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Biomedical subjects

A Ferry

Publications and source records attributed to A Ferry.

At least 37 records · Page 2Linked to original sources

[A survey on the management of myocardial infarction in France.The Infarctus Top Chrono Survey].

An enquiry was carried out between December 1989 and January 1990 involving 749 cardiologists and 8,846 general practioners based throughout France to evaluate the number of myocardial infarctions diagnosed each year, to determine how the patients are transported to hospital and to assess the average delays of transportation. This enquiry showed that cardiologists diagnosed 15 cases of myocardial infarction per year: their first reflex is to visit the patient, sometimes accompanied by the emergency medical service if available at the time of the patient's call, or to advise the patient to call the emergency service straight away if it is not possible for them to visit the patient immediately. The delay of transportation is less than 30 minutes in 45% of cases and over 60 minutes in 10% of cases. Regional differences were observed and are analysed. General practitioners diagnose 4 cases of myocardial infarction per year: the principal attitude is the same as that of the cardiologists, except that the general practitioner is available to visit the patient more often and is called out more easily. The means of transport and the delays of transportation are very similar to those observed with the cardiologists. This analysis of the management of myocardial infarction in France in 1990 may help organise actions to shorten the time between the onset of chest pain and the institution of thrombolytic therapy.

Family Practice↗

Effect of moderate exercise on rat T-cells.

The aim of this study was a detailed examination of the effects of moderate exercise on T-cells in adult male Wistar rats. The T-cell populations were compared in sedentary rats (C, n = 5) and in rats trained for 4 weeks on a treadmill (30-60 min.day-1, 6 days.week-1, 20-30 m.min-1) and sacrificed at rest (T-rest, n = 5). In the T-rest rats, there were higher percentages of CD4+CD8-, CD4-CD8+ and CD4-CD8- thymocytes (P < 0.05, P < 0.05 and P < 0.01 respectively) and of CD4-CD8+ splenocytes (P < 0.01), and a lower percentage of CD4-CD8+ cells in the lymph nodes (P < 0.01). Compared with T-rest or C rats, trained rats (n = 5) or untrained rats (n = 5) sacrificed immediately after a running session (60 min, 30 m.min-1) had a higher percentage of mononucleated cells CD4+CD8- in the blood (P < 0.05 and P < 0.01). Lastly, compared with C rats, rats (n = 5) sacrificed immediately after their 5th day of training (30-60 min.day-1) presented a higher total splenocyte population (P < 0.05) and greater in vitro production of T-cell growth factor (interleukin 2 + Interleukin 4) by splenocytes in response to a mitogen (P < 0.01). These results would indicate that moderate endurance training modifies the cellular composition of lymphoid organs, without impairing the in vitro functions of T-cells.

Animals↗

Glycogen depletion and resynthesis in the rat after downhill running.

To study the effect of downhill running on glycogen metabolism, 94 rats were exercised by running for 3 h on the level or down an 18 degrees incline. Muscle and liver glycogen concentrations were measured before exercise and 0, 48 and 52 h postexercise. Rats were not fed during the first 48 h of recovery but ingested a glucose solution 48 h postexercise. Downhill running depleted glycogen in the soleus muscle and liver significantly more than level running (P less than 0.01). The amount of glycogen resynthesized in the soleus muscle and liver in fasting or nonfasting rats was not altered significantly by downhill running (P greater than 0.05). On every day of recovery the rats were injected with dexamethasone, which induced similar increases in glycogen concentration in the soleus muscle and liver after the 52nd h of the postexercise period in the case of downhill and level running. The glycogen depletion and repletion results indicated that, under our experimental conditions, downhill running in the rat, a known model of eccentric exercise, affected muscle glycogen metabolism differently from eccentric cycling in humans.

Animals↗

Splenic immunomodulation with swimming-induced stress in rats.

In order to determine the effects of swimming-induced stress, young male Wistar rats swam for a single session of 2 h duration, or for one 2-h session a day for five consecutive days. The absolute number of splenic mononuclear cells and the in vitro proliferation of mitogen-stimulated (PHA) T lymphocytes were studied. A single swimming session did not significantly diminish the number of splenic mononuclear cells, but it did significantly reduce splenic T-lymphocyte proliferation. This effect on T-lymphocyte proliferation was significantly blocked, in part, by subcutaneous injection of naltrexone before a swimming session. It was not significantly blocked by pre-exercise oral administration of aminoglutethimide. Repeated swimming sessions induced no significant changes in immune parameters. In conclusion, these data suggest that immunosuppression seen with a single swimming-induced stress period may partly be due to endogenous opioids, and that repetition of the swimming session reduced swimming-induced immunomodulation.

Aminoglutethimide↗

Immunomodulations of thymocytes and splenocytes in trained rats.

