1,740 research outputs found

    Prostaglandin E2 Prevents Ovariectomy-Induced Cancellous Bone Loss in Rats

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    The object of this study was to determine whether prostaglandin E2, (PGE2) can prevent ovariectomy induced cancellous bone loss. Thirty-five 3-month-old female Sprague-Dawley rats were divided into two groups. The rats in the first group were ovariectomized (OVX) while the others received sham operation (sham-OVX). The OVX group was further divided into three treatment groups. The daily doses for the three groups were 0,1 and 6 mg PGE2/kg for 90 days. Bone histomorphometric analyses were performed on double-fluorescent-labeled undecalcified proximal tibial metaphysis (PTM). We confirmed that OVX induces massive cancellous bone loss (-80%) and a higher bone turnover (+143%). The new findings from the present study demonstrate that bone loss due to ovarian hormone deficiency can be prevented by a low-dose (1 mg) daily administration of PGE2. Furthermore, a higher-dose (6 mg) daily administration of PGE2 not only prevents bone loss but also adds extra bone to the proximal tibial metaphyses. PGE, at the 1-mg dose level significantly increased trabecular bone area, trabecular width, trabecular node density, density of node to node, ratio of node to free end, and thus significantly decreased trabecular separation from OVX controls. At this dose level, these same parameters did not differ significantly from sham-OVX controls. However, at the 6-mg dose level PGE2, there were significant increases in trabecular bone area, trabecular width, trabecular node density, density of node to node, and ratio of node to free end, while there was significant decrease in trabecular separation from both OVX and sham-operated controls. The changes in indices of trabecular bone microanatomical structure indicated that PGE2 prevented bone loss as well as the disconnection of existing trabeculae. In summary, PGE2, administration to OVX rats decreased bone turnover and increased bone formation parameters resulting in a positive bone balance that prevented bone loss (in both lower and higher doses) and added extra bone to metaphyses of OVX rats (in higher dose). These findings support the strategy of the use of bone stimulation agents in the prevention of estrogen depletion bone loss (postmenopausal osteoporosis)

    Exchange interactions and temperature dependence of the magnetization in half--metallic Heusler alloys

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    We study the exchange interactions in half-metallic Heusler alloys using first-principles calculations in conjunction with the frozen-magnon approximation. The Curie temperature is estimated within both mean-field (MF) and random-phase-approximation (RPA) approaches. For the half-Heusler alloys NiMnSb and CoMnSb the dominant interaction is between the nearest Mn atoms. In this case the MF and RPA estimations differ strongly. The RPA approach provides better agreement with experiment. The exchange interactions are more complex in the case of full-Heusler alloys Co2_2MnSi and Co2_2CrAl where the dominant effects are the inter-sublattice interactions between the Mn(Cr) and Co atoms and between Co atoms at different sublattices. For these compounds we find that both MF and RPA give very close values of the Curie temperature slightly underestimating experimental quantities. We study the influence of the lattice compression on the magnetic properties. The temperature dependence of the magnetization is calculated using the RPA method within both quantum mechanical and classical approaches.Comment: New figures and discussio

    Viral and host factors required for avian H5N1 influenza A virus replication in mammalian cells

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    Following the initial and sporadic emergence into humans of highly pathogenic avian H5N1 influenza A viruses in Hong Kong in 1997, we have come to realize the potential for avian influenza A viruses to be transmitted directly from birds to humans. Understanding the basic viral and cellular mechanisms that contribute to infection of mammalian species with avian influenza viruses is essential for developing prevention and control measures against possible future human pandemics. Multiple physical and functional cellular barriers can restrict influenza A virus infection in a new host species, including the cell membrane, the nuclear envelope, the nuclear environment, and innate antiviral responses. In this review, we summarize current knowledge on viral and host factors required for avian H5N1 influenza A viruses to successfully establish infections in mammalian cells. We focus on the molecular mechanisms underpinning mammalian host restrictions, as well as the adaptive mutations that are necessary for an avian influenza virus to overcome them. It is likely that many more viral and host determinants remain to be discovered, and future research in this area should provide novel and translational insights into the biology of influenza virus-host interactions

    The substructure of three repetitive DNA regions of Schistosoma haematobium group species as a potential marker for species recognition and interbreeding detection

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    The file attached is the Published/publisher’s pdf version of the article.© The Author(s). 2017 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

    Hazard Analysis of Critical Control Points Assessment as a Tool to Respond to Emerging Infectious Disease Outbreaks

