The feasibility of fertility preservation in adolescents with Klinefelter syndrome.

STUDY QUESTION: Is fertility preservation feasible after the onset of puberty in adolescents with Klinefelter syndrome (KS)? SUMMARY ANSWER: Fertility preservation counseling should be an integral part of the care of XXY adolescents. Frozen ejaculated or testicular spermatozoa and even frozen immature germ cells can give them the potential to conceive their genetic progeny. However, no biological or clinical parameters were predictive of mature or immature germ cell retrieval. WHAT IS KNOWN ALREADY: KS is the commonest sex chromosome disorder observed in azoospermic infertile males. Testicular sperm extraction success decreases with age and after testosterone therapy. Arguably, spermatozoa should be retrieved from KS males at the onset of puberty and before testosterone therapy to increase the chance of success. STUDY DESIGN, SIZE, DURATION: A retrospective study was performed in eight KS adolescents, aged between 15 and 17 years, who were referred for counseling about their future fertility to the center CECOS (Centre d'Etude et de Conservation des Oeufs et du Sperme humain) at Rouen University Hospital between October 2008 and December 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS: The patients were first seen with their parents and then separately. It was proposed to them that they should provide a semen sample, if this was azoospermic, two other semen samples spaced by 3 months were collected. If azoospermia was confirmed, a bilateral testicular biopsy was proposed for sperm retrieval and testicular tissue preservation. Each adolescent met the psychologist before undergoing testicular biopsy. Paraffin-embedded testicular tissue was evaluated after staining with hematoxylin-eosin and saffron and immunostaining using vimentin, anti-Müllerian hormone, androgen receptor and MAGE-A4 antibodies. Sertoli cell maturity, germ cell identification and lamina propria alteration were assessed on seminiferous tubules. MAIN RESULTS AND THE ROLE OF CHANCE: KS adolescents were not deeply concerned about their future fertility and only became involved in the process of fertility preservation after at least three medical consultations. The parents agreed immediately that fertility preservation should be attempted. Seven non-mosaic XXY adolescents presented with azoospermia and one XXY/XY adolescent had oligozoospermia. Increased plasma levels of FSH and LH as well as bilateral testicular hypotrophy were observed in all patients. The XXY/XY adolescent banked four semen samples before testosterone replacement therapy. Two patients refused testicular biopsy. Five patients accepted a bilateral testicular biopsy. Spermatozoa were retrieved in one patient, elongated spermatids and spermatocytes I in a second patient. LIMITATIONS, REASONS FOR CAUTION: The number of patients enrolled in our study was low because the diagnosis of KS is only rarely made before or at the onset of puberty. Most XXY males are diagnosed in adulthood within the context of male infertility. WIDER IMPLICATIONS OF THE FINDINGS: Spermatozoa can be retrieved in semen sample and in testicular tissue of adolescent Klinefelter patients. Furthermore, the testis may also harbor spermatogonia and incompletely differentiated germ cells. However, the physician should discuss with the patient and his parents over a period of several months before collecting a semen sample and performing bilateral testicular biopsy. Fertility preservation might best be proposed to adolescent Klinefelter patients just after the onset of puberty when it is possible to collect a semen sample and when the patient is able to consider alternative options to achieve fatherhood and also to accept the failure of spermatozoa or immature germ cell retrieval.

Relationship between conventional sperm parameters and motile sperm organelle morphology examination (MSOME).

With the motile sperm organelle morphology examination (MSOME), spermatozoa morphology may be assessed directly on motile spermatozoa at high magnification (up to 6600×). This procedure describes more precisely spermatozoa abnormalities, especially head vacuoles. However, no consensus has been established concerning normal or abnormal MSOME criteria. The aim of our study was to define MSOME vacuole criteria assessed objectively with a digital imaging system software to establish a potential relationship between conventional semen parameters. A total of 440 semen samples were obtained from males consulting in Rouen University Hospital Reproductive Biology Laboratory. Conventional semen analysis (volume, sperm concentration, progressive motility, vitality and morphology) and MSOME assessment {sperm head length, width and area as well as vacuole number, vacuole area and relative vacuole area to sperm head [RVA (%) = [vacuole area (µm(2))/head area (µm(2))] × 100)]} were performed for each semen sample. Among our 440 males, 109 presented normal conventional semen parameters and 331 abnormal ones. Sperm head vacuoles were significantly larger in abnormal semen samples (p < 0.0001). RVA was the most discriminative MSOME criterion between normal and abnormal semen samples according to ROC curves analysis, and was negatively correlated with poor sperm morphology (r = -0.53, p < 0.0001). We concluded to (i) the normal occurrence of vacuoles in sperm head whatever the normality or abnormality of semen parameters, (ii) the discriminative function of the RVA to distinguish semen samples with normal and abnormal parameters, and (iii) the strong correlation between high RVA and poor sperm morphology.

