378 research outputs found

    Accuracy of MSCT Coronary Angiography with 64 Row CT Scanner—Facing the Facts

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    Improvements in multislice computed tomography (MSCT) angiography of the coronary vessels have enabled the minimally invasive detection of coronary artery stenoses, while quantitative coronary angiography (QCA) is the accepted reference standard for evaluation thereof. Sixteen-slice MSCT showed promising diagnostic accuracy in detecting coronary artery stenoses haemodynamically and the subsequent introduction of 64-slice scanners promised excellent and fast results for coronary artery studies. This prompted us to evaluate the diagnostic accuracy, sensitivity, specificity, and the negative und positive predictive value of 64-slice MSCT in the detection of haemodynamically significant coronary artery stenoses

    High resolution micro arthrography of hard and soft tissues in a murine model

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    SummaryObjectiveRecent developments on high resolution micro computed tomography (μCT) allow imaging of soft tissues in small animal joints. Nevertheless, μCT images cannot distinguish soft tissues from synovial fluid due to their similar mass density, limiting the 3D assessment of soft tissues volume and thickness. This study aimed to evaluate a lead chromate contrast agent for μCΤ arthrography of rat knee joints ex vivo.DesignIntact tibiofemoral rat joints were injected with the contrast agent at different concentrations and imaged using a μCT at 2.7 μm isotropic voxel size. Cartilage thickness was measured using an automated procedure, validated against histological measurements, and analyzed as a function of μCT image resolution. Changes in hard and soft tissues were also analyzed in tibiofemoral joints 4 weeks after surgical destabilization of the medial meniscus (DMM).ResultsThe contrast agent diffused well throughout the whole knee cavity without penetrating the tissues, therefore providing high contrast at the boundaries between soft tissues and synovial fluid space. Thickness analysis of cartilage demonstrated a high similarity between histology and μ-arthrography approaches (R2 = 0.90). Four weeks after surgical DMM, the development of osteophytes (Oph) and cartilage ulcerations was recognizable with μCT, as well as a slight increase in trabecular bone porosity, and decrease in trabecular thickness.ConclusionsA lead chromate-based contrast agent allowed discriminating the synovial fluid from soft tissues of intact knee joints, and thus made possible both qualitative and quantitative assessment of hard and soft tissues in both intact and DMM tibiofemoral joints using high resolution μCT

    Functional polymorphisms in the P2X7 receptor gene are associated with stress fracture injury

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    Context: Military recruits and elite athletes are susceptible to stress fracture injuries. Genetic predisposition has been postulated to have a role in their development. The P2X7 receptor (P2X7R) gene, a key regulator of bone remodelling, is a genetic candidate that may contribute to stress fracture predisposition. Objective: To evaluate the putative contribution of P2X7R to stress fracture injury in two separate cohorts, military personnel and elite athletes. Methods: In 210 Israeli Defence Forces (IDF) military conscripts, stress fracture injury was diagnosed (n=43) based on symptoms and a positive bone scan. In a separate cohort of 518 elite athletes, self-reported medical imaging scan-certified stress fracture injuries were recorded (n=125). Non-stress fracture controls were identified from these cohorts who had a normal bone scan or no history or symptoms of stress fracture injury. Study participants were genotyped for functional SNPs within the P2X7R gene using proprietary fluorescence-based competitive allele-specific PCR assay. Pearson Chi-square (χ2) tests, corrected for multiple comparisons, were used to assess associations in genotype frequencies. Results: The variant allele of P2X7R SNP rs3751143 (Glu496Ala- loss of function) was associated with stress fracture injury, while the variant allele of rs1718119 (Ala348Thr- gain of function) was associated with a reduced occurrence of stress fracture injury in military conscripts (P<0.05). The association of the variant allele of rs3751143 with stress fractures was replicated in elite athletes (P<0.05), whereas the variant allele of rs1718119 was also associated with reduced multiple stress fracture cases in elite athletes (P<0.05). Conclusions: The association between independent P2X7R polymorphisms with stress fracture prevalence supports the role of a genetic predisposition in the development of stress fracture injury

