Anais de Evento

In vitro maturation of human oocytes selected by brilliant cresyl blue staining

Helena Von Eye Corleta, E.G. VALÉRIO, M. CONZATTI, ANA PAULA DE SOUZA KUSSLER, ANITA MYLIUS PIMENTEL, D.D ALCOBA, J. TORNQUIST, I.S. BRUM

Em: ESHRE, 2013, London, v. 28, n. 0, p. 155-155.

Motivo: Produção Colaborador HMV

Setor HMV: Nucleo Reprodução Humana

Área da saúde: Outro

Resumo: Study question: Evaluate the efficiency and safety of Brilliant Cresyl Blue (BCB) staining as a selection of developmentally competent immature human oocytes before in vitro maturation (IVM). Summary answer: BCB test can be a good marker in pre-selection procedures of developmentally competent human oocytes and, apparently, it is not toxic to the gamete. What is known already: Growing oocytes synthesize glucose-6-phosphate dehydrogenase (G6PDH), but this enzyme is inactivated in oocytes that have completed their growth phase. Once BCB can be reduced by G6PDH, the selection of developmentally competent oocytes before IVM by BCB staining is widely used for many animal species (bovine, porcine, mice, etc). Using animal models, it has been already demonstrated that this selection can improve not only nuclear and cytoplasmic oocyte maturation, but also fertilization and blastocyst rates. Study design, size, duration: Cross sectional experiment – control versus treatment groups. Three kinds of patients were included in the study: 6 hormonal stimulated patients with immature oocytes at retrieval (17 oocytes); 3 ooforectomized patients (20 oocytes recovered); and 32 pregnant patients during cesarean section (92 oocytes recovered). Participants/materials, setting, methods: Immature oocytes were divided into groups: control (disposed directly to IVM) and treated - exposed to BCB 26 mM during 60 minutes. After staining, treated group was classified as cytoplasm coloration, BCB positive or negative, and then disposed to IVM. After 24 and 48 hours of IVM nuclear status was checked. Main results and the role of chance: The IVM rate of immature oocytes recovered from stimulated and ooforectomized patients was equal among groups (control, BCB positive and BCB negative) either after 24 or 48 hours of IVM. Nevertheless, IVM was higher in BCB positive compared to BCB negative after 24 and 48 hours of IVM analyzing oocytes recovered from all patients (P ¼ 0.024 and P ¼ 0.015) and from cesarean patients (P ¼ 0.004 and P ¼ 0.032). The control group was equal to BCB positive. The meiosis resumption rate (absence of germinal vesicle) after 24 hours of IVM was equal among groups, but higher in BCB positive compared to other groups after 48 hours when all gametes were analyzed jointly (P ¼ 0.035). Degeneration rate was lower in BCB positive compared to their counterparts when oocytes were analyzed jointly (P ¼ 0.002). Limitations, reason for caution: Human oocytes that can be destined to research are limited.We have to look for effects of ovarian puncture during cesarean section after some years. As the eggs were not fertilized, embryo characteristics were not accessed; so the effects ofBCBon human embryo development remain unknown. Wider implications of the findings: In human oocytes theIVMrate ofBCBpositive was higher than that observed for BCB negative, but equal to control group. The degeneration rate was lower in BCB positive oocytes, compared to other groups (control and BCB negative). These results were similar to that described in animals. Study funding/competing interest(s): The experimentwas supported by university hospital and it has not any vested conflict.

Link: http://www.posters2view.eu/eshre2013/data/93.pdf

Envie um e-mail para os autores