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Biomedical subjects

F Anselme

Publications and source records attributed to F Anselme.

45 records · Page 3Linked to original sources

Release of cytokines by blood monocytes during strenuous exercise.

During strenuous exercise in endurance athletes, monocytes are activated and there is an acute inflammation and hypoxemia possibly due to lesional pulmonary edema. IL-6 and TNF-alpha released by monocytes may be implicated in the acute phase of lesional pulmonary edema. A study was carried out to determine whether TNF-alpha and IL-6 are released during strenuous exercise, and, if adrenalin released during exercise alters their generation. Ten young and six master athletes underwent an incremental exercise test. Arterial blood was drawn at rest, at the end of the exercise, and 20 minutes afterwards. Monocytes were isolated and incubated for 18 hours in the presence or absence of adrenalin. Il-6 and TNF-alpha were measured in monocyte supernatants. The spontaneous release of IL-6 or TNF-alpha was increased in young athletes when compared to older subjects. The spontaneous release of TNF-alpha was increased, but not significantly, by exercise and there was no correlation between the release of IL-6 and TNF-alpha and lung function measured during hypoxemia. Adrenalin inhibited the release of IL-6 or TNF-alpha. Correlations were observed between the in vitro release of IL-6 or TNF-alpha and age, VO2max, maximal ventilation and maximal power output of the subjects.

Adult↗

Exercise-induced hypoxemia in older athletes.

To determine whether exercise induces hypoxemia in highly trained older "master" athletes (MA), as it does in certain elite endurance-trained young athletes (YA), 10 MA (65.3 +/- 2.6 yr), 10 control subjects (CS; 68.3 +/- 2.2 yr), and 10 endurance-trained YA (23.3 +/- 1.1 yr) performed an incremental exercise test. During testing, blood samples for arterial blood gas analysis were drawn during the last 20 s of each load. Lung exchanges were measured using a breath-by-breath automated exercise device. Exercise-induced hypoxemia (EIH) appeared in all MA and 8 of 10 YA, whereas there were no changes in the blood gases of CS. In MA, arterial PO2 decreased significantly from 40% of maximal O2 uptake onward and was associated with a significant increase in the ideal alveolar-arterial O2 difference from 60% onward. The MA also showed a lower ventilation for a given absolute load compared with CS. In all subjects arterial PCO2 rose slightly but significantly during the work, but this increase was most marked in MA. The EIH differed between MA and YA in the following ways: 1) all MA showed a drop in arterial PO2 during exercise, 2) this drop appeared earlier and was significantly greater for a given load in MA, and 3) EIH appeared at a lower level of training regimen in MA. This hypoxemia was at first isolated, probably at least partially due to relative hypoventilation, and then was associated with a widened ideal alveolar-arterial O2 difference, which may have been due to an increase in extravascular lung water.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Histamine and exercise-induced hypoxemia in highly trained athletes.

To determine whether exercise-induced hypoxemia in extreme athletes results from an increase in histamine level during maximal incremental exercise, seven young athletes [YA; age 22.2 +/- 1.23 (SE) yr] and seven master athletes (MA; age 66.2 +/- 2.94 yr), all of whom were known to develop exercise-induced hypoxemia, were compared with age-matched control groups (young controls and older controls, respectively). During maximal incremental exercise, blood samples for arterial blood gas analysis and for plasma and total histamine were drawn at rest and at 50, 75, and 100% of maximal O2 uptake. The percentage of histamine released (%H) was calculated from plasma and total histamine samples. In all athletes (MA and YA groups), exercise induced an increase in %H with a concomitant decrease in arterial PO2 (PaO2); in control groups there was no change in either histamine levels or PaO2. When the data for the YA and MA groups were combined, a correlation was observed between the increase in %H and the drop in PaO2. Nevertheless, further studies are required to establish whether histamine plays a causative role in hypoxemia or is a response to injury.

Adult↗

[Treatment of supraventricular arrhythmia by permanent cardiac pacing].

