128 research outputs found
Glucose-induced fibronectin and collagen type III expression in renal fibroblasts can occur independent of TGF-β1
Glucose-induced fibronectin and collagen type III expression in renal fibroblasts can occur independent of TGF-β1.BackgroundVarious renal cell types have been shown to contribute to the excessive matrix deposition observed in diabetic nephropathy. The present study examined the effect of high ambient glucose and transforming growth factor-β1 (TGF-β1) on matrix production by human renal fibroblasts.MethodsHuman renal fibroblasts (TK173) were used to examine the effects of high glucose and TGF-β1 on fibronectin and collagen type III expression. Stable transfectants were generated of TK173 cells expressing a dominant negative TGF-β type II receptor. Matrix components were measured in enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR).ResultsFibronectin secretion by renal fibroblasts was increased upon exposure to high glucose, but with delayed kinetics compared to TGF-β1-induced fibronectin. Exposure to high glucose resulted in an increased secretion of latent TGF-β1. However, treatment with neutralizing pan-specific anti-TGF-β antibodies could not attenuate the effects of glucose. Furthermore, collagen type III was up-regulated by high glucose, but not by TGF-β1. Importantly, fibroblasts expressing a dominant negative TGF-β type II receptor were defective in TGF-β1-induced fibronectin production, whereas glucose-induced fibronectin and collagen type III were unaffected.ConclusionsThese data show that in renal fibroblasts exposure to high glucose can increase matrix production independent of endogenous TGF-β1. Although glucose activation is accompanied by an increased production of latent TGF-β1, which can have an important role in vivo, the data suggest involvement of alternative growth factors in the mechanism by which hyperglycemic conditions can modulate matrix accumulation in diabetic nephropathy
Influence of obesity on the development of osteoarthritis of the hip: a systematic review
OBJECTIVE: To evaluate the evidence for the influence of obesity as a risk
factor for the occurrence of osteoarthritis (OA) of the hip. METHODS: A
bibliographical search of Medline, EMBASE and the Cochrane library until
April 2000 was carried out. Articles describing studies of the
relationship between obesity and the occurrence of hip OA were selected.
The quality of the studies was assessed with a standardized set of
criteria. The outcome of the studies was compared with respect to study
characteristics and the quality score for the study. A best-evidence
synthesis was used to summarize the results of the individual studies.
RESULTS: Five longitudinal and seven cross-sectional studies were included
in this review. There was no association between outcome and study design
or methodological quality. The associations between obesity and hip OA
were, however, stronger in studies in which the diagnosis of hip OA was
based not only on radiological criteria but also on clinical symptoms.
Overall, moderate evidence was found for a positive association between
obesity and the occurrence of hip OA, with an odds ratio of approximately
2. CONCLUSION: The evidence for a positive influence of obesity on the
development of hip OA is moderate
Clinical prognostic factors for patients with anterior knee pain in physical therapy
Background: Although many authors have studied the prognostic factors that may contribute to anterior knee pain, synthesis of the existing evidence has not been performed.
Purpose: The purpose of this systematic review is to summarize and examine existing prognostic models in patients with anterior knee pain that first present to physical therapists (primary care setting).
Design: Systematic review
Method: For this review Pubmed, Embase and Cinahl databases were searched and published papers that reported prognostic models for patients with anterior knee pain that first present to physical therapists (primary care setting) were selected. The authors extracted and summarized the univariate and multivariate predictors and evaluated which predictors consistently appeared to be relevant to pain, function, or recovery.
