Células de linhagem McCoy como um possível modelo contendo receptores CD4+ para estudos da replicação do HIV

Several studies have recently shown the use of recombinant rabies virus as potential vector-viral vaccine for HIV-1. The sequence homology between gp 120 and rabies virus glycoprotein has been reported. The McCoy cell line has therefore been used to show CD4+ or CD4+ like receptors. Samples of HIV-1 were isolated, when plasma of HIV-1 positive patients was inoculated in the McCoy cell line. The virus infection was then studied during successive virus passages. The proteins released in the extra cellular medium were checked for protein activity, by exposure to SDS Electrophoresis and blotting to nitro-cellulose filter, then reacting with sera of HIV positive and negative patients. Successive passages were performed, and showed viral replication, membrane permeabilization, the syncytium formation, and the cellular lysis (cytopathic effect). Flow cytometry analysis shows clear evidence that CD4+ receptors are present in this cell line, which enhances the likelihood of easy isolation and replication of HIV. The results observed allow the use of this cell line as a possible model for isolating HIV, as well as for carrying out studies of the dynamics of viral infection in several situations, including exposure to drugs in pharmacological studies, and possibly studies and analyses of the immune response in vaccine therapies.Recentes estudos demonstraram o uso do vírus raiva como modelo vetor para produzir vacinas expressando as glicoproteínas do vírus HIV-1. A homologia na seqüência entre gp120 do vírus HIV-1 e a glicoproteína G do vírus rábico já foi previamente relatada. Devido a estes fatos a linhagem de célula McCoy utilizada com sucesso para a replicação do vírus rábico foi utilizada para demonstrar a replicação do HIV-1. Amostra de HIV-1 foi isolada de plasma de um paciente soro positivo e inoculada em células de linhagem McCoy e então a infecção viral foi estudada em passagens sucessivas do vírus nesta célula. As proteínas liberadas no meio extra celular foram analisadas quanto a atividade biológica pela técnica de eletroforese em gel de poliacrilamida e imunotransferência em membrana de nitro-celulose reagindo com soros positivos para HIV-1 e soros de pacientes negativos. As passagens sucessivas do HIV-1 em células demonstraram a replicação viral, o aumento da permeabilidade da membrana citoplasmática, a formação de sinsício e lise celular. Análises com citometria de fluxo mostraram com clara evidência a presença de receptores CD4+ o que possivelmente deve ser a causa que possibilita a facilidade do isolamento e replicação do vírus HIV-1 nesta célula. Concluindo os resultados observados permitem utilizar esta linhagem celular como um possível modelo para isolamentos de HIV, bem como realizar estudos da dinâmica de infecção viral em diversas situações inclusive de exposição a drogas em estudos farmacológicos, e talvez estudos e análises da resposta imune em terapias vacinais

Unbalanced sex in plot in experimentation with chickens

Estudou-se a influência do desbalanceamento de sexo na parcela, em frangos de corte, em quatro idades (I) de abate: 44, 48, 52 e 56 dias e cinco tamanhos de parcelas (TP): 10 (P10), 20 (P10), 30 (P30), 40 (P40) e 50 (P50) aves. O trabalho foi realizado no Centro Nacional de Pesquisa de Suínos e Aves, em Concórdia, SC, em 1986, com os dados de pesagens (Pi) obtidos por simulação. Cada combinação I e TP constituiu um experimento, sendo o tratamento-controle (TC) atribuído à parcela com 50% machos (M) e 50% fêmeas (F). Os demais tratamentos foram organizados considerando-se todas as combinações de sexo na parcela, mantendo-se o número de aves de um determinado sexo igual ao TC. Os graus de concordância, de enviezamento e de achatamento dos valores de Pi, com a distribuição normal, foram medidos, respectivamente, pela estatística D de Lilliefors, do coeficiente de assimetria (a3) e de curtose (a4). O desbalanceamento de sexo (ds) na parcela altera o nível de significância na comparação de tratamento, sendo o desbalanceamento com relação a machos mais prejudicial que o de fêmeas. Uma diferença de aproximadamente 0,20% na média de qualquer tratamento em relação ao controle, devido ao ds, é suficiente para alterar o nível de significância na vizinhança de α = 0,05, em experimentos com dez ou mais aves por parcela. The influence of unbalanced sex in the plot of broilers was studied in four ages for slaughtering (A): 44, 48, 52 and 56 days, and five size plots (P): 10 (P10); 20 (P20); 30 (P30); 40 (P40) and 50 (P50) birds. The experiment was carried out in the Centro Nacional de Pesquisa de Suínos e Aves (Swine and Poultry National Research Center) at Concórdia, SC, Brazil, in 1986, with weight data (Wi) obtained by simulation. Each combination A and P resulted an experiment, and the plot containing 50% males (M) and 50% females (F) was considered the control treatment (CT). The other treatments were organized considering all of the sex combinations in the plot, maintaining the number of birds of a determined sex equal to the control treatment (CT). The agreement, the slope and the squash of the Wi data with the normal distribution were calculated, respectively, by Lilliefors test (D), coefficient of asymmetry (a3) and coefficient of curtosis (a4). The influence of unbalanced sex (US) alterates the level of significancy in the comparison of treatments. The unbalance in relation to males is more severe than in relation to females. A difference of about 0.20% in the average of any treatment compared to the control, due to US, is enough to alterate the significancy level around α = 0.05 in experiments with more than ten birds by plot.

