Biomedical subjects

J Selva

Publications and source records attributed to J Selva.

At least 19 recordsLinked to original sources

PubMed2006

[Long-term effects of environmental endocrine disruptors on male fertility].

Several epidemiologic studies have demonstrated during the last 50 years an increased incidence in testis cancer, male genital tract malformations (cryptorchidism and hypospadias) and a decrease in sperm quality in men. These three pathologies seem to be linked and to belong to the testicular dysgenesis syndrome (TDS). It was suggested that TDS is a consequence of intra-uterine exposure to environmental compounds that disrupt the metabolism of native hormones. Such substances are so called endocrine disruptors (EDs). EDs are present in our daily environment such as food and water (through the use of pesticides), cosmetics, house-care products etc. Experimental models have been carried out to (i) establish a link between EDs exposure and SDT and (ii) identify the mechanisms that are involved in. After a brief definition of EDs and having underlined the importance of the window of exposure to EDs, several mechanisms will be described such as (i) intergenerational transmission (epigenetic), (ii) programmed cell death of testicular cells, (iii) modification of the androgenic signal and (iv) role of the germ cells-nourishing cells. To conclude, we will try to propose some biomarkers that would be useful to identify the potential link between fetal exposure to anti-androgenic EDs and male testicular pathology.

Androgen Antagonists↗

PubMed2006

[Late paternity: spermatogenetic aspects].

The effect of maternal age on the risk of meiotic abnormality is well documented. In contrast little is known about the effect of the paternal age. The question of the risk related to paternal age is raised because of the increased demand of Assisted Reproduction Techniques for older men. This review focuses on the alterations of male semen parameters, testis histology and genetic risks related to age. The motility, vitality and morphology of spermatozoa and semen volume are found decreasing with age. Histomorphometric studies reveal various alterations including a thickening of the basal membrane when spermatogenesis is arrested. The number of germinal and Sertoli cells decreases with increased age. Up to 95 years old, we could find subjects with complete spermatogenesis. Chromosomal analyses in different studies have provided controversial results. Our investigation on subjects aged from 29 to 102 showed that the rate of aneuploidy in the group of aged subjects with preserved spermatogenesis was not statistically different from the young control group. However the incidence of postmeiotic aneuploidy was increased when spermiogenesis had stopped. On the other hand from epidemiological studies, autosomal dominant diseases are known to be associated with paternal age. However, in the case of achondroplasia and Apert syndrome, direct DNA sperm analysis did not reveal significant increase in the mutation frequency with paternal age.

Adult↗

PubMed2006

Evidence of a high proportion of premature unbalanced separation of sister chromatids in the first polar bodies of women of advanced age.

BACKGROUND: Maternal ageing is the only aetiological factor unequivocally linked to aneuploidy. Two mechanisms seem to explain these abnormalities in oocytes: non-disjunction and premature unbalanced separation of sister chromatids (PSSC). Previous studies of unfertilized oocytes argue for a major role of PSSC in the aetiology of aneuploidy for women of advanced age, but in vitro ageing of the oocytes could influence the results. METHODS: Owing to the high prevalence of aneuploidy in women of advanced age, chromosomal screening of the first polar body just before ICSI was offered to women (from 38 years of age) included in an assisted reproduction programme. RESULTS: Among 141 oocytes from 29 women (mean age 40 years and 2 months), 43 (30.5%) were abnormal. Sixty-five abnormalities were found and PSSC was involved in 80% of cases. CONCLUSION: These results are in accordance with previous studies and confirm, in 'fresh' oocytes, the major role of PSSC in the aetiology of aneuploidy in women of advanced age.

Adult↗

PubMed2006

Mid-trimester hyperechogenic bowel in a fetus of Japanese origin carrying a new mutation of CFTR gene (L548Q).

We present a case of a fetus with hyperechogenic bowel, in which the L548Q mutation was detected in the mother of Japanese origin and the deltaF508 mutation in the father of Caucasian origin. The fetus proved to be compound heterozygous. Research into cystic fibrosis transmembrane conductance regulator (CFTR) mutations in this case was triggered by the fact that the fetus had a characteristic hyperechogenic bowel image with normal karyotype and no indications of intrauterine infections. Hyperechogenic bowel is highly indicative of a CFTR gene mutation. The incidence of cystic fibrosis (CF) in fetuses with mid-trimester hyperechogenic bowel is 5%, but once the most frequent mutations have been accounted for, rarer mutations must be investigated.

Abnormalities, Multiple↗

PubMed2006

Partial trisomy 20p resulting from recombination of a maternal pericentric inversion: case report of a prenatal diagnosis by chorionic villus sampling.

We report a case of prenatal diagnosis of trisomy 20p resulting from a maternal pericentric inversion. The diagnosis was confirmed on both chorionic villi and amniotic cells. This case underlines the fact that prenatal ultrasound diagnosis of this structural anomaly is difficult. The only early sonographic feature was increased nuchal translucency.

Adult↗

PubMed2005

The intra-lingual course of the nerves of the tongue.

The intra-lingual course of the nerves of tongue has never been studied in the human by the Sihler method. This technique was applied to six human tongues and allowed coloration of the nerves and illustration of the tongue. The course of the hypoglossal, glossopharyngeal, and lingual nerves was defined. Constant anastomoses between the lingual and hypoglossal nerves, between the glossopharyngeal nerve and the hypoglossal and lingual nerves, were demonstrated and may help explain the "neck-tongue" syndrome. This cartography of the nerves of the tongue allowed the definition of the motor and sensory consequences of tongue surgery.

Aged↗

PubMed2005

Dandy-Walker syndrome and corpus callosum agenesis in 5p deletion.

5p deletion syndrome commonly known as cri du chat is well described in affected neonates with catlike cry and hypotonia. Karyotyping will usually show a deletion of the short arm of one chromosome 5 with variable breakpoints. Only a few cases have been reported prenatally, and the fetal form of the syndrome has not been clearly individualised. We report a new case of 5p deletion syndrome diagnosed prenatally in association with Dandy-Walker syndrome and agenesis of the corpus callosum. Other brain anomalies have been reported previously, but this unusual association suggests the use of a specific probe in the investigation of these malformations.

Abortion, Eugenic↗

PubMed2005

[Aging and spermatogenesis: an histologic, cytogenetic and apoptosis study].

OBJECTIVE: The increase of frequency of Assisted Reproductive Techniques (ART) for elder men raises the question of the genetic risk for the offspring. Our aim was to evaluate the influence of ageing on the testicular histology, the aneuploidy rate in testis postmeiotic cells and the DNA fragmentation in sperm. PATIENTS AND METHODS: We performed a histomorphometric study of 36 men aged from 61 to 102 years and 10 young men from 29 to 40 years. The aneuploidy rate was evaluated by fluorescent in situ hybridation (FISH X, Y, 18) and DNA fragmentation in spermatozoa was evaluated by TUNEL. RESULTS: Histomorphometry showed various alterations of testicular histology with age including thickening of the basal membrane when spermatogenesis was arrested. The number of germinal cells and Sertoli cells decreased with age with important individual variations. Nevertheless spermatogenesis could be possible until 95 years. The rate of aneuploidy was not influenced by age when spermatogenesis was complete. However, we observed an increased aneuploidy rate in postmeiotic cells when spermiogenesis was arrested. On the other hand apoptosis was not increased with age. DISCUSSION AND CONCLUSION: Our study confirms that spermatogenesis is possible until a very advanced age (95 years) without any specific chromosome risk. The question of mutagenesis remains to be solved.

Adult↗

PubMed2004

[Genomic instability and male infertility].

Knowledge of the human genome has opened the genomic era. The genome instability, its causes and the possible consequences especially about fertility start to be understood. This instability can be observed on chromosome structure but also on genes. Different chromosomes rearrangements involved in infertility including translocations and Y chromosome deletions are described. The Y chromosome is a model of instability, and this instability is the source of its evolution. All those rearrangements are the results of illegitimate recombinations between homologous sequences. On genes we find punctual and dynamic mutations, polymorphisms and epigenetic abnormalities. They all are the results of ADN replication mistakes not corrected by the cellular machine. This machinery is the guardian of the genome integrity and in case of abnormality the programmed cellular death is induced. The knowledge of all these instability mechanisms is essential to appreciate the risk for the offspring after intracytoplasmic sperm injection. Indeed we go round physiological barriers without a complete understanding of the mechanisms involved. Thus, this is an important challenge for research teams but also for all assisted reproduction centers, dealing with ART. Genome is unstable - the very basis of its evolution. But this is also the cause of mistakes with pathological consequences like infertility and mental retardation.

