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P Cohen-Bacrie

Publications and source records attributed to P Cohen-Bacrie.

11 recordsLinked to original sources
PubMed2000

Embryos with high implantation potential after intracytoplasmic sperm injection can be recognized by a simple, non-invasive examination of pronuclear morphology.

Embryos are conventionally selected for transfer based on the evaluation of the cleavage speed and extent of blastomere fragmentation. Here we examined whether the predictive value of these criteria, as indicators of the chance of embryo implantation, can be further potentiated by adding previously described criteria reflecting the regularity of pronuclear development. In a group of embryos selected for transfer in 380 fresh embryo transfer cycles according to the conventional criteria, the transfer of only those embryos that developed from zygotes judged normal at the pronuclear stage (pattern 0) gave significantly higher pregnancy (44.8%) and implantation (30.2%) rates compared with the pregnancy (22.1%; P < 0. 05) and implantation rates (11.2%; P < 0.001) for the transfers of only those embryos that developed from zygotes judged abnormal (non-pattern 0). The transfer of only one pattern 0 embryo was sufficient for the optimal chance of pregnancy (no differences in pregnancy rates after transfer of one, two or three pattern 0 embryos), whereas the transfer of two pattern 0 embryos mostly resulted in a twin pregnancy. The inclusion of the criteria based on pronuclear morphology can thus lead to the application of a single embryo transfer policy and optimize the selection of embryos for transfer and cryopreservation.

Cell Nucleus↗
PubMed1998

Differentiation of spermatogenic cells during in-vitro culture of testicular biopsy samples from patients with obstructive azoospermia: effect of recombinant follicle stimulating hormone.

In-vitro differentiation of spermatogenic cells is a potential approach to the treatment of male sterility due to spermatogenic arrest. This is a pilot study evaluating meiotic, morphogenetic and cytoplasmic maturation of spermatogenic cells from 18 patients with obstructive azoospermia, during in-vitro culture of partly disintegrated testicular biopsy samples in the presence or absence of recombinant follicle stimulating hormone (rFSH). Meiotic progression was detectable only in the presence of rFSH in culture medium. FSH-dependent condensation, peripheral migration and protrusion of spermatid nuclei, together with FSH-independent flagellar growth, were the main events indicating post-meiotic sperm cell differentiation. rFSH also promoted the progression of spermatid cytoplasmic maturation, reflected by acceleration of acrosomal development. These differentiation events appeared to be mediated by humoral activity of Sertoli cells, without the need for a direct Sertoli-sperm cell contact. These findings provide a background for similar studies in patients with non-obstructive azoospermia. If reproducible in the latter group, transmeiotic in-vitro differentiation of primary spermatocytes may be useful in cases of complete maturation arrest, whereas the development of culture-specific forms may help select viable spermatids in cases of complete spermiogenesis failure.

Acrosome↗
PubMed1998

Germ cell apoptosis in men with complete and incomplete spermiogenesis failure.

Germ cell apoptosis was evaluated in 11 men suffering from nonobstructive azoospermia and enrolled in a spermatid conception programme. In six of these patients, round spermatids (Sa stage) were the most advanced spermatogenic cells recovered from testicular biopsy samples. This condition is referred to as complete spermiogenesis failure. In the remaining five men, a few late elongated spermatids (Sd stage) were unexpectedly found in the testicular biopsy samples on the day of treatment. This condition is referred to as incomplete spermiogenesis failure. Germ cell apoptosis in both groups of patients was examined by analysing cell smears prepared from mechanically disintegrated testicular tissues using terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL), which detects apoptosis-specific DNA fragmentation, and annexin-V binding, detecting apoptosis-related translocation of plasma membrane phosphatidylserine to the membrane's outer surface. Both methods were combined, in double-fluorescence labelling preparations, with immunocytochemical detection of proacrosin, a specific germline marker. Patients with complete spermiogenesis failure had significantly higher frequencies of primary spermatocytes and round spermatids carrying the apoptosis-specific DNA damage in comparison with patients with incomplete spermiogenesis failure. Surprisingly, apoptosis-related phosphatidylserine externalization occurs rarely until the advanced stages of spermiogenesis. Since externalized phosphatidylserine is expected to be involved in the recognition of apoptotic cells by phagocytes, apoptotic spermatocytes and round spermatids may not be removed easily by phagocytosis. The high frequency of DNA damage in round spermatids from patients with complete spermiogenesis failure explains the low success rates of spermatid conception in these cases. The evaluation of apoptosis can help predict success rates of spermatid conception.

Annexin A5↗
PubMed1998

[Non-obstructive azoospermia and ICSI].

50 cases of non obstructive azoospermia required testicular sperm extraction and ICSI. Results are promising but ability to find spermatozoa remains questionable. Further studies are necessary to improve success of the method. Genetic research also need to be developed for better understanding the process.

