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Biomedical subjects

N Gilbert

Publications and source records attributed to N Gilbert.

33 records · Page 2Linked to original sources
PubMed1994

The relation between climatic temperature and sudden infant death syndrome differs among communities: results from an ecologic analysis.

We examined the negative relation between temperature and the sudden infant death syndrome (SIDS) in 22 communities in seven countries. We estimated the percentage increase in SIDS rate for a 1 degree C drop in climatic temperature. The relation differed substantially among communities. In New Zealand and Australia (10 communities), the association was consistently strong; in Europe (seven communities), it varied from strong to weak; and in the USA (five communities), it was moderate or weak. We postulate that low climatic temperature indirectly increases the incidence of SIDS, particularly in countries where outdoor climatic temperature modifies the indoor temperature and clothing habits.

Australia↗
PubMed1994

Power and limits of laser scanning confocal microscopy.

In confocal microscopy, the object is illuminated and observed so as to rid the resulting image of the light from out-of-focus planes. Imaging may be performed in the reflective or in the fluorescence mode. Confocal microscopy allows accurate and non-destructive optical sectioning in a plane perpendicular or parallel to the optical axis of the microscope. Further digital three-dimensional treatments of the data may be performed so as to visualize the specimen from a variety of angles. Several examples illustrating each of these possibilities are given. Three-dimensional reconstitution of nuclear components using a cubic representation and a ray-tracing based method are also given. Instrumental and experimental factors can introduce some bias into the acquisition of the 3-D data set: self-shadowing effects of thick specimens, spherical aberrations due to the sub-optimum use of the objective lenses and photo-bleaching processes. This last phenomenon is the one that most heavily hampers the quantitative analysis needed for a 3-D reconstruction. We delineate each of these problems and indicate to what extent they can be solved. Some tips are given for the practice of confocal microscope and image recovery: how to determine empirically the thickness of the optical slices, how to deal with extreme contrasts in an image, how to prevent artificial flattening of the specimens. Finally, future prospects in the field are outlined. Particular mention of the use of pulsed lasers is made as they may be an alternative to UV-lasers and a possible means to attenuate photodamage to biological specimens.

Animals↗
PubMed1994

Three-dimensional co-localization of nucleolar argyrophilic components and DNA in cell nuclei by confocal microscopy.

Silver dots deposited specifically on proteins of the nucleolar organizer regions (Ag-NOR proteins) after a one-step silver staining technique were visualized in cells in culture, in cells in smears, and in tissue sections, with a scanning laser confocal microscope working in the reflectance mode. After specific labeling of DNA with the fluorescent dye chromomycin A3, DNA and silver dots could be observed either individually or simultaneously. Therefore, it was possible to study the three-dimensional organization of nucleolar silver-stained structures relative to DNA with a high X, Y, and Z resolution. Our results showed that the argyrophilic components are organized as a twisted necklace structure within interphase nucleoli of cells in culture. We also demonstrated a striking three-dimensional symmetric disposition of NORs within the two sets of chromosomes in telophase cells. Similar results were obtained for cells in smears, although their three-dimensional organization was somewhat disturbed due to air-drying. We also demonstrated that silver dots cannot be visualized in the reflectance mode within sections of paraffin-embedded tissues. However, their simultaneous demonstration in non-confocal transmitted light, together with that of DNA in confocal mode, appeared very useful to study their localization within nuclei and mitotic chromosomes.

Adenocarcinoma↗
PubMed1992

Climatic temperature and variation in the incidence of sudden infant death syndrome between the Australian states.

OBJECTIVE: To describe the relationship between climatic temperature and the incidence of sudden infant death syndrome (SIDS) for the Australian States and examine the extent to which differences in climatic temperature might explain the regional variation of SIDS in Australia. DESIGN: Case series study. A generalised linear model was used to model the association between monthly average temperature and the incidence of SIDS. SETTING: The report is population based. Data are available from all Australian States. SUBJECTS: Cases of SIDS from birth to less than 12 months of age occurring in Queensland (1981-1987), New South Wales (1981-1987), Victoria (1984-1987), Tasmania (1975-1989), South Australia (1980-1989), and Western Australia (1980-1988). RESULTS: Every one degree Celsius decrease in average monthly temperature within the range 9 degrees C to 25 degrees C is associated with a 10.6% (95% confidence interval, 9.6%-11.7%) increase in the incidence of SIDS. Climatic temperature accounts for 84% of the interstate variation in the rate of SIDS. After controlling for the effect of temperature, a significant overall difference in SIDS incidence remains (P less than 0.0001) for the Australian States. CONCLUSION: Climatic temperature accounts for most but not all of the regional variation of SIDS incidence in the Australian States. The remaining variation may reflect differences in the maternal and infant characteristics of the State populations.

