906 research outputs found
Harmonic Superspaces in Low Dimensions
Harmonic superspaces for spacetimes of dimension are constructed.
Some applications are given.Comment: 16, kcl-th-94-15. Two further references have been added (12 and 13)
and a few typographical errors have been correcte
Bisphosphonates alter trabecular bone collagen cross-linking and isomerization in beagle dog vertebra
Changes in organic matrix may contribute to the anti-fracture efficacy of anti-remodeling agents. Following one year of treatment in beagle dogs, bisphosphonates alter the organic matrix of vertebral trabecular bone, while raloxifene had no effect. These results show that pharmacological suppression of turnover alters the organic matrix component of bone.
INTRODUCTION:
The collagen matrix contributes significantly to a bone's fracture resistance yet the effects of anti-remodeling agents on collagen properties are unclear. The goal of this study was to assess changes in collagen cross-linking and isomerization following anti-remodeling treatment.
METHODS:
Skeletally mature female beagles were treated for one year with oral doses of vehicle (VEH), risedronate (RIS; 3 doses), alendronate (ALN; 3 doses), or raloxifene (RAL; 2 doses). The middle dose of RIS and ALN and the lower dose of RAL approximate doses used for treatment of post menopausal osteoporosis. Vertebral trabecular bone matrix was assessed for collagen isomerization (ratio of alpha/beta C-telopeptide [CTX]), enzymatic (pyridinoline [PYD] and deoxypyridinoline [DPD]), and non-enzymatic (pentosidine [PEN]) cross-links.
RESULTS:
All doses of both RIS and ALN increased PEN (+34-58%) and the ratio of PYD/DPD (+14-26%), and decreased the ratio of alpha/beta CTX (-29-56%) compared to VEH. RAL did not alter any collagen parameters. Bone turnover rate was significantly correlated to PEN (R = -0.664), alpha/beta CTX (R = 0.586), and PYD/DPD (R = -0.470).
CONCLUSIONS:
Bisphosphonate treatment significantly alters properties of bone collagen suggesting a contribution of the organic matrix to the anti-fracture efficacy of this drug class.The authors thank Dr. Keith Condon, Diana Jacob, Mary Hooser, and Lauren Waugh for histological preparation. This work was supported by NIH Grants AR047838 and AR007581 and research grants from The Alliance for Better Bone Health (Procter & Gamble Pharmaceuticals and sanofi-aventis), and Lilly Research Laboratories, as well as an unrestricted grant from Eli Lilly to INSERM. Merck and Co. kindly provided the alendronate. This investigation utilized an animal facility constructed with support from Research Facilities Improvement Program Grant Number C06 RR10601-01 from the National Center for Research Resources, National Institutes of Health
The community paediatric respiratory infection surveillance study protocol:a feasibility, prospective inception cohort study
INTRODUCTION: Paediatric respiratory tract infections (RTIs) are common reasons for primary care consultations and antibiotic prescribing. Locally relevant syndromic and microbiological surveillance information has the potential to improve the care of children with RTIs by normalising illness (parents) and reducing uncertainty (clinicians). Currently, most RTI studies are conducted at the point of healthcare service consultation, leaving the community burden, microbiology, symptom duration and proportion consulting largely unknown. This study seeks to establish the feasibility of (mainly online) participant recruitment and retention, and the acceptability/comparability of parent versus nurse-collected microbiological sampling, to inform the design of a future surveillance intervention study. Evidence regarding consultation rates and symptom duration is also sought. METHODS AND ANALYSIS: A community-based, feasibility prospective inception cohort study, recruiting children aged ≥3 months and <16 years and their parents via general practitioner surgery invitation letter, aiming to collect data on 300 incident RTIs by July 2016. Following informed consent, parents provide baseline (demographic) data online, and respond to weekly emails to confirm the absence/presence of new RTI symptoms. Once symptomatic, parents provide daily data online (RTI symptoms, school/day-care attendance, time off work, health service use, medication), and a research nurse visits to collect clinical examination data and microbiological (nasal and saliva) swabs. Parents are invited to provide symptomatic (at nurse visit, but without nurse assistance) and asymptomatic (alone) swabs on recovery. A review of primary care medical notes will gather medical history, health service utilisation, referral and antibiotic prescribing rates. Feasibility will be assessed using recruitment and retention rates, data completeness; and acceptability by quantitative survey and qualitative interviews. Symptomatic parent and nurse swab pairs will be compared for microbe isolation
Excessive collagen turnover products are released during colorectal cancer progression and elevated in serum from metastatic colorectal cancer patients
