89 research outputs found

    Investigation of therapeutic efficacy and mechanisms of polysaccharide of dendrobium officinale in alleviating cigarette-induced pulmonary inflammation

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    Posters: no. 13PS36Dendrobium officinale is a medicinal plant from the Orchidaceae family. It has been listed in the latest edition of the Chinese Pharmacopoeia as medicinal material Dendrobii Officinalis Caulis (Tiepishihu) because of its treatment efficacy. According to the Pharmacopoeia it benefits the stomach, promotes the production of body fluid, nourishes yin and eliminates evil-heat. Consequently it com...published_or_final_versio

    COVID-19 vaccine-readiness for anti-CD20-depleting therapy in autoimmune diseases

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    Although most autoimmune diseases are considered to be CD4 T cell- or antibody-mediated, many respond to CD20-depleting antibodies that have limited influence on CD4 and plasma cells. This includes rituximab, oblinutuzumab and ofatumumab that are used in cancer, rheumatoid arthritis and off-label in a large number of other autoimmunities and ocrelizumab in multiple sclerosis. Recently, the COVID-19 pandemic created concerns about immunosuppression in autoimmunity, leading to cessation or a delay in immunotherapy treatments. However, based on the known and emerging biology of autoimmunity and COVID-19, it was hypothesised that while B cell depletion should not necessarily expose people to severe SARS-CoV-2-related issues, it may inhibit protective immunity following infection and vaccination. As such, drug-induced B cell subset inhibition, that controls at least some autoimmunities, would not influence innate and CD8 T cell responses, which are central to SARS-CoV-2 elimination, nor the hypercoagulation and innate inflammation causing severe morbidity. This is supported clinically, as the majority of SARS-CoV-2-infected, CD20-depleted people with autoimmunity have recovered. However, protective neutralizing antibody and vaccination responses are predicted to be blunted until naive B cells repopulate, based on B cell repopulation kinetics and vaccination responses, from published rituximab and unpublished ocrelizumab (NCT00676715, NCT02545868) trial data, shown here. This suggests that it may be possible to undertake dose interruption to maintain inflammatory disease control, while allowing effective vaccination against SARS-CoV-29, if and when an effective vaccine is available

    The effects of male age on sperm analysis by motile sperm organelle morphology examination (MSOME)

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    <p>Abstract</p> <p>Background</p> <p>This study aimed to investigate the influence of age on sperm quality, as analysed by motile sperm organelle morphology examination (MSOME).</p> <p>Methods</p> <p>Semen samples were collected from 975 men undergoing evaluation or treatment for infertility. Sperm cells were evaluated at 8400× magnification using an inverted microscope equipped with Nomarski (differential interference contrast) optics. Two forms of spermatozoa were considered: normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV, defined as vacuoles occupying > 50% of the sperm nuclear area). At least 200 spermatozoa per sample were evaluated, and the percentages of normal and LNV spermatozoa were determined. The subjects were divided into three groups according to age: Group I, less than or equal to 35 years; Group II, 36-40 years; and Group III, greater than or equal to 41 years.</p> <p>Results</p> <p>There was no difference in the percentages of normal sperm between the two younger (I and II) groups (<it>P ></it>0.05). The percentage of normal sperm in the older group (III) was significantly lower than that in the younger (I and II) groups (<it>P </it>< 0.05). There was no difference in the percentage of LNV spermatozoa between the younger (I and II) groups (<it>P ></it>0.05). The percentage of LNV spermatozoa was significantly higher in the older group (III) than in the younger (I and II) groups (<it>P </it>< 0.05). Regression analysis demonstrated a significant decrease in the incidence of normal sperm with increasing age (<it>P </it>< 0.05; r = -0.10). However, there was a significant positive correlation between the percentage of spermatozoa with LNV and male age (<it>P </it>< 0.05, r = 0.10).</p> <p>Conclusion</p> <p>The results demonstrated a consistent decline in semen quality, as reflected by morphological evaluation by MSOME, with increased age. Considering the relationship between nuclear vacuoles and DNA damage, these age-related changes predict that increased paternal age should be associated with unsuccessful or abnormal pregnancy as a consequence of fertilisation with damaged spermatozoa. Given that sperm nuclear vacuoles can be evaluated more precisely at high magnification, these results support the routine use of MSOME for ICSI as a criterion for semen analysis.</p

