[Study on phenotypic and genotypic characterization of clinical multidrug-resistant Escherichia coli isolates].

OBJECTIVE: To study the mechanisms on drug susceptibility and resistance of clinically multidrug-resistant Escherichia coli isolates, to provide information on related treatment. METHODS: The susceptibility of E. coli strains that isolated from different kinds of samples in the last 3 years on drugs was analyzed by agar dilution test, with strains that exhibiting resistances to cefotaxime, ciprofloxacin and amikacin simultaneously collected for further analysis. Resistant genes which mediate resistance to ß-lactamases, fluoroquinolone and aminoglycoside as well as phylogenic type were detected by PCR amplification while genetic relation was analyzed by PFGE. Transferability of resistant plasmids was identified by conjugation test. RESULTS: In total, 137 multidrug-resistant E. coli isolates were collected. Only 1% of the isolates exhibited resistance to both imipenem and meropenem while 4% of the strains were resistant to piperacillin/tazobactam. Most (85%) of the isolates were positive to ESBL and majority of them produced CTX-M. Target substitution and production of methylases were the main mechanisms causing resistance to fluoroquinolones and aminoglycosides respectively. CONCLUSION: The main source of clinical multidrug-resistance was collected from urine samples. Carbapenem and enzyme inhibitor-containing antibiotics seemed to be the available antibiotics that were sensitivity to the clinically multidrug-resistant E. coli isolates.

[The protective role of adiponectin in Con A-induced mouse liver injury].

OBJECTIVE: To evaluate the role of adiponectin in regulating tumor necrosis factor alpha (TNF alpha) production and preventing fulminant autoimmunological damage of hepatocytes following concanavalin A (Con A) injection into mice. METHODS: Three days after recombinant plasmids pAA-neo-mAd were injected into the mice via the tail veins, Con A was injected into the mice. Mice transfected with empty pAA-neo vector served as controls. The serum levels of alanine aminotransferase (ALT), TNF alpha and adiponectin were detected, and histological examination of livers was carried out at different time points after the Con A injection. All results were subjected to statistical analyses. RESULTS: Histological examinations showed that the damage in livers of mice with high serum adiponectin levels was milder than that of the controls. The serum levels of ALT and TNF alpha were both lower than those of the controls (P less than 0.01, respectively). Statistical analyses showed the serum levels of ALT was negatively related to the levels of adiponectin in the sera (r=-0.5034). CONCLUSION: Adiponectin is effective in protecting hepatocytes from Con A-induced immunological injury. The mechanism of this protective effect may be caused by inhibiting the synthesis and/or release of TNF alpha.

Present status of serum lipid levels in Beijing professional populations and its trend of changes over 15 years--a collaborative study of seven research and clinical laboratories in Beijing.

BACKGROUND: China's economy has been growing rapidly since 1980, which may have affected blood lipid levels. We carried out a study on serum lipid levels and prevalence of lipid abnormalities in Beijing professional populations in 2001-2002 and assessed the changing trends of lipid levels by comparing the results with that of a similar study in 1984-1986. METHODS: The study population included 31,068 government employees, medical and educational workers and scientific research personnel (male/female 6:4). All participants had physical examination and blood chemistry tests. Lipid parameters analyzed included total cholesterol, low- and high-density lipoprotein (LDL and HDL) cholesterol and triglyceride. RESULTS: Total cholesterol, LDL cholesterol and triglyceride concentrations increased significantly as compared with the 1984-1986 study, but the variations of lipid levels with age and sex remained unchanged. Age-adjusted prevalence of dyslipidemia and its distribution in different sexes and age groups were statistically analyzed. Comparing the results with the data of the US in the 1990s, total cholesterol concentration was lower by 16 mg/dl in men and 18 mg/dl in women, whereas LDL cholesterol concentration was lower by 20 mg/dl in men and 15 mg/dl in women. HDL cholesterol was significantly higher than the US in both genders. CONCLUSIONS: The mean levels of total cholesterol (LDL cholesterol ) increased rapidly in the 1980s, stabilized and descended slightly in 1990s. Coronary lipid risk level in Beijing professional populations is significantly lower than in the US.