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Biomedical subjects

A H Smith

Publications and source records attributed to A H Smith.

At least 145 records · Page 8Linked to original sources
PubMed1983

Mortality and social class in New Zealand II: male mortality by major disease groupings.

Social class differences in male mortality in New Zealand were investigated for each major disease grouping. The patterns found were similar to those for England and Wales with the lower social classes having mortality rates significantly higher than those of the upper social classes for each major cause of death. The strongest social class mortality gradients were found for deaths from accidents, poisonings and violence; diseases of the respiratory system; endocrine, nutritional and metabolic diseases; diseases of the genito-urinary system; and diseases of the digestive system. The gradients for coronary heart disease and neoplasms were weaker, but in the same direction as those found for other disease groupings.

Accidents↗
PubMed1983

Mortality and social class in New Zealand. I: overall male mortality.

Social class differences in New Zealand male mortality are investigated using two different systems of social class classification. In each case it is found that the lower social classes have mortality rates significantly higher than those of the upper social classes with the mortality rate of the lowest class being approximately twice that of the highest class on a six-category scale. The relative risk is higher in the younger age-groups. When the British Registrar-General's scale is used New Zealand exhibits a social class mortality gradient similar to that previously found in England and Wales, but the lowest social class experiences a particularly high mortality rate.

Adolescent↗
PubMed1983

Computer assessment of alternative rubella vaccination strategies in New Zealand.

Results from a dynamic computer model of rubella vaccination programmes indicate that consideration should be given to vaccinating all one-year-old girls and boys and revaccinating all girls at about 11 years of age, as well as continuing with the programme for susceptible women in the childbearing age group. With vaccine-induced immunity decaying at about 1% annually, the vaccination of 80 to 95% of all one-year-olds, 95% of 11 year old girls, and 5% of women aged 15 to 33 annually is expected to reduce congenital rubella syndrome deformities to less than 5% of the 1980 incidence by 1994, and to negligible levels thereafter. In comparison, continuation of the present scheme may reduce deformities to only 69% of 1980 levels by 1994 with a slow decline to 25% in 2010. (The 1980 levels used were computer generated to eliminate short-term fluctuations, and do not apply to actual figures from that year.) For convenience and better compliance, measles vaccine and the initial rubella vaccine may be given in combined form at 15 months without altering the effect of either. The rate of decay of immunity after vaccination is critically important in congenital rubella syndrome prediction, so that further accurate monitoring of immune status and congenital rubella incidence is essential.

Adolescent↗
PubMed1983

Mortality attributable to smoking in New Zealand.

Relative risks for mortality due to various smoking related diseases were derived from a review of the literature on the epidemiology of smoking related illness. These were used, together with the New Zealand 1976 census data on smoking habits and the National Health Statistics mortality data, to derive the proportion of deaths which can be attributed to cigarette smoking. The results indicate that about 15 percent of deaths in New Zealand (3693 deaths annually) are attributable to smoking. This is comprised of 19 percent of all male deaths and 8 percent of all female deaths in 1976.

Adolescent↗
PubMed1983

Replacement of colonic mucosa by free and pedicled grafts of ileal mucosa in the dog.

Mucosal proctectomy and ileo-anal anastomosis is a relatively new operation in the treatment of patients with ulcerative colitis. The diseased rectal mucosa is removed and gastrointestinal continuity is restored by replacing it with full thickness ileum. The main disadvantage of the operation is frequency of bowel action and in an attempt to resolve this problem the feasibility of replacing colonic mucosa with grafts of ileal mucosa alone was explored. Both free and pedicled autografts of ileal mucosa were grafted into isolated loops of canine colon, denuded of mucosa and submucosa. All the free grafts failed to survive (eight dogs) and histological examinations confirmed graft rejection. All the pedicled grafts (seven dogs) were successful and retained the histological characteristics of normal ileum. Net movement and bidirectional transport of water and electrolytes were measured in six dogs with pedicled grafts and in four control dogs with intact full thickness ileal loops. Whereas the control loops absorbed water and electrolytes, the grafted loops secreted water, sodium, and potassium and absorbed significantly less chloride. The mucosa of the colon can thus be replaced successfully by grafts of ileal mucosa provided that an intact blood supply is preserved. The capacity and sensation of the neorectum after mucosal proctectomy may be improved if mucosal grafts were used instead of full thickness ileum. Before this procedure could be used in man, however, practical problems would have to be overcome and the secretion of water and electrolytes corrected.

