Articles de revues : « Rsc2 »

1

Andrej Kupecsek et Juliana Monárová. « The influence of fertilization and tillage method on the formation root system capacity and grain production of spring barley ». Acta Agraria Debreceniensis, n^o 44 (20 novembre 2011) : 89–93. http://dx.doi.org/10.34101/actaagrar/44/2613.

Texte intégral

Résumé :

To evaluate the interaction of year x variety, year x tillage method and year x fertilization on the grain yield and root system capacity (RSC) of spring barley, we ran polyfactorial field trials in agroecological conditions of a warm corn production area in Slovakia, at Malanta, in 2009 and 2010. The RSC measurements were done using LCR - meter at a frequency of 1 kHz and they took place in four growth stages: at leaf development in the stage of four leaves (RSC1), in full tillering (RSC2), in the stage heading (RSC 3) and at the stage of ripening (RSC4). The values of grain yield, RSC1, RSC2, RSC3, RSC4 reached in 2009 comparison to 2010 were significantly lower. The highest yield in 2009 was reached by variety Marthe (4.49 t.ha-1) and by variety Bojos (7.19 t ha-1) in 2010. The highest values of RSC in observed growth stages were achieved by variety Bojos in 2009, and in 2010 also besides RSC1. Within both years, difference in yields between tillage methods was not observed. The values of RSC in growth stage of 4 leaves and tillering was higher at conventional tillage, butthe values of RSC3 and RSC4 were higher with minimized tillage. The highest grain yield and values of RSC in every growth stage were achieved on the fertilization variant “c“ in 2009 and on the fertilization variant “b“ in 2010. The correlation relationships between grain yield and RSC were significant and positive in every growth stage. The strongest relationship was found among grain yield and RSC (r=0.6047).

Styles APA, Harvard, Vancouver, ISO, etc.

2

Bungard, David, Michelle Reed et Edward Winter. « RSC1 and RSC2 Are Required for Expression of Mid-Late Sporulation-Specific Genes in Saccharomyces cerevisiae ». Eukaryotic Cell 3, n^o 4 (août 2004) : 910–18. http://dx.doi.org/10.1128/ec.3.4.910-918.2004.

Texte intégral

Résumé :

ABSTRACT Rsc1 and Rsc2 are alternative bromodomain-containing subunits of the ATP-dependent RSC chromatin remodeling complex in Saccharomyces cerevisiae. Smk1 is a sporulation-specific mitogen-activated protein kinase homolog that is required for the postmeiotic events of spore formation. In this study we show that RSC1 and RSC2 are haploinsufficient for spore formation in a smk1 hypomorph. Moreover, diploids lacking Rsc1 or Rsc2 show a subset of smk1-like phenotypes. High-copy-number RSC1 plasmids do not suppress rsc2-Δ/rsc2-Δ sporulation defects, and high-copy-number RSC2 plasmids do not suppress rsc1-Δ/rsc1-Δ sporulation defects. Mid-late sporulation-specific genes, which are normally expressed while key steps in spore assembly occur and which include genes that are required for spore wall formation, are not expressed in cells lacking Rsc1 or Rsc2. We speculate that the combined action of Rsc1 and Rsc2 at mid-late promoters is specifically required for the proper expression of this uniquely timed set of genes. Our data suggest that Smk1 and Rsc1/2 define parallel pathways that converge to provide signaling information and the expression of gene products, respectively, that are required for spore morphogenesis.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Wong, Michael C. V. L., Suzanna R. S. Scott-Drew, Matthew J. Hayes, Philip J. Howard et James A. H. Murray. « RSC2, Encoding a Component of the RSC Nucleosome Remodeling Complex, Is Essential for 2μm Plasmid Maintenance in Saccharomyces cerevisiae ». Molecular and Cellular Biology 22, n^o 12 (15 juin 2002) : 4218–29. http://dx.doi.org/10.1128/mcb.22.12.4218-4229.2002.

Texte intégral

Résumé :

ABSTRACT The stable maintenance of the 2μm circle plasmid depends on its ability to overcome intrinsic maternal inheritance bias, which in yeast normally results in the failure to transmit DNA molecules efficiently to daughter cells. In addition to the plasmid proteins Rep1 and Rep2 acting on the plasmid DNA locus STB, it is likely that other chromosomally encoded yeast proteins are required. We have isolated mutants of yeast unable to maintain 2μm and found that RSC2 is essential for 2μm to overcome maternal inheritance bias. Rsc2 is part of a multisubunit RSC chromatin remodeling complex, and we show that in the absence of Rsc2 the chromatin structure of the STB region is significantly altered and the Rep1 protein loses its normal localization to subnuclear foci. Rsc1, a closely related homolog of Rsc2 present in an alternative form of the RSC complex, is not required for 2μm maintenance and does not replace the requirement for Rsc2 when overexpressed. This represents the first specific role for Rsc2 that has been related to a change in chromatin structure, as well as the first direct evidence linking chromatin structure to 2μm segregation.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Baetz, Kristin K., Nevan J. Krogan, Andrew Emili, Jack Greenblatt et Philip Hieter. « The ctf13-30/CTF13 Genomic Haploinsufficiency Modifier Screen Identifies the Yeast Chromatin Remodeling Complex RSC, Which Is Required for the Establishment of Sister Chromatid Cohesion ». Molecular and Cellular Biology 24, n^o 3 (1 février 2004) : 1232–44. http://dx.doi.org/10.1128/mcb.24.3.1232-1244.2003.

Texte intégral

Résumé :

ABSTRACT The budding yeast centromere-kinetochore complex ensures high-fidelity chromosome segregation in mitosis and meiosis by mediating the attachment and movement of chromosomes along spindle microtubules. To identify new genes and pathways whose function impinges on chromosome transmission, we developed a genomic haploinsufficiency modifier screen and used ctf13-30, encoding a mutant core kinetochore protein, as the reference point. We demonstrate through a series of secondary screens that the genomic modifier screen is a successful method for identifying genes that encode nonessential proteins required for the fidelity of chromosome segregation. One gene isolated in our screen was RSC2, a nonessential subunit of the RSC chromatin remodeling complex. rsc2 mutants have defects in both chromosome segregation and cohesion, but the localization of kinetochore proteins to centromeres is not affected. We determined that, in the absence of RSC2, cohesin could still associate with chromosomes but fails to achieve proper cohesion between sister chromatids, indicating that RSC has a role in the establishment of cohesion. In addition, numerous subunits of RSC were affinity purified and a new component of RSC, Rtt102, was identified. Our work indicates that only a subset of the nonessential RSC subunits function in maintaining chromosome transmission fidelity.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Rossio, Valentina, Elena Galati, Matteo Ferrari, Achille Pellicioli, Takashi Sutani, Katsuhiko Shirahige, Giovanna Lucchini et Simonetta Piatti. « The RSC chromatin-remodeling complex influences mitotic exit and adaptation to the spindle assembly checkpoint by controlling the Cdc14 phosphatase ». Journal of Cell Biology 191, n^o 5 (22 novembre 2010) : 981–97. http://dx.doi.org/10.1083/jcb.201007025.

Texte intégral

Résumé :

Upon prolonged activation of the spindle assembly checkpoint, cells escape from mitosis through a mechanism called adaptation or mitotic slippage, which is thought to underlie the resistance of cancer cells to antimitotic drugs. We show that, in budding yeast, this mechanism depends on known essential and nonessential regulators of mitotic exit, such as the Cdc14 early anaphase release (FEAR) pathway for the release of the Cdc14 phosphatase from the nucleolus in early anaphase. Moreover, the RSC (remodel the structure of chromatin) chromatin-remodeling complex bound to its accessory subunit Rsc2 is involved in this process as a novel component of the FEAR pathway. We show that Rsc2 interacts physically with the polo kinase Cdc5 and is required for timely phosphorylation of the Cdc14 inhibitor Net1, which is important to free Cdc14 in the active form. Our data suggest that fine-tuning regulators of mitotic exit have important functions during mitotic progression in cells treated with microtubule poisons and might be promising targets for cancer treatment.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Chambers, Anna L., Laurence H. Pearl, Antony W. Oliver et Jessica A. Downs. « The BAH domain of Rsc2 is a histone H3 binding domain ». Nucleic Acids Research 41, n^o 19 (31 juillet 2013) : 9168–82. http://dx.doi.org/10.1093/nar/gkt662.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

7

Hajra, Sujata, Santanu Kumar Ghosh et Makkuni Jayaram. « The centromere-specific histone variant Cse4p (CENP-A) is essential for functional chromatin architecture at the yeast 2-μm circle partitioning locus and promotes equal plasmid segregation ». Journal of Cell Biology 174, n^o 6 (11 septembre 2006) : 779–90. http://dx.doi.org/10.1083/jcb.200603042.

Texte intégral

Résumé :

The centromere protein A homologue Cse4p is required for kinetochore assembly and faithful chromosome segregation in Saccharomyces cerevisiae. It has been regarded as the exquisite hallmark of centromeric chromatin. We demonstrate that Cse4 resides at the partitioning locus STB of the 2-μm plasmid. Cse4p-STB association is absolutely dependent on the plasmid partitioning proteins Rep1p and Rep2p and the integrity of the mitotic spindle. The kinetochore mutation ndc10-1 excludes Cse4p from centromeres without dislodging it from STB. Cse4p-STB association lasts from G1/S through late telophase during the cell cycle. The release of Cse4p from STB chromatin is likely mediated through spindle disassembly. A lack of functional Cse4p disrupts the remodeling of STB chromatin by the RSC2 complex, negates Rep2p binding and cohesin assembly at STB, and causes plasmid missegregation. Poaching of a specific histone variant by the plasmid to mark its partitioning locus with a centromere tag reveals yet another one of the molecular trickeries it performs for achieving chromosome- like fidelity in segregation.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Nelson, Kristin M., Glenn M. Young et Virginia L. Miller. « Identification of a Locus Involved in Systemic Dissemination of Yersinia enterocolitica ». Infection and Immunity 69, n^o 10 (1 octobre 2001) : 6201–8. http://dx.doi.org/10.1128/iai.69.10.6201-6208.2001.

Texte intégral

Résumé :

ABSTRACT A putative LysR-type transcriptional activator, Hre20, was identified previously in an in vivo expression technology screen designed to identify factors which are expressed early during infection by Yersinia enterocolitica (G. M. Young and V. L. Miller, Mol. Microbiol. 25:319–328, 1997). An insertion in hre20, now designated rscR, resulted in increased splenic dissemination of bacteria during infection in a BALB/c mouse model. A nonpolar mutation was generated inrscR, and examination of this strain in the BALB/c mouse model demonstrated that the mutation in rscR was responsible for the increased dissemination to the spleen that was seen in the original experiments. RscR is homologous to the LysR family of transcriptional regulators; thus, a screen was undertaken to identify genes regulated by RscR. A strain containing an insertion in the chromosomal rscR gene and carrying rscR on a plasmid under the control of the inducible araBAD promoter was mutagenized with an mTn5Km-2 transposon containing a promoterless lacZY. Eighteen insertions were identified which appeared to respond to levels of RscR, and these were classified into four allelic groups based on Southern blot hybridization analysis. Representative members were sequenced from three allelic groups. Sequencing revealed insertions in an ORF with no known homologues, a homologue of OmpF of Serratia marcescens, and a locus (designated rscBAC) with similarity to thehmwABC locus of Haemophilus influenzae. ThehmwABC locus promotes adherence of H. influenzae to host cells (S. J. Barenkamp and J. W. St. Geme III, Infect. Immun. 62:3320–3328, 1994; J. W. St. Geme III, S. Falkow, and S. J. Barenkamp, Proc. Natl. Acad. Sci. USA 90:2875–2879, 1993). A strain containing a deletion mutant of rscA, the hmwA homologue, exhibits increased splenic dissemination of bacteria during infection in a BALB/c mouse model, similar to the rscR mutant. This suggests that the phenotype of an rscR mutant is due to the loss of RscA.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Hooshyar, Mohsen, Daniel Burnside, Maryam Hajikarimlou, Katayoun Omidi, Alexander Jesso, Megan Vanstone, Adamo Young et al. « Actin-Related Protein 6 (Arp6) Influences Double-Strand Break Repair in Yeast ». Applied Microbiology 1, n^o 2 (16 juillet 2021) : 225–38. http://dx.doi.org/10.3390/applmicrobiol1020017.

