309 research outputs found

    Association between footwear use and neglected tropical diseases: a systematic review and meta-analysis

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    BACKGROUND The control of neglected tropical diseases (NTDs) has primarily focused on preventive chemotherapy and case management. Less attention has been placed on the role of ensuring access to adequate water, sanitation, and hygiene and personal preventive measures in reducing exposure to infection. Our aim was to assess whether footwear use was associated with a lower risk of selected NTDs. METHODOLOGY We conducted a systematic review and meta-analysis to assess the association between footwear use and infection or disease for those NTDs for which the route of transmission or occurrence may be through the feet. We included Buruli ulcer, cutaneous larva migrans (CLM), leptospirosis, mycetoma, myiasis, podoconiosis, snakebite, tungiasis, and soil-transmitted helminth (STH) infections, particularly hookworm infection and strongyloidiasis. We searched Medline, Embase, Cochrane, Web of Science, CINAHL Plus, and Popline databases, contacted experts, and hand-searched reference lists for eligible studies. The search was conducted in English without language, publication status, or date restrictions up to January 2014. Studies were eligible for inclusion if they reported a measure of the association between footwear use and the risk of each NTD. Publication bias was assessed using funnel plots. Descriptive study characteristics and methodological quality of the included studies were summarized. For each study outcome, both outcome and exposure data were abstracted and crude and adjusted effect estimates presented. Individual and summary odds ratio (OR) estimates and corresponding 95% confidence intervals (CIs) were calculated as a measure of intervention effect, using random effects meta-analyses. PRINCIPAL FINDINGS Among the 427 studies screened, 53 met our inclusion criteria. Footwear use was significantly associated with a lower odds of infection of Buruli ulcer (OR=0.15; 95% CI: 0.08-0.29), CLM (OR=0.24; 95% CI: 0.06-0.96), tungiasis (OR=0.42; 95% CI: 0.26-0.70), hookworm infection (OR=0.48; 95% CI: 0.37-0.61), any STH infection (OR=0.57; 95% CI: 0.39-0.84), strongyloidiasis (OR=0.56; 95% CI: 0.38-0.83), and leptospirosis (OR=0.59; 95% CI: 0.37-0.94). No significant association between footwear use and podoconiosis (OR=0.63; 95% CI: 0.38-1.05) was found and no data were available for mycetoma, myiasis, and snakebite. The main limitations were evidence of heterogeneity and poor study quality inherent to the observational studies included. CONCLUSIONS/SIGNIFICANCE Our results show that footwear use was associated with a lower odds of several different NTDs. Access to footwear should be prioritized alongside existing NTD interventions to ensure a lasting reduction of multiple NTDs and to accelerate their control and elimination. PROTOCOL REGISTRATION PROSPERO International prospective register of systematic reviews CRD42012003338

    The cubicle warrior: the marionette of the digitalized warfare

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    In the last decade we have entered the era of remote controlled military technology. The excitement about this new technology should not mask the ethical questions that it raises. A fundamental ethical question is who may be held responsible for civilian deaths. In this paper we will discuss the role of the human operator or so-called ‘cubicle warrior’, who remotely controls the military robots behind visual interfaces. We will argue that the socio-technical system conditions the cubicle warrior to dehumanize the enemy. As a result the cubicle warrior is morally disengaged from his destructive and lethal actions. This challenges what he should know to make responsible decisions (the so-called knowledge condition). Nowadays and in the near future, three factors will influence and may increase the moral disengagement even further due to the decrease of locus of control orientation: (1) photo shopping the war; (2) the moralization of technology; (3) the speed of decision-making. As a result, cubicle warriors cannot be held reasonably responsible anymore for the decisions they make

    The Tri-Trophic Interactions Hypothesis: Interactive Effects of Host Plant Quality, Diet Breadth and Natural Enemies on Herbivores

