457 research outputs found
Polyfunctional T cell responses in children in early stages of chronic Trypanosoma cruzi infection contrast with monofunctional responses of long-term infected adults
Background: Adults with chronic Trypanosoma cruzi exhibit a poorly functional T cell compartment, characterized by monofunctional (IFN-Îł-only secreting) parasite-specific T cells and increased levels of terminally differentiated T cells. It is possible that persistent infection and/or sustained exposure to parasites antigens may lead to a progressive loss of function of the immune T cells. Methodology/Principal Findings: To test this hypothesis, the quality and magnitude of T. cruzi-specific T cell responses were evaluated in T. cruzi-infected children and compared with long-term T. cruzi-infected adults with no evidence of heart failure. The phenotype of CD4+ T cells was also assessed in T. cruzi-infected children and uninfected controls. Simultaneous secretion of IFN-Îł and IL-2 measured by ELISPOT assays in response to T. cruzi antigens was prevalent among T. cruzi-infected children. Flow cytometric analysis of co-expression profiles of CD4+ T cells with the ability to produce IFN-Îł, TNF-α, or to express the co-stimulatory molecule CD154 in response to T. cruzi showed polyfunctional T cell responses in most T. cruzi-infected children. Monofunctional T cell responses and an absence of CD4+TNF-α+-secreting T cells were observed in T. cruzi-infected adults. A relatively high degree of activation and differentiation of CD4+ T cells was evident in T. cruzi-infected children. Conclusions/Significance: Our observations are compatible with our initial hypothesis that persistent T. cruzi infection promotes eventual exhaustion of immune system, which might contribute to disease progression in long-term infected subjects.Fil: Albareda, MarĂa Cecilia. DirecciĂłn Nacional de Instituto de InvestigaciĂłn. AdministraciĂłn Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de ParasitologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva PerĂłn"; ArgentinaFil: de Rissio, Ana MarĂa. DirecciĂłn Nacional de Instituto de InvestigaciĂłn. AdministraciĂłn Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de ParasitologĂa; ArgentinaFil: Tomas, Gonzalo. DirecciĂłn Nacional de Instituto de InvestigaciĂłn. AdministraciĂłn Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de ParasitologĂa; ArgentinaFil: Serjan, Alicia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. FernĂĄndez"; ArgentinaFil: Alvarez, MarĂa Gabriela. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva PerĂłn"; ArgentinaFil: Viotti, Rodolfo Jorge. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva PerĂłn"; ArgentinaFil: Fichera, Laura Edith. DirecciĂłn Nacional de Instituto de InvestigaciĂłn. AdministraciĂłn Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de ParasitologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Esteva, MĂłnica InĂ©s. DirecciĂłn Nacional de Instituto de InvestigaciĂłn. AdministraciĂłn Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de ParasitologĂa; ArgentinaFil: Potente, Daniel Fernando. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva PerĂłn"; ArgentinaFil: Armenti, Alejandro. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva PerĂłn"; ArgentinaFil: Tarleton, Rick L.. University of Georgia; Estados UnidosFil: Laucella, Susana Adriana. DirecciĂłn Nacional de Instituto de InvestigaciĂłn. AdministraciĂłn Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de ParasitologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Haplotypes of intron 4 of the estrogen receptor alpha gene and hip fractures: a replication study in Caucasians
<p>Abstract</p> <p>Background</p> <p>Despite their great impact, few genetic association studies have used hip fractures as an endpoint. However, the association of two polymorphisms on intron 4 of estrogen receptor alpha (<it>ESR1</it>) with hip fractures was recently reported in a Chinese population. The aim of this study was to investigate whether such association is also present in Caucasians.</p> <p>Methods</p> <p>We analyzed those two SNPs and another neighbour SNP located on the exon 4 of <it>ESR1 </it>in 787 patients with hip fractures and 953 controls from Spain.