'Why does cultural studies want history?'

Cultural studies has often been accused of maintaining too strong a focus on the contemporary and the immediate as a result of its primary interest in popular culture and the media. The role of history, such criticisms suggest, has been displaced by this contemporary emphasis. Nonetheless, much cultural studies work takes a principled stand on the necessity of historicising the products of its research. Consequently, it is worth asking, with British historian Carolyn Steedman--'why does cultural studies want history?' This article begins to answer that question through the discussion of some aspects of a specific research project within Australian cultural studies.

Experimental study of phase equilibria in the PbO-ZnO-"Fe2O3"-(CaO+SiO2) system in air for the lead and zinc blast furnace sinters (CaO/SiO2 weight ratio of 0.933 and PbO/(CaO+SiO2) ratios of 2.0 and 3.2)

Experimental studies on phase equilibria and liquidus in the multicomponent system PbO-ZnO-CaO-SiO2-FeO-Fe2O3 in air have been conducted over the temperature range between 1323 K (1050 degreesC) and 1623 K (1350 degreesC) to characterize the phase relations of the complex slag systems encountered in lead and zinc blast furnace sinters. The liquidus in two pseudoternary sections ZnO-Fe2O3-(PbO + CaO + SiO2) with the CaO/SiO2 weight ratio of 0.933 and PbO/(CaO + SiO2) weight ratios of 2.0 and 3.2 have been constructed.

Seroprevalence of human parvovirus B19 in a suburban population in São Paulo, Brazil

OBJECTIVE: To analyze the prevalence of IgG antibodies to human parvovirus B19. METHODS: Cross-sectional study in a suburban community in São Paulo, Southeastern Brazil, between November 1990 and January 1991. Randomly selected (N=435) representative samples of sera were collected from healthy children older than 15 days old and adults up to 40 years old. IgG antibodies were detected using ELISA. RESULTS: High prevalence of IgG antibodies to B19 parvovirus was found in 87% of newborns. The prevalence of maternally derived IgG antibodies exponentially plunged up to the 19th month of age. Low prevalence of antibodies was found in the first 4 years of life, increasing up to 72% in those aged 31-40 years. It was estimated that the average age of first infection in this population is 21 ± 7 years old and the optimal age for vaccination with a hypothetical vaccine would be 1 year of age. CONCLUSIONS: Parvovirus B19 IgG antibody prevalence was high in newborns and those aged 31-40 years. The analysis by age groups showed a pattern similar to that found in previous studies, i.e., low prevalence of infection in children that increases with age.

O efeito da aplicação da Estimulação Elétrica Funcional na reabilitação em adultos com lesão medular completa. Revisão Sistemática

Introdução: A Lesão Medular (LM) é um dos mais devastadores e traumáticos eventos que um Ser Humano pode vivenciar do ponto de vista clínico e emocional, demonstrando-se fundamental a disponibilização de recursos específicos para que o indivíduo possa enfrentar e gerir a sua nova realidade da melhor maneira possível. Alguns estudos têm vindo a demonstrar os benefícios de programas de reabilitação com estimulação elétrica funcional (EEF). Portanto, é de importante relevância perceber os reais efeitos da intervenção na recuperação de indivíduos com este diagnóstico. Objetivo: Analisar as evidências de abordagens de aplicação de correntes de estimulação elétrica funcional (EEF) para coadjuvar na reabilitação em adultos com lesão medular completa. Métodos: Foi conduzida uma pesquisa dos artigos preferencialmente estudos randomized controlled trials RCT´s e estudos quasi-experimentais com os mesmos participantes foram admitidos complementarmente aos experimentais compreendidos entre 2004 e 2013, bem como as citações e as referências bibliográficas de cada estudo nas principais bases de dados de ciências da saúde (Elsevier – Science Direct, Highwire Press, PEDro, PubMed, Scielo Portugal, Clinical Key, B-on, Biomed Central, LILACS- Literatura Latino-Americana e do Caribe em Ciências da Saúde) com as palavras-chave: “spinal cord injuries”, “rehabilitation, electric stimulation funtional”, “FES”, “therapy” em todas as combinações possíveis. Os estudos RCT’s foram analisados independentemente por dois revisores quanto aos critérios de inclusão e qualidade dos estudos. Resultados: Dos 857 estudos identificados apenas sete foram incluídos. Destes, dois apresentaram um score 3/10, um apresentou 4/10, um apresentou um score 5/10. O score total bem como o preenchimento ou não de cada critério encontram-se detalhados na tabela 1 e organizados por ordem alfabética de autores. Todos os estudos incluíram indivíduos com Lesão Medular Completa, idades entre 16 e 68 anos com diagnóstico de acordo com a American Spinal Injury Association (ASIA).Os programas de intervenção dividiram-se em programas de programas de força, densidade mineral óssea, cardiorrespiratório e de atividade física. Dos estudos incluídos, cinco apresentaram melhorias na reabilitação funcional para o grupo experimental, demonstrando assim uma influência positiva da estimulação elétrica funcional em lesões medulares completas. Apenas dois estudos não apresentaram diferenças estatisticamente significativas com relevância clínica. Conclusão: Há uma tendência notória do benefício dos programas com EEF em pacientes com lesões medulares completas parece melhorar a capacidade cardiorrespiratória, a densidade mineral óssea, a força e atividade física, dos indivíduos. Contudo, mais estudos com elevada qualidade metodológica serão essenciais para conceber o real efeito da sua aplicação. Palavras-chave: lesão medular completa; estimulação elétrica funcional, randomized controlled trials, revisão sistemática.