Texte intégral

Résumé :

DNA double-strand breaks (DSBs) are the most deleterious form of DNA damage and are repaired through non-homologous end-joining (NHEJ) or homologous recombination (HR). Repair initiation, regulation and communication with signaling pathways require several histone-modifying and chromatin-remodeling complexes. In budding yeast, this involves three primary complexes: INO80-C, which is primarily associated with HR, SWR1-C, which promotes NHEJ, and RSC-C, which is involved in both pathways as well as the general DNA damage response. Here we identify ARP6 as a factor involved in DSB repair through an RSC-C-related pathway. The loss of ARP6 significantly reduces the NHEJ repair efficiency of linearized plasmids with cohesive ends, impairs the repair of chromosomal breaks, and sensitizes cells to DNA-damaging agents. Genetic interaction analysis indicates that ARP6, MRE11 and RSC-C function within the same pathway, and the overexpression of ARP6 rescues rsc2∆ and mre11∆ sensitivity to DNA-damaging agents. Double mutants of ARP6, and members of the INO80 and SWR1 complexes, cause a significant reduction in repair efficiency, suggesting that ARP6 functions independently of SWR1-C and INO80-C. These findings support a novel role for ARP6 in DSB repair that is independent of the SWR1 chromatin remodeling complex, through an apparent RSC-C and MRE11-associated DNA repair pathway.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Shim, Eun Yong, Soo Jin Hong, Ji-Hyun Oum, Yvonne Yanez, Yu Zhang et Sang Eun Lee. « RSC Mobilizes Nucleosomes To Improve Accessibility of Repair Machinery to the Damaged Chromatin ». Molecular and Cellular Biology 27, n^o 5 (18 décembre 2006) : 1602–13. http://dx.doi.org/10.1128/mcb.01956-06.

Texte intégral

Résumé :

ABSTRACT Repair of DNA double-strand breaks (DSBs) protects cells and organisms, as well as their genome integrity. Since DSB repair occurs in the context of chromatin, chromatin must be modified to prevent it from inhibiting DSB repair. Evidence supports the role of histone modifications and ATP-dependent chromatin remodeling in repair and signaling of chromosome DSBs. The key questions are, then, what the nature of chromatin altered by DSBs is and how remodeling of chromatin facilitates DSB repair. Here we report a chromatin alteration caused by a single HO endonuclease-generated DSB at the Saccharomyces cerevisiae MAT locus. The break induces rapid nucleosome migration to form histone-free DNA of a few hundred base pairs immediately adjacent to the break. The DSB-induced nucleosome repositioning appears independent of end processing, since it still occurs when the 5′-to-3′ degradation of the DNA end is markedly reduced. The tetracycline-controlled depletion of Sth1, the ATPase of RSC, or deletion of RSC2 severely reduces chromatin remodeling and loading of Mre11 and Yku proteins at the DSB. Depletion of Sth1 also reduces phosphorylation of H2A, processing, and joining of DSBs. We propose that RSC-mediated chromatin remodeling at the DSB prepares chromatin to allow repair machinery to access the break and is vital for efficient DSB repair.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Titus, Laura C., T. Renee Dawson, Deborah J. Rexer, Kathryn J. Ryan et Susan R. Wente. « Members of the RSC Chromatin-Remodeling Complex Are Required for Maintaining Proper Nuclear Envelope Structure and Pore Complex Localization ». Molecular Biology of the Cell 21, n^o 6 (15 mars 2010) : 1072–87. http://dx.doi.org/10.1091/mbc.e09-07-0615.

Texte intégral

Résumé :

The assembly, distribution, and functional integrity of nuclear pore complexes (NPCs) in the nuclear envelope (NE) are key determinants in the nuclear periphery architecture. However, the mechanisms controlling proper NPC and NE structure are not fully defined. We used two different genetic screening approaches to identify Saccharomyces cerevisiae mutants with defects in NPC localization. The first approach examined green fluorescent protein (GFP)-Nic96 in 531 strains from the yeast Tet-promoters Hughes Collection with individual essential genes expressed from a doxycycline-regulated promoter (TetO7-orf). Under repressive conditions, depletion of the protein encoded by 44 TetO7-orf strains resulted in mislocalized GFP-Nic96. These included STH1, RSC4, RSC8, RSC9, RSC58, ARP7, and ARP9, each encoding components of the RSC chromatin remodeling complex. Second, a temperature-sensitive sth1-F793S (npa18-1) mutant was identified in an independent genetic screen for NPC assembly (npa) mutants. NPC mislocalization in the RSC mutants required new protein synthesis and ongoing transcription, confirming that lack of global transcription did not underlie the phenotypes. Electron microscopy studies showed significantly altered NEs and nuclear morphology, with coincident cytoplasmic membrane sheet accumulation. Strikingly, increasing membrane fluidity with benzyl alcohol treatment prevented the sth1-F793S NE structural defects and NPC mislocalization. We speculate that NE structure is functionally linked to proper chromatin architecture.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Behera, Ajay Kumar, Sasmita Mohapatra, Rabindra Mahapatra et Harish Das. « Effect of Big Data Analytics in Reverse Supply Chain ». International Journal of Information Systems and Supply Chain Management 15, n^o 1 (janvier 2022) : 1–14. http://dx.doi.org/10.4018/ijisscm.287128.

Texte intégral

Résumé :

The main purpose of this paper is to know about the recent status of big data analytics (BDA) on various manufacturing and reverse supply chain levels (RSCL) in Indian industries. In particular, it emphasises on understanding of BDA concept in Indian industries and proposes a structure to examine industries’ development in executing BDA extends in reverse supply chain management (RSCM). A survey was conducted through questionnaires on RSCM levels of 330 industries. Of the 330 surveys that were mailed, 125 completed surveys were returned, corresponding to a response rate of 37.87 percent, which was slightly greater than previous studies (Queiroz and Telles, 2018).The information of Indian industries with respect to BDA, the hurdles with boundaries to BDA-venture reception, and the connection with reverse supply chain levels and BDA learning were recognized.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Shim, Eun Yong, Jia-Lin Ma, Ji-Hyun Oum, Yvonne Yanez et Sang Eun Lee. « The Yeast Chromatin Remodeler RSC Complex Facilitates End Joining Repair of DNA Double-Strand Breaks ». Molecular and Cellular Biology 25, n^o 10 (15 mai 2005) : 3934–44. http://dx.doi.org/10.1128/mcb.25.10.3934-3944.2005.

Texte intégral

Résumé :

ABSTRACT Repair of chromosome double-strand breaks (DSBs) is central to cell survival and genome integrity. Nonhomologous end joining (NHEJ) is the major cellular repair pathway that eliminates chromosome DSBs. Here we report our genetic screen that identified Rsc8 and Rsc30, subunits of the Saccharomyces cerevisiae chromatin remodeling complex RSC, as novel NHEJ factors. Deletion of RSC30 gene or the C-terminal truncation of RSC8 impairs NHEJ of a chromosome DSB created by HO endonuclease in vivo. rsc30Δ maintains a robust level of homologous recombination and the damage-induced cell cycle checkpoints. By chromatin immunoprecipitation, we show recruitment of RSC to a chromosome DSB with kinetics congruent with its involvement in NHEJ. Recruitment of RSC to a DSB depends on Mre11, Rsc30, and yKu70 proteins. Rsc1p and Rsc2p, two other RSC subunits, physically interact with yKu80p and Mre11p. The interaction of Rsc1p with Mre11p appears to be vital for survival from genotoxic stress. These results suggest that chromatin remodeling by RSC is important for NHEJ.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Treich, I., L. Ho et M. Carlson. « Direct interaction between Rsc6 and Rsc8/Swh3, two proteins that are conserved in SWI/SNF-related complexes ». Nucleic Acids Research 26, n^o 16 (1 août 1998) : 3739–45. http://dx.doi.org/10.1093/nar/26.16.3739.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

15

Romeo, Martin J., Melinda L. Angus-Hill, Andrew K. Sobering, Yoshiaki Kamada, Bradley R. Cairns et David E. Levin. « HTL1 Encodes a Novel Factor That Interacts with the RSC Chromatin Remodeling Complex in Saccharomyces cerevisiae ». Molecular and Cellular Biology 22, n^o 23 (1 décembre 2002) : 8165–74. http://dx.doi.org/10.1128/mcb.22.23.8165-8174.2002.

Texte intégral

Résumé :

ABSTRACT RSC is an essential chromatin remodeling complex in Saccharomyces cerevisiae that performs central roles in transcriptional regulation and cell cycle progression. Here we identify Htl1 as a novel factor that associates with the RSC complex both physically and functionally. We isolated HTL1 through a genetic screen for mutants that displayed additive growth defects with a conditional mutation in the protein kinase C gene (PKC1), which has been suggested through genetic connections to interact functionally with RSC. Several lines of evidence connect HTL1 to RSC function. First, an htl1Δ mutant displayed temperature-sensitive growth and a G2/M cell cycle arrest at restrictive temperatures, a phenotype similar to that of strains with conditional mutations in essential RSC components. Second, we isolated RSC3, which encodes a component of the RSC complex, as a dosage suppressor of the htl1Δ growth arrest. Third, an htl1Δ mutant displayed additive growth defects with conditional rsc3 alleles. Fourth, overexpression of HTL1 suppressed the growth defect of a strain with a conditional mutation in another RSC component, RSC8. Finally, we demonstrate that Htl1 is a nuclear protein that can associate in vivo with a fraction of the RSC complex. We propose that an RSC-Htl1 complex acts coordinately with protein kinase C to regulate the G2/M transition.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Pauer, Frank, Markus Erhart, Rüdiger Mews et Dietmar Stalke. « Fluorosulfonium Hexafluoroarsenate RSF2+AsF6⁻ / Fluorosulfonium Hexafluoroarsenates, RSF2+AsF6⁻ ». Zeitschrift für Naturforschung B 45, n^o 3 (1 mars 1990) : 271–76. http://dx.doi.org/10.1515/znb-1990-0301.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

17

Hsieh, Jung-Fa. « NUMERICAL ANALYSIS OF DISPLACEMENTS IN SPATIAL MECHANISMS WITH SPHERICAL JOINTS UTILIZING AN EXTENDED D-H NOTATION ». Transactions of the Canadian Society for Mechanical Engineering 34, n^o 3-4 (septembre 2010) : 417–31. http://dx.doi.org/10.1139/tcsme-2010-0025.

Texte intégral

Résumé :

Spherical joints consist of a pair of concave and convex spherical surfaces engaged in such a way as to prevent translational motion of the ball and socket whilst simultaneously allowing three degrees of rotational freedom. The kinematics of spatial mechanisms comprising links and joints are commonly analyzed using the Denavit-Hartenberg (D-H) notation. However, whilst this method allows the kinematics of mechanisms containing prismatic, revolute, helical and cylindrical joints to be explicitly defined, it cannot be directly applied to mechanical systems containing spherical pairs. Accordingly, this paper proposes an extended D-H notation which allows the independent parameters of any spatial mechanism, including one with spherical pairs, to be derived for analysis and synthesis purposes. The validity of the proposed notation is demonstrated via its application to the analysis of mechanisms containing revolute (R), spherical (S), cylindrical (C) and prismatic (P) joints. The results confirm the viability of the extended D-H notation as a means of analyzing the displacements of mechanical systems containing kinematic chains such as RSCR, RSCP, CSSR and CSSP.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Dewerchin, M., HR Lijnen, JM Stassen, F. De Cock, T. Quertermous, MH Ginsberg, EF Plow et D. Collen. « Effect of chemical conjugation of recombinant single-chain urokinase- type plasminogen activator with monoclonal antiplatelet antibodies on platelet aggregation and on plasma clot lysis in vitro and in vivo ». Blood 78, n^o 4 (15 août 1991) : 1005–18. http://dx.doi.org/10.1182/blood.v78.4.1005.1005.

