Trichomonas vaginalis is the etiological agent of trichomoniasis, the most common non-viral sexually transmitted disease (STD) in world, with 276.4 million new cases each year. T. vaginalis can be naturally infected with Mycoplasma hominis and Trichomonasvirus species. This study aimed to evaluate the prevalence of T. vaginalis infected with four distinct T. vaginalis viruses (TVVs) and M. hominis among isolates from patients in Porto Alegre city, South Brazil. An additional goal of this study was to investigate whether there is association between metronidazole resistance and the presence of M. hominis during TVV infection. The RNA expression level of the pyruvate ferredoxin oxidoreductase (PFOR) gene was also evaluated among metronidazole-resistant and metronidazole-sensitive T. vaginalis isolates. A total of 530 urine samples were evaluated, and 5.7% samples were positive for T. vaginalis infection. Among them, 4.51% were isolated from female patients and 1.12% were from male patients. Remarkably, the prevalence rates of M. hominis and TVV-positive T. vaginalis isolates were 56.7% and 90%, respectively. Most of the T. vaginalis isolates were metronidazole-sensitive (86.7%), and only four isolates (13.3%) were resistant. There is no statistically significant association between infection by M. hominis and infection by TVVs. Our results refute the hypothesis that the presence of the M. hominis and TVVs is enough to confer metronidazole resistance to T. vaginalis isolates. Additionally, the role of PFOR RNA expression levels in metronidazole resistance as the main mechanism of resistance to metronidazole could not be established. This study is the first report of the T. vaginalis infection by M. hominis and TVVs in a large collection of isolates from South Brazil.

Tissue accumulation of homocysteine occurs in classical homocystinuria, a metabolic disease characterized biochemically by cystathionine β-synthase deficiency. Vascular manifestations such as myocardial infarction, cerebral thrombosis, hepatic steatosis, and pulmonary embolism are common in this disease and poorly understood. In this study, we investigated the effect of chronic hyperhomocysteinemia on some parameters of oxidative stress (thiobarbituric acid-reactive substances, protein carbonyl content, 2',7'-dichlorofluorescein fluorescence assay, and total radical-trapping antioxidant potent) and activities of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) in the rat lung. Reduced glutathione content and glucose 6-phosphate dehydrogenase activity, as well as nitrite levels, were also evaluated. Wistar rats received daily subcutaneous injections of Hcy (0.3-0.6 μmol/g body weight) from the 6th to the 28th days-of-age and the control group received saline. One and 12 h after the last injection, rats were killed and the lungs collected. Hyperhomocysteinemia increased lipid peroxidation and oxidative damage to protein, and disrupted antioxidant defenses (enzymatic and non-enzymatic) in the lung of rats, characterizing a reliable oxidative stress. In contrast, this amino acid did not alter nitrite levels. Our findings showed a consistent profile of oxidative stress in the lung of rats, elicited by homocysteine, which could explain, at least in part, the mechanisms involved in the lung damage that is present in some homocystinuric patients.

N-Acetylaspartic acid (NAA) accumulates in Canavan disease, a severe inherited neurometabolic disorder clinically characterized by mental retardation, hypotonia, macrocephaly, and seizures. The mechanisms of brain damage in this disease remain poorly understood. Recent studies developed by our research group showed that NAA induces oxidative stress in vitro and in vivo in cerebral cortex of rats. Lipoic acid is considered as an efficient antioxidant which can easily cross the blood-brain barrier. Considering the absence of specific treatment to Canavan disease, this study evaluates the possible prevention of the oxidative stress promoted by NAA in vivo by the antioxidant lipoic acid to preliminarily evaluate lipoic acid efficacy against pro-oxidative effects of NAA. Fourteen-day-old Wistar rats received an acute administration of 0.6 mmol NAA/g body weight with or without lipoic acid (40 mg/kg body weight). Catalase (CAT), glutathione peroxidase (GPx), and glucose 6-phosphate dehydrogenase activities, hydrogen peroxide content, thiobarbituric acid-reactive substances (TBA-RS), spontaneous chemiluminescence, protein carbonyl content, total antioxidant potential, and DNA-protein cross-links were assayed in the cerebral cortex of rats. CAT, GPx activities, and total antioxidant potential were significantly reduced, while hydrogen peroxide content, TBA-RS, spontaneous chemiluminescence, and protein carbonyl content were significantly enhanced by acute administration of NAA. Those effects were all prevented by lipoic acid pretreatment. Our results clearly show that lipoic acid may protect against the oxidative stress promoted by NAA. This could represent a new therapeutic approach to the patients affected by Canavan disease.

SYNOPSIS

Diante da onipresença das tecnologias digitais móveis na vida das crianças, observa-se que são produzidos novos modos pelos quais a criança explora o mundo. Este estudo qualitativo, exploratório e descritivo pretendeu explorar o brincar com os tablets e seus desdobramentos. Participaram do estudo quatro crianças em idade pré-escolar (3 a 6 anos), residentes na região metropolitana de Porto Alegre, que faziam uso dos tablets em seu cotidiano. Observações de hora de jogo foram realizadas em três diferentes momentos em uma brinquedoteca. O estudo apontou que a criança prefere o brincar com tablets ao brincar não digital e que ele pode ser importante no desenvolvimento de algumas habilidades cognitivas. Entretanto, devido ao predomínio de um brincar criança-tela, prejuízos no desenvolvimento motor e nas interações interpessoais que acontecem no mundo real podem ser notados. A partir das observações constata-se que o brincar com tablets não se opõe ao brincar não digital, apenas acontece em um outro domínio e se apresenta como um novo e ainda pouco explorado universo representacional, podendo coexistir com outras modalidades de brincar.