Brachial Plexus Morphology and Vascular Supply in the Wistar Rat

Introduction: The rat is probably the animal species most widely used in experimental studies on nerve repair. The aim of this work was to contribute to a better understanding of the morphology and blood supply of the rat brachial plexus. Material and Methods: Thirty adult rats were studied regarding brachial plexus morphology and blood supply. Intravascular injection and dissection under an operating microscope, as well as light microscopy and scanning electron microscopy techniques were used to define the microanatomy of the rat brachial plexus and its vessels. Results: The rat brachial plexus was slightly different from the human brachial plexus. The arterial and venous supply to the brachial plexus plexus was derived directly or indirectly from neighboring vessels. These vessels formed dense and interconnected plexuses in the epineurium, perineurium, and endoneurium. Several brachial plexus components were accompanied for a relatively long portion of their length by large and constant blood vessels that supplied their epineural plexus, making it possible to raise these nerves as flaps. Discussion: The blood supply to the rat brachial plexus is not very different from that reported in humans, making the rat a useful animal model for the experimental study of peripheral nerve pathophysiology and treatment. Conclusion: Our results support the homology between the rat and the human brachial plexus in terms of morphology and blood supply. This work suggests that several components of the rat brachial plexus can be used as nerve flaps, including predominantly motor, sensory or mixed nerve fibers. This information may facilitate new experimental procedures in this animal model.

The effect of Zymomonas mobilis culture on experimental Schistosoma mansoni infection

C57Bl/10 male mice infected with Schistosoma mansoni were distributed into mixed, prophylactic and curative groups. A culture of Zymomonas mobilis was orally administered to mice. A 61% protection from the infection was observed in the curative group (p <0.05). Histopathological study of the livers and intestines showed similar results.

Nanomateriais manufaturados : avaliação de segurança através da caracterização dos seus efeitos genéticos