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    Highly pathogenic avian influenza virus (HPAI) strain H5N1 has had direct and indirect economic impacts arising from direct mortality and control programmes in over 50 countries reporting poultry outbreaks. HPAI H5N1 is now reported as the most widespread and expensive zoonotic disease recorded and continues to pose a global health threat. The aim of this research was to assess the potential of utilising Hazard Analysis of Critical Control Points (HACCP) assessments in providing a framework for a rapid response to emerging infectious disease outbreaks. This novel approach applies a scientific process, widely used in food production systems, to assess risks related to a specific emerging health threat within a known zoonotic disease hotspot. We conducted a HACCP assessment for HPAI viruses within Vietnam’s domestic poultry trade and relate our findings to the existing literature. Our HACCP assessment identified poultry flock isolation, transportation, slaughter, preparation and consumption as critical control points for Vietnam’s domestic poultry trade. Introduction of the preventative measures highlighted through this HACCP evaluation would reduce the risks posed by HPAI viruses and pressure on the national economy. We conclude that this HACCP assessment provides compelling evidence for the future potential that HACCP analyses could play in initiating a rapid response to emerging infectious diseases

    Identification of the factors associated with outcomes in a condition management programme

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    <p>Background: A requirement of the Government’s Pathways to Work (PtW) agenda was to introduce a Condition Management Programme (CMP). The aim of the present study was to identify the differences between those who engaged and made progress in this telephone-based biopsychosocial intervention, in terms of their health, and those who did not and to determine the client and practitioner characteristics and programme elements associated with success in a programme aimed at improving health.</p> <p>Methods: Data were obtained from the CMP electronic spreadsheets and clients paper-based case records. CMP standard practice was that questionnaires were administered during the pre- and post-assessment phases over the telephone. Each client’s record contains their socio-demographic data, their primary health condition, as well as the pre- and post-intervention scores of the health assessment tool administered. Univariate and multivariate statistical analysis was used to investigate the relationships between the database variables. Clients were included in the study if their records were available for analysis from July 2006 to December 2007.</p> <p> Results: On average there were 112 referrals per month, totalling 2016 referrals during the evaluation period. The majority (62.8%) of clients had a mental-health condition. Successful completion of the programme was 28.5% (575 “completers”; 144 “discharges”). Several factors, such as age, health condition, mode of contact, and practitioner characteristics, were significant determinants of participation and completion of the programme. The results showed that completion of the CMP was associated with a better mental-health status, by reducing the number of clients that were either anxious, depressed or both, before undertaking the programme, from 74% to 32.5%.</p> <p>Conclusions: Our findings showed that an individual's characteristics are associated with success in the programme, defined as completing the intervention and demonstrating an improved health status. This study provides some evidence that the systematic evaluation of such programmes and interventions could identify ways in which they could be improved.</p&gt

