Occurrence of haloacetic acids (HAAs) and trihalomethanes (THMs) in drinking water of Taiwan

In this study, water samples were collected from 86 water treatment plants for analysis of haloacetic acids (HAAs) and trihalomethanes (THMs) from February to March, 2007 and from July to August, 2007. Both seasonal and geographical variations of disinfection by-products (DBPs) in drinking water of Taiwan were presented. The results showed that the five HAA concentrations (HAA5) were 1.0-38.9 microg/L in the winter and 0.2-46.7 microg/L in the summer; and the total THMs were ND-99.4 microg/L in the winter and ND-133.2 microg/L in the summer. For samples taken from the main Taiwan island, dichloroacetic acid (29.4-31.7%) and trichloroacetic acid (25.3-27.6%) were the two major HAA species, and trichloromethane was the major THM species (49.9-62.2%) in finished water. For water treatment plants located on the offshore islands outside of Taiwan, high bromide concentration was found in raw water, and higher percentage of brominated THMs and HAAs were formed in the overall formation. A statistically significant (P < 0.005) logarithmic linear regression model was found to be useful to describe the correlations between TTHM and HAA5 or nine HAAs (HAA5 = 1.219 x TTHM (0.754), R(2) = 0.658; HAA9 = 1.824 x TTHM (0.735), R(2) = 0.678). No apparent difference was observed for DBPs concentrations between finished water and distribution samples in this study.

Preconditioning somatothermal stimulation on right seventh intercostal nerve territory increases hepatic heat shock protein 70 and protects the liver from ischemia-reperfusion injury in rats

Hyperthermic preconditioning attenuates the heat-induced cellular response to a subsequent severe heat challenge. However, it is impractical to perform whole-body hyperthermia in humans. This study was designed to test the hypotheses that hepatic heat shock protein 70 (Hsp70) could be induced by local somatothermal stimulation (LSTS) on right seventh intercostal nerve territory and that preconditioning the rats with LSTS protects the liver from subsequent ischemia-reperfusion injury. LSTS was brought about by application of a heating rod above right seventh intercostal nerve territory in male Sprague-Dawley rats. Hepatic gene expression of Hsp70 was assessed by Western blot and reverse transcription polymerase chain reaction (RT-PCR). Finally, serum ALT and AST and the lipid peroxidation product malondialdehyde (MDA) were evaluated in ischemic-reperfused rats preconditioned by application of LSTS on right seventh intercostal nerve territory. The results showed that hepatic gene expression of Hsp70 was upregulated in rats treated with LSTS. When animals were preconditioned with LSTS, followed by subsequent ischemia-reperfusion injury of the liver, there were significant decreases in liver enzymes (ALT/AST) and MDA formation in rats pretreated with one dose of LSTS (LSTS-1 group) as compared with those not treated with LSTS (control group) or treated with three doses of LSTS (LSTS-3 group). We conclude that mild local heat stress (one dose) on right seventh intercostal nerve territory upregulates hepatic gene expression of Hsp70 and protects the liver from subsequent ischemia-reperfusion injury. This might provide an easily applicable method for those patients facing ischemia-reperfusion challenge of the liver, as in liver resection and liver transplantation.

Freeze crystallization of imipenem

This work is a study of the freeze crystallization process developed for the production of a rapidly soluble and stable crystalline form of imipenem, an antibiotic. The objective is to understand the relationship between process conditions and the product crystallinity during the freeze crystallization. Solutions of imipenem and sodium bicarbonate, a drug stabilizer, were crystallized in acetone-water solvent systems at various ratios and temperatures. The degree of crystallinity of the resulting products was measured using an X-ray powder diffraction analysis technique. The acetone-water S-L phase diagram was used to correlate the resulting degrees of crystallinity of imipenem products and equilibrium properties of the system. It was discovered that the conversion of amorphous imipenem to crystalline products was directly related to the percentage of equilibrium liquid during the freeze crystallization. Solubility data indicated that imipenem is virtually insoluble in these equilibrium liquid phases. This suggests that the phase transition from the amorphous state to the crystalline state is mediated by the presence of the liquid phase.

Survey on use of antimicrobial agents and bacterial resistance in Huashan Hospital

A cross-section study was carried out to assess the general patterns in use of antimicrobial agents and the trends of bacterial resistance in Huashan Hospital. Of 2,400 patients whose charts were reviewed, 61% were given such drugs. 3,596 antibiotic courses were prescribed. Gentamicin was most frequently used. Results of the susceptibility test of 320 bacterial strains showed a high percentage of resistance against gentamicin, ampicillin, and chloramphenicol. Our findings suggest that antibiotic policies in the hospital need reappraising.