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Biomedical subjects

C A Miller

Publications and source records attributed to C A Miller.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Evidence for an interaction between apolipoprotein E genotype, gender, and Alzheimer disease.

Carriers of the apolipoprotein E (APOE) epsilon4 allele show significantly higher risk of Alzheimer disease (AD). The aim of this present study was to test the hypothesis that a significant interaction exists between APOE genotype and gender on AD. Interactions of epsilon4 by gender, although indicated in the literature, require further verification. A total of 195 past or current control or AD participants in an ongoing longitudinal study of aging and dementia were genotyped. All subjects were at least 60 years old; demented subjects met clinical or pathologic criteria for late-onset AD. Logistic regression analysis and proportional hazard models were used to evaluate joint effects of APOE and gender. A significant statistical interaction between APOE and gender was shown (p = 0.04) in logistic regression analysis. Women carrying one or more APOE-epsilon4 allele were more likely to develop AD [odds ratio (OR) = 7.8, 95% confidence interval (CI) = 3.2-19. 1]. For men, the presence of the APOE-epsilon4 allele was not associated with a statistically significant increased risk (OR = 1.6, 95% CI = 0.5-5.3). The interaction term in the proportional hazards model neared (p = 0.07) statistical significance, and a similar but reduced gender effect was shown. The analysis suggests that the presence of one or more APOE-epsilon4 allele confers a substantially greater risk of AD to women than to men. These findings in part may account for reports of increased risk of AD faced by women.

Aged↗
PubMedDate not supplied

Transcutaneous muscle stimulation promotes muscle growth in immobilized patients.

Muscular activity is a fundamental determinant of muscle mass. Transcutaneous muscle stimulation (TMS) may reverse muscle atrophy and lean mass loss in immobile patients by "artificial exercise." Four paraplegic patients with upper motor neuron lesions entered The Ohio State University Clinical Research Center for a 21-day metabolic balance study. After 6 days of baseline monitoring, each underwent isometric tetanic contractions (15 sec on; 45 sec off) of all major lower extremity muscle groups with TMS for 10 hr daily. Cross-sectional areas of muscle plus bone were calculated with CAT scan planimetry at 7 levels in both lower extremities before and after the TMS period. Three patients completed the metabolic balance study. TMS produced significant growth of innervated thigh and calf muscles in all paraplegic patients. Little growth occurred where bone and tendon predominate. No significant changes in nitrogen balance (urine and stool excretion), potassium balance (urine excretion only), or phosphate balance (urine excretion only) could be demonstrated. Two possible explanations are (1) that the patients may have been underfed and (2) that perhaps due to an increase in metabolic rate owing to the stimulation, lean tissue in other locations may have been mobilized to meet leg muscle demands. Future studies will incorporate metabolic monitoring of oxygen consumption and CO2 production during the experiment.

Electric Stimulation Therapy↗
PubMedDate not supplied

Self-emulsification of surfactant-oil mixtures produced by diffusion and chemical reaction.

Drops having diameters of order 100 microm and containing various combinations of oils, surfactants, and in some cases alcohols were injected into water or aqueous salt or buffer solutions. The resulting dynamic behavior was observed by videomicroscopy. Spontaneous emulsification yielding oil droplets a few microns in diameter was seen in a variety of systems when diffusion and/or chemical reaction caused inversion of the drop from an oil-continuous to a water-continuous phase, leading to local supersaturation in oil. Surfactants used included nonionic (C12E6), anionic (Aerosol-OT), and zwitterionic (tetradecyldimethylamine oxide). In some experiments inversion occurred because a lipophilic surfactant was converted to a hydrophilic surfactant, e.g., a double-chain phospholipid to two single-chain surfactants.

Diffusion↗