[Assisted reproductive technologies with sperm donation]. / Assistance médicale à la procréation avec don de spermatozoïdes.

INTRODUCTION: The purpose of this review is to relate to the operating rules of CECOS in France and the legal, medical and ethical issues raised by sperm donation. MATERIAL AND METHODS: Review of articles and consensus conferences on this subject published in Medline (PubMed) selected from 1973 and 2011 according to their relevance and Acts recorded on official legislative French websites. RESULTS: The operating rules of CECOS were established by the Act of July 29, 2004, revised 6 August 2004 and July 7, 2011. Of the 21,759 children born of ART in France in 2009, 5.1% are from a sperm donation. From 1973 to 2006, 44,045 children are born after a sperm donation. Between 1973 and 2006, 16,971 donors are presented in the CECOS and only 10,347 donors have completely made their donation process. The main indication for use of donor sperm (75% of applications) is represented by men of infertile couples with nonobstructive azoospermia, the second indication is infertile men with oligospermia. In azoospermia, the application is usually performed after failure of testicular or epididymal surgical specimen. In oligozoospermia, claims made most often after several failures of intraconjugal ART. CONCLUSION: Many questions are still present around the conception of children by sperm donation. The legitimacy of maintaining anonymity in the gift remains widely debated.

Assessment of acrosome and nuclear abnormalities in human spermatozoa with large vacuoles.

BACKGROUND: Spermatozoa with large vacuoles (SLV) may have a negative impact on embryo development. The origin of these vacuoles is unknown. We evaluated acrosome and nucleus alterations in isolated SLV, versus unselected spermatozoa. METHODS: We studied 20 patients with teratozoospermia. Spermatozoa from the native semen sample and spermatozoa presenting a vacuole occupying >13.0% total head area, isolated under high magnification (×6600), were assessed. Confocal and transmission electron microscope evaluations were performed on SLV and native sperm, respectively. Acrosome morphology and DNA fragmentation were analysed using proacrosin immunolabelling (monoclonal antibody 4D4) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay. Chromatin condensation was evaluated with aniline blue staining. Sperm aneuploidy was assessed using fluorescence in situ hybridization. RESULTS: SLV represented 38.0 ± 5.10% of motile spermatozoa obtained after gradient density centrifugation. Vacuoles were mainly in the anterior and median sperm head (45.7 ± 2.90 and 46.1 ± 3.00%, respectively). Abnormal acrosomes were increased in SLV compared with unselected spermatozoa (77.8 ± 2.49 versus 70.6 ± 2.62%; P = 0.014). Microscopic observations showed an exclusively nuclear localization of large vacuoles. Complete DNA fragmentation was higher in native spermatozoa (P < 0.0001) than SLV, while chromatin condensation was altered in SLV (P < 0.0001). Aneuploidy and diploidy rates were increased in SLV (P < 0.0001). CONCLUSIONS: Sperm vacuoles were exclusively nuclear. In our selected teratozoospermic population, aneuploidy and chromatin condensation defects were the main alterations observed in SLV. Based on results from this small sample of spermatozoa, we propose a global impairment of the spermatogenesis process as a common origin of the morphological alterations.

[Pneumopathies induced by amiodarone. Clinical, paraclinical and physiopathological data. Apropos of 2 cases]. / Pneumopathies à l'amiodarone. Données cliniques, paracliniques et physiopathologiques. A propos de 2 observations.

