Gene - maltreatment interplay in adult ADHD symptoms: main role of a gene-environment correlation effect in a Brazilian population longitudinal study.

Childhood maltreatment correlates with attention-deficit/hyperactivity disorder (ADHD) in previous research. The interaction between ADHD genetic predisposition and maltreatment's impact on ADHD symptom risk remains unclear. We aimed to elucidate this relationship by examining the interplay between a polygenic score for ADHD (ADHD-PGS) and childhood maltreatment in predicting ADHD symptoms during young adulthood. Using data from the 2004 Pelotas (Brazil) birth cohort comprising 4231 participants, we analyzed gene-environment interaction (GxE) and correlation (rGE). We further explored rGE mechanisms through mediation models. ADHD symptoms were assessed at age 18 via self-report (Adult Self Report Scale - ASRS) and mother-reports (Strength and Difficulties Questionnaire - SDQ). The ADHD-PGS was derived from published ADHD GWAS meta-analysis. Physical and psychological child maltreatment was gauged using the Parent-Child Conflict Tactics Scale (CTSPC) at ages 6 and 11, with a mean score utilized as a variable. The ADHD-PGS exhibited associations with ADHD symptoms on both ASRS (ß = 0.53; 95% CI: 0.03; 1.03, p = 0.036), and SDQ (ß = 0.20; 95% CI: 0.08; 0.32, p = 0.001) scales. The total mean maltreatment score was associated with ADHD symptoms using both scales [(ßASRS = 0.51; 95% CI: 0.26;0.77) and (ßSDQ = 0.24; 95% CI: 0.18;0.29)]. The ADHD-PGS was associated with total mean maltreatment scores (ß = 0.09; 95% CI: 0.01; 0.17; p = 0.030). Approximately 47% of the total effect of ADHD-PGS on maltreatment was mediated by ADHD symptoms at age 6. No evidence supported gene-environment interaction in predicting ADHD symptoms. Our findings underscore the significant roles of genetics and childhood maltreatment as predictors for ADHD symptoms in adulthood, while also indicating a potential evocative mechanism through gene-environment correlation.

Physical activity and serum interleukin-6 in relation to bone density in young adults / Atividade física e interleucina-6 sérica em relação à densidade óssea em adultos jovens

Physical activity (PA) and inflammation influence bone density through multiple physiological mechanisms, but current evidence is not robust on the structure mediating these relationships. There-fore, the aim of this study was to investigate the associations of PA, and serum interleukin-6 (IL-6) on bone density. Cross-sectional analysis in the Pelotas (Brazil) 1982 Birth Cohort with participants aged 30-years old. PA was objectively measured by accelerometry. Bone mineral density (g/cm2) was evaluated for the lumbar spine and femoral neck using dual-energy X-ray absorptiometry. Crude and adjusted linear regressions and mediation analyses were performed. In both sexes, the overall PA was positively associated with femoral neck bone density, but not lumbar spine. For men, the mean of femoral neck were 0.027, 0.042, and 0.032 higher in the second, third, and fourth quartiles, respectively, compared to the first quartile (reference). Among women, higher bone density values were found in the third (0.021) and fourth (0.027) quartiles of overall PA compared to the lowest quartile. Among females, moderate-to-vigorous intensity physical activity presented a positive rela-tionship with all sites of bone density. The indirect effect through IL-6 was not significant. Physical activity was associated with gains in bone density. The findings reinforce recommendations for PA in adulthood to promote bone health

A atividade física (AF) e a inflamação influenciam a densidade óssea através de múltiplos mecanismos fisiológicos, mas a atual evidência não é robusta sobre a estrutura de mediação dessas relações. Portanto, o objetivo deste estudo foi investigar as associações de AF e interleucina-6 sérica (IL-6) na densidade óssea. Análise transversal na Coorte de Nascimentos de 1982 Pelotas (Brasil) em participantes com 30 anos de idade. AF foi medida objetivamente por acelerometria. Densidade mineral óssea (g/cm2) foi avaliada para a coluna lombar e colo do fêmur usando absorciometria de raios-X de dupla energia. Foram realizadas regressões lineares brutas e ajustadas e análises de mediação. Em ambos os sexos, a AF total foi positivamente associada à densidade óssea do colo do fêmur, mas não à coluna lombar. Para os homens, as médias do colo do fêmur foram 0,027, 0,042 e 0,032 maiores no segundo, terceiro e quarto quartis, respectivamente, em relação ao primeiro quartil (referência). Entre as mulheres, os maiores valores de densidade óssea foram encontrados no terceiro (0,021) e quarto (0,027) quartis de AF total em comparação ao quartil mais baixo. No sexo feminino, a atividade física de intensidade moderada a vigorosa apresentou relação positiva com todos os locais de densidade óssea. O efeito indireto através da IL-6 não foi significativo. A atividade física foi associada a ganhos de densidade óssea. Os achados reforçam recomendações de AF na idade adulta para promover a saúde óssea

