Search PubMed⌕ Search

Biomedical subjects

M Mas

Publications and source records attributed to M Mas.

81 records · Page 5Linked to original sources
PubMed1978

Antiandrogenic effects of the pineal gland and melatonin in castrated and intact prepubertal male rats.

In castrated prepubertal rats, pinealectomy enhanced the testosterone-induced growth response of the seminal vesicles and melatonin inhibited this effect in a dose-related manner. In entire animals, the serum concentration of LH was increased after pinealectomy with no significant changes in other parameters. Administration of melatonin to intact, pinealectomized rats did not affect the serum concentrations of LH or testosterone but caused a dose-related decrease in the weight of the seminal vesicles. The highest dose of melatonin tested reduced the weight of the ventral prostate gland and the uptake of radioactivity by both the ventral prostate gland and the testes after injection of [5-3H]uridine. It is suggested that the pineal gland and melatonin may exert an antagonistic effect on the biological activity of androgens administered to castrated rats and that melatonin can reduce the growth of the accessory sex organs of intact, pinealectomized rats, in spite of a high concentration of LH in the serum. The well-known inhibitory influence of systemically administered melatonin on the accessory sex organs in male rats may be due to its antagonistic effect at a peripheral level.

Animals↗
PubMed1977

Effects of constant light exposure and blindness on the oxidative metabolism of selected brain areas in male rats.

Male rats were housed in continuous illumination or blinded when 21 day-old and killed 69 days later. The continuous illumination exposure increased the weights of testes and sex accessory organs and reduced the pineal gland weight. Blindness decreased weights of testes, sex accessory organs and anterior pituitary. The oxygen consumption rate of the hypothalamus was higher in the blinded animals than in the controls and lower in the continuously illuminated rats. No one of such groups showed significant changes in the oxygen consumption by either the amygdala or the hippocampus.

Animals↗
PubMedDate not supplied

Remote assistance experiment during the manned space flight Altair.

This remote assistance trial, performed within the framework of the manned space flight Altair, was carried out by CADMOS (CNES), with the cooperation of the Sub-directorate of CNES Operational Systems, Medes, LBM of Tours and Christol Consultants. It consisted of supplying the cosmonaut performing the Orthostatism experiment (echograph acquisition) on board the Mir station with realtime assistance by an expert (LBM of Tours) working from the ground on the CADMOS premises. The various steps of the approach followed during the preparation phase are described, as well as the technical means of communication used between the Mir station and CADMOS.

Astronauts↗
PubMedDate not supplied

Post-mortem dopamine dynamics assessed by voltammetry and microdialysis.

The effects of total brain ischemia (decapitation) on striatal extracellular levels of dopamine (DA) dihydroxyphenyl acetic acid (DOPAC) and ascorbic acid (AA) in chloral hydrate anesthetized rats were monitored at 1-min intervals by differential normal pulse voltammetry (DNPV) with numerical deconvolution of the catechol peak. Changes in pH were assessed by the shift of AA oxidation potential and incorporated into the computational procedure. The AA peak showed a sharp, short-lived (less than 15 min) postdecapitation rise, followed by a slower secondary increase. The DA signal increased 100-fold in the first 20 min followed by a slow decline. DOPAC levels fell 80% within 15 min after death. The post-mortem changes in extracellular DA and DOPAC were verified by a similar experiment using microdialysis. These observations probably reflect massive release and impaired uptake of DA combined with reduced monoamine oxidase activity. Changes in membrane permeability to DOPAC as a consequence of a post-mortem drop in pH may also contribute to the decline in extracellular DOPAC levels.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Combining programmed intracavernous PGE1 injections and sildenafil on demand to salvage sildenafil nonresponders.

In a prospective, placebo-controlled, one group crossover design study, we tested whether adding programmed intracavernous PGE1 injections (IC-PGE1) can improve the effectiveness of sildenafil in erectile dysfunction (ED) patients unresponsive to monotherapy with this drug. In all, 40 ED patients who had experienced unsatisfactory erections with both the 50 and 100 mg sildenafil doses were treated with four bi-weekly 20 microg IC-PGE1 injections given in the clinic and provided with either placebo or 50 mg sildenafil capsules for the next 4 weeks. Thereafter, they were crossed over to the other oral treatment for an additional 4-week period. The IIEF-Erectile Function domain score (IIEF-EFS), the main outcome measure, was found considerably higher (P<0.001) with the combined IC-PGE1-50 mg sildenafil treatment than with IC-PGE1-placebo or sildenafil alone (50 or 100 mg) in a subset of 26 subjects (65%). They thus shifted from the 'severe' or 'moderate' to the 'mild' grading of ED classification.

Aged↗
PubMedDate not supplied

Feasibility of fluorescent detection of pathogens on pork carcasses.

The direct immunofluorescent detection of pathogens on pork skin is evaluated. Calibrate contamination of pork skin with Salmonella Typhimurium (ST) and Listeria monocytogenes (Lm) is developed in 2 h at 4 degrees C. Then a specific indirect immunofluorescent staining protocol is optimized in order to obtain specific and intensive signals able to be detected by electronic cameras (deported microscopy). Despite the individual staining of ST and Lm is possible on pork skin and is specific and bright, the deported microscopy failed to detect these particles. After respectively 3 and 6 h, we obtain micro-colonies of ST and Lm. Due to the limited power of the video camera used, only the microscope permits the detection on the skin. However, our work gives standard conditions to mime the pathogens contamination and staining directly on a biological matrix such as pork skin. This work is a first step in the development of direct and rapid detection of pathogens on biological matrix.

Animals↗