progression/death was higher for ISS stage II/III versus I (HR, 2.91, CI: 1.01-8.41, p=0.048), high-risk FISH versus standard-risk (HR, 2.23 CI: 0.81-6.10, p=0.12), age > 60 years versus ≤60 years (HR: 3.55, CI: 1.26-10.04, p=0.017) and patients who did not achieve m-CR during treatment versus patients who did (HR, 7.65 CI: 2.77-21.11, p<0.001). We identified a very high risk group defined by high risk FISH at diagnosis and persistent MRD positivity, with a median PFS of 29.4 months (figure1). Conclusions: MRD status by ASO-RQ-PCR is a predictor of outcome significantly superior to standard risk factors in NDMM patients and the achievement of m-CR seems to overcome the high risk FISH status in PFS analysis. Molecular CR rate and reduction of tumor burden obtained after consolidation can be enhanced with Lenalidomide maintenance. Based on these preliminary results, the assessment and monitoring of MRD should be suggested as a better prognostic indicator than CR, and the potential role of a MRD-guided therapy should be investigated in future prospective trials. Figure 1 PFS of patients stratified by MRD status (molecular-CR vs no molecular-CR) and FISH (high risk vs standard risk) Figure 1. PFS of patients stratified by MRD status (molecular-CR vs no molecular-CR) and FISH (high risk vs standard risk) Disclosures Oliva: Celgene: Honoraria; Takeda: Honoraria; Amgen: Honoraria. Larocca:Amgen, Celgene, BMS, Janssen-Cilag: Honoraria. Offidani:Janssen: Honoraria; Celgene: Honoraria, Research Funding. Palumbo:Janssen Cilag: Honoraria; Takeda: Employment, Honoraria. Boccadoro:Sanofi, Celgene, Amgen, Janssen, Novartis, Abbivie, BMS: Honoraria; Celgene, Janssen, Amgen, BMS, Mundipharma, Novartis, Sanofi: Research Funding.
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Rondoni, Michela, Emanuela Ottaviani, Daniela Cilloni, Pier Paolo Piccaluga, Stefania Paolini, Ilaria Iacobucci, Simona Soverini et al. "Chronic Eosinophilic Leukaemia (CEL) with FIP1L1-PDGFRalpha Rearrangement (F/P): The Response to Imatinib (IM) Is Durable. A Report of 33 Patients with A Follow –up of 30 to 92 Months." Blood 114, n.º 22 (20 de noviembre de 2009): 3894. http://dx.doi.org/10.1182/blood.v114.22.3894.3894.

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Abstract Abstract 3894 Poster Board III-830 Background An interstitial deletion in the long arm of chromosome 4 leads to the formation of the fusion gene FIP1L1-PDGFRalpha (F/P) coding for a constitutively activated form of PDGFRalpha. The fusion gene represents a marker of CEL, and it predicts a dramatic response to imatinib mesylate (IM). Different F/P transcripts have been described, but the correlation with kinetic of molecular response to IM and with the clinical presentation is unknown. Remission duration is also still undefined. Aim The aim of this study was to evaluate the duration of IM response in F/P positive (F/P+) CEL patients and the correlation between their clinical behaviour and molecular characteristics of the transcripts. Design and methods A prospective phase 2 multicentre study of the use of IM 400 mg/daily in patients with hypereosinophilic syndrome, independently of F/P status was established in 2001. Hypereosinophilic syndrome was defined according to Chusid criteria (Blood, 1994; 83: 2759-2779). The presence of F/P transcript was investigated on bone marrow cells using a nested reverse transcriptase polymerase chain reaction (RT-PCR), as reported by Cools J (N Engl J Med. 2003; 348:1199-200). The samples were also purified and sequenced using the Big Dye Terminator Cycle Sequencing Kit (Applied Biosystems). Patients at diagnosis were systematically screened for organ damage with instrumental evaluation (chest radiography, echocardiogram, abdomen ultrasonography) and for the presence of symptoms. 72 patients were treated with IM 100 to 400 mg daily; the 33 F/P+ were monitored every three months for two years then every six months using nested RT-PCR. We will present the result of the 33 F/P+ patients. Results Median follow-up was of 51 months (range 30-92 months). There were 32 males and one female patients. Organ involvement was recorded in 42% of patients, with notably no skin involvement, splenomegaly reported in 7, cardiac involvement in 5, and in 2 cases the peculiar site of localization of soft tissue. After imatinib therapy all patients achieved a complete hematologic response (CHR) in less than one month, and PCR negativity in a median time of 3 months (range 1-9). They became negative for organ localizations and free of symptoms. No patient experienced cardiac failure. All patients who continue imatinib therapy remained in CHR and RT-PCR negative, with a dose of 100 to 400 mg daily. From September 2007 all patients except one (late responder) were treated with 100 mg daily. In six patients IM treatment was discontinued for variable period for different reasons, and in 5 cases the fusion transcript became rapidly detectable; CHR was maintained, other than in one case and the transcript was again undetectable upon treatment resumption, other than in one case. Twenty-eight samples were evaluable for sequencing. Molecular analysis demonstrate an extreme variability of FIP1L1-PDGFRA junction sequences, with FIP1L1 breackpoints scattered between exon 9 to 18, with several splicing variants, whereas all breackpoints in PDGFRA are located within exon 12. Fusion gene sequencing demonstrate an extreme variability, with lack of whole exons of FIP1L1, deletion of exons, with the presence of introns in a minority of cases. Region of FIP1L1 varies in length from 109 to more than 500 nucleotides. Transcript of the only female patient is the same of one of the males. No evidence of correlation was noted with kinetic of molecular response or with the presence at diagnosis of peculiar organ involvement. More complexity of transcript is noted in patients with longer history of disease prior to imatinib therapy. Interpretation and conclusion with this large series of patients we can confirm that the response to imatinib therapy is durable, is not influenced by the biologic features, but depends on continuous therapy. More complexity and variability in FIP1L1-PDGFRalpha transcripts does not lead to differences in terms of response to the therapy or phenotype of disease at diagnosis. Disclosures: Pane: Novartis: Research Funding; Ministero dell'Università/PRIN: Research Funding; Regione Campania: Research Funding; Ministero della Salute/Progetto integrato Oncologia: Research Funding. Saglio:Novartis: Honoraria; Celgene: Honoraria. Baccarani:Novartis Pharma: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bristol-Mayer Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau.
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Nesrine, Lenchi, Kebbouche Salima, Khelfaoui Mohamed Lamine, Laddada Belaid, BKhemili Souad, Gana Mohamed Lamine, Akmoussi Sihem y Ferioune Imène. "Phylogenetic characterization and screening of halophilic bacteria from Algerian salt lake for the production of biosurfactant and enzymes". World Journal of Biology and Biotechnology 5, n.º 2 (15 de agosto de 2020): 1. http://dx.doi.org/10.33865/wjb.005.02.0294.

