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S Wing

Publications and source records attributed to S Wing.

At least 19 recordsLinked to original sources
PubMed1995

The shifting stroke belt. Changes in the geographic pattern of stroke mortality in the United States, 1962 to 1988.

BACKGROUND AND PURPOSE: The factors that contribute to the Stroke Belt--a concentration of high stroke mortality rates in the southeastern United States--remain unidentified. Previous hypotheses that focused on physical properties of the area have not been confirmed. This study describes changes in the locations of areas with the highest rates of stroke mortality and the implications for new hypotheses regarding the Stroke Belt. METHODS: We calculated annual, age-adjusted stroke mortality rates for black women, black men, white women, and white men for the years 1962 to 1988 using a three-piece log-linear regression model. Maps were produced with the state economic area (SEA) as the unit of analysis. The baseline Stroke Belt was defined as the area with the largest concentration of high-quintile SEAs in 1962. RESULTS: The concentration of high-rate SEAs tended to shift away from the Piedmont region of the Southeast and toward the Mississippi River valley. For example, whereas among black women in 1962, 72% of SEAs in the baseline Stroke Belt were in the highest quintile, by 1988 this percentage had dropped to 48%. Similar patterns were observed for the other race/sex groups. CONCLUSIONS: Temporal changes in the location of areas with the highest stroke mortality rates suggest that new hypotheses for understanding the geographic pattern of stroke mortality should consider temporal trends in a variety of medical, socioeconomic, and behavioral factors.

Adult↗
PubMed1992

Extraneuronal uptake of noradrenaline in rabbit dental pulp: evidence of identity with uptake1.

The extraneuronal removal and disposition of noradrenaline in rabbit dental pulp was examined in view of earlier evidence that the tissue possessed an extraneuronal uptake process resembling neuronal uptake1. Pulp, which had been depleted of sympathetic nerves by homolateral superior cervical ganglionectomy, was incubated in vitro with 3H-noradrenaline in low concentrations (0.025 or 0.18 mumol/l). When the metabolising enzymes (monoamine oxidase, catechol-O-methyl transferase) were active, 3H retention by the denervated pulp, as indicated by the 3H content after the tissue had been washed for 30 min following incubation with 3H-noradrenaline, was less than 3% of that of the innervated pulp. When the enzymes were inhibited, retention rose to approximately 30% of that of the innervated pulp. Analysis of the time course of the 3H efflux indicated that the 3H-noradrenaline in the denervated pulp had accumulated in a single compartment characterised by a t1/2 for efflux of several hours. Accumulation did not occur under Na(+)-free conditions, and was inhibited by desipramine (IC50 less than 0.03 mumol/l) and by substrates of neuronal uptake1. Mean IC50 values of the latter were very similar to those for inhibition of neuronal uptake1 and comprised (in mumol/l): (+)amphetamine (0.29), dopamine (0.31), tyramine (0.39), (-)noradrenaline (0.70), (-)adrenaline (1.50), 5-hydroxytryptamine (20) and bretylium (35). Uptake2 inhibitors were less active (O-methyl isoprenaline, IC50 = 60 mumol/l) than uptake1 inhibitors, or were without inhibitory effects at the concentrations tested (hydrocortisone, 210 mumol/l; 2-methoxy oestrone, 10 mumol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Antihypertensive treatment and US trends in stroke mortality, 1962 to 1980.

OBJECTIVES: This study examines the association between increases in antihypertensive pharmacotherapy and declines in stroke mortality among 96 US groups stratified by race, sex, age, metropolitan status, and region from 1962 to 1980. METHODS: Data on the prevalence of controlled hypertension and socioeconomic profiles were obtained from three successive national health surveys. Stroke mortality rates were calculated using data from the National Center for Health Statistics and the Bureau of the Census. The association between controlled hypertension trends and stroke mortality declines was assessed with weighted regression. RESULTS: Prior to 1972, there was no association between trends in controlled hypertension and stroke mortality declines (beta = 0.04, P = .69). After 1972, groups with larger increases in controlled hypertension experienced slower rates of decline in stroke mortality (beta = 0.16, P = .003). Faster rates of decline were modestly but consistently related to improvements in socioeconomic indicators only for the post-1972 period. CONCLUSIONS: These results do not support the hypothesis that increased antihypertensive pharmacotherapy has been the primary determinant of recent declines in stroke mortality. Additional studies should address the association between declining stroke mortality and trends in socioeconomic resources, dietary patterns, and cigarette smoking.

Black or African American↗
PubMed1992

Geographic and socioeconomic variation in the onset of decline of coronary heart disease mortality in white women.

