Inhibition of interleukin-1β-stimulated collagenase and stromelysin expression in human tendon fibroblasts by epigallocatechin gallate ester

The medicinal benefits of green tea (Camellia sinensis) consumption have been attributed to bioavailable polyphenols, notably epigallocatechin gallate (EGCG). We have assessed the effects of EGCG and its non-esterified counterpart EGC on the expression of the collagenases, matrix metalloproteinases (MMP)-1 and -13, and the stromelysin, MMP-3, in human tendon-derived fibroblasts. Interleukin (IL)-1ß increased MMP-1, -3 and -13 mRNA and output at least 30-fold. EGCG reduced this stimulation, by 20–30% at 2.5 µM and more than 80% at 25 µM, and had a smaller effect on MMP-2 mRNA expression, which was not stimulated by IL-1ß. In all experiments EGCG was at least 10-fold more potent than EGC. EGCG reduced the stimulation of p54 JNK/SAPK phosphorylation by IL-1ß but did not affect p38 MAPK phosphorylation, the degradation of I?B or the activating phosphorylation of NF?B. We conclude that EGCG reduces the IL-1-stimulated expression of both collagenase and stromelysin mRNA species, an effect which may be mediated by inhibition of the JNK/SAPK pathway. Taken together with previous reports of EGCG effects on the expression and/or activity of gelatinases and aggrecanases, our results underline the importance of extracellular matrix breakdown as a potential target for the actions of green tea polyphenols

‘Treading water but drowning slowly’: what are GPs’ experiences of living and working with mental illness and distress in England? A qualitative study

Objectives This paper provides an in-depth account of general practitioners’ (GPs) experiences of living and working with mental illness and distress, as part of a wider study reporting the barriers and facilitators to help-seeking for mental illness and burn-out, and sources of stress/distress for GP participants. Design Qualitative study using in-depth interviews with 47 GP participants. The interviews were audio recorded, transcribed, anonymised and imported into NVivo V.11 to facilitate data management. Data were analysed using a thematic analysis employing the constant comparative method. Setting England. Participants A purposive sample of GP participants who self-identified as: (1) currently living with mental distress, (2) returning to work following treatment, (3) off sick or retired early as a result of mental distress or (4) without experience of mental distress. Interviews were conducted face to face or over the telephone. Results The findings report GP participants’ in-depth experiences of distress and mental illness with many recollecting their distressing experiences and significant psychological and physical symptoms relating to chronic stress, anxiety, depression and/or burn-out, and a quarter articulating thoughts of suicide. Many talked about their shame, humiliation and embarrassment at their perceived inability to cope with the stresses of their job and/or their symptoms of mental illness. Conclusions These findings paint a concerning picture of the situation affecting primary care doctors, with participants’ accounts suggesting there is a considerable degree of mental ill health and reduced well-being among GPs. The solutions are complex and lie in prevention and provision. There needs to be greater recognition of the components and cumulative effect of occupational stressors for doctors, such as the increasing workload and the clinical and emotional demands of the job, as well as the need for a culture shift within medicine to more supportive and compassionate work environments

A clinical, biological, and biomaterials perspective into tendon injuries and regeneration

Tendon injury is common and debilitating, and it is associated with long-term pain and ineffective healing. It is estimated to afflict 25% of the adult population and is often a career-ending disease in athletes and racehorses. Tendon injury is associated with high morbidity, pain, and long-term suffering for the patient. Due to the low cellularity and vascularity of tendon tissue, once damage has occurred, the repair process is slow and inefficient, resulting in mechanically, structurally, and functionally inferior tissue. Current treatment options focus on pain management, often being palliative and temporary and ending in reduced function. Most treatments available do not address the underlying cause of the disease and, as such, are often ineffective with variable results. The need for an advanced therapeutic that addresses the underlying pathology is evident. Tissue engineering and regenerative medicine is an emerging field that is aimed at stimulating the body's own repair system to produce de novo tissue through the use of factors such as cells, proteins, and genes that are delivered by a biomaterial scaffold. Successful tissue engineering strategies for tendon regeneration should be built on a foundation of understanding of the molecular and cellular composition of healthy compared with damaged tendon, and the inherent differences seen in the tissue after disease. This article presents a comprehensive clinical, biological, and biomaterials insight into tendon tissue engineering and regeneration toward more advanced therapeutics

