Abstract Oral mucositis (OM) is a painful inflammatory oral condition that affects children who undergo chemotherapy. Oxidative stress is a known OM mediator and pro-inflammatory cytokines contribute to the amplification of the immune response. Objective: To investigate the possible associations of rs4880 (superoxide dismutase 2, SOD2 47 C/T), rs7943316 (catalase, CAT −21 A/T), rs1800629 (tumor necrosis factor α, TNF- α −308 G/A), and rs1800795 (interleukin 6, IL-6 −174 G/C) polymorphisms with chemo-induced OM occurrence and severity in oncopediatric patients. Methodology: We conducted a single-center, observational cross-sectional study with sample collection of oral epithelial cells from 95 children and adolescents with hematological cancers who underwent chemotherapy, followed by genomic DNA extraction. Single-nucleotide polymorphisms (SNPs) were assessed with PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). Demographic data and information concerning OM occurrence were obtained from dental charts of the multidisciplinary oral care team. Information on OM severity was obtained from appropriately-filled Oral Assessment Guide records. Descriptive and inferential statistics were conducted with Student's T test, chi-squared test, and Fisher's exact test, with p≤0.05. Results: The mean age was 10 years-old and most patients were male individuals (57.89%). Female sex was considered a protective factor for OM occurrence (OR=4.83; CI=[1.14; 16.57]). The AA genotype for CAT was the most frequent amongst individuals with severe OM (p=0.04). The GA genotype for TNF- α was the most frequent amongst individuals without severe OM (p=0.03). For SOD2 and IL-6 , the most frequent genotypes were CT and GG respectively for all groups (p>0.05). Conclusion: The AA genotype for CAT −21 A/T was a tendency among the group with severe OM. Data on TNF- α −308 G/A were inconclusive. No associations were detected for SOD2 47 C/T and IL-6 −174 G/C polymorphisms in oncopediatric patients with chemo-induced oral mucositis.

Abstract The association between Periodontitis and Systemic Lupus Erythematosus (SLE) has been primarily based on their similar pathophysiology and both are associated with genetic polymorphisms. Objectives: To investigate an association between the methylation-related gene polymorphisms DNMT3B (rs2424913) and MTHFR (rs1801133) to Systemic Lupus Erythematosus (SLE) and Periodontitis. Methodology: In total, 196 individuals of all genders aged 24 to 60 years old were allocated into four groups based on their systemic and periodontal status, namely: Healthy control (n=60), periodontitis (n=51), SLE (n=47), and SLE + periodontitis (n=38). Individuals with SLE were stratified according to disease activity (SLEDAI) in inactive or active. We performed polymorphism analysis using PCR-RFLP with genomic DNA from mouthwash. We analyzed data using Fisher’s Exact, Chi-square test, and regression models. Results: Periodontal status were similar in subjects with periodontitis alone and combined with SLE. SLE patients with periodontitis had a longer SLE diagnosis than SLE only (p=0.001). For DNMT3 B polymorphism, the periodontitis, SLE, and Inactive SLE + periodontitis groups showed a higher frequency of T allele and TT genotypes compared to healthy controls (p<0.05). Regression analyses showed that the TT genotype is a strong risk factor for periodontitis (OR=4.53; CI95%=1.13–18.05) and also for SLE without periodontitis (OR=11.57; CI95%=3.12–42.84) and SLE with periodontitis (OR=5.27; CI95%=1.25–22.11) when compared to control. Conclusion: SLE patients with periodontitis had a longer length of SLE diagnosis. The DNMT3B (rs2424913) polymorphism was associated with periodontitis and SLE alone or combined with periodontitis. Our study contributes to understanding the genetic mechanisms involved in periodontitis and SLE susceptibility.

Abstract Background: the biological activity of vitamin D depends on the activity of its receptor or VDR. On the other hand, the activity of this receptor is influenced by its state of methylation. The objective of this study was to verify if the BsmI polymorphism of the VDR gene influences its methylation profile in adolescents. Secondly, it was to verify if the status of some metabolic factors (oxidative stress, inflammation, lipid profile, and glycemia) in the serum, and gender-adjusted vitamin D levels are independent factors with an influence on the VDR methylation profile. Methods and results: the study included 198 adolescents of both sexes, aged 15-19 years, who underwent testing for VDR gene methylation polymorphisms, serum vitamin D levels, and metabolic, oxidative stress, and systemic inflammation markers. It was observed that the BB genotype was less methylated than the other groups (26.1 % versus 30.3 %, and 29.3 % for Bb and bb, respectively), although without statistical differences between them. The odds ratio indicated a protection of 13 % (partially methylated) for vitamin D status, while alpha glycols increased the risk ratio (of being partially methylated) by 3 %. MDA was protective at a 28 % chance of risk that adolescents with higher levels of lipid peroxidation would be hypomethylated. Conclusion: we conclude that the methylation profile of the VDR gene is not influenced by the different BsmI polymorphism genotypes, and that serum vitamin D and serum markers of oxidative stress and inflammation can modulate this profile.