</p> <p>Results</p> <p>The allelic frequencies differed markedly from those reported in Asian populations. Nevertheless, haplotypes including the rs3020314 and rs1884051 loci in intron 4 showed a significant association with hip fractures (omnibus test p = 0.006 in the whole group and 0.00005 in women). In the sex-stratified analysis, the association was significant in females, but not in males. In women, the CA haplotype appeared to have a protective influence, being present in 6.5% of the controls, but only in 3% of patients with fractures (odds ratio 0.39; 95% confidence interval 0.26-0.59; estimated population preventive fraction 3.5%). The inclusion of the rs1801132 SNP of exon 4 further increased the statistical significance of the association (odds ratio 0.17; 95% CI 0.08-0.37; p = 0.00001). Each SNP appeared to contribute independently to the association. No genotype-related differences in gene expression were found in 42 femoral bone samples.</p> <p>Conclusions</p> <p>This study confirms the association of some polymorphisms in the region of exon 4/intron 4 of <it>ESR1 </it>and hip fractures in women. However, there are marked differences in allele frequencies between Asian and Caucasian populations.</p
Standardizing effect size from linear regression models with log-transformed variables for meta-analysis
Background: Meta-analysis is very useful to summarize the effect of a treatment or a risk factor for a given disease.
Often studies report results based on log-transformed variables in order to achieve the principal assumptions of a
linear regression model. If this is the case for some, but not all studies, the effects need to be homogenized.
Methods: We derived a set of formulae to transform absolute changes into relative ones, and vice versa, to allow
including all results in a meta-analysis. We applied our procedure to all possible combinations of log-transformed
independent or dependent variables. We also evaluated it in a simulation based on two variables either normally or
asymmetrically distributed.
Results: In all the scenarios, and based on different change criteria, the effect size estimated by the derived set of
formulae was equivalent to the real effect size. To avoid biased estimates of the effect, this procedure should be
used with caution in the case of independent variables with asymmetric distributions that significantly differ from
the normal distribution. We illustrate an application of this procedure by an application to a meta-analysis on the
potential effects on neurodevelopment in children exposed to arsenic and manganese.
Conclusions: The procedure proposed has been shown to be valid and capable of expressing the effect size of a
linear regression model based on different change criteria in the variables. Homogenizing the results from different
studies beforehand allows them to be combined in a meta-analysis, independently of whether the transformations
had been performed on the dependent and/or independent variables
Effects of an exercise programme with people living with HIV: Research in a disadvantaged setting
This study aimed to analyse the physical health effects of a community based 10-week physical activity programme with people living with HIV. It was developed, implemented and evaluated in a disadvantaged community in South Africa. A pre-post research design was chosen. Major recruitment and adherence challenges resulted in a small sample. Among the 23 participants who took part in both baseline and final testing, compliant participants (n = 12) were compared to non-compliant participants (n = 11). Immunological (CD4, viral load), anthropometric (height, weight, skinfolds and waist to hip ratio), muscular strength (h1RM) and cardiopulmonary fitness (time on treadmill) parameters were measured. The compliant and non-compliant groups were not different at baseline. Muscular strength was the parameter most influenced by compliance with the physical activity programme (F = 4.516, p = 0.047). Weight loss and improvement in cardiopulmonary fitness were restricted by the duration of the programme, compliance and influencing factors (e.g. nutrition, medication). The increase in strength is significant and meaningful in the context, as the participants goals were to look healthy and strong to avoid HIV related stigma. The improvements in appearance were a motivational factor, especially since the changes were made visible in a short time. Practical implications for health promotion are described. More research contextualised in disadvantaged settings is needed.DHE
Oestradiol-17ÎČ plasma concentrations after intramuscular injection of oestradiol benzoate or oestradiol cypionate in llamas (Lama glama)
