311 research outputs found
Role of Rho-kinase in mediating contraction of chicken embryo femoral arteries
Rho-kinase-dependent Ca(2+) sensitization is an essential process for contraction of mammalian vascular smooth muscle but the information about its effects in non-mammalian vessels is scarce. We aimed to investigate, using the Rho-kinase inhibitor hydroxyfasudil, the potential role of the Rho-kinase pathway of Ca(2+) sensitization in depolarization- and agonist-mediated contraction of chicken embryo (at day 19 of the 21 days of incubation) femoral arteries. Contraction elicited by KCl (125 mM) comprised two phases (phasic and tonic contraction), both of which were abolished in the absence of extracellular Ca(2+). Hydroxyfasudil (10 μM) left the initial phasic component nearly intact but abolished the tonic component. Hydroxyfasudil also induced a marked impairment of the contractions elicited by phenylephrine (PE), the thromboxane A(2) mimetic U46619, and endothelin-1. In contrast, inhibition of protein kinase C (PKC) by chelerythrine did not affect KCl- or PE-induced contractions, indicating lack of participation of PKC-mediated Ca(2+) sensitization. Incubation under chronic hypoxia (15% O(2) from day 0) impaired embryonic growth but did not significantly affect hydroxyfasudil-mediated relaxation. In summary, our findings are indicative of a role for Rho-kinase activity in depolarization- and agonist-induced force generation in chicken embryo femoral arteries
Pattern and Predictors of Weight Gain During Pregnancy Among HIV-1-Infected Women from Tanzania
Progression of HIV disease is often accompanied by weight loss and wasting. Gestational weight gain is a strong determinant of maternal and neonatal outcomes; however, the pattern and predictors of weight gain during pregnancy among HIV-positive women are unknown. We obtained monthly anthropometric measurements in a cohort of 957 pregnant women from Tanzania who were HIV infected. We estimated the weekly rate of weight gain at various points during the second and third trimesters of pregnancy and computed rate differences between levels of sociodemographic, nutritional, immunologic, and parasitic variables at the first prenatal visit. The change in mid-upper arm circumference (MUAC) from baseline to delivery was also examined. The rate of weight gain decreased progressively during pregnancy. There was an average decline of 1 cm in MUAC between weeks 12 and 38. Lower level of education and helminthic infections at first visit were associated with decreased adjusted rates of weight gain during the third trimester. High baseline MUAC, not contributing to household income, lower serum retinol and selenium concentrations, advanced clinical stage of HIV disease, and malaria infection were related to decreased rates of weight gain during the second trimester. Low baseline CD4 T-cell counts were related to a poorer pattern of weight gain throughout pregnancy. Prevention and treatment of parasitic infections and improvement of nutritional status are likely to enhance the pattern of gestational weight gain among HIV-infected women
Accuracy of the Chinese lunar calendar method to predict a baby's sex: a population-based study
Villamor E, Dekker L, Svensson T, Cnattingius S. Accuracy of the Chinese lunar calendar method to predict a baby's sex: a population-based study. Paediatric and Perinatal Epidemiology 2010.We estimated the accuracy of a non-invasive, inexpensive method (the Chinese lunar calendar, CLC) to predict the sex of a baby from around the time of conception, using 2 840 755 singleton births occurring in Sweden between 1973 and 2006. Maternal lunar age and month of conception were estimated, and used to predict each baby's sex, according to a published algorithm. Kappa statistics were estimated for the actual vs. the CLC-predicted sex of the baby.Overall kappa was 0.0002 [95% CI −0.0009, 0.0014]. Accuracy was not modified by year of conception, maternal age, level of education, body mass index or parity. In a validation subset of 1000 births in which we used a website-customised algorithm to estimate lunar dates, kappa was −0.02 [95% CI −0.08, 0.04]. Simulating the misuse of the method by failing to convert Gregorian dates into lunar did not change the results. We conclude that the CLC method is no better at predicting the sex of a baby than tossing a coin and advise against painting the nursery based on this method's result.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79303/1/j.1365-3016.2010.01129.x.pd
Impacto medioambiental del uso de nanopartÃculas
En la actualidad, la nanotecnologÃa está experimentando un rápido desarrollo gracias a la aparición de novedosas aplicaciones en diversos campos como la medicina, la electrónica o la agricultura. Este creciente interés conlleva un aumento de la producción de nanopartÃculas en la industria y nos sitúa en un nuevo escenario en el que es importante valorar el impacto que pueden tener en el medioambiente y sus efectos tóxicos sobre los seres vivos. Las propiedades únicas, que les confiere su tamaño, son la razón de su uso en las distintas aplicaciones, pero son estas mismas propiedades las que se plantean como un riesgo para los seres vivos. Cada vez son más los estudios que investigan sobre el posible efecto de los nanomateriales en el medioambiente para determinar asà si, a pesar de sus aspectos positivos, pueden considerarse un riesgo para la salud. Para evaluar esta posible toxicidad, se utilizan modelos en toda clase de organismos, desde bacterias unicelulares hasta animales de gran complejidad.
