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Biomedical subjects

P C Richardson

Publications and source records attributed to P C Richardson.

At least 19 recordsLinked to original sources
PubMed1988

Biochemical deficiencies of coenzyme Q10 in HIV-infection and exploratory treatment.

AIDS patients (2 groups) had a blood deficiency (p less than 0.001) of coenzyme Q10 vs. 2 control groups. AIDS patients had a greater deficiency (p less than 0.01) than ARC patients. ARC patients had a deficiency (p less than 0.05) vs. control. HIV-infected patients had a deficiency (p less than 0.05) vs. control. The deficiency of CoQ10 increased with the increased severity of the disease, i.e., from HIV positive (no symptoms) to ARC (constitutional symptoms, no opportunistic infection or tumor) to AIDS (HIV infection, opportunistic infection and/or tumor). This deficiency, a decade of data on CoQ10 on the immune system, on IgG levels, on hematological activity constituted the rationale for treatment with CoQ10 of 7 patients with AIDS or ARC. One was lost to follow-up; one expired after stopping CoQ10; 5 survived, were symptomatically improved with no opportunistic infection after 4-7 months. In spite of poor compliance of 5/7 patients, the treatment was very encouraging and at times even striking.

AIDS-Related Complex↗
PubMed1981

Bioenergetics in clinical medicine. XVI. Reduction of hypertension in patients by therapy with coenzyme Q10.

Six untreated hypertensive patients and ten on therapy, but having elevated blood pressures, were treated with coenzyme Q10(CoQ10); 14/16 patients showed reductions (p less than 0.05-less than 0.001) in systolic pressures; 11/16 showed reductions (p less than 0.05-less than 0.001) in diastolic pressure; 9/10 showed reductions of elevated pressures to a normal range. By impedance cardiography and electrocardiography, there were no changes in cardiac outputs, stroke volumes and Heather Indices except for a few patients with changes of doubtful biological significance. 3/16 patients had exceptionally low basal specific activities of the succinate dehydrogenase-coenzyme Q10 reductase in blood which increased to a normal range on treatment. A greater deficiency of CoQ10 in the vascular system than in blood is likely. We consider that (1) the mechanism of reduction of elevated blood pressures by CoQ10 is based upon normalization or autoregulation of peripheral resistance rather than cardiac regulation, and (2) that the therapeutic activity of CoQ10 is not pharmacodynamic, but results from a translational increase in levels of CoQ10-enzymes in vascular tissue during ca. 4-12 weeks.

Blood Pressure↗
PubMed1978

Classification of sleep stage with period analysis features derived from the EEG.

This paper details our experience with the use of regression analysis and discriminant analyses, combined with a Bayes classifier, to evaluate the usefulness of a series of features derived in real time from a single channel of EEG. These features were 1) the number of zero crossings, 2) the number of zero crossings of the first derivative of the EEG, and 3) the number of zero crossings of the second derivative and five additional "histogram" measures. Each histogram measure represented the number of occurrences of a zero crossing interval falling within an arbitrarily selected range of values. The distributions of several measures conditioned on sleep stage are presented along with night-to-night and subject-to-subject variations in the measures. These details provide a basis for understanding effectiveness and limitations of zero crossing measures and the regression and discriminant analysis techniques. Our results permitted a range of 57-90% accurate classification with just zero crossing measures with the cross-correlation between computer- and hand-scored nightly sleep patterns ranging from 0.63-0.94. We consider these to be good and acceptable accuracies for this type of analysis.

Electroencephalography↗
PubMed1976

Detection of cyclic sleep phenomena using instantaneous heart rate.

The development of the Heart Beat Domain and the Fourier transform of the Heart Beat Domain (which we call the Beatquency Domain) has provided new and useful tools for the quantitative analysis of sleep level patterns. This method of analysis has produced remarkable intersubject as well as intra-subject consistency and the only physiologic parameter required in the analysis is beat-by-beat heart rate. This analytical tool was designed to aid in the detection of sleep cycles, or more specifically, the rhythmic transitions from REM+ (awake Stages 1 and REM combined) to NREM (Stage 2, 3 and 4 combined) over a normal night of sleep. Employing this method on minute-by minute sleep recordings from 9 normal sleep subjects, 2 complete nights each, we were able to distinguish between the REM+ and NREM stages with an average accuracy of approximately 80%. Considering that beat-by-beat heart rate was our only criteria, we felt that the algorithm performed with significant success.

Heart Rate↗
PubMed1976

A double blind trial of gefarnate and placebo in the treatment of gastric ulcer.

Forty-five patients with chronic gastric ulcers were treated as out-patients in a double-blind comparison of gefarnate (geranyl farnesylacetate), 50 mg four times daily, with the same number of dummy capsules daily for five weeks. The mean percentage reduction in ulcer size assessed by radiography was 70-4 per cent in the gefarnate patients compared with 27-8 per cent in those receiving placebo capsules. This difference is statistically significant (p less than 0-05, with a two-tailed test). No change in the electrolyte balance occurred in any of the patients and no side-effects were reported. These results suggest that gefarnate promotes the healing of gastric ulcers in ambulant patients. Its apparent absence of side-effects makes it a safe ans useful drug.

Clinical Trials as Topic↗