Puberty in the male chimpanzee: time-related variations in circulating inhibin.

Circulating immunoreactive inhibin concentrations were determined in male chimpanzees (n = 12) during a 36-mo period starting 18 mo before the onset of pubertal testicular growth (Po). Serum levels of inhibin started to increase, together with LH and testosterone, 6 mo before a rise in FSH and Po. Before Po, inhibin was not related to gonadotropins but was related to testosterone levels (r = 0.263; p < 0.005; R2 = 7%). After Po, inhibin remained related to testosterone (r = 0.289, p < 0.01) but became inversely related to gonadotropins; FSH was the best predictor (r = -0.382, p < 0.0005; R2 = 30%) of this relationship. During the progressive rise in circulating inhibin, FSH increased and plateaued during 9 mo, then dropped to prepubertal levels. These findings suggest that a specific closed-loop negative feedback system for the secretion of FSH by inhibin is not functional before the onset of puberty in the chimpanzee. This feedback system seems to fully operate several months after the LH rise and may be related to the complete maturation of both Sertoli cells and spermatogenesis.

Puberty in the male chimpanzee: progressive maturation of semen characteristics.

Cellular and biochemical characteristics of semen obtained by masturbation were studied in 5 pubertal chimpanzees during 1.5 yr. The dental age corresponding to the beginning of the pubertal testicular growth (Po) ranged from 5.0 to 8.3 years (mean = 6.7 +/- 1.2 yr). Time-related variations of all studied parameters were analyzed according to Po and, therefore, independently of the dental age. The emission of first ejaculates, and therefore the onset of activity of the accessory sex gland, was estimated to occur 4 mo after Po. The ejaculate volume (n = 132, r = 0.704, p less than 0.001), as well as the total amounts of l-carnitine (n = 65, r = 0.649, p less than 0.001), fructose (r = 0.522, p less than 0.001), citrate (r = 0.748, p less than 0.001), and acid phosphatase (r = 0.756, p less than 0.001) increased with time. First-obtained ejaculates contained no spermatozoa. Spermarche was estimated to occur 9.4 mo after Po. Total sperm count increased with time (r = 0.595, p less than 0.001). The motility and viability of spermatozoa increased with time (r = 0.474, p less than 0.01 and r = 0.632, p less than 0.001, respectively) while their morphology did not vary. The volume of the liquefied fraction and its content in free spermatozoa considered as available for fecundation remained low until the end of the study, most likely because of a delayed maturation of the prostate. This study shows that the maturation of the male genital tract is a progressive process. (ABSTRACT TRUNCATED AT 250 WORDS)

Puberty in the male chimpanzee: time-related variations in luteinizing hormone, follicle-stimulating hormone, and testosterone.

The onset of pubertal testicular growth (Po) occurred in 12 out of 20 male chimpanzees surveyed monthly for at least 3.7 yr. When animals were synchronized according to Po, the mean weight gain was found to be higher before than after Po, and testicular volume started to rise immediately after Po. The earlier significant hormonal events were a rapid rise in LH and a slight testosterone increase occurring 6 mo before Po. Thereafter, the levels of LH remained elevated while testosterone continued to rise in parallel with the testicular volume. FSH levels increased suddenly at Po, 6 mo after the LH increase. FSH remained elevated for only 9 mo, then dropped to prepubertal levels. The dissociation between onsets of pubertal increases in LH and FSH secretions suggests that the complete reawakening of the hypothalamic-pituitary unit lasts several months. The secondary drop of FSH, occurring at the time of spermarche, may be induced by factor(s) secreted by the testis.

[Alcohol and psychotropic drugs in fatal traffic accidents (the Nord-Pas-de-Calais region, France)]. / Alcool et psychotropes dans les accidents mortels de la circulation (région Nord-Pas de Calais, France).

