892 research outputs found
Preliminary study of the presence of antibodies against excretory-secretory antigens from protoscoleces of Echinococcus granulosus in dogs with intestinal echinococcosis
Acquired hemophilia as the cause of life-threatening hemorrhage in a 94-year-old man: a case report
<p>Abstract</p> <p>Introduction</p> <p>Acquired factor VIII deficiency is a rare entity that can lead to severe and life-threatening bleeding. We describe a case of severe bleeding from the tongue secondary to acquired hemophilia and discuss treatment options, including aminocaproic acid and recombinant factor VIII, which have not been widely reported in the literature for the management of such patients.</p> <p>Case presentation</p> <p>A 94-year-old Caucasian man presented to our institution with diffuse bruising and extensive bleeding from the tongue secondary to mechanical trauma. He had no prior history of bleeding and his medical history was unremarkable except for dementia and hypertension. Coagulation studies revealed a prolonged activated partial thromboplastin time and a mixing study was consistent with the presence of an inhibitor. Quantitative assays revealed a reduced level of factor VIII activity (1%) and the presence of a factor VIII inhibitor, measured at seven Bethesda units, in the serum. Oral prednisone therapy (60mg/day) was given. He also received intravenous aminocaproic acid and human concentrate of factor VIII (Humate-P) and topical anti-thrombolytic agents (100 units of topical thrombin cream). His hospital course was prolonged because of persistent bleeding and the development of profuse melena. He required eight units of packed red blood cells for transfusion. Hospitalization was also complicated by bradycardia of unclear etiology, which started after infusion of aminocaproic acid. His activated partial thromboplastin time gradually normalized. He was discharged to a rehabilitation facility three weeks later with improving symptoms, stable hematocrit and resolving bruises.</p> <p>Conclusions</p> <p>Clinicians should suspect a diagnosis of acquired hemophilia in older patients with unexplained persistent and profound bleeding from uncommon soft tissues, including the tongue. Use of factor VIII (Humate-P) and aminocaproic acid can be useful in this coagulopathy but clinicians should be aware of possible life-threatening side effects in older patients, including bradycardia.</p
Tuberculosis
Asserts that despite progress in controlling tuberculosis (TB), the decline in incidence has been disappointing, pointing to the need for new strategies and more effective tools. HIV/AIDS is one factor that challenges effective control of TB, especially in Southern African countries. Three key elements are needed to achieve effective TB control and to meet the Sustainable Development Goals: (1) early and accurate diagnosis and drug-sensitivity testing, (2) patient access to and completion of effective treatment, and (3) prevention of progression from latent infection to disease. Prevention requires vaccination and screening of individual at high risk as well as interventions such as air disinfection and the use of masks and respirators in hospitals and other congregate settings. Recommendations stress the need to strengthen health systems in high-burden countries by emphasizing community-based care over hospital care; to improve information systems to ensure patient adherence and manage medication supply chains; and to invest in research to develop the necessary interventions. Fundamentally, current global TB control strategies must undergo revision and receive significant research funding
A randomised control trial of low glycaemic index carbohydrate diet versus no dietary intervention in the prevention of recurrence of macrosomia
<p>Abstract</p> <p>Background</p> <p>Maternal weight and maternal weight gain during pregnancy exert a significant influence on infant birth weight and the incidence of macrosomia. Fetal macrosomia is associated with an increase in both adverse obstetric and neonatal outcome, and also confers a future risk of childhood obesity. Studies have shown that a low glycaemic diet is associated with lower birth weights, however these studies have been small and not randomised <abbrgrp><abbr bid="B1">1</abbr><abbr bid="B2">2</abbr></abbrgrp>. Fetal macrosomia recurs in a second pregnancy in one third of women, and maternal weight influences this recurrence risk <abbrgrp><abbr bid="B3">3</abbr></abbrgrp>.</p> <p>Methods/Design</p> <p>We propose a randomised control trial of low glycaemic index carbohydrate diet vs. no dietary intervention in the prevention of recurrence of fetal macrosomia.</p> <p>Secundigravid women whose first baby was macrosomic, defined as a birth weight greater than 4000 g will be recruited at their first antenatal visit.</p> <p>Patients will be randomised into two arms, a control arm which will receive no dietary intervention and a diet arm which will be commenced on a low glycaemic index diet.</p> <p>The primary outcome measure will be the mean birth weight centiles and ponderal indices in each group.</p> <p>Discussion</p> <p>Altering the source of maternal dietary carbohydrate may prove to be valuable in the management of pregnancies where there has been a history of fetal macrosomia. Fetal macrosomia recurs in a second pregnancy in one third of women. This randomised control trial will investigate whether or not a low glycaemic index diet can affect this recurrence risk.</p> <p>Current Controlled Trials Registration Number</p> <p>ISRCTN54392969</p
Transmission Selects for HIV-1 Strains of Intermediate Virulence: A Modelling Approach
Recent data shows that HIV-1 is characterised by variation in viral virulence factors that is heritable between infections, which suggests that viral virulence can be naturally selected at the population level. A trade-off between transmissibility and duration of infection appears to favour viruses of intermediate virulence. We developed a mathematical model to simulate the dynamics of putative viral genotypes that differ in their virulence. As a proxy for virulence, we use set-point viral load (SPVL), which is the steady density of viral particles in blood during asymptomatic infection. Mutation, the dependency of survival and transmissibility on SPVL, and host effects were incorporated into the model. The model was fitted to data to estimate unknown parameters, and was found to fit existing data well. The maximum likelihood estimates of the parameters produced a model in which SPVL converged from any initial conditions to observed values within 100–150 years of first emergence of HIV-1. We estimated the 1) host effect and 2) the extent to which the viral virulence genotype mutates from one infection to the next, and found a trade-off between these two parameters in explaining the variation in SPVL. The model confirms that evolution of virulence towards intermediate levels is sufficiently rapid for it to have happened in the early stages of the HIV epidemic, and confirms that existing viral loads are nearly optimal given the assumed constraints on evolution. The model provides a useful framework under which to examine the future evolution of HIV-1 virulence
