The impact of stress and stress hormones on endogenous clocks and circadian rhythms

In mammals, daily rhythms in physiology and behavior are under control of a circadian pacemaker situated in the suprachiasmatic nucleus (SCN). This master clock receives photic input from the retina and coordinates peripheral oscillators present in other tissues, maintaining all rhythms in the body synchronized to the environmental light-dark cycle. In line with its function as a master clock, the SCN appears to be well protected against unpredictable stressful stimuli. However, available data indicate that stress and stress hormones at certain times of day are capable of shifting peripheral oscillators in, e.g., liver, kidney and heart, which are normally under control of the SCN. Such shifts of peripheral oscillators may represent a temporary change in circadian organization that facilitates adaptation to repeated stress. Alternatively, these shifts of internal rhythms may represent an imbalance between precisely orchestrated physiological and behavioral processes that may have severe consequences for health and well-being

Pre-test metyrapone impairs memory recall in fear conditioning tasks: lack of interaction with I--adrenergic activity

Cognitive processes, such as learning and memory, are essential for our adaptation to environmental changes and consequently for survival. Numerous studies indicate that hormones secreted during stressful situations, such as glucocorticoids (GCs), adrenaline and noradrenaline, regulate memory functions, modulating aversive memory consolidation and retrieval, in an interactive and complementary way. Thus, the facilitatory effects of GCs on memory consolidation as well as their suppressive effects on retrieval are substantially explained by this interaction. On the other hand, low levels of GCs are also associated with negative effects on memory consolidation and retrieval and the mechanisms involved are not well understood. the present study sought to investigate the consequences of blocking the rise of GCs on fear memory retrieval in multiple tests, assessing the participation of (3-adrenergic signaling on this effect. Metyrapone (GCs synthesis inhibitor; 75 mg/kg), administered 90 min before the first test of contextual or tone fear conditioning (TFC), negatively affected animals' performances, but this effect did not persist on a subsequent test, when the conditioned response was again expressed. This result suggested that the treatment impaired fear memory retrieval during the first evaluation. the administration immediately after the first test did not affect the animals' performances in contextual fear conditioning (CFC), suggesting that the drug did not interfere with processes triggered by memory reactivation. Moreover, metyrapone effects were independent of beta-adrenergic signaling, since concurrent administration with propranolol (2 mg/kg), alpha,beta-adrenergic antagonist, did not modify the effects induced by metyrapone alone. These results demonstrate that pre-test metyrapone administration led to negative effects on fear memory retrieval and this action was independent of a beta-adrenergic signaling.Associacao Fund de Incentivo a Pesquisa (AFIP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Amparo Pesquisa do Estado de São PauloUniversidade Federal de São Paulo, Dept Psicobiol, BR-04024002 São Paulo, BrazilUniv Fed ABC, Ctr Matemat Comp & Cognicao, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, BR-04024002 São Paulo, BrazilFundacao de Amparo Pesquisa do Estado de São Paulo: FAPESP 2011/16977-8Web of Scienc

Empreendedorismo e Inovação: um Estudo de Caso da Rede Empreendedora da UTFPR – Câmpus Curitiba / Entrepreneurship and Innovation: a Case Study of Federal Technology University - Paraná's Entrepreneurial Network - Câmpus Curitiba

As redes possibilitam ao empreendedor manter contatos, ampliar as oportunidades de negócios, além de fomentar a competitividade do mercado através dos relacionamentos. Dentro desse contexto, a Rede Empreendedora da Universidade Tecnológica Federal do Paraná tem como objetivo fomentar, organizar e fortalecer ações de parceria entre empreendedores, com base no conhecimento científico e tecnológico gerado na universidade. O objetivo deste artigo, portanto, é identificar as expectativas das empresas em participar da Rede Empreendedora da UTFPR – câmpus Curitiba. Nesse contexto, adotar-se-á como procedimento metodológico uma abordagem qualitativa, aplicando os métodos de pesquisa exploratória e descritiva. Quanto à classificação, utilizou-se a pesquisa-ação destacando os procedimentos realizados na gestão da rede. A coleta de dados foi realizada através da aplicação de um questionário enviado por e-mail às empresas inscritas na rede. Observou-se que a expectativa dos participantes com relação à geração de novos negócios é boa, sendo a organização de rodada de negócios e reuniões entre os membros envolvidos o melhor canal de interação entre os participantes. O objetivo é fortalecer as redes de relacionamento e proporcionar interação, networking, além de visibilidade das empresas participantes. Ou seja, o conhecimento sobre a expectativa do usuário com relação aos novos negócios é fundamental para direcionar os gestores, tornando a ferramenta de relacionamento mais efetiva e referência de sucesso aos demais câmpus e Instituições de Ensino. 

Effect of androgen treatment during foetal and/or neonatal life on ovarian function in prepubertal and adult rats

We investigated the effects of different windows of testosterone propionate (TP) treatment during foetal and neonatal life in female rats to determine whether and when excess androgen exposure would cause disruption of adult reproductive function. Animals were killed prepubertally at d25 and as adults at d90. Plasma samples were taken for hormone analysis and ovaries serial sectioned for morphometric analyses. In prepubertal animals, only foetal+postnatal and late postnatal TP resulted in increased body weights, and an increase in transitory, but reduced antral follicle numbers without affecting total follicle populations. Treatment with TP during both foetal+postnatal life resulted in the development of streak ovaries with activated follicles containing oocytes that only progressed to a small antral (smA) stage and inactive uteri. TP exposure during foetal or late postnatal life had no effect upon adult reproductive function or the total follicle population, although there was a reduction in the primordial follicle pool. In contrast, TP treatment during full postnatal life (d1-25) resulted in anovulation in adults (d90). These animals were heavier, had a greater ovarian stromal compartment, no differences in follicle thecal cell area, but reduced numbers of anti-Mullerian hormone-positive smA follicles when compared with controls. Significantly reduced uterine weights lead reduced follicle oestradiol production. These results support the concept that androgen programming of adult female reproductive function occurs only during specific time windows in foetal and neonatal life with implications for the development of polycystic ovary syndrome in women

Analysis of host responses to Mycobacterium tuberculosis antigens in a multi-site study of subjects with different TB and HIV infection states in sub-Saharan Africa.

BACKGROUND: Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. METHODS: We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. RESULTS: There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST(-) and TST(+) contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST(+) contacts (LTBI) compared to TB and TST(-) contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. CONCLUSIONS: Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may be useful for vaccine efficacy trials

The future of dialects: Selected papers from Methods in Dialectology XV

Traditional dialects have been encroached upon by the increasing mobility of their speakers and by the onslaught of national languages in education and mass media. Typically, older dialects are “leveling” to become more like national languages. This is regrettable when the last articulate traces of a culture are lost, but it also promotes a complex dynamics of interaction as speakers shift from dialect to standard and to intermediate compromises between the two in their forms of speech. Varieties of speech thus live on in modern communities, where they still function to mark provenance, but increasingly cultural and social provenance as opposed to pure geography. They arise at times from the need to function throughout the different groups in society, but they also may have roots in immigrants’ speech, and just as certainly from the ineluctable dynamics of groups wishing to express their identity to themselves and to the world. The future of dialects is a selection of the papers presented at Methods in Dialectology XV, held in Groningen, the Netherlands, 11-15 August 2014. While the focus is on methodology, the volume also includes specialized studies on varieties of Catalan, Breton, Croatian, (Belgian) Dutch, English (in the US, the UK and in Japan), German (including Swiss German), Italian (including Tyrolean Italian), Japanese, and Spanish as well as on heritage languages in Canada