Texte intégral

Résumé :

Abstract The murine monoclonal antiplatelet antibodies MA-TSPI-1 (directed against human thrombospondin) and MA-PMI-2, MA-PMI-1, and MA-LIBS-1 (directed against ligand-induced binding sites [LIBS] on human platelet glycoprotein IIb/IIIa) were conjugated with recombinant single-chain urokinase-type plasminogen activator (rscu-PA) using the cross-linking reagent N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). The conjugates (rscu-PA/MA-TSPI-1, rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, and rscu-PA/MA-LIBS-1), purified by immunoadsorption and gel filtration, were obtained with recoveries of 34% to 45%, with an average stoichiometry of 1.6 to 1.8 IgG molecules per rscu-PA molecule, and with unaltered specific activities and affinities. Preincubation of human platelet-rich plasma with rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, or unconjugated rscu-PA resulted in partial inhibition of ADP-induced aggregation; 25% inhibition was obtained with 63 micrograms/mL rscu-PA and with 6 micrograms u-PA/mL rscu-PA/MA-PMI-2 or 1.2 micrograms u- PA/mL rscu-PA/MA-PMI-1. In an in vitro system composed of a 125I-fibrin- labeled platelet-rich human plasma clot immersed in normal human plasma, the conjugates had threefold to greater than 15-fold less fibrinolytic potency than unconjugated rscu-PA. The thrombolytic potency of rscu-PA/MA-PMI-1 and rscu-PA/MA-LIBS-1 was compared with that of rscu-PA and that of a control conjugate rscu-PA/MA-1C8 in a pulmonary embolism model in the hamster, using clots prepared from platelet-poor or platelet-rich human plasma. Lysis was measured 30 minutes after the end of a 60-minute intravenous infusion of the thrombolytic agents. rscu-PA, rscu-PA/MA-PMI-1, rscu-PA/MA-LIBS-1, as well as rscu-PA/MA-1C8 had comparable thrombolytic potencies (percent lysis per dose administered) towards platelet-poor human plasma clots. In contrast, the thrombolytic potency of rscu-PA/MA-PMI-1 and of rscu- PA/MA-LIBS-1 towards platelet-rich clots was 2.3- to 3-fold higher than that of rscu-PA (P less than .005) and fivefold to sevenfold higher than that of the control conjugate (P less than .01).

Styles APA, Harvard, Vancouver, ISO, etc.

19

Dewerchin, M., HR Lijnen, JM Stassen, F. De Cock, T. Quertermous, MH Ginsberg, EF Plow et D. Collen. « Effect of chemical conjugation of recombinant single-chain urokinase- type plasminogen activator with monoclonal antiplatelet antibodies on platelet aggregation and on plasma clot lysis in vitro and in vivo ». Blood 78, n^o 4 (15 août 1991) : 1005–18. http://dx.doi.org/10.1182/blood.v78.4.1005.bloodjournal7841005.

Texte intégral

Résumé :

The murine monoclonal antiplatelet antibodies MA-TSPI-1 (directed against human thrombospondin) and MA-PMI-2, MA-PMI-1, and MA-LIBS-1 (directed against ligand-induced binding sites [LIBS] on human platelet glycoprotein IIb/IIIa) were conjugated with recombinant single-chain urokinase-type plasminogen activator (rscu-PA) using the cross-linking reagent N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). The conjugates (rscu-PA/MA-TSPI-1, rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, and rscu-PA/MA-LIBS-1), purified by immunoadsorption and gel filtration, were obtained with recoveries of 34% to 45%, with an average stoichiometry of 1.6 to 1.8 IgG molecules per rscu-PA molecule, and with unaltered specific activities and affinities. Preincubation of human platelet-rich plasma with rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, or unconjugated rscu-PA resulted in partial inhibition of ADP-induced aggregation; 25% inhibition was obtained with 63 micrograms/mL rscu-PA and with 6 micrograms u-PA/mL rscu-PA/MA-PMI-2 or 1.2 micrograms u- PA/mL rscu-PA/MA-PMI-1. In an in vitro system composed of a 125I-fibrin- labeled platelet-rich human plasma clot immersed in normal human plasma, the conjugates had threefold to greater than 15-fold less fibrinolytic potency than unconjugated rscu-PA. The thrombolytic potency of rscu-PA/MA-PMI-1 and rscu-PA/MA-LIBS-1 was compared with that of rscu-PA and that of a control conjugate rscu-PA/MA-1C8 in a pulmonary embolism model in the hamster, using clots prepared from platelet-poor or platelet-rich human plasma. Lysis was measured 30 minutes after the end of a 60-minute intravenous infusion of the thrombolytic agents. rscu-PA, rscu-PA/MA-PMI-1, rscu-PA/MA-LIBS-1, as well as rscu-PA/MA-1C8 had comparable thrombolytic potencies (percent lysis per dose administered) towards platelet-poor human plasma clots. In contrast, the thrombolytic potency of rscu-PA/MA-PMI-1 and of rscu- PA/MA-LIBS-1 towards platelet-rich clots was 2.3- to 3-fold higher than that of rscu-PA (P less than .005) and fivefold to sevenfold higher than that of the control conjugate (P less than .01).

Styles APA, Harvard, Vancouver, ISO, etc.

20

Spriggs, DJ, JM Stassen, Y. Hashimoto et D. Collen. « Thrombolytic properties of human tissue-type plasminogen activator, single-chain urokinase-type plasminogen activator, and synergistic combinations in venous thrombosis models in dogs and rabbits ». Blood 73, n^o 5 (1 avril 1989) : 1207–12. http://dx.doi.org/10.1182/blood.v73.5.1207.1207.

Texte intégral

Résumé :

Abstract Thrombolysis with single and combined four-hour intravenous (IV) infusions of recombinant tissue-type plasminogen activator (rt-PA), recombinant single-chain urokinase-type plasminogen activator of 54,000 molecular weight (mol wt) (rscu-PA), and rscu-PA-32 kD, an rscu-PA derivative of 32,000 mol wt was studied in a femoral vein thrombosis model in the dog and in a jugular vein thrombosis model in the rabbit. In both species, the dose-response curves were linear, and no systemic activation of the fibrinolytic system or fibrinogen breakdown was observed. The steady-state levels of rt-PA-, rscu-PA-, and rscu-PA-32 kD-related antigens in plasma were proportional to the infusion rates. In the dog model, 25% lysis was obtained with 0.11 mg/kg rt-PA, 0.8 mg/kg rscu-PA, and 0.37 mg/kg rscu-PA-32 kD. Combinations of rt-PA and rscu-PA were 2.6 times more active (P less than .005) than anticipated on the basis of their pharmacologic additive effects, whereas combinations of rt-PA and rscu-PA-32 kD were 2.7 times more active (P less than .05). In the rabbit model, 25% lysis was obtained with 0.24 mg/kg rt-PA, 0.75 mg/kg rscu-PA, and 1.25 mg/kg rscu-PA-32 kD. Combinations of rt-PA and rscu-PA have a fivefold synergistic interaction, but surprisingly no synergism was observed between rt-PA and rscu-PA-32 kD. This study shows that synergism between rt-PA and rscu-PA occurs both in rabbits and dogs in a relatively narrow concentration range that allows a fractional reduction of the total equipotent dose by a factor of 2.5-fold to fivefold. Combination therapy is not associated with systemic fibrinolytic activation. This range of synergistic interaction, although limited, may be useful in devising the best thrombolytic therapy for patients with thromboembolic disease.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Spriggs, DJ, JM Stassen, Y. Hashimoto et D. Collen. « Thrombolytic properties of human tissue-type plasminogen activator, single-chain urokinase-type plasminogen activator, and synergistic combinations in venous thrombosis models in dogs and rabbits ». Blood 73, n^o 5 (1 avril 1989) : 1207–12. http://dx.doi.org/10.1182/blood.v73.5.1207.bloodjournal7351207.

Texte intégral

Résumé :

Thrombolysis with single and combined four-hour intravenous (IV) infusions of recombinant tissue-type plasminogen activator (rt-PA), recombinant single-chain urokinase-type plasminogen activator of 54,000 molecular weight (mol wt) (rscu-PA), and rscu-PA-32 kD, an rscu-PA derivative of 32,000 mol wt was studied in a femoral vein thrombosis model in the dog and in a jugular vein thrombosis model in the rabbit. In both species, the dose-response curves were linear, and no systemic activation of the fibrinolytic system or fibrinogen breakdown was observed. The steady-state levels of rt-PA-, rscu-PA-, and rscu-PA-32 kD-related antigens in plasma were proportional to the infusion rates. In the dog model, 25% lysis was obtained with 0.11 mg/kg rt-PA, 0.8 mg/kg rscu-PA, and 0.37 mg/kg rscu-PA-32 kD. Combinations of rt-PA and rscu-PA were 2.6 times more active (P less than .005) than anticipated on the basis of their pharmacologic additive effects, whereas combinations of rt-PA and rscu-PA-32 kD were 2.7 times more active (P less than .05). In the rabbit model, 25% lysis was obtained with 0.24 mg/kg rt-PA, 0.75 mg/kg rscu-PA, and 1.25 mg/kg rscu-PA-32 kD. Combinations of rt-PA and rscu-PA have a fivefold synergistic interaction, but surprisingly no synergism was observed between rt-PA and rscu-PA-32 kD. This study shows that synergism between rt-PA and rscu-PA occurs both in rabbits and dogs in a relatively narrow concentration range that allows a fractional reduction of the total equipotent dose by a factor of 2.5-fold to fivefold. Combination therapy is not associated with systemic fibrinolytic activation. This range of synergistic interaction, although limited, may be useful in devising the best thrombolytic therapy for patients with thromboembolic disease.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Srivastava, Girish K., David Rodriguez-Crespo, Amar K. Singh, Clara Casado-Coterillo, Ivan Fernandez-Bueno, Maria T. Garcia-Gutierrez, Joaquin Coronas et J. Carlos Pastor. « Chitosan Feasibility to Retain Retinal Stem Cell Phenotype and Slow Proliferation for Retinal Transplantation ». BioMed Research International 2014 (2014) : 1–10. http://dx.doi.org/10.1155/2014/287896.

Texte intégral

Résumé :

Retinal stem cells (RSCs) are promising in cell replacement strategies for retinal diseases. RSCs can migrate, differentiate, and integrate into retina. However, RSCs transplantation needs an adequate support; chitosan membrane (ChM) could be one, which can carry RSCs with high feasibility to support their integration into retina. RSCs were isolated, evaluated for phenotype, and subsequently grown on sterilized ChM and polystyrene surface for 8 hours, 1, 4, and 11 days for analysing cell adhesion, proliferation, viability, and phenotype. Isolated RSCs expressed GFAP, PKC, isolectin, recoverin, RPE65, PAX-6, cytokeratin 8/18, and nestin proteins. They adhered (28 ± 16%, 8 hours) and proliferated (40 ± 20 cells/field, day 1 and 244 ± 100 cells/field, day 4) significantly low(P<0.05)on ChM. However, they maintained similar viability (>95%) and phenotype (cytokeratin 8/18, PAX6, and nestin proteins expression, day 11) on both surfaces (ChM and polystyrene). RSCs did not express alpha-SMA protein on both surfaces. RSCs express proteins belonging to epithelial, glial, and neural cells, confirming that they need further stimulus to reach a final destination of differentiation that could be provided inin vivocondition. ChM does not alternate RSCs behaviour and therefore can be used as a cell carrier so that slow proliferating RSCs can migrate and integrate into retina.

