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Biomedical subjects

M Monnier

Publications and source records attributed to M Monnier.

At least 19 recordsLinked to original sources
PubMed2005

[The Transplantation Law of October 8, 2004].

The Transplantation Law was approved by Parliament on 8 October 2004. Its key features are a ban on trade in human organs, tissue and cells; the non-entitlement of donors of their next of kin to payment for organs; the definition of when death is considered to have occurred; the need for consent before removal takes place; the criteria for donations by living persons; the criteria and procedure for assigning donated organs to recipients; xenotransplantation; and the transplantation of human embryonic and fetal tissue and cells. As things stand at present, the law is expected to take effect at the beginning of 2007. The current fragmented legislation on transplant medicine will therefore be replaced in two years' time by a modern, consistent and comprehensive legal framework.

Informed Consent↗
PubMed2000

UV-laser photoisomerization of fumaryl chloride: the first identification of maleoyl chloride: matrix isolation infrared and ab initio studies.

Fourier transform infrared spectra of fumaryl chloride 1 isolated in an argon matrix at 10 K have been analyzed. The comparison between the ab initio HF/6-31G calculated infrared spectra with the experimental ones reveals the existence of three planar conformers, the cis cis 1a, the cis trans 1b and the trans trans 1c. Laser UV irradiation of 1 at lambda = 340 nm yields maleoyl chloride 2 by a carbon carbon double bond photoisomerization process. The first identification of this compound was performed by comparison of the experimental infrared spectra with the calculated ones at the MP2/6-1G** level. AM1 semiempirical and ab initio calculations were used to calculate the structure and the relative stability of the three non planar maleoyl chloride conformers.

Argon↗
PubMed2000

Free radical scavenging and antioxidant effects of lactate ion: an in vitro study.

Divergent literature data are found concerning the effect of lactate on free radical production during exercise. To clarify this point, we tested the pro- or antioxidant effect of lactate ion in vitro at different concentrations using three methods: 1) electron paramagnetic resonance (EPR) was used to study the scavenging ability of lactate toward the superoxide aion (O(2)(-).) and hydroxyl radical (.OH); 2) linoleic acid micelles were employed to investigate the lipid radical scavenging capacity of lactate; and 3) primary rat hepatocyte culture was used to study the inhibition of membrane lipid peroxidation by lactate. EPR experiments exhibited scavenging activities of lactate toward both O(2)(-). and.OH; lactate was also able to inhibit lipid peroxidation of hepatocyte culture. Both effects of lactate were concentration dependent. However, no inhibition of lipid peroxidation by lactate was observed in the micelle model. These results suggested that lactate ion may prevent lipid peroxidation by scavenging free radicals such as O(2)(-). and.OH but not lipid radicals. Thus lactate ion might be considered as a potential antioxidant agent.

Animals↗
PubMed2000

Assessment of hypothalamic-pituitary-adrenal axis and sympathetic nervous system activity in pregnant sows through the measurement of glucocorticoids and catecholamines in urine.

We validated the use of urine to monitor changes in the activity of both the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS) in swine. Ten pregnant sows were fitted with venous catheters 3 wk after mating. In the early (wk 6), middle (wk 9), and late (wk 14) stages of gestation, blood and urine were collected over 24 h to monitor diurnal changes in plasma cortisol, urinary cortisol, and urinary catecholamines (norepinephrine [NE] and epinephrine [EPI]). Dexamethasone suppression tests (DST) and ovine corticotropin-releasing hormone (CRH) challenge tests were also performed at each stage of gestation. All plasma and urinary values changed markedly around the clock. Diurnal variations of urinary cortisol were comparable to those in plasma, with a late nocturnal peak and a trough occurring in the evening. During the dark period, urinary catecholamines were lower than during the light period. Norepinephrine increased sharply after lights came on and peaked after meal time. Epinephrine began to rise at the end of the dark period and peaked just before meal time. Average plasma cortisol increased with the stage of gestation, due to higher levels during daylight hours. Dexamethasone at 2000 (20 microg/kg i.v.) decreased plasma cortisol at 0830 and nocturnal cortisol excretion. The magnitude of the decrease in plasma ACTH and urinary cortisol after DST was lower in late than in early and midgestation, indicating increased feedback resistance at that stage. The CRH (1 microg/kg i.v.) increased plasma and urinary cortisol. Peak levels occurred 30 min and 2 to 3 h after the injection, respectively. Catecholamines and cortisol in urine produced during the night (2000 to 0800) and the early morning (0400 to 0800 and 0800 to 0900) were highly correlated with their 24-h excretion rate. These results indicate that it is possible to monitor changes in the HPA axis and SNS activity through urinary measurements in pigs.

