Experimental toxoplasmosis in Balb/c mice. Prevention of vertical disease transmission by treatment and reproductive failure in chronic infection

In a study of congenital transmission during acute infection of Toxoplasma gondii, 23 pregnant Balb/c mice were inoculated orally with two cysts each of the P strain. Eight mice were inoculated 6-11 days after becoming pregnant (Group 1). Eight mice inoculated on the 10th-15th day of pregnancy (Group 2) were treated with 100 mg/kg/day of minocycline 48 h after inoculation. Seven mice inoculated on the 10th-15th day of pregnancy were not treated and served as a control (Group 3). Congenital transmission was evaluated through direct examination of the brains of the pups or by bioassay and serologic tests. Congenital transmission was observed in 20 (60.6%) of the 33 pups of Group 1, in one (3.6%) of the 28 pups of Group 2, and in 13 (54.2%) of the 24 pups of Group 3. Forty-nine Balb/c mice were examined in the study of congenital transmission of T. gondii during chronic infection. The females showed reproductive problems during this phase of infection. It was observed accentuated hypertrophy of the endometrium and myometrium. Only two of the females gave birth. Our results demonstrate that Balb/c mice with acute toxoplasmosis can be used as a model for studies of congenital T. gondii infection. Our observations indicate the potential of this model for testing new chemotherapeutic agents against congenital toxoplasmosis.

Vertical human immunodeficiency virus type 1 - HIV-1 -transmission - a review

Several factors appear to affect vertical HIV-1 transmission, dependent mainly on characteristics of the mother (extent of immunodeficiency, co-infections, risk behaviour, nutritional status, immune response, genetical make-up), but also of the virus (phenotype, tropism) and, possibly, of the child (genetical make-up). This complex situation is compounded by the fact that the virus may have the whole gestation period, apart from variable periods between membrane rupture and birth and the breast-feeding period, to pass from the mother to the infant. It seems probable that an extensive interplay of all factors occurs, and that some factors may be more important during specific periods and other factors in other periods. Factors predominant in protection against in utero transmission may be less important for peri-natal transmission, and probably quite different from those that predominantly affect transmission by mothers milk. For instance, cytotoxic T lymphocytes will probably be unable to exert any effect during breast-feeding, while neutralizing antibodies will be unable to protect transmission by HIV transmitted through infected cells. Furthermore, some responses may be capable of controlling transmission of determined virus types, while being inadequate for controlling others. As occurence of mixed infections and recombination of HIV-1 types is a known fact, it does not appear possible to prevent vertical HIV-1 transmission by reinforcing just one of the factors, and probably a general strategy including all known factors must be used. Recent reports have brought information on vertical HIV-1 transmission in a variety of research fields, which will have to be considered in conjunction as background for specific studies.

Vertical toxoplasmosis in a murine model. Protection after immunization with antigens of Toxoplasma gondii incorporated into liposomes

Distinct Toxoplasma gondii antigens were entrapped within liposomes and evaluated for their ability to protect Balb/c mice against congenital transmission: soluble tachyzoite antigen (L/STAg), soluble tissue cyst antigen (L/SCAg), soluble tachyzoite plus tissue cyst (L/STCAg) or purified 32kDa antigen of tachyzoite (L/pTAg). Soluble tachyzoite antigen alone in PBS (STAg) or emulsified in Freund's Complete Adjuvant (FCA/STAg) was also evaluated. Dams were inoculated subcutaneously with these antigens 6, 4 and 2 weeks prior to a challenge with four tissue cysts of the P strain of T. gondii orally between 10 and 14 days of pregnancy. Significant diminution differences were observed between the frequency of infected pups born of the dams immunized with the antigens incorporated into liposomes and that of pups born of the dams immunized with antigen emulsified in FCA or non immunized group (p<0.05). There was a significant decrease in the number of pups born dead in the groups L/STAg, L/SCAg and L/pTAg when compared with pups from all other groups (p <0.05). All dams immunized with or without adjuvant showed an antibody response and a proliferation of T-cells. However, no correlation was found between immune response and protection against the challenge.

Entre el Gulag y el supermercado : en busca de Alexander Zinoviev

Aquest treball, que còpia en part el títol del llibre de Symons, intenta configurar-se també sobre un doble plànol expositiu. El priemr pla el primer objectiu-, es el més obvi: oferir un panorama del contingut de les principals obres d'un autor, Alexander Zinoviev, i tractar de contextualitzar-les (efectuant per allò incursions al pensament d'altres autors - a mode de breus razzies predatòries). Però el treball aspira a incloure una segona trama: l'intent d'observar una trajectòria intel·lectual determinada -en aquest cas, la de Zinoviev- de d'una certa distància i esbrinar si pot extreure's alguna lliçó no ja de les teories que l'autor va consignar per escrit, sinó de l'actitud existencial i intel·lectual amb la que un individu es va enfrontar als cataclismes produïts pels successius derrumbaments i encumbraments de les grans ideologies de la seva època.