Chromosomes, Human, Y↗

PubMed2002

Prenatal diagnosis of a 45,X male with a SRY-bearing chromosome 21.

Male phenotype associated with a 45,X karyotype is an infrequent finding. We present a case diagnosed prenatally on amniocentesis performed for maternal age. The male phenotype was associated with a translocation of a distal part of Yp including the pseudoautosomal SHOX gene and SRY gene on the short arm of a chromosome 21. By DNA analysis we could show that the X chromosome was of maternal origin and that the breakpoint was in interval 3 of the Y chromosome. Mechanisms and genetic counselling are discussed based on a review of published cases of 45,X and XX males.

Adult↗

PubMed2002

[Consequences of oocyte dysmorphy on the fertilization rate and embryo development after intracytoplasmic sperm injection. A prospective multicenter study].

OBJECTIVES: This prospective study aimed to evaluate the impact of oocyte dysmorphy on the fertilization rate and embryonic development rate in an ICSI programme. PATIENTS AND METHODS: Three hundred and two couples have been included during 302 ICSI cycles, and 1970 oocytes have been studied in 4 ART centres. After decoronisation, 18 morphological criteria, including the size and shape of the oocyte, the thickness of the zona pellucida, the presence or not of debris in the perivitelline space, as well as the appearance of the cytoplasm and polar body have been noted. RESULTS: In total 61.3% of the oocytes presented a dysmorphy, involving, almost equally, the different oocyte compartments. Among the dysmorphic oocytes, half presented more than one anomaly. On average, 9.2% of the oocytes were lysed the day after the micro-injection. The oocytes presenting an enlarged perivitelline space, or multiple vacuoles had a significantly raised lyse rate, 16.3% and 27.8%, respectively. The day after micro-injection, 61.3% of the intact oocytes were fertilized. The rate of fertilization was correlated to the number of abnormalities per oocyte: 1 anomaly: 64.6%, > or = 3 anomalies: 54.6%. The oocytes presenting a large perivitelline space had a slightly lowered fertilization rate (53.4%). On the other hand, those showing a cytoplasm containing refractile bodies had a slightly raised fertilization rate (68.6%). We did not see any statistically significant difference between the different types of oocytes concerning embryonic development at d2. CONCLUSION: These results confirm and contribute new elements with respect to previously published data, showing that (i) oocyte morphology little affects fertilization and the first stages of embryonic development; (ii) certain dysmorphies, (enlargement of the perivitelline space) are specifically deleterious at certain stages in the process (lowering the fertilization rate); (iii) certain morphological differences (the presence of refringent bodies) are not anomalies, but can reflect physiological cellular changes.

Cell Size↗

PubMed2001

An idiopathic infertility with oocytes metaphase I maturation block: case report.

BACKGROUND: A case of idiopathic primary infertility was attributed to a block in oocyte meiosis affecting the transition between metaphase I and metaphase II. METHODS AND RESULTS: A couple suffering unexplained primary infertility was unsuccessfully treated by various means of assisted reproductive technology. After four unsuccessful pregnancy attempts using intrauterine inseminations (IUI), IVF was attempted (all oocytes remained unfertilized), followed by an ICSI cycle. None of the retrieved oocytes expelled the polar body, and therefore were not injected. The failure of these assisted reproduction cycles was, in both cases, due to the immaturity of the oocytes recovered. Cytogenetic analysis of the oocytes retrieved for ICSI provided evidence of meiotic arrest. Using cytogenetic staging criteria we were able to show that this arrest occurred between metaphase I and anaphase I. CONCLUSIONS: Meiotic blocks affecting oocytes have already been described for various mammals. We discuss here mechanisms that might be involved in this possibly inherited disorder in humans, and ways in which our knowledge of them could be increased.

Adult↗

PubMed2000

ESHRE guidelines for good practice in IVF laboratories. Committee of the Special Interest Group on Embryology of the European Society of Human Reproduction and Embryology.

Education has always been a priority for the European Society of Human Reproduction and Embryology (ESHRE). Many efforts have been dedicated to promoting knowledge of techniques, procedures and strategies in order to ensure use of the highest quality practices in reproductive medicine. The need to develop a set of guidelines was a logical consequence that found its first expression in 1990, when Focus on Reproduction (vol. 1, pp. 10-38) published the first guidelines which were distributed among the membership. Five years later a new, more complete edition with several novel techniques and developments appeared in Human Reproduction (vol. 10, pp. 1246-1271). Both have proved to be invaluable references. Five more years have now passed. The necessity to produce current guidelines for good IVF laboratory practice has provided the strongest motivation. This originated from the increasing awareness that embryologists have a duty to prevent unintentional incidents that might result from poor practice in the laboratory. Therefore, the Embryology Special Interest Group (SIG) undertook to draw up guidelines aimed at giving support and guidance to the laboratory staff. All the aspects required to provide a safe working system were taken into consideration by members of the SIG and their effort produced this document. We hope that it will assist staff in achieving the best clinical outcome for their patients.

Cryopreservation↗

PubMed2000

Assisted hatching.

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Embryo, Mammalian↗

PubMed1998

Chromosome 21 detection in human oocyte fluorescence in situ hybridization: possible effect of maternal age.

PURPOSE: The purpose of this study was to evaluate, among 100 uncleaved oocytes, the incidence of numerical and structural chromosome 21 and X abnormalities and to analyze the influence of various factors, such as in vitro (IVF) indications, follicle stimulation protocols, and women's age. METHODS: We investigated 150 uncleaved oocytes from 128 patients after an IVF attempt. After cytogenetic analysis (Giemsa) 100 oocytes (66%) were selected for fluorescence in situ hybridization (FISH). Fluorescent probes for human chromosomes X and 21 were used simultaneously according to standard procedures for their hybridization and detection. RESULTS AND CONCLUSIONS: We analyzed by the FISH protocol 100 metaphase II oocytes with 22 to 25 chromosomes. Our results demonstrate a high rate of disomy for chromosome 21 in human oocytes. Among them, eight were disomic (8%) and three were nullosomic (3%) for chromosome 21. Only one disomy of chromosome X was noted. The various indications of IVF and the different folliculogenesis stimulating protocols did not seem to influence the results but suggested a correlation between the maternal age and the aneuploidy rate of chromosome 21.

Adult↗

PubMed1997

Pregnancy outcome after artificial insemination or IVF with frozen semen donor: a collaborative study of the French CECOS Federation on 21,597 pregnancies.

OBJECTIVE: To assess pregnancies and conceptus after artificial insemination (AID) or IVF with frozen semen donor (IVF-D) on sufficiently large study population in order to distinguished minor variations. STUDY DESIGN: From 1987 to 1994, all pregnancies obtained after AID or IVF-D were registered prospectively in the French CECOS Federation data base. Different factors were recorded for this study: first menarche age of the recipient women, cycle length, insemination date in the conception cycle, maternal age at delivery, hormonal treatments, donor age, sperm conservation length and follow up of the pregnancy: miscarriage, tubal pregnancy, time at delivery, sex of the foetus, weight, malformation. RESULTS: 21,597 pregnancies obtained after AID and 3381 after IVF-D were registered. 2% were lost to follow up. Foetal loss rate is 18% after AID and 21.5% after IVF-D (p < 0.001). The tubal pregnancy rate is 0.9% after AID and 1.7% after IVF-D (p < 0.0001). 18,128 children were born after AID and 3313 after IVF-D. After AID, the twin pregnancy rate is 6.9% and the multiple pregnancy (> or = 3 foetus) rate is 0.7%. After IVF-D, these rates are 24.8% and 4.2% respectively (p < 0.0001). After AID the mean weight at delivery, sex ratio, premature rate, intra uterine growth retardation rate are not different from national rates published in 1995. The foetus malformation rate (including medical abortions) is 1.9% after AID and 2.7% after IVF-D (p < 0.009). After AID the trisomy 21 rate increases with the mother age but also with the donors age if the maternal age is equal. The birth defects rate is not different from those registered in Paris, Strasbourg and Marseille. The birth defects rate observed after IVF-D is not different from the rate observed after IVF with husband semen. (2.74% versus 2.99%; p = 0.16). CONCLUSION: After AID the miscarriage and tubal pregnancy rate, the children's weight, the premature rate is not different from that of the general French population. Sex ratio is normal as is the global malformation rate. The multiple pregnancy rate (x 7 for twin and by 10 for multiple pregnancies more than 3 foetus) is high, showing the influence of ovulation induction treatment. The birth chromosomal abnormalities rate is normal and correlated not only to the mother's age but also to the donor's age. This result without clear biological explanation will require further verification in a greater population. Practically speaking, these observations encourages lowering the age limit for semen donors less than 45 years. IVF-D practice instead of AID doubles the tubal pregnancy rate (0.9% versus 1.7% and increases the twin pregnancy rate by 2.5% and the multiple pregnancy (> or = 3 fetus) rate by 3. It is necessary to promote good practice for AID for which the pregnancy rate is very different from one centre to another within the centres with AID low results a too high rate of IVF-D. Finally we can say that pregnancies from IVF-D or IVF with husband semen are not significantly different. In other words pregnancy outcome is not changed after sperm cryopreservation.

