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Mixtures of Intrinsically Disordered Neuronal Protein Tau and Anionic Liposomes Reveal Distinct Anionic Liposome-Tau Complexes Coexisting with Tau Liquid-Liquid Phase Separated Coacervates
Microtubules (MTs) are protein nanotubes comprised of αβ-tubulin heterodimers that actas structural components of the cytoskeleton and carry a net negative charge. Tau, an intrinsically disordered neuronal protein and polyampholyte with an overall positive charge, is a microtubule associated protein, which binds to anionic domains of microtubules (MTs) and suppresses their dynamic instability. Aberrant tau-MT interactions are implicated in Alzheimer’s and other neurodegenerative diseases. Here, we studied the interactions between full length human protein tau and other negatively charged binding substrates, as revealed by differential-interference-contrast (DIC) and fluorescence microscopy. As binding substrates we chose anionic liposomes (ALs) containing either 1,2-dioleoyl-sn-glycero-3- phosphatidylserine (DOPS, -1e) or 1,2-dioleoyl-sn-glycero-3-phosphatidylglycerol (DOPG, - 1e) mixed with zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) to mimic anionic plasma membranes of axons where tau resides. At low salt concentrations (0 to 10 mM KCl or NaCl) with minimal charge screening, reaction mixtures of tau and ALs resulted in the formation of distinct states of AL-tau complexes coexisting with liquid-liquid phase separated tau self-coacervates arising from the polyampholytic nature of tau containing cationic and anionic domains. AL-tau complexes exhibited distinct types of morphologies, including, large ≈20-30 micron giant multi-lamellar liposomes with bound tau-membrane domains and finite-sized assemblies of smaller liposomes glued together through the cationic domains of tau. As the ionic strength of the solution was increased to near and above physiological salt concentrations (≈150 mM 1:1 electrolyte), AL-tau complexes remained stable while tau self-coacervate droplets were found to dissolve indicative of breaking of inter- and intra- tau (anionic/cationic) electrostatic bonds due to increased charge screening. The findings are consistent with the hypothesis that cationic domains of tau may interact with anionic domains of the lumen facing lipid monolayer of the axon plasma membranes (where most anionic lipids reside), suggesting the possibility of transient yet robust interactions at physiologically relevant ionic strengths
Fibromyalgia in Behçet's disease: a narrative review.
IntroductionFibromyalgia is characterised by chronic widespread pain and tenderness. It has often been reported to occur concomitantly with chronic rheumatological conditions. Behçet's disease is a chronic relapsing, multisystem, autoinflammatory disease. There is only limited understanding of a potential relationship between fibromyalgia and Behçet's disease.AimGiven the potential detrimental influence of pain on the outcome of chronic disease, the aim of this narrative review is to gain an understanding of the incidence and presentation of fibromyalgia in Behçet's disease.MethodsElectronic databases Scopus, Medline, PubMed and UpToDate were searched.ResultsA total of 269 studies were identified, and limitations and exclusion/inclusion criteria were applied to ensure accurate and comparable selection of studies; four studies were selected. All cases were assessed for the presence of fibromyalgia according to the 1990 or 2010 diagnostic criteria of the American College of Rheumatology, with Behçet's disease diagnosed according to the International Study Group (ISG) for Behçet's disease criteria. A higher prevalence of fibromyalgia (5.7-37.1%) was reported in Behçet's disease compared to that of the general population (2.9-4.7%).DiscussionWhile an increased prevalence of fibromyalgia was found in patients with Behçet's disease, this needs to be considered within the context of limited available evidence. The potential impact of these conditions on the disease activity of each other is not clear and may require a prospective study.ConclusionFibromyalgia appears to be more prevalent in those with Behçet's disease than would be expected in the overall population. Significance: This review provides some evidence that fibromyalgia is more prevalent in those with Behçet's disease. To ensure appropriate patient treatment choices, it is important that both conditions are diagnosed where they co-exist
Biotribology of the ageing skin—why we should care
Ageing of populations has emerged as one of the most pressing societal, economic and healthcare challenges currently facing most nations across the globe. The ageing process itself results in degradation of physiological functions and biophysical properties of organs and tissues, and more particularly those of the skin. Moreover, in both developed and emerging economies, population ageing parallels concerning increases in lifestyle-associated conditions such as Type 2 diabetes, obesity and skin cancers. When considered together, these demographic trends call for even greater urgency to find clinical and engineering solutions for the numerous age-related deficits in skin function.
