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Biomedical subjects

W L Wilson

Publications and source records attributed to W L Wilson.

At least 19 recordsLinked to original sources

Relationship of optical density and skinfold measurements: effects of age and level of body fatness.

We examined relationships between skinfold (SKF) and optical density (delta OD) measurements across age and levels of body fatness (%BF) for 151 women, 20 to 72 years. There were significant (p < .05) relationships between delta ODs and SKFs at all sites, except the thigh. The interaction (SKF x Age) was significant (p < .05) for pectoral and biceps delta ODs. Slope comparisons indicated the relationships for younger (29 years) and older (59 years) women differed significantly from zero and each other (p < .05). Analysis of SKF x %BF interactions revealed that relationships between SKFs and delta ODs at the pectoral and biceps sites for leaner (22% BF) women differed significantly from zero (p < .05) and were larger than those for obese (39% BF) women (p < or = .05). Thus, the relationship between SKFs and delta ODs is stronger for younger and leaner women compared to older and fatter women. These findings may reflect differences in fat layering due to age or body fatness and provide insight as to why the manufacturer's near-infrared (NIR) equation significantly underestimates the %BF of obese women.

Adipose Tissue

Predictive accuracy of three field methods for estimating relative body fatness of nonobese and obese women.

Three methods of body composition assessment were used to estimate percent body fat (%BF) in nonobese (n = 77) and obese (n = 71) women, 20-72 yrs of age. Skinfolds (SKF), bioelectrical impedance (BIA), and near-infrared interactance (NIR) methods were compared to criterion-derived %BF from hydrostatic weighing (%BFHW). Nonobese subjects had < 30% BFHW and obese subjects had > or = 30% BFHW. The Jackson, Pollock, and Ward SKF equation and the manufacturer's equations for BIA (Valhalla) and NIR (Futrex-5000) were used. For nonobese women there were no significant differences between mean %BFHW and %BFSKF, %BFBIA, and %BFNIR. The rs and SEEs were 0.65 and 3.4% BF for SKF, 0.61 and 3.6% BF for BIA, and 0.58 and 3.7% BF for NIR for nonobese subjects. For obese women, mean %BFHW was significantly underestimated by the SKF, BIA, and NIR methods. The rs and SEEs for the obese group were 0.59 and 3.4% BF for SKF, 0.56 and 3.5% BF for BIA, and 0.36 and 3.9% BF for NIR. The total errors of the equations ranged from 5.6 to 8.0% BF in the obese group. It is concluded that all three field methods accurately estimate %BF for nonobese women; however, none of the methods is suitable for estimating %BF for obese women.

Adipose Tissue

Effect of caloric deficit and dietary manipulation on aerobic and anaerobic exercise.

Twelve competitive wrestlers restricted their caloric intake (92 kJ/kg FFW/day) for 7 days, using a high (HC) or normal (NC) carbohydrate diet to determine the acute effect of caloric deficiency on aerobic and anaerobic exercise performance as well as growth hormone (hGH) and insulin-like growth factor 1 (IGF-1) levels. The subjects were tested while on a eucaloric diet and at the end of the dietary restriction. Neither the dietary restriction nor composition had an effect on the ability to complete an 8-minute run at 85% of maximal capacity, but both produced an increased fat utilization during the run. The responses to the Wingate Anaerobic Test indicated that the NC group had a significant reduction in total and mean power output (-7% & -6%, respectively; p less than 0.05), whereas the HC group maintained all power measures. The caloric restriction, regardless of dietary composition, increased the exercise hGH response more for the NC group than the HC group (p less than 0.05). IGF-1 levels were significantly lowered by the diet, but the diet composition had no effect. These results indicate that even during caloric restriction, a high carbohydrate diet better maintains anerobic exercise performance. Furthermore, the composition of the diet appears to have no effect on the resting hGH and IGF-1 responses to caloric deficits. However, carbohydrate composition may have an effect on the gGH response to exercise.

Adult

High-performance liquid chromatographic analysis of penicillin V benzathine oral suspensions.

A rapid high-performance liquid chromatographic assay for penicillin V content of penicillin V benzathine bulk drug and oral suspensions is described. Dilution of the oral suspension with methanol containing 1,3,5-trimethoxybenzene as the internal standard allowed for direct analysis on a reversed-phase column with a mobile phase of 53% methanol in 0.05 M aqueous pH 3.5 phosphate buffer. A relative standard deviation of less than 1% was obtained on commercial formulations, and the system was linear over a range 10-40 microgram injected.

Chromatography, High Pressure Liquid

Isolation and identification of a fluorophore from ampicillin degradation.

A fluorescent impurity in ampicillin has been isolated and identified as 2-hydroxy-3-phenylpyrazine. The product is formed under acidic conditions similar to those employed in some fluorometric assay procedures. The mechanism of the reaction is proposed to involve cyclization by condensation of the penilloaldehyde of ampicillin. The structure was confirmed by independent synthesis.

Ampicillin

Treatment of advanced malignancy with CCNU (NSC 79037): a phase II cooperative study with long-term follow up.

CCNU (1-[2-chloroethyl]-3-cyclohexyl-1-nitrosourea, NSC-79037) was used to treat advanced malignancies in 329 evaluable patients. The treatment dosage was 130 mg/m2 for patients with adequate bone marrow reserve and 100 mg/m2 for those with compromised bone marrow. Oral treatment was repeated at 6-week intervals unless hematologic toxicity intervened. There were four complete responses: two in ovarian cancer, one with small cell carcinoma of the lung, and one with melanoma. Tumor response greater than 50% reduction in tumor size occurred in 39 patients (11.9%) while stable disease (no change or decrease or increase of less than 50% in tumor size) was noted in 152 patients (46.2%). Tumor progression occurred in 130 cases. Melanomas and ovarian and lung cancers had the highest response rates. Bone marrow depression was the major side effect of treatment; there was a significant positive correlation between the severity of leukopenia and thrombocytopenia and tumor response to treatment.

Humans

A randomized pilot study comparing two regimens in the treatment of squamous cell carcinoma.

Thirty-five patients with epithelial carcinomas not considered to be surgically resectable were randomized to receive two different chemotherapy regimens. Regimen 1 was CCNU followed by bleomycin, and Regimen 2 was a combination of CCNU, bleomycin, methotrexate, and vinblastine. Five of 14 patients treated with CCNU-bleomycin had partial responses. Three of 15 patients treated with the four-drug combination had a partial response. The toxicity of the four-drug regimen was significantly greater than that of the two-drug regimen, while the response rate was greater among those patients treated with two drugs. No significant clinical infections occurred despite the fact that leukopenia and thrombocytopenia were more severe and frequent with the four-drug regimen. Most importantly, the two-drug regimen is well tolerated as an outpatient procedure. Two of the two-drug and one of the four-drug recipients were converted from an inoperable to an operable state. In view of the fact that there has not heretofore been an effective chemotherapeutic regimen for Stage III and IV squamous carcinoma, this is a significant observation. It is of note that patients with squamous cell carcinoma of the head and neck were those who responded best to this treatment, although the treatment is worthy of consideration for advanced squamous carcinoma in other areas.

Bleomycin