Results: Nine studies were included. The quality scores of these s
Model-based cap thickness and peak cap stress prediction for carotid MRI
A rupture-prone carotid plaque can potentially be identified by calculating the peak cap stress (PCS). For these calculations, plaque geometry from MRI is often used. Unfortunately, MRI is hampered by a low resolution, leading to an overestimation of cap thickness and an underestimation of PCS. We developed a model to reconstruct the cap based on plaque geometry to better predict cap thickness and PCS. We used histological stained plaques from 34 patients. These plaques were segmented and served as the ground truth. Sections of these plaques contained 93 necrotic cores with a cap thickness <0.62 mm which were used to generate a geometry-based model. The histological data was used to simulate in vivo MRI images, which were manually delineated by three experienced MRI readers. Caps below the MRI resolution (n = 31) were (digitally removed and) reconstructed according to the geometry-based model. Cap thickness and PCS were determined for the ground truth, readers, and reconstructed geometries. Cap thickness was 0.07 mm for the ground truth, 0.23 mm for the readers, and 0.12 mm for the reconstructed geometries. The model predicts cap thickness significantly better than the readers. PCS was 464 kPa for the ground truth, 262 kPa for the readers and 384 kPa for the reconstructed geometries. The model did not predict the PCS significantly better than the readers. The geometry-based model provided a significant improvement for cap thickness estimation and can potentially help in rupture-risk prediction, solely based on cap thickness. Estimation of PCS estimation did not improve, probably due to the complex shape of the plaques
Evaluation of measurement properties of self-administered PROMs aimed at patients with non-specific shoulder pain and “activity limitations”: a systematic review
Objective: To critically appraise and compare the measurement properties of self-administered patient-reported outcome measures (PROMs) focussing on the shoulder, assessing “activity limitations.” Study design: Systematic review. The study population had to consist of patients with shoulder pain. We excluded postoperative patients or patients with generic diseases. The methodological quality of the selected studies and the results of the measurement properties were critically appraised and rated using the COSMIN checklist. Results: Out of a total of 3427 unique hits, 31 articles, evaluating 7 different questionnaires, were included. The SPADI is the most frequently evaluated PROM and its measurement properties seem adequate apart from a lack of information regarding its measurement error and c
Effect of Palivizumab Prophylaxis on Respiratory Syncytial Virus Infection in Very Preterm Infants in the First Year of Life in The Netherlands
Respiratory Syncytial Virus (RSV) poses a severe threat to infants, particularly preterm infants. Palivizumab, the standard preventive prophylaxis, is primarily utilized in high-risk newborns due to its cost. This study assessed palivizumab’s effectiveness in preventing RSV infections in predominantly very preterm infants during their first year of life. Serum samples from a prospective multicentre cohort study in the Netherlands were analyzed to assess RSV infection rates by measuring IgG levels against three RSV proteins: nucleoprotein, pre-fusion, and post-fusion protein. Infants were stratified based on gestational age (GA), distinguishing very preterm (≤32 weeks GA) from moderate/late preterm (>32 to ≤36 weeks GA). In very preterm infants, palivizumab prophylaxis significantly reduced infection rates (18.9% vs. 48.3% in the prophylaxis vs. non-prophylaxis group. Accounting for GA, sex, birth season, and birth weight, the prophylaxis group showed significantly lower infection odds. In infants with >32 to ≤36 weeks GA, the non-prophylaxis group (55.4%) showed infection rates similar to the non-prophylaxis ≤32-week GA group, despite higher maternal antibody levels in the moderate/late preterm infants. In conclusion, palivizumab prophylaxis significantly reduces RSV infection rates in very premature infants. Future research should explore clinical implications and reasons for non-compliance, and compare palivizumab with emerging prophylactics like nirsevimab aiming to optimize RSV prophylaxis and improve preterm infant outcomes
Empathy in multiple sclerosis-correlates with cognitive, psychological and occupational functioning
Background Recent studies report deficits in social cognition in individuals with multiple sclerosis (MS). Social cognitive skills such as empathy are important for adequate social and occupational functioning. Our objectives are: (1) to examine whether empathy differs between individuals with MS and healthy controls, (2) to examine relations between empathy and cognitive, psychological and occupational functioning. Methods 278 individuals with MS (relapsing-remitting subtype) and 128 healthy controls from the MS@Work study participated in this investigation. The participants completed questionnaires about demographics, cognitive, psychological and occupational functioning, and underwent neurological and neuropsychological examinations. Mann-Whitney U-tests were used to examine group differences in empathy. Pearson and Spearman rank correlation analyses were used to examine relations between empathy and the other measures. Results Empathy did not differ between individuals with MS and healthy controls. In individuals with MS, higher empathy was correlated with a higher educational level (X2(df) = 13.2(2), p = 0.001), better verbal learning (r = 0.20, p = 0.001), less symptoms of depression (r=−0.21, p = 0.001), higher extraversion (r = 0.25, p ≤ 0.001), agreeableness (r = 0.55, p ≤ 0.001) and conscientiousness (r = 0.27, p ≤ 0.001) and better occupational functioning in terms of work scheduling and output demands (r = 0.23, p = 0.002) and less cognitive/psychological work barriers (r = −0.21, p = 0.001). In healthy controls, higher empathy was correlated with less symptoms of depression (r = −0.34, p ≤ 0.001), less fatigue (r = −0.37, p ≤ 0.001), higher agreeableness (r = 