UNLABELLED: Consumption of alcohol and tranquilizers reaches a very high level in France. Studies about simultaneous alcohol and psychotropic drugs involvement in motor related fatalities have never been described in this country. A retrospective study was done on 482 fatalities broken down by drivers and pedestrians within one year (1987) in Région Nord-Pas de Calais (France). METHOD: 132 cases met the criteria for complete study. Blood samples obtained at the time of death were analysed for alcohol (BAC) by gas-chromatography and assayed for barbiturates (BA), benzodiazepines (BE) and tricyclic antidepressants (TA) by Emit. RESULTS: Out of 132 fatalities there were 86% men (mean age 38.5 years) and 14% women (mean age 46 years). 57% belonged to the working population. Of the fatalities, 38% occurred from Friday 8 p.m. to Sunday 12 p.m. We distinguished 3 categories: pedestrians (18.2%), 2-wheel vehicles (19%) and 4-wheel vehicles (62.8%). Alcohol involvement is given in Table 2. [table: see text] Notice that 53% were above the legal limit (0.8 g/l) and 34.8% had no alcohol. Psychotropic drugs were detected in 10.6% of the cases (Table 3). [table: see text] BZ were found in 50% of men and 100% of women. drugs and alcohol were present simultaneously in 8.3% of the individuals. Results are in % of total in Table 4: [table: see text] Positive BAC and positive drugs are not related. No significant difference was found in the distribution of alcohol between positive or negative drugs findings. Our results are consistent with those described by North-American authors, but largely superior to those from French or other studies done only on injured persons.

Influence of ejaculation frequency on semen characteristics in chimpanzees (Pan troglodytes).

Semen samples were obtained by masturbation from 6 chimpanzees and the spontaneously liquefied fraction and the remaining coagulum were studied separately. When semen was collected once or twice a week, large intra-individual variations were observed for all measures. The liquefied fraction represented 26.5 +/- 3.2% (weighted mean +/- s.d.) of the total ejaculate but contained 51.3 +/- 3.8% of all emitted spermatozoa. Fructose concentration was higher in the coagulum than in the liquefied fraction (29.3 +/- 3.0 mumol/ml vs 12.0 +/- 2.7 mumol/ml, P less than 0.001) whereas acid phosphatase was less concentrated in the coagulum than in the liquefied fraction (3.5 +/- 0.3 x 10(3) IU/ml vs 13.0 +/- 0.9 x 10(3) IU/ml, P less than 0.001). L-Carnitine and citrate concentrations did not differ between the two fractions of the ejaculate. When semen collection was repeated every hour for 5 h, the ejaculate volume increased from 2.6 +/- 0.7 to 4.7 +/- 0.6 ml (P less than 0.001), whereas total sperm count decreased from 1278 +/- 872 x 10(6) to 587 +/- 329 x 10(6) (P less than 0.05) between the 1st and the 6th ejaculate. In the spontaneously liquefied fraction, the sperm count decreased from 984 to 369 x 10(6). The 6 successive ejaculates gave a total of 20.2 +/- 7.6 ml and 4278 +/- 2884 x 10(6) spermatozoa. The increase of the ejaculate volume was essentially due to an increase of the volume of the coagulum which closely correlated with total amount of fructose (from seminal vesicles) (r = 0.913, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Acetylcarnitine and spermatozoa: relationship with epididymal maturation and motility in the boar and man ]. / Acétylcarnitine et spermatozoïdes: relation avec la maturation épididymaire et la mobilité chez le verrat et l'homme.

The level of carnitine and acetylcarnitine in spermatozoa of boar epididymal origin and of human ejaculates was demonstrated. In the epididymal fluid of boars, the concentration of carnitine (nmol/mg protein) began to increase from 20 in the distal caput to rise progressively to 700 in the distal cauda. By contrast, the carnitine content of spermatozoa only started to increase in the proximal cauda where the concentration of carnitine in the fluid was 200-300 nmol/mg protein, then gradually increased in spermatozoa from more distal sites. The increase in the acetylcarnitine content of spermatozoa paralleled that of the carnitine amount, represented 50% of total carnitine (carnitine + acetylcarnitine) and coincided with the acquisition of progressive motility. In two populations of human seminal spermatozoa selected by migration and characterised by a very large difference in their percentage of progressively motile cells, higher carnitine and acetylcarnitine contents (40%) were found in migrated spermatozoa compared to the residual population. These results suggest that accumulation of carnitine and its metabolite may be an important factor in the acquisition and the maintenance of progressive motility. Measurement of acetylcarnitine content of human seminal spermatozoa could be used as a marker of epididymal maturation.

Cellular and biochemical characteristics of semen obtained from pubertal chimpanzees by masturbation.

