431 research outputs found
Revisiting the internal conformational dynamics and solvation properties of cyclodextrins
Molecular dynamics simulations were used to investigate the internal conformational dynamics and solvation properties of the three natural cyclodextrins, <FONT FACE=Symbol>a-, b</FONT>- and gamma-cyclodextrin in aqueous solution at room temperature. These glucose-derived oligosacharides present a molecular structure that confers them the ability to complex guest molecules and change their physicochemical properties. The structural behavior of cyclodextrins in solution is crucial for their complexation abilities. Analyses of the obtained trajectories show that inter-glucose hydrogen bonds between the secondary hydroxyl groups are present in solution, but show a very dynamical character where alternative hydrogen bonds to water molecules can be formed. Despite the lower hydrophilicity of the cyclodextrins inner-cavities, they were found to be solvated and the number of water molecules inside the cavity roughly doubles per glucose unit added to the ring. The residence times for water molecules inside the cavities are inversely proportional to the cavity size
DNA methylation biomarkers of myocardial infarction and cardiovascular disease
Background: The epigenetic landscape underlying cardiovascular disease (CVD) is not completely understood and the clinical value of the identifed biomarkers is still limited. We aimed to identify diferentially methylated loci associ‑ ated with acute myocardial infarction (AMI) and assess their validity as predictive and causal biomarkers. Results: We designed a case-control, two-stage, epigenome-wide association study on AMI (ndiscovery=391, nvalidation=204). DNA methylation was assessed using the Infnium MethylationEPIC BeadChip. We performed a fxed efects meta-analysis of the two samples. 34 CpGs were associated with AMI. Only 12 of them were available in two independent cohort studies (n~1800 and n~2500) with incident coronary and cardiovascular disease (CHD and CVD, respectively). The Infnium HumanMethylation450 BeadChip was used in those two studies. Four of the 12 CpGs were validated in association with incident CHD: AHRR-mapping cg05575921, PTCD2-mapping cg25769469, intergenic cg21566642 and MPO-mapping cg04988978. We then assessed whether methylation risk scores based on those CpGs improved the predictive capacity of the Framingham risk function, but they did not. Finally, we aimed to study the causality of those associations using a Mendelian randomization approach but only one of the CpGs had a genetic infuence and therefore the results were not conclusive. Conclusions: We have identifed 34 CpGs related to AMI. These loci highlight the relevance of smoking, lipid metab‑ olism, and infammation in the biological mechanisms related to AMI. Four were additionally associated with incident CHD and CVD but did not provide additional predictive informatio
Influence of IL-6, IL-8, and TGF-\u3b21 gene polymorphisms on the risk of human papillomavirus-infection in women from Pernambuco, Brazil
Human papillomavirus (HPV) infections are strongly associated with the development of cervical intraepithelial neoplasias and invasive cervical cancer. Polymorphisms in cytokine-encoding genes and behavioural cofactors could play an important role in protecting an individual against viral infections and cancer. Here, we investigated whether IL-6 -174 G>C, IL-8 +396 G>T, and TGF-\u3b21 +869 G>C and +915 G>C polymorphisms were associated with susceptibility to HPV infection in women from north-east (Pernambuco) Brazil. We analysed 108 healthy uninfected women (HC) and 108 HPV-positive women with cervical lesions. Genetic polymorphisms were assessed using Sanger sequencing and polymerase chain reaction-restriction fragment length polymorphism. Comparison of the distribution of the genotypic and allelic frequencies of the IL-18 +396 T>G polymorphism between HPV infected woman an uninfected controls showed that the GG genotype and G allele were both more frequent in the HC group, and were associated with protection from HPV infection (p = 0.0015; OR = 0.29 CI95% = 0.13-0.61; p = 0.0005; OR = 0.45 CI95% 0.29-0.7, respectively). Individuals from the control group could have previously had HPV infection that was spontaneously eliminated; however, it was undetectable at the time of sample collection. Based on our findings, we hypothesize that the IL-8 +396 G>T polymorphism could interfere with susceptibility to HPV infection, by modulating the ability of immune system to fight the virus
Vasodilator activity of extracts of field Alpinia purpurata (Vieill) K: Schum and A. zerumbet (Pers.) Burtt et Smith cultured in vitro
