Tribological testing of skin products: gender, age, and ethnicity on the volar forearm

Background/purpose: Few studies have focused on the simultaneous measurement of the friction and electrical properties of skin. This work investigates the feasibility of using these measurements to differentiate between the effects of chemicals commonly applied to the skin. In addition, this study also compares the condition of the skin and its response to application of chemicals across gender, ethnicity, and age at the volar forearm.
Method: Friction and electrical tests were performed on 59 healthy volunteers with the UMT Series Micro-Tribometer (UMT). A 13-mm-diameter copper cylindrical friction/electrical probe was pressed onto the skin with a weight of 20 g and moved across the skin at a constant velocity of 0.4 mm/s. Each volunteer served as his or her own control. The friction and electrical impedance measurements were performed for polyvinylidene chloride occlusion and for the application of glycerin and petrolatum.
Results: No differences were found across age, gender, or ethnicity at the volar forearm. Polyvinylidene chloride (PVDC) occlusion showed a small increase in the friction and a small decrease in the electrical impedance; petrolatum increased the friction by a greater amount but its effect on the impedance was comparable to PVDC occlusion; glycerin increased the friction by an amount comparable to petrolatum, but it decreased the impedance to a much greater degree than petrolatum or the PVDC occlusion. An amplitude/mean measurement of the friction curves of glycerin and petrolatum showed that glycerin has a significantly higher amplitude/mean than petrolatum.
Conclusion: The properties of the volar forearm appear to be independent of age, gender, and ethnicity. Also, the simultaneous measurement of friction and electrical impedance was useful in differentiating between compounds administered to the skin.     

Participation Patterns in Home‐Based Family Support Programs: Ethnic Variations*

This study investigated the relationship between ethnicity and retention among families participating in a national network of home‐based family support programs. Using archival data collected on 224 African American, 227 European American, and 219 Latino American mothers of newborns and 153 home visitors, multivariate analyses indicate greater participation by African American and Latino parents as compared with European American parents. Retention predictors vary by ethnicity. Strategies to form a supportive parent‐provider alliance are discussed.     

Racial and ethnic disparities in self‐assessed health status: Evidence from the national survey of families and households

We examined racial and ethnic disparities in global health assessment and functional limitations of daily activities among whites, blacks and Hispanics, and within the Hispanic origin among Mexicans, Puerto Ricans, Cubans, and ‘Others’. Logistic regressions were employed to estimate the log odds of reporting ‘poor health’ and ‘having functional limitations’ among 12 814 respondents from the 1987—1988 National Survey of Families and Households. Compared with whites, blacks had an increased risk of reporting poor health and functional limitations. Hispanics had even a higher risk of reporting poor health, but did not have an increased risk of reporting functional limitations. Among Hispanics, Mexicans were more likely than whites to report poor health, whereas Puerto Ricans were more likely than whites to experience functional limitations. Both race and ethnicity remain important factors in explaining the disparities in self‐assessed health status independent of socioeconomic status (SES). Meanwhile, the way self‐assessed health status varies with ethnicity is importantly stratified by SES as measured by income and education. These results suggest that future research should analyze the interplay between ethnicity and SES rather than assuming measuring either captures all the important variation.     

Ethnicity,Hypertension, Coronary Heart Disease and Renal Diseases in South Africa

This paper reviews the impact of race and environment upon hypertension, coronary heart disease and renal diseases in South Africa. Inequalities of socioeconomic status, lifestyle, and access to South African health care have produced striking differences in the prevalence and complications of hypertension. Coronary heart disease is ‘epidemic’ in the white and Indian population and is still relatively uncommon in blacks. There are different histological patterns of glomerulonephritis among the racial groups, which may lead to end‐stage renal disease. Hypertension is an important cause of end‐stage renal disease in the black population whilst analgesic nephropathy is important in the white population. Efforts are now being made to comprehend these daunting realities and to minimize the inequalities.     

