329 research outputs found

    Establishing inoculum threshold levels for Bean common mosaic virus strain blackeye cowpea mosaic infection in cowpea seed

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    Bean common mosaic virus strain blackeye cowpea mosaic (BCMV-BlCM) is an important seed-borne virus infecting cowpea and is transmitted both by seeds and aphids. Infected cowpea seeds can act as primary source of inoculum for disease epidemics. Four field experiments were conducted during 2003 - 2006 to assess the role of different amounts of seed-borne inoculum in the dissemination of BCMVBlCM virus in cowpea under field conditions. The identity of BCMV-BlCM was confirmed by ELISA and IC-RT-PCR. Plants infected at an early growth stage appeared to serve as the primary source for subsequent virus spread by aphids. The mean disease incidence during four field experiments reached88-93% in plots sown with 10% infected seed. The disease incidence in plots sown with 5% infected seed recorded 46-63% while for plants raised from 3 and 2% BCMV-BlCM seed infection, disease incidence reached 32-49% and 17-23%, respectively. Mean yield losses in terms of seed yield per plant from four field experiments were 74 and 54% for initial seed infection of 10 and 5%, respectively. Seed infection of 2% BCMV-BlCM incidence resulted in an average of 24% mean seed yield loss/plant-1. The infection appeared to decrease the seed yield in terms of number and size. The BCMV incidence in harvested seed ranged from 0.3 - 19% for the different levels of initial seed infection. The field experiments demonstrated that sowing > 1% BCMV-BlCM infected seed can lead to significant losses in grain yield, while the spread of BCMV-BlCM infection resulting from sowing 1% infected seed did not significantly decrease seed yield. The role of establishing damage or inoculum thresholds from BCMVBlCM seed-borne infections is discussed in the present study.Keywords: Cowpea, potyvirus, seed-borne virus, thresholds, yield los

    Risk assessment and suicide by patients with schizophrenia in secondary mental healthcare: a case-control study

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    Objectives: To investigate the role of risk assessment in predicting suicide in patients with schizophrenia spectrum disorders (SSDs) receiving secondary mental healthcare. We postulated that risk assessment plays a limited role in predicting suicide in these patients. Design: Retrospective case–control study. Setting: Anonymised electronic mental health record data from the South London and Maudsley National Health Service (NHS) Foundation Trust (SLaM) (London, UK) linked with national mortality data. Participants: In 242 227 SLaM service users up to 31 December 2013, 635 suicides were identified. 96 (15.1%) had a SSD diagnosis. Those who died before 1 January 2007 (n=25) were removed from the analyses. Thus, 71 participants with SSD who died from suicide over the study period (cases) were compared with 355 controls. Main outcome measure: Risk of suicide in relation to risk assessment ratings. Results: Cases were younger at first contact with services (mean±SD 34.5±12.6 vs 39.2±15.2) and with a higher preponderance of males (OR=2.07, 95% CI 1.18 to 3.65, p=0.01) than controls. Also, suicide occurred within 10 days after last contact with services in half of cases, with the most common suicide methods being hanging (14) and jumping (13). Cases were more likely to have the following ‘risk assessment’ items previously recorded: suicidal history (OR=4.42, 95% CI 2.01 to 9.65, p<0.001), use of violent method (OR=3.37, 95% CI 1.47 to 7.74, p=0.01), suicidal ideation (OR=3.57, 95% CI 1.40 to 9.07, p=0.01) and recent hospital discharge (OR=2.71, 95% CI 1.17 to 6.28, p=0.04). Multiple regression models predicted only 21.5% of the suicide outcome variance. Conclusions: Predicting suicide in schizophrenia is highly challenging due to the high prevalence of risk factors within this diagnostic group irrespective of outcome, including suicide. Nevertheless, older age at first contact with mental health services and lack of suicidal history and suicidal ideation are useful protective markers indicative of those less likely to end their own lives

