828 research outputs found
Transmissão materno-fetal de diferentes subtipos de HIV-1 entre gestantes infectadas na Nigéria
The rate of mother-to-child transmission (MTCT) of HIV as well as the implications of the circulating multiple subtypes to MTCT in Nigeria are not known. This study was therefore undertaken to determine the differential rates of MTCT of HIV-1 subtypes detected among infected pregnant women before ARV intervention therapy became available in Nigeria. Twenty of the HIV-positive women who signed the informed consent form during pregnancy brought their babies for follow-up testing at age 18-24 months. Plasma samples from both mother and baby were tested for HIV antibody at the Department of Virology, UCH, Ibadan, Nigeria. All positive samples (plasma and peripheral blood mononuclear cells - PBMCs) were shipped to the Institute of Tropical Medicine, Antwerp, Belgium, where the subtype of the infecting virus was determined using the HMA technique. Overall, a mother-to-child HIV transmission rate of 45% was found in this cohort. Specifically, 36.4%, 66.7% and 100% of the women infected with HIV-1 CRF02 (IbNg), G and B, respectively, transmitted the virus to their babies. As far as it can be ascertained, this is the first report on the rate of MTCT of HIV in Nigeria. The findings reported in this paper will form a useful reference for assessment of currently available therapeutic intervention of MTCT in the country.A taxa de transmissĂŁo materno-fetal (MTCT) do HIV bem como as implicaçÔes dos mĂșltiplos subtipos circulantes para MTCT na NigĂ©ria nĂŁo sĂŁo conhecidos. Este estudo foi realizado para determinar as diferentes taxas de MTCT dos subtipos de HIV-1 detectados entre gestantes infectadas antes que a administração da terapia ARV estivesse disponĂvel na NigĂ©ria. Vinte das mulheres HIV positivas que assinaram o consentimento durante a gravidez trouxeram seus filhos para seguimento na idade de 18-24 meses. Amostras de plasma de ambos, mĂŁe e filho foram testadas para anticorpos HIV no Departamento de Virologia, UCH, Ibadan, NigĂ©ria. Todas as amostras positivas (plasma e cĂ©lulas mononucleares do sangue perifĂ©rico - PBMCs) foram enviadas para o Instituto de Medicina Tropical da AntuĂ©rpia, BĂ©lgica, onde os subtipos de vĂrus infectantes foram determinados utilizando-se a tĂ©cnica HMA. No conjunto, uma taxa de transmissĂŁo de HIV, materno-fetal, de 45% foi encontrada neste grupo. Especificamente, 36,4%, 66,7% e 100% das mulheres infectadas com HIV-1 CRF02 (IbNg), G e B, respectivamente, transmitiram o vĂrus para seus filhos. AtĂ© onde pode ser verificado, este Ă© o primeiro relato da taxa de MTCT do HIV na NigĂ©ria. Os achados relatados neste trabalho serĂŁo uma Ăștil referĂȘncia para estimar a qualidade das terapĂȘuticas atuais disponĂveis para MTCT neste paĂs
Hydrologisch jaarboek 2007: VMM meetstations: bekkens van de IJzer, Brugse polders, Leie, Gentse Kanalen, Bovenschelde, Dender, Benedenschelde, Dijle & Zenne, Nete, Demer, Maas
Coupled root water and solute uptake - a functional structural model
Understanding the distribution and fate of solutes in the soil-plant continuum is of interest for regulatory authorities, customers and producers. For example pesticide legalization requires certain modelling and experimental studies before the substance can be released on the market. The modelling approach used in these procedures, however, does not hold detailed information about the fate of the solute in the plant root system, but treats the root system only as a linear sink term. Uptake is determined as fraction of transpiration of the concentration in the dissolved phase. With an increasing availability of more detailed modelling approaches within the last years, we focus on a more comprehensive description of pesticide uptake by plant roots. R-SWMS is a three dimensional model for water movement in soil and plant roots (1). It also includes solute transport within the roots, which is realized as a particle tracking algorithm (2). We coupled this model to Partrace, another particle tracking algorithm that solves the convection-dispersion-equation in the soil. Active or passive solute transport across the root membrane is possible. While active transport, namely Michaelis-Menten kinetics, requires energy input from the plant, passive transport can be either driven by advective water uptake and/or by the local concentration gradient between root and soil. Root membrane conductance is determined by the lipophilic properties of the solute. Within the root system solutes are transported via the advective water flux. We further implemented microbial decay and sorption to both soil and roots. Benchmarking the coupled 3D model with an analytical solution for a single root at steady state flow conditions showed a good agreement. Using this new approach we could derive global uptake parameters in silico and compare the simulation results to data from hydroponic experiments. The detailed modelling approach enables tracking solutes in time, space and phase within the soil and root system. This novel simulation tool can be used to investigate the influence of soil properties, root system architectures, solute properties, meteorological conditions as well as plant management strategies on plant solute uptake to gain a deeper understanding of solute uptake and transport parameters
Reduced capacity of antibodies from patients infected with human immunodeficiency virus type 1 (HIV-1) group O to neutralize primary isolates of HIV-1 group M viruses
Neutralizing antibody patterns in sera of persons infected with human immunodeficiency virus type 1 (HIV-1) groups M and a to their homologous and heterologous primary isolates were determined in a peripheral blood mononuclear cell-based neutralization assay and correlated with their ability to bind to V3 loop synthetic peptides. Most HIV-1 group M sera (9/16) neutralized HIV-1 group a viruses, whereas fewer group a sera (3/13) only weakly neutralized HIV-1 group M viruses. Group M sera neutralizing HIV-1 group a viruses neutralized other HIV-1 group M viruses with titers of 1:10-1:1280. V3 loop binding capacity of sera did not reflect their neutralizing capacity of the homologous isolate. Despite the reduced neutralizing capacity of group a-infected patients ' sera to group M viruses, some group M- infected patients ' sera neutralized both HIV-1 group M and a isolates, suggesting that they share some conserved neutralizing epitopes. Nucleic acid sequence analysis of the envelope gene of hu-man immunodeficiency virus type 1 (HIV-1) isolates has thus far distinguished at least 8 subtypes, A-H [1-3], which to-gether are referred to as HIV-1 group M (for major). However, the relevance of these genetic subtypes in terms of neutraliza
