RESUMEN
In some IVF cycles, no fresh embryo transfer in the stimulated cycle is advisable. The cryopreservation of zygotes and the transfer of blastocysts in a cryo-embryo transfer is an option to circumvent an inadequate uterine environment due to risk of ovarian hyperstimulation syndrome, inappropriate endometrium build up, endometrial polyps or uterine myomas. For this strategy, highly secure and safe cryopreservation protocols are advisable. This study describes a protocol for aseptic vitrification of zygotes that results in high survival rates and minimizes the potential risk of contamination in liquid nitrogen during cooling and long-term storage. In mouse zygotes, there was no difference in efficiency as compared with a conventional open vitrification system. In IVF patients, aseptically vitrified zygotes showed no difference in blastocyst formation rate as compared with sibling zygotes kept in fresh culture. A clinical study comprising 173 cryo-cycles with a transfer of blastocysts originating from vitrified zygotes showed an ongoing pregnancy rate of 40.9%. The live birth rate per patient was 36.8%. A combination of good clinical results and increased safety conditions due to aseptic vitrification encourages the use of cryo-embryo transfer for patients with a suboptimal uterine environment in a fresh cycle. In stimulated IVF cycles, high doses of hormones are given to stimulate multifollicular growth. One drawback of the hormonal substitution is that the uterine environment is not at the same time optimally prepared for embryo implantation. A solution, which is increasingly under discussion, is to cryopreserve the embryos obtained in the stimulated cycle and to transfer them back into the optimal uterine environment in a subsequent cryo-cycle. This procedure requires highly secure and safe cryopreservation protocols in order to ensure benefits for both pregnancy and birth rates. We have established a protocol for the vitrification of zygote-stage embryos in aseptic devices, which minimize the potential risk of contamination during cooling and storage. The vitrified zygotes showed the same blastocyst development as compared with sibling zygotes in fresh culture. A clinical study comprising 173 cryo-cycles with transfer of blastocysts originating from vitrified zygotes shows an ongoing pregnancy rate of 40.9%. The live birth rate per patient was 36.8%. A combination of good clinical results and increased safety conditions due to aseptic vitrification conditions contributes to a change in transfer strategy and encourages us to increase the cryo-embryo transfer rate for an optimal uterine environment.
Asunto(s)
Criopreservación/métodos , Transferencia de Embrión , Infertilidad Femenina/terapia , Enfermedades Uterinas/etiología , Vitrificación , Cigoto , Adulto , Animales , Bélgica/epidemiología , Tasa de Natalidad , Criopreservación/instrumentación , Ectogénesis , Femenino , Humanos , Infertilidad Femenina/complicaciones , Ratones , Ratones Endogámicos , Síndrome de Hiperestimulación Ovárica/epidemiología , Síndrome de Hiperestimulación Ovárica/fisiopatología , Embarazo , Índice de Embarazo , Distribución Aleatoria , Estudios Retrospectivos , Riesgo , Enfermedades Uterinas/complicaciones , Enfermedades Uterinas/epidemiología , Adulto JovenRESUMEN
Spermatozoa selection at high magnification before intracytoplasmic sperm injection seems to be positively associated with pregnancy rates after day 3 embryo transfers. The aim was to demonstrate an association between the presence of vacuoles in sperm nuclei and the competence of embryos to develop to day 5. Grading of spermatozoa at x 6000-x 12,500 magnification: grade I, no vacuoles; grade II,
Asunto(s)
Blastocisto/citología , Desarrollo Embrionario , Espermatozoides/ultraestructura , Adulto , Núcleo Celular/ultraestructura , Transferencia de Embrión , Femenino , Humanos , Recién Nacido , Infertilidad Masculina/patología , Infertilidad Masculina/terapia , Masculino , Embarazo , Resultado del Embarazo , Inyecciones de Esperma Intracitoplasmáticas/métodos , Vacuolas/ultraestructuraRESUMEN
To determine the best day for the selection and transfer of a single embryo, a prospective, randomized study was undertaken that compared the ongoing pregnancy rate (PR) after single embryo transfer (SET) on day 3 with that after single blastocyst transfer (SBT) on day 5. Our results show an overall significantly higher PR after SBT (32.8%) compared with SET (23.2%), and a PR of 40.8% after SBT versus 25.6% after excellent-quality embryos became available.
