Artykuły w czasopismach: „CLFR”

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Zakeri-Milani, Parvin, Zohreh Fasihi, Jafar Akbari, Ensieh Jannatabadi, Mohammad Barzegar-Jalali, Raimar Loebenberg i Hadi Valizadeh. "Crystal-liquid Fugacity Ratio as a Surrogate Parameter for Intestinal Permeability". Journal of Pharmacy & Pharmaceutical Sciences 19, nr 3 (18.08.2016): 312. http://dx.doi.org/10.18433/j3ks4p.

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Background: We assessed the feasibility of using crystal-liquid fugacity ratio (CLFR) as an alternative parameter for intestinal permeability in the biopharmaceutical classification (BCS) of passively absorbed drugs. Methods: Dose number, fraction of dose absorbed, intestinal permeability, and intrinsic dissolution rate were used as the input parameters. CLFR was determined using thermodynamic parameters i.e., melting point, molar fusion enthalpy, and entropy of drug molecules obtained using differential scanning calorimetry. Results: The CLFR values were in the range of 0.06-41.76 mole percent. There was a close relationship between CLFR and in vivo intestinal permeability (r > 0.8). CLFR values of greater than 2 mole percent corresponded to complete intestinal absorption. Applying CLFR versus dose number or intrinsic dissolution rate, more than 92% of tested drugs were correctly classified with respect to the reported classification system on the basis of human intestinal permeability and solubility. Conclusion: This investigation revealed that the CLFR might be an appropriate parameter for quantitative biopharmaceutical classification. This could be attributed to the fact that CLFR could be a measure of solubility of compounds in lipid bilayer which was found in this study to be directly proportional to the intestinal permeability of compounds. This classification enables researchers to define characteristics for intestinal absorption of all four BCS drug classes using suitable cutoff points for both intrinsic dissolution rate and crystal-liquid fugacity ratio. Therefore, it may be used as a surrogate for permeability studies. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

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Ezzat, Shahira M., i Amira Abdel Motaal. "Isolation of New Cytotoxic Metabolites from Cleome droserifolia Growing in Egypt". Zeitschrift für Naturforschung C 67, nr 5-6 (1.06.2012): 266–74. http://dx.doi.org/10.1515/znc-2012-5-605.

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The sulforhodamine B (SRB) assay was used to assess the cytotoxicity of the aqueous (AqEx) and ethanolic (AlEx) extracts, respectively, of the aerial parts of Cleome droserifolia (Forssk.) Del. against two human cancer cell lines, breast (MCF7) and colon (HCT116) adenocarcinoma. AqEx exhibited higher cytotoxic activity, thus its four subfractions, namely n-hexane (HxFr), chloroform (ClFr), ethyl acetate (EtFr), and n-butanol (BuFr) fractions, were also tested. Purifi cation of the more active ClFr and EtFr yielded nine compounds. Six terpenoids, guai-7(11),8-diene (C1), 1-hydroxy-guai-3,10(14)-diene (C2), 18-hydroxydollabela- 8(17)-ene (C3), (24E)-stigmasta-5,8-dien-3β-ol (C4), teucladiol [1α,5β-guai-10(14)- ene-4β,6β-diol] (C5), and buchariol (4,10-epoxy-6α-hydroxyguaiane) (C6), were isolated from ClFr and three fl avonol glycosides, isorhamnetin-3-O-β-D-glucoside (F1), quercetin- 3`-methoxy-3-O-(4``-acetylrhamnoside)-7-O-α-rhamnoside (F2), and kaempferol-4`-methoxy- 3,7-O-dirhamnoside (F3), were isolated from EtFr. Compounds C3 and F2 are new in nature. The isolated compounds were identifi ed using various spectroscopic methods (UV, IR, 1H NMR,13C NMR, HMQC, HMBC, and COSY). Compounds C1, C3, F2, and F3 showed significant cytotoxic activities against the two tested cell lines comparable to those of the anticancer drug doxorubicin®. The new compound C3 was the most active as it had the lowest IC50 values, (1.9 ± 0.08) and (1.6 ± 0.09) μg/ml corresponding to 6.5 and 5.4 μM, against MCF7 and HCT116 cells, respectively

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Jasien, Paul G. "Stabilities of hypervalent chlorine fluorides (ClF3, ClF5 and ClF7)". Chemical Physics Letters 188, nr 1-2 (styczeń 1992): 135–39. http://dx.doi.org/10.1016/0009-2614(92)85102-g.

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Wang, Gang, Fan Shen, Fasi Wang i Zeshao Chen. "Design and experimental study of a solar CPV system using CLFR concentrator". Sustainable Energy Technologies and Assessments 40 (sierpień 2020): 100751. http://dx.doi.org/10.1016/j.seta.2020.100751.

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Duggal, Rohit, i RavindraJilte. "Numerical analysis of synthetic fluids in three-dimensional trapezoidal cavity used for CLFR plant". Materials Today: Proceedings 16 (2019): 413–20. http://dx.doi.org/10.1016/j.matpr.2019.05.109.

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Serag-Eldin, M. A. "Thermal design of a roof-mounted CLFR collection system for a desert absorption chiller". International Journal of Sustainable Energy 33, nr 3 (8.02.2013): 506–24. http://dx.doi.org/10.1080/14786451.2012.761998.

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Kim, Hyung Don, Ji Yeon Lee, Jeong-Yong Park, Dong Hwi Kim, Min Hye Kang, Hyun-A. Seong, Kyung Hye Seo i Yun-Jeong Ji. "Neuroprotective Effects of Coreopsis lanceolata Flower Extract against Oxidative Stress-Induced Apoptosis in Neuronal Cells and Mice". Antioxidants 10, nr 6 (12.06.2021): 951. http://dx.doi.org/10.3390/antiox10060951.

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(1) Background: Coreopsis lanceolata L. is a perennial plant of the family Asteraceae, and its flower is known to contain flavonoids with various bioactivities. We evaluated the effect of Coreopsis lanceolata L. flower (CLF) extracts on H2O2-induced oxidative stress (OS) in neuronal cells and mouse neurons. (2) Methods: The flowering part of CL was used as CLF1 (70% ethanol extract) and CLF2 (water extract), and 10 types of phenolic compounds were quantified using high-performance liquid chromatography. To evaluate the neuroprotective effects of CLF, the antioxidant activities of the extracts were measured, and the expression levels of antioxidant enzymes and proteins related to OS-induced apoptosis in neuronal cells and mouse neurons treated with the extracts were investigated. (3) Results: In the in vitro study, CLF ameliorated H2O2-induced oxidative stress and induced the expression of antioxidant enzymes in PC12 cells. Furthermore, CLF1 enhanced the expression of the Bcl-xL protein but reduced the expression of Bax and the cleavage of caspase-3. In the same manner, CLF1 showed neuroprotective effects against OS in vivo. Pretreatment with CLF1 (200 mg/kg) increased the Bcl-2 protein and decreased Bax compared with the 1-methyl-4-phenylpyridinium ion (MPP+)-treated C57BL/6 mice model group. Our results suggest that the protective effects of CLF1 on MPP+-induced apoptosis may be due to its anti-apoptotic activity, through regulating the expression of the Bcl-2 family. (4) Conclusions: CLF1 exerts neuroprotective effects against OS-induced apoptosis in PC12 cells in a Parkinson’s disease model mouse. This effect may be attributable to the upregulation of Bcl-2 protein expression, downregulation of Bax expression, and inhibition of caspase-3 activation. These data indicate that CLF may provide therapeutic value for the treatment of progressive neurodegenerative diseases.