Styles APA, Harvard, Vancouver, ISO, etc.

23

van der Kaaden, Marieke E., Dingeman C. Rijken, J. Kar Kruijt, Theo J. C. van Berkel et Johan Kuiper. « The Role of the Low-Density Lipoprotein Receptor-Related Protein (LRP) in the Plasma Clearance and Liver Uptake of Recombinant Single-chain Urokinase-type Plasminogen Activator in Rats ». Thrombosis and Haemostasis 77, n^o 04 (1997) : 710–17. http://dx.doi.org/10.1055/s-0038-1656039.

Texte intégral

Résumé :

SummaryUrokinase-type plasminogen activator (u-PA) is used as a thrombolytic agent in the treatment of acute myocardial infarction. In vitro, recombinant single-chain u-PA (rscu-PA) expressed in E.coli is recognized by the Low-Density Lipoprotein Receptor-related Protein (LRP) on rat parenchymal liver cells. In this study we investigated the role of LRP in the liver uptake and plasma clearance of rscu-PA in rats. A preinjection of the LRP inhibitor GST-RAP reduced the maximal liver uptake of 125I-rscu-PA at 5 min after injection from 50 to 30% of the injected dose and decreased the clearance of rscu-PA from 2.37 ml/min to 1.58 ml/min. Parenchymal, Kupffer and endothelial cells were responsible for 40, 50 and 10% of the liver uptake, respectively. The reduction in liver uptake of rscu-PA by the preinjection of GST-RAP was caused by a 91 % and 62% reduction in the uptake by parenchymal and Kupffer cells, respectively. In order to investigate the part of rscu-PA that accounted for the interaction with LRP, experiments were performed with a mutant of rscu-PA lacking residues 11-135 (= deltal25- rscu-PA). Deletion of residues 11-135 resulted in a 80% reduction in liver uptake and a 2.4 times slower clearance (0.97 ml/min). The parenchymal, Kupffer and endothelial cells were responsible for respectively 60, 33 and 7% of the liver uptake of 125I-deltal25-rscu-PA. Preinjection of GST-RAP completely reduced the liver uptake of delta 125-rscu-PA and reduced its clearance to 0.79 ml/min. Treatment of isolated Kupffer cells with PI-PLC reduced the binding of rscu-PA by 40%, suggesting the involvement of the urokinase-type Plasminogen Activator Receptor (u-PAR) in the recognition of rscu-PA. Our results demonstrate that in vivo LRP is responsible for more than 90% of the parenchymal liver cell mediated uptake of rscu-PA and for 60% of the Kupffer cell interaction. It is also suggested that u-PAR is involved in the Kupffer cell recognition of rscu-PA.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Kaur, Jasmine, et Swatantra Jain. « Vi antigen of Salmonella enetrica serovar Typhi — biosynthesis, regulation and its use as vaccine candidate ». Open Life Sciences 7, n^o 5 (1 octobre 2012) : 825–38. http://dx.doi.org/10.2478/s11535-012-0082-8.

Texte intégral

Résumé :

AbstractVi capsular polysaccharide (Vi antigen) was first identified as the virulence antigen of Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever in humans. The presence of Vi antigen differentiates S. Typhi from other serovars of Salmonella. Vi antigen is a linear polymer consisting of α-1,4-linked-N-acetyl-galactosaminuronate, whose expression is controlled by three chromosomal loci, namely viaA, viaB and ompB. Both viaA and viaB region are present on Salmonella Pathogenicity Island-7, a large, mosaic, genetic island. The viaA region encodes a positive regulator and the viaB locus is composed of 11 genes designated tviA-tviE (for Vi biosyhthesis), vexA-vexE (for Vi antigen export) and ORF 11. Vi polysaccharide is synthesized from UDP-N-acetyl glucosamine in a series of steps requiring TviB, TviC, and TviE, and regulation of Vi polysaccharide synthesis is controlled by two regulatory systems, rscB-rscC (viaA locus) and ompR-envZ (ompB locus), which respond to changes in osmolarity. This antigen is highly immunogenic and has been used for the formulation of one of the currently available vaccines against typhoid. Despite advancement in the area of vaccinology, its pace of progress needs to be accelerated and effective control programmes will be needed for proper disease management.

Styles APA, Harvard, Vancouver, ISO, etc.

25

Lijnen, HR, B. Van Hoef, F. De Cock et D. Collen. « The mechanism of plasminogen activation and fibrin dissolution by single chain urokinase-type plasminogen activator in a plasma milieu in vitro ». Blood 73, n^o 7 (15 mai 1989) : 1864–72. http://dx.doi.org/10.1182/blood.v73.7.1864.1864.

Texte intégral

Résumé :

Abstract The relative contribution of several mechanisms to plasminogen activation and fibrin dissolution by urokinase-type plasminogen activator (u-PA) in vitro was quantitated. The activation of plasminogen by recombinant single chain u-PA (rscu-PA), by its two chain derivative (rtcu-PA) and by a plasmin-resistant mutant, rscu-PA- Glu158, obeys Michaelis-Menten kinetics with catalytic efficiencies of 0.00064, 0.046, and 0.00005 L/mumol.s for native plasminogen (Glu- plasminogen) and of 0.0061, 1.21, and 0.0004 L/mumol.s for partially degraded plasminogen (Lys-plasminogen). In a purified system consisting of a fibrin clot submerged in a plasminogen solution, the equi- effective doses (50% lysis in one hour) for rscu-PA, rtcu-PA, and rscu- PA-Glu158 were 16, 6.5, and 32,000 ng/mL for Glu-plasminogen and two- to fourfold lower for Lys-plasminogen. In a plasma milieu, 50% lysis in two hours was obtained for a plasma clot with 2.1 micrograms/mL rscu- PA, 0.5 micrograms/mL rtcu-PA, and greater than 200 micrograms/mL rscu- PA-Glu158 and for a purified fibrin clot with 1.3 micrograms/mL rscu-PA and 0.27 microgram/mL rtcu-PA. After predigestion of a purified fibrin clot with plasmin, the apparent potency of rscu-PA and rtcu-PA increased by 40% and 20%, respectively. In conclusion, rscu-PA has an intrinsic plasminogen activating potential that is only about 1% of that of rtcu-PA and that is 13 times higher than that of rscu-PA- Glu158. Conformational transition of Glu-plasminogen to Lys-plasminogen enhances its sensitivity to activation by all u-PA moieties ten- to 20- fold. Predigestion of fibrin clots with associated increased binding of plasminogen results in a minor apparent increase of the fibrinolytic potency of rscu-PA and rtcu-PA. The relative fibrinolytic potency of rtcu-PA is two to three orders of magnitude higher than that of rscu-PA- Glu158 but only two- to five-fold higher than that of rscu-PA, both in purified systems and in a plasma milieu. These results indicate that conversion of rscu-PA to rtcu-PA constitutes the primary mechanism of fibrin dissolution.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Lijnen, HR, B. Van Hoef, F. De Cock et D. Collen. « The mechanism of plasminogen activation and fibrin dissolution by single chain urokinase-type plasminogen activator in a plasma milieu in vitro ». Blood 73, n^o 7 (15 mai 1989) : 1864–72. http://dx.doi.org/10.1182/blood.v73.7.1864.bloodjournal7371864.

Texte intégral

Résumé :

The relative contribution of several mechanisms to plasminogen activation and fibrin dissolution by urokinase-type plasminogen activator (u-PA) in vitro was quantitated. The activation of plasminogen by recombinant single chain u-PA (rscu-PA), by its two chain derivative (rtcu-PA) and by a plasmin-resistant mutant, rscu-PA- Glu158, obeys Michaelis-Menten kinetics with catalytic efficiencies of 0.00064, 0.046, and 0.00005 L/mumol.s for native plasminogen (Glu- plasminogen) and of 0.0061, 1.21, and 0.0004 L/mumol.s for partially degraded plasminogen (Lys-plasminogen). In a purified system consisting of a fibrin clot submerged in a plasminogen solution, the equi- effective doses (50% lysis in one hour) for rscu-PA, rtcu-PA, and rscu- PA-Glu158 were 16, 6.5, and 32,000 ng/mL for Glu-plasminogen and two- to fourfold lower for Lys-plasminogen. In a plasma milieu, 50% lysis in two hours was obtained for a plasma clot with 2.1 micrograms/mL rscu- PA, 0.5 micrograms/mL rtcu-PA, and greater than 200 micrograms/mL rscu- PA-Glu158 and for a purified fibrin clot with 1.3 micrograms/mL rscu-PA and 0.27 microgram/mL rtcu-PA. After predigestion of a purified fibrin clot with plasmin, the apparent potency of rscu-PA and rtcu-PA increased by 40% and 20%, respectively. In conclusion, rscu-PA has an intrinsic plasminogen activating potential that is only about 1% of that of rtcu-PA and that is 13 times higher than that of rscu-PA- Glu158. Conformational transition of Glu-plasminogen to Lys-plasminogen enhances its sensitivity to activation by all u-PA moieties ten- to 20- fold. Predigestion of fibrin clots with associated increased binding of plasminogen results in a minor apparent increase of the fibrinolytic potency of rscu-PA and rtcu-PA. The relative fibrinolytic potency of rtcu-PA is two to three orders of magnitude higher than that of rscu-PA- Glu158 but only two- to five-fold higher than that of rscu-PA, both in purified systems and in a plasma milieu. These results indicate that conversion of rscu-PA to rtcu-PA constitutes the primary mechanism of fibrin dissolution.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Ko, Seo Hee, Jong-Wook Song, Jae-Kwang Shim, Sarah Soh et Young-Lan Kwak. « Low Intraoperative Cerebral Oxygen Saturation Is Associated with Acute Kidney Injury after Off-Pump Coronary Artery Bypass ». Journal of Clinical Medicine 12, n^o 1 (2 janvier 2023) : 359. http://dx.doi.org/10.3390/jcm12010359.

Texte intégral

Résumé :

By monitoring the brain as the index organ of global oxygen supply–demand balance including major organs, regional cerebral oxygen saturation (rScO2) may indicate adequacy of renal perfusion. The aim of this study was to investigate the relationship between perioperative rScO2 and acute kidney injury (AKI) after off-pump coronary artery bypass (OPCAB). AKI was diagnosed according to the Kidney Disease: Improving Global Outcomes criteria. Collected rScO2 variables were baseline, mean, and lowest value during surgery, maximal percentage decrease from baseline, and areas under the threshold below an absolute value of 50% (AUT50) and of 80% of baseline (AUT80%base). Among 580 patients, AKI developed in 143 (24.7%) patients. Patients with AKI had lower baseline, mean, and lowest rScO2 and higher AUT50 and AUT80%base than those without AKI despite routine efforts to restore the rScO2 values within 20% of the baseline. Among the rScO2 variables, the area under the receiver operating characteristic curve of mean rScO2 was the highest (0.636), which was used for the multivariable logistic regression. Multivariable logistic regression revealed mean rScO2 as an independent predictor of AKI (odds ratio, 0.964; 95% confidence interval, 0.937–0.990; p = 0.008), along with chronic kidney disease and emergency surgery. Low intraoperative mean rScO2 was independently associated with AKI after OPCAB, which may serve as an early marker of renal injury.

Styles APA, Harvard, Vancouver, ISO, etc.

28

SANGIORGI, DAVIDE. « On the bisimulation proof method ». Mathematical Structures in Computer Science 8, n^o 5 (octobre 1998) : 447–79. http://dx.doi.org/10.1017/s0960129598002527.