Animals↗
PubMed1983

Catalysis of the reduction of vanadate by psychotropic drugs.

It has been suggested that vanadium may be of aetiological importance in manic depressive psychosis. Therefore, the ability of psychotropic drugs to catalyze the reduction of vanadate ion by reduced nicotinamide adenine dinucleotide (NADH) was investigated. The most active drug was methylene blue but all the phenothiazines and all the monoamine oxidase inhibitors tested showed catalytic activity. A large number of drugs showed no catalytic activity, eg. tricyclic antidepressants and benzodiazepines.

Catalysis↗
PubMed1983

Relationship between blood pressure and modernity among Ponapeans.

In the Micronesian island of Ponape blood pressures were found in 1947 and again in 1953 to be very low and to show no difference between age groups. As part of the US Trust Territory of the Pacific from 1945, the island had begun to change in the direction of modernity, the changes being most dramatic in the capital town of Kolonia, but no part of the island being unaffected. After a generation of modernization, a cross-sectional study was done to assess the impact of changing way of life on blood pressure. Communities were sampled at three levels of impact of modernization: the capital town of Kolonia, an intermediate area, and a remote area. No differences in salt intake were found for the three areas; but the population in the most modern area was younger and heavier. No consistent ecological differences were found in blood pressure level. Since there is considerable variation in modernity within each area, a Guttman-type scale of individual modernity was developed. No trends of variation of blood pressure with modernization were found to be consistent for both sexes and all areas. However, among males in the most modern area both systolic and diastolic pressures increased consistently with increasing modernity, controlling for age. For diastolic pressures, significant increases were found for all males, Kolonia males, and intermediate area males. When body mass as well as age were controlled, the strength of the trends decreased. But among Kolonia males the increase of diastolic pressure with increasing modernity remained highly significant; that of systolic pressure, marginally significant.

Adult↗
PubMed1983

Effects of weightlessness on body composition in the rat.

Five male rats were exposed to 18.5 days of weightlessness in the Soviet mission COSMOS 1129 (flight group) and killed after reentry. They were immediately dissected into three major body subdivisions: musculoskeletal system, skin, and pooled viscera analyzed for fat, water, solids, and six elements. These results, expressed as percentages of the fat-free body or its components, were compared with two groups of terrestrial controls: one subjected to a flight simulation in a spacecraft mock-up and the other under standard vivarium conditions. Relative to the control groups the flight group showed 1) a reduced fraction of total body water, 2) a net shift of body water from skin to viscera, 3) a marked diminution in fraction of extracellular water in the fat-free body, 4) a marked reduction in fraction of bone mineral, 5) no change in the quantity of stored fat or adrenal masses, and 6) a net increase in total muscle mass as indicated by total body creatine, protein, and body cell mass.

Adipose Tissue↗
PubMed1983

Surface markers, antigens, and receptors on murine T and B cells: part 2.

