An evaluation of cefaclor in Pakistani children with pharyngotonsillitis.

OBJECTIVE: To assess the efficacy, safety of cefaclor for the treatment of pharyngotonsillitis in Pakistani children. METHOD: Pakistani children between the ages of two to twelve years and diagnosed with pharyngotonsillitis were eligible to participate in the study. Cefaclor was administered three times daily for a total dose of 20-40 mg/kg/day, depending on the severity of the infection, for 7 days. Patients were evaluated on the basis of symptomatic response and antibiotic susceptibility pattern as a result of bacteriological examination. RESULTS: Based on observed pre-therapy signs/symptoms of infection with pharyngotonsillitis, 99% of patients (95% CI=94.9% to 100.0%) were reported as having a symptomatic response of Cure or Improvement by end of study. Group A b-haemolytic Streptococci was the most prevalent pathogen isolated pre-therapy (occurring in 45% of patients). Of all patients for whom this pathogen was isolated, 64% had complete eradication by end of therapy, while there was persistence or superinfection in 36% of patients. Only 9 occurrences of non-serious adverse events were observed among 7 of the 107 patients, including diarrhea (5), nausea (1), vomiting (1), rash (1) and stomatitis (1). CONCLUSION: Based on the high symptomatic response rate of 99% and the positive safety data, cefaclor was found to be effective and safe in treating Pakistani children with pharyngotonsillitis.

Biosynthesis of exopolysaccharide by Pseudomonas aeruginosa.

In batch cultures of Pseudomonas aeruginosa, the maximum rate of exopolysaccharide synthesis occurred during exponential growth. In nitrogen-limited continuous culture, the specific rate of exopolysaccharide synthesis increased from 0.27 g g of cell-1 h-1 at a dilution rate (D) of 0.05 h-1 to 0.44 g g of cells h-1 at D=0.1 H-1. The yield of exopolysaccharide on the basis of glucose used was in the range of 56 to 64%. Exopolysaccharide was also synthesized in carbon-limited cultures at 0.19 g g of cell-1 h-1 at D=0.05 h-1 in a 33% yield. Nonmucoid variants appeared after seven generations in continuous culture and rapidly increased in proportion to the total number of organisms present.

Studies on mitochondria membrane proteins in Saccharomyces cerevisiae under different degrees of glucose repression.

Mitochondrial membrane proteins synthesized in vivo in the presence of cycloheximide were analyzed on electrofocusing polyacrylamide gels. Five of the six protein bands observed have their isoelectric points below pH 7. The six proteins are not synthesized when both cycloheximide and chloramphenicol are present, and they are absent in a petite mutant lacking mitochondrial deoxyribonucleic acid (DNA), leading to the conclusion that the proteins are synthesized on mitochondrial ribosomes. By labeling cells of Saccharomyces cerevisiae cultivated in a chemostat under different degrees of glucose limitation, the effect of glucose repression on the synthesis of the mitochondrial membrane proteins was determined. Two of the protein bands showed a relatively reduced synthesis under the strongest glucose repression tested. The specific activity of the cytochrome oxidase and the percentage of mitochondrial DNA in the total DNA were found to be influenced at a lower level of glucose repression.

Characterization of insoluble protein fractions of mitochondria from Saccharomyces cerevisiae.

Saccharomyces cerevisiae was grown in a chemostat in the presence of excess oxygen. Cells harvested from fully derepressed and strongly repressed steady states show typical promitochondria-like structures under conditions of strong repression. Insoluble membrane proteins were extracted from highly purified mitochondria and submitted to isoelectric focusing in 6% polyacrylamide gels. Some 20 protein bands were obtained from derepressed cells. The pattern was clearly different (quantitatively and possibly qualitatively) from repressed mitochondria. In contrast to ribosomal proteins, insoluble membrane protein fractions were found in the acid section (pH 4 to 6.8) of the ampholyte gels. It can be concluded that glucose repression plays a prominent role in the synthesis of the functional mitochondrial membranes.