Texte intégral

Résumé :

The most popular method for establishing bisimilarities among processes is to exhibit bisimulation relations. By definition, [Rscr ] is a bisimulation relation if [Rscr ] progresses to [Rscr ] itself, i.e., pairs of processes in [Rscr ] can match each other's actions and their derivatives are again in [Rscr ].We study generalisations of the method aimed at reducing the size of the relations to be exhibited and hence relieving the proof work needed to establish bisimilarity results. We allow a relation [Rscr ] to progress to a different relation [Fscr ] ([Rscr ]), where [Fscr ] is a function on relations. Functions that can be safely used in this way (i.e., such that if [Rscr ] progresses to [Fscr ] ([Rscr ]), then [Rscr ] only includes pairs of bisimilar processes) are sound. We give a simple condition that ensures soundness. We show that the class of sound functions contains non-trivial functions and we study the closure properties of the class with respect to various important function constructors, like composition, union and iteration. These properties allow us to construct sophisticated sound functions – and hence sophisticated proof techniques for bisimilarity – from simpler ones.The usefulness of our proof techniques is supported by various non-trivial examples drawn from the process algebras CCS and π-calculus. They include the proof of the unique solution of equations and the proof of a few properties of the replication operator. Among these, there is a novel result that justifies the adoption of a simple form of prefix-guarded replication as the only form of replication in the π-calculus.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Chedgy, ECP, G. Lowe, R. Tang, C. Krebs, A. Sawka, H. Vaghadia, ME Gleave et AI SO. « Surgical placement of rectus sheath catheters in a cadaveric cystectomy model ». Annals of The Royal College of Surgeons of England 100, n^o 2 (février 2018) : 120–24. http://dx.doi.org/10.1308/rcsann.2017.0169.

Texte intégral

Résumé :

Introduction Surgically inserted rectus sheath catheters (RSCs) are used increasingly for analgesia after cystectomy and other abdominal surgery. Currently, there is little information on the optimal positioning of RSCs to allow maximal spread of local anaesthetic. This study sought to assess the spread of dye injected via RSCs and to highlight the extent of its coverage in a fresh unembalmed cadaveric cystectomy model in order to confirm the nerve endings that are likely to be anaesthetised with RSCs. Methods Four cadavers underwent lower midline incision with limited bladder mobilisation. A RSC was inserted into the eight hemiabdomens. The RSCs were positioned either anterior (n=5) or posterior to the rectus muscle (n=3). Dye was injected down the RSCs to evaluate spread. The eight hemiabdomens were dissected anatomically to determine the surface area of dye spread and nerve root involvement. Results The mean surface area of dye spread with anteriorly placed RSCs was 30.6cm2 anterior and 25.9cm2 posterior to the rectus muscle. The mean surface area of dye spread with posteriorly placed RSCs was 11.3cm2 anterior and 37.3cm2 posterior to the rectus muscle. The mean number of nerve roots stained with anteriorly and posteriorly placed RSCs was 3.8 and 2.7 respectively. Subcutaneous spread of dye was seen with one anterior RSC insertion. Peritoneal spread was seen with one anteriorly positioned RSC. Conclusions This study has demonstrated efficient nerve root infiltration with anteriorly and posteriorly positioned RSCs. It appears that dye spreads between the fibres of the rectus muscle rather than out laterally to the nerve roots when spreading from its initial compartment.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Hurst, D. F., E. G. Hall, A. F. Jordan, L. M. Miloshevich, D. N. Whiteman, T. Leblanc, D. Walsh, H. Vömel et S. J. Oltmans. « Comparisons of temperature, pressure and humidity measurements by balloon-borne radiosondes and frost point hygrometers during MOHAVE-2009 ». Atmospheric Measurement Techniques 4, n^o 12 (16 décembre 2011) : 2777–93. http://dx.doi.org/10.5194/amt-4-2777-2011.

Texte intégral

Résumé :

Abstract. We compare coincident, in situ, balloon-borne measurements of temperature (T) and pressure (P) by two radiosondes (Vaisala RS92, Intermet iMet-1-RSB) and similar measurements of relative humidity (RH) by RS92 sondes and frost point hygrometers. Data from a total of 28 balloon flights with at least one pair of radiosondes are analyzed in 1-km altitude bins to quantify measurement differences between the sonde sensors and how they vary with altitude. Each comparison (T, P, RH) exposes several profiles of anomalously large measurement differences. Measurement difference statistics, calculated with and without the anomalous profiles, are compared to uncertainties quoted by the radiosonde manufacturers. Excluding seven anomalous profiles, T differences between 19 pairs of RS92 and iMet sondes exceed their measurement uncertainty limits (2 σ) 31% of the time and reveal a statistically significant, altitude-independent bias of 0.5 ± 0.2 °C. Similarly, RS92-iMet P differences in 22 non-anomalous profiles exceed their uncertainty limits 23% of the time, with a disproportionate 83% of the excessive P differences at altitudes >16 km. The RS92-iMet pressure differences increase smoothly from −0.6 hPa near the surface to 0.8 hPa above 25 km. Temperature and P differences between all 14 pairs of RS92 sondes exceed manufacturer-quoted, reproducibility limits (σ) 28% and 11% of the time, respectively. About 95% of the excessive T differences are eliminated when 5 anomalous RS92-RS92 profiles are excluded. Only 5% of RH measurement differences between 14 pairs of RS92 sondes exceed the manufacturer's measurement reproducibility limit (σ). RH measurements by RS92 sondes are also compared to RH values calculated from frost point hygrometer measurements and coincident T measurements by the radiosondes. The influences of RS92-iMet Tand P differences on RH values and water vapor mixing ratios calculated from frost point hygrometer measurements are examined.

Styles APA, Harvard, Vancouver, ISO, etc.

31

MEINTJES, PETER L., et ALLEN G. RODRIGO. « EVOLUTION OF RELATIVE SYNONYMOUS CODON USAGE IN HUMAN IMMUNODEFICIENCY VIRUS TYPE-1 ». Journal of Bioinformatics and Computational Biology 03, n^o 01 (février 2005) : 157–68. http://dx.doi.org/10.1142/s0219720005000953.

Texte intégral

Résumé :

Mutation in Human Immunodeficiency Virus type-1 (HIV-1) is extremely rapid, a consequence of a low-fidelity viral reverse transcription process. The envelope gene has been shown to accumulate substitutions at a rate of approximately 1% per year and can frequently spend a long time in the host (approximately 10 years). The relative synonymous codon usage (RSCU) in HIV-1 is known to be different from that of the human host. However, by reengineering the protein coding sequences of HIV-1 to reflect the RSCU patterns observed in humans, a large increase in protein expression is observed. It is reasonable to suggest that within a host there may be a selective drive for change in the RSCU of HIV-1 towards human RSCU.To test this hypothesis we analyzed HIV-1 partial envelope sequences from eight patients sampled serially in time. For each sequence, an RSCU table was constructed. Sequences were labelled as "early" or "late" depending on whether they were sampled before or after the mid-point of the study. Using the RSCU values as descriptor variables, a Principal Components Analysis (PCA) was performed. The first three components clearly discriminated between early and late sequences. We also constructed pooled groupwise RSCU tables for early and late sequences. The viral RSCU values of each of the groups were correlated with human RSCU. If there is selection for host-adaptation in RSCU, we expect that "late" viral RSCUs would tend to be more highly correlated with human RSCU than "early" viral RSCUs. In fact, tests of significance suggest that this is the case. However, closer examination of the data revealed that the apparent trend towards human RSCU can be attributed to the homogenization of the codon usage by mutation pressure rather than host adaptation.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Sun, Bomin, Xavier Calbet, Anthony Reale, Steven Schroeder, Manik Bali, Ryan Smith et Michael Pettey. « Accuracy of Vaisala RS41 and RS92 Upper Tropospheric Humidity Compared to Satellite Hyperspectral Infrared Measurements ». Remote Sensing 13, n^o 2 (6 janvier 2021) : 173. http://dx.doi.org/10.3390/rs13020173.

Texte intégral

Résumé :

Radiosondes are important for calibrating satellite sensors and assessing sounding retrievals. Vaisala RS41 radiosondes have mostly replaced RS92 in the Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) and the conventional network. This study assesses RS41 and RS92 upper tropospheric humidity (UTH) accuracy by comparing with Infrared Atmospheric Sounding Interferometer (IASI) upper tropospheric water vapor absorption spectrum measurements. Using single RS41 and RS92 soundings at three GRUAN and DOE Atmospheric Radiation Measurement (ARM) sites and dual RS92/RS41 launches at three additional GRUAN sites, collocated with cloud-free IASI radiances (OBS), we compute Line-by-Line Radiative Transfer Model radiances for radiosonde profiles (CAL). We analyze OBS-CAL differences from 2015 to 2020, for daytime, nighttime, and dusk/dawn separately if data is available, for standard (STD) RS92 and RS41 processing, and RS92 GRUAN Data Processing (GDP; RS41 GDP is in development). We find that daytime RS41 (even without GDP) has ~1% smaller UTH errors than GDP RS92. RS41 may still have a dry bias of 1–1.5% for both daytime and nighttime, and a similar error for nighttime RS92 GDP, while standard RS92 may have a dry bias of 3–4%. These sonde humidity biases are probably upper limits since “cloud-free” scenes could still be cloud contaminated. Radiances computed from European Centre for Medium-Range Weather Forecasts (ECMWF) analyses match better than radiosondes with IASI measurements, perhaps because ECMWF assimilates IASI measurements. Relative differences between RS41 STD and RS92 GDP, or between radiosondes and ECMWF humidity profiles obtained from the radiance analysis, are consistent with their differences obtained directly from the RH measurements.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Imura, Y., JM Stassen, T. Kurokawa, S. Iwasa, HR Lijnen et D. Collen. « Thrombolytic and pharmacokinetic properties of an immunoconjugate of single-chain urokinase-type plasminogen activator (u-PA) and a bispecific monoclonal antibody against fibrin and against u-PA in baboons ». Blood 79, n^o 9 (1 mai 1992) : 2322–29. http://dx.doi.org/10.1182/blood.v79.9.2322.2322.

Texte intégral

Résumé :

Abstract Targeting of plasminogen activators to the fibrin component of a thrombus with the use of monoclonal antibodies (MA) directed against human fibrin may enhance their thrombolytic potency and fibrin- specificity. The thrombolytic and pharmacokinetic properties of rscu- PA/MA-FU1–74, an immunoconjugate of recombinant single-chain urokinase- type plasminogen activator (rscu-PA) and a bispecific MA directed against u-PA and against the beta-chain of human fibrin (MA-FU1–74), were investigated in baboons with a [125I]fibrin-labeled autologous blood clot in the femoral vein. Continuous intravenous infusion of rscu- PA/MA-FU1–74 (1:1.2 molar ratio) over 2 hours showed a fivefold increased thrombolytic potency (lysis per unit dose) over that of unconjugated rscu-PA, as evidenced both by a higher maximal rate of lysis (380% +/- 68% v 78% +/- 25% lysis per mg u-PA equivalent of compound administered per kg body weight, P less than .001), and by a lower dose at which the maximal rate of lysis occurs (0.19 +/- 0.03 v 0.82 +/- 0.10 mg compound per kg body weight, P less than .001). The specific thrombolytic activity (percent lysis per unit steady-state plasma u-PA antigen level) was lower for rscu-PA/MA-FU1–74 than for rscu-PA, as shown by both a lower maximal rate of lysis (60% +/- 13% v 220% +/- 22% lysis per microgram/mL u-PA antigen level in plasma, P less than .001) and a higher plasma antigen level at which maximal lysis is achieved (1.2 +/- 0.17 v 0.20 +/- 0.01 microgram/mL, P less than .001). The thrombolytic potency of rscu-PA/MA-UK1–3, an immunoconjugate of rscu-PA with the parental anti-u-PA antibody was similar to that of unconjugated rscu-PA. Clot lysis was achieved without systemic fibrinogen or alpha 2-antiplasmin consumption, and with a minor transient prolongation of the bleeding time. After the end of the infusions, u-PA-related antigen disappeared from plasma in a biphasic manner, with an initial half-life of 3.3 +/- 0.4 minutes for rscu-PA, 13 +/- 1 minutes for rscu-PA/MA-FU1–74, and 13 +/- 1 minutes for rscu-PA/MA-UK1–3, with corresponding plasma clearances of 340 +/- 28, 10 +/- 1, and 37 +/- 4 mL/min, respectively (mean +/- SEM). rscu- PA/MA-FU1–74 has a fivefold higher thrombolytic potency than unconjugated rscu-PA, as a result both of fibrin targeting by the specific idiotype of the antibody and of a slower plasma clearance.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Imura, Y., JM Stassen, T. Kurokawa, S. Iwasa, HR Lijnen et D. Collen. « Thrombolytic and pharmacokinetic properties of an immunoconjugate of single-chain urokinase-type plasminogen activator (u-PA) and a bispecific monoclonal antibody against fibrin and against u-PA in baboons ». Blood 79, n^o 9 (1 mai 1992) : 2322–29. http://dx.doi.org/10.1182/blood.v79.9.2322.bloodjournal7992322.