Cryopreservation↗
PubMed1996

Combined use of proacrosin immunocytochemistry and autosomal DNA in situ hybridisation for evaluation of human ejaculated germ cells.

The recently reported human pregnancies and births after fertilising oocytes with round spermatids recovered from the ejaculate of men with non-obstructive azoospermia have underscored the need for a more accurate evaluation of the nuclear and cytoplasmic maturation status of ejaculated germ cells. In this study we describe our first experience with a method combining the immunocytochemical visualisation of proacrosin with autosomal DNA fluorescence in situ hybridisation (FISH) to assess ejaculated germ cells from patients with a spermiogenesis defect. The proacrosin immunoreactivity, analysed with the use of the monoclonal antibody 4D4, has been detected in cells of round spermatid size presenting a haploid FISH figure as well as in larger cells whose ploidy corresponds to primary and secondary spermatocytes. These observations are in agreement with previously published results obtained, with the use of the same antibody, by immunocytochemical analysis of histological sections of testicular tissue. All the cells of round spermatid size possessing proacrosin immunoreactivity were found to be haploid by FISH. On the other hand, some of the haploid cells of round spermatid size did not possess proacrosin immunoreactivity. The structural pattern of proacrosin immunoreactivity was highly variable both in spermatids and in younger spermatogenic cells. These data show that cell size is the main criterion to be used for the identification of ejaculated round spermatids, whereas the presence of the developing acrosome represents only an auxiliary criterion. The scoring of acrosomal development in ejaculated spermatids may be useful as part of pre-treatment diagnosis before the inclusion of infertile couples in a spermatid conception programme.

Acrosin↗
PubMed1991

[The importance of the preoperative measurement of hemoglobin concentration. Evaluation of a colorimetric method (Hemocue)].

The present study compares two methods of haemoglobin measurement during surgery in 40 patients aged 1 to 85 years. The reference method is the Coulter STKS based on red cell count and mean cellular content in haemoglobin measurement. The method tested (Hemocue-Diagnostics Transfusion) allows instantaneous determination of haemoglobin on a 10 mu sample by measuring infrared absorption by haemoglobin in the 565 and 880 nm wavelengths. These methods have been compared using the method of assessment of agreement described by Bland and Altman. As previous reports suggested that the precision of haemoglobin measurement by Hemocue could depend on the capillary or venous site of sampling, we assessed agreement of the two methods of measurement of haemoglobin at both sites. In addition, the relationship between hematocrit and haemoglobin measured by either method has been assessed. On venous samples, there was a good agreement between the two methods of measurement of haemoglobin (n = 47), with a mean difference of -0.166 g/dl-1 and agreement limits of -1.041 g/dl-1 and +0.195 g/dl-1. Ninety six percent of the observed differences to two methods were within the 95% confidence interval. On capillary samples, there was a poor agreement between Hemocue and Coulter since the mean difference was -0.272 g/dl-1 with the following limits of agreement: -2.356 g/dl-1 and +1.812 g/dl-1. Only 92% of the observed differences were within the 95% confidence interval, with 17% of these being greater than the clinically accepted limit of 1 g/dl-1. The precision of Hemocue measurement of capillary blood haemoglobin was only +/- 16%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Transvaginal sonographically controlled ovarian puncture for oocyte retrieval for in vitro fertilization.

Two hundred twenty-two patients took part in a trial of follicle puncture via the transvaginal route under sonographic control for the purpose of in vitro fertilization (IVF). Induction protocols were mainly human menopausal gonadotropin (hMG) + human chorionic gonadotropin (hCG) and clomiphene + hMC + hCG. In 79.7% oocyte aspiration could be achieved without difficulty via the transvaginal route. An average number of 4.7 oocytes per attempt was obtained; 10.7% evolutive pregnancies were obtained. No major incident was noted. This technique offers several crucial advantages: it reduces surgical risk, reduces the length of the patient's stay in hospital as well as the overall cost of the procedure, and it also makes possible puncture in some cases hitherto regarded as excluded.

Female↗
PubMedDate not supplied

[Microinjection in France: report of the BLEFCO multicentric study].

In order to evaluate the assisted fertilizations in France, BLEFCO association has analysed 436 and 1,781 attempts for SUZI and ICSI respectively. For SUZI, the transfer rate was 62% and the pregnancy per attempt rate was 10%. For ICSI, whatever indications, the transfer rate was 86% and the pregnancy per attempt rate was 21%. ICSI in cases of altered sperm without previous IVF represented 46% of ICSI attempts. No relationship between the transfer rate and the indication of ICSI has been observed. However, in case of unexplained fertilization failures, the pregnancy per attempt rate is significantly lower when compared to the other indications.

Cytoplasm↗