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Biomedical subjects

G A Chase

Publications and source records attributed to G A Chase.

At least 109 records · Page 6Linked to original sources

Assessment of plasma total cholesterol as a test to detect elevated low density (beta) lipoprotein cholesterol levels (type IIa hyperlipoproteinemia) in young subjects from a population-based sample.

The measurement of plasma total cholesterol as a screening test for an increased plasma level of low density lipoprotein cholesterol (greater than age- and sex-adjusted 95th percentile) with a normal plasma triglyceride level (type IIa hyperlipoproteinemia) was assessed in 1325 young subjects, aged 6 to 19 years, from seven North American populations during the years 1972-1976. When the age- and sex-specific 95th percentile for total cholesterol was used as the cutpoint for hypercholesterolemia, almost one third of young subjects with type IIa hyperlipoproteinemia were undetected (false negatives), and 40% of the test results were falsely positive. Ninety-eight per cent of all non-type IIa subjects were correctly identified. Lowering the percentile cutpoint decreased the false negative results but increased the false positive results; increasing the cutpoint had an opposite effect. Females had higher percentile cholesterol values than males; when extrinsic, arbitrary cholesterol cutpoints (175-210 mg/100 ml) for screening were used, there were fewer false negative but more false positive results in the females than in the males. When the prevalence of type IIa hyperlipoproteinemia was increased from 5 to 50%, the false positive tests decreased from 40 to 2%. A two-step screening for hypercholesterolemia did not improve efficiency. The use of plasma total cholesterol as a test for type IIa hyperlipoproteinemia in a general population results in a relatively large number of false positive and false negative tests.

Adolescent↗

Fat and cholesterol intakes of white adults in Columbia, Maryland. Upper-middle socioeconomic level subjects.

In a cross-sectional study of white adults with upper-level socioeconomic status (in Columbia, Maryland), intakes of total, saturated, and polyunsaturated fat and of cholesterol were assessed. The intakes were compared with dietary recommendations made by the Inter-Society Commission for Heart Disease Resources, the American Heart Association, and the Senate Select Committee. Only moderate dietary changes were needed for a menu modification that conforms to the dietary recommendations for men. If the group studied reflects the impact of public health nutrition education, areas in need of attention seem to be a reduction in the amount and a change in the quality of dietary fat.

Adult↗

A genetic-epidemiologic study of human immune responsiveness to allergens in an industrial population: I. Epidemiology of reported allergy and skin-test positivity.

Four hundred six subjects, comprising a 10% random sample of all employees, and a sample of "self-reported" allergic employees of a light industrial plant participated in an epidemiologic study of allergy. Puncture skin testing with a wide variety of crude allergens revealed a significantly higher prevalence of IgE-mediated sensitivity in males than females (29% males and 7% females in a random group; 60% males and 30% females in a self-reported allergic group); however, reported prevalence rates for "allergy" and different allergic symptoms were generally not different between males and females. Interestingly, reported asthma was greater in skin-test-positive subjects than in skin-test-negative subjects. We also noted a decrease in skin-test positivity with increasing age in self-reported allergic subjects. This was significant in the case of several crude allergens but not in the case of positivity to at least one allergen. We also found evidence that people born in and who have been resident in "Zone I) (MD, PA, Del, NJ, or DC) for most of their lives exhibit a greater prevalence of skin-test positivity than people who were born in and have lived for much of their lives in the northeastern United States (east of the Mississippi River and to the north of South Carolina) other than in Zone I.

Adolescent↗

The East Baltimore study. II. Familial aggregation of plasma lipid levels in juveniles in a black inner-city population.

Familial aggregation of plasma lipid levels among 676 black juveniles, aged less than 20 years and residing in 202 households in East Baltimore, Maryland, was assessed by the intraclass correlation coefficient of residuals from sex-specific cubic regressions on age. Significant aggregation of both plasma cholesterol (r = 0.23, p less than 0.005) and plasma triglyceride (r = 0.27, p less than 0.005) levels were found. In addition, no effect on familial aggregation was found for each of several measures of family structure: number of juvenile household members, closeness in age, all children over 9 years of age, or shared surname. Two methods of classifying juvenile household size were compared. An association between classification method and juvenile household size was demonstrated (p less than 0.005) for the distributions of households and of children. The intraclass correlation coefficients for plasma cholesterol and plasma triglyceride for households classified by number of juveniles were higher than the coefficients for the house grouped by the number of juveniles admitted to the study, when compared for each classification number, 2 through 4. Evidence for an effect on familial aggregation of the socioeconomic status was shown by a comparison of intraclass correlation coefficients from households in East Baltimore with those from white and black households from the Columbia Medical Plan which have higher levels of occupation and education. Higher correlations were shown for the groups with higher socioeconomic status, regardless of race.

Adolescent↗

Evaluating primary nursing in hospitals: examination of effects on nursing staff.

