ABSTRACT
The advent of in vitro fertilization (IVF) in animals and humans implies an extraordinary change in the environment where the beginning of a new organism takes place. In mammals fertilization occurs in the maternal oviduct, where there are unique conditions for guaranteeing the encounter of the gametes and the first stages of development of the embryo and thus its future. During this period a major epigenetic reprogramming takes place that is crucial for the normal fate of the embryo. This epigenetic reprogramming is very vulnerable to changes in environmental conditions such as the ones implied in IVF, including in vitro culture, nutrition, light, temperature, oxygen tension, embryo-maternal signaling, and the general absence of protection against foreign elements that could affect the stability of this process. The objective of this review is to update the impact of the various conditions inherent in the use of IVF on the epigenetic profile and outcomes of mammalian embryos, including superovulation, IVF technique, embryo culture and manipulation and absence of embryo-maternal signaling. It also covers the possible transgenerational inheritance of the epigenetic alterations associated with assisted reproductive technologies (ART), including its phenotypic consequences as is in the case of the large offspring syndrome (LOS). Finally, the important scientific and bioethical implications of the results found in animals are discussed in terms of the ART in humans.
Subject(s)
Humans , Animals , Fertilization in Vitro/ethics , Developmental Biology/ethics , Epigenomics/ethics , Mammals/growth & development , Superovulation/ethics , Risk , Reactive Oxygen Species/metabolism , Preimplantation Diagnosis , Bioethical Issues , Embryo Culture Techniques/methods , Embryonic Development/drug effects , Genes, Developmental/physiologyABSTRACT
A literatura aponta que crianças com diagnóstico de deficiência visual e outras deficiências associadas estão em risco de desenvolvimento. No presente estudo, foram observadas três crianças com esse perfil (quatro a 10 anos), no contexto de grupos de convivência, com o intuito de identificar indícios de desenvolvimento e exemplos de apropriação de práticas sociais. Deu-se destaque aos diferentes usos de objetos, à participação em atividades e à linguagem como lugares para se observar esses processos. Foi realizado estudo de caso e análise microgenética. As sessões semanais foram filmadas e transcritas. Recortou-se o material documentado em episódios que fossem significativos para o propósito do estudo. A análise evidenciou a importância dos processos de significação na constituição dos sujeitos. Os resultados foram discutidos em termos de suas implicações para programas de intervenção.
Studies on the development of children with visual impairment associated with other disabilities indicate risks for development. In the present study, three children with this profile (aged four to 10 years) were observed in social group contexts. The aim was to identify indications of development and examples of appropriation of social practices. In order to visualize those processes, the study focused on different uses of objects, participation in activities and language. A case study and microgenetic analysis were carried out. Weekly sessions were filmed and transcribed; episodes were selected from the material that had been registered according to relevance related to the purpose of the study. The analysis showed the importance of signification processes for the constitution of subjects. The results were discussed in terms of implications for intervention programs.
ABSTRACT
É relatado o caso de uma criança cega congênita de quatro anos, com alterações no desenvolvimento, analisado de acordo com as concepções de linguagem constitutiva (Franchi, 1977/1992) e mediação semiótica (Rodríguez & Moro, 1999). Sete sessões de intervenção, compreendendo um intervalo de dois anos, foram transcritas e analisadas. A adaptação da metodologia utilizada por Rodríguez e Moro permitiu que se observassem as aquisições de uso de objetos (desde usos menos convencionais até usos mais convencionais), a participação em brincadeiras (ex: acompanhamento de cantigas infantis) e o surgimento de diferentes modos de comunicação. A análise deu significado a diferentes aspectos da interação entre a criança e adultos, expandindo a proposta das autoras, em relação ao papel da mediação semiótica. Discutem-se as implicações do estudo para a área de Educação Especial.
The case of a 4 year old congenitally blind child, with developmental alterations, was analyzed, according to assumptions of constitutive language (Franchi, 1977) and semiotic mediation (Rodríguez & Moro, 1999). Seven sessions of intervention were transcribed and analyzed, comprising a period of two years. The adaptation of the methodology of Rodríguez & Moro allowed the observation of the following aspects: the acquisition of use of objects (from less conventional uses to more conventional uses), the participation in play activities (eg: nursery rhymes) and the appearance of different modes of communication. Different aspects of the adult-child interaction were given significance, expanding the scope of the original proposition in relation to the role of semiotic mediation. The implications of the study to the area of Special Education were discussed.