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41.
Thomas Walker Lisa Klasson Mohammed Sebaihia Mandy J Sanders Nicholas R Thomson Julian Parkhill Steven P Sinkins 《BMC biology》2007,5(1):39-9
Background
Wolbachia are obligate endosymbiotic bacteria maternally transmitted through the egg cytoplasm that are responsible for several reproductive disorders in their insect hosts, such as cytoplasmic incompatibility (CI) in infected mosquitoes. Species in the Culex pipiens complex display an unusually high number of Wolbachia-induced crossing types, and based on present data, only the wPip strain is present. 相似文献42.
Hattan N Ban K Tanaka E Abe S Sekka T Sugio Y Mohammed MU Sato E Shinozai Y Onishi Y Suma H Handa S Kawada S Hori S Iida A Nakazawa H Mori H 《American journal of physiology. Heart and circulatory physiology》2000,279(3):H1392-H1396
We examined whether transmyocardial revascularization (TMR) relieves myocardial ischemia by increasing regional perfusion via the transmural channels in acute canine experiments. Regional blood flow during transient coronary ligation (2 min) was compared before and 30 min after TMR, and at the third transient ischemia the mid-left ventricle (LV) was cut and immediately frozen along the short axis for the analysis of NADH fluorescence in the regions around the TMR channels. In low-resolution analysis (2-4 g tissue or 2-3 cm(2) area), regional perfusion was not significantly altered after TMR, and NADH fluorescence was observed throughout the ischemic region without significant spatial variation. High-resolution analysis (2.8 mg, 1 mm x 1 mm) revealed that the flow after TMR was lower, and NADH fluorescence was higher in the regions close to the channels (1-2 mm) than in the regions 3-4 mm away from them. Creating TMR channels did not improve the regional perfusion and rather aggravated the local ischemia in the vicinity of the channels in the immediate phase. 相似文献
43.
AFN-1252 is a potent inhibitor of enoyl-ACP reductase from Burkholderia pseudomallei—Crystal structure,mode of action,and biological activity
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Krishnamurthy Narasimha Rao Anirudha Lakshminarasimhan Sarah Joseph Swathi U Lekshmi Ming-Seong Lau Mohammed Takhi Kandepu Sreenivas Sheila Nathan Rohana Yusof Noorsaadah Abd Rahman Murali Ramachandra Thomas Antony Hosahalli Subramanya 《Protein science : a publication of the Protein Society》2015,24(5):832-840
Melioidosis is a tropical bacterial infection caused by Burkholderia pseudomallei (B. pseudomallei; Bpm), a Gram-negative bacterium. Current therapeutic options are largely limited to trimethoprim-sulfamethoxazole and β-lactam drugs, and the treatment duration is about 4 months. Moreover, resistance has been reported to these drugs. Hence, there is a pressing need to develop new antibiotics for Melioidosis. Inhibition of enoyl-ACP reducatase (FabI), a key enzyme in the fatty acid biosynthesis pathway has shown significant promise for antibacterial drug development. FabI has been identified as the major enoyl-ACP reductase present in B. pseudomallei. In this study, we evaluated AFN-1252, a Staphylococcus aureus FabI inhibitor currently in clinical development, for its potential to bind to BpmFabI enzyme and inhibit B. pseudomallei bacterial growth. AFN-1252 stabilized BpmFabI and inhibited the enzyme activity with an IC50 of 9.6 nM. It showed good antibacterial activity against B. pseudomallei R15 strain, isolated from a melioidosis patient (MIC of 2.35 mg/L). X-ray structure of BpmFabI with AFN-1252 was determined at a resolution of 2.3 Å. Complex of BpmFabI with AFN-1252 formed a symmetrical tetrameric structure with one molecule of AFN-1252 bound to each monomeric subunit. The kinetic and thermal melting studies supported the finding that AFN-1252 can bind to BpmFabI independent of cofactor. The structural and mechanistic insights from these studies might help the rational design and development of new FabI inhibitors. 相似文献
44.
