Urinary tricyclic antidepressant screening: comparison of results obtained with Abbott FPIA reagents and Syva EIA reagents

Human urine was tested for tricyclic antidepressants with fluorescence polarization immunoassay (FPIA) reagents on Abbott's ADx system and with EIA reagents on Syva's ETS system. A 75-ng/mL imipramine calibrator cutoff was used with the ADx system and a 300-ng/mL nortriptyline calibrator cutoff with the ETS system. The ETS system was adapted to analyze tricyclic antidepressant (TCA) samples using the Syva Emittox serum TCA assay. Negative urine was spiked with various tricyclic and tetracyclic antidepressants, phenothiazines, and other medications with potential to interfere with the assays. Verification of samples was performed by thin-layer chromatography and gas chromatography/mass spectrometry. The different compounds were added to urine at concentrations of 200, 400 and 1,000 ng/mL. At 1,000 ng/mL all TCA compounds tested gave positive results with the ADx and ETS systems. However, some non-TCA medications spiked at 1,000 ng/mL gave false positive results with both systems. The tetracyclic antidepressants did not cross-react and gave negative results. Clomipramine-spiked urine at 400 ng/mL yielded a false negative result on the ETS system.     

Psychological approaches to the treatment of asthma.

Outcome literature on psychological treatment for asthma covers psychoeducational self-management programs, relaxation therapy, biofeedback, and family therapy. Psychoeducational approaches now being standardized in a national program are cost-effective. They produce improved adjustment, increased medication compliance, greater perceived self-competence in managing symptoms, and decreased use of medical services. Significant effects have been found for relaxation therapy, although it is not clear whether the effectiveness depends on whole-body relaxation or specifically facial- or respiratory-muscle relaxation. Family therapy is helpful to some asthmatics. Active components in these methods remain to be identified as do the populations whom they can best serve. Biofeedback for respiratory resistance, trachea sounds, and vagal tone shows promise but has not been given adequate clinical testing.     

Drug screening in the workplace

Drug use is pervasive in our society. Because Americans who use and abuse drugs are part of the working population, employers will continue to be affected by employees with substance abuse problems. The social, economic, and legal costs to business have created a new awareness, and companies are recognizing the need to take special measures to control drug and alcohol use. Urine drug screening has been identified as a valuable tool in discovering, documenting, and ultimately controlling drug use in the workplace. This article deals with the complex issues involved in designing and implementing an industrial drug screening program. The various laboratory techniques are identified and discussed, with special emphasis on their advantages and limitations.     

Common bile duct calculi: updated experience with dissolution with methyl tertiary butyl ether

The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.     

Do shrimp‐allergic individuals tolerate shrimp‐derived glucosamine?

BACKGROUND: There is concern that shrimp-allergic individuals may react to glucosamine-containing products as shrimp shells are a major source of glucosamine used for human consumption. OBJECTIVE: The purpose of this study was to determine whether shrimp-allergic individuals can tolerate therapeutic doses of glucosamine. METHODS: Subjects with a history of shrimp allergy were recruited and tested for both shrimp reactivity via a prick skin test and shrimp-specific IgE by an ImmunoCAP assay. Fifteen subjects with positive skin tests to shrimp and an ImmunoCAP class level of two or greater were selected for a double-blind placebo-controlled food challenge (DBPCFC) using glucosamine-chondroitin tablets containing 1,500 mg of synthetically produced (control) or shrimp-derived glucosamine. Immediate reactions, including changes in peak flow and blood pressure, and delayed reactions (up to 24 h post-challenge) via questionnaire were noted and assessed. RESULTS: All subjects tolerated 1,500 mg of both shrimp-derived or synthetic glucosamine without incident of an immediate hypersensitivity response. Peak flows and blood pressures remained constant, and no subject had symptoms of a delayed reaction 24 h later. CONCLUSION: This study demonstrates that glucosamine supplements from specific manufacturers do not contain clinically relevant levels of shrimp allergen and therefore appear to pose no threat to shrimp-allergic individuals.     

Clinical MR imaging with a Helmholtz-type surface coil

Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution.