Do Caucasian and Asian clocks tick differently?

The Period 3 and Clock genes are important components of the mammalian molecular circadian system. Studies have shown association between polymorphisms in these clock genes and circadian phenotypes in different populations. Nevertheless, differences in the pattern of allele frequency and genotyping distribution are systematically observed in studies with different ethnic groups. To investigate and compare the pattern of distribution in a sample of Asian and Caucasian populations living in Brazil, we evaluated two well-studied polymorphisms in the clock genes: a variable number of tandem repeats (VNTR) in PER3 and a single nucleotide polymorphism (SNP) in CLOCK. The aim of this investigation was to search for clues about human evolutionary processes related to circadian rhythms. We selected 109 Asian and 135 Caucasian descendants. The frequencies of the shorter allele (4 repeats) in the PER3 gene and the T allele in the CLOCK gene among Asians (0.86 and 0.84, respectively) were significantly higher than among Caucasians (0.69 and 0.71, respectively). Our results directly confirmed the different distribution of these polymorphisms between the Asian and Caucasian ethnic groups. Given the genetic differences found between groups, two points became evident: first, ethnic variations may have implications for the interpretation of results in circadian rhythm association studies, and second, the question may be raised about which evolutionary conditions shaped these genetic clock variations.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Associação Fundo de Incentivo à Pesquisa (AFIP)Universidade Federal de São Paulo (UNIFESP) Instituto do Sono Departamento de PsicobiologiaUniversidade de São Paulo Escola de Artes, Ciências e Humanidades Curso de GerontologiaUNIFESP, Instituto do Sono Depto. de PsicobiologiaFAPESP: 98/14303-

Rastreamento de polimorfismos no gene HIOMT e associações com os fenótipos circadianos

HIOMT is a gene that encodes hydroxyindole-O-methyltransferase,\ud the final enzyme in the melatonin synthesis pathway. As the\ud timing of melatonin synthesis is different for morning and evening\ud people, it is possible that polymorphisms in genes coding for the\ud enzymes which participate in melatonin synthesis can influence this\ud hormone synthesis and release patterns that may result in different\ud circadian outputs. The aim of this study was to search for polymorphisms\ud in the HIOMT gene and to verify possible associations\ud between genetic variations in this gene and circadian phenotypes\ud in a Brazilian population sample. Among the 44 extreme morning\ud and the 48 extreme evening people, ten polymorphisms were found,\ud being two of them not described so far. Haploview analyses\ud showed linkage disequilibrium between pairs of polymorphisms\ud in the promoter B region. Also, the haplotype AG (rs4446909,\ud rs5989681) is associated with evening preference. The analysis\ud of these data indicates that polymorphisms in the HIOMT gene\ud exhibit a possible trend to influence circadian phenotypes in this\ud Brazilian population sample, possibly affecting the rate and/or level\ud of melatonin synthesisO HIOMT é um gene que codifica para a hidroxindole-O-metiltransferase,\ud a enzima final na via de síntese da melatonina. Uma\ud vez que a temporização da síntese de melatonina é diferente para\ud pessoas matutinas e vespertinas, é possível que polimorfismos nos\ud genes codificantes para as enzimas que participam da síntese da melatonina\ud possam influenciar os padrões de síntese e liberação deste\ud hormônio, resultando em diferentes respostas circadianas. O objetivo\ud deste estudo foi buscar por polimorfismos no gene HIOMT\ud e verificar a existência de possíveis associações entre as variações\ud genéticas neste gene e os fenótipos circadianos em uma amostra da\ud população brasileira. Entre os 44 indivíduos matutinos extremos e\ud os 48 vespertinos extremos, dez polimorfismos foram encontrados,\ud sendo dois deles ainda não descritos até o momento. Análises do\ud Haploview mostraram um desequilíbrio de ligação entre pares de\ud polimorfismos na região do promotor B. Ainda, o haplótipo AG\ud (rs4446909, rs5989681) está associado com a preferência vespertina. A análise destes dados indica que polimorfismos no gene HIOMT\ud exibem uma tendência na influência sobre os fenótipos circadianos\ud na amostra da população brasileira investigada, podendo afetar a\ud taxa e/ou o nível da síntese de melatoninaThis research was funded by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Centros de Pesquisa, Inovação e Difusão (CEPID), Grant # 1998/14303-3, and Associação Fundo de Incentivo à Psicofarmacologia (AFIP

Efficiency of daily kombucha consumption in reducing glycemic levels and hypercholesterolemia

Diabetes is one of the most common comorbidities in the world. The scientific community is constantly looking for therapeutic alternatives, pharmacological or not, to treat this disease. In this concern, an integrative review of studies published on this topic in the last ten years was carried out. Experimental studies have shown glycemic and lipid rates reduction in diabetic guinea pigs under daily kombucha consumption. Such studies showed blood sugar levels reduction of up to 56% of these specimens, as well as a significant reduction of free radicals, hepatoprotection and reduction of transaminases in these animals

Is there a relationship between hippocampus-dependent memory and 5-ht2a receptors? Insights from a systematic review / Há uma relação entre a memória hipocampo-dependente e receptores 5-HT2a? Insights de uma revisão sistemática