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    Several influential hypotheses in plant-herbivore and herbivore-predator interactions consider the interactive effects of plant quality, herbivore diet breadth, and predation on herbivore performance. Yet individually and collectively, these hypotheses fail to address the simultaneous influence of all three factors. Here we review existing hypotheses, and propose the tri-trophic interactions (TTI) hypothesis to consolidate and integrate their predictions. The TTI hypothesis predicts that dietary specialist herbivores (as compared to generalists) should escape predators and be competitively dominant due to faster growth rates, and that such differences should be greater on low quality (as compared to high quality) host plants. To provide a preliminary test of these predictions, we conducted an empirical study comparing the effects of plant (Baccharis salicifolia) quality and predators between a specialist (Uroleucon macolai) and a generalist (Aphis gossypii) aphid herbivore. Consistent with predictions, these three factors interactively determine herbivore performance in ways not addressed by existing hypotheses. Compared to the specialist, the generalist was less fecund, competitively inferior, and more sensitive to low plant quality. Correspondingly, predator effects were contingent upon plant quality only for the generalist. Contrary to predictions, predator effects were weaker for the generalist and on low-quality plants, likely due to density-dependent benefits provided to the generalist by mutualist ants. Because the TTI hypothesis predicts the superior performance of specialists, mutualist ants may be critical to A. gossypii persistence under competition from U. macolai. In summary, the integrative nature of the TTI hypothesis offers novel insight into the determinants of plant-herbivore and herbivore-predator interactions and the coexistence of specialist and generalist herbivores

    Epigenetic Silencing of Nucleolar rRNA Genes in Alzheimer's Disease

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    Background: Ribosomal deficits are documented in mild cognitive impairment (MCI), which often represents an early stage Alzheimer’s disease (AD), as well as in advanced AD. The nucleolar rRNA genes (rDNA), transcription of which is critical for ribosomal biogenesis, are regulated by epigenetic silencing including promoter CpG methylation. Methodology/Principal Findings: To assess whether CpG methylation of the rDNA promoter was dysregulated across the AD spectrum, we analyzed brain samples from 10 MCI-, 23 AD-, and, 24 age-matched control individuals using bisulfite mapping. The rDNA promoter became hypermethylated in cerebro-cortical samples from MCI and AD groups. In parietal cortex, the rDNA promoter was hypermethylated more in MCI than in advanced AD. The cytosine methylation of total genomic DNA was similar in AD, MCI, and control samples. Consistent with a notion that hypermethylation-mediated silencing of the nucleolar chromatin stabilizes rDNA loci, preventing their senescence-associated loss, genomic rDNA content was elevated in cerebrocortical samples from MCI and AD groups. Conclusions/Significance: In conclusion, rDNA hypermethylation could be a new epigenetic marker of AD. Moreover, silencing of nucleolar chromatin may occur during early stages of AD pathology and play a role in AD-related ribosoma

    Centrosome clustering and Cyclin D1 gene amplification in double minutes are common events in chromosomal unstable bladder tumors

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    Background: Aneuploidy, centrosome abnormalities and gene amplification are hallmarks of chromosome instability (CIN) in cancer. Yet there are no studies of the in vivo behavior of these phenomena within the same bladder tumor. Methods: Twenty-one paraffin-embedded bladder tumors were analyzed by conventional comparative genome hybridization and fluorescence in situ hybridization (FISH) with a cyclin D1 gene (CCND1)/centromere 11 dual-color probe. Immunofluorescent staining of α, β and γ tubulin was also performed. Results: Based on the CIN index, defined as the percentage of cells not displaying the modal number for chromosome 11, tumors were classified as CIN-negative and CIN-positive. Fourteen out of 21 tumors were considered CIN-positive. All T1G3 tumors were included in the CIN-positive group whereas the majority of Ta samples were classified as CIN-negative tumors. Centrosome clustering was observed in six out of 12 CIN-positive tumors analyzed. CCND1 amplification in homogeneously staining regions was present in six out of 14 CIN-positive tumors; three of them also showed amplification of this gene in double minutes. Conclusions: Complex in vivo behavior of CCND1 amplicon in bladder tumor cells has been demonstrated by accurate FISH analysis on paraffin-embedded tumors. Positive correlation between high heterogeneity, centrosome abnormalities and CCND1 amplification was found in T1G3 bladder carcinomas. This is the first study to provide insights into the coexistence of CCND1 amplification in homogeneously staining regions and double minutes in primary bladder tumors. It is noteworthy that those patients whose tumors showed double minutes had a significantly shorter overall survival rate (p < 0.001)

