Repetitive, negligible force reaching in rats induces pathological overloading of upper extremity bones.

Work-related repetitive motion disorders are costly. Immunohistochemical changes in bones resulting from repetitive reaching and grasping in 17 rats were examined. After 3-6 weeks, numbers of ED1+ macrophages and osteoclasts increased at periosteal surfaces of sites of muscle and interosseous membrane attachment and metaphyses of reach and nonreach forelimbs. These findings indicate pathological overloading leading to inflammation and subsequent bone resorption. INTRODUCTION: Sixty-five percent of all occupational illnesses in U.S. private industry are attributed to musculoskeletal disorders arising from the performance of repeated motion, yet the precise mechanisms of tissue pathophysiology have yet to be determined for work-related musculoskeletal disorders. This study investigates changes in upper extremity bone tissues resulting from performance of a voluntary highly repetitive, negligible force reaching and grasping task in rats. MATERIALS AND METHODS: Seventeen rats reached an average of 8.3 times/minute for 45-mg food pellets for 2 h/day, 3 days/week for up to 12 weeks. Seven rats served as normal or trained controls. Radius, ulna, humerus, and scapula were collected bilaterally as follows: radius and ulna at 0, 3, 4, 5, 6, and 12 weeks and humerus and scapula at 0, 4, and 6 weeks. Bones were examined for ED1-immunoreactive mononuclear cells and osteoclasts. Double-labeling immunohistochemistry was performed for ED1 (monocyte/macrophage lineage cell marker) and TRACP (osteoclast marker) to confirm that ED1+ multinucleated cells were osteoclasts. Differences in the number of ED1+ cells over time were analyzed by ANOVA. RESULTS: Between 3 and 6 weeks of task performance, the number of ED1+ mononuclear cells and osteoclasts increased significantly at the periosteal surfaces of the distal radius and ulna of the reach and nonreach limbs compared with control rats. These cells also increased at periosteal surfaces of humerus and scapula of both forelimbs by 4-6 weeks. These cellular increases were greatest at muscle attachments and metaphyseal regions, but they were also present at some interosseous membrane attachments. The number of ED1+ cells decreased to control levels in radius and ulna by 12 weeks. CONCLUSIONS: Increases in ED1+ mononuclear cells and osteoclasts indicate that highly repetitive, negligible force reaching causes pathological overloading of bone leading to inflammation and osteolysis of periosteal bone tissues.     

An Evaluation of Barrier Efficacy and Cognitive Evaluation Theory as Predictors of Exercise Attendance

The purpose of this study was to evaluate the barrier efficacy and cognitive evaluation theory with regard to predicting exercise attendance. Participants consisted of 189 undergraduates attending not-for-credit fitness classes at a regional comprehensive university in the Midwest. A revised 17-item version of the Intrinsic Motivation Inventory was used to assess exercise enjoyment and the three components of self-determination theory (competence, autonomy, and relatedness). A modified version of the Self-Efficacy Scale was used to assess self-efficacy. Attendance was significantly correlated with competency and self-efficacy. Regression results revealed that class, relatedness, and competence accounted for a significant amount of variance in attendance. Future research should examine the effects of competence-enhancing strategies on exercise adherence.     

Tetrabenazine therapy of pediatric hyperkinetic movement disorders.

Tetrabenazine (TBZ), a presynaptic dopamine depletor and postsynaptic dopamine receptor blocker, is widely used for the treatment of hyperkinetic movement disorders in adults. However, reports of its use in children are limited. We review the efficacy and tolerability of TBZ therapy in 31 children with hyperkinetic movement disorders refractory to other medications. TBZ was effective in reducing the severity of movement disorders resistant to treatment with other medicines. When compared to adult patients, pediatric patients required higher doses. Side effects were similar to the adult population; however, children had a lower incidence of drug-induced Parkinsonism.     

Initial steps taken by nine primary care practices to implement alcohol screening guidelines with hypertensive patients: the AA-TRIP project.

Many medical conditions are caused or exacerbated by heavy drinking, necessitating alcohol screening and discussion in primary care practices. This is particularly true of hypertension, the most common primary diagnosis in the United States, which has been linked to the regular consumption of 3 or more standard alcoholic beverages a day. The Accelerating Alcohol Screening-Translating Research into Practice (AA-TRIP) project was designed to improve detection and management of alcohol problems in primary care patients with hypertension. Medical providers are being trained using the Practice Partner Research Network's- Translating Research into Practice (PPRNet-TRIP) quality improvement model. This includes a multi-method intervention (electronic medical records, on-site academic detailing, practice feedback reports and annual network meetings) to help practices increase adherence to clinical guidelines. Qualitative analyses of initial steps taken by nine primary care practices toward the routine implementation of alcohol screening guidelines are presented. Organizational factors and provider and patient characteristics all influenced the method and consistency of alcohol screening and intervention. Perceived time constraints, patient sensitivity to questions about alcohol, and possible stigma associated with a diagnosis of alcoholism were also relevant barriers requiring problem solving.     