    Biologics for chronic rhinosinusitis

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    BACKGROUND: This living systematic review is one of several Cochrane Reviews evaluating the medical management of patients with chronic rhinosinusitis. Chronic rhinosinusitis is common. It is characterised by inflammation of the nasal and sinus linings, nasal blockage, rhinorrhoea, facial pressure/pain and loss of sense of smell. It occurs with or without nasal polyps.   'Biologics' are medicinal products produced by a biological process. Monoclonal antibodies are one type, already evaluated in related inflammatory conditions (e.g. asthma and atopic dermatitis). OBJECTIVES: To assess the effects of biologics for the treatment of chronic rhinosinusitis. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; CENTRAL (2019, Issue 9); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 September 2019. SELECTION CRITERIA: Randomised controlled trials (RCTs) with at least three months follow-up comparing biologics (currently, monoclonal antibodies) against placebo/no treatment in patients with chronic rhinosinusitis. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. Our primary outcomes were disease-specific health-related quality of life (HRQL), disease severity and serious adverse events (SAEs). The secondary outcomes were avoidance of surgery, extent of disease (measured by endoscopic or computerised tomography (CT) score), generic HRQL and adverse events (nasopharyngitis, including sore throat). We used GRADE to assess the certainty of the evidence for each outcome. MAIN RESULTS: We included eight RCTs. Of 986 adult participants, 984 had severe chronic rhinosinusitis with nasal polyps; 43% to 100% of participants also had asthma. Three biologics, with different targets, were evaluated: dupilumab, mepolizumab and omalizumab. All the studies were sponsored or supported by industry. Anti-IL-4Rα mAb (dupilumab) versusplacebo/no treatment (all receiving intranasal steroids) Three studies (784 participants) evaluated dupilumab. Disease-specific HRQL was measured with the SNOT-22 (score 0 to 110; minimal clinically important difference (MCID) 8.9 points). At 24 weeks, the SNOT-22 score was 19.61 points lower (better) in participants receiving dupilumab (mean difference (MD) -19.61, 95% confidence interval (CI) -22.54 to -16.69; 3 studies; 784 participants; high certainty). Symptom severity measured on a 0- to 10-point visual analogue scale (VAS) was 3.00 lower in those receiving dupilumab (95% CI -3.47 to -2.53; 3 studies; 784 participants; moderate certainty). The risk of serious adverse events may be lower in the dupilumab group (risk ratio (RR) 0.45, 95% CI 0.28 to 0.75; 3 studies; 782 participants; low certainty).  The number of participants requiring nasal polyp surgery (actual or planned) during the treatment period is probably lower in those receiving dupilumab (RR 0.17, 95% CI 0.05 to 0.52; 2 studies; 725 participants; moderate certainty). Change in the extent of disease using the Lund Mackay computerised tomography (CT) score (0 to 24, higher = worse) was -7.00 (95% CI -9.61 to -4.39; 3 studies; 784 participants; high certainty), a large effect favouring the dupilumab group.  The EQ-5D visual analogue scale (0 to 100, higher = better; MCID 8 points) was used to measure change in generic quality of life. The mean difference favouring dupilumab was 8.59 (95% CI 5.31 to 11.86; 2 studies; 706 participants; moderate certainty). There may be little or no difference in the risk of nasopharyngitis (RR 0.95, 95% CI 0.72 to 1.25; 3 studies; 783 participants; low certainty). Anti-IL-5 mAb (mepolizumab) versusplacebo/no treatment (all receiving intranasal steroids) Two studies (137 participants) evaluated mepolizumab. Disease-specific HRQL measured with the SNOT-22 at 25 weeks was 13.26 points lower (better) in participants receiving mepolizumab (95% CI -22.08 to -4.44; 1 study; 105 participants; low certainty; MCID 8.9).  It is very uncertain whether there is a difference in s ymptom severity: on a 0- to 10-point VAS symptom severity was -2.03 lower in those receiving mepolizumab (95% CI -3.65 to -0.41; 1 study; 72 participants; very low certainty). It is very uncertain if there is difference in the risk of serious adverse events (RR 1.57, 95% CI 0.07 to 35.46; 2 studies; 135 participants, very low certainty). It is very uncertain whether or not the overall risk that patients still need surgery at trial end is lower in the mepolizumab group (RR 0.78, 95% CI 0.64 to 0.94; 2 studies; 135 participants; very low certainty). It is very uncertain whether mepolizumab reduces the extent of disease as measured by endoscopic nasal polyps score (scale range 0 to 8). The mean difference was 1.23 points lower in the mepolizumab group (MD -1.23, 95% -1.79 to -0.68; 2 studies; 137 participants; very low certainty). The difference in generic quality of life (EQ-5D) was 5.68 (95% CI -1.18 to 12.54; 1 study; 105 participants; low certainty), favouring the mepolizumab group. This difference is smaller than the MCID of 8 points. There may be little or no difference in the risk of nasopharyngitis (RR 0.73, 95% 0.36 to 1.47; 2 studies; 135 participants; low certainty). Anti-IgE mAb (omalizumab) versus placebo/no treatment (all receiving intranasal steroids) Three very small studies (65 participants) evaluated omalizumab. We are very uncertain about the effect of omalizumab on disease-specific HRQL, severe adverse events, extent of disease (CT scan scores), generic HRQL and adverse effects. AUTHORS' CONCLUSIONS: In adults with severe chronic rhinosinusitis and nasal polyps, using regular topical nasal steroids, dupilumab improves disease-specific HRQL compared to placebo, and reduces the extent of the disease as measured on a CT scan. It probably also improves symptoms and generic HRQL and there is no evidence of an increased risk of serious adverse events. It may reduce the need for further surgery. There may be little or no difference in the risk of nasopharyngitis. In similar patients, mepolizumab may improve both disease-specific and generic HRQL. It is uncertain whether it reduces the need for surgery or improves nasal polyp scores. There may be little or no difference in the risk of nasopharyngitis. It is uncertain if there is a difference in symptom severity and the risk of serious adverse events. We are uncertain about the effects of omalizumab

    Multi-parallel qPCR provides increased sensitivity and diagnostic breadth for gastrointestinal parasites of humans: field-based inferences on the impact of mass deworming