    A systematic review of interventions addressing limited health literacy to improve asthma self-management

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    Background: Supported asthma self-management improves health outcomes. However, people with limited health literacy, especially in lower-middle-income countries (LMICs), may need tailored interventions to enable them to realise the benefits. We aimed to assess the clinical effectiveness of asthma self-management interventions targeted at people with limited health literacy and to identify strategies associated with effective programmes. Methods: Following Cochrane methodology, we searched ten databases (January 1990 – June 2018; updated October 2019), without language restriction. We included controlled experimental studies whose interventions targeted health literacy to improve asthma self-management. Selection of papers, extraction of data and quality assessment were done independently by two reviewers. The primary outcomes were clinical (asthma control) and implementation (adoption/adherence to intervention). Analysis was narrative. Results: We screened 4318 titles and abstracts, reviewed 52 full-texts and included five trials. One trial was conducted in a LMIC. Risk of bias was low in one trial and high in the other four studies. Clinical outcomes were reported in two trials, both at high risk of bias: one of which reported a reduction in unscheduled care (number of visits in 6-month (SD); Intervention:0.9 (1.2) vs Control:1.8 (2.4), P = 0.001); the other showed no effect. None reported uptake or adherence to the intervention. Behavioural change strategies typically focused on improving an individual’s psychological and physical capacity to enact behaviour (eg, targeting asthma-related knowledge or comprehension). Only two interventions also targeted motivation; none sought to improve opportunity. Less than half of the interventions used specific self-management strategies (eg, written asthma action plan) with tailoring to limited health literacy status. Different approaches (eg, video-based and pictorial action plans) were used to provide education. Conclusions: The paucity of studies and diversity of the interventions to support people with limited health literacy to self-manage their asthma meant that the impact on health outcomes remains unclear. Given the proportion of the global population who have limited health literacy skills, this is a research priority

    Idiopathic sclerosing mesenteritis in paediatrics: Report of a successfully treated case and a review of literature

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    A 6 year old female with symptoms of small bowel obstruction underwent an exploratory laparotomy which revealed widespread evidence of inflammatory fibrotic adhesions involving the jejunal mesentery. In view of persistent growth failure, chronic anaemia, elevated acute phase reactants and imaging evidence of a diffuse progressive inflammatory process, the child was treated with corticosteroids and methotrexate with complete response. The literature on juvenile idiopathic sclerosing mesenteritis has been reviewed

    Transient peak-strain matching partially recovers the age-impaired mechanoadaptive cortical bone response

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    Mechanoadaptation maintains bone mass and architecture; its failure underlies age-related decline in bone strength. It is unclear whether this is due to failure of osteocytes to sense strain, osteoblasts to form bone or insufficient mechanical stimulus. Mechanoadaptation can be restored to aged bone by surgical neurectomy, suggesting that changes in loading history can rescue mechanoadaptation. We use non-biased, whole-bone tibial analyses, along with characterisation of surface strains and ensuing mechanoadaptive responses in mice at a range of ages, to explore whether sufficient load magnitude can activate mechanoadaptation in aged bone. We find that younger mice adapt when imposed strains are lower than in mature and aged bone. Intriguingly, imposition of short-term, high magnitude loading effectively primes cortical but not trabecular bone of aged mice to respond. This response was regionally-matched to highest strains measured by digital image correlation and to osteocytic mechanoactivation. These data indicate that aged bone’s loading response can be partially recovered, non-invasively by transient, focal high strain regions. Our results indicate that old murine bone does respond to load when the loading is of sufficient magnitude, and bones’ age-related adaptation failure may be due to insufficient mechanical stimulus to trigger mechanoadaptation