Texte intégral

Résumé :

Targeting of plasminogen activators to the fibrin component of a thrombus with the use of monoclonal antibodies (MA) directed against human fibrin may enhance their thrombolytic potency and fibrin- specificity. The thrombolytic and pharmacokinetic properties of rscu- PA/MA-FU1–74, an immunoconjugate of recombinant single-chain urokinase- type plasminogen activator (rscu-PA) and a bispecific MA directed against u-PA and against the beta-chain of human fibrin (MA-FU1–74), were investigated in baboons with a [125I]fibrin-labeled autologous blood clot in the femoral vein. Continuous intravenous infusion of rscu- PA/MA-FU1–74 (1:1.2 molar ratio) over 2 hours showed a fivefold increased thrombolytic potency (lysis per unit dose) over that of unconjugated rscu-PA, as evidenced both by a higher maximal rate of lysis (380% +/- 68% v 78% +/- 25% lysis per mg u-PA equivalent of compound administered per kg body weight, P less than .001), and by a lower dose at which the maximal rate of lysis occurs (0.19 +/- 0.03 v 0.82 +/- 0.10 mg compound per kg body weight, P less than .001). The specific thrombolytic activity (percent lysis per unit steady-state plasma u-PA antigen level) was lower for rscu-PA/MA-FU1–74 than for rscu-PA, as shown by both a lower maximal rate of lysis (60% +/- 13% v 220% +/- 22% lysis per microgram/mL u-PA antigen level in plasma, P less than .001) and a higher plasma antigen level at which maximal lysis is achieved (1.2 +/- 0.17 v 0.20 +/- 0.01 microgram/mL, P less than .001). The thrombolytic potency of rscu-PA/MA-UK1–3, an immunoconjugate of rscu-PA with the parental anti-u-PA antibody was similar to that of unconjugated rscu-PA. Clot lysis was achieved without systemic fibrinogen or alpha 2-antiplasmin consumption, and with a minor transient prolongation of the bleeding time. After the end of the infusions, u-PA-related antigen disappeared from plasma in a biphasic manner, with an initial half-life of 3.3 +/- 0.4 minutes for rscu-PA, 13 +/- 1 minutes for rscu-PA/MA-FU1–74, and 13 +/- 1 minutes for rscu-PA/MA-UK1–3, with corresponding plasma clearances of 340 +/- 28, 10 +/- 1, and 37 +/- 4 mL/min, respectively (mean +/- SEM). rscu- PA/MA-FU1–74 has a fivefold higher thrombolytic potency than unconjugated rscu-PA, as a result both of fibrin targeting by the specific idiotype of the antibody and of a slower plasma clearance.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Hurst, D. F., E. G. Hall, A. F. Jordan, L. M. Miloshevich, D. N. Whiteman, T. Leblanc, D. Walsh, H. Vömel et S. J. Oltmans. « Comparisons of temperature, pressure and humidity measurements by balloon-borne radiosondes and frost point hygrometers during MOHAVE 2009 ». Atmospheric Measurement Techniques Discussions 4, n^o 4 (11 juillet 2011) : 4357–401. http://dx.doi.org/10.5194/amtd-4-4357-2011.

Texte intégral

Résumé :

Abstract. We compare coincident, balloon-borne, in situ measurements of temperature and pressure by two radiosondes (Vaisala RS92, Intermet iMet-1-RSB) and measurements of relative humidity (RH) by Vaisala RS92 sondes and frost point hygrometers. Data from a total of 28 balloon flights with mixed payloads are analyzed in 1-km altitude bins to quantify measurement biases between sensors and how they vary with altitude. The disparities between sensors determined here are compared to measurement uncertainties quoted by the two radiosonde manufacturers. Our comparisons expose several flight profiles with anomalously large measurement differences. Excluding these anomalous profiles, 33 % of RS92-iMet median temperature differences exceed the uncertainty limits calculated from manufacturer-quoted uncertainties. A statistically significant, altitude-independent bias of about 0.5 ± 0.2 °C is revealed for the RS92-iMet temperature differences. Similarly, 23 % of RS92-iMet median pressure differences exceed the quoted uncertainty limits, with 83 % of these excessive differences above 16 km altitude. The pressure differences are altitude dependent, increasing from −0.6 ± 0.9 hPa at the surface to 0.7 ± 0.1 hPa above 15 km. Temperature and pressure differences between redundant RS92 sondes on the same balloon exceed manufacturer-quoted reproducibility limits 20 % and 2 % of the time, respectively, with most of the excessive differences belonging to anomalous difference profiles. Relative humidity measurements by RS92 sondes are compared to other RS92 sondes and to RH values calculated using frost point hygrometer measurements and coincident radiosonde temperature measurements. For some flights the RH differences are anomalously large, but in general are within the ±5 % RH measurement uncertainty limits quoted for the RS92. The quantitative effects of RS92 and iMet pressure and temperature differences on frost point-based water vapor mixing ratios and RH values, respectively, are also presented.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Murniece, Sniedze, Martin Soehle, Indulis Vanags et Biruta Mamaja. « Regional Cerebral Oxygen Saturation Monitoring during Spinal Surgery in Order to Identify Patients at Risk for Cerebral Desaturation ». Applied Sciences 10, n^o 6 (19 mars 2020) : 2069. http://dx.doi.org/10.3390/app10062069.

Texte intégral

Résumé :

Background: Near infrared spectroscopy (NIRS) devices are non-invasive and monitor cerebral oxygen saturation (rScO2) continuously. NIRS interventional protocol is available in order to avoid hypoxic brain injury. Methods: We recruited patients scheduled for spinal surgery (n = 44). rScO2 was monitored throughout the surgery using INVOS 4100 cerebral oximeter. If the rScO2 values dropped more than 20% below baseline, or there was an absolute drop to below 50%, NIRS interventional protocol was followed. Results: In two patients rScO2 decreased by more than 20% from baseline values. In one patient rScO2 decreased to below 50%. NIRS protocol was initiated. As the first step, correct head position was verified–in one patient rScO2 increased above the threshold value. In the two remaining patients, mean arterial pressure was raised by injecting Ephedrin boluses as the next step. rScO2 raised above threshold. Patients with desaturation episodes had longer medium time of the operation (114 ± 35 versus 200 ± 98 min, p = 0.01). Pearson’s correlation showed a negative correlation between rScO2 and duration of operation (r = −0.9, p = 0.2). Receiver operating characteristic curve analysis showed blood loss to be a strong predictor for possible cerebral desaturation (Area under the curve (AUC): 0.947, 95%CI: 0.836–1.000, p = 0.04). Conclusion: Patients with higher blood loss might experience cerebral desaturation more often than spinal surgery patients without significant blood loss.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Curtis, James A., Zeina N. Seikaly et Michelle S. Troche. « Respiratory–Swallow Coordination Training Improves Swallowing Safety and Efficiency in a Person With Anoxic Brain Injury ». American Journal of Speech-Language Pathology 29, n^o 4 (12 novembre 2020) : 1965–75. http://dx.doi.org/10.1044/2020_ajslp-20-00095.

Texte intégral

Résumé :

Purpose The aim of this study was to assess the effects of respiratory–swallow coordination training (RSCT) on respiratory–swallow coordination (RSC), swallowing safety (penetration/aspiration), and swallowing efficiency (pharyngeal residue) in a person with anoxic brain injury. Method A 68-year-old man with anoxic brain injury, tachypnea, and severe dysphagia was recruited to participate in a prospective AABAA single-subject experimental design. RSC, swallowing safety, and swallowing efficiency were measured at each assessment using respiratory inductive plethysmography and flexible endoscopic evaluations of swallowing. Data were analyzed descriptively using Cohen's d effect size. Outcome measures were compared pre-RSCT to post-RSCT, and pre-RSCT to a 1-month retention assessment. Results Improvements in RSC were observed immediately post-RSCT ( d = 0.60). These improvements were maintained upon retention assessment 1 month later ( d = 0.60). Additionally, improvements in swallowing safety ( d = 1.73), efficiency ( d = 1.73), and overall dysphagia severity ( d = 1.73) were observed immediately post-RSCT and were maintained upon retention assessment 1 month later ( d = 1.73). Conclusions Clinically meaningful improvements in RSC were observed following four sessions of RSCT, which were subsequently associated with large improvements in swallowing safety and efficiency. RSCT may be an efficacious, clinically feasible skill-based exercise for people with anoxic brain injury, suboptimal RSC, and dysphagia. Future work is needed to expand these findings in a larger cohort of people with dysphagia.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Keum, Jong-Soo, et Woon Jae Jang. « An Analysis of Technical Efficiency in the Korean RCC/RSC ». Journal of Korean navigation and port research 29, n^o 3 (1 avril 2005) : 215–20. http://dx.doi.org/10.5394/kinpr.2005.29.3.215.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

39

Geszvain, Kati, et Karen L. Visick. « The Hybrid Sensor Kinase RscS Integrates Positive and Negative Signals To Modulate Biofilm Formation in Vibrio fischeri ». Journal of Bacteriology 190, n^o 13 (25 avril 2008) : 4437–46. http://dx.doi.org/10.1128/jb.00055-08.

Texte intégral

Résumé :

ABSTRACT Overexpression of the Vibrio fischeri sensor kinase RscS induces expression of the syp (symbiosis polysaccharide) gene cluster and promotes biofilm phenotypes such as wrinkled colony morphology, pellicle formation, and surface adherence. RscS is predicted to be a hybrid sensor kinase with a histidine kinase/ATPase (HATPase) domain, a receiver (Rec) domain, and a histidine phosphotransferase (Hpt) domain. Bioinformatic analysis also revealed the following three potential signal detection domains within RscS: two transmembrane helices forming a transmembrane region (TMR), a large periplasmic (PP) domain, and a cytoplasmic PAS domain. In this work, we genetically dissected the contributions of these domains to RscS function. Substitutions within the carboxy-terminal domain supported identification of RscS as a hybrid sensor kinase; disruption of both the HATPase and Rec domains eliminated induction of syp transcription, wrinkled colony morphology, pellicle formation, and surface adherence, while disruption of Hpt resulted in decreased activity. The PAS domain was also critical for RscS activity; substitutions in PAS resulted in a loss of activity. Generation of a cytoplasmic, N-terminal deletion derivative of RscS resulted in a partial loss of activity, suggesting a role for localization to the membrane and/or sequences within the TMR and PP domain. Finally, substitutions within the first transmembrane helix of the TMR and deletions within the PP domain both resulted in increased activity. Thus, RscS integrates both inhibitory and stimulatory signals from the environment to regulate biofilm formation by V. fischeri.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Ma, Zhaopeng, Zhangxi Hu, Yunyan Deng, Lixia Shang, Christophere J. Gobler et Ying Zhong Tang. « Laboratory Culture-Based Characterization of the Resting Stage Cells of the Brown-Tide-Causing Pelagophyte, Aureococcus anophagefferens ». Journal of Marine Science and Engineering 8, n^o 12 (16 décembre 2020) : 1027. http://dx.doi.org/10.3390/jmse8121027.