Most pacemakers are used for the treatment of bradyarrhythmias. However, a small number of pacemakers has been implanted for the treatment of supraventricular tachycardia resistant to medical therapy. The results of small reported series show long-term pacing to be effective in terminating reentrant atrial and junctional tachycardia. This has led to an improved quality of life and fewer hospital admissions in the majority of patients. Although there are a number of limitations to the widespread use of this mode of treatment, the development of pacing techniques has improved our understanding of the mechanism of termination of tachycardia which has been fully used in ventricular tachyarrhythmias. In addition to the curative treatment of sustained junctional tachycardia, pacemakers have been implanted to prevent the occurrence of new episodes with seemingly equally satisfactory results. However, cardiac pacing for this indication is much less common now because of the very good results obtained recently by radiofrequency ablation techniques. The prevention of atrial arrhythmias, vagally-induced atrial tachyarrhythmias and the bradycardia-tachycardia syndrome are good indications for permanent pacing. The prevention of atrial fibrillation in sinus node dysfunction by pacing is becoming more popular with the emergence of new modes (DDI and rate-adjusted modes) and original arrhythmia preventing algorithms. The discussion about the real efficacy of atrial pacing in sinus node dysfunction is disappearing as results of prospective randomised trials confirming this efficacy become available, especially in preventing atrial fibrillation.

Arrhythmias, Cardiac↗

Pulmonary gas exchange and breathing pattern during and after exercise in highly trained athletes.

Highly trained athletes (HT) have been found to show arterial hypoxaemia during strenuous exercise. A lack of compensatory hyperpnoea and/or a limitation of pulmonary diffusion by pulmonary interstitial oedema have been suggested as causes, but the exact role of each is not clear. It is known, however, that interstitial pulmonary oedema may result in rapid shallow breathing (RSB). The purpose of this study was therefore twofold: firstly, to determine the exact role of a lack of compensatory hyperpnoea versus a widened in ideal alveolar minus arterial oxygen partial pressure difference [PA(i)-aO2] in the decrease in partial pressure of oxygen in arterial blood (PaO2) and, secondly, to detect RSB during recovery in HT. Untrained subjects (UT) and HT performed exhausting incremental exercise. During rest, exercise testing, and recovery, breathing pattern, respiratory gas exchange, and arterial blood gases were measured. The PA(i)-aO2 and the difference in tidal volume (VT) between exercise and recovery for the same level of ventilation, normalized to vital capacity of the subject [delta VT(%VC)], were then calculated. A large positive delta VT(%VC) was considered to be the sign of RSB. HT showed a marked hypoxaemia (F = 11.6, P < 0.0001), higher partial pressure of carbon dioxide in arterial blood (F = 3.51, P < 0.05), and lower ideal partial pressure of oxygen in alveolar gas (P < 0.001). The relationship between PA(i)-aO2 and oxygen consumption was the same for the two groups. The widening PA(i)-aO2 persisted throughout recovery for both HT and UT. The RSB was observed in HT during recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Current status of aortic valvuloplasty in patients aged 80 and over. Apropos of a recent series of 70 patients (1989-90)].

In contrast with aortic valve replacement, the treatment of choice for severe aortic stenosis because of the better long-term results, percutaneous aortic valvuloplasty, has only limited indications, mainly because of the high rate of restenosis. However, in very elderly patients, the surgical risk is high, sometimes prohibitive. For this reason, the authors report their latest results with this technique in a series of octogenarians. Between January 1989 and December 1990, 70 aortic valvuloplasties were performed in octogenarians (average age 85 +/- 3 years). The indications were advanced age > or = 85 years (46%), poor left ventricular ejection fraction < 40% (20%), secere associated coronary artery disease (3%), associated extracardiac pathology (11%), poor general condition (11%) or refusal of surgery (4%). The great majority of these patients (83%) were very symptomatic: 70.5% had Grade III-IV dyspnoea, 20% had Grade III-IV angina and 20% had syncopal attacks. Valvuloplasty reduced the mean transvalvular pressure gradients from 61 +/- 23 to 30 +/- 11 mmHg (p < 0.01) and increased aortic valve surface area from 0.53 +/- 0.19 to 0.94 +/- 0.12 cm2 (p < 0.001). There were two deaths (2.9%) in the catheterization laboratory and 4 (5.7%) complications during the hospital period (myocardial infarction: 1, cerebrovascular accident: 1, severe aortic regurgitation: 1 and complete atrio-ventricular block: 1). There were no serious vascular complications. The average duration of the hospital period was 6 +/- 5 days. Clinical follow-up of 17 +/- 7 months was obtained in 97% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

[Electrophysiological evaluation of ventricular tachycardia].

