Ultra-endurance events in tropical environments and countermeasures to optimize performances and health.

Physical performance in a tropical environment, combining high heat and humidity, is a difficult physiological challenge that requires specific preparation. The elevated humidity of a tropical climate impairs the thermoregulatory mechanisms by limiting the rate of sweat evaporation. Hence, a proper management of whole-body temperature is required to complete an ultra-endurance event in such an environment. In these long-duration events, which can last from 8 to 20 h, held in hot and humid settings, performance is tightly linked to the ability in maintaining an optimal hydration status. Indeed, the rate of withdrawal in these longer races was associated with lower water intake, and the majority of finishers exhibited alterations in electrolyte balance (e.g., sodium). Hence, this work reviews the effects on performance of high heat and humidity in two representative ultra-endurance sports, ultramarathons and long-distance triathlons, and several countermeasures to counteract the impact of these harsh environmental stresses and maintain a high level of performance, such as hydration, cooling strategies and heat acclimation.

Validity of dynamical analysis to characterize heart rate and oxygen consumption during effort tests.

Performance is usually assessed by simple indices stemming from cardiac and respiratory data measured during graded exercise test. The goal of this study is to characterize the indices produced by a dynamical analysis of HR and VO2 for different effort test protocols, and to estimate the construct validity of these new dynamical indices by testing their links with their standard counterparts. Therefore, two groups of 32 and 14 athletes from two different cohorts performed two different graded exercise testing before and after a period of training or deconditioning. Heart rate (HR) and oxygen consumption (VO2) were measured. The new dynamical indices were the value without effort, the characteristic time and the amplitude (gain) of the HR and VO2 response to the effort. The gain of HR was moderately to strongly associated with other performance indices, while the gain for VO2 increased with training and decreased with deconditioning with an effect size slightly higher than VO2 max. Dynamical analysis performed on the first 2/3 of the effort tests showed similar patterns than the analysis of the entire effort tests, which could be useful to assess individuals who cannot perform full effort tests. In conclusion, the dynamical analysis of HR and VO2 obtained during effort test, especially through the estimation of the gain, provides a good characterization of physical performance, robust to less stringent effort test conditions.

Circannual rhythms of sperm parameters of fertile men.

Mean monthly values for ejaculate volume, sperm density, and percentage of motile sperm were calculated from semen analyses performed on volunteered donors to the laboratory from 1979 to 1986. The data of 4,196 ejaculates were computerized by the single Cosinor method for searching on circannual rhythms of the parameters. The study does not detect circannual rhythms, neither of the ejaculate volume nor of the percentage of motile sperm. A statistically significant high-amplitude seasonal variation was detected in sperm court, the highest values being recorded in late winter and early spring, the lowest values being recorded in late summer.

[Proacrosin, an acrosomal marker for the detection of spermatogenic cells in ejaculates from azoospermic men]. / La proacrosine, un marqueur acrosomal pour la détection des cellules spermatiques dans le sperme éjaculé de patients azoospermes.

Between January 2003 and April 2004, a prospective study was performed on ejaculates from non-obstructive azoospermic men (n = 95), for the identification of spermatogenic cells using an immunohistochemical labeling for proacrosin. 48.4% of ejaculates (46/95) displayed labeled spermatogenic cells. A 38/95 (40%) of men had testicular sperm extraction (TESE) followed by intracytoplasmic sperm injection (i.c.s.i.). Testicular spermatozoa were extracted from 21 men (52.5%). The sensitivity of detecting spermatogenic cells is 66.7% in predicting the presence of testicular spermatozoa, and its specificity is 76.5%. Compared to histopathological diagnostic testicular biopsy, the detection of spermatogenic cells using proacrosin immunohistochemical method offers a predictive parameter for successful TESE. The immunohistochemical method for proacrosin has the advantages of simplicity and low cost. It could be used to predict spermatogenesis from non-obstructive azoospermic men. Further evaluation is required with extensive results to improve sensitivity and specificity.