Texte intégral

Résumé :

Life history (life cycle) plays a vital role in the ecology of some microalgae; however, the well-known brown-tide-causing pelagophyte Aureococcus anophagefferens has been barely investigated in this regard. Recently, based mainly on detections in marine sediments from China, we proved that this organism has a resting stage. We, therefore, conducted a follow-up study to characterize the resting stage cells (RSCs) of A. anophagefferens using the culture CCMP1984. The RSCs were spherical, larger than the vegetative cells, and smooth in cell surface and contained more aggregated plastid but more vacuolar space than vegetative cells. RSCs contained a conspicuous lipid-enriched red droplet. We found a 9.9-fold decrease in adenosine triphosphate (ATP) content from vegetative cells to RSCs, indicative of a "resting" or dormant physiological state. The RSCs stored for 3 months (at 4 °C in darkness) readily reverted back to vegetative growth within 20 days after being transferred to the conditions for routine culture maintenance. Our results indicate that the RSCs of A. anophagefferens are a dormant state that differs from vegetative cells morphologically and physiologically, and that RSCs likely enable the species to survive unfavorable conditions, seed annual blooms, and facilitate its cosmopolitan distribution that we recently documented.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Yan, Juntao, Jinhong Liu, Ya Sun, Guangsen Song, Deng Ding, Guozhi Fan, Bo Chai, Chunlei Wang et Linbing Sun. « Investigation on the Preparation of Rice Straw-Derived Cellulose Acetate and Its Spinnability for Electrospinning ». Polymers 13, n^o 20 (9 octobre 2021) : 3463. http://dx.doi.org/10.3390/polym13203463.

Texte intégral

Résumé :

Rice straw-derived cellulose (RSC) with purity of 92 wt.% was successfully extracted from rice straw by a novel and facile strategy, which integrated the C2H5OH/H2O autocatalytic process, dilute alkali treatment and H2O2 bleaching process. Influencing factors of the cellulose extraction were systematically examined, such as ethanol concentration, alkali concentration, H2O2 bleaching process and so on; the optimal extraction conditions of cellulose was determined. A series of rice straw-derived cellulose acetate (RSCA) with different degree of substitution (DS) were prepared by the acetylation reaction; the effects of Ac2O/cellulose ratio, reaction temperature and reaction time on the acetylation reaction were investigated. Results of FTIR and XRD analysis demonstrated that highly purified RSC and RSCA were prepared comparing with the commercial cellulose and cellulose acetate. Solubility analysis of RSCA with different DS indicated as-prepared RSCA with DS of 2.82 possessed the best solubleness, which was suitable for electrospinning. Moreover, the flexible RSCA fibrous membrane was easily fabricated by a facile electrospinning method. Our proposed method provided a strategy for realizing the high-value utilization of waste rice straw resource, as prepared RSC and RSCA can be used as chemical raw material, and electrospun RSCA fibrous membrane has various applications in medical materials, food packaging, water purification and so on.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Soutourina, Julie, Véronique Bordas-Le Floch, Gabrielle Gendrel, Amando Flores, Cécile Ducrot, Hélène Dumay-Odelot, Pascal Soularue et al. « Rsc4 Connects the Chromatin Remodeler RSC to RNA Polymerases ». Molecular and Cellular Biology 26, n^o 13 (1 juillet 2006) : 4920–33. http://dx.doi.org/10.1128/mcb.00415-06.

Texte intégral

Résumé :

ABSTRACT RSC is an essential, multisubunit chromatin remodeling complex. We show here that the Rsc4 subunit of RSC interacted via its C terminus with Rpb5, a conserved subunit shared by all three nuclear RNA polymerases (Pol). Furthermore, the RSC complex coimmunoprecipitated with all three RNA polymerases. Mutations in the C terminus of Rsc4 conferred a thermosensitive phenotype and the loss of interaction with Rpb5. Certain thermosensitive rpb5 mutations were lethal in combination with an rsc4 mutation, supporting the physiological significance of the interaction. Pol II transcription of ca. 12% of the yeast genome was increased or decreased twofold or more in a rsc4 C-terminal mutant. The transcription of the Pol III-transcribed genes SNR6 and RPR1 was also reduced, in agreement with the observed localization of RSC near many class III genes. Rsc4 C-terminal mutations did not alter the stability or assembly of the RSC complex, suggesting an impact on Rsc4 function. Strikingly, a C-terminal mutation of Rsc4 did not impair RSC recruitment to the RSC-responsive genes DUT1 and SMX3 but rather changed the chromatin accessibility of DNases to their promoter regions, suggesting that the altered transcription of DUT1 and SMX3 was the consequence of altered chromatin remodeling.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Declerck, P. J., H. R. Lijnen, M. Verstreken et D. Collen. « Role of α2-Antiplasmin in Fibrin-Specific Clot Lysis with Single-Chain Urokinase-Type Plasminogen Activator in Human Plasma ». Thrombosis and Haemostasis 65, n^o 04 (1991) : 394–98. http://dx.doi.org/10.1055/s-0038-1648159.

Texte intégral

Résumé :

SummaryThe role of plasma α2-antiplasmin (α2-AP) in the fibrinspecificity of clot lysis by recombinant single-chain urokinase-type plasminogen activator (rscu-PA) and in the conversion of rscu-PA to its two-chain derivative (rtcu-PA, urokinase) was investigated in an in vitro human plasma clot lysis system. Fifty % lysis in 2 h of a 0.1 ml 125l-fibrin labeled human plasma clot immersed in 0.5 ml normal human plasma was obtained with 1.4 ± 0.15 µg/ml rscu-PA (mean ± SD, n = 8). This was associated with degradation of 23 ± 7% of fibrinogen and generation of 0.20 ± 0.09 µg/ml rtcu-PA. In α2-AP-depleted plasrna 50% clot lysis in 2 h required 2-fold less rscu-PA which was associated with 3-fold more extensive fibrinogen degradation and 2-fold more rtcu-PA generation. Fifty % lysis in? h, of a 0.1 ml α2-AP-depleted plasma clot, subriersed in 0.5 ml normal plasma, was obtained with 0.80 ± 0.05 µg/ml rscu-PA (n = 3, p <0.001 vs normal clot) and was associated with 17 ± 6% fibrinogen breakdown (p : 0.22 vs normal clot) and 0.08 ± 0.02 µg/ml rtcu-PA generation (p < 0.05 vs normal clot). In α2-AP-depleted plasma the equipotent rscu-PA concentration was 4-fold lower than in normal plasma and was associated with 3-fold more fibrinogen degradation and a similar extent of rtcu-PA generationThus, α2-AP in plasma contributes significantly to the fibrinspecificity of rscu-PA, primarily via prevention of conversion in plasma of rscu-PA to rtcu-PA. Clot associated α2-AP increases the resistance of the clot to lysis with rscu-PA, but plays an only minor role in the fibrin-specificity of clot lysis in normal plasma.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Deng, Meie, Anlu Zhang, Wei Luo, Canwei Hu, Meng Huang et Congxi Cheng. « Impact of Governance Structure of Rural Collective Economic Organizations on Trading Efficiency of Collective Construction Land of China ». Land 12, n^o 2 (31 janvier 2023) : 381. http://dx.doi.org/10.3390/land12020381.

Texte intégral

Résumé :

In order to enable urban economic development, the use of the right value and asset value of rural collective construction land (RCCL) is increasingly becoming apparent and this market is experiencing rapid development. However, the arrangement of the governance structure of rural shareholding cooperatives (RSCs) can seriously affect the efficiency of collective construction land market transactions, since the governance of RSCs is related to the interests of farmers. Protecting the rights and interests of farmers while improving the governance efficiency of RSCs is a considerable challenge worldwide. To better deal with this challenge, this study used a field survey in Nanhai District, Guangdong Province, China, to estimate how the governance structure of RSCs affect the efficiency of RCCL market transactions. Tobit models were constructed, and the results show that (1) most of the governance functions of RSCs were not separate from the administrative management of the village committees, which leads to low efficiency of RSCs’ governance; (2) leaders of rural collective economic organizations played a key role in governance efficiency; (3) from the perspective of collective land property rights, most village shareholders did not have decision-making power or supervisory authority in the RCCL transfers because they could not complete access to transaction information. Furthermore, most villagers felt that the amount of income distributed was unreasonable, and the rights and interests of farmers and village shareholders were not guaranteed by the RSCs. Therefore, we suggest that the Chinese authorities should strengthen their current efforts to construct a more open and fair governance structure of the RSCs and thus improve their market transaction efficiency. Our work provides some insights into ways to improve the governance structure and market transaction efficiency of RSCs, which can further contribute to the development of the RCCL market in other areas of China and worldwide.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Kurokawa, Tomofumi, Susumu Iwasa, Atsushi Kakinuma, Jean-Marie Stassen, H. Roger Lijnen et Desire Collen. « Enhancement of Clot Lysis In Vitro and In Vivo with a Bispecific Monoclonal Antibody Directed against Human Fibrin and against Urokinase-Type Plasminogen Activator ». Thrombosis and Haemostasis 66, n^o 06 (1991) : 684–93. http://dx.doi.org/10.1055/s-0038-1646486.

Texte intégral

Résumé :

SummaryA hybrid hybridoma (FU1-74), secreting a bispecific monoclonal antibody (bs mAb), was obtained by fusion of a murine hybridoma secreting a monoclonal antibody (mAb) specific for human fibrin with a murine hybridoma secreting a mAb against urokinase-type plasminogen activator (u-PA). The bs mAb (MA-FU1-74), purified to homogeneity from mouse ascitic fluid, migrated as a single band with apparent M r 150,000 on non-reduced SDS-PAGE and had an affinity for both human fibrin (K a = 2 × 107 M–1) and for u-PA (K a = 108 M–1) comparable to that of the mAbs obtained from the respective parental hybridomas. MA-FU1-74 did not influence the enzymatic activity of two-chain u-PA (tcu-PA) towards plasminogen or towards a chromogenic substrate. The complex of MA-FU1-74 with recombinant single chain u-PA (rscu-PA) or with tcu-PA (urokinase) enhanced the fibrinolytic potency of the plasminogen activator towards clotted human plasma 20-fold and 5-fold, respectively.In a hamster pulmonary embolism model, the rscu-PA/MA-FU1-74 complex had a 13- to 17-fold increased thrombolytic potency (percent lysis per mg/kg u-PA administered) relative to that of rscu-PA. The specific thrombolytic activity (percent lysis per εg/ml steady state plasma level of u-PA antigen) of the complex was, however, not significantly different from that of rscu-PA. The complex of rscu-PA with the parental anti-u-PA mAb (MA-UK1-3) had only a 2-fold enhanced thrombolytic potency relative to that of rscu-PA and had a 5-fold decreased specific thrombolytic activity. The plasma clearance rates of the complexes of rscu-PA with both MA-FU1-74 and MA-UK1-3 were about 10-fold lower than that of rscu-PA. In a rabbit jugular vein thrombosis model, the rscu-PA/MA-FU1-74 complex had a 4-fold enhanced thrombolytic potency, an unchanged specific thrombolytic activity and 20-fold reduced plasma clearance. In both animal models, the rscu-PA/MA-FUl-74 complex did not cause more extensive systemic activation of the fibrinolytic system than rscu-PA.It is concluded that the bispecific anti-fibrin/anti-u-PA mAb MA-FU1-74 targets u-PA to the fibrin clot, resulting in a significantly enhanced thrombolytic potency of the plasminogen activator.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Prodduturvar, Pranitha, Ben McCormick, Wadad Mneimneh, Valeria Dal Zotto, Leander Grimm, Paul Rider, John Hunter et al. « Exosomal markers (CD63 and CD9) expression using immunohistochemistry (IHC) in patients with right-sided and left-sided colon cancer. » Journal of Clinical Oncology 37, n^o 15_suppl (20 mai 2019) : e15119-e15119. http://dx.doi.org/10.1200/jco.2019.37.15_suppl.e15119.