Genetic regulation of body size and morphology in children: a twin study of 22 anthropometric traits

Background Anthropometric measures show high heritability, and genetic correlations have been found between obesity-related traits. However, we lack a comprehensive analysis of the genetic background of human body morphology using detailed anthropometric measures. Methods Height, weight, 7 skinfold thicknesses, 7 body circumferences and 4 body diameters (skeletal breaths) were measured in 214 pairs of twin children aged 3–18 years (87 monozygotic pairs) in the Autonomous Region of Madeira, Portugal. Factor analysis (Varimax rotation) was used to analyze the underlying structure of body physique. Genetic twin modeling was used to estimate genetic and environmental contributions to the variation and co-variation of the anthropometric traits. Results Together, two factors explained 80% of the variation of all 22 anthropometric traits in boys and 73% in girls. Obesity measures (body mass index, skinfold thickness measures, as well as waist and hip circumferences) and limb circumferences loaded most strongly on the first factor, whereas height and body diameters loaded especially on the second factor. These factors as well as all anthropometric measures showed high heritability (80% or more for most of the traits), whereas the rest of the variation was explained by environmental factors not shared by co-twins. Obesity measures showed high genetic correlations (0.75–0.98). Height showed the highest genetic correlations with body diameter measures (0.58–0.76). Correlations between environmental factors not shared by co-twins were weaker than the genetic correlations but still substantial. The correlation patterns were roughly similar in boys and girls. Conclusions Our results show high genetic correlations underlying the human body physique, suggesting that there are sets of genes widely affecting anthropometric traits. Better knowledge of these genetic variants can help to understand the development of obesity and other features of the human physique.The project “Genetic and environmental influences on physical activity, fitness and health: the Madeira family study” was supported by FCT - Fundação para a Ciência e a Tecnologia (The Portuguese National Funding Agency for Science, Research and Technology), reference POCI/DES/56834/2004. Open Access funding provided by University of Helsinki including Helsinki University Central Hospital

Experience and Innovation Factory: Adaptation of an Experience Factory Model for a Research and Development Laboratory

This paper aims to present a knowledge management proposal for a software factory organization. A software factory requires a holistic organization, in which many factors must be taken into account, such as: people management and business management. The complexity of the structure leads us to elaborate on an adapted model of Experience Factory to meets the needs of research and development laboratories. The construction of the adapted model used a bibliographical research about Experience Factory models, the characterization of the project, a mapping between the project’s characteristics and the activities of the Experience Factory models. The Experience Factory models attend to the main characteristics identified for the Software Factory Laboratory (SFL): development, capacitation, training, research and innovation. Finally, we tested and analyzed the results on the proposed model on the knowledge generated by the SFL during the software development process

Capture Rates of Compact Objects by Supermassive Black Holes

Capture rates of compact objects were calculated by using a recent solution of the Fokker-Planck equation in energy-space, including two-body resonant effects. The fraction of compact objects (white dwarfs, neutron stars and stellar black holes) was estimated as a function of the luminosity of the galaxy from a new grid of evolutionary models. Stellar mass densities at the influence radius of central supermassive black holes were derived from brightness profiles obtained by Hubble Space Telescope observations. The present study indicates that the capture rates scale as $\propto M_{bh}^{-1.048}$, consequence of the fact that dwarf galaxies have denser central regions than luminous objects. If the mass distribution of supermassive black holes has a lower cutoff at $\sim 1.4\times 10^6$ M$_{\odot}$ (corresponding to the lowest observed supermassive black hole mass, located in M32), then 9 inspiral events are expected to be seen by LISA (7-8 corresponding to white dwarf captures and 1-2 to neutron star and stellar black hole captures) after one year of operation. However, if the mass distribution extends down to $\sim 2\times 10^5$ M$_{\odot}$, then the total number of expected events increases up to 579 (corresponding to $\sim$ 274 stellar black hole captures, $\sim$ 194 neutron star captures and $\sim$ 111 white dwarf captures).Comment: 8 pages, 3 figures; accepted for publication in PR

