1,092 research outputs found

    Tracking the source of the hepatitis B virus-specific CD8 T cells during lamivudine treatment

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    Lamivudine treatment in chronic hepatitis B leads to the reconstitution of virus-specific T cells in the circulation, but it is not clear whether this is the preferential result of T cell efflux from the liver or lymph nodes. To address this question, the frequency and function of liver-, lymph node-, and blood-derived hepatitis B virus (HBV)-specific CD8 T cells were analyzed in patients treated with lamivudine and undergoing liver transplantation. HBV-specific CD8 T cells, identified in portal lymph nodes, were able to expand in vitro after antigen-specific stimulation and displayed a heterogeneous profile of cytokine production. These findings suggest that the peripherally reconstituted HBV-specific CD8 T cells can originate from precursor cells within lymph nodes

    Coats-like Vasculopathy in Inherited Retinal Disease: Prevalence, Characteristics, Genetics, and Management

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    Purpose: To describe the largest, most phenotypically and genetically diverse cohort of patients with inherited retinal disease (IRD)-related Coats-like vasculopathy (CLV). Design: Multicenter retrospective cohort study. Participants: A total of 67 patients with IRD-related CLV. Methods: Review of clinical notes, ophthalmic imaging, and molecular diagnosis from 2 international centers. Main Outcome Measures: Visual function, retinal imaging, management, and response to treatment were evaluated and correlated. Results: The prevalence of IRD-related CLV was 0.5%; 54% of patients had isolated retinitis pigmentosa (RP), 21% had early-onset severe retinal dystrophy, and less frequent presentations were syndromic RP, sector RP, cone-rod dystrophy, achromatopsia, PAX6-related dystrophy, and X-linked retinoschisis. The overall age of patients at CLV diagnosis was 30.7 Ā± 16.9 years (1ā€“83). Twenty-one patients (31%) had unilateral CLV, and the most common retinal features were telangiectasia, exudates, and exudative retinal detachment (ERD) affecting the inferior and temporal retina. Macular edema/schisis was observed in 26% of the eyes, and ERD was observed in 63% of the eyes. Fifty-four patients (81%) had genetic testing, 40 of whom were molecularly solved. Sixty-six eyes (58%) were observed, 17 eyes (15%) were treated with a single modality, and 30 eyes (27%) had a combined approach. Thirty-five eyes (31%) were ā€œgood responders,ā€ 42 eyes (37%) were ā€œpoor responders,ā€ 22 eyes (19%) had low vision at baseline and were only observed, and 12 eyes (11%) did not have longitudinal assessment. Twenty-one observed eyes (62%) responded well versus 14 (33%) treated eyes. Final best-corrected visual acuity was significantly worse than baseline (P = 0.002); 40 patients (60%) lost 15 ETDRS letters or more over follow-up in 1 or both eyes, and 21 patients (31%) progressed to more advanced stages of visual impairment. Conclusions: Inherited retinal diseaseā€“related CLV is rare, sporadic, and mostly bilateral; there is no gender predominance, and it can occur in diverse types of IRD at any point of the disease, with a mean onset in the fourth decade of life. Patients with IRD-related CLV who have decreased initial visual acuity, ERD, CLV changes affecting 2 or more retinal quadrants, and CRB1-retinopathy may be at higher risk of a poor prognosis. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article

    Feasibility and Coverage of Implementing Intermittent Preventive Treatment of Malaria in Pregnant women Contacting Private or Public Clinics in Tanzania: Experience-based Viewpoints of Health Managers in Mkuranga and Mufindi districts.