A cross-national mixed-method study of reality pedagogy
This mixed-methods cross-national study investigated the effectiveness of reality pedagogy (an approach in which teachers become part of students’ activities, practices and rituals) in terms of changes in student perceptions of their learning environment and attitudes towards science. A questionnaire was administered to 142 students in grades 8–10 in the Bronx, New York City and Dresden, Germany. The questionnaire combines learning environment scales from the Constructivist Learning Environment Survey and the What Is Happening In this Class? Questionnaire with attitude scales from the Test of Science-Related Attitudes. Student interviews were used to support questionnaire findings. Quantitative data analyses revealed that reality pedagogy had a greater impact on students in the Bronx than in Dresden, with qualitative data clarifying differences in how reality pedagogy was enacted in each geographic area. Overall, our findings add to the body of evidence concerning the effectiveness of reality pedagogy as an approach to teaching and learning science across a variety of contexts. © 2016 Springer Science+Business Media Dordrech
Learning environment, attitudes and anxiety across the transition from primary to secondary school mathematics
Past research has revealed that, relative to primary-school students, high-school students have less-positive attitudes to mathematics and perceive their classroom environments and teacher–student relationships less favourably. This study involved the transition experience of 541 students in 47 classes in 15 primary (year 7) and secondary (year 8) government and Catholic schools in metropolitan and regional South Australia. Scales were adapted from three established instruments, namely, the What Is Happening In this Class?, Test of Mathematics Related Attitudes and Revised Mathematics Anxiety Ratings Scale, to identify changes across the transition from primary to secondary school in terms of the classroom learning environment and students’ attitude/anxiety towards mathematics. Relative to year 7 students, year 8 students reported less Involvement, less positive Attitude to Mathematical Inquiry, less Enjoyment of Mathematics and greater Mathematics Anxiety. Differences between students in Years 7 and 8 were very similar for male and female students, although the magnitude of sex differences in attitudes was slightly different in Years 7 and 8
Ultrasonic 3-D Reconstruction of Inclusions in Solids Using the Inverse Born Algorithm
Considerable progress has been made in recent years in the development of signal processing algorithms for use in ultrasonic non-destructive evaluation which yield the size, shape, and orientation of a flaw. This kind of flaw information is necessary in order that failure predictions of materials and components can be made from non-destructive tests. The signal processing algorithms that have been developed for ultrasonics are based upon both direct and inverse approximate solutions to the elastic wave scattering problem, and cover various ranges of the parameter ka where k=2π/λ is the wave number of the ultrasound and a is a flaw size dimension. In order to use these algorithms effectively in the determination of flaw parameters, it has been found necessary to obtain measurements of the flaw at several viewing angles. At this time, there is no ultrasonic transducer available which permits this to be done efficiently and conveniently in the long and intermediate wavelength end of the spectrum. This region has been shown to be quite rich in flaw information and is appropriate to ultrasonic NDE in many practical applications (e.g., thick wall sections).</p
Sustained CD28 Expression Delays Multiple Features of Replicative Senescence in Human CD8 T Lymphocytes
CD28 costimulatory signal transduction in T lymphocytes is essential for optimal telomerase activity, stabilization of cytokine mRNAs, and glucose metabolism. During aging and chronic infection with HIV-1, there are increased proportions of CD8 T lymphocytes that lack CD28 expression and show additional features of replicative senescence. Moreover, the abundance of these cells correlates with decreased vaccine responsiveness, early mortality in the very old, and accelerated HIV disease progression. Here, we show that sustained expression of CD28, via gene transduction, retards the process of replicative senescence, as evidenced by enhanced telomerase activity, increased overall proliferative potential, and reduced secretion of pro-inflammatory cytokines. Nevertheless, the transduced cultures eventually do reach senescence, which is associated with increased CTLA-4 gene expression and a loss of CD28 cell surface expression. These findings further elucidate the central role of CD28 in the replicative senescence program, and may ultimately lead to novel therapies for diseases associated with replicative senescence
Cytosolic Sequestration of Prep1 Influences Early Stages of T Cell Development
Objective: Prep1 and Pbx2 are the main homeodomain DNA-binding proteins of the TALE (three amino acid loop extension) family expressed in the thymus. We previously reported reduced Pbx2 expression and defective thymocyte maturation in Prep1 hypomorphic mice. To further investigate the role of this homeodomain DNA-binding protein in T cell development, we generated transgenic mice expressing the N-terminal fragment of Pbx1 (Pbx1NT) under the control of the Lck proximal promoter. Principal Findings: Pbx1NT causes Prep1 cytosolic sequestration, abolishes Prep1-dependent DNA-binding activity and results in reduced Pbx2 expression in developing thymocytes. Transgenic thymi reveal increased numbers of CD4 2 CD8 2 CD44 2 (DN3 and DN4) thymocytes, due to a higher frequency of DN2 and DN4 Pbx1NT thymocytes in the S phase. Transgenic thymocytes however do not accumulate at later stages, as revealed by a normal representation of CD4/CD8 double positive and single positive thymocytes, due to a higher rate of apoptotic cell death of DN4 Pbx1NT thymocytes. Conclusion: The results obtained by genetic (Prep1 hypomorphic) and functional (Pbx1NT transgenic) inactivation of Prep
- …