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Biomedical subjects

R B Williams

Publications and source records attributed to R B Williams.

301 records · Page 17Linked to original sources
PubMedDate not supplied

The relationship between hostility and beta-adrenergic receptor physiology in health young males.

OBJECTIVE: We examined the relationship between hostility and mononuclear leukocyte (MNL) beta-adrenergic receptor function in a sample of young healthy males. METHOD: Thirty subjects were selected for having scored above 20 (N = 11) and below 14 (N = 19) on the Cook-Medley Hostility (Ho) scale. MNL beta-adrenergic receptor function was characterized in terms of receptor density (Bmax) and ligand-binding affinity (Kd) in homogenized cells, and intracellular cyclic adenosine monophosphate (cAMP) responses to saline, isoproterenol, and forskolin in whole cells. Subjects also completed the Multidimensional Anger Inventory (MAI), which assesses dimensions of anger. RESULTS: Relative to men with low Ho scores, men with Ho scores above 20 showed lower receptor number and greater forskolin-stimulated cAMP. Moreover, high hostile men reported a greater frequency of anger, longer duration of anger, more frequent brooding, and a hostile outlook. CONCLUSIONS: These data indicate that adrenergic receptor down-regulation is associated with hostility. This association may be linked to hostile persons' propensity for excessive and prolonged neuroendocrine responses to either psychological stressors or the experience of chronic stress associated with frequent and prolonged bouts of anger.

Adolescent↗
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Neuroendocrine, cardiovascular, and emotional responses of hostile men: the role of interpersonal challenge.

OBJECTIVE: We examined the effects of hostility and harassment on neuroendocrine, cardiovascular, and emotional responses in 52 healthy white men. METHODS: Subjects were preselected on the basis of scores in the top and bottom quartiles (above 23 and below 15, respectively) on the Cook and Medley Hostility (Ho) scale. Subjects participated in a solvable anagram task. Thirty subjects were harassed by the technician during the task. RESULTS: Harassed subjects with high Ho scores exhibited enhanced and prolonged blood pressures, heart rate, forearm blood flow, forearm vascular resistance, norepinephrine, testosterone, and cortisol responses relative to low-Ho subjects in the harassed condition and high and low-Ho subjects in the nonharassed condition. Heightened physiological reactivity in high-Ho subjects was correlated with arousal of negative affects. CONCLUSIONS: The findings are consistent with the general hypothesis that high hostile men show excessive behaviorally-induced cardiovascular and neuroendocrine responsivity to interpersonal challenging situations. Moreover, in high-Ho men, the stress-induced cardiovascular and neuroendocrine hyperreactivity is associated with the arousal of negative affects such as anger.

Adolescent↗
PubMedDate not supplied

Social support and hostility as predictors of depressive symptoms in cardiac patients one month after hospitalization: a prospective study.

OBJECTIVE: Hospitalization for cardiac disease is associated with an increased risk for depression, which itself confers a poorer prognosis. Few prospective studies have examined the determinants of depression after hospitalization in cardiac patients, and even fewer have examined depression within the weeks after hospital discharge. The present study assessed the prospective relations among perceptions of social support and trait hostility in predicting symptoms of depressive symptoms at 1 month after hospitalization for a diagnostic angiography in 506 coronary artery disease (CAD) patients. METHOD: A series of structural equation models 1) estimated the predictive relations of social support, hostility, and depressive symptoms while in the hospital to symptoms of depression 1 month after hospitalization, and 2) compared these relations across gender, predicted risk classification, and age. RESULTS: Social support assessed during hospitalization was independently negatively associated with depressive symptoms 1 month after hospitalization, after controlling for baseline symptoms of depression, gender, disease severity, and age. Hostility was an indirect predictor of postdischarge depressive symptomology by way of its negative relation with social support. This pattern of relations did not differ across gender, predicted risk classification, and age. CONCLUSIONS: Our findings suggest that a patient's perceived social support during hospitalization is a determinant of depressive symptoms 1 month later. The relation of social support and hostility to subsequent depressive symptoms was similar across a variety of populations.

Adult↗
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Depressive symptoms and survival of patients with coronary artery disease.

OBJECTIVE: Multiple studies have shown that high levels of depressive symptoms increase the mortality risk of patients with established coronary disease. This investigation divided depressive symptoms into groups to assess their relative effectiveness in predicting survival. METHODS: Questionnaires about the presence of depressive symptoms were administered to 1250 patients with significant coronary disease while they were hospitalized for diagnostic coronary angiography. Follow-up for mortality due to cardiac disease was conducted annually for up to 19.4 years. Factor analysis was used to divide items on the Zung Self-Rating Depression Scale into four groups: Well-Being, Negative Affect, Somatic, and Appetite. In addition, responses to a single item regarding feelings of hopelessness were available for 920 patients. RESULTS: Well-Being and Somatic symptoms significantly predicted survival (p < or = .01). Negative Affect items were also related to survival (p = .0001) and interacted with age. A 2-SD difference in the Negative Affect term was associated with a relative risk of 1.29 for patients >50 years old and 1.70 for younger ones. Only Negative Affect remained significant in a model with the other symptom groups. Hopelessness also predicted survival with a relative risk of 1.5. Both the Hopelessness and Negative Affect items remained as independent predictors in the same model. All models controlled for severity of disease and treatment. With one exception (income and Hopelessness), results were essentially unchanged by additional controls for age, gender, and income. CONCLUSIONS: Depressive symptoms differentially predicted survival, with depressive affect and hopelessness being particularly important. These effects were independent of disease severity and somatic symptoms and may be especially important in younger patients.