Semen characteristics were studied in 6 wild-born chimpanzees with dental ages ranging approximately from 6 to 12 years. The animals formed 2 groups, early pubertal (EP, N = 3, 6-9 years) and late pubertal (LP, N = 3, 11-12 years). Mean body weight, testicular volume and serum androgen concentration were significantly lower in Group EP (32.2 +/- 1.6 kg, 34.0 +/- 7.7 cm3, 2.1 +/- 0.1 ng/ml) than in Group LP (55.7 +/- 5.7 kg, P less than 0.01; 100.5 +/- 11.9 cm3, P less than 0.01; 3.6 +/- 0.7 ng/ml, P less than 0.05). Ejaculates were obtained by masturbation in all subjects. The mean ejaculate volume was lower in Group EP (0.56 +/- 0.20 ml) than in Group LP (3.77 +/- 0.73 ml, P less than 0.01). In Group EP, 2 animals were azoospermic while the third produced semen with means of 57.1 x 10(6) spermatozoa per ml, 20% motility and 40% vitality. These values were low when compared with the mean values of Group LP (376 x 10(6) spermatozoa per ml, 67% motility and 78% vitality). Mean total sperm count was correlated with testicular volume (r = 0.84) and serum androgen concentration (r = 0.96). The mean concentrations of L-carnitine, fructose, citrate and acid phosphatase for the two groups were not significantly different; but, related to the differences in ejaculate volumes, their total amounts in total ejaculate were lower in Group EP than in Group LP. These results suggest that, in chimpanzees, mechanisms of seminal plasma production and ejaculation are functional early in the reproductive life and that the emission of spermatozoa occurs later.

The distribution of carnitine and acetylcarnitine in the epididymis and epididymal spermatozoa of the boar.

In the epididymal fluid of boars, the concentration of carnitine (nmol/mg protein) began to increase from 20 in the distal caput, then rose progressively to 700 in the distal cauda. By contrast, the carnitine content of spermatozoa only started to increase in the proximal cauda where the concentration of carnitine in the fluid was 200-300 nmol/mg protein then gradually increased in spermatozoa from more distal sites. The increase in the acetylcarnitine content of spermatozoa paralleled that of the carnitine amount and represented 50% of the total carnitine (carnitine + acetylcarnitine). We conclude that the acetylcarnitine content of epididymal spermatozoa may be used as a marker of maturation.

Levels of seminal free L(-) carnitine in fertile and infertile men.

Data about the levels of free L-carnitine, an epididymal marker in human semen, are contradictory and unclear, particularly in their relationship to fertility. This can perhaps be explained by the absence of any studies of seminal L-carnitine in a large group of fertile men, and by the lack of consideration of factors influencing its secretion. In this study, free L-carnitine was determined using a spectrophotometric method in deproteinized semen samples from fertile (n = 162) and infertile men without azoospermia (n = 303). Our results can be summarized as follows: Infertile men were found to have significantly lower (P less than 0.001) seminal carnitine levels (755 +/- SD 499 nmoles) compared with fertile men (1010 +/- 570). Percentiles have been calculated for fertile men, and 'normal' values proposed (10th percentile = 390 and 90th percentile = 1830 nmoles). Distribution of the levels of L-carnitine were asymmetric in fertile as well as in infertile men (median: 922 nmoles vs 645). In both groups, a significant increase in carnitine levels was observed with increasing length of abstinence, and a decrease in the ratio of carnitine/days of abstinence. Methodological, physiological and pathological factors which may explain these results are discussed.

Reversible inhibition of sperm production and gonadotrophin secretion in men following combined oral medroxyprogesterone acetate and percutaneous testosterone treatment.

Six men requesting male contraception received a daily oral dose of 20 mg medroxyprogesterone acetate (MPA) in combination with 50 or 100 mg percutaneous testosterone for 1 year. From the third month the sperm concentration was less than 10(6)/ml for all the men at one time or another during treatment, and usually less than 5 X 10(6)/ml, with an average reduction of 95% with respect to pre-treatment values. The sperm count returned to previous values 3-6 months after cessation of the treatment. While FSH and LH secretion was inhibited throughout the treatment period, plasma testosterone levels were not reduced. Oestradiol levels were unaffected while dihydrotestosterone was elevated. The secretory activity of the prostate and seminal vesicles was not appreciably affected; seminal carnitine concentration was reduced during the treatment with a subsequent return to pretreatment values. No pregnancies occurred during treatment. There was no impairment of libido in the subjects, nor any incidence of gynaecomastia, or increase in average body weight. The only observed metabolic side-effect was a moderate increase in glycaemia. A synergistic action of MPA and testosterone is proposed to explain the inhibition of gonadotrophin secretion.