The eosinophil cationic protein (ECP) is a human antimicrobial protein involved in the host immune defense that belongs to the pancreatic RNase A family. ECP displays a wide range of antipathogen activities. The protein is highly cationic and its bactericidal activity is dependant on both cationic and hydrophobic surface exposed residues. Previous studies on ECP by site-directed mutagenesis indicated that the RNase activity is not essential for its bactericidal activity. To further understand the ECP bactericidal mechanism, we have applied enzymatic and chemical limited cleavage to search for active sequence determinants.Following a search for potential peptidases we selected the Lys-endoproteinase, which cleaves the ECP polypeptide at the carboxyl side of its unique Lys residue, releasing the N-terminal fragment (0-38).Chemical digestion using cyanogen bromide released several complementary peptides at the protein N-terminus. Interestingly, ECP treatment with cyanogen bromide represents a new example of selective chemical cleavage at the carboxyl side of not only Met but also Trp residues. Recombinant ECP was denatured and carboxyamidomethylated prior to enzymatic and chemical cleavage. Irreversible denaturation abolishes the protein bactericidal activity.The characterization of the digestion products by both enzymatic and chemical approaches identifies a region at the protein N-terminus, from residues 11 to 35, that retains the bactericidal activity. The most active fragment, ECP(0-38), is further compared to ECP derived synthetic peptides. The region includes previously identified stretches related to lipopolysaccharide binding and bacteria agglutination. The results contribute to define the shortest ECP minimized version that would retain its antimicrobial properties. The data suggest that the antimicrobial RNase can provide a scaffold for the selective release of cytotoxic peptides. 相似文献
45.
Nicky Spence Nancy C.L. Rodrigues Polykarpos Angelos Nomikos Khalid Mohammed Yaseen Mansour Abdullah Alshehri 《Journal of musculoskeletal & neuronal interactions》2020,20(4):480
Objectives:The purpose of this study is to establish whether physiotherapists’ ratings are consistent, when using the Action Research Arm Test (ARAT) to score a chronic stroke patient.Methods:This was part of a large project establishing the reliability in chronic stroke. This study used a correlational design comparing the association between physiotherapist scores of the same patient, to establish the ARAT’s inter-rater reliability. The COSMIN checklist was followed to enhance the methodology of the study.Results:Twenty physiotherapists (8 female and 12 male) aged between 25 and 53 years were selected. There were no participant dropouts or withdrawals. The sample size was normally distributed. The physiotherapists appeared representative of the UK physiotherapy population, with the exception of gender. The distribution of scores showed a normal distribution with standard deviation of score of 1.9. The Kendall’s W test showed 0.711 of agreement between the raters. The scores achieved statistical significance showing consistency between physiotherapists’ scores with chronic stroke. Limitations of the study were the use of a small single center convenience sample that may reduce the generalizability of the findings.Conclusions:The ARAT is consistent when scored by physiotherapists in a chronic stroke population. The inter-rater reliability range was (0.70 to 0.90) which is categorized as good. 相似文献
46.