Texte intégral

Résumé :

e15119 Background: Embryologically, the right colon (cecum, ascending colon, hepatic flexure and proximal two-thirds of the transverse colon) is derived from the midgut, whereas the left colon (sigmoid colon, descending colon, splenic flexure and distal third of the transverse colon) is derived from the hindgut. There are clinical, pathological and molecular differences between patients with right-sided colon cancer (RSCC) and left-sided colon cancer (LSCC). Exosomes mediate intercellular communications and interactions and have pivotal roles in cancer behavior. CD63 and CD9 are widely accepted exosomal markers. Here we explored CD63 and CD9 expression using immunohistochemistry (IHC) in patients with RSCC and LSCC. Methods: Between 2015 and 2018, 63 patients underwent colon surgical resection for whom we had available tissues for CD63 and CD9 IHC staining. Two pathologists independently scored CD63 and CD9 expression in the tumor and adjacent normal mucosa (ANM). Staining intensity was graded from 1-3. Staining percentage was estimated in 10% increments. Mean quick-score (Q-score) was calculated (intensity x percentage). Unpaired t test was used for statistical analysis. Results: Median age was 64 (range 33-78). Females represented 60% of our cohort. Caucasians, African Americans and other Ethnicities represented 55%, 40% and 5% respectively. The sidedness was designated as RSCC in 52% and as LSCC in 48%. The ANM and Tumor CD63 Q scores were 225 vs 191 (p = 0.009) in RSCC and 224 vs 154 (p = 0.0001) in LSCC respectively. The ANM and Tumor CD9 Q scores are 134 vs 152 (p = 0.142) in RSCC and 135 vs 154 (p = 0.137) in LSCC respectively. In patients with RSCC and LSCC, the mean Tumor CD63 Q score is 191 vs 154 (p = 0.024), while the mean ANM CD63 Q score is 225 vs 224 (p = 0.920). The mean Tumor CD9 Q score is 152 and 154 (p = 0.883) and the mean ANM CD9 Q score is 134 vs 135 (p = 0.926). Conclusions: In our cohort of patients with RSCC and LSCC, the exosomal marker CD63 expression is lower in the tumor compared to the ANM. While ANM CD63 expression was similar between RSCC and LSCC, tumor CD63 expression was higher in RSCC compared to LSCC. The exosomal marker CD9 was not found to have significant differential expression between ANM and tumor and between RSCC and LSCC. To our knowledge, this is the first study to explore exosomal markers expression using IHC in patients with RSCC and LSCC.

Styles APA, Harvard, Vancouver, ISO, etc.

47

McCormick, Ben, Pranitha Prodduturvar, Wadad Mneimneh, Valeria Dal Zotto, Leander Grimm, Paul Rider, John Hunter et al. « Exosomal markers (CD63 and CD9) expression and their prognostic significance using immunohistochemistry in right-sided and left-sided colon cancer. » Journal of Clinical Oncology 38, n^o 4_suppl (1 février 2020) : 182. http://dx.doi.org/10.1200/jco.2020.38.4_suppl.182.

Texte intégral

Résumé :

182 Background: Exosomes play pivotal roles in cancer progression, metastasis and chemoresistance. CD63 and CD9 are widely accepted exosomal markers. Their pattern of expression and prognostic significance in patients with RSCC and LSCC is unknown. This study explored CD63 and CD9 expression and prognostic significance in patients with RSCC and LSCC using immunohistochemistry (IHC). Methods: Between 2015 and 2018, 63 patients underwent surgical resection of colon cancer for whom we had available tissues for CD63 and CD9 IHC staining. Two pathologists independently scored the CD63 and CD9 expression in the tumor and adjacent normal mucosa (ANM). Staining intensity was graded 1-3 and staining percentage was estimated in 10% increments. Mean Quick-score (Q-score) (intensity X percentage of staining) was calculated. Results: RSCC and LSCC represented 52% and 48% of the patients respectively. The ANM and Tumor CD63 Q-scores were 225 vs 191 (p = 0.009) in RSCC and 224 vs 154 (p = 0.0001) in LSCC, respectively. The ANM and Tumor CD9 Q-scores were 134 vs 152 (p = 0.142) in RSCC and 135 vs 154 (p = 0.137) in LSCC, respectively. In patients with RSCC and LSCC, the mean Tumor CD63 Q-score was 191 vs 154 (p = 0.024), while the mean ANM CD63 Q-score was 225 vs 224 (p = 0.920). The mean Tumor CD9 Q-score was 152 and 154 (p = 0.883), and the mean ANM CD9 Q-score was 134 vs 135 (p = 0.926). In our cohort, there was no difference in progression free survival (PFS) between patients with RSCC and LSCC (p = 0.2349). In all patients, there was no difference in PFS in patients with CD63 expression < 100 and ≥100 (p = 0.8284). Among patients with RSCC, there was a significantly lower PFS in patients with CD63 expression < 100 vs. ≥100 (p = 0.0259). However, among patients with LSCC, there was no difference in PFS in patients with CD63 expression < 100 vs. ≥100 (p = 0.3494). Conclusions: To our knowledge, this is the first study to show a difference in exosomal marker (CD63) expression pattern and its prognostic significance in patients with RSCC and LSCC. There was a significant positive correlation between progression free survival in patients with RSCC and higher exosomal expression.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Lu, HR, HR Lijnen, JM Stassen et D. Collen. « Comparative thrombolytic properties of bolus injections and continuous infusions of a chimeric (t-PA/u-PA) plasminogen activator in a hamster pulmonary embolism model ». Blood 78, n^o 1 (1 juillet 1991) : 125–31. http://dx.doi.org/10.1182/blood.v78.1.125.bloodjournal781125.

Texte intégral

Résumé :

The recombinant chimeric plasminogen activator, rt-PA-delta FE/scu-PA- e, consisting of amino acids 1 to 3 and 87 to 274 of tissue-type plasminogen activator (t-PA) and amino acids 138 to 411 of single-chain urokinase-type plasminogen activator (scu-PA), has a markedly increased thrombolytic potency following its continuous intravenous infusion in animal models of venous thrombosis (Collen et al, Circulation, in press). In the present study, the thrombolytic potencies of intravenous bolus injections of rt-PA-delta FE/scu-PA-e, of recombinant t-PA (rt- PA), and of recombinant scu-PA (rscu-PA), given alone or in combination, were compared with those of intravenous infusions in a hamster pulmonary embolism model. Dose-dependent clot lysis was obtained in the absence of systemic activation of the fibrinolytic system and fibrinogen breakdown. In bolus injection experiments, the maximal rate of clot lysis, expressed in percent clot lysis per milligrams per kilogram compound administered, was 120 +/- 10 for rt- PA, 54 +/- 8 for rscu-PA, and 2,100 +/- 500 for rt-PA-delta FE/scu-PA-e (P less than .01 v rt-PA or rscu-PA). Comparative results with continuous infusion over 1 hour were 270 +/- 64, 99 +/- 18, and 1,500 +/- 250 (P less than .01 v rt-PA or rscu-PA) percent lysis per mg/kg compound infused for rt-PA, rscu-PA, and rt-PA-delta FE/scu-PA-e, respectively. Thus, rt-PA and rscu-PA are more potent when administered as an infusion than as a bolus, whereas rt-PA-delta FE/scu-PA-e is at least as potent when administered as a bolus. Combined bolus injections of rt-PA and rscu-PA had a 2.2-fold synergistic effect on clot lysis, but no synergism was observed with combined bolus injections or with combined infusions of rt-PA and rt-PA-delta FE/scu-PA-e, or of rscu-PA and rt-PA-delta FE/scu-PA-e. The present study thus shows that rt-PA- delta FE/scu-PA-e is much more potent for clot lysis than rt-PA or rscu- PA when administered as a bolus injection, but no synergistic interaction is observed between the chimera and either rt-PA or rscu-PA.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Kirshenbaum, A. S., J. P. Goff, S. W. Kessler, J. M. Mican, K. M. Zsebo et D. D. Metcalfe. « Effect of IL-3 and stem cell factor on the appearance of human basophils and mast cells from CD34+ pluripotent progenitor cells. » Journal of Immunology 148, n^o 3 (1 février 1992) : 772–77. http://dx.doi.org/10.4049/jimmunol.148.3.772.

Texte intégral

Résumé :

Abstract Hemopoietic stem cell factor (SCF), which is the ligand for the proto-oncogene c-kit receptor (allelic with W locus) and the product of Sl locus of the mouse, has recently been cloned. The human homologue has also been cloned, and recombinant protein (human rSCF) expressed and purified to homogeneity. To determine the effect of human rSCF in the presence or absence of human rIL-3 on human bone marrow-derived mast cells and basophils, human CD34+ pluripotent progenitor cells, highly enriched (greater than 99%) from bone marrow mononuclear cells, were cultured over agarose surfaces (interphase cultures) in the presence of human rIL-3, human rIL-3 and increasing concentrations of human rSCF, or human rSCF alone. Over 3 to 4 wk, human rSCF acted synergistically with human rIL-3 at all concentrations, producing a three- to fivefold increase in total, mast cell, and basophil numbers over human rIL-3 alone when used at 100 ng/ml. The percentage of cell types in the human rIL-3 and human rIL-3 plus human rSCF cultures, however, remained the same, with basophils constituting 18 to 35% of the final cultured cells, and mast cells 3% or less of the final cell number. In the presence of human rSCF alone, the combined total percentage of mast cells and basophils was 0 to 1.0%, the majority of cells being macrophages. Mast cells cultured in human rIL-3 plus human rSCF, but not human rIL-3 alone, were berberine sulfate positive, suggesting the presence of heparin proteoglycans within granules. Electron microscopic examination of cultures supplemented with human rIL-3 and rSCF, but not human rIL-3 alone, revealed that after 3 wk in culture, mast cell granules contained tryptase and exhibited scroll, reticular, and homogeneous patterns as seen previously in CD34+/3T3 fibroblast cocultures. Thus, CD34+ cells cultured in the presence of both human rIL-3 and rSCF give rise to cultures containing increased numbers of basophils and mast cells, with the mast cells by ultrastructural studies showing evidence of maturation although the percentages of basophils and mast cells arising in these cultures remained unchanged.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Li, Na, Jin Long Yin, Cui Li, Da Gang Wang, Yong Qing Yang, A. Karthikeyan, He Xiang Luan et Hai Jian Zhi. « NB-LRR gene family required for Rsc4-mediated resistance to Soybean mosaic virus ». Crop and Pasture Science 67, n^o 5 (2016) : 541. http://dx.doi.org/10.1071/cp15165.

Texte intégral

Résumé :

Soybean mosaic virus (SMV) causes one of the most destructive viral diseases in soybean (Glycine max). The soybean cultivar Dabaima carries the Rsc4 gene for SMV resistance. The genomic region containing Rsc4 was previously localised within a 100-kb region on chromosome 14. The corresponding region contains three complete nucleotide-binding site (NB) and leucine-rich repeat (LRR) type genes and one incomplete gene that is likely non-functional. Quantitative real-time polymerase chain reaction analysis revealed that three candidate genes encoding NB-LRR proteins were differentially expressed in resistant and susceptible lines when the plants were inoculated with SMV strain SC4. To test the involvement of the three candidate genes in Rsc4 mediated resistance, the three genes were silenced using a Bean pod mottle virus (BPMV)-based vector construct. Silencing of three candidate genes attenuated the Rsc4-mediated resistance and induced SMV symptoms in Dabaima plants. Moreover, Rsc4 candidate genes were 78% downregulated when compared with the empty BPMV vector-treated plants. From these results, we concluded that at least one of the three candidate genes encoding NB-LRR proteins is required for Rsc4 resistance to SMV.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Rsc2 »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres