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OBJECTIVE To understand the effects of meropenem on the biofilms of Pseudomonas aeruginosa lasR/rhlR mutations in vitro.METHODS The biofilms of PAEO1 and its lasR,rhlR,and lasR rhlR mutants were incubated in a polyvinyl chloride tube in 0.9% saline for three days,then were immersed in meropenem solution of 26 ?g/ml for 24 hours,and examined by scanning electron microscopy(SEM).RESULTS After three days incubation,PAEO1 biofilms showed a well-developed structure,however,the biofilms of PAEO1 lasR,rhlR,and lasR rhlR mutants were thin and poor developed;after 24 hours in meropenem solution,PAEO1 biofilm become rareness,whereas PAEO1 lasR,rhlR,and lasR rhlR mutants biofilms were almost destructed and only small pieces left.CONCLUSIONS lasR/rhlR Genes play probably an important role in the formation of P.aeruginosa biofilm and in the resistance to meropenem.
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OBJECTIVE To understand the effects of lasR/rhlR mutations on the biofilm formation of Pseudomonas aeruginosa in vitro.METHODS The biofilms of PAEO1 and lasR,rhlR,and lasR rhlR mutants were incubated in a polyvinyl chloride tube in 0.9% saline and studied by means of scanning electronic microscopy(SEM) after three days′ incubation.RESULTS After 3 day′s incubation,PAEO1 biofilm showed a well-developed structure,whereas thin and poor developed biofilms were seen in lasR/rhlR mutant groups.CONCLUSIONS lasR/rhlR Genes play probably an important role in the formation of P.aeruginosa biofilm in vitro.
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Designing experimentation is the most important phase in function experimentation teaching,and a simulation process of science research.Students choose the topic freely,design schema and practice by themselves.Based on pathophysilolgy,the article has practiced functional designing experimentation among the students of clinical medicine in 2006 grade.Results indicated that the practice of designing experimentation is helpful for raising general diathesis and innovative ability of students,and it will be the focus of function experimentation innovation in future.
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Aim To study the effects of smoking and glonoine on intracellular free Ca2+ concentration([Ca2+]i) in vascular smooth muscle cell in rabbits with atherosclerosis,and to explore the effects of smoking on atherosclerosis and biologic action of glonoine.Methods An atherosclerosis in rabbits was produced.The vascular smooth muscle cells were isolated.The cells were loaded by Fluo-3/AM.[Ca2+]i in vascular smooth muscle cell was measured by flow cytometer(FCM).The spatial distribution and the dynamic changes of [Ca2+]i in single vascular smooth muscle cells were determined by laser scanning confocal microscopy(LSCM).Results Atherosclerosis plaques in arteriae aorta were observed and the degrees were different in various groups.[Ca2+]i in vascular smooth muscle cells in rabbits with atherosclerosis markedly increased[(48.45?5.31) vs that in saline control(38.09?2.57),P
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<p><b>OBJECTIVE</b>To investigate the antagonistic effect and mechanism of the effect of cyproheptadine (Cyp) on endotoxic shock in rats.</p><p><b>METHODS</b>Endotoxic shock was produced in rats by i.v. injection of lipopolysaccharides (LPS) (5 mg/kg). Tumor necrosis factor (TNF(alpha)) mRNA expression was assessed by Northern blot. Plasma TNF(alpha) content was measured by radioimmunoassay. Plasma superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured. The intracellular free calcium concentration ([Ca(2+)](i)) in single endothelial cells was determined by laser scanning confocal microscopy (LSCM).