Asunto(s)
Transferencia de Embrión/tendencias , Adulto , Femenino , Humanos , Embarazo , Índice de Embarazo/tendencias , Estudios Prospectivos , Factores de TiempoRESUMEN
BACKGROUND: The aim of this study was to investigate whether a higher incidence of hyperinsulinism is found in women who have suffered from ovarian hyperstimulation syndrome (OHSS) as compared with other IVF patients. Additionally, we also assessed whether any abnormalities in the haemostatic system were more frequent in women with a past history of OHSS. METHODS: A pilot study was carried out involving OHSS patients and matched IVF patients. Homeostasis model assessment (HOMA) of insulin sensitivity was calculated. The main outcome measures were: insulin sensitivity, coagulation anomalies, factor V Leiden mutations, methylene tetrahydrofolate reductase (MTHFR) polymorphism and prothrombin gene mutation, protein C and protein S deficiency. RESULTS: No increased incidence in hyperinsulism nor in abnormalities of the haemostatic system were observed. CONCLUSIONS: This pilot study does not provide evidence for an increased prevalence of hyperinsulinism among women who have developed OHSS in the past.
Asunto(s)
Síndrome de Hiperestimulación Ovárica/metabolismo , Adulto , Factor V/genética , Femenino , Predisposición Genética a la Enfermedad/genética , Humanos , Hiperinsulinismo/etiología , Metilenotetrahidrofolato Reductasa (NADPH2) , Mutación , Síndrome de Hiperestimulación Ovárica/complicaciones , Síndrome de Hiperestimulación Ovárica/genética , Síndrome de Hiperestimulación Ovárica/fisiopatología , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/genética , Polimorfismo Genético , Protrombina/genética , Factores de Riesgo , Índice de Severidad de la Enfermedad , Trombosis/etiología , Trombosis/genéticaRESUMEN
The potato (Solanum tuberosum L.) mitochondrial cox3/ sdh4 gene cluster was previously identified by heterologous hybridization using a Marchantia polymorpha sdh4 probe. In this work, this potato gene cluster was cloned, sequenced and its expression was evaluated. The gene sequence and gene locus organization were found to be similar to the corresponding gene cluster in other dicot species, where known. Northern hybridizations with potato and cauliflower (Brassica oleraceae) mtRNA and RT-PCR analyses using potato mtRNA indicated that cox3 and sdh4 are co-transcribed in both species, generating a complex transcription pattern, where several transcripts from 1.1 kb to 4.4 kb are found. The potato transcript from this cluster displayed 14 and 13 RNA-editing sites, in the cox3 and sdh4 genes respectively, which changed the codon identity to amino acids and created a sdh4 partially edited stop codon. Forty-three cDNA clones were analyzed for editing process and revealed different partial-editing with no apparent sequential processing in the sdh4 gene.
Asunto(s)
Proteínas de Arabidopsis , ADN Mitocondrial/genética , Complejo IV de Transporte de Electrones/genética , Genes de Plantas , Proteínas de la Membrana/genética , Proteínas de Plantas/genética , Edición de ARN , Solanum tuberosum/genética , Transcripción Genética , Secuencia de Bases , Secuencia Conservada , Expresión Génica , Datos de Secuencia Molecular , ARN/genética , ARN Mitocondrial , Homología de Secuencia de Ácido NucleicoRESUMEN
Previous investigations have shown that the lipid composition of cerebral membranes and dopaminergic neurotransmission are changed under chronic alpha-linolenic acid diet deficiency in the rat. This study investigated whether these changes could be reversed and if the stage of brain maturation might play a role in the recovery process. The effects of reversion on the fatty acid (FA) composition and dopaminergic neurotransmission were studied in brain regions known to be affected by such deficiency (i.e., the prefrontal cortex and nucleus accumbens) in 2-month-old animals. Dopamine release under pharmacological stimulation was studied using a dual-probe microdialysis method. Vesicular monoamine transporters were studied using quantitative autoradiography. The reversal diet, with adequate levels of n-6 and n-3 polyunsaturated fatty acids (PUFAs), was given to deficient rats at different stages of development (0, 7, 14, or 21 days of age). The results showed that when given during the lactating period, this diet was able to restore both the FA composition of brain membranes and the parameters of dopaminergic neurotransmission studied. However, when given from weaning, it allowed partial recovery of biochemical parameters but no recovery of neurochemical factors. The occurrence of profound n-3 PUFA deficiency during the lactating period could therefore be an environmental insult leading to irreversible damage to specific brain functions.