1,725 research outputs found
The prevalence of tenosynovitis of the interosseous tendons of the hand in patients with rheumatoid arthritis.
AIM: The aim of this study was to establish the prevalence of tenosynovitis affecting the interosseous tendons of the hand in a rheumatoid arthritis (RA) population and to assess for association with metacarpophalangeal (MCP) joint synovitis, flexor tendon tenosynovitis or ulnar drift. METHODS: Forty-four patients with RA underwent hand MRI along with 20 normal controls. Coronal 3D T1 VIBE sequences pre- and post-contrast were performed and reconstructed. The presence of interosseous tendon tenosynovitis was recorded alongside MCP joint synovitis, flexor tendon tenosynovitis and ulnar drift. RESULTS: Twenty-one (47.7 %) patients with RA showed interosseous tendon tenosynovitis. Fifty-two (14.8 %) interosseous tendons showed tenosynovitis amongst the RA patients. Interosseous tendon tenosynovitis was more commonly seen in association with adjacent MCP joint synovitis (p < 0.001), but nine MCP joints (5.1 %) showed adjacent interosseous tenosynovitis in the absence of joint synovitis. Interosseous tendon tenosynovitis was more frequently seen in fingers which also showed flexor tendon tenosynovitis (p < 0.001) and in patients with ulnar drift of the fingers (p = 0.01). CONCLUSION: Tenosynovitis of the hand interosseous tendons was found in 47.7 % of patients with RA. In the majority of cases this was adjacent to MCP joint synovitis; however, interosseous tendon tenosynovitis was also seen in isolation. KEY POINTS: • Tenosynovitis of the interosseous tendons of the hand occurs in rheumatoid arthritis. • Interosseous tendon tenosynovitis has a prevalence of 47.7 % in patients with RA. • Interosseous tendon tenosynovitis is related to MCP joint synovitis in the adjacent joints
Evolution of tetraspanin antigens in the zoonotic Asian blood fluke Schistosoma japonicum
BACKGROUND: Despite successful control efforts in China over the past 60 years, zoonotic schistosomiasis caused by Schistosoma japonicum remains a threat with transmission ongoing and the risk of localised resurgences prompting calls for a novel integrated control strategy, with an anti-schistosome vaccine as a core element. Anti-schistosome vaccine development and immunisation attempts in non-human mammalian host species, intended to interrupt transmission, and utilising various antigen targets, have yielded mixed success, with some studies highlighting variation in schistosome antigen coding genes (ACGs) as possible confounders of vaccine efficacy. Thus, robust selection of target ACGs, including assessment of their genetic diversity and antigenic variability, is paramount. Tetraspanins (TSPs), a family of tegument-surface antigens in schistosomes, interact directly with the host's immune system and are promising vaccine candidates. Here, for the first time to our knowledge, diversity in S. japonicum TSPs (SjTSPs) and the impact of diversifying selection and sequence variation on immunogenicity in these protiens were evaluated. METHODS: SjTSP sequences, representing parasite populations from seven provinces across China, were gathered by baiting published short-read NGS data and were analysed using in silico methods to measure sequence variation and selection pressures and predict the impact of selection on variation in antigen protein structure, function and antigenic propensity. RESULTS: Here, 27 SjTSPs were identified across three subfamilies, highlighting the diversity of TSPs in S. japonicum. Considerable variation was demonstrated for several SjTSPs between geographical regions/provinces, revealing that episodic, diversifying positive selection pressures promote amino acid variation/variability in the large extracellular loop (LEL) domain of certain SjTSPs. Accumulating polymorphisms in the LEL domain of SjTSP-2, -8 and -23 led to altered structural, functional and antibody binding characteristics, which are predicted to impact antibody recognition and possibly blunt the host's ability to respond to infection. Such changes, therefore, appear to represent a mechanism utilised by S. japonicum to evade the host's immune system. CONCLUSION: Whilst the genetic and antigenic geographic variability observed amongst certain SjTSPs could present challenges to vaccine development, here we demonstrate conservation amongst SjTSP-1, -13 and -14, revealing their likely improved utility as efficacious vaccine candidates. Importantly, our data highlight that robust evaluation of vaccine target variability in natural parasite populations should be a prerequisite for anti-schistosome vaccine development
Normal values and test–retest variability of stimulated-echo diffusion tensor imaging and fat fraction measurements in the muscle
OBJECTIVES:
To assess the test–retest variability of both diffusion parameters and fat fraction (FF) estimates in normal muscle, and to assess differences in normal values between muscles in the thigh.
METHODS:
29 healthy volunteers (mean age 37 years, range 20–60 years, 17/29 males) completed the study. Magnetic resonance images of the mid-thigh were acquired using a stimulated echo acquisition mode-echoplanar imaging (STEAM-EPI) imaging sequence, to assess diffusion, and 2-point Dixon imaging, to assess FF. Imaging was repeated in 19 participants after a 30 min interval in order to assess test–retest variability of the measurements.
