Software for animal randomization: A tool for increasing the reproducibility of science.

Poorly designed preclinical studies may compromise human health due to erroneous conclusions regarding treatment effects in addition to contributing to experimental irreproducibility and wasted resources. Randomization is one of the crucial steps to enhance scientific rigor and is a commonly recognized bias-reducing instrument that increases the reliability and reproduction of studies involving animals (even with syngeneic animals). This procedure should be considered when planning a study and reported during data publication. In this context, this work aimed to highlight the importance of adopting quality measures in preclinical trials, with an emphasis on animal randomization. The 'Mouse Randomization' app was developed to help researchers estimate an adequate sample size to obtain significant statistical power, ensuring the ethical use of animals. This app is freely available on the internet to carry out animal randomization and calculate sample sizes for in vivo experiments. We believe that this brief discussion about animal randomization could raise awareness among researchers on how to improve the quality of preclinical research, increasing reproducibility and avoiding animal misuse.

Comparative antifungal susceptibility analyses of Cryptococcus neoformans VNI and Cryptococcus gattii VGII from the Brazilian Amazon Region by the Etest, Vitek 2, and the Clinical and Laboratory Standards Institute broth microdilution methods.

Early diagnosis, efficient clinical support, and proper antifungal therapy are essential to reduce death and sequels caused by cryptococcosis. The emergence of resistance to the antifungal drugs commonly used for cryptococcosis treatment is an important issue of concern. Thus, the in vitro antifungal susceptibility of clinical strains from northern Brazil, including C. neoformans VNI (n = 62) and C. gattii VGII (n = 37), to amphotericin B (AMB), 5-flucytosine, fluconazole, voriconazole, and itraconazole was evaluated using the Etest and Vitek 2 systems and the standardized broth microdilution (CLSI-BMD) methodology. According to the CLSI-BMD, the most active in vitro azole was voriconazole (C. neoformans VNI modal MIC of 0.06 µg/ml and C. gattii VGII modal MIC of 0.25 µg/ml), and fluconazole was the least active (modal MIC of 4 µg/ml for both fungi). Modal MICs for amphotericin B were 1 µg/ml for both fungi. In general, good essential agreement (EA) values were observed between the methods. However, AMB presented the lowest EA between CLSI-BMD and Etest for C. neoformans VNI and C. gattii VGII (1.6% and 2.56%, respectively, P < .05 for both). Considering the proposed Cryptococcus spp. epidemiological cutoff values, more than 97% of the studied isolates were categorized as wild-type for the azoles. However, the high frequency of C. neoformans VNI isolates in the population described here that displayed non-wild-type susceptibility to AMB is noteworthy. Epidemiological surveillance of the antifungal resistance of cryptococcal strains is relevant due to the potential burden and the high lethality of cryptococcal meningitis in the Amazon region.

Detection and genotyping of Trypanosoma cruzi from açai products commercialized in Rio de Janeiro and Pará, Brazil.

BACKGROUND: Several cases of food-borne acute Chagas disease (ACD) have been reported in the Brazilian Amazon so far. Up to 2004, the occurrence of ACD by oral transmission, associated with food consumption, was rare. Recent cases of ACD in Brazil have been attributed to the consumption of juice from the açai palm containing reservoir animals or insect vectors waste, infected with Trypanosoma cruzi. This study aimed to determine the T. cruzi contamination rate and to genotype the parasite in food samples prepared from açai, which are commercialized in Rio de Janeiro and the Pará States in Brazil. METHODS: The amplificability of DNA extracted from açai samples, and T. cruzi and Triatominae detection were performed by conventional PCR. Molecular characterization was done by multilocus PCR analysis, to determine the parasite discrete type units (DTUs) based on the size of PCR products in agarose gels, using the intergenic region of the spliced leader (SL), 24 Sα rDNA and nuclear fragment A10 as targets. RESULTS: From the 140 samples of açai-based products analyzed, T. cruzi DNA was detected in 14 samples (10%); triatomine DNA was detected in one of these 14 samples. The parasite genotyping demonstrated that food samples containing açai showed a mixture of T. cruzi DTUs with TcIII, TcV and TcI prevailing. CONCLUSIONS: In this study, the molecular detection and identification of T. cruzi from açai-based manufactured food samples, was performed for the first time. Although parasite DNA is a marker of possible contamination during food manufacturing, our findings do not indicate that açai is a source of Chagas disease via oral transmission per se, as live parasites were not investigated. Nevertheless, a molecular approach could be a powerful tool in the epidemiological investigation of outbreaks, supporting previous evidence that açai-based food can be contaminated with T. cruzi. Furthermore, both food quality control and assessment of good manufacturing practices involving açai-based products can be improved, assuring the safety of açai products.

[Residual concentration of hexachlorocyclohexane in a contaminated site in Cidade dos Meninos, Duque de Caxias, Rio de Janeiro, Brazil, after calcium oxide treatment]. / Concentração residual de hexaclorociclohexano em área contaminada na Cidade dos Meninos, Duque de Caxias, Rio de Janeiro, Brasil, após tratamento com óxido de cálcio.

Hexachlorocyclohexanes (HCHs) are currently considered potentially carcinogenic to humans. In Brasil, severe soil contamination by HCHs has been identified at Cidade dos Meninos, Duque de Caxias, Rio de Janeiro, where an old HCH factory was abandoned 40 years ago, leaving 1,700 local residents at risk. Calcium oxide treatment was performed on the most heavily contaminated (focus) area. Analysis of superficial soil samples collected years after treatment still showed high residual HCH. Contamination levels as high as 6,200mg/Kg and 7,320mg/Kg were found for alpha- and beta-HCH isomers. For the gamma- and delta-HCH isomers, concentrations reached up to 140mg/Kg and 530mg/Kg, respectively. The results showed that calcium oxide treatment was not efficient to decontaminate the soil in this area.