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Biomedical subjects

D A Black

Publications and source records attributed to D A Black.

At least 19 recordsLinked to original sources
PubMed2000

The modern geriatric day hospital.

Geriatric day hospitals have played a major role in the rehabilitation of older people, although the evidence base has proved thin. As the provision of geriatric medicine changes, they need to develop new roles such as responding to subacute crises, providing specialist services and ensuring comprehensive geriatric assessment before long-term care.

Aged↗
PubMed1999

Health insurance coverage of the unemployed: COBRA and the potential effects of Kassebaum-Kennedy.

We use the April 1993 Current Population Survey to examine the health insurance coverage decisions of the unemployed and to simulate the potential effects of the new Kassebaum-Kennedy legislation. After controlling for demographic characteristics, COBRA eligibility raises the probability of health insurance coverage by 0.095, while eligibility for spouse employer insurance increases the likelihood of coverage by 0.318, and eligibility for both increases the likelihood of coverage by 0.341. In our simulations, we find that had Kassebaum-Kennedy been in effect in April 1993, 9.0 percent of the unemployed would be eligible to take up coverage, and the coverage rate of the unemployed would have been increased by 0.85 percent to 1.5 percent from 41.6 percent. Our estimates of the effect of Kassebaum-Kennedy on health insurance coverage are much lower than those reported by the Government Accounting Office prior to the passage of the legislation.

Eligibility Determination↗
PubMed1999

Iron deficiency anaemia and aspirin use in old age.

Aspirin is being increasingly prescribed for cardiovascular protection, but is also recognized to have significant gastrointestinal side-effects. Whether chronic aspirin consumption causes iron deficiency is undetermined, and there is little information available regarding iron deficiency and aspirin use in old age. We studied the relationship between iron deficiency anaemia and regular aspirin prescription in old age.

Aged↗
PubMed1997

Emergency day hospital assessments.

OBJECTIVE: To describe the use of a geriatric day hospital for emergency multidisciplinary assessment as an alternative to immediate hospital admission for some groups of frail older people. DESIGN: Retrospective study of change in clinical practice. SETTING: District general hospital. INTERVENTION: Immediate multidisciplinary assessment of selected patients instead of requested emergency hospital admission. OUTCOMES: (1) Data were collected on 67 consecutive referrals. In 63% the patient needs could be met without emergency hospital admission on the day of assessment. (2) Of the 42 patients originally not admitted only 29% were subsequently admitted within the next three months. CONCLUSIONS: Emergency day hospital assessments can be used as an alternative to immediate hospital admission for some frail older people.

Aged↗
PubMed1995

Education for health services management: a graduate student survey of an Australian program.

This article reports the results of a study which was designed to evaluate a revised Master's of Health Administration program in the School of Health Services Management at the University of New South Wales, Australia. The original program was established in 1956; during the 1970s, humanities-based subjects such as sociology and quality assurance were added to the traditional financial and management subjects. During 1987-88, health-oriented subjects such as public health and epidemiology were included as compulsory subjects. To assess the program, a cross-sectional study of 1990 to 1992 graduates was undertaken. The study revealed that students found that the traditional financial and management subjects and the health-related subjects were useful to their jobs. The study also demonstrated significant career advancement for a majority of graduates. Two-thirds of the respondents stated that their initial objectives for enrolling in the course had been met.

Adult↗
PubMed1988

Hepatic stores of retinol and retinyl esters in elderly people.

Post-mortem concentrations of hepatic retinol and retinyl esters were determined in 40 subjects aged over 65 years to assess the effects of disease and malnutrition on vitamin A reserves. Three groups of patients (mean age 79.6 years) were studied: (1) previously healthy, (2) chronically ill, (3) chronically ill and wasted. There was no significant difference in height or age between the groups, but group 3 was lighter than both group 1 (P less than 0.001) and group 2 (P less than 0.05). Free retinol and retinyl esters were measured by high pressure liquid chromatography, and the total hepatic retinol calculated. Analysis of variance showed that the three groups differed significantly (P less than 0.02) with regard to total retinol, retinyl palmitate and total retinyl ester content.

Aged↗
PubMed1988

Pseudotumour cerebri in a patient with Castleman's disease.

A patient with systemic Castleman's disease (angiofollicular lymph node hyperplasia) including bone changes and peripheral neuropathy, is described. She also had pseudotumour cerebri, and, as this association has been reported previously, it is unlikely to be due to chance.

Adult↗
PubMed1988

Oxypurine cycle in human erythrocytes regulated by pH, inorganic phosphate, and oxygen.

The effect of pH, PO2, and inorganic phosphate on the uptake and metabolism of hypoxanthine by erythrocytes has been studied. Uptake of hypoxanthine and accumulation of inosine 5'-monophosphate (IMP) were markedly increased at acid pH, high external phosphate concentrations, and low PO2. Release of accumulated IMP as hypoxanthine occurred at alkaline pH values and low external phosphate concentrations. Conditions favoring IMP accumulation gave rise, in the absence of hypoxanthine, to a corresponding increase in 5'-phosphoribosyl-1-pyrophosphate. Intracellular phosphate concentrations were markedly pH dependent and a model is presented whereby hypoxanthine uptake and release are controlled by intracellular concentrations of inorganic phosphate and 2,3-bisphosphoglycerate. These allosteric effectors influence, in opposing ways, two enzymes governing IMP accumulation, namely 5'-phosphoribosyl-1-pyrophosphate synthetase and 5'-nucleotidase. These metabolic properties suggest that the erythrocyte could play a role in the removal of hypoxanthine from anoxic tissue.

