Correlação entre a taxa de fertilização e o fuso meiótico em oócitos humanos: Uma meta-análise

Objective: To investigate the relationship between the presence of meiotic spindle in human oocytes and fertilization rates in ICSI cycles. Methods: Search strategies included online surveys of databases from 1990 to 2008. Nine trials fulfilled the inclusion criteria Results: According to the meta-analysis, the results showed statistically significant higher fertilization rate (p<0.0001) when the meiotic spindle was viewed than when it was not. There was heterogeneity in this comparison. Conclusion: The presence of a birefringent meiotic spindle in human oocytes can predict a higher fertilization rate. This observation has clinical relevance mainly in countries where there is a legal limit on the number of oocytes to be fertilized. Copyright - SBRA - Sociedade Brasileira de Reprodução Assistida.

Revisando os efeitos da concentração de oxigênio sobre o desenvolvimento embrionário

Despite the fact that the processes of embryo development and implantation of mammals do not occur in atmospheric tension in vivo, it is common practice in laboratories for in vitro fertilization (IVF) the culture of embryos in an oxygen tension of 20%. The discrepancy between the tensions of oxygen leads to important discussions about their effects in vitro embryo development. It is believed that the culture of embryo in atmospheric oxygen tension can be detrimental to the quality of the data for predisposing them to the negative interference of reactive oxygen species (ROS), resulting in oxidative stress, leading to deleterious effects on metabolism embryo gene expression and blastocysts grown in those conditions. Faced with arguments for and against the culture of embryos in vitro oxygen tensions similar to those found in vivo, this revies article aims to condense and discuss the literature concerning the influence of oxygen tension on the quality of in vitro culture.

Cost-effectiveness comparison between pituitary down-regulation with a gonadotropin-releasing hormone agonist short regimen on alternate days and an antagonist protocol for assisted fertilization treatments

Objective: To compare cost-effectiveness between pituitary down-regulation with a GnRH agonist (GnRHa) short regimen on alternate days and GnRH antagonist (GnRHant) multidose protocol on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcome. Design: Prospective, randomized. Setting: A private center. Patient(s): Patients were randomized into GnRHa (n = 48) and GnRHant (n = 48) groups. Intervention(s): GnRHa stimulation protocol: administration of triptorelin on alternate days starting on the first day of the cycle, recombinant FSH (rFSH), and recombinant hCG (rhCG) microdose. GnRHant protocol: administration of a daily dose of rFSH, cetrorelix, and rhCG microdose. Main Outcome Measure(s): ICSI outcomes and treatment costs. Result(s): A significantly lower number of patients underwent embryo transfer in the GnRHa group. Clinical pregnancy rate was significantly lower and miscarriage rate was significantly higher in the GnRHa group. It was observed a significant lower cost per cycle in the GnRHa group compared with the GnRHant group ($5,327.80 ± 387.30 vs. $5,900.40 ± 472.50). However, mean cost per pregnancy in the GnRHa was higher than in the GnRHant group ($19,671.80 ± 1,430.00 vs. $11,328.70 ± 907.20). Conclusion(s): Although the short controlled ovarian stimulation protocol with GnRHa on alternate days, rFSH, and rhCG microdose may lower the cost of an individual IVF cycle, it requires more cycles to achieve pregnancy. Clinical Trial Registration Number: NCT01468441. © 2013 by American Society for Reproductive Medicine.

Índice preditor de reserva ovariana (ORPI) para controle de estimulação ovariana individualizado

Objective: to expand the evaluation of a new ovarian response prediction index (ORPI), which was based on the AMH, AFC and age, and to verify its reability as a predictor of ovarian response to stimulation in assisted reproductive technology (ART) cycles. Methods: A total of 129 patients enrolled in the ICSI programme were included. The ORPI values were calculated by multiplying the AMH level (ng/ml) by the number of antral follicles (2-9 mm), and the result was divided by the age (years) of the patient (ORPI=(AMH × AFC)/Patient age). Results: Spearman's test revealed significant correlations (P<0.0001) between the ORPI and the number of oocytes collected and the number of follicles. Logistic regression revealed that ORPI values were significantly associated with the likelihood of collecting ≥4 oocytes (OR=45.56), ≥4 MII oocytes (OR=6.01) and ≥15 oocytes (OR=6.15; P<0.0001). Based on the ROC curves, the ORPI accurately predicted a low ovarian response (<4 oocytes retrieved; area under the curve (AUC):0.91), collection of ≥4 MII oocytes (AUC:0.85) and an excessive ovarian response (≥15 oocytes retrieved; AUC:0.89). Conclusions: The ORPI exhibited an excellent ability to predict a low ovarian response and a good ability to predict a collection of ≥ 4 MII oocytes, an excessive ovarian response. The ORPI might be used to improve the cost-benefit ratio of ovarian stimulation regimens by guiding the selection of medications and by modulating the doses and regimens according to the actual needs of the patients. © Todos os direitos reservados a SBRA - Sociedade Brasileira de Reprodução Assistida.

