136 research outputs found

    Serum immunoglobulin G, M and A response to Cryptosporidium parvum in Cryptosporidium-HIV co-infected patients

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    <p>Abstract</p> <p>Background</p> <p><it>Cryptosporidium parvum</it>, the protozoan parasite, causes a significant enteric disease in immunocompromised hosts such as HIV patients. The present study was aimed to compare serum IgG, IgM and IgA responses to crude soluble antigen of <it>C. parvum </it>in HIV seropositive and seronegative patients co-infected with <it>Cryptosporidium </it>and to correlate the responses with symptomatology.</p> <p>Methods</p> <p><it>Cryptosporidium parvum </it>specific serum antibody (IgG, IgM and IgA) responses were assessed by ELISA in 11 HIV seropositive <it>Cryptosporidium </it>positive (Group I), 20 HIV seropositive <it>Cryptosporidium </it>negative (Group II), 10 HIV seronegative <it>Cryptosporidium </it>positive (Group III), 20 HIV seronegative <it>Cryptosporidium </it>negative healthy individuals (Group IV) and 25 patients with other parasitic diseases (Group V).</p> <p>Results</p> <p>A positive IgG and IgA antibody response was observed in significantly higher number of <it>Cryptosporidium </it>infected individuals (Gp I and III) compared to <it>Cryptosporidium </it>un-infected individuals (Gp II, IV and V) irrespective of HIV/immune status. Sensitivity of IgG ELISA in our study was found to be higher as compared to IgM and IgA ELISA. The number of patients with positive IgG, IgM and IgA response was not significantly different in HIV seropositive <it>Cryptosporidium </it>positive patients with diarrhoea when compared to patients without diarrhoea and in patients with CD4 counts <200 when compared to patients with CD4 counts >200 cells/μl.</p> <p>Conclusion</p> <p>The study showed specific serum IgG and IgA production in patients infected with <it>Cryptosporidium</it>, both HIV seropositive and seronegative as compared to uninfected subjects suggesting induction of <it>Cryptosporidium </it>specific humoral immune response in infected subjects. However, there was no difference in number of patients with positive response in HIV seropositive or seronegative groups indicating that HIV status may not be playing significant role in modulation of <it>Cryptosporidium </it>specific antibody responses. The number of patients with positive IgG, IgM and IgA response was not significantly different in patients with or without history of diarrhoea thereby indicating that <it>Cryptosporidium </it>specific antibody responses may not be necessarily associated with protection from symptomatology.</p

    Abrasive, Silica Phytoliths and the Evolution of Thick Molar Enamel in Primates, with Implications for the Diet of Paranthropus boisei

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    Background: Primates—including fossil species of apes and hominins—show variation in their degree of molar enamel thickness, a trait long thought to reflect a diet of hard or tough foods. The early hominins demonstrated molar enamel thickness of moderate to extreme degrees, which suggested to most researchers that they ate hard foods obtained on or near the ground, such as nuts, seeds, tubers, and roots. We propose an alternative hypothesis—that the amount of phytoliths in foods correlates with the evolution of thick molar enamel in primates, although this effect is constrained by a species ’ degree of folivory. Methodology/Principal Findings: From a combination of dietary data and evidence for the levels of phytoliths in plant families in the literature, we calculated the percentage of plant foods rich in phytoliths in the diets of twelve extant primates with wide variation in their molar enamel thickness. Additional dietary data from the literature provided the percentage of each primate’s diet made up of plants and of leaves. A statistical analysis of these variables showed that the amount of abrasive silica phytoliths in the diets of our sample primates correlated positively with the thickness of their molar enamel, constrained by the amount of leaves in their diet (R 2 = 0.875; p,.0006). Conclusions/Significance: The need to resist abrasion from phytoliths appears to be a key selective force behind the evolution of thick molar enamel in primates. The extreme molar enamel thickness of the teeth of the East African homini

    Molecules cooled below the Doppler limit

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    The ability to cool atoms below the Doppler limit -- the minimum temperature reachable by Doppler cooling -- has been essential to most experiments with quantum degenerate gases, optical lattices and atomic fountains, among many other applications. A broad set of new applications await ultracold molecules, and the extension of laser cooling to molecules has begun. A molecular magneto-optical trap has been demonstrated, where molecules approached the Doppler limit. However, the sub-Doppler temperatures required for most applications have not yet been reached. Here we cool molecules to 50 uK, well below the Doppler limit, using a three-dimensional optical molasses. These ultracold molecules could be loaded into optical tweezers to trap arbitrary arrays for quantum simulation, launched into a molecular fountain for testing fundamental physics, and used to study ultracold collisions and ultracold chemistry

    Characterization of the Fecal Microbiome from Non-Human Wild Primates Reveals Species Specific Microbial Communities

