An aviator with an unusual gait: a rare disease teaches some everyday lessons.

Muscular diseases including the dystrophies and myopathies are often incompatible with a variety of occupations including aviation and military duty. Many of these diseases present early in life, are readily diagnosable, and are therefore rare in the aviation community because of pre-screening and selection. Some forms, however, may not present until adulthood during an established aviation career. Furthermore, although initial presentations may be subtle and insidious, the potential occupational and aeromedical ramifications of these diseases can be profound. The following report describes the case of a subjectively asymptomatic career military aviation officer who presented with an unusual gait, and was subsequently determined to have one of the late-presenting muscle disease variants: Anterior compartment Distal Myopathy. The patient's presentation and progression, diagnostic evaluation, prognosis, aeromedical risk and disposition, and issues of occupational and aeromedical significance are discussed.

Tinea pedis: diagnosis and treatment.

The authors review the common dermatophyte genera and the forms of tinea pedia they cause. They also provide a differential diagnosis, review diagnostic procedures, and outline the pathophysiology of this complex condition. A classification and treatment plan is provided, with an extensive review of recent clinical trials. The aim of the article is to expand practitioners' treatment options for individualizing treatment plans.

Simple sensitive solid-phase extraction of paraquat from plasma using cyanopropyl columns.

We report an inexpensive, sensitive paraquat quantitation method which is simple to perform. First, 5 mL of blanks, standards, or patient plasma are applied to 1-mL cyanopropyl extraction columns equipped with 15-mL reservoirs. The samples are drawn through the columns under vacuum, followed by a rinse with 15-20 mL of 0.1M NH4OH. Paraquat is eluted with 0.8 mL 0.1M HCl, which is then neutralized with 25 microL concentrated NH4OH. Sodium dithionite reagent (0.23M in 4M NaOH) is added (100 microL) and the color produced is measured by absorbance difference (A395-A460). The assay is linear up to at least 4.35 microM paraquat. The lower limit of quantitation is 0.23 microM. Lipemic and icteric sera do not affect the method, but easily visible hemolysis elevates the concentrations measured by up to 0.7 microM, independent of paraquat concentration. Equimolar amounts of diquat with paraquat, at paraquat concentrations from 0.4 to 4.0 microM, elevate apparent paraquat concentrations by 0.08-0.28 microM. At 0.632, 1.92, and 4.06 microM paraquat, within-run coefficients of variation (CVs) were 6.27, 7.23, and 2.14%, and between-run CVs were 6.82, 8.42, and 4.43%, respectively.

Efficient extraction of basic, neutral, and weakly acidic drugs from plasma for analysis by gas chromatography-mass spectrometry.

We describe a method for efficiently extracting basic, neutral, and weakly acidic drugs from plasma for toxicological analysis by gas chromatography-mass spectrometry (GC/MS). The 2-mL plasma sample is diluted with an equal volume of saturated NaCl containing triethylamine, 10 mmol/L, and then extracted twice with 4 mL of an equivolume solution of dichloromethane/acetone. The organic (top) phases are combined, then mixed with 1 mL of water, 200 mg of NaHCO3, and 100 microliters of acetic anhydride. This mixture is then heated at 75 degrees C until the solvents have boiled off and aqueous acetylation is complete (less than 30 min). After addition of 1 mL of water and 2 g of NaCl, the sample is extracted twice with 2 mL of dichloromethane/acetone (2/1 by vol). The combined extracts are dried and then subjected to thin-layer chromatography on a blank Toxi-Lab Toxi-A chromatogram with 1-chlorobutane as the developing solvent (about 6 min). After the lipids have migrated with the mobile phase, the drugs are eluted from the origin with acetone/triethylamine (29/1 by vol), evaporated, and reconstituted in injection solvent. With this procedure drugs are recovered relatively quickly (less than 2 h) and the GC/MS total ion chromatograms are very clean. Studies with 13 basic, neutral, and weakly acidic drugs showed that all except theophylline were extracted with recoveries of at least 75%.

Versatile, efficient system for extracting drugs from urine for gas chromatographic/mass spectrometric analysis.

This is a method for efficiently extracting a wide variety of drugs from urine for toxicological analysis by gas chromatography/mass spectrometry. Before extraction, the urine sample is acetylated, diluted with an equal volume of water, and saturated with NaCl. This solution is then mixed with an equal volume of dichloromethane/acetone (2:1 by vol). The organic (top) phase is aspirated and evaporated, and the residue is redissolved in a suitable solvent for injection or further derivatization. This procedure is suitable for all drugs except carboxylate-containing drugs, which may be isolated by replacing the acetylation step with acidification of the urine to pH 2. Studies with 16 drugs containing amino, amide, alcoholic hydroxyl, phenolic hydroxyl, carboxylate groups, or combinations thereof, showed that all drugs except theophylline and benzoylecgonine were extracted with analytical recoveries ranging from 70% to 100%.

Laboratory assessment of three new monitors of blood glucose: Accu-Chek II, Glucometer II, and Glucoscan 2000.

We describe a laboratory assessment of three new monitors of blood glucose concentrations: the Boehringer "Accu-Chek II" (B), the Ames "Glucometer II" (A), and the Lifescan "Glucoscan 2000" (L). Inherent imprecision (CV) of each monitor was less than 2%. Maximum difference between individual monitors of the same type was less than or equal to 0.5 mmol/L. The volume of blood applied to the test strips is not critical, but duration of blood incubation or color development should be precise. Two types of test strips retained sufficient color 48 h after development to allow checking of the original measurement, and would be suitable as quality-control "spot" checks. Correlation coefficients for results for whole-blood glucose vs those for serum glucose (measured with the Beckman ASTRA-8) were: 0.992 (B), 0.967 (A), and 0.988 (L). Bias plots of these data showed positive bias for A (0.45 mmol/L) and L (0.17 mmol/L) in relation to serum-glucose measurements, but a negative bias of 0.32 mmol/L for B. Calibration solutions are not interchangeable. Although these versions of the monitors are probably not analytically superior to earlier models, they are easier to use.

Amplification of D-xylose and D-glucose isomerase activities in Escherichia coli by gene cloning.

A recombinant plasmid, designated pUC1002, was constructed by ligation of a HindIII restriction endonuclease fragment of Escherichia coli chromosomal DNA to vector plasmid pMB9. Strains carrying this plasmid were selected by transformation of an E. coli strain bearing the xyl-7 mutation to a xylose-positive (Xyl+) phenotype. Strains containing pUC1002 produced coordinately elevated levels of D-xylose isomerase and D-xylulose kinase. Under appropriate conditions, the isomerase also efficiently catalyzed the conversion of D-glucose to D-fructose.

Reproductive Biology of Selaginella: I. Determination of Megasporangia by 2-Chloroethylphosphonic Acid, an Ethylene-releasing Compound.

Control clumps of Selaginella wallacei Heiron., sprayed with distilled water with Tween 20, produced a high proportion of microsporangia. Similar clumps sprayed with 2-chlorethyl-phosphonic acid, and ethylene-releasing compound (Ethephon), at 7.65 and 76.5 mg/liter produced almost exclusively megasporangia. Treatment of Selaginella pallescens (Presl) Spring with Ethephon at 34 mg/liter caused the production of megasporangia in the microsporangiate files of the strobili. The possibility that ethylene may be involved in the regulation of heterospory in Selaginella is discussed.