Biomedical subjects

M Bergère

Publications and source records attributed to M Bergère.

10 recordsLinked to original sources

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↗

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↗

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↗

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

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↗

PubMed1996

[Intracytoplasmic injection of spermatozoa].

Management of male infertility has been totally changed with the development of intracytoplasmic sperm injection (ICSI). This technique, used for in vitro fertilization, consists in injecting a single spermatozoa into the ovum. Intracytoplasmic sperm injection can be proposed in case of severe male sterility (oligoasthenospermia) or after repeated failure of in vitro fertilization. Satisfactory rates of fecondation and pregnancy have been obtained. Results have also been obtained with sperm taken from the epididymis or testis. The risks involved concern the transmission of poorly understood genetic defects leading to the infertility. The rates of reported malformations and chromosome anomalies are quite low. Intracytoplasmic sperm injection can be useful in managing most cases of male infertility which to date have had to rely on donor sperm. Long-term results have not yet been obtained.

Female↗

PubMed1995

Cytogenetic analysis of uncleaved oocytes after intracytoplasmic sperm injection.

PURPOSE: This work analyzes the causes of cleavage failure after intracytoplasmic sperm injection (ICSI) and the effect of the procedure on the chromosomes of the oocytes. METHODS: Ninety-seven uncleaved oocytes from 39 patients with severe male infertility or repeated IVF failure were fixed; 79 were analyzable. We checked the decondensation stage of spermatozoa nucleus and the chromosomal abnormalities of the oocytes. RESULTS: Among the fixed oocytes, the spermatozoa nucleus was present in 97% of the cases, and it was undecondensed in 89% of the cases, showing no evolution at all. A low rate (2.6%) of premature chromosome condensation (PCC) of the spermatozoa and a low rate (2.5%) of female diploïdy were observed. Among the oocytes that could be karyotyped, we observed a high rate (45%) of chromosome breakage. CONCLUSION: ICSI fertilization failure was due mostly to the complete lack of evolution of the spermatozoa nucleus. Oocyte selection before ICSI seemed to lower the PCC rate. The high rate of oocyte chromosomal breakage rate has to be confirmed.

Chromosome Aberrations↗

PubMed1988

[Thyroid function and trisomy 21. TSH increase and rT3 deficiency].

An excess of thyrotropin (TSH) with normal levels of tetraiodothyronine (T4) and of 3,5,3'-triiodothyronine (T3) was confirmed in the serum of 78 trisomy 21 children. A severe deficiency of 3,3',5'-triiodo-thyronine (rT3 or reverse T3) was observed and the decrease of the rT3/TSH ratio was highly significant. These new facts suggest that the rT3 deficiency plays a peculiar role in trisomy 21 (maybe through the regulation of one or few steps of monocarbons' metabolism). A systematic control of thyroid function (including the patient's rT3 level) is mandatory for the follow-up of every trisomy 21 patient.

Adolescent↗

PubMedDate not supplied

[Cytogenetic analysis of human oocytes after sperm microinjection].

After standard in vitro fertilization (IVF) chromosome analysis of uncleaved oocytes has shown that in about 80% of the cases, there was no fertilization at all while in 10% of the cases there was a premature chromosome condensation and a development arrest. After micro-injection our results suggest that both the technique itself and the pathologies which require micro-injection can influence the results. On the other hand about 20-30% of the metaphase II oocytes are cytogenetically abnormal after IVF attempt while ICSI might increase chromosome breakage. Our results suggest that both the technique used and the gamete pathologies can influence the different steps of development arrest.

Chromosome Aberrations↗

PubMedDate not supplied

[Are desquamated trophoblastic cells retrieved from the cervix suitable for a prenatal diagnosis?].

Prenatal diagnosis based on sampling of fetal tissues, amniotic fluid or chorionic villi is associated with the risk of miscarriage and fetal damage. These risks would be avoided if diagnosis could be performed in desquamated trophoblast cells recovered non-invasively from the maternal cervix. We report on our experience of fetal karyotyping on endocervical lavage using in situ hybridization (FISH) and DNA amplification (PCR) fetal sex was correctly predicted in 8/10 cases by FISH and in 6/10 by PCR. FISH appeared to be a reliable technique for karyotyping when trophoblast can be recovered from the maternal endocervix (8/10).

Female↗