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Environments containing significant concentration of NaCl such as salt lakes harbor extremophiles microorganisms which have a great biotechnology interest. To explore the diversity of Bacteria in Chott Tinsilt (Algeria), an isolation program was performed. Water samples were collected from the saltern during the pre-salt harvesting phase. This Chott is high in salt (22.47% (w/v). Seven halophiles Bacteria were selected for further characterization. The isolated strains were able to grow optimally in media with 10–25% (w/v) total salts. Molecular identification of the isolates was performed by sequencing the 16S rRNA gene. It showed that these cultured isolates included members belonging to the Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus genera with less than 98% of similarity with their closest phylogenetic relative. The halophilic bacterial isolates were also characterized for the production of biosurfactant and industrially important enzymes. Most isolates produced hydrolases and biosurfactants at high salt concentration. In fact, this is the first report on bacterial strains (A4 and B4) which were a good biosurfactant and coagulase producer at 20% and 25% ((w/v)) NaCl. In addition, the biosurfactant produced by the strain B4 at high salinity (25%) was also stable at high temperature (30-100°C) and high alkalinity (pH 11).Key word: Salt Lake, Bacteria, biosurfactant, Chott, halophiles, hydrolases, 16S rRNAINTRODUCTIONSaline lakes cover approximately 10% of the Earth’s surface area. The microbial populations of many hypersaline environments have already been studied in different geographical regions such as Great Salt Lake (USA), Dead Sea (Israel), Wadi Natrun Lake (Egypt), Lake Magadi (Kenya), Soda Lake (Antarctica) and Big Soda Lake and Mono Lake (California). Hypersaline regions differ from each other in terms of geographical location, salt concentration and chemical composition, which determine the nature of inhabitant microorganisms (Gupta et al., 2015). Then low taxonomic diversity is common to all these saline environments (Oren et al., 1993). Halophiles are found in nearly all major microbial clades, including prokaryotic (Bacteria and Archaea) and eukaryotic forms (DasSarma and Arora, 2001). They are classified as slight halophiles when they grow optimally at 0.2–0.85 M (2–5%) NaCl, as moderate halophiles when they grow at 0.85–3.4 M (5–20%) NaCl, and as extreme halophiles when they grow at 3.4–5.1 M (20–30%) NaCl. Hyper saline environments are inhabited by extremely halophilic and halotolerant microorganisms such as Halobacillus sp, Halobacterium sp., Haloarcula sp., Salinibacter ruber , Haloferax sp and Bacillus spp. (Solomon and Viswalingam, 2013). There is a tremendous demand for halophilic bacteria due to their biotechnological importance as sources of halophilic enzymes. Enzymes derived from halophiles are endowed with unique structural features and catalytic power to sustain the metabolic and physiological processes under high salt conditions. Some of these enzymes have been reported to be active and stable under more than one extreme condition (Karan and Khare, 2010). Applications are being considered in a range of industries such as food processing, washing, biosynthetic processes and environmental bioremediation. Halophilic proteases are widely used in the detergent and food industries (DasSarma and Arora, 2001). However, esterases and lipases have also been useful in laundry detergents for the removal of oil stains and are widely used as biocatalysts because of their ability to produce pure compounds. Likewise, amylases are used industrially in the first step of the production of high fructose corn syrup (hydrolysis of corn starch). They are also used in the textile industry in the de-sizing process and added to laundry detergents. Furthermore, for the environmental applications, the use of halophiles for bioremediation and biodegradation of various materials from industrial effluents to soil contaminants and accidental spills are being widely explored. In addition to enzymes, halophilic / halotolerants microorganisms living in saline environments, offer another potential applications in various fields of biotechnology like the production of biosurfactant. Biosurfactants are amphiphilic compounds synthesized from plants and microorganisms. They reduce surface tension and interfacial tension between individual molecules at the surface and interface respectively (Akbari et al., 2018). Comparing to the chemical surfactant, biosurfactant are promising alternative molecules due to their low toxicity, high biodegradability, environmental capability, mild production conditions, lower critical micelle concentration, higher selectivity, availability of resources and ability to function in wide ranges of pH, temperature and salinity (Rocha et al., 1992). They are used in various industries which include pharmaceuticals, petroleum, food, detergents, cosmetics, paints, paper products and water treatment (Akbari et al., 2018). The search for biosurfactants in extremophiles is particularly promising since these biomolecules can adapt and be stable in the harsh environments in which they are to be applied in biotechnology.OBJECTIVESEastern Algeria features numerous ecosystems including hypersaline environments, which are an important source of salt for food. The microbial diversity in Chott Tinsilt, a shallow Salt Lake with more than 200g/L salt concentration and a superficies of 2.154 Ha, has never yet been studied. The purpose of this research was to chemically analyse water samples collected from the Chott, isolate novel extremely or moderate halophilic Bacteria, and examine their phenotypic and phylogenetic characteristics with a view to screening for biosurfactants and enzymes of industrial interest.MATERIALS AND METHODSStudy area: The area is at 5 km of the Commune of Souk-Naâmane and 17 km in the South of the town of Aïn-Melila. This area skirts the trunk road 3 serving Constantine and Batna and the railway Constantine-Biskra. It is part the administrative jurisdiction of the Wilaya of Oum El Bouaghi. The Chott belongs to the wetlands of the High Plains of Constantine with a depth varying rather regularly without never exceeding 0.5 meter. Its length extends on 4 km with a width of 2.5 km (figure 1).Water samples and physico-chemical analysis: In February 2013, water samples were collected from various places at the Chott Tinsilt using Global Positioning System (GPS) coordinates of 35°53’14” N lat. and 06°28’44”E long. Samples were collected randomly in sterile polythene bags and transported immediately to the laboratory for isolation of halophilic microorganisms. All samples were treated within 24 h after collection. Temperature, pH and salinity were measured in situ using a multi-parameter probe (Hanna Instruments, Smithfield, RI, USA). The analytical methods used in this study to measure ions concentration (Ca2+, Mg2+, Fe2+, Na+, K+, Cl−, HCO3−, SO42−) were based on 4500-S-2 F standard methods described elsewhere (Association et al., 1920).Isolation of halophilic bacteria from water sample: The media (M1) used in the present study contain (g/L): 2.0 g of KCl, 100.0/200.0 g of NaCl, 1.0 g of MgSO4.7HO2, 3.0 g of Sodium Citrate, 0.36 g of MnCl2, 10.0 g of yeast extract and 15.0 g agar. The pH was adjusted to 8.0. Different dilutions of water samples were added to the above medium and incubated at 30°C during 2–7 days or more depending on growth. Appearance and growth of halophilic bacteria were monitored regularly. The growth was diluted 10 times and plated on complete medium agar (g/L): glucose 10.0; peptone 5.0; yeast extract 5.0; KH2PO4 5.0; agar 30.0; and NaCl 100.0/200.0. Resultant colonies were purified by repeated streaking on complete media agar. The pure cultures were preserved in 20% glycerol vials and stored at −80°C for long-term preservation.Biochemical characterisation of halophilic bacterial isolates: Bacterial isolates were studied for Gram’s reaction, cell morphology and pigmentation. Enzymatic assays (catalase, oxidase, nitrate reductase and urease), and assays for fermentation of lactose and mannitol were done as described by Smibert (1994).Optimization of growth conditions: Temperature, pH, and salt concentration were optimized for the growth of halophilic bacterial isolates. These growth parameters were studied quantitatively by growing the bacterial isolates in M1 medium with shaking at 200 rpm and measuring the cell density at 600 nm after 8 days of incubation. To study the effect of NaCl on the growth, bacterial isolates were inoculated on M1 medium supplemented with different concentration of NaCl: 1%-35% (w/v). The effect of pH on the growth of halophilic bacterial strains was studied by inoculating isolates on above described growth media containing NaCl and adjusted to acidic pH of 5 and 6 by using 1N HCl and alkaline pH of 8, 9, 10, 11 and 12 using 5N NaOH. The effect of temperature was studied by culturing the bacterial isolates in M1 medium at different temperatures of incubation (4°C–55°C).Screening of halophilic bacteria for hydrolytic enzymes: Hydrolase producing bacteria among the isolates were screened by plate assay on starch, tributyrin, gelatin and DNA agar plates respectively for amylase, lipase, protease and DNAse activities. Amylolytic activity of the cultures was screened on starch nutrient agar plates containing g/L: starch 10.0; peptone 5.0; yeast extract 3.0; agar 30.0; NaCl 100.0/250.0. The pH was 7.0. After incubation at 30 ºC for 7 days, the zone of clearance was determined by flooding the plates with iodine solution. The potential amylase producers were selected based on ratio of zone of clearance diameter to colony diameter. Lipase activity of the cultures was screened on tributyrin nutrient agar plates containing 1% (v/v) of tributyrin. Isolates that showed clear zones of tributyrin hydrolysis were identified as lipase producing bacteria. Proteolytic activity of the isolates was similarly screened on gelatin nutrient agar plates containing 10.0 g/L of gelatin. The isolates showing zones of gelatin clearance upon treatment with acidic mercuric chloride were selected and designated as protease producing bacteria. The presence of DNAse activity on plates was determined on DNAse test agar (BBL) containing 10%-25% (w/v) total salt. After incubation for 7days, the plates were flooded with 1N HCl solution. Clear halos around the colonies indicated DNAse activity (Jeffries et al., 1957).Milk clotting activity (coagulase activity) of the isolates was also determined following the procedure described (Berridge, 1952). Skim milk powder was reconstituted in 10 mM aqueous CaCl2 (pH 6.5) to a final concentration of 0.12 kg/L. Enzyme extracts were added at a rate of 0.1 mL per mL of milk. The coagulation point was determined by manual rotating of the test tube periodically, at short time intervals, and checking for visible clot formation.Screening of halophilic bacteria for biosurfactant production. Oil spread Assay: The Petridis base was filled with 50 mL of distilled water. On the water surface, 20μL of diesel and 10μl of culture were added respectively. The culture was introduced at different spots on the diesel, which is coated on the water surface. The occurrence of a clear zone was an indicator of positive result (Morikawa et al., 2000). The diameter of the oil expelling circles was measured by slide caliber (with a degree of accuracy of 0.02 mm).Surface tension and emulsification index (E24): Isolates were cultivated at 30 °C for 7 days on the enrichment medium containing 10-25% NaCl and diesel oil as the sole carbon source. The medium was centrifuged (7000 rpm for 20 min) and the surface tension of the cell-free culture broth was measured with a TS90000 surface tensiometer (Nima, Coventry, England) as a qualitative indicator of biosurfactant production. The culture broth was collected with a Pasteur pipette to remove the non-emulsified hydrocarbons. The emulsifying capacity was evaluated by an emulsification index (E24). The E24 of culture samples was determined by adding 2 mL of diesel oil to the same amount of culture, mixed for 2 min with a vortex, and allowed to stand for 24 h. E24 index is defined as the percentage of height of emulsified layer (mm) divided by the total height of the liquid column (mm).Biosurfactant stability studies : After growth on diesel oil as sole source of carbone, cultures supernatant obtained after centrifugation at 6,000 rpm for 15 min were considered as the source of crude biosurfactant. Its stability was determined by subjecting the culture supernatant to various temperature ranges (30, 40, 50, 60, 70, 80 and 100 °C) for 30 min then cooled to room temperature. Similarly, the effect of different pH (2–11) on the activity of the biosurfactant was tested. The activity of the biosurfactant was investigated by measuring the emulsification index (El-Sersy, 2012).Molecular identification of potential strains. DNA extraction and PCR amplification of 16S rDNA: Total cellular DNA was extracted from strains and purified as described by Sambrook et al. (1989). DNA was purified using Geneclean® Turbo (Q-BIO gene, Carlsbad, CA, USA) before use as a template in polymerase chain reaction (PCR) amplification. For the 16S rDNA gene sequence, the purified DNA was amplified using a universal primer set, forward primer (27f; 5′-AGA GTT TGA TCM TGG CTC AG) and a reverse primer (1492r; 5′-TAC GGY TAC CTT GTT ACG ACT T) (Lane, 1991). Agarose gel electrophoresis confirmed the amplification product as a 1400-bp DNA fragment.16S rDNA sequencing and Phylogenic analysis: Amplicons generated using primer pair 27f-1492r was sequenced using an automatic sequencer system at Macrogene Company (Seoul, Korea). The sequences were compared with those of the NCBI BLAST GenBank nucleotide sequence databases. Phylogenetic trees were constructed by the neighbor-joining method using MEGA version 5.05 software (Tamura et al., 2011). Bootstrap resembling analysis for 1,000 replicates was performed to estimate the confidence of tree topologies.Nucleotide sequence accession numbers: The nucleotide sequences reported in this work have been deposited in the EMBL Nucleotide Sequence Database. The accession numbers are represented in table 5.Statistics: All experiments were conducted in triplicates. Results were evaluated for statistical significance using ANOVA.RESULTSPhysico-chemical parameters of the collected water samples: The physicochemical properties of the collected water samples are reported in table 1. At the time of sampling, the temperature was 10.6°C and pH 7.89. The salinity of the sample, as determined in situ, was 224.70 g/L (22,47% (w/v)). Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions (table 1). SO4-2 and Mg+2 was present in much smaller amounts compared to Na +and Cl- concentration. Low levels of calcium, potassium and bicarbonate were also detected, often at less than 1 g/L.Characterization of isolates. Morphological and biochemical characteristic feature of halophilic bacterial isolates: Among 52 strains isolated from water of Chott Tinsilt, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for further characterization (table 2). The colour of the isolates varied from beige, pale yellow, yellowish and orange. The bacterial isolates A1, A2, A4, B1 and B5 were rod shaped and gram negative (except B5), whereas A3 and B4 were cocci and gram positive. All strains were oxidase and catalase positive except for B1. Nitrate reductase and urease activities were observed in all the bacterial isolates, except B4. All the bacterial isolates were negative for H2S formation. B5 was the only strain positive for mannitol fermentation (table 2).We isolated halophilic bacteria on growth medium with NaCl supplementation at pH 7 and temperature of 30°C. We studied the effect of NaCl, temperature and pH on the growth of bacterial isolates. All the isolates exhibited growth only in the presence of NaCl indicating that these strains are halophilic. The optimum growth of isolates A3 and B1 was observed in the presence of 10% NaCl, whereas it was 15% NaCl for A1, A2 and B5. A4 and B4 showed optimum growth in the presence of 20% and 25% NaCl respectively. A4, B4 and B5 strains can tolerate up to 35% NaCl.The isolate B1 showed growth in medium supplemented with 10% NaCl and pH range of 7–10. The optimum pH for the growth B1 was 9 and they did not show any detectable growth at or below pH 6 (table 2), which indicates the alkaliphilic nature of B1 isolate. The bacterial isolates A1, A2 and A4 exhibited growth in the range of pH 6–10, while A3 and B4 did not show any growth at pH greater than 8. The optimum pH for growth of all strains (except B1) was pH 7.0 (table 2). These results indicate that A1, A2, A3, A4, B4 and B5 are neutrophilic in nature. All the bacterial isolates exhibited optimal growth at 30°C and no detectable growth at 55°C. Also, detectable growth of isolates A1, A2 and A4 was observed at 4°C. However, none of the bacterial strains could grow below 4°C and above 50°C (table 2).Screening of the halophilic enzymes: To characterize the diversity of halophiles able to produce hydrolytic enzymes among the population of microorganisms inhabiting the hypersaline habitats of East Algeria (Chott Tinsilt), a screening was performed. As described in Materials and Methods, samples were plated on solid media containing 10%-25% (w/v) of total salts and different substrates for the detection of amylase, protease, lipase and DNAse activities. However, coagulase activity was determined in liquid medium using milk as substrate (figure 3). Distributions of hydrolytic activity among the isolates are summarized in table 4.From the seven bacterial isolates, four strains A1, A2, A4 and B5 showed combined hydrolytic activities. They were positive for gelatinase, lipase and coagulase. A3 strain showed gelatinase and lipase activities. DNAse activities were detected with A1, A4, B1 and B5 isolates. B4 presented lipase and coagulase activity. Surprisingly, no amylase activity was detected among all the isolates.Screening for biosurfactant producing isolates: Oil spread assay: The results showed that all the strains could produce notable (>4 cm diameter) oil expelling circles (ranging from 4.11 cm to 4.67 cm). The average diameter for strain B5 was 4.67 cm, significantly (P < 0.05) higher than for the other strains.Surface tension and emulsification index (E24): The assimilation of hydrocarbons as the sole sources of carbon by the isolate strains led to the production of biosurfactants indicated by the emulsification index and the lowering of the surface tension of cell-free supernatant. Based on rapid growth on media containing diesel oil as sole carbon source, the seven isolates were tested for biosurfactant production and emulsification activity. The obtained values of the surface tension measurements as well as the emulsification index (E24) are shown in table 3. The highest reduction of surface tension was achieved with B5 and A3 isolates with values of 25.3 mN m−1 and 28.1 mN m−1 respectively. The emulsifying capacity evaluated by the E24 emulsification index was highest in the culture of isolate B4 (78%), B5 (77%) and A3 (76%) as shown in table 3 and figure 2. These emulsions were stable even after 4 months. The bacteria with emulsification indices higher than 50 % and/or reduction in the surface tension (under 30 mN/m) have been defined as potential biosurfactant producers. Based on surface tension and the E24 index results, isolates B5, B4, A3 and A4 are the best candidates for biosurfactant production. It is important to note that, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was choosen for futher analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4.biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was chosen for further analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4. The biosurfactant produced by this strain was shown to be thermostable giving an E-24 Index value greater than 78% (figure 4A). Heating of the biosurfactant to 100 °C caused no significant effect on the biosurfactant performance. Therefore, the surface activity of the crude biosurfactant supernatant remained relatively stable to pH changes between pH 6 and 11. At pH 11, the value of E24 showed almost 76% activity, whereas below pH 6 the activity was decreased up to 40% (figure 4A). The decreases of the emulsification activity by decreasing the pH value from basic to an acidic region; may be due to partial precipitation of the biosurfactant. This result indicated that biosurfactant produced by strain B4 show higher stability at alkaline than in acidic conditions.Molecular identification and phylogenies of potential isolates: To identify halophilic bacterial isolates, the 16S rDNA gene was amplified using gene-specific primers. A PCR product of ≈ 1.3 kb was detected in all the seven isolates. The 16S rDNA amplicons of each bacterial isolate was sequenced on both strands using 27F and 1492R primers. The complete nucleotide sequence of 1336,1374, 1377,1313, 1305,1308 and 1273 bp sequences were obtained from A1, A2, A3, A4, B1, B4 and B5 isolates respectively, and subjected to BLAST analysis. The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus as shown in table 5. The halophilic isolates A2 and A4 showed 97% similarity with the Halomonas variabilis strain GSP3 (accession no. AY505527) and the Halomonas sp. M59 (accession no. AM229319), respectively. As for A1, it showed 96% similarity with the Halomonas venusta strain GSP24 (accession no. AY553074). B1 and B4 showed for their part 96% similarity with the Salinivibrio costicola subsp. alcaliphilus strain 18AG DSM4743 (accession no. NR_042255) and the Planococcus citreus (accession no. JX122551), respectively. The bacterial isolate B5 showed 98% sequence similarity with the Halobacillus trueperi (accession no. HG931926), As for A3, it showed only 95% similarity with the Staphylococcus arlettae (accession no. KR047785). The 16S rDNA nucleotide sequences of all the seven halophilic bacterial strains have been submitted to the NCBI GenBank database under the accession number presented in table 5. The phylogenetic association of the isolates is shown in figure 5.DICUSSIONThe physicochemical properties of the collected water samples indicated that this water was relatively neutral (pH 7.89) similar to the Dead Sea and the Great Salt Lake (USA) and in contrast to the more basic lakes such as Lake Wadi Natrun (Egypt) (pH 11) and El Golea Salt Lake (Algeria) (pH 9). The salinity of the sample was 224.70 g/L (22,47% (w/v). This range of salinity (20-30%) for Chott Tinsilt is comparable to a number of well characterized hypersaline ecosystems including both natural and man-made habitats, such as the Great Salt Lake (USA) and solar salterns of Puerto Rico. Thus, Chott Tinsilt is a hypersaline environment, i.e. environments with salt concentrations well above that of seawater. Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions, as in most hypersaline ecosystems (with some exceptions such as the Dead Sea). These chemical water characteristics were consistent with the previously reported data in other hypersaline ecosystems (DasSarma and Arora, 2001; Oren, 2002; Hacěne et al., 2004). Among 52 strains isolated from this Chott, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for phenotypique, genotypique and phylogenetique characterization.The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus. Genera obtained in the present study are commonly occurring in various saline habitats across the globe. Staphylococci have the ability to grow in a wide range of salt concentrations (Graham and Wilkinson, 1992; Morikawa et al., 2009; Roohi et al., 2014). For example, in Pakistan, Staphylococcus strains were isolated from various salt samples during the study conducted by Roohi et al. (2014) and these results agreed with previous reports. Halomonas, halophilic and/or halotolerant Gram-negative bacteria are typically found in saline environments (Kim et al., 2013). The presence of Planococcus and Halobacillus has been reported in studies about hypersaline lakes; like La Sal del Rey (USA) (Phillips et al., 2012) and Great Salt Lake (Spring et al., 1996), respectively. The Salinivibrio costicola was a representative model for studies on osmoregulatory and other physiological mechanisms of moderately halophilic bacteria (Oren, 2006).However, it is interesting to note that all strains shared less than 98.7% identity (the usual species cut-off proposed by Yarza et al. (2014) with their closest phylogenetic relative, suggesting that they could be considered as new species. Phenotypic, genetic and phylogenetic analyses have been suggested for the complete identification of these strains. Theses bacterial strains were tested for the production of industrially important enzymes (Amylase, protease, lipase, DNAse and coagulase). These isolates are good candidates as sources of novel enzymes with biotechnological potential as they can be used in different industrial processes at high salt concentration (up to 25% NaCl for B4). Prominent amylase, lipase, protease and DNAase activities have been reported from different hypersaline environments across the globe; e.g., Spain (Sánchez‐Porro et al., 2003), Iran (Rohban et al., 2009), Tunisia (Baati et al., 2010) and India (Gupta et al., 2016). However, to the best of our knowledge, the coagulase activity has never been detected in extreme halophilic bacteria. Isolation and characterization of crude enzymes (especially coagulase) to investigate their properties and stability are in progress.The finding of novel enzymes with optimal activities at various ranges of salt concentrations is of great importance. Besides being intrinsically stable and active at high salt concentrations, halophilic and halotolerant enzymes offer great opportunities in biotechnological applications, such as environmental bioremediation (marine, oilfiel) and food processing. The bacterial isolates were also characterized for production of biosurfactants by oil-spread assay, measurement of surface tension and emulsification index (E24). There are few reports on biosurfactant producers in hypersaline environments and in recent years, there has been a greater increase in interest and importance in halophilic bacteria for biomolecules (Donio et al., 2013; Sarafin et al., 2014). Halophiles, which have a unique lipid composition, may have an important role to play as surface-active agents. The archae bacterial ether-linked phytanyl membrane lipid of the extremely halophilic bacteria has been shown to have surfactant properties (Post and Collins, 1982). Yakimov et al. (1995) reported the production of biosurfactant by a halotolerant Bacillus licheniformis strain BAS 50 which was able to produce a lipopeptide surfactant when cultured at salinities up to 13% NaCl. From solar salt, Halomonas sp. BS4 and Kocuria marina BS-15 were found to be able to produce biosurfactant when cultured at salinities of 8% and 10% NaCl respectively (Donio et al., 2013; Sarafin et al., 2014). In the present work, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% NaCl. To our knowledge, this is the first report on biosurfactant production by bacteria under such salt concentration. Biosurfactants have a wide variety of industrial and environmental applications (Akbari et al., 2018) but their applicability depends on their stability at different environmental conditions. The strain B4 which can produce biosurfactant at 25% NaCl showed good stability in alkaline pH and at a temperature range of 30°C-100°C. Due to the enormous utilization of biosurfactant in detergent manufacture the choice of alkaline biosurfactant is researched (Elazzazy et al., 2015). On the other hand, the interesting finding was the thermostability of the produced biosurfactant even after heat treatment (100°C for 30 min) which suggests the use of this biosurfactant in industries where heating is of a paramount importance (Khopade et al., 2012). To date, more attention has been focused on biosurfactant producing bacteria under extreme conditions for industrial and commercial usefulness. In fact, the biosurfactant produce by strain B4 have promising usefulness in pharmaceutical, cosmetics and food industries and for bioremediation in marine environment and Microbial enhanced oil recovery (MEOR) where the salinity, temperature and pH are high.CONCLUSIONThis is the first study on the culturable halophilic bacteria community inhabiting Chott Tinsilt in Eastern Algeria. Different genera of halotolerant bacteria with different phylogeneticaly characteristics have been isolated from this Chott. Culturing of bacteria and their molecular analysis provides an opportunity to have a wide range of cultured microorganisms from extreme habitats like hypersaline environments. Enzymes produced by halophilic bacteria show interesting properties like their ability to remain functional in extreme conditions, such as high temperatures, wide range of pH, and high salt concentrations. These enzymes have great economical potential in industrial, agricultural, chemical, pharmaceutical, and biotechnological applications. Thus, the halophiles isolated from Chott Tinsilt offer an important potential for application in microbial and enzyme biotechnology. In addition, these halo bacterial biosurfactants producers isolated from this Chott will help to develop more valuable eco-friendly products to the pharmacological and food industries and will be usefulness for bioremediation in marine environment and petroleum industry.ACKNOWLEDGMENTSOur thanks to Professor Abdelhamid Zoubir for proofreading the English composition of the present paper.CONFLICT OF INTERESTThe authors declare that they have no conflict of interest.Akbari, S., N. H. Abdurahman, R. M. Yunus, F. Fayaz and O. R. Alara, 2018. Biosurfactants—a new frontier for social and environmental safety: A mini review. Biotechnology research innovation, 2(1): 81-90.Association, A. P. H., A. W. W. Association, W. P. C. 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Schleifer, W. B. Whitman, J. Euzéby, R. Amann and R. Rosselló-Móra, 2014. Uniting the classification of cultured and uncultured bacteria and archaea using 16s rRNA gene sequences. Nature reviews microbiology, 12(9): 635-645
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Shanaj Parvin, Most y Md Ehsanul Haque. "Microrna Regulation of Nodule Zone-Specific Gene Expression In Soybean". Journal of Natural Products and Natural Products Synthesis 1, n.º 1 (25 de junio de 2021): 15–21. http://dx.doi.org/10.55124/jnns.v1i1.82.

