Reactivite thermique de la peau scrotale chez l’homme

Although the existence of heat exchange between the testicular artery and the adjacent veins is well known, it may be insufficient to maintain the lower temperature of the testis. In order to investigate the role of the scrotum in testicular thermoregulation, the dynamics of scrotal and other skin temperatures was studied in relation to thermal stress. The results of this study revealed that the scrotal skin exhibited a greater thermal inertia than did other skin areas. This finding may be due to modifications in scrotal blood flow patterns as temperature increased, as well as changes in the scrotal surface area. Other possible thermoregulatory factors may include the evaporation of sweat from the scrotum. In conclusion, there seems to be a complex collection of mechanisms, rather than a single specific mechanism, regulating testicular temperature.     

Dosage de la testostérone plasmatique chez l’homme

The measurement of testosterone in plasma is the main tool to investigate the endocrine function of the testis. Radioimmunoassay of total testosterone using³H-testosterone as tracer, after steroid extraction and chromatography avoids the interactions of steroids and plasma proteins in the assay. It can be considered as a method of reference. Direct methods, without extraction and chromatography, and using non-radioactive tracers have been developped. They are easier and faster to perform but less accurate because of the aforementioned interactions. In the plasma, testosterone is mainly bound with a high affinity to SBP and with a low affinity to albumin. Non-SBP-bound testosterone is considered to represent the fraction of the testosterone available for target cells. Non-SBP-bound testosterone can be measured after precipitation of SBP by ammonium sulfate. This procedure is usefull to investigate androgenicity when plasma SBP concentrations are altered such as in hyperthyroidism, aging and severe exocrine testicular failure. Plasma free testosterone can be mesured by equilibrium dialysis, a procedure not suitable for routine assay or more easily but less accuratly by direct measurement in the plasma with methods using tracer analogs. The interpretation of testosterone measurement must take into account moment-to-moment and nycthemeral variations. The inter-subject variations of plasma testosterone concentrations are large, the decrease with aging is very progressive. Testosterone has a permisive effect on male sexual function with a threshold level above which no relationship between plasma testosterone concentration and sexual “performances” could be demonstrated. Because of the multifactorial control of human sexual function, the threshold value is difficult to determine for a given patient.     

Aspects cliniques et biologiques de l’azoospermie chez l’homme infertile en Tunisie

Objective

It is now very important to investigate azoospermia because the introduction of the intracytoplasmic sperm injection technique during the last decade has allowed many infertile men to achieve their dreams of fatherhood. The purpose of this study was to define the characteristics of infertile men with azoospermia, and to analyse the clinical and laboratory features and the causes of infertility in Tunisia. The authors also discuss various aspects that they consider to be very important in the diagnosis of male fertility.

Material and Methods

This retrospective study analysed the parameters of physical examination, laboratory tests, semen analysis, radiographic examinations, testicular biopsy, karyotype and AZF microdeletions.

Results

Based on the results of endocrinological and cytogenetic examinations, the aetiology of azoospermia was considered to be secretory in 43 cases of azoospermia. Physical examination revealed a high percentage of hypotrophic/atrophic testes (43.9%). Serum follicle stimulating hormone levels were high in 58.5% of cases. The overall incidence of chromosomal abnormalities was 31.4%. The most frequent anomaly was Klinefelter syndrome (9 cases). Seven out of 28 patients (25%) with nonobstructive azoospermia had AZF deletions. None of the patients with excretory azoospermia and severe oligospermia had an abnormal karyotype or AZF microdeletions. 48.8% of patients presented a varicocele, 13.9% had cryptorchidism and 13.0% had a history of genital tract infection.

Conclusion

In line with the literature, genetic abmormalities are the main causes of severe forms of impaired spermatogenesis in the Tunisian population.     

Cryptorchidie: influence sur la fertilité de l’âge au moment de l’orchidopexie, du siège et de la taille du testicule et de l’existence d’anomalies épididymaires

Despite surgical treatment, cryptorchidism is the most common cause of infertility. Through a literature review, the authors report current data on the influence of age at the time of orchidopexy, testicular size, the position of the testis, and the existence of epididymal anomalies on fertility.     

