Biomedical subjects

H Davis

Publications and source records attributed to H Davis.

At least 91 records · Page 5Linked to original sources

PubMed1995

Control of sexually transmitted diseases in Haiti: results and implications of a baseline study among pregnant women living in Cité Soleil Shantytowns.

Women attending Haitian slum-based antenatal clinics were evaluated for sexually transmitted diseases (STDs): 110 (11%) of 996 were syphilis seroreactive, 313 (35%) of 903 had trichomoniasis, 110 (12%) of 897 had gonococcal or chlamydial cervical infection (or both), and 418 (47%) of 891 had at least one STD. Syphilis seroreactivity was associated with illiteracy (P = .007), lower socioeconomic status (P < .001), and a history of spontaneous abortion (P = .02). Of 663 evaluated sera, 56 (8%) had human immunodeficiency virus (HIV) antibodies. In multivariate analysis, positive HIV serostatus was associated with syphilis seroreactivity (P = .006), partner's unemployment (P = .002), and history of a previous sex partner (P = .04). Risk factors for gonococcal or chlamydial cervical infection were evaluated. Clinical assessment of cervical discharge, a World Health Organization algorithm, and a decision model based on local risk factors were 64%, 77%, and 89% sensitive, respectively, and 44%, 38%, and 43% specific, respectively, for predicting cervical infection. Alternative treatment approaches should be validated while waiting for affordable, simple, rapid, and accurate laboratory diagnostic tests for gonococcal and chlamydial cervical infections.

Abortion, Spontaneous↗

PubMed1994

Increasing rates of cervical and lumbar spine surgery in the United States, 1979-1990.

STUDY DESIGN: Data from annual national surveys of hospitalizations were used to review trends. OBJECTIVES: The trends in rates of hospitalizations with cervical and lumbar spine surgery were examined among persons > or = 25 years old. SUMMARY OF BACKGROUND DATA: Preliminary analysis of national survey data indicated that during 1979 to 1990 the number of spine operations increased markedly. METHODS: Data from the National Hospital Discharge Survey were used to calculate age-adjusted rates of hospitalizations. RESULTS: From 1979-81 to 1988-90, in each sex, the rate of hospitalizations with cervical spine surgery increased > 45%, with the rates for cervical fusion surgery increasing > 70%. The rate of hospitalizations with lumbar spine surgery increased > 33% in each sex, with the rate for lumbar fusion surgery increasing > 60% in each sex, the rate for lumbar disc surgery increasing 40% among males and 21% among females, and the rate for lumbar exploration/decompression surgery increasing > 65% in each sex. CONCLUSIONS: Between 1979 and 1990, rates of hospitalizations with cervical and lumbar spine surgery increased markedly among both sexes and for different categories of spine surgery.

Adult↗

PubMed1994

Cluster analysis of MCMI and MCMI-II on chronic PTSD victims.

A cluster analysis was used to identify groups of inpatients with confirmed post-traumatic stress disorder (PTSD) due to combat. In Study 1 the MCMI was administered to 256 subjects, in addition to the MMPI, PTSD measures, and background variables. Three clusters resulted: a Traumatic Personality (8-2), Schizoid Influence (8-2-1), and Antisocial Influence (8-6). Comparison on the MCMI symptom scales, MMPI, and PTSD scales showed that the Antisocial Influence cluster was "healthier" on all measures. The Schizoid Influence was most psychopathological. In Study 2 the MCMI-II was administered to 136 new subjects who met the same criteria as in Study 1. Four clusters resulted: Global (1-2-6A-6B-8A-8B), Subclinical (1), Aggressive (6A-6B-8A), and Detached/Self-defeating (1-2-8A-8B).

Adult↗

PubMed1994

Mexican-American mothers' reports of the weights and heights of children 6 months through 11 years old.

OBJECTIVE: To determine the accuracy of mothers' reports of their children's weights and heights. DESIGN AND SETTING: Cross-sectional survey of Mexican Americans in five southwestern states. SUBJECTS: Interviews were held with mothers of 2,578 children aged 6 months to 11 years old. MAIN OUTCOME MEASURES: Sensitivity and specificity of categories formed from reported values, and correlation of reported and measured values. RESULTS: Probability of mothers answering "don't know" was 24% for children's weights and 51% for heights. On the average, mothers overestimated weights at the 15th percentile or lower for age and sex and underestimated weights at the 85th percentile or higher. On the average, they underestimated heights. Categories of low and high weight, height, and body mass index were created by applying absolute-value cutoffs to reported values. All the categories had low sensitivity or specificity. Age-group-specific correlation coefficients between reported and measured values ranged from .79 to .89 for weight and from .32 (for 6- through 23-month-olds) to .70 (for 9- through 11-year-olds) for height. APPLICATIONS: The use of categories formed by applying absolute-value cutoffs to mother-reported values results in frequent misclassification of individuals. Therefore, such categories should not be used to estimate relative risks associated with weight, height, and body mass index. The good correlation of mother-reported and measured weights indicates that despite their inaccuracies, reported weights well reflect the relative ranking of measured weights. Thus, the use of reported weights as a continuous variable in multivariate analyses might cause only small errors in the coefficient for weight.