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Nitrogen is a paramount important essential element for all living organisms. It has been found to bea crucial structural component of proteins, nucleic acids, enzymes and other cellular constituents which are inevitable for all forms of life. In the atmosphere, the percentage of nitrogen is very high (N2, 78%) compared to other inorganic gases. However, most organisms have practically no direct access to this nitrogen. While plants can not directly uptake nitrogen from atmosphere, they are capable of assimilating other forms of nitrogen, for example ammonium (NH4+) and nitrate (NO3-). For agricultural crop production, artificial fixation of nitrogen is heavily utilized and it is an expensive process that requires high temperatures (at least 400 °C) and pressures (around 200 atm). It has been conspicuously demonstrated that indiscriminate use of fertilizer hampers soil physical, chemical and micro biological properties and also a potential risk to environment e.g. water quality. Besides, chemically manufactured fertilizers are depleted from soils in various ways, for instance; denitrifying bacteria, volatilization, and leaching. Consequently, it results relatively poor availability of nitrogen to get into plants. On the flipside, only 1-2% of the nitrogen fixation in the world occurs through the natural process of lightening. Notably, microbial fixation is well characterized in diazotrophs for example; Rhizobia and Frankia, and blue-green algae. Against the backdrop, we are accentuated on an environmentally friendlyand themost sustainable approach to increase productivity for legume and non-legume crops. Till today, the term biological nitrogen fixation (BNF) has received much attention as a sustainable alternative; this process facilitates atmospheric nitrogen to convert into ammonia by rhizobia in specialized plan organs termed “root nodules”. This review article seeks to better understand plant mechanisms involved in the development of root nodules in soybean. Soybean (Glycine max) is one of the most important oil crops and a source of animal feed protein in the world. It has a salient feature to fix atmospheric nitrogen through symbioses with compatible rhizobia that yields to determinate type nodule (Oldroyd, Murray et al. 2011). Biological nitrogen fixation in soybean nodules reduces the use of chemical nitrogen fertilizers resulting in cost-savings to producers and minimizes environmental damage due to nitrogen run-off. A better understanding of how nodules form and function is important for selection or generation of soybean genotypes with better nitrogen fixation capacity. Soybean nodules originate from root cortex via de novo cell differentiation (Oldroyd 2013). Consequently, two major nodule development zones are formed for instance; the nodule primordium (Npr) in the middle and it is encircled by nodule parenchyma (Npa). At later time point, the Npr gives rise to N-fixation zone and the Npa holds vascular bundles. It is not clear what early signaling pathways driving the conspicuous development of the nodule zones. My research is aimed at filling this knowledge gap by illustrating the molecular signatures that paves the way to cellular differentiation in root nodule development in soybean. Based on initial evidence obtained by the Subramanian lab, we hypothesize that microRNAs (miRNAs) play important regulatory roles in spatio-temporal expression of their target genes during nodule developmental in soybean. For instance, the regulation of auxin sensitivity by miR160 has been found to be crucial for formation of nodule primordia and vasculature in the parenchyma (Marie Turner 2013). Against this backdrop, this review article focused on nuclear and cytoplasmic transcriptome as well as miRNA profiles of parenchyma and primordial tissues and determine the relative abundance and differentially expressed mRNAs and regulatory role of miRNAs in cell differentiation and nodule development. Root nodule a sustainable alternative to fix atmospheric nitrogen Atmospheric nitrogen percentage is very high (N2, 78%) compared to other inorganic gases (Mary Elvira 1932). However, most of the organisms have practically no direct access to this nitrogen. Nevertheless, plants can not directly uptake nitrogen from atmosphere but they are capable of assimilating only very specific forms of nitrogen, for example ammonium (NH4+) and nitrate (NO3-) (Bytnerowicz and Fenn 1996, Peter M. Vitousek 1997) (Sponseller, Gundale et al. 2016). Virtually, nitrogen has been found to be a crucial structural component of proteins, nucleic acids, enzymes, and other cellular constituents which are inevitable for all forms of life (O'Brien, Vega et al. 2016). For agricultural crop production, artificial fixation of nitrogen is heavily utilized. It is an expensive process that requires high temperatures (approx. 400 °C) and pressures (approx. 200 atm) (Witschi 2000). It has been conspicuously demonstrated that indiscriminate use of N fertilizer hampers the diversity of the bacterial community and decreases soil C and N concentrations (Verzeaux, Alahmad et al. 2016). Notably, it has been demonstrated as a potential risk to environment e.g. water quality (Zhao, Sha et al. 2016) (Sponseller, Gundale et al. 2016). Besides, chemically manufactured fertilizers are depleted from soils in various ways, for instance; denitrifying bacteria, volatilization, and leaching (Johnson 1996, Peter M. Vitousek 1997). Consequently, it results relatively poor availability of nitrogen to get into plants. On the flipside, over 90 % of the nitrogen fixation in the world occurs through the natural process of lightening and microorganisms. Furthermore, microbial fixation is well characterized in diazotrophs for example; Rhizobia and Frankia, and blue-green algae (Cheng 2008). It has been demonstrated that Bradyrhizobium strains substantially escalated soybean grain yield, and protein content up to 57% and 26%, respectively (Zimmer, Messmer et al. 2016). Against the backdrop, we are accentuated on an environmentally friendly and a sustainable approach to increase the productivity for legume and non-legume crops. Literature mining depicted that biological nitrogen fixation in soybean nodules reduces the use of chemical nitrogen fertilizers resulting in cost-savings to producers and minimizes environmental damage due to nitrogen run-off. Rhizobia infection leads to the root nodule development In the natural environment, plants are continuously confronted with pathogenic and symbiotic microbes. Symbioses involves mutual exchange of diffusible signal molecules, first endophytic bacteria (rhizobia) are attracted by the plant root exudates flavonoids which are perceived and triggered the bacterial nodulation (nod) genes. Consequently, the bacteria synthesize specific lipochito-oligosaccharides, called nodulation (Nod) factors. This signal is perceived by the LysM receptor like kinase of host plant, it induces the root hair curling, and bacteria get access into the host epidermis through infection threads (ITs) and initiate cell division within the root cortex, leading to the progression of the root nodule meristem. In later stages of the interaction, bacteria are released from the infection threads into the plant cells, surrounded by membrane of plant origin. These bacteria multiply within the host cells and differentiate into the nitrogen fixing bacteroids (Udvardi and Day 1997) (Oldroyd 2013). Till now, integration of genetic and genomic approaches has revealed twenty-six genes to be involved in nodule development of Medicago truncatualaand Lotus japonicum (Kouchi, Imaizumi-Anraku et al. 2010). In addition, deep sequencing of the Medicago truncatularoot transcriptome has uncovered thousands of genes to be induced during Nod factor signaling and its resulting ethylene (ET) biosynthesis throughout the multiple development stages of indeterminate nodule (Larrainzar, Riely et al. 2015). Albeit the molecular mechanism of such regulation is not well understood. There has been a large-scale transcriptome analysis of B. japonicum-inoculated and mock-inoculated soybean root hairs. It has showed that a total of 1,973 soybean genes differentially expressed during root hair infection, particularly NFR5 and NIN genes (Libault, Farmer et al. 2010). Nevertheless, the signaling mechanisms directing the cellular differentiation of nodule are not known. Soybean root nodule organogenesis Soybean (Glycine max) has a genome size of 1.1 to1.5 Gb, it is partially diploidized tetraploid. It is one of the most important oil crops and a source of animal feed protein in the world (soybase.org/sb_about.php). It has a salient feature to fix atmospheric nitrogen through symbioses with compatible rhizobia that yields to determinate type nodule (Udvardi and Day 1997) (Oldroyd, Murray et al. 2011). Notwithstanding of the economic and environmental importance, there has been very few studies about quantitative trait loci (QTL) that controlling BNF traits, for instance nodule number, ration of nodule dry weight with nodule number, and shoot dry weight (SDW). It has been reported via composite interval mapping that approximately six QTLs bears very small effect on BNF traits (Santos, Geraldi et al. 2013). Besides, it has been demonstrated in earlier studies that nodules originate from root cortex via de novo cell differentiation into two different cell types, parenchymal and primordium (Celine Charon 1997) (Oldroyd&Downie 2008; Oldroyd 2013). In addition, early nodulin genes in legume for instance; Enod 40 gene reported to be expressed in root pericycle during the rhizobia infection and later it occupied in the dividing cortical cells (H. Kouchi and S. Hata 1993). Among the two major nodule development zones, the nodule primordium (Npr) in the middle which is encircled by nodule parenchyma (Npa). At later time point, the Npr gives rise to N-fixation zone and the Npa holds vascular bundles. Lately, a β- expansin gene, GmEXPB2 fused with GUS reporter gene which was observed to be preferentially expressed in nodule vascular trace and nodule vascular bundles. It indicated that GmEXPB2 might be crucial for nodule organogenesis. Over expression of GmEXPB2 contrast to suppressed GmEXPB2 transgenic lines found to be escalated