L’apport de la scintigraphie dans la pathologie de l’appareil locomoteur de l’enfant et de l’adolescent. Regards croisés du clinicien et du scintigraphiste

This paper summarizes and clarifies the clinician's reasoning in front of a lesion of the musculoskeletal system and his appeal to the examinations of imaging and to his choices. It proposes an analysis of the criteria of choice of bone scanning in this arsenal of exploration. It details the keys of the dialogue between the clinician and the nuclear physician: firstly, the clinician determines the elements of his request and its areas of doubt and uncertainty, and his diagnosis of probability and, secondly, the nuclear physician adapts the nature of the examination according to the problem posed.     

Physiopathologie des troubles de l’érection chez l’homme paraplégique

Peripheral mechanisms responsible for penile erection are dependant upon a complex control by the nervous system, including peripheral nervous pathways, spinally mediated reflex loops and supraspinal nervous structures. Spinal cord injury is accompanied by a partial or a complete modification of these controls. In relation to the reflexogenic or psychogenic origin of penile erection, spinal cord injury does not cause the same effects. Reflexogenic erections sitll occur after spinal cord injury at a suprasacral level. After lesions at a level lower than the thoracolumbar spinal cord, tumescence following psychogenic stimulation has been observed. The hypotheses resulting from clinical and experimental observations and explaining the differences at the origin of these response are detailed. The recent developments in the neurophysiology of penile erection and the role of neurotransmitters allow a more analytical approach of the phenomenous and also bring new insights into possible compensatory pathways following spinal cord injury.     

Contraception thermique de l’homme

Several characteristics of spermatogenesis are heat-dependent in mammals. A similar process does exist in man in whom a qualitatively and quantitatively normal spermatozoa out put occurs for a mean testicular temperature ranging between 33 and 34.5°C. As in many animal species, an induced increase in the testis temperature results in a decreased spermatozoa out put and quality, decrease which is a function of both the intensity and the duration of the increase in temperature as well as the heated target (whole body, scrotum, testes). A daily increase of 1 to 2°C in the testis temperature for at least the waking hours induces on spermatogenesis an inhibitory effect strong enough to temporarily suppress the fecundity, i.e. to achieve a male contraception, withtout any major side-effects as reported for 37 couples during 411 cycles of exposure. Both spermatogenesis and fecundity recover initial values within one year after the heatng is stopped.     

Incidences de la restriction calorique et du Nickel sur l’aromatase testiculaire du rat

This study was designed to determine whether intermittent fasting induces malnutrition that, according to many authors, accentuates the cytotoxic effects of environmental pollutants, or caloric restriction that reduces these effects. Ninety six male Wistar rats (180g) were divided into two groups: one group was fed daily (N) and the other group was fed every second day (J) for one month. At the end of one month, each group was then divided into two subgroups, one subgroup received an injection of 0.9% NaCI (groups NO and JO), the other subgroup received an injection of 4 mg/kg NiCI^b2 (groups NNi and JNi). Intermittent fasting was continued in parallel to treatment for 1, 3, 5 and 10 days. Under these experimental conditions, nickel increased testicular aromatase activity and altered total RNA, while no alteration of these biomarkers was observed with intermittent fasting. The combination of these two factors, nickel and intermittent fasting, did not amplify these effects. In contrast, protection of RNA by intermittent fasting was observed, especially overexpression of aromatase mRNA.     

L’irradiation des spermatozoïdes au Laser HeNe à faible énergie chez la souris et chez l’homme

Introduction

The effects of low energy He?Ne 630 laser (LEL) irradiation on various aspects of cell metabolism, including proliferation, respiration, ATP synthesis and Ca²⁺ uptake, have been recently recognized in somatic cells, animal spermatozoa and embryonic cells.