RESULTS:
Intraclass correlation coefficients (ICCs) for test–retest variability were 0.99 [95% confidence interval, (CI): 0.98, 1] for FF, 0.94 (95% CI: 0.84, 0.97) for mean diffusivity and 0.89 (95% CI: 0.74, 0.96) for fractional anisotropy (FA). FF was higher in the hamstrings than the quadriceps by a mean difference of 1.81% (95% CI:1.63, 2.00)%, p < 0.001. Mean diffusivity was significantly lower in the hamstrings than the quadriceps (0.26 (0.13, 0.39) x10- 3 mm2s−1, p < 0.001) whereas fractional anisotropy was significantly higher in the hamstrings relative to the quadriceps with a mean difference of 0.063 (0.05, 0.07), p < 0.001.
CONCLUSIONS:
This study has shown excellent test-retest, variability in MR-based FF and diffusion measurements and demonstrated significant differences in these measures between hamstrings and quadriceps in the healthy thigh.
ADVANCES IN KNOWLEDGE:
Test–retest variability is excellent for STEAM-EPI diffusion and 2-point Dixon-based FF measurements in the healthy muscle. Inter- and intraobserver variability were excellent for region of interest placement for STEAM-EPI diffusion and 2-point Dixon-based FF measurements in the healthy muscle. There are significant differences in FF and diffusion measurements between the hamstrings and quadriceps in the normal muscle
Thermally fluctuating superconductors in two dimensions
We describe the different regimes of finite temperature dynamics in the
vicinity of a zero temperature superconductor to insulator quantum phase
transition in two dimensions. New results are obtained for a low temperature
phase-only hydrodynamics, and for the intermediate temperature quantum-critical
region. In the latter case, we obtain a universal relationship between the
frequency-dependence of the conductivity and the value of the d.c. resistance.Comment: Presentation completely revised; 4 pages, 2 figure
Criticality in correlated quantum matter
At quantum critical points (QCP)
\cite{Pfeuty:1971,Young:1975,Hertz:1976,Chakravarty:1989,Millis:1993,Chubukov:1
994,Coleman:2005} there are quantum fluctuations on all length scales, from
microscopic to macroscopic lengths, which, remarkably, can be observed at
finite temperatures, the regime to which all experiments are necessarily
confined. A fundamental question is how high in temperature can the effects of
quantum criticality persist? That is, can physical observables be described in
terms of universal scaling functions originating from the QCPs? Here we answer
these questions by examining exact solutions of models of correlated systems
and find that the temperature can be surprisingly high. As a powerful
illustration of quantum criticality, we predict that the zero temperature
superfluid density, , and the transition temperature, , of
the cuprates are related by , where the exponent
is different at the two edges of the superconducting dome, signifying the
respective QCPs. This relationship can be tested in high quality crystals.Comment: Final accepted version not including minor stylistic correction
Abrupt Onset of Second Energy Gap at Superconducting Transition of Underdoped Bi2212
The superconducting gap - an energy scale tied to the superconducting
phenomena-opens on the Fermi surface at the superconducting transition
temperature (TC) in conventional BCS superconductors. Quite differently, in
underdoped high-TC superconducting cuprates, a pseudogap, whose relation to the
superconducting gap remains a mystery, develops well above TC. Whether the
pseudogap is a distinct phenomenon or the incoherent continuation of the
superconducting gap above TC is one of the central questions in high-TC
research. While some experimental evidence suggests they are distinct, this
issue is still under intense debate. A crucial piece of evidence to firmly
establish this two-gap picture is still missing: a direct and unambiguous
observation of a single-particle gap tied to the superconducting transition as
function of temperature. Here we report the discovery of such an energy gap in
underdoped Bi2212 in the momentum space region overlooked in previous
measurements. Near the diagonal of Cu-O bond direction (nodal direction), we
found a gap which opens at TC and exhibits a canonical (BCS-like) temperature
dependence accompanied by the appearance of the so-called Bogoliubov
quasiparticles, a classical signature of superconductivity. This is in sharp
contrast to the pseudogap near the Cu-O bond direction (antinodal region)
measured in earlier experiments. The emerging two-gap phenomenon points to a
picture of richer quantum configurations in high temperature superconductors.Comment: 16 pages, 4 figures, authors' version Corrected typos in the abstrac
Baricitinib inhibits structural joint damage progression in patients with rheumatoid arthritis – a comprehensive review
Baricitinib is an oral selective inhibitor of Janus kinase (JAK)1 and JAK2 that has proved effective and well tolerated in the treatment of rheumatoid arthritis (RA) in an extensive programme of clinical studies of patients with moderate-to-severe disease. In a phase 2b dose-ranging study of baricitinib in combination with traditional disease-modifyingantirheumatic drugs (DMARDs) in RA patients, magnetic resonance imaging showed that baricitinib 2 mg or 4 mgonce daily provided dose-dependent suppression of synovitis, osteitis, erosion and cartilage loss at weeks 12 and 24versus placebo. These findings correlated with clinical outcomes and were confirmed in three phase 3 studies (RA-BEGIN, RA-BEAM and RA-BUILD) using X-rays to assess structural joint damage. In patients naïve to DMARDs (RA-BEGINstudy), baricitinib 4 mg once daily as monotherapy or combined with methotrexate produced smaller mean changesin structural joint damage than methotrexate monotherapy at week 24. Differences versus methotrexate werestatistically significant for combined therapy. In patients responding inadequately to methotrexate (RA-BEAM study),baricitinib 4 mg plus background methotrexate significantly inhibited structural joint damage at week 24 versus placebo, and the results were comparable to those observed with adalimumab plus background methotrexate. Inpatients responding inadequately to conventional synthetic DMARDs (csDMARDs; RA-BUILD study), baricitinib 4 mgagain significantly inhibited radiographic progression compared with placebo at week 24. Benefits were also observedwith baricitinib 2 mg once daily, but the effects of baricitinib 4 mg were more robust. The positive effects of baricitinib4 mg on radiographic progression continued over 1 and 2 years in the long-term extension study RA-BEYOND, withsimilar effects to adalimumab and significantly greater effects than placebo. Findings from the phase 3 studies ofpatients with RA were supported by preclinical studies, which showed that baricitinib has an osteoprotective effect, increasing mineralisation in bone-forming cells. In conclusion, baricitinib 4 mg once daily inhibits radiographic jointdamage progression in patients with moderate-to-severe RA who are naïve to DMARDs or respond inadequately to csDMARDs, including methotrexate, and the beneficial effects are similar to those observed with adalimumab
MRI in acute muscle tears in athletes: can quantitative T2 and DTI predict return to play better than visual assessment?
