Accuracy of body mass index in volunteer firefighters.

BACKGROUND: Obesity is prevalent among career firefighters and may contribute to heart attacks, a leading cause of on-duty fatalities. The US National Fire Protection Association estimates that 800 000 of 1.1 million firefighters are volunteers. Body mass index (BMI) is commonly used to assess obesity, but little is known about its accuracy in volunteer firefighters, in whom muscle mass may be higher, given firefighting's physical demands, reducing its accuracy in identifying obesity. AIMS: To evaluate the accuracy of BMI in identifying obese volunteer firefighters. METHODS: Height, weight and body composition were measured in 73 male volunteer firefighters (mean age 40±12). The proportions with BMI ≥ 25kg/m(2), ≥30kg/ m(2) and percent fat ≤ 20th percentile were determined. Using the age-specific 20th percentile for percent fat (Cooper Clinic) as the criterion for being over-fat, the accuracy of BMI was assessed using sensitivity and specificity calculations. RESULTS: The means ± standard deviation of BMI and percent fat were 32±6 and 25±5, respectively. The proportions with a BMI ≥ 25 and ≥30 were 90% and 60%, respectively. Fifty-one percent had a percent fat ≤ 20th percentile. The measure BMI ≥ 25 had a perfect sensitivity (1.0) and low specificity (0.19) and BMI ≥ 30 had a high sensitivity (0.89) and moderate specificity (0.69). CONCLUSIONS: Although BMI ≥ 30 accurately predicted being over-fat, it misclassified large and lean firefighters. Although BMI should be used cautiously, it can identify over-fat firefighters at risk of cardiovascular disease, and its measurement is cost-effective and simple.

Evaluation of quantitative structure property relationships necessary for enantioresolution with lambda- and sulfobutylether lambda-carrageenan in capillary electrophoresis.

Lambda-carrageenan, a linear, high molecular weight sulfated polysaccharide, was successfully employed in both its native and sulfobutyl derivatized form as a chiral selector in capillary electrophoresis for the separation of enantiomers of basic pharmaceutical compounds. In order to characterize the chiral selectivity properties of this chiral selector, various structurally related racemic compounds were analyzed for enantiomeric interactions using capillary electrophoresis. The results of these studies were then rationalized and analyzed utilizing a general quantitative structure-property relationship (QSPR) evaluation in order to predict critical analyte structural requirements for successful enantiomeric separation. Important structural components of the analytes were found to include the aromatic content, the type of substitution on the aromatic ring, presence of a primary or secondary protonated amine, and an overall positive charge to the molecule.

Disordered breathing and oxygen desaturation during sleep in patients with chronic obstructive lung disease (COLD).

Seven patients with chronic obstructive lung disease (COLD) were monitored during their overnight sleep to determine the occurrence of disordered breathing and oxygen desaturation. Nasal and oral airflows were sensed by thermistor probes, chest wall movement by impedance pneumography and arterial oxygen saturation by ear oximetry. These variables were correlated with electroencephalographic and electrooculographic tracings. The subjects had a mean base line oxygen saturation of 89.2 per cent and slept an average of 218 minutes. Six of these seven subjects had one to 30 episodes of oxygen desaturation (decrease more than 4 per cent), 4 seconds to 30 minutes in duration, with declines in saturation as great as 36 per cent. In two subjects, saturation dropped to less than 50 per cent. Breathing was disordered in five of the seven subjects and included apnea and hypopnea. Subjects experienced from nine to 37 episodes of disordered breathing. Disordered breathing caused 42 per cent of the episodes of desaturation, all of which were less than 1 minute in duration. The mean maximum decline in saturation was 7.6 per cent. All episodes of desaturation lasting longer than 5 minutes occurred in rapid eye movement (REM) sleep and were not caused by disordered breathing. The mean maximal decrease in saturation was 22 per cent. This study reveals that disordered breathing is common in subjects with COLD and often causes desaturation but that it cannot explain all episodes of sleep desaturation.

Complete amino acid sequence of the major component myoglobin of finback whale (Balaenoptera physalus).

The complete amino acid sequence of the major component myoglobin from finback whale, Balaenoptera physalus, was determined by the automated Edman degradation of several large peptides obtained by specific cleavages of the protein. Three easily separable peptides were obtained by cleaving with cyanogen bromide at the two methionine residues and one large peptide was isolated after cleavage with (2-p-nitrophenylsulfenyl)-3-methyl-3'-bromoindolenine. More than 60% of the covalent structure was established by the sequential degradation of three of these peptides and the apomyoglobin. An additional 30% of the primary sequence was established with peptides obtained from tryptic digestion of both the apomyoglobin and the acetimidoapomyoglobin, and the final 10% of the sequence was completed after digestion of the two larger cyanogen bromide peptides with S. aureus strain V8 protease. This myoglobin differs from that of the sperm whale, Physeter catodon, at 15 positions, from that of the arctic minke whale, Balaenoptera acutorostrata, at 3 positions, and from that of the California gray whale, Eschrichtius gibbosus, at 4 positions. All of the substitutions observed in this sequence fit easily into the three-dimensional structure of the sperm whale myoglobin.