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981.
982.
The RpoS sigma factor in proteobacteria regulates genes in stationary phase and in response to stress. Although of conserved
function, the RpoS regulon may have different gene composition across species due to high genomic diversity and to known environmental
conditions that select for RpoS mutants. In this study, the distribution of RpoS homologs in prokaryotes and the differential
dependence of regulon members on RpoS for expression in two γ-proteobacteria (Escherichia coli and Pseudomonas aeruginosa) were examined. Using a maximum-likelihood phylogeny and reciprocal best hits analysis, we show that the RpoS sigma factor
is conserved within γ-, β-, and δ-proteobacteria. Annotated RpoS of Borrelia and the enteric RpoS are postulated to have separate evolutionary origins. To determine the conservation of RpoS-dependent
gene expression across species, reciprocal best hits analysis was used to identify orthologs of the E. coli RpoS regulon in the RpoS regulon of P. aeruginosa. Of the 186 RpoS-dependent genes of E. coli, 50 proteins have an ortholog within the P. aeruginosa genome. Twelve genes of the 50 orthologs are RpoS-dependent in both species, and at least four genes are regulated by RpoS
in other γ-proteobacteria. Despite RpoS conservation in γ-, β-, and δ-proteobacteria, RpoS regulon composition is subject
to modification between species. Environmental selection for RpoS mutants likely contributes to the evolutionary divergence
and specialization of the RpoS regulon within different bacterial genomes. 相似文献
983.
Chao-Wei Chiang Yi Huang Ka-Wai Leong Lih-Chyang Chen Hua-Chien Chen Shu-Jen Chen Chen-Kung Chou 《Journal of biomedical science》2010,17(1):35
Background
Protein Kinase C (PKC) is a serine/threonine kinase that involved in controlling of many cellular processes such as cell proliferation and differentiation. We have observed previously that TPA (12-O-tetradecanoylphorbol 13-acetate) induces cell cycle arrest in G0/G1 phase in human hepatoma HepG2 cells. However, is there any miRNA involved in PKCα mediated cell growth arrest is still unknown. 相似文献984.
Aim: To estimate the ethylene diamine tetraacetic acid (EDTA) concentration at which the L1 enzyme activity in the cell extracts of Stenotrophomonas maltophilia can be mostly inhibited. Methods and Results: The effective inhibition concentration of EDTA against the L1 enzyme in the cell extracts was firstly evaluated by using the L2 isogenic mutant of S. maltophilia KJ, KJΔL2, as the assayed strain. Approximately 92% L1 activity was inhibited by 10 mmol l?1 EDTA, which is 100‐fold higher than that from previously reported protocols (0·1 mmol l?1). Three phylogenetic clusters of L1 proteins were revealed from 11 clinical S. maltophilia isolates, with a L1 protein divergence of 0–11%. The EDTA concentration required to inhibit the L1 enzymes of different phylogenetic clusters was estimated to be 10 mmol l?1. Conclusion: The previous nitrocefin‐EDTA protocol for differentially quantifying the L1 and L2 activity in the cell extracts has been modified by raising the added EDTA concentration to 10 mmol l?1. Significance and Impact of the Study: A rapid and accurate method for determination of L1 and L2 activity will provide a convenient tool for enzyme characterization and induction mechanism study of S. maltophilia. 相似文献
985.
Sheung‐Fat Ko Yi‐Ling Chen Pei‐Hsun Sung John Y. Chiang Yi‐Ching Chu Chung‐Cheng Huang Chi‐Ruei Huang Hon‐Kan Yip 《Journal of cellular and molecular medicine》2020,24(17):10088-10099
Acute liver ischaemia‐reperfusion injury (IRI), commonly encountered during liver resection and transplantation surgery, is strongly associated with unfavourable clinical outcome. However, a prompt and accurate diagnosis and the treatment of this entity remain formidable challenges. This study tested the hypothesis that 31P‐magnetic resonance spectroscopy (31P‐MRS) findings could provide reliable living images to accurately identify the degree of acute liver IRI and melatonin‐pretreated mitochondria was an innovative treatment for protecting the liver from IRI in rat. Adult male SD rats were categorized into group 1 (sham‐operated control), group 2 (IRI only) and group 3 (IRI + melatonin [ie mitochondrial donor rat received intraperitoneal administration of melatonin] pretreated mitochondria [10 mg/per rat by portal vein]). By the end of study period at 72 hours, 31P‐MRS showed that, as compared with group 1, the hepatic levels of ATP and NADH were significantly lower in group 2 than in groups 1 and 3, and significantly lower in group 3 than in group 1. The liver protein expressions of mitochondrial‐electron‐transport‐chain complexes and mitochondrial integrity exhibited an identical pattern to 31P‐MRS finding. The protein expressions of oxidative stress, inflammatory, cellular stress signalling and mitochondrial‐damaged biomarkers displayed an opposite finding of 31P‐MRS, whereas the protein expressions of antioxidants were significantly progressively increased from groups 1 to 3. Microscopic findings showed that the fibrotic area/liver injury score and inflammatory and DNA‐damaged biomarkers exhibited an identical pattern of cellular stress signalling. Melatonin‐pretreated mitochondria effectively protected liver against IRI and 31P‐MRS was a reliable tool for measuring the mitochondrial/ATP consumption in living animals. 相似文献
986.
Szu-Ying Lee Yin-Cheng Chen I-Chieh Tsai Chung-Jen Yen Shu-Neng Chueh Hsueh-Fang Chuang Hon-Yen Wu Chih-Kang Chiang Hui-Teng Cheng Kuan-Yu Hung Jenq-Wen Huang 《PloS one》2013,8(3)
Purpose
Diabetes mellitus (DM) is the most common cause of end-stage renal disease and is an important risk factor for morbidity and mortality after dialysis. However, glycemic control among such patients is difficult to assess. The present study examined glycemic control parameters and observed glucose variation after refilling different kinds of fresh dialysate in peritoneal dialysis (PD) patients.Methods
A total of 25 DM PD patients were recruited, and continuous glucose monitoring system (CGMS) was applied to measure interstitial fluid (ISF) glucose levels at 5-min intervals for 3 days. Patients filled out diet and PD fluid exchange diaries. The records measured with CGMS were analyzed and correlated with other glycemic control parameters such as fructosamine, albumin-corrected fructosamine (AlbF), glycosylated hemoglobin (HbA1c), and glycated albumin levels.Results
There were significant correlations between mean ISF glucose and fructosamine (r = 0.45, P<0.05), AlbF (r = 0.54, P<0.01), and HbA1c (r = 0.51, P<0.01). The ISF glucose levels in glucose-containing dialysate increased from approximately 7–8 mg/dL within 1 hour of exchange in contrast to icodextrin dialysate which kept ISF glucose levels unchanged.Conclusion
HbA1c and AlbF significantly correlated with the mean ISF glucose levels, indicating that they are reliable indices of glycemic control in DM PD patients. Icodextrin dialysate seems to have a favorable glycemic control effect when compared to the other glucose-containing dialysates. 相似文献987.
988.
989.
990.
Jiin-Chyr Hsu Yung-Fu Chen Wei-Sheng Chung Tan-Hsu Tan Tainsong Chen John Y Chiang 《Biomedical engineering online》2013,12(Z1):S4