Objectives
To assess the ability of quantitative T2, diffusion tensor imaging (DTI) and radiologist’s scores to detect muscle changes following acute muscle tear in soccer and rugby players. To assess the ability of these parameters to predict return to play times.
Methods
In this prospective, longitudinal study, 13 male athletes (age 19 to 34 years; mean 25 years) underwent MRI within 1 week of suffering acute muscle tear. Imaging included measurements of T2 and DTI parameters. Images were also assessed using modified Peetrons and British athletics muscle injury classification (BAMIC) scores. Participants returned for a second scan within 1 week of being determined fit to return to play. MRI measurements were compared between visits. Pearson’s correlation between visit 1 measurements and return to play times was assessed.
Results
There were significant differences between visits in BAMIC scores (Z = − 2.088; p = 0.037), modified Peetrons (Z = − 2.530; p = 0.011) and quantitative MRI measurements; T2, 13.12 ms (95% CI, 4.82 ms, 21.42 ms; p = 0.01); mean diffusivity (0.22 (0.04, 0.39); p = 0.02) and fractional anisotropy (0.07 (0.01, 0.14); p = 0.03). BAMIC scores showed a significant correlation with return to play time (Rs = 0.64; p = 0.02), but modified Peetrons scores and quantitative parameters did not.
Conclusions
T2 and DTI measurements in muscle can detect changes due to healing following muscle tear. Although BAMIC scores correlated well with return to play times, in this small study, quantitative MRI values did not, suggesting that T2 and DTI measurements are inferior predictors of return to play time compared with visual scoring.
Key Points
• Muscle changes following acute muscle tear can be measured using T2 and diffusion measurements on MRI.
• Measurements of T2 and diffusion using MRI are not as good as a radiologist’s visual report at predicting return to play time after acute muscle tear
Low incidence of limb-girdle muscular dystrophy type 2C revealed by a mutation study in Japanese patients clinically diagnosed with DMD
<p>Abstract</p> <p>Background</p> <p>Limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive muscle dystrophy that resembles Duchenne muscular dystrophy (DMD). Although DMD is known to affect one in every 3500 males regardless of race, a widespread founder mutation causing LGMD2C has been described in North Africa. However, the incidence of LGMD2C in Japanese has been unknown because the genetic background remains uncharacterized in many patients clinically diagnosed with DMD.</p> <p>Methods</p> <p>We enrolled 324 patients referred to the Kobe University Hospital with suspected DMD. Mutations in the dystrophin or the SGCG genes were analyzed using not only genomic DNA but also cDNA.</p> <p>Results</p> <p>In 322 of the 324 patients, responsible mutations in the dystrophin were successfully revealed, confirming DMD diagnosis. The remaining two patients had normal dystrophin expression but absence of γ-sarcoglycan in skeletal muscle. Mutation analysis of the SGCG gene revealed homozygous deletion of exon 6 in one patient, while the other had a novel single nucleotide insertion in exon 7 in one allele and deletion of exon 6 in the other allele. These mutations created a stop codon that led to a γ-sarcoglycan deficiency, and we therefore diagnosed these two patients as having LGMD2C. Thus, the relative incidence of LGMD2C among Japanese DMD-like patients can be calculated as 1 in 161 patients suspected to have DMD (2 of 324 patients = 0.6%). Taking into consideration the DMD incidence for the overall population (1/3,500 males), the incidence of LGMD2C can be estimated as 1 per 560,000 or 1.8 per million.</p> <p>Conclusions</p> <p>To the best of our knowledge, this is the first study to demonstrate a low incidence of LGMD2C in the Japanese population.</p
Phase II placebo-controlled study of nepafenac ophthalmic suspension 0.1% for postoperative inflammation and ocular pain associated with cataract surgery in Japanese patients
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