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Hoshi, Akira, David R. Mills, Antoine Bittar i Takeo S. Saitoh. "Screening of high melting point phase change materials (PCM) in solar thermal concentrating technology based on CLFR". Solar Energy 79, nr 3 (wrzesień 2005): 332–39. http://dx.doi.org/10.1016/j.solener.2004.04.023.

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Gomes, A. R., S. Vinga, M. Zavolan i H. de Lencastre. "Analysis of the Genetic Variability of Virulence-Related Loci in Epidemic Clones of Methicillin-Resistant Staphylococcus aureus". Antimicrobial Agents and Chemotherapy 49, nr 1 (styczeń 2005): 366–79. http://dx.doi.org/10.1128/aac.49.1.366-379.2005.

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ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) isolates have previously been classified into major epidemic clonal types by pulsed-field gel electrophoresis in combination with multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec typing. We aimed to investigate whether genetic variability in potentially polymorphic domains of virulence-related factors could provide another level of differentiation in a diverse collection of epidemic MRSA clones. The target regions of strains representative of epidemic clones and genetically related methicillin-susceptible S. aureus isolates from the 1960s that were sequenced included the R domains of clfA and clfB; the D, W, and M regions of fnbA and fnbB; and three regions in the agr operon. Sequence variation ranged from very conserved regions, such as those for RNAIII and the agr interpromoter region, to the highly polymorphic R regions of the clf genes. The sequences of the clf R domains could be grouped into six major sequence types on the basis of the sequences in their 3′ regions. Six sequence types were also observed for the fnb sequences at the amino acid level. From an evolutionary point of view, it was interesting that a small DNA stretch at the 3′ clf R-domain sequence and the fnb sequences agreed with the results of MLST for this set of strains. In particular, clfB R-domain sequences, which had a high discriminatory capacity and with which the types distinguished were congruent with those obtained by other molecular typing methods, have potential for use for the typing of S. aureus. Clone- and strain-specific sequence motifs in the clf and fnb genes may represent useful additions to a typing methodology with a DNA array.

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Bae, Sung Hun, Sun-Young Chang i So Hee Kim. "Slower Elimination of Tofacitinib in Acute Renal Failure Rat Models: Contribution of Hepatic Metabolism and Renal Excretion". Pharmaceutics 12, nr 8 (30.07.2020): 714. http://dx.doi.org/10.3390/pharmaceutics12080714.

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Tofacitinib is a Jak inhibitor developed as a treatment for rheumatoid arthritis. Tofacitinib is metabolized mainly through hepatic CYP3A1/2, followed by CYP2C11. Rheumatoid arthritis tends to increase renal toxicity due to drugs used for long-term treatment. In this study, pharmacokinetic changes of tofacitinib were evaluated in rats with gentamicin (G-ARF) and cisplatin-induced acute renal failure (C-ARF). The time-averaged total body clearance (CL) of tofacitinib in G-ARF and C-ARF rats after 1-min intravenous infusion of 10 mg/kg was significantly decreased by 37.7 and 62.3%, respectively, compared to in control rats. This seems to be because the time-averaged renal clearance (CLR) was significantly lower by 69.5 and 98.6%, respectively, due to decreased creatinine clearance (CLCR). In addition, the time-averaged nonrenal clearance (CLNR) was also significantly lower by 33.2 and 57.4%, respectively, due to reduction in the hepatic CYP3A1/2 and CYP2C11 subfamily in G-ARF and C-ARF rats. After oral administration of tofacitinib (20 mg/kg) to G-ARF and C-ARF rats, both CLR and CLNR were also significantly decreased. In conclusion, an increase in area under plasma concentration-time curves from time zero to time infinity (AUC) of tofacitinib in G-ARF and C-ARF rats was due to the significantly slower elimination of tofacitinib contributed by slower hepatic metabolism and urinary excretion of the drug.

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Bode, Christiaan César, i Thomas John Sheer. "A techno-economic feasibility study on the use of distributed concentrating solar power generation in Johannesburg". Journal of Energy in Southern Africa 21, nr 2 (1.05.2010): 2–11. http://dx.doi.org/10.17159/2413-3051/2010/v21i2a3249.

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The technical and financial feasibility of small-scale distributed Concentrating Solar Thermal Power (CSP) systems for urban areas in Johannesburg, South Africa, is investigated. The University of the Witwatersrand (Wits), located in central Johannes-burg, is used as the basis of a case study for the im-plementation of these systems. A number of proven CSP technologies were identified and a technology screening was performed to identify suitable technologies for possible implementation, for a reference output of 120 kW(e). From these, a number of systems were chosen for more detailed evaluation and the hourly energy production of these systems was analysed, using local weather data. The Compound Linear Fresnel Reflector system (CLFR) proved to be most suitable because of the space and cost benefits it offers. Systems that integrate organic Rankine cycles (ORC) as well as thermal storage and hybridisation were also investigated. The levelised cost of electricity (LEC) was predicted to be between R4.31 and R3.18 per kWh. Currently these technologies cannot compete financially with the price of local, fossil produced electricity, but with the increase in electricity tariffs and demand for clean reliable power CSP technologies, may become competitive in distributed generation systems in urban areas.

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Gritsenko, V. A., A. R. Mavzyutov, T. M. Pashkova, O. L. Kartashova, Ya V. Tyapaeva i Yu P. Belozertseva. "GENETIC PROFILE STAPHYLOCOCCUS AUREUS, ISOLATED FROM BACTERIAL CARRIERS AND PATIENTS WITH INFECTIOUS INFLAMMATORY PATHOLOGY". Journal of microbiology epidemiology immunobiology, nr 4 (28.08.2018): 56–62. http://dx.doi.org/10.36233/0372-9311-2018-4-56-62.

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Aim. A comparative genetic evaluation of the pathogenic potential of Staphylococcus aureus strains isolated from bacterial carriers and patients with infectious inflammatory pathology. Materials and methods. The presence of pathogenicity genes (ssp, spa, clfA and clfB) in 163 strains of S. aureus isolated from the mucous membrane of the nasal cavity of bacterial carriers, from the vaginal discharge of women with uterine myoma, the contents of the pustules of newborns with perinatal pyoderma, and the transudate of venous-trophic ulcers lower limbs and purulent wounds in patients with diabetic foot syndrome. Results. It was shown that the frequency of occurrence of ssp, spa, clfA and clfB genes in clinical strains of S. aureus depended on the source of their isolation. In all cultures of S. aureus (except vaginal isolates), the most common gene was ssp (in 66.7 - 94.6% of cases), which was found isolated or in different combinations with other genes (spa, clfA, clfB). It has been established that the genetic profiles of strains of S. aureus isolated from bacterial carriers and patients with infectious inflammatory pathology (perinatal pyoderma, purulent wounds in diabetic foot syndrome) show a pronounced similarity in the presence of ssp, spa, clfA and clfB genes. Conclusion. The possible role of asymptomatic carriage of strains of S. aureus with a pathogenic potential in the development of endogenous infections of different localization is discussed.

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PRASAD, VIVEK, PAPIYA GHOSAL CHOWDHURY i SHALINI SRIVASTAVA. "Purification of Two Basic 1, 3-b-Glucanase Isoforms from Cyamopsis tetragonoloba (L.)Taub. Induced to Resist Virus Infections". Israel Journal of Plant Sciences 49, nr 1 (1.01.2001): 15–19. http://dx.doi.org/10.1560/7uwd-rgnp-clfr-b4c5.