Epidemiology of interleukin-6: the 30-year follow-up of the 1982 Pelotas (Brazil) birth cohort study.

BACKGROUND: Cardiovascular diseases are the main cause of death globally. Interleukin-6 (IL-6) is a biomarker of cardiovascular risk. AIM: To investigate factors associated with IL-6 concentration in serum, from early life up to 30 years of age. SUBJECTS AND METHODS: In the 2012-2013 follow-up, IL-6 was measured in 2809 participants of the 1982 Pelotas Birth Cohort (1369 males). Multivariable linear regressions, stratified by sex, were performed to evaluate the associations of African ancestry, family income and maternal education at birth, monthly income and education at 30 years, smoking status, harmful alcohol intake, physical activity, and body composition with IL-6, considering a conceptual hierarchical framework. RESULTS: Males with low educational levels and current smokers had the highest mean IL-6. Among females, African ancestry and low monthly income were associated with the highest mean values for the outcome. Physical activity had an inverse association with IL-6 concentration among females. A direct relationship was observed between the measures of adiposity on IL-6, in both sexes. CONCLUSION: Body composition was the main predictor for the outcome evaluated in males and females. Thus, the avoidance of overweight remains an important strategy for the prevention and control of cardiovascular risk and biomarkers associated with these diseases.

Food processing and cardiometabolic risk factors: a systematic review.

OBJECTIVE To systematically review the evidence for the association between food consumption according to processing and cardiometabolic factors in adults and/or the elderly. METHOD Two independent evaluators analyzed the electronic databases PubMed, Web of Science and Lilacs until December 2018. We used the following terms: (convenience foods OR food processing OR highly-processed OR industrialized foods OR minimally-processed OR prepared foods OR processed foods OR ultra-processed OR ultraprocessed OR ultra processed OR unprocessed) AND (metabolic syndrome OR hypertension OR blood pressure OR diabetes mellitus OR glucose OR glycaemia OR insulin OR cholesterol OR triglycerides OR blood lipids OR overweight OR obesity) AND (adult OR adults OR adulthood OR aged OR elderly OR old). We assessed methodological and evidence qualities, and also extracted information for the qualitative synthesis from the selected studies. RESULTS Of the 6,423 studies identified after removing duplicates, eleven met the eligibility criteria. The main food classification we used was Nova. The consumption of ultra-processed foods was positively associated with overweight and obesity, high blood pressure and metabolic syndrome. All articles included met more than 50% of the methodological quality criteria. The quality of evidence was considered moderate for the outcome overweight and obesity and weak for hypertension and metabolic syndrome. CONCLUSIONS The Nova food classification stands out in the area of nutritional epidemiology when assessing the effects of food processing on health outcomes. Although caution is required in the interpretation, the results indicated that the consumption of ultra-processed foods can have an unfavorable impact in the health of individuals.

Food processing and cardiometabolic risk factors: a systematic review / Processamento de alimentos e fatores de risco cardiometabólicos: revisão sistemática

