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Biomedical subjects

R B Williams

Publications and source records attributed to R B Williams.

At least 127 records · Page 7Linked to original sources
PubMed1990

Sternotomy infection: poor prediction by acute phase response and delayed hypersensitivity.

Two hundred twenty-one consecutive adult cardiac surgical patients were examined prospectively for nutritional protein state, acute phase protein response, and delayed hypersensitivity reaction in an attempt to identify patients at high risk for the development of sternal wound infection, which occurred in 6 patients (2.7%). There was no significant correlation between preoperative nutritional protein concentrations (retinol-binding protein, prealbumin, and transferrin) and acute phase protein levels (C-reactive protein, alpha 1-acid glycoprotein, and complements B and C3), nor a statistically significant relationship between nutritional state or acute phase protein response and the development of sternal infection. Preoperative complement C3 levels were elevated, however, in 80.0% of those in whom sternal infections developed compared with 30.6% of those with well-healed wounds. Similarly, postoperative concentrations of alpha 1-acid glycoprotein were elevated in 80.0% of those in whom sternal infections developed compared with 28.6% of those with well-healed wounds. There was no correlation between delayed hypersensitivity and the risk of sternal infection, nor between preoperative nutritional protein and acute phase protein values. Seventy-three percent of patients were anergic on postoperative day 2. Stepwise logistic regression showed that age, body weight, preoperative intensive care unit stay, repeat median sternotomy, internal mammary artery grafting, postoperative hemorrhage, and postoperative cardiac arrest correlated with the development of sternal infection, whereas transfusion requirement, reexploration for bleeding, and the operation performed did not. We conclude that routine delayed hypersensitivity testing is of no value in predicting high-risk cardiac surgical patients when the anergy battery is placed on the preoperative day. Although statistically insignificant, possibly due to the small number of patients in whom sternal infection developed in this study (type II error), a larger study might find preoperative complement C3 and post-operative alpha 1-acid glycoprotein levels to be predictive of patients at risk for the development of sternal wound infection. The final logistic model for the predicted risk 2%) of sternal wound infection is: PREDSWC = exp(EQ)/1 + exp(EQ) where EQ = (0.38 x age) + (0.24 x weight) + (5.42 x preop ICU) + (4.39 x redo) + (7.14 x IMA) + (4.49 x hemorrhage) + (8.81 x arrest) - 62.72, and where preop ICU, redo, hemorrhage, and arrest are defined as yes (1) or no (0), IMA-is defined as 0, 1, or 2, age is in years, and weight is in kilograms.

Acute-Phase Proteins↗
PubMed1990

Do benzodiazepines have a role in the prevention or treatment of coronary heart disease and other major medical disorders?

Increased coronary disease rates, as well as increased all-cause mortality, in persons with high levels of hostility/anger and in persons suffering from panic disorder or phobic anxiety suggest that biological concomitants of these traits/conditions lead to major medical illnesses. Benzodiazepines have effects, e.g. blunting of stress hormone responses, that could prevent disease in persons so predisposed. It will be necessary to identify subgroups with sufficiently high absolute rates of disease risk to justify pharmacological interventions, and then to carry out controlled prevention trials to document the benefits, before such approaches can be recommended for the general population. This approach (use of drugs when other measures fail) is now standard for more traditional risk factors, such as hyperlipidemia and hypertension. In contrast to primary prevention, a stronger case can be made for the use of benzodiazepines in secondary prevention. Research has shown benzodiazepine treatment to improve control of angina and to reduce "silent ischemia", directly suggesting clinical benefits to be gained from the effects of benzodiazepines to reduce stress hormone responses. While benzodiazepines have long been prescribed for the postmyocardial infarction patient, there are no controlled clinical trials documenting such benefits. These are now clearly in order so that the use of benzodiazepines in coronary patients can be advised on a rational basis.

Anti-Anxiety Agents↗
PubMed1989

Clinical correlates and prognostic significance of type A behavior and silent myocardial ischemia on the treadmill.