Resumen Antecedentes: la actividad biológica de la vitamina D depende de la actividad de su receptor, el VDR. Por otro lado, la actividad de este receptor está influenciada por su estado de metilación. El objetivo de este estudio es verificar si el polimorfismo BsmI del gen VDR influye en el perfil de metilación del mismo en los adolescentes. En segundo lugar, verificar si los factores metabólicos (estrés oxidativo, inflamación, perfil lipídico y glucemia) del suero y la vitamina D ajustada por sexo actúan independientemente de los polimorfismos sobre el perfil de metilación del VDR. Métodos y resultados: el estudio incluyó a 198 adolescentes de ambos sexos, de 15 a 19 años de edad, que se sometieron a análisis de polimorfismos de metilación del gen VDR, niveles de vitamina D, marcadores metabólicos, estrés oxidativo e inflamación sistémica. Se observó que el genotipo BB estaba menos metilado que los otros grupos (26,1 % contra 30,3 % y 29,3 % para Bb y bb respectivamente), aunque sin diferencias estadísticas entre ellos. El odds ratio indicó una protección del 13 % (parcialmente metilado) para el estado de la vitamina D, mientras que los alfa glicoles aumentaron el índice de riesgo (de estar parcialmente metilado) en un 3 %. La MDA fue protectora con un 28 % de probabilidad de riesgo de que los adolescentes con niveles más altos de peroxidación lipídica fueran hipometilados. Conclusión: concluimos que el perfil de metilación del gen VDR no está influenciado por los diferentes genotipos del polimorfismo BsmI y que la vitamina D y los marcadores de estrés oxidativo e inflamación en el suero pueden modular este perfil.

Resumo O presente estudo investigou a relação entre cinco polimorfismos genéticos e o desenvolvimento de mucosite oral em pacientes pediátricos recebendo quimioterapia com metrotexato. O estudo longitudinal foi conduzido com 64 pacientes e a mucosite oral avaliada pelo Oral Assessment Guide modificado, que tem como objetivo diagnosticar e classificar a mucosite oral. Células epiteliais bucais foram obtidas por bochecho e o DNA foi extraído. Os polimorfismos MTHFR (rs1801133), DNMT3B (rs2424913), ABCC2 (rs717620), ABCG2 (rs2231137) e ABCG2 (rs2231142), foram analisados pela técnica de PCR-RFLP. Dados demográficos, hematológicos e bioquímicos foram coletados a partir de registros médicos. Análise estatística foi realizada utilizando o software SPSS adotando um valor de p=0,05. Observou-se que, o sexo masculino foi predominante (56,2%), e a idade média foi de 10,8 anos (± 4.9). A mucosite oral acometeu 65,6% dos pacientes, dos quais, 61,9% desenvolveram a forma grave da doença. Para o gene ABCG2 (rs2231142), o alelo raro A e o genótipo CA foram mais frequentes em indivíduos com mucosite (p= 0.02; RR = 0.60; CI = 0.387 - 0.813). A gravidade da doença foi observada principalmente em pacientes mais jovens (mediana = 9 anos; p=0.02). Além disso, os pacientes com mucosite oral grave apresentaram menor contagem de leucócitos (mediana = 2150 mm3) em comparação aos pacientes com a forma leve/moderada (mediana = 4200 mm3; p=0.03). Pacientes do sexo feminino e aumento a cada 10.000 plaquetas foram fatores de proteção contra o aparecimento de mucosite oral (p=0.02). Concluiu-se que a presença do polimorfismo rs2231142 aumenta o risco de o paciente desenvolver a mucosite oral, bem como pacientes mais jovens e menor contagem de leucócitos contribui com a severidade.