ABSTRACT OBJECTIVE To systematically review the evidence for the association between food consumption according to processing and cardiometabolic factors in adults and/or the elderly. METHOD Two independent evaluators analyzed the electronic databases PubMed, Web of Science and Lilacs until December 2018. We used the following terms: (convenience foods OR food processing OR highly-processed OR industrialized foods OR minimally-processed OR prepared foods OR processed foods OR ultra-processed OR ultraprocessed OR ultra processed OR unprocessed) AND (metabolic syndrome OR hypertension OR blood pressure OR diabetes mellitus OR glucose OR glycaemia OR insulin OR cholesterol OR triglycerides OR blood lipids OR overweight OR obesity) AND (adult OR adults OR adulthood OR aged OR elderly OR old). We assessed methodological and evidence qualities, and also extracted information for the qualitative synthesis from the selected studies. RESULTS Of the 6,423 studies identified after removing duplicates, eleven met the eligibility criteria. The main food classification we used was Nova. The consumption of ultra-processed foods was positively associated with overweight and obesity, high blood pressure and metabolic syndrome. All articles included met more than 50% of the methodological quality criteria. The quality of evidence was considered moderate for the outcome overweight and obesity and weak for hypertension and metabolic syndrome. CONCLUSIONS The Nova food classification stands out in the area of nutritional epidemiology when assessing the effects of food processing on health outcomes. Although caution is required in the interpretation, the results indicated that the consumption of ultra-processed foods can have an unfavorable impact in the health of individuals.

RESUMO OBJETIVO Revisar sistematicamente as evidências da associação entre consumo de alimentos de acordo com o processamento e fatores cardiometabólicos em adultos e idosos. MÉTODOS Dois avaliadores independentes analisaram as bases de dados eletrônicas PubMed, Web of Science e Lilacs até dezembro de 2018. Os seguintes termos foram utilizados: (convenience foods OR food processing OR highly-processed OR industrialized foods OR minimally-processed OR prepared foods OR processed foods OR ultra-processed OR ultraprocessed OR ultra processed OR unprocessed) AND (metabolic syndrome OR hypertension OR blood pressure OR diabetes mellitus OR glucose OR glycaemia OR insulin OR cholesterol OR triglycerides OR blood lipids OR overweight OR obesity) AND (adult OR adults OR adulthood OR aged OR elderly OR old). Nos estudos incluídos foram avaliadas as qualidades metodológica e de evidência, além de extraídas informações para a síntese qualitativa. RESULTADOS Dos 6.423 estudos identificados após a remoção das duplicatas, onze preencheram os critérios de elegibilidade. A principal classificação de alimentos utilizada foi a Nova. O consumo de alimentos ultraprocessados foi positivamente associado com excesso de peso e obesidade, hipertensão arterial e síndrome metabólica. Todos os artigos incluídos preencheram mais de 50% dos critérios de qualidade metodológica. A qualidade de evidência foi considerada moderada para o desfecho excesso de peso e obesidade e fraca para hipertensão arterial e síndrome metabólica. CONCLUSÕES A classificação de alimentos Nova se destaca na área da epidemiologia nutricional ao avaliar os efeitos do processamento de alimentos sobre desfechos em saúde. Embora seja necessária prudência na interpretação, os resultados indicam que o consumo de alimentos ultraprocessados pode ter impacto desfavorável sobre a saúde dos indivíduos.

The Role of MIR9-2 in Shared Susceptibility of Psychiatric Disorders during Childhood: A Population-Based Birth Cohort Study.

BACKGROUND: It has been suggested that microRNAs (miRNAs; short non-protein-coding RNA molecules that mediate post-transcriptional regulation), including mir-9 and mir-34 families, are important for brain development. Current data suggest that mir-9 and mir-34 may have shared effects across psychiatric disorders. This study aims to explore the role of genetic polymorphisms in the MIR9-2 (rs4916723) and MIR34B/C (rs4938723) genes on the susceptibility of psychiatric disorders in children from the 2004 Pelotas Birth Cohort. METHODS: Psychiatric disorders were assessed in 3585 individuals using Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), criteria through the application of standard semi-structured interviews (using the Development and Well-Being Assessment, DAWBA) at the six-years-of-age follow-up. The outcome was defined as the presence of any mental disorder. We also considered two broad groups of internalizing and externalizing disorders to further investigate the role of these variants in mental health. RESULTS: We observed an association between rs4916723 (MIR9-2) and the presence of any psychiatric disorder (odds ratios (OR) = 0.820; 95% CI = 0.7130-0.944; p = 0.006) and a suggestive effect on internalizing disorders (OR = 0.830; 95% CI = 0.698-0.987; p = 0.035). rs4938723 (MIR34B/C) was not associated with any evaluated outcome. CONCLUSION: The study suggests that MIR9-2 may have an important role on a broad susceptibility for psychiatric disorders and may be important mainly for internalization problems.

