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Biomedical subjects

R McDermott

Publications and source records attributed to R McDermott.

At least 37 records · Page 2Linked to original sources
PubMed2000

Reduced prevalence of impaired glucose tolerance and no change in prevalence of diabetes despite increasing BMI among Aboriginal people from a group of remote homeland communities.

OBJECTIVE: To examine trends in glucose tolerance and coronary risk among Aboriginal people from a group of homeland communities in central Australia during a 7-year follow-up period. RESEARCH DESIGN AND METHODS: Community-based screenings of adult volunteers were performed in 1988 (n = 437; 93% response rate) and in 1995 (n = 424; 85% response rate). A health promotion intervention program commenced after the 1988 survey that focused on the benefits of exercise and appropriate diet. RESULTS: Mean (95% CI) BMI increased significantly from 22.8 kg/m2 (22.3-23.2) to 24.2 kg/m2 (23.8-24.7) during the follow-up period (P < 0.001). This increase was similar for men and women and across all age-groups. The increase in BMI was greater among subjects residing adjacent to a store compared with those residing in communities located far from a store (P < 0.001). Decreases were evident in the prevalence of impaired glucose tolerance (IGT) (from 22.5 to 10.1% among women, P < 0.001; from 12.2 to 6.5% among men, P = 0.074) and hypercholesterolemia (from 36.7 to 25.8% among women, P < 0.01; from 52.4 to 44.0% among men, P = 0.147), but no change was evident in the prevalence of diabetes. Smoking remained rare among women (<4%) and decreased among men (from 52.9 to 40.8%, P < 0.05). CONCLUSIONS: The trends in glucose intolerance were clearly better than have been observed in other Aboriginal communities. The institution of an intervention program corresponded with reductions in the prevalence of IGT, hypercholesterolemia, and smoking. The prevalence of diabetes remained unaltered despite a significant increase in mean BMI, possibly because of the promotion of increased physical activity levels.

Adolescent↗
PubMed1999

Glycated hemoglobin as an indicator of social environmental stress among indigenous versus westernized populations.

BACKGROUND: This study assessed whether glycated hemoglobin concentration, an indicator of psychogenic stress, differs between indigenous populations and non-indigenous reference groups. METHODS: Multivariate and stratified analyses were undertaken of cross-sectional data from multi-center community-based diabetes diagnostic and risk factor screening initiatives in Canada and Australia. Population groups were Australian Aborigines (n = 116), Torres Strait Islanders (n = 156), Native Canadians (n = 155), Greek migrants to Australia (n = 117), and Caucasian Australians (n = 67). Measurements included fasting glycated hemoglobin (HbA(1c)) concentration, fasting and 2-h post-load glucose concentrations, body mass index, waist-to-hip ratio, and demographic variables. RESULTS: Mean HbA(1c) concentrations were greater for indigenous groups than for Greek migrants and Caucasian Australians (P < 0. 0001). The covariate adjusted indigenous versus non-indigenous difference (95% CI) was 0.90 (0.58-1.22) percentage units, 18.2% higher for indigenous people. Stratified analyses indicated greater HbA(1c) for indigenous than for non-indigenous persons with normoglycemia (P = 0.009), impaired glucose tolerance (P = 0.097), and diabetes (P < 0.0001). CONCLUSIONS: HbA(1c) concentrations are greater for indigenous than for non-indigenous groups. Social changes, low control, and living conditions associated with westernization may be inherently stressful at the biological level for indigenous populations in westernized countries.

Acculturation↗
PubMed1999

Diabetes incidence in an Australian aboriginal population. An 8-year follow-up study.

OBJECTIVE: To examine prospectively the association between age, BMI, and subsequent incidence of type 2 diabetes in Australian aboriginal people. RESEARCH DESIGN AND METHODS: We performed a stratified analysis of incidence data from a community-based longitudinal study. Measures included fasting and 2-h postload glucose concentrations, and BMI, stratified into four categories. Subjects were 882 male and female participants in diabetes screening initiatives in two remote Australian aboriginal communities, free from diabetes at baseline, ages 15-77 years. RESULTS: There were 46 incident cases of diabetes over 2,808 person-years of follow-up. BMI modified strongly the sex- and community-adjusted association between age and diabetes incidence (P < 0.001). Adjusted for age, sex, and community, the population diabetes incidence rate was 20.3 cases/1,000 person-years, with BMI-specific rates of 10.7-47.2 cases/1,000 person-years, and relative risks (95% CI) for BMI strata beyond the reference category (< 25 kg/m2) of 3.3 (1.5-7.0), 2.7 (1.1-6.8), and 4.4 (1.7-11.6), respectively. The population's attributable risk (95% CI) associated with BMI beyond the reference category was 70.1% (58.1-82.4). CONCLUSIONS: BMI-specific diabetes incidence rates in Australian aboriginal people are among the highest in the world. Diabetes incidence in the lowest BMI category (10.7 cases/1,000 person-years) is two to five times greater than corresponding rates for non-aboriginal populations. An urgent need exists to prevent weight gain associated with diabetes. Further study is required to determine for aboriginal people an optimal range of BMI, likely lower than that suggested for non-aboriginal populations.