RESUMO - Os nanomateriais manufaturados (NMs), isto é, fabricados deliberadamente para fins específicos, apresentam propriedades físico-químicas únicas como a dimensão, área superficial ou funcionalização, que lhes conferem caraterísticas mecânicas, óticas, elétricas e magnéticas muito vantajosas para aplicações industriais e biomédicas. Efetivamente, a tecnologia baseada nos NMs, ou nanotecnologia, foi identificada como uma key enabling technology, impulsionadora do crescimento económico dos países industrializados, devido ao seu potencial para melhorar a qualidade e desempenho de muitos tipos de produtos e de processos. Contudo, a expansão da utilização de NMs contrasta com a insuficiente avaliação de risco para a saúde humana e para o ambiente, sendo considerados como um risco emergente para a saúde pública. As incertezas sobre a segurança dos NMs para a saúde pública advêm sobretudo de estudos epidemiológicos em humanos expostos a nanomateriais produzidos como consequência dos processos e atividades humanas e da poluição. Uma das principais preocupações relativamente aos efeitos adversos dos NMs na saúde humana é o seu potencial efeito carcinogénico, que é sugerido por alguns estudos experimentais, como no caso dos nanomateriais de dióxido de titânio ou dos nanotubos de carbono. Para avaliar em curto termo as propriedades carcinogénicas de um composto, utilizam-se frequentemente ensaios de genotoxicidade em linhas celulares de mamífero ou ensaios em modelos animais, em que se analisa uma variedade de lesões genéticas potencialmente relacionados com o processo de carcinogénese. No entanto, a investigação sobre as propriedades genotóxicas dos NMs não foi, até hoje, conclusiva. O presente estudo tem por objectivo principal caracterizar os efeitos genotóxicos associados à exposição a nanomateriais manufaturados, de forma a contribuir para a avaliação da sua segurança. Constituíram objectivos específicos deste estudo: i) avaliar a genotoxicidade dos NMs em três tipos de células humanas expostas in vitro: linfócitos humanos primários, linha celular de epitélio brônquico humano (BEAS-2B) e linha celular de adenocarcinoma epitelial de pulmão humano (A549); ii) avaliar a sua genotoxicidade num modelo de ratinho transgénico; iii) investigar alguns mecanismos de acção que poderão contribuir para a genotoxicidade dos nanomateriais, como a contribuição de lesões oxidativas para a genotoxicidade induzida pelos NMs in vitro, e a investigação da sua bioacumulação e localização celular in vivo. Foram analisados os efeitos genotóxicos associados à exposição a duas classes de NMs, dióxido de titânio e nanotubos de carbono de parede múltipla, bem como a um NM de óxido de zinco, candidato a ser utlilizado como controlo positivo de dimensão nanométrica. Os xx NMs utilizados foram previamente caracterizados com detalhe relativamente às suas características físico-químicas e também relativamente à sua dispersão em meio aquoso e no meio de cultura. A metodologia incluiu ensaios de citotoxicidade e de genotoxicidade in vitro, designadamente, ensaios de quebras no DNA (ensaio do cometa) e nos cromossomas (ensaio do micronúcleo) em células humanas expostas a várias concentrações de NMs, por comparação com células não expostas. Também foram realizados ensaios in vivo de quebras no DNA, quebras cromossómicas e ainda um ensaio de mutações em vários órgãos de grupos de ratinhos transgénicos LacZ, expostos por via intravenosa a duas doses de dióxido de titânio. Foi investigada a existência de uma relação dose-resposta após exposição das células humanas ou dos animais a NMs. A contribuição de lesões oxidativas para a genotoxicidade após exposição das células aos NMs in vitro foi explorada através do ensaio do cometa modificado com enzima. Realizaram-se estudos histológicos e citológicos para deteção e localização celular dos NMs nos órgãos-alvo dos ratinhos expostos in vivo. Os resultados demonstraram efeitos genotóxicos em alguns dos NMs analisados em células humanas. No entanto, os efeitos genotóxicos, quando positivos, foram em níveis reduzidos, ainda que superiores aos valores dos controlos, e a sua reprodutibilidade era dependente do sistema experimental utilizado. Para outros NMs, a evidência de genotoxicidade revelou-se equívoca, conduzindo à necessidade de esclarecimento através de ensaios in vivo. Para esse fim, recorreu-se a uma análise integrada de múltiplos parâmetros num modelo animal, o ratinho transgénico baseado em plasmídeo contendo o gene LacZ exposto a um NM de dióxido de titânio, NM-102. Embora tenha sido demonstrada a exposição e a acumulação do NM no fígado, não se observaram efeitos genotóxicos nem no fígado, nem no baço nem no sangue dos ratinhos expostos a esse NM. Neste estudo concluiu-se que algumas formas de dióxido de titânio e nanotubos de carbono de parede múltipla produzem efeitos genotóxicos em células humanas, contribuindo para o conjunto de evidências sobre o efeito genotóxico desses NMs. As diferenças observadas relativamente à genotoxicidade entre NMs do mesmo tipo, mas distintos em algumas das suas características físico-quimicas, aparentemente não são negligenciáveis, pelo que os resultados obtidos para um NM não devem ser generalizados ao grupo correspondente. Para além disso, a genotoxicidade equívoca verificada para o NM-102 em células humanas expostas in vitro, não foi confirmada no modelo in vivo, pelo que o valor preditivo da utilização dos ensaios in vitro para a identificação de NMs com efeitos genotóxicos (e portanto potencialmente carcinogénicos) ainda tem de ser esclarecido antes de ser possível extrapolar as conclusões para a saúde humana. Por sua vez, como a informação aqui produzida pelas metodologias in vitro e in vivo não reflete os efeitos de exposição continua ou prolongada, que poderá conduzir a efeitos genotóxicos distintos, esta xxi deverá ser complementada com outras linhas de evidência relativamente à segurança dos NMs. Perante a incerteza dos níveis de exposição real do organismo humano e do ambiente, a segurança da utilização dos NMs não pode ser garantida a longo prazo e, tendo em conta a elevada produção e utilização destes NMs, são prementes futuros estudos de monitorização ambiental e humana.