Abstract The study investigated the relationship between genetic polymorphisms and the development of oral mucositis in pediatric patients undergoing chemotherapy involving methotrexate. A longitudinal study was conducted with 64 patients, and oral mucositis was evaluated by the modified Oral Assessment Guide, which aims to diagnose and classify oral mucositis. Epithelial cells were obtained by mouthwash and DNA was extracted. The polymorphisms MTHFR (rs1801133), DNMT3B (rs2424913), ABCC2 (rs717620), ABCG2 (rs2231137) and ABCG2 (rs2231142) were analyzed by PCR-RFLP method. Demographic, hematological and biochemical data were collected from medical records. Statistical analysis was performed using the SPSS software adopting a p-value of 0.05. Male sex predominated (56.2%), and the mean age was 10.8 years (± 4.9). Oral mucositis affected 65.6% of the patients, of which 61.9% developed the severe form of the disease. For the ABCG2 gene (rs2231142), the rare A allele and CA genotype were more frequent in individuals with mucositis (p= 0.02; RR = 0.60; CI = 0.387 - 0.813). The severity of the disease was mainly observed in younger patients (median = 9 years; p=0.02). Patients with severe oral mucositis presented lower leukocytes count (median = 2.150 mm3) compared to patients with the mild/moderate form (median = 4.200 mm3; p=0.03). Female patients and each 10,000-platelet increase were protective factors against the onset of oral mucositis (p=0.02). It is concluded that rs2231142 polymorphism increases the likelihood of oral mucositis and younger patients and patients with low leukocytes counts are more likely to develop severe form.

Abstract Objective: to verify the association of serum concentrations of 25-hydroxyvitamin D and glycemic levels with the genetic variants rs1544410 and rs2228570 of the VDR gene in adolescents from the Northeast region of Brazil. Materials and methods: a cross-sectional epidemiological study with 208 adolescents from public schools in the city of João Pessoa (Paraíba, Brazil) between 15 and 19 years of age. Blood samples were collected for DNA extraction and analysis of polymorphisms rs1544410 and rs2228570, as well as biochemical analyses (25-hydroxyvitamin D, parathyroid hormone, calcium and glycemia). Results: the mean age was 17.7 (± 1.14) years. Half of adolescents had sufficient serum levels of 25-hydroxyvitamin D and the other half had insufficient/deficient vitamin. The most frequent genotypic distribution was bb and Ff and of lesser frequency BB and ff. There was a significant relationship between the genotypes of rs1544410 and glycemia values (p = 0.049) in the relationships between the genotypes BBxbb (p = 0.012) and Bbxbb (p = 0.037); (p = 0.036, OR = 2.15, 95 % CI = 1.05-4.41), and in the BB+Bb group analysis when compared to the bb (p = 0.025, OR = 1.89, 95 % CI = 1.08-3.29) presented higher risk of glycemia above the median. On the other hand, when Bb+bb was analyzed in relation to BB, adolescents had a greater chance of blood glucose below the median (p = 0.025, OR = 0.66, CI = 0.47-0.95). Conclusion: this study showed a significant relation of glycemia with the distribution of rs1544410 polymorphism genotypes.

Resumen Objetivo: verificar la asociación de las concentraciones séricas de 25-hidroxivitamina D y los niveles de glucemia con las variantes genéticas rs1544410 y rs2228570 del gen VDR en adolescentes de la región noreste de Brasil. Materiales y métodos: se realizó un estudio epidemiológico transversal con 208 adolescentes de escuelas públicas en la ciudad de João Pessoa (Paraíba, Brasil) de entre 15 y 19 años de edad. Se recogieron muestras de sangre para la extracción de ADN y el análisis de los polimorfismos rs1544410 y rs2228570, así como para análisis bioquímicos (25-hidroxivitamina D, hormona paratiroidea, calcio y glucemia). Resultados: la edad media fue de 17,7 (± 1,14) años. La mitad de los adolescentes tenía niveles séricos suficientes de 25-hidroxivitamina D y la otra mitad, vitamina insuficiente/deficiente. La distribución genotípica más frecuente fue bb y Ff y la de menor frecuencia, BB y ff. Hubo una relación significativa entre los genotipos de rs1544410 y los valores de glucemia (p = 0,049) en las relaciones entre los genotipos BBxbb (p = 0,012) y Bbxbb (p = 0,037); (p = 0,036, OR = 2,15, IC 95 % = 1,05-4.41), y el análisis del grupo BB + Bb en comparación con el bb (p = 0,025, OR = 1,89, IC 95 % = 1,08-3,29) mostró un mayor el riesgo de glucemia, por encima de la mediana. Por otro lado, cuando se analizó Bb+bb en relación con la BB, los adolescentes tuvieron una mayor probabilidad de que la glucosa en sangre estuviera por debajo de la mediana (p = 0,025, OR = 0,66, IC = 0,47-0,95). Conclusión: este estudio mostró una relación significativa entre la glucemia y la distribución de genotipos de polimorfismo rs1544410.

