Biomedical subjects

R Mieusset

Publications and source records attributed to R Mieusset.

46 records · Page 3Linked to original sources

PubMed1988

Glycerophosphocholine in seminal plasma of fertile and infertile men.

Glycerophosphocholine (GPC) was measured in seminal plasma from 65 fertile men, 276 infertile men and 10 men before and after vasectomy, using a new enzymatic method. Extra-epididymal excretion of GPC accounted for 30% of the total seminal levels of GPC. From a diagnostic point of view, GPC determination did not appear to be a specific tool which could discriminate between secretory and excretory azoospermia. Although the seminal content of GPC was related positively to the total sperm count in both fertile and infertile men, there was an inverse relationship between the level of GPC and sperm motility when considering classes displaying the same total sperm count. This was observed in all classes from infertile men as well as in fertile men with a total sperm count lower than 200 x 10(6) sperm/ejaculate. These results suggest a possible role of GPC in the regulation of human sperm motility, which warrants further investigation.

Glycerylphosphorylcholine↗

PubMed1988

Simple, rapid enzymatic determination of glycerophosphocholine in human seminal plasma.

We have devised a new enzymatic determination of sn-glycero-3-phosphocholine (GPC) in human seminal plasma. This is based on GPC hydrolysis by a phosphodiesterase (PDE), free choline being then determined by the choline oxidase method. The whole procedure involves a first incubation in the presence of choline oxidase and catalase, to eliminate the excess of choline present in seminal plasma (10-fold, compared with GPC). Absorbance and concentration are linearly related up to at least 100 nmol per assay, analytical recovery ranges between 89% and 105%, and intra- and interassay CVs are 3.2% and 5.6%, respectively, at the highest substrate concentration. Using this procedure, we found seminal plasma from 21 fertile men to contain 5.22 (SD 3.33) mumol per ejaculate--within the same range as previously reported values obtained chromatographically. After vasectomy, GPC in seminal plasma decreased to 28% of its original value, as determined in 10 volunteers. Thus this new method displays appropriate characteristics of specificity, reliability, and convenience, allowing its use in routine evaluation of male fertility.

Alcohol Oxidoreductases↗

PubMed1987

Association of scrotal hyperthermia with impaired spermatogenesis in infertile men.

Scrotal temperatures, testicular volumes, and sperm characteristics were studied in 150 infertile, nonazoospermic men and in 37 fertile men, used as a control group. The mean scrotal temperature values of the infertile men were significantly greater than those observed in the fertile men (+0.4 degrees C for the right; +0.5 degrees C for the left). In the infertile men, it was found that the higher the scrotal temperature, the more alterated the sperm characteristics. The only clinical element that seemed to be linked to the existence of scrotal hyperthermia in the infertile men was testicular hypotrophy. Although the scrotal temperatures of the infertile men with varicocele were significantly higher than those of the fertile men, they did not significantly differ from those of the infertile men without varicocele. No other specific pathologic factor, infectious or surgical urogenital history was found to be responsible for the scrotal hyperthermia observed in the infertile men.

Body Temperature↗

PubMed1987

Hyperthermia and human spermatogenesis: enhancement of the inhibitory effect obtained by 'artificial cryptorchidism'.

Decreased sperm count and motility were observed in men after induction of local testicular hyperthermia by raising the testicles into the inguinal canal during the day in adult volunteers. A similar technique in which the testicles were better maintained in the inguinal canal resulted in more marked suppression of spermatogenesis. As assessed by the total motile sperm count, the mean inhibitory effect of hyperthermia was at least 97% after 2 months using this technique. This effect of 'artificial cryptorchidism' may be of practical interest in the manipulation of male fertility.

Adult↗

PubMed1987

Effects of artificial cryptorchidism on sperm morphology.

In a diurnal artificial cryptorchidism (AC) experiment intended to provide a male contraceptive method, oligoasthenozoospermia was found as early as the fourth month, accompanied by an increase in the mean percentage of abnormally shaped spermatozoa. A detailed morphologic study concerning 19 volunteers exposed for 6 to 24 months demonstrated that the overall increase of the mean percentage of abnormally shaped spermatozoa resulted from the percentage increase of elongated, thin, and irregular heads and of bent tails. This increase is probably caused by the rise in environmental testicular temperature induced by AC. A return to baseline values was observed within 12 months after the end of the experiment.

Adult↗

PubMed1986

[Varicocelectomy for infertility is more effective in cases of sperm count less than 5 million/ml. Apropos of 70 cases].

