BACKGROUND Calpains are proteins belonging to the multi-gene family of calcium-dependent cysteine peptidases that undergo tight on/off regulation, and uncontrolled proteolysis of calpains is associated with severe human pathologies. Calpain orthologues are expanded and diversified in the trypanosomatids genome. OBJECTIVES Here, we characterised calpains in Leishmania braziliensis, the main causative agent of cutaneous leishmaniasis in Brazil. METHODS/FINDINGS In total, 34 predicted calpain-like genes were identified. After domain structure evaluation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) during in vitro metacyclogenesis revealed (i) five genes with enhanced expression in the procyclic stage, (ii) one augmented gene in the metacyclic stage, and (iii) one procyclic-exclusive transcript. Western blot analysis revealed that an antibody against a consensus-conserved peptide reacted with multiple calpain-like proteins, which is consistent with the multi-gene family characteristic. Flow cytometry and immunocytochemistry analyses revealed the presence of calpain-like molecules mainly in the cytoplasm, to a lesser extent in the plasma membrane, and negligible levels in the nucleus, which are all consistent with calpain localisation. Eventually, the calpain inhibitor MDL28170 was used for functional studies revealing (i) a leishmaniostatic effect, (ii) a reduction in the association index in mouse macrophages, (iii) ultra-structural alterations conceivable with autophagy, and (iv) an enhanced expression of the virulence factor GP63. CONCLUSION This report adds novel insights into the domain structure, expression, and localisation of L. braziliensis calpain-like molecules.

Resumo Introdução: Distúrbios do ritmo circadiano têm sido relatados em estudos com crianças e adolescentes deprimidos. O objetivo deste estudo foi avaliar se existe relação entre a potência espectral de 24 horas do ritmo de atividade e repouso e sintomas clínicos de depressão em adolescentes. Métodos: Seis adolescentes com idade entre 14 e 17 anos foram recrutados para o estudo. Eles foram diagnosticados com depressão maior de acordo com os critérios do Manual Diagnóstico e Estatístico de Transtornos Mentais, 4ª edição (DSM-IV), identificados utilizando-se o instrumento Schedule for Affective Disorders and Schizophrenia for School Aged Children: Present and Lifetime Version (K-SADS-PL). Os sintomas depressivos foram avaliados pelo questionário Children's Depression Rating Scale - Revised (CDRS-R) e por avaliações clínicas. A atividade motora foi monitorada por um período de 13 semanas consecutivas e registrada a cada 10 minutos utilizando-se monitores de atividades usados no pulso. Todos os pacientes utilizaram o antidepressivo sertralina começando após a primeira semana até o final do estudo. Resultados: Foi observada uma relação entre escores altos no CDRS-R e valores baixos de potência espectral de 24 horas no ritmo de atividade e repouso. Conclusão: A potência espectral de 24 horas do ritmo de atividade e repouso apresentou uma correlação significativa (negativa) com os sintomas clínicos de depressão.

Abstract Introduction: Disorders of circadian rhythms have been reported in studies of both depressed children and of depressed adolescents. The aim of this study was to evaluate whether there is a relationship between the 24-hour spectral power (24h SP) of the activity/rest rhythm and the clinical course of depression in adolescents. Methods: Six 14 to 17-year-old adolescents were recruited for the study. They were all suffering from major depressive disorder, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria, as identified by the Schedule for Affective Disorders and Schizophrenia for School Aged Children: Present and Lifetime Version (K-SADS-PL). Depressive symptoms were assessed using the Children's Depression Rating Scale - Revised (CDRS-R) and clinical evaluations. Locomotor activity was monitored over a period of 13 consecutive weeks. Activity was measured for 10-minute periods using wrist-worn activity monitors. All patients were prescribed sertraline from after the first week up until the end of the study. Results: We found a relationship between high CDRS values and low 24-hour spectral power. Conclusions: The 24h SP of the activity/rest rhythm correlated significantly (negatively) with the clinical ratings of depression.

A doença de Chagas causada pelo Trypanosoma cruzi afeta cerca de oito milhões de pessoas em países em desenvolvimento, sendo classificada como uma doença tropical negligenciada pela Organização Mundial da Saúde. A quimioterapia disponível para esta doença é baseada em dois nitro-heterocíclicos, nifurtimox e benznidazol, ambos com graves efeitos colaterais e eficácia variável, e assim novos medicamentos visando um tratamento mais eficiente são necessários com urgência. Nos últimos 20 anos, temos desenvolvido em colaboração com grupos focados em química medicinal, um programa de quimioterapia experimental da doença de Chagas, investigando a eficácia, seletividade, toxicidade, alvos celulares e mecanismos de ação de diferentes classes de compostos sobre T. cruzi. Neste artigo, apresentamos uma visão geral desses estudos, enfocando protótipos naftoquinoidais e derivados, examinando a sua síntese, a atividade e mecanismo de ação, o que foi realizado e o que precisa ser abordado, avaliando e discutindo possíveis melhorias. Esta mini-revisão discute nosso esforço continuado visando a caracterização biológica e a síntese de compostos naftoquinoidais, auxiliando no desenvolvimento de um novo arsenal de drogas candidatas com eficácia contra o T. cruzi.