Type A patients with coronary artery disease (CAD) tend to ignore or underreport symptoms, especially during challenging tasks such as the treadmill exercise test. To determine whether type A CAD patients might be more likely than type B patients to have silent ischemia during exercise and consequently a worse prognosis, 403 patients with stable CAD who had significant coronary disease on angiography, a positive Bruce protocol treadmill test and a structured interview to assess type A behavior were studied. Median follow-up time was 6 years. Type A patients were more likely to experience silent ischemia during exercise than were type B patients (35 vs 25%, p = 0.05). Patients with silent ischemia during exercise had a history of fewer anginal episodes/week, and type A patients with silent ischemia were less likely to have had a history of typical angina. However, using the Cox model, there were no significant differences in survival between type A patients and B patients with silent ischemia (4-year survival 86 vs 79%, p = 0.44) and no significant differences in survival between type A patients with silent ischemia and type A patients with symptomatic ischemia (6-year survival 86 vs 80%, p = 0.59). Similar results were obtained for infarction-free survival. Type A patients are more likely than type B patients to have silent ischemia during exercise, but long-term survival is not affected.

Angina Pectoris↗
PubMed1989

Type A behavior and survival: a follow-up study of 1,467 patients with coronary artery disease.

Patients with documented coronary artery disease, admitted to Duke Medical Center between 1974 and 1980, were assessed for type A behavior pattern and were followed until 1984. The relation of type A behavior to survival was tested using data from coronary angiography to control for disease severity. Cox model regression analyses demonstrated an interaction (p less than 0.01) between type A behavior and an index of disease severity in the prediction of cardiovascular death. Among those with relatively poor left ventricular function, type A patients had better survival than type B. This difference was not present among patients with better prognoses. Type A behavior did not predict the subsequent incidence of nonfatal myocardial infarctions. Differential risk modification and differential selection into postinfarction status are possible explanations for the findings. These results need not conflict with the proposition that type A behavior plays a role in the pathogenesis of coronary artery disease.

Adult↗
PubMed1989

Patterns of cardiovascular responses to stress as a function of race and parental hypertension in men.

This study investigated cardiovascular responses to two stressors known to elicit either beta-adrenergic (mental arithmetic) or alpha-adrenergic (forehead cold pressor) reactivity in Black and White men. Participants in each group were selected for presence or absence of parental hypertension. Based on previous research, Blacks were expected to show smaller cardiovascular responses to the beta-adrenergic mental arithmetic task and greater responses to the alpha-adrenergic cold pressor relative to the Whites. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, forearm blood flow, and forearm vascular resistance were assessed during a resting baseline, a prestress period, and during and after each experimental procedure. Unlike previous findings, no significant racial differences in cardiovascular responses were found during either task. However, Black participants had significantly higher SBP and DBP levels throughout the cold pressor periods. Parental history did not significantly influence cardiovascular responses in either group. The results are discussed in relation to previous research on racial differences in stress reactivity and their implications for future research.

Adrenergic Fibers↗
PubMed1989

Race, parental history of hypertension, and patterns of cardiovascular reactivity in women.

This study examined the interaction of race and parental history of hypertension on patterns of cardiovascular responses among women. Two stressors were used that produce different patterns of cardiovascular reactivity: mental arithmetic, primarily a beta-adrenergic stimulus, and the cold face stimulus, which evokes alpha-adrenergic (i.e. vascular) activity. Systolic and diastolic blood pressure, heart rate, forearm blood flow, and forearm vascular resistance were assessed before, during, and after arithmetic and cold face stimulus. Both tasks produced the expected patterns of cardiovascular adjustment, although no Black-White differences occurred during arithmetic. However, Black subjects did show a slower recovery of diastolic blood pressure following arithmetic. The cold face stimulus produced significantly greater changes in systolic blood pressure in the Black than in the White women. Parental history of hypertension did not relate significantly to reactivity. The results provide limited support for the idea that Black females exhibit a greater pressor response than White females to a stimulus that produces primarily vascular rather than cardiac changes. These findings are discussed in relation to previous findings with males and with respect to their implications for the role of reactivity in Black-White differences in hypertension prevalence.

