Biomedical subjects

C B Taylor

Publications and source records attributed to C B Taylor.

At least 19 recordsLinked to original sources

PubMed1992

Effects of anger on left ventricular ejection fraction in coronary artery disease.

This study examined the comparative potency of several psychological stressors and exercise in eliciting myocardial ischemia as measured by left ventricular (LV) ejection fraction (EF) changes using radionuclide ventriculography. Twenty-seven subjects underwent both exercise (bicycle) and psychological stressors (mental arithmetic, recall of an incident that elicited anger, giving a short speech defending oneself against a charge of shoplifting) during which EF, blood pressure, heart rate and ST segment were measured. Eighteen subjects had 1-vessel coronary artery disease (CAD), defined by greater than 50% diameter stenosis in 1 artery as assessed by arteriography. Nine subjects served as healthy control subjects. Anger recall reduced EF more than exercise and the other psychological stressors (overall F [3.51] = 2.87, p = .05). Respective changes in EF for the CAD patients were -5% during anger recall, +2% during exercise, 0% during mental arithmetic and 0% during the speech stressor. More patients with CAD had significant reduction in EF (greater than or equal to 7%) during anger (7 of 18) than during exercise (4 of 18). The difference in EF change between patients with CAD and healthy control subjects was significant for both anger (t25 = 2.23, p = 0.04) and exercise (t25 = 2.63, p = 0.01) stressors. In this group of patients with CAD, anger appeared to be a particularly potent psychological stressor.

Anger↗

PubMed1992

Imipramine and alprazolam effects on stress test reactivity in panic disorder.

The reactivity of 40 panic disorder patients on mental arithmetic, cold pressor, and 5% CO2 inhalation stressors was tested before and after 8 weeks of treatment with imipramine, alprazolam, or placebo. Mean levels of subjective and physiological stress measures were compared during a baseline before any stressors were given, and at anticipation, stressor, and recovery periods for each stressor. After treatment, imipramine patients differed from the other two treatment groups on the prestressor baseline in showing higher systolic blood pressure (mean difference about 10 mmHg), higher diastolic blood pressure (10 mm Hg), higher heart rate (15 bpm), less respiratory sinus arrhythmia, shorter pulse transit time, and lower T-wave amplitude. Respiratory measures, electrodermal measures, body movement, and self-reported anxiety and excitement did not distinguish the groups. Reactivity to the stress tests was unaffected by the medications, but tonic differences present in the baseline persisted.

Adult↗

PubMed1992

Is puberty a risk factor for eating disorders?

OBJECTIVE: To examine the association between stage of sexual maturation and eating disorder symptoms in a community-based sample of adolescent girls. PARTICIPANTS: All sixth- and seventh-grade girls (N = 971) enrolled in four northern California middle schools. MAIN VARIABLES EXAMINED: Pubertal development measured using self-reported Tanner stage and body mass index (kg/m2). The section of the Structured Clinical Interview for DSM-III-R Disorders (SCID) discussing bulimia nervosa was used to evaluate symptoms of bulimia nervosa. RESULTS: Girls manifesting eating disorder symptoms, while not significantly older than their peers without such symptoms, were more developmentally advanced as determined with Tanner self-staging. The odds ratio for the association between sexual maturity and symptoms was 1.8 (95% confidence interval, 1.2 to 2.8); ie, at each age, an increase in sexual maturity of a single point was associated with a 1.8-fold increase in the odds of presenting symptoms. The odds ratio for the association between body mass index (adjusted for sexual maturity) and symptoms was 1.02 (95% confidence interval, 1.0 to 1.05). There was no independent effect of age or of the interaction between age and the sexual maturity index. CONCLUSIONS: These results suggest that (1) puberty may be a risk factor for the development of eating disorders, and (2) prevention efforts might best be directed at prepubertal and peripubertal adolescents.

Adolescent↗

PubMed1992

Stress test reactivity in panic disorder.

The psychological and physiological reactivity of 52 patients with panic disorder to mental arithmetic, cold pressor, and 5% carbon dioxide inhalation tests was compared with that of 26 age- and sex-matched normal subjects. In general, patients with panic disorder were neither more physiologically reactive to these stressors than normal subjects nor slower to recover from them, but they were tonically more anxious and much more likely to ask to stop carbon dioxide inhalation or to report panic attacks during this test. Patients who reported panic attacks (46%) had manifested greater anticipatory anxiety before the gas was delivered, accompanied with increased beta-adrenergic cardiac tone. Thus, anticipatory anxiety can be an important factor in panic provocation. Physiological measures varied greatly in their sensitivity to phasic or tonic anxiety. Carbon dioxide stimulated large increases in respiratory minute volume, but these increases were no greater for patients than for normal subjects.