Con el objetivo de conocer mejor las consecuencias medioambientales que puede acarrear hacer uso de la nanotecnologÃa, el presente trabajo se centrará en describir y clasificar las nanopartÃculas, en evaluar su ciclo de vida y de qué manera pueden ser emitidas al medioambiente, el tipo de impacto, tanto positivo como negativo, que pueden llegar a tener en los ecosistemas, y en especial sobre los seres vivos, y en evaluar la necesidad de una regulación más o menos estricta respecto a ellas. Debido a su diversidad, se analizará las nanopartÃculas de forma general, buscando estudiar el impacto de una gran variedad de ellas, incluyendo aquellas con mayor interés actual.Nowadays, nanotechnology is gaining a lot of interest from industry thanks to the emergence of new applications in different fields such as medicine, electronics or agriculture. This increasing interest leads to a bigger production of nanoparticles in the industry and places us in new scenarios where the impact that they might have on the environment and living beings needs to be assessed. The unique properties that nanoparticles have thanks to their small size, are the reason for their numerous applications, but they might also be the main menace to the environment. The number of studies which assess the possible ecotoxicity of nanomaterials has been increasing over the last years in order to determine if, despite the positive aspects, they should be considered a health risk. For the purpose of evaluating their possible toxicity, models are used in all types of organisms, from unicellular bacteria to complex animal species.
In order to understand better the environmental consequences of nanotechnology, this bibliographic work aims to describe and classify nanoparticles, evaluate their life cycle and how they can be released to the environment, the type of impact, either positive or negative that they might have on the ecosystems, particularly on living beings, and to assess the need of a more severe legislation with regard to them. Due to their diversity, nanoparticles will be discussed in generic terms looking to study the impact of a great variety of them, including the ones with the most interest in the industry.Universidad de Sevilla. Grado en Farmaci
Vitamin D Status and TB Treatment Outcomes in Adult Patients in Tanzania: A Cohort Study.
Vitamin D is an immunomodulator and can alter response to tuberculosis (TB) treatment, though randomised trials have been inconclusive to date. We present one of the first comprehensive analysis of the associations between vitamin D status and TB treatment, T-cell counts and nutritional outcomes by HIV status. Cohort study. Outpatient clinics in Tanzania. 25-hydroxyvitamin D levels were assessed in a cohort of 677 patients with TB (344 HIV infected) initiating anti-TB treatment at enrolment in a multivitamin supplementation (excluding vitamin D) trial (Clinicaltrials.gov identifier: NCT00197704). Information on treatment outcomes such as failure and relapse, HIV disease progression, T-cell counts and anthropometry was collected routinely, with a median follow-up of 52 and 30 months for HIV-uninfected and HIV-infected patients, respectively. Cox and binomial regression, and generalised estimating equations were used to assess the association of vitamin D status with these outcomes. Mean 25-hydroxyvitamin D concentrations at enrolment were 69.8 (±21.5) nmol/L (27.9 (±8.6) ng/mL). Vitamin D insufficiency (<75 nmol/L) was associated with a 66% higher risk of relapse (95% CI 4% to 164%; 133% higher risk in HIV-uninfected patients). Each unit higher 25-hydroxyvitamin D levels at baseline were associated with a decrease of 3 (p=0.004) CD8 and 3 (p=0.01) CD3 T-cells/µL during follow-up in patients with HIV infection. Vitamin D insufficiency was also associated with a greater decrease of body mass index (BMI; -0.21 kg/m(2); 95% CI -0.39 to -0.02), during the first 8 months of follow-up. No association was observed for vitamin D status with mortality or HIV disease progression. Adequate vitamin D status is associated with a lower risk of relapse and with improved nutritional indicators such as BMI in patients with TB, with or without HIV infection. Further research is needed to determine the optimal dose of vitamin D and effectiveness of daily vitamin D supplementation among patients with TB
A Trial of the Effect of Micronutrient Supplementation on Treatment Outcome, T Cell Counts, Morbidity, and Mortality in Adults with Pulmonary Tuberculosis.
Tuberculosis (TB) often coincides with nutritional deficiencies. The effects of micronutrient supplementation on TB treatment outcomes, clinical complications, and mortality are uncertain. We conducted a randomized, double-blind, placebo-controlled trial of micronutrients (vitamins A, B complex, C, and E, as well as selenium) in Dar es Salaam, Tanzania. We enrolled 471 human immunodeficiency virus (HIV)-infected and 416 HIV-negative adults with pulmonary TB at the time of initiating chemotherapy and monitored them for a median of 43 months. Micronutrients decreased the risk ofTB recurrence by 45% overall (95% confidence interval [CI], 7% to 67%; P = .02) and by 63% in HIV-infected patients (95% CI, 8% to 85%; P = .02). There were no significant effects on mortality overall; however, we noted a marginally significant 64% reduction of deaths in HIV-negative subjects (95% CI, -14% to 88%; P = .08). Supplementation increased CD3+ and CD4+ cell counts and decreased the incidence of extrapulmonary TB and genital ulcers in HIV-negative patients. Micronutrients reduced the incidence of peripheral neuropathy by 57% (95% CI, 41% to 69%; P < .001), irrespective of HIV status. There were no significant effects on weight gain, body composition, anemia, or HIV load. Micronutrient supplementation could improve the outcome in patients undergoing TB chemotherapy in Tanzania
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