The authors report the cases of two men with coronary artery disease by amiodarone for 8 and 24 months respectively. They developed clinical and radiological changes of diffuse interstitial pneumonia, characterised by an inflammatory syndrome, restrictive changes on spirometry, reduced CO transfer and abnormal blood gases. Broncho-alveolar lavage showed a lymphocytosis with a large quantity of iodine in the macrophages and the presence of amiodarone and its metabolite in the supernatant fluid. The responsibility of this drug is imputed and the patients were cured within 3 months of its withdrawal with regression of clinical, radiological, spirometric and control alveolar lavage abnormalities. A favourable outcome without steroid therapy is practically unknown in the literature. These cases illustrate the possible risk of alveolitis or diffuse interstitial pneumonia during long term amiodarone therapy, the pathogenesis of which is discussed: iodine overload, direct drug toxicity or an immunological mechanism.

[Changes in sweating during exertion. Effects of beta-blocker treatment]. / Variations sudorales à l'effort. Effets d'un traitement bêtabloquant.

Eccrine sweat secretion is studied during physical stress after the administration of a B-blocking agent: Butofilolol. 20 voluntary normotensive subjects, age 24 + 2 ans are submitted to 2 exercises stress test (ergometric bicycle) performed at on week interval. Butofilolol is administrated at a posology of 200 mg, 24 hours and 2 hours, before the test as well as placebo (double blind). Local sweat output is measured 1 min after stress and in the interscapulary region with an evaporimeter. Sweat weight, sweat electrolyte concentrations (sodium, chloride) are analysed from filters papers placed on the forehead. With butofilolol, significative increases of sweet output (+13%), sweat weight (+20%), and sodium (+20%), chloride (+26%) elimination are observed. The subjective observation of the effects of B-blocking agents is confirmed. The way of action of Butofilolol discussed.

[Data on the echocardiogram, pressure profile during exertion, and ambulatory blood pressure measurements in borderline arterial hypertension]. / Données de l'échocardiogramme, du profil tensionnel d'effort et de la mesure de la tension artérielle en ambulatoire dans l'hypertension artérielle limite.

Comparative study is performed between echocardiographic measurements (TM), exercise test blood pressure profile (ETP) and ambulatory blood pressure load (BPL) in 26 borderline hypertensive subjects (19 males, 7 females). An abnormal ETP is found for 15 subjects (57 p. 100), an abnormal BPL for 10 subjects (38 p. 100). The diastolic interventricular septum thickness (IVS) and the diastolic posterior wall thickness (PWT) are abnormal (greater than 11 mm) for 6 and 3 subjects. Patient with pathologic ETP or/and BPL have greater IVS and PWT than other subjects (p less than 0,001). A good correlation is found between individual activity systolic blood pressure or 24 hours systolic blood pressure means values and PWT, IVS or left ventricular mass. These 3 examinations lead to a better assessment of cardiovascular strain and allow a better diagnosis and therapeutic approach in borderline hypertensive patients.

[Role of ambulatory blood pressure measurement in the evaluation of the cardiovascular load in high altitude workers]. / Place de la mesure de la pression artérielle en ambulatoire dans l'évaluation de la charge cardiovasculaire de salariés travaillant en haute altitude.

UNLABELLED: This study evaluates ambulatory blood pressure ABP measurement as a technique for measuring the cardiovascular load in maintenance mechanics working on mechanical lifts at altitudes of over 2,500 meters (stress due to altitude and intensive static and dynamic work). METHOD: 25 normotensive workers were studied during real working conditions. Each subject underwent a maximal stress test, and echocardiography. An ABP recording (Spacelab 90207) with BP measurement every 15 minutes and continuous heart rate (HR) monitoring (Essilor IFC85), during 24 hours were performed on the same day. ANALYSIS: study of BP levels and their factors of variation, comparison of this data with continuous HR measurements, and with results of the stress test and echocardiography. RESULTS: even in difficult conditions (while balancing on cables and cable towers), ABP measurements is possible (less than 10% missing values). Systolic (SBP) and diastolic (DBP) blood pressure and HR values adjusted for age are significantly higher during work activity (9:00-12:00, 14:00-15:00) in these subjects than in reference normotensive subjects. ABP did not differ significantly between different types of work while the equivalent mechanical load (work load that gives a stress test HR equal to the mean HR during work) reveals a different between work activities. At night SBP remains higher and HR values lower than in control subjects. In comparison with reference criteria, 3 subjects were considered as having an abnormally high ABP during the daytime. ABP results were not linked with number of years in the profession nor with the altitude at which the subject worked or lived. Although 40% of subjects have a left ventricular mass index greater than 135 g:m2, there is no link between ultrasound and ABP parameters. CONCLUSION: while ABP measurement seems possible in this type of professional activity, BP values do not appear to be correlated to work level measured. The absence of correlation with left ventricular mass, suggests that the process of cardiovascular adaptation is different from that in even moderately hypertensive subjects.