Chagas disease is caused by the parasite Trypanosoma cruzi and affects approximately eight million individuals in the developing world; it is also classified as a neglected tropical disease by the World Health Organization. The available therapy for this disease is based on two nitroheterocycles, nifurtimox and benznidazole, both of which exhibit severe side effects and variable efficacy; therefore, new drugs and better treatment schedules are urgently needed. For the past 20 years, we have been collaborating with groups focused on medicinal chemistry to produce experimental therapies for Chagas disease by investigating the efficacy, selectivity, toxicity, cellular targets and mechanisms of action of different classes of compounds against T. cruzi. In this report, we present an overview of these studies, focusing on naphthoquinonoid prototypes and discuss their synthesis, activity and mechanisms of action. Furthermore, we summarise the research that has been performed to date and suggest future research directions while assessing and discussing potential improvements. This mini-review discusses our continued efforts toward the biological characterisation and synthesis of naphthoquinoidal compounds, aiming to contribute to the development of a new arsenal of candidate drugs that exhibit effective anti-T. cruzi activity

Chronotype is an established concept designed to identify distinct phase relationships between the expression of circadian rhythms and external synchronizers in humans. Although it has been widely accepted that chronotype is subjected to ontogenetic modulation, there is no consensus on the interaction between age and gender. This study aimed to determine the relationship between age- and gender-related changes in the morningness-eveningness character in a large sample of people. A total of 14,650 volunteers were asked to complete the Brazilian version of the Horne and Östberg chronotype questionnaire. The data demonstrated that, on average, women were more morning-oriented than men until the age of 30 and there were no significant differences between men and women from 30 to 45 years of age. In contrast to the situation observed until the age of 30, women older than 45 years were more evening-oriented than men. These results suggest that the ontogenetic development of the circadian timekeeping system is more plastic in men, as represented by the larger amplitude of chronotype changes throughout their aging process. The phase delay of adolescence and phase advance of the elderly seem to be phenomena that are more markedly present in men than in women. Thus, our data, for the first time, provide support that sharply opposes the view that there is a single path toward morningness as a function of age, regardless of gender.

O vírus linfotrópico de células T-humanas do tipo II (HTLV-II) é identificado em muitos grupos de ameríndios. No Brasil, tem sido encontrado em indivíduos da população urbana, bem como em índios oriundos da região Amazônica. Os Índios Guaraní, do Sul do país, foram investigados para infecção por HTLV-I/II. Três indivíduos, oriundos de uma amostra de 52 índios, demonstraram sororeatividade para HTLV-II (ensaio imunoenzimático e Western blot). Este estudo preliminar foi o primeiro a identificar a presença de infecção por HTLV-II em ameríndios do Sul do Brasil.

Human T-cell lymphotropic virus type II (HTLV-II) is found in many New World Indian groups on the American continent. In Brazil, HTLV-II has been found among urban residents and Indians in the Amazon region, in the North. Guaraní Indians in the South of Brazil were studied for HTLV-I/II infection. Among 52 individuals, three (5.76%) showed positive anti-HTLV-II antibodies (enzyme-linked immunosorbent assay and Western blot). This preliminary report is the first seroepidemiological study showing HTLV-II infection among Indians in the South of Brazil.

O vírus linfotrópico de células T-humanas do tipo II (HTLV-II) é identificado em muitos grupos de ameríndios. No Brasil, tem sido encontrado em indivíduos da população urbana, bem como em índios oriundos da região Amazônica. Os Índios Guaraní, do Sul do país, foram investigados para infecção por HTLV-I/II. Três indivíduos, oriundos de uma amostra de 52 índios, demonstraram sororeatividade para HTLV-II (ensaio imunoenzimático e Western blot). Este estudo preliminar foi o primeiro a identificar a presença de infecção por HTLV-II em ameríndios do Sul do Brasil.

Human T-cell lymphotropic virus type II (HTLV-II) is found in many New World Indian groups on the American continent. In Brazil, HTLV-II has been found among urban residents and Indians in the Amazon region, in the North. Guaraní Indians in the South of Brazil were studied for HTLV-I/II infection. Among 52 individuals, three (5.76%) showed positive anti-HTLV-II antibodies (enzyme-linked immunosorbent assay and Western blot). This preliminary report is the first seroepidemiological study showing HTLV-II infection among Indians in the South of Brazil.

OBJETIVO: Avaliar as concentrações de interleucina-2 (IL-2) na secreção nasofaríngea de crianças (0-24 meses) acometidas de bronquiolite viral aguda pelo vírus respiratório sincicial nas primeiras 12 horas de hospitalização e correlacionar os níveis encontrados com a gravidade da doença. MÉTODOS: Estudo prospectivo com amostragem seqüencial realizado no período de junho a agosto de 1999. Foram incluídos 62 pacientes previamente hígidos, internados com diagnóstico de bronquiolite viral aguda caracterizado por pródromos recentes de coriza e/ou obstrução nasal que evoluíram com pelo menos dois dos seguintes sinais: disfunção respiratória, taquipnéia, sibilos ou crepitações. Todos os pacientes tiveram a presença de vírus respiratório sincicial detectada no aspirado nasofaríngeo. As amostras de secreção nasofaríngea foram obtidas nas primeiras 12 horas de hospitalização. As dosagens de IL-2 foram realizadas por ensaio imunoenzimático. A gravidade da doença foi avaliada por: medida da saturação de oxigênio da hemoglobina por oximetria de pulso, sistema de escore clínico modificado, tempo de uso de oxigênio, tempo de hospitalização e necessidade de ventilação mecânica, sendo estas variáveis comparadas em relação às medianas de IL-2 através dos testes de Spearman e Kruskal-Wallis e, para a análise categorizada da interleucina, através do teste de qui-quadrado. RESULTADOS: A mediana de idade dos pacientes foi 2,2 (1,3-4) meses. O sexo masculino foi observado em 54% dos casos. Saturação de oxigênio da hemoglobina por oximetria de pulso na hospitalização foi < 95% em 66,1% dos pacientes. A média do tempo de uso de oxigênio foi 4,7 dias (±3,54). A média do tempo de hospitalização foi de 4,25 dias (±1,76). Ventilação mecânica foi utilizada em 4,8% dos casos. Os níveis de IL-2 na secreção nasofaríngea variaram de 0 a 40.256 ng/ml, com mediana de 86 ng/ml (4,4-457,3). Não houve diferença estatisticamente significativa entre os níveis de IL-2 e a gravidade da doença. CONCLUSÕES: Os níveis de IL-2 apresentaram valores com grande dispersão. Não houve associação entre bronquiolite viral aguda pelo vírus respiratório sincicial e aumento nos níveis de IL-2 na secreção nasofaríngea.

OBJECTIVE: To assess interleukin-2 concentrations in nasopharyngeal secretion of children (0-24 months) with acute respiratory syncytial virus bronchiolitis, within the first 12 hours of hospital admission, and compare the levels of IL-2 with the severity of the illness. METHODS: Prospective study performed between June and August 1999. The study included 62 patients, previously healthy, hospitalized with acute viral bronchiolitis characterized by recent prodromes of coryza and/or nasal obstruction, which evolved to at least two of the following signs: respiratory dysfunction, tachypnea, wheezing or rales, and detection of respiratory syncytial virus in nasopharyngeal aspirate. The nasopharyngeal specimens were collected within 12 hours of hospital admission. The interleukin-2 levels were obtained by enzyme immunoassay. Severity of illness was assessed through oxygen saturation by pulse oximetry, Modified Clinical Score System, time of supplemental oxygen required, length of hospital stay, and mechanical ventilation. Spearman's correlation and Kruskal-Wallis test were used to compared these variables in relation to the median of interleukin-2. The chi-square test was used for categorical analysis of interleukin-2. RESULTS: The mean age of patients was 2.2 (1.3-4) months. Males comprised 54% of cases. Hemoglobin oxygen saturation by pulse oximetry at hospital admission was below 95% in 66.1% of patients. The mean time of supplemental oxygen use was 4.7 days (±3.54). The mean length of hospital stay was 4.25 days (±1.76). Mechanical ventilation was used in 4.8% of patients. The values of interleukin-2 in nasopharyngeal aspirates varied from 0 to 40,256 ng/ml with median of 86 ng/ml (4.4 - 457.3). The study showed no statistical difference between levels of IL-2 and severity of illness. CONCLUSIONS: The interleukin-2 levels showed a heterogeneous behavior. We found no association between interleukin-2 levels in nasopharyngeal secretion and respiratory syncytial virus bronchiolitis.

This article is a transcription of an electronic symposium held on February 5, 2001 by the Brazilian Society of Neuroscience and Behavior (SBNeC) during which eight specialists involved in clinical and experimental research on sleep and dreaming exposed their personal experience and theoretical points of view concerning these highly polemic subjects. Unlike most other bodily functions, sleep and dreaming cannot, so far, be defined in terms of definitive functions that play an ascribable role in maintaining the organism as a whole. Such difficulties appear quite clearly all along the discussions. In this symposium, concepts on sleep function range from a protective behavior to an essential function for maturation of the nervous system. Kleitman's hypothesis [Journal of Nervous and Mental Disease (1974), 159: 293-294] was discussed, according to which the basal state is not the wakeful state but sleep, from which we awake to eat, to protect ourselves, to procreate, etc. Dreams, on the other hand, were widely discussed, being considered either as an important step in consolidation of learning or simply the conscious identification of functional patterns derived from the configuration of released or revoked memorized information.

The present article is the adapted version of an electronic symposium organized by the Brazilian Society of Neuroscience and Behavior (SBNeC) which took place on June 14, 2000. The text is divided into three sections: I. The main issues, II. Chronodrugs, and III. Methods. The first section is dedicated to the perspectives of chronobiology for the next decade, with opinions about the trends of future research being emitted and discussed. The second section deals mostly with drugs acting or potentially acting on the organism's timing systems. In the third section there are considerations about relevant methodological issues concerning data analysis.