Objective To investigate the histological changes of the right ventricular remodeling in Xinjiang Mar-mota baibacina which are adapted to high-altitude hypoxia .Methods Hematoxylin and eosin and Masson staining was used to examine the pathological changes and degree of fibrosis , and immunohistochemical technique was used to detect connexin 43 ( CX43) expression in the right ventricular myocardium .Results In the right ventricular myocardium , cardio-myocyte hypertrophy and increased amount of collagen fibers were observed .The right ventricular hypertrophy index and weight index of Marmota baibacina were significantly higher , and expression of CX43 was significantly reduced than that of normal rats ( P<0.05 for both ) .Conclusions High-altitude hypoxia induces right ventricular remodeling in Xinjiang Marmota baibacina.It can be used as an ideal animal model for studies on the mechanisms of hypoxia adaptation on high -altitude plateau .

OBJECTIVE To investigate the antimicrobial resistance of hospital-and community-acquired pathogens collected from 10 teaching hospitals located at different areas in China in 2006.METHODS According to the study protocol,the strains of Streptococcus pneumoniae,meticillin-susceptible Staphylococcus aureus(MSSA),Escherichia coli and Klebsiella pneumoniae were collected and sent to the central lab for reidentification and susceptibility testing.The minimal inhibitory concentrations(MICs) of antimicrobial agents against Str.pneumoniae were determined by Etest method and MICs of antimicrobial agents against S.aureus,E.coli and K.pneumoniae strains were determined by agar dilution method.WHONET5.4 software was used to analyze the data.RESULTS Among 353 Str.pneumoniae strains,74.2% were penicillin-susceptible(PSSP),9.6% were penicillin-intermediate(PISP) and 16.2% were penicillin-resistant(PRSP).Strains from different hospitals showed different sensitivity to penicillin.Among ?-lactam antibiotics,cefuroxime showed the lowest susceptibility rate of 0%(for PRSP) to 76.7%(for PSSP).The susceptibility rate to ceftriaxone and amoxicillin-clavulanic acid was 98.1% and 98.9% in PSSP group,61.8% and 64.7% in PISP group,and 15.8% and 10.5% in PRSP group.The ESBLs rate was 56.2% among 267 Escherichia strains and 42.7% among 206 K.pneumoniae strains.For ESBLs-producing strains,the susceptibility rates to cefotaxime and ceftriaxone were low and the rate to ceftazidime was relatively high among ?-lactam antibiotics.73.4% MSSA strains produced ?-lactamase.?-Lactam antibiotics tested showed high susceptibility against MSSA strains.The susceptibility rate was 98.9-100%.The susceptibility rate to ciprofloxacin and levofloxacin was 80.8% and 88.1%,separately.CONCLUSIONS Fluoroquinolones show high susceptibility against Str.pneumoniae.Ceftriaxone and amoxicillin-clavulanic acid have relatively high susceptibility among ?-lactams.For MSSA and non-ESBLs-producing E.coli and K.pneumoniae strains,?-lactams show high susceptibility.For ESBLs-producing E.coli and K.pneumoniae strains,the susceptibility rates to cefotaxime and ceftriaxone are low and that to ceftazidime,cefepime and cefoperazone-sulbactam are relatively high.

Objective To investigate antimicrobial resistance among Streptococcus pneumoniae clinically isolated from 14 teaching hospitals located at different areas in China in 2005-2008 and to give logical guidance for clinical empirical therapy.Methods A total of 1 317 non-repetitive S.pneumoniae isolates in 14 teaching hospitals from 2005-2008 were collected and sent to the central lab for reidentification and susceptibility testing, including 271 isolates collected in 2005, 391 isolates collected in 2006, 363 isolates collected in 2007 and 292 isolates collected in 2008. Most of the isolates were from community-acquired respiratory tract infections, which were isolated from outpatient or emergency department patients with respiratory tract infections or those patients with respiratory tract infections within ≤48 hours hospitalization.The districts where the organisms were isolated include North China, Northeast China, South China, Central and Northwest China and East China.The patients included adults, teenagers and children.The minimum inhibitory concentrations (MICs) or inhibitory zone diameter of 17 antimicrobial agents were determined by Etest method, agar dilution method or disk diffusion method.WHONET5.5 software was used to analyze susceptibility rate, intermediate rate, resistance rate, MIC50 and MIC90.Results Linezolid (100%) and fluoroquinolones (95.2%-99.7%) showed excellent activities against S.pneumoniae.Among β-lactams, amoxicillin-clavulanic acid remained high activities (73.8%-92.1%),followed by penicillin, ceftriaxone and cefepime with year-over-year decrease in activities.The activities of three second-generation cephalosporins were low (36.3%-38.4% in 2008).The activities of erythromycin, azithromycin, clindamycin, trimethoprim/sulfamethoxazole and tetracycline against S.pneumoniae were poor and decreased year over year.The incidence of penicillin non-susceptible S.pneumoniae (PNSP) was increasing especially for PISP (from 4.4% in 2005 to 20.2% in 2008).The incidence of PNSP in North China was low (6.0%), while this value were high in central China and East China (30.1% and 38.7%, separately).The incidence of PNSP in adults (15.7%) was obviously lower than that in children(≤5 years:33.0%) and teenagers (6-17 years:38.2%).Conclusions linezolid and fluoroquinolones showed excellent in vitro activity against S.pneumoniae, followed by penicillin and cephalosporins with year-over-year decrease of activity. Clinicians should pay more attention when using those antimicrobial agents with poor activity against S.pneumoniae, which include macrolides, clindamycin, trimethoprim/sulfamethoxazole and tetracycline.