28 research outputs found

    Correction to: Muscle B mode ultrasound and shear-wave elastography in idiopathic inflammatory myopathies (SWIM): criterion validation against MRI and muscle biopsy findings in an incident patient cohort

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    Correction to: BMC Rheumatology (2022) 6:47. https://doi.org/10.1186/s41927-022-00276-

    Muscle B mode ultrasound and shear-wave elastography in idiopathic inflammatory myopathies (SWIM): criterion validation against MRI and muscle biopsy findings in an incident patient cohort

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    Background B mode ultrasound (US) and shear wave elastography (SWE) are easily accessible imaging tools for idiopathic inflammatory myopathies (IIM) but require further validation against standard diagnostic procedures such as MRI and muscle biopsy. Methods In this prospective cross-sectional study we compared US findings to MRI and muscle biopsy findings in a group of 18 patients (11 F, 7 M) with active IIM (dermatomyositis 6, necrotising autoimmune myopathy 7, inclusion body myositis 4, overlap myositis 1) who had one or both procedures on the same muscle. US domains (echogenicity, fascial thickness, muscle bulk, shear wave speed and power doppler) in the deltoid and vastus lateralis were compared to MRI domains (muscle oedema, fatty infiltration/atrophy) and muscle biopsy findings (lymphocytic inflammation, myonecrosis, atrophy and fibro-fatty infiltration). A composite index score (1–4) was also used as an arbitrary indicator of overall muscle pathology in biopsies. Results Increased echogenicity correlated with the presence of fatty infiltration/atrophy on MRI (p = 0.047) in the vastus lateralis, and showed a non-significant association with muscle inflammation, myonecrosis, fibrosis and fatty infiltration/atrophy (p > 0.333) Severe echogenicity also had a non-significant association with higher composite biopsy index score in the vastus lateralis (p = 0.380). SWS and US measures of fascial thickness and muscle bulk showed poor discrimination in differentiating between pathologies on MRI or muscle biopsy. Power Doppler measures of vascularity correlated poorly with the presence of oedema on MRI, or with inflammation or fatty infiltration on biopsy. Overall, US was sensitive in detecting the presence of muscle pathology shown on MRI (67–100%) but showed poorer specificity (13–100%). Increased echogenicity showed good sensitivity when detecting muscle pathology (100%) but lacked specificity in differentiating muscle pathologies (0%). Most study participants rated US as the preferred imaging modality. Conclusions Our findings show that US, in particular muscle echogenicity, has a high sensitivity, but low specificity, for detecting muscle pathology in IIM. Traditional visual grading scores are not IIM-specific and require further modification and validation. Future studies should continue to focus on developing a feasible scoring system, which is reliable and allows translation to clinical practice

    Intestinal PPARγ signalling is required for sympathetic nervous system activation in response to caloric restriction.

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    Nuclear receptor PPARγ has been proven to affect metabolism in multiple tissues, and has received considerable attention for its involvement in colon cancer and inflammatory disease. However, its role in intestinal metabolism has been largely ignored. To investigate this potential aspect of PPARγ function, we submitted intestinal epithelium-specific PPARγ knockout mice (iePPARγKO) to a two-week period of 25% caloric restriction (CR), following which iePPARγKO mice retained more fat than their wild type littermates. In attempting to explain this discrepancy, we analysed the liver, skeletal muscle, intestinal lipid trafficking, and the microbiome, none of which appeared to contribute to the adiposity phenotype. Interestingly, under conditions of CR, iePPARγKO mice failed to activate their sympathetic nervous system (SNS) and increase CR-specific locomotor activity. These KO mice also manifested a defective control of their body temperature, which was overly reduced. Furthermore, the white adipose tissue of iePPARγKO CR mice showed lower levels of both hormone-sensitive lipase, and its phosphorylated form. This would result from impaired SNS signalling and possibly cause reduced lipolysis. We conclude that intestinal epithelium PPARγ plays an essential role in increasing SNS activity under CR conditions, thereby contributing to energy mobilization during metabolically stressful episodes