Adrenocorticotropic Hormone↗
PubMed1998

Adrenal medulla responsiveness to the sympathetic nervous activity in sprinters and untrained subjects during a supramaximal exercise.

The purpose of this study was to compare the adrenal medullar responsiveness to the sympathetic nervous activity between sprinters and untrained subjects after a supramaximal exercise (Wingate-test). Thirteen subjects took part in this study: 7 male athletes (20.3+/-1.8 years) competing in sprint running (S) and 6 untrained men (UT) (21+/-1.3 years). They performed an incremental treadmill test to determine the maximal oxygen uptake (VO2max), a force-velocity test and a Wingate-test on 3 different days, separated by a maximal interval of 15 days. The maximal power (Wmax) and the mean power (W) were determined from the Wingate-test on a cycle ergometer. Plasma lactate, adrenaline and noradrenaline concentrations were determined at rest (La0, A0, NA0), immediately after the Wingate-test (Amax, NAmax) and after 5 minutes recovery (Lamax, A5 and NA5). S exhibited higher performances than UT during the Wingate-test as shown by their significantly higher values of Wmax (1111+/-38 w in S vs 886+/-148 w in UT), W (822+/-37 w in S vs 646+/-69 w in UT) and Lamax (16.8+/1.8 mmol x l(-1) in S vs 12.2+/-2.5 mmol x l(-1) in UT). At the end of the test the NAmax values were similar in both groups whereas the Amax were significantly higher in S (7.6 +/- 1.4 nmol x l(-1) in S vs 3.6 +/- 3.2 nmol x l(-1) in UT). This leads to a higher Amax/NAmax ratio for sprinters compared to untrained subjects (0.7+/-0.2 in S vs 0.3+/-0.2 in UT, p < 0.05). As the disappearance of A (estimated by the Amax-A5 difference) was not lower in S (6.4+/1.5 nmol x l(-1) in S vs 1.8+/-4 nmol x l(-1) in UT), the higher Amax values in S might be explained by a greater secretion level of A. Conversely the identical NAmax values in both groups suggested that this kind of exercise induced the same sympathetic input in S and UT. Consequently the higher Amax/NAmax ratio in S argued in favor of a higher responsiveness of the adrenal medulla of sprinters to the same sympathetic input.

Adrenal Medulla↗
PubMed1995

A test to approach maximal lactate steady-state in 12-year old boys and girls.

The purpose of this study was to measure the running velocity corresponding to the individual maximal lactate steady-state of a group of 12-year old boys and girls on a treadmill. This running velocity (v MLST) was compared with the maximal aerobic running velocity (v a max) at which maximal oxygen uptake (VO2 max) occurs. Thirteen pupils of the same school whose puberal maturation corresponded to the end of stage 2 and the beginning of stage 3 of Tanner: 6 boys (12.2 years old +/- 0.5, 38.4 +/- 2 kg, 150 +/- 4.8 cm: group 1) and 7 girls (12.3 years old +/- 0.5, 37.6 +/- 6 kg, 151.4 +/- 5.6 cm: group 2) carried out two tests at one week interval. The first test was a maximal incremental test for the determination of VO2 max with Douglas's bag method and v a max. The purpose of the second test was the determination of maximal lactate steadystate velocity (v MLST) With two stages of ten minutes at 60 +/- 5% and 74 +/- 4.5% v a max separated by 40 minutes of complete rest (Billat, 1992); VO2max and v a max were significantly different, equal to 49.4 +/- 7 ml.min-1.kg-1, 40.4 +/- 4.7 ml.min-1.kg-1 and 12.6 +/- 0.2 km.h-1, 11.2 +/- 1.2 km.h-1 for group 1 and 2 respectively (P < 0.05). Moreover, maximal lactate steady state velocity (v MLST) was respectively equal to 64.8 +/- 12.5% and 64.6% +/- 12.5% VO2 max respectively, representing 67.8 +/- 6.2% and 68.8% +/- 8.3% v a max and was not significantly different for group 1 and 2. In conclusion, this study shows that maximal lactate steady-state velocity is not significantly different between young boys and girls of 12 years old, when expressed in fraction of VO2 max or v a max. However, VO2 max and v a max were significantly higher in boys: +27.2 and +11.6% higher respectively.

Child↗
PubMed1994

Lactate and catecholamine responses in male and female sprinters during a Wingate test.

