PubMed Health⌕ Search

Biomedical subjects

W H Mueller

Publications and source records attributed to W H Mueller.

At least 19 recordsLinked to original sources
PubMed1991

Retinoic acid induces the expression of alkaline phosphatase in P19 teratocarcinoma cells.

Retinoic acid (RA), the natural acid derivative of vitamin A, can induce the differentiation of some cell lines, such as the murine P19 teratocarcinoma cell line. RA can alter the expression of specific genes and the level of the corresponding protein. This report describes the effect of RA on the level of the alkaline phosphatase (ALP) mRNA and protein in P19 teratocarcinoma cells. RA caused a rapid, dose-dependent, and protein synthesis-dependent induction of ALP activity. The increased enzyme activity was detected 4 h after initiation of treatment and maximum induction of ALP activity required 48 h of RA exposure. Increased enzymatic activity was coincidental with increased levels of both a 67-kDa ALP protein and ALP mRNA. By Northern (RNA) blot analysis the increase of a 2.7-kilobase ALP mRNA was observed within 3 h of RA treatment. The RA-induced enhanced ALP mRNA level did not appear to be mainly due to the stabilization of preexisting mRNA, but rather to an increase in transcription of the ALP gene.

Alkaline Phosphatase↗
PubMed1991

Which measure of body fat distribution is best for epidemiologic research?

Multivariate associations were sought between risk factor levels (total cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides, glucose, and systolic and diastolic blood pressures) and two sets of anthropometric variables (four circumferences and six skinfolds) to select a set of anthropometric indicators of body fat distribution that correlate most highly with risk of disease. Subjects were men (n = 285) and women (n = 672) from a study of gallbladder disease in a Mexican American population in Starr County, Texas, 1985-1986. The canonical correlations showed that circumferences (0.49-0.61) and skinfolds (0.42-0.60) were equally well correlated to risk factor levels independently of sex and age. Weights from the canonical analyses suggest that measurements at or above the waist and on the lower limb (thigh) are most heavily loaded toward risk (waist = highest risk; thigh = lowest risk). The simplest and most reliable index of body fat distribution for both sexes is the ratio of waist to thigh circumferences. The more commonly used waist/hip ratio proved more valid in women, but not in men. Simple skinfold indices of body fat distribution were more poorly correlated to risk factor levels than the corresponding circumference ratios. In women, body mass index and waist circumference by themselves did as well as body fat distribution indices in explaining variation in risk factors, suggesting the involvement of visceral fat in the body fat/body fat distribution disease relation.

Adipose Tissue↗
PubMed1991

Which measure of body fat distribution is best for epidemiologic research among adolescents?

Body fat distribution is a cardiovascular health risk factor in adults. The development of body fat distribution patterns in childhood remains to be explored and the appropriate index and relations of body fat distribution to cardiovascular risk factors in children is not clear. Data are available from the US Health Examination Survey (1966-1970), which included measurements of skinfold thickness, body and limb circumferences, biologic maturity, and risk factors (blood pressure, total cholesterol). Using canonical correlation analysis, the relation between sets of anthropometric variables and risk factors was explored, controlling for age, race, sex, and maturity stage. The relation of various body fat distribution and fatness indices used in adult studies to the risk factors was also explored using stepwise regression and partial correlation analyses. The first canonical correlations were significant between risk factors and both sets of anthropometric variables (skinfolds, 0.36-0.46; circumferences, 0.39-0.54). However, neither method revealed a clear cut pattern suggesting a role of centralized fatness. Rather, body fatness or size appeared to be the major correlate with risk factors in both races (black, white) and sexes and in each maturity status group. In the stepwise regression analysis, a body fatness or "size" variable (e.g., body mass index, hip circumference) invariably entered on step one. Only among the sexually mature did body fat distribution indices enter on the second step in a consistent manner. No one index seemed "better," although indices based on skinfold measures entered more often than the waist/hip ratio.