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    BACKGROUND: Host-associated microbes comprise an integral part of animal digestive systems and these interactions have a long evolutionary history. It has been hypothesized that the gastrointestinal microbiome of humans and other non-human primates may have played significant roles in host evolution by facilitating a range of dietary adaptations. We have undertaken a comparative sequencing survey of the gastrointestinal microbiomes of several non-human primate species, with the goal of better understanding how these microbiomes relate to the evolution of non-human primate diversity. Here we present a comparative analysis of gastrointestinal microbial communities from three different species of Old World wild monkeys. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed fecal samples from three different wild non-human primate species (black-and-white colobus [Colubus guereza], red colobus [Piliocolobus tephrosceles], and red-tailed guenon [Cercopithecus ascanius]). Three samples from each species were subjected to small subunit rRNA tag pyrosequencing. Firmicutes comprised the vast majority of the phyla in each sample. Other phyla represented were Bacterioidetes, Proteobacteria, Spirochaetes, Actinobacteria, Verrucomicrobia, Lentisphaerae, Tenericutes, Planctomycetes, Fibrobacateres, and TM7. Bray-Curtis similarity analysis of these microbiomes indicated that microbial community composition within the same primate species are more similar to each other than to those of different primate species. Comparison of fecal microbiota from non-human primates with microbiota of human stool samples obtained in previous studies revealed that the gut microbiota of these primates are distinct and reflect host phylogeny. CONCLUSION/SIGNIFICANCE: Our analysis provides evidence that the fecal microbiomes of wild primates co-vary with their hosts, and that this is manifested in higher intraspecies similarity among wild primate species, perhaps reflecting species specificity of the microbiome in addition to dietary influences. These results contribute to the limited body of primate microbiome studies and provide a framework for comparative microbiome analysis between human and non-human primates as well as a comparative evolutionary understanding of the human microbiome

    Measuring Health Utilities in Children and Adolescents: A Systematic Review of the Literature.

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    BACKGROUND: The objective of this review was to evaluate the use of all direct and indirect methods used to estimate health utilities in both children and adolescents. Utilities measured pre- and post-intervention are combined with the time over which health states are experienced to calculate quality-adjusted life years (QALYs). Cost-utility analyses (CUAs) estimate the cost-effectiveness of health technologies based on their costs and benefits using QALYs as a measure of benefit. The accurate measurement of QALYs is dependent on using appropriate methods to elicit health utilities. OBJECTIVE: We sought studies that measured health utilities directly from patients or their proxies. We did not exclude those studies that also included adults in the analysis, but excluded those studies focused only on adults. METHODS AND FINDINGS: We evaluated 90 studies from a total of 1,780 selected from the databases. 47 (52%) studies were CUAs incorporated into randomised clinical trials; 23 (26%) were health-state utility assessments; 8 (9%) validated methods and 12 (13%) compared existing or new methods. 22 unique direct or indirect calculation methods were used a total of 137 times. Direct calculation through standard gamble, time trade-off and visual analogue scale was used 32 times. The EuroQol EQ-5D was the most frequently-used single method, selected for 41 studies. 15 of the methods used were generic methods and the remaining 7 were disease-specific. 48 of the 90 studies (53%) used some form of proxy, with 26 (29%) using proxies exclusively to estimate health utilities. CONCLUSIONS: Several child- and adolescent-specific methods are still being developed and validated, leaving many studies using methods that have not been designed or validated for use in children or adolescents. Several studies failed to justify using proxy respondents rather than administering the methods directly to the patients. Only two studies examined missing responses to the methods administered with respect to the patients' ages

    Ancillary human health benefits of improved air quality resulting from climate change mitigation

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    <p>Abstract</p> <p>Background</p> <p>Greenhouse gas (GHG) mitigation policies can provide ancillary benefits in terms of short-term improvements in air quality and associated health benefits. Several studies have analyzed the ancillary impacts of GHG policies for a variety of locations, pollutants, and policies. In this paper we review the existing evidence on ancillary health benefits relating to air pollution from various GHG strategies and provide a framework for such analysis.</p> <p>Methods</p> <p>We evaluate techniques used in different stages of such research for estimation of: (1) changes in air pollutant concentrations; (2) avoided adverse health endpoints; and (3) economic valuation of health consequences. The limitations and merits of various methods are examined. Finally, we conclude with recommendations for ancillary benefits analysis and related research gaps in the relevant disciplines.</p> <p>Results</p> <p>We found that to date most assessments have focused their analysis more heavily on one aspect of the framework (e.g., economic analysis). While a wide range of methods was applied to various policies and regions, results from multiple studies provide strong evidence that the short-term public health and economic benefits of ancillary benefits related to GHG mitigation strategies are substantial. Further, results of these analyses are likely to be underestimates because there are a number of important unquantified health and economic endpoints.</p> <p>Conclusion</p> <p>Remaining challenges include integrating the understanding of the relative toxicity of particulate matter by components or sources, developing better estimates of public health and environmental impacts on selected sub-populations, and devising new methods for evaluating heretofore unquantified and non-monetized benefits.</p