nodule number, nodule mass and nitrogenase activity. It further suggested that GmEXPB2 might have influenced over root architecture, nodule formation and development, and profoundly yielding to biological N2 fixation (Li, Zhao et al. 2015). Even though, it is not clear what early signaling pathways driving the conspicuous development of the nodule zones. Against the back drop, to understand the regulation of auxin sensitivity by miR160 which is believed to be crucial for the formation of nodule primordia (Marie Turner 2013). Figure 1 a. Illustrating the progression of root nodule development through Rhizobial bacterial infection in the plant root leading to the determinate nodule (Oldroyd 2013). b. Nodule development zones A. Nodule primordial zone (Enod 40 gene) in the middle B. surrounding parenchyma (Enod 2 gene), differentiated from cortex (collected from Sen Subramanian lab). Regulatory small RNAs biogenesis and its molecular functions Regulatory small RNAs are ranged between 20 to 24 nucleotides which are ubiquitous elements of endogenous plant transcriptomics, a common response to exogenous viral infections and introduced double-stranded RNA (Axtell 2013). Three core enzymes families, for instance; RNAdependent RNA polymerase (RDR), Dicer like (DCL), and Argonaute (AGO) proteins paves the way of small RNA biogenesis and function in plants. Firstly, ribonuclease type III or DICERLIKE1 involves in the yield of a fold-back precursor RNA or primary miRNA (primiRNA) transcripts using an RNA templates in the nuclei. Later, the resulting miRNA-miRNA duplex which is originated in nucleus then translocated into cytoplasm. The guided miRNAmolecule is incorporated into ARGONAUTE (AGO) to form an active RISC complex to specific target RNAs that are complementary to the miRNA, and this process eventually follows up mRNA cleavage, represses the translation of the mRNAs or Chromatin modification. This phenomenon accentuated as an inhibition or silencing of the gene expression, which play a crucial role in the developmental process in plant and animal (Chapman and Carrington 2007) (Axtell 2013). Fig. 2 Regulation of gene expression events via RISC complex (modified from https://www.google.com/?gws_rd=ssl#q=mirna+picture+in+plants accessed on 7th February, 2016) Fig. 3 Gene expression events occurring in typical plant cell (modified https://www.google.com/search?q=transcription+and+translation accessed on 7th February, 2016) It has been found in several studies that most plant miRNAs are non-coding RNA, and small 21-24 nucleotide long (Cuperus, Fahlgren et al. 2011). It requires DCL1-clade DCL for their biogenesis and AGO1-clade AGO for their function (Wu, Zhou et al. 2010, Manavella, Koenig et al. 2012). In rice (Oryza sativa), DCL3 has been reported in the biogenesis of 24nt long miRNA that incorporated in AGO4 to regulate the target gene expression primarily through mRNA cleavage (Wu, Zhou et al. 2010). Argonaute proteins (AGO) form RNA inducing silencing complexes (RISC) with small RNAswhich is known as post-transcriptional gene silencing. It has typically four domains, for instance:N-terminal, PAZ, MID and PIWI domains. The MID-PIWI lobes are belongs to the C-terminus. It has been studied that MID-domains contains the specificity loop to recognize and bind to the 5’-phosphate of smRNAs. The PIWI domains contained the catalytic active site D-E-D-H/D. PAZ domain anchored the 2-nt overhang at the 3’ end of miRNAs. The N-terminal domain involved in the separation of miRNA-miRNA duplex and the slicer activity of the mRNA (Song, Smith et al.2004). There has been an expansion and duplications of AGO family members during plantevolution (Singh, Gase et al. 2015). The functional diversification of AGOs is indicating sRNAdirected regulatory pathways. The binding preference of AGO and sRNA is mainly assigned by the sequence of sRNA. In Arabidopsis, 10 AGO have been extensively studied (Liu et al. 2014). It has been demonstrated that AtAGO10 like AtAGO1, it recognized distinct structural features in miR165/miR166 duplex than involved by AtGO1. AtAGO10 found to regulate shoot apical meristem by decoying miR165/miR166 and subsequent repression of homeodomain-leucinezipper (HD-ZIP) gene expression (Zhu, Hu et al. 2011). Notably, 22 AGO proteins have been reported in Soybean (Glycine max). It has been found that genome duplication in Soybean resulted such a proliferation of AGOs. For example: its genome encodes two copies of AGO1, AGO2, AGO5, AGO4/9, AGO6 and AGO7 (Xiang Liu 2014). However, the molecular function of the plant AGO genes yet not very clear. There are several miRNA families that are conserved across the vast evolutionary distances from flowering plants to mosses (Cuperus, Fahlgren et al. 2011). It has been observed in another study that miRNA, and its target pairing found to be stable for a prolonged periods of plant evolution. On the flip side, another group demonstrated that conserved plant miRNAs and their targets are to somehow flexible. For instance; miR159 is a highly conserved miRNA that targets not only a subset of MYB mRNAs but also observed to target a non MYB mRNA, SGN-U567133 (Buxdorf, Hendelman et al. 2010). A mutant tomato transgenic line (miR159-resistant line) showed higher level of the SGN-U567133 transcript and exhibited defects in leaf and flower development. This result suggests that miR159 involves in a post-transcriptional regulation. Additionally, it is found to be crucial for the normal tomato development. Recently, the identification of miRNAs in the regulation of photoperiodic pathways in soybean have been reported through high throughput sequencing and qRT-PCR. Six libraries were constructed using Illumina Solexa, for instance; 0, 8, and 16 h under short day treatment, similar time points considered for the long the long day treatment. A total of 163 miRNAs families were reported which covered 318 plant miRNAs, and unclassified 81 novel predicted miRNAs. As expected, significant differences in abundance between short day and long day treatment was observed (Wenbin Li 2015). These findings provided evidence of miRNA in the regulation of flowering time that ultimately affects the seed yield and quality of soybean. The complex regulatory network of miRNA-mRNA interactions during viral infection has been revealed via small RNA seq (sRNA), degradome seq, and genome-wide transcriptome analysis. There has been a total of 253 soybean miRNAs found to be two-folds abundance compared with mock-inoculated control demonstrated through sRNA seq analysis. Among them 105 miRNAs were identified as potential targets of 125 transcripts that has been validated by degradome seq analyses. In addition, 2679 genes were detected via genome wide transcriptomic analysis. These genes have been differentially expressed during infection of soybean mosaic virus and among them 71 genes projected to induce in defense response (Hui Chen 2016). These findings suggested the regulatory role miRNA that governed the target gene expression during viral infection. Furthermore, the regulatory role of microRNAs (miRNAs) during Soybean- Bradyrhizobium japonicum mutualistic association was studied first by Subramanian et al. 2008. They sequenced approximately 350000 small RNAs of soybean root sample which were inoculated with B. japonicum. It helps to detect 20 conserved miRNAs loci based on the similarity to miRNAs in another plant species. In addition, 35 novel miRNAs were identified based on potential hairpin forming precursors in Soybean EST as well as shotgun genomic sequences (Subramanian, Fu et al. 2008). These findings advocated the potential role of miRNAs in the regulation of legumerhizobiumsymbiosis. In another study, 120 hairpin-forming precursor genes have been identified in soybean by Turner et al. In addition, they reported three novel miRNAs for instance; miR160, miR164 and miR393 found to be involved in auxin signaling (Turner, Yu et al. 2012). Moreover, the plant hormone auxin is thought to have a pivotal role in nodule organogenesis in determinate and indeterminate type of nodule. It indicates a redundancy and diversity of miRNAs family members that governs the formation of root nodule. It has been illustrated that auxin receptor gene family hushed by over expressed microRNA393. These plant roots found to be hypersensitive to auxin and yielded normal nodule. This observation advocated that only minimal/reduced auxin signaling is required for determinate nodule development. Likewise, overexpressed microRNA160 hushed a set of repressor auxin response transcription factor. These plant roots were hypersensitive to auxin and observed not to be reluctant in epidermal responses to rhizobia. Notably, it yielded to lower sized nodule primordium (Marie Turner 2013). This observation indicated that auxin hypersensitivity inhibits nodule organogenesis Organ specific expression of profile of miRNA and the potential targets were also studied. Two genes (Glyma10g10240 and Glyma17g05920) which were the target of miR169 but detected to be highly expressed in soybean nodule. Likewise, three potential targets of gma-new-miR13587 demonstrated to be highly expressed in the nodules than in the roots. As expected, gma-newmiR13587 found to be poorly expressed in the nodules than in the roots (Turner, Yu et al. 2012). There was an inverse expression pattern observed in between roots and nodules. Li et al., studied the transgene expression of three novel miRNAs namely, miR482, miR1512, and miR1515 in Soybean. They noticed a significant increase of nodule numbers while root length and later root density were normal in all tested miRNA lines. As expected, there were differential expression of these miRNAs in supernodulating and nonnodulating soybean mutants. They reported that 6 novel miRNAs decoyed 22 predicted target genes. And it was estimated via real time polymerase chain reaction and qRT-PCR (Li, Deng et al. 2010). It advocates that miRNAs have the signatory roles in soybean nodule development. Sequencing of small RNAs and Parallel analysis of RNA ends (PARE) libraries revealed to identify 284 nodule miRNAs, more than 500 target genes, and including 178 novel soybean miRNAs. It has been reported that ENOD93 only found to be expressed in nodule tissue not in other plant parts of Soybean. Ectopic