The results suggest that inherited absence of this carcinogen detoxification pathway may not be associated with sporadic colorectal adenocarcinoma in the present cases. However, a higher frequency of GSTT1 null genotype in patients diagnosed before the age of 60 years suggests that this genotype could influence the age of disease onset in Brazil.

We investigated the influence of the polymorphism D104N of the COL18A1 gene, encoding endostatin, on the occurrence of sporadic breast cancer in 181 patients and 448 controls. The homozygous 104NN polymorphism was found in five patients but was absent in controls (2.8% vs 0.0%; P = 0.002). Individuals with this genotype had a significantly increased risk for disease. Our results suggest, for the first time, that the homozygous 104NN polymorphism, even at low frequency, constitutes an important inherited determinant of the disease.

These results suggest a role for the MTHFR 677TT plus 677CT genotype in increasing SCA diagnosed at a low age in southeastern Brazil, but additional studies with larger sample sizes should be carried out to clarify this issue.

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Previous studies have shown that under short photoperiod exposure spermatogenesis in golden hamster regresses leading to sexual inactivity. It is known that this regression is related to changes in somatic and germ cells (spermatocytes and spermatids). However, the photoperiod effects on spermatogonial biology have not been studied in detail yet. In this regard, this study was carried out to investigate the morphology, kinetics and niches of different spermatogonial types in golden hamsters under long- and short-photoperiod. Six spermatogonial generations such as type A undifferentiated (A(und)), type A differentiating (A(1), A(2), A(3)), intermediate (In) and type B spermatogonia were characterized, and were morphologically similar irrespective of the photoperiod exposure. The short photoperiod was inhibitory to A(und) spermatogonia and preleptotene but had no effect on the number of differentiating (A(1) to B) spermatogonia. In golden hamsters exposed to stimulatory-photoperiod, the interstitial components were positioned mainly in triangular areas around the seminiferous tubules and, in this situation, the A(und) spermatogonia were clearly positioned in niches (p < 0.05) in all stages studied. On the other hand, during the inhibitory-photoperiod where the seminiferous tubules have smaller diameter, the interstitial components were more homogenously distributed and the triangular areas were not clearly observed. In this case, the niches were identified only at stage VII (p < 0.05), although there was a trend of being positioned in niches area in all the stages studied. Thus, these findings suggest that the A(und) spermatogonia location in the seminiferous epithelium and the niche position are directly related to the position of the interstitial components.

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BackgroundHigh meat intake and low consumption of vegetables, fruits and whole grains have been associated with increased risk of colorectal cancer in some relevant cohort studies conducted in distinct ethnic populations. The role of the dietary pattern on the risk of sporadic colorectal adenocarcinoma (SCA) in Brazil is unknown; therefore, it was the aim of the present study.MethodsThe dietary patterns of 169 patients with SCA and 101 controls were analysed by food frequency recall. Crude odds ratios were calculated and given within 95 % confidence intervals.ResultsPatients reported higher average intakes of beef (32.0 ± 1.8 versus 23.7 ± 1.6, P = 0.0069), chicken (18.1 ± 0.9 versus 12.2 ± 0.8, P = 0.0002), and pork (8.9 ± 0.9 versus 3.4 ± 0.5, P < 0.0001). These individuals had a 1.025, 1.069, and 1.121-fold increased risk of SCA.Similar consumption of fish, vegetables, fruits and whole grains was reported by patients and controls.ConclusionsMeat consumption is greater in patients with SCA in the Brazilian population. Considering the study population – characterized by ethnic heterogeneity –, the environmental factor related to food habits may be associated with higher incidence of this disease in Brazil.