The illusion of clocks: a threat to health

The mechanistic or digitality of watches is the immutability of the length of time slices. However, historically 24 hours timing had as a reference, at first, the environmental cues associated with the conditions of the day and night that are dif erent in dif erent places on earth. The emergence of a subfield of biology, Chronobiology in the mid-twentieth century led to the interpretation that the apprehension of time of a day as mechanical regularity alienates human perception of daily temporality as the integration between environmental and biological temporality. I intend to show here that this perceptual misunderstanding of the 24h temporality can result in a physiological temporal disorganization that is the source or is associated with the source of many modern diseasesA mecanicidade ou digitalidade dos relógios representa a imutabilidade da duração de frações de tempo. A contagem das 24h de um dia teve como referência, a princípio, as pistas ambientais associadas às condições do dia e da noite que são diferentes em diferentes locais da terra e portanto mutáveis. A emergência de uma sub-área da Biologia, a Cronobiologia, em meados do século XX permitiu a interpretação de que a apreensão do tempo de um dia como regularidade mecânica aliena os seres humanos da percepção da temporalidade diária como integração entre temporalidade ambiental e temporalidade biológica. Pretendo demonstrar que esse equívoco perceptual da duração do tempo de um dia pode ter como consequência uma desorganização temporal fisiológica que é a origem ou está associada a origem de muitas doenças modernas

Mesenteric-Portal Vein Resection during Pancreatectomy for Pancreatic Cancer

The aim of the present study was to determine the outcome of patients undergoing pancreatic resection with (VR+) or without (VR 12) mesenteric-portal vein resection for pancreatic carcinoma. Between January 1998 and December 2012, 241 patients with pancreatic cancer underwent pancreatic resection: in 64 patients, surgery included venous resection for macroscopic invasion of mesenteric-portal vein axis. Morbidity and mortality did not differ between the two groups (VR+: 29% and 3%; VR 12: 30% and 4.0%, resp.). Radical resection was achieved in 55/64 (78%) in the VR+ group and in 126/177 (71%) in the VR 12 group. Vascular invasion was histologically proven in 44 (69%) of the VR+ group. Survival curves were not statistically different between the two groups. Mean and median survival time were 26 and 15 months, respectively, in VR 12 versus 20 and 14 months, respectively, in VR+ group . In the VR+ group, only histologically proven vascular invasion significantly impacted survival , while, in the VR 12 group, R0 resection and tumor\u2019s grading significantly influenced long-term survival. Vascular resection during pancreatectomy can be performed safely, with acceptable morbidity and mortality. Long-term survival was the same, with or without venous resection. Survival was worse for patients with histologically confirmed vascular infiltration

Influence of chronotype and social zeitgebers on sleep/wake patterns

Inter-individual differences in the phase of the endogenous circadian rhythms have been established. Individuals with early circadian phase are called morning types; those with late circadian phase are evening types. The Horne and Östberg Morningness-Eveningness Questionnaire (MEQ) is the most frequently used to assess individual chronotype. The distribution of MEQ scores is likely to be biased by several fact, ors, such as gender, age, genetic background, latitude, and social habits. The objective of the present study was to determine the effect of different social synchronizers on the sleep/wake cycle of persons with different chronotypes. Volunteers were selected from a total of 1232 UFPR undergraduate students who completed the MEQ. Thirty-two subjects completed the study, including 8 morning types, 8 evening types and 16 intermediate types. Sleep schedules were recorded by actigraphy for 1 week on two occasions: during the school term and during vacation. Sleep onset and offset times, sleep duration, and mid-sleep time for each chronotype group were compared by the Mann-Whitney U-test separately for school term and vacation. School term and vacation data were compared by the Wilcoxon matched-pair test. Morning types showed earlier sleep times and longer sleep duration compared with evening types (23:00 ± 44 and 508.9 ± 50.27 vs 01:08 ± 61.95 and 456.44 ± 59.08, for the weekdays during vacation). During vacation, the subjects showed later sleep times, except for the morning types, who did not exhibit differences for sleep onset times. The results support the idea that social schedules have an impact on the expression of circadian rhythmicity but this impact depends on the individual chronotype.Universidade Federal do Paraná Departamento de Fisiologia Setor de Ciências BiológicasUniversidade Federal de São Paulo (UNIFESP) Departamento de Psicobiologia/Instituto de SonoUNIFESP, Depto. de Psicobiologia/Instituto de SonoSciEL

