Escherichia coli O157:H7 generates a unique biochemical profile on MicroScan conventional gram-negative identification panels.

More than 90% of the strains of Escherichia coli O157:H7 that were identified on a MicroScan gram-negative dried conventional (overnight) panel gave one of two unique biochemical profile numbers that were not detected in other d-sorbitol-negative E. coli or in other strains isolated from pathogenic processes. This suggests that the panel has the capability of being used as a preliminary screening tool for O157:H7 strains involved in hemorrhagic colitis when MacConkey-sorbitol agar is not available.     

X型胶原蛋白与骨骼生长发育关系的研究进展

X型胶原是近年来发现的一种新型胶原,它只存在于生长发育期的即将骨化的软骨内,以液态均相的形式分布于细胞外基质,并启动软骨骨化。它具有特异性合成、局限性分布、一过性存在的特征。许多骨骼系统疾病与X型胶原的异常有着密切的关系。     

Pharmacokinetics of glycyrrhizin after intravenous administration to rats.

A simple high-performance liquid chromatographic method was developed to study the pharmacokinetics of glycyrrhizin in the rat after bolus intravenous administration at a dose of 20, 50, or 100 mg/kg. The decline in the concentration of glycyrrhizin in plasma was generally biexponential at each dose, but the terminal disposition became much slower as the dose was increased. A greater-than-proportional increase in the glycyrrhizin concentration in plasma was observed with an increase in the dose, a result suggesting a dose-dependent glycyrrhizin disposition. The disposition of drug in plasma at each dose fitted well to a two-compartment pharmacokinetic model. The apparent total body clearance decreased significantly with increases in the dose. On the other hand, the apparent distribution volume after intravenous administration was unaffected by the dose. The results indicate that the pharmacokinetics of glycyrrhizin is nonlinear.     

Theophylline disposition in obese rats

A dietary-induced animal model of obesity was examined to assess the mechanisms of obesity-altered changes in theophylline clearance and distribution. Obesity was induced over several months in Sprague-Dawley rats by feeding a palatable "cafeteria" diet containing approximately 60% fat in addition to normal chow (6% fat). Body composition (fat volume and fat-free mass) was measured by a standard tritium dilution method. Obese male rats achieved body weights up to 55% larger than normal controls. Theophylline disposition was not affected by the cafeteria diet or ages of the animals. Theophylline was measured in serum by high-performance liquid chromatography after a 20-mg/kg i.v. dose of drug, and total clearance and steady-state volume of distribution (Vss) were calculated. Absolute clearance (uncorrected for body size parameters) was similar in normal (26.8 +/- 5.4 ml/h) and obese (22.5 +/- 3.6 ml/h) male rats, indicating that total metabolic function remained constant in spite of increased body and liver weights. The Vss increased proportionally with total body weight (0.42-0.48 ml/g). Analysis of drug in fat (partition coefficient = 0.091) indicated limited fat uptake of theophylline. The increase of fat-free mass in obesity was found to account for similar Vss per gram values between normal and obese animals. The diet failed to induce obesity in female rats and the latter exhibited lower drug clearances, even upon adjustment for body weight. The dietary obese male rat resembles the human with respect to theophylline pharmacokinetics and allows demonstration of appropriate normalization of parameters for abnormal body weights under controlled experimental conditions.     

Primary malignant melanoma of the oesophagus: A case report and literature review

We report a case of primary malignant melanoma of the oesophagus (PMMO), followed by a review of recent literature. Surgical resection for operable tumours remains the current practice. In general, the prognosis of PMMO is poor, with a median survival of 10 months. Recent advances, including chemoendocrine and chemoimmunotherapy, might help improve overall survival. Combined endoscopic and systemic therapy is an alternative for patients unfit for surgery, or in patients with metastatic disease.     

Systemic lupus erythematosus: an overview

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease of unknown etiology in which the normal immune responses are directed against healthy organs and tissues. The disregulated immune system produces antibodies that attack the skin, joints, kidneys, heart, and brain. Some people experience mild rashes and arthritis, others suffer debilitating fever, fatigue, joint pain, and severe organ and/or life-threatening disease. This article provides a medical overview of the epidemiology of SLE, the challenges of diagnosing SLE, the complexity of the clinical manifestations and treatment issues, and the impact of SLE on patients' lives. We also discuss the progress in understanding the disease and its therapy over the last century.