[Hypothalamic mechanism of the antiovulatory action of sulpiride]. / Mécanisme hypothalamique de l'action anti ovulatoire du sulpiride

The antiovulatory effect of sulpiride is mediated via inhibition of the LH-RH release: when given during 10 days in guinea pigs, sulpiride is able to promote an increase of LH-RH immunoreactive substance in anterior hypothalamic and suprachiasmatic neurons. This storage probably related with inhibition of LH-RH release, is permitted by catecholamines, since metatyrosine administration prevent this sulpiride effect. On the other hand, when administered to hamsters sulpiride is able to promote stimulation of hypothalamic catecholaminergic neurons of tubero infundibular and anterior periventricularis nuclei. The hypothalamic aminergic action upon sulpiride antiovulatory effect is discussed.

[Correlation of the penetration test of zona-free hamster ovocytes and other sperm parameters. Value of this test in evaluating male infertility]. / Corrélation entre le test de pénétration des ovocytes de hamster dépellucidés et les autres paramètres du sperme. Valeur de ce test dans l'évaluation de la fertilité masculine.

On investigating infertility in 162 couples the zona-free hamster egg penetration test was carried out. As a control we tested the ejaculates of 34 fertile men. There is a significant correlation between the percentage of oocytes that were penetrated and the count (p less than 0.001) in motility after one hour (p less than 0.001) and the count after migration (p less than 0.001). The outcome in 129 infertile couples made it possible for us to confirm that the percentage of oocytes penetrated, the initial motility and the number of motile sperms after migration are the best parameters for assessing sperm function that are known (p much less than 0.001) for investigating male fertility. Finally a study of the test in fertile sperm donors made it possible for us to raise statistically significantly the numbers of pregnancies per artificial insemination cycle when the percentage of oocytes penetrated is higher than 50% (p much less than 0.001). Although the egg penetration test did not prove male sterility it can be considered an extra test to be carried out over and above the sperm count and post-coital test in evaluating the fertilisation capacity of sperm.

[Cytology of peritoneal fluid in the diagnosis of pelvic endometriosis]. / Apport de la cytologie du liquide péritonéal dans le diagnostic d'endométriose pelvienne.

Fluid was collected from the Ponch of Douglas at laparoscopy or laparotomy in 104 women. Macrophages were always present. The Schiff's histochemical reaction was positive inside the cytoplasm in cases of pelvic endometriosis in our study. This technique allows characterization of the cell population in cases of chronic pelvic inflammation and confirmation of the diagnosis of mild endometriosis.

[Analysis of the results obtained in fertilization in vitro according to the degree and type of teratospermia]. / Analyse des résultats obtenus en fécondation in vitro selon le degré et le type de tératospermie.

The aim of this study was to evaluate the consequences of sperm morphology abnormalities on fertilization capacity. We selected 115 couples who consulted for in vitro fertilization at the Salengro Maternity Ward (Lille, France). Teratospermia was > 40% in all. The mean rate of cleavage was 23% and was significantly lower than in a population which had had in vitro fertilization for a tube indication (63%, p < or = 0.001). In addition, this level was significantly correlated with teratospermia (p < or = 0.05). The ROC method demonstrated that above the threshold of 74% teratospermia, fertilization decreases significantly. We distinguished several types of abnormal morphology and demonstrated a weak correlation between head abnormalities and the rate of cleavage, a stronger correlation between abnormalities of the intermediary piece and rate of cleavage and finally the absence of any correlation between flagella abnormalities and the rate of fertilization. Teratospermia is therefore an important factor in evaluating fertilization capacity. A better selection of normal spermatoids could improve the chance of success in cases of male sterility.

[Enkephalin-like immunoreactivity in Leydig cell tumor]. / Immunoréactivité de type enképhaline au sein d'une tumeur à cellules de Leydig.