Expression profiling of metalloproteinases and tissue inhibitors of metalloproteinases in normal and degenerate human achilles tendon

To profile the messenger RNA (mRNA) expression for the 23 known genes of matrix metalloproteinases (MMPs), 19 genes of ADAMTS, 4 genes of tissue inhibitors of metalloproteinases (TIMPs), and ADAM genes 8, 10, 12, and 17 in normal, painful, and ruptured Achilles tendons. Tendon samples were obtained from cadavers or from patients undergoing surgical procedures to treat chronic painful tendinopathy or ruptured tendon. Total RNA was extracted and mRNA expression was analyzed by quantitative real-time reverse transcription–polymerase chain reaction, normalized to 18S ribosomal RNA. In comparing expression of all genes, the normal, painful, and ruptured Achilles tendon groups each had a distinct mRNA expression signature. Three mRNA were not detected and 14 showed no significant difference in expression levels between the groups. Statistically significant (P < 0.05) differences in mRNA expression, when adjusted for age, included lower levels of MMPs 3 and 10 and TIMP-3 and higher levels of ADAM-12 and MMP-23 in painful compared with normal tendons, and lower levels of MMPs 3 and 7 and TIMPs 2, 3, and 4 and higher levels of ADAMs 8 and 12, MMPs 1, 9, 19, and 25, and TIMP-1 in ruptured compared with normal tendons. The distinct mRNA profile of each tendon group suggests differences in extracellular proteolytic activity, which would affect the production and remodeling of the tendon extracellular matrix. Some proteolytic activities are implicated in the maintenance of normal tendon, while chronically painful tendons and ruptured tendons are shown to be distinct groups. These data will provide a foundation for further study of the role and activity of many of these enzymes that underlie the pathologic processes in the tendon

What challenges did junior doctors face while working during the COVID-19 pandemic? A qualitative study.

Objectives This paper reports findings exploring junior doctors’ experiences of working during the COVID-19 pandemic in the UK.Design Qualitative study using in-depth interviews with 15 junior doctors. Interviews were audio-recorded, transcribed, anonymised and imported into NVivo V.12 to facilitate data management. Data were analysed using reflexive thematic analysis.Setting National Health Service (NHS) England.Participants A purposive sample of 12 female and 3 male junior doctors who indicated severe depression and/or anxiety on the DASS-21 questionnaire or high suicidality on Paykel’s measure were recruited. These doctors self-identified as having lived experience of distress due to their working conditions.Results We report three major themes. First, the challenges of working during the COVID-19 pandemic, which were both personal and organisational. Personal challenges were characterised by helplessness and included the trauma of seeing many patients dying, fears about safety and being powerless to switch off. Work-related challenges revolved around change and uncertainty and included increasing workloads, decreasing staff numbers and negative impacts on relationships with colleagues and patients. The second theme was strategies for coping with the impact of COVID-19 on work, which were also both personal and organisational. Personal coping strategies, which appeared limited in their usefulness, were problem and emotion focused. Several participants appeared to have moved from coping towards learnt helplessness. Some organisations reacted to COVID-19 collaboratively and flexibly. Third, participants reported a positive impact of the COVID-19 pandemic on working practices, which included simplified new ways of working—such as consistent teams and longer rotations—as well as increased camaraderie and support.Conclusions The trauma that junior doctors experienced while working during COVID-19 led to powerlessness and a reduction in the benefit of individual coping strategies. This may have resulted in feelings of resignation. We recommend that, postpandemic, junior doctors are assigned to consistent teams and offered ongoing support

SLAMBench 3.0:Systematic Automated Reproducible Evaluation of SLAM Systems for Robot Vision Challenges and Scene Understanding

As the SLAM research area matures and the number of SLAM systems available increases, the need for frameworks that can objectively evaluate them against prior work grows. This new version of SLAMBench moves beyond traditional visual SLAM, and provides new support for scene understanding and non-rigid environments (dynamic SLAM). More concretely for dynamic SLAM, SLAMBench 3.0 includes the first publicly available implementation of DynamicFusion, along with an evaluation infrastructure. In addition, we include two SLAM systems (one dense, one sparse) augmented with convolutional neural networks for scene understanding, together with datasets and appropriate metrics. Through a series of use-cases, we demonstrate the newly incorporated algorithms, visulation aids and metrics (6 new metrics, 4 new datasets and 5 new algorithms)