Adipose Tissue↗
PubMed1991

Blood pressure and obesity in childhood and adolescence. Epidemiologic aspects.

Blood pressure and body mass index (BMI) are first considered independently, and then jointly, on the basis of both cross-sectional and longitudinal epidemiologic studies. The relations between these two attributes are investigated further by analysis of the "velocity curves" of age increments, from ages 6 to 24, in both blood pressure (systolic and fifth-phase diastolic) and BMI, from data from the US Health and Nutrition Examination Survey, 1971-1974. The results of both reported studies and the present exploratory analysis indicate sometimes strong but quite variable relations between blood pressure and BMI, which differ by age, gender, and the particular blood pressure measure under consideration.

Adolescent↗
PubMed1990

Body fat distribution and osteoarthritis.

The association of body fat distribution with single and combined site osteoarthritis was investigated using data from the US Health Examination Survey I, 1960-1962 (HES I) and the first National Health and Nutrition Examination Survey I, 1971-1975 (NHANES I). The study included 1,636 adults aged 35-79 years from HES I with hands and feet radiographs and four anthropometric fat distribution measures--subscapular and triceps skinfolds, waist girth, and seat breadth--and 3,885 adults aged 45-74 from NHANES I with knee radiographs and subscapular and triceps skinfold measures. Sex-specific data, adjusted for age, race, and body mass index, were analyzed using polychotomous logistic regression. There was a positive association of body mass index with knee osteoarthritis and with combined hands and feet osteoarthritis. A peripheral body girth pattern was associated with combined site osteoarthritis of the hands and feet; however, there was no consistent pattern of association of body fat distribution with knee osteoarthritis nor with osteoarthritis of the hands or feet only. These findings suggest that the central body fat pattern observed in previous studies to be associated with cardiovascular and gallbladder disease, and with diabetes, is not associated with osteoarthritis of the hands, feet, or knees.

Adipose Tissue↗
PubMed1989

Reliability, dependability, and precision of anthropometric measurements. The Second National Health and Nutrition Examination Survey 1976-1980.

The components of reliability for eight anthropometric measures were studied in 95 male and 134 female subjects from the Second National Health and Nutrition Examination Survey (NHANES II). The contributions to unreliability variance (Sr2) that occur as a result of measuring errors (Sp2, imprecision variance) and of intrasubject fluctuations in a measurement due to physiologic factors (Sd2, undependability) were estimated (Sr2 = Sp2 + Sd2). Unreliability was then related to the between-subject variance (S2) to estimate the reliability (R = 1 - (Sr2/S2)) of the measurement. Four of the anthropometric measurements (weight, height, sitting height, and arm circumference) had reliabilities in excess of R = 0.97. In the first three of these, measurement imprecision made up two thirds or less of unreliability, and undependability (Sd2) was stable by two weeks. Lesser but still acceptable reliabilities were obtained for triceps and subscapular skinfolds, bitrochanteric breadth, and elbow breadth (R = 0.81-0.95). For these variables imprecision (Sp2) was the major source of error. Furthermore, the unreliability (Sr2) between observers was twice as high or more than the unreliability within observers for these variables, evidence that imprecision (Sp2) is the single most important source of unreliability in these anthropometric measurements. Unreliability standard deviations of skinfolds increased in a linear manner with skinfold thickness corresponding to an unreliability coefficient of variation of 13-19 per cent. None of the other measurements showed such scale effects. Analyses of the kind suggested will help epidemiologists decide whether reliability can be increased by improving precision, and whether there is a need to improve reliability in the first place. Reliability appears to be adequate for all anthropometry in the NHANES II.

Adult↗
PubMed1988

Weight history and hypertension.

The relationship between weight change and hypertension was examined among men and women 25-64 years of age surveyed in the National Health and Nutrition Examination Survey (NHANES-I). Any single weight measurement (current weight, weight at an earlier age, or the difference between these two weights) was found to be a significant univariate predictor of hypertension, with current weight being most predictive. Initial weight and weight change were not associated with increased blood pressure, however, when controlling for current weight. These results do not distinguish a difference in risk of hypertension in adults with overweight or obesity of long-standing vs that of adults with overweight or obesity of more recent onset.