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    Evidence on healthcare managers' experience on operational feasibility of malaria intermittent preventive treatment for malaria during pregnancy (IPTp) using sulphadoxine-pyrimethamine (SP) in Africa is systematically inadequate. This paper elucidates the perspectives of District Council Health Management Team (CHMT)s regarding the feasibility of IPTp with SP strategy, including its acceptability and ability of district health care systems to cope with the contemporary and potential challenges. The study was conducted in Mkuranga and Mufindi districts. Data were collected between November 2005 and December 2007, involving focus group discussion (FGD) with Mufindi CHMT and in-depth interviews were conducted with few CHMT members in Mkuranga where it was difficult to summon all members for FGD. Participants in both districts acknowledged the IPTp strategy, considering the seriousness of malaria in pregnancy problem; government allocation of funds to support healthcare staff training programmes in focused antenatal care (fANC) issues, procuring essential drugs distributed to districts, staff remuneration, distribution of fANC guidelines, and administrative activities performed by CHMTs. The identified weaknesses include late arrival of funds from central level weakening CHMT's performance in health supervision, organising outreach clinics, distributing essential supplies, and delivery of IPTp services. Participants anticipated the public losing confidence in SP for IPTp after government announced artemither-lumefantrine (ALu) as the new first-line drug for uncomplicated malaria replacing SP. Role of private healthcare staff in IPTp services was acknowledged cautiously because CHMTs rarely supplied private clinics with SP for free delivery in fear that clients would be required to pay for the SP contrary to government policy. In Mufindi, the District Council showed a strong political support by supplementing ANC clinics with bottled water; in Mkuranga such support was not experienced. A combination of health facility understaffing, water scarcity and staff non-adherence to directly observed therapy instructions forced healthcare staff to allow clients to take SP at home. Need for investigating in improving adherence to IPTp administration was emphasised. High acceptability of the IPTp strategy at district level is meaningless unless necessary support is assured in terms of number, skills and motivation of caregivers and availability of essential supplies

