1,130 research outputs found

    Continuous increase of cardiovascular diseases, diabetes, and non-HIV related cancers as causes of death in HIV-infected individuals in Brazil: An analysis of nationwide data

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    Introduction: After antiretroviral therapy (ART) became available, there was a decline in the number of deaths in persons infected with HIV. Thereafter, there was a decrease in the proportion of deaths attributed to opportunistic infections and an increase in the proportion of deaths attributed to chronic comorbidities. Herein we extend previous observations from a nationwide survey on temporal trends in causes of death in HIV-infected patients in Brazil. Methods: We describe temporal trends in causes of death among adults who had HIV/AIDS listed in the death certificate to those who did not. All death certificates issued in Brazil from 1999 to 2011 and listed in the national mortality database were included. Generalized linear mixed-effects logistic models were used to study temporal trends in proportions. Results: In the HIV-infected population, there was an annual adjusted average increase of 6.0%, 12.0%, 4.0% and 4.1% for cancer, external causes, cardiovascular diseases (CVD) and diabetes mellitus (DM), respectively, compared to 3.0%, 4.0%, 1.0% and 3.9%, in the non-HIV group. For tuberculosis (TB), there was an adjusted average increase of 0.3%/year and a decrease of 3.0%/year in the HIV and the non-HIV groups, respectively. Compared to 1999, the odds ratio (OR) for cancer, external causes, CVD, DM, or TB in the HIV group were, respectively, 2.31, 4.17, 1.76, 2.27 and 1.02, while for the non-HIV group, the corresponding OR were 1.31, 1.63, 1.14, 1.62 and 0.67. Interactions between year as a continuous or categorical variable and HIV were significant (p <0.001) for all conditions, except for DM when year was considered as a continuous variable (p = 0.76). Conclusions: Non HIV-related co-morbidities continue to increase more rapidly as causes of death among HIV-infected individuals than in those without HIV infection, highlighting the need for targeting prevention measures and surveillance for chronic diseases among those patients. © 2014 Paula et al

    Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

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    The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species

    Outcomes of TB Treatment by HIV Status in National Recording Systems in Brazil, 2003–2008

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    BACKGROUND: Although the Brazilian national reporting system for tuberculosis cases (SINAN) has enormous potential to generate data for policy makers, formal assessments of treatment outcomes and other aspects of TB morbidity and mortality are not produced with enough depth and rigor. In particular, the effect of HIV status on these outcomes has not been fully explored, partly due to incomplete recording in the national database. METHODOLOGY/PRINCIPAL FINDINGS: In a retrospective cohort study, we assessed TB treatment outcomes, including rates of cure, default, mortality, transfer and multidrug resistant TB (MDR-TB) among a purposively chosen sample of 161,481 new cases reported in SINAN between 2003 and 2008. The study population included all new cases reported in the six States with the highest level of completeness of the HIV status field in the system. These cases were mostly male (67%), white (62%), had pulmonary TB (79%) and a suspect chest X ray (83%). Treatment outcomes were best for those HIV negative cases and worst for those known HIV positive patients (cure rate of 85.7% and 55.7% respectively). In multivariate modeling, the risk of having an unfavorable outcome (all outcomes except cure) was 3.09 times higher for those HIV positive compared with those HIV negative (95% CI 3.02-3.16). The risk of death and default also increased with HIV positivity. The group without a known HIV status showed intermediate outcomes between the groups above, suggesting that this group includes some with HIV infection. CONCLUSIONS: HIV status played an important role in TB treatment outcomes in the study period. The outcomes observed in those with known HIV were poor and need to be improved. Those in the group with unknown HIV status indicate the need for wider HIV testing among new TB cases

    Bio-nanotechnology application in wastewater treatment

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    The nanoparticles have received high interest in the ïŹeld of medicine and water puriïŹcation, however, the nanomaterials produced by chemical and physical methods are considered hazardous, expensive, and leave behind harmful substances to the environment. This chapter aimed to focus on green-synthesized nanoparticles and their medical applications. Moreover, the chapter highlighted the applicability of the metallic nanoparticles (MNPs) in the inactivation of microbial cells due to their high surface and small particle size. Modifying nanomaterials produced by green-methods is safe, inexpensive, and easy. Therefore, the control and modiïŹcation of nanoparticles and their properties were also discussed

