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Biomedical subjects

A Rogers

Publications and source records attributed to A Rogers.

At least 145 records · Page 8Linked to original sources

Return migration to region of birth among retirement-age persons in the United States.

This study addresses some of the methodological difficulties one encounters in assessing the question of whether older persons display an increasing tendency to return to their state of birth after reaching retirement age. It reanalyzes previously studied data on the question and concludes that there is no indication that elderly people are more prone than nonelderly to "return home" to their native state.

Aged↗

Longer life but worse health? Measurement and dynamics.

A number of recent cross-sectional studies of longevity and health among the elderly have concluded that recent positive trends in the prolongation of life have not been matched by similar trends in the extension of healthy life. This paper challenges that pessimistic conclusion by examining conceptual issues related to the measurement and dynamics of the mortality-disability process. It uses data from the 1986 Longitudinal Study of Aging (U.S. Department of Health and Human Services, 1988) to illustrate its principal points.

Aged↗

Interregional elderly migration and population redistribution in four industrialized countries. A comparative analysis.

Though differing in cultures, languages, and socioeconomic attributes, the industrialized nations of the world share a common characteristic: relatively low fertility levels and relatively high proportions of elderly people. These elderly persons are not spread uniformly across their national territories; they exhibit distinct population geographies. This article examines the elderly migration and population redistribution process in four industrialized countries, identifies their principal retirement regions, and analyzes the sources of regional elderly population growth in these regions. It concludes that the United Kingdom and the United States are approaching the final stages of their "elderly mobility transition," whereas Japan is only entering the first stage, with Italy occupying a position somewhere in between.

Aged↗

Transitional cell carcinoma of upper urinary tract: some prognostic indicators.

Thirty cases of transitional cell carcinoma were reviewed over a twenty-year period. The incidence of bladder tumor recurrence was no different in those who had complete or incomplete nephroureterectomy. Grade and stage correlated well with survival. Intravenous urogram findings at presentation were important prognostic indicators.

Adult↗

Cancer pain management with a controlled-release oral morphine preparation.

An open-label pilot study was conducted to assess the efficacy and acceptability of a controlled-release oral morphine formulation, MS Contin tablets, when administered "by the clock" two to three times daily as a substitute for opioids given on request to patients with pain caused by advanced cancer. Initially, four-hourly does of standard "immediate-release" oral morphine sulfate tablets were substituted for the patients' prior analgesic medication and titrated to individual needs. Forty of the 47 patients enrolled in the study were subsequently switched to an eight-hourly MS Contin regimen (three patients became too ill to continue the study, and four left the study during the immediate-release titration phase because of adverse reactions that may have been drug related). Small "rescue" doses of standard oral morphine were available to the patients, but they were taken infrequently. Twenty-one of the 37 patients maintained on the eight-hourly schedule consented to be treated with, and were subsequently stabilized on, MS Contin administered every 12 hr, with a reduction of over 20% in their average daily morphine dose. Most of the patients rated the controlled-release medication superior to the standard oral morphine tablets in terms of both convenience and adequacy of relief.

Administration, Oral↗

Treatment of a murine model of systemic candidiasis with liposomal amphotericin B bearing antibody to Candida albicans.

Survival of mice infected with an intravenous injection of Candida albicans was observed in a short-term (21-day) survival study. Concentration of C. albicans in the kidneys, liver, and spleen was determined at various times. The effects of treatment with the commercial formulation of amphotericin B (fAMB), liposomal amphotericin B (LAMB), and liposomal amphotericin B bearing external antibody specific for C. albicans (LAMB-Ab) were compared. In single intravenous treatment dosages of 0.6 mg of amphotericin B/kg, the liposomal forms of the drug (LAMB and LAMB-Ab) enhanced the percentage survival and mean survival time of mice in comparison with those treated with the unencapsulated antifungal compound, fAMB (p less than 0.03 and p less than 0.001, respectively). LAMB-Ab, at this dosage, produced an increase in the survival (p less than 0.007) of mice over that produced by LAMB. LAMB-Ab treatment caused a greater than 3-fold increase over fAMB. The percentage of LAMB-Ab-treated mice which survived for 21 days was almost double that of the LAMB-treated mice. The increase in survival following this treatment did not, however, lead to the eradication of C. albicans in all mice which survived to the end of the experiment.

Amphotericin B↗

The elderly mobility transition. Growth, concentration, and tempo.

The redistribution of the elderly population in the United States is receiving increased attention as the sociodemographic consequences of the uneven geography of the aged are becoming more evident to state and local policymakers. Prospects for the future may be illuminated with the development of a conceptual framework for analyzing such redistribution processes. This article suggests that the notion of an Elderly Mobility Transition may be useful in such analyses, and it sets out three measures that could be used to depict the evolution of the transition: growth, concentration, and tempo.