Adolescent↗
PubMed1989

Altered pituitary hormone response to naloxone in hypertension development.

Endogenous opioid regulation of blood pressure is altered during stress in young adults at risk for hypertension. We studied the effects of the opioid antagonist naloxone on the secretion of corticotropin and beta-endorphin during psychological stress in young adults with mildly elevated casual arterial pressures. Naloxone-induced secretion of both corticotropin and beta-endorphin was significantly diminished in persons at enhanced risk for hypertension compared with the low blood pressure control group. Results suggest that opioidergic inhibition of anterior pituitary function is altered in hypertension development.

Adolescent↗
PubMed1989

Beta and alpha adrenergic reactivity elicitable stress study with special reference of electrocardiographic T-wave amplitude.

Twenty-six healthy young Caucasian males were defined into high hostile (Hi-Ho) group and low hostile (Lo-Ho) group assessed by Cook-Madley's Hostility (Ho) scale. Mental arithmetic task (MA) and forehead cold stimulus task (FCS) were loaded to both Hi-Ho and Lo-Ho groups. Electrocardiographic T-wave amplitude (TWA), heart rate (HR) and coefficient of variance of 100 R-R intervals (CVR-R) were measured continuously during MA and FCS task periods. Greater TWA attenuation was found in Hi-Ho group (p less than 0.05). Although no significant intergroup difference was represented in HR and CVR-R, HR increased significantly (p less than 0.01) in whole subjects and CVR-R was tend to be suppressed during MA period. In addition, comparison of these physiological responses were performed between Type-A and Type-B groups classified by Jenkins' Activity Survey Form-T (JAS-T). There was no significant difference in reactivity of TWA, HR and CVR-R to both two tasks between high and low Type-A scored groups. Previous data suggested that the TWA reactivity in Hi-Ho subjects to cognitive stress showed similar pattern in Type-A individuals. However, autonomic nervous interaction could not be clarified in Hi-Ho subjects. The differentiation of method for assessment of behavioral pattern was also discussed.

Adolescent↗
PubMed1988

Racial differences in cardiovascular reactivity to mental arithmetic.

One hypothesized mechanism for the higher rates and greater severity of essential hypertension among blacks is that this group is particularly susceptible to stress-induced beta-adrenergically mediated cardiovascular hyperreactivity. In this study, we compared the cardiovascular responses to mental arithmetic in 20 white and 17 black, young, normotensive males. Contrary to expectations, the black subjects exhibited significantly smaller changes in heart rate, and systolic and diastolic blood pressure. These findings suggest that cardiovascular reactivity to a mental stressor known to produce beta-adrenergically mediated responses may be lower in some normotensive blacks compared to their white counterparts.

Black or African American↗
PubMed1988

Physiological responses to catecholamine infusions in type A and type B men.

To determine whether there are basic biological differences between Type A and Type B men, we compared hemodynamic, electrophysiologic and neuroendocrine responses to equipotent doses of isoproterenol (ISO) and norepinephrine (NE) in 10 Type A and 10 Type B men ages 18 to 29. Results showed equal hemodynamic and neuroendocrine responses to graded ISO doses in Type A and Type B individuals. In contrast, Type A men showed a more prolonged decrease in electrocardiographic T-wave amplitude (TWA) than did Type B men. Post hoc analyses of the correlates of TWA recovery during high-dose ISO infusion provide preliminary evidence for a more robust parasympathetic antagonism of sympathetic nervous system effects in Type B men, especially those with low scores on the Cook-Medley Ho scale. These findings suggest that, in addition to cognitively mediated increases in sympathetic nervous system reactivity, Type As may also be placed at increased risk of developing coronary heart disease by reduced levels of parasympathetic antagonism of sympathetic effects.

Adolescent↗