A total of six male and six female sprinters at the same national competition level and aged 18-20 years performed a force/velocity test and a 30-s supramaximal exercise test (Wingate test) on 2 different days, separated by a maximal interval of 15 days. The maximal anaerobic power (Wmax) was determined from the force/velocity test, and the mean anaerobic power (W) from the Wingate test. Immediately after the Wingate test, a 5-ml venous blood sample was drawn via a heparinized catheter in an antebrachial vein for subsequent catecholamine (adrenaline and noradrenaline) analysis. After 5 min recovery a few microliters of capillary blood were also taken for an immediate lactate determination. Even expressed per kilogram lean body mass, Wmax and W were significantly lower in women. The lactate and adrenaline responses induced by the Wingate test were also less pronounced in this group whereas the noradrenaline levels were not significantly different in men and women. Above all, very different relationships appeared between lactate, adrenaline, noradrenaline and W according to sex. Thus, as reported by other authors, the adrenergic response to a supramaximal exercise seemed to be lower in women than in men. Nevertheless a different training status between the two groups, even at same national competition level, could not be excluded and might contribute, at least in part, to the gender differences observed in the present study.

Adolescent↗
PubMed1994

Glucoregulation and hormonal changes during prolonged exercise in boys and girls.

A group of 17 children, 8.5-11 years old, performed a 60-min cycle exercise at 60% of maximal oxygen uptake (VO2max) 2 h after a standardized breakfast. They were 10 young boys (pubertal stage = 1) and 7 young girls (pubertal stage < or = 2) of similar VO2max (respective values were 48.5 ml min-1 kg-1, SEM 1.8; 42.1 ml min-1 kg-1, SEM 2.4). Blood samples of 5 ml were withdrawn by heparinized catheter, the subjects being in a supine position, 30 min before the test, then after 0, 15, 30 and 60 min of exercise and following 30 min recovery. Haematocrit was immediately measured. Thereafter plasma was analysed for glucose, non-esterified fatty acid, glycerol, catecholamine (noradrenaline, adrenaline), insulin and glucagon concentrations. This study showed two main results. First, the onset of exercise induced a significant glucose decrease (of about 11.4%) in all the children. Secondly, both the glycaemic and the hormonal responses were obviously different according to the sex. In boys only, the initial glucose drop was significantly correlated to the pre-exercise insulin values. Whatever the time, the glycaemic levels and the catecholamine responses were lower in girls than in boys, whereas the insulin values remained higher. However, none of these two hormonal parameters seemed to be really responsible for the lower glucose values in girls. On the one hand, the great individual variability of noradrenaline and adrenaline and differences in their relative intensity at the end of the exercise between boys and girls might contribute to the lower catecholamine levels in girls.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1992

Glucose and free fatty acid utilization during prolonged exercise in prepubertal boys in relation to catecholamine responses.

Ten prepubertal boys performed 60-min cycle exercise at about 60% of their maximal oxygen uptake as previously measured. To measure packed cell volume, plasma glucose, free fatty acids (FFA), glycerol and catecholamines, blood samples were drawn at rest using a heparinized catheter and at the 15th, 30th and 60th min of the exercise and after 30 min of recovery. At rest, the blood glucose concentrations were at the lowest values for normal. Exercise induced a small decrease of blood glucose which was combined with an abrupt increase of the noradrenaline concentration during the first 15 min. The FFA and glycerol concentrations increased throughout the exercise linearly with that of adrenaline. Compared to adults, the FFA uptake expressed per minute and per litre of oxygen uptake was greater in children. These results suggested that it is difficult for children to maintain a constant blood glucose concentration and that prolonged exercise provided a real stimulus to hypoglycaemia. An immediate and large increase in noradrenaline concentration during exercise and a greater utilization of FFA was probably used by children to prevent hypoglycaemia.

Blood Glucose↗
PubMed1991

[Mycobacterium marinum granuloma in a fish fancier. Apropos of a case with sporotrichoid lesions].

A 43-year-old fish fancier with fish tank granuloma presented with a sporotrichoid-like skin infection of the right arm with multiple papulo-nodular lesions along the lymphatic drainage. Acid fast bacilli were found in skin biopsy specimens and Mycobacterium marinum grew in cultures. The clinical and histopathological findings in M. marinum infection are reviewed and the differential diagnosis, laboratory findings with this atypical mycobacterium, and therapeutic modalities are discussed. Finally, the importance of an adequate and pertinent patient's history for a correct and timely diagnosis is stressed.

Adult↗
PubMed1991

Impact of dietary tryptophan and behavioral type on growth performance and plasma amino acids of young pigs.

