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Biomedical subjects

C B Taylor

Publications and source records attributed to C B Taylor.

At least 163 records · Page 9Linked to original sources
PubMed1985

Cholesterol oxidation derivatives and arterial endothelial damage.

Three groups of New Zealand male while rabbits were given either 2.5 mg/kg of 25-hydroxycholesterol, cholestane-3 beta, 5 alpha, 6 beta-triol or vehicle only, intravenously. 24 h after treatment, the luminal surfaces of aortae of rabbits receiving 25-hydroxycholesterol were examined by scanning electron microscopy (SEM) and showed numerous balloon-like protrusions and crater-like defects as well as circulating, formed elements adhering on the luminal surface. The luminal surface of aortae of rabbits given cholestane-3 beta, 5 alpha, 6 beta-triol had similar but more frequent lesions when compared with those of the 25-hydroxycholesterol group. Microthrombi were occasionally found. The aortae of the control group had significantly fewer lesions. Transmission electron-microscopic studies showed intracytoplasmic vacuoles and diffuse subendothelial edema in the aortae of the two groups receiving the oxidation derivatives of cholesterol. The balloon-like protrusions and crater-like defects observed by SEM appeared to represent the initial sterol-induced endothelial cell injury. Repeated episodes of arterial injury followed by thrombus formation could eventually lead to atherosclerosis.

Animals↗
PubMed1985

Mediated smoking cessation programs in the Stanford Five-City Project.

Two mediated smoking cessation programs were subjected to a field evaluation. The Quit Kit is a printed self-help package, and "Calling It Quits" consists of five segments which were aired on the local television news. A sample of 239 persons requested the Quit Kit and were followed. At the 2-month and 12-month follow-ups, respectively, 13.6% and 17.9% of those surveyed reported abstinence. Results indicate the potential of mediated interventions.

Adult↗
PubMed1985

The Stanford Five-City Project: design and methods.

The Stanford Five-City Project is a large experimental field study of community health education for the prevention of cardiovascular disease. It will provide data on fundamental questions in cardiovascular disease epidemiology, communication, health education, behavior change, and community organization, and will also test the ability of a potentially cost-effective program to prevent cardiovascular disease at the community level. This paper describes the purposes, hypotheses, design, and methods of the Five-City Project as a reference for future papers describing results. It is hypothesized that a 20% decrease in cardiovascular disease risk will lead to a significant decline in cardiovascular disease event rates in two treatment communities compared with three reference communities as a result of a six-year intervention program of community-wide health education and organization. Risk factor change will be assessed through four surveys of independent samples and in a repeatedly surveyed cohort. Cardiovascular disease event rates will be assessed through continuous community surveillance of fatal and nonfatal myocardial infarction and stroke.

Adolescent↗
PubMed1985

Comparison of beta enolase and myoglobin as histological markers of rhabdomyosarcoma.

A comparative study of beta enolase and myoglobin as markers of muscle differentiation in rhabdomyosarcoma was carried out, using an immunoperoxidase peroxidase antiperoxidase technique. Material from 26 cases of childhood rhabdomyosarcoma was studied and subdivided into embryonal and alveolar types. Positive cytoplasmic staining for beta enolase was seen in 85% of tumours studied (91% alveolar, 79% embryonal), whereas positive staining for myoglobin was detected in only 69% of tumours (82% alveolar, 64% embryonal). beta Enolase and myoglobin are useful in the histological diagnosis of rhabdomyosarcoma, and of the two, beta enolase seems to be the more sensitive.

Cell Differentiation↗
PubMed1985

Influence of cholesterol oxidation derivatives on membrane bound enzymes in cultured aortic smooth muscle cells.

Cholestane-3 beta, 5 alpha, 6 beta-triol and 25-hydroxycholesterol are two of the most cytotoxic and also relatively abundant of the autoxidation derivatives of cholesterol. Cultured aortic smooth muscle cells which were incubated with 10 micrograms/ml of either sterol for 24 to 48 hr showed a marked decrease of 5'-nucleotidase activity in isolated crude membranes. It was further demonstrated that 5'-nucleotidase activity was also markedly decreased in plasma membrane-enriched fractions when cells were incubated with cholestane-3 beta,5 alpha,6 beta-triol. Na+,K+-ATPase activity in crude membranes showed a significant decrease (32%) only in cells incubated with cholestane-3 beta,5 alpha,6 beta-triol for 48 hr. There was no effect on Na+,K+-ATPase activity in cells incubated for 24 hr with either sterol.

