排序方式: 共有62条查询结果,搜索用时 31 毫秒
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Y E Polotsky E M Dragunskaya V G Seliverstova T A Avdeeva M G Chakhutinskaya I Kétyi A Vertényl B Ralovich L Em?dy I Málovics N V Safonova E S Snigirevskaya E I Karyagina 《Acta microbiologica Academiae Scientiarum Hungaricae》1977,24(3):221-236
Macroscopic, light and electron microscopic alterations in ligated rabbit intestinal loops challenged with five standard enterotoxigenic Escherichia coli (ETEC) and twenty-three enteropathogenic E. coli (EEC-I) strains, freshly isolated from infantile enteritis cases, were investigated. Only two O26 : K60 : H11 strains produced enterotoxin. Their living cultures, sterile filtrates of the fluid medium and ultrasonic lysates of the bacteria resulted in pronounced hypersecretion of the intestinal epithelium followed by fluid accumulation and loop dilatation. These two E. coli strains, similarly as the other loop-negative EEC-I strains, were able to penetrate into the intestinal epithelium. In contrast to the standard ETEC strains, the EEC-I bacteria, adhering to the brush border, intruded into the microvilli, multiplied on the outer epithelial cell membrane making close contact with it and, causing, shedding of microvilli, penetrated into enterocytes becoming enclosed in membrane-bound phagosome-like vacuoles, appeared in the lamina propria and elicited mild focal polymorphonuclear infiltration. 相似文献
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Bogush TA Dudko EA Beme AA Bogush EA Kim AI Polotsky BE Tjuljandin SA Davydov MI 《Biochemistry. Biokhimii?a》2010,75(12):1421-1427
This review considers data on expression of different types of estrogen receptors (ERα and ERβ) in in vitro cultured cells of non-small cell lung cancer and also in human and animal lung tumors. Estrogens are shown to play an important
role in genesis and development of non-small cell lung cancer because the estrogen-stimulated cell proliferation as well as
antiestrogen-caused inhibition of proliferation occurred only in the cells expressing different types of estrogen receptors.
In general, the situation is similar to that observed in breast cancer, but in the cells of non-small cell lung cancer not
ERα are expressed in more than half of cases but ERβ. Just estrogen receptors β play the crucial role in inducing cell proliferation
in response to estrogens, and ERβ is a prognostic marker of a favorable course of non-small cell lung cancer. Data on the
interactions between ER and EGFR signaling pathways, as well as on the additive antitumor effect of antiestrogens (tamoxifen
and fulvestrant) combined with tyrosine kinase inhibitors (gefitinib, erlotinib, and vandetanib) are considered. The review
also includes data on the influence of estrogens on genesis and development of lung cancer in humans and animals and the frequency
of ERα and ERβ expression in non-small cell lung cancer in tissues from patients of the two sexes. Problems of quantitative
determination of α and β estrogen receptors in the tumor cells are also discussed. 相似文献
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We study equilibrium aspects of molecular recognition of two biomolecules using idealized model systems and methods from statistical physics. Starting from the basic experimental findings we demonstrate exemplarily how an idealized coarse-grained model for the investigation of molecular recognition of two biomolecules can be developed. In addition we provide details regarding two model systems for the recognition of a flexible and a rigid biomolecule respectively, the latter taking into account conformational changes. We focus particularly on the interplay and influence of the correlations of the residue distributions of the biomolecules on the recognition process. 相似文献
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Savransky V Bevans S Nanayakkara A Li J Smith PL Torbenson MS Polotsky VY 《American journal of physiology. Gastrointestinal and liver physiology》2007,293(4):G871-G877
Obstructive sleep apnea (OSA) causes chronic intermittent hypoxia (CIH) during sleep. OSA is associated with nonalcoholic steatohepatitis (NASH) in obese individuals and may contribute to progression of nonalcoholic fatty liver disease from steatosis to NASH. The purpose of this study was to examine whether CIH induces inflammatory changes in the liver in mice with diet-induced hepatic steatosis. C57BL/6J mice (n = 8) on a high-fat, high-cholesterol diet were exposed to CIH for 6 mo and were compared with mice on the same diet exposed to intermittent air (control; n = 8). CIH caused liver injury with an increase in serum ALT (461 +/- 58 U/l vs. 103 +/- 16 U/l in the control group; P < 0.01) and AST (637 +/- 37 U/l vs. 175 +/- 13 U/l in the control group; P < 0.001), whereas alkaline phosphatase and total bilirubin levels were unchanged. Histology revealed hepatic steatosis in both groups, with mild accentuation of fat staining in the zone 3 hepatocytes in mice exposed to CIH. Animals exposed to CIH exhibited lobular inflammation and fibrosis in the liver, which were not evident in control mice. CIH caused significant increases in lipid peroxidation in serum and liver tissue; significant increases in hepatic levels of myeloperoxidase and proinflammatory cytokines IL-1beta, IL-6, and CXC chemokine MIP-2; a trend toward an increase in TNF-alpha; and an increase in alpha1(I)-collagen mRNA. We conclude that CIH induces lipid peroxidation and inflammation in the livers of mice on a high-fat, high-cholesterol diet. 相似文献