The ability to induce and terminate ventricular tachycardia reproducibly by programmed stimulation has led to the development of electrophysiological investigations for the management of patients suffering from spontaneous arrhythmias. The investigation consists in introducing several multipolar catheter electrodes under local anaesthesia which are then positioned in contact with the endocardium in several regions of the heart. There is no consensus as to an ideal stimulation protocol for these patients but the basic principle is the introduction of one or several ventricular extrasystoles every 8 beats in sinus rhythm or during a controlled ventricular paced rhythm. At present, the major indication is rarely diagnostic in the presence of wide QRS complex tachycardias difficult to analyse by electrocardiography. On the other hand, electrophysiological investigations are highly recommended in cases of unexplained syncope in patients with documented or suspected heart disease, in symptomatic patients with intraventricular conduction defects in whom ventricular arrhythmias are suspected as the cause of symptoms or after cardiac arrest without transmural infarction or, for many teams, after the 48th hour of transmural infarction. Electrophysiological investigations are also justified in patients in whom surgical or catheter ablation of an arrhythmogenic focus is planned because of resistance to antiarrhythmic drug therapy. Evaluation of the efficacy of antiarrhythmic drugs by repeated investigations is common in the United States but is not so widely accepted in Europe.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Pacing, Artificial↗

Caffeine increases maximal anaerobic power and blood lactate concentration.

The aim of this study was to specify the effects of caffeine on maximal anaerobic power (Wmax). A group of 14 subjects ingested caffeine (250 mg) or placebo in random double-blind order. The Wmax was determined using a force-velocity exercise test. In addition, we measured blood lactate concentration for each load at the end of pedalling and after 5 min of recovery. We observed that caffeine increased Wmax [964 (SEM 65.77) W with caffeine vs 903.7 (SEM 52.62) W with placebo; P less than 0.02] and blood lactate concentration both at the end of pedalling [8.36 (SEM 0.95) mmol.l-1 with caffeine vs 7.17 (SEM 0.53) mmol.l-1 with placebo; P less than 0.01] and after 5 min of recovery [10.23 (SEM 0.97) mmol.l-1 with caffeine vs 8.35 (SEM 0.66) mmol.l-1 with placebo; P less than 0.04]. The quotient lactate concentration/power (mmol.l-1.W-1) also increased with caffeine at the end of pedalling [7.6.10(-3) (SEM 3.82.10(-5)) vs 6.85.10(-3) (SEM 3.01.10(-5)); P less than 0.01] and after 5 min of recovery [9.82.10(-3) (SEM 4.28.10(-5)) vs 8.84.10(-3) (SEM 3.58.10(-5)); P less than 0.02]. We concluded that caffeine increased both Wmax and blood lactate concentration.

Adult↗

Effects of moderate exercise on the pharmacokinetics of caffeine.

The effect of moderate exercise on the kinetics of caffeine in 12 healthy volunteers-6 heavy coffee drinkers (HD) and 6 light coffee drinkers (LD) has been studied. Kinetics at Rest was measured first (R): the subjects remained at rest for 8 h after a single 250 mg dose of caffeine. One week later, the Exercise Kinetics (E) was measured under the same conditions, but with the subjects performing moderate exercise (30% of VO2 max) during the first hour of the study. Exercise raised the maximal plasma caffeine concentrations (R: 7.28: E: 10.45) and reduced both the half-life (R 3.99 h: E 2.29 h) and the volume of distribution (R 37 l: E 20.9 l). Both during exercise and at rest. HD had a greater half-life elimination and volume of distribution than LD. The results suggest potentiation of the effects of caffeine during exercise and an increase in its distribution due to regular heavy coffee intake.

Administration, Oral↗