Body Height↗

PubMed1994

Consistency of children's hemodynamic responses to laboratory stressors.

Hemodynamic responses to three standard laboratory stressors (i.e., postural change, video game, forehead cold) were evaluated in 341 children (170 males) who had a mean age of 11.2 +/- 2.6 years. Inter-task consistency was evaluated for five physiological parameters for all stressor pairings. Evidence of consistency in systolic and diastolic blood pressure, heart rate, cardiac output, and total peripheral resistance responses to all three stressors was observed. The highest and most consistent correlations across stressors were observed for cardiac output and total peripheral resistance responses. The need for clarification in the categorization of laboratory stressors used to measure reactivity is discussed.

Blood Pressure↗

PubMed1994

Self-described weight status of Mexican-American adolescents.

PURPOSE: To evaluate Mexican-American adolescents' descriptions of their weight status. METHODS: Data were from the Hispanic Health and Nutrition Examination Survey, conducted in 1982-1983 among Mexican-Americans in five southwestern states. The current study used data on 429 males and 485 non-pregnant females 12-19 years old. In an interview, participants were asked to describe their weight status (underweight, about the right weight, overweight); in an examination (performed two to four weeks after the interview), weights and heights were measured. Each participant's body-mass index (weight/height2) was calculated, and single year of age-and-sex-specific BMI cutoffs were used to determine each participant's BMI decile. RESULTS: The overweight description was chosen by 46% of females and 23% of males, and the underweight description by 7% of females and 17% of males. The percentage of adolescents self-described as overweight rose with increasing BMI percentile, the rise starting in the 30-39th percentiles for females and in 60-69th percentiles for males. CONCLUSIONS: These findings suggest that many Mexican-American adolescents misperceive their weight status.

Adolescent↗

PubMed1994

Fruit and vegetable food frequencies by fourth and fifth grade students: validity and reliability.

OBJECTIVE: Due to the increased emphasis on fruit and vegetable (F+V) consumption and a desire to use the simplest dietary assessment method appropriate to determine F+V intake, we assessed the reliability and validity of weekly and monthly fruit and vegetable food frequency questionnaires (F+V FFQ) among fourth and fifth grade students by comparing them to food records previously validated through school lunch observations. METHODS: The multiethnic sample (primarily African-American and Caucasian) included predominantly lower-middle socioeconomic students from 10 classes at one elementary school. F+V FFQ were printed on optical scanning forms and classroom administered on two occasions. Students completed preprinted food record forms at school and received new forms weekly. To allow comparison between the F+V FFQ and food records, a dietitian abstracted information from the records according to a written protocol and transferred it to F+V FFQ forms covering respective time periods. F+V FFQ were converted to estimated daily servings and aggregated to create five F+V indices plus three summary indices. Statistical analyses included Spearman correlations and paired t-tests. RESULTS: Students demonstrated acceptable reliability in completing food records as well as weekly and monthly F+V FFQ; however, validity was unacceptable for both F+V FFQ versions due to significant overreporting. CONCLUSION: Of the two methods studied, the food record procedure is preferred over the FFQ procedure for collecting self-reported F+V consumption data among fourth and fifth grade students.

Child↗

PubMed1994

Pressor reactivity, ethnicity, and 24-hour ambulatory monitoring in children from hypertensive families.

We assessed blood pressure responses of a multiethnic (Black and White) sample of 120 children of hypertensive families to orthostasis, video game, forehead cold, and dynamic exercise, and monitored the children's ambulatory pressure 24 hours later. Thirteen children were studied twice (1-year stability). The Black children exhibited higher 24-hour ambulatory systolic and diastolic pressures than the White children. Regardless of ethnicity, peak and mean systolic pressures during each task were generally positively correlated with mean systolic pressure while the children were awake and asleep. Associations between diastolic pressor responses and ambulatory measurements were somewhat dependent upon ethnicity and task. Relatively few reactivity-ambulatory correlations were significant, using pressor reactivity change scores. The children who participated twice exhibited significant 1-year stability for most ambulatory and pressor measurements. Children's pressor responses to laboratory tasks may generalize to the natural environment.

Adolescent↗

PubMed1994

Accuracy of fourth- and fifth-grade students' food records compared with school-lunch observations.

