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Control Session (control + session)
Selected AbstractsDoes an Energy Drink Modify the Effects of Alcohol in a Maximal Effort Test?ALCOHOLISM, Issue 9 2004Sionaldo Eduardo Ferreira Background: There are popular reports on the combined use of alcohol and energy drinks (such as Red Bull® and similar beverages, which contain caffeine, taurine, carbohydrates, etc.) to reduce the depressant effects of alcohol on central nervous system, but no controlled studies have been performed. The main purpose of this study was to verify the effects of alcohol, and alcohol combined with energy drink, on the performance of volunteers in a maximal effort test (cycle ergometer) and also on physiological indicators (oxygen uptake, ventilatory threshold, respiratory exchange rate, heart rate, and blood pressure), biochemical variables (glucose, lactate, insulin, cortisol, ACTH, dopamine, noradrenaline, and adrenaline), and blood alcohol levels. Methods: Fourteen healthy subjects completed a double-blind protocol made up of four sessions: control (water), alcohol (1.0 g/kg), energy drink (3.57 ml/kg Red Bull®), and alcohol + energy drink, each 1 week apart. The effort test began 60 min after drug or control ingestion, and the dependent variables were measured until 60 min after the test. Results: Heart rate at the ventilatory threshold was higher in the alcohol and alcohol + energy drink sessions in comparison with control and energy drink sessions. Although in comparison to the control session, the peak oxygen uptake was 5.0% smaller after alcohol ingestion, 1.4% smaller after energy drink, and 2.7% smaller after the combined ingestion, no significant differences were detected. Lactate levels (30 min after drug ingestion, 30 and 60 min after the effort test) and noradrenaline levels (30 min after the effort test) were higher in the alcohol and alcohol + energy drink sessions compared with the control session. Conclusions: The performance in the maximal effort test observed after alcohol + energy drink ingestion was similar to that observed after alcohol only. No significant differences between alcohol and alcohol + energy drink were detected in the physiological and biochemical parameters analyzed. Our findings suggest that energy drinks, at least in the tested doses, did not improve performance or reduce alterations induced by acute alcohol ingestion. [source] 12 Effects of synchronized intestinal electrical stimulation on small intestinal motility in dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006J YIN Our previous studies showed that synchronized gastric electrical stimulation enhanced antral contractions, accelerated gastric emptying in dogs. It has never been reported whether synchronized electrical stimulation could improve small intestinal motility. The aim of this study was to investigate the effects of synchronized intestinal electrical stimulation (SIES) on small bowel motility in both fasting and fed states in dogs. Methods:, Five healthy female dogs (18,24 kg) were equipped with a duodenal cannula for the measurement of small bowel motility using manometry. Two pairs of bipolar electrodes were implanted on the small intestinal serosa with an interval of 25 cm; the first one was 10 cm beyond the pylorus and used for stimulation. The experiment was consisted of four sessions in each dog with a randomized order. In the fasting state, 20 min after occurrence of phase III, SIES was initiated and maintained for 45 min, small bowel motility was recorded during the entire experiment, and no stimulation was performed in the control session. In other two sessions, dogs were fed with solid meal at the beginning of the experiment; glucagon (0.1 mg kg1) was injected 20 min after feeding, SIES was initiated at the same time for 20 min followed by 20 min recovery period. The stimulus was composed of train of pulses with on-time of 0.5 s, frequency of 20 Hz, pulse width of 2 ms and amplitude of 4 mA. Results:, 1). In the fasting state, SIES induced small intestinal contractions during phase I. The motility index was 5.2 ± 0.6 in the control session and significantly increased to 10.3 ± 0.7 with SIES (P = 0.003). 