Abstract Genetic and epigenetic changes have been associated with periodontitis in various genes; however, little is known about genes involved in epigenetic mechanisms and in oxidative stress. Objective: This study aims to investigate the association of polymorphisms C677T in MTHFR (rs1801133) and −149C→T in DNMT3B (rs2424913), as well as the methylation profiles of MTHFR, miR-9-1, miR-9-3, SOD1, and CAT with periodontitis. The association between polymorphisms and DNA methylation profiles was also analyzed. Methodology: The population studied was composed of 100 nonsmokers of both sexes, divided into healthy and periodontitis groups. Genomic DNA was extracted from the epithelial buccal cells, which were collected through a mouthwash. Polymorphism analysis was performed through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while methylation-specific PCR (MSP) or combined bisulfite restriction analysis techniques were applied for methylation analysis. Results: For DNMT3B, the T allele and the TT genotype were detected more frequently in the periodontitis group, as well as the methylated profile on the miR-9-1 promoter region. There was also a tendency towards promoter region methylation on the CAT sequence of individuals with periodontal disease. Conclusion: The polymorphism −149C→T in DNMT3B (rs2424913) and the methylated profile of the miR-9-1 promoter region are associated with periodontitis.

Durante a Primeira Semana Nacional de Ciências e Tecnologia, em 2004, centros e museus de ciência, universidades e escolas implementaram atividades com o objetivo de divulgar ciência para a população. O DNA Vai à Escola se juntou ao Conselho de Informação e Biotecnologia e praticou a extração de DNA de frutas em supermercados de 11 cidades brasileiras. Este artigo descreve a formação da rede nacional de pessoas interessadas em transmitir informações sobre genética para o público leigo e a implementação de uma atividade de divulgação científica de baixo orçamento em vários pontos do país, simultaneamente. Apresenta ainda o impacto causado pela atividade e as percepções daqueles envolvidos na sua organização.

During the first National Science and Technology Week held in 2004, science centers and museums, universities and schools engaged in activities with the idea of divulging science to the people. Demonstrations of the extraction of DNA from fruits were conducted in supermarkets in 11 Brazilian cities by two institutions, DNA Vai à Escola and Conselho de Informação e Biotecnologia. This article describes the formation of a national network of people interested in communicating information about genetics to the lay public and the implementation of a low-cost science communication activity in different parts of the country simultaneously. It also analyzes the impact caused by this initiative and the perceptions of those involved in its organization.

DNA methylation is mediated by DNA methyltransferases (DNMTs) that add a methyl group to the 5'-carbon of cytosine. The enzyme methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate in the rate-limiting step of the cycle involving the methyl donor S-adenosyl-L-methionine (SAM). The MTHFR C677T polymorphism results in a thermolabile enzyme with reduced activity that is predicted to influence the DNA methylation status. In this study, we investigated the impact of the MTHFR C677T polymorphism on the global DNA methylation of oral epithelial cells obtained from 54 healthy subjects. There were no significant differences in global DNA methylation among the MTHFR CC, CT and TT genotypes (p = 0.75; Kruskal-Wallis test).

CONTEXTO E OBJETIVO: A doença aterosclerótica é a principal causa de morte no Brasil. Trata-se de doença multifatorial e sua prevenção passa pela identificação e controle dos fatores de risco. A concentração plasmática moderadamente aumentada de homocisteína (hiperhomocisteinemia) tem sido considerada importante fator de risco para várias doenças vasculares. Mutações na enzima metilenotetrahidrofolato redutase (MTHFR), envolvida no metabolismo de homocisteína, têm sido investigadas como fatores de risco para doenças vasculares. O polimorfismo G1793A foi descrito em 2002 e existem poucos estudos sobre sua implicação em doenças. O objetivo do presente trabalho foi verificar a prevalência do polimorfismo MTHFR G1793A em indivíduos portadores de doença arteriocoronariana (DAC) precoce. TIPO DE ESTUDO E LOCAL: Estudo transversal com grupo controle realizado em Clínica Cardiológica Particular e Laboratório de Biologia Molecular (Universidade do Vale do Itajaí). MÉTODOS: Foram estudados 74 pacientes DAC+ precoce e 40 DAC- com resultado angiográfico normal. O DNA foi extraído de amostras de sangue. Dados moleculares foram obtidos através de PCR/RFLP e eletroforese em gel de agarose. RESULTADOS: A ocorrência de heterozigotos G1793A foi similar em ambos os grupos controle (5%) e teste (6,25%), mostrando que na população estudada não existiu correlação entre o marcador e a ocorrência de DAC precoce. Não houve associação entre o polimorfismo e os fatores de risco para aterosclerose. CONCLUSÕES: A frequência do alelo 1793A no grupo teste (3,4%) foi parecida com a encontrada nos indivíduos do controle (2,5%). Não houve correlação entre o polimorfismo G1793A e a ocorrência de DAC precoce na população estudada.

