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Biomedical subjects

G Pieralisi

Publications and source records attributed to G Pieralisi.

13 recordsLinked to original sources

Metabolic changes induced by maximal exercise in human subjects following L-carnitine administration.

In double-blind cross-over experiments, ten moderately trained male subjects were submitted to two bouts of maximal cycle ergometer exercise separated by a 3 day interval. Each subject was randomly given either L-carnitine (2 g) or placebo orally 1 h before the beginning of each exercise session. At rest L-carnitine supplementation resulted in an increase of plasma-free carnitine without a change in acid-soluble carnitine esters. Treatment with L-carnitine induced a significant post-exercise decrease of plasma lactate and pyruvate and a concurrent increase of acetylcarnitine. The determination of the individual carnitine esters in urine collected for 24 h after the placebo exercise trial revealed a decrease of acetyl carnitine and a parallel increase of a C4 carnitine ester, probably isobutyrylcarnitine. Conversely, acetylcarnitine was strongly increased and C4 compounds were almost suppressed in the L-carnitine loading trial. These results suggest that L-carnitine administration prior to high-intensity exercise stimulates pyruvate dehydrogenase activity, thus diverting pyruvate from lactate to acetylcarnitine formation.

Acetylcarnitine↗

Influence of L-carnitine administration on maximal physical exercise.

The effects of L-carnitine administration on maximal exercise capacity were studied in a double-blind, cross-over trial on ten moderately trained young men. A quantity of 2 g of L-carnitine or a placebo were administered orally in random order to these subjects 1 h before they began exercise on a cycle ergometer. Exercise intensity was increased by 50-W increments every 3 min until they became exhausted. After 72-h recovery, the same exercise regime was repeated but this time the subjects, who had previously received L-carnitine, were now given the placebo and vice versa. The results showed that at the maximal exercise intensity, treatment with L-carnitine significantly increased both maximal oxygen uptake, and power output. Moreover, at similar exercise intensities in the L-carnitine trial oxygen uptake, carbon dioxide production, pulmonary ventilation and plasma lactate were reduced. It is concluded that under these experimental conditions pretreatment with L-carnitine favoured aerobic processes resulting in a more efficient performance. Possible mechanisms producing this effect are discussed.

Administration, Oral↗

Effects of fructose-1,6-diphosphate on heart rate, ventilation, oxygen consumption and endurance performance.

A controlled study was carried out in 12 healthy male volunteers to evaluate the effects of fructose-1,6-diphosphate (FDP) on cardiac and respiratory parameters and work capacity during maximal muscular exercise on a cycloergometer. Each subject was studied in 3 sessions, separated by at least 36 hours. Workload started at 50 watts with stepwise increases, consisting of 25 watts every 3 minutes, up to muscular exhaustion or until the predicted maximum heart rate was attained. The first session, with no treatment, served as the control test; in the other two sessions, each subject received, prior to exercising, a single intravenous dose of either 7.5 g dextrose or 15 g FDP, according to a within-subject comparative study design. In resting conditions and during the exercise, heart rate, ventilation (VE), and oxygen consumption (VO2) were monitored. At the end of each session, the total work (TW) performed and the maximum oxygen consumption (VO2 max) were computed. No difference was found between the values obtained in the control and dextrose treatment sessions. The increments in heart rate, VE and VO2 at each workload observed after FDP treatment were lower (p less than 0.01) than those in control and dextrose sessions. A 25% increase in TW associated with a 12% increase in VO2 max was observed after FDP (p less than 0.01). The data indicate that FDP is potentially capable of improving muscular performance, and several possible mechanisms of action for the observed effects are discussed.

Adult↗

Inhaled beclomethasone dipropionate administered through a new spacer device: a controlled clinical study.

This 4-week, randomized, parallel-group study compared the efficacy and safety of a metered-dose inhaler equipped with a new spacer device (Jet spacer) with those of a standard actuator in the administration of inhaled beclomethasone dipropionate (0.5 mg twice daily) in 66 adults with chronic obstructive pulmonary disease (COPD) who were responsive to beta 2-agonists. Lung function values, symptom scores, and daily consumption of a beta 2-agonist determined efficacy. At baseline and after treatment, levels of morning serum and 24-hour urinary cortisol were measured in half of the patients (one center). Ease of use of the two devices was expressed by patients at the final visit. Lung function values and clinical symptoms improved in both groups (P < .01 at the final visit); the Jet group reported a better outcome (P < .05 between groups) than the standard-actuator group for predicted normal values of forced expiratory volume in 1 second, forced vital capacity, and bronchial noises. Salbutamol consumption decreased in both groups. One patient in the Jet group and 5 patients in the standard-actuator group reported adverse reactions. No significant between-group differences were found in plasma and urinary cortisol levels. The Jet device was judged easier to use (P < .05 between groups) than the standard actuator. In conclusion, the jet device was more effective than a standard actuator in reducing local adverse reactions to inhaled beclomethasone dipropionate in adults with COPD, with a better efficacy profile.

Adolescent↗

Effects of a standardized ginseng extract combined with dimethylaminoethanol bitartrate, vitamins, minerals, and trace elements on physical performance during exercise.

The subjects of this double-blind, randomized, crossover study were 50 healthy male sports teachers aged 21 to 47 years. Every day for six weeks each subject received two capsules of a preparation containing ginseng extract, dimethylaminoethanol bitartrate, vitamins, minerals, and trace elements, or two capsules of placebo. The subjects then performed an exercise test on a treadmill at increasing work loads. The total work load and maximal oxygen consumption during exercise were significantly greater after the ginseng preparation than after placebo. At the same work load, oxygen consumption, plasma lactate levels, ventilation, carbon dioxide production, and heart rate during exercise were significantly lower after the ginseng preparation than after placebo. The effects of ginseng were more pronounced in the subjects with maximal oxygen consumption below 60 ml/kg/min during exercise than in the subjects with levels of 60 ml/kg/min or above. The results indicate that the ginseng preparation increased the subjects' work capacity by improving muscular oxygen utilization.

Adult↗

Dantrolene sodium in traumatic muscle contracture: double-blind clinical and pharmacological trial.

Thirty athletes with muscular contractures were enrolled in a double-blind study of dantrolene sodium and placebo to evaluate the decontracture activity and tolerance of the drug after eight days of treatment. The efficacy of the drug was assessed by studying pain at rest, during movement, and during pressure, as well as muscular tension and functional recovery. Twenty-eight patients completed the study. At the end of treatment, a decrease in pain was observed at rest (71.4% of patients treated with dantrolene and 21.4% of placebo-treated patients), during movement (78.6% and 35.7%, respectively), and during compression. The most noticeable effects were seen in the reduction of muscular tension (100% in the patients treated with dantrolene sodium and 35.7% in the placebo-treated patients) and in functional recovery (100% and 28%, respectively). In addition to the clinical study, an evaluation of the effects of dantrolene and placebo on overall performance and on the action of the respiratory system was conducted with six healthy subjects by means of basal respiratory measurement and ergospirometry before and after single-dose treatment. This study showed that dantrolene sodium is useful in the treatment of traumatic contracture, and that it does not alter an individual's overall performance. Dantrolene sodium represents a valid treatment to accompany analgesic, anti-inflammatory, and rehabilitation therapy of posttraumatic lesions in athletes.

Adolescent↗