102 research outputs found

    Ferrets exclusively synthesize Neu5Ac and express naturally humanized influenza A virus receptors

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    Mammals express the sialic acids ​N-acetylneuraminic acid (​Neu5Ac) and ​N-glycolylneuraminic acid (​Neu5Gc) on cell surfaces, where they act as receptors for pathogens, including influenza A virus (IAV). ​Neu5Gc is synthesized from ​Neu5Ac by the enzyme cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH). In humans, this enzyme is inactive and only ​Neu5Ac is produced. Ferrets are susceptible to human-adapted IAV strains and have been the dominant animal model for IAV studies. Here we show that ferrets, like humans, do not synthesize ​Neu5Gc. Genomic analysis reveals an ancient, nine-exon deletion in the ferret CMAH gene that is shared by the Pinnipedia and Musteloidia members of the Carnivora. Interactions between two human strains of IAV with the sialyllactose receptor (sialic acid—α2,6Gal) confirm that the type of terminal sialic acid contributes significantly to IAV receptor specificity. Our results indicate that exclusive expression of ​Neu5Ac contributes to the susceptibility of ferrets to human-adapted IAV strains

    Clonal transitions and phenotypic evolution in Barrett esophagus

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    BACKGROUND & AIMS: Barrett's esophagus (BE) is a risk factor for esophageal adenocarcinoma but our understanding of how it evolves is poorly understood. We investigated BE gland phenotype distribution, the clonal nature of phenotypic change, and how phenotypic diversity plays a role in progression. METHODS: Using immunohistochemistry and histology, we analyzed the distribution and the diversity of gland phenotype between and within biopsy specimens from patients with nondysplastic BE and those who had progressed to dysplasia or had developed postesophagectomy BE. Clonal relationships were determined by the presence of shared mutations between distinct gland types using laser capture microdissection sequencing of the mitochondrial genome. RESULTS: We identified 5 different gland phenotypes in a cohort of 51 nondysplastic patients where biopsy specimens were taken at the same anatomic site (1.0-2.0 cm superior to the gastroesophageal junction. Here, we observed the same number of glands with 1 and 2 phenotypes, but 3 phenotypes were rare. We showed a common ancestor between parietal cell-containing, mature gastric (oxyntocardiac) and goblet cell-containing, intestinal (specialized) gland phenotypes. Similarly, we have shown a clonal relationship between cardiac-type glands and specialized and mature intestinal glands. Using the Shannon diversity index as a marker of gland diversity, we observed significantly increased phenotypic diversity in patients with BE adjacent to dysplasia and predysplasia compared to nondysplastic BE and postesophagectomy BE, suggesting that diversity develops over time. CONCLUSIONS: We showed that the range of BE phenotypes represents an evolutionary process and that changes in gland diversity may play a role in progression. Furthermore, we showed a common ancestry between gastric and intestinal-type glands in BE

    Arylpyrrole and fipronil analogues that inhibit the motility and/or development of Haemonchus contortus in vitro

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    Due to widespread drug resistance in parasitic nematodes, there is a need to develop new anthelmintics. Given the cost and time involved in developing a new drug, the repurposing of known chemicals can be a promising, alternative approach. In this context, we tested a library (n = 600) of natural product-inspired pesticide analogues against exsheathed third stage-larvae (xL3s) of Haemonchus contortus (barber's pole worm) using a whole-organism, phenotypic screening technique that measures the inhibition of motility and development in treated larvae. In the primary screen, we identified 32 active analogues derived from chemical scaffolds of arylpyrrole or fipronil. The seven most promising compounds, selected based on their anthelmintic activity and/or limited cytotoxicity, are arylpyrroles that reduced the motility of fourth-stage larvae (L4s) with significant potency (IC50 values ranged from 0.04 ± 0.01 μM to 4.25 ± 0.82 μM, and selectivity indices ranged from 10.6 to 412.5). Since the parent structures of the active compounds are uncouplers of oxidative phosphorylation, we tested the effect of selected analogues on oxygen consumption in xL3s using the Seahorse XF24 flux analyser. Larvae treated with the test compounds showed a significant increase in oxygen consumption compared with the untreated control, demonstrating their uncoupling activity. Overall, the results of the present study have identified natural product-derived molecules that are worth considering for chemical optimisation as anthelmintic drug leads. Keywords: Arylpyrrole, Fipronil, Haemonchus contortus, Anthelmintic, Drug discover

    Integrated palliative care in Europe: a qualitative systematic literature review of empirically-tested models in cancer and chronic disease

