Publications by authors named "Helena Pereira da Silva Zamith"

Introduction: Monitoring water quality in mobile dialysis (MD) services, assessing critical points and characterizing the risks inherent in the process, is essential to avoid risks to the patient's health. This study evaluated the microbiological quality of water in the MD of 36 hospitals with intensive treatment in the city of Rio de Janeiro.

Methods: 204 water samples were collected from the points of entry to the network (NET), post-osmosis (PO) and dialysis solution (DS).

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Chronic exposure to benzene is a risk factor for hematological malignancies. Gasoline-station workers are exposed to benzene in gasoline, via both inhalation and dermal contact (attendants and managers) or inhalation (workers in the on-site convenience stores and offices). We have studied the exposure of these workers to benzene and the resulting genotoxic and immunotoxic effects.

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Some of the adverse side-effects such as leukocytosis, hyperinsulinemia, hypoglycemia and sensitization to histamine, caused by diphtheria, tetanus and whole cell pertussis (DTwP) vaccines are related to the presence of non-inactivated pertussis toxin (PTx) residues (NiPTxR). The CHO cell clustering assay is an in vitro assay to measure NiPTxR in DTwP vaccines based on the ability of active PTx to cause cellular clustering. To study the biochemical mechanism involved in the clustering effect in CHO cells induced by PTx and by two DTwP vaccines, the levels of total cyclic cAMP were measured and compared to those obtained after treatment with cholera toxin (CTx) able to induce CHO cells elongation instead of cell clustering.

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Background: Only benznidazole (Bnz) (1) and nifurtimox (Nfx) (2) are licensed for the treatment of Chagas disease although their safety and efficacy profile are far from ideal. Farmanguinhos from Fiocruz has developed seven nitroimidazole compounds (4-10) analogs of megazol (3).

Objectives: To evaluate whether the genotoxic effect of 3 was abolished in the seven nitroimidazoles (4-10) analogs using the in vitro alkaline comet assay (CA) and the in vitro cytokinesis-block micronucleus assay (CBMN) in whole human blood cells (WHBC) and correlate this effect with their trypanocidal activity using bloodstream trypomastigote forms of Trypanosoma cruzi.

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Megazol (7) is a 5-nitroimidazole that is highly active against Trypanosoma cruzi and Trypanosoma brucei, as well as drug-resistant forms of trypanosomiasis. Compound 7 is not used clinically due to its mutagenic and genotoxic properties, but has been largely used as a lead compound. Here, we compared the activity of 7 with its 4H-1,2,4-triazole bioisostere (8) in bloodstream forms of T.

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