    The Biochemistry, Ultrastructure, and Subunit Assembly Mechanism of AMPA Receptors

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    The AMPA-type ionotropic glutamate receptors (AMPA-Rs) are tetrameric ligand-gated ion channels that play crucial roles in synaptic transmission and plasticity. Our knowledge about the ultrastructure and subunit assembly mechanisms of intact AMPA-Rs was very limited. However, the new studies using single particle EM and X-ray crystallography are revealing important insights. For example, the tetrameric crystal structure of the GluA2cryst construct provided the atomic view of the intact receptor. In addition, the single particle EM structures of the subunit assembly intermediates revealed the conformational requirement for the dimer-to-tetramer transition during the maturation of AMPA-Rs. These new data in the field provide new models and interpretations. In the brain, the native AMPA-R complexes contain auxiliary subunits that influence subunit assembly, gating, and trafficking of the AMPA-Rs. Understanding the mechanisms of the auxiliary subunits will become increasingly important to precisely describe the function of AMPA-Rs in the brain. The AMPA-R proteomics studies continuously reveal a previously unexpected degree of molecular heterogeneity of the complex. Because the AMPA-Rs are important drug targets for treating various neurological and psychiatric diseases, it is likely that these new native complexes will require detailed mechanistic analysis in the future. The current ultrastructural data on the receptors and the receptor-expressing stable cell lines that were developed during the course of these studies are useful resources for high throughput drug screening and further drug designing. Moreover, we are getting closer to understanding the precise mechanisms of AMPA-R-mediated synaptic plasticity

    Pan-cancer analysis of whole genomes

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    Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

    The role of inflammation in irritable bowel syndrome (IBS)

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    Qin Xiang Ng,1,2 Alex Yu Sen Soh,1 Wayren Loke,2 Donovan Yutong Lim,3 Wee-Song Yeo1 1National University Hospital, National University Health System, Singapore; 2MOH Holdings Pte Ltd, Singapore; 3Institute of Mental Health, Singapore Abstract: Irritable bowel syndrome (IBS) is a complex, functional gastrointestinal &shy;disorder characterized by chronic abdominal pain or discomfort and altered bowel habits. Despite the global prevalence and disease burden of IBS, its underlying pathophysiology remains unclear. Inflammation may play a pathogenic role in IBS. Studies have highlighted the persistence of mucosal inflammation at the microscopic and molecular level in IBS, with increased recruitment of enteroendocrine cells. Substantial overlaps between IBS and inflammatory bowel disease have also been reported. This review thus aimed to discuss the body of evidence pertaining to the presence of mucosal inflammation in IBS, its putative role in the disease process of IBS, and its clinical relevance. Increased mast cell density and activity in the gut may correlate with symptoms of visceral hypersensitivity. As evidenced by patients who develop postinfectious IBS, infective gastroenteritis could cause systemic inflammation and altered microbiome diversity, which in turn perpetuates a cycle of chronic, low-grade, subclinical inflammation. Apart from mucosal inflammation, neuroinflammation is probably involved in the pathophysiology of IBS via the &ldquo;gut&ndash;brain&rdquo; axis, resulting in altered neuroendocrine pathways and glucocorticoid receptor genes. This gives rise to an overall proinflammatory phenotype and dysregulated hypothalamic&ndash;pituitary&ndash;adrenal axis and serotonergic (5-HT) functioning, which could, at least in part, account for the symptoms of IBS. Although a definite and reproducible pattern of immune response has yet to be recognized, further research into anti-inflammatories may be of clinical value. Keywords: irritable bowel syndrome, postinfectious, inflammation, microbiom

    A meta-analysis of cyclosporine treatment for Stevens&ndash;Johnson syndrome/toxic epidermal necrolysis