Influence of statins on postoperative wound complications after inguinal or ventral herniorrhaphy

The lipid-lowering agents, statins, are the most commonly prescribed class of drugs in the western world. Because of their widespread use, many patients undergo surgical procedures while on statins. Statins, in addition to cholesterol-lowering effects, also have anticoagulant, immunosuppressive, and antiproliferative properties that may affect the risk of local wound complications. This study investigated the relationship between statins and postoperative wound complications in a large cohort of patients undergoing inguinal or ventral hernia repair. Data mining was performed in the Veterans Integrated Service Network (VISN)16 Data Warehouse. This database contains clinical and demographic information about all veterans cared for at the ten VA Medical Centers that comprise the South Central VA Healthcare Network in the mid-south region of the US. Aggregate data (age, body mass index, smoking history, gender, race, history of diabetes, statin use, and postoperative wound complications) were obtained for all patients who underwent inguinal or ventral hernia repair during the period October 1, 1996–November 30, 2004. During the period of the query, 10,782 patients (10,676 male, 106 female), 1,242 (11.5%) of whom received statins, underwent herniorrhaphy. Statin use did not affect the risk of wound infection or delayed wound healing. Statin use was, however, associated with an increased rate of local postoperative bleeding complications (P=0.01). When the type of hernia, age, smoking, diabetes, and body mass index were included in a multivariate analysis, statins remained borderline significant as an independent predictor of wound hematoma/postoperative bleeding (P=0.04), odds ratio 1.6 (95% CI 1.03–2.44). Patients who undergo inguinal herniorrhaphy while on statins have an increased risk of postoperative wound hematoma/hemorrhage. Focus on additional factors that may affect the propensity to postoperative bleeding and on meticulous intraoperative hemostasis are particularly important in such patients.     

MESENTERIC CYST

Mesenteric cyst is one of the rarest abdominal tumours, with approximately 820 cases reported since 1507. The incidence varies from 1 per 100000 to 250000 admissions. The lack of characteristic clinical features and radiological signs may present great diagnostic difficulties. The cyst may present in one of three ways: (i) non-specific abdominal features; (ii) an incidental finding; or (iii) an acute abdomen. Abdominal pain is the major presenting symptom. Abdominal mass is found in more than 50% of cases and 40% of cases are discovered incidentally. More than one aetiological mechanism is probably involved in the development of mesenteric cysts. Mesenteric cysts have been reported from the duodenum to the rectal mesentery but are most commonly located in the ileal mesentery. Malignant cysts occur in less than 3% of cases. Enucleation of the cyst is the treatment of choice. Knowledge of these tumours is important due to the various complications associated with suboptimal surgical management. Two cases of mesenteric cysts are presented including a recurrent mesenteric cyst in a post-partum woman demonstrating the inferior technique of internal marsupialization. The association of mesenteric cyst with pregnancy is discussed.     

Inappropriate Vancomycin Prescribing Based on Criteria from the Centers for Disease Control and Prevention

Increasing reports of vancomycin resistance have raised concerns about the future effectiveness of this drug in treatment of critically ill patients with gram-positive infections. Due to these concerns the Centers for Disease Control and Prevention (CDC) recently published criteria that delineate the prudent use of vancomycin. Using these criteria, we attempted to determine the appropriateness of vancomycin prescribing patterns at our institution. A retrospective chart review was performed for 135 hospitalized patients treated between May 1993 and April 1994. Inappropriate empiric vancomycin use was documented in 81 (60%) of these patients. When culture results were available, 28 (21%) patients inappropriately received the drug. Results of this study are similar to those of other studies of vancomycin use in hospitals based on non-CDC criteria. If CDC criteria are to have a positive impact on physicians' vancomycin prescribing patterns, significant educational efforts will be required.     

Nitrous oxide does not exacerbate pulmonary hypertension or ventricular dysfunction in patients with mitral valvular disease

Using the rapid-response thermistor pulmonary artery catheter and transoesophageal echocardiography, this study examined the effects of 100 per cent oxygen, 70 per cent nitrous oxide/30 per cent oxygen, and 70 per cent nitrogen/30 per cent oxygen on the pulmonary circulation and ventricular function in ten patients with pulmonary hypertension. In comparison with baseline measurements, nitrous oxide administration resulted in small but statistically significant (P less than 0.05) changes in mean arterial pressure (76 +/- 14 to 67 +/- 12), mean pulmonary arterial pressure (37 +/- 14 to 33 +/- 13 mmHg), and cardiac output (3.7 +/- 1.4 to 3.2 +/- 1.1 L.min-1). Seventy per cent nitrogen resulted in no significant changes from baseline. The repeat 100 per cent oxygen measurements were nearly identical to the nitrous oxide measurements. It is concluded that nitrous oxide does not exacerbate pulmonary hypertension or ventricular dysfunction during high-dose fentanyl anaesthesia in patients with mitral valvular disease.