ABSTRACT
RESUMO Objetivo: A síndrome de Leigh é uma doença neurodegenerativa com incidência de 1:40.000 nados-vivos. Apresenta ampla heterogeneidade clínica, bioquímica e genética, mas com alterações neuropatorradiológicas homogêneas. Não existe tratamento específico, e o prognóstico é reservado. O objetivo deste estudo foi familiarizar os profissionais de saúde com a doença. Descrição do caso: Menina de 16 meses, com hipotonia axial e atraso do desenvolvimento psicomotor. Dos exames realizados: cariótipo, potenciais auditivos evocados e avaliação oftalmológica normais; presença de hiperlactacidemia e hipocitrulinemia. Após a realização de ressonância magnética cerebral sob anestesia, observou-se agravamento da hipotonia com necessidade de internação por episódios de cianose/apneia. O eletroencefalograma não mostrou atividade epileptiforme. A neuroimagem revelou hipersinal lenticular bilateral com lesão do putâmen e do globo pálido esquerdo. Encontrou-se a mutação 8993T>G (MT-ATP6) no DNA mitocondrial. Comentários: De 10 a 30% dos doentes com síndrome de Leigh apresentam mutações do DNA mitocondrial. A descompensação com agravamento neurológico após intervenção anestésica está descrita e, nesse caso, apoiou o diagnóstico. Importante alertar para casos semelhantes, com diminuição de exames invasivos para diagnóstico.
ABSTRACT Objective: Leigh syndrome is a neurodegenerative disorder with an incidence of 1:40,000 live births. It presents wide clinical, biochemical, and genetic heterogeneity, but with homogenous neuropatoradiological alterations. There is no specific treatment, and the prognosis is reserved. This case report aimed familiarize health professionals with the disease. Case Description: A 16-month-hold girl who was followed in outpatient clinic due to axial hypotonia and delayed psychomotor development. Karyotype, auditory evoked potentials and ophthalmologic evaluation were normal. Evidence of hyperlactacidemia and hypocitrullinemia was detected in the patient. After performing brain magnetic resonance under anesthesia, hypotonia got worse, and the patient was hospitalized after an episode of cyanosis and apnea. The electroencephalogram showed no epileptiform activity. Neuroimaging revealed bilateral lenticular hyperintensity, especially in the putamen and in the left globus pallidus regions. Molecular analysis revealed an 8993T>G (MT-ATP6) mutation in the mitochondrial DNA. Comments: Between 10 and 30% of individuals with Leigh syndrome have mitochondrial DNA mutations. The decompensation after anesthetic intercurrences is typically associated with neurological deterioration and, in this case, increased the diagnosis suspicion. It is important to alert for similar cases and to reduce invasive diagnostic tests if the diagnosis is suspected.
Subject(s)
Humans , Female , Infant , DNA, Mitochondrial/genetics , Leigh Disease/genetics , MutationABSTRACT
There are evidences that Bryconamericus aff. iheringii represents a species complex. DNA molecular markers have been effective in studies on phylogeny, taxonomy, and identification of cryptic species. In this study, partial sequences of genes of ATPase 6 and 8 were used to assess genetic diversity within and among populations of B. aff. iheringii of sub-basins of Tibagi, Pirapó and Ivaí rivers, belonging to the Upper Paraná river basin. The analysis of the sequences of genes pointed out high genetic diversity in B. aff. iheringii from the sub-basins studied with genetic distance values comparable to those found among different species. There was a division of the individuals into five groups. The comparison with other species of Bryconamericus that have sequences available in GenBank confirmed that the individuals studied have relevant values of genetic distance, found among different species. Nevertheless, with the available data it is not possible to refute the hypothesis that the populations correspond to a group resulting from hybridization or that there might have been introgression of mitochondrial DNA among different species.
Há indícios de que Bryconamericus aff. iheringii represente um complexo de espécies. Os marcadores moleculares de DNA têm sido eficazes em estudos de filogenia, taxonomia e identificação de espécies crípticas. Neste estudo, as seqüências parciais de genes da ATPase 6 e 8 foram utilizados para avaliar a diversidade genética dentro e entre populações de B. aff. iheringii das sub-bacias dos rios Tibagi, Pirapó e Ivaí, pertencentes a bacia do Alto Rio Paraná. As análises das seqüências dos genes apresentaram alta diversidade genética em B. aff. iheringii das sub-bacias estudadas, com valores de distâncias genéticas semelhantes às encontradas entre espécies diferentes. Houve uma divisão dos indivíduos em cinco grupos. A comparação com outras espécies de Bryconamericus que têm seqüências disponíveis no GenBank confirmou que os indivíduos estudados possuem valores relevantes de distância genética encontrados entre espécies diferentes. No entanto, com os dados disponíveis não é possível descartar a hipótese de que as populações correspondem a um grupo resultante de hibridação, nem que houve introgressão de DNA mitocondrial entre espécies diferentes.