    Adenoidectomy for otitis media with effusion (OME) in children

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    BACKGROUND: Otitis media with effusion (OME) is an accumulation of fluid in the middle ear cavity, common amongst young children. The fluid may cause hearing loss. When persistent, it may lead to developmental delay, social difficulty and poor quality of life. Management of OME includes watchful waiting, autoinflation, medical and surgical treatment. Adenoidectomy has often been used as a potential treatment for this condition. OBJECTIVES: To assess the benefits and harms of adenoidectomy, either alone or in combination with ventilation tubes (grommets), for OME in children. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 20 January 2023. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised trials in children aged 6 months to 12 years with unilateral or bilateral OME. We included studies that compared adenoidectomy (alone, or in combination with ventilation tubes) with either no treatment or non-surgical treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Primary outcomes (determined following a multi-stakeholder prioritisation exercise): 1) hearing, 2) otitis media-specific quality of life, 3) haemorrhage. SECONDARY OUTCOMES: 1) persistence of OME, 2) adverse effects, 3) receptive language skills, 4) speech development, 5) cognitive development, 6) psychosocial skills, 7) listening skills, 8) generic health-related quality of life, 9) parental stress, 10) vestibular function, 11) episodes of acute otitis media. We used GRADE to assess the certainty of evidence for each outcome. Although we included all measures of hearing assessment, the proportion of children who returned to normal hearing was our preferred method to assess hearing, due to challenges in interpreting the results of mean hearing thresholds. MAIN RESULTS: We included 10 studies (1785 children). Many of the studies used concomitant interventions for all participants, including insertion of ventilation tubes or myringotomy. All included studies had at least some concerns regarding the risk of bias. We report results for our main outcome measures at the longest available follow-up. We did not identify any data on disease-specific quality of life for any of the comparisons. Further details of additional outcomes and time points are reported in the review. 1) Adenoidectomy (with or without myringotomy) versus no treatment/watchful waiting (three studies) After 12 months there was little difference in the proportion of children whose hearing had returned to normal, but the evidence was very uncertain (adenoidectomy 68%, no treatment 70%; risk ratio (RR) 0.97, 95% confidence interval (CI) 0.65 to 1.46; number needed to treat to benefit (NNTB) 50; 1 study, 42 participants). There is a risk of haemorrhage from adenoidectomy, but the absolute risk appears small (1/251 receiving adenoidectomy compared to 0/229, Peto odds ratio (OR) 6.77, 95% CI 0.13 to 342.54; 1 study, 480 participants; moderate certainty evidence). The risk of persistent OME may be slightly lower after two years in those receiving adenoidectomy (65% versus 73%), but again the difference was small (RR 0.90, 95% CI 0.81 to 1.00; NNTB 13; 3 studies, 354 participants; very low-certainty evidence). 2) Adenoidectomy (with or without myringotomy) versus non-surgical treatment No studies were identified for this comparison. 3) Adenoidectomy and bilateral ventilation tubes versus bilateral ventilation tubes (four studies) There was a slight increase in the proportion of ears with a return to normal hearing after six to nine months (57% adenoidectomy versus 42% without, RR 1.36, 95% CI 0.98 to 1.89; NNTB 7; 1 study, 127 participants (213 ears); very low-certainty evidence). Adenoidectomy may give an increased risk of haemorrhage, but the absolute risk appears small, and the evidence was uncertain (2/416 with adenoidectomy compared to 0/375 in the control group, Peto OR 6.68, 95% CI 0.42 to 107.18; 2 studies, 791 participants). The risk of persistent OME was similar for both groups (82% adenoidectomy and ventilation tubes compared to 85% ventilation tubes alone, RR 0.96, 95% CI 0.86 to 1.07; very low-certainty evidence). 4) Adenoidectomy and unilateral ventilation tube versus unilateral ventilation tube (two studies) Slightly more children returned to normal hearing after adenoidectomy, but the confidence intervals were wide (57% versus 46%, RR 1.24, 95% CI 0.79 to 1.96; NNTB 9; 1 study, 72 participants; very low-certainty evidence). Fewer children may have persistent OME after 12 months, but again the confidence intervals were wide (27.2% compared to 40.5%, RR 0.67, 95% CI 0.35 to 1.29; NNTB 8; 1 study, 74 participants). We did not identify any data on haemorrhage. 5) Adenoidectomy and ventilation tubes versus no treatment/watchful waiting (two studies) We did not identify data on the proportion of children who returned to normal hearing. However, after two years, the mean difference in hearing threshold for those allocated to adenoidectomy was -3.40 dB (95% CI -5.54 to -1.26; 1 study, 211 participants; very low-certainty evidence). There may be a small reduction in the proportion of children with persistent OME after two years, but the evidence was very uncertain (82% compared to 90%, RR 0.91, 95% CI 0.82 to 1.01; NNTB 13; 1 study, 232 participants). We noted that many children in the watchful waiting group had also received surgery by this time point. 6) Adenoidectomy and ventilation tubes versus non-surgical treatment No studies were identified for this comparison. AUTHORS' CONCLUSIONS: When assessed with the GRADE approach, the evidence for adenoidectomy in children with OME is very uncertain. Adenoidectomy may reduce the persistence of OME, although evidence about the effect of this on hearing is unclear. For patients and carers, a return to normal hearing is likely to be important, but few studies measured this outcome. We did not identify any evidence on disease-specific quality of life. There were few data on adverse effects, in particular postoperative bleeding. The risk of haemorrhage appears to be small, but should be considered when choosing a treatment strategy for children with OME. Future studies should aim to determine which children are most likely to benefit from treatment, rather than offering interventions to all children

    A single residue substitution in the receptor-binding domain of H5N1 hemagglutinin is critical for packaging into pseudotyped lentiviral particles