70 patients, out of a total of 664 infertile subjects with a varicocele, presenting a sperm count of less than 5 X 10(6)/ml, were operated and followed for a mean period of 8 months. 80% of the 70 varicoceles were voluminous, compared with 23% in the general population. There was a statistically significant difference between the presence of a large varicocele and the presence of testicular hypotrophy or a sperm count of less than 5 X 10(6)/ml. Histological examination of 80 testes revealed a defect of maturation in 36% of cases (T2), corresponding to reversible histological lesions. The histological lesions predominantly involved the tube (66%) followed by the basement membrane (52%) and the interstitium (42%). The difference between the pre- and post-operative sperm counts was statistically significant (p less than 0.001). We obtained a 36% paternity rate after a mean post-operative delay of 8 months. The authors consider that the larger the varicocele, the more severe the histological lesions (maturation defect = T2). These cases have a very good chance of post-operative improvement as a result of restoration of spermatogenesis. This improvement is more marked when the lesions of the basement membrane and interstitial lesions are less severe. This concept of a "large pathogenic varicocele" which responds well to surgical cure raises doubts about the concept of sub-clinical pathogenic reflux detected by Doppler examination or by phlebography resulting, far too often at the present time, in an embolisation procedure.

Humans↗

PubMed1986

[Epididymal prognostic factor in epididymo-deferential anastomosis].

Results of a 1981 study are complemented and analyzed with respect to epididymal histology in 94 patients undergoing uni- or bilateral epididymo-deferential anastomosis. Testicular histology was normal in all patients. Epididymal histology could be differentiated into two main groups: one with normal or only slightly altered epididymis, the other with major epididymal lesions. Repermeabilization was more frequent and of better quality (10 X 10(6) sperm/ml or more) in the first group, in which there were also all the pregnancies. Previous genital infection or injury is of poor prognosis due to the severe epididymal lesions present.

Epididymis↗

PubMed1985

Inhibiting effect of artificial cryptorchidism on spermatogenesis.

In order to provide a contraceptive method in man, an attempt at inhibition of spermatogenesis was made by means of thermogenesis induced by artificial cryptorchidism. This experimental protocol consists of pushing up the testicles into the inguinal canal and keeping them there, each day during waking hours, by means of an adapted athletic supporter. Fourteen men volunteered for this protocol during a 6- to 12-month period. They all had a normal semen analysis before starting the experiment. The total sperm count, the sperm count per milliliter, the motility, the motile sperm count per milliliter, and the total motile sperm count dropped significantly after the first or second month; they reached their lowest values after the sixth month and remained stable during the next 6 months. At that time the average values reached were a total sperm count of 12 to 34 X 10(6)/ejaculate, a sperm count of 3 to 10 X 10(6)/ml, a motility of 21% to 34%, a motile sperm count of 1 to 3 X 10(6)/ml, and a total motile sperm count of 4 to 12 X 10(6)/ejaculate.

Adult↗

PubMedDate not supplied

Sperm morphology in fertile men and its age related variation.

The different kinds of abnormalities of spermatozoa and their age related variations are studied in a population of 214 fertile men. Coiled tails (7%), bent tails (5.2%), thin heads (2.6%), microcephalic (2.6%), cytoplasmic droplets (2.5%), irregular heads (2%), macrocephalic (0.9%), duplicated heads (0.7%) and duplicated tails (0.5%) are found in this order. Age is positively correlated with the percentage of microcephalic, macrocephalic and duplicate heads and coiled tails and negatively correlated with the percentage of no tail spermatozoa: these age-related variations are involved in the 90th percentile.

Adult↗

PubMedDate not supplied

[Treatments of testicular cancer and protection of spermatogenesis].

The deleterious effects of chimio or radio-therapy on spermatogenesis of men treated for testicular cancer are well known. Retroperitoneal lymphadenectomy is a risk for ejaculation process. Semen cryopreservation seems to be obligatory before any deleterious treatment. Prophylactic measures do exist such as lead protection during x-rays therapy, drugs with less toxicity but similar efficiency, selective lymphadenectomy. Moreover, positive results were reported form realised in animals to protect spermatogenesis. In men treated for testicular cancer, 4 protective studies were reported using either GnRH analogs (3 studies) or medroxyprogesterone (one study). No protective effects were obtained in these trials, and the reasons for such failure are discussed. Finally, new potential possibilities of spermatogenesis protection are suggested supported by the results of animal experiments or the occurrence of new drugs such as use of steroids, GnRH antagonist or testicular hypothermia.

Antineoplastic Agents↗