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Biomedical subjects

P Aretini

Publications and source records attributed to P Aretini.

6 recordsLinked to original sources

Methyl group metabolism gene polymorphisms as modifier of breast cancer risk in Italian BRCA1/2 carriers.

BRCA1 and 2 are major cancer susceptibility genes but their penetrance is highly variable. The folate metabolism plays an important role in DNA methylation and its alterated metabolism is associated with cancer risk. The role of allele variants 677T and 1298C (MTHFR gene) and 2756G (MS gene) has been investigated as potentially modifying factors of BRCA gene penetrance, evaluated as age at first diagnosis of cancer, in 484 BRCA1/BRCA2 carriers and in 108 sporadic breast cancer cases as a control group. The genotype analysis has been performed by means of PCR/RFLP's. The analysis of association between a particular genotype and disease risk was performed using Cox Regression with time to breast or ovarian cancer onset as the end-point. The presence of 677T allele confers an increased risk of breast cancer in BRCA1 carriers (P = 0.007) and the presence of 1298C allele confers an increased risk of breast cancer in sporadic cases (P = 0.015).

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

Genetic alterations in hereditary breast cancer.

Genetic linkage studies have led to the identification of highly penetrant genes as the possible cause of inherited cancer risk in many cancer-prone families. Most women with a family history of breast/ovarian cancer have tumors characterized by alterations in particular genes, mainly BRCA1 and BRCA2, but also CHK2, ATM, STK11 and others. This paper examines the BRCA1 and BRCA2 genes, focusing on the Italian pattern of mutations. The function of these two genes, classified as tumor suppressors, is linked with key metabolic mechanisms such as DNA damage repair, regulation of gene expression and cell cycle control. The pathological BRCA allelic variants may cause alteration of protein function, transcriptional activity and DNA repair; accumulation of the defects leads to widespread chromosome instability that may be directly responsible for cancer formation. In fact, mutations in BRCA1 and BRCA2, conferring a highly increased susceptibility to breast and ovarian cancer, do not lead to cancer by themselves. The current consensus is that these are 'caretaker' genes, which, when inactivated, allow other genetic defects to accumulate. The nature of these other molecular events may define the pathway through which BRCA1 and BRCA2 act. The BRCA mutation spectrum is complex, and the significance of most nucleotide alterations is difficult to understand. Moreover, the mutation pattern seems to be related to ethnicity. The Italian Consortium of Hereditary Breast and Ovarian Cancer has reviewed 1758 families; 23% have been found to be carriers of pathogenetic mutations in BRCA1 or BRCA2. Founder mutations have been described in geographically restricted areas of Italy; a regional founder effect has been demonstrated in Italy for the mutations BRCA1 5083del19 and BRCA2 8765delAG, and a probable new founder mutation has been characterized in Tuscany. The presence of founder mutations has practical implications for genetic testing.

Adult↗

Antimutagenesis studies of magnesium and calcium salts.

Magnesium is a microelement that is essential for biological functions and particularly for cellular metabolism. It has a central role in protein, lipid, carbohydrate, and nucleic acid synthesis, and it is important for muscular physiology and nerve excitability. Magnesium has an important role in the stability of biological membranes, it controls immune phenomena, and it activates over 300 enzymes. However, the mechanism of action of magnesium salts has not been well investigated and, in particular, its antimutagenesis properties and its effects in the detoxification of free radicals need further study. We investigated the effect of magnesium chloride, sulphate, carbonate, and oxide on the yeast Saccharomyces cerevisiae D7 strain, to evaluate their ability to protect against genotoxic damage. We found that magnesium salts induced antimutagenic effects in the cells harvested in the logarithmic phase by decreasing the induction of hydrogen peroxide. This, however, did not occur in the stationary phase. We also studied calcium salts of the type corresponding to those of magnesium and their protective role against the oxidative damage of free radicals and enzymatic activities, such as catalase, glutathione peroxidase, and superoxide dismutase, which are involved in antioxidative defenses.

Antimutagenic Agents↗

Antimutagenesis and anticancer effects.

Cancer development is a multistage process wherein mutational events play an important role. Various antimutagen components, in particular magnesium and selenium, have been reported to have anticarcinogenic properties. These two oligoelements display different behaviors according to their concentrations. The different effects of magnesium and selenium depend on the different mechanisms of cell absorption. The importance of antimutagenesis studies in cancer prevention is reported and a review of the basic mechanisms operative in antimutagenesis, including some data on known antimutagens, is made.

Animals↗

HPV testing and Pap test: role for a combined approach in a non-screened population.

The aim of the present study was to test the polymerase chain reaction (PCR) as a tool to identify human papillomavirus (HPV) in routine cytological samples scraped from the uterine cervix. Moreover, attention has been focused on the correlation between HPV types and early intraepithelial lesions. The study involved 586 women who had undergone conventional Pap test. Analysis of HPV infection was performed by PCR and HPV typing by dot blot. In a group of 78 cases histologically diagnosed as high-grade squamous intraepithelial lesions (HSILs), the cytological diagnosis was correct in 92.3% and the HPV test was positive in 89.8% of cases; combined positivity at Pap and/or HPV tests raised this figure to 99.0%. In a group of 67 cases histologically diagnosed as low-grade squamous intraepithelial lesions (LSILs), the cytological diagnosis was correct in 73.1% and the PCR-based HPV test was positive in 64.2%; combined positivity at Pap and/or HPV tests raised this figure to 91.0%. This study confirms the limitations of screening programs based on Pap test only. Our results suggest, in fact, that adding the HPV test to primary screening could increase the yield of preinvasive cervical lesions.

Adult↗