Adult↗

PubMed1992

Effect of a six-month aerobic exercise training program on cardiovascular responsivity in healthy middle-aged adults.

The purpose of this study was to determine the effects of a six month aerobic exercise training regimen on cardiovascular responsivity to mental arithmetic in healthy middle-aged men and women. Subjects were randomly assigned to a moderate intensity exercise intervention or to an assessment-only control group. Before and after the intervention subjects' heart rates and blood pressures were measured doing a mental arithmetic task (N = 83). Other physiological and psychosocial measures included the Type A structured interview and a maximal exercise treadmill test. Validated adherence to the exercise regimen exceeded 75% and there were significant increases in aerobic capacity in those subjects receiving exercise training. Exercise did not significantly reduce cardiovascular responsivity to the stress task. Type A behavior did not interact with reactivity across exercisers or controls nor was it significantly correlated with adherence. The results are discussed with respect to factors that have been previously reported to potentially influence the exercise/reactivity relationship.

Arousal↗

PubMed1992

Pubertal stage and panic attack history in sixth- and seventh-grade girls.

OBJECTIVE: Although the incidence of first panic attacks appears to peak during adolescence, little is known about which features of adolescence contribute to the risk of a first panic episode. The purpose of this study was to compare the relative importance of age and pubertal stage in explaining the occurrence of panic attacks in adolescents. METHOD: From a school-based sample of sixth- and seventh-grade girls, 754 subjects completed both a structured clinical interview determining history of one or more panic episodes and a self-assessment of Tanner stages of pubertal development. A multiple logistic regression analysis was performed with panic attack history as the dependent variable and pubertal stage, age, and their interaction as the independent variables. RESULTS: A history of one or more four-symptom panic attacks was found in 5.3% of the girls (N = 40). After age was controlled for, pubertal stage was significantly related to panic attack history. At each age, higher rates of panic attacks were found in the more physically mature girls. CONCLUSIONS: Pubertal stage, after adjustment for the effects of age, appears to predict panic attack occurrence in young adolescent girls. Understanding the link between puberty and panic may offer clues regarding the onset and etiology of panic attacks.

Adolescent↗

PubMed1992

Psychological precursors of panic attacks.

The ongoing experience of panic disorder was assessed in 20 female subjects, to determine psychological precursors to panic attacks. Measures of anxiety, threat, control, prediction of panic, and symptoms were assessed at hourly intervals during waking hours for one week. Measures were taken using a portable computerised diary which prompted for and stored responses. Patients' ratings of the prediction of panic attacks were the only significant precursors to panic attacks. This supports recent research that expectancy is important in panic onset. The data also suggested that anxiety levels follow a circadian pattern.

Adolescent↗

PubMed1992

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↗

PubMed1991

Group- vs home-based exercise training in healthy older men and women. A community-based clinical trial.

OBJECTIVE: --To determine the effectiveness of group- vs home-based exercise training of higher and lower intensities among healthy, sedentary older adults. DESIGN: --Year-long randomized, controlled trial comparing (1) higher-intensity group-based exercise training; (2) higher-intensity home-based exercise training; (3) lower-intensity home-based exercise training; or (4) assessment-only control. SETTING: --General community located in northern California. PARTICIPANTS: --One hundred sixty women and 197 men 50 to 65 years of age who were sedentary and free of cardiovascular disease. One out of nine persons contacted through a community random-digit-dial telephone survey and citywide promotion were randomized. INTERVENTIONS: --For higher-intensity exercise training, three 40-minute endurance training sessions per week were prescribed at 73% to 88% of peak treadmill heart rate. For lower-intensity exercise training, five 30-minute endurance training sessions per week were prescribed at 60% to 73% of peak treadmill heart rate. MAIN OUTCOME MEASURES: --Treadmill exercise test performance, exercise participation rates, and heart disease risk factors. RESULTS: --Compared with controls, subjects in all three exercise training conditions showed significant improvements in treadmill exercise test performance at 6 and 12 months (P less than .03). Lower-intensity exercise training achieved changes comparable with those of higher-intensity exercise training. Twelve-month exercise adherence rates were better for the two home-based exercise training conditions relative to the group-based exercise training condition (P less than .0005). There were no significant training-induced changes in lipid levels, weight, or blood pressure. CONCLUSIONS: --We conclude that (1) this community-based exercise training program improved fitness but not heart disease risk factors among sedentary, healthy older adults; (2) home-based exercise was as effective as group exercise in producing these changes; (3) lower-intensity exercise training was as effective as higher-intensity exercise training in the home setting; and (4) the exercise programs were relatively safe.

Aged↗

PubMed1991

Effect of long-term community health education on body mass index. The Stanford Five-City Project.