The aim of this study was to describe the effects of training (running) on thymus and spleen cells in the rat. Young Wistar control rats (n = 6), rats trained for 4 wk (n = 5), and rats trained for 4 wk followed by 1 wk of intensive training (3 h/day, n = 6) were studied. Various lymphocyte surface and nuclear markers were determined by immunocytochemistry. The results show that 4 wk of training 1) decreased the percentage of bromodeoxyuridine (BrdU+) thymocytes (cell in phase S of the cycle, immature thymocytes; P less than 0.05) and the viability of thymocytes stimulated with concanavalin A (Con A; P less than 0.05) and 2) increased the absolute number of CD8+ (suppressor/cytotoxic T cells; 29%) and the percentage of CD8+ splenocytes (P less than 0.01). An additional week of intensive training in the 4-wk trained rats induced 1) a decrease in the absolute number of thymocytes (25%, P less than 0.05), TCR+ thymocytes, splenocytes (28%, P less than 0.01), T, CD4+ (helper T cells; 34%), and CD8+ (31%) splenocytes (P less than 0.01) and 2) an increase in the viability of splenocytes after stimulation with Con A for 72 h (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Blood mononuclear cells energy metabolism response to muscular exercise.

In a study of 4 enzymatic activities in human blood mononuclear cells before and immediately after standard maximal exercise test (25 min) on treadmill we noted: (1) a significant decrease in the activity of the pyruvate dehydrogenase complex (PDHc); (2) a significant increase in the activity of the citrate synthase (CS); and (3) no significant changes in the activities of cytochrome c oxydase and succinate cytochrome reductase. Although non-specifically stimulated (antigen or even mitogen), the blood mononuclear cells responded metabolically to muscular exercise. Pyruvate dehydrogenase (PDHc) activity of blood mononuclear cells appeared to decrease via enzyme interconversion regulation of PDHc. It is not known if these changes can be linked to the studies indicated altered immune function after a single bout of exercise.

Adult↗

[Dystrophin expression in skeletal muscles in endurance-trained hypo-hyperthyroid and growth-hormone treated rats].

The aim of this study was to determine the effect of chronic muscular exercise, thyroid status and growth hormone administration on skeletal muscle dystrophin expression. Relative abundance of dystrophin (quantity in arbitrary units/50 micrograms of protein) was measured by immunoblotting and densimometry. Our results indicate that relative abundance of dystrophin in slow-or fast-twicht muscle was not modified by chronic muscular exercise (5 weeks), thyroxine administration (4 weeks), antithyroid drug treatment (6 weeks) or growth hormone administration (6 weeks).

Actinin↗

The pharmacokinetics of d-sotalol and d,l-sotalol in healthy volunteers.

The pharmacokinetics of d-sotalol has been studied in six healthy volunteers given single doses of 0.25, 0.50, 1, 2 mg.kg-1 i.v. and one 100 mg oral dose in comparison with the kinetics of 1 mg.kg-1 i.v. of dl-sotalol. There was no significant difference in the disposition of the d-enantiomer and the racemate. The terminal half-life averaged 7.2 h, and the kinetics was linear, with a mean total clearance of 0.13 l.h-1.kg-1. Renal clearance of d-sotalol represented 56 to 77% of total clearance. The absolute systemic availability of oral d-sotalol was close to 100% and the elimination half-life of the oral-d-enantiomer was similar to that of the i.v. form (7.5 h).

Administration, Oral↗

Effect of previous supramaximal work on lacticaemia during supra-anaerobic threshold exercise.

Twelve male and female subjects (eight trained, four untrained) exercised for 30 min on a treadmill at an intensity of maximal O2 consumption (% VO2max) 90.0%, SD 4.7 greater than the anaerobic threshold of 4 mmol.l-1 (Than = 83.6% VO2max, SD 8.9). Time-dependent changes in blood lactate concentration [( lab]) during exercise occurred in two phases: the oxygen uptake (VO2) transient phase (from 0 to 4 min) and the VO2 steady-state phase (4-30 min). During the transient phase, [lab] increased markedly (1.30 mmol.l-1.min-1, SD (0.13). During the steady-state phase, [lab] increased slightly (0.02 mmol.l-1.min-1, SD 0.06) and when individual values were considered, it was seen that there were no time-dependent increases in [lab] in half of the subjects. Following hyperlacticaemia (8.8 mmol.l-1, SD 2.0) induced by a previous 2 min of supramaximal exercise (120% VO2max), [lab] decreased during the VO2 transient (-0.118 mmol.l-1.min-1, SD 0.209) and steady-state (-0.088 mmol.l-1.min-1, SD 0.103) phases of 30 min exercise (91.4% VO2max, SD 4.8). In conclusion, it was not possible from the Than to determine the maximal [lab] steady state for each subject. In addition, lactate accumulated during previous supramaximal exercise was eliminated during the VO2 transient phase of exercise performed at an intensity above the Than. This effect is probably largely explained by the reduction in oxygen deficit during the transient phase. Under these conditions, the time-course of changes in [lab] during the VO2 steady state was also affected.