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Miajlovic, Helen, Anthony Loughman, Marian Brennan, Dermot Cox i Timothy J. Foster. "Both Complement- and Fibrinogen-Dependent Mechanisms Contribute to Platelet Aggregation Mediated by Staphylococcus aureus Clumping Factor B". Infection and Immunity 75, nr 7 (16.04.2007): 3335–43. http://dx.doi.org/10.1128/iai.01993-06.

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ABSTRACT Staphylococcus aureus can stimulate activation and aggregation of platelets, which are thought to be factors in the development of infective endocarditis. Previous studies have identified clumping factor A (ClfA) and fibronectin binding proteins A and B (FnBPA and FnBPB) as potent platelet aggregators. These proteins are able to stimulate rapid platelet aggregation by either a fibrinogen- or a fibronectin-dependent process which also requires antibodies specific to each protein. Slower aggregation has been seen in other systems where specific fibrinogen binding ligands are absent and platelet aggregation is mediated by complement and specific antibodies. Bacteria expressing ClfB aggregate platelets with a longer lag time than ClfA or FnBPA and FnBPB. In order to investigate whether ClfB causes platelet aggregation in a complement- or fibrinogen-dependent manner, a non-fibrinogen-binding mutant of ClfB (ClfB Q235A) was constructed. Lactococcus lactis expressing ClfB Q235A was able to stimulate platelet aggregation in platelet-rich plasma without a significant increase in lag time. The requirements for platelet aggregation were investigated using gel-filtered platelets. Fibrinogen and specific anti-ClfB antibodies were found to be sufficient to allow platelet aggregation mediated by the wild-type ClfB protein. It seems that ClfB causes platelet aggregation by a fibrinogen-dependent mechanism. The non-fibrinogen-binding ClfB mutant was unable to stimulate platelet aggregation under these conditions. However, bacteria expressing ClfB Q235A caused platelet aggregation in a complement-dependent manner which required specific anti-ClfB antibodies.

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Randinitis, Edward J., Jeffery R. Koup, George Rausch, Robert Abel, Nicola J. Bron, Neil J. Hounslow, Artemios B. Vassos i Allen J. Sedman. "Clinafloxacin Pharmacokinetics in Subjects with Various Degrees of Renal Function". Antimicrobial Agents and Chemotherapy 45, nr 9 (1.09.2001): 2536–42. http://dx.doi.org/10.1128/aac.45.9.2536-2542.2001.

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ABSTRACT As the primary route for elimination of clinafloxacin is renal clearance (CLR) of unchanged drug, studies were conducted to determine the pharmacokinetic profile of clinafloxacin following administration to young and elderly subjects, subjects with various degrees of renal function, and subjects requiring dialysis. These were open-label studies in which subjects received single oral clinafloxacin doses. Sixteen young subjects (18 to 35 years old) and 16 elderly subjects (>65 years old) were enrolled in a study comparing pharmacokinetic profiles of clinafloxacin in young and elderly subjects. Twenty subjects having various degrees of renal function were enrolled into one of three groups based on degree of renal function as measured by creatinine clearance (CLCR). Twelve subjects with severe renal impairment requiring dialysis enrolled in a third study. Clinafloxacin was generally well tolerated by all subjects. Clinafloxacin pharmacokinetic profiles in elderly subjects were dependent only on age-related decreases in renal function. Clinafloxacin maximum concentrations in plasma, areas under the concentration-time curves, and terminal elimination half-life values increased with decreasing CLCR values. Total apparent body clearance of clinafloxacin from the plasma after oral administration (CLoral) and CLR were dependent on CLCR according to the following relationships: CLoral = 2.3 · CLCR + 77 and CLR = 1.74 · CLCR. Hemodialysis had no significant effect on clinafloxacin clearance. Based on the relationship between CLCR and clinafloxacin CLoral and CLR values, the clinafloxacin dose should be halved in patients having a CLCR of <40 ml/min. Further dose adjustment is not warranted in patients requiring hemodialysis.

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Takahashi, Yoshinao, Korehito Kato i Hitoshi Habuka. "Development of SiC Etching by Chlorine Fluoride Gas". Materials Science Forum 1004 (lipiec 2020): 731–37. http://dx.doi.org/10.4028/www.scientific.net/msf.1004.731.

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Amorphous SiC and 4H-SiC were etched by chlorine fluoride (ClF), chlorine trifluoride (ClF3), fluorine (F2) and chlorine (Cl2) gases, in order to evaluate the etching capability of various reactive gases. The gaseous byproducts of SiC etching were observed by the quadrupole mass spectrometry. The ClF showed slow etching rate of amorphous SiC and 4H-SiC, while ClF3 and F2 quickly etched them. By the ClF gas, the etching rate of amorphous SiC was 120 nm/min at 400 °C. The ClF gas was expected to be suitable for a shallow etching, because of its moderate etching rate even at high temperatures.

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Kalashnikova, Viktoriya. "Pathogenic potential of Staphylococcus aureus colonizing the nasal cavity and lungs of monkeys". Russian veterinary journal 2020, nr 5 (25.11.2020): 21–26. http://dx.doi.org/10.32416/2500-4379-2020-5-21-26.

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In this paper, data are presented on the study of genetic determinants of pathogenicity in S. aureus isolated from the respiratory tract of monkeys (nasal cavity and lungs) collected during 2017‒2019. The aim of this work is to determine some genes of pathogenicity and their combinations in S. aureus isolated from the nasal cavity of clinically healthy monkeys and from the lungs of monkeys that died from pneumonia. There was a high frequency of detection of adhesion genes (fnBpA ― 74.4 %, fnBpB ― 79.1 %, clfA ― 95.4 %, clfB ― 95.4 %), hemolysins (hla ― 83.7 %, hlb ― 81.4 %), Panton-Valentine leukocidin (pvl ― 48.1 %), which are regarded as markers of the increased pathogenicity of the microbe, as well as combinations of various genovariants. The hemolysin α gene was detected more often in S. aureus isolated from the lungs of monkeys with pneumonia (87.4 %), and the hemolysin β gene was found in almost all S. aureus isolated from the nasal cavity (96.2 %). Genes for fibronectin-binding proteins (fnBpA/B) were found with a high frequency in isolates detected from the nasal cavity, while the clumping factor gene (clfA/B) were isolated in 100 % of S. aureus studied. The genovariant hla-hlb-fnBpA-fnBpB-clfA-clfB was detected in almost half of the isolates (48.1%), the presence of all studied pathogenicity determinants (pvl-hla-hlb-fnBpA-fnBpB-clfA-clfB) was noted in 24.8 % S. aureus. Analysis of the high frequency of prevalence of genes responsible for the expression of pathogenicity factors confirms the pathogenicity of studied S. aureus isolates, detected in monkeys. Most of the isolates belonged to group IV of the regulatory gene (55.8%) and agr I takes second place (40.8 %). PCR detection of pvl, hla, hlb, fnBpA, fnBpB, clfA, clfB genes can be used to demonstrate the pathogenicity of S. aureus isolates from various animal biomaterials and serve as a criterion for epidemiological assessment in studying the S. aureus circulation in monkeys kept in captivity.

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Scharf, Peter, i Reinhart Ahlrichs. "Geometry and binding energy of ClF and ClF3". Chemical Physics 100, nr 2 (grudzień 1985): 237–42. http://dx.doi.org/10.1016/0301-0104(85)85006-0.