Objectives

1- To analyze thein vitro effects of LEL irradiation on the mouse IVF model. 2- To assess the effects of experimental LEL irradiation on human spermatozoa in the sperm-zona free hamster egg penetration (SPA) model.

Material & Methods

1- In a mouse IVF model, pooled oocytes were incubated for 24 h. with LEL-irradiated and non-irradiated epididymal mouse spermatozoa. The percentage of fertilized eggs, intracellular Ca²⁺ and Ca²⁺ uptake as well as the effects of reactive oxygen scavengers were compared in the two groups. 2- In the enhanced SPA model, with overnight TEST-Yolk preincubation, LEL-irradiated and non-irradiated ejaculated spermatozoa from 43 infertile men were incubated for 3 h with fresh zona-free hamster eggs. The percentage of eggs penetrated (SPA%) by irradiated or control sperm was compared. Acrosome reaction (AR) and Hemizona Assay (HZA) were also performed on the same ejaculates.

Results

1- In mice, brief LEL irradiation enhanced intracellular Ca²⁺ influx and increased thein vitro fertilization capacity of spermatozoa. Mitochondrial Ca²⁺ transport mechanisms and H₂O₂ appeared to be involved in these LEL effects. 2- In the 43 male patients, AR and SPA were correlated, while SPA and HZA were poorly correlated. In the whole group, the mean SPA% of LEL-irradiated and control sperm were not significantly different: 49.8±39.9 and 51.0±34.9, respectively. No significant change was observed in 50% of cases. Following irradiation, SPA% increased in 25% of cases and decreased in 25% of cases. However, classifying all cases according to the SPA cut-off point of 30% as poor and good sperm in this enhanced SPA model, showed that LEL irradiation significantly increased SPA% only in the poor sperm subgroup (n=16) from 5.5.±8.9 to 23.1±25.2 (p<0.0001). This increase was observed in 50% of these patients. In the good sperm category (n=27), no improvement of SPA% was observed. On the contrary, LEL irradiation decreased SPA% from 76.1±24.4 to 67.6±28.

Conclusion

In a mouse IVF model, LEL irradiation of spermatozoa improved intracellular Ca²⁺influx and egg fertilization. H₂O₂ seems to participate in the biochemical cascade transforming light signals into a biological response. In man, using the SPA model, LEL sperm irradiation might improve the penetration capacity only in the case of poor quality sperm, by increasing sperm egg penetration in one half of cases, otherwise LEL is ineffective. Further studies are required to confirm these results, but LEL should not be considered for clinical use until its safety has been proven. (Supported by grants from the Chief Scientist Office, Ministry of Health)     

Développementin vitro de la lignée germinale foetale mâle chez le rat, la souris et l’homme

The key role of the foetal germ cell line in the reproductive capacity of the adult has been known for a long time. More recently, the observed increase in male reproductive disorders such as the decline of sperm count and quality and the increased incidence of testicular cancer has been postulated to be due to alterations of foetal and neonatal testicular development in response to increasing environmental pollution. However, few tools are available to study foetal and neonatal germ cell line development and the effects of physiological or toxic substances on this process. The authors have developed an organ culture system in which foetal or neonatal testis is grown on a filter floating on a synthetic medium free of serum, hormones or biological factors. This study, using rats and mice, first compared the long-term morphological and functional development of Sertoli and germ cells in thisin vivo system. In rats, these cells developed normally over a period of two weeksin vitro. Fewer cells were produced thanin vivo, but a similar level of differentiated function was observed. Germ cells, which are difficult to maintainin vitro, resumed mitosis after a quiescent period, at the same time asin vivo. Similar results were obtained with mouse fetuses, but this model was less efficient. This culture model can be used to study post-natal development of the germ cell lineage in testes derived from foetuses on the last day of foetal life and invalidated for P63, that do not survive after birth. This gene was found to be involved in the regulation of germ apoptosis which resumes after birth in the mouse. Lastly, this model applied to the human species (from 6 to 12 weeks of gestation) showed that testicular architecture and germ cells can be maintained for 4 days with better efficiency at younger stages than at older stages. p]In conclusion, testicular architecture and intercellular communications are sufficiently preserved to sustain gametogenesisin vitro with no added factors. This method is potentially useful to study the effects of various factors, particularly xenobiotics.     