Paraoxonase 1 serum activity in women: the effects of menopause, the C(-107)T polymorphism and food intake

ABSTRACT Objective The aims of this study were to investigate changes in serum paraoxonase 1 (PON1) activity in women at the pre and postmenopausal stages and its association with the PON1 C(-107)T polymorphism and food intake profile. Subjects and methods A cross-sectional study with female patients aged between 35 and 59 years old was conducted. Women were divided into two groups: premenopausal (n = 40) and postmenopausal (n = 36). Women enrolled in the study had serum PON1, total cholesterol, HDL, LDL, glucose and HbA1c, as well as the BMI measured. Additionally, women were genotyped for the PON1 T(-107)C polymorphism and the food intake profile was obtained through interview. Results Glucose (p = 0.03), HbA1c (p = 0.002) and total cholesterol (p = 0.002)concentrations were higher in post than premenopausal women, however PON1 activity was not different (p > 0.05). Carriers of the C allele had higher PON1 activity (CC: 88.9 ± 6.5 U/mL and CT: 79.9 ± 4.7 U/mL) than women of the TT genotype (66.6 ± 5.9 U/mL) (p < 0.05). However, the model predicting PON1 activity was slightly better when genotype, total fat and cholesterol content in the diet were all included. Conclusion In sum, we observed that the PON1 C(-107)T genotype was the major regulator of PON1 activity, and menopause had no effect on PON1 activity. The lipid and glycemic profile were altered in postmenopausal women.

Paraoxonase 1 serum activity in women: the effects of menopause, the C(-107)T polymorphism and food intake.

OBJECTIVE: The aims of this study were to investigate changes in serum paraoxonase 1 (PON1) activity in women at the pre and postmenopausal stages and its association with the PON1 C(-107)T polymorphism and food intake profile. SUBJECTS AND METHODS: A cross-sectional study with female patients aged between 35 and 59 years old was conducted. Women were divided into two groups: premenopausal (n = 40) and postmenopausal (n = 36). Women enrolled in the study had serum PON1, total cholesterol, HDL, LDL, glucose and HbA1c, as well as the BMI measured. Additionally, women were genotyped for the PON1 T(-107)C polymorphism and the food intake profile was obtained through interview. RESULTS: Glucose (p = 0.03), HbA1c (p = 0.002) and total cholesterol (p = 0.002)concentrations were higher in post than premenopausal women, however PON1 activity was not different (p > 0.05). Carriers of the C allele had higher PON1 activity (CC: 88.9 ± 6.5 U/mL and CT: 79.9 ± 4.7 U/mL) than women of the TT genotype (66.6 ± 5.9 U/mL) (p < 0.05). However, the model predicting PON1 activity was slightly better when genotype, total fat and cholesterol content in the diet were all included. CONCLUSION: In sum, we observed that the PON1 C(-107)T genotype was the major regulator of PON1 activity, and menopause had no effect on PON1 activity. The lipid and glycemic profile were altered in postmenopausal women.

Overweight trajectory and cardio metabolic risk factors in young adults.

BACKGROUND: Obesity is one of the conditions that increases the risk of cardiovascular disease. Studies about obesity trajectory and cardio metabolic outcomes at adulthood are still scarce. Therefore, we aimed to assess the association between patterns of overweight over the life-course and cardio metabolic risk factors in young adults. METHODS: In 1982, the maternity hospitals in Pelotas were visited daily and those newborns whose family lived in the urban area of the city were identified (n = 5914), and have prospectively followed for several occasions. Weight and height were measured at every visit. BMI-for-age z-score was calculated using the WHO Child Growth Standards. Overweight and obesity were defined as a BMI greater than or equal to 25 kg/m2 and 30 kg/m2 respectively. This was the definition adopted for evaluations overweight and obesity at 30 years. The participants were divided into eight groups according to the presence of overweight or obesity in childhood, adolescence and adulthood. Blood pressure, random blood glucose, HDL cholesterol, LDL cholesterol triglycerides and fat mass were measured. RESULTS: From 2219 participants with anthropometric data in childhood, adolescence and adulthood, 25% never had been overweight, whereas 11.6% were overweight in the three periods. Random blood glucose, SBP and DBP were higher among those subjects who were always overweight/ obese or only overweight/obese during adolescence and adulthood. The participants who were never overweight/obese or only in childhood or adolescence had a lower cardiovascular risk profile (higher HDL cholesterol, lower blood pressure, lower random glucose, lower LDL cholesterol) at 30 years. Fat mass captured from 25 to 100% of the association of overweight and obesity trajectory with cardiometabolic risk factors. CONCLUSIONS: The tracking of overweight/obesity is associated with an adverse cardio metabolic profile and this association is largely mediated by fat mass in adulthood.