FOOD CONCENTRATION AND TEMPERATURE EFFECTS ON LIFE CYCLE CHARACTERISTICS OF TROPICAL CLADOCERA (Daphnia gessneri Herbst, Diaphanosoma sarsi Richard, Moina reticulata (Daday)): I. DEVELOPMENT TIME

The effects of food concentration and temperature on embryonic and postem-bryonic duration of three tropical species, Daphnia gessneri(1.5mm), Diaphanosoma sarsi(1.2mm) and Moina reticulata(0.8mm), were investigated as part of life cycle studies which included growth, body size and reproduction. These are the very first experimental studies undertaken on these species. The long-term growth experiments were performed under controlled laboratory conditions at all combinations of temperature (22"C, 27"C and 32"C) and constant food concentration (0.03, 0.05, 0.10, 0.25, 0.50 and 1.00 mgC/L) of the unicellular green alga Scenedesmus acutus.Animals were examined twice daily throughout their life cycle from the neonate to third adult instar. In all three species, temperature exerted the most powerful influence on embryonic duration but there was also a smaller food effect. In D. gessneri,postembry-onic durations remained more or less the same at food levels 0.25 mgC/L but were influenced by temperature. At food concentrations of 0.1 mgC/L or lower, postembryonic durations became increasingly prolonged, particularly at high temperatures. This threshold concentration is affected by temperature: in D. gessneri,it was 0.1 mgC/L at 22oC and 27oC but higher at 32oC (between 0.25 and 0.50 mgC/L). At the same temperature of 27oC, the food threshold level varied between species: it was higher (0.25 mgC/L) for D. sarsiand lower (0.05 mgC/L) for M. reticulatacompared with D. gessneri(0.1 mgC/L). In both embryonic and postembryonic durations there is a body size effect as the absolute durations were longest in the largest species and shortest in the smallest species In all three species, prolongation of postembryonic duration at combinations of high temperature and lowered food levels was accompanied by increased number of juvenile instars.

Multivariate Analysis for Animal Selection in Experimental Research

Background: Several researchers seek methods for the selection of homogeneous groups of animals in experimental studies, a fact justified because homogeneity is an indispensable prerequisite for casualization of treatments. The lack of robust methods that comply with statistical and biological principles is the reason why researchers use empirical or subjective methods, influencing their results. Objective: To develop a multivariate statistical model for the selection of a homogeneous group of animals for experimental research and to elaborate a computational package to use it. Methods: The set of echocardiographic data of 115 male Wistar rats with supravalvular aortic stenosis (AoS) was used as an example of model development. Initially, the data were standardized, and became dimensionless. Then, the variance matrix of the set was submitted to principal components analysis (PCA), aiming at reducing the parametric space and at retaining the relevant variability. That technique established a new Cartesian system into which the animals were allocated, and finally the confidence region (ellipsoid) was built for the profile of the animals’ homogeneous responses. The animals located inside the ellipsoid were considered as belonging to the homogeneous batch; those outside the ellipsoid were considered spurious. Results: The PCA established eight descriptive axes that represented the accumulated variance of the data set in 88.71%. The allocation of the animals in the new system and the construction of the confidence region revealed six spurious animals as compared to the homogeneous batch of 109 animals. Conclusion: The biometric criterion presented proved to be effective, because it considers the animal as a whole, analyzing jointly all parameters measured, in addition to having a small discard rate.