<p>Abstract</p> <p>Background</p> <p>Llamas (<it>Lama glama</it>) are induced ovulators and the process of ovulation depends on dominant follicular size. In addition, a close relationship between behavioural estrus and ovulation is not registered in llamas. Therefore, the exogenous control of follicular development with hormones aims to predict the optimal time to mate. Oestradiol-17ÎČ (E<sub>2</sub>) and its esters are currently used in domestic species, including camelids, in synchronization treatments. But, in llamas, there is no reports regarding the appropriate dosages to be used and most protocols have been designed by extrapolation from those recommended for other ruminants. The aim of the present study was to characterize plasma E<sub>2 </sub>concentrations in intact female llamas following a single intramuscular (i.m.) injection of two oestradiol esters: oestradiol benzoate (EB) and oestradiol cypionate (ECP).</p> <p>Methods</p> <p>Twelve non pregnant and non lactating sexually mature llamas were i.m. injected on day 0 with 2.5 mg of EB (EB group, n = 6) or ECP (ECP group, n = 6). Blood samples were collected immediately before injection, at 1, 6, 12, 24 h after treatment and then daily until day 14 post injection. Changes in hormone concentrations with time were analyzed in each group by analysis of variance (ANOVA) using a repeated measures (within-SS) design. Plasma E<sub>2 </sub>concentrations and area under the concentration-time curve (AUC) values were compared between groups by ANOVA. In all cases a Least-Significant Difference test (LSD) was used to determine differences between means. Hormonal and AUC data are expressed as mean ± S.E.M.</p> <p>Results</p> <p>Peak plasma E<sub>2 </sub>concentrations were achieved earlier and were higher in EB group than in ECP group. Thereafter, E<sub>2 </sub>returned to physiological concentrations earlier in EB group (day 5) than in ECP group (day 9). Although plasma E<sub>2 </sub>profiles differed over time among groups there were no differences between them on AUC values.</p> <p>Conclusions</p> <p>The i.m. injection of a single dose of both oestradiol esters resulted in plasma E<sub>2 </sub>concentrations exceeding physiological values for a variable period. Moreover, the plasma E<sub>2 </sub>profiles observed depended on the derivative of oestradiol administered. This basic information becomes relevant at defining treatment protocols including oestrogens in llamas.</p
A more fine-grained measure towards animal welfare: a study with regards to gender differences in Spanish students
The environmental issue is nowadays taking more importance in the environmental awareness all around the world, and in this field, animal consideration is more and more spread. A highlighted part in globalisation is the animal welfare awareness. This article presents a study comparing attitudes towards animals among secondary and university students in reference to gender. It was carried out on 1394 Spanish participants from 11 to 26Â years. The instrument used in the study is the reviewed version of the Animal Welfare Attitude Scale which was renamed as âAnimal Welfare Attitude-Revised Scaleâ (AWA-R Scale), with a Cronbach a reliability value of 0.85. It is subdivided into four components namely C1: animal abuse for pleasure or due to ignorance; C2: leisure with animals; C3: farm animals; and C4: animal abandonment. These components have been deeply detailed by a confirmatory factor analysis (CFA), which highly contributes to define the position of participants for the different dimensions of animal welfare. It is concluded that significant differences exist between malesâ and femalesâ attitudes in all components of the AWA-R Scale. It is also suggested that two social characteristicsâpeopleâs attitudes towards animals and towards environmental protectionâare, at the very least, coexistent and may indeed be interdependent. These differences between gender in matters of socialisation could thus be reflected in environmental attitudes, and also in others related to them, i.e. animal welfare attitudes
Antiproliferative effects of Tubi-bee propolis in glioblastoma cell lines
Propolis is a resin formed by a complex chemical composition of substances that bees collect from plants. Since ancient times, propolis has been used in folk medicine, due to its biological properties, that include antimicrobial, anti-inflammatory, antitumoral and immunomodulatory activities. Glioblastoma is the most common human brain tumor. Despite the improvements in GBM standard treatment, patientsâ prognosis is still very poor. The aim of this work was to evaluate in vitro the Tubi-bee propolis effects on human glioblastoma (U251 and U343) and fibroblast (MRC-5) cell lines. Proliferation, clonogenic capacity and apoptosis were analyzed after treatment with 1 mg/mL and 2 mg/mL propolis concentrations for different time periods. Additionally, glioblastoma cell lines were submitted to treatment with propolis combined with temozolomide (TMZ). Data showed an antiproliferative effect of tubi-bee propolis against glioblastoma and fibroblast cell lines. Combination of propolis with TMZ had a synergic anti-proliferative effect. Moreover, propolis caused decrease in colony formation in glioblastoma cell lines. Propolis treatment had no effects on apoptosis, demonstrating a cytostatic action. Further investigations are needed to elucidate the molecular mechanism of the antitumor effect of propolis, and the study of its individual components may reveal specific molecules with antiproliferative capacity