    Clinicoradiological manifestations of paraganglioma syndromes associated with succinyl dehydrogenase enzyme mutation

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    BACKGROUND: Paragangliomas are rare tumours derived from the autonomic nervous system that have increasingly been recognised to have a genetic predisposition. Mutations of the enzyme succinyl dehydrogenase (SDH) have proven to result in paraganglioma formation. There are four subunits (A through D) that form the enzyme complex and are associated with different genophenotypic expressions of disease. SDHB and SDHD mutations are more common, whereas SDHA and SDHC mutations are rare. Patients with SDHB mutations are prone to extra-adrenal pheochromocytomas, malignant disease and extra-paraganglial neoplasia, whereas SDHD mutations have a greater propensity for multiple, benign head and neck paragangliomas. METHODS: Diagnosis of a sporadic paraganglioma or pheochromocytoma should lead to a full genetic workup of the patient and family if SDH mutations are found. RESULTS: Further annual screening will be required depending on the mutation, which can have a significant impact on radiologists and the resources of the radiology department. CONCLUSION: We present our imaging experience with a series of patients with proven SDH mutations resulting in paragangliomas with a review of the literature

    Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions

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    The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions

    Effect of Immediate Initiation of Antiretroviral Treatment in HIV-Positive Individuals Aged 50 Years or Older

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    BACKGROUND: Clinical guidelines recommend immediate initiation of combined antiretroviral therapy for all HIV-positive individuals. However, those guidelines are based on trials of relatively young participants. METHODS: We included HIV-positive antiretroviral therapy-naive, AIDS-free individuals aged 50-70 years after 2004 in the HIV-CAUSAL Collaboration. We used the parametric g-formula to estimate the 5-year risk of all-cause and non-AIDS mortality under (1) immediate initiation at baseline and initiation at CD4 count, (2) <500 cells/mm, and (3) <350 cells/mm. Results were presented separately for the general HIV population and for a US Veterans cohort with high mortality. RESULTS: The study included 9596 individuals (28% US Veterans) with median (interquantile range) age of 55 (52-60) years and CD4 count of 336 (182-513) at baseline. The 5-year risk of all-cause mortality was 0.40% (95% confidence interval (CI): 0.10 to 0.71) lower for the general HIV population and 1.61% (95% CI: 0.79 to 2.67) lower for US Veterans when comparing immediate initiation vs initiation at CD4 <350 cells/mm. The 5-year risk of non-AIDS mortality was 0.17% (95% CI: -0.07 to 0.43) lower for the general HIV population and 1% (95% CI: 0.31 to 2.00) lower for US Veterans when comparing immediate initiation vs initiation at CD4 <350 cells/mm. CONCLUSIONS: Immediate initiation seems to reduce all-cause and non-AIDS mortality in patients aged 50-70 years

    The Evolution of Compact Binary Star Systems

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    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

    Effect Estimates in Randomized Trials and Observational Studies:Comparing Apples With Apples

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    Effect estimates from randomized trials and observational studies might not be directly comparable because of differences in study design, other than randomization, and in data analysis. We propose a 3-step procedure to facilitate meaningful comparisons of effect estimates from randomized trials and observational studies: 1) harmonization of the study protocols (eligibility criteria, treatment strategies, outcome, start and end of follow-up, causal contrast) so that the studies target the same causal effect, 2) harmonization of the data analysis to estimate the causal effect, and 3) sensitivity analyses to investigate the impact of discrepancies that could not be accounted for in the harmonization process. To illustrate our approach, we compared estimates of the effect of immediate with deferred initiation of antiretroviral therapy in individuals positive for the human immunodeficiency virus from the Strategic Timing of Antiretroviral Therapy (START) randomized trial and the observational HIV-CAUSAL Collaboration
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