Trends in cigarette smoking among children in a southern community, 1976–1994: The Bogalusa Heart Study

Cigarette smoking among adolescents continues to be a major public health problem in the United States. Smoking trends from 1976–1977 to 1992–1994 were examined in the Bogalusa Heart Study, an investigation of cardiovascular disease risk factors among black and white, male and female adolescents in a semirural town in the southern United States. Age-race-sex specific χ² tests for trends over five survey periods were conducted. In almost every age group, black boys and girls were less likely to be current smokers or to have ever smoked or tried cigarettes, as compared with white boys and girls, respectively (P < 0.01). Within age groups, few significant trends in smoking status from 1976–1977 through 1992–1994 were observed among white boys and girls. Among black males and females, however, sharp decreases were observed among all age groups in the prevalence of having ever smoked or tried cigarettes (P = 0.0001) and among the older age groups in the prevalence of being a current smoker (P = 0.0001). Thus, substantial declines in the prevalence of smoking were observed among black children but not among white children. Further research is required to understand why these ethnic differences in smoking occurred so that public health programs may target further the smoking behaviors in children.     

Classifying ethnicity utilizing the Canadian mortality data base

The study of ethnic differences in disease is a methodological challenge as ethnicity is often not identified in existing datasets and surrogate measures need to be used. We have developed a novel methodology combining last name and country of birth to study mortality patterns of Canadians of South Asian (SA) and Chinese (CH) ethnic origin and have compared death rates among SA, CH, and White (WH) Canadians.

Methods. SA and CH were identified in the Canadian Mortality Data Base (CMDB) using the last name and country of birth of the deceased. Records of people who had been born in countries with large South Asian and Chinese populations (e.g. India, Pakistan, China, Hong Kong) were selected and manually screened by last name. A name directory was then created of distinct South Asian and Chinese names and this directory was used to search all other records in the CMDB for SA and CH deaths. Where necessary, other identifying characteristics such as first name and parents’ last name were also used. Population counts were obtained from the Census self‐reported question on ethnicity for SA and CH. WH were identified as non‐immigrant Canadians who were neither SA nor CH. The method of assigning ethnicity in the CMDB and Census were assessed for comparability and issues of validity and reliability were addressed.

Results. Using this method, 10 989 SA and 21 548 CH deaths were identified. There was marked heterogeneity in birthplace, with only 56% of SA born in South Asia and only 74% of CH born in Greater China. Last names had high validity for self‐reported ethnicity in a population sample of SA and were highly reproducible. Mortality rates varied dramatically between groups studied. SA and WH had high rates of ischemic heart disease while stroke mortality was similar among all three groups. Cancer death rates were high in CH and WH and much lower in SA.

Conclusion. Last names and country of birth can be used to determined ethnicity of SA and CH with validity and reliability, and leads to a more accurate classification than country of birth alone. The contrasting patterns observed in mortality from major causes of death suggest many interesting hypotheses for further study.     

Epidemiology of self‐reported past heavy drinking in Hispanic adults

Objectives. Self‐reports of past heavy drinking correlate with the current drinking practices and with risk of mortality in non‐Hispanic males. The prevalence of past heavy drinking has not been reported in Hispanic populations.

Methods. Using data from the Hispanic Health and Nutrition Examination Survey (HHANES) we (1) report on the prevalence, duration and severity of past heavy drinking in three Hispanic groups, (2) compare the current alcohol consumption patterns among past heavy drinkers and those who do not report a history of past heavy drinking and (3) compare the risk factor profiles and health indicators in these two groups.

Results. The prevalence of past heavy drinking among Mexican American and Puerto Rican males ranged from 28–35% while the rates for Cuban American males ranged from 7–16%. The rates for Hispanic women were much lower (1–8%). The average years of past heavy drinking ranged from 2.3–14.9 years, while the alcohol consumption during the past heavy drinking period ranged from 24.4–44.0 drinks per week. Past heavy drinkers tended to consume more alcohol at present than did never heavy drinkers with the greatest differences found for Mexican American females. Comparisons of the risk factors and health indicators by drinking status revealed a higher prevalence of smoking among past heavy drinkers (50–60%) versus never heavy drinkers (34–43%). Past heavy drinking Mexican American females also reported significantly more chronic conditions and depressive symptoms than did never heavy drinkers.