Coronary Disease↗
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Characteristics of socially isolated patients with coronary artery disease who are at elevated risk for mortality.

OBJECTIVES: Social isolation has been linked to poor survival in patients with coronary artery disease (CAD). Few studies have closely examined the psychosocial characteristics of CAD patients who lack social contact. METHODS: Social isolation was examined as a predictor of mortality in 430 patients with significant CAD. More isolated patients were compared with their less isolated counterparts on factors that might help explain the association between isolation and survival. RESULTS: The mortality rate was higher among isolated individuals. Those with three or fewer people in their social support network had a relative risk of 2.43 (p = .001) for cardiac mortality and 2.11 (p = .001) for all-cause mortality, controlling for age and disease severity. Adjustments for income, hostility, and smoking status did not alter the risk due to social isolation. With the exception of lower income, higher hostility ratings, and higher smoking rates, isolated patients did not differ from nonisolated patients on demographic indicators, disease severity, physical functioning, or psychological distress. Isolated patients reported less social support and were less pleased with the way they got along with network members, but they did not report less satisfaction with the amount of social contact received. CONCLUSIONS: Patients with small social networks had an elevated risk of mortality, but this greater risk was not attributable to confounding with disease severity, demographics, or psychological distress. These findings have implications for mechanisms linking social isolation to mortality and for the application of psychosocial interventions.

Aged↗
PubMedDate not supplied

Central nervous system serotonin function and cardiovascular responses to stress.

OBJECTIVE: The objective of this study was to evaluate the impact of indices of central nervous system (CNS) serotonin function on cardiovascular reactivity to mental stress. METHODS: Lumbar puncture was performed on 54 healthy volunteers to obtain cerebrospinal fluid (CSF) for determination of 5-hydroxyindoleacetic acid (5HIAA) levels. Genotypes were determined with respect to a functional polymorphism of the serotonin transporter gene promoter region (5HTTLPR). Subjects then underwent mental stress testing. RESULTS: Persons with one or two long (l) 5HTTLPR alleles had CSF levels of the major serotonin metabolite, 5HIAA, that were 50% higher than those of persons with the s/s 5HTTLPR genotype. Persons with one or two l alleles or higher CSF 5HIAA levels also exhibited greater blood pressure and heart rate responses to a mental stress protocol. CONCLUSIONS: These findings suggest the 5HTTLPR polymorphism affects CNS serotonin function, and they are consistent with the general hypothesis that CNS serotonin function is involved in the regulation of potentially health-damaging biobehavioral characteristics. In particular, the l allele could contribute, through its association with increased cardiovascular reactivity to stress, to increased risk of cardiovascular disease.

Adult↗
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Endogenous opiate peptides, stress reactivity, and risk for hypertension.

Endogenous opiate peptides can regulate neuroendocrine and circulatory responses to behavioral stress and may be important in the pathogenic effects of sympathoadrenal reactivity. We tested this hypothesis by examining the effect of the opiate antagonist naloxone on blood pressure responses to behavioral stress in young adults with high, medium, or low casual blood pressures. Naloxone increased mean arterial pressure responses to stress in subjects with low casual pressure, but had no significant effect on responses in subjects with high casual pressure. These results suggest opioidergic inhibition of sympathetic nervous system responses may be deficient in persons at risk for essential hypertension.

Adolescent↗
PubMedDate not supplied

Fifty years of anticoccidial vaccines for poultry (1952-2002).