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Mesarwi Omar A. Sharma Ellora V. Jun Jonathan C. Polotsky Vsevolod Y. 《Sleep and biological rhythms》2015,13(1):2-17
Sleep and Biological Rhythms - It has recently become clear that obstructive sleep apnea (OSA) is an independent risk factor for the development of metabolic syndrome, a disorder of defective... 相似文献
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E. A. Anedchenko A. A. Dmitriev G. S. Krasnov O. O. Kondrat’eva E. P. Kopantsev T. V. Vinogradova M. V. Zinov’eva I. B. Zborovskaya B. E. Polotsky O. V. Sacharova V. I. Kashuba E. R. Zabarovsky V. N. Senchenko 《Molecular Biology》2008,42(6):859-869
Chromosomal and genome abnormalities of 3p are frequent in many epithelial tumors, including lung cancer. Several critical regions with a high frequency of hemi-and homozygous deletions in tumors are known for 3p, and more than 20 cancer-related genes occur in 3p21.3. Quantitative real-time PCR was used to measure the mRNA level for tumor-suppressor and candidate genes of 3p21.3 (RBSP3/CTDSPL, NPRL2/G21, RASSF1A, ITGA9, HYAL1, and HYAL2) in major types of non-small cell lung cancer (NSCLC): squamous cell lung cancer (SCC) and lung adenocarcinoma (AC). A significant (2-to 100-fold) and frequent (44–100%) decrease in mRNA levels was observed in NSCLC. The mRNA level decrease and its frequency depended on the histological type of NSCLC for all genes. The downregulation of RASSF1A and ITGA9 was significantly associated with AC progression; the same tendency was observed for RBSP3/CTDSPL, NPRL2/G21, HYAL1, and HYAL2. In SCC, the downregulation of all genes was not associated with the clinical stage, tumor cells differentiation, and metastasis in lymph nodes. The RBSP3/CTDSPL, NPRL2/G21, ITGA9, HYAL1, and HYAL2 mRNA levels significantly (5-to 13-fold on average) decreased at a high frequency (83–100%) as early as SCC stage I. Simultaneous downregulation of all six genes was observed in some tumor samples and was independent of the gene position in 3p21.3 and the functions of the protein products. The Spearman correlation coefficient r s was 0.63–0.91, p < 0.001. The highest r s values were obtained for gene pairs ITGA9-HYAL2 and HYAL1-HYAL2, whose products mediate cell-cell adhesion and cell-matrix interactions; coregulation of the genes was assumed on this basis. Both genetic and epigenetic mechanisms proved to be important for downregulation of RBSP3/CTDSPL and ITGA9. This finding supported the hypothesis that the cluster of cancerrelated genes in the extended 3p21.3 locus is simultaneously inactivated during the development and progression of lung cancer and other epithelial tumors. A significant and frequent decrease in the mRNA level of the six genes in SCC could be important for developing specific biomarker sets for early SCC diagnosis and new approaches to gene therapy of NSCLC. 相似文献
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Audrey Liu Luis Pichard Hartmut Schneider Susheel P Patil Philip L Smith Vsevolod Polotsky Alan R Schwartz 《Journal of applied physiology》2008,105(4):1237-1245
We characterized the passive structural and active neuromuscular control of pharyngeal collapsibility in mice and hypothesized that pharyngeal collapsibility, which is elevated by anatomic loads, is reduced by active neuromuscular responses to airflow obstruction. To address this hypothesis, we examined the dynamic control of upper airway function in the isolated upper airway of anesthetized C57BL/6J mice. Pressures were lowered downstream and upstream to the upper airway to induce inspiratory airflow limitation and critical closure of the upper airway, respectively. After hyperventilating the mice to central apnea, we demonstrated a critical closing pressure (Pcrit) of -6.2 +/- 1.1 cmH(2)O under passive conditions that was unaltered by the state of lung inflation. After a period of central apnea, lower airway occlusion led to progressive increases in phasic genioglossal electromyographic activity (EMG(GG)), and in maximal inspiratory airflow (Vi(max)) through the isolated upper airway, particularly as the nasal pressure was lowered toward the passive Pcrit level. Moreover, the active Pcrit fell during inspiration by 8.2 +/- 1.4 cmH(2)O relative to the passive condition (P < 0.0005). We conclude that upper airway collapsibility (passive Pcrit) in the C57BL/6J mouse is similar to that in the anesthetized canine, feline, and sleeping human upper airway, and that collapsibility falls markedly under active conditions. Active EMG(GG) and Vi(max) responses dissociated at higher upstream pressure levels, suggesting a decrease in the mechanical efficiency of upper airway dilators. Our findings in mice imply that anatomic and neuromuscular factors interact dynamically to modulate upper airway function, and provide a novel approach to modeling the impact of genetic and environmental factors in inbred murine strains. 相似文献