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Biomedical subjects

D M Claman

Publications and source records attributed to D M Claman.

6 recordsLinked to original sources

Hypothermia and afterdrop following open water swimming: the Alcatraz/San Francisco Swim Study.

To determine whether or not participants in open water swim events experience hypothermia and afterdrop, rectal temperature was measured for up to 45 minutes in 11 subjects following the New Year's Day Alcatraz Swim. This event was held in open water (11.7 degrees C [53.0 degrees F]) in the San Francisco Bay, and participants did not wear wetsuits or other protective clothing. Biophysical parameters, including surfacelvolume ratio, body mass index, and percent body fat were measured before the swim, and statistical analysis was done to determine predictors of temperature decrease and afterdrop duration. Applying the American Heart Association definition of hypothermia (less than 36.0 C [96.8 degrees F]), hypothermia was seen in 5 of the 11 subjects. Using a more rigorous and traditional definition (less than 35.0 degrees C [95.0 degrees F]), hypothermia was seen in only one subject. Afterdrop, defined as continued cooling following removal from cold stress, was seen in 10 of the 11 subjects. Surface/volume ratio (S/V) and body mass index (BMI) predicted the lowest recorded temperatures (P < .05; r(S/V) = -.71, r(BMI) = .72) and afterdrop duration (P < .05; r(SN) = -.75, r(BMI) = .69). These results suggest that hypothermia and afterdrop can occur commonly after recreational open water swimming, and that participants should be observed for signs of temperature decrease following removal from cold stress.

Adult↗

Analysis of induced sputum to examine the effects of prednisone on airway inflammation in asthmatic subjects.

To determine whether induced sputum samples might provide a useful means for evaluating the effects of therapy on airway mucosal inflammation, we examined induced sputum samples obtained before and after 6 days of treatment with prednisone (0.5 mg/kg/day) or placebo in a randomized, double-blind study of 24 asthmatic subjects. Induced sputum was analyzed for total and differential cell counts and for concentrations of eosinophil cationic protein, albumin, and mucin-like glycoprotein. We found that the mean (+/- SEM) percentage of eosinophils in sputum samples from the prednisone-treated group fell from 14.1% +/- 5.0% at baseline to 1.8% +/- 0.8% after treatment, a decrease significantly greater than in the placebo-treated group (from 10.3% +/- 4.9% to 11.1% +/- 4.0%; p = 0.002). The absolute number of eosinophils also decreased significantly more in the prednisone-treated group than in the placebo-treated group (p = 0.04). In addition, eosinophil cationic protein levels in induced sputum fell more in the prednisone-treated group than in the placebo-treated group (from 324 +/- 131 ng/ml to 144 +/- 84 ng/ml vs 173 +/- 50 ng/ml to 188 +/- 47 ng/ml; p = 0.002). Furthermore, prednisone treatment was associated with a significant increase in peak expiratory flow, an effect that was significantly correlated with the decrease in eosinophil percentage in induced sputum (rs = 0.64, p = 0.04). Prednisone treatment was not associated with any significant change in the concentrations of albumin or mucin-like glycoprotein. We conclude that analysis of induced sputum is a useful noninvasive method for studying the effects of asthma therapy on airway eosinophilic inflammation.

Adult↗

A bifunctional thymidylate synthetase-dihydrofolate reductase in protozoa.

Thymidylate synthetase and dihydrofolate reductase exist as a bifunctional protein in a number of species of protozoa which span diverse groups of the subkingdom. The enzymes copurify upon gel filtration and on affinity chromatography columns specific for dihydrofolate reductase. The bifunctional protein has been found in species of Crithidia, Leishmania, Trypanosoma, Plasmodium, Eimeria, Tetrahymena and Euglena. For reasons unknown, neither enzyme could be detected in Entamoeba histolytica or E. invadens. Since neither enzyme has yet been found as a separate protein in protozoa, it is likely that the bifunctional protein is widespread among these primitive eukaryotes. In most cases, the apparent size of the native protein is approximately twice that of the subunit possessing thymidylate synthetase. Further, with one exception, the subunit sizes are close to the sum of the subunit sizes of the separate enzymes found in other sources.

Animals↗