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Deivanayagam, Champion C. S., Samuel Perkins, Sita Danthuluri, Rick T. Owens, Todd Bice, Tamanna Nanavathy, Timothy J. Foster, Magnus Höök i Sthanam V. L. Narayana. "Crystallization of ClfA and ClfB fragments: the fibrinogen-binding surface proteins of Staphylococcus aureus". Acta Crystallographica Section D Biological Crystallography 55, nr 2 (1.02.1999): 554–56. http://dx.doi.org/10.1107/s0907444998012426.

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Recombinant constructs encoding the fibrinogen-binding domains of ClfA and ClfB from Staphylococcus aureus have been crystallized. ClfA was crystallized in the orthorhombic space group P212121 with unit-cell parameters a = 39.58, b = 81.39 and c = 112.65 Å. A complete data set was recorded to 2.1 Å resolution and had a Vm of 2.3 Å3 Da−1 with 46.5% solvent, suggesting one molecule per asymmetric unit. Co-crystals of ClfA with the 17 amino-acid C-terminal peptide of fibrinogen γ-chain diffracted to 2.1 Å resolution and had unit-cell parameters a = 39.11, b = 81.39 and c = 109.51 Å in the space group P212121. ClfB was crystallized in the tetragonal space group P41212 or P43212 with unit-cell parameters a = 96.31, b = 96.31 and c = 84.13 Å and diffracted to 2.45 Å resolution. The estimated Vm of 2.6 Å3 Da−1 with 53% solvent indicated one molecule in the asymmetric unit.

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Khwileh, Ahmad, Debasis Ganguly i Gareth J. F. Jones. "Utilisation of Metadata Fields and Query Expansion in Cross-Lingual Search of User-Generated Internet Video". Journal of Artificial Intelligence Research 55 (27.01.2016): 249–81. http://dx.doi.org/10.1613/jair.4775.

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Recent years have seen significant efforts in the area of Cross Language Information Retrieval (CLIR) for text retrieval. This work initially focused on formally published content, but more recently research has begun to concentrate on CLIR for informal social media content. However, despite the current expansion in online multimedia archives, there has been little work on CLIR for this content. While there has been some limited work on Cross-Language Video Retrieval (CLVR) for professional videos, such as documentaries or TV news broadcasts, there has to date, been no significant investigation of CLVR for the rapidly growing archives of informal user generated (UGC) content. Key differences between such UGC and professionally produced content are the nature and structure of the textual UGC metadata associated with it, as well as the form and quality of the content itself. In this setting, retrieval effectiveness may not only suffer from translation errors common to all CLIR tasks, but also recognition errors associated with the automatic speech recognition (ASR) systems used to transcribe the spoken content of the video and with the informality and inconsistency of the associated user-created metadata for each video. This work proposes and evaluates techniques to improve CLIR effectiveness of such noisy UGC content. Our experimental investigation shows that different sources of evidence, e.g. the content from different fields of the structured metadata, significantly affect CLIR effectiveness. Results from our experiments also show that each metadata field has a varying robustness to query expansion (QE) and hence can have a negative impact on the CLIR effectiveness. Our work proposes a novel adaptive QE technique that predicts the most reliable source for expansion and shows how this technique can be effective for improving the CLIR effectiveness for UGC content.

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Nash, Kevin A. "Effect of Drug Concentration on Emergence of Macrolide Resistance in Mycobacterium avium". Antimicrobial Agents and Chemotherapy 45, nr 6 (1.06.2001): 1607–14. http://dx.doi.org/10.1128/aac.45.6.1607-1614.2001.

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ABSTRACT The emergence of antibiotic resistance in mycobacteria involves the selection of mutant variants within a susceptible bacterial population. However, it is unclear whether antimycobacterial drugs act just as selective agents or can influence the rate of appearance of resistant mutants. The present study was initiated to address this issue by monitoring the effects of antimicrobial agents on the appearance and growth of clarithromycin (CLR)-resistant (CLRr) bacilli in broth cultures of Mycobacterium avium. Preexposure ofM. avium to CLR had a significant dose effect on the emergence of resistance, with concentrations of 4 to 8 μg/ml resulting in a maximal (∼104-fold) increase in the number of CLRr bacilli after a 4-day incubation. In addition, a dose effect was found with azithromycin. The use of combinations of CLR with either ethambutol (EMB) or rifabutin (RFB) resulted in fewer resistant bacilli compared to the use of CLR alone. The lowest active concentration of EMB (4 μg/ml) was equivalent to the EMB MIC (4 to 8 μg/ml) for the parental CLRs strain and the emergent CLRr variants, and thus, the antiresistance effect was probably the result of the bacteriostatic effect of EMB on CLRr bacilli. However, RFB was an order of magnitude more active (0.05 μg/ml) at reducing resistance than suggested by the MIC of this agent (0.5 to 1 μg/ml). These results indicate that the emergence of resistance was not simply the selection of a preexisting subpopulation of resistant bacilli. Further analysis suggested that early events in the emergence of resistance involved organisms (progenitors) that acquired a resistance phenotype. In addition, the progenitors appeared to be in a transient state, able to develop into a stable resistant lineage in the presence of CLR, or able to revert to the wild type in nonselective conditions.

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Fiskus, Warren, Christopher P. Mill, Dimuthu Perera, Christine Birdwell, Qing Deng, Haopeng Yang, Bernardo H. Lara i in. "BET proteolysis targeted chimera-based therapy of novel models of Richter Transformation-diffuse large B-cell lymphoma". Leukemia 35, nr 9 (2.03.2021): 2621–34. http://dx.doi.org/10.1038/s41375-021-01181-w.

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AbstractRichter Transformation (RT) develops in CLL as an aggressive, therapy-resistant, diffuse large B cell lymphoma (RT-DLBCL), commonly clonally-related (CLR) to the concomitant CLL. Lack of available pre-clinical human models has hampered the development of novel therapies for RT-DLBCL. Here, we report the profiles of genetic alterations, chromatin accessibility and active enhancers, gene-expressions and anti-lymphoma drug-sensitivity of three newly established, patient-derived, xenograft (PDX) models of RT-DLBCLs, including CLR and clonally-unrelated (CLUR) to concomitant CLL. The CLR and CLUR RT-DLBCL cells display active enhancers, higher single-cell RNA-Seq-determined mRNA, and protein expressions of IRF4, TCF4, and BCL2, as well as increased sensitivity to BET protein inhibitors. CRISPR knockout of IRF4 attenuated c-Myc levels and increased sensitivity to a BET protein inhibitor. Co-treatment with BET inhibitor or BET-PROTAC and ibrutinib or venetoclax exerted synergistic in vitro lethality in the RT-DLBCL cells. Finally, as compared to each agent alone, combination therapy with BET-PROTAC and venetoclax significantly reduced lymphoma burden and improved survival of immune-depleted mice engrafted with CLR-RT-DLBCL. These findings highlight a novel, potentially effective therapy for RT-DLBCL.

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Kim, So H., Won B. Kim i Myung G. Lee. "Effect of Probenecid on the Renal Excretion Mechanism of a New Carbapenem, DA-1131, in Rats and Rabbits". Antimicrobial Agents and Chemotherapy 43, nr 1 (1.01.1999): 96–99. http://dx.doi.org/10.1128/aac.43.1.96.