[Determination of physiologic disturbances due to rotating shift schedules using ambulatory measurement of the arterial pressure]. / Approche des perturbations physiologiques du travail posté par mesure de la pression artérielle en ambulatoire.

UNLABELLED: Technological progress has led to the creation of jobs requiring minimal physical labor, high mental concentration, and rotating shift schedules. This study evaluates the physiological effects of rotating shift work on the cardiovascular system. METHODS: blood pressure (BP) and heart rate were recorded automatically (Spacelabs) under ambulatory conditions over a 24 h period in 15 quality control technicians at a chemical factory, during each one of their 3 shifts: morning (4 am-12 noon), afternoon (12 noon to 8 pm) and night (8 pm to 4 am). RESULTS: mean Bp and HR did not differ significantly between the 3 shifts when the work period was taken into account. (table; see text) Activity appears to prevail over circadian rythm and to determine BP and HR levels. Techniques using chronological series analysis which take BP variability into account (Fourier harmonic transformations) show that night work considerably modifies the modes of BP and HR variation (going to sleep, waking-up, variability at work). CONCLUSION: BP and HR measurement provide a pratical approach to the analysis of physiological disturbances induced by rotating shift work in employees with mentally demanding jobs.

[Analysis of the risk of backache in the occupational environment]. / Analyse du risque lombalgique en milieu professionnel.

In a cross-sectional, and one year retrospective study low back pain risk was analysed in a sample of 1812 subjects stratified by five professions: nurses, industrial workers, truck drivers, construction workers and white collar workers. Data were collected by occupational physicians during annual systematic examinations. Relative risks were significantly higher in nurses and industrial worker occupations than in the control group of white collar employees. Multivariate analysis points out that heavy or light handling, bad postures, non-sitting jobs and exposure to vibration or inclemency are the prevalent occupational factors of low back pain. Housekeeping among females and gardening or odd jobs in males are less but significant extra-professional factors. Prevention should include instruction in lifting techniques and improvement in work conditions.

[Development of a job-exposure matrix in the heavy-metal industry in France]. / Elaboration d'une matrice emplois-expositions dans l'industrie productrice de métaux durs en France.

A job exposure matrix (JEM) was developed by a committee of experts using the DELPHI method, in the French hard metal industry, in order to assess occupational exposures to cobalt along with tungsten carbide resulting from the industrial process. This JEM is part of a nested case-control study, carried out within the historical cohort of workers ever employed in these factories, aimed at assessing lung cancer risk. The committee included 8 experts: hygienists, chemical engineers, occupational physicians and epidemiologists. The JEM was developed in four stages: (i) visit of factories, (ii) definition of lines (job-periods) and columns (exposures) of the JEM, (iii) definition of coding procedures, (iv) coding the cells of the JEM. This last stage used a method derived from the DELPHI method. Throughout the study period 1945-1994. 320 job-periods and 21 agents were defined. A quantitative assignment (level 0 to level 9) along with a frequency code (1 to 3) was attempted for 4 agents, whereas only a qualitative assignment (non exposed/exposed, i.e. 0/l) was done for the other agents. An additional probability code (1 to 3) was assigned to all agents. This procedure led to 46 columns and 14,720 cells in the JEM. When applying the DELPHI method, the consensus of the committee was obtained for 85% of all cells after the first individual assignment of experts, 88% after the second individual assignment and 100% after the third assignment by the experts all together. In order to validate the JEM, these expert assignments will be brought together with the results of exposure measurements that were performed in some workplaces of these factories. The JEM will also be linked with the data base of the case-control study for the exposure assessment of cases and controls.

[Exposure to asbestos: role of respiratory function tests as tools for screening and follow-up]. / Exposition à l'amiante: la place des épreuves fonctionnelles respiratoires comme outil de dépistage et de suivi.

