Musculoskeletal ultrasound objective structured clinical examination: an assessment of the test.

OBJECTIVE: To determine the reliability and validity of an objective structured clinical examination (OSCE) for musculoskeletal ultrasound (MSUS). METHODS: A 9-station OSCE was administered to 35 rheumatology fellows trained in MSUS and to 3 expert faculty (controls). Participants were unaware of joint health (5 diseased/4 healthy). Faculty assessors (n = 9) graded image quality with predefined checklists and a 0-5 global rating, blinded to who performed the study. Interrater reliability, correlation between a written multiple choice question examination (MCQ) and OSCE performance, and comparison of fellow OSCE results with those of the faculty were measured to determine OSCE reliability, concurrent validity, and construct validity. RESULTS: Assessors' interrater reliability was good (intraclass correlation coefficient [ICC] 0.7). Score reliability was good in the normal wrist and ankle stations (ICC 0.7) and moderate in the abnormal wrist and ankle stations (ICC 0.4). MCQ grades significantly correlated with OSCE grades (r = 0.52, P < 0.01). The fellows in the bottom quartile of the MCQ scored 3.07 on the OSCE, significantly worse than the top quartile fellows (3.32) and the faculty (3.29; P < 0.01). Scores also significantly discriminated bottom quartile fellows from faculty in the normal wrist and ankle stations (3.38 versus 3.78; P < 0.01), but not in the abnormal stations (3.37 versus 3.49; P = 0.08). CONCLUSION: MSUS OSCE is a reliable and valid method for evaluation of MSUS skill. Normal joint assessment stations are more reliable than abnormal joint assessment stations and better discriminate poorly performing fellows from faculty. Therefore, MSUS OSCE with normal joints can be used for the assessment of MSUS skill competency.

Mechanism of internal anal sphincter relaxation by CORM-1, authentic CO, and NANC nerve stimulation.

The present studies compared the effects of CO-releasing molecule (CORM-1), authentic CO, and nonadrenergic noncholinergic (NANC) nerve stimulation in the internal anal sphincter (IAS). Functional in vitro experiments and Western blot studies were conducted in rat IAS smooth muscle. We examined the effects of CORM-1 (50-600 microM) and authentic CO (5-100 microM) and NANC nerve stimulation by electrical field stimulation (EFS; 0.5-20 Hz, 0.5-ms pulse, 12 V, 4-s train). The experiments were repeated after preincubation of the tissues with the neurotoxin TTX, the guanylate cyclase inhibitor 1H-(1,2,4)oxadiazolo-(4,3-a)quinoxalin-1-one (ODQ), the selective heme oxygenase (HO) inhibitor tin protoporphyrin IX (SnPP-IX), the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine (L-NNA), and SnPP-IX + L-NNA. We also investigated the effects of the HO substrate hematin (100 microM). CORM-1, as well as CO, produced concentration-dependent IAS relaxation, whereas hematin had no effect. TTX abolished and L-NNA significantly blocked IAS relaxation by EFS without any effect on CORM-1 and CO. ODQ blocked IAS relaxation by CORM-1, authentic CO, and EFS. SnPP-IX had no significant effect on IAS relaxation by CORM-1, CO, or EFS. The presence of neuronal nitric oxide synthase, HO-1, and HO-2 in IAS smooth muscle was confirmed by Western blot studies. CORM-1 and CO, as well as NANC nerve stimulation, produced IAS relaxation via guanylate cyclase/cGMP-dependent protein kinase activation. The advent of CORM-1 with potent effects in the IAS has significant implications in anorectal motility disorders with regard to pathophysiology and therapeutic potentials.