Adult↗
PubMed1987

Relative reliability of circumferences and skinfolds as measures of body fat distribution.

The question has arisen whether patterns of body fat distribution can be identified by body circumferences, a method which is said to be more reliable and simpler than skinfold thickness or like measures of subcutaneous fat (Ashwell et al., Int. J. Obes. 6: 143-152, 1982). Here we address the question of whether body circumferences are inherently more reliable than skinfold thicknesses in 77 intra- and 224 interexaminer replicates from the Health Examination Survey of 12 to 17-year-olds in the U.S.A. Reliability of six body circumferences (0.96) was significantly (P less than .01) higher than that of skinfold thicknesses at five sites (0.91), suggesting that circumferences are a more reliable method. However, the reliability of skinfolds is still high, and skinfolds may be used in studies which focus on preadults or other groups in which the validity of circumferences as measures of body fat distribution is unknown.

Adipose Tissue↗
PubMed1987

Centralized obesity and cardiovascular disease risk in Mexican Americans.

The association between body fat distribution patterns and cardiovascular disease risk variables (high density lipoprotein (HDL) cholesterol, total cholesterol, diastolic and systolic blood pressures, and fasting blood glucose levels) was sought in a sample of Mexican American adults who were studied during 1981-1983 in Starr County, Texas. In the sample, all diabetics were excluded to see whether centralized obesity carried any risk for cardiovascular disease independent of diabetes. A component of centralized body fat distribution was identified through the use of principal components analysis of five skinfold measurements, which included the upper and lower extremities and trunk areas. The centralized obese were compared with generalized (peripheral) obese and nonobese controls in four subgroups of the population: younger and older adult males and females. The means of all cardiovascular risk variables were in a direction indicating that the centralized obese were significantly at greater risk than nonobese controls (in particular, HDL cholesterol, total cholesterol, and blood glucose levels). The generalized obese differed from the centralized obese in having significantly lower blood glucose levels, and tended to be intermediate between centralized obese and nonobese controls in the other variables. The data confirm that centralized obesity as defined by a linear combination of skinfold measures works in the same way as the waist-to-hip circumference ratio in describing a body build factor which heightens the risk of cardiovascular disease in the obese independent of the clinical diabetic state.

Adult↗
PubMed1987

Body circumferences as alternatives to skinfold measurements of body fat distribution in Mexican-Americans.

The ratios of circumferences (waist/hip, waist/thigh) have been proposed in lieu of skinfold measurements for studies of obesity and body fat distribution. The purpose of this paper is to present our experience in measuring a series of body circumferences and skinfolds in an obese population, and seek the relationship between these two kinds of variables as indicators of fatness and body fat distribution using canonical correlation analysis. With this method, weighted vectors of circumferences on the one hand and skinfolds on the other, are formed in such a way that the correlation between the two sets of variables is maximized. The weights (regression coefficients) and their signs help us select the best combination of circumferences which describe a component of centralized obesity. Our experience showed that 21 percent of women would have been excluded from this multivariate analysis due to skinfolds what could not be measured (mainly due to poor fold definition). Few men were so excluded (6 per cent), and almost all circumferences could be measured in both sexes. A first canonical correlation was substantial (0.84 in women, 0.89 in men) and appeared to relate to level of fatness. A second canonical correlation was moderate (0.59 in women, 0.42 in men) and statistically significant (P less than 0.01) in both sexes. Only in women was it independent of age, but in both sexes it reflected differences in central and peripheral (especially lower limb) fat. The simple waist/thigh ratio correlated well with the second canonical variate (0.79 in women, 0.67 in men).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1985

Alternative measurements of obesity: accuracy of body silhouettes and reported weights and heights in a Mexican American sample.