    Simultaneous transcriptional profiling of bacteria and their host cells

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    We developed an RNA-Seq-based method to simultaneously capture prokaryotic and eukaryotic expression profiles of cells infected with intracellular bacteria. As proof of principle, this method was applied to Chlamydia trachomatis-infected epithelial cell monolayers in vitro, successfully obtaining transcriptomes of both C. trachomatis and the host cells at 1 and 24 hours post-infection. Chlamydiae are obligate intracellular bacterial pathogens that cause a range of mammalian diseases. In humans chlamydiae are responsible for the most common sexually transmitted bacterial infections and trachoma (infectious blindness). Disease arises by adverse host inflammatory reactions that induce tissue damage & scarring. However, little is known about the mechanisms underlying these outcomes. Chlamydia are genetically intractable as replication outside of the host cell is not yet possible and there are no practical tools for routine genetic manipulation, making genome-scale approaches critical. The early timeframe of infection is poorly understood and the host transcriptional response to chlamydial infection is not well defined. Our simultaneous RNA-Seq method was applied to a simplified in vitro model of chlamydial infection. We discovered a possible chlamydial strategy for early iron acquisition, putative immune dampening effects of chlamydial infection on the host cell, and present a hypothesis for Chlamydia-induced fibrotic scarring through runaway positive feedback loops. In general, simultaneous RNA-Seq helps to reveal the complex interplay between invading bacterial pathogens and their host mammalian cells and is immediately applicable to any bacteria/host cell interaction. © 2013 Humphrys et al

    Clustering of tau-immunoreactive pathology in chronic traumatic encephalopathy

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    Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder which may result from repetitive brain injury. A variety of tau-immunoreactive pathologies are present, including neurofibrillary tangles (NFT), neuropil threads (NT), dot-like grains (DLG), astrocytic tangles (AT), and occasional neuritic plaques (NP). In tauopathies, cellular inclusions in the cortex are clustered within specific laminae, the clusters being regularly distributed parallel to the pia mater. To determine whether a similar spatial pattern is present in CTE, clustering of the tau-immunoreactive pathology was studied in the cortex, hippocampus, and dentate gyrus in 11 cases of CTE and 7 cases of Alzheimer’s disease neuropathologic change (ADNC) without CTE. In CTE: (1) all aspects of tau-immunoreactive pathology were clustered and the clusters were frequently regularly distributed parallel to the tissue boundary, (2) clustering was similar in two CTE cases with minimal co-pathology compared with cases with associated ADNC or TDP-43 proteinopathy, (3) in a proportion of cortical gyri, estimated cluster size was similar to that of cell columns of the cortico-cortical pathways, and (4) clusters of the tau-immunoreactive pathology were infrequently spatially correlated with blood vessels. The NFT and NP in ADNC without CTE were less frequently randomly or uniformly distributed and more frequently in defined clusters than in CTE. Hence, the spatial pattern of the tau-immunoreactive pathology observed in CTE is typical of the tauopathies but with some distinct differences compared to ADNC alone. The spread of pathogenic tau along anatomical pathways could be a factor in the pathogenesis of the disease

    Community perceptions of health and chronic disease in South Indian rural transitional communities: A qualitative study

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    BACKGROUND: Chronic diseases are now the leading cause of death and disability worldwide; this epidemic has been linked to rapid economic growth and urbanisation in developing countries. Understanding how characteristics of the physical, social, and economic environment affect behaviour in the light of these changes is key to identifying successful interventions to mitigate chronic disease risk. DESIGN: We undertook a qualitative study consisting of nine focus group discussions (FGDs) (n=57) in five villages in rural Andhra Pradesh, South India, to understand people's perceptions of community development and urbanisation in relation to chronic disease in rural transitional communities. Specifically, we sought to understand perceptions of change linked to diet, physical activity, and pollution (because these exposures are most relevant to chronic diseases), with the aim of defining future interventions. The transcripts were analysed thematically. RESULTS: Participants believed their communities were currently less healthy, more polluted, less physically active, and had poorer access to nutritious food and shorter life expectancies than previously. There were contradictory perceptions of the effects of urbanisation on health within and between individuals; several of the participants felt their quality of life had been reduced. CONCLUSIONS: In the present study, residents viewed change and development within their villages as an inevitable and largely positive process but with some negative health consequences. Understanding how these changes are affecting populations in transitional rural areas and how people relate to their environment may be useful to guide community planning for health. Measures to educate and empower people to make healthy choices within their community may help reduce the spread of chronic disease risk factors in future years

    Oral rehabilitation with implant-based prostheses of two adult patients treated for childhood rhabdomyosarcoma

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    Background Rhabdomyosarcoma is the most common malignant tumor in the nasal and paranasal sinus area at childhood. Multimodal treatment for this disorder has severe side effects due to normal tissue damage. As a result of this treatment, facial growth retardation and oral abnormalities such as malformation of teeth and microstomia can cause esthetic and functional problems. Case reports Two cases are presented of patients with severe midfacial hypoplasia and reduced oral function as a result of treatment of rhabdomyosarcoma of the nasopharyngeal and nasal-tonsil region. With a combined surgical (osteotomy, distraction osteogenesis, implants) and prosthetic (implant-based overdenture) treatment, esthetics and function were improved