Subject(s)
Adenosine Triphosphatases , Characidae , Characiformes , Genetic MarkersABSTRACT
Characidae is the largest and more diversified family from Characiformes and presents several classification problems, with several genera currently allocated as incertae sedis, such as the genus Hemigrammus. The upper Paraná river floodplain is an environment with high fish diversity. There is at least one species of Hemigrammus, however there are divergences among some authors about the number and the identification of the species from this genus. Therefore the goal of this study was to characterize, using a molecular approach, individuals of Hemigrammus from the upper Paraná river floodplain and to compare them with individuals from the type locality of Hemigrammus marginatus, since this is the only species distributed in this floodplain. For this, the DNA was extracted and a partial region from the mitochondrial genes ATPase 6 and ATPase 8 were amplified and sequenced. The results evidenced the existence of two species of Hemigrammus in the floodplain, although impossible to be distinguished only through morphological traits. High nucleotide diversity among individuals from the upper Paraná river in relation to those from the type locality was also observed, indicating that both species of Hemigrammus present in the upper Paraná river floodplain are not Hemigrammus marginatus.
Characidae é a maior e mais diversificada família de Characiformes e apresenta vários problemas de classificação, com inúmeros gêneros alocados atualmente como incertae sedis, dentre estes Hemigrammus. A planície de inundação do alto rio Paraná é um ambiente com alta diversidade de peixes. Existe neste ambiente pelo menos uma espécie de Hemigrammus, entretanto, existem divergências entre alguns autores quanto ao número e a identificação das espécies deste gênero. Portanto, o objetivo deste trabalho foi realizar a caracterização molecular de indivíduos de Hemigrammus da planície de inundação do alto rio Paraná e compará-los com exemplares da localidade-tipo de Hemigrammus marginatus, tendo em vista ser esta a única espécie identificada de Hemigrammus com distribuição na referida planície. Para isso, foi extraído o DNA, amplificado e sequenciado uma região parcial dos genes mitocondriais ATPase 6 e ATPase 8. Os resultados demonstraram a existência de duas espécies de Hemigrammus na planície de inundação do alto rio Paraná, embora impossíveis de serem diferenciadas apenas pelos caracteres morfológicos utilizados atualmente. Alta diversidade nucleotídica entre os exemplares do alto rio Paraná em relação aos da localidade-tipo também foi observada, indicando que ambas as espécies de Hemigrammus presente na planície de inundação do alto rio Paraná não são da espécie Hemigrammus marginatus.
Subject(s)
Animals , DNA , DNA, Mitochondrial , Adenosine Triphosphatases , Characiformes , CharacidaeABSTRACT
To investigate the effects of hyperoxia on mitochondrial multienzyme complex Ⅲ (cytochrome, Cytb) and V (ATPase6, 8) in premature newborn rat lung, the l-day-old preterrn SD rats were randomly assigned to hyperoxia group and air group. The rats in hyperoxia group were con- tinuously exposed to 85% oxygen and those in air group to room air. After 1, 4, 7, 10, 14 day(s) of exposure, these rats were killed, total lung RNA was extracted and Cytb, ATPase6, 8 mRNA were detected by reverse transcription polymerase chain reaction (RT-PCR). Western blotting was used to detect the expression of Cytb protein in lung tissue. The results showed that compared with air group, Cytb mRNA expression was significantly increased (P>0.05) after 1, 4 day(s) of exposure. The general tendency decreased after 7 days, and its expression became weak but difference in mRNA expression between the two groups was not significant (P>0.05). ATPase6 mRNA expression was significantly increased 1 day after the exposure (P<0.05) and did not show any significant change 4, 7, 10 days after the exposure (P>0.05). At the 14th day, ATPase6 mRNA expression was significantly increased (P<0.05). ATPase8 mRNA expression did not show any significant change 1, 4, l0 day(s) after the exposure (P>0.05). At the 7th and 14th day, ATPase8 mRNA expression was significantly increased (P<0.05). Western blotting showed that Cytb protein expression was increased 1,4 day(s) after the exposure, but the difference between the two groups was not significant (P>0.05). The gen- eral tendency was decreased after 7 days, and its expression became weak but difference was not sig- nificant 7, 10 days after the exposure (P>0.05). At day 14 its expression became significantly weak (P<0.05). We are led to conclude that exposure to high concentrations of oxygen can significantly change the expression of Cytb and ATPase6, 8, which results in uncoupling of oxidative phosphorylation in mitochondrial respiration chain, and plays an important role in the mechanism of hyperoxia-induced lung injury.