Cristina Wide Pissetti

Genetic and Functional Role of TNF-alpha in the Development Trypanosoma cruzi Infection

TNF-alpha plays an important role in trypanocidal mechanisms and is related to tissue injury. This cytokine has been detected in the heart of human chagasic patients where it is associated with tissue damage. This study investigated whether TNF-alpha levels and the presence of genetic polymorphisms are associated with the presence of T. cruzi infection and/or with the development of the cardiac form in chronic chagasic patients. Genomic DNA of 300 subjects from an endemic area was extracted and analyzed by PCR using specific primers. TNF-alpha was assayed in culture supernatants by ELISA. An association was observed between the absence of the TNF-238A allele and negative serology. Furthermore, seropositive individuals carrying the TNF-238A allele produced significantly higher TNF-alpha levels without stimulation (p = 0.04) and after stimulation with LPS (p = 0.007) and T. cruzi antigens (p = 0.004). The present results suggest that the polymorphism at position -238 influences susceptibility to infection and that this allele is associated with higher TNF-alpha production in seropositive individuals.

Genotoxic effects of anesthetics in operating room personnel evaluated by micronucleus test

Exposure to certain chemical agents causes damage to the genetic material. There is controversy about the genotoxic and/or mutagenic effect caused by acute or chronic anesthetics exposure. The aim of this research was to assess and compare the frequency of micronuclei (MN) in professionals working in operating rooms and other hospital areas. The genotoxic and cytotoxic effects were evaluated in lymphocytes using the micronucleus test and the proliferative index, respectively. We examined peripheral blood lymphocyte cultures from 30 operating room professionals (exposed group) and 30 professionals non-exposed in other hospital areas of the same hospital (control group). There was no statistically significant difference in proliferative index between the groups. Nevertheless, there was an increase in MN frequency in binucleated (BN) cells in the exposed group (p=0.0003) compared to the control group. Moreover, there was a statistically significant difference between genders (p=0.0187), and the frequency of MN in BN cells from women was higher than in men. Therefore, gender influenced the frequency of MN. The age and period of working time in an operating room influenced the MN frequency only in women professionals. Thereby, there was a genotoxic effect in occupationally exposed professionals, and the micronucleus test could be used in the biomonitoring of human populations for evaluating the risk of developing cancer.

CASPASE-8 gene polymorphisms (rs13416436 and rs2037815) are not associated with preeclampsia development in Brazilian women

Abstract Background: Preeclampsia is responsible for considerable mortality and morbidity of mother and sibling. The etiology of preeclampsia is still unknown. Family studies indicate the involvement of genes located on chromosome 2 in preeclampsia development. Considering the importance of apoptosis and chromosome 2, one promising candidate for the study of the genetic cause of this syndrome is the CASPASE-8 gene, which was chosen as the subject of this study. Objective: The aim of this study was to determine the frequencies of the genotypes for CASP8 gene polymorphisms (rs13416436 and rs2037815) and to associate these with preeclampsia development in Brazilian women. Methods: Women with and without preeclampsia were investigated. Accordingly, peripheral blood was collected and DNA extracted, followed by genotyping using Real-time PCR with hydrolysis probe (Taqman® Life Technologies). Results: The results showed no association between genotypes and preeclampsia development for both polymorphisms studied (χ2 = 1.03; p = 0.59, for rs13416436 and χ2 = 1.06; p = 0.58 for rs2037815). Conclusions: It seems that CASP8 gene polymorphisms (rs13416436 and rs2037815) are not important candidates for the development of preeclampsia. Other genes related to the apoptosis process or other polymorphisms in this gene should be studied in order to understand better the etiology of preeclampsia.

Papel protetor do alelo G do polimorfismo no gene Interleucina 10 (-1082G/A) contra o desenvolvimento de pré-eclâmpsia

PURPOSE To identify the frequency of polymorphism in the IL-10 gene, rs1800896 (-1082 A/G), in women with preeclampsia (PE) and in women in a control group and to associate the presence of this polymorphism with protection against the development of PE. METHODS This was a case-control study conducted on 54 women with PE, classified according to the criteria of the National High Blood Pressure Education Program, and on 172 control women with at least two healthy pregnancies. The proposed polymorphism was studied by the technique of real time polymerase chain reaction (qPCR), with hydrolysis probes. Statistical analysis was performed using the χ2 test. Odds ratio and confidence interval of 95% were used to measure the strength of association between the studied polymorphism and the development of PE. RESULTS Statistically increased frequency of the AG genotype was observed among control women (85 versus 15% in women with PE). The G allele was significantly more frequent among control women than PE women (χ2 test, p = 0.01). The odds ratio for carriers of the G allele was 2.13, indicating a lower risk of developing PE compared to non-carriers. CONCLUSIONS Thus, an association is suggested to occur between the presence of the G allele of the polymorphism in the IL-10 rs1800896 (-1082 A/G) gene and protection against the development of PE. More studies investigating the contribution of these variations and the mechanisms by which they affect the risk of developing PE still need to be undertaken.

Polymorphism in the lymphotoxin-alpha gene, position +252 (rs909253), is not associated with preeclampsia development in Brazilian women

PURPOSE To investigate the frequencies of polymorphic allele and genotypes for the LT-α gene, position +252 (rs909253), in Brazilian women with preeclampsia. METHODS This is a case-control study, in which 30 women with preeclampsia, classified according to the criteria of the National High Blood Pressure Education Program, and 115 women in the control group, with at least two healthy pregnancies, were selected. Peripheral blood was collected, and DNA was extracted, followed by genotyping, using specific primers and restriction analysis. The genotypes obtained were AA, AG and GG. Statistical analysis was performed using the χ2 association test. The Hardy-Weinberg Equilibrium was tested using the Haploview Program. RESULTS The results showed no association between genotypes and preeclampsia development (χ2=2.0; p=0.4). When the AG and GG genotypes were grouped according to allele G presence or absence (genotype AA), the data showed that the presence of allele G was not significantly different between cases (women with preeclampsia) and controls (χ2=0.0; p=1.0). The LT-α gene polymorphism, position +252 (rs909253), seems not to be an important candidate for the development of preeclampsia. Other inflammatory genes should be researched, and studies involving gene-environment interactions should be performed, in order to reach a better understanding of the etiology of the preeclampsia.