Despite widespread support in the nursing literature for the adoption of primary nursing as the optimal method of organizing hospital nursing care, little empirical evidence exists as to its effects on patients or nursing staff. This study compares units that have employed primary nursing for at least five months (N = 31) with nonprimary units (N = 20) in two large university-affiliated hospitals. Comparisons are made with respect to structural attributes of nursing units, nurses' perceptions of their jobs and units, and three outcomes: nurses' job satisfaction, absenteeism rates and resignation rates for the units. No significant differences are found between primary and nonprimary nursing with respect to measures of job satisfaction. Primary units at one hospital exhibit lower resignation and absenteeism rates than do nonprimary units. The adoption of primary nursing is discussed in light of these findings.

Absenteeism↗

Determinants of hospital staff nurse turnover.

Organizational and nonorganizational determinants of staff nurse turnover are investigated in a panel study of 1,259 nurses employed in two university-affiliated hospitals. Findings are consistent with a causal chain in which perceived autonomy, job satisfaction, intent to leave the hospital and turnover are a sequence of outcomes reflecting the successive stages of a nurse's decision to resign. Both personal characteristics and job-related attributes are predictive at various stages of the process, although family status variables have no significant effects. Implications for hospital management of turnover are discussed.

Analysis of Variance↗

Evaluating reasons for nursing turnover: comparison of exit interview and panel data.

Data from a study of nursing turnover are used to compare findings based on two techniques for evaluating the reasons for resignations within the same population of hospital nurses during one year. The techniques are: (1) exit interviews, in which resigning nurses were asked to report in an open-ended format their major reasons for leaving their jobs; and (2) a prospective panel study, in which nurses who resigned are compared with nurses who remained, and actual turnover is predicted. Results show that due to the absence of a comparison group of remaining nurses and of baseline data, causal inferences based on exit interview data alone are overly simplistic and misleading for management purposes. Results of the panel study are more informative, although implications for hospital management are more complex. Use of the prospective panel design is recommended for hospitals concerned with evaluating nursing job conditions during a period of high turnover and staff nurse shortages.

Evaluation Studies as Topic↗

The Columbia population study. III. Volunteer status, educational background, and plasma total cholesterol level in a prepaid health care program.

From 1972 through 1975 a study of plasma lipid levels was conducted at the Columbia Medical Plan (a prepaid group practice in an upper-middle-class suburban community) in accordance with nationally standardized interview, blood-drawing and laboratory procedures of the Lipid Research Clinics Program. Data were obtained from a large group of volunteers from the plan as well as from subjects selected by random sampling from membership rolls. Of 2,591 fasting, nonpregnant adults (age greater than or equal to 20 years), 825 were volunteers and 1,766 were randomly selected subjects. Analysis of the plasma total cholesterol values indicated a possible association of volunteer status and higher educational levels with a lower plasma total cholesterol level. Age- and sex-specific comparisons confirmed this finding, although the magnitude of the differences was quite small from the standpoint of clinical risk. The data suggest that even within educational strata, self-selection for cholesterol screening was associated with a lower cholesterol level.

Adult↗

Is ABH nonsecretor status a risk factor for obstructive lung disease?

In a multidisciplinary study of risk factors for chronic obstructive pulmonary disease (COPD), a significantly more impairment of forced expiration was observed in ABH nonsecretors than in ABH secretors among 1017 white adults. (ABH refers to the "A" and "B" antigens of the ABO blood group system and "H", the heterogenetic substance which is found in persons of all ABO types including type "O".) Nonsecretors had significantly lower mean values of forced expiratory volume in one second as a percentage of forced vital capacity (FEV1/FVC%) and a significantly larger proportion of them had aberrant values, defined as FEV1/FVC% less than 68. These differences remained when mean values or rates of aberrancy were adjusted for other factors reported to alter risk of airway obstruction. In view of the known COPD-peptic ulcer and nonsecretor-duodenal ulcer associations, these findings suggest that the ability to secrete ABH antigens into secretions of the respiratory and gastrointestinal tract may have a protective effect on epithelialized organs in general, or on the lung and portions of the gut specifically.

ABO Blood-Group System↗

Male and female physician career patterns: specialty choices and graduate training.

During the decade of the seventies the proportion of entering U.S. medical school classes consisting of women increased from 9 to 25%. National data on 74,265 physicians from seven graduation cohorts (1970 to 1976) reveal that this phenomenon has resulted in a trend toward convergence of male and female career patterns in several important areas: specialty choice during graduate medical education, patterns of switching specialties and subspecialization, and duration of graduate medical training. In addition, whereas both sexes show an increased tendency to select general internal medicine and family practice, the lower rate at which women subspecialize within pediatrics and the increasing rate at which they select obstetrics/gynecology suggest a shifting orientation toward primary care among women.

Career Choice↗

Alcohol consumption and airway obstruction.