    A Toxin–Antitoxin System Promotes the Maintenance of an Integrative Conjugative Element

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    SXT is an integrative and conjugative element (ICE) that confers resistance to multiple antibiotics upon many clinical isolates of Vibrio cholerae. In most cells, this ∼100 Kb element is integrated into the host genome in a site-specific fashion; however, SXT can excise to form an extrachromosomal circle that is thought to be the substrate for conjugative transfer. Daughter cells lacking SXT can theoretically arise if cell division occurs prior to the element's reintegration. Even though ∼2% of SXT-bearing cells contain the excised form of the ICE, cells that have lost the element have not been detected. Here, using a positive selection-based system, SXT loss was detected rarely at a frequency of ∼1×10−7. As expected, excision appears necessary for loss, and factors influencing the frequency of excision altered the frequency of SXT loss. We screened the entire 100 kb SXT genome and identified two genes within SXT, now designated mosA and mosT (for maintenance of SXT Antitoxin and Toxin), that promote SXT stability. These two genes, which lack similarity to any previously characterized genes, encode a novel toxin-antitoxin pair; expression of mosT greatly impaired cell growth and mosA expression ameliorated MosT toxicity. Factors that promote SXT excision upregulate mosAT expression. Thus, when the element is extrachromosomal and vulnerable to loss, SXT activates a TA module to minimize the formation of SXT-free cells

    Evaluation of 22 genetic variants with Crohn's Disease risk in the Ashkenazi Jewish population: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>Crohn's disease (CD) has the highest prevalence among individuals of Ashkenazi Jewish (AJ) descent compared to non-Jewish Caucasian populations (NJ). We evaluated a set of well-established CD-susceptibility variants to determine if they can explain the increased CD risk in the AJ population.</p> <p>Methods</p> <p>We recruited 369 AJ CD patients and 503 AJ controls, genotyped 22 single nucleotide polymorphisms (SNPs) at or near 10 CD-associated genes, <it>NOD2</it>, <it>IL23R</it>, <it>IRGM</it>, <it>ATG16L1</it>, <it>PTGER4</it>, <it>NKX2-3</it>, <it>IL12B</it>, <it>PTPN2</it>, <it>TNFSF15 </it>and <it>STAT3</it>, and assessed their association with CD status. We generated genetic scores based on the risk allele count alone and the risk allele count weighed by the effect size, and evaluated their predictive value.</p> <p>Results</p> <p>Three <it>NOD2 </it>SNPs, two <it>IL23R </it>SNPs, and one SNP each at <it>IRGM </it>and <it>PTGER4 </it>were independently associated with CD risk. Carriage of 7 or more copies of these risk alleles or the weighted genetic risk score of 7 or greater correctly classified 92% (allelic count score) and 83% (weighted score) of the controls; however, only 29% and 47% of the cases were identified as having the disease, respectively. This cutoff was associated with a >4-fold increased disease risk (p < 10e-16).</p> <p>Conclusions</p> <p>CD-associated genetic risks were similar to those reported in NJ population and are unlikely to explain the excess prevalence of the disease in AJ individuals. These results support the existence of novel, yet unidentified, genetic variants unique to this population. Understanding of ethnic and racial differences in disease susceptibility may help unravel the pathogenesis of CD leading to new personalized diagnostic and therapeutic approaches.</p

    The Interplay between Entamoeba and Enteropathogenic Bacteria Modulates Epithelial Cell Damage