Although earlier investigators experimented with anticoccidial vaccines, the world's first commercially successful product was developed by Prof S. A. Edgar of Auburn University, Auburn, AL. This product contained live, nonattenuated Eimeria tenella oocysts and was first marketed by Dorn and Mitchell, Inc., in 1952. Under the trade names of DM Cecal Coccidiosis Vaccine, Coxine, NObiCOX, and CocciVac, it went through several formulations containing various Eimeria species that parasitize chickens, and a further product containing turkey Eimeria species was also developed. After many product and company changes, one turkey and two chicken formulations of CocciVac are still marketed worldwide by Schering-Plough Animal Health, Inc. Chicken and turkey formulations of Immucox, a similar type of vaccine, were developed by Dr. E.-H. Lee and first marketed in 1985 in Canada by Vetech Laboratories, Inc. In 1974, Dr. T. K. Jeffers of Hess and Clark, Inc., Ashland, OH, published his discovery of precocious lines of coccidia, which facilitated the development of the first attenuated anticoccidial vaccine. For commercial reasons, Jeffers was unable to do this himself, but this first attenuated vaccine was designed by Dr. M. W. Shirley and colleagues at the Houghton Poultry Research Station (HPRS) in the United Kingdom. The vaccine was commercially developed under license in the United Kingdom by Glaxo Animal Health Ltd. and then Pitman-Moore, Inc., and launched in The Netherlands during 1989 under the trade name Paracox. After further changes in company ownership, two formulations for chickens are now marketed worldwide by Schering-Plough Animal Health, Inc. Attenuation of coccidia by embryo adaptation was reported in 1972 in the United Kingdom by Dr. P. L. Long, who originally worked at the HPRS and later became a professor at the University of Georgia, Athens, GA. An embryo-adapted line of E. tenella was included with precocious lines of other species in a series of three attenuated vaccines for chickens under the trade name Livacox, developed by Dr. P. Bedrník and launched in the Czech Republic in 1992 by Biopharm. The formulations of all other commercially available live anticoccidial vaccines for poultry are currently based upon the scientific principles established for the CocciVac, Paracox or Livacox vaccines.

Animals↗
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Prognostic importance of social and economic resources among medically treated patients with angiographically documented coronary artery disease.

OBJECTIVE: To evaluate the hypothesis that diminished social and economic resources impact adversely on cardiovascular mortality in patients with coronary artery disease. DESIGN: Inception cohort study of patients undergoing cardiac catheterization from 1974 through 1980 and followed up through 1989. SETTING: Tertiary care university medical center. PATIENTS: Consecutive sample of 1965 medically treated patients with stenosis 75% or greater of at least one major coronary artery. Five hundred patients were not enrolled due to logistic problems; 33 refused; 64 had missing data on key medical variables. The final study population included 1368 patients, 82% male, with a median age of 52 years. MAIN OUTCOME MEASURE: Survival time until cardiovascular death. RESULTS: Independent of all known baseline invasive and noninvasive medical prognostic factors, patients with annual household incomes of $40,000 or more had an unadjusted 5-year survival of 0.91, compared with 0.76 in patients with incomes of $10,000 or less (Cox model adjusted hazard ratio, 1.9; 95% confidence interval, 1.57 to 2.32; P = .002). Similarly, unmarried patients without a confidant had an unadjusted 5-year survival rate of 0.50, compared with 0.82 in patients who were married, had a confidant, or both (adjusted hazard ratio, 3.34; 95% confidence interval, 1.84 to 6.20; P less than .0001). CONCLUSIONS: Low levels of social and economic resources identify an important high-risk group among medically treated patients with coronary artery disease, independent of important medical prognostic factors. Additional study will be required to see if interventions to increase these resources improve prognosis.

Cardiac Catheterization↗
PubMedDate not supplied

Evaluation of a mixture of trimethoprim and sulphaquinoxaline for the treatment of bacterial and coccidial diseases of poultry.

Representative experiments from work undertaken to develop a synergistic mixture of trimethoprim and sulphaquinoxaline for the preventive treatment of certain poultry diseases are described. Sulphaquinoxaline in the diet for four days was shown to achieve at least an 85 per cent higher blood level than nine other sulphonamides in chicks, and the efficacies of various trimethoprim/sulphaquinoxaline regimes in the diet or in the drinking water were demonstrated against pasteurellosis, colisepticaemia and five kinds of coccidiosis. Regimes for bacterial diseases were begun one day before infection but those for coccidial diseases were begun on the same day as infection or later. Overall, a total dose of 30 mg/kg bodyweight/day (trimethoprim/sulphaquinoxaline = 1:3) controlled these seven diseases. The same treatment was also shown to control sulphaquinoxaline-resistant strains of Escherichia coli and Eimeria acervulina. Although both drinking water and food were used for drug administration, twice the inclusion rate was required in food to that in water for equivalent efficacy. The significance of different modes of expression of dosages for bacterial and coccidial diseases is explained.

Animal Feed↗
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Psychosocial factors and coronary disease. A national multicenter clinical trial (ENRICHD) with a North Carolina focus.

In addition to traditional risk factors (cigarette smoking, high blood pressure, and elevated cholesterol) psychosocial factors (depression, social isolation, and low socioeconomic status) have an adverse impact on prognosis of patients with CAD. Several studies of psychosocial and behavioral treatments provide encouraging evidence for the clinical efficacy of psychosocial interventions in CAD patients. A new, multicenter clinical trial now underway (see sidebar) will evaluate the impact of psychosocial interventions (compared to usual care) on all-cause mortality and nonfatal MI in post-MI patients with depression or perceived low levels of social support or both.

Clinical Trials as Topic↗