Les récepteurs aux œstrogènes dans le testicule et l’appareil reproducteur du primate et de l’homme

The impact of oestrogens on the male reproductive system remains the subject of intensive research activity and debate. Oestrogen action is mediated via high affinity intracellular receptors expressed in target tissues. Two subtypes of oestrogen receptor known as REα (NR3A1) and ERß (NR3A2) have been cloned and hERß variant isoforms identified. In target cells these receptors can exist as homo- or heterodimers. We have used immunohistochemistry to examine the patterns of expression of ERs in human and non-human primates as a first step in determining the cellular targets for oestrogen action in the male. REα was detected in the epithelial cells of efferent ductules (ED) occasionally in epithelial and stromal cells within the epididymis but was undetectable in human or primate testes. Using a polyclonal antibody raised against the hinge domain of ERß, immunopositive staining was detected in multiple cell types within the testis and in epithelial and stromal cell nuclei throughout the male reproductive system (ED, epididymis, vas deferens, seminal vesicles, prostate) and in the bladder. We have also used monoclonal antibodies that distinguish between wild type, full-length ERß (ERß1), and a splice variant isoform called ERßcx/ERß2 that does not bind oestrogens. ERß1 and ERß2 proteins were both detected in human testis and have distinct but overlapping patterns of expression. ERß1 was also detected in ED, epididymis and vas. In conclusion, oestrogen receptors are widely expressed in the male urogenital system and with the exception of the ED there are more cells that express ERß than REα. In the adult human the testicular cells most likely to be targets for oestrogens are round spermatids in which levels of expression of full-length wild type receptor (ERß1) are high.     

Infection génitale à chlamydia chez l’homme et retentissement sur la fécondité

Chlamydia trachomatis is responsible for the most common sexually transmitted disease, up to 40% of the non gonococcal urethritis. It is a compulsary intracellular parasite. Its peculiar metabolism makes the bacteria interfere with the host cell immunity. Infection can become chronic and induce inflammation, if not properly treated, by permanent emission of antigens and heat shock proteins, and stimulation of Tcells. Autoimmunization against sperm can occur and impair fertilization and embryo implantation. Thus, Chlamydial infection can be associated with male infertility because of tissue damage, altered movement and antisperm immunization. PCR and LCR are to date the most sensitive detection techniques for c.trachomatis. Our study aim was to determine the prevalence of Chlamydial infection by PCR in 6 groups of men in andrologic practice. The highest prevalences have been found in the infertile men group and in the symptomatic group. No Chlamydia culture was found positive in any group. The association of PCR with anti C. trachomatis seminal IgA and seric IgG are useful tools for andrologic exploration.     

Fertilité de l’homme en fonction de l’âge

The aim of this work was to analyse the evolution of sperm characteristics according to age. To this end we analysed the spermogram of 2,126 men aged 20 to 64 who came for consultation for feminine indications for in vitro fertilization at the Clermont-Ferrand Human Reproduction Unit during the period 1980 to 1994. A search for a link between the age of the patient at the time of the spermogram and 10 sperm parameters, by studying a linear regression, did not reveal any evidence of a significant correlation between the age and the parameters studied. The mean values for volume, concentration of spermatozoa, percentage of mobile forms (normal, diminished), percentage of typical and mobile forms and percentage of abnormal forms were compared for age classes covering 5 years. These values showed no significant difference according to the age classes. Between 20 and 60 years the essential parameters of the spermogram seem generally to be independent of age, from which it can be deduced that ejaculate quality remains the same until 50 years of age. However a bias in the recruitment of the population studied and a very wide spread for the values for a given age mean that we may not have detected fluctuations in sperm characteristics linked with age.     