So far, the presence of an enkephalin-like immunoreactivity has never been reported in Leydig cell tumors at our knowledge. A 39 years old man having a painful gynecomastia and an impotency changing in time has been studied. At clinical examination, he was normal, without palpable testis tumor. The sperm count analysis showed an oligoastheno-spermia. Plasma testosterone (T) was low and plasma estradiol (E2) was high, varying from day to day. T/E2 ratio was always low (20 to 72 - N:220-240) and fell after HCG administration. Plasma LH was normal and plasma FSH was low. 17 hydroxyprogesterone (17 OH-P)/T ratio was increased (0.7 - N:0.23). A small tumor was localized in the left testis by ultrasonography. The spermatic vein catheterization, which was only possible on the left side, showed a decreased T, a high E2 and a low T/E2 ratio (19 - N:304). After unilateral orchidectomy, the histological study confirmed the diagnosis of Leydig cell tumor. With antibodies raised against synthetic Met-en-kephalin, it has been possible to detect an enkephalin-like immunoreactivity in the tumoral cells as well as in the surrounding normal cells.

[Hormone levels, celioscopy and ovarian histology in the hirsutism-anovulation syndrome]. / Dosages hormonaux, coelioscopie et histologie ovarienne dans le syndrome hirsutisme-anovulation.

Among 50 women with hirsutism, spanio- or amenorrhoea and anovulation, coelioscopy and histological examination of ovarian biopsies showed that 26 had typically polycystic ovaries (PCO), 17 had "borderline ovaries" (BO)--i.e. apparently normal or subnormal but with histological abnormalities identical to those of PCO--and 7 had normal ovaries. The hormonal profiles of BO and PCO were very similar. An increase in LH or in LH response to LHRH, which is regarded as characteristic of polycystic ovarian disease, was only observed in 75% of women with PCO or BO. The PCO and BO detection value of simple basal LH determination was slightly enhanced by the LHRH test, and no further enhancement was observed after repeated LHRH injections. 38% of PCO's and 75% of BO's were associated with adrenal hyperandrogenism, as evidenced by a rise in dehydroepiandrosterone values. Thus, more than one half of hirsute and non-ovulating women have polycystic ovaries. Most of these can be diagnosed by hormonal investigations without having recourse to coelioscopy. However, some do not display, at least permanently, the hormonal profile characteristic of polycystic ovarian disease.

[Melatonin and gonadoliberin (LH-RH) cells in rat hypothalamus]. / Mélatonine et cellules à gonadolibérine (LH-RH) de l'hypothalamus du rat.

Immature female rats were induced to ovulate by an injection of pregnant mare serum: melatonin, intraperitonealy injected, induce an increase of LH-RH immunoreactive neurons in the hypothalamus. These neurons are localized in septo preoptic, infundibular and premammillary areas.

[Copper - a major contraceptive agent?]. / Le cuivre, agent contraceptif majeur?

PIP: The effect of copper ions on the motility of human sperm was studied in vitro to determine whether copper is toxic to sperm. Sperm samples from 30 men of proven fertility who had high quality sperm were collected, separated from the seminal fluid, and resuspended in Menezzo, a chemical medium designed to resemble the secretions of the Fallopian tubes. Menezzo contains all the known constituents which aid sperm capacitation, including mineral salts, organic compounds, free amino acids, and enzymes. Its pH is between 7.4 and 7.6. After 1 hour of incubation the dead and weak sperm were separated out and only mobile sperm were tested. Crystallized copper sulfate was added to 4 of the 5 sperm-Menezzo mixtures. The final concentrations were of 1 millimolar, .1 millimolar, .01 millimolar, and .001 millimolar. Sperm motility showed a statistically significant decrease in the concentration of 1 millimolar but only after a latency period of at least 5 hours. At lesser concentrations and in shorter time periods no significant difference was observed compared to the control. The copper released from a copper IUD into the uterine fluid does not exceed a concentration of .1 millimolar. The lower concentration and the long latency period before the toxic effect manifests itself, seem to indicate that copper has no direct contraceptive effect. Copper is however known to promote inflammatory reactions, and it may work in vivo through the intermediacy of the leukocytes in the uterine cavity, either by directly stimulating phagocytosis or by release of substances toxic to sperm.^ieng

Paracrine factors in adult rat testis gonadotrophin control of opioids and LHRH like peptide.