During cancer progression, the homeostasis of the extracellular matrix becomes imbalanced with an excessive collagen remodeling by matrix metalloproteinases. As a consequence, small protein fragments of degraded collagens are released into the circulation. We have investigated the potential of protein fragments of collagen type I, III and IV as novel biomarkers for colorectal cancer. Specific fragments of degraded type I, III and IV collagen (C1M, C3M, C4M) and type III collagen formation (Pro-C3) were assessed in serum from colorectal cancer patients, subjects with adenomas and matched healthy controls using well-characterized and validated ELISAs. Serum levels of the biomarkers were significantly elevated in colorectal cancer patients compared to subjects with adenomas (C1M, Pro-C3, C3M) and controls (C1M, Pro-C3). When patients were stratified according to their tumour stage, all four biomarkers were able to differentiate stage IV metastatic patients from all other stages. Combination of all markers with age and gender in a logistic regression model discriminated between metastatic and non-metastatic patients with an AUROC of 0.80. The data suggest that the levels of these collagen remodeling biomarkers may be a measure of tumour activity and invasiveness and may provide new clinical tools for monitoring of patients with advanced stage colorectal cancer
Cathepsin-S degraded decorin are elevated in fibrotic lung disorders - development and biological validation of a new serum biomarker
Reconstructing ‘the Alcoholic’: Recovering from Alcohol Addiction and the Stigma this Entails
Public perception of alcohol addiction is frequently negative, whilst an important part of recovery is the construction of a positive sense of self. In order to explore how this might be achieved, we investigated how those who self-identify as in recovery from alcohol problems view themselves and their difficulties with alcohol and how they make sense of others’ responses to their addiction. Semi-structured interviews with six individuals who had been in recovery between 5 and 35 years and in contact with Alcoholics Anonymous were analysed using Interpretative Phenomenological Analysis. The participants were acutely aware of stigmatising images of ‘alcoholics’ and described having struggled with a considerable dilemma in accepting this identity themselves. However, to some extent they were able to resist stigma by conceiving of an ‘aware alcoholic self’ which was divorced from their previously unaware self and formed the basis for a new more knowing and valued identity
Hot and cold fibrosis: The role of serum biomarkers to assess immune mechanisms and ECM-cell interactions in human fibrosis
\ua9 2025 The Author(s)Fibrosis is a pathological condition characterised by excessive accumulation of extracellular matrix (ECM) components, particularly collagens, leading to tissue scarring and organ dysfunction. In fibrosis, an imbalance between collagen synthesis (fibrogenesis) and degradation (fibrolysis) results in the deposition of fibrillar collagens disrupting the structural integrity of the ECM and, consequently, tissue architecture. Fibrosis is associated with a wide range of chronic diseases, including cirrhosis, kidney fibrosis, pulmonary fibrosis, and autoimmune diseases. Recently, the concept of “hot” and “cold” fibrosis has emerged, referring to the immune status within fibrotic tissues and the nature of fibrogenic signalling. Hot fibrosis is characterised by active immune cell infiltration and inflammation, while cold fibrosis is associated with auto- and paracrine myofibroblast activation, immune cell exclusion and quiescence. In this article, we explore the relationship between hot and cold fibrosis, the role of various types of collagens and their biologically active fragments in modulating the immune system, and how serological ECM biomarkers can help improve our understanding of the disease-relevant interactions between immune and mesenchymal cells in fibrotic tissues. Additionally, we draw lessons from immuno-oncology research in solid tumours to shed light on potential strategies for fibrosis treatment and highlight the advantage of having a “hot fibrotic environment” to treat fibrosis by enhancing collagen degradation through modulation of the immune system
Making use of expertise: A qualitative analysis of the experience of breastfeeding support for first-time mothers
