Synthesis and HIV-1 reverse transcriptase inhibitor activity of some 2,5,6-substituted benzoxazole, benzimidazole, benzothiazole and oxazolo(4,5-b)pyridine derivatives.

In this study, the synthesis of some benzoxazoles and their analogues were described and their antiviral activities were studied together with the previously synthesized 2,5,6-trisubstituted benzoxazole, benzothiazole, benzimidazole and oxazolo(4,5-b)pyridine derivatives. The reverse transcriptase (RT) inhibitory activity of these compounds was determined using a commercial kit and assay system which utilizes the scintillation proximity assay principle. The results are concentration at which the compound inhibits RT activity by 50%). The compounds inhibited the in vitro binding of thymidine to the RT enzyme exhibiting IC50 values between 6.3 x 10(5) mumol/l-0.34 mumol/l and their activities were compared to some standard drugs such as 3'-azido-2',3'-dideoxythymidine triphosphate and dideoxythymidine triphosphate.

Effect of potassium citrate therapy on stone recurrence and residual fragments after shockwave lithotripsy in lower caliceal calcium oxalate urolithiasis: a randomized controlled trial.

BACKGROUND AND PURPOSE: To evaluate the efficacy of potassium citrate treatment in preventing stone recurrences and residual fragments after shockwave lithotripsy (SWL) for lower pole calcium oxalate urolithiasis. PATIENTS AND METHODS: One hundred ten patients who underwent SWL because of lower caliceal stones and who were stone free or who had residual stone 4 weeks later were enrolled in the study. The average patient age was 41.7 years. All patients had documented simple calcium oxalate lithiasis without urinary tract infection and with normal renal morphology and function. Four weeks after SWL, patients who were stone free (N = 56) and patients who had residual stones (N = 34) were independently randomized into two subgroups that were matched for sex, age, and urinary values of citrate, calcium, and uric acid. One group was given oral potassium citrate 60 mEq per day, and the other group served as controls. RESULTS: In patients who were stone free after SWL and receiving medical treatment, the stone recurrence rate at 12 months was 0 whereas untreated patients showed a 28.5% stone recurrence rate (P < 0.05). Similarly, in the residual fragment group, the medically treated patients had a significantly greater remission rate than the untreated patients (44.5 v 12.5%; P < 0.05). CONCLUSION: Potassium citrate therapy significantly alleviated calcium oxalate stone activity after SWL for lower pole stones in patients who were stone free. An important observation was the beneficial effect of medical treatment on stone activity after SWL among patients with residual calculi.

A reference interval study of urinary lactulose excretion: a useful test of intestinal permeability in adults.

BACKGROUND/AIMS: Measurement of lactulose excretion in urine following oral ingestion is used as a noninvasive method of assessing small intestinal permeability. The aim of this study was to determine the adult reference interval of urinary lactulose excretion following oral administration. METHODS: Thirty seven volunteers (mean age 37.3 +/- 15 years) with no history of gastrointestinal disease were recruited as study subjects. All subjects were fasted overnight (10 hours), emptied their bladders and then drank a 50-mL solution containing 15 mL of Duphalac (10 g lactulose) and 35 mL flavoured water. Urine was collected for six hours in a bottle. Comparisons were made for 37 samples. RESULTS: In adults, the mean urinary lactulose concentration was 0.58 +/- 0.39 mmol/L. CONCLUSION: This study determined the adult reference range for lactulose excreted in the urine, using a sensitive quantitative assay based on hydrolysing lactulose and enzymatically assaying fructose, one of the component monosaccharides.