Adult↗

Changes in blood leucocyte populations induced by acute maximal and chronic submaximal exercise.

Absolute (x 10(3).mm-3) or relative (%) numbers of blood leucocyte types (monocytes, lymphocytes, neutrophils) and lymphocyte subsets (T11+, T4+, T8+, B1+, and NKH1+) reacting with specific monoclonal antibodies were determined at rest, immediately after maximal exercise on a treadmill, in six controls (C), and in six young cyclists before training (BT) and after 5 months of training (AT). Maximal exercise significantly increased the absolute number (mobilization) of virtually all the types of leucocytes and subsets of lymphocytes in C, BT and AT subjects. In these subjects mobilization of natural killer cells (NKH1+) and cytotoxic/suppressor T lymphocytes (T8+) was greater than mobilization of the other leucocyte types and lymphocyte subsets; however, maximal exercise induced no significant changes in the relative numbers of any leucocyte types and lymphocyte subsets, except in the case of T4+ lymphocytes in At cyclists. Chronic submaximal exercise induced increased mobilization of neutrophils and decreased mobilization of lymphocytes during maximal exercise, except in the case of B lymphocytes (B1+) and NKH1+ cells, and decreases in the absolute and relative number of neutrophils at rest. It remains to be seen how these results can explain the modifications of leucocyte activities noted in vitro after isolated or chronic exercise.

Adult↗

Influence of food on the pharmacokinetics of perindopril and the time course of angiotensin-converting enzyme inhibition in serum.

Food has been shown to reduce the bioavailability of the angiotensin-converting enzyme inhibitor captopril, but not the bioavailability of inhibitors administered as ester prodrugs. Perindopril is the ester pro-drug of the angiotensin-converting enzyme inhibitor perindoprilat. The influence of food on the pharmacokinetics of perindopril (4 mg administered orally) and the time course of angiotensin-converting enzyme inhibition in serum was studied in a randomized crossover short-term study of 12 healthy subjects. Food significantly decreased the relative availability of perindoprilat by 35% +/- 42%, the fractional urinary excretion of perindoprilat from 19% +/- 7% to 13% +/- 4% (p less than 0.05), and the partial metabolic clearance of perindopril to perindoprilat from 102 +/- 57 ml.min-1 to 72 +/- 32 ml.min-1 (p less than 0.05). These changes were associated with a significant decrease in the area under the percent angiotensin-converting enzyme inhibition-versus-time curve by 15% (p less than 0.05). Food did not alter the total amount of drug recovered in urine as perindopril and its metabolites, and it did not alter perindoprilat renal clearance. We concluded that food alters the conversion of perindopril to its active metabolite perindoprilat after single-dose administration of perindopril.

Administration, Oral↗

Immunomodulations induced in rats by exercise on a treadmill.

Various regimens of treadmill exercise (0% slope) were used with rats: 60 min at 15 m/min (T-15), 180 min at 10 m/min (T-10), and 60 min/day at 15 m/min for 6 consecutive days (T-15-6). Exercise resulted in 1) decreases in the absolute number of mononuclear spleen cells in T-10 rats, 2) significant increases in in vitro splenic T-cell blastogenesis in response to phytohemagglutinin in T-10 rats, and 3) significant decreases in T-cell blastogenesis in T-15-6 rats. T-15-6 rats were given aminoglutethimide per os before exercise sessions to study the role of corticosteroids in the alteration of splenic T-cell blastogenesis. Aminoglutethimide significantly increased the T-cell blastogenesis in these T-15-6 rats compared with those not given aminoglutethimide, whereas it had no effect on immune parameters of sedentary rats. These results show that immunomodulations in the rat depend on the treadmill exercise regimen employed. If the mechanisms of the immunomodulation induced by isolated exercise of long duration are not elucidated, these data suggest that corticosteroids are involved in the alteration in T-cell blastogenesis induced by chronic muscular exercise.

Aminoglutethimide↗

Blood lactate during submaximal exercises. Comparison between intermittent incremental exercises and isolated exercises.