Chemical dependence on crack: experiences and perceptions of internship students of a medical school

Study design: Cross-sectional and qualitative study. Objectives: This study investigates experiences and identifies the perceptions of ninth-term intern medical students of a public university on the crack addiction issue. Methods: A qualitative-approach and cross-sectional study which had as the research tool a semi-structured, individual interview allowing broad speech of students. Recording reports were transcribed and content analysis carried out according to Bardin. Results: categories were identified concerning the feeling of experience, the students’ perception on crack addiction and their learning on the subject, physical impairments and additional damages, besides how society should deal with the addiction on crack. The feelings of compassion and preservation are present in their experiences. Students point out economic, professional and family issues as the sources of serious crack addiction consequences. They also take into account the social and existential damages, the self-destruction, violence and weight loss caused on crack users, as well as the codependency. There is a great concern on the part of students related to prevention, education, information, elimination of prejudice, as well as demands of government efforts to combat crack. Conclusion: The intern medical students consider crack addiction both a social problem and a disease; define learning about addiction by crack insufficient throughout the course. Their experiences and perceptions generate positive impacts since they prospect better prepared graduates who shall receive the one addicted and his family in a broader, more effective and humane wayModelo de estudo: Estudo transversal e qualitativo. Objetivos: Este trabalho investiga as vivências e identifica as percepções dos discentes do internato do nono período de medicina de uma universidade pública, sobre dependência química pelo crack. Metodologia: Estudo transversal de abordagem qualitativa, cujo instrumento da pesquisa foi uma entrevista individual, utilizando-se um roteiro semiestruturado, que permite amplo discurso dos discentes. As falas das gravações foram transcritas e depois realizada a análise do conteúdo segundo Bardin. Resultados: Foram identificadas categorias referentes ao sentimento da vivência, à percepção do discente sobre a dependência do crack e seu aprendizado sobre o tema, aos comprometimentos físicos, aos outros prejuízos causados e a como a sociedade deve lidar diante da dependência química pelo crack. Os sentimentos de compaixão e de preservação estão presentes em suas vivências. Os discentes relacionam as questões econômicas, profissionais e familiares como fontes das graves consequências do crack. Valorizam os prejuízos sociais e existenciais, a autodestruição, a violência e o emagrecimento que o crack causa aos usuários, além da codependência. É grande a preocupação dos discentes com a prevenção, educação, informação, eliminação do preconceito e cobranças de ações governamentais para combate ao crack. Conclusão: Os discentes do internato consideram a dependência química pelo crack como problema social e doença. Definem como insuficiente o aprendizado sobre a dependência química pelo crack durante o curso. Suas vivências e percepções geram impactos positivos, pois apontam para futuros egressos melhor preparados, que deverão acolher o dependente e sua família de forma mais ampla, humana e efica

Genome wide scan for quantitative trait loci affecting tick resistance in cattle (Bos taurus × Bos indicus)

<p><b>Abstract</b></p> <p><b>Background</b></p> <p>In tropical countries, losses caused by bovine tick <it>Rhipicephalus (Boophilus) microplus</it> infestation have a tremendous economic impact on cattle production systems. Genetic variation between <it>Bos taurus</it> and <it>Bos indicus</it> to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (<it>Bos indicus</it>) × Holstein (<it>Bos taurus</it>) cross.</p> <p>Results</p> <p>Through a whole genome scan with microsatellite markers, we were able to map six genomic regions associated with bovine tick resistance. For most QTL, we have found that depending on the tick evaluation season (dry and rainy) different sets of genes could be involved in the resistance mechanism. We identified dry season specific QTL on BTA 2 and 10, rainy season specific QTL on BTA 5, 11 and 27. We also found a highly significant genome wide QTL for both dry and rainy seasons in the central region of BTA 23.</p> <p>Conclusions</p> <p>The experimental F2 population derived from Gyr × Holstein cross successfully allowed the identification of six highly significant QTL associated with tick resistance in cattle. QTL located on BTA 23 might be related with the bovine histocompatibility complex. Further investigation of these QTL will help to isolate candidate genes involved with tick resistance in cattle.</p