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    Integrated Palliative Care (PC) strategies are often implemented following models, namely standardized designs that provide frameworks for the organization of care for people with a progressive life-threatening illness and/or for their (in)formal caregivers. The aim of this qualitative systematic review is to identify empirically-evaluated models of PC in cancer and chronic disease in Europe. Further, develop a generic framework that will consist of the basis for the design of future models for integrated PC in Europe. Methods: Cochrane, PubMed, EMBASE, CINAHL, AMED, BNI, Web of Science, NHS Evidence. Five journals and references from included studies were hand-searched. Two reviewers screened the search results. Studies with adult patients with advanced cancer/chronic disease from 1995 to 2013 in Europe, in English, French, German, Dutch, Hungarian or Spanish were included. A narrative synthesis was used. Results: 14 studies were included, 7 models for chronic disease, 4 for integrated care in oncology, 2 for both cancer and chronic disease and 2 for end-of-life pathways. The results show a strong agreement on the benefits of the involvement of a PC multidisciplinary team: better symptom control, less caregiver burden, improvement in continuity and coordination of care, fewer admissions, cost effectiveness and patients dying in their preferred place. Conclusion: Based on our findings, a generic framework for integrated PC in cancer and chronic disease is proposed. This framework fosters integration of PC in the disease trajectory concurrently with treatment and identifies the importance of employing a PC-trained multidisciplinary team with a threefold focus: treatment, consulting and training

    To what degree is palliative care integrated in guidelines and pathways for adult cancer patients in Europe: a systematic literature review

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    Palliative Care (PC) aims to improve the quality of life for patients with cancer and their families and its benefits have been demonstrated by several studies. The objective of this systematic review is to assess the integration of PC in the content of guidelines/pathways of adult cancer patients in Europe. Methods We included studies of adult patients with cancer published from 01/01/1995 and 31/12/2013 in Europe in six languages. We searched nine electronic databases, hand-searched six journals and also performed citation tracking. Studies were ranked using Emanuel's Integrated Palliative Care (IPC) criteria, a tool containing 11 domains to assess PC content in guidelines. Two reviewers screened the results and narrative synthesis has been employed. Results We identified a total of 28,277 potentially relevant articles from which 637 were eligible for full-text screening. The final review included 60 guidelines and 14 pathways. Eighty percent (80 %) of the guidelines/pathways emphasize a holistic approach and 66 % focus on PC interventions aimed at reducing suffering. Fifty seven percent (57 %) did not discuss referral criteria for PC. Of all studies, five fulfilled at least 10/11 IPC criteria. Differences existed with regard to the referral criteria for bereavement care and the continuous adjustment of goals of care. Conclusion Overall, most of the identified guidelines/pathways highlighted the importance of the holistic approach of IPC. The studies that were found to fulfil at least 10/11 Emanuel's IPC criteria could serve as benchmarks of IPC

    Towards integration of palliative care in patients with chronic heart failure and chronic obstructive pulmonary disease:a systematic literature review of European guidelines and pathways

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    Despite the positive impact of Palliative Care (PC) on the quality of life for patients and their relatives, the implementation of PC in non-cancer health-care delivery in the EU seems scarcely addressed. The aim of this study is to assess guidelines/pathways for integrated PC in patients with advanced Chronic Heart Failure (CHF) and Chronic Obstructive Pulmonary Disease (COPD) in Europe via a systematic literature review. Methods Search results were screened by two reviewers. Eligible studies of adult patients with CHF or COPD published between 01/01/1995 and 31/12/2013 in Europe in 6 languages were included. Nine electronic databases were searched, 6 journals were hand-searched and citation tracking was also performed. For the analysis, a narrative synthesis was employed. Results The search strategy revealed 26,256 studies without duplicates. From these, 19 studies were included in the review; 17 guidelines and 2 pathways. 18 out of 19 focused on suffering reduction interventions, 13/19 on a holistic approach and 15/19 on discussions of illness prognosis and limitations. The involvement of a PC team was mentioned in 13/19 studies, the assessment of the patients’ goals of care in 12/19 and the advance care planning in 11/19. Only 4/19 studies elaborated on aspects such as grief and bereavement care, 7/19 on treatment in the last hours of life and 8/19 on the continuation of goal adjustment. Conclusion The results illustrate that there is a growing awareness for the importance of integrated PC in patients with advanced CHF or COPD. At the same time, however, they signal the need for the development of standardized strategies so that existing barriers are alleviated

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

    HLA-DQA1*05 carriage associated with development of anti-drug antibodies to infliximab and adalimumab in patients with Crohn's Disease

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    Anti-tumor necrosis factor (anti-TNF) therapies are the most widely used biologic drugs for treating immune-mediated diseases, but repeated administration can induce the formation of anti-drug antibodies. The ability to identify patients at increased risk for development of anti-drug antibodies would facilitate selection of therapy and use of preventative strategies.This article is freely available via Open Access. Click on Publisher URL to access the full-text

    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

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    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
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