There is now a body of research evaluating breastfeeding interventions and exploring mothers’ and health professionals’ views on effective and ineffective breastfeeding support. However, this literature leaves relatively unexplored a number of questions about how breastfeeding women experience and make sense of their relationships with those trained to provide breastfeeding support. The present study collected qualitative data from 22 breastfeeding first-time mothers in the UK on their experiences of, and orientation towards, relationships with maternity care professionals and other breastfeeding advisors. The data were obtained from interviews and audio-diaries at two time points during the first five weeks post-partum. We discuss a key theme within the data of ‘Making use of expertise’ and three subthemes which capture the way in which the women’s orientation towards those assumed to have breastfeeding expertise varied according to whether the women (i) adopted a position of consulting experts versus one of deferring to feeding authorities (ii) experienced difficulty interpreting their own and their baby’s bodies and (iii) experienced the expertise of health workers as empowering or disempowering. Although sometimes mothers felt empowered by aligning themselves with the scientific approach and ‘normalising gaze’ of healthcare professionals, at other times this gaze could be experienced as objectifying and diminishing. The merits and limitations of a person-centred approach to breastfeeding support are discussed in relation to using breastfeeding expertise in an empowering rather than disempowering way
Socially sensitive lactation: Exploring the social context of breastfeeding
Many women report difficulties with breastfeeding and do not maintain the practice for as long as intended. Although psychologists and other researchers have explored some of the difficulties they experience, fuller exploration of the relational contexts in which breastfeeding takes place is warranted to enable more in-depth analysis of the challenges these pose for breastfeeding women. This article is based on qualitative data collected from 22 first-time breastfeeding mothers through two phases of interviews and audio-diaries which explored how the participants experienced their relationships with significant others and the wider social context of breastfeeding in the first five weeks postpartum. Using a thematic analysis informed by symbolic interactionism, we develop the overarching theme of 'Practising socially sensitive lactation' which captures how participants felt the need to manage tensions between breastfeeding and their perceptions of the needs, expectations and comfort of others. We argue that breastfeeding remains a problematic social act, despite its agreed importance for child health. While acknowledging the limitations of our sample and analytic approach, we suggest ways in which perinatal and public health interventions can take more effective account of the social challenges of breastfeeding in order to facilitate the health and psychological well-being of mothers and their infants
Bone turnover markers for early detection of fracture healing disturbances: A review of the scientific literature
Imaging techniques are the standard method for assessment of fracture healing processes. However, these methods are perhaps not entirely reliable for early detection of complications, the most frequent of these being delayed union and non-union. A prompt diagnosis of such disorders could prevent prolonged patient distress and disability. Efforts should be directed towards the development of new technologies for improving accuracy in diagnosing complications following bone fractures. The variation in the levels of bone turnover markers (BTMs) have been assessed with regard to there ability to predict impaired fracture healing at an early stage, nevertheless the conclusions of some studies are not consensual. In this article the authors have revised the potential of BTMs as early predictors of prognosis in adult patients presenting traumatic bone fractures but who did not suffer from osteopenia or postmenopausal osteoporosis. The available information from the different studies performed in this field was systematized in order to highlight the most promising BTMs for the assessment of fracture healing outcome.As técnicas imagiológicas são o método convencional para a avaliação dos processos de cicatrização das fraturas. No entanto, estes métodos não são talvez totalmente confiáveis para a deteção precoce de complicações, as mais frequentes destas sendo o atraso da união e a não-união. Um diagnóstico eficaz destas desordens poderia prevenir a dor e a incapacidade prolongada do paciente. Esforços devem ser dirigidos no sentido do desenvolvimento de novas tecnologias para melhorar a exatidão no diagnóstico de complicações após fraturas ósseas. A variação nos níveis dos marcadores do turnover ósseo (BTMs) têm sido avaliados com vista à sua capacidade para prever o comprometimento da cicatrização das fraturas numa fase inicial, no entanto, as conclusões de alguns estudos não são consensuais. Neste artigo os autores fizeram uma revisão do potencial dos BTMs como fatores de previsibilidade precoce do prognóstico em doentes adultos que apresentavam fraturas ósseas traumáticas mas que não sofriam de osteopenia ou osteoporose pós-menopausa. A informação disponível nos diferentes estudos realizados neste campo foi sistematizada com vista a evidenciar-se os BTMs mais promissores para a avaliação da evolução da cicatrização das fraturas.SFRH/BD/45018/200
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