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    BACKGROUND: Although chronic morbidity in humans from soil transmitted helminth (STH) infections can be reduced by anthelmintic treatment, inconsistent diagnostic tools make it difficult to reliably measure the impact of deworming programs and often miss light helminth infections. METHODS: Cryopreserved stool samples from 796 people (aged 2-81 years) in four villages in Bungoma County, western Kenya, were assessed using multi-parallel qPCR for 8 parasites and compared to point-of-contact assessments of the same stools by the 2-stool 2-slide Kato-Katz (KK) method. All subjects were treated with albendazole and all Ascaris lumbricoides expelled post-treatment were collected. Three months later, samples from 633 of these people were re-assessed by both qPCR and KK, re-treated with albendazole and the expelled worms collected. RESULTS: Baseline prevalence by qPCR (n = 796) was 17 % for A. lumbricoides, 18 % for Necator americanus, 41 % for Giardia lamblia and 15% for Entamoeba histolytica. The prevalence was <1% for Trichuris trichiura, Ancylostoma duodenale, Strongyloides stercoralis and Cryptosporidium parvum. The sensitivity of qPCR was 98% for A. lumbricoides and N. americanus, whereas KK sensitivity was 70% and 32%, respectively. Furthermore, qPCR detected infections with T. trichiura and S. stercoralis that were missed by KK, and infections with G. lamblia and E. histolytica that cannot be detected by KK. Infection intensities measured by qPCR and by KK were correlated for A. lumbricoides (r = 0.83, p < 0.0001) and N. americanus (r = 0.55, p < 0.0001). The number of A. lumbricoides worms expelled was correlated (p < 0.0001) with both the KK (r = 0.63) and qPCR intensity measurements (r = 0.60). CONCLUSIONS: KK may be an inadequate tool for stool-based surveillance in areas where hookworm or Strongyloides are common or where intensity of helminth infection is low after repeated rounds of chemotherapy. Because deworming programs need to distinguish between populations where parasitic infection is controlled and those where further treatment is required, multi-parallel qPCR (or similar high throughput molecular diagnostics) may provide new and important diagnostic information

    Microbial contributions to the persistence of coral reefs

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    On contemplating the adaptive capacity of reef organisms to a rapidly changing environment, the microbiome offers significant and greatly unrecognised potential. Microbial symbionts contribute to the physiology, development, immunity and behaviour of their hosts, and can respond very rapidly to changing environmental conditions, providing a powerful mechanism for acclimatisation and also possibly rapid evolution of coral reef holobionts. Environmentally acquired fluctuations in the microbiome can have significant functional consequences for the holobiont phenotype upon which selection can act. Environmentally induced changes in microbial abundance may be analogous to host gene duplication, symbiont switching / shuffling as a result of environmental change can either remove or introduce raw genetic material into the holobiont; and horizontal gene transfer can facilitate rapid evolution within microbial strains. Vertical transmission of symbionts is a key feature of many reef holobionts and this would enable environmentally acquired microbial traits to be faithfully passed to future generations, ultimately facilitating microbiome-mediated transgenerational acclimatisation (MMTA) and potentially even adaptation of reef species in a rapidly changing climate. In this commentary, we highlight the capacity and mechanisms for MMTA in reef species, propose a modified Price equation as a framework for assessing MMTA and recommend future areas of research to better understand how microorganisms contribute to the transgenerational acclimatisation of reef organisms, which is essential if we are to reliably predict the consequences of global change for reef ecosystems

    Two novel HLA-A*0201 T-cell epitopes in avian H5N1 viral nucleoprotein induced specific immune responses in HHD mice

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    The influenza A nucleoprotein (NP) is an attractive target for avian flu vaccine development because of its high conversancy in the evolutionary chain of the virus. Here we identified two novel HLA-A*0201 restricted NP epitopes, named H5N1 NP373-381 AMDSNTLEL (NP373) and NP458-466 FQGRGVFEL (NP458), using computational bioinformatic analysis. The NP peptides showed a high binding affinity to HLA-A*0201 on T2 cells, and were able to induce the activation of the cytotoxic T cells in the human peripheral blood mononuclear cells. We examined the potential of using NP373 and NP458 peptide sequences supplemented with a single-chain trimer as potential DNA vaccine candidates in an HHD transgenic mouse model. A gene gun delivery system was used for administrating the vaccine candidates into the animals. The results from cytotoxicity and ELISPOT assays indicated that a significant amount of IFN-γ was secreted by the T cells of the vaccinated mice, and the T cells were able to eliminate the corresponding peptide-loaded T2 cells. The discovery of these novel immunogenic NP peptides provides valuable information for avian flu vaccine design and construction
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