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-

Simple Detection of Large InDeLS by DHPLC: The ACE Gene as a Model

Insertion-deletion polymorphism (InDeL) is the second most frequent type of genetic variation in the human genome. For the detection of large InDeLs, researchers usually resort to either PCR gel analysis or RFLP, but these are time consuming and dependent on human interpretation. Therefore, a more efficient method for genotyping this kind of genetic variation is needed. In this report, we describe a method that can detect large InDeLs by DHPLC (denaturating high-performance liquid chromatography) using the angiotensin-converting enzyme (ACE) gene I/D polymorphism as a model. The InDeL targeted in this study is characterized by a 288 bp Alu element insertion (I). We used DHPLC at nondenaturating conditions to analyze the PCR product with a flow through the chromatographic column under two different gradients based on the differences between D and I sequences. The analysis described is quick and easy, making this technique a suitable and efficient means for DHPLC users to screen InDeLs in genetic epidemiological studies

SMAD4 loss enables EGF, TGF\u3b21 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells

Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor \u3b21 (TGF\u3b21) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGF\u3b21 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGF\u3b21 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/\u3b2-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGF\u3b21 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-\u3baB and PI3K/AKT in response to TGF\u3b21 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/\u3b2-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGF\u3b21 and S100A8/A9 mainly inhibit NF-\u3baB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner

Polimorfismos em receptores hipocretinérgicos e insônia

Hypocretin system has been described as one of the most important neurotransmission systems involved in the waking process. The system’s lack of function, caused by mutation or neuron death, leads to sharp sleepiness in mammals. It has been proposed that a hyperactive hypocretin system can result in hyperarousal episodes and insomnia. Hypocretins 1 and 2 are bind to two known receptors that are widely distributed in the brain. The current study sought to analyze if either polymorphism in hypocretin receptor 1 or in hypocretin receptor 2 are associated to insomnia. We enrolled 83 insomnia patients, confirmed their clinical insomnia symptoms by means of polysomnographic recordings, comparing single nucleotide polymorphism frequencies in both hypocretin receptors and to those from healthy control patients who had no sleep disorders as confirmed by two nights of sleeping records. Our results show no association to either receptor polymorphism or insomniaO sistema de neurotransmissão hipocretinérgico tem sido descrito como um dos mais importantes envolvidos no processo de manutenção do alerta. A ausência da função neste sistema, por mutação ou morte neuronal, leva à sonolência excessiva em mamíferos. Tem sido proposto que um sistema hipocretinérgico hiperativo pode resultar em episódios de alerta e insônia. As hipocretinas 1 e 2 se ligam a dois receptores conhecidos e amplamente distribuídos no cérebro. No presente estudo, buscamos investigar se existe associação entre variações genéticas nos receptores das hipocretinas e a insônia. Foram incluídos 83 pacientes insones, com sintomas clínicos confirmados por registro polissonográfico e investigadas as frequências de polimorfismos em ambos os receptores de hipocretina comparados com uma amostra controle sem distúrbios de sono. Nossos resultados não mostraram associação entre polimorfismos nestes nos dois receptores com insôniaFAPESP 05/58077-2CEPID 98/14303-3AFI

Glucocorticoid receptors modulate dendritic spine plasticity and microglia activity in an animal model of Alzheimer's disease

Abstract Chronic exposure to high circulating levels of glucocorticoids (GCs) may be a key risk factor for Alzheimer's Disease (AD) development and progression. In addition, hyper-activation of glucocorticoid receptors (GRs) induces brain alterations comparable to those produced by AD. In transgenic mouse models of AD, GCs increase the production of the most important and typical hallmarks of this dementia such as: Aβ40, Aβ42 and tau protein (both the total tau and its hyperphosphorylated isoforms). Moreover, GCs in brain are pivotal regulators of dendritic spine turnover and microglia activity, two phenomena strongly altered in AD. Although it is well-established that GCs primes the neuroinflammatory response in the brain to some stimuli, it is unknown whether or how GRs modulates dendritic spine plasticity and microglia activity in AD. In this study, we evaluated, using combined Golgi Cox and immunofluorescence techniques, the role of GR agonists and antagonists on dendritic spine plasticity and microglia activation in hippocampus of 3xTg-AD mice. We found that dexamethasone, an agonist of GRs, was able to significantly reduce dendritic spine density and induced proliferation and activation of microglia in CA1 region of hippocampus of 3xTg-AD mice at 6 and 10 months of age. On the contrary, the treatment with mifepristone, an antagonist of GRs, strongly enhanced dendritic spine density, decreased microglia density and improved the behavioural performance of 3xTg-AD mice. Additionally, primary microglial cells in vitro were directly activated by dexamethasone. Together, these data demonstrate that stress exacerbates AD and promotes a rapid progression of the pathology acting on both neurons and glial cells, supporting an important pro-inflammatory role of GC within CNS in AD. Consequently, these results further strengthen the need to test clinical interventions that correct GCs dysregulation as promising therapeutic strategy to delay the onset and slow down the progression of AD