    Functional similarities between pigeon \u27milk\u27 and mammalian milk : induction of immune gene expression and modification of the microbiota

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    Pigeon &lsquo;milk&rsquo; and mammalian milk have functional similarities in terms of nutritional benefit and delivery of immunoglobulins to the young. Mammalian milk has been clearly shown to aid in the development of the immune system and microbiota of the young, but similar effects have not yet been attributed to pigeon &lsquo;milk&rsquo;. Therefore, using a chicken model, we investigated the effect of pigeon &lsquo;milk&rsquo; on immune gene expression in the Gut Associated Lymphoid Tissue (GALT) and on the composition of the caecal microbiota. Chickens fed pigeon &lsquo;milk&rsquo; had a faster rate of growth and a better feed conversion ratio than control chickens. There was significantly enhanced expression of immune-related gene pathways and interferon-stimulated genes in the GALT of pigeon &lsquo;milk&rsquo;-fed chickens. These pathways include the innate immune response, regulation of cytokine production and regulation of B cell activation and proliferation. The caecal microbiota of pigeon &lsquo;milk&rsquo;-fed chickens was significantly more diverse than control chickens, and appears to be affected by prebiotics in pigeon &lsquo;milk&rsquo;, as well as being directly seeded by bacteria present in pigeon &lsquo;milk&rsquo;. Our results demonstrate that pigeon &lsquo;milk&rsquo; has further modes of action which make it functionally similar to mammalian milk. We hypothesise that pigeon &lsquo;lactation&rsquo; and mammalian lactation evolved independently but resulted in similarly functional products

    Tuberculosis and Indoor Biomass and Kerosene Use in Nepal: A Case–Control Study

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    BackgroundIn Nepal, tuberculosis (TB) is a major problem. Worldwide, six previous epidemiologic studies have investigated whether indoor cooking with biomass fuel such as wood or agricultural wastes is associated with TB with inconsistent results.ObjectivesUsing detailed information on potential confounders, we investigated the associations between TB and the use of biomass and kerosene fuels.MethodsA hospital-based case-control study was conducted in Pokhara, Nepal. Cases (n = 125) were women, 20-65 years old, with a confirmed diagnosis of TB. Age-matched controls (n = 250) were female patients without TB. Detailed exposure histories were collected with a standardized questionnaire.ResultsCompared with using a clean-burning fuel stove (liquefied petroleum gas, biogas), the adjusted odds ratio (OR) for using a biomass-fuel stove was 1.21 [95% confidence interval (CI), 0.48-3.05], whereas use of a kerosene-fuel stove had an OR of 3.36 (95% CI, 1.01-11.22). The OR for use of biomass fuel for heating was 3.45 (95% CI, 1.44-8.27) and for use of kerosene lamps for lighting was 9.43 (95% CI, 1.45-61.32).ConclusionsThis study provides evidence that the use of indoor biomass fuel, particularly as a source of heating, is associated with TB in women. It also provides the first evidence that using kerosene stoves and wick lamps is associated with TB. These associations require confirmation in other studies. If using kerosene lamps is a risk factor for TB, it would provide strong justification for promoting clean lighting sources, such as solar lamps

    Comparing the Clinical and Histological Diagnosis of Leprosy and Leprosy Reactions in the INFIR Cohort of Indian Patients with Multibacillary Leprosy

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    Leprosy affects skin and peripheral nerves. Although we have antibiotics to treat the mycobacterial infection, the accompanying inflammation is a major part of the disease process. This can worsen after starting antibacterial treatment with episodes of immune mediated inflammation, so called reactions. These are associated with worsening of nerve damage. However, diagnosing these reactions is not straightforward. They can be diagnosed clinically by examination or by microscopic examination of the skin biopsies. We studied a cohort of 303 newly diagnosed leprosy patients in India and compared the diagnosis rates by clinical examination and microscopy and found that the microscopic diagnosis has higher rates of diagnosis for both types of reaction. This suggests that clinicians and pathologists have different thresholds for diagnosing reactions. More work is needed to optimise both clinical and pathological diagnosis. In this cohort 43% of patients had Borderline Tuberculoid leprosy, an immunologically active type, and 20% of the biopsies showed only minimal inflammation, perhaps these patients had very early disease or self-healing. The public health implication of this work is that leprosy centres need to be supported by pathologists to help with the clinical management of difficult cases
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