Adenosine Diphosphate↗
PubMed1988

Malabsorption: common causes and their practical diagnosis.

Malabsorption may present as non-specific ill health and malnutrition in the elderly. Outside major medical centers, however, investigation is often thought to be difficult and unrewarding, and screening tests unreliable. Therefore, a direct approach is suggested to identify treatable small bowel disease in those elderly patients with a clinical possibility of malabsorption. It is based on the use of plain abdominal x-ray, endoscopy with duodenal biopsy, and small bowel meal.

Aged↗
PubMed1987

Mental state and presentation of myocardial infarction in the elderly.

Atypical presentations of myocardial infarction are more common in the elderly. Fifty-three cases of myocardial infarction were found by prospectively screening all acute medical admissions aged over 75 years. The presenting symptom was compared with an assessment of mental state using a simple scoring system. Atypical presentations were found to be significantly (P = less than 0.001) associated with an impaired mental score.

Aged↗
PubMed1987

Transit time in ulcerative proctitis.

Whole-gut transit time was measured by the time taken for an orally administered dose of brilliant blue dye to disappear from the stool in 20 patients with ulcerative proctitis and in 20 age- and sex-matched controls. Ten of the patients had active, and 10 inactive disease. The dye usually appeared in the stool with the next bowel movement after ingestion in both patients and controls; however, the time at which the dye disappeared from the stool (transit time) was prolonged to 76.1 h in the patients, compared with 50.2 h in the controls (p less than 0.01). This delay occurred both in patients with active disease at 70.5 h (p less than 0.05) and in those with inactive disease at 81.8 h (p less than 0.05). This prolongation of transit time may be relevant to both the pathogenesis and treatment of ulcerative proctitis.

Benzenesulfonates↗
PubMed1986

Chromatid behavior in late mitosis: a scanning electron microscopy analysis of mammalian cell lines with various chromosome numbers.

Chromatid activity during the process of nuclear reformation following metaphase is a period of mitosis where little precise information is available. Nuclear reformation requires that chromosomes, at metaphase and chromatids during anaphase and telophase align, position and associate in a clearly defined sequence to insure the specific design of each nucleus. Four cell lines with chromosome numbers ranging from seven to almost seventy were chosen to determine whether the process of nuclear assembly is the same throughout. Chromosomal alignment at metaphase is found to be radial in all four cell lines. Chromosome positioning is essentially the same in all four, where the smaller chromosomes are located centrally and longer ones are positioned peripherally in a radial alignment. Chromosomal association is directly related to chromosome number. The more chromosomes in a one dimensional plane occupying a given area, the closer the association. In comparing the HeLaS3 and muntjac chromatids, the former has the closer association at metaphase. Since association is the most important aspect of chromatid behavior in nuclear reformation, chromatid positioning becomes a vital process during anaphase movement. Chromatid positions established during anaphase determines later positioning in the interphase nucleus because of the subsequent interconnection of adjacent chromatids by the formation of a fibrous meshwork. This fibrous meshwork, formed in anaphase and early telophase, functions to stabilize chromatids following their positioning and it also serves as a substrate or matrix for the assembly of nuclear envelope.

Anaphase↗
PubMed1985

Nuclear reformation following metaphase in HeLa S3 cells: three-dimensional visualization of chromatid rearrangements.

Nuclear reformation from chromatids following metaphase was visualized three-dimensionally for the first time in mammalian cells (HeLa S3) by scanning electron microscopy (SEM). Anaphase and telophase configurations free of mitotic apparatus, cytoskeletal elements and nuclear envelope were prepared using a slightly modified standard cytological procedure which permitted visualization of chromatid position and orientation. Mid-anaphase alignments were observed to be more complex than previously revealed by light and transmission electron microscopy (TEM). One pole consisted of chromatids joined along their lateral length, the other pole consisted of telomeres, apparently of the longest chromatids, aligned in a double concentric layer. As anaphase progressed, re-association of these chromatids appeared to occur progressively along their lateral length toward their telomeres. Morphological evidence is presented suggesting that this lateral re-association may involve interchromatid fibers. After complete joining, structures resembling a hollow half sphere had formed. Based on different preparative procedures for SEM and published TEM analysis, it is this shell-like configuration upon which the nuclear envelope is reestablished in early telophase. As telophase progressed there was loss in depth of the internal chamber resulting in a disc configuration. Following loss of chromatid outline from the surface of this structure, interphase nuclear shape was assumed. Morphometric determinations revealed relative dimensions of chromatid configurations and supported the conclusion that nuclear reformations proceeded by discrete steps. The complexity of such a process, as revealed by SEM analysis, is discussed.

Cell Cycle↗
PubMed1984

Chromosome stabilizing structures in mitotic Indian muntjac (Muntiacus muntjak) cells.

A new technique which removes all membranes, cytoskeletal elements, organelles, but preserves intact metaphase, anaphase and telophase configurations is combined with scanning electron microscopy (SEM) as an approach for direct visualization of chromosomal behavior in late mitosis. With this approach we are able to confirm the presence of a centromeric ring which stabilizes the centromeres during the cell cycle and present evidence for a lattice-like sheet of interchromatidic fibers in late mitosis.

Anaphase↗