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

Estudo dos linfócitos T CD4, CD8 e B em pacientes com narcolepsia

Narcolepsy is characterized by excessive daytime sleep and cataplexy. Little is known about the possible difference in pathophysiology between patients with or without cataplexy. OBJECTIVE: To quantify T CD4, T CD8 and B lymphocytes in subgroups of patients with narcolepsy and the presence or absence of the HLA-DQB1*0602 allele between groups. METHOD: Our study was prospective and controlled (transversal) with 22 narcoleptic patients and 23 health control subjects. Patients underwent an all-night polysomnographic recording (PSG) and a multiple sleep latency Test (MSLT). The histocompatibility antigen allele (HLA-DQB1*0602), T CD4, CD8 and B lymphocytes were quantified in control subjects and in narcoleptics. RESULTS: The HLA-DQB1*0602 allele was identified in 10 (62.5%) of our 16 cataplexic subjects and in 2 (33.3%) of the 6 patients without cataplexy (p=0.24). In control subjects, HLA-DQB1*0602 allele was identified in 5 (20%). A significant decrease in T CD4 and B lymphocytes was found in narcoleptic patients with recurrent cataplexy when compared with our patients without cataplexy. CONCLUSION: Autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis were associated with a decrease in sub-group of T CD4 and B lymphocytes. A drop in B lymphocytes count in reumathoid arthritis might, it is posited, be correlated to the presence of HLA-DRB1 allele along with an overall worsened outcome of the affliction. The theory of an increase in consumption of B lymphocytes over the maturation phase has likewise been put forward. Our study reinforces the view that narcolepsy should be considered from an immunological perspective.A narcolepsia é caracterizada por sonolência excessiva diurna e cataplexia. Pouco se sabe sobre as diferenças fisiopatológicas entre pacientes com e sem cataplexia. OBJETIVO: Quantificar os linfócitos T CD4, T CD8 e B e a presença do alelo HLA-DQB1*0602 nos subgrupos de pacientes com narcolepsia. MÉTODO: O estudo foi prospectivo e controlado (transversal) com 22 pacientes portadores de narcolepsia e 23 sujeitos controle. Os pacientes realizaram polissonografia (PSG) de noite inteira e teste de múltiplas latências do sono (TMLS). O alelo do antígeno de histocompatibilidade (HLA-DQB1*0602) e os linfócitos T CD4, T CD8 e B foram quantificados nos pacientes e sujeitos controle. RESULTADOS: O alelo HLA-DQB1*0602 foi encontrado em 10 (62,5%) dos 16 pacientes com cataplexia e em 2 (33,3%) dos 6 pacientes sem cataplexia (p=0,24). Nos sujeitos controle, o alelo HLA-DQB1*0602 foi encontrado em 5 sujeitos (20%). Um aumento significativo de linfócitos T CD4 e uma diminuição de linfócitos B foi observado no grupo de pacientes com cataplexia freqüente quando comparado ao grupo de pacientes sem cataplexia. CONCLUSÃO: Doenças auto-imunes como lupus eritematoso sistêmico e artrite reumatóide têm sido associadas com diminuição de linfócitos T CD4 e B. Na artrite reumatóide, diminuição de linfócitos B e presença do alelo HLA-DRB1 tem sido associada a pior evolução. Para essa doença, a teoria de um maior consumo de linfócitos B em suas fases de maturação tem sido aventada. Os achados do nosso estudo reforçam a teoria imunológica da narcolepsia.UNIFESP-EPM Sleep Disorders InstituteUNIFESP, EPM, Sleep Disorders InstituteSciEL