Being overweight is a risk factor for cardiovascular heart disease and other medical problems. The purpose of this study was to examine the effect of a community-wide cardiovascular risk reduction trial (the Stanford Five-City Project) on body mass index. In the Stanford Five-City Project, two treatment cities (n = 122,800) received a 6-year mass media and community organization cardiovascular risk reduction intervention. Changes in the treatment cities were compared with two control cities (n = 197,500) for changes in knowledge of risk factors, blood pressure, plasma cholesterol level, smoking rate, body mass index, and resting pulse rate after 5-1/3 years of the education program. Both cohort and cross-sectional (independent) samples were used in the study. In the independent surveys, subjects in the treatment communities gained significantly less weight than subjects in the control communities (0.57 kg compared with 1.25 kg) over 6 years. In the cohort, there were no significant overall differences. The study provides some evidence that a community health education program may help reduce weight gain over time, but more effective methods must be developed if this important risk factor is to be favorably affected in broad populations.

Adult↗

PubMed1991

Impact of pubertal development on body fat distribution among white, Hispanic, and Asian female adolescents.

Variation in the waist/hip ratio (WHR) may be related to changes in hormonal secretion associated with pubertal maturation. We therefore studied the effects of race, pubertal development, and body fatness on WHR during adolescence in a multiethnic population. A total of 688 white, Asian, and Hispanic female adolescents (mean (+/- SD) 12.4 +/- 0.7 years), participating in the evaluation of a multisite school-based health education program, were included in these analyses. Self-assessed stage of puberty and measurements of height, weight, waist circumference, and hip circumference were obtained from each participant. The WHR and age-adjusted body mass index were calculated. Analysis of covariance demonstrated that puberty significantly affects hip circumference and WHR but not waist circumference among female adolescents. Age and fatness, as reflected by age-adjusted body mass index, contributed significantly to both circumferences and to the WHR. There was a significant effect of ethnicity on hip circumference but not on waist circumference or the WHR. These results confirm that pubertal stage exerts a significant effect on the hip circumference and WHR in female adolescents, even after the effects of fatness and age are controlled. Studies of body fat distribution during late childhood and adolescence should include assessments of pubertal maturation.

Adipose Tissue↗

PubMed1991

How "blind" are double-blind studies?

Psychopharmacological studies usually attempt to eliminate "nonspecific" influences on outcome by double-blind designs. In a randomized, double-blind comparison of alprazolam, imipramine, and placebo, the great majority of panic disorder patients (N = 59) and their physicians were able to rate accurately whether active drug or placebo had been given. Moreover, physicians could distinguish between the two types of active drugs. Inasmuch as correct rating was possible halfway through treatment, concerns about the internal validity of the double-blind strategy arise.

Adult↗

PubMed1991

Opioid antagonist impedes exposure.

Exposure is a rapid and effective treatment for simple phobias. This study tested the assumption that endorphin release may be involved in exposure to a feared situation. Thirty spider-phobic Ss underwent exposure to 17 phobic-related, graded performance tasks. Half the Ss were randomly assigned to naltrexone, an opioid antagonist, and half to a placebo. Measures of heart rate, blood pressure, self-efficacy, anxiety, and cognitions were obtained during treatment. Six of the 15 Ss in the naltrexone group dropped out after the 10th step in the treatment compared with 1 of the 15 Ss in the placebo group, chi 2(1, N = 30) = 4.7, p = .03. The naltrexone group took significantly longer to complete the first 10 steps (the last step that included all Ss) compared with the placebo group, F(9, 252) = 2.17, p = .024. Maximum heart rate and anxiety were significantly greater at Step 10 in the naltrexone group, but no differences were found for self-efficacy or cognitions. The study provides further evidence that the endogenous opioid system may be involved in the process of exposure.

Adult↗

PubMed1991

High blood pressure and marital discord: not being nasty matters more than being nice.

Theories linking anger and blood pressure (BP) reactivity to cardiovascular disease must be able to identify naturally occurring stressors that arouse emotion with sufficient frequency to cause chronic physiologic stress. We examine the impact of normal family arguments on 43 patients (24 women, 19 men) with essential hypertension. Patients and their partners discussed a threatening disagreement for 10 min while BP and conversation were recorded. Discussing problems increased BP, but the causal pathways differed by sex. In women, hostile interaction and marital dissatisfaction were associated with increased BP; "supportive" or "neutral" exchanges were unrelated to BP. In men, BP fluctuations were related only to the patient's speech rate. These findings are consistent with other research on sex differences in communication and social problem-solving styles and implicate different mechanisms (frequent anger, active coping) through which marital discord could increase risk. Implications for intervention are considered.