May A. Alsayb Ali Dakhilallah D. Alsamiri Hatem Q. Makhdoom Turki Alwasaidi Haitham Mohammed Osman Waleed H. Mahallawi 《Saudi Journal of Biological Sciences》2021,28(7):4010-4015
By the beginning of 2021, the battle against coronavirus disease 2019 (COVID-19) remains ongoing. Investigating the adaptive immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19, in patients who have recovered from this disease could contribute to our understanding of the natural host immune response. We enrolled 38 participants in this study. 7 healthy participants and 31 COVID-19 patients who had recovered from COVID-19 and categorized them into 3 groups according to their previous clinical presentations: 10 moderate, 9 mild, and 12 asymptomatic. Flow cytometry analysis of peripheral lymphocyte counts in recovered patients showed significantly increased levels of CD4+ T cells in patients with a history of mild and moderate COVID-19 symptoms compared with those healthy individuals (p < 0.05 and p < 0.0001 respectively). whereas no significant difference was observed in the CD8+ T cell percentage in COVID-19-recovered patients compared with healthy individuals. Our study demonstrated that antibodies against the SARS-CoV-2 spike protein (anti-S) IgG antibody production could be observed in all recovered COVID-19 patients, regardless of whether they were asymptomatic (p < 0.05)or presented with mild (p < 0.0001) or moderate symptoms (p < 0.01). Anti-S IgG antibodies could be detected in participants up to 90 days post-infection. In conclusion, the lymphocyte levels in recovered patients were associated with the clinical presentation of the disease, and further analysis is required to investigate relationships between different clinical presentations and lymphocyte activation and function. 相似文献
47.
Effects of thyroxine exposure on the Twist 1 +/− phenotype: A test of gene–environment interaction modeling for craniosynostosis
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48.
Sileshi Belew Mestawet Getachew Sultan Suleman Tesfaye Mohammed Habetewold Deti Matthias D'Hondt Evelien Wynendaele Zeleke Mekonnen Jozef Vercruysse Luc Duchateau Bart De Spiegeleer Bruno Levecke 《PLoS neglected tropical diseases》2015,9(9)
BackgroundThere is a worldwide upscale in mass drug administration (MDA) programs to control the morbidity caused by soil-transmitted helminths (STHs): Ascaris lumbricoides, Trichuris trichiura and hookworm. Although anthelminthic drugs which are used for MDA are supplied by two pharmaceutical companies through donation, there is a wide range of brands available on local markets for which the efficacy against STHs and quality remain poorly explored. In the present study, we evaluated the drug efficacy and quality of two albendazole brands (Bendex and Ovis) available on the local market in Ethiopia.Conclusion/SignificanceThe study revealed that differences in efficacy between the two brands of albendazole (ABZ) tablets against hookworm are linked to the differences in the in-vitro drug release profile. Differences in uptake and metabolism of this benzimidazole drug among different helminth species may explain that this efficacy difference was only observed in hookworms and not in the two other species. The results of the present study underscore the importance of assessing the chemical and physicochemical quality of drugs before conducting efficacy assessment in any clinical trials to ensure appropriate therapeutic efficacy and to exclude poor drug quality as a factor of reduced drug efficacy other than anthelminthic resistance. Overall, this paper demonstrates that “all medicines are not created equal”. 相似文献
49.
50.
Protein secretion in Pseudomonas aeruginosa: characterization of seven xcp genes and processing of secretory apparatus components by prepilin peptidase 总被引:22,自引:0,他引:22
Marc Bally Alain Filloux Mohammed Akrim Geneviéve Ball ree Lazdunski Jan Tommassen 《Molecular microbiology》1992,6(9):1121-1131
The xcp genes are required for the secretion of most extracellular proteins by Pseudomonas aeruginosa. The products of these genes are essential for the transport of exoproteins across the outer membrane after they have reached the periplasm via a signal sequence-dependent pathway. To date, analysis of three xcp genes has suggested the conservation of this secretion pathway in many Gram-negative bacteria. Furthermore, the xcpA gene was shown to be identical to pilD, which encodes a peptidase involved in the processing of fimbrial (pili) subunits, suggesting a connection between pili biogenesis and protein secretion. Here the nucleotide sequences of seven other xcp genes, designated xcpR to -X, are presented. The N-termini of four of the encoded Xcp proteins display similarity to the N-termini of type IV pili, suggesting that XcpA is involved in the processing of these Xcp proteins. This could indeed be demonstrated in vivo. Furthermore, two other proteins, XcpR and XcpS, show similarity to the PilB and PilC proteins required for fimbriae assembly. Since XcpR and PilB display a canonical nucleotide-binding site, ATP hydrolysis may provide energy for both systems. 相似文献