Nowadays, the high blood pressure is one of the main causes of death and cardiovascular diseases. Vasodilator drugs are frequently used to treat arterial hypertension. Experiments were undertaken to determine whether hydroalcoholic extracts obtained from leaves of field-grown Alpinia purpurata and A. zerumbet cultured in vitro under different plant growth regulators induce a vasodilator effect on Wistar rat mesenteric vascular bed pre-contracted with norepinephrine. Plant extracts were able to induce a long-lasting endothelium-dependent vasodilation. Efficiency on activity of A. purpurata reached 87% at concentration of 60 μg. The extract of A. zerumbet maintained in medium containing IAA, induced the relaxation (17.4%) at 90 μg, as compared to the control (MS0) that showed a better vasodilator effect (60%). These results are in agreement with the quantification of phenolic compounds in the extracts, which were 50% lower for those plants cultured in IAA. A. purpurata was assayed for the first time in relation to its vasodilator activity. This paper showed a strong probability of correlation between the pharmacological activities of A. purpurata with their content in phenolic compounds.Atualmente, a hipertensão arterial é uma das maiores causas de morte e de doenças cardiovasculares. Os vasodilatadores são freqüentemente utilizados no tratamento da hipertensão. Extratos hidroalcoólicos de Alpinia purpurata de campo e de A. zerumbet cultivada in vitro sob diferentes reguladores de crescimento vegetal foram ensaiados no leito mesentérico de ratos Wistar. Os extratos de A. purpurata e A. zerumbet produziram efeito vasodilatador com padrão de resposta dose-dependente de duração prolongada. Extratos da espécie A. purpurata tiveram efeito vasodilatador de 87% na dose de 60 μg. O extrato obtido de folhas de A. zerumbet oriundas das culturas mantidas em meio contendo AIA (ácido indol acético) inibiu o relaxamento (17,4%) na dose de 90 μg em relação ao controle (MS0), com o qual foi verificado melhor efeito vasodilatador (60%). Estes resultados estão de acordo com a concentração de fenóis totais que foi 50% menor para os extratos de plantas cultivadas in vitro em AIA. A espécie A. purpurata foi pela primeira vez ensaiada quanto à atividade vasodilatadora. Os resultados obtidos indicaram a presença de substâncias fenólicas provavelmente correlacionadas à ação terapêutica de A. purpurata
Risk Factors for Type 2 Diabetes Mellitus in Children
This study investigates risk factors for type 2 diabetes mellitus in a population of children in public schools, Fortaleza, CE, Brazil. A total of 727 children aged 6 to 11 years old from 12 schools were evaluated between March and June 2008. A form addressing socio-demographic data, body mass index, blood pressure, capillary blood glucose and waist circumference was applied. A total of 54.1% of the children were female, 21.7% were overweight, 6.6% were obese, 27% had central obesity, 6.2% showed altered capillary glucose, and 17% high blood pressure. In relation to risk factors, 53.4% presented no risk factors; 24.3% had at least one factor and 18.8% two risk factors. Nurses can intervene in schools through educational health programs encouraging the adoption of healthy habits and identifying children at risk of type 2 diabetes mellitus.El estudio tuvo como objetivo identificar factores de riesgo para diabetes mellitus tipo 2 en una población de niños de escuelas públicas de Fortaleza, Brasil. Fueron evaluadas 727 niños de 6 a 11 años, de 12 escuelas, en los meses de marzo a junio de 2008. Fue aplicado un formulario abordando aspectos sociodemográficos, índice de masa corporal, presión arterial, glucemia capilar y, circunferencia de la cintura. Fue identificado que 54,1% de los sujetos eran del sexo femenino, 21,7% tenían exceso de peso, 27% obesidad central, 6,2% alteraciones en la glucemia y 17,9% presión arterial elevada. En relación a los factores de riesgo, 53,4% no lo presentaban, 24,3% tenían por lo menos un factor y 18,8% dos factores. La enfermería puede actuar en las escuelas por medio de acciones de educación en salud, incentivando la adopción de hábitos de vida saludables y identificando niños con riesgo para diabetes mellitus tipo 2.O estudo teve como objetivo identificar fatores de risco para diabetes mellitus tipo 2 numa população de crianças de escolas públicas de Fortaleza, CE, Brasil. Foram avaliadas 727 crianças de 6 a 11 anos de 12 escolas, nos meses de março a junho de 2008. Foi aplicado formulário abordando aspectos sociodemográficos, índice de massa corporal, pressão arterial, glicemia capilar e circunferência da cintura. Dos sujeitos, 54,1% eram do sexo feminino, 21,7% tinham excesso de peso, 27% obesidade central, 6,2% alterações glicêmicas e 17,9% pressão arterial elevada. Em relação aos fatores de risco, 53,4% não apresentavam, 24,3% tinham pelo menos um fator e 18,8%, dois. A enfermagem pode atuar nas escolas por meio de ações de educação em saúde, incentivando a adoção de hábitos de vida saudáveis e na identificação de crianças com risco para diabetes mellitus tipo 2
Molecular epidemiological investigation of Mayaro virus in febrile patients from Goiania City, 2017-2018.
