965 resultados para FETAL ABNORMALITIES


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Cocaine is a widely used drug and its abuse is associated with physical, psychiatric and social problems. Abnormalities in newborns have been demonstrated to be due to the toxic effects of cocaine during fetal development. The mechanism by which cocaine causes neurological damage is complex and involves interactions of the drug with several neurotransmitter systems, such as the increase of extracellular levels of dopamine and free radicals, and modulation of transcription factors. The aim of this review was to evaluate the importance of the dopaminergic system and the participation of inflammatory signaling in cocaine neurotoxicity. Our study showed that cocaine activates the transcription factors NF-κB and CREB, which regulate genes involved in cellular death. GBR 12909 (an inhibitor of dopamine reuptake), lidocaine (a local anesthetic), and dopamine did not activate NF-κB in the same way as cocaine. However, the attenuation of NF-κB activity after the pretreatment of the cells with SCH 23390, a D1 receptor antagonist, suggests that the activation of NF-κB by cocaine is, at least partially, due to activation of D1 receptors. NF-κB seems to have a protective role in these cells because its inhibition increased cellular death caused by cocaine. The increase in BDNF (brain-derived neurotrophic factor) mRNA can also be related to the protective role of both CREB and NF-κB transcription factors. An understanding of the mechanisms by which cocaine induces cell death in the brain will contribute to the development of new therapies for drug abusers, which can help to slow down the progress of degenerative processes.

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O objetivo deste estudo foi avaliar, por meio da ultrassonografia convencional modo B, as características sonográficas e a biometria dos rins de fetos caninos, bem como determinar os índices vasculares da artéria renal dos conceptos ao Doppler Triplex. Foram utilizadas 24 fêmeas Shi-tzu e Pugs pesando de quatro a 10 kg e com idade entre quatro e seis anos. Ao modo B, a ecobiometria renal fetal, a regularidade da superfície renal, a ecotextura e a relação córtico-medular foram avaliadas durante a quinta, sexta, sétima e oitava semanas gestacionais. Ao Doppler Triplex, durante o mesmo período em que se realizou o exame convencional, foram determinados o pico de velocidade sistólica (PVS), a velocidade diastólica final (EDV) e o índice de resistência vascular (RI) e de pulsatividade (PI). Ao modo B, não foram detectadas alterações em rins fetais, e à ecobiometria renal dos fetos, foi possível determinar medidas renais importantes, verificando-se aumento das biometrias no decorrer do desenvolvimento fetal (P<0,0001). Ao Doppler Triplex, determinaram-se os índices vasculares da artéria renal fetal, sendo que os valores para PSV e EDV aumentaram no decorrer das semanas gestacionais (P<0,05) e permaneceram constantes para PI e RI (P>0,05). Concluiu-se que o modo B e o Doppler Triplex são ferramentas importantes para a avaliação do desenvolvimento renal fetal, com a utilização da ecobiometria renal e avaliação dos indices vasculares da artéria renal de fetos caninos.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Problem The most common DNA lesion generated by oxidative stress (OS) is 7, 8-dihydro-8-oxoguanine (8-oxoG) whose excision repair is performed by 8-oxoguanine glycosylase (OGG1). We investigated OGG1 expression changes in fetal membranes from spontaneous preterm birth (PTB) and preterm premature rupture of the membranes (pPROM) and its changes in vitro in normal fetal membranes exposed to OS inducer water-soluble cigarette smoke extract (CSE). Method of study DNA damage was determined in amnion cells treated with CSE by comet and FLARE assays. OGG1 mRNA expression and localization in fetal membranes from clinical specimens and in normal term membranes exposed to CSE were examined by QRT-PCR and by immunohistochemistry. Results DNA strand and base damage was seen in amnion cells exposed to CSE. OGG1 expression was 2.5-fold higher in PTB samples compared with pPROM (P=0.045). No significant difference was seen between term and pPROM or PTB and term. CSE treatment showed a nonsignificant decrease in OGG1. OGG1 was localized to both amnion and chorion with less intense staining in pPROM and CSE-treated membranes. Conclusion Increased OS-induced DNA damage predominated by 8-oxoG is likely to persist in fetal cells due to reduced availability of base excision repair enzyme OGG1. This can likely lead to fetal cell senescence associated with some adverse pregnancy outcome.