Quality of life in patients with hereditary haemorrhagic telangiectasia (HHT)
Background: There are very few studies about general quality of life parameters, standards for the description of health status and comparison with general population data on patients with Hereditary hemorrhagic telangiectasia (HHT), a rare disease in which epistaxis is a cardinal symptom. Purpose: To assess the quality of life in a population of Spanish patients with HHT and compare it with the general population. Design and methods: Between January 1st 2005 and December 31st 2013, 187 adult patients diagnosed with HHT who were admitted to the HHT Unit of the Hospital Sierrallana, completed on their first visit, the EuroQol 5D-3L (five dimensions and three levels) quality of life descriptive test and the visual analog scale (VAS). The numerical social index value was also determined and the subjective effect of the nasal epistaxis on their quality of life was estimated classified as mild, moderate or severe. Results: Patients with HHT had greater problems than the general population in the five dimensions of the EuroQol 5D-3L, particularly considering pain/discomfort and anxiety/depression. In the VAS and the social index value, patients with HHT also scored lower than the general population, particularly older patients, males, and patients with HHT2. They also had values similar to those of populations with chronic illnesses. The subjective perception of the severity of epistaxis correlated strongly with the VAS and social index values. Conclusions: The quality of life of patients with HHT, estimated using the EuroQol 5D-3L scale, is affected across all dimensions. The scores are similar to those seen in cases of other chronic diseases. Older patients, males and the carriers of the ACVRL1 mutation generally have worse scores on these scales. The VAS and the social index value are index that correlate well with the severity of the clinical symptoms associated mainly with epistaxis
A chemical survey of exoplanets with ARIEL
Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planetâs birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25â7.8 ÎŒm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10â100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed â using conservative estimates of mission performance and a full model of all significant noise sources in the measurement â using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL â in line with the stated mission objectives â will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
Chagas Cardiomiopathy: The Potential of Diastolic Dysfunction and Brain Natriuretic Peptide in the Early Identification of Cardiac Damage
Chagas disease remains a major cause of morbidity and mortality in several
countries of Latin America and has become a potential public health problem in
countries where the disease is not endemic as a result of migration flows.
Cardiac involvement represents the main cause of mortality, but its diagnosis is
still based on nonspecific criteria with poor sensitivity. Early identification
of patients with cardiac damage is desirable, since early treatment may improve
prognosis. Diastolic dysfunction and elevated brain natriuretic peptide levels
are present in different cardiomyopathies and in advanced phases of Chagas
disease. However, there are scarce data about the role of these parameters in
earlier forms of the disease. We conducted a study to assess the diastolic
function, regional systolic abnormalities and brain natriuretic peptide levels
in the different forms of Chagas disease. The main finding of our investigation
is that diastolic dysfunction occurs before any cardiac dilatation or motion
abnormality. In addition, BNP levels identify patients with diastolic
dysfunction and Chagas disease with high specificity. The results reported in
this study could help to early diagnose myocardial involvement and better
stratify patients with Chagas disease
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