The contribution of water contact behavior to the high Schistosoma mansoni Infection rates observed in the Senegal River Basin
Background: Schistosomiasis is one of the major parasitic diseases in the world in terms of people infected and those at risk. Infection occurs through contact with water contaminated with larval forms of the parasite, which are released by freshwater snails and then penetrate the skin of people. Schistosomiasis infection and human water contact are thus essentially linked, and more knowledge about their relationship will help us to develop appropriate control measures. So far, only few studies have related water contact patterns to infection levels. Methods: We have conducted detailed direct water contact observations in a village in Northern Senegal during the first years of a massive Schistosoma mansoni outbreak to determine the role of human water contact in the extent of the epidemic. We quantified water contact activities in terms of frequency and duration, and described how these vary with age and sex. Moreover, we assessed the relationship between water contact-and infection intensity patterns to further elucidate the contribution of exposure to the transmission of schistosomiasis. Results: This resulted in over 120,000 recorded water contacts for 1651 subjects over 175 observation days. Bathing was the main activity, followed by household activities. Frequency and duration of water contact depended on age and sex rather than season. Water contacts peaked in adolescents, women spent almost twice as much time in the water as men, and water contacts were more intense in the afternoon than in the morning, with sex-specific intensity peaks. The average number of water contacts per person per day in this population was 0.42; the average time spent in the water per person per day was 4.3 minutes. Conclusions: The observed patterns of water contact behavior are not unusual and have been described before in various other settings in sub-Saharan Africa. Moreover, water contact levels were not exceptionally high and thus cannot explain the extremely high S. mansoni infection intensities as observed in Northern Senegal. Comparison with fecal egg counts in the respective age and sex groups further revealed that water contact levels did not unambiguously correspond with infection levels, indicating that factors other than exposure also play a role in determining intensity of infection
A new version of the HBSC Family Affluence Scale - FAS III: Scottish qualitative findings from the International FAS Development Study
A critical review of the Family Affluence Scale (FAS) concluded that FAS II was no longer discriminatory within very rich or very poor countries, where a very high or a very low proportion of children were categorised as high FAS or low FAS respectively (Currie et al. 2008). The review concluded that a new version of FAS - FAS III - should be developed to take into account current trends in family consumption patterns across the European region, the US and Canada. In 2012, the FAS Development and Validation Study was conducted in eight countries - Denmark, Greenland, Italy, Norway, Poland, Romania, Slovakia and Scotland. This paper describes the Scottish qualitative findings from this study. The Scottish qualitative fieldwork comprising cognitive interviews and focus groups sampled from 11, 13 and 15Â year-old participants from 18 of the most- and least- economically deprived schools. These qualitative results were used to inform the final FAS III recommendations.Publisher PDFPeer reviewe
Physical activity and beverage consumption in preschoolers: Focus groups with parents and teachers
Background: Qualitative research is a method in which new ideas and strategies can be discovered. This qualitative study aimed to investigate parentsâ and teachersâ opinions on physical activity and beverage consumption of preschool children. Through separate, independent focus groups, they expressed their perceptions on childrenâs current physical activity and beverage consumption levels, factors that influence and enhance these behaviours, and anticipated barriers to making changes.
Methods: Multi-cultural and multi-geographical focus groups were carried out in six European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain). In total, twenty-four focus groups with 122 parents and eighteen focus groups with 87 teachers were conducted between October 2010 and January 2011. Based on a semi-structured interview guide, questions on preschoolersâ physical activity (opinions on preschoolersâ physical factivity, how to increase physical activity, facilitators and barriers of physical activity) and beverage consumption (rules and policies, factors influencing promotion of healthy drinking, recommendations for future intervention development) were asked. The information was analyzed using qualitative data analysis software (NVivo8).
Results: The focus group results indicated misperceptions of caregivers on preschoolersâ physical activity and beverage consumption levels. Caregivers perceived preschoolers as sufficiently active; they argue that children need to learn to sit still in preparation for primary school. At most preschools, children can drink only water. In some preschools sugar-sweetened beverages like chocolate milk or fruit juices, are also allowed. It was mentioned that sugar-sweetened beverages can be healthy due to mineral and vitamin content, although according to parents their daily intake is limited. These opinions resulted in low perceived needs to change behaviours.
Conclusions: Although previous research shows need of change in obesity-related behaviours, the participants in the current study didnât perceive such. The awareness of parents and teachers needs to be raised concerning their shared responsibility about healthy behaviours in preschoolers. Providing preschool teachers with ready-to-use classroom material will encourage them to change physical activity and beverage consumption, and to implement related activities in the classroom. Involvement in activities that their children perform at preschool will motivate parents to extend these behaviours to the home environment.
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