    Podmaniczky Frigyes levele Arany Jánosnak

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    Tendinopathy is a common and progressive musculoskeletal disease. Increased apoptosis is an end-stage tendinopathy manifestation, but its contribution to the pathology of the disease is unknown. A previously established in vivo model of fatigue-damage accumulation shows that increased apoptosis is correlated with the severity of induced tendon damage, even in early onset of the disease, supporting its implication in the pathogenesis of the disease. Consequently, this study aimed to determine: (1) whether apoptosis could be inhibited after fatigue damage and (2) whether its inhibition could lead to remodeling of the extracellular matrix (ECM) and pericellular matrix (PCM), to ultimately improve the mechanical properties of fatigue-damaged tendons. The working hypothesis was that, despite the low vascular nature of the tendon, apoptosis would be inhibited, prompting increased production of matrix proteins and restoring tendon mechanical properties. Rats received 2 or 5 d of systemic pan-caspase inhibitor (Q-VD-OPh) or dimethyl sulfoxide (DMSO) carrier control injections starting immediately prior to fatigue loading and were sacrificed at days 7 and 14 post-fatigue-loading. Systemic pan-caspase inhibition for 2 d led to a surprising increase in apoptosis, but inhibition for 5 d increased the population of live cells that could repair the fatigue damage. Further analysis of the 5 d group showed that effective inhibition led to an increased population of cells producing ECM and PCM proteins, although typically in conjunction with oxidative stress markers. Ultimately, inhibition of apoptosis led to further deterioration in mechanical properties of fatigue-damaged tendons

    Microarchitecture Influences Microdamage Accumulation in Human Vertebral Trabecular Bone

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    It has been suggested that accumulation of microdamage with age contributes to skeletal fragility. However, data on the age-related increase in microdamage and the association between microdamage and trabecular microarchitecture in human vertebral cancellous bone are limited. We quantified microdamage in cancellous bone from human lumbar (L2) vertebral bodies obtained from 23 donors 54–93 yr of age (8 men and 15 women). Damage was measured using histologic techniques of sequential labeling with chelating agents and was related to 3D microarchitecture, as assessed by high-resolution μCT. There were no significant differences between sexes, although women tended to have a higher microcrack density (Cr.Dn) than men. Cr.Dn increased exponentially with age (r = 0.65, p < 0.001) and was correlated with bone volume fraction (BV/TV; r = −0.55; p < 0.01), trabecular number (Tb.N; r = −0.56 p = 0.008), structure model index (SMI; r = 0.59; p = 0.005), and trabecular separation (Tb.Sp; r = 0.59; p < 0.009). All architecture parameters were strongly correlated with each other and with BV/TV. Stepwise regression showed that SMI was the best predictor of microdamage, explaining 35% of the variance in Cr.Dn and 20% of the variance in diffuse damage accumulation. In addition, microcrack length was significantly greater in the highest versus lowest tertiles of SMI. In conclusion, in human vertebral cancellous bone, microdamage increases with age and is associated with low BV/TV and a rod-like trabecular architecture

    A guideline for placement of an infra-acetabular screw based on anatomic landmarks via an intra-pelvic approach

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    Background: Due to demographic changes, more and more fracture patterns involving anterior acetabular structures occur. The infra-acetabular screw is seen a useful tool to increase stability in fixation of the acetabular cup. However, the exact position of this screw in relation to anatomic landmarks which are intra-operatively palpable via an intra-pelvic approach has not yet been determined. Methods: This biomorphometric experimental study references the ideal screw position of an infra-acetabular screw to anatomic landmarks palpable via an intra-pelvic approach. Therefore, we created a computer tomography-based 3D-model of 40 patients (20 women, 20 men) who received a computer tomography (CT) scan of the pelvis for any other reason than an acetabular fracture. Results: The entry point of an ideal infra-acetabular was of high constancy. At mean, this point was 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence. This reference is independent of age, gender, or physical dimensions. However, we found gender-dependent differences for the angulation and the length of the screw. Conclusions: This study provides a comprehensive guideline to determine the ideal entry point for an infra-acetabular screw via an intra-pelvic approach. The entry point is located 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence
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