2). In the fed state, glucagon substantially and significantly inhibited small intestinal motility. The motility index was 11.3 ± 0.7 after feeding and reduced to 3.4 ± 0.5 with glucagon injection (P < 0.001). SIES significantly enhanced glucagon-induced small intestinal postprandial hypomotility. The motility index was 3.4 ± 0.5 in the control session and increased to 6.0 ± 0.3 with the presence of SIES (P = 0.03). Conclusions:, Intestinal electrical stimulation synchronized with intestinal slow waves induces intestinal contractions during phase I and enhanced small intestinal postprandial hypomotility induced by glucagon. SIES may have the therapeutic potential for treating small intestinal motility disorders. (Supported by a grant from American Diabetes Association). [source] 47 Effects of retrograde gastric electrical stimulation on gastric motility and plasma hormones in dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006G SONG Aims:, The aim of this study was to investigate the effect of different parameters of RGES with trains of long pulses in turning gastric slow waves into tachygastria, and evaluate the effects of RGES with the efficient trains of pulses on gastric slow waves, gastric emptying of solids and plasma concentrations of satiety-related peptides and glucose. Methods:, Seven female dogs implanted with four pairs of gastric electrodes were studied in two experiments. The first experiment included a series of sessions with different pacing parameters in the fasting state, each lasting 10 min. The second experiment included two randomized sessions (control and RGES). Gastric emptying of solid was measured by scintigraphy for a period of 4 h. Blood samples were collected at 45 and 15 min before, 30, 60 and 120 min after the meal. Plasma leptin, insulin and glucagon were measured using radioimmunoassay method. Plasma glucose was assessed with a commercially available glucometer. RGES was applied via the distal pair of electrodes (2 cm above the pylorus) with trains of pulses. RGES was initiated 30 min before the first blood sample and maintained for a period of 2.5 h. Gastric slow waves and symptomatic response were also recorded in each session. Results:, (1) RGES with pulse trains (12 trains/min) was able to turn regular gastric slow waves into tachygastria. (2) RGES with the efficient parameters (frequency: 40 Hz; pulse width: 2 ms; amplitude: 5 mA; train on-time, 2 s; off-time, 3 s) was capable of delaying gastric emptying of solids (P < 0.05). (3) Compared with the control session without RGES, the total AUC's of plasma insulin with RGES was significantly decreased in the fasting and postprandial periods (p < 0.05). However, the total area under curves (AUC's) of plasma leptin, glucagon, and glucose were not significantly affected by RGES (p > 0.05). (4) This method of GES induced no noticeable symptoms. Conclusion:, RGES with at a tachygastrial frequency decreases gastric emptying of solids and plasma insulin, but has no effects on plasma leptin, glucagons, and glucose. [source] The effect of whole-body sunbed ultraviolet A exposure on the pharmacokinetics of the photolabile drug nifedipinePHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 3 2000H. S. Al-Ajmi The calcium antagonist nifedipine absorbs ultraviolet A (UVA) radiation and readily photodegrades in vitro to a toxic nitroso-pyridine photoproduct. We examined whether whole body exposure of normal subjects to sunbed UVA radiation would affect the pharmacokinetics of nifedipine. Eight healthy, male, Caucasian volunteers (phototypes I,III) participated in this ethically approved, randomised, cross-over study. Each subject attended on 2 occasions, one week apart, and on each occasion was given a single oral dose (10 mg) of nifedipine following which blood samples were collected at 0, 0.5, 1. 1.5, 2, 2.5, 3, 3.5, 4, 5, 6 and 7 h. During one of the visits, 15 min after nifedipine ingestion, a whole-body UVA (sunbed comprising Philips R-UVA lamps) dose of 70% of the individual's predetermined minimal phototoxic dose was delivered over a period of 17,36 min. Plasma nifedipine levels were measured using a standard reverse-phase high-performance liquid chromatography method. The area under the plasma concentration-time curve (AUC) of nifedipine during the UVA irradiation session (median 206 ng,·,ml,1,·,h,1) was significantly higher than during the non-irradiation control session (median 174.5 ng,·,ml,1,·,h,1) (P=0.03; 95% C.I. for difference in medians 9.9 to 55.9 ng,·,ml,1,·,h,1). UVA irradiation did not significantly affect any of the other measured pharmacokinetic parameters (Cmax, t1/2, tmax). We demonstrate that sunbed UVA irradiation does not lead to in vivo photodegradation of nifedipine in healthy humans after a single dose. The apparent increase in AUC during UVA irradiation may be due to slightly slower metabolism of nifedipine in the presence of toxic photoproduct(s) or due to blood distribution changes affecting liver blood flow. [source] | ||||||||||