BACKGROUND: Regional, metropolitan, and socioeconomic factors related to the onset of decline of coronary heart disease (CHD) mortality among White women are reported. Such studies are important for planning population-level interventions. METHODS: Mortality data for 1962 to 1978 were used, to estimate the year of onset of decline. Ecological analyses of socioeconomic data from the US census were used to emphasize structural and organizational aspects of changes in disease, rather than as a substitute for an individual-level design. RESULTS: Onset of decline of CHD mortality among White women was estimated to have occurred by 1962 in 53% of 507 state economic areas (SEAs), ranging from 79% in the Northeast to 39% in the South. Metropolitan areas experienced earlier onset of decline than did nonmetropolitan areas. Average income, education, and occupational levels were highest in early onset areas and declined across onset categories. CONCLUSIONS: The results provide additional evidence for previously observed geographic and social patterns of CHD decline. Emphasis on structural economic factors determining the shape of the CHD epidemic curve does not detract from the medical importance of risk factors, but underscores the importance of community development to public health improvements. The results are consistent with the idea that the course of the CHD epidemic in the United States has been strongly influenced by socioeconomic development.

Adult↗
PubMed1992

Social inequality of stroke mortality among US black populations, 1968 to 1987.

Though the rate of stroke mortality in the United States has been declining for all race-sex-specific groups, rates for blacks are among the highest in the world. Studies of the geographic and social variation of stroke mortality between populations have focused solely on either trends or social determinants, but not on both. In addition, conclusions have concentrated on the comparison of whites to nonwhites. The purpose of this study was to investigate the variation in stroke mortality trends, from 1968 to 1987, between US black populations categorized by the socioeconomic structure of the state economic area. The educational achievement profile of the population (percentage of the state economic area that had not completed high school) was used as an indicator of socioeconomic development. This aggregate study assessed whether (1) an inverse relationship existed between stroke mortality and educational achievement category, and (2) levels and trends of stroke mortality by educational achievement category varied from 1968 to 1987, for each age-gender-specific group (35 to 64, 65 to 74, and 75 to 84 years). Results showed an inverse relationship between educational achievement level of communities and stroke mortality, as well as a rank-ordering in level of educational achievement for all age-gender-specific groups. The absolute difference in rates among educational achievement levels clearly converged over time, with greater convergence in the period 1968 to 1978 than 1979 to 1987. The percent declines were similar across education categories. Results suggest that geographic inequalities in stroke mortality, in relation to socioeconomic structure, have converged over time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Mortality among workers at Oak Ridge National Laboratory. Evidence of radiation effects in follow-up through 1984.

White men hired at the Oak Ridge (Tenn) National Laboratory between 1943 and 1972 were followed up for vital status through 1984 (N = 8318, 1524 deaths). Relatively low mortality compared with that in US white men was observed for most causes of death, but leukemia mortality was elevated in the total cohort (63% higher, 28 deaths) and in workers who had at some time been monitored for internal radionuclide contamination (123% higher, 16 deaths). Median cumulative dose of external penetrating radiation was 1.4 mSv; 638 workers had cumulative doses above 50 mSv (5 rem). After accounting for age, birth cohort, a measure of socioeconomic status, and active worker status, external radiation with a 20-year exposure lag was related to all causes of death (2.68% increase per 10 mSv) primarily due to an association with cancer mortality (4.94% per 10 mSv). Studies of this population through 1977 did not find radiation-cancer mortality associations, and identical analyses using the shorter follow-up showed that associations with radiation did not appear until after 1977. The radiation-cancer dose response is 10 times higher than estimates from the follow-up of survivors of the bombings of Hiroshima and Nagasaki, Japan, but similar to one previous occupational study. Dose-response estimates are subject to uncertainties due to potential problems, including measurement of radiation doses and cancer outcomes. Longer-term follow-up of this and other populations with good measurement of protracted low-level exposures will be critical to evaluating the generalizability of the results reported herein.

Cause of Death↗
PubMed1991

Silicosis and lung cancer in North Carolina dusty trades workers.