Adaptation, Psychological↗

PubMed1991

Comparative phenomenology of early-onset versus late-onset panic attacks: a pilot survey.

Studies of panic attacks in older adults are virtually nonexistent. The authors surveyed 520 adults with panic attacks; 445 were younger than age 55, 57 were 55 years old or older but had their first panic attack before age 55, and 18 were 55 years old or older and had their first panic attack at age 55 or later. The respondents with late-onset panic attacks reported fewer symptoms during their attacks and were less avoidant than both groups of respondents with early-onset panic attacks.

Age Factors↗

PubMed1991

Insulin-like growth factor-I as a reflection of body composition, nutrition, and puberty in sixth and seventh grade girls.

Large variations in nutritional intake have profound effects on the GH-insulin-like growth factor-I (IGF-I) axis in children and adults, but the effect of normal variations in nutrition on IGF-I concentrations is largely unstudied, particularly during puberty. We measured serum IGF-I concentrations in 325 sixth and seventh grade girls (12.4 +/- 0.7 yr) at the beginning of a multisite school-based health curriculum. The mean serum IGF-I level among the 243 girls with complete data was 573 +/- 244 micrograms/L. Pubertal stage was significantly associated with IGF-I (P less than 0.0001, by analysis of variance). Mean concentrations rose from 427 +/- 198 micrograms/L among those at the earliest pubertal stages to 639 +/- 219 micrograms/L among the mature girls. After adjusting for the association with the stage of pubertal development, serum IGF-I was not significantly associated with measures of body composition (body mass index, triceps skin fold thickness, waist/hip ratio, height, and weight). Additionally, IGF-I concentrations were not associated with nutritional intake (total calories, total protein, total fat, and total carbohydrate) or such measures of nutrition as serum iron, hemoglobin, red cell mean corpuscular volume, white cell count, and cholesterol. IGF-I concentrations, however, were significantly correlated with transferrin concentrations, another possible index of nutritional status (r = 0.29; P less than 0.0001). IGF-I is not a clinically useful index of nutritional status among normal pubertal girls.

Adolescent↗

PubMed1991

Characterization of Int-5, a locus associated with early events in mammary carcinogenesis.

Three chemically-induced precancerous mammary hyperplasias, independently isolated in BALB/c mice, all contained mouse mammary tumor virus (MMTV) proviral DNA integrated into a common region in chromosomal DNA, designated Int-5 (Formerly Int-H, Gray et al., 1986). This site was cloned from a hyperplastic outgrowth (D2) into lambda phage. A 1.7 Kb Hind III DNA fragment, which flanks the 5' end of the MMTV insert, was generated from the cloned Int-5 region. This fragment was used as probe (IH-2) to localize Int-5 to mouse chromosome 9. The IH-2 sequence was highly conserved in DNA of several mammalian species including man, in three other widely divergent vertebrate phyla, and in C. elegans. The Int-5 region, containing 5.6 Kb 5' and 12.8 Kb 3' to the MMTV integration site in D2, was cloned in EMBL-3 from a BALB/c genomic DNA library. cDNA complementary to poly A+ lactating mammary gland RNA, annealed with Sst-1 fragments spanning most of the BALB/c Int-5 clone. The highest level of Int-5 specific poly A+ mRNA was detected in D2 tumor. Lactating mammary gland and D2 hyperplastic alveolar nodule contained 5-fold less Int-5 RNA while liver contained 8-fold less Int-5 RNA. Int-5 cDNA (IH-3) annealed with two RNA species of approximately 3.3 and 4.0 Kb. These data are consistent with the hypothesis that Int-5 contains an oncogene, different from any other previously described, involved in early events in some models of chemical carcinogenesis.

Animals↗

PubMed1990

Effects of communitywide education on cardiovascular disease risk factors. The Stanford Five-City Project.

To test whether communitywide health education can reduce stroke and coronary heart disease, we compared two treatment cities (N = 122,800) and two control cities (N = 197,500) for changes in knowledge of risk factors, blood pressure, plasma cholesterol level, smoking rate, body weight, and resting pulse rate. Treatment cities received a 5-year, low-cost, comprehensive program using social learning theory, a communication-behavior change model, community organization principles, and social marketing methods that resulted in about 26 hours of exposure to multichannel and multifactor education. Risk factors were assessed in representative cohort and cross-sectional surveys at baseline and in three later surveys. After 30 to 64 months of education, significant net reductions in community averages favoring treatment occurred in plasma cholesterol level (2%), blood pressure (4%), resting pulse rate (3%), and smoking rate (13%) of the cohort sample. These risk factor changes resulted in important decreases in composite total mortality risk scores (15%) and coronary heart disease risk scores (16%). Thus, such low-cost programs can have an impact on risk factors in broad population groups.

Adult↗