Tryptophan (TRP) content in the protein of the weaning diet was varied from deficient (.70 g/16 g N) to adequate (1.15 g/16 g N) and excess (1.60 g/16 g N) in diets fed to 108 pigs from d 5 to d 26 after weaning (W) and in 72 pigs from d 26 after weaning to slaughter (100 kg live weight) to assess immediate and long-term effects of TRP on performance. Daily weight gain and feed efficiency were improved when dietary TRP was increased from deficient to adequate (+60 and +40%, respectively). Concurrently, daily feed intake was elevated moderately (+15%). No further improvement was observed with excess TRP. In the low TRP group, gain/feed was significantly poorer up to 25 kg live weight, but this effect did not continue later. Although no compensatory growth could be shown in the group fed the deficient diet, growth retardation was very small (1.5%; P greater than .10) at slaughter. Early changes in TRP supply did not affect either carcass or meat quality. Behavioral reactivity, as determined on day W + 5 in an "open-field" test, did not affect early performance, but growth rate during the growing-finishing stage (3.2%) or the whole period (2.5%) was greater by nonemotional than by emotional pigs. Plasma amino acid contents in blood samples, withdrawn on day W + 15 (fed state) and W + 17 (fasted state), were consistent with the effect of TRP on growth rates. However, in the fasted state, a diet x reactivity interaction suggested that TRP removal from the plasma was less rapid in nonemotional than in emotional pigs. Furthermore, increased plasma concentrations of essential amino acids and urea in the latter group suggested that protein and amino acid catabolism was more rapid in emotional than in nonemotional pigs. These data are discussed relative to the effect of the behavioral type of pig on its TRP requirement.

Amino Acids↗
PubMed1991

Impact of dietary tryptophan and behavioral type on behavior, plasma cortisol, and brain metabolites of young pigs.

The behavioral reactivity in an "open-field" test and plasma cortisol levels were studied in 72 pigs from 12 litters fed for 3 wk one of three diets with different levels of tryptophan: deficient (.14%), adequate (.23%), or excess (.32%). "Open-field" tests were performed three times: 5 d (day W + 5), 23 d (day W + 23) and 45 d (day W + 45) after weaning. The exploration time and the number of grunts provided an adequate measure of the individual emotional reactivity at day W + 5. Significant correlations were obtained between exploration time and the number of grunts at each time (r = -.83 at day W + 5; r = -.46 at day W + 23; r = -.71 at day W + 45). The distinction between animals remained (P less than .05) in terms of exploration time at both 23 and 45 d after weaning. At day W + 23, exploration time was lower in the group fed the adequate diet than in the two other groups. This effect was maintained subsequently after feeding all pigs the same adequate diet (day W + 45). In 36 pigs slaughtered at day W + 23, brain TRP concentration was higher with the excess dietary TRP than with deficient or adequate levels. Conversely, other plasma amino acids (particularly threonine) accumulated only in the brains of pigs fed the deficient diet. Plasma cortisol level assayed at weaning (W) and 2 wk later increased with age and was higher in 16-h fasted (day W + 15) than in 3-h fasted (day W + 17) pigs. Correlations were observed within litters in the fasting state, between the cortisol level and behavioral traits measured at day W + 23 (r = .70 for number of grunts, r = -.60 for exploration time). Dietary TRP did not affect the plasma cortisol level irrespective of the nutritional state after weaning. However, an interaction was noted between plasma cortisol and TRP status (P less than .05). Although dietary TRP induced large variations in brain amino acids and 5-hydroxyindole concentrations, changes in behavioral and cortisol responses were relatively minor.

Amino Acids↗
PubMed1987

Changes in pulse wave velocity with age in man: a longitudinal series over 20 years.

Measurements of pulse wave velocity (PWV) carried out systematically in the same 60 healthy individuals over 20 years confirmed that average PWV progressively increases with age, and more rapidly after age 45. The PWV increase mainly results from the decreased extensibility of the thoracic aorta in the aortic-popliteat arterial system. This longitudinal study showed that PWVs of most individuals do not closely follow the average cross-sectional trend, but vary considerably in type. Therefore, PWV by itself is hardly a close correlate of an individual's physiological age or life expectancy. Individuals with a constantly high PWV or a late abrupt increase are exceptional; a possible relation to an increased mean arterial pressure and decreased arterial extensibility as in hypertonia is mentioned.

Adult↗
PubMed1985

[Radioimmunologic determination of ACTH in the rabbit: stress-ACTH-corticosteroid relationship and diarrhea].

Plasma ACTH was measured in young and adult rabbits with a CEA-SORIN kit. The reliability of the analysis was controlled by liquid chromatography, several biochemical tests such as parallelism and reproducibility and several physiological tests such as plasma ACTH response to ethylic ether stress, to adrenalectomy, to dexamethasone and metopyrone. In young diarrhoeic rabbit plasma, ACTH (293 +/- 45 pg/ml) and corticosteroid (111 +/- 13 ng/ml) levels were significantly much higher than in young healthy rabbits (ACTH: 130 +/- 35 pg/ml; corticosteroids: 66 +/- 7 ng/ml). Furthermore, transporting young rabbits by car caused such violent stress that plasma ACTH levels increased from 52 +/- 11 to 130 +/- 35 pg/ml. A causal relationship between stress - ACTH and diarrhoea is discussed.

Adrenal Cortex Hormones↗