Search PubMedSearch

Biomedical subjects

C B Taylor

Publications and source records attributed to C B Taylor.

At least 19 recordsLinked to original sources

Insulin-like growth factor binding protein-3 in normal pubertal girls.

IGFBP-3 concentrations rise in the second decade of life. To test the hypothesis that the stage of pubertal development, independent of chronological age, was associated with these increases we measured serum IGFBP-3 concentrations by radioimmunoassay in 324 sixth and seventh grade girls (12.3 +/- 0.7 years) at the beginning of a multisite school-based health curriculum. The mean (+/- SD) serum IGFBP-3 among the 242 girls with complete data was 4.0 +/- 0.7 mg/l. Pubertal stage was significantly associated with IGFBP-3 (p less than 0.0001, ANOVA). Mean concentrations rose from 3.5 +/- 0.7 mg/l among those with the earliest pubertal stages to 4.2 +/- 0.7 mg/l among the mature girls. IGF-I and IGFBP-3 concentrations were significantly correlated (Spearman's r = 0.43, p less than 0.0001). After controlling for the association between pubertal development and IGFBP-3 concentrations, only the waist/hip ratio, among the various measures of body composition, was significantly associated with IGFBP-3 concentration (Spearman's r = -0.23, p = 0.0002). Likewise, none of the measures of nutrition: intake of total calories, protein, fat and carbohydrate; serum iron; red cell mean corpuscular volume; or cholesterol; were significantly associated with IGFBP-3 concentrations. There was, however, a small, but significant association between IGFBP-3 concentrations and both serum transferrin and blood hemoglobin concentrations. Pubertal stage has a significant impact on IGFBP-3 concentrations and those attempting to utilize IGFBP-3 concentrations during adolescence should be cognizant of the subject's pubertal stage.

Adolescent

Cytotoxicity of oxidation derivatives of cholesterol on cultured aortic smooth muscle cells and their effect on cholesterol biosynthesis.

Aortic smooth muscle cell death is an important initial lesion of atherosclerosis. A number of autooxidation products of cholesterol which has been recognized recently has the capability of inducing rabbits' aortic smooth cell death in vitro. Twelve oxidation derivatives of cholesterol, available commercially, were dissolved in small amounts of ethanol, then added to the culture medium at levels not exceeding 0.8%. The medium contained 10% fetal calf's serum which served as an in situ vehicle for the sterols. The degrees of cytotoxicity were graded and measured as percentage of dying and dead cells in the cultures within 24 hr. 25-Hydroxycholesterol and cholesthan-3 beta, 5 alpha, 6 beta-triol, were the most toxic compounds among the sterols tested. When these oxidation derivatives of cholesterol were added to these cultured cells, they significantly depressed activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase, a regulatory enzyme of cholesterol biosynthesis (up to 83% inhibition by 25 hydroxycholesterol at a 3 microgram/ml concentration in culture medium) but the sequence of degree of inhibition was not exactly correlated with that of cytotoxicity. Various mechanisms are speculated. Purified cholesterol showed no cytotoxic effect and minimal inhibition of cholesterol biosynthesis.

Animals

Effects of relaxation therapy on cardiac performance and sympathetic activity in patients with organic heart disease.

Six patients, with surgically implanted tantalum myocardial markers, were trained in deep muscle relaxation therapy. Analysis of individual responses and group means of blood pressure and ventricular dimensions during relaxation showed a decrease in plasma norepinephrine levels and indices of myocardial contractility compared to the control state. Heart rate changes in individuals during relaxation were directly correlated with changes in plasma norepinephrine levels, although group means for heart rate did not change significantly between control and relaxation periods. Base-line plasma norepinephrine levels were directly correlated with systolic blood pressure and were inveresly correlated with a measure of myocardial contractility. These data suggest that physiological changes during relaxation may be mediated through the sympathetic nervous system.

Aged

Experimental arteriosclerosis in Rhesus monkeys induced by multiple risk factors: cholesterol, vitamin D, and nictotine.

Forty-four rhesus monkeys were given various regimens involving three vasotoxic factors: dietary hypercholesteremia, hypervitaminosis D2 and nicotinism for period ranging from 14 to 62 weeks. When administered singly, no or only early disease was observed. The combined three "risk factor" group demonstrated the most impressive arteriosclerosis. Major arteriosclerotic changes: fat, calcium and mensenchyme of thirty standardized segments of aorta, coronary and limb arteries of all monkeys were graded according to a standardized system. Statistical analysis revealed that the total arteriosclerotic scores of the three vasotoxic factor group was significantly greater than those of any other group and that this was the only group with significant coronary arteriosclerosis as well as complicated lesions such as thrombosis or occlusion of arterial luminae of the extremities. A lowering of the vitamin D2 dosage, resulting in a lengthening of the survival time of animals which should allow sufficient time for complicated disease to develop, is recommended for future studies.

Animals

A rapid behavioral treatment for needle phobics.

A morbid fear of injections and injection paraphernalia can on occasion seriously compromise both the inpatient and outpatient treatment of medical illnesses. Two individuals with a severe needle phobia were treated using participant modeling. In both cases, this very rapid treatment resulted in a remission of symptoms, that in one case persisted at 1 year follow-up post-treatment.

Adult

Effect of auto-oxidation products from cholesterol on aortic smooth muscle cells: an in vitro study.

Purified cholesterol is quite unstable when stored in air at room temperature. Products of cholesterol auto-oxidation were concentrated from several lots of USP-grade cholesterol by recrystallizing cholesterol from the methanol extract, retaining the mother liquor, and evaporating the residuum to dryness under vacuum. By application of thin-layer chromatography and gas-liquid chromatography, major, individual, oxidation compounds were identified and quantitated. Biological activities of these oxidation compounds were studied by using cultured rabbits' aortic smooth muscle cells. The concentrate of the auto-oxidation products of cholesterol showed remarkable in vitro cytotoxic effects, whereas purified cholesterol at the same concentration produced no toxic effects. The concentrate was further separated into six thin-layer chromatographical fractions. The results showed that 25-hydroxycholesterol and cholestane-3beta, 5alpha, 6beta-triol were probably responsible for the biological toxicity of the concentrate

Aorta

Relaxation therapy and high blood pressure.

Thirty-one patients receiving medical treatment for essential hypertension were randomly distributed into three groups: (1) relaxation therapy, (2) nonspecific therapy, and (3) medical treatment only. The nonspecific therapy group spent the same amount of time with the therapists as the relaxation group but was not given a specific therapy. Blood pressures were measured at a different time and in a different place from the behavioral treatments. The relaxation therapy group showed a significant reduction in blood pressure postreatment compared with the nonspecific therapy and medical treatment only groups, even when those patients whose medication was increased were excluded from the data analysis. At follow-up six months post-treatment, the relaxation group showed a slight decrement in treatment effects, while both the nonspecific therapy and medical treatment only groups showed continued improvement; thus, there was not a significant difference between groups.

Blood Pressure

Simple techniques to treat medical phobias.

Participant modelling, a behaviourally-orientated treatment technique, is an effect method of treating phobias associated with minor medical procedures or apparatus such as needles or intravenous catheters. The steps in this technique are described and two cases of severe needle phobias successfully treated with participant modelling are presented to illustrate further its application.

Adult

The development of glycolytic and pentose phosphate shunt enzymes in human brain.

A quantitative enzyme analysis of 32 fetal human brains of 6--42 weeks gestational age range was carried out for the major glycolytic and pentose phosphate shunt enzymes. A critical period of raised enzyme levels was observed at 14 weeks. The glycolytic rate was probably controlled by the activities of hexokinase and phosphofructokinase which appear from the development patterns to have independent genetic sites. A rise in most enzyme activities was experienced in the final weeks of gestation towards levels consistent with those of adult tissues. Pentose phosphate shunt enzyme levels remained virtually unchanged during gestation after 14 weeks.

Brain

Neonatal islet cell transplantation in the diabetic rat: effect on hepatic enzyme activity and glucose homeostasis.

Intraperitoneal transplantation of collagenase-digested, isogeneic, neonatal rat pancreatic tissue successfully reversed streptozotocin-induced diabetes in 77% of recipients. The low serum immunoreactive insulin, hyperglycaemia, glycosuria and weight loss, characteristic of the diabetic animal, were corrected and the reduced activities of hepatic glucokinase and pyruvate kinase, and the low glycogen concentration of the liver of diabetic rats were restored to normal. Forty-three per cent of the successfully transplanted rats became normoglycaemic within 1 month of transplantation whereas 57% took from 1 to 6 months to achieve normoglycaemia and displayed a mild glucose intolerance when subjected to a glucose load. The rats which had not become normoglycaemic 6 months after transplantation showed some amelioration of the diabetic state, as shown by increased serum immunoreactive insulin and hepatic glycogen concentration and a slow weight gain compared with diabetic controls.

Animals