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ABSTRACT The effects of probenecid, an anion transport inhibitor, on the renal excretion mechanism of a new anionic carbapenem, DA-1131, were investigated after a 1-min intravenous infusion of DA-1131 at 100 mg/kg of body weight to rabbits and 50 mg/kg to rats with or without probenecid at 50 mg/kg for both species. In control rabbits, the renal clearance (CLR) of DA-1131 and the glomerular filtration rate based on creatinine clearance (CLCR) were 6.14 ± 2.09 and 2.26 ± 0.589 ml/min/kg, respectively. When considering the less than 10% plasma protein binding of DA-1131 in rabbits, renal tubular secretion of DA-1131 was observed in rabbits. The CLR of DA-1131 (3.87 ± 0.543 ml/min/kg) decreased significantly with treatment with probenecid in rabbits, indicating that the renal tubular secretion of DA-1131 was inhibited by probenecid. However, in control rats, the CLR of DA-1131 (5.80 ± 1.94 ml/min/kg) was comparable to the CLCR(4.29 ± 1.64 ml/min/kg), indicating that DA-1131 was mainly excreted by glomerular filtration in rats. Therefore, it could be expected that the CLR of DA-1131 could not be affected by treatment with probenecid in rats; this was proved by a similar CLR of DA-1131 with treatment with (6.93 ± 0.675 ml/min/kg) or without (5.80 ± 1.94 ml/min/kg) probenecid. Therefore, the renal secretion of DA-1131 is a factor in rabbits but is not a factor in rats.

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Sonola, Valery S., Abdul Katakweba, Gerald Misinzo i Mecky I. Matee. "Multiplex PCR detection of antibiotic resistance and virulence genes in multidrug-resistant Staphylococcus aureus isolated from chickens, humans, rodents, and soil in Northern Tanzania". German Journal of Microbiology 3, nr 2 (wrzesień 2023): 1–11. http://dx.doi.org/10.51585/gjm.2023.2.0024.

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Staphylococcus aureus (S. aureus) is a zoonotic pathogen with public health and veterinary importance. We investigated the presence of antibiotic resistance genes (ARGs) and virulence genes (VGs) in 57 multidrug-resistant (MDR) S. aureus isolated from humans (n=17), chickens (n=14), rodents (n=13), and soil (n=13) using multiplex PCR. Overall, the distribution of ARGs revealed that the tetK was found in 18/57 (31.6%), mecA in 16/57 (28.1%), tetL in 5/57 (8.9%), and ermC in 1/57 (1.8%), while ermA and tetM were not detected. For VGs, the clfB was found in 6/57 (10.5 %), coa in 8/57 (14.0%), clfA in 3/57 (5.3%), hlg in 1/57 (1.8%), ebpS in 2/57 (3.5%), fnbB in 2/57 (3.5%), luk-PV in 6/57 (10.5%) and tst in 1/57 (1.8%). Resistance genes (tetK and mecA) and virulence determinants (clfB, coa, and luk-PV) were common in all sample sources, while tst, hlg, and fnbB were specific to human, chicken, and rodent isolates, respectively. Erythromycin phenotypic resistance results correlated with the presence of ermC (r=0.42), tetL (r=0.98), and mecA (r=0.51), while tetracycline resistance correlated with tetL (r=1.00) and mecA (r=0.57) genes and methicillin resistance correlated with mecA (r=0.55) and tetL (r=0.98) genes. Positive correlations were noted between ARG (ermC) and VGs; clfA (r=0.57), hlg (r=1.00), and clfB (r=0.43), and between tetK and clfB (r=0.39); tetK and coa (r=0.36) genes. Principal component analysis (PCA) shows that tetL, ermC, and mecA contributed to tetracycline, erythromycin, and methicillin resistance, respectively. The widespread presence of resistance and virulence genes, often in combination, among MDR S. aureus in isolates from humans, chicken, rodents, and soil samples require comprehensive One-Health interventions.

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Serray, Bahija, Salwa Oufrid, Imane Hannaoui, Fatna Bourjilate, Nabila Soraa, Mostafa Mliji, Mohammed Sobh, Abderrahmane Hammoumi, Mohammed Timinouni i Mohamed El Azhari. "Genes encoding adhesion factors and biofilm formation in methicillin-resistant Staphylococcus aureus in Morocco". Journal of Infection in Developing Countries 10, nr 08 (31.08.2016): 863–69. http://dx.doi.org/10.3855/jidc.8361.

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Introduction: Infections involving methicillin-resistant Staphylococcus aureus (MRSA) remain a serious threat to hospitalized patients worldwide. MRSA is characterized by recalcitrance to antimicrobial therapy, which is a function not only of widespread antimicrobial resistance, but also the capacity to form biofilms. The present study evaluated the presence of genes encoding adhesion factors and the biofilm-forming capacity in MRSA. Methodology: In this study, 53 isolates of MRSA, recovered from December 2010 to May 2014 in a mother and child hospital, CHU Mohamed VI in Marrakech, Morocco, were screened for the presence of bap and ica genes associated with biofilm formation, and for bbp, cna, ebpS, eno, fib, fnbA, fnbB, clfA, and clfB genes that encode microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). The biofilm formation assay was performed in 96-well microtiter polystyrene plates. The presence of genes was determined by polymerase chain reaction (PCR). Results: An association was found between icaD gene detection and biofilm formation; 100% of the strains harbored icaD and produced biofilm. None of the isolates harbored bap or bbp. Furthermore, 96.23% isolates were positive for fnbA, 60.37% for eno, 43.39% for clfA and clfB, 11.32% for cna, 9.34% for ebpS, 5.66% for fib, and 1.89% for fnbA. Conclusions: Our findings showed that the MRSA carriage in Marrakech children was high. The genetic variations of adhesion genes require further investigation.

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Bonapace, Charles R., Roger L. White, Lawrence V. Friedrich, E. Douglas Norcross i John A. Bosso. "Pharmacokinetics of Cefepime in Patients with Thermal Burn Injury". Antimicrobial Agents and Chemotherapy 43, nr 12 (1.12.1999): 2848–54. http://dx.doi.org/10.1128/aac.43.12.2848.

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ABSTRACT The pharmacokinetics of cefepime following administration of a single 2-g dose were evaluated for 12 adult patients with thermal burn injury and suspected or documented infection. Serial blood and urine samples for cefepime concentration determination were obtained for 24 h following drug administration. Serum and urine cefepime concentrations were determined by high-performance liquid chromatography and serum concentrations were fit to a two-compartment pharmacokinetic model. Mean (standard deviation [SD]) age, actual body weight (ABW), percent total body surface area burned, and days postburn at the time of study were 41 (13) years, 84 (22) kg, 36 (17)%, and 9 (3) days, respectively. Mean (SD) measured creatinine clearance (CLCR), total clearance (CLT), renal clearance (CLR), alpha phase half-life, beta phase half-life, and volume of distribution at steady state (V SS) were 135 (31) ml/min, 8.8 (2.4) liters/h, 8.1 (2.0) liters/h, 0.33 (0.14) h, 2.8 (0.6) h, and 0.43 (0.10) liters/kg ABW, respectively. Cefepime CLT and CLR in burn patients were similar to previously reported values for healthy volunteers when normalized by CLCR. Stepwise multiple regression was used to associate CLT with CLCR and days postburn (r 2 = 0.861), CLRwith CLCR and days postburn (r 2 = 0.773), nonrenal clearance with percent third-degree (% 3°) burn and albumin concentration (r 2 = 0.550), andV SS only with % 3° burn (r 2 = 0.624). Simulated steady-state serum concentrations obtained by using the patients’ pharmacokinetic parameters exceeded the susceptibility interpretive standard (breakpoint) of cefepime for at least 60% of the dosing interval with dosing regimens of 1 g every 8 h (q8h), 2 g q8h, and 2 g q12h. Despite differences in pharmacokinetic parameters between our patients and healthy volunteers, it appears that these dosing regimens may be adequate in similar burn patients.