High-fat Diet Promotes Cardiac Remodeling in an Experimental Model of Obesity

AbstractBackground:Although nutritional, metabolic and cardiovascular abnormalities are commonly seen in experimental studies of obesity, it is uncertain whether these effects result from the treatment or from body adiposity.Objective:To evaluate the influence of treatment and body composition on metabolic and cardiovascular aspects in rats receiving high saturated fat diet.Methods:Sixteen Wistar rats were used, distributed into two groups, the control (C) group, treated with isocaloric diet (2.93 kcal/g) and an obese (OB) group, treated with high-fat diet (3.64 kcal/g). The study period was 20 weeks. Analyses of nutritional behavior, body composition, glycemia, cholesterolemia, lipemia, systolic arterial pressure, echocardiography, and cardiac histology were performed.Results:High-fat diet associates with manifestations of obesity, accompanied by changes in glycemia, cardiomyocyte hypertrophy, and myocardial interstitial fibrosis. After adjusting for adiposity, the metabolic effects were normalized, whereas differences in morphometric changes between groups were maintained.Conclusion:It was concluded that adiposity body composition has a stronger association with metabolic disturbances in obese rodents, whereas the high-fat dietary intervention is found to be more related to cardiac morphological changes in experimental models of diet-induced obesity.

Transferring QTL technology to the pig breeding industry (PigQTech) - a demonstration project

The aim of the project has been to demonstrate how the farm animal breeding industry can utilise gene mapping technology to accelerate genetic improvement. Previous theoretical studies had suggested that the use of marker assisted selection could potentially increase the annual improvement for quantitative traits like backfat with about 10% and for more difficult traits such as meat quality and reproduction by as much as 40-60% compared with existing technology. The work has comprised two major tasks: 1. Commercially relevant populations have been screened for segregation at QTLs identified in experimental populations. The aim has been to establish optimal strategies for QTL detection in commercial pig populations and the extent to which QTLs explaining major phenotypic differences between divergent lines used in experimental studies also explain quantitative variation within commercial lines. The results are important for specifying future strategies for finding economically valuable QTLs. 2. Marker assisted backcrossing has been used to demonstrate how a QTL allele can be introgressed from one breed to another. The work has focused on the major fatness QTL on pig chromosome 4 previously identified in a wild pig/Large White intercross. The end result was not designed to be a commercially viable product in its own right, but the process has validated a number of points of major importance for the exploitation of QTLs in livestock.

Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project.

We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.

Caffeine intake and CYP1A2 variants associated with high caffeine intake protect non-smokers from hypertension.

The 15q24.1 locus, including CYP1A2, is associated with blood pressure (BP). The CYP1A2 rs762551 C allele is associated with lower CYP1A2 enzyme activity. CYP1A2 metabolizes caffeine and is induced by smoking. The association of caffeine consumption with hypertension remains controversial. We explored the effects of CYP1A2 variants and CYP1A2 enzyme activity on BP, focusing on caffeine as the potential mediator of CYP1A2 effects. Four observational (n = 16 719) and one quasi-experimental studies (n = 106) including European adults were conducted. Outcome measures were BP, caffeine intake, CYP1A2 activity and polymorphisms rs762551, rs1133323 and rs1378942. CYP1A2 variants were associated with hypertension in non-smokers, but not in smokers (CYP1A2-smoking interaction P = 0.01). Odds ratios (95% CIs) for hypertension for rs762551 CC, CA and AA genotypes were 1 (reference), 0.78 (0.59-1.02) and 0.66 (0.50-0.86), respectively, P = 0.004. Results were similar for the other variants. Higher CYP1A2 activity was linearly associated with lower BP after quitting smoking (P = 0.049 and P = 0.02 for systolic and diastolic BP, respectively), but not while smoking. In non-smokers, the CYP1A2 variants were associated with higher reported caffeine intake, which in turn was associated with lower odds of hypertension and lower BP (P = 0.01). In Mendelian randomization analyses using rs1133323 as instrument, each cup of caffeinated beverage was negatively associated with systolic BP [-9.57 (-16.22, -2.91) mmHg]. The associations of CYP1A2 variants with BP were modified by reported caffeine intake. These observational and quasi-experimental results strongly support a causal role of CYP1A2 in BP control via caffeine intake.