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Biomedical subjects

R B Williams

Publications and source records attributed to R B Williams.

At least 73 records · Page 4Linked to original sources
PubMed1997

Surrogate assessment of coronary artery disease patients' functional capacity.

An investigation of the surrogate assessment of coronary artery disease (CAD) patients' functional capacity was conducted using 193 patient and surrogate rater dyads. Mean age of patients and surrogate raters were 60.4 and 54.4 years, respectively. Patients and surrogates independently completed a brief questionnaire that assessed health and psychosocial factors. The Duke Activity Status Index (DASI) was contained in the patients' questionnaire, while a similar form modified to assess patients' functional capacity was imbedded in the surrogates' questionnaire. Results indicated similar psychometric characteristics and clinical validity for patients' self-report and surrogates' ratings, suggesting that the Surrogate Rating Form of the Duke Activity Status Index (DASI-SRF) is a reliable and valid proxy method of assessing patient's functional capacity when this information may not be obtained directly from the patient. Further, while there were no effects of surrogates' health and psychological characteristics on their ratings of patients' functional capacity, in comparison with other surrogates, spouses were more likely to rate patients higher in functional capacity. Exploration of the patient/care provider relationship via concurrent use of the DASI and DASI-SRF is discussed.

Adult↗
PubMed1997

Relation of mood ratings and neurohormonal responses during daily life in employed women.

Diurnal variations in urinary norepinephrine, epinephrine, cortisol, and self-reported mood states were examined in 101 employed women. Urine was collected on 2 consecutive workdays at 3 time periods: (1) overnight, (2) daytime, and (3) evening. Self-reports of 14 mood states were combined to correspond with the urinary collection periods. Factor analyses revealed 3 mood factors: Pressured (rushed, busy, stressed, hassled, and tense), Distressed (afraid, depressed, bored, and nervous), and Contented (satisfied, thoughtful, excited, and calm). The Distressed factor was significantly associated with norepinephrine excretion (p <.001). The Pressured factor was significantly associated with cortisol, epinephrine, and norepinephrine excretion (p <.001) independent of age, ethnicity, marital status, parental status, department within the company and activity level. Secretion of urinary hormones and the Pressured factor followed the same diurnal pattern. Specifically, as women's self-ratings of feeling pressured initially increased and then decreased over the course of the workday, urinary hormones also peaked and then dropped. Once time of day was statistically controlled, however, the mood factors were no longer significantly related to the urinary hormones.

Journal Article↗
PubMed1997

The influence of dietary cholesterol on cardiac and hepatic Beta-adrenergic receptors in egyptian sand rats.

We examined the effects of dietary cholesterol on cardiac and hepatic beta-adrenergic receptor functioning. Age-matched adult desert rodents (Psammomys obesus) were randomized to either a 5% cholesterol diet (CD, n = 20), or normal rabbit chow (RC, n = 18). After a 2-month exposure to the diets, animals were sacrificed and tissue from both heart and liver were retained for radioligand bindings studies. In heart tissue, cholesterol fed animals, relative to controls, showed an increased production of adenosine 3,5>-cyclic monophosphate (cAMP) in response to isoproterenol. Cholesterol supplementation was not associated with an increase in heart beta-adrenergic receptor number. Animals fed the 5% cholesterol diet showed significant increases in the number of beta-adrenergic receptor sites in hepatic tissue (M = 13.2 vs. 10.4 pmol/mg protein, CD and RC, respectively). The increased number of receptor sites in the liver was accompanied by a significant increase in isoproterenol-stimulated cAMP production. Results are supportive of the hypothesis that dietary cholesterol contributes to an upregulation of beta-adrenergic receptor function in cardiac, as well as hepatic tissue. These findings may be relevant to the observations of excessive stress-induced cardiovascular reactivity in persons with high cholesterol levels.

Journal Article↗
PubMed1997

Differential responsivity of monocyte cytokine and adhesion proteins in high- and low-hostile humans.

