Relationship between Oxidative Stress and Physical Activity in Women with Squamous Intraepithelial Lesions in a Cervical Cancer Control Program in the Brazilian Amazon.

Human papillomavirus (HPV) infection is recognized as the most common sexually transmitted disease in the world, and there is a consensus on its role in the etiology of preneoplastic epithelial changes in the cervix. Through the process of lipid peroxidation, oxidative stress is found in the course of premalignant and malignant changes. Moreover, the level of physical activity can exert an influence on markers of oxidative stress, lowering the serum levels of these markers. Objective. To determine the relationship between levels of malondialdehyde (MDA) and the level of physical activity in women with squamous intraepithelial lesion (SIL) of the cervix. Methods. A cross-sectional study was conducted with 46 women participating in a cervical cancer control program. The women had been submitted to the cytopathological exam and were divided into two groups: 18 with SIL and 28 controls. MDA concentrations were determined, and the International Physical Activity Questionnaire (IPAQ) was administered on the same day as the gynecological appointment (prior to the Papanicolaou test). Results. The SIL group had higher MDA levels than the control group (mean: 47.63 ± 9.57 vs. 9.32 ± 4.79, respectively) and a lower IPAQ score (median: 713.5 vs. 1875, respectively). A weak correlation was found between the MDA level and IPAQ score (r 2 = -0.34, p = 0.018). Conclusion. The women with SIL had higher levels of oxidative stress and were less physically active than the women in the control group. These findings suggest that physical exercise exerts an influence on markers of oxidative stress in the development of intraepithelial squamous lesions.

Somatosensory Psychophysical Losses in Inhabitants of Riverside Communities of the Tapajós River Basin, Amazon, Brazil: Exposure to Methylmercury Is Possibly Involved.

The purpose of this work was to evaluate the somatosensory system of methylmercury-exposed inhabitants living in the communities of the Tapajós river basin by using psychophysical tests and to compare with measurements performed in inhabitants of the Tocantins river basin. We studied 108 subjects from Barreiras and São Luiz do Tapajós, two communities of the Tapajós river basin, State of Pará, Amazon, Brazil, aged 13-53 years old. Mercury analysis was performed in head hair samples weighting 0.1-0.2 g by using atomic absorption spectrometry. Three somatosensory psychophysical tests were performed: tactile sensation threshold, vibration sensation duration, and two-point discrimination. Semmes-Weinstein 20 monofilaments with different diameters were used to test the tactile sensation in the lower lip, right and left breasts, right and left index fingers, and right and left hallux. The threshold was the thinner monofilament perceived by the subject. Vibration sensation was investigated using a 128 Hz diapason applied to the sternum, right and left radial sides of the wrist, and right and left outer malleoli. Two trials were performed at each place. A stopwatch recorded the vibration sensation duration. The two-point discrimination test was performed using a two-point discriminator. Head hair mercury concentration was significantly higher in mercury-exposed inhabitants of Tapajós than in non-exposed inhabitants of Tocantins (p < 0.01). When all subjects were divided in two groups independently of age-mercury-exposed and non-exposed-the following results were found: tactile sensation thresholds in mercury-exposed subjects were higher than in non-exposed subjects at all body parts, except at the left chest; vibration sensation durations were shorter in mercury-exposed than in non-exposed subjects, at all locations except in the upper sternum; two-point discrimination thresholds were higher in mercury-exposed than in non-exposed subjects at all body parts. There was a weak linear correlation between tactile sensation threshold and mercury concentration in the head hair samples. No correlation was found for the other two measurements. Mercury-exposed subjects had impaired somatosensory function compared with non-exposed control subjects. Long-term mercury exposure of riverside communities in the Tapajós river basin is a possible but not a definitely proven cause for psychophysical somatosensory losses observed in their population. Additionally, the relatively simple psychophysical measures used in this work should be followed by more rigorous measures of the same population.

Monitoring mercury exposure in reproductive aged women inhabiting the Tapajós river basin, Amazon.

Among Amazonian communities, exposure to methylmercury is associated mainly with fish consumption that may affect fetal development in pregnant women. Therefore a temporal assessment was performed to assess the exposure of reproductive aged women to mercury who reside in the riparian communities of São Luís do Tapajós and Barreiras located in the Tapajós basin of the Brazilian Amazon from 1999 to 2012. The total mercury concentration in the 519 hair samples was assessed by cold vapor atomic absorption spectrometry. Data analysis showed that the average total mercury concentration decreased from 1.066 to 0.743 µg/g in those years. In 1999 the proportion of volunteers with mercury levels ≥ 10 µg/g was approximately 68 %. In general, exposure to mercury decreased among women of reproductive age, but the potential risks to reproduction and human health is still an issue as 22 % of the woman continued showing high mercury levels (≥ 10 µg/g) in 2012.