Since 1940, 760 cases of silicosis have been diagnosed as part of the State of North Carolina's (NC) pneumoconiosis surveillance program for dusty trades workers. Vital status was ascertained through 1983 for 714 cases that had been diagnosed since 1940 and death certificates were obtained for 546 of the 550 deceased. Mortality from tuberculosis, cancer of the intestine and lung, pneumonia, bronchitis, emphysema, asthma, pneumoconiosis, and kidney disease was significantly increased in whites. Mortality from tuberculosis, ischemic heart disease, and pneumoconiosis was significantly increased in non-whites. The standardized mortality ratio (95% CI) for lung cancer based on U.S. rates was 2.6 (1.8-3.6) in whites, 2.3 (1.5-3.4) in those who had no exposure to other known occupational carcinogens, and 2.4 (1.5-3.6) in those who had no other exposure and who had been diagnosed for silicosis while employed in the NC dusty trades. Age-adjusted lung cancer rates in silicotics who had no exposure to other known occupational carcinogens were 1.5 (.8-2.9) times higher than that in a referent group of coal miners with coalworkers' pneumoconiosis (CWP) and 2.4 (1.5-3.9) times higher than that in a referent group of non-silicotic metal miners. Age- and smoking-adjusted rates in silicotics were 3.9 (2.4-6.4) times higher than that in metal miners. This analysis effectively controls for confounding by age, cigarette smoking, and exposure to other known occupational carcinogens, and it is unlikely that other correlates of silica exposure could explain the excess lung cancer mortality in the silicotics.

Adult↗
PubMed1991

Analyses of black and white differentials in the age trajectory of mortality in two closed cohort studies.

We examine the relationship of age to mortality in blacks and whites in two cohort studies, the 20-year follow-up of the Evans County, Georgia. Study population and the 25-year follow-up of the Charleston Heart Study population. We conducted analyses with two parametric forms of hazard models (Gompertz and Weibull) for total mortality experience and considered the fit of the two hazard models in each study both separately and with the data pooled. We evaluated the robustness of conclusions about differences in the age pattern of mortality for blacks and whites by comparing results from the two hazard models. Where the tests were non-nested, we used an information-based statistic (AIC) to compare the fit of the models to the data. Results were robust to the selection of the hazard function, that is both models provided evidence that mortality rates at younger ages were lower for white than black females but that mortality rates increased more rapidly with age for white females. The absolute differences and the differences in the rates of increase were in the same direction, but smaller, for males. Though both models represented the general features of mortality patterns, the information statistic suggested better performance of the Gompertz function. The Gompertz function was also less sensitive to the initial age of determination of mortality exposure.

Adult↗
PubMed1991

Variation in the magnitude of black-white differences in stroke mortality by community occupational structure.

STUDY OBJECTIVE: The aim was to examine the patterns of black-white differences in stroke mortality across communities with varying levels of occupational structure in the southern region of the United States DESIGN: Annual age adjusted race-sex specific rates for stroke mortality were calculated for the years 1979-1981 and related to socioeconomic conditions. SETTING: The study involved 211 state economic areas comprising the southern region of the USA. STUDY POPULATION: Data on stroke mortality for black and white men and women between the ages of 35 and 74 years living in the study area were acquired from the National Center for Health Statistics. MEASUREMENTS AND MAIN RESULTS: Occupational structure was measured as the proportion of white collar workers in each state economic area, and is an indicator of the employment opportunities and related social and economic resources of a community. Stratified analyses and linear regression modelling indicate that communities of lower occupational structure have (a) higher levels of stroke mortality for all four race-sex groups (p less than 0.05) and (b) larger racial inequalities in stroke mortality (p less than 0.01). For men and women, the excess stroke mortality among blacks compared to whites is larger in communities of lower occupational structure. CONCLUSIONS: Consideration of occupational structure and related patterns of economic development is crucial for understanding the distribution of stroke mortality within and between racial groups, as well as for planning effective public health interventions. The larger racial inequalities in communities of lower occupational structure in the south suggest that aspects of the black experience which are conducive to high rates of stroke mortality are exacerbated in those communities. Public health interventions to reduce the racial and social inequalities in stroke mortality should recognise the social context within which nutritional, occupational, medical care, and environmental determinants of stroke are distributed.

Adult↗
PubMed1990

Trends in the geographic inequality of cardiovascular disease mortality in the United States, 1962-1982.

Substantial geographic variation of cardiovascular disease (CVD) mortality within the U.S. has been recognized for decades. Analyses reported here address the question of whether relative geographic inequality has increased or decreased during the period of rapidly declining CVD mortality 1962-1982. Trends in geographic inequality, as measured by the weighted coefficient of variation of State Economic Area rates, are analyzed for whites and blacks by sex for 10-year age groups 35-44 to 85 and over. The average annual percent change in the coefficient of variation for each demographic group is presented for all cause mortality, all CVD, stroke and ischemic heart disease. In general, geographic inequalities declined in total mortality for all except the youngest age group. This is consistent with reports of a strong convergence of age-adjusted cancer mortality in U.S. counties. By contrast, increasing geographic inequality dominates in the CVD categories, especially for whites in heart disease and stroke. At younger ages, increases in the coefficient of variation for all race-sex groups exceeded 1% per year in stroke and 2% per year in heart disease. These results suggest that factors influencing the percent decline of CVD mortality are not reaching communities of the U.S. equally. Since increases in relative inequality are strongest in the younger age groups, the pattern of inequality may be accentuated as these cohorts move into ages of higher mortality.

