Recovery of Pseudomonas aeruginosa colonial dissociants on a protease detection medium.

Dialyzed brain heart infusion-skim milk agar medium facilitated the recovery of colonial dissociants of Pseudomonas aeruginosa. Differences in colonial morphology as well as in proteolytic activity were readily visualized, thus permitting facile isolation of segregating colony types for further biochemical, serological, and susceptibility studies.     

Cyproheptadine in levodopa-induced dyskinesia in parkinsonism

The neuroendocrine properties and the beneficial effects of cyproheptadine in tardive dyskinesia led to the testing of this drug in levodopa-induced dyskinesia. Cyproheptadine administered to 6 parkinsonian patients in doses of up to 42 mg/day was of no significant benefit in either dyskinesia or symptom control. Improvement in appetite was reported by 3 patients. These observations suggested that different mechanisms may be responsible in the pathogenesis of phenothiazine and amine-induced dyskinesia. The failure to control levodopa-induced dyskinesia selectively with serotonin agonists and antagonists and the accentuation of the dyskinesia in the presence of anticholinergic agents further suggest that substances that increase directly central cholinergic activity may be effective in the control of levodopa-induced dyskinesia.     

A comparison of four treadmill protocols for determination of maximum oxygen uptake in 10- to 12-year-old boys

Little information is available regarding the relative effectiveness of various treadmill exercise protocols in eliciting maximal oxygen consumption (VO2 max) values in children. In this study of 10- to 12-year-old boys, running protocols produced significantly higher VO2 max levels compared with walking, but there were no important differences in continuous, intermittent, and handrail-supported running schedules. The intermittent run protocols, however, prolonged the test duration. Studies examining VO2 max in children should utilize standard criteria for demonstrating peak oxygen intake. In this study criteria of VO2 plateau, peak heart rate over 198 and respiratory quotient exceeding 1.0 were satisfied most commonly with running protocols.     

Regional Anaesthesia Techniques for Orthopaedic Surgery

Background

In recent years, there has been a significant resurgence of interest in regional anaesthesia techniques. Despite various advantages, regional anaesthesia is not used to its full potential in orthopaedic surgeries.

Methods

This study was conducted to evaluate the efficacy and safety of regional anaesthesia techniques in 400 consecutive patients, posted for orthopaedic surgeries in a tertiary care centre. Data was analysed for patient profile, type of surgery, nature of anaesthetic technique used, success rate, complications and satisfaction level of patients.

Result

Age of patients ranged from three months to 92 years with male preponderance (84.5 %). Regional anaesthesia was used in 85% cases. Most frequently used technique for upper limbs was supraclavicular brachial plexus block (12.05 %) followed by interscalene block (5.58 %) and intravenous regional anaesthesia or Bier''s block (2.64 %). For lower limbs, subarachnoid block was used in 50 % cases followed by combined spinal-epidural technique (21.47 %) and paravertebral block (4.70 %). Less commonly used techniques like lumbar plexus block, popliteal fossa block, sciatic + femoral nerve blocks were found to be useful but incidence of partial blocks was high. Overall success rate was 96.17 %. In 22.05 % cases supplementation with analgesic / sedative was needed, whereas in 3.82 % cases, technique was converted into general anaesthesia. There was no major complication. Six patients had reversible sensory neuropathy. In 91.64 % cases, satisfaction level was good to excellent.

Conclusion

Skilfully performed techniques in regional anaesthesia can facilitate excellent surgical anaesthesia and postoperative pain management.Key Words: Regional anaesthesia, Orthopaedic surgery, Central neuraxial block, Peripheral nerve block     

Simulation tests to assess occupational exposure to airborne asbestos from asphalt-based roofing products

This study sought to evaluate exposure from specific products to evaluate potential risk from roof repair activities. Five asbestos-containing fibered roof coatings and plastic cements, representing a broad range of these types of products, were tested in exposure simulations. These products were applied to representative roof substrates. Release of asbestos fibers during application and sanding of the product shortly thereafter (wet sanding) were tested initially. Other roof substrates were cured to simulate a product that had been on a rooftop for several months and then were tested to evaluate release of fibers during hand sanding and hand scraping activities. Additional tests were also conducted to evaluate asbestos release during product removal from tools and clothing. Two personal (n = 84) and background/clearance (n = 49) samples were collected during each 30-min test and analyzed for total fiber concentration [phase-contrast microscopy (PCM)] and for asbestos fiber count [transmission electron microscopy (TEM)]. PCM concentrations ranged from <0.005 to 0.032 fibers per cubic centimeter (f cc(-1)). Chrysotile fibers were detected in 28 of 84 personal samples collected. TEM concentrations ranged from <0.0021 to 0.056 f cc(-1). Calculated 8-h time-weighted averages (TWAs) ranged from 0.0003 to 0.002 f cc(-1) and were comparable to the background TWA concentration of 0.0002 f cc(-1) measured in this study. Based on these results, it is unlikely that roofers were exposed to airborne asbestos concentrations above the current or historical occupational guidelines during scraping and sanding of these products during roof repair.     

Effect of the radiolabel mediator tropolone on lymphocyte structure and function

The in vitro use of the radioisotope indium 111 (111In) was examined as a radiolabel for lymphocytes obtained from both normal individuals and patients with a variety of lymphoid malignancies. Successful cell labeling requires a chelator. The traditional agent oxine, has proved to be toxic to the lymphoid lineage. Cellular uptake of 111In mediated by the chelator oxine was compared with that of a new chelator, tropolone. Oxine provided better labeling efficiency (48%) than tropolone (35%) for the labeling of normal lymphocytes. By contrast, lymphocytes from patients with chronic lymphocytic leukemia had a nearly twofold greater labeling efficiency when tropolone was substituted for oxine. Further studies demonstrated that tropolone induced functional injury to lymphocytes when mitogenic response to concanavalin A, pokeweed mitogen, and phytohemagglutinin was assessed. Similar toxicity was found when tropolone was compared with oxine. In addition, tropolone produced damaging structural changes seen by both scanning and transmission electron microscopic examination. These changes were both variable and not predictable. Shortening of the incubation time of the chelator with the cell provided the least amount of cellular injury. These findings suggest that tropolone be used as an alternative mediator of lymphocyte labeling with 111In only under critically defined conditions.