</p><p><b>RESULTS</b>Cyp 5 mg/kg injected immediately after i.v. LPS raised the mean arterial blood pressure (MABP) of shocked rats and improved their 24 h survival rate. Meanwhile, Cyp markedly decreased TNF(alpha) mRNA levels in rat liver (18 +/- 10 vs. LPS + saline 38 +/- 10, P < 0.01) as well as plasma TNF(alpha) content [(7.8 +/- 2.4) microg/L vs. LPS + saline (21.5 +/- 3.2) microg/L, P < 0.01)]. It enhanced plasma SOD activity [(1037.2 +/- 112.8) NU/L vs LPS + saline (615.4 +/- 92.6) NU/L, P < 0.01], reduced the MDA content [(5.2 +/- 1.1) micromol/L vs. LPS + saline (9.8 +/- 1.5) micromol/L, P < 0.01], and inhibited TNF(alpha)-induced [Ca(2+)](i) elevation.</p><p><b>CONCLUSION</b>Cyp exerts an anti-endotoxic shock effect by inhibiting TNF(alpha) gene expression, enhancing SOD activity, reducing lipid peroxidation, and preventing [Ca(2+)](i) overload.</p>
Subject(s)
Animals , Rats , Cyproheptadine , Pharmacology , Histamine H1 Antagonists , Pharmacology , Malondialdehyde , Blood , Rats, Wistar , Shock, Septic , Drug Therapy , Metabolism , Superoxide Dismutase , Blood , Tumor Necrosis Factor-alpha , GeneticsABSTRACT
AIM: To study the effects of cyproheptadine (Cyp) and anisodamine (Ani)on the changes of intracellular free Ca 2+ concentration ([Ca 2+ ] i) induced by tumor necrosis factor (TNF ?) in single endothelial cells, and to explore the mechanisms of TNF ?-mediated shock and antishock actions of Cyp and Ani. METHODS: Human umbilical vein endothelial cell strains(ECV304) were seed in 35 mm tissue culture dish with 2 mL DMEM culture medium. The cultured cells were loaded by Fluo-3/AM. The spatial distribution and the dynamic changes of [Ca 2+ ] i in single endothelial cell was determined by laser scanning confocal microscopy(LSCM). RESULTS: [Ca 2+ ] i in single endothelial cell after stimulation of TNF ? rapidly increased in a dose-dependent manner and approached the peak value within 60 seconds, afterwards, decreased and kept above the basal level. The confocal scanning image showed that [Ca 2+ ] i elevation was more obvious in nuclear than in cytoplasma, and decreased slowly. Cyp (3?10 -5 , 6?10 -5 mol/L) and Ani (2?10 -5 , 4?10 -5 mol?L -1 ) markedly inhibited TNF ? (1.2?10 -9 mol?L -1 )-induced [Ca 2+ ] i elevation. CONCLUSIONS: TNF ? markedly induces elevation of [Ca 2+ ] i in single endothelial cell, it may be an important mechanism of TNF ?-induced shock and tissue injury. Cyp and Ani obviously suppress TNF ?-induced [Ca 2+ ] i elevation, which probably is one of the mechanisms of their antishock effects.
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OBJECTIVE To understand the importance of quorum sensing(QS)system in Pseudomonas aeruginosa(PAE)biofilm infection in lungs,the pathogenic effects of the wild-type P.aeruginosa PAEO1 were compared with QS double mutants PAEO1 lasR rhlR and PAEO1 lasⅠ rhⅡ in vivo.METHODS Rats were challenged intratracheally with alginate embedded PAE strain PAEO1 and the mutants of QS in the concentration of 1?109 colony-forming units per milliliter(CFU/ml).Two weeks post intratracheal challenge with P.aeruginosa,parameters were evaluated.RESULTS Two weeks after challenge,significantly milder microscopic and macroscopic lung pathology(P
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This paper reported the effect of captopril (SQ14225) on rabbits hemorrhagic shock. After late hemorrhagic shock model (MABP 40mmHg, maintained for 90min) was replicated, 26 rabbits were divided randomly into a captopril-treated group (n=13) and a control group (n=13). In the treated group, captopril(1mg/kg) was infused with normal saline (15ml/kg), low molecular dextran (15ml/kg)and shed blood, an hour later, the MABP, CVP and renal blood flow rose markedly, the platelet aggregation was significantly lowered and mesenteric microcireulation was improved remarkably. Three hours later, the various indexes mentioned above returned almost to normal (before the shock). The survival rate in 5 hours was 91.7%. The difference between the control and the treated group was quite significant (P