Efficacy of single-dose 500 mg mebendazole in soil-transmitted helminth infections: a review.

Soil-transmitted helminthiasis (STH) is caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), and Ancylostoma duodenale and Necator americanus (hookworms). Mebendazole is one of the recommended preventive chemotherapy agents for STH. This review summarizes the efficacy data from 29 studies with single-dose 500 mg mebendazole in STH treatment and compares the results with those of a recently conducted phase 3 study of a 500 mg mebendazole chewable tablet against A. lumbricoides and T. trichiura infections. Studies that reported efficacy results against at least one STH infection were selected from the literature and efficacy data by each STH type were abstracted and pooled. Single-dose 500 mg mebendazole treatment resulted in a cure rate of 92.6% (range: 72.5-100%) for A. lumbricoides, 27.6% (range: 8.4-100%) for T. trichiura and 25.5% (range: 2.9-91.1%) for hookworms. Egg reduction rate for A. lumbricoides was 97.9% (range: 89.8-100%), for T. trichiura it was 72.9% (range: 31.6-93.0%) and for hookworms it was 72.0% (range: -6.5% (denoting an increase in egg count) to 98.3%). Similar results were observed in the studies that were placebo-controlled. In the phase 3 study, the cure rate and egg reduction rate reported was 83.7% and 97.9%, respectively, for A. lumbricoides and 33.9% and 59.7%, respectively, for T. trichiura. In conclusion, single-dose 500 mg mebendazole showed a high cure rate against A. lumbricoides and a substantial reduction in faecal egg count for all STH types. These results are consistent with the recently conducted phase 3 study of a new 500 mg chewable mebendazole tablet.

Microplate differential calorimetric biosensor for ascorbic acid analysis in food and pharmaceuticals.

In this paper we report on the development of a label-free low-volume (12.5 microL), high-throughput microplate calorimetric biosensor for fast ascorbic acid quantification in food and pharmaceutical products. The sensor is based on microplate differential calorimetry (MiDiCal) technology in which the heat generation, due to the exothermic reaction between ascorbic acid and ascorbate oxidase, is differentially monitored between two neighboring wells of an IC-built wafer. A severe discrepancy is found between expected and observed sensor readings. To investigate the underlying mechanisms of these findings a mathematical model, taking into account the biochemical reactions and diffusion properties of oxygen, ascorbic acid, and ascorbate oxidase, is developed. This model shows that oxygen depletion in the microliter reaction volumes, immediately after injection of sample (ascorbic acid) into the well, causes the enzymatic reaction to slow down. Calibration experiments show that the sensor's signal is linearly correlated to the area under the output versus time profile for the ascorbic acid concentration range from 2.4 to 350 mM with a limit of detection of 0.8 mM. Validation experiments on fruit juice samples, food supplements, and a pain reliever supplemented with ascorbic acid reveal that the designed method correlates well with HPLC reference measurements. The main advantages of the presented biosensor are the low analysis cost due to the low amounts of enzyme and reagents required and the possibility to integrate the device in fully automated laboratory analysis systems for high-throughput screening and analysis.

Double-blind comparison of ketanserin with placebo in patients with essential hypertension.

Two double-blind multicenter trials were performed to compare the antihypertensive action of ketanserin, at an oral dosage of 20 mg three times daily, with that of placebo over a period of four to six weeks. A subset of patients was treated in a crossover fashion for either four weeks (36 patients) or six weeks (24 patients). The patients had essential hypertension, with a diastolic blood pressure greater than or equal to 95 mmHg measured in sitting position at the end of a placebo run-in period of at least one week. In a first trial, 78 of 82 patients completed the four-week study period, where the mean drop of the systolic/diastolic blood pressure was -14/-12 mmHg in the ketanserin group (n = 32) versus -8/-5 mmHg in the placebo group (n = 46). This difference is statistically significant (p = 0.05/p less than 0.01). In 13 patients who after the initial ketanserin treatment were further treated with placebo in crossover for four weeks, the blood pressure rose slightly (+1/+3 mmHg). In the alternative group (n = 23), the blood pressure fell by -10/-7 mmHg after placebo and decreased further by -10/-8 mmHg after ketanserin. In a second trial, 24 patients completed a two by six week crossover treatment. In 12 patients assigned to the sequence placebo-ketanserin, there was a drop of the systolic/diastolic blood pressure by -7/-4 mmHg after placebo and an additional drop by -26/-10 mmHg after ketanserin.(ABSTRACT TRUNCATED AT 250 WORDS)