CONTEXT AND OBJECTIVE: Atherosclerotic disease is the leading cause of death in Brazil. It is a complex disease and its prevention involves identification and control of risk factors. Moderately increased plasma homocysteine concentration (hyperhomocysteinemia) has been considered to be a risk factor for several vascular diseases. Mutations in the methylenetetrahydrofolate reductase (MTHFR) enzyme, which is involved in homocysteine metabolism, have been investigated as potential vascular disease risk factors. G1793A polymorphism was described in 2002 and there are few studies analyzing its involvement in diseases. The objective of this study was to investigate the prevalence of G1793A polymorphism in subjects with early coronary artery disease (CAD). DESIGN AND SETTING: Cross-sectional study with control group conducted at a private cardiology clinic and a molecular biology laboratory (Universidade do Vale do Itajaí). METHODS: We studied 74 early-onset CAD+ patients and 40 CAD- individuals with normal angiography results. DNA was extracted from blood samples. Molecular data were obtained via PCR/RFLP and agarose gel electrophoresis. RESULTS: The occurrence of G1793A heterozygotes was similar in the control (5%) and test (6.25%) groups, thus showing that in the population studied there was no correlation between the marker and occurrences of early CAD. There was also no association between the polymorphism and the risk factors for atherosclerosis. CONCLUSIONS: The frequency of the 1793A allele in the test group (3.4%) was similar to what was found in the control individuals (2.5%). There was no correlation between G1793A polymorphism and occurrences of early CAD in this population.

A mutação (C677T) no gene que codifica a enzima metilenotetrahidrofolato redutase (MTHFR) tem sido associada a hiperhomocisteinemia e possivelmente ao risco elevado para doenças vasculares. O objetivo deste trabalho foi otimizar sua detecção por PCR para faciliar estudos populacionais. Foram testadas metodologias alternativas de purificação do DNA genômico humano e os resultados obtidos permitiram padronizar uma técnica com redução de reagentes para extração de DNA por precipitação com NaCl. Foram realizados experimentos variando a concentração dos componentes da reação de PCR que permitiram definir que reações contendo metade do volume inicial de deoxinucleotídeos e iniciadores (primers), assim como 0,5U de Taq DNA polimerase produzem essencialmente a mesma quantidade de amplificado que a reação anteriormente utilizada. Testou-se ainda, a redução do volume da reação de PCR com objetivo de utilizar o produto de amplificação diretamente para digestão com a enzima HinfI, evitando assim, etapas de pipetagem que acarretam em risco de contaminação. Obteve-se sucesso com 15 mL de volume final; que permitiu a utilização do sistema de PCR completo para digestão do produto amplificado. A importância deste estudo pode ser justificada pela significância que as doenças vasculares apresentam em termos populacionais e por este polimorfismo estar potencialmente relacionado com o risco de DAC (doença artério-coronariana) precoce.

A common mutation C677T in methylenetetrahydrofolate reductase (MTHFR) gene, involved in the metabolism of homocysteine, has been suggested to play a role in increasing cardiovascular disease risk. In order to facilitate the obtainment of population data, the objective of this work was improve its PCR detection. Leucocytes DNA purification alternative protocols were tested and a new low cost method of NaCl precipitation was developed. The composition of PCR mixture was also tested and it defined that the concentration of deoxynucleotides, primers and Taq DNA polimerase could be reduced in a half. The final volume of PCR mixture was reduced to 15 µL, enabling the utilization of the same tube to amplification and HinfI digestion processes, avoiding extra steps. The significance of cardiovascular disease in populational data and the possibility of involvement of this mutation as risk factor of precocious ACD (arterial cardiovascular disease) justify this work.