Retinoic acid inhibits junctional communication between animal cells

Retinoic acid inhibits junctional communication between a varietyof vertebrate cell types in culture. It reduces the intercellulartransfer of ³H-nucleotides between Syrian hamster kidney fibroblasts(BHK 21/13), Chinese hamster lung fibro-blasts (V79), rat liverepithelial cells (BRL), Swiss mouse embryo fibroblasts (3T3),rainbow trout gonadal fibroblasts (RTG2) and Xenopus embryofibroblasts (Xen). It also reduces metabolic cooperation betweenhypoxanthine-guanine phosphoribosyl transferase deficient mutantand wild-type BHK cells. The inhibition is rapid (intercellulartransfer of iontophoretically injected Lucifer Yellow CH betweenBRL cells is completely blocked after the cells have been exposedto 10^–4 M retinoic acid for 5 min), and is fully reversedwhen the drug is removed. Based on these results and the observationthat the amount of gap junctional protein isolated from cellsgrown in the presence of retinoic acid for 1 h is the same andafter 24 h is increased (1.3- to 3.1-fold) compared with theamount isolated from untreated cells, we suggest that the inhibitoryeffect is mediated by the reversible closure of junctional channels.     

Severe Combined Immunodeficiency (SCID)-Associated Dyschromia with Subsequent Repigmentation: A Report of Two Patients

Abstract:  Severe combined immunodeficiency (SCID) often presents with mucosal infections, cutaneous infections and eczematous rashes. We present two patients with history of SCID diagnosed at an early age who experienced diffuse dyschromia associated with their bone marrow and stem cell transplants. Dyschromias may be caused by numerous factors including medications, genetics, environmental contacts, or as a sequela of underlying chronic disease. These case reports describe progressive repigmentation to original skin color after the occurrence of dyschromia in two patients with SCID.     

Trauma to the elbow and forearm

Elbow and forearm trauma constitute a significant percentage of upper extremity injuries. A thorough understanding of the anatomy and mechanism of injury is necessary for obtaining the most accurate radiographic interpretation in both the pediatric and adult populations. Proper radiographic positioning and choice of the best imaging modality are crucial to ensure the best orthopedic treatment and reduce the incidence of post-treatment complications.     

Radiology of wrist and hand injuries in athletes

Traumatic injuries are a major cause of hand and wrist pain in athletes. Wrist injuries include fractures, dislocations, and instability patterns. Hand injuries include tendon injuries, ligamentous injuries, and fractures. In this article we have presented the radiographic appearance of the more common of these injuries.     

How serious of a problem is staff turnover in substance abuse treatment? A longitudinal study of actual turnover

In the substance abuse treatment field, the annual turnover rate is cited as being anywhere between 19% and 50% (J.A. Johnson & P.M. Roman, 2002; S.L. Gallon, R.M. Gabriel, J.R.W. Knudsen, 2003; H.K. Knudsen, J.A. Johnson, & P.M. Roman, 2003; A.T. McLellan, D. Carise, & H.D. Kleber, 2003). However, no research to date has evaluated these claims by tracking turnover longitudinally using organizational turnover data from substance abuse treatment centers. This research presents the results of a longitudinal study designed to systematically examine actual turnover among counselors and clinical supervisors. Twenty-seven geographically dispersed treatment organizations, serving a wide range of clients in the public and private sector, provided data for the study over a 2-year time span (2008–2009). The annual turnover rate was 33.2% for counselors and 23.4% for clinical supervisors. For both groups, the majority of turnover was voluntary (employee-initiated). Specific reasons for turnover were largely consistent across the two groups, with the most common reason being a new job or new opportunity. The findings are discussed in terms of the unique employment context of substance abuse treatment. Practical recommendations are also discussed to help stem the tide of turnover in the field of substance abuse treatment.     

Knee injuries: high-resolution MR imaging

Recent technologic advances have made high-resolution magnetic resonance (MR) imaging of the knee a clinical reality. Ten healthy volunteers and 30 patients with suspected knee injuries were imaged using receive-only surface coils and two-dimensional multisection or three-dimensional selective acquisition techniques. Arthroscopic and/or surgical correlation was available in 15 patients. Tears of the cruciate ligament, medial collateral ligament, and meniscus are illustrated. Nonorthogonal views of the anterior cruciate ligament are useful for demonstrating both femoral and tibial attachments in the same section. The posterior cruciate ligament is usually well seen on sagittal views. T2-weighted images are helpful for demonstrating collateral ligament tears and meniscal tears when joint effusion is present. Thin sections (1-5 mm) are necessary to define many meniscal and cruciate tears. High-resolution, thin-section MR imaging can be used to diagnose soft-tissue injuries of the knee and has the potential to become a major imaging method in the evaluation of knee injuries.     

Port-Site Pyoderma Gangrenosum – A Rare Complication of Surgical Trauma

We report a case of pyoderma gangrenosum occurring at the site of a laparoscopic port insertion following laparoscopic inguinal hernia repair.