expression of miR393j-3p and RNAi silencing approach to ENOD93 expression showed a significant reduction in nodule formation (Zhe Yan 2015). Therefore, this study showed a list of miRNAs and their potential target of nodulation genes. In the model legume (Medicago truncatula), 25 conserved miRNA families and 100 novel miRNA reads were detected by high-throughput sequencing. The expression of MtHAP2-1 (encodes a CCAAT binding transcription factor) to meristematic zones was restricted by miR169a which is found to be critical for the development of indeterminate type of nodule (Combier, Frugier et al. 2006). In another study, HDZIPIII transcripts were inhibited by overexpression of miR166, it dropped the number of symbiotic nodule and lateral root (Boualem, Laporte et al. 2008). To get insights into key genes of nodule zones, transcript profiles of specific cells/tissues were investigated at different time points from indeterminate nodules of M. truncatulausing laser capture micro dissection. It has been demonstrated from the comprehensive gene expression map that selected genes enriched in different cell/tissue types (Limpens, Moling et al. 2013). These findings indicated that organ specific gene expression could be controlled by the presence or absence of miRNAs. Recently, Agrobacterium rhizogenesmediated hairy root transformation has been applied as tool for exploring cell type specific gene expression in tomato. Cell type or tissue specific promoter introduced into INTACT and TRAP constructs via gateway cloning technology to develop binary vectors. INTACT method used to capture biotin tagged nuceli from specific cell types and TRAP method used for profiling of mRNAs or foot printing of individual ribosomes (Ron 2014). TRAP methodology is not required tissue fixation or single cell suspension. It has been successfully used to date in organisms ranging from D. melanogaster to mice and human cultured cells. Multiple ribosomes or Polyribosomes (polysomes) are engaged in translation on a single mRNA. To evaluate the translation state of an mRNA, ribosomal subunits, ribosomes, and polysomes can be isolated from detergent-treated cell extracts (Heiman, Kulicke et al. 2014). In this study, we would perform polysome isolation deploying gene cassettes ENOD40p:HF-GFP-RPL18 for primordial tissues, and ENOD2p:HF-GFP-RPL18 for parenchymal tissues in Glycine max root nodules that express an epitope tagged version of ribosomal protein L18. Over the last one decade, there has been several microarrays-based studies which characterized transcriptional variations deployed in nodule formation. It has been embedded with couple of shortcomings, for instance; relative late time points study, incomplete representation of plant genes,discrimination of close paralogs, and reduced sensitivity. Lately, next generation sequencingtechnology have widened the horizon of transcription analyses in different legume species to detectsymbiosis induced changes in late nodule developmental stages. Against this backdrop, we areaccentuated to reveal early transcriptional changes induced in determinate type of soybean noduleby Bradyrhizobium japonicum. In determinate type of nodule, two major nodule development zones are formed for instance, the nodule primordium (Npr) in the middle and it is encircled by nodule parenchyma (Npa). At later time point, the Npr converted to N-fixation zone and the Npa contained vascular bundles. Of these facts, it is not clear what early signaling pathways driving the conspicuous development of thenodule zones. In this context, mechanisms regulate the distinct gene expression profiles in Npr andNpa cell types has not understood clearly. The proposed research study is aimed at filling this knowledge gap byillustrating the molecular signatures that paves the way to cellular differentiation in root noduledevelopment in soybean considering four different time points (5 dai, 7 dai, 10 dai& 14 dai). The hypothesisis microRNAs(miRNAs) play important regulatory roles in spatio-temporal expression of their target genesduring nodule developmental in soybean. For example, a gradient of microRNA localizationbetween nodule primordium and parenchyma cells could result in distinct differentiation of thesecell types. To test this hypothesis, one has to obtain both cell type-specific miRNA andtranscriptome (miRNA target) profiles. Since, the majority of miRNA regulation occurs in thecytoplasm, we reasoned that comparison of nuclear and ribosomal transcriptome profiles wouldreveal genes whose expression is potentially regulated by post transcriptional mechanisms such asmiRNA cleavage. Combining this information with cell type-specific miRNA profiles, andto test the above hypothesis and identify key miRNA-target pairs important for nodule celldifferentiation. The use of translating ribosome affinity purification (TRAP) of nodule zonecells, namely from parenchyma and primordial tissues, to obtain cytoplasmic transcriptomes data. Techniques to determine cell type specific expression profiles: TRAP methods TRAP is termed translating ribosome affinity purification, combines cell-type-specific transgene expression with affinity purification of translating ribosomes. It supersedes the need for tissue fixation, and facilitates to study the cell type-specific mRNA profiles of any genetically defined cell type. It has been successfully used to date in organisms ranging from D. melanogaster to mice, and human cultured cells. Multiple ribosomes or Polyribosomes (polysomes) are engaged in translation on a single mRNA. To evaluate the translation state of an mRNA, ribosomal subunits, ribosomes, and polysomes can be isolated from detergent-treated cell extracts. In this study, the polysome isolation using gene cassettes ENOD40p:HF-GFP-RPL18 for primordial tissues, and ENOD2p:HF-GFP-RPL18 for parenchymal tissues in Glycine max root nodules that express an epitope tagged version of ribosomal protein L18 RPL18(Heiman, Kulicke et al. 2014, Ron 2014). Relative abundance and differentially expressed mRNAs profile in two different tissue specific zones would help to understand the effect of regulatory role of miRNAs in cell differentiation and nodule development. References: Axtell, M. J. (2013). "Classification and comparison of small RNAs from plants." Annu Rev PlantBiol 64: 137-159. Boualem, A., et al. (2008). "MicroRNA166 controls root and nodule development in Medicago truncatula." Plant J 54(5): 876-887. Buxdorf, K., et al. (2010). "Identification and characterization of a novel miR159 target not relatedto MYB in tomato." Planta 232(5): 1009-1022. Celine Charon, C. J., Eva Kondorosi, Adam Kondorosi and Martin Crespi (1997). "enod40 inducesdedifferentiation and division of root cortical cells in legumes." Proc. Natl Acad. Sci. USA. 94:8901-8906. Chapman, E. J. and J. C. Carrington (2007). "Specialization and evolution of endogenous small RNA pathways." Nat Rev Genet 8(11): 884-896. Cheng, Q. (2008). "Perspectives in biological nitrogen fixation research." J Integr Plant Biol 50(7):786-798. Combier, J. P., et al. (2006). "MtHAP2-1 is a key transcriptional regulator of symbiotic nodule development regulated by microRNA169 in Medicago truncatula." Genes Dev 20(22): 3084-3088. Cuperus, J. T., et al. (2011). "Evolution and functional diversification of MIRNA genes." Plant Cell 23(2): 431-442. Hiroshi Kouchi1, K.-i. T., Rollando B. So2, Jagdish K. Ladha2 and Pallavolu M. Reddy2 (1999). "Rice ENOD40: isolation and expression analysis in rice and transgenic soybean root nodules." The Plant Journal 18(2): 121-129. Johnson, D. S. O. a. G. V. (1996). "Fertilizer Nutrient Leaching and Nutrient Mobility: A Simple Laboratory Exercise." Nat. Resour. L. ife Sci. Educ 25(2): 128-131. Kouchi, H. and Hata, S. (1993) Isolation and characterization of novel nodulin cDNAs representing genes expressed at early stages of soybean nodule development. Gen. Genet. 238, 106–119. Li, H., et al. (2010). "Misexpression of miR482, miR1512, and miR1515 increases soybean nodulation." Plant Physiol 153(4): 1759-1770. Manavella, P. A., et al. (2012). "Plant secondary siRNA production determined by microRNAduplexstructure." Proc Natl Acad Sci U S A 109(7): 2461-2466. Marie Turner, e. a. (2013). "Ectopic Expression of miR160 Results in Auxin Hypersensitivity, Cytokinin Hyposensitivity, and Inhibition of Symbiotic Nodule Development in Soybean." Plant Physiology 162(2013): 2042–2055. Oldroyd GE, Downie JA. (2008). “Coordinating nodule morphogenesis with rhizobial infection inlegume. Annual Review of Plant Biology 59:519-546. Singh, R. K., et al. (2015). "Molecular evolution and diversification of the Argonaute family of proteins in plants." BMC Plant Biol 15: 23. Song, J. J., et al. (2004). "Crystal structure of Argonaute and its implications for RISC slicer activity." Science 305(5689): 1434-1437. Sponseller, R. A., et al. (2016). "Nitrogen dynamics in managed boreal forests: Recent advances and future research directions." Ambio 45 Suppl 2: 175-187. Subramanian, S., et al. (2008). "Novel and nodulation-regulated (2012). microRNAs in soybean roots." BMC Genomics 9: 160. Turner, M., et al. "Genome organization and characteristics of soybean microRNAs." BMCGenomics 13: 169. Udvardi and Day (1997). "Metabolite transport across symbiotic membranes of legume nodules." Annual Review of Plant Physiology and Plant Molecular Biology 48: 493-523. Weeks, Marry Elvira (1932). “The discovery of the elements. IV. Three impotant gases”. Journal of Chemical Education. 9 (2): 215 Wu, L., et al. (2010). "DNA methylation mediated by a microRNA pathway." Mol Cell 38(3): 465-475. Xiang Liu, T. L., Yongchao Dou, Bin Yu, and Chi Zhang (2014). "Identification of RNA silencingcomponents in soybean and sorghum." BMC Bioinform 15: 4. Zhe Yan, M. S. H., SiwaretArikit, Oswaldo Valdes-Lopez, JixianZhai, Jun Wang1,Marc Libault1, Tieming Ji, LijuanQiu, Blake C. Meyers and Gary Stacey (2015). "Identification of microRNAs and their mRNA targets during soybean nodule development: functional analysis of the role of miR393j-3p in soybean nodulation." New Phytologist 207: 748–759. Zhu, H., et al. (2011). "Arabidopsis Argonaute10 specifically sequesters miR166/165 to regulate shoot apical meristem development." Cell 145(2): 242-256.
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41