Mayaro virus (MAYV) has historically been associated with sylvatic transmission; however, urban outbreaks have been reported in Brazil, including cases of co-detection with dengue virus (DENV). Therefore, we performed a molecular survey to investigate MAYV circulation and cocirculation with DENV within Goiania, a major city in Central-West Brazil. Among 375 subjects with arbovirus-like symptoms, 259 were positive for DENV and 26 for MAYV. Of these, 17 were coinfected with DENV-2, suggesting co-transmission of the viruses. The most common complaints at the time of inclusion were myalgia, headache, fever, arthralgia, retro-orbital pain, and skin rash. No specific symptoms were associated with MAYV when either detected alone or co-detected with DENV, compared to that when DENV was detected alone. Most MAYV-infected subjects were women with no recent travel history to rural/sylvatic areas. Phylogenetic reconstruction indicated that the MAYV identified in this study is closely related with a lineage observed in Peru, belonging to genotype D. Our results corroborate the growing circulation of MAYV in urban environments in Brazil and reinforce the need to implement laboratory diagnosis in the Unified Health System, considering that the clinical manifestations of Mayaro fever are similar to those of other arboviruses, particularly dengue. Furthermore, most cases occurred in association with DENV-2. Further phylogenetic studies are needed to evaluate MAYV, which has not been widely examined
XRCC1 gene polymorphisms in a population sample and in women with a family history of breast cancer from Rio de Janeiro (Brazil)
The X-ray repair cross-complementing Group1 (XRCC1) gene has been defined as essential in the base excision repair (BER) and single-strand break repair processes. This gene is highly polymorphic, and the most extensively studied genetic changes are in exon 6 (Arg194Trp) and in exon 10 (Arg399Gln). These changes, in conserved protein sites, may alter the base excision repair capacity, increasing the susceptibility to adverse health conditions, including cancer. In the present study, we estimated the frequencies of the XRCC1 gene polymorphisms Arg194Trp and Arg399Gln in healthy individuals and also in women at risk of breast cancer due to family history from Rio de Janeiro. The common genotypes in both positions (194 and 399) were the most frequent in this Brazilian sample. Although the 194Trp variant was overrepresented in women reporting familial cases of breast cancer, no statistically significant differences concerning genotype distribution or intragenic interactions were found between this group and the controls. Thus, in the population analyzed by us, variants Arg194Trp and Arg399Gln did not appear to have any impact on breast cancer susceptibility
XRCC1 gene polymorphisms in a population sample and in women with a family history of breast cancer from Rio de Janeiro (Brazil)
The X-ray repair cross-complementing Group1 (XRCC1) gene has been defined as essential in the base excision repair (BER) and single-strand break repair processes. This gene is highly polymorphic, and the most extensively studied genetic changes are in exon 6 (Arg194Trp) and in exon 10 (Arg399Gln). These changes, in conserved protein sites, may alter the base excision repair capacity, increasing the susceptibility to adverse health conditions, including cancer. In the present study, we estimated the frequencies of the XRCC1 gene polymorphisms Arg194Trp and Arg399Gln in healthy individuals and also in women at risk of breast cancer due to family history from Rio de Janeiro. The common genotypes in both positions (194 and 399) were the most frequent in this Brazilian sample. Although the 194Trp variant was overrepresented in women reporting familial cases of breast cancer, no statistically significant differences concerning genotype distribution or intragenic interactions were found between this group and the controls. Thus, in the population analyzed by us, variants Arg194Trp and Arg399Gln did not appear to have any impact on breast cancer susceptibility
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