Fourth- and fifth-grade students' food records completed by using a labor-intensive approach (with daily monitoring) or a less labor-intensive approach (with weekly monitoring) were compared with school-lunch observations. Records were completed at three elementary schools for 14-23 d by students in 26 classes. Record pages were printed forms with areas for recording items consumed, number of servings, and locations of meals. Students were randomly selected for lunch observation. Kappa coefficients and percent of agreement for interobserver reliability for both approaches combined ranged from 0.43 to 0.91 and 72.6% to 95.5%, respectively, on 24 observations. Pearson correlations for 117 record/observation matches were significant for eight and three of nine meal items for the daily and weekly monitoring approaches, respectively. Thus, students were reasonably accurate in keeping records and more accurate with the more labor-intensive approach. Researchers need to select an approach based on the degree of accuracy desired and available finances.

Child↗

PubMed1994

Ethnic differences in the myocardial and vascular reactivity to stress in normotensive girls.

Cardiovascular reactivity to stress has been proposed as a mechanism partially responsible for the increased prevalence of essential hypertension in African-Americans compared with whites. However, few studies have examined ethnic differences in cardiovascular reactivity among women. The present study evaluated potential ethnic differences in the cardiovascular reactivity to three laboratory stressors (postural change, video game challenge, forehead cold stimulation). The sample consisted of 171 normotensive girls (74 whites, 97 African-Americans) with a mean age of 11.1 +/- 2.7 years, all with positive family histories of essential hypertension. African-American girls showed higher resting diastolic blood pressures and higher resting total peripheral resistance compared with white girls. African-American girls also exhibited higher peak responses in systolic and diastolic blood pressure and total peripheral resistance and lower cardiac index responses during video game challenge and forehead cold stressor. The findings extend previous observations of ethnic differences in blood pressure reactivity to stress and indicate that concomitant increases in total peripheral resistance appear to account for the greater blood pressure reactivity in African-American girls.

Adolescent↗

PubMed1994

1-year stability and prediction of cardiovascular functioning at rest and during laboratory stressors in youth with family histories of essential hypertension.

Blood pressure (BP). heart rate, cardiac index, and total peripheral resistance index were measured at rest and in response to postural change, forehead cold stimulation, and a video game challenge in a sample of 128 White and 155 African-American normotensive youth with family histories of essential hypertension (EH). These measurements were readministered 1 year later (12.5 +/- 3.2 months). Moderate temporal stability was observed for all resting and absolute stress responses. Reliability estimates for reactivity change scores were lower, although some were within acceptable ranges. African-American youth exhibited greater BP and peripheral resistance index reactivity to forehead cold on both evaluations. After controlling for various anthropometric and demographic parameters and the pertinent previous year's resting cardiovascular (CV) parameter, mean video game systolic blood pressure (SBP) responses were predictive of resting SBP whereas absolute forehead cold and video game diastolic responses predicted resting diastolic blood pressure (DBP) 1 year later. Mean video game DBP responses were also predictive of resting peripheral resistance index after controlling for significant demographic and anthropometric measures. CV reactivity is discussed with regard to possible value in prediction of changes in resting BP and cardiac structure prior lo establishment of EH.

Journal Article↗

PubMed1994

The weights and heights of Mexican-American adolescents: the accuracy of self-reports.

The accuracy of Mexican-American adolescents' self-reported weights, heights, and body mass indexes was evaluated with data from the Hispanic Health and Nutrition Examination Survey. On average, adolescents with low measured body mass indexes and high measured body mass indexes overestimated and underestimated their weights, respectively. Categories of low and high body mass indexes created by applying cutoffs to reported body mass indexes had low sensitivities. For weight, height, and body mass indexes, measured and reported values were highly correlated. This high correlation suggests that adolescents' reported values can be used as continuous variables in multivariate analyses with only small errors resulting in the coefficients for weight, height, and body mass index.

Adolescent↗

PubMed1994

The pros and cons of vision screening.

Following the implementation of the DSE Regulations last year vision screening has become routine for many OHNs. Hazel Davis examines the pros and cons of current equipment and techniques.

Humans↗

PubMed1994

The effect of adiposity on children's left ventricular mass and geometry and haemodynamic responses to stress.

This study evaluated the relationship between adiposity, left ventricular mass and geometry, and haemodynamic parameters at rest and during laboratory stressors in a sample of 69 normotensive children with positive family histories of essential hypertension. Children were classified as overweight if they were above the 85th percentile of weight-for-height for their age and gender compared to national normative data. Nineteen children (7 whites, 12 blacks) were classified as overweight and the remaining 50 (26 whites, 24 blacks) were not overweight. Overweight children were found to have higher resting systolic and diastolic blood pressures, heart rates (HR), cardiac output (CO) and stroke volumes (SV), and lower resting total peripheral resistance than the non-overweight children. No differences were noted in haemodynamic reactivity to the stressors. Echocardiographic findings indicated that the overweight children had greater left ventricular mass indexed by height2.7, interventricular septal thickness and left ventricular end diastolic diameter (LVEDD) compared to non-overweight children. These findings are the first to indicate that the higher resting pressures of overweight normotensive children are a reflection of increased normotensive children are a reflection of increased preload (i.e. greater HR, SV, CO, LVEDD). These findings point out the early deleterious effects of obesity on the cardiovascular system in the young and highlight the need for effective obesity prevention and intervention programmes.