5'-Nucleotidase↗
PubMed1985

Effects of oxygenated derivatives of cholesterol on cholesterol uptake by cultured aortic smooth muscle cells.

The cytotoxicity of oxygenated derivatives of cholesterol on the cultured cells may not only be due to their potent inhibition of cholesterol biosynthesis, but also could be related to their capability for inhibiting cholesterol uptake from exogenous sources, particularly in arterial cells, which synthesize cholesterol at a very slow rate. In cultured aortic smooth muscle cells, the most potent inhibitor of cholesterol uptake was cholestane-3 beta,5 alpha,6 beta triol, which at 100 micrograms/ml medium reduced uptake of cholesterol to 10% of the control. The next most potent inhibitors were 5 alpha,6 alpha- epoxycholesterol and 25-hydroxycholesterol, which reduced uptake of cholesterol to 60%. 7 alpha- and 7 beta-hydroxycholesterol and 7-ketocholesterol inhibited cholesterol uptake to 30-50%. A consequence of their inhibitory effects on cholesterol uptake could be a depletion of cell membrane cholesterol, resulting in alterations in membrane structure and function and eventually in cell death.

Animals↗
PubMed1984

Effects of cholesterol autoxidation derivatives on hexose transport in cultured aortic smooth muscle cells.

Several cholesterol autoxidation derivatives known to be cytotoxic to arterial smooth muscle cells both in vivo and in vitro were shown to inhibit hexose transport in these cells in culture. Cholestane-3 beta, 5 alpha, 6 beta-triol was the most potent inhibitory sterol. The rapid onset of inhibition (15 min) and the reversibility of the effect upon removal of the sterol from the tissue culture medium suggests that the effect may be due to incorporation of the sterol into the plasma membrane. 25-Hydroxycholesterol, a potent inhibitor of sterol biosynthesis in cultured arterial smooth muscle cells, did not affect hexose transport up to 8 hr of incubation. The cytotoxic effect of 25-hydroxycholesterol, therefore, may be a consequence of the reduced sterol biosynthesis caused by this sterol.

Animals↗
PubMed1984

Seven-day activity and self-report compared to a direct measure of physical activity.

To determine how well a seven-day interview-administered activity recall used in a large epidemiologic study at Stanford University reflected seven days of self-reported activity and directly measured physical activity, 30 white males, mean age 52 years, recorded daily physical activity for a week, and half of these wore an ambulatory solid-state minicomputer (Vitalog) which measures continuous heart rate and motion. Total hours of moderate, hard, and hard plus very hard activity were not significantly different for weekdays and weekends for self-report and recall and were significantly correlated. Total energy expenditure for subjects wearing the Vitalog averaged 38.5 +/- 6.7 kcal/kg/day compared to an average of 37.7 +/- 4.5 kcal/kg/day for recall or 39.6 +/- 7.2 kcal/kg/day for self-report. Conditioning activities are best remembered followed by home or leisure and job activities. Mean hours of sleep per week night were significantly greater reported by self-report than reported by recall, but the two were significantly correlated. It is concluded that a seven-day activity recall accurately reflects mean kcal/day expenditure, with conditioning activities being the best recalled. A self-report log used in conjunction with an interview-based seven-day recall might maximize accuracy of recall.

Adult↗
PubMed1984

Stress factors in the development of coronary artery disease.

The epidemiologic evidence that stress contributes to cardiovascular disease is reviewed. No one characterization of stress has been associated with all manifestations of cardiovascular disease, yet specific characterizations have been associated with particular manifestations of disease. Type A behavior pattern is a risk factor for coronary artery disease (CAD) and is correlated with the severity and progression of atherosclerosis demonstrated angiographically. Work overload with job dissatisfaction also predisposes to CAD. Socioeconomic disadvantage in a society of urbanization and industrialization increases the risk of hypertension and CAD, while chronic states of anxiety, depression, and helplessness are associated with angina and sudden death. Traumatic life events, especially involving loss of or threat to self-esteem, may precipitate sudden death in patients with preexisting CAD. There is evidence that the mechanism linking the experience of stress and the development of acute coronary events is exposure to sympathetic hyperarousal and a deficit in soothing. Research is needed to determine if work environments can be designed to minimize hyperarousal and provide protective outlets for individuals experiencing such arousal.

