693 research outputs found

    Chemical Characterization and Source Apportionment of Household Fine Particulate Matter in Rural, Peri-urban, and Urban West Africa

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    Household air pollution in sub-Saharan Africa and other developing regions is an important cause of disease burden. Little is known about the chemical composition and sources of household air pollution in sub-Saharan Africa, and how they differ between rural and urban homes. We analyzed the chemical composition and sources of fine particles (PM2.5) in household cooking areas of multiple neighborhoods in Accra, Ghana, and in peri-urban (Banjul) and rural (Basse) areas in The Gambia. In Accra, biomass burning accounted for 39–62% of total PM2.5 mass in the cooking area in different neighborhoods; the absolute contributions were 10–45 μg/m3. Road dust and vehicle emissions comprised 12–33% of PM2.5 mass. Solid waste burning was also a significant contributor to household PM2.5 in a low-income neighborhood but not for those living in better-off areas. In Banjul and Basse, biomass burning was the single dominant source of cooking-area PM2.5, accounting for 74–87% of its total mass; the relative and absolute contributions of biomass smoke to PM2.5 mass were larger in households that used firewood than in those using charcoal, reaching as high as 463 μg/m3 in Basse homes that used firewood for cooking. Our findings demonstrate the need for policies that enhance access to cleaner fuels in both rural and urban areas, and for controlling traffic emissions in cities in sub-Saharan Africa

    Modelling the Effects of Mass Drug Administration on the Molecular Epidemiology of Schistosomes

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    As national governments scale up mass drug administration (MDA) programs aimed to combat neglected tropical diseases (NTDs), novel selection pressures on these parasites increase. To understand how parasite populations are affected by MDA and how to maximize the success of control programmes, it is imperative for epidemiological, molecular and mathematical modelling approaches to be combined. Modelling of parasite population genetic and genomic structure, particularly of the NTDs, has been limited through the availability of only a few molecular markers to date. The landscape of infectious disease research is being dramatically reshaped by next-generation sequencing technologies and our understanding of how repeated selective pressures are shaping parasite populations is radically altering. Genomics can provide high-resolution data on parasite population structure, and identify how loci may contribute to key phenotypes such as virulence and/or drug resistance. We discuss the incorporation of genetic and genomic data, focussing on the recently sequenced Schistosoma spp., into novel mathematical transmission models to inform our understanding of the impact of MDA and other control methods. We summarize what is known to date, the models that exist and how population genetics has given us an understanding of the effects of MDA on the parasites. We consider how genetic and genomic data have the potential to shape future research, highlighting key areas where data are lacking, and how future molecular epidemiology knowledge can aid understanding of transmission dynamics and the effects of MDA, ultimately informing public health policy makers of the best interventions for NTDs

    Online Game Addiction and the Level of Depression Among Adolescents in Manila, Philippines

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    Introduction: World Health Organization recognizes online game addiction as a mental health condition. The rise of excessive online gaming is emerging in the Philippines, with 29.9 million gamers recorded in the country. The incidence of depression is also increasing in the country. The current correlational analysis evaluated the association between online game addiction and depression in Filipino adolescents. Methods: A paper-and-pencil self-administered questionnaire assessing depression and online game addiction was distributed from August to November, 2018. The questionnaire included socio-demographic profiles of the respondents, and the 14-item Video Game Addiction Test (VAT) (Cronbach's ?=0.91) and the Patient Health Questionnaire-9 (Cronbach's ?=0.88) to determine levels of online game addiction and depression, respectively. Multiple regression analyses were used to test the association between depression and online game addiction. Results: Three hundred adolescents (59% males, 41% females) participated in the study. Fifty-three out of 300 respondents (12.0% males, 5.7% females) had high level of online game addiction as reflected in their high VAT scores. In this study, 37 respondents (6.7% males, 5.7% females) had moderately severe depression and 6 (2.0%) females had severe depression. Online game addiction was positively correlated with depression in this study (r=0.31; p<0.001). When multiple regression analysis was computed, depression was found to be a predictor of online game addiction (Coefficient=0.0121; 95% CI-8.1924 - 0.0242; p=0.05). Conclusion: Depression, as associated with online game addiction, is a serious threat that needs to be addressed. High level of online game addiction, as positively correlated to the rate of depression among adolescents in Manila, could potentially be attributed to the booming internet industry and lack of suffiicent mental health interventions in the country. Recommended interventions include strengthening depression management among adolescents and improving mental health services for this vulnerable population groups in schools and within the communities