A paracrine regulation involves agents which are produced by one cell type and act on an other one within an organ. In rodent testis, local control mechanisms modulate the actions of the gonadotrophins according to local requirements. Two groups of peptides-opioids and testicular LHRH are defined as paracrine factors and in vivo they are both modified by HCG. In vitro, after HCG exposure, we first localized an opioid like material in Sertoli cells cytoplasma by immunohistochemistry. This material is detected in freeze dried homologous culture media using a dot immunobinding technique. With a longer HCG exposure, an LHRH like material is then visualized in the basal compartment of the Sertoli cells and it is detected in freeze dried homologous culture media by the same technical procedure than for opioid material. By adding synthetic enkephalins to culture medium, we obtain the same results as with the endogenous opioid material, excreted after HCG addition. If naloxone a potent opiate antagonist, is added to the culture medium previously to HCG or enkephalins, the Sertoli cells cytoplasma are no more immunoreactives with the anti-enkephalin serum and no LHRH material is neither visualized by immunohistochemical technique neither detected in culture media. We conclude that testicular opioids, synthetized by the Leydig cells and which have specific Sertoli cells receptors are one Leydig-Sertoli paracrine communication factor. One way of response to their receptor fixation is the synthesis and excretion by Sertoli cells of testicular LHRH. This one is known to act on Leydig cells via specific receptors and it is one Sertoli-Leydig cells paracrine communication factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum and seminal gonadotropins in normal and infertile men: correlations with sperm count, prolactinemia, and seminal prolactin.

Serum and seminal gonadotropins were evaluated in 30 normozoospermic and 30 oligozoospermic patients. Mean values of basal serum gonadotropins were higher in the oligozoospermic group than in the normozoospermic group: 3.8 versus 1.8 ng/ml and 3.3 versus 2.2 ng/ml for FSH and LH, respectively. Seminal FSH levels were comparable in the normozoospermic and oligozoospermic groups (0.8 versus 0.8 ng/ml, respectively) and were constantly lower than serum FSH levels in both groups. Seminal LH values were constantly higher than serum LH values in the normozoospermic group, whereas in the oligozoospermic group seminal LH values were higher, similar, or lower than serum LH values. However, no significant difference was noted between the two groups for seminal LH values: 3.6 (normozoospermic group) versus 4.1 ng/ml (oligozoospermic group).

[Importance of the study of the cytology and proteins of the spinal fluid in lumbago]. / Intérêt de l'étude de la cytorachie et de la protéinorachie dans les lombalgies.

In the cerebrospinal fluid (C.S.F.) of hundred patients suffering from lumbago we have studied the existence of cytobiochemical and cytoradiological correlations in order to confirm the demonstration of cytologic and biochemical signs of organicisty or seriousness of this frequent pathology. We have realized cytorachia, that is to say differential cells counts and formulas on C.S.F. samples after cytocentrifugation and staining associated with biochemical determinations. Cytologically 96% of C.S.F. samples had normal count but 67% of them had a disturbed formula often associated with hyperproteinorachia. We have found lymphocytes and histiomonocytes the normal cells of C.S.F. but also neutrophilic, eosinophilic and basophilic polymorphonuclears and above all leptomeningeal cells. A disturbed cytorachia is often related with a pathological radiological picture (68% of cases). A cytologic anomaly with hyperproteinorachia in the same C.S.F. sample seems to be a sign of seriousness and to reveal a resistance to medical treatment. A technical presentation of cytorachia and an attempt of physiopathological explanation of observed cytologic abnormalities are proposed.

Actin-binding properties and colocalization with actin during spermiogenesis of mammalian sperm calicin.