Adolescent↗
PubMed1998

Ethics, epidemiology and the thrifty gene: biological determinism as a health hazard.

This paper briefly describes the rise of the thrifty genotype hypothesis as an explanation for the late twentieth century epidemic of diabetes, particularly in post-colonial indigenous societies. It looks at some of the ethical consequences of the biological deterministic paradigm, particularly the popular confusion of "genes" with "race" and how this paradigm served to exclude consideration of social determinants of disease in epidemiological thinking. Some alternative hypotheses to the thrifty gene theory are explored, together with the consequences of acceptance of these other theories in terms of public health action. Finally, there is a need for epidemiology to be continually conscious, critical and transparent with respect to the general disease (and wellness) theory under which it operates if it is to be truly a science rather than a collection of methodologies.

Biological Evolution↗
PubMed1998

The contribution of community health surveys to aboriginal health in the 1990s.

Community health surveys take place in many Aboriginal communities. We considered these surveys to determine their potential to contribute to Aboriginal health in the 1990s. Community health surveys--also known as health audits, community health screenings or check-ups--usually consist of a team of health professionals travelling to an Aboriginal community to measure a wide variety of parameters on as many of the people in the community as possible. For the individual participant, community health surveys represent a sporadic screening program which should meet the World Health Organization's criteria for screening. From the population health perspective, these surveys represent prevalence surveys which may contribute little new knowledge regarding Aboriginal health and do not, of themselves, change the urgent need for preventive health programs. Community health surveys should meet minimum scientific standards (i.e. have a clearly stated aim and use valid measurements and statistical techniques) and should incorporate practically feasible protocols and services for the follow-up of individuals with screen-detected abnormalities. They must have ethical and community approval and incorporate genuine consultation and feedback of results to the Aboriginal communities involved, in order for them to be justified.

Australia↗
PubMed1998

Beneficial impact of the homelands movement on health outcomes in central Australian aborigines.

OBJECTIVE: This study compares prevalence of obesity, hypertension and diabetes in two groups of Aboriginal adults: those living in homelands versus centralised communities in central Australia. It also compares weight gain, incidence of diabetes, mortality and hospitalisation rates between the groups over a seven-year period. METHODS: Baseline survey of 826 Aboriginal adults in rural central Australian communities in 1987-88 with a follow-up survey of 416 (56% response rate, excluding deaths). Each time, they had a 75 g oral glucose tolerance test (OGTT), and blood pressure and anthropometry measurement. Deaths and hospitalisations for all of the original cohort were recorded for the seven-year period. RESULTS: Homelands residents had a lower baseline prevalence of diabetes (risk ratio [RR] = 0.77, 0.59-1.00), hypertension (RR = 0.66, 0.54-0.80) and overweight/obesity (RR = 0.70, 0.59-0.83). The incidence of diabetes was lower among homelands residents (RR = 0.70, 0.46-1.06). They were less likely to die than those living in centralised communities (RR = 0.56, 0.37-0.85) and less likely to be hospitalised for any cause (RR = 0.79, 0.71-0.87), particularly infections (RR = 0.70, 0.61-0.80), injury involving alcohol (RR = 0.61, 0.47-0.79) and other injury (RR = 0.75, 0.60-0.93). Mean age at death was 58 and 48 years for residents of homelands and centralised communities respectively. CONCLUSION: Aboriginal people who live in homelands communities appear to have more favourable health outcomes with respect to mortality, hospitalisation, hypertension, diabetes and injury, than those living in more centralised settlements in Central Australia. These effects are most marked among younger adults.

Adult↗
PubMed1997

Uniqueness of the S-cone pedicle in the human retina and consequences for color processing.