PIP: 6 men requesting male contraception received a daily oral dose of 20 mg medroxyprogesterone acetate (MPA) in combination with 50 or 100 mg percutaneous testosterone for 1 year. From the 3rd month, the sperm concentration was 1 million ml for all the men at 1 time or another during treatment, and usually 5x1 million/ml, with an average reduction of 95% with respect to pretreatment values. The sperm count returned to previous values 3-6 months after cessation of the treatment. While follicle stimulating hormone and luteinizing hormone secretion was inhibited throughout the treatment period, plasma testosterone levels were not reduced. Estradiol levels were unaffected while dihydrotestosterone was elevated. The secretory activity of the prostate and seminal vesicles was not appreciably affected; seminal carnitine concentration was reduced during the treatment with a subsequent return to pretreatment values. No pregnancies occurred during treatment. There was no impairment of libido in the subjects, nor any incidence of gynecomastia, or increase in average body weight. The only observed metabolic side effect was a moderate increase in glycemia. A synergistic action of MPA and testosterone is proposed to explain the inhibition of gonadotropin secretion.

[Semen characteristics and fertility (author's transl)]. / Paramètres du sperme et fertilité.

The semen characteristics of 215 fertile men (F = fathers requesting vasectomy) and of 409 infertile men (I) have been analysed under strictly identical conditions. The mean values for volume, sperm concentration, and the percentages of motile, vital and morphologically normal spermatozoa were greater in group F than in I. Seminal variations were much greater in cases of testicular lesions (cryptorchidism, hypotrophy) than in varicocele, although there remains a difference between F and I even after exclusion of all clinical lesions suggesting a role for other factors in the origin of much cases of infertility. Other than in cases of azoospermia, there is no difference in the function of the accessory glands detectable by the assay of seminal biochemical markers: fructose (seminal vesicles) acid phosphatase and citrate (prostate); only L-carnitine (epididymal marker) is elevated in the fertile men, however this difference is only a reflection of the observed difference in sperm concentration in combination with the close correlation between sperm concentration and L-carnitine values.

Free L-carnitine in human seminal plasma.

It has often been suggested that determination of free L(-)-carnitine in seminal plasma may provide a good indication of epididymal function. However, there has been disagreement regarding the origin of L(-)-carnitine (epididymis and seminal vesicles) and its concentration in human seminal plasma. In this study, free L(-)-carnitine was determined after deproteinization with an enzymatic spectrophotometric method. In 29 semen samples from fathers and with normal spermiograms (semen volume between 2 and 6 ml, sperm count over 20.10(6)/ml, more than 50% motile spermatozoa), the total free L(-)-carnitine in the seminal plasma was 1010 nmoles (SD: +/- 480), in 16 samples from vasectomized men it was 131 nmoles (SD: +/- 77), and in 5 from men with agenesis of the vas deferens and seminal vesicles it was 21 nmoles (SD: +/- 25). These results suggest that free L(-)-carnitine in the seminal fluid is predominantly of epididymal origin. The results of free L(-)-carnitine determinations in split ejaculates and the absence of a correlation between L(-)-carnitine and fructose concentrations in semen from normal subjects indicate that the seminal vesicles make only on minor contribution to L(-)-carnitine in the seminal plasma.

John Shaw Billings as a Bibliographer.

The influences that a man's childhood have on his life are, it is well known, great. Life is essentially a part of the things that happen to the individual and it is the manner in which one relates oneself to these things that determines what one is. With these facts in mind this study of John Shaw Billings as a bibliographer has been approached. His early life has been reviewed as an influence on his later achievements. Stress has been placed on those events which led to his bibliographic activities.Dr. Billings was prolific in many fields. Others have given detailed analyses of his writings (1, 2). The present study will consider only his bibliographic works. The description of these follows the brief outline of his childhood and youth.