Adult↗
PubMed1990

Intravenous bicarbonate and sodium chloride both prolong endurance during intense cycle ergometer exercise.

To determine the effects of neutralizing exercise systemic acidosis via the intravenous route upon endurance and metabolic responses, eight lean, normal, postabsorptive men exercised to exhaustion at about 80% of their VO2 max (69 +/- 3%, mean +/- SEM, of maximum power output) on a cycle ergometer. Exercise studies were performed either with no infusion (control) or with a total infusion volume of about 1.5 L, mainly as 1.3% sodium bicarbonate or as 0.9% sodium chloride (NaCl), infused (double-blind) throughout exercise. The sodium bicarbonate was to prevent acid-base change, the sodium chloride was as a control for the volume infused. Arterialized venous blood and breath-by-breath analysis of expired gases were obtained. [H+] (nmol.L-1) and [HCO3-] (mmol.L-1) at exhaustion were similar in control and NaCl (46.5 +/- 1.8, 19.9 +/- 0.9), but remained unchanged from rest values with bicarbonate (38.4 +/- 0.9, 24.8 +/- 1.5, p less than 0.005 vs control and NaCl). At exhaustion, VO2, VCO2, RER, heart rate, and systolic BP as well as FFA, glycerol, alanine, insulin, norepinephrine, and epinephrine did not differ among protocols. Endurance was markedly prolonged (p less than 0.01) with bicarbonate (31.9 +/- 5.8 min) and NaCl (31.8 +/- 4.1 min) compared with the control (19.0 +/- 2.9 min) condition. Plasma glucose at exhaustion was higher (p less than 0.025) in the control compared to bicarbonate and NaCl experiments, while lactate was higher (p less than 0.025) in the bicarbonate than in the control and NaCl experiments. Thus, the prolonged endurance with sodium bicarbonate infusion could not be explained either by its effect of maintaining blood acid-base equilibrium or concomitant metabolic changes.

Acid-Base Equilibrium↗
PubMed1988

Stroke mortality maps. United States whites aged 35-74 years, 1962-1982.

We mapped average age-adjusted stroke mortality rates for white men and white women aged 35-74 years for state economic areas (counties or groups of counties) in the continental United States for three 7-year periods between 1962 and 1982. Despite the decline of national stroke mortality rates, rates in some areas failed to decline between 1962-1968 and 1969-1975. All areas experienced declines in 1976-1982, by which time some rates in the highest decile of the rate distribution were comparable to rates that had been in the lowest decile in 1962-1968. An east-west gradient of high-to-low stroke mortality rates was evident for both white men and white women in all three periods. Within the eastern part of the United States, high rates appeared more commonly in the South, and more so for white men than for white women. The "stroke belt" (area of very high stroke mortality rates in the coastal plain of the South) became less concentrated over the 2 decades, while a clustering of state economic areas with high rates along the Mississippi River and in the Ohio River valley became more pronounced.

Adult↗
PubMed1988

Socioenvironmental characteristics associated with the onset of decline of ischemic heart disease mortality in the United States.

The relation of community socioenvironmental characteristics to timing of the onset of decline of ischemic heart disease (IHD) mortality was investigated among the 507 State Economic Areas of the continental United States. Onset of decline was measured using data for White men aged 35-74 and classified as early (1968 or before) vs late (after 1968). Ten socioenvironmental characteristics derived from US Census Bureau data were strongly related to onset of decline. Areas with the poorest socioenvironmental conditions were two to 10 times more likely to experience late onset than those areas with the highest levels. We found that income-related characteristics could account for most of the difference in onset of decline of IHD between metropolitan and non-metropolitan places. We conclude that community socioenvironmental characteristics provide the context for changes in risk factors and medical care.

Adult↗
PubMed1987

Changing association between community occupational structure and ischaemic heart disease mortality in the United States.

The changing association between community occupational structure and ischaemic heart disease mortality in white men and women of the United States from 1968 to 1982 has been investigated. Occupational structure was represented by the proportion of workers in white-collar jobs. A negative association, with lower mortality in communities with higher levels of white-collar employment, emerged over the period in both men and women. The results for men may be interpreted as suggesting a recapitulation in the US of the changing association between social class and heart disease observed in Britain. Occupational structure, however, reflects resources and opportunities in a community derived from its contribution to the national and international economy. Thus the growing inequalities in heart disease mortality presented in this ecological study relate more appropriately to communities than to individual workers.

Adult↗