Quali-quantitative analysis of best selling drugs from pharmacy, street market and traditional herbal medicine: a pilot study of market surveillance in Senegal.

A pilot study of market surveillance in Senegal has been performed analyzing best selling drugs from an official pharmacy and a street market in two principal cities of Senegal and some traditional preparations from herbal medicine from the same market. A simple and rapid gas chromatography method with mass spectrometry detection has been applied after a liquid-liquid extraction of pharmaceutical products and traditional preparations at acidic, neutral and basic pH with chloroform-isopropanol (9:1, v/v). The assay was validated in the range from 10mg to 250 mg/g powder preparations with good determination coefficients (r(2)≥ 0.99) for the calibration curves. At three concentrations spanning the linear dynamic ranges of the calibration curves, mean recoveries of substances under investigation were always higher than 90% and intra-assay and inter-assay precision and accuracy were always better than 15%. The four best selling drugs purchased from a Dakar local pharmacy exactly contained the amount of active principles reported in the respective labels while the best selling drugs freely purchased from Kaolack market contained an amount of active ingredients lower than that declared on the label. No pharmacological active compound, but salicylic acid was found in one of the traditional herbal preparations. This pilot study showed that whereas official drugs sold in pharmacies at prices accessible for a very few portion of the population contained the amount of active principles as reported in the labels, those from street market bought by the majority of population contained an amount of active ingredients lower than that declared on the label and finally traditional herbal preparations seldom contain pharmacological active principles.

Neuromechanical evidence of improved neuromuscular control around knee joint in volleyball players.

The aim of the present work was to verify that skilled volleyball players present specific adaptations in both neuromuscular control and movement biomechanics, showing an improved neuromuscular control around the knee joint than in non-jumper athletes. Seven male volleyball players and seven male non-jumper athletes were recruited for this study. The following tests were performed in a random order: single countermovement jump (CMJ), single squat jump. At the end of the series, subjects performed a repetitive CMJ test. Electromyographic signals were recorded from vastus lateralis and biceps femoris muscles on both sides. Ground reaction forces and moments were measured with a force plate. Volleyball athletes performed better in all tests and were more resistant to fatigue than non-jumper athletes. Furthermore, volleyball athletes showed a reduced co-activation of knee flexor/extensor muscles. The present results seem to stand for a neural adaptation of the motor control scheme to training.

Can continuous physical training counteract aging effect on myoelectric fatigue? A surface electromyography study application.

OBJECTIVES: To compare the myoelectric onset of muscle fatigue in physically active trained young skiers with respect to elderly skiers and to test whether continuous training can counteract the selective loss of type II muscle fibers usually observed with aging. DESIGN: An observational, cross-sectional study of the myoelectric onset of muscle fatigue in the left tibialis anterior muscles. SETTING: Surface electromyography recorded with portable devices at a downhill ski rescue lodge in the Italian Alps. PARTICIPANTS: Fifty-four physically trained, active skiers (43 men, 11 women; age range, 24-85y). INTERVENTIONS: Questionnaire on physical activity and 2 sustained isometric voluntary contractions at 20% and 2 at 80% of the maximal voluntary contraction level. MAIN OUTCOME MEASURES: Isometric contractions and mean and median spectral frequencies calculated to monitor the myoelectric manifestations of muscle fatigue. RESULTS: Fatigue indices did not differ significantly between younger and older subjects and, thus, did not show a correlation between myoelectric manifestations of muscle fatigue and age in physically active subjects. CONCLUSION: It appears possible that aging skeletal muscles subjected to continuous exercise develop an adaptive response that counteracts the selective loss of type II muscle fibers usually observed in the muscles of elderly sedentary subjects. Our results suggest that physical activity could be considered in the elderly within a broad rehabilitative framework in which appropriate and even tailored physical training could be planned to counteract the physiologic effects of aging on muscle fiber distribution.