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    Ā© 2012 Tang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Serological studies for influenza infection and vaccine response often involve microneutralization and hemagglutination inhibition assays to evaluate neutralizing antibodies against human and avian influenza viruses, including H5N1. We have previously characterized lentiviral particles pseudotyped with H5-HA (H5pp) and validated an H5pp-based assay as a safe alternative for high-throughput serological studies in BSL-2 facilities. Here we show that H5-HAs from different clades do not always give rise to efficient production of H5pp and the underlying mechanisms are addressed. Methodology/Findings: We have carried out mutational analysis to delineate the molecular determinants responsible for efficient packaging of HA from A/Cambodia/40808/2005 (H5Cam) and A/Anhui/1/2005 (H5Anh) into H5pp. Our results demonstrate that a single A134V mutation in the 130-loop of the receptor binding domain is sufficient to render H5Anh the ability to generate H5Anh-pp efficiently, whereas the reverse V134A mutation greatly hampers production of H5Cam-pp. Although protein expression in total cell lysates is similar for H5Anh and H5Cam, cell surface expression of H5Cam is detected at a significantly higher level than that of H5Anh. We further demonstrate by several independent lines of evidence that the behaviour of H5Anh can be explained by a stronger binding to sialic acid receptors implicating residue 134. Conclusions: We have identified a single A134V mutation as the molecular determinant in H5-HA for efficient incorporation into H5pp envelope and delineated the underlying mechanism. The reduced binding to sialic acid receptors as a result of the A134V mutation not only exerts a critical influence in pseudotyping efficiency of H5-HA, but has also an impact at the whole virus level. Because A134V substitution has been reported as a naturally occurring mutation in human host, our results may have implications for the understanding of human host adaptation of avian influenza H5N1 virusesThis work was supported by grants from the Research Fund for the Control of Infectious Diseases of Hong Kong (RFCID#08070972), the Area of Excellence Scheme of the University Grants Committee (grant AoE/M-12/-06 of the Hong Kong Special Administrative Region, China), the French Ministry of Health, and the RESPARI project of the Institut Pasteur International Network

    A model to control the epidemic of H5N1 influenza at the source

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    <p>Abstract</p> <p>Background</p> <p>No country is fully prepared for a 1918-like pandemic influenza. Averting a pandemic of H5N1 influenza virus depends on the successful control of its endemicity, outbreaks in poultry and occasional spillage into human which carries a case-fatality rate of over 50%. The use of perimetric depopulation and vaccination has failed to halt the spread of the epidemic. Blanket vaccination for all poultry over a large geographical area is difficult. A combination of moratorium, segregation of water fowls from chickens and vaccination have been proved to be effective in the Hong Kong Special Administrative Region (HKSAR) since 2002 despite endemicity and outbreaks in neighbouring regions. Systematic surveillance in southern China showed that ducks and geese are the primary reservoirs which transmit the virus to chickens, minor poultry and even migratory birds.</p> <p>Presentation of the hypothesis</p> <p>We hypothesize that this combination of moratorium, poultry segregation and targeted vaccination if successfully adapted to an affected district or province in any geographical region with high endemicity would set an example for the control in other regions.</p> <p>Testing the hypothesis</p> <p>A planned one-off moratorium of 3 weeks at the hottest month of the year should decrease the environmental burden as a source of re-infection. Backyard farms will then be re-populated by hatchlings from virus-free chickens and minor poultry only. Targeted immunization of the ducks and geese present only in the industrial farms and also the chickens would be strictly implemented as blanket immunization of all backyard poultry is almost impossible. Freely grazing ducks and geese would not be allowed until neutralizing antibodies of H5 subtype virus is achieved. As a proof of concept, a simple mathematical model with susceptible-infected-recovered (SIR) structure of coupled epidemics between aquatic birds (mainly ducks and geese) and chickens was used to estimate transmissibility within and between these two poultry populations. In the field the hypothesis is tested by prospective surveillance of poultry and immunocompetent patients hospitalized for severe pneumonia for the virus before and after the institution of these measures.</p> <p>Implications of the Hypothesis</p> <p>A combination of targeted immunization with the correct vaccine, segregation of poultry species and moratorium of poultry in addition to the present surveillance, biosecurity and hygienic measures at the farm, market and personal levels could be important in the successful control of the H5N1 virus in poultry and human for an extensive geographical region with continuing outbreaks. Alternatively a lesser scale of intervention at the district level can be considered if there is virus detection without evidence of excess poultry deaths since asymptomatic shedding is common in waterfowls.</p

    Design, implementation and evaluation of a national campaign to distribute nine million free LLINs to children under five years of age in Tanzania.