Adipose Tissue↗

PubMed1993

Measuring fruit and vegetable preferences among 4th- and 5th-grade students.

BACKGROUND: Achievement of the nation's Year 2000 fruit and vegetable goal of five or more daily servings may relate to children's preferences for fruits and vegetables. There are, however, no easily administered instruments for measuring preferences for fruits and vegetables among children. METHODS: An initial questionnaire systematically varied preparation methods after focus group discussions had indicated that this had an impact on fruit and vegetable preferences. The three-part questionnaire (fruits, vegetables, fruit and/or vegetable snacks) was classroom administered. Internal consistencies and test-retest reliabilities were acceptable. Principal components analyses, however, revealed food-specific rather than preparation factors; thus, preparation was eliminated from a revised questionnaire. RESULTS: Repeat classroom administration of the revised questionnaire yielded acceptable internal consistencies and test-retest reliabilities. Preferences were higher for fruits than vegetables. Principal components analyses indicated single fruit and vegetable factors and a two-factor solution for snacks (vegetables, fruits). Pearson correlations between preferences and consumption were significant, but accounted for only a small fraction of the variance. Correlations between fruit exposure and preferences, and between vegetable exposure and preferences were 0.55 and 0.51, respectively. CONCLUSION: The revised questionnaire provides a reliable, valid, and simple tool for assessing fruit and vegetable preferences of 4th- and 5th-grade students. The relationship between these preferences and actual consumption is weak; however, making fruits and vegetables more available may enhance preferences.

Child↗

PubMed1993

Naturally occurring atriocaval mesotheliomas in rats.

Atriocaval mesotheliomas were observed in two control Sprague-Dawley rats out of a total of 2889 rats examined. Both neoplasms were located at the base of the interventricular septum. Microscopically, the neoplasms consisted of varying proportions of glandular structures and a fibrous tissue stroma. Glandular structures were lined by a single layer of cuboidal to low columnar epithelium with cells containing a moderate amount of eosinophilic fibrillar to granular cytoplasm and a pleomorphic vesicular round nucleus with coarsely clumped chromatin and often a single eccentric prominent nucleolus. Epithelial cells were stained with antibodies raised against both vimentin and cytokeratin. Electron microscopical features included the presence of microvilli, terminal bars composed of modified tight junctions and desmosomes at the lateral and apical borders, and numerous tonofilaments associated with desmosomes.

Animals↗

PubMed1993

Ethnicity, gender, family history of myocardial infarction, and hemodynamic responses to laboratory stressors in children.

Relationship among ethnicity, gender, grandparents' histories of early myocardial infarction, and hemodynamic responses to forehead cold and treadmill exercise were examined in 87 6-to-8-year-olds (57 White, 30 Black). Boys had greater increases in systemic vascular resistance and decreases in cardiac index to forehead cold. Girls had greater increases and quicker recovery in heart rate to dynamic exercise. Blacks had greater increases and slower recovery in diastolic pressure to exercise and forehead cold. Blacks showed greater increases and slower recovery in systemic vascular resistance to forehead cold. Positive-family-history children had greater increases in diastolic pressure and systemic vascular resistance to forehead cold and greater diastolic pressure increases to exercise. Positive-family-history Blacks had greater increases in systolic pressure to exercise and slower recovery than all other groups.

Black or African American↗

PubMed1993

Relationship between family environment and children's hemodynamic responses to stress: a longitudinal evaluation.

Because interpersonal relationships may have an impact on the risk of developing cardiovascular disease, the authors examined the prospective relationship of family functioning upon hemodynamic stress responses in 87 6- to 8-year-old children. The parents completed the cohesion, conflict, expressiveness, and control subscales of the Family Environment Scale; 2 years later, the authors assessed the children's hemodynamic responses to postural change, forehead cold stimulation, and treadmill exercise. Maternal reports of greater cohesion and expressiveness were related to less increases in systolic pressure and systemic vascular resistance in response to the forehead cold. Mothers' reports of expressiveness were related to lower systolic pressure and cardiac index reactivity to postural change. Fathers' reports of greater control were associated with greater diastolic pressure and vascular resistance increases to forehead cold and to greater vascular resistance responses to exercise. Paternal reports of greater conflict were associated with greater systemic vascular resistance increases and with lower cardiac index increases to exercise. Results suggest family functioning may predict later hemodynamic reactivity to stress. The findings are discussed in terms of previous research on parent-child interaction patterns and children's cardiovascular health.

Arousal↗