Evaluation of genotoxicity after acute and chronic exposure to 2,4-dichlorophenoxyacetic acid herbicide (2,4-D) in rodents using machine learning algorithms.

2,4-Dichlorophenoxyacetic acid (2,4-D) is one of the most widely used herbicides in the world, but its mutagenic and carcinogenic potential is still controversial. We simulated environmental exposure to 2,4-D, with the objective of evaluating the genotoxic effect of acute and chronic exposure to 2,4-D in rodents. We also evaluated the performance of machine learning algorithms in detecting differences in exposure groups through recognition performed from genotoxic characteristics. In the acute phase, 88 Swiss mice were used, distributed in five groups and exposed to nebulizations at different time intervals (24, 48, 72 and 192 hr). In the chronic phase, 88 Wistar rats were used, distributed in two groups (inhaled and oral) and exposed for six months. Femoral bone marrow cells were collected for a micronucleus test and comet assay. Data were evaluated by pattern recognition algorithms. In acute exposure, medium and high concentrations induced DNA damage in the comet assay, but these concentrations did not increase micronucleated cells. In the chronic exposure, there was an increase in micronuclei and DNA damage in the comet assay in all exposed groups regardless of the exposure route. The data showed a robust pattern of distinction between exposed and nonexposed groups to 2,4-D. Our data showed that both acute inhalation exposure and chronic oral and inhalation exposure to 2,4-D can cause genotoxic effects regardless of concentration. Machine learning showed a clear distinction between the control groups and those exposed to 2,4-D, and the effects of exposure are not concentration-dependent.

The influence of water pH on the genesis of cadmium-induced cancer in a rat model.

Cadmium is a heavy metal that is widely used in industry and can cause tumours in multiple organs. The purpose of our study was to investigate the effect of water pH in the genesis of cadmium-induced cancer. We divided 98 male Wistar rats into 7 groups: group A - 15 rats that received cadmium chloride (CdCl2- 400 mg/L) in their drinking water at a neutral pH of 7.0; group B - 15 rats that received CdCl2(400 mg/L) in their drinking water at an acidic pH of 5.0; group C - 15 rats that received CdCl2(400 mg/L) in their drinking water at a basic pH of 8.0; group D - 15 rats that received water at an acidic pH of 5.0; group E - 15 rats that received water at a basic pH of 8.0; group F - 15 rats that received water at a neutral pH of 7.0; and group G - 8 rats that were subcutaneously injected with a single dose of cyclophosphamide (50 mg/kg). Groups A through F were euthanised 6 months after the start of the experiment and group G was euthanised 24 hours after cyclophosphamide injection. We collected the liver, kidneys, pancreas, prostate, seminal vesicles and testes for histopathological analysis and the bone marrow for micronuclei testing. In all of the groups, neither neoplastic lesions nor an increase in micronuclei (p>0.05) were observed in the liver, kidney, pancreas, seminal vesicles and testes. We found that animals exposed to cadmium had grade one prostatic intraepithelial neoplasia, but this was found more frequently in animals from group B (p<0.05). The acidic pH increased the formation of pre-neoplastic lesions in the prostate glands of cadmium-exposed animals.

Cytopathology: a useful technique for diagnosing oral lesions?: a systematic literature review.

Oropharyngeal cancer is the 11th most common cancer worldwide. The diagnostic method of choice for oral cavity lesions is biopsy and pathological examination. Cytopathology is a simple and inexpensive method, but it is not yet widespread among dental professionals. The aim of this study was to evaluate the evidence for the effectiveness of cytopathology in diagnosing oral lesions. We conducted a systematic literature review of randomized clinical trials that compared the diagnostic accuracies of oral lesion cytology and histopathology. We used the following search terms: cytology, oral lesions, and oral cancer. The meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Between 1967 and 2010, there were 80 relevant articles in the literature, 14 of which were included in this study. The I-square for sensitivity was 80.2%, and the specificity value was 96.7%. The pooled sensitivity was 0.942 [95% confidence interval (CI): 0.926-0.955], and the pooled specificity was 0.970 (95% CI: 0.963-0.975). The area under the curve was 0.9901. Our study suggests that cytology has good sensitivity and specificity for the diagnosis of oral lesions and allows the use of other associated techniques, such as DNA analysis, which may improve the accuracy of cytology.