Among pulmonary function tests, spirometries and flow-volume curves are used in occupational or environmental field. They require the compromise between simple and sufficiently performance to be useful. Limitation factors explain the low sensitivity and the absence of specificity related to asbestos (tobacco...). The wide interindividual variation compared to standards limits meaning for early detection. A significant epidemiological difference makes no sense for individual detection. The carbon monoxide diffusing capacity, even classical, has restricted uses. Unlike diffuse pleural thickening, the worst cases with circumscribed pleural plaques lead to limited lung capacity decline. If not, they are associated to pulmonary abnormalities or tobacco. The early asbestos-related parenchyma diseases are associated to restrictive ventilator disorders, small airway obstruction or isolated single breath carbon monoxide diffusing limitation, leading to great difficulties for specific early detection criteria validation. Comparative pulmonary changes over time greater than the physiological pulmonary slope should be a good alert indicator.

[How do we reduce the under-reporting of occupational primary lung cancer]. / Sous-déclaration des cancers bronchiques professionnels.

UNLABELLED: The under-reporting of occupational lung cancer is due to insufficient recognition of occupational exposure and inadequate medico-legal action. MATERIALS AND METHODS: All cases of primary bronchial carcinoma seen at the University Hospital of Grenoble between October 1996 and December 1998 completed a standardised questionnaire set by a physician in occupational medicine. When evidence of exposure to occupational carcinogens was established a claim for occupational disease was made and the outcomes of these claims were obtained from the Department of Social Security at the end of 2000. RESULTS: Asbestos was the most common carcinogenic agent found, followed by crystalline silica, diesel fumes, metals, paints and ionising radiation. Among the 305 patients in the study with primary bronchial carcinoma 20% were able to make a claim for occupational disease whereas only 2% would have claimed otherwise. The Department of Social Security accepted 77% of the 39 claims for occupational disease submitted, thus giving a 12% incidence of occupational bronchial carcinoma in this group. CONCLUSION: It is important to inform and instruct doctors of the environmental risks that are additional to those of tobacco smoking and of the need of inquire into any exposure to carcinogenic agents in order to ensure that the victims receive the appropriate medico-legal benefits. Improved primary prevention alone might eventually avoid the development of up to 3 500 cases of occupation bronchial carcinoma per year in France.

[Ambulatory measurement of arterial pressure. Diagnostic, prognostic and therapeutic value]. / Mesure ambulatoire de la pression artérielle. Intérêt diagnostique, pronostique et thérapeutique.

The invasive and non-invasive techniques now available for automatic monitoring of blood pressure have provided new sets of physiological as well as diagnostic and therapeutic data. Recordings of blood pressure variations over a 24-hour period have shown that it increases during the day and decreases at night, that these physiological changes are more pronounced in the elderly than in young subjects and also that they depend on the degree of physical activity. The clinical applications of these techniques rest on the possibility of recording a blood pressure-activity profile over time, in order to speak, ultimately, in terms of blood pressure load activity. By reference to a normal blood pressure profile, genuinely hypertensive subjects can be differentiated better from those overactive, hyperemotional subjects who are perhaps not suffering from true hypertension. Finally, 24-hour recordings repeated over periods of several days or weeks enable the clinicians to assess therapeutic effectiveness and to envisage an authentic chronotherapy.

[Relationships between air conditioning, airborne microorganisms and health]. / Etude des relations entre climatisation, micro-organismes aéroportés et santé.

Concurrently with the increase of air-conditioning, potentially severe or frequent new diseases have emerged, giving rise to social and economical consequences. The first part of this work is a state of the art review of the relationships between air-conditioning, airborne microorganisms and health, through a technical, metrological and medical approach. The second part presents four studies performed in this field. Two of them deal with the relationship between airborne microorganisms and technical features of air-conditioning. Measurements performed on actual sites demonstrated the benefit of using high efficiency filters and low risk components in air-conditioning systems. The third study was aimed to look for a relationship between airborne microorganisms and sick building syndrome symptoms. Statistical analyses of individual data revealed significant associations between airborne bacteria or fungi and symptoms. These results may be the first step in determining a dose-response relationship, in order to define threshold limit values in this field. In the fourth study, the contribution of particle counting in assessing exposure to airborne microorganisms was explored by monitoring simultaneous variations of microbial and particle concentrations. The results showed that associating particle counting may allow to detect microbial variations instantaneously, and therefore improve the assessment of exposure to airborne microorganisms.

[A case of thymolipoma in a child (author's transl)]. / Un cas de thymolipome chez l'enfant.