The assessment of obesity by anthropometry or body composition in studies of chronic disease epidemiology is not always feasible. In this paper we test the accuracy and validity of two alternative methods: body silhouettes and reported weights and heights in a sample of Mexican American adults (n = 166) participating in the Diabetes Alert Study. The body silhouettes were those developed by A. Stunkard and colleagues. We compared the silhouettes obtained independently by three different observers, one with minimal experience in assessing obesity, the other two skilled in anthropometry. Correlations between the expert observers were 0.89-0.90. Those between the expert and less skilled observers were lower (0.64 to 0.85) and were better for female than male subjects. Results suggest an acceptable level of precision for persons with some training in obesity assessment. Body silhouettes compared well with the body mass index (r = 0.85 to 0.92 for the expert vs r = 0.65 to 0.84 for the less skilled observer), being higher for female subjects. The body silhouettes are thus useful for categorizing normal, overweight and obese individuals. The poorer performance on male subjects may relate to the female-like obesity depicted in both sexes in this particular set of silhouettes. A substantial proportion of subjects could not recall their weight or height. For those who could recall their measurements, accuracy was good but measurement error higher than that for measured variables. These problems of recall in this sample from rural Texas point to the potential usefulness of the body silhouette method when actual height and weight measurements cannot be made.

Adolescent↗
PubMed1979

A multivariate analysis of fatness and relative fat patterning.

Skinfold measurements (triceps, subscapular, suprailiac and medial calf) in four samples (376 boys, 352 girs, 338 men and 380 women from rural Colombia) were subjected to principal components analysis to identify components of obesity and relative fat patterning. Three components emerged which were similar in the four samples: a first component of fatness explaining 70-80% of the variance and two fat pattern components each explaining 10-15% of the variance: trunk-extremity and upper-lower body. Fatness and the trunk-extremity pattern components changed with age in children (7-12 years), but none of the components changed with age in adults (25-60+). The fatter tended to be more patterned in both age groups. Canonical correlation analysis revealed that socioeconomic status was more related to fatness than to patterning. With the exception of brothers, all first degree relatives (sib, parent-off-spring) and spouses were correlated in fatness. Some of the correlations between relatives--usually sibs, but not spouses--were also significant for the pattern components, suggesting a genetic basis for the known stability of this characteristic (Garn, '55a). Principal components analysis is a useful multivariate alternative for quantitative studies of anthropometric patterning.

Adipose Tissue↗
PubMed1979

A multinational Andean genetic and health program. VIII. Lung function changes with migration between altitudes.

Studies of lung function in high altitude populations have suggested the influence of hypoxic environment on the development of this characteristic independent of confounding variables such as ethnicity and habitual exercise. However, often the effect of altitude on vital capacity is greater in children than adults, suggesting that more than developmental adaptation is operative. Also selective migration could account for the similarity of migrants and permanent residents at a destination altitude. To explore these problems we studied the lung function (FVC, FEV1, PFR) of 377 individuals who had migrated between altitudes in northern Chile. Migrant measurements were adjusted to those of permanent residents of appropriate age, sex and height at the altitudes of origin and destination. The measurements were then related to ethnicity (Spanish-Aymara ancestry), occupation and permanence, the latter combining information on both age at migration to and length of stay at a destination altitude. Upward migration was associated with increased chest depth, FVC and FEV1, but not height or other chest measurements. Downward migration had no significant effect. The flow-dependent test PFR was so sensitive to observer variability and occupation that it was difficult to establish its relationship to permanence. Unlike the body measurements, lung function measurements (especially PFR) tended to deviate from permanent controls at the origin altitude in a direction suggestive of selective migration, nor was permanence itself independent of ethnicity and occupation. Because of these difficulties the question of developmental adaptation in lung function may not be answerable in cross-sectional studies like the present and previous efforts, but rather in longitudinal investigations in which the control is the individual him/herself.

Adaptation, Physiological↗