    Structural and regulatory analysis of quorum sensing in Rhizobium leguminosarum

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    In the present work, we have studied the role of quorum-sensing regulatory systems in Rhizobium-legume symbiosis. Competition assays suggest that inactivation of quorum sensing systems significantly affects the competitiveness of Rhizobium leguminosarum bv. viciae UPM791 (Rl UPM791) when compared to other strains. Structural analysis through HPLC / mass spectrometry revealed that the signals produced by Rl UPM791 correspond to: C6-HSL, C7-HSL, C8-HSL and 3OH-C14-HSL; also, small amounts of C4-HSL have been detected. We are also analyzing the complex regulation of AHL signal molecules. We have evidence indicating that an Rl UPM791 plasmid (pUPM791d) participates in a regulatory network acting on the chromosomal system cinRI. We are using concurrent strategies (sequencing of pUPM791d and random mutagenesis) to identify the mechanism responsible for the control of pUPM791d over AHL production in Rl UPM791

    Clinical and Genomic Profile of Primary Cranial Neurolymphomatosis

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    Emily B Wolf,1 Robin Imperial,1 Liuyan Jiang,2 Amit K Agarwal,3 Han W Tun1 1Division of Hematology and Medical Oncology, Mayo Clinic Florida, Jacksonville, FL, USA; 2Department of Laboratory Medicine and Pathology, Mayo Clinic Florida, Jacksonville, FL, USA; 3Department of Radiology, Mayo Clinic Florida, Jacksonville, FL, USACorrespondence: Han W Tun, Division of Hematology and Medical Oncology, Mayo Clinic Florida, 4500 San Pablo Road S, Jacksonville, FL, 32224, USA, Email [email protected]: Primary cranial neurolymphomatosis (PCNL) is a rare subtype of primary CNS lymphoma (PCNSL) in which infiltrative lymphomatous involvement is confined to cranial nerves. Here, we report a case of PCNL with successful genomic profiling. A 57-year-old male had a lengthy prediagnostic phase spanning approximately 30 months, characterized by multiple episodes of cranial neuropathies managed by steroids. At the time of diagnosis, the patient had right-sided cranial neuropathies involving cranial nerves (CN) V, VI, and VII. Pathological findings of the right cavernous lesion biopsy were consistent with large B-cell lymphoma-infiltrating nerve fibers. The clinical course was aggressive and refractory, characterized by relentless progression with the development of cervical spinal neurolymphomatosis, cerebrospinal fluid involvement, and ependymal and intraparenchymal cerebral involvement, despite multiple lines of therapy, including chemoimmunotherapy, Bruton’s tyrosine kinase inhibitor, radiation, autologous stem cell transplant, chimeric antigen receptor T-cell therapy (CAR-T), and whole-brain radiation. The patient survived for 22 months from the time of the initial diagnosis and 52 months after the first episode of cranial neuropathy. Next-generation sequencing identified mutations (MYD88, CD79b, and PIM1) that are frequently observed in PCNSL. The unusual findings included a total of 22 mutations involving PIM1, indicating a highly active aberrant somatic hypermutation and two missense CXCR4 mutations. CXCR4 mutations have never been described in PCNSL and may have implications for disease biology and therapeutic interventions. We provide a literature review to further elucidate PCNL.Keywords: DLBCL, cranial nerve, autologous stem cell transplant, CAR-T cell therapy, next generation sequencin

    Nicotianamine Synthase 2 Is Required for Symbiotic Nitrogen Fixation in Medicago truncatula Nodules

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    Symbiotic nitrogen fixation carried out by the interaction between legumes and diazotrophic bacteria known as rhizobia requires relatively large levels of transition metals. These elements are cofactors of many key enzymes involved in this process. Metallic micronutrients are obtained from soil by the roots and directed to sink organs by the vasculature, in a process mediated by a number of metal transporters and small organic molecules that facilitate metal delivery in the plant fluids. Among the later, nicotianamine is one of the most important. Synthesized by nicotianamine synthases (NAS), this molecule forms metal complexes participating in intracellular metal homeostasis and long-distance metal trafficking. Here we characterized the NAS2 gene from model legume Medicago truncatula. MtNAS2 is located in the root vasculature and in all nodule tissues in the infection and fixation zones. Symbiotic nitrogen fixation requires of MtNAS2 function, as indicated by the loss of nitrogenase activity in the insertional mutant nas2-1, phenotype reverted by reintroduction of a wild-type copy of MtNAS2. This would result from the altered iron distribution in nas2-1 nodules shown with X-ray fluorescence. Moreover, iron speciation is also affected in these nodules. These data suggest a role of nicotianamine in iron delivery for symbiotic nitrogen fixation
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