A new case of asymptomatic thymolipoma in a 4.5 years old girl is reported. It was discovered during systematic medical investigation. Its radiological characteristics and the lack of evolutivity made the authors suspect the diagnosis before operating. A total surgical extraction of the 300 g weighing tumor was performed through a right thoracotomy. No complication occurred in the post-operative time. Others authors already indicated the scarcity of this affection (less than 10 cases in children) as well as the special radiological characteristics of this tumor and the noticeable clinical tolerance often despite a large bulk. Histologically the tumor is made of an infiltrating of the normal thymic tissue by proliferating adipose adulte cells, the benignity of which is demonstrated by the evolution. In this study a differential diagnosis between thymolipoma and other mediastinal tumors is made and also some pathogenic assessments. Surgery always is required for treatment.

[Prognosis factors in donor semen insemination: a 10-years follow-up study of 188 patients]. / Facteurs pronostiques en insémination avec sperme de donneur : suivi rétrospectif d'une cohorte de 188 patientes.

OBJECTIVES: Improving our practice by a constant evaluation is essential in the field of donor semen insemination (DI). Our center examined the prognosis factors for DI success in order to standardize patient treatment options. PATIENTS AND METHODS: We retrospectively analysed all couples referred for DI from January 2000 till December 2010. RESULTS: We analysed 551 cycles among 188 patients. Pregnancy rate by stimulation cycle was 19,8% with birth rate of 16.7%. The rate of pregnancy was improved till the fourth trial then plateau. On a patient-based analysis, success factors were age (P=0.04), previous successful DSI (P=0.02), and no previous failure of an ICSI-C (P=0.035). On a cycle-based analysis, success factors were the number of follicles greater than 15mm (P=0.04) and than 18mm (P=0.001). The percentage of 68.1 patients obtained a child by IVF-D after a failed DI. CONCLUSION: There are two predictive factors for DI success: the age of the patient and the number of mature follicles. It seems accurate to referred patients to IVF-D after four unsuccessful cycles of DSI. This recommendation may be adapted according to patient's age and hormonal evaluation.

Modification of chromosomal architecture in human spermatozoa with large vacuoles.

Human normal spermatozoa present a specific chromatin organization, illustrated particularly by the non-random chromosome positioning. Spermatozoa with large vacuoles, described using motile sperm organelle morphology organization (MSOME), are associated with nuclear alterations, such as abnormal chromatin condensation and aneuploidy. To question a probable association between large nuclear vacuoles and chromatin disorganization, we evaluated chromosomes X, Y and 18 topography in normal spermatozoa (NS) compared with spermatozoa with large vacuoles (SLV). After centrifugation on a gradient density system, 229 NS (spermatozoa presenting a normal nuclear shape and a vacuole area <6.5% of head area) from 10 normal semen samples and 221 SLV (spermatozoa presenting a vacuole area >13% of head area) from 10 semen samples with teratozoospermia were selected using MSOME. A three-colour FISH was carried out using α-satellite centromeric probes for chromosomes X, Y and 18. For each chromosome, longitudinal and spatial positioning of centromeres was analysed. Distribution of each chromosome was non-random in NS and in SLV, whatever the methodology used. Using longitudinal positioning, distribution of chromosome 18 and chromosome Y centromeres did not differ significantly between SLV and NS. On the contrary, chromosome X centromeres were more frequently positioned in the posterior region of sperm nucleus in SLV (p = 0.01). Considering spatial positioning, distributions differed significantly between SN and SLV for chromosome Y (p = 0.02) and chromosome 18 (p < 10(-4) ) and marginally for chromosome X (p = 0.08). Our study concluded to a modification in chromosomes X, Y and 18 centromere topography between NS and SLV, representing a novel and supplementary evidence to argue chromatin disorganization in SLV.

[Male gamete spermatozoon or spermatid?]. / Gamète mâle un spermatozoïde ou une spermatide?

Normal spermatogenesis results from a balance between process of cell proliferation, cell differentiation and apoptosis that concern somatic cells and germ cells. Dysfunction of spermatogenesis may be the result of constitutional or acquired abnormalities of spermatogonia stem cells or somatic cells. To overcome these problems, it seems necessary to implement preventive measures for germ stem cell preservation or substitute measures to replace them, the objective being to replicate in vivo or in vitro the process of spermatozoa production. This article will discuss the different experimental strategies for considering the in vivo or in vitro production of spermatozoa, outside the physiological process.