C-Peptide and cardiovascular risk factors among young adults in a southern Brazilian cohort.

BACKGROUND: Proinsulin connecting peptide (C-Peptide) is a marker of the beta-cell function and has been considered a marker of insulin resistance whose evidence suggests were associated with cardiovascular mortality. Our study aims to evaluate the association of C-Peptide with metabolic cardiovascular risk factors among young adults followed since birth in southern Brazil. METHODS: In 1982, maternity hospital in Pelotas, a southern Brazilian city, were visited daily and all births were identified. Live births whose family lived in the urban area of the city were identified, their mothers interviewed, and these subjects have been prospectively followed. Casual hyperglycemia patients were excluded from analysis. C-Peptide was assessed at 23 years, when transversely analyzed its association with cardiometabolic and hemodynamic risk factors, and longitudinally 30 years of age. RESULTS: At age 23, 4297 individuals were evaluated, and C-Peptide was measured in 3.807. In a cross-sectional analysis at 23 years of age, C-Peptide was positively associated with waist circumference, body mass index, glycaemia, triglycerides, and C-reactive protein. The association with HDL cholesterol was negative. In the longitudinal analysis at 30 years, C-Peptide remained associated with BMI, waist circumference, glycated hemoglobin, triglycerides, and C-reactive protein, whereas the association was negative for HDL. CONCLUSION: In the Pelotas birth cohort, the C-Peptide was associated with obesity indicators (waist circumference and BMI) cross-sectional (23 years) and longitudinal (30 years). We also observed cross-sectional and longitudinal associations of C-Peptide with cardiometabolic and inflammatory risk factors.

Conditions of gestation, childbirth and childhood associated with C-peptide in young adults in the 1982 Birth Cohort in Pelotas-RS; Brazil.

BACKGROUND: The connecting peptide in insulin has been associated with cardiovascular risk and overall mortality in the adult population. However, its early determinants are unknown. Assess the association of exposures during pregnancy, delivery, and childhood with C-peptide among 22-23 years old individuals prospectively followed since birth, in a southern Brazilian city. METHODS: In 1982, all hospital births in the city were identified and those livebirths whose families lived in the urban area were evaluated (n = 5914). The 1982 Pelotas Birth Cohort has prospectively followed these subjects at different moments. In this study, we evaluated the association of C-peptide with exposures occurring during pregnancy, delivery and childhood. In the 22-23 years follow-up visit, we tried to follow the whole cohort and the subjects were interviewed, examined and donated a blood sample. C-peptide was measured using the chemiluminescence immunoassay technique (Immulite®-Siemens, Germany). RESULTS: In the 22-23 years visit, 4297 subjects were interviewed and the C-peptide was measured in 3807. The geometric mean of C-peptide was 0.83 ng/mL and the mean was higher among women. In the adjusted analysis, C-peptide was positively associated with family income at birth, lower among children of non-white mothers (0.90; CI95% 0.84-0.96), higher among females (1.22; CI95% 1.16-1.28), and positively associated with rapid weight gain between two and four years of age (1.18; CI95% 1.05-1.32). CONCLUSION: Family income at birth, non-white maternal skin color, and rapid weight gain between two and four years of age were associated with high levels of C-peptide.

Stem cells: therapeutic potential in dentistry.

AIM: The aim of this paper is to present a review and discussion of the current status of stem cell research with regard to tooth generation. BACKGROUND: Stem cells have been isolated from the pulp tissue of both deciduous and permanent teeth as well as from the periodontal ligament. Dental pulp stem cells demonstrate the capacity to form a dentin pulp-like complex in immunocompromised mice. A tooth-like structure was successfully formed, using a heterogeneous mixture of dental enamel epithelium, pulp mesenchymal cells, and scaffolds. CONCLUSION: The scientific community understands the need for more investigations to completely understand the conditions that would best favor the creation of a tooth substitute. Recent gains in the understanding of the molecular regulation of tooth morphogenesis, stem cell biology, and biotechnology offers the opportunity to realize this goal. CLINICAL SIGNIFICANCE: These findings, combined with the recent progress in stem cell research and tissue engineering, might allow the development of alternatives for current materials and therapies used to treat tooth tissue loss (e.g., enamel, dentin, pulp), reconstruct dentoalveolar and craniofacial bone defects, and eventually replace an entire tooth.