This study tested the general hypothesis that high- and low-hostile respondents would show different patterns of change in monocyte cytokine and adhesion protein (MCAP) expression in response to pharmacologically induced alterations in sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) balance. On 3 separate days, 4 high- and 4 low-hostile respondents received isoproterenol infusions after saline, atropine (PNS blockade), or neostigmine (PNS stimulation) pre-treatment. Dual color flow cytometry with fluorescently labeled monoclonal antibodies to CD 14 (monocyte market), interleukin-1, leukocyte function activator (LFA-1), Class II major histocompatibility complex (MHC-II), and tumor necrosis factor was used to quantify cytokine and adhesion protein expression on monocytes in blood samples drawn before and after the combination drug infusions on the 3 test days in each respondents. Following PNS stimulation and istoproterenol infusion there was a decrease (compared to saline pretreatment) in MHC II expression in high hostiles that was significantly (p<.02) different from an increase in low hostiles. A similar trend (p = .08) was seen for LFA-1 expression, with high hostiles showing an increase and low hostiles a decrease. These findings support the broad hypothesis that high-and low-hostile respondents will show different MCAP responses to pharmacologically induced alterations in SNS-PNS balance. Such differences could contribute to accelerated atherogenesis among high-hostile individuals.

Journal Article↗
PubMed1997

Personality factors differentially predict exercise behavior in men and women.

Personality assessed with the Minnesota Multiphasic Personality Inventory (MMPI) in college was used to predict exercise behavior measured at midlife in 3,630 men and 796 women enrolled in the University of North Carolina Alumni Heart Study. Logistic regression models were fitted for each of the MMPI clinical scales to test the predictive effect of personality, gender, and their interaction on adult exercise behavior. Lower depression, social introversion, and psychopathic deviance scores were associated with increased probability of exercising in midlife for both men and women. Furthermore, better psychological health (indexed by lower hypochondriases and psychasthenia) in college was generally predictive of increased exercise for men, whereas higher scores on these same factors predicted midlife exercise for women. There were two other patterns of gender interactions: (a) for men, lower scores on hysteria and schizophrenia scales were associated with increased probability of exercising at midlife, whereas these factors were unrelated to exercise for women and (b) for women, lower ego strength and higher college scores on paranoia and mania were associated with exercise behavior at midlife. These data suggest that early adulthood personality predictors of exercise behavior at midlife are both gender-neutral and gender-specific; that is, where no gender differences exist, healthier personality traits predict exercise at midlife, and when gender differences do occur, healthier college patterns of personality predict exercise behavior for men and sedentary behavior for women.

Adolescent↗
PubMed1997

The role of psychosocial factors in human disease: lessons from animal models.

Studies with humans have identified certain psychosocial characteristics that are associated with increased risk of developing life-threatening illnesses, as well as biological and behavioral mechanisms whereby risk is mediated. In this paper I review research wherein the use of animal models increases our understanding of the mechanisms acting in humans, using research on psychosocial risk factors and the "SES gradient" as examples.

Humans↗
PubMed1996

Depression and long-term mortality risk in patients with coronary artery disease.

Previous research has established that patients with coronary artery disease (CAD) have an increased risk of death if they are depressed at the time of hospitalization. Follow-up periods have been short in these studies; therefore, the present investigation examined this phenomenon over an extended period of time. Patients with established CAD (n = 1,250) were assessed for depression with the Zung Self-Rating Depression Scale (SDS) and followed for subsequent mortality. Follow-up ranged up to 19.4 years. SDS scores were associated with increased risk of subsequent cardiac death (p = 0.002) and total mortality (p < 0.001) after controlling for initial disease severity and treatment. Patients with moderate to severe depression had a 69% greater odds of cardiac death and a 78% greater odds of mortality from all causes than nondepressed patients. Increased risk was not confined to the initial months after hospitalization. Patients with high SDS scores at baseline still had a higher risk of cardiac death > 5 years later (p < 0.005). Compared with the nondepressed, patients with moderate to severe depression had an 84% greater risk 5 to 10 years later and a 72% greater risk after > 10 years. Patients with mild depression had intermediate levels of risk in all models. The heightened long-term risk of depressed patients suggests that depression may be persistent or frequently recurrent in CAD patients and is associated with CAD progression, triggering of acute events, or both.