Efeito do tratamento com extrato de pituitaria equina (EPE) e hCG no índice de recuperação de oócitos e maturação folicular em equinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Agonista versus antagonista do GnRH em ciclos de reprodução assistida: morfologia oocitária

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Agonista versus antagonista do GnRH em ciclos de reprodução assistida: DNA fragmentação e apoptose das células da granulosa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da resposta inflamatória no soro e líquido folicular em pacientes com anovulação crônica submetidas a hiperestimulação ovariana controlada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A influência da ativação oocitária artificial com ionóforo de cálcio A23187 em pacientes submetidos a ciclos de injeção intracitoplasmática utilizando diferentes origens de espermatozóides

Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB

O direito na era das novas tecnologias reprodutivas: modelo jurídico hegemônico e heterogeneidade na parentalidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Correlação da maturação e da morfologia do oócito humano com as características do fuso meiótico e da zona pelúcida

Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB

Artificial activation of bovine and equine oocytes with cycloheximide, roscovitine, strontium, or 6-dimethylaminopurine in low or high calcium concentrations

Knowledge on parthenogenetic activation of oocytes is important to improve the efficiency of nuclear transfer (NT) and intracytoplasmic sperm injection (ICSI) because artificial activation of oocyte (AOA) is an essential step to achieve embryo production. Although different procedures for AOA have been established, the efficiency of in vitro production of embryos remains low, especially in equines and Bos taurus bovines. In an attempt to improve the techniques of NT and ICSI in bovine and equine species, we tested different combinations of drugs that had different mechanisms of action for the parthenogenetic activation of oocytes in these animals. The oocytes were collected, in vitro matured for 24 to 30 h and activated artificially, in the presence of low or high concentrations of calcium, with combinations of calcium ionophore (ionomycin) with cycloheximide, roscovitine, strontium, or 6-dimethylaminopurine (6-DMAP). For assessment of activation rates, oocytes were stained with Hoechst 33342 and observed under an inverted microscope. We showed that all combinations of drugs were equally efficient in activating bovine oocytes, with the best results obtained when high concentrations of calcium were adopted. For equine oocytes, high concentrations of calcium were not beneficial for the parthenogenetic activation and the combination of ionomycin with either 6-DMAP or roscovitine was effective in inducing artificial activation of oocytes. We believe that our preliminary findings provide some clues for the development of a better AOA protocol to be used with these species.

Preservation of wild feline semen by freeze-drying: experimental model

According to the Convention on International Trade in Endangered Species, 36 wild feline species are threatened by extinction or severely endangered, and to save them is the target of several conservation programs. This study aimed to assess the viability of the freeze-drying technique for domestic cat sperm cells, with the ultimate goal of transferring this technology to the wild feline species. The domestic cat is an excellent experimental model for wild felids. It is in this scenario that the freeze-drying process (low-temperature vacuum dehydration) of sperm cells shows its value in preserving male cats' germplasm. Results from membrane and DNA integrity analysis are promising and validates the use of frozen-dried sperm samples in intracytoplasmic sperm injections (ICSIs). Further studies are still necessary to evaluate the ICSI embryo production using domestic cat frozen-dried sperm and the possibility of using such technology with wild felines.

Biotecnologias aplicadas à reprodução de éguas velhas

The acceptance of biotechnology for the most equine breeders association had a significant effect in the horse industry, gaining popularity around the world, because the increasing on the genetic gain, allowing the use of sub fertile mares and stallions with high genetics value on reproduction. The embryos in vitro production of human and cattle has been used with success, however in vitro embryo production is not efficient in the horse, as oocyte transfer (OT) and intracytoplasmatic sperm injection (ICSI). The oocyte transfer has been used especially in subfertile old mares presenting reproductive pathologies as: endometrite, cervical and uterine adhesions, blocked oviduct, perineal laceration and ovulation failures. During oocyte recovery process, the oocytes must be collected from immature follicles that need be matured in vitro or in vivo matured oocytes from pre-ovulatory follicles through the transvaginal aspiration guided by ultrasound. The recovered oocyte is transferred to a previously inseminated recipient mare, through the flank laparotomy. The intracytoplasmatic sperm injection (ICSI) is a procedure of in vitro fertilization that needs only one sperm that is aspirated and injected inside the oocyte. The oocytes used, can be from mature and immature follicles. Fresh, cooled and frozen semen can be used, because the procedure not requires a functional sperm. The use of Piezo drill resulted in a breakthrough the pellucid zone, allowing the vibration per minute provided in the sperm injection pipette, a major result of cleaved oocytes, due to a better sperm injection in the oocyte. The embryo transfer can be straight inside the oviduct, as also transcervical transferred after embryo culture produced in vitro. In conclusion both procedures (OT and ICSI) are effective to be used on equine assisted reproduction, getting results even lower than expected, but satisfactory from animal genetically superior

Injeção Intracitoplasmática de Espermatozoide em Equinos

As técnicas de reprodução assistida utilizadas para os equinos estão em grande desenvolvimento, mesmo com a escassa disponibilidade de ovários de abatedouro para serem feitos estudos e a relação animal/indivíduo entrando, neste caso, a política do bem estar animal e outros fatores que serão discutidos ao longo desta revisão. Podemos afirmar que a técnica de ICSI promove resultados favoráveis à evolução da reprodução assistida, juntamente com outras técnicas, as quais muitas vezes são utilizadas para aprimorar o desenvolvimento e a produção de embriões, não mais necessitando do animal em si e sim de novas técnicas em produção in vitro. Oócito equino tolera o estresse de injeção mecânica de espermatozoides no ooplasma, ou seja, há grande viabilidade da técnica em discussão. O sêmen de baixa qualidade ou com baixo número de espermatozóides pode ser utilizado, seguramente na ICSI, o método pode ser uma ferramenta para avaliar a maturação citoplasmática ou mesmo para substituir outras técnicas já descritas em literatura, mas que não alcançaram a eficiência esperada