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Tsompanidou, Eleni, Emma L. Denham, Mark J. J. B. Sibbald, Xiao-mei Yang, Jolien Seinen, Alexander W. Friedrich, Girbe Buist i Jan Maarten van Dijl. "The Sortase A Substrates FnbpA, FnbpB, ClfA and ClfB Antagonize Colony Spreading of Staphylococcus aureus". PLoS ONE 7, nr 9 (7.09.2012): e44646. http://dx.doi.org/10.1371/journal.pone.0044646.

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Randriamanakoto, Zara, P. Väisänen i P. Ranaivomanana. "The SUNBIRD Survey: Insights into small-scale star formation mechanisms through near-infrared study of Young Massive Clusters". Proceedings of the International Astronomical Union 17, S373 (sierpień 2021): 87–92. http://dx.doi.org/10.1017/s1743921322004653.

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AbstractWe draw the K-band luminosity functions (CLFs) of young massive clusters (YMCs) hosted by 34 SUNBIRD targets to evaluate the impact of the host galaxy environment on their YMC properties. The depth and high resolution of the NIR images (PSF ∼ 0.1”) allow us to test whether CLF power-law slopes (α) of high star-forming galaxies are similar to those of gas-poor low star formation rate (SFR) galaxies. We found that α ranges between 1.53 and 2.41 with a median value of 1.87 ± 0.23. We also performed correlation searches between α and the host global properties and noticed that α decreases with an increasing SFR and SFR density. On sub-galactic scales, CLF slopes of cluster-rich galaxies differ by ∼0.5. Our NIR CLF analyses suggest that the extreme environment of high SFR galaxies such as the SUNBIRD sample is likely to affect the formation mechanisms of YMCs and hence to govern the ongoing small-scale SF processes of the host galaxy.

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Fronzoni, G., M. Stener i P. Decleva. "Theoretical description of the NEXAFS Cl 1s and 2p spectra of ClF and ClF3". Chemical Physics 246, nr 1-3 (lipiec 1999): 127–45. http://dx.doi.org/10.1016/s0301-0104(99)00124-x.

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Gurfil, P. "Non-linear missile guidance synthesis using control Lyapunov functions". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 219, nr 2 (1.02.2005): 77–87. http://dx.doi.org/10.1243/095441005x9085.

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This paper derives a new non-linear guidance law aimed at interception of highly manoeuvring targets. The guidance law is developed based on the theory of control Lyapunov functions (CLFs), a methodology for universal stabilization of non-linear systems which is also inverse optimal with respect to some performance measure. The three-dimensional guidance dynamics are formulated in a fixed-line-of-sight coordinate system, yielding matching between the target and missile accelerations. Closed-form expressions for the CLF guidance commands are given. Simulation shows that the new guidance scheme significantly outperforms augmented proportional navigation in short-range engagements.

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Abd Zaid, A. M., i N. J. Kandala. "RAPID DISCRIMINATION AMONG METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS ISOLATES USING VARIABLE NUMBER TANDEM REPEAT ANALYSIS IN A SAMPLE OF IRAQI PATIENTS AND". IRAQI JOURNAL OF AGRICULTURAL SCIENCES 52, nr 5 (21.10.2021): 1185–93. http://dx.doi.org/10.36103/ijas.v52i5.1456.

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There is so little information available in Iraq about genetic variability in methicillin resistant Staphylococcus aureus (MRSA), so current study aimed to use six tandem repeat loci of multilocus variable number tandem repeat (MLVA) typing to discriminate among MRSA, so to achieve the aim of this study, six loci, clfA, clfB, sdrC, spa, sspa and sav1078 were selected for multiplex PCR. The PCR product were subjected to capillary electrophoresis by using ABI-Genetic analyzer, then the data were analyzed by using GeneMapper™ Software 5. Fragment sizes were converted into repeats number. The total number of repeats are used to generate allelic profile. The allelic profile used to draw the minimum spanning tree and dendrogram , all the 85 MRSA isolates are clustered into 54 MLVA type.

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Zhou, Xiao-Jian, Suzanne Swan, William B. Smith, Thomas C. Marbury, Gloria Dubuc-Patrick, George C. Chao i Nathaniel A. Brown. "Pharmacokinetics of Telbivudine in Subjects with Various Degrees of Renal Impairment". Antimicrobial Agents and Chemotherapy 51, nr 12 (17.09.2007): 4231–35. http://dx.doi.org/10.1128/aac.00557-07.

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ABSTRACT This study evaluates the effect of renal impairment on the pharmacokinetics of telbivudine. Thirty-six subjects were assigned, on the basis of creatinine clearance (CLCR), to 1 of 5 renal function groups with 6 to 8 subjects per group: normal renal function; mild, moderate, or severe renal impairment; or end-stage renal disease [ESRD] requiring hemodialysis. Subjects received a single oral dose of telbivudine at 600 mg (normal function and mild impairment), 400 mg (moderate impairment), or 200 mg (severe impairment and ESRD); plasma and/or urine samples were collected over a 48-h period for pharmacokinetic analyses. Telbivudine was well tolerated by all subjects. The pharmacokinetics of 600 mg of telbivudine were comparable for subjects with mild renal impairment and normal renal function. Likewise, for subjects with moderate to severe impairment, including ESRD, reduced doses from 200 to 400 mg produced plasma exposure similar to that for subjects with normal renal function. These results indicate that the pharmacokinetics of telbivudine were dependent on renal function, especially for subjects with moderate to severe renal impairment or ESRD. Apparent total plasma clearance, renal clearance (CLR), and urinary excretion of telbivudine decreased as renal function deteriorated. A linear relationship was established between CLR and CLCR. In ESRD subjects, a routine 3.5- to 4-h hemodialysis session removed telbivudine from plasma at an extraction ratio of ∼45%, representing a ∼23% reduction in total exposure. These results suggest that while no adjustment of the telbivudine dose appears necessary for subjects with mild renal impairment, dose adjustment is warranted for those with moderate to severe renal impairment or ESRD in order to achieve optimal plasma exposure.

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Wan, Min-Tao, i Chin-Cheng Chou. "CHARACTERIZATION OF BACTERIAL ADHESION AND BIOFILM FORMATION ABILITY OF LIVESTOCK-ASSOCIATED METHICILLIN-RESISTANTSTAPHYLOCOCCUS AUREUSISOLATED FROM SWINE AND SLAUGHTERHOUSE WASTEWATERS". Taiwan Veterinary Journal 40, nr 02 (czerwiec 2014): 101–7. http://dx.doi.org/10.1142/s1682648514500140.

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Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) ST9 has emerged as a potential zoonotic pathogen for humans and animals. Bacterial adhesion factors and biofilms mediate host colonization and infection of MRSA. This study investigated the dynamics of microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), biofilm formation gene (intercellular adhesion [ica]), and biofilm expression in MRSA from the nasal samples of asymptomatic pigs (the nasal group, n = 147) and swine slaughterhouse wastewater samples (the environmental group, n = 86). Biofilm formation was quantified by microtiter plate assay. The most prevalent MSCRAMM profile was clfA-clfB-spa-eno-ebps-fib and more than 70% of the LA-MRSA ST9 isolates harbored the biofilm formation gene. Environmental MRSA harbored lower levels of the ica locus and MSCRAMMs (clfA and fib) than did the nasal group, suggesting possible gene loss. Biofilm production in the nasal group was higher than in the environmental group, indicating the difference in biofilm formation in MRSA isolates from different ecological niches. The higher prevalence of MSCRAMMs, biofilm formation gene, and biofilm production in LA-MRSA ST9 may enhance the persistence and infectivity of MRSA in the swine population and present a threat to the health of livestock as well as farm workers.