From a tribological perspective, detrimental alterations of skin biophysical properties with age have fundamental consequences on how one interacts with the body's inner and outer environments. This stems from the fact that, besides being the largest organ of the human body, and also nearly covering its entirety, the skin is a multifunctional interface which mediates these interactions.
The aim of this paper is to present a focused review to discuss some of the consequences of skin ageing from the viewpoint of biotribology, and their implications on health, well-being and human activities. Current and future research questions/challenges associated with biotribology of the ageing skin are outlined. They provide the background and motivation for identifying future lines of research that could be taken up by the biotribology and biophysics communities
A pragmatic randomised controlled trial of hydrotherapy and land exercises on overall well being and quality of life in rheumatoid arthritis
Background \ud
Hydrotherapy is highly valued by people with rheumatoid arthritis yet few studies have compared the benefits of exercises in heated water against exercises on land. In particular, data on quality of life is rarely reported. This is especially important because patients treated with hydrotherapy often report an enhanced sense of well-being. We report a randomised controlled trial in which we compared the effects of hydrotherapy with exercises on land on overall response to treatment, physical function and quality of life in patients with rheumatoid arthritis. \ud
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Methods \ud
One hundred and fifteen patients with RA were randomised to receive a weekly 30-minute session of hydrotherapy or similar exercises on land for 6 weeks. Our primary outcome was a self-rated global impression of change – a measure of treatment effect on a 7-point scale ranging from 1(very much worse) to 7 (very much better) assessed immediately on completion of treatment. Secondary outcomes including EuroQol health related quality of life, EuroQol health status valuation, HAQ, 10 metre walk time and pain scores were collected at baseline, after treatment and 3 months later. Binary outcomes were analysed by Fisher's exact test and continuous variables by Wilcoxon or Mann-Whitney tests. \ud
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Results \ud
Baseline characteristics of the two groups were comparable. Significantly more patients treated with hydrotherapy (40/46, 87%) were much better or very much better than the patients treated with land exercise (19/40, 47.5%), p < 0.001 Fisher's exact test. Eleven patients allocated land exercise failed to complete treatment compared with 4 patients allocated hydrotherapy (p = 0.09). Sensitivity analyses confirmed an advantage for hydrotherapy if we assumed non-completers would all not have responded (response rates 70% versus 38%; p < 0.001) or if we assumed that non-completers would have had the same response as completers (response rates 82% versus 55% p = 0.002). Ten metre walk time improved after treatment in both cases (median pre-treatment time for both groups combined 10.9 seconds, post-treatment 9.1 s, and 3 months later 9.6 s). There was however no difference between treatment groups. Similarly there were no significant differences between groups in terms of changes to HAQ, EQ-5D utility score, EQ VAS and pain VAS. \ud
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Conclusion \ud
Patients with RA treated with hydrotherapy are more likely to report feeling much better or very much better than those treated with land exercises immediately on completion of the treatment programme. This perceived benefit was not reflected by differences between groups in 10-metre walk times, functional scores, quality of life measures and pain scores
Clinical and cost-effectiveness of autologous chondrocyte implantation for cartilage defects in knee joints : systematic review and economic evaluation
Objective: To support a review of the guidance issued
by the National Institute for Health and Clinical
Excellence (NICE) in December 2000 by examining the
current clinical and cost-effectiveness evidence on
autologous cartilage transplantation.
Data sources: Electronic databases.
Review methods: Evidence on clinical effectiveness
was obtained from randomised trials, supplemented by
data from selected observational studies for longer
term results, and for the natural history of chondral
lesions. Because of a lack of long-term results on
outcomes such as later osteoarthritis and knee
replacement, only illustrative modelling was done, using
a range of assumptions that seemed reasonable, but
were not evidence based.
Results: Four randomised controlled trials were
included, as well as observational data from case series.
The trials studied a total of 266 patients and the
observational studies up to 101 patients. Two studies
compared autologous chondrocyte implantation (ACI)
with mosaicplasty, the third compared ACI with
microfracture, and the fourth compared matrix-guided
ACI (MACI®) with microfracture. Follow-up was 1 year
in one study, and up to 3 years in the remaining three
studies. The first trial of ACI versus mosaicplasty found
that ACI gave better results than mosaicplasty at 1 year.