Coronary Disease↗
PubMed1996

The ratio of the water and food consumption of chickens and its significance in the chemotherapy of coccidiosis.

An investigation was made of the relationship between the water and food consumption of healthy and sick chickens Using coccidiosis as a disease model, and uninfected chickens as healthy controls, male birds of an egg-production breed and males and females of a meat-production breed were found to have simultaneously reduced water and food intakes 4 days after infection with Eimeria acervulina or E. maxima, and from 4 to 6 days after infection with E. tenella. This phenomenon was associated with reduction of weight gains and poor food conversion ratios. Whether birds were healthy or sick, and regardless of the degree reduction of dietary intake, there was a more or less constant relationship between their food and water consumption. The ratio of the weights of water and food consumed had a value of about 1.9, with a range of 1.1-2.4. It is concluded that neither water nor food has an advantage over the other as a vehicle for chemotherapy. However, other factors, such as case and speed of administration, and avoidance of adsorption onto food particles, favour the drinking-water route.

Animal Husbandry↗
PubMed1996

Psychosocial factors: role in cardiac risk and treatment strategies.

Recent epidemiologic research has identified several psychosocial factors that impact unfavorably on prognosis among patients with established coronary heart disease (CHD). Several biologic and behavioral characteristics have been identified in patients with these psychosocial risk factors that are biologically plausible mediators of their adverse impact on prognosis. Several small-scale clinical trials offer encouraging evidence that both behavioral and pharmacologic interventions have the potential to ameliorate the health-damaging effects of psychosocial risk factors in patients with CHD. In this article we review the evidence on these points and offer recommendations as to how incorporation of this new knowledge into clinical care of the patient with CHD can lead to reduced mortality and morbidity rates in this population.

Behavior Therapy↗
PubMed1996

Interpersonal Hostility Assessment Technique: description and validation against the criterion of coronary artery disease.

High levels of hostility are associated with adverse health outcomes. The Interpersonal Hostility Assessment Technique (IHAT; Barefoot, 1992) measures hostility from verbal behavior during a standardized interview. Four types of behaviors are scored as hostility: evading the question, irritation, and indirect and direct challenges to the interviewer. The sum of the frequencies of these acts is a Hostile Behavior Index (HBI), which is divided into two components: verbal, scored with speech content in mind, and paraverbal, based on vocal stylistics. This study examined characteristics of IHAT assessments in 129 male coronary patients. Satisfactory interrater reliabilities were obtained. The HBI correlated highly (.58) with coronary artery disease severity after controlling for traditional risk factors. This relation was not affected by question topic or by differential weighting of the four hostile behaviors. Both HBI components were significantly correlated with disease. Results are discussed in terms of their implications for hostility assessment.

Adult↗
PubMed1996

Correlates of perceived social support and equality of interpersonal relationships at mid-life.

An investigation into the correlates of perceived social support and the equality of interpersonal relationships at mid-life was conducted using a sample of 3954 adults from the University of North Carolina Alumni Heart Study (UNCAHS). Participants ranged in age from forty to fifty years. Results suggested that while the number of family roles and social activities are the same for men and women, women perceive a greater availability of social support and report they give more than they take in relationships with family. There was no association found between the perceived availability of social support and global indices of equality of interpersonal relationships; suggesting an independence between these two psychological aspects of social support. Further, multiple regression correlational analyses indicated gender, level of social activity, and self-esteem as significant predictors of perceived social support; with self-esteem being the best single predictor. Relatedly, gender and number of children were found to be significant predictors of the perceived equality of relationships with family. These findings suggest differences in mid-life men and women's psychological perception of the availability of social support, and the give and take of relationships with family.

