Meningiomas: An Overview of the Landscape of Copy Number Alterations in Samples from an Admixed Population.

Meningiomas are considered the most common intracranial tumors, affecting mainly women. Studies in mixed populations can be of great importance to clarify issues related to the genetic diversity of tumors and their development. Considering that data obtained from analyses of the profile of copy number alterations (CNA) have been a useful diagnostic indicator for many types of tumors and that meningiomas show a complex pattern of gains and losses in the number of copies, our objective was to analyze the CNA profile in 33 samples of meningiomas of different histological grades (WHO Grade I-III) from patients in a city located in the Amazon region of Brazil, using aCGH. We found that the female to male ratio was 3 : 1. The aCGH analysis revealed a total of 2304 CNA, with an average of 69.8 ± 57.4 per case, of which 1197 were gains (52%), 926 were losses (40.2%), 105 were amplifications (4. 5%), and 76 were deletions (3.3%). A significant relationship was observed between the type of CNA and the degree of the tumor (chi-square test: χ 2 = 65,844; p < 0.0001; contingency coefficient: C = 0.1772; p < 0.0001). Evaluating the recurrent changes in at least 50% of the samples, we observe as the most frequent losses of the segments 22q13.1-q13.2 (82%), 1p35.3 (76%), and 14q13.1-q13.2 (67%), involving all histopathological grades. The analysis of these regions showed the inclusion of genes with functions such as regulation, maintenance of cell survival, reorganization of the cytoskeleton, cell signaling, and DNA repair, among others. However, overall, the profiles observed in meningiomas of this admixed population were very similar to the ones observed in Caucasian groups. An interesting finding was a recurrent gain of 8p22 observed only in grade I meningiomas, a region which includes DLC1, a suppressor candidate gene probably implicated in the developments or progression of meningiomas, usually found deleted, when related to CNAs.

Chronic intoxication by methylmercury leads to oxidative damage and cell death in salivary glands of rats.

Methylmercury (MeHg) is one of the most toxic species of mercury, causing several systemic damages; however, its effect on the salivary glands has rarely been explored to date. This study was aimed at analyzing the mercury deposit, oxidative stress markers, and cell viability in parotid and submandibular rat salivary glands after chronic methylmercury intoxication. Herein, forty male Wistar rats (40 days old) were used in the experiment. The animals of the experimental group were intoxicated by intragastric gavage with MeHg at a dose of 0.04 mg per kg body weight per day for 35 days, whereas the control group received only corn oil, a diluent. After the period of intoxication, the glands were obtained for evaluation of total mercury deposit, cell viability, and the malondialdehyde (MDA) and the nitrite levels. Our results indicated mercury deposits in salivary glands, with a decrease in cell viability, higher levels of MDA in both glands of intoxicated animals, and a higher concentration of nitrite only in the submandibular gland of the mercury group. Thus, the intoxication by MeHg was able to generate deposits and oxidative stress in salivary glands that resulted in a decrease in cell viability in both types of glands.

Distribuição dos fenótipos de grupos sangüíneos ABO e Lewis na presença de indicadores patológicos em uma população infantil da cidade de Belém do Pará / Dostribution of the phenotypes of blood groups ABO and Lewis in the presence of pathological indicators in an infantile population of Belém city

Na região Amazônica, infecções entéricas e outras parsitoses gastrointestinais têm um papel central na patogênese da desnutrição infantil e no retardo do crescimento. Foram estudadas 150 crianças da população de Belém (Pará-Brasil) a fim de identificar associações entre as infecções parasitárias intestinais e os grupos sangüíneos ABH e Lewis. Observou-se uma freqüência significativa do fenótipo secretor de substância H, particularmente nos grupos sangüíneos O/A2, associada com essas infecções e outras alterações hematológicas. Estas condições também foram consideradas como uma das causas das discordância entre os fenótipos Lewiw salivar e sangüíneo. A assoociação parece ser biologicamente aceita, desde que estes marcadores genéticos têm sido correlacionados com as doenças infecciosas através da aderência de microorganismo às células epiteliais com especificidades fenótípicas