The nucleus of mammalian spermatozoa is surrounded by a rigid layer, the perinuclear theca, which is divided into a subacrosomal layer and a postacrosomal calyx. Among the proteins characterized in the perinuclear theca, calicin is one of the main components of the calyx. Its sequence contains three kelch repeats and a BTB/POZ domain. We have studied the association of boar calicin with F-actin and the distribution of boar and human calicin during spermiogenesis compared with the distribution of actin. Calicin was purified from boar sperm heads under nondenaturating conditions. The molecule bound actin with high affinity (K(d) = approximately 5 nM), and a stoichiometry of approximately one calicin per 12 actin monomers was observed. Gel filtration studies showed that calicin forms homomultimers (tetramers and higher polymers). According to immunocytochemical results, calicin is present (together with actin) in the acrosomal region of round spermatids and is mainly localized in the postacrosomal region of late spermatids and spermatozoa. Taken together, the results suggest that the affinity of calicin to F-actin allows targeting of calicin at the subacrosomal space of round spermatids, and that its ability to form homomultimers contributes to the formation of a rigid calyx.

Gonadotrophin-like substance in the testis. Immunocytochemical localization in the guinea pig.

A gonadotrophin-like material (GLM) was observed by immunocytochemical methods in prepuberal guinea pig testes, not only on Sertoli and interstitial cells, but also on spermatogonia and spermatocytes. The intracellular cytoplasmic localization of GLM is discussed in relation to the receptor internalization theory. Variations between young and adult animals allowed us to approach the physiological significance of testicular GLM.

Distribution of gelsolin in human testis.

Gelsolin, an actin-binding and severing protein present in many mammalian cells, was characterized in human testis. Although abundant in testicular extracts, gelsolin was not detected in purified spermatogenic cells by immunoblot analysis. Immunofluorescence studies of testis sections showed that gelsolin has two main localizations: peritubular cells and the seminiferous epithelium. In peritubular cells, gelsolin was present together with alpha-SM actin, in agreement with the myoid cell characteristics of these cells. In a large proportion of the tubules, gelsolin was found mainly, together with actin, in the apical part of the seminiferous epithelium. This localization of gelsolin also was observed in seminiferous tubules with a partial or complete absence of germinal cells, which evokes a presence of gelsolin at the apex of Sertoli cells. However, in normal testis, a complex pattern of gelsolin labeling was also present, mostly in the apical third of the epithelium, around cells or groups of cells, mainly spermatids, and, less frequently, in various other localizations from the apical to the basal part of the seminiferous epithelium. Taken together, these observations suggest that gelsolin may play different functions in the seminiferous epithelium: (1) regulation of the dynamic alterations of the actin cytoskeleton in the apical cytoplasm of Sertoli cells, and (2) modification of actin filaments assemblies in specific structures at germ cell-Sertoli cell contacts. Thereby, the actin-modulating properties of gelsolin are probably involved in reorganization of the seminiferous epithelium related to germ cell differentiation.

Immunolocalization of inhibin and activin alpha and betaB subunits and expression of corresponding messenger RNAs in the human adult testis.

Inhibin B is a testicular peptide hormone that regulates FSH secretion in a negative feedback loop. Inhibin B is a dimer of an alpha and a beta(B) subunit. In adult testes, the cellular site of production is still controversial, and it was hypothesized that germ cells contribute to inhibin B production. To determine which cell types in the testes may produce inhibin B, the immunohistochemical localization of the two subunits of inhibin B were examined in adult testicular biopsies with normal spermatogenesis, spermatogenic arrest, or Sertoli cell only (SCO) tubules. Moreover, using in situ hybridization with mRNA probes, the mRNA expression patterns of inhibin alpha and inhibin/activin beta(B) subunits have been investigated. In all testes, Sertoli cells and Leydig cells showed positive immunostaining for inhibin alpha subunit and expressed inhibin alpha subunit mRNA. Using inhibin beta(B) subunit immunoserum on testes with normal spermatogenesis and with spermatogenic arrest, intense labeling was located in germ cells from pachytene spermatocytes to round spermatids but not in Sertoli cells. Inhibin beta(B) subunit mRNA expression was intense in germ cells from spermatogonia to round spermatids and in Sertoli cells in these testes. In testes with SCO, high inhibin beta(B) subunit mRNA labeling density was observed in both Sertoli cells and Leydig cells, whereas beta(B) subunit immunostaining was negative for Sertoli cells and faintly positive for Leydig cells. These results agree with the recent opinion that inhibin B in adult men is possibly a joint product of Sertoli cells and germ cells.