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Chen, Lin, Zi-Yun Tang, Shi-Yun Cui, Zhen-Bao Ma, Hua Deng, Wei-Li Kong, Li-Wen Yang, Chao Lin, Wen-Guang Xiong i Zhen-Ling Zeng. "Biofilm Production Ability, Virulence and Antimicrobial Resistance Genes in Staphylococcus aureus from Various Veterinary Hospitals". Pathogens 9, nr 4 (4.04.2020): 264. http://dx.doi.org/10.3390/pathogens9040264.

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Staphylococcus aureus (S. aureus) is one of the most clinically important zoonotic pathogens, but an understanding of the prevalence, biofilm formulation ability, virulence, and antimicrobial resistance genes of S. aureus from veterinary hospitals is lacking. By characterizing S. aureus in different origins of veterinary hospitals in Guangzhou, China, in 2019, we identified with the presence of S. aureus in pets (17.1%), veterinarians (31.7%), airborne dust (19.1%), environmental surfaces (4.3%), and medical device surfaces (10.8%). Multilocus sequence typing (MLST) and Staphylococcus protein A (spa) typing analyses demonstrated methicillin-sensitive S. aureus (MSSA) ST398-t571, MSSA ST188-t189, and methicillin-resistant S. aureus (MRSA) ST59-t437 were the most prevalent lineage. S. aureus with similar pulsed-field gel electrophoresis (PFGE) types distributed widely in different kinds of samples. The crystal violet straining assays revealed 100% (3/3) of MRSA ST59 and 81.8% (9/11) of MSSA ST188 showed strong biofilm formulation ability, whereas other STs (ST1, ST5, ST7, ST15, ST88, ST398, ST3154 and ST5353) showed weak biofilm production ability. Polymerase chain reaction (PCR) confirmed the most prevalent leucocidin, staphylococcal enterotoxins, ica operon, and adhesion genes were lukD-lukE (49.0%), sec-sel (15.7%), icaA-icaB-icaC-icaR (100.0%), and fnbB-cidA-fib-ebps-eno (100.0%), respectively. Our study showed that the isolates with strong biofilm production ability had a higher prevalence in clfA, clfB, fnbA and sdrC genes compared to the isolates with weak biofilm production ability. Furthermore, 2 ST1-MRSA isolates with tst gene and 1 ST88-MSSA isolate with lukS/F-PV gene were detected. In conclusion, the clonal dissemination of S. aureus of different origins in veterinary hospitals may have occurred; the biofilm production capacity of S. aureus is strongly correlated with ST types; some adhesion genes such as clfA, clfB, fnbA, and sdrC may pose an influence on biofilm production ability and the emergence of lukS/F-PV and tst genes in S. aureus from veterinary hospitals should raise our vigilance.

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Atshan, Salman Sahab, Rukman Awang Hamat, Marco J. L. Coolen, Gary Dykes, Zamberi Sekawi, Benjamin J. Mullins, Leslie Thian Lung Than, Salwa A. Abduljaleel i Anthony Kicic. "The Role of Subinhibitory Concentrations of Daptomycin and Tigecycline in Modulating Virulence in Staphylococcus aureus". Antibiotics 10, nr 1 (3.01.2021): 39. http://dx.doi.org/10.3390/antibiotics10010039.

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Staphylococcus aureus (S. aureus) infections are notoriously complicated by the ability of the organism to grow in biofilms and are difficult to eradicate with antimicrobial therapy. The purpose of the current study was to clarify the influence of sub-inhibitory concentrations (sub-MICs) of daptomycin and tigecycline antibiotics on biofilm adhesion factors and exoproteins expressions by S. aureus clinical isolates. Six clinical isolates representing positive biofilm S. aureus clones (3 methicillin-sensitive S. aureus (MSSA) and 3 methicillin-resistant S. aureus (MRSA)) were grown with sub-MICs (0.5 MIC) of two antibiotics (daptomycin and tigecycline) for 12 h of incubation. RNA extracted from culture pellets was used via relative quantitative real-time-PCR (qRT-PCR) to determine expression of specific adhesion (fnbA, fnbB, clfA, clfB, fib, ebps, cna, eno) and biofilm (icaADBC) genes. To examine the effect of sub-MIC of these antibiotics on the expression of extracellular proteins, samples from the culture supernatants of six isolates were collected after 12 h of treatment with or without tigecycline in order to profile protein production via 2D gel sodium dodecyl sulfate-polyacrylamide gel electrophoresis (2D gel-SDS-PAGE). Sub-MIC treatment of all clinical MRSA and MSSA strains with daptomycin or tigecycline dramatically induced or suppressed fnbA, fnbB, clfA, clfB, fib, ebps, cna, eno, and icaADBC gene expression. Furthermore, sub-MIC use of tigecycline significantly reduced the total number of separated protein spots across all the isolates, as well as decreasing production of certain individual proteins. Collectively, this study showed very different responses in terms of both gene expression and protein secretion across the various isolates. In addition, our results suggest that sub-MIC usage of daptomycin and tigecycline could signal virulence induction by S. aureus via the regulation of biofilm adhesion factor genes and exoproteins. If translating findings to the clinical treatment of S. aureus, the therapeutic regimen should be adapted depending on antibiotic, the virulence factor and strain type.

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Lee, Myung G., Young H. Choi i Inchul Lee. "Effects of Diabetes Mellitus Induced by Alloxan on the Pharmacokinetics of Metformin in Rats: Restoration of Pharmacokinetic Parameters to the Control State by Insulin Treatment". Journal of Pharmacy & Pharmaceutical Sciences 11, nr 1 (26.03.2008): 88. http://dx.doi.org/10.18433/j35p4x.

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To test the effect of insulin treatment on the pharmacokinetics of metformin in rats with diabetes mellitus induced by alloxan (DMIA rats). The following results were reported from other studies. Metformin was metabolized via hepatic CYP2C11, 2D1, and 3A1/2 in rats. In DMIA rats, the protein expression and mRNA levels of hepatic CYP2C11 and 3A1/2 decreased and increased, respectively. In rat model of diabetes mellitus induced by streptozotocin, the protein expression of hepatic CYP2D1 was not changed. The increase in hepatic CYP1A2, 2B1, and 2E1, and decrease in hepatic CYP2C11 in DMIA rats was returned to the controls by insulin treatment. METHODS. Metformin (100 mg/kg) was administered intravenously and orally to the control rats, DMIA rats, and DMIA rats with insulin treatment for 3 weeks (DMIA rats with insulin). RESULTS. After intravenous administration of metformin to the DMIA rats, the CLR and CLNR of the drug were significantly slower than the controls. After oral administration of metformin to the DMIA rats, the AUC of the drug was also significantly greater than the controls. After intravenous administration of metformin to the DMIA rats with insulin, the significantly slower CLNR of the drug in the DMIA rats was returned to the controls. The altered pharmacokinetic indices observed following intravenous and oral administration of metformin to DMIA rats returned to the control values in the DMIA rats with insulin. CONCLUSIONS. The significantly slower CLNR of metformin in the DMIA rats could be due to the decrease in hepatic CYP2C11 than the controls. The comparable CLNR of metformin between the DMIA rats with insulin and the control rats could be due to restoration of hepatic CYP enzyme changes in DMIA rats to the controls.

