Silent osteonecrosis of the femoral head following high-dose corticosteroids in patients with systemic rheumatic diseases

Background: Osteonecrosis (ON) is known to be one of the most disabling complications following corticosteroid (CS) medications. However, evidence regarding risk of asymptomatic prevalence of ON among different diseases and the impact of variable steroid regimens are conflicting. We aimed to determine the prevalence of ON of femoral head in asymptomatic patients with systemic rheumatic diseases who received high-dose CS and also clarify its relationship with different dosages and regimens. Methods: In this cross-sectional study, 50 consecutive patients receiving high-dose CS for rheumatic diseases who have no pelvic pain were recruited. MRI of both hips was performed on all patients using a 1.5 Tesla to diagnose ON. Results: Of 50 subjects, 18 (36) developed ON of the femoral head. Groups with and without ON were comparable in terms of sex, age and mean starting CS dose. There was no statistical difference in the type of CS regimen including daily dose, peak dose and cumulative dose between the two groups. However, silent ON was associated with both the cumulative CS dose and the duration of CS therapy. Conclusion: According to high prevalence of ON in our selected patients with no other identifiable risk factor for ON, monitoring of high risk patients with periodic hip MRI would help diagnose necrosis in early stage

Simple Synchronous Detector for Spectroscopic Studies

Lock-in-amplifiers are used in many applications for signal processing and offer the ability to discriminate high levels of noise. While these instruments are very powerful and offer many features, they are not portable and are expensive. An economical and easy to use alternative circuit is presented which incorporates pre-amplification, reference, and synchronous detection on one circuit board. The design can be used in laboratory or process control situations where its small size and low cost are advantageous. The circuit was successfully applied to moderate and high level signals as seen in flame infrared emission detection and in a portable radiometer for rocket plume studies

Diagnostic value of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis.

Background Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been of diagnostic value in Northern European Caucasian patients with rheumatoid arthritis (RA). In these populations, anti-CCP antibodies are associated with the HLA-DRB1 shared epitope. We assessed the diagnostic value of anti-CCP antibodies in Greek patients with RA where the HLA shared epitope was reported in a minority of patients. Methods Using an enzyme-linked immunosorbent assay (ELISA) (CCP2) kit, we tested anti-CCP antibodies in serum samples from 155 Greek patients with RA, 178 patients with other rheumatic diseases, and 100 blood donors. We also determined rheumatoid factor (RF) and compared it to anti-CCP antibodies for area under the curve (AUC), sensitivity, specificity and likelihood ratios. Results Sensitivity of anti-CCP2 antibodies and RF for RA was 63.2% and 59.1%, and specificity was 95.0% and 91.2%, respectively. When considered simultaneously, the AUC for anti-CCP antibodies was 0.90 with 95% CI of 0.87 to 0.93 and the AUC for RF was 0.71 with 95% CI of 0.64 to 0.77. The presence of both antibodies increased specificity to 98.2%. Anti-CCP antibodies were positive in 34.9% of RF-negative RA patients. Anti-CCP antibodies showed a correlation with the radiographic joint damage. Anti-CCP-positive RA patients had increased the swollen joint count and serum CRP concentration compared to anti-CCP-negative RA patients (Mann-Whitney U test, p = 0.01, and p < 0.001, respectively). However, no correlation was found between anti-CCP antibodies and DAS28 score (r = 0.13, p = 0.12). Conclusion In Greek patients with RA, anti-CCP2 antibodies exhibit a better diagnostic value than RF and a correlation with radiological joint damage and therefore are useful in everyday rheumatology practice

The comparison between two methods of basic life support instruction: Video self-instruction versus traditional method

Introduction: Medical education is changing and evolving. Teachers need to re-evaluate their medical teaching practice to enhance student learning. The data about the ideal training method of Basic Life Support (BLS) is lacking. The goal of this study was to analyse the use and performance of video self-instruction (VSI) method in BLS, in order to develop an efficient BLS training method. Methods: Eighty-one undergraduate medical interns were enrolled in a prospective clinical study in 2011. They were divided into VSI group and traditional group. We provided the first group with a DVD containing a 20-minute training video while the second group took part in a 4-hour training class of BLS. Subjects participated in a pre-test and post-test based on 2010 American Heart Association Resuscitation guideline. Results: The average scores of VSI group and the traditional group before training were 8.85±2.42 and 8.57±2.22 respectively (p=0.592). After training, the average scores of the VSI and the traditional group were 20.24±0.83 and 18.05±1.86 respectively. VSI group achieved slightly better scores compared with the traditional group (p<0.001). Conclusions: Training through VSI achieves more satisfying results than the traditional lecture method. VSI method can be considered a useful technique in undergraduate educational programs. Developing VSI can increase significantly the access to the BLS training. © 2015, Medcom Limited. All rights reserved

Radiometer for the Investigation of Infrared Emissions from Flames and Rocket Plumes

A prototypical radiometer using standard one inch interference filters and a lead selenide detector was constructed for use in flame and rocket plume studies. This radiometer was designed to employ a 600 Hz chopper and chopper frequency/phase reference circuit for signal processing. Bandpass filters centered for either 2.7 mum or 4.45 mum were placed in the optical path. The passed carbon dioxide or water vapor band energy irradiated the lead selenide detector, resulting in an output voltage. This signal was then fed into a dedicated synchronous detector. The signal was then recorded by a computer system equipped with an analog-to-digital converter board. Infrared emission data was collected from two inch rocket motors and from a special burner based flame

On the dependence of the leak-rate of seals on the skewness of the surface height probability distribution

Seals are extremely useful devices to prevent fluid leakage. We present experimental result which show that the leak-rate of seals depend sensitively on the skewness in the height probability distribution. The experimental data are analyzed using the critical-junction theory. We show that using the top-power spectrum result in good agreement between theory and experiment.Comment: 5 pages, 9 figure

Leak-rate of seals: comparison of theory with experiment

Seals are extremely useful devices to prevent fluid leakage. We present experimental results for the leak-rate of rubber seals, and compare the results to a novel theory, which is based on percolation theory and a recently developed contact mechanics theory. We find good agreement between theory and experiment.Comment: 6 pages, 10 figure