Diagnostic, traitement et surveillance de l’hypogonadisme de survenue tardive chez l’homme: Recommandations officielles de l’International Society for the Study of the Aging Male (ISSAM) et commentaires

There is increasing interest in the subject of hormone changes in the aging male, which is likely to become particularly important with the expected growth in the population of men over 50. The main concerns at present are androgen decline in the aging male (ADAM), or partial androgen deficiency of the aging male (PADAM), commonly known as the andropause. Although progress has been made in our knowledge of androgen deficiency in the aging male, it is still incomplete and sometimes confusing, and some aspects of androgen replacement therapy remain controversial. The International Society for the Study of the Aging Male (ISSAM) therefore felt it was a good time to review the current situation by publishing a series of practical and official guidelines concerning the diagnosis, treatment and monitoring of late-onset hypogonadism in males. The aim of this study is to present and discuss the French translation of these recent international guidelines.     

Influence du muscle deltoïde sur la courbure du corps de l’humérus chez les hommes modernes et les Néandertaliens

When observed in medial view, the humeral diaphysis shows two main types of curvature. It can be either more or less regularly distributed along the bone, or distally deported. Both types are about equally represented among modern humans, while the “regular” type largely prevails in Neandertals. Our hypothesis is that the distal curvature is the resultant of the action of the triceps brachial that “pulls” the bone in the posterior direction and of the deltoid that, in some cases, would be powerful enough to “straighten” the superior part of the diaphysis. Our results indicate that, in modern humans, bones with a distal curvature are indeed more frequent in males and on the right side and that their deltoid tuberosity is on average wider, more developed and more prominent as compared to bones with a regular curvature. This suggests a stronger solicitation of the deltoid muscle associated to this morphology. The high percentage of humeri showing a regular curvature observed in Neandertals would therefore be explainable by the fact that their deltoid tuberosity is averagely narrow, poorly developed and forming a weak prominence which likely attests of a moderate activity of this muscle in most of them.     

Traumatisme du testicule chez l’enfant

Introduction

The testicular trauma is uncommon in children and the literature about this topic is very poor. The aim was to investigate the testicular trauma in children from a retrospective study.

Materials and methods

All the French pediatric surgical departments were requested to send their cases of testicular trauma reported between 2000 and 2009. The analysis was performed from the data and the operative report. Isolated scrotal wounds, testicular torsions revealed by trauma, and incomplete files were excluded.

Results

Fifteen departments sent their data and 2 had no cases. From 60 cases, 15 were excluded and 45 selected. The mean age was 12.3 years (2 days–18 years). The circumstances of the trauma were 23 knocks (foot, knee, and fist), 13 falls, 4 motorcycle accidents, 4 unknown traumas, and 1 obstetrical trauma. There were 4 wounds and 41 without wound. A color Doppler sonography was performed in 34 cases (75.5%) with an accurate diagnosis in 30 cases; 2 testicular fractures and 1 intratesticular hematoma were not confirmed at surgery, and 1 epididymal hematoma was not seen on sonography. The lesions were testicular fractures (15), intratesticular hematomas (8), benign testicular blunt traumas (6), spermatic cord hematomas (6), epididymal hematomas (6), isolated hematoceles (3), and avulsion (1). Surgical treatment was done in 33 children and 12 had nonoperative treatment. Among the 15 testicular fractures, 13 were operated (8 sutures and 5 partial orchidectomies) and 2 were only observed. For the intratesticular hematomas, a surgical treatment was performed in 5 children and a nonoperative treatment in 3, with a good evolution. Only 20 children were controlled beyond 4 months, especially the testicular fractures and no secondary testicular atrophy was seen.

Conclusion

The testicular trauma in children is rare and the prognosis is rather good. The color Doppler sonography now allows a good diagnosis in most cases and the surgery can be often avoided in benign blunt trauma. In this situation, it is important to repeat sonography 24 or 48 hours after trauma to ensure there is no fracture or other lesion necessitating a surgical treatment.