Buccal cells submitted to three different storage conditions before DNA extraction

This study evaluated quantitatively and qualitatively the effect of the storage time of samples before the application of the cell lysis solution (CLS) for extracting DNA from buccal cells (BC). BC from the upper and lower gutter region were collected from 5 volunteers using special cytobrushes (Gentra), totaling 3 collections for each individual. In the control group (n=10), CLS was applied soon after BC collection. In the other two groups, samples were stored at room temperature (n=10) or at 4°C (n=10). After CLS application, DNA was extracted according to the manufacturer's instructions (Puregene DNA Buccal Cell Kit; Gentra Systems, Inc.). The DNA obtained was evaluated by two calibrated blind examiners using spectrophotometry and analysis of DNA bands (0.8 percent agarose gel electrophoresis). The obtained data were submitted to one-way ANOVA. The means and standard deviations for DNA extracted under immediate, room temperature and cooling temperature conditions were 3.5 ± 0.7, 3.0 ± 0.6 and 4.1 ± 1.8 µg, respectively (p=0.385). No significant differences were found in relation to the amount of DNA for the different storage conditions. However, in the visual analysis of the DNA bands, no trace of DNA degradation was detected when CSL was applied soon after DNA collection, while DNA bands with degradation could be observed in the other groups. Within the limitations of the study, it may be concluded that CLS should be applied soon after DNA collection in order to obtain high-quality DNA from BC.

Buccal cells submitted to three different storage conditions before DNA extraction.

This study evaluated quantitatively and qualitatively the effect of the storage time of samples before the application of the cell lysis solution (CLS) for extracting DNA from buccal cells (BC). BC from the upper and lower gutter region were collected from 5 volunteers using special cytobrushes (Gentra), totaling 3 collections for each individual. In the control group (n=10), CLS was applied soon after BC collection. In the other two groups, samples were stored at room temperature (n=10) or at 4 degrees C (n=10). After CLS application, DNA was extracted according to the manufacturer's instructions (Puregene DNA Buccal Cell Kit; Gentra Systems, Inc.). The DNA obtained was evaluated by two calibrated blind examiners using spectrophotometry and analysis of DNA bands (0.8% agarose gel electrophoresis). The obtained data were submitted to one-way ANOVA. The means and standard deviations for DNA extracted under immediate, room temperature and cooling temperature conditions were 3.5+/-0.7, 3.0+/-0.6 and 4.1+/-1.8 microg, respectively (p=0.385). No significant differences were found in relation to the amount of DNA for the different storage conditions. However, in the visual analysis of the DNA bands, no trace of DNA degradation was detected when CSL was applied soon after DNA collection, while DNA bands with degradation could be observed in the other groups. Within the limitations of the study, it may be concluded that CLS should be applied soon after DNA collection in order to obtain high-quality DNA from BC.

Comparison between DNA obtained from buccal cells of the upper and lower gutter area.

This study compared quantitatively and qualitatively the DNA extracted from buccal cells collected from the upper or lower gutter areas. Buccal cells were collected from the upper (n=15) and lower gutter (n=15) region from 15 volunteers using a special cytobrush (Gentra), totaling 2 collections from each individual. DNA was extracted from the samples according to the manufacturer's instructions. The DNA obtained was qualitatively and quantitatively evaluated by 2 calibrated blind examiners using spectrophotometry and analysis of DNA bands (0.8% agarose gel electrophoresis). Data was statistically analyzed by one-way ANOVA (alpha=0.05). Means and standard derivation (SD) for total DNA yield from the upper and lower gutter area were 12.2 microg (12.0) and 9.4 microg (8.5), respectively (p=0.821). There was higher (p<0.05) DNA purity for the upper gutter (1.79; 0.05) when compared to lower gutter area (1.66; 0.10). Regarding to the DNA quality, no differences were observed between the 2 location sites, but all samples showed similar degree of degradation. In conclusion, it would be recommendable that buccal cells for DNA extraction be collected from the upper gutter area in the attempt to increase DNA purity.