One of the greatest challenges that has confronted the cellular biologist for the past decade has been the understanding of the basic mechanisms that underlie the interaction of antigen with the cell surface and the subsequent cell-to-cell interaction that follows through a chain of events to what constitutes an immune response. The dialogue of the cell-surface membrane between antigen and cell-surface recognition structures is of fundamental importance in the determination of the pathway that leads through a chain of precise, genetically regulated steps of differentiation. This insight of the molecular level has provided the basis for our current thinking. It demonstrates that the cell membrane surfaces are genetically defined and regulated and that immunobiologic mechanisms are fundamentally interconnected. The membrane and its structure serve a very important function, both in terms of conducting biological dialogue at the cell surface and the translation of this dialogue to physiological events that lead to limiting, suppressing, or controlling an immune response, as opposed to permitting, inducing, or overwhelming an immune response. These concepts are aligned with the Burnet's clonal selection theory of immunity. One of the inevitable assumptions of this theory is that heterogeneity of lymphocytes exists at the level of cell-surface antigen receptors. Similarly, the variety of responses, both cell-mediated and humoral, against a specific antigen implies that functional heterogeneity of lymphocytes also exists. Thus, an understanding of the immune system should incorporate those features of lymphocytes which govern immune recognition and those that relate to subsequent immune function. Over the past decade, evidence has been accumulating that there is considerable heterogeneity among lymphoid cell subpopulations. Our current understanding of this degree of heterogeneity largely stems from the discovery of cell-surface markers which are unique to subpopulations of lymphoid cells and the observation that certain specific immunologically mediated events are predominantly, if not exclusively, expressed by some lymphoid cells but not others. These studies have been further extended by the description of the sequential ontogenetic appearance of the cell-surface markers as relation to the acquisition of immune competence. The purpose of this review is to summarize our current knowledge of the cell-surface markers that are present on lymphoid cells.

Animals↗
PubMed1982

Computer predictions of New Zealand doctor numbers.

Considerable debate has been generated about "the coming crisis in medical manpower" with most current analyses predicting a large surplus of doctors in the late 1980s. However, predictions can be complex because of potential fluctuations in the input variables due to political and social factors. Variables affecting active doctor numbers include the numbers of medical students graduating each year, immigration, emigration, the proportions of males and females, age at retirement, and extent of part-time work. A computer simulation is described which enables the relative effects of these variables to be compared. It is found that adjustments in the medical school intake have a relatively small short-term effect compared with the effects of adjustments in several of the other variables, particularly immigration numbers.

Computers↗
PubMed1982

Serum retinol and the inverse relationship between serum cholesterol and cancer.

Several human studies have shown an inverse relation between vitamin A intake (and serum concentrations of retinol and carotene) and cancer. Serum cholesterol concentrations have also been reported in inverse relation to cancer. In a study of 3102 people in Evans County, Georgia, who were followed for over 12-14 years to assess the incidence of cancer there was an inverse association between the risk of cancer and both serum retinol and serum cholesterol concentrations. The data also showed an unexpectedly strong correlation between serum retinol and total cholesterol concentrations. The inverse relationship with cancer was stronger with serum retinol than with cholesterol, which suggested that the association with cholesterol might be secondary. This suggestion may also explain the cholesterol-cancer association reported in several other cohort studies. Further studies of the relation between serum concentrations of cholesterol, retinol, and carotene and the incidence of cancer are needed.

Cholesterol↗
PubMed1982

The effect of digoxin on the response to lithium therapy in mania.

Patients suffering from manic-depressive psychosis, manic type (ICD 296.0), were treated with lithium carbonate and randomly allocated to two groups, one received digoxin and the other matching placebo for 7 days. Severity of mania was rated by psychiatrists on the Manic Rating Scale and Analogue Line on days 0 and 7 and by nurses daily on the Hargreaves Rating Scale, Psychotic Rating. Fourteen patients received digoxin and lithium carbonate and 14 patients received placebo and lithium carbonate. Improvement in the placebo lithium group was significantly greater than that in the digoxin lithium group. This trial suggests, therefore, that the effect of inhibition of membrane cation carrier is to reduce the response to lithium. This result is in keeping with our hypothesis that an increase in Na-K ATPase is essential to the therapeutic effect of lithium carbonate. It does not, however, exclude the possibility that the observations resulted from the inhibition by digoxin of lithium entry into the brain.

Adult↗