Overall, 88% had excellent or good results with ACI
versus 69% with mosaicplasty. About half of the
biopsies after ACI showed hyaline cartilage. The second
trial of ACI versus mosaicplasty found little difference in
clinical outcomes at 2 years. Disappointingly, biopsies
from the ACI group showed fibrocartilage rather than
hyaline cartilage. The trial of ACI versus microfracture
also found only small differences in outcomes at
2 years. Finally, the trial of MACI versus microfracture
contained insufficient long-term results at present, but
the study does show the feasibility of doing ACI by the
MACI technique. It also suggested that after ACI, it
takes 2 years for full-thickness cartilage to be
produced. Reliable costs per quality-adjusted life-year
(QALY) could not be calculated owing to the absence
of necessary data. Simple short-term modelling
suggests that the quality of life gain from ACI versus
microfracture would have to be between 70 and 100%
greater over 2 years for it to be more cost-effective
within the £20,000–30,000 per QALY costeffectiveness
thresholds. However, if the quality of life
gains could be maintained for a decade, increments
relative to microfracture would only have to be
10–20% greater to justify additional treatment costs
within the cost-effectiveness band indicated above.
Follow-up from the trials so far has only been up to
2 years, with longer term outcomes being
uncertain.
Conclusions: There is insufficient evidence at present
to say that ACI is cost-effective compared with
microfracture or mosaicplasty. Longer term outcomes
are required. Economic modelling using some
assumptions about long-term outcomes that seem
reasonable suggests that ACI would be cost-effective because it is more likely to produce hyaline cartilage,
which is more likely to be durable and to prevent
osteoarthritis in the longer term (e.g. 20 years).
Further research is needed into earlier methods of
predicting long-term results. Basic science research is
also needed into factors that influence stem cells to
become chondrocytes and to produce high-quality
cartilage, as it may be possible to have more patients
developing hyaline cartilage after microfracture. Study
is also needed into cost-effective methods of
rehabilitation and the effect of early mobilisation on
cartilage growth
Co-morbidities and mortality in patients with sickle cell disease in England: A 10-year cohort analysis using hospital episodes statistics (HES) data
Patients with a primary diagnosis of sickle cell disease (SCD) with or without crisis during the 10-year period January 2009 to December 2018 were identified in the HES Admitted Patient Care (APC) dataset and matched with the Office for National Statistics (ONS) mortality dataset. Three sub-cohorts were defined: ‘crises’, ‘transfusions’ and ‘other SCD’. APC records were examined for co-morbidities commonly associated with SCD and 10-year mortality rates compared with the general population. After data cleaning and exclusions, 9503 patients remained (entire cohort), with 1171, 201, and 8131 in crises, transfusions, and other SCD sub-cohorts, respectively. Median numbers of co-morbidities per patient were 2 (Interquartile range (IQR): 1–4), 2 (IQR: 1–3), and 1 (IQR: 0–2) in the crises, transfusions, and other SCD sub-cohorts, respectively. The majority of patients in the crises (63.2%) and transfusions (56.3%) cohorts had ≥2 co-morbidities, compared with 25.3% in the other SCD sub-cohort. Crude 10-year mortality rate was 5.3% (entire cohort), compared with 8.0% (crises) and 11.4% (transfusions) sub-cohorts; all rates were substantially higher than in age-sex matched general population. Our study adds further evidence that morbidity and mortality associated with SCD in England is high
The angiogenic factor midkine is regulated by dexamethasone and retinoic acid during alveolarization and in alveolar epithelial cells
<p>Abstract</p> <p>Background</p> <p>A precise balance exists between the actions of endogenous glucocorticoids (GC) and retinoids to promote normal lung development, in particular during alveolarization. The mechanisms controlling this balance are largely unknown, but recent evidence suggests that midkine (MK), a retinoic acid-regulated, pro-angiogenic growth factor, may function as a critical regulator. The purpose of this study was to examine regulation of MK by GC and RA during postnatal alveolar formation in rats.</p> <p>Methods</p> <p>Newborn rats were treated with dexamethasone (DEX) and/or all-trans-retinoic acid (RA) during the first two weeks of life. Lung morphology was assessed by light microscopy and radial alveolar counts. MK mRNA and protein expression in response to different treatment were determined by Northern and Western blots. In addition, MK protein expression in cultured human alveolar type 2-like cells treated with DEX and RA was also determined.</p> <p>Results</p> <p>Lung histology confirmed that DEX treatment inhibited and RA treatment stimulated alveolar formation, whereas concurrent administration of RA with DEX prevented the DEX effects. During normal development, MK expression was maximal during the period of alveolarization from postnatal day 5 (PN5) to PN15. DEX treatment of rat pups decreased, and RA treatment increased lung MK expression, whereas concurrent DEX+RA treatment prevented the DEX-induced decrease in MK expression. Using human alveolar type 2 (AT2)-like cells differentiated in culture, we confirmed that DEX and cAMP decreased, and RA increased MK expression.</p> <p>Conclusion</p> <p>We conclude that MK is expressed by AT2 cells, and is differentially regulated by corticosteroid and retinoid treatment in a manner consistent with hormonal effects on alveolarization during postnatal lung development.</p
Patterns of analgesic use, pain and self-efficacy: a cross-sectional study of patients attending a hospital rheumatology clinic
Background: Many people attending rheumatology clinics use analgesics and non-steroidal anti-inflammatories for persistent musculoskeletal pain. Guidelines for pain management recommend regular and pre-emptive use of analgesics to reduce the impact of pain. Clinical experience indicates that analgesics are often not used in this way. Studies exploring use of analgesics in arthritis have historically measured adherence to such medication. Here we examine patterns of analgesic use and their relationships to pain, self-efficacy and demographic factors.