Himanshu, Kaushik Chakraborty y Tarak K. Patra. "Developing efficient deep learning model for predicting copolymer properties". Physical Chemistry Chemical Physics, 2023. http://dx.doi.org/10.1039/d3cp03100d.

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42

Budel, Juliana C. C., Melanie K. Hess, Timothy P. Bilton, Hannah Henry, Ken G. Dodds, Peter H. Janssen, John C. McEwan y Suzanne J. Rowe. "Low-cost sample preservation methods for high-throughput processing of rumen microbiomes". Animal Microbiome 4, n.º 1 (6 de junio de 2022). http://dx.doi.org/10.1186/s42523-022-00190-z.

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Abstract Background The use of rumen microbial community (RMC) profiles to predict methane emissions has driven interest in ruminal DNA preservation and extraction protocols that can be processed cheaply while also maintaining or improving DNA quality for RMC profiling. Our standard approach for preserving rumen samples, as defined in the Global Rumen Census (GRC), requires time-consuming pre-processing steps of freeze drying and grinding prior to international transportation and DNA extraction. This impedes researchers unable to access sufficient funding or infrastructure. To circumvent these pre-processing steps, we investigated three methods of preserving rumen samples for subsequent DNA extraction, based on existing lysis buffers Tris-NaCl-EDTA-SDS (TNx2) and guanidine hydrochloride (GHx2), or 100% ethanol. Results Rumen samples were collected via stomach intubation from 151 sheep at two time-points 2 weeks apart. Each sample was separated into four subsamples and preserved using the three preservation methods and the GRC method (n = 4 × 302). DNA was extracted and sequenced using Restriction Enzyme-Reduced Representation Sequencing to generate RMC profiles. Differences in DNA yield, quality and integrity, and sequencing metrics were observed across the methods (p < 0.0001). Ethanol exhibited poorer quality DNA (A260/A230 < 2) and more failed samples compared to the other methods. Samples preserved using the GRC method had smaller relative abundances in gram-negative genera Anaerovibrio, Bacteroides, Prevotella, Selenomonas, and Succiniclasticum, but larger relative abundances in the majority of 56 additional genera compared to TNx2 and GHx2. However, log10 relative abundances across all genera and time-points for TNx2 and GHx2 were on average consistent (R2 > 0.99) but slightly more variable compared to the GRC method. Relative abundances were moderately to highly correlated (0.68 ± 0.13) between methods for samples collected within a time-point, which was greater than the average correlation (0.17 ± 0.11) between time-points within a preservation method. Conclusions The two modified lysis buffers solutions (TNx2 and GHx2) proposed in this study were shown to be viable alternatives to the GRC method for RMC profiling in sheep. Use of these preservative solutions reduces cost and improves throughput associated with processing and sequencing ruminal samples. This development could significantly advance implementation of RMC profiles as a tool for breeding ruminant livestock.
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43

Wang, Bing, Vadim M. Gumerov, Ekaterina P. Andrianova, Igor B. Zhulin y Irina Artsimovitch. "Origins and Molecular Evolution of the NusG Paralog RfaH". mBio 11, n.º 5 (27 de octubre de 2020). http://dx.doi.org/10.1128/mbio.02717-20.

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ABSTRACT The only universally conserved family of transcription factors comprises housekeeping regulators and their specialized paralogs, represented by well-studied NusG and RfaH. Despite their ubiquity, little information is available on the evolutionary origins, functions, and gene targets of the NusG family members. We built a hidden Markov model profile of RfaH and identified its homologs in sequenced genomes. While NusG is widespread among bacterial phyla and coresides with genes encoding RNA polymerase and ribosome in all except extremely reduced genomes, RfaH is mostly limited to Proteobacteria and lacks common gene neighbors. RfaH activates only a few xenogeneic operons that are otherwise silenced by NusG and Rho. Phylogenetic reconstructions reveal extensive duplications and horizontal transfer of rfaH genes, including those borne by plasmids, and the molecular evolution pathway of RfaH, from “early” exclusion of the Rho terminator and tightened RNA polymerase binding to “late” interactions with the ops DNA element and autoinhibition, which together define the RfaH regulon. Remarkably, NusG is not only ubiquitous in Bacteria but also common in plants, where it likely modulates the transcription of plastid genes. IMPORTANCE In all domains of life, NusG-like proteins make contacts similar to those of RNA polymerase and promote pause-free transcription yet may play different roles, defined by their divergent interactions with nucleic acids and accessory proteins, in the same cell. This duality is illustrated by Escherichia coli NusG and RfaH, which silence and activate xenogenes, respectively. We combined sequence analysis and recent functional and structural insights to envision the evolutionary transformation of NusG, a core regulator that we show is present in all cells using bacterial RNA polymerase, into a virulence factor, RfaH. Our results suggest a stepwise conversion of a NusG duplicate copy into a sequence-specific regulator which excludes NusG from its targets but does not compromise the regulation of housekeeping genes. We find that gene duplication and lateral transfer give rise to a surprising diversity within the only ubiquitous family of transcription factors.
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44

Roja Rani, Pallavali, Mohamed Imran, J. Vijaya Lakshmi, Bani Jolly, S. Afsar, Abhinav Jain, Mohit Kumar Divakar et al. "Insights from genomes and genetic epidemiology of SARS-CoV-2 isolates from the state of Andhra Pradesh". Epidemiology and Infection 149 (2021). http://dx.doi.org/10.1017/s0950268821001424.

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Abstract Coronavirus disease 2019 (COVID-19) emerged from a city in China and has now spread as a global pandemic affecting millions of individuals. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is being extensively studied in terms of its genetic epidemiology using genomic approaches. Andhra Pradesh is one of the major states of India with the third-largest number of COVID-19 cases with a limited understanding of its genetic epidemiology. In this study, we have sequenced 293 SARS-CoV-2 genome isolates from Andhra Pradesh with a mean coverage of 13324X. We identified 564 high-quality SARS-CoV-2 variants. A total of 18 variants mapped to reverse transcription polymerase chain reaction primer/probe sites, and four variants are known to be associated with an increase in infectivity. Phylogenetic analysis of the genomes revealed the circulating SARS-CoV-2 in Andhra Pradesh majorly clustered under the clade A2a (20A, 20B and 20C) (94%), whereas 6% fall under the I/A3i clade, a clade previously defined to be present in large numbers in India. To the best of our knowledge, this is the most comprehensive genetic epidemiological analysis performed for the state of Andhra Pradesh.
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45

"ABO discrepancy due to the para-Bombay phenotype: a case report". Journal of Men's Health, 2023. http://dx.doi.org/10.22514/jomh.2023.123.

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In this study, we aimed to determine and analyze the genetic differences of the FUT1 and FUT2 genes within an individual exhibiting the Para-Bombay phenotype. Standard serological tests were conducted to analyze the ABO phenotype. The amplification of FUT1 and FUT2 genes was conducted by polymerase chain reaction and amplicons were sequenced. The determination of the ABO genotype was conducted by sequencing exons 1 to 7 of the ABO gene. The Lewis phenotype was defined as Le(a−b+); Despite this, red blood cells (RBCs) did not show signs of A, B and H antigens using the serological method utilized in this study. However, Analyses of sequencing and cloning demonstrated the existence of a FUT1 mutation at position c.658C>T and an inactive allele FUT1*01N.06 (c.551_552delAG). Genetic testing for ABO blood types was subsequently determined to be ABO*B.01/ABO*B.01 (c.297A>G; c.526C>G; c.657C>T; c.703G>A; c.796C>A; c.803G>C; c.930G>A). Heterozygosity for indel and missense mutation within the coding region of FUT1 are likely to be responsible for development of the Para-Bombay phenotype.
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46

Ren, He, Jiarong Zhang, Tingting Yang, Xiaomeng Zhang, Jinding Liu, Chong Chen, Yan Shi et al. "Analysis of homozygous allele mismatches in paternity tests with massively parallel sequencing". ELECTROPHORESIS, 30 de noviembre de 2023. http://dx.doi.org/10.1002/elps.202300130.