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    BACKGROUND\ud \ud After a national voucher scheme in 2004 provided pregnant women and infants with highly subsidized insecticide-treated nets (ITNs), use among children under five years (U5s) in mainland Tanzania increased from 16% in 2004 to 26.2% in 2007. In 2008, the Ministry of Health and Social Welfare planned a catch-up campaign to rapidly and equitably deliver a free long-lasting insecticidal net (LLIN) to every child under five years in Tanzania.\ud \ud METHODS\ud \ud The ITN Cell, a unit within the National Malaria Control Programme (NMCP), coordinated the campaign on behalf of the Ministry of Health and Social Welfare. Government contractors trained and facilitated local government officials to supervise village-level volunteers on a registration of all U5s and the distribution and issuing of LLINs. The registration results formed the basis for the LLIN order and delivery to village level. Caregivers brought their registration coupons to village issuing posts during a three-day period where they received LLINs for their U5s. Household surveys in five districts assessed ITN ownership and use immediately after the campaign.\ud \ud RESULTS\ud \ud Nine donors contributed to the national campaign that purchased and distributed 9.0 million LLINs at an average cost of $7.07 per LLIN, including all campaign-associated activities. The campaign covered all eight zones of mainland Tanzania, the first region being covered separately during an integrated measles immunization/malaria LLIN distribution in August 2008, and was implemented one zone at a time from March 2009 until May 2010. ITN ownership at household level increased from Tanzania's 2008 national average of 45.7% to 63.4%, with significant regional variations. ITN use among U5s increased from 28.8% to 64.1%, a 2.2-fold increase, with increases ranging from 22.1-38.3% percentage points in different regions.\ud \ud CONCLUSION\ud \ud A national-level LLIN distribution strategy that fully engaged local government authorities helped avoid additional burden on the healthcare system. Distribution costs per net were comparable to other public health interventions. Particularly among rural residents, ITN ownership and use increased significantly for the intended beneficiaries. The upcoming universal LLIN distribution and further behaviour change communication will further improve ITN ownership and use in 2010-2011

    New insights into the genetic diversity of Schistosoma mansoni and S. haematobiumin Yemen

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    The file attached is the Published/publisherā€™s pdf version of the article.Ā© 2015 Sady et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

    Wanted dead or alive : high diversity of macroinvertebrates associated with living and ā€™deadā€™ Posidonia oceanica matte

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    The Mediterranean endemic seagrass Posidonia oceanica forms beds characterised by a dense leaf canopy and a thick root-rhizome ā€˜matteā€™. Death of P. oceanica shoots leads to exposure of the underlying matte, which can persist for many years, and is termed ā€˜deadā€™ matte. Traditionally, dead matte has been regarded as a degraded habitat. To test whether this assumption was true, the motile macroinvertebrates of adjacent living (with shoots) and dead (without shoots) matte of P. oceanica were sampled in four different plots located at the same depth (5ā€“6 m) in Mellieha Bay, Malta (central Mediterranean). The total number of species and abundance were significantly higher (ANOVA; P<0.05 and P<0.01, respectively) in the dead matte than in living P. oceanica matte, despite the presence of the foliar canopy in the latter. Multivariate analysis (MDS) clearly showed two main groups of assemblages, corresponding to the two matte types. The amphipods Leptocheirus guttatus and Maera grossimana, and the polychaete Nereis rava contributed most to the dissimilarity between the two different matte types. Several unique properties of the dead matte contributing to the unexpected higher number of species and abundance of motile macroinvertebrates associated with this habitat are discussed. The findings have important implications for the conservation of bare P. oceanica matte, which has been generally viewed as a habitat of low ecological value.peer-reviewe

    Are mice good models for human neuromuscular disease? Comparing muscle excursions in walking between mice and humans

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    The mouse is one of the most widely used animal models to study neuromuscular diseases and test new therapeutic strategies. However, findings from successful pre-clinical studies using mouse models frequently fail to translate to humans due to various factors. Differences in muscle function between the two species could be crucial but often have been overlooked. The purpose of this study was to evaluate and compare muscle excursions in walking between mice and humans
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