Comparison between DNA obtained from buccal cells of the upper and lower gutter area

This study compared quantitatively and qualitatively the DNA extracted from buccal cells collected from the upper or lower gutter areas. Buccal cells were collected from the upper (n=15) and lower gutter (n=15) region from 15 volunteers using a special cytobrush (Gentra), totaling 2 collections from each individual. DNA was extracted from the samples according to the manufacturer's instructions. The DNA obtained was qualitatively and quantitatively evaluated by 2 calibrated blind examiners using spectrophotometry and analysis of DNA bands (0.8 percent agarose gel electrophoresis). Data was statistically analyzed by one-way ANOVA (?=0.05). Means and standard derivation (SD) for total DNA yield from the upper and lower gutter area were 12.2 ?g (12.0) and 9.4 ?g (8.5), respectively (p=0.821). There was higher (p<0.05) DNA purity for the upper gutter (1.79; 0.05) when compared to lower gutter area (1.66; 0.10). Regarding to the DNA quality, no differences were observed between the 2 location sites, but all samples showed similar degree of degradation. In conclusion, it would be recommendable that buccal cells for DNA extraction be collected from the upper gutter area in the attempt to increase DNA purity.

O objetivo do presente estudo foi comparar quantitativamente e qualitativamente o DNA extraído de células epiteliais bucais coletadas do fundo de sulco superior e inferior. Foram coletadas células bucais do fundo de sulco superior (n=15) e inferior (n=15) de 15 voluntários utilizando escovas citológicas especiais (Gentra), totalizando 2 coletas por voluntário. Após a coleta o DNA foi extraído conforme o protocolo indicado pelo fabricante (Puregene DNA Buccal Cell Kit; Gentra Systems, Inc.). O DNA obtido foi avaliado quantitativamente e qualitativamente por dois examinadores calibrados cegos utilizando espectrofotometria e análise das bandas de DNA (gel de agarose 0,8 por cento, por eletroforese). Os dados foram submetidos a ANOVA a um critério, com p<0,05. As médias e desvio padrão (DP) para o rendimento total de DNA do fundo de sulco superior e inferior foram respectivamente 12,2 ?g (12,0) e 9,4 ?g (8,5) (p=0,821). Houve maior (p<0,05) pureza de DNA no fundo de sulco superior (1,79; 0,05) quando comparado com o fundo de sulco inferior (1,66; 0,10). Quanto à qualidade do DNA, não foi observado diferenças entre os dois locais testados, no entanto todas as amostras mostraram níveis de degradação semelhantes. Em conclusão seria recomendável coletar células bucais, para extração de DNA, do fundo de sulco superior na tentativa de aumentar a pureza do DNA.

Conhecimentos atuais sobre a biologia dos melanócitos no folículo piloso humano / Current Knowledge on the biology of melanocytes in the human hair follice

Os processos de crescimento e pigmentação do cabelo não são completamente conhecidos. Da mesma forma, o papel que os melanócitos foliculares desempenham nesses processos ainda não foi esclarecido. A identificação do destino dos melanócitos foliculares ao final da fase de crescimento do folículo piloso e a localização do reservatório dessas células, que voltam a povoar a porção inferior do novo folículo ao final da fase telógena do ciclo de crescimento do cabelo, constituem objeto de estudo. Investigações têm sido realizadas visando identificar se os melanócitos são responsáveis por algum sinal molecular de comunicação envolvido com as mudanças observadas na estrutura do folículo piloso durante o ciclo do cabelo. Alguns fatores têm sido descritos como participantes dos processos essenciais para a biologia dos melanócitos. A importância da proteína antiapoptótica, Bcl-2, para a manutenção dos melanócitos já foi demonstrada. A via SCF/kit foi mencionada como um mecanismo primário para a regulação dos processos de proliferação e diferenciação dos melanócitos. Por outro lado, o mecanismo de ação dos androgênios sobre as células do folículo piloso tem sido objeto de muitos estudos que tentam explicar como esses hormônios participam da regulação dos processos de crescimento e pigmentação do cabelo. Portanto, o objetivo dessa revisão é apresentar os atuais conhecimentos envolvendo a biologia dos melanócitos foliculares