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    In amoebiasis, a human disease that is a serious health problem in many developing countries, efforts have been made to identify responsible factors for the tissue damage inflicted by the parasite Entamoeba histolytica. This amoeba lives in the lumen of the colon without causing damage to the intestinal mucosa, but under unknown circumstances becomes invasive, destroying the intestinal tissue. Bacteria in the intestinal flora have been proposed as inducers of higher amoebic virulence, but the causes or mechanisms responsible for the induction are still undetermined. Mixed intestinal infections with Entamoeba histolytica and enteropathogenic bacteria, showing exacerbated manifestations of disease, are common in endemic countries. We implemented an experimental system to study amoebic virulence in the presence of pathogenic bacteria and its consequences on epithelial cells. Results showed that amoebae that ingested enteropathogenic bacteria became more virulent, causing more damage to epithelial cells. Bacteria induced release of inflammatory proteins by the epithelial cells that attracted amoebae, facilitating amoebic contact to the epithelial cells and higher damage. Our results, although a first approach to this complex problem, provide insights into amoebic infections, as interplay with other pathogens apparently influences the intestinal environment, the behavior of cells involved and the manifestations of the disease

    Justice and Corporate Governance: New Insights from Rawlsian Social Contract and Sen’s Capabilities Approach

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    By considering what we identify as a problem inherent in the ‘nature of the firm’—the risk of abuse of authority—we propound the conception of a social contract theory of the firm which is truly Rawlsian in its inspiration. Hence, we link the social contract theory of the firm (justice at firm’s level) with the general theory of justice (justice at society’s level). Through this path, we enter the debate about whether firms can be part of Rawlsian theory of justice showing that corporate governance principles enter the “basic structure.” Finally, we concur with Sen’s aim to broaden the realm of social justice beyond what he calls the ‘transcendental institutional perfectionism’ of Rawls’ theory. We maintain the contractarian approach to justice but introduce Sen’s capability concept as an element of the constitutional and post-constitutional contract model of institutions with special reference to corporate governance. Accordingly, rights over primary goods and capabilities are (constitutionally) granted by the basic institutions of society, but many capabilities have to be turned into the functionings of many stakeholders through the operation of firms understood as post-constitutional institutional domains. The constitutional contract on the distribution of primary goods and capabilities should then shape the principles of corporate governance so that at post-constitutional level anyone may achieve her/his functionings in the corporate domain by exercising such capabilities. In the absence of such a condition, post-constitutional contracts would distort the process that descends from constitutional rights and capabilities toward social outcomes

    A Thermophilic Ionic Liquid-Tolerant Cellulase Cocktail for the Production of Cellulosic Biofuels

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    Generation of biofuels from sugars in lignocellulosic biomass is a promising alternative to liquid fossil fuels, but efficient and inexpensive bioprocessing configurations must be developed to make this technology commercially viable. One of the major barriers to commercialization is the recalcitrance of plant cell wall polysaccharides to enzymatic hydrolysis. Biomass pretreatment with ionic liquids (ILs) enables efficient saccharification of biomass, but residual ILs inhibit both saccharification and microbial fuel production, requiring extensive washing after IL pretreatment. Pretreatment itself can also produce biomass-derived inhibitory compounds that reduce microbial fuel production. Therefore, there are multiple points in the process from biomass to biofuel production that must be interrogated and optimized to maximize fuel production. Here, we report the development of an IL-tolerant cellulase cocktail by combining thermophilic bacterial glycoside hydrolases produced by a mixed consortia with recombinant glycoside hydrolases. This enzymatic cocktail saccharifies IL-pretreated biomass at higher temperatures and in the presence of much higher IL concentrations than commercial fungal cocktails. Sugars obtained from saccharification of IL-pretreated switchgrass using this cocktail can be converted into biodiesel (fatty acid ethyl-esters or FAEEs) by a metabolically engineered strain of E. coli. During these studies, we found that this biodiesel-producing E. coli strain was sensitive to ILs and inhibitors released by saccharification. This cocktail will enable the development of novel biomass to biofuel bioprocessing configurations that may overcome some of the barriers to production of inexpensive cellulosic biofuels
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