Biomedical subjects

A M Junca

Publications and source records attributed to A M Junca.

39 records · Page 3Linked to original sources

PubMedDate not supplied

[Indications for intracytoplasmic sperm injection: possible influence of oocyte quality on the results].

Intracytoplasmic sperm injection is theoretically the first line treatment of many forms of severe male infertility, but the prognostic factors are to be determined according to the indications. Thus the results of two clinical teams working with the same biological Unit show statistically different pregnancy rates per oocyte pick-up (15.9% versus 35.7% - p < 0.02) and per transfer (16.9% versus 34.9% - p < 0.03). They could by explained by female factors such as age and ovarian response to stimulation, which probably have influence on embryonic quality.

Cytoplasm↗

PubMedDate not supplied

[Fertility tests (hamster, electronic microscopy): are they useful?].

Tests of sperm function are often considered to be able to predict the in vivo or in vitro fertility of a given patient although they only assess part of the process of sperm fertilizing ability. It appears from the literature, that the sperm penetration assay (SPA) which investigates the sperm fusiogenic and nuclear functions cannot accurately predict the in vivo fertility and there is still much debate on the reliability of its correlation with in vitro fertilization (IVF) principally in cases of severe sperm deficiency. With the development of new techniques of assisted fertilization, by-passing the zona pellucida, a test of sperm fusion, hetero or homospecific as well, could be interesting. Considering sperm ultrastructure and beyond some specific morphological alterations of the whole sperm population that can be responsible for the infertility, such studies were not able, as yet, to reveal significative differences between semen fertile in vitro or not.

Animals↗

PubMedDate not supplied

[Oocyte maturation and intracytoplasmic sperm injection].

Intracytoplasmic sperm injection (ICSI), treatment of severe male infertility allows an accurate evaluation of oocyte maturity at recovery after corona-cell removal. In cycles comprising a GnRH analog desensitization and a stimulation by hMG or FSH, 12% of oocytes aspirated from follicles (> 14 mm), 34 hours post-hCG are still immature, in prophase or metaphase 1. They are able to achieve meiosis in vitro in 66% of the cases and will be fertilized (2 PN) by ICSI in 51% of the cases as the in vivo mature oocytes of the same cohort. Nevertheless, the quality of cytoplasmic maturation and consequently of embryonic viability remains to be assessed as there still are few pregnancies arising from in vitro matured oocytes. ICSI also represents the only way to obtain normal fertilization in some exceptional but observed anomalies of oocyte maturation, particularly when there is a lack of zona reaction leading to repetitive polyspermy in conventional IVF.

Adult↗