This is a systematic review with the aim of analyzing the role of 5-HT2A receptors in hippocampal-dependent memory. In order to do this, we searched the PubMed, Science Direct, and Neuron databases between October 23 and 29, 2018, using the following descriptor combinations: memory, 5-HT2A, and hippocampus, present in the title, abstract, or keywords, with no restrictions on study date or language. Following search and selection, we analyzed risk of bias, and the results were subsequently synthesized according to the experimental model. Out of 40 articles, four were included in qualitative analysis. The data indicate that the 5-HT2A receptors in the hippocampus play an important role in the memory consolidation process, although they do not interfere in the encoding or retrieval processes of these memories. Additionally, chronic use of receptor agonists in models of Alzheimer’s disease also demonstrates better performance in the object recognition tests. The action of 5-HT2A receptors has also been shown to be important to aversive memory formation, thus attributing a prominent role to these receptors in hippocampal-dependent memory processes

Oral health of an indigenous population in northeastern Brazil: a cross-sectional Study of the Fulni-ô ethnic group

ABSTRACT BACKGROUND: There is a lack of studies evaluating the oral health of traditional indigenous communities in Brazil. OBJECTIVES: Thus, the objective of this study was to describe the oral health characteristics of the indigenous Fulni-ô ethnic group in Northeast Brazil. DESIGN AND SETTING: A cross-sectional observational investigation was conducted within the Project on Atherosclerosis among Indigenous Populations. METHODS: This study included participants of both sexes from the Fulni-ô ethnic group. The participants included in this investigation underwent a comprehensive oral health evaluation by a registered and experienced dentist to assess oral health and identify potentially malignant oral lesions. Participants with suspicious lesions were referred for biopsy. Shapiro-Wilk, Mann-Whitney, and Student’s t-tests were used, and measures of central tendency and dispersion were described. Statistical significance was 5%. RESULTS: A total of 104 individuals were included in this study. The prevalence of the use of tobacco derivatives was 94.0%, with similarities between sexes. The prevalence of oral changes in this study population was 84.4%. Fifty-one individuals who underwent oral reassessment were referred for oral lesion biopsy. CONCLUSIONS: This study demonstrated a high prevalence of oral alterations in the Fulni-ô population. Histopathological analyses indicated the presence of mild oral epithelial dysplasia in five cases

Interactions of polymorphisms in different clock genes associated with circadian phenotypes in humans

Several studies have shown that mutations and polymorphisms in clock genes are associated with abnormal circadian parameters in humans and also with more subtle non-pathological phenotypes like chronotypes. However, there have been conflicting results, and none of these studies analyzed the combined effects of more than one clock gene. Up to date, association studies in humans have focused on the analysis of only one clock gene per study. Since these genes encode proteins that physically interact with each other, combinations of polymorphisms in different clock genes could have a synergistic or an inhibitory effect upon circadian phenotypes. In the present study, we analyzed the combined effects of four polymorphisms in four clock genes (Per2, Per3, Clock and Bmal1) in people with extreme diurnal preferences (morning or evening). We found that a specific combination of polymorphisms in these genes is more frequent in people who have a morning preference for activity and there is a different combination in individuals with an evening preference for activity. Taken together, these results show that it is possible to detect clock gene interactions associated with human circadian phenotypes and bring an innovative idea of building a clock gene variation map that may be applied to human circadian biology

Rastreamento de polimorfsmos no gene HIOMT e associações com os fenótipos circadianos

HIOMT is a gene that encodes hydroxyindole-O-methyltransfe-rase, the final enzyme in the melatonin synthesis pathway. As the timing of melatonin synthesis is different for morning and evening people, it is possible that polymorphisms in genes coding for the enzymes which participate in melatonin synthesis can influence this hormone synthesis and release patterns that may result in different circadian outputs. The aim of this study was to search for polymorphisms in the HIOMT gene and to verify possible associations between genetic variations in this gene and circadian phenotypes in a Brazilian population sample. Among the 44 extreme morning and the 48 extreme evening people, ten polymorphisms were found, being two of them not described so far. Haploview analyses showed linkage disequilibrium between pairs of polymorphisms in the promoter B region. Also, the haplotype AG (rs4446909, rs5989681) is associated with evening preference. The analysis of these data indicates that polymorphisms in the HIOMT gene exhibit a possible trend to influence circadian phenotypes in this Brazilian population sample, possibly affecting the rate and/or level of melatonin synthesis

The G619A Aa-nat gene polymorphism does not contribute to sleep time variation in the brazilian population

Genes involved in melatonin synthesis, such as Aa-nat, may be important for our understanding of diurnal preference and circadian rhythm disturbances in humans. in Japan, Hohjoh et al. reported increased allelic frequencies of the 619A allele of the G619A Aa-nat gene polymorphism in a sample of Delayed Sleep Phase Syndrome (DSPS) patients. the present study sought to analyze G619A polymorphism frequency in a Brazilian sample, including DSPS patients. We found almost no allelic variation for G619A polymorphism in our sample, except for two heterozygous samples out of 551. Our results leave open the question of whether there would be an association if there were some genetic variation in our population. It is important to analyze different ethnic groups in order to validate the effect of G619A polymorphism on sleep timing.Universidade Federal de São Paulo, Dept Psychobiol, Sleep Inst, BR-04024002 São Paulo, BrazilUniv Fed Parana, Dept Physiol, BR-80060000 Curitiba, Parana, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, Sleep Inst, BR-04024002 São Paulo, BrazilWeb of Scienc