Conclusions. Prevalence rates of past heavy drinking among Mexican American and Puerto Rican males are approximately three times higher than rates reported for non‐Hispanic male populations.     

Cardiovascular and plasma catecholamine response to static exercise in normotensive blacks and whites

Objectives. The objectives of the present study were (1) to evaluate the presser response to an isometric handgrip exercise in normotensive black and white males; (2) to measure plasma catecholamine levels pre‐ and post‐exercise, as an index of sympathetic nervous system activity; and (3) to quantify the pressor response to bolus intravenous injections of phenylephrine (an α‐specific agonist).

Methods. Cardiovascular and catecholamine responses to an isometric handgrip exercise (3 minutes at 30% MVC) were measured in 15 normotensive blacks and whites. In another phase of the study, pressor responses to bolus injections of phenylephrine were assessed to evaluate α‐adrenergic sensitivity.

Results. The blood pressure in the blacks increased from 119/69 to 160/120 mm HG during isometric exercise, while in the whites it increased from 118/67 to 153/110 mm HG. The blacks exhibited a greater diastolic blood pressure reactivity, as evidenced by a significant race × time interaction (p < 0.05). The heart rate responses were not significantly different between the two groups. The plasma levels of norepinephrine were similar at rest, but were 25% lower in the blacks than in the whites following isometric exercise (p < 0.01). Black subjects also demonstrated an increased pressor response to intravenous injections of phenylephrine at rest (p<0.05).

Conclusions. The enhanced vascular sensitivity to norepinephrine may have contributed to the greater exercise pressor response in the blacks.     

Mapping the prevalence of sickle cell and beta thalassaemia in England: estimating and validating ethnic-specific rates

A range of estimates for sickle cell and beta thalassaemia have been derived for the different ethnic groups living in the U.K., reflecting uncertainty over the true population value in certain countries and the heterogeneity within and between countries of origin comprising the same ethnic group. These were validated against six community screening programmes, with the estimated range correctly predicting the number of affected births observed by the programmes. In England approximately 3000 affected babies (0.47%) carry sickle cell trait and 2800 (0.44%) carry beta thalassaemia trait annually: with approximately 178 (0.28 per 1000 conceptions) affected by sickle cell disease (SCD) and 43 (0.07 per 1000) by beta thalassaemia major/intermedia. Allowing for termination, about 140-175 (0.22-0.28 per 1000) affected infants are born annually with SCD and from 10 to 25 (0.02-0.04 per 1000) with beta thalassaemia major/intermedia. These are the first evidence-based rates for sickle cell and beta thalassaemia for use in the U.K., and should underpin the future planning of services. The long-term solution to monitoring changes in the rates of trait and disease in the population is to introduce a standardized instrument for collecting ethnicity for all community screening programmes.     

Aging and immigration: Who are the elderly?

Much U.S. research in aging and the social sciences of health compares beliefs, conditions, or behaviors of racial groups. In immigration studies, social identity is most often delineated by virtue of foreign origin with respect to a host country. Thus, nationality is often the marker of difference. The present article joins two generally separate streams of research, gerontologic and immigration research in the United States. The paper considers data from several studies of seniors in Cleveland, Ohio in the 1990s; the Black and White Caregivers and the Use of Services of Black and White Elderly. These are considered not in terms of their original research goals, but rather in terms of a reflective examination of assumptions regarding the identity of the elders and caregivers that framed the two studies. The results show that racial terms conceal, not reveal, the actual ethnic and therefore, cultural, affiliations of the seniors. We suggest that because racial classification is an impediment to, rather than a facilitator of, cultural comparisons, such terms should not be used to compare, predict or explain beliefs or behaviors. The revelation of distinct, highly varied ethnic groups within asserted homogeneous racial groups has implications for immigration studies. These are discussed in the final section as relates to psychiatric and social issues.