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AbstractIn paternity testing, short tandem repeats (STRs) allele mismatches are often detected. Nowadays, polymerase chain reaction‐ and capillary electrophoresis (CE)‐based STR genotyping is the most commonly used method to distinguish alleles based on their length. However, it could not detect alleles of the same size with sequence differences. Massively parallel sequencing (MPS) can determine not only allele sizes but also sequences, which could explain the causes of allele mismatches. Additionally, more types of genetic markers can be detected in a single assay, which increases the discriminatory power and facilitates the analysis of paternity tests. In this study, we analyzed 11 cases with homozygous allele mismatches from routine DNA trio paternity tests using the CE platform. Samples were sequenced using the ForenSeq DNA Signature Prep Kit and the MiSeq FGx Sequencing System. The results show that of the eight father–child mismatch cases and three mother–child mismatch cases, five cases with D5S818 and D8S1179 and one case at D13S317 were classified as non‐amplification. The other three cases and two cases could be defined as mutations. This study suggests that MPS‐based STR genotyping can provide additional information that allows more accurate interpretation of allelic mismatches in paternity testing.
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47

Montgomery, JoLynn P., Juan Luis Marquez, Jennifer Nord, Aleksandra R. Stamper, Elizabeth A. Edwards, Nicholas Valentini, Christopher J. Frank et al. "Detection of a Human Adenovirus Outbreak, Including Some Critical Infections, Using Multi-Pathogen Testing at a Large University, September 2022—January 2023". Open Forum Infectious Diseases, 5 de abril de 2024. http://dx.doi.org/10.1093/ofid/ofae192.

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Abstract Background Human adenoviruses (HAdV) can cause outbreaks of flu-like illness in university settings. Most infections in healthy young adults are mild; severe illnesses rarely occur. In Fall 2022, an adenovirus outbreak was identified in university students. Methods HAdV cases were defined as university students 17 to 26 years-old who presented to University Health Service or nearby emergency department with flu-like symptoms (e.g., fever, cough, headache, myalgia, nausea) and were confirmed adenovirus infections by polymerase chain reaction (PCR). Demographic and clinical characteristics were abstracted from electronic medical records, clinical severity was categorized as mild, moderate, severe, or critical. We performed contact investigations among critical cases. A subset of specimens was sequenced to confirm the HAdV type. Results From September 28, 2022, to January 30, 2023, 90 PCR-confirmed cases were identified (51% female; mean age=19.6 years). Most cases (88.9%) had mild illness. Seven cases required hospitalization, including two critical cases that required intensive care. Contact investigation identified 44 close contacts; 6 (14%) were confirmed HAdV cases and 8 (18%) reported symptoms but never sought care. All typed HAdV-positive specimens (n=36) were type 4. Conclusions While most students with confirmed HAdV had mild illness, seven otherwise healthy students had severe or critical illness. Between the relatively high number of hospitalizations and proportion of close contacts with symptoms who did not seek care, the true number of HAdV cases was likely higher. Our findings illustrate the need to consider a wide range of pathogens, even when other viruses are known to be circulating.
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48

Dermawan, Josephine K., Yu Wei Cheng, Zheng Jin Tu, Anders Meyer, Omar Habeeb, Youran Zou, John R. Goldblum et al. "Diagnostic Utility of a Custom 34-Gene Anchored Multiplex PCR-Based Next-Generation Sequencing Fusion Panel for the Diagnosis of Bone and Soft Tissue Neoplasms With Identification of Novel USP6 Fusion Partners in Aneurysmal Bone Cysts". Archives of Pathology & Laboratory Medicine, 4 de noviembre de 2020. http://dx.doi.org/10.5858/arpa.2020-0336-oa.

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Context.— Bone and soft tissue tumors are heterogeneous, diagnostically challenging, and often defined by gene fusions. Objective.— To present our experience using a custom 34-gene targeted sequencing fusion panel. Design.— Total nucleic acid extracted from formalin-fixed, paraffin-embedded (FFPE) tumor specimens was subjected to open-ended, nested anchored multiplex polymerase chain reaction and enrichment of 34 gene targets, thus enabling detection of known and novel fusion partners. Results.— During a 12-month period, 145 patients were tested as part of routine clinical care. Tumor percentage ranged from 10% to 100% and turnaround time ranged from 3 to 15 (median, 7.9) days. The most common diagnostic groups were small round blue cell tumors, tumors of uncertain differentiation, fibroblastic/myofibroblastic tumors, and adipocytic tumors. In-frame fusion transcripts were identified in 64 of 140 cases sequenced (46%): in 62 cases, the detection of a disease-defining fusion confirmed the morphologic impression; in 2 cases, a germline TFG-GPR128 polymorphic fusion variant was detected. Several genes in the panel partnered with multiple fusion partners specific for different diagnoses, for example, EWSR1, NR4A3, FUS, NCOA2, and TFE3. Interesting examples are presented to highlight how fusion detection or lack thereof was instrumental in establishing accurate diagnoses. Novel fusion partners were detected for 2 cases of solid aneurysmal bone cysts (PTBP1-USP6, SLC38A2-USP6). Conclusions.— Multiplex detection of fusions in total nucleic acid purified from FFPE specimens facilitates diagnosis of bone and soft tissue tumors. This technology is particularly useful for morphologically challenging entities and in the absence of prior knowledge of fusion partners, and has the potential to discover novel fusion partners.
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Prihandini, Peni Wahyu, Almira Primasari, Aryogi Aryogi, Muchamad Luthfi y Dwi Nur Happy Hariyono. "Genetic polymorphisms of the 5' untranslated regions of the HSP70 gene in Indonesian cattle populations". Veterinary World, 27 de enero de 2022, 168–72. http://dx.doi.org/10.14202/vetworld.2022.168-172.

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Background and Aim: Heat shock proteins (HSPs) are a group of proteins that play a significant role in protecting cells against cellular stress. HSP70 is a conserved, sensitive, and abundant gene associated with heat stress's physiological adaptability. The objective of this study was to reveal the polymorphisms of the partial sequences of the HSP70 gene (5' untranslated region [UTR]) in seven cattle populations in Indonesia. Materials and Methods: Polymerase chain reaction products (551 bp) of the HSP70 gene amplified from 102 animals representing seven cattle populations (Bali, Belgian Blue × Peranakan Ongole [PO] cross, Galekan, Jabres, Madura, PO, and Rambon) were sequenced by DNA sequencing method. Results: Fourteen single-nucleotide polymorphisms (SNPs), generally found at a low frequency, were detected. Among these SNPs, only 1117G>A, 1125A>C, and 1204T>C were polymorphic in all the analyzed breeds. A Chi-square test showed that the majority of the loci were in Hardy–Weinberg equilibrium (p>0.05). Varying levels of observed (0.050-0.571) and expected heterozygosity (0.049-0.500) were noted. The polymorphism information content values (0.048-0.375) indicated that the SNPs in the HSP70 gene showed low-to-moderate polymorphism in the studied populations. Thirty-six haplotypes were defined according to the identified SNPs, of which haplotype Hap5 (CGACGAGAGTGTCC) and Hap4 (CGACGAGAGTGCCC) were generally dominant in the studied samples. The phylogenetic tree showed a close relationship between Bali and Rambon cattle and between Galekan and Jabres cattle, while the Belgian Blue × PO crossbred cattle were farther apart. Conclusion: The polymorphisms in the 5' UTR of the HSP70 gene identified in this study should be further investigated in a larger population to unravel the association between the SNPs and thermotolerance in Indonesian local cattle populations.
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50

von Rotz, Matthias, Richard Kuehl, Ana Durovic, Sandra Zingg, Anett Apitz, Fanny Wegner, Helena M. B. Seth-Smith et al. "A systematic outbreak investigation of SARS-CoV-2 transmission clusters in a tertiary academic care center". Antimicrobial Resistance & Infection Control 12, n.º 1 (21 de abril de 2023). http://dx.doi.org/10.1186/s13756-023-01242-y.

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Abstract Background We sought to decipher transmission pathways in healthcare-associated infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within our hospital by epidemiological work-up and complementary whole genome sequencing (WGS). We report the findings of the four largest epidemiologic clusters of SARS-CoV-2 transmission occurring during the second wave of the pandemic from 11/2020 to 12/2020. Methods At the University Hospital Basel, Switzerland, systematic outbreak investigation is initiated at detection of any nosocomial case of SARS-CoV-2 infection, as confirmed by polymerase chain reaction, occurring more than five days after admission. Clusters of nosocomial infections, defined as the detection of at least two positive patients and/or healthcare workers (HCWs) within one week with an epidemiological link, were further investigated by WGS on respective strains. Results The four epidemiologic clusters included 40 patients and 60 HCWs. Sequencing data was available for 70% of all involved cases (28 patients and 42 HCWs), confirmed epidemiologically suspected in house transmission in 33 cases (47.1% of sequenced cases) and excluded transmission in the remaining 37 cases (52.9%). Among cases with identical strains, epidemiologic work-up suggested transmission mainly through a ward-based exposure (24/33, 72.7%), more commonly affecting HCWs (16/24, 66.7%) than patients (8/24, 33.3%), followed by transmission between patients (6/33, 18.2%), and among HCWs and patients (3/33, 9.1%, respectively two HCWs and one patient). Conclusions Phylogenetic analyses revealed important insights into transmission pathways supporting less than 50% of epidemiologically suspected SARS-CoV-2 transmissions. The remainder of cases most likely reflect community-acquired infection randomly detected by outbreak investigation. Notably, most transmissions occurred between HCWs, possibly indicating lower perception of the risk of infection during contacts among HCWs.
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