Adult↗
PubMed1995

Job strain and the prevalence and outcome of coronary artery disease.

BACKGROUND: It has been hypothesized that jobs that have both high psychological demands and low decision latitude ("job strain") can lead to coronary disease. The objective of this study was to test whether job strain was correlated with the presence of coronary disease at angiography or with long-term outcome in patients with angiographic coronary disease. METHODS AND RESULTS: Employed patients under the age of 65 years undergoing diagnostic coronary angiography completed a self-administered questionnaire about their job duties and work environment. Job strain was measured by the method of Karasek. Patients were separated into three groups, based on extent of coronary disease: significant disease (> or = 75% stenosis), insignificant disease (> 0% but < 75% stenosis), and normal coronary arteries. Statistical analyses were performed using logistic regression and the Cox proportional hazards model. The 1489 patients enrolled had a median age of 52 years; 76% were male and 88% were white. By design, all patients were employed, 60% in white-collar jobs and only 16% in jobs requiring heavy labor. Traditional cardiac risk factors were most prevalent in the 922 patients with significant coronary artery disease, at intermediate levels in the 204 patients with insignificant disease, and least prevalent in the 363 patients with normal coronary arteries (all P < .01). Job strain was actually more common in patients with normal coronary arteries (35%) than in patients with insignificant (26%) or significant disease (25%, P < .002). In a multivariate analysis, job strain was not significantly correlated with the presence of coronary disease. Job strain was not correlated with angina frequency at the time of angiography. Job strain was not a predictor of cardiac events (cardiac death or nonfatal myocardial infarction) during follow-up. CONCLUSIONS: Job strain was not correlated with the prevalence or severity of coronary artery disease in a cohort of patients undergoing coronary angiography. The outcome of patients with angiographically defined coronary disease was not affected by the level of job strain as measured by the method of Karasek.

Adult↗
PubMed1995

Use of prostate-specific antigen for prostate cancer screening in primary care practice.

OBJECTIVE: To examine prostate-specific antigen (PSA) as a screening test in randomly selected primary care practices. DESIGN: Chart abstractions of a random selection of 552 men (age, > or = 50 years) and physician and practice-level surveys. SETTING: Fifty-eight randomly selected, nonteaching, non-governmental, primary care practices in a 43-county area in Virginia. MAIN OUTCOME MEASURES: Documented evidence of PSA screening for asymptomatic male patients and physician self-report on regular (annual or biannual) use of PSA screening. RESULTS: Of 496 asymptomatic men, 123 (25%) seen in a 1-year period had documentation of PSA screening. Sixty (50%) of 120 asymptomatic men with documentation of a health maintenance examination had a PSA screening, whereas only 63 (17%) of 376 men without health maintenance examination had a PSA screening (chi 2, P < .001), after adjusting for race, insurance status, and age. Comparison of PSA screening use before and after the November 1992 publication of the American Cancer Society guidelines on PSA screening revealed that PSA screening after the publication date was 26%, compared with 19% before the data (P = .045), adjusting for health maintenance examination and the length of time for which the patient was eligible for screening. Logistic regression on physician self-report of regular vs not regular PSA use found an odds ratio of 6.12 (95% confidence interval, 1.28 to 29.30) for influence of the guidelines and 0.96 (95% confidence interval, 0.93 to 0.99) for the proportion receiving Medicaid or uninsured in the practice. CONCLUSIONS: Despite controversy over PSA as a screening test, PSA screening has now spread substantially in primary care practice.

Aged↗
PubMed1995

Effects of oxidized LDL on mononuclear phagocytes: inhibition of induction of four inflammatory cytokine gene RNAs, release of NO, and cytolysis of tumor cells.