Failure to demonstrate experimental vertical transmission of the epidemic strain of Chikungunya virus in Aedes albopictus from La Réunion Island, Indian Ocean

Aedes albopictus was responsible for transmission in the first outbreak of chikungunya (CHIK) on La Réunion Island, Indian Ocean, in 2005-2006. The magnitude of the outbreak on this island, which had been free of arboviral diseases for over 30 years, as well as the efficiency of Ae. albopictus as the main vector, raises questions about the maintenance of the CHIK virus (CHIKV) through vertical transmission mechanisms. Few specimens collected from the field as larvae were found to be infected. In this study, Ae. albopictus originating from La Réunion were orally infected with a blood-meal containing 10(8) pfu/mL of the CHIKV epidemic strain (CHIKV 06.21). Eggs from the first and second gonotrophic cycles were collected and raised to the adult stage. The infectious status of the progeny was checked (i) by immunofluorescence on head squashes of individual mosquitoes to detect the presence of viral particles or (ii) by quantitative RT-PCR on mosquito pools to detect viral RNA. We analysed a total of 1,675 specimens from the first gonotrophic cycle and 1,709 from the second gonotrophic cycle without detecting any viral particles or viral RNA. These laboratory results are compared to field records.

Vertical Transmission of Pneumocystis jirovecii in Humans

This study is part of the project “Pneumocystis Pathogenomics: Unravelling the Colonization-to-Disease Shift,” a Coordination Action supported by the European Commission (ERANET PathoGenoMics). This study was partially supported by the Spanish Ministry of Health (FIS 03/1743). M.A.M.-C. and C.d.l.H. were supported by the Spanish Ministry of Health (FIS CP-04/217 and FIS CM-04/146).

Horizontal, but not vertical, biotic interactions affect fine-scale plant distribution patterns in a low-energy system

Studies of species range determinants have traditionally focused on abiotic variables (typically climatic conditions), and therefore the recent explicit consideration of biotic interactions represents an important advance in the field. While these studies clearly support the role of biotic interactions in shaping species distributions, most examine only the influence of a single species and/or a single interaction, failing to account for species being subject to multiple concurrent interactions. By fitting species distribution models (SDMs), we examine the influence of multiple vertical (i.e., grazing, trampling, and manuring by mammalian herbivores) and horizontal (i.e., competition and facilitation; estimated from the cover of dominant plant species) interspecific interactions on the occurrence and cover of 41 alpine tundra plant species. Adding plant-plant interactions to baseline SDMs (using five field-quantified abiotic variables) significantly improved models' predictive power for independent data, while herbivore-related variables had only a weak influence. Overall, abiotic variables had the strongest individual contributions to the distribution of alpine tundra plants, with the importance of horizontal interaction variables exceeding that of vertical interaction variables. These results were consistent across three modeling techniques, for both species occurrence and cover, demonstrating the pattern to be robust. Thus, the explicit consideration of multiple biotic interactions reveals that plant-plant interactions exert control over the fine-scale distribution of vascular species that is comparable to abiotic drivers and considerably stronger than herbivores in this low-energy system.

Mecanismos da linha de frente e orientações empresariais: tradução, adaptação e validação de uma escala

O trabalho de linha de frente das empresas pode ser observado como uma luta de três frentes. O cliente exige atenção e qualidade de serviço, de um lado, a organização exige eficiência e produtividade, de outro, e o pessoal da linha de frente é metaforicamente apanhado no centro. Essa abordagem surgiu como um tema relevante para Marinova, Ye e Singh (2008), que desenvolveram uma escala que avalia esses elementos por meio de cinco dimensões: duas orientações (produtividade e qualidade) e três mecanismos (autonomia, coesão e feedback). O objetivo principal neste artigo foi adaptar a escala e verificar se ela pode ser utilizada no Brasil. Para isso, ela foi submetida a tradução e validação semântica, adaptação ao contexto de pesquisa e validação estatística. A escala foi aplicada em 105 estudantes de graduação e pós-graduação, e seus resultados foram estatisticamente satisfatórios, validando a versão brasileira da escala.