Methods: Consecutive patients were approached in a hospital rheumatology out-patient clinic. Pattern of analgesic use was assessed by response to statements such as 'I always take my tablets every day.' Pain and self-efficacy (SE) were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Arthritis Self-Efficacy Scale (ASES). Influence of factors on pain level and regularity of analgesic use were investigated using linear regression. Differences in pain between those agreeing and disagreeing with statements regarding analgesic use were assessed using t-tests.
Results: 218 patients (85% of attendees) completed the study. Six (2.8%) patients reported no current pain, 26 (12.3%) slight, 100 (47.4%) moderate, 62 (29.4%) severe and 17 (8.1%) extreme pain. In multiple linear regression self efficacy and regularity of analgesic use were significant (p < 0.01) with lower self efficacy and more regular use of analgesics associated with more pain.
Low SE was associated with greater pain: 40 (41.7%) people with low SE reported severe pain versus 22 (18.3%) people with high SE, p < 0.001. Patients in greater pain were significantly more likely to take analgesics regularly; 13 (77%) of those in extreme pain reported always taking their analgesics every day, versus 9 (35%) in slight pain. Many patients, including 46% of those in severe pain, adjusted analgesic use to current pain level. In simple linear regression, pain was the only variable significantly associated with regularity of analgesic use: higher levels of pain corresponded to more regular analgesic use (p = 0.003).
Conclusion: Our study confirms that there is a strong inverse relationship between self-efficacy and pain severity. Analgesics are often used irregularly by people with arthritis, including some reporting severe pain
Samanantar: The Largest Publicly Available Parallel Corpora Collection for 11 Indic Languages
We present Samanantar, the largest publicly available parallel corpora
collection for Indic languages. The collection contains a total of 49.7 million
sentence pairs between English and 11 Indic languages (from two language
families). Specifically, we compile 12.4 million sentence pairs from existing,
publicly-available parallel corpora, and additionally mine 37.4 million
sentence pairs from the web, resulting in a 4x increase. We mine the parallel
sentences from the web by combining many corpora, tools, and methods: (a)
web-crawled monolingual corpora, (b) document OCR for extracting sentences from
scanned documents, (c) multilingual representation models for aligning
sentences, and (d) approximate nearest neighbor search for searching in a large
collection of sentences. Human evaluation of samples from the newly mined
corpora validate the high quality of the parallel sentences across 11
languages. Further, we extract 83.4 million sentence pairs between all 55 Indic
language pairs from the English-centric parallel corpus using English as the
pivot language. We trained multilingual NMT models spanning all these languages
on Samanantar, which outperform existing models and baselines on publicly
available benchmarks, such as FLORES, establishing the utility of Samanantar.
Our data and models are available publicly at
https://indicnlp.ai4bharat.org/samanantar/ and we hope they will help advance
research in NMT and multilingual NLP for Indic languages.Comment: Accepted to the Transactions of the Association for Computational
Linguistics (TACL
Strong Association of De Novo Copy Number Mutations with Autism
We tested the hypothesis that de novo copy number variation (CNV) is associated with autism spectrum disorders (ASDs). We performed comparative genomic hybridization (CGH) on the genomic DNA of patients and unaffected subjects to detect copy number variants not present in their respective parents. Candidate genomic regions were validated by higher-resolution CGH, paternity testing, cytogenetics, fluorescence in situ hybridization, and microsatellite genotyping. Confirmed de novo CNVs were significantly associated with autism (P = 0.0005). Such CNVs were identified in 12 out of 118 (10%) of patients with sporadic autism, in 2 out of 77 (3%) of patients with an affected first-degree relative, and in 2 out of 196 (1%) of controls. Most de novo CNVs were smaller than microscopic resolution. Affected genomic regions were highly heterogeneous and included mutations of single genes. These findings establish de novo germline mutation as a more significant risk factor for ASD than previously recognized
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