The purpose of this study was to investigate more fully the shape and content of ribbons and synapses to second-order neurons in the short-wavelength cone (S-cone, blue cone) pedicle and to learn more concerning the uniqueness of the S-cone system in the primate retina. A piece of well-fixed peripheral human retina (10 mm, 35 degrees nasal to the fovea) was serially thick sectioned in the tangential plane from the level of the outer segments to the tops of the cone pedicles. Then serial electron microscope (EM) sections were collected through the whole depth of the pedicle-occupying region into the neuropil of the outer plexiform layer (OPL). The resultant EM micrograph montages of a large field of cone pedicles were perused, and S-cone pedicles were identified. Serial micrographs of a single S-cone pedicle, picked out of the montages, were digitized and reconstructed by computer three-dimensional methods. The S-cone pedicle arose from a slightly oblique axon and projected 0.5-1 microm more vitread in the OPL than other cone pedicles. It was bilobed in shape, with synaptic invaginations and ribbons in both lobes. No cone-contacting telodendria projected from the S-cone pedicle itself, but a small number of neighboring cones sent telodendria to its surface to make small gap junctions. Neighboring rod spherules also made small gap junctions. Four robust bipolar cell dendrites, most likely from S-cone-specific bipolar cells, made synapses at ribbons and basal (distal) junctions. A small number of other bipolar cell dendrites made narrow-cleft basal junction only. The majority of lateral elements were thought to be from HII horizontal cells, and a minority from HI horizontal cells. We conclude that the S-cone pedicle has a unique morphology and connectivity to second-order neurons that makes it quite different from the other two longer wavelength cone systems, and we speculate on the consequences for color processing in the visual system in general.

Adult↗
PubMed1997

Outcomes-based resource allocation for indigenous health services: a model for northern Australia?

Wide differentials continue to exist in mortality rates and other health outcomes between Aboriginal and non-Aboriginal Australians. In the Northern Territory (NT), where Aborigines make up 24% of the population, the all-causes age-adjusted Standardised Mortality Ratio for Aborigines compared to non-Aborigines has remained above 3 since the late 1970s, with significant regional variations. During 1995 an expenditure analysis was undertaken for primary health care (PHC) services in different regions of the NT and compared to mortality ratios. At the same time a method for needs-based funding was being developed which could replace the existing historical funding arrangements. In the first instance, the application of a simplified version of this Resource Allocation Formula (RAF) resulted in a significant shift of resources for new prevention program funding to regions of relatively high mortality and low per capita PHC expenditure. However, developing RAFs to redistribute at the margin within the NT is likely to generate further inequities between losing NT programs and counterparts in other states. If outcomes-based resource allocation is to be meaningful nationally, the reference point for the RAF should be national average PHC expenditure rather than existing state averages. There is a need for a combined approach to outcomes-based planning which takes into account both the equity arguments of resource allocation models and efficacy arguments to maximise health gains. Some of these arguments are explored in this paper.

Australia↗
PubMed1997

Are there ethnic differences in the association between body weight and resistance, measured by bioelectrical impedance?

OBJECTIVE: To describe ethnic differences in the relationship between body size and body composition. Knowledge about such differences is important when studying obesity-related complications, such as hypertension and non-insulin dependent diabetes, because it may not be possible to generalize results from one study population to other populations. DESIGN: Cross-sectional study. SUBJECTS: Four groups of different ethnic identity (2987 Caucasians (Danes), 243 predominantly Melanesian (Torres Strait Islanders from northern Australia), 206 Australian Aborigines and 146 Polynesians (New Zealand Samoans), aged 30-70 y, were studied. MEASUREMENTS: We examined associations between body weight and bioelectrical impedance, as a measure of body composition. RESULTS: Except for Australian Aborigines, associations (slopes) between body weight and resistance were generally constant in the different ethnic groups, once height and age differences had been considered, indicating that this relationship may involve a certain universality, that is independent of the population specificity for impedance measurement. Systematic differences in instrument readings or electrodes did not seem to be responsible for the differences found. CONCLUSION: With the exception of Australian Aborigines, there may be a constant relation between body size and body composition (total body water or fat free mass) of different ethnic groups, that depends on gender and age category only.

Adult↗
PubMed1994

Immune function of patients receiving recombinant human interleukin-6 (IL-6) in a phase I clinical study: induction of C-reactive protein and IgE and inhibition of natural killer and lymphokine-activated killer cell activity.

Interleukin-6 (IL-6) is a cytokine that acts on a variety of cell types, including myeloid progenitor cells and B and T lymphocytes. It has been found to activate cytotoxic T cells and natural killer (NK) cells and to induce T-cell-mediated antitumour effects in animal models. In a phase I clinical trial of recombinant human IL-6, 20 patients with advanced cancer were entered to receive daily subcutaneous injections of IL-6 over 7 days followed by a 2-week observation period and another 4 weeks of daily IL-6 injections. Doses varied between 0.5 microgram/kg and 20 micrograms/kg body weight and immune functions were monitored throughout. At all dose levels IL-6 administration led to a marked increase in serum levels of C-reactive protein and a moderate rise in complement factor C3. The proportions of CD4, CD8 or HLA-DR lymphocytes in peripheral blood did not alter with IL-6 treatment nor did the in vitro proliferation of peripheral blood mononuclear cells induced by either phytohaemagglutinin, pokeweed mitogen or fixed Staphylococcus aureus. By contrast, NK cell activity, lymphokine-activated killer (LAK) cell activity and proliferation induced by in vitro culture with interleukin-2 (IL-2) were suppressed at doses exceeding 2.5 micrograms/kg. Serum IgE levels were consistently elevated over the IL-6 dose range but IgM, IgG and IgA levels were unaffected. In summary there is a dose-dependent induction of acute-phase proteins by in vivo IL-6 treatment. At higher IL-6 doses there is a suppressive effect on NK and LAK activity measured in vitro. IL-6 may thus be useful in combination cytokine therapies that seek to suppress LAK and favour cytotoxic T lymphocyte responses. The rise in IgE levels in response to IL-6 was unexpected and suggests a more pivotal role than previously known for the control of IgE production; this could include IgE-related diseases.