0.59, p ≤ 0.001) and better occupational functioning in terms of work ability as compared to lifetime best (r = 0.28, p = 0.001) and less cognitive/psychological work barriers (r = −0.34, p ≤ 0.001). Empathy did not differ between unemployed and employed individuals with MS or healthy controls. Conclusion Empathy did not differ between individuals with MS and healthy controls. Within both investigated groups, higher empathy was weakly to moderately correlated with less symptoms of depression, higher agreeableness and better occupational functioning. We also found unique correlations for empathy within the investigated groups. Longitudinal studies are needed to further examine social cognition in relation to cognitive, psychological and occupational functioning in both individuals with MS and healthy controls. It would be particularly interesting to concurrently examine changes in the brain network involved with social cognition
Migratory birds reinforce local circulation of avian influenza viruses
Migratory and resident hosts have been hypothesized to fulfil distinct roles in infectious disease dynamics. However, the contribution of resident and migratory hosts to wildlife infectious disease epidemiology, including that of low pathogenic avian influenza virus (LPAIV) in wild birds, has largely remained unstudied. During an autumn H3 LPAIV epizootic in free-living mallards (Anas platyrhynchos) - a partially migratory species - we identified resident and migratory host populations using stable hydrogen isotope analysis of flight feathers. We investigated the role of migratory and resident hosts separately in the introduction and maintenance of H3 LPAIV during the epizootic. To test this we analysed (i) H3 virus kinship, (ii) temporal patterns in H3 virus prevalence and shedding and (iii) H3-specific antibody prevalence in relation to host migratory strategy. We demonstrate that the H3 LPAIV strain causing the epizootic most likely originated from a single introduction, followed by local clonal expansion. The H3 LPAIV strain was genetically unrelated to H3 LPAIV detected both before and after the epizootic at the study site. During the LPAIV epizootic, migratory mallards were more often infected with H3 LPAIV than residents. Low titres of H3-specific antibodies were detected in only a few residents and migrants. Our results suggest that in this LPAIV epizootic, a single H3 virus was present in resident mallards prior to arrival of migratory mallards followed by a period of virus amplification, importantly associated with the influx of migratory mallards. Thus migrants are suggested to act as local amplifiers rather than the often suggested role as vectors importing novel strains from afar. Our study exemplifies that a multifaceted interdisciplinary approach offers promising opportunities to elucidate the role of migratory and resident hosts in infectious disease dynamics in wildlife
Age-specific SARS-CoV-2 transmission differed from human rhinovirus in households during the early COVID-19 pandemic
Objectives: Children are generally considered main drivers of transmission for respiratory viruses, but the emergence of SARS-CoV-2 challenged this paradigm. Human rhinovirus (RV) continued to co-circulate throughout the pandemic, allowing for direct comparison of age-specific infectivity and susceptibility within households between these viruses during a time of low SARS-CoV-2 population immunity. Methods: Households with children were prospectively monitored for ≥23 weeks between August 2020 and July 2021. Upon onset of respiratory symptoms in a household, an outbreak study was initiated, including questionnaires and repeated nasal self-sampling in all household members. Swabs were tested by PCR. Age-stratified within-household secondary attack rates (SARs) were compared between SARS-CoV-2 and RV. Results: A total of 307 households participated, including 582 children and 627 adults. Overall, SAR was lower for SARS-CoV-2 than for RV (aOR 0.55) and age distributions differed between both viruses (p < 0.001). Following household exposure, children were significantly less likely to become infected with SARS-CoV-2 compared to RV (aOR 0.16), whereas this was opposite in adults (aOR 1.71). Conclusion: In households, age-specific susceptibility to SARS-CoV-2 and RV differs and drives differences in household transmission between these pathogens. This highlights the importance of characterizing age-specific transmission risks, particularly for emerging infections, to guide appropriate infection control interventions.</p
Defective Connective Tissue Remodeling in Smad3 Mice Leads to Accelerated Aneurysmal Growth Through Disturbed Downstream TGF-β Signaling
Aneurysm-osteoarthritis syndrome characterized by unpredictable aortic aneurysm formation, is caused by SMAD3 mutations. SMAD3 is part of the SMAD2/3/4 transcription factor, essential for TGF-β-activated transcription. Although TGF-β-related gene mutations result in aneurysms, the underlying mechanism is unknown. Here, we examined aneurysm formation and progression in Smad3−/− animals. Smad3−/− animals developed aortic aneurysms rapidly, resulting in premature death. Aortic wall immunohistochemistry showed no increase in extracellular matrix and collagen accumulation, nor loss of vascular smooth muscle cells (VSMCs) but instead revealed medial elastin disruption and adventitial inflammation. Remarkably, matrix metalloproteases (MMPs) were not activated in VSMCs, but rather specifically in inflammatory areas. Although Smad3−/− aortas showed increased nuclear pSmad2 and pErk, indicating TGF-β receptor activation, downstream TGF-β-activated target genes were not upregulated. Increased pSmad2 and pErk staining in pre-aneurysmal Smad3−/− aortas implied that aortic damage and TGF-β receptor-activated signaling precede aortic inflammation. Finally, impaired downstream TGF-β activated transcription resulted in increased Smad3−/− VSMC proliferation. Smad3 deficiency leads to imbalanced activation of downstream genes, no activation of MMPs in VSMCs, and immune responses resulting in rapid aortic wall dilatation and rupture. Our findings uncover new possibil
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