Biomedical subjects

L Bujan

Publications and source records attributed to L Bujan.

45 records · Page 3Linked to original sources

PubMed1991

Luteinizing hormone pulse frequency and in vitro bioactivity in male idiopathic infertility.

We investigated 51 patients with idiopathic oligospermia and 10 control subjects. Blood samples were collected every 20 minutes from 10 P.M. to 10 A.M. and luteinizing hormone (LH) pulsatility was analyzed. A pool of all samples obtained from each subject was used to measure bioactive LH in an in vitro mouse Leydig cell bioassay and immunoactive LH in an immunoradiometric assay. Mean immunoactive LH pulse frequency was higher and mean bioactive to immunoactive LH ratio was lower in infertile men than in controls. There was a significant negative correlation between bioactive LH to immunoreactive LH ratio and LH pulse frequency. These data indicate that the defect in the gonadal axis in oligospermic men resides not in the hypothalamic-pituitary function but rather in the testis itself.

Adult↗

PubMed1989

Testicular size in infertile men: relationship to semen characteristics and hormonal blood levels.

Testicular volume was assessed in 1029 infertile men and found to be normal in 704; 71 patients had unilateral and 213 had bilateral testicular hypotrophy; 4 had unilateral and 37 had bilateral atrophy. Sperm count and motility decreased in accordance with testicular volume. The lowest mean sperm counts and lowest mean motility percentages were found in patients with bilateral testicular atrophy. An increase in mean FSH and LH was also significantly linked to decreasing testicular volume; the increase in the former was not related to a drop in sperm count. A significant correlation was found between testicular volume and spermatogenesis and testicular volume is considered to be a reliable indicator of testicular function.

Follicle Stimulating Hormone↗

PubMed1989

Increased levels of serum follicle-stimulating hormone and luteinizing hormone associated with intrinsic testicular hyperthermia in oligospermic infertile men.

A Negative correlation between spermatozoa output and serum gonadotropin levels, as well as between scrotal temperature and spermatozoa output, has been found in man. However, no studies have been done on the relationship between scrotal temperature and serum gonadotropin levels. This paper reports such data from 212 infertile men. The upper limit for normal scrotal temperature was defined as the 90th percentile value (35.3 C) of a control group of 64 fertile men whose mean serum FSH and LH levels were 6.0 +/- 0.8 (+/- SE) and 6.4 +/- 0.7 IU/L, respectively. This value for scrotal temperature (35.3 C) was used to classify infertile men into 3 groups: bilateral hyperthermia (n = 56), unilateral hyperthermia (n = 40), and bilateral normothermia (n = 116). In the unilateral and bilateral hyperthermic groups serum LH and FSH levels were significantly increased compared with those in the normothermic group. The mean serum testosterone values were similar in all groups. To study the relationships between serum gonadotropin levels or spermatozoa output and scrotal temperature, the infertile men also were divided into classes according to their spermatozoa output. These classes were subdivided into two groups, normothermic or hyperthermic, according to whether the left scrotal temperature was equal to or less than, or more than 35.3 C. For the infertile men whose spermatozoa output was more than 60 X 10(6) spermatozoa/ejaculate (normospermia), there was no significant difference between the serum gonadotropin levels of the normothermic (n = 42) and the hyperthermic (n = 20) groups. Among the oligospermic men (spermatozoa output, 0.1-60 X 10(6) spermatozoa/ejaculate), the hyperthermic group (n = 65) had significantly higher serum gonadotropin levels and significantly smaller testicular volumes than the normothermic group (n = 71). The two oligospermic groups also had significantly higher serum FSH values than the infertile normospermic groups. These results were not linked to the presence of a varicocele or a history of cryptorchidism, as the prevalence of varicocele and cryptorchidism was equally distributed within the groups studied. We conclude that the increase in serum gonadotropin levels in the case of a decrease in spermatozoa output is significantly greater in the presence of associated scrotal hyperthermia.

Adult↗

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↗

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↗

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↗