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    Qin Xiang Ng,1,2 Michelle Lee Zhi Qing De Deyn,3 Nandini Venkatanarayanan,4 Collin Yih Xian Ho,2 Wee-Song Yeo,5 1Department of Medicine, National University Hospital, National University Health System, Singapore; 2MOH Holdings Pte Ltd, Singapore; 3Department of Medicine, James Cook University Hospital, Middlesbrough, UK; 4Department of Medicine, Nottingham University Hospitals NHS Trust, Queen&rsquo;s Medical Centre, Nottingham, UK; 5Department of Paediatrics, National University Hospital, National University Health System, Singapore Background: Stevens&ndash;Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are dermatologic emergencies with high morbidity and mortality risk. Cyclosporine, an immunomodulatory agent, is sometimes used off-label, and its role continues to be debated. This meta-analysis aimed to provide an update of current evidence and to clarify the role of cyclosporine in SJS/TEN treatment better.Methods: Using the keywords [cyclosporine OR cyclosporine OR ciclosporin OR CsA] AND [Steven-Johnson OR SJS OR toxic epidermal OR epidermal necrolysis OR TEN OR hypersensitivity OR dermatologic OR burns], a preliminary search on the PubMed, Ovid, Web of Science, and Google Scholar Database yielded 615 papers published in English between January 1, 1960 and July 1, 2017. The inclusion criteria for this review were: 1) published retrospective or prospective study (excluding single case reports); 2) patients with clinical diagnosis of SJS or TEN; 3) trial of cyclosporine treatment; and 4) available survival/mortality data.Results: A total of 12 studies, with a total of 358 SJS/TEN patients were reviewed. Two studies were excluded from the meta-analysis as they did not report SCORe of toxic epidermal necrosis/predicted mortality data; one was excluded because of possible data irregularities. Meta-analysis of nine studies revealed a significant reduction in mortality risk with cyclosporine therapy (standardized mortality ratio 0.320; 95% CI: 0.119&ndash;0.522; P=0.002). Cyclosporine was also generally well tolerated with little adverse effects or increased infection, albeit the patients tended to be critically ill. Publication bias was observed in the funnel plot and Egger test (P=0.0467).Conclusion: Currently available evidence are predominantly open trials and retrospective studies with a significant risk of bias, perhaps owing to the rarity and life-threatening nature of the condition. Given its immunomodulatory actions, cyclosporine could be a potential treatment option for SJS/TEN in addition to best supportive measures. Further confirmation with robust randomized, controlled trials or larger case series is necessary and should be encouraged. Keywords: SJS, TEN, epidermal necrolysis, cyclosporine, CsA, meta-analysi

    Distinct electroluminescent properties of triphenylamine derivatives in blue organic light-emitting devices

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    Two highly fluorescent triphenylamines (TPA) end-capped respectively with one and three pyrene arms, namely N,N-diphenyl-4-(pyren-1-yl)aniline (PyTPA) and 4,4′,4′′-trispyrenylphenylamine (TPyPA), have been designed, synthesized and applied as hole-transporting emitters in organic light-emitting devices (OLEDs). While the two compounds have similar chemical structures (the only difference being the number of pyrene arms), devices based on them show distinct electroluminescent characteristics. PyTPA-based devices exhibit intense deep-blue emission with Commission Internationale de L'Eclairage coordinates (CIE) of (0.14, 0.11); whilst TPyPA-based devices emit white light with CIE of (0.31, 0.35). It is considered that the three electron-donating pyrene arms in TPyPA increase its electron-donating ability, which facilitates exciplex formation with the electron-transporter. This gives rise to a yellow exciplex emission and thus shifts the electroluminescence from deep-blue to white. More importantly, both devices can operate at record-low driving voltages (<4V at 20 mA cm -2), indicating the TPA-cored emitters offer not only high luminance efficiencies, but also good hole-injection and transporting features. © 2011 The Royal Society of Chemistry.link_to_subscribed_fulltex
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