Adult↗
PubMed1984

Cerebrospinal fluid enolase isoenzymes and neurotoxicity in early treatment of lymphoblastic leukaemia.

Serial measurements of enolase in the cerebrospinal fluid were made in 19 children with lymphoblastic leukaemia undergoing their first 6 weeks of antineoplastic treatment. The neurone-specific gamma enolase value rose appreciably in nearly all patients during the first two weeks of treatment, which comprised chemotherapy only, but the mean values for this isoenzyme failed to show any further rise during the subsequent cranial irradiation. In contrast the alpha enolase value, which is derived predominantly from glial tissue, rose progressively to attain its highest value during radiotherapy. A consideration of the likely rate of clearance of gamma enolase from the cerebrospinal fluid and the time sequence of administration of the several chemotherapeutic agents in UKALL VIII suggests that asparaginase may be the main causative agent in the rise of this marker of neuronal damage.

Asparaginase↗
PubMed1984

An investigation of beta enolase as a histological marker of rhabdomyosarcoma.

Sections from 21 tumours diagnosed as primary or metastatic rhabdomyosarcoma were stained for alpha and beta enolase. The cases were subdivided into embryonal and alveolar subtypes (38% and 62%, respectively). Positive cytoplasmic staining for alpha enolase was seen in all but one case, and cytoplasmic staining for beta enolase was seen in some cells in 18 of the 21 cases (86% of the total, 88% of the alveolar subgroup, and 85% of the embryonal subgroup). No cells stained positively for beta enolase in the control series of neuroblastomas, fibrosarcomas, Wilms' sarcomas, and an osteosarcoma. The results show that beta enolase is a sensitive marker of muscular differentiation in rhabdomyosarcoma.

Clinical Enzyme Tests↗
PubMed1984

Cerebrospinal fluid enolase in stroke.

This study relates the level of alpha and gamma enolase in cerebrospinal fluid sampled within 4 days of a stroke to the volume of the cerebral infarct measured on the CT image and to the clinical outcome of the patient. Twenty-eight patients were studied, two with transient ischaemic attacks and 26 with completed stroke due to infarction. The cerebrospinal fluid enolase was raised in the two patients with transient ischaemic attacks and 23 with completed stroke. There was a positive correlation between the volume of the infarct and the level of cerebrospinal fluid alpha and gamma enolase. A high cerebrospinal fluid enolase was always associated with a poor prognosis.

Adult↗
PubMed1983

Effects of early postmyocardial infarction exercise testing on self-perception and subsequent physical activity.

The effects of exercise testing 3 weeks after clinically uncomplicated myocardial infarction (MI) on subsequent physical activity were evaluated in 40 consecutive men with a mean age of 52 +/- 9 years. Patients' confidence in their ability to perform various physical activities was evaluated with self-efficacy scales which patients completed before and after a symptom-limited treadmill exercise test. Increases in confidence (self-efficacy) for activities similar to treadmill exercise (walking, stair climbing, and running) were greatest after treadmill exercise, whereas increases for dissimilar activities (sexual intercourse and lifting) were greatest after test results were explained by a physician and nurse. The intensity and duration of subsequent physical activity at home were more highly correlated with self-efficacy after treadmill exercise than with peak treadmill heart rate. Of the 8 patients whose treadmill tests were limited by angina pectoris, 7 had self-efficacy scores which remained low after treadmill testing or which decreased from initially high values after treadmill testing. These patients had lower peak heart rates and work loads than patients whose self-efficacy increased or remained high after treadmill testing. After MI, patients' perception of their capacity for physical activity and their actual patterns of subsequent physical activity are influenced by early treadmill testing in a manner which is congruent with these patients' treadmill performance.

Adult↗