To clarify the basis of the reported association between alcohol and pulmonary disease, the relationship between intake of alcohol and pulmonary function was examined in 2,539 community-dwelling adult participants in an ongoing longitudinal study of risk factors for airway obstruction. Forced expiratory volume in 1 s, expressed as a percentage of forced vital capacity, was used as the indicator of airway obstruction, and forced vital capacity expressed as a percentage of the predicted value was used as an index of restriction. Although crude (unadjusted) mean values of the ratio of forced expiratory volume in 1 s to forced vital capacity were significantly lower for heavy than for light drinkers, the difference disappeared when adjustment was made for numerous confounding factors (including such recognized risk factors for pulmonary disease as cigarette smoking, low socioeconomic status, male sex, and age). There was also no evidence of an association between consumption of alcohol and airway restriction. Although these findings do not rule out a possible effect of alcohol on pulmonary disease, its impact, if any, is probably the result of interaction with other factors associated with alcoholism, if not derived primarily from those other factors.

Adult↗

Patterns of forced expiratory flows in groups at risk for chronic obstructive pulmonary disease.

In a modified case-control study of obstructive pulmonary disease (COPD), airways obstruction has been found to be associated with age, sex, protease inhibitor type, socioeconomic status (SES) and smoking. In this paper patterns of forced expiratory flows are examined in persons demonstrating various risk factors. Two broad patterns of flow limitation emerge. The first pattern, characterized by lower flows at high lung volumes, is found in first-degree relatives of patients with COPD and subjects with a low SES. This pattern, consistent dysfunction of large airways, may reflect reversible decreases of airway caliber. The second pattern, characterized by lower flows at low lung volumes, is found in older subjects. This pattern, consistent with nonhomogeneously emptying lungs or dysfunction of small airways, may reflect more chronic irreversible changes. Smokers and male subjects exhibit both patterns of flow limitation when compared with subjects who had never smoked and female subjects. It is possible that the combination of the patterns reflects a particularly high risk for the development of COPD in male smokers.

Adult↗

Job satisfaction among hospital nurses: a longitudinal study.

Data from a two-wave panel study of staff nurses in two hospitals are used to assess the relative importance of several types of independent variables as determinants of job satisfaction. Both organizational and nonorganizational determinants are examined, with the formed including both perceptual and structural measures. Job satisfaction is measured in two ways using both Overall and Multi-Facet indicators. The independent variables were measured five months before the dependent variables were measured in order to attenuate contamination problems. Findings indicate that perceptions of job and nursing unit attributes, particularly autonomy and task delegation, predict satisfaction most strongly. In addition, a nurse's own characteristics are found to be more important than either structural attributes of nursing units or job characteristics in predicting job satisfaction.

Adult↗

Association of HLA antigens and total serum immunoglobulin E level with allergic response and failure to respond to ragweed allergen Ra3.

We have applied rigorous statistical analysis to human immune response and HLA data in allergic subjects having varying sensitivity to the minor ragweed allergen, Ra3. By using regression analysis on a series of subsets of Ra3 responders and nonresponders, we obtained data supporting the concept of discrete "responder" and "nonresponder" phenotypes. We found significant positive associations between Ra3 response and total serum IgE and the presence of HLA antigens of the A2 crossreacting group (A2 and A28), and significant negative associations with antigens of the A3 crossreacting group (A3 and A11). Our results suggest that alleles of the HLA-A locus may function either as immune response or immune suppressor genes or that such alleles are epistatic to the response or suppressor genes. Our data add further support to previous findings that HLA-associated specific IgE response is strongly influenced by genetic regulation of basal IgE level.

Allergens↗

Paternal age effect in fibrodysplasia ossificans progressiva.

Analysis by the method of Smith (1972) of birth order and parental age data collected from 38 of 42 patients with fibrodysplasia ossificans progressive shows a significant paternal age effect. This finding among the sporadically occurring cases would support the proposition that this condition usually arises as a new dominant mutation.

Adult↗

The Columbia Population Study. II. Familial aggregation of plasma cholesterol and triglycerides.

We studied familial aggregation patterns of plasma cholesterol and triglyceride concentrations in a sample of 242 families in a prepaid medical care setting. Three analytic methods of progressive sophistication--case finding, correlation, and multiple regression--were used. Case-finding analyses detected only slight association of elevated lipid levels in parent-offspring pairs. The results suggest that when probands are randomly selected from a free-living population, the value of screening families in which one member is shown to have elevated lipid levels is limited mainly to identifying "hypercholesterolemic" offspring of "hypercholesterolemic" fathers. Correlations of plasma lipid levels were significant for various pairs of first-degree relatives but negligible for spouses. Multiple regression also supported the predictive value of family members' lipid levels. Taken together, the results of these analyses provide strong evidence for familial aggregations of plasma cholesterol and lipid levels. The distinction of genetic and environmental contributions is a priority for future research.

Adolescent↗