    The Core and Accessory Genomes of Burkholderia pseudomallei: Implications for Human Melioidosis

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    Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, can exhibit significant ecological flexibility that is likely reflective of a dynamic genome. Using whole-genome Bp microarrays, we examined patterns of gene presence and absence across 94 South East Asian strains isolated from a variety of clinical, environmental, or animal sources. 86% of the Bp K96243 reference genome was common to all the strains representing the Bp “core genome”, comprising genes largely involved in essential functions (eg amino acid metabolism, protein translation). In contrast, 14% of the K96243 genome was variably present across the isolates. This Bp accessory genome encompassed multiple genomic islands (GIs), paralogous genes, and insertions/deletions, including three distinct lipopolysaccharide (LPS)-related gene clusters. Strikingly, strains recovered from cases of human melioidosis clustered on a tree based on accessory gene content, and were significantly more likely to harbor certain GIs compared to animal and environmental isolates. Consistent with the inference that the GIs may contribute to pathogenesis, experimental mutation of BPSS2053, a GI gene, reduced microbial adherence to human epithelial cells. Our results suggest that the Bp accessory genome is likely to play an important role in microbial adaptation and virulence

    An Update on Imaging in Rheumatoid Arthritis

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    Purpose of Review: Modern imaging modalities allow accurate detection of both inflammation and damage in rheumatoid arthritis (RA) joints. This narrative review aims to summarize the recent literature relating to magnetic resonance imaging (MRI), musculoskeletal ultrasound (MSUS) and high-resolution peripheral quantitative computerized tomography (HR-pQCT). Recent Findings: Imaging has aided understanding of the pathogenesis of RA: HR-pQCT studies suggest that cortical micro-channels may facilitate erosive changes in the setting of synovitis. Both MRI and MSUS studies have aimed to quantify the degree of changes seen in asymptomatic people where age-related changes are common, highlighting the importance of understanding the thresholds of ‘normality’. Whilst synovitis has been considered the characteristic feature of RA, there is growing evidence that imaging-detected tenosynovitis may be of importance in predicting the development of RA, diagnosing RA and predicting flare in stable RA. Much focus has been placed on recent MRI and MSUS studies demonstrating that systematic repeated imaging of RA treated with tight control strategies does not improve outcomes at the group level; however these studies did not explore pre-test probability issues at the individual patient level. The literature is somewhat mixed on whether MRI and MSUS may provide useful guidance on which patients in remission can safely have therapy de-escalated. Recent work has also continued to validate and refine pathology definitions and semi-quantitative scoring for these tools as outcome measures in clinical trials. Summary: A review of recently published literature allowed the identification of several themes: understanding pathogenesis, attempts to define ‘normal’ joints on imaging, the utility of imaging in the diagnosis of RA, predicting the development of RA in at risk populations and the relevance to Ra clinical practice and trials

    Imaging in the diagnosis of idiopathic inflammatory myopathies; indications and utility

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    Introduction: Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of muscle diseases that carry a significant morbidity and mortality risk. The utilization of imaging in the diagnostic pathway of IIM is therefore important to obtain early diagnosis and even monitor patients over time. Areas covered: Magnetic resonance imaging (MRI) has been the main imaging modality used to detect myositis but limitations include cost and accessibility, leading to delays in time to scan, and patient contraindications. This has led to the exploration of other imaging techniques to diagnose and monitor response to therapy. This article is based primarily on a literature search via PubMed using Boolean terms ‘myositis’ and the various imaging modalities. Expert opinion: Imaging is sensitive to pathology in IIM and may contribute to the diagnostic process. Learning how specific imaging features can distinguish different forms of IIM may allow more rapid diagnosis of myositis subtype and treatment planning, and to monitor disease activity particularly in patients who respond poorly to treatment. However, more work is needed to investigate the validity and relative utility of these imaging modalities

    In vivo pro- and anti-inflammatory cytokines in normal and patients with rheumatoid arthritis

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    Annals of the Academy of Medicine Singapore36296-9
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