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Meagher, Alison K., Alan Forrest, Craig R. Rayner, Mary C. Birmingham i Jerome J. Schentag. "Population Pharmacokinetics of Linezolid in Patients Treated in a Compassionate-Use Program". Antimicrobial Agents and Chemotherapy 47, nr 2 (luty 2003): 548–53. http://dx.doi.org/10.1128/aac.47.2.548-553.2003.

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ABSTRACT Data obtained from 318 adult patients treated under the linezolid compassionate-use protocol were used to develop a population model of the pharmacokinetics of intravenous and oral linezolid. All of the patients received 600 mg of linezolid every 12 h, intravenously and/or orally. Blood samples (2 to 10 per patient; median, 4) were obtained and assayed for linezolid by high-performance liquid chromatography. These data and patient covariates were modeled by iterative two-stage analysis, and model discrimination was done by Akaike's information criterion. Of the patient covariates considered (age, sex, ideal body weight, baseline serum albumin, hepatic or renal dysfunction, underlying malignancy, organ transplantation, surgical status, global severity of illness, site of infection, route of administration, and location of care [intensive-care unit, general floor, or outpatient]), only normalized creatinine clearance (CLCR) and body weight explained significant portions of the variance and were incorporated into the pharmacokinetic model. The final model included central and peripheral compartments with parallel capacity-limited (nonrenal) and first-order (renal [CLR]) clearances. Volumes and clearances were normalized to the ideal body weight, and CLR was modeled as proportional to CLCR. Compared to previously studied adult volunteers, intrinsic clearance was ∼60% higher and the maximum rate of metabolism was twice as high in these debilitated patients, resulting in lower area under the time-concentration curve (AUC) values (P < 0.001). The derived 24-h AUC, averaged over the first 7 days of treatment, ranged between 57 and 871 (median, 191) μg/ml · 24 h. Despite these variations, linezolid provided high rates of clinical cure, as well as microbiological success, in the patients treated in the compassionate-use program. The mechanism(s) of these pharmacokinetic differences is unknown and requires further mechanistic study.

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Gladys Pinilla, Gladys, Angela Bautista, Claudia Cruz, Bibiana Chavarro, Jeannette Navarrete, Liliana Muñoz i Jennifer Gutiérrez. "Determinación de factores de adhesión asociados a la formación de biopelícula en aislamientos clínicos de Staphylococcus aureus y Staphylococcus epidermidis". Nova 15, nr 27 (10.08.2017): 67. http://dx.doi.org/10.22490/24629448.1959.

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<p>Los factores de adhesión son determinantes de virulencia que se expresan en microorganismos que tienen la capacidad de formar biopelícula, contribuyendo a la gravedad de infecciones intrahospitalarias. Dentro de estos componentes de la superficie microbiana que reconocen moléculas de adhesión de matriz conocidas como MSCRAMMs, se incluyen el factor de unión a fibronectina A y B, (FnbA y B) factor de aglutinación A y B (ClfA y B) y factor de unión a fibrinógeno (Fib), que se han descrito en Staphylococcus aureus y reaccionan con proteínas de la matriz extracelular humana. El objetivo de este estudio fue determinar la presencia de estos factores de adhesión relacionados con la formación de biopelicula en Staphylococcus. Método. Se caracterizaron fenotípica y genotípicamente 30 aislamientos clínicos de Staphylococcus aureus y Staphylococcus epidermidis, provenientes de pacientes inmunocomprometidos en tres instituciones hospitalarias de Bogotá. La producción de Biopelícula se determinó mediante Rojo Congo y Cristal violeta y mediante PCR convencional y múltiplex se amplificaron los genes FnbA y B, ClfA y B y Fib, así como los genes del operón ica ADBC. Resultados. Todos los aislamientos clínicos fueron positivos genotípica y fenotípicamente para la producción de Biopelícula, encontrándose<br />la presencia del operón completo en el 88.9%, los factores ClfA y ClfB en un 70%; Fib en un 60%, FnbB en un 23% y FnbA en el 17%. Conclusiónes. En este estudio se evidenció la presencia de estos factores de virulencia en S. pidermidis, los cuáles hasta el momento se han reportado únicamente en S.aureus. Este hallazgo es importante ya que se sugiere la relación con transferencia horizontal de genes entre estas especies, siendo el S. epidermidis un importante reservorio genético, y un importante patobionte causal de infecciones nosocomiales, asociado con dispositivos médicos.</p>

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Mandich, Mary L., M. L. Steigerwald i W. D. Reents. "The effects of chloro substitution on the electronic structure of ClCr+, ClMn+, and ClFe+ and their reactivity with small alkanes". Journal of the American Chemical Society 108, nr 20 (październik 1986): 6197–202. http://dx.doi.org/10.1021/ja00280a015.

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Jimenez-Fabian, Issac, Abraham Jalbout i Abderahim Boutalib. "Conformational study on the structures and energies of the weakly bound complexes of AlCl3 with diatomic molecules". Open Chemistry 5, nr 4 (1.12.2007): 1007–18. http://dx.doi.org/10.2478/s11532-007-0046-4.

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AbstractIn this work we present the results of high level ab initio calculations on weakly bound complexes of aluminium trichloride and hydrogen halides, HX, halogens, X2 and diatomic interhalogens, XY (where X, Y = F, Cl, Br). Based upon these calculations we have predicted that all structures in the staggered conformation (except for Cl3AlFH and Cl3AlClH) are stable minima while those in the eclipsed configurations are transition state structures. In the XH complexes the strength of interaction with the Cl3Al group is FH > ClH > BrH. In the case of X2 species it is Br2 > F2 > Cl2, and finally in the XY (YX) group it is: FBr > ClBr > FCl > BrCl > BrF > ClF.

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Kim, Wook-Hee, Jihye Seo, Jinwoong Kim i Beomseok Nam. "clfB-tree". ACM Transactions on Storage 14, nr 1 (4.04.2018): 1–17. http://dx.doi.org/10.1145/3129263.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 17, nr 2 (marzec 2001): 132–43. http://dx.doi.org/10.1016/s0267-3649(01)00217-5.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 17, nr 3 (maj 2001): 202–16. http://dx.doi.org/10.1016/s0267-3649(01)00322-3.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 17, nr 5 (wrzesień 2001): 343–60. http://dx.doi.org/10.1016/s0267-3649(01)00514-3.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 17, nr 4 (lipiec 2001): 272–88. http://dx.doi.org/10.1016/s0267-3649(01)00719-1.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 17, nr 6 (listopad 2001): 427–40. http://dx.doi.org/10.1016/s0267-3649(01)01120-7.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 18, nr 3 (maj 2002): 212–32. http://dx.doi.org/10.1016/s0267-3649(02)00519-8.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 18, nr 4 (lipiec 2002): 285–302. http://dx.doi.org/10.1016/s0267-3649(02)00719-7.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 18, nr 5 (październik 2002): 366–82. http://dx.doi.org/10.1016/s0267-3649(02)00922-6.

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Saxby, Stephen. "CLSR BRIEFING". Computer Law & Security Review 18, nr 6 (listopad 2002): 446–63. http://dx.doi.org/10.1016/s0267-3649(02)01122-6.

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