Antibodies, Antinuclear↗
PubMed1993

A phase I study of intravenous bryostatin 1 in patients with advanced cancer.

Bryostatin 1 is a novel antitumour agent derived from Bugula neritina of the marine phylum Ectoprocta. Nineteen patients with advanced solid tumours were entered into a phase I study to evaluate the toxicity and biological effects of bryostatin 1. Bryostatin 1 was given as a one hour intravenous infusion at the beginning of each 2 week treatment cycle. A maximum of three treatment cycles were given. Doses were escalated in steps from 5 to 65 micrograms m-2 in successive patient groups. The maximum tolerated dose was 50 micrograms m-2. Myalgia was the dose limiting toxicity and was of WHO grade 3 in all three patients treated at 65 micrograms m-2. Flu-like symptoms were common but were of maximum WHO grade 2. Hypotension, of maximum WHO grade 1, occurred in six patients treated at doses up to and including 20 micrograms m-2 and may not have been attributable to treatment with bryostatin 1. Cellulitis and thrombophlebitis occurred at the bryostatin 1 infusion site of patients treated at all dose levels up to 50 micrograms m-2, attributable to the 60% ethanol diluent in the bryostatin 1 infusion. Subsequent patients treated at 50 and 65 micrograms m-2 received treatment with an intravenous normal saline flush and they did not develop these complications. Significant decreases of the platelet count and total leucocyte, neutrophil and lymphocyte counts were seen in the first 24 h after treatment at the dose of 65 micrograms m-2. Immediate decreases in haemoglobin of up to 1.9g dl-1 were also noted in patients treated with 65 micrograms m-2, in the absence of clinical evidence of bleeding or haemodynamic compromise. No effect was observed on the incidence of haemopoietic progenitor cells in the marrow. Some patients' neutrophils demonstrated enhanced superoxide radical formation in response to in vitro stimulation with opsonised zymosan (a bacterial polysaccharide) but in the absence of this additional stimulus, no bryostatin 1 effect was observed. Lymphocyte natural killing activity was decreased 2 h after treatment with bryostatin 1, but the effect was not consistently seen 24 h or 7 days later. With the dose schedule examined no antitumour effects were observed. We recommend that bryostatin 1 is used at a dose of 35 to 50 micrograms m-2 two weekly in phase II studies in patients with malignancies including lymphoma, leukaemia, melanoma or hypernephroma, for which pre-clinical investigations suggest antitumour activity.

Adult↗
PubMed1986

Vinblastine, adriamycin, and cyclophosphamide in the treatment of adenocarcinoma of the breast.

Thirty-two stage IV patients and one stage III patient with evaluable adenocarcinoma of the breast received treatment with vinblastine, adriamycin, and cyclophosphamide. One patient was unevaluable because of early death. Twenty-two of 32 patients (69%) achieved complete or partial remissions and seven (22%) stabilized, including two (6%) minor responses. One of the three (9%) patients failing treatment had had extensive prior chemotherapy. Five of seven patients over the age of 70 years achieved partial remissions. A sixth had a minor response. Three of five performance status 3 and one of two performance status 4 patients responded. Overall response rate (p less than 0.01) and complete remission rate (p less than 0.05) were greatest in soft tissue disease. Granulocytopenia was dose-limiting, and recommended starting doses are vinblastine 4 mg/m2, adriamycin 40 mg/m2, and cyclophosphamide 400 mg/m2. These doses produce granulocytopenia in the majority of patients, but recovery is rapid. Overall, this is a well-tolerated regimen comparable in efficacy to other adriamycin-containing combinations. Use of standard white blood count criteria instead of granulocyte criteria for determining dose alterations and time of retreatment would have resulted in markedly excessive dose reductions and treatment delays and in a marked reduction in permitted dose escalations. This could potentially have reduced the response rate.

Adenocarcinoma↗
PubMed1985

Institutional security indicator report: a management tool to bridge the communications gap.

This article discusses a system developed by the Security Department of Hillcrest Hospital, to measure and report the level of security-related problems in the institution. This "Institutional Security Indicator Report" is one of the components of a Management Information System which is designed to measure workload and its effect on the utilization of personnel, level of quality, and other information which provides managers with sound qualitative, quantitative and financial data.

Financial Management↗