Em busca de uma abordagem não atomizada para o exame das relações entre liderança transformacional e comprometimento organizacional

As pesquisas tradicionais sobre liderança fazem uso de uma abordagem atomizada, que desconsidera os efeitos de diferentes padrões (gestalts) do construto e prioriza a lógica de uma variável por vez. A partir dessa crítica, o objetivo no presente trabalho é analisar a relação de distintas gestalts (configurações) de liderança transformacional com o comprometimento organizacional. Para a consecução desse objetivo, foram analisados 331 questionários de funcionários de oito organizações do setor de serviços. O método de pesquisa é classificado como levantamento (survey), com amostragem não probabilística por conveniência. Para o tratamento dos dados, fez-se uso da técnica de modelagem de equações estruturais no processo de análise da validade e confiabilidade das escalas. Na sequência, a análise de cluster evidenciou três configurações de liderança, denominadas: desorientação, subliderança e conversão. Para a verificação da influência dessas gestalts sobre o comprometimento organizacional, foi testado um modelo linear generalizado - MANCOVA fatorial. Os resultados indicaram a relação entre as configurações de liderança transformacional e as dimensões afetiva, instrumental e normativa do comprometimento; entretanto, para o comprometimento instrumental, a relação é mediada pelo grau de instrução dos liderados. Por fim, são discutidas as implicações dos achados empíricos.

Ensino da disciplina administração em enfermagem: em busca de um novo paradigma

Neste trabalho as autoras apresentam, um relato da experiência sobre o ensino da disciplina Administração em Enfermagem, da Escola de Enfermagem da USP, descrevendo como esta vem sendo inserida no novo currículo do curso de graduação em Enfermagem.

Suicídio: um ensaio em busca de um des-velamento do tema

Este ensaio propõe-se a des-velar facetas do tema suicídio por meio do discurso de diferentes autores que tratam do tema, bem como mediante os contatos que pude ter, durante os estágios de aprendizado, coin pessoas que tentaram suicídio. Minha trajetória acadêmica inclui uma incursão pelas idéias da fenomnenologia, particularmente pelos pensamentos de Heidegger, ou seja, análise existencial do homem enquanto ser-aí. Nesse sentido, a compreensão da pessoa que decide colocar fim à sua existência, pode se constituir, na perspectiva desta análise, como um caminho para reconstrução e redimensionamento de suas perspectivas existenciais.

Influence of initial foot dorsal flexion on vertical jump and running performance.

Several studies (on an inclined platform or with special shoes) have reported improved jump performance when the ankle was in a dorsiflexion (DF) position. The present study aims to test whether shoes inducing moderate DF modify vertical jump performance and energy cost. Twenty-one young, healthy female subjects (30 +/- 6 yr, 58 +/- 6 kg, O2max 45 +/- 3 mLxkg-1xmin-1, mean +/- SD) participated in the study. Jump performance was tested with subjects either wearing 4 degrees DF or standard (S) shoes. The jump tests (performed on a force platform) consisted of squat jump (SJ), countermovement jump (CMJ), and continuous jumps (CJ) during 15 seconds. Measured parameters were jump height, speed at take off, and maximal and average power. Oxygen uptake was measured on a treadmill while subjects ran at 95% of the anaerobic threshold during a 7-minute steady-state period. As compared with S shoes, DF shoes significantly improved the height of SJ (31 +/- 4 cm vs. 34 +/- 4 cm, p = 0.0001), CMJ (32 +/- 4 cm vs. 34 +/- 4 cm, p = 0.0004), and CJ (17.5 +/- 4.2 cm vs. 22.0 +/- 6.0 cm, p = 0.0001). Speed at take off was also significantly higher. Mean power significantly increased in SJ and CJ but not in CMJ. Oxygen uptake was not different between conditions (p = 0.40). Dorsiflexion shoes induce a significant increase in jump performance. These results are in accordance with the concept that a DF of the ankle may induce an increase of the length and strength of the triceps surae (higher torque). However, wearing DF shoes did not require more energy during running. Dorsiflexion shoes could be used to increase jump performance in several sports such as volleyball in which jump height is essential.

A busca das melhores evidências

A prática baseada em evidências é uma abordagem que envolve a definição de um problema, a busca e avaliação crítica das evidências disponíveis, implementação das evidências na prática e avaliação dos resultados obtidos. Para a implementação desta abordagem, na enfermagem, o enfermeiro necessita saber como obter, interpretar e integrar as evidências oriundas de pesquisas na assistência prestada ao cliente e seu familiares. Fundamentados na literatura apresentamos considerações teóricas acerca da hierarquia das evidências e onde realizar a busca das melhores evidências.

A busca da graduação em enfermagem como opção dos técnicos e auxiliares de enfermagem

Este estudo teve como objetivo apreender os motivos que levam técnicos e auxiliares de enfermagem a buscarem a graduação nesta profissão. Realizado em um hospital escola, na cidade de São Paulo, sob a perspectiva da pesquisa qualitativa e como metodologia, a História Oral Temática e a Análise Categorial Temática. Deste trabalho participaram onze colaboradores: três técnicas de enfermagem e oito auxiliares de enfermagem.