    Asthma control in adolescents 10 to 11 y after exposure to the World Trade Center disaster

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    Background: Little is known about asthma control in adolescents who were exposed to the World Trade Center (WTC) attacks of 11 September 2001 and diagnosed with asthma after 9/11. This report examines asthma and asthma control 10–11 y after 9/11 among exposed adolescents. Methods: The WTC Health Registry adolescent Wave 3 survey (2011–2012) collected data on asthma diagnosed by a physician after 11 September 2001, extent of asthma control based on modified National Asthma Education and Prevention Program criteria, probable mental health conditions, and behavior problems. Parents reported healthcare needs and 9/11-exposures. Logistic regression was used to evaluate associations between asthma and level of asthma control and 9/11-exposure, mental health and behavioral problems, and unmet healthcare needs. Results: Poorly/very poorly controlled asthma was significantly associated with a household income of ≤$75,000 (adjusted odds ratio (AOR): 3.0; 95% confidence interval (CI): 1.1–8.8), having unmet healthcare needs (AOR: 6.2; 95% CI: 1.4–27.1), and screening positive for at least one mental health condition (AOR: 5.0; 95% CI: 1.4–17.7), but not with behavioral problems. The impact of having at least one mental health condition on the level of asthma control was substantially greater in females than in males. Conclusions: Comprehensive care of post-9/11 asthma in adolescents should include management of mental health-related comorbidities. The collapse and burning of the World Trade Center (WTC) towers on 11 September 2001 (9/11) exposed hundreds of thousands of people to a complex mixture of dust, debris, and jet fuel combustion byproducts (1). It is estimated that over 25,000 persons in lower Manhattan developed asthma symptoms after exposure to the WTC terrorist attacks and the subsequent rescue and recovery efforts (1). In the years immediately following 9/11, new-onset asthma rates were elevated among exposed adults and many of those affected continued to experience respiratory symptoms (i.e., coughing, shortness of breath) years later (1,2). An estimated 25,000 children were living or attending school in lower Manhattan near the WTC on 9/11, and potentially were in the path of the dust cloud of building debris and smoke after the collapse of the towers, as well as for several months following the attacks, and could have inhaled particulate matter and toxic substances (3,4). Associations between 9/11-related exposures and both asthma diagnosis and persistent respiratory symptoms among children and adolescents have been documented (4,5,6). A previous report found that 2 to 3 y after 9/11, over half of children under 18 y of age who were enrolled in the World Trade Center Health Registry (Registry) reported new or worsening respiratory symptoms (53%), and 5.7% reported a post-9/11 diagnosis of asthma, both of which were associated with exposure to the dust cloud that resulted from the collapse of buildings on 9/11 (4). A subsequent study of Registry enrollees under 18 y old found that respiratory symptoms persisted up to 7 y post-9/11 (5). The WTC Environmental Health Center which collected clinical data on a sample of children an average of 7.8 y after 9/11, reported new onset provider-diagnosed asthma in 21.4% of children, and found that dust cloud exposure was associated with pulmonary function abnormalities, such as isolated low forced vital capacity pattern and an obstructive pattern consistent with asthma (6). Although the association between asthma and 9/11-exposure in children and adolescents has been documented, little is known about asthma control in this population. Large population-based surveys consistently show that poor asthma control is common in many children with asthma (7,8). Asthma control is affected by many factors, including healthcare access (9,10), socioeconomic status (9,10), and comorbid mental health conditions (11,12,13). It has been observed that adolescents with symptomatic asthma are more likely than adolescents without asthma to have lower perceived well-being, more negative behaviors, and a greater number of physical and mental health comorbidities (14). Several studies found that depression has been associated with uncontrolled asthma (11,12). In adults with 9/11-related asthma, having at least one mental health condition has been associated with poorly controlled asthma (15). However, little is known about the association between mental health conditions and the level of asthma control especially among 9/11-exposed adolescents. Previous studies of adult Registry enrollees found that those with unmet healthcare needs are more likely to have severe mental health symptoms, comorbid mental and physical health problems, and have lower quality of life (1,16). Unmet healthcare needs among adolescents have been shown to be associated with poorer health status and functioning, including asthma control (17). Poorly controlled asthma has also been associated with unmet healthcare needs related to cost or access barriers (18), such as an inability to pay for asthma medications and not having access to asthma specialists (19). The goal of this study was to evaluate asthma control 10–11 y after 9/11 among Registry as children, and to determine whether poor asthma control is associated with specific factors including adolescent 9/11-exposure, adverse mental health, behavior problems, and unmet healthcare needs
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