Values of oxygen consumption, carbon dioxide production, ventilation and blood lactate concentration were determined in eight active male subjects during the minute following submaximal square-wave exercise on a treadmill under two sets of conditions. Square-wave exercise was (1) integrated in a series of intermittent incremental exercises of 4-min duration separated by 1-min rest periods; (2) isolated, of 4- and 12-min duration, and of intensity corresponding to each of the intermittent incremental periods of exercise. For square-wave exercise of the same duration (4 min) and intensity, no significant differences in the above-mentioned parameters were noted between intermittent incremental exercise and isolated exercise. Only at high work rate (greater than 92% maximal oxygen uptake), were blood lactate levels in three subjects slightly higher after 12-min of isolated exercise than after the 4-min periods of isolated exercise. Examination of these results suggests that (1) 80-90% of the blood lactate concentration observed under our experimental conditions results from the accumulation of lactate in the blood during the period of oxygen deficit; (2) therefore the blood lactate concentration/exercise intensity relationship, for the most part, appears to represent the lactate accumulated early in the periods of intermittent incremental exercise.

Adult↗

Effects of falipamil (AQ-A 39) on heart rate and blood pressure in resting and exercising healthy volunteers.

Falipamil (AQ-A 39) is a new verapamil derivative which exerts antitachycardic effects by a direct action on the sinus node. Its effects on heart rate (HR), blood pressure (BP) and ECG intervals were studied in 12 healthy volunteers, at rest and during bicycle exercise tests. In a double-blind, cross-over, single-dose study, the effects of falipamil (100 and 200 mg) during 8-h post-dosing were compared with those of placebo. Falipamil did not modify resting HR, BP, and electrocardiogram (ECG) intervals significantly. Maximal exercise HR significantly decreased by 5.3 +/- 2.9 (SD)% and 11.2 +/- 3.6% 2 h after the 100- and 200-mg dose respectively, whereas placebo had no effect. Exercise BP was not significantly modified by falipamil. The slopes of HR-workload relationships significantly decreased with falipamil. Peak plasma concentrations of falipamil occurred 1-1.5 h after absorption, and the falipamil-induced decrease in exercise HR over 8 h postdosing was proportional to falipamil plasma concentrations. These results suggest that falipamil decreases HR at exercise in normal subjects and may exert antianginal effects in patients with myocardial ischemia.

Adult↗

Pharmacokinetics and effects on exercise heart rate of PK 11195 (52028 RP), an antagonist of peripheral benzodiazepine receptors, in healthy volunteers.

PK 11195 (or 52028 RP; 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide), an antagonist of the peripheral-type benzodiazepine receptors which are coupled to calcium channels, was administered to 10 healthy volunteers in order to study the pharmacokinetics and cardiovascular effects of the drug. PK 11195 was randomly administered intravenously (10 mg) and orally in three single dosages (100, 200 and 400 mg). Placebo was only given orally. Heart rate and blood pressure were recorded at rest and during exercise tests which were performed at 0, 1, 3, 6 and 24 h after dosing on each study day. The results showed that after IV administration, PK 11195 was rapidly distributed in two or three open compartments. Its elimination T 1/2 was short (3.7 +/- 3.0 h) with high interindividual variability. After oral ingestion the pharmacokinetics of PK 11195 were linear over the range of 100-400 mg single oral doses with a stable absolute bioavailability (33%). T 1/2 elimination was prolonged (7-12 h) and the presence of secondary increases in plasma concentration at 8-10 h and 22-24 h after drug absorption may have been related to enterohepatic cycling. No unchanged PK 11195 could be detected in urine. PK 11195 did not significantly modify heart rate and blood pressure at rest or during exercise and was well tolerated by the subjects. These data suggest a high inter-individual variability in PK 11195 disposition with extensive metabolism in normal exercising volunteers.

Administration, Oral↗

Blood lactate accumulation in intermittent supramaximal exercise.

Blood lactate accumulation rate and oxygen consumption have been studied in six trained male runners, aged 20 to 30 years. Subjects ran on a treadmill at a rate representing 172 +/- 5% VO2max for four 45 s sessions, separated by 9 min rest periods. Oxygen consumption was measured throughout. Blood lactate was determined in samples taken from the ear and VO2 was measured at the end of each exercise session, and two, five and nine minutes later. After the fourth exercise session, the same measurements were made every five min for 30 min. 4 subjects repeated a single exercise of the same type, duration and intensity and the same measurements were taken. With repetitive intermittent exercise, gradual increases in blood lactate concentration [( LA]b) occurred, whereas its rate of accumulation (delta[LA]b) decreased. The amount of oxygen consumed during each 45 s exercise session remained unchanged for a given subject. After cessation of intermittent exercise, the half-time of blood lactate was 26 min, whereas it was only 15 min after a single exercise session. VO2 values, on the other hand, returned to normal after 15 to 20 min. All other conditions being equal, the gradual decrease in delta[LA]b during intermittent exercise could be explained if the lactate produced during the first exercise session is used during the second period, and/or if the diffusion space of lactate increases. The diffusion space seems to be multi-compartmental on the basis of half-time values noted for [LA]b after intermittent exercise, compared with those noted after a single exercise session.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