DC-SIGN and DC-SIGNR Bind Ebola Glycoproteins and Enhance Infection of Macrophages and Endothelial Cells

AbstractEbola virus exhibits a broad cellular tropism in vitro. In humans and animal models, virus is found in most tissues and organs during the latter stages of infection. In contrast, a more restricted cell and tissue tropism is exhibited early in infection where macrophages, liver, lymph node, and spleen are major initial targets. This indicates that cellular factors other than the broadly expressed virus receptor(s) modulate Ebola virus tropism. Here we demonstrate that the C-type lectins DC-SIGN and DC-SIGNR avidly bind Ebola glycoproteins and greatly enhance transduction of primary cells by Ebola virus pseudotypes and infection by replication-competent Ebola virus. DC-SIGN and DC-SIGNR are expressed in several early targets for Ebola virus infection, including dendritic cells, alveolar macrophages, and sinusoidal endothelial cells in the liver and lymph node. While DC-SIGN and DC-SIGNR do not directly mediate Ebola virus entry, their pattern of expression in vivo and their ability to efficiently capture virus and to enhance infection indicate that these attachment factors can play an important role in Ebola transmission, tissue tropism, and pathogenesis

Tendinopathy—from basic science to treatment

Chronic tendon pathology (tendinopathy), although common, is difficult to treat. Tendons possess a highly organized fibrillar matrix, consisting of type I collagen and various 'minor' collagens, proteoglycans and glycoproteins. The tendon matrix is maintained by the resident tenocytes, and there is evidence of a continuous process of matrix remodeling, although the rate of turnover varies at different sites. A change in remodeling activity is associated with the onset of tendinopathy. Major molecular changes include increased expression of type III collagen, fibronectin, tenascin C, aggrecan and biglycan. These changes are consistent with repair, but they might also be an adaptive response to changes in mechanical loading. Repeated minor strain is thought to be the major precipitating factor in tendinopathy, although further work is required to determine whether it is mechanical overstimulation or understimulation that leads to the change in tenocyte activity. Metalloproteinase enzymes have an important role in the tendon matrix, being responsible for the degradation of collagen and proteoglycan in both healthy patients and those with disease. Metalloproteinases that show increased expression in painful tendinopathy include ADAM (a disintegrin and metalloproteinase)-12 and MMP (matrix metalloproteinase)-23. The role of these enzymes in tendon pathology is unknown, and further work is required to identify novel and specific molecular targets for therapy

A Complete Expression Profile of Matrix-Degrading Metalloproteinases in Dupuytren’s Disease

Dupuytren’s disease (DD) is a common fibrotic condition of the palmar fascia, leading to deposition of collagen-rich cords and finger contractions. The metzincin superfamily contains key enzymes in the turnover of collagen and other extracellular matrix macromolecules. A number of broad-spectrum matrix metalloproteinase inhibitors, used in cancer clinical trials, caused side effects of DD-like contractures. We tested the hypothesis that changes in the expression of specific metalloproteinases underlie or contribute to the fibrosis and contracture seen in DD. We collected tissue from patients with DD and used normal palmar fascia as a control. We profiled the expression of the entire matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinases (TIMP), and a disintegrin and metalloproteinase domain with thrombospondin motif (ADAMTS) gene families in these tissues using real-time reverse-transcription polymerase chain reaction. A number of metalloproteinases and inhibitors are regulated in DD. The expression of 3 key collagenases, MMP1, MMP13, and MMP14 is increased significantly in the DD nodule, as is the expression of the collagen biosynthetic enzyme ADAMTS14. The expression of MMP7, an enzyme with broad substrate specificity, is increased in the DD nodule and remains equally expressed in the DD cord. TIMP1 expression is increased significantly in DD nodule compared with normal palmar fascia. This study measured the expression of all MMP, ADAMTS, and TIMP genes in DD. Contraction and fibrosis may result from: (1) increased collagen biosynthesis mediated by increased ADAMTS-14; (2) an increased level of TIMP-1 blocking MMP-1– and MMP-13–mediated collagenolysis; and (3) contraction enabled by MMP-14–mediated pericellular collagenolysis (and potentially MMP-7), which may escape inhibition by TIMP-1. The complete expression profile will provide a knowledge-based approach to novel therapeutics targeting these genes