A critical step in development of atherosclerosis is the interaction of oxidized low-density lipoprotein (LDL) with mononuclear phagocytes. Oxidized LDL, as well as acetyl-LDL, is rapidly taken up into macrophages via a family of scavenger receptors. We report that macrophages treated with oxidized LDL have markedly lower levels of mRNA specific for the genes MCP-1, TNF-alpha, IL-1 alpha, and KC as measured by Northern blot analyses of lipopolysaccharide (LPS)-stimulated macrophages. By contrast, acetyl-LDL does not inhibit these genes at the doses at which oxidized-LDL is effective. Similar effects are observed whether the LDL is oxidized in the presence of Cu2+ or of Fe2+. Such inhibition also occurs when maleylated bovine serum albumin (BSA), which also clears by one or more scavenger receptors on macrophages, is used as the stimulant. Fe2+ or Cu2+ oxidized LDL inhibits release of nitric oxide when triggered by LPS and direct cytolysis of tumor cells when triggered by maleylated BSA or LPS. Taken together, the data presented indicate that oxidized LDL inhibits induction of several important gene RNAs as well as functional markers that characterize the development of inflammatory and fully activated macrophages.

Animals↗
PubMed1995

Patient use of a computer for prevention in primary care practice.

A computerized health information system for prevention can provide an efficient way to enhance the doctor-patient interaction and provide patient-specific education materials. A computer system called HealthTouch was developed by family physicians and placed in 29 randomly selected primary care practices in Virginia for 1 year. Data were collected from three sources: randomly selected patients' charts, the HealthTouch data base, and patient telephone interviews. Data from these sources were combined, and frequency distributions and comparisons of responses by demographic attributes were analyzed using the chi-square statistic. During the study year, 9799 adult patients used the HealthTouch system. HealthTouch users were younger, on average, than the overall patient population, and the majority (89%) were either very satisfied or satisfied with the system. Computers are effective tools to collect, organize, and store patient information about prevention.

Adult↗
PubMed1995

Age differences in reported recollective experience are due to encoding effects, not response bias.

Three experiments examined whether reduced recollective experience reported in old age is due to a criterion shift towards more cautious responses by older subjects. In Experiment 1 Young and Old subjects took a recognition test without specific instructions on how they should encode the presented words. For recognised items subjects indicated whether they recollected the item's previous occurrence or whether they just knew it had been on the list. They then rated their confidence that the word came from the study list. Although overall recognition levels were equivalent, older adults recollected less and reported more know responses than the younger subjects. However, there was no overall difference in confidence, contrary to a criterion shift explanation. In Experiment 2A specific encoding instructions removed the age-related change in recollective experience entirely. Experiment 2B reproduced the test conditions of Experiment 2A, but without specific encoding instructions, and replicated the pattern of know responding found in Experiment 1. Thus the three experiments together suggest that the amount of recollection experienced by the elderly is not explicable in terms of cautiousness, but is driven by the encoding carried out by the elderly at presentation.

Age Factors↗
PubMed1995

Coccidiosis: a radiological study of sulphaquinoxaline distribution in infected and uninfected chickens.

Using scintillation counting and autoradiographical techniques, the whole-body distribution in week-old uninfected chickens of the anticoccidial agent sulphaquinoxaline (SQ) labelled with 35S was established at various time intervals after a single oral dose either alone or following continuous in-feed medication with unlabelled SQ, and after a single intravenous dose. The distribution was also established in chickens infected with the coccidia Eimeria acervulina or E. tenella, after a single oral dose of radiolabelled SQ administered either alone or following continuous in-feed medication with unlabelled SQ, as for uninfected chicks. In all uninfected chicks, SQ was rapidly absorbed from the gut and was distributed to all tissues. It appeared at high concentrations in the bile and kidneys 0.5 h after dosing. In chickens that had previously received unlabelled SQ in the diet, a radiolabelled dose maintained steadier tissue concentrations than the sharp rise and fall detected after a single oral dose. Intravenous dosing of uninfected chicks showed that SQ was secreted by the crop, gizzard and caecal epithelia into their lumina. Infection with E. acervulina or E. tenella coincided with an overall 3.5-fold sustained increase of SQ concentration in chick tissues. An updated hypothesis including these new observations for the anticoccidial mode of action of SQ in chickens is expounded.

Absorption↗