Aged↗

Active life among the elderly in the United States: multistate life-table estimates and population projections.

Calculations of multistate life expectancy not only measure how long a population may live beyond a certain age, but also what fractions of this continuing lifetime will be spent in an independent or dependent status. Many Americans aged 70 and over are leading long, active lives; large numbers of individuals who become dependent, moreover, do so temporarily and return to independent status. Men and women have disparate total and active life expectancies, however, reflecting differential survival patterns and varying rates of transition among statuses. Policy makers must consider the increased size of the future elderly population, and changes in its age composition and functional status, when planning relevant health services.

Activities of Daily Living↗

Forecasting mortality: a parameterized time series approach.

This article links parameterized model mortality schedules with time series methods to develop forecasts of U.S. mortality to the year 2000. The use of model mortality schedules permits a relatively concise representation of the history of mortality by age and sex from 1900 to 1985, and the use of modern time series methods to extend this history forward to the end of this century allows for a flexible modeling of trend and the accommodation of changes in long-run mortality patterns. This pilot study demonstrates that the proposed procedure produces medium-range forecasts of mortality that meet the standard tests of accuracy in forecast evaluation and that are sensible when evaluated against the comparable forecasts produced by the Social Security Administration.

Adolescent↗

Stable growth in native-dependent multistate population dynamics.

"Users of multistate life tables and projections have recognized that the Markovian assumptions underlying such models are unduly restrictive and should be relaxed whenever data permit. Efforts to include the influences of previous occupancies have included the incorporation of place-of-birth dependence. This paper addresses the stable growth properties of such generalized multistate models. It shows how place-of-birth-specific stable growth measures can be calculated without projection simply by solving the characteristic equation. An example using Canadian data illustrates the argument." (SUMMARY IN FRE)

Americas↗

Age patterns of elderly migration: an international comparison.

Age-specific rates of migration exhibit remarkably persistent regularities in age profile. These regularities seem to hold all over the world and across time. This article identifies some of the principal antecedents of such regularities, focusing especially on the age patterns of migration exhibited by the elderly. It examines the differentials introduced by gender, distance, and marital status.

Aged↗

Haemodynamic response to magnesium administration in mineralocorticoid-salt and two-kidney, one clip renovascular hypertension.

Recent interest has centred on the role of divalent cations in hypertension, particularly in relation to the renin-angiotensin system. This study was undertaken to determine the hypotensive effect of magnesium administration in relation to the state of activation of the renin-angiotensin system. The mean blood pressure (MBP) and heart rate (HR) response to either the acute intravenous administration of a pharmacological dose of MgSO4 or vehicle was determined in conscious mineralocorticoid-salt (DOCA-salt, low-renin) and two-kidney, one clip renovascular, high-renin hypertensive rats. Baseline MBP was higher in the renovascular than in the DOCA-salt rats, while there was no difference in HR or serum Mg concentration between the two. Following administration of MgSO4, serum Mg increased equally in both the DOCA-salt (1.4 +/- 0.8 to 4.9 +/- 0.16 mEq/l; P less than 0.001) and in the renovascular rats (1.8 +/- 0.14 to 4.4 +/- 0.27 mEq/l; P less than 0.001). Magnesium administration significantly lowered MBP over the 1-h infusion in the DOCA-salt (167 +/- 8 to 145 +/- 5 mmHg, P less than 0.001) but not the renovascular hypertensive rats (191 +/- 5 to 183 +/- 4, NS). We conclude that the blood pressure lowering effect of Mg is related, in part, to the state of activation of the renin-angiotensin system. The mechanism of this differential effect remains to be determined.

Animals↗

On Wright's mechanism for intergroup selection.

A haploid model of Wright's (1945) intergroup selection is described. Several approximate analyses as well as Monte Carlo simulation show that Wright's mechanism leads to powerful selection for group advantageous traits in the face of strong local selection against them. Intergroup selection is favored by small local subpopulation size and by high, not low, rates of immigration into local groups, although the dependence on migration rate is not strong. These results and others cast doubt on the primacy of genic selfishness as a tenet of Darwinian theory.

Animals↗

Acid-base disturbances in gastrointestinal disease.

Gastrointestinal disorders are associated with severe and often complex acid-base disturbances. We review the most important types of metabolic alkalosis and metabolic acidosis associated with gastrointestinal disorders, excluding liver disease. Special emphasis is placed on pathophysiologic mechanisms. This information may help the clinician understand the generation and maintenance of these disorders and to plan an effective therapeutic approach.

Acid-Base Imbalance↗