Adult↗

PubMed1997

Incidence of AZF (azoospermia factor) deletions and familial forms of infertility among patients requiring intracytoplasmic spermatozoa injection (ICSI).

PURPOSE: The aim of our study was to determine the incidence of AZF deletions and familial forms of infertility suggesting autosomal mutations among patients requiring intracytoplasmic sperm injection with ejaculated sperm. METHODS: Cases with obstructive pathologies were excluded; 81 patients were classified according to the numeration of spermatozoa. The distribution was as follows: 10 cases with normal numeration (greater than 20 million/ml) (group 1), 10 cases with between 10 and 20 million/ml (group 2), 6 cases with between 5 and 10 million/ml (group 3), 15 cases with between 1 and 5 million/ml (group 4), 29 cases with less than 1 million/ml (group 5), and 11 azoospermic patients (group 6). The infertility of 11 of the 81 patients might be explained by testicular ectopy. RESULTS: We found two deletions limited to the AZFc region among our 81 infertile patients--one deletion in group 5 and one deletion in group 4 (both groups of oligozoospermic patients)--and no deletion in the groups with normal or subnormal numerations. We found six familial forms of infertility. We did not find any AZF deletion, neither in these 6 patients nor in the 11 with testicular ectopy. The identification of these families of infertile men will allow research of autosomal genes involved in male infertilities. CONCLUSIONS: It is important to test deletions of the AZFc region for oligozoospermic patients, and familial forms of infertility do not seem to concern the same individuals.

Chromosome Deletion↗

PubMed1997

Cryopreserved immature mouse oocytes: a chromosomal and spindle study.

PURPOSE: Cryopreservation of human oocytes might provide an alternative approach to freezing supernumerary embryos obtained during IVF. This process, performed on immature denuded prophase 1 mouse oocytes, was investigated. METHODS: We first investigated the capacity of frozen, immature, murine oocytes to continue in vitro maturation after thawing. We then evaluated the risk to offspring from chromosomal damage by cytogenetical and cytological (spindle) analysis. Finally, we attempted to determine the reasons for and the stage of maturation failure. RESULTS: A total of 700 immature oocytes was frozen, 629 (90%) were recovered intact after thawing, and 53% extruded the first polar body, versus 74% for the control group. Freezing was not accompanied by an increase in aneuploidy in maturing oocytes (18 and 15% for thawed and control oocytes, respectively). Consequently, the first meiotic division occurred normally, without an increase in nondisjunction. Spindle analysis demonstrated only a few abnormalities (15 and 2% for thawed and control oocytes, respectively) incompatible with further development. Oocytes arrested during in vitro maturation were mainly at the metaphase I stage (64 and 76% for thawed and control oocytes, respectively). Whereas 17% of thawed oocytes were blocked before the formation of the first meiotic spindle, this never occurred in the control group. CONCLUSIONS: Immature murine oocytes can withstand cryo-preservation, which is encouraging for future human application of this technique.

Animals↗