Australia↗
PubMed1992

Sudden infant death syndrome: factors contributing to the difference in incidence between Victoria and Tasmania.

OBJECTIVE: To examine how much of the difference in incidence of sudden infant death syndrome (SIDS) between Tasmania and Victoria could be accounted for by the effect of differing climatic temperature and the effect of the differing prevalence of maternal and infant characteristics in the two State populations. DESIGN: A two population ecological comparison. Two previously published predictive models were applied to quantify the contribution of several factors to the higher incidence of SIDS in Tasmania compared with Victoria. SETTING: A population based study involving the two Australian States of Tasmania and Victoria. PATIENTS: The characteristics of the 1985 to 1987 live birth cohorts of Tasmania and Victoria were examined. Cases were defined as all infants dying in 1985 to 1987 whose cause of death was stated as SIDS. RESULTS: The rate of SIDS for Tasmania and Victoria 1985 to 1987 was 3.76 per 1000 live births and 2.18 per 1000 live births respectively. Adjustment of the Tasmanian rate for the effect of the interstate difference in climatic temperature resulted in a lower Tasmanian rate of 2.92 per 1000 live births. Adjustment for the effect of interstate differences in maternal age, birthweight, infant sex, month of birth and intention to breast-feed at hospital discharge decreased the Tasmanian rate to 2.47 per 1000 live births. CONCLUSION: Approximately 82% of the interstate difference in SIDS incidence between Tasmania and Victoria from 1985 to 1987 can be accounted for by differences in climatic temperature, maternal age, birth-weight, infant sex, month of birth and feeding intention at hospital discharge.

Adult↗
PubMed1990

Interstate differences in trends in coronary mortality and risk factors in Australia.

Mortality from coronary heart disease has declined by approximately 50% in Australia over the past 20 years and now accounts for approximately 25% of all deaths. Most of the decline in mortality from all causes in each State of Australia over the period 1972-1988 is due to the decline in mortality from coronary heart disease. In Tasmania, the rate of decline in mortality from all causes is significantly less in both sexes (P less than 0.01) than in the mainland States, and the discrepancy is due to a lesser decline in mortality from coronary heart disease (P less than 0.01). Trends in deaths related to hypertension show no differences between Tasmania and the other States, which suggests that the discrepancy with coronary heart disease is due to factors other than the prevalence and/or treatment of hypertension. Analysis of trends data on cigarette smoking prevalence, and cross-sectional data on plasma cholesterol levels and diet, shows that Tasmanian differences in food intake (including fat and cholesterol), in plasma cholesterol levels and (to a lesser extent) in cigarette smoking are consistent with, but are unlikely to explain completely, the slower rate of decline in mortality from coronary heart disease.

Australia↗
PubMed1987

Patient education program to teach energy conservation behaviors to patients with rheumatoid arthritis: a pilot study.

We report a prospective, randomized pilot study comparing a new workbook-based program, designed to teach patients with rheumatoid arthritis (RA) energy conservation behaviors, with standard occupational therapy (OT). Sixteen patients took part in the new program and nine received the standard therapy. Data on the number of tender or swollen joints, grip strength, walk time, activities of daily living, psychologic adjustment to illness, and daily activity log, were measured before and three months after intervention. Eleven percent of those who received standard therapy and 50% of those who received the workbook increased their amount of physically active time (p = .10). Twenty-two percent of the control group and 50% of those in the workbook group achieved a better balance of rest and physical activity (p = .07). We conclude that the adoption of energy conservation behaviors is different in the two groups. This initial study suggests that interrupting physical activity with rest periods may result in increased physical activity in patients with RA.

Arthritis, Rheumatoid↗
PubMed1984

Welfare for profit: moral, empirical and theoretical perspectives.

Since the 1960s there has been an increasing number of proprietary agencies engaged in the delivery of social services in the United States. This development has generally been greeted with disfavour by welfare state advocates. Various arguments have been put forward against welfare for profit on moral, empirical and theoretical grounds. This paper analyzes these arguments and proposes several basic conditions that would seem to have significant bearing on the choice between profit and nonprofit providers for a given service.

Ethics, Institutional↗
PubMed1982

The plight of universal social services.

In the early 1960s, the motivating theme of social services in the American welfare state was reduction of economic dependency. At that time services were highly selective, aimed mainly at poor people. Between 1960 and 1980 there was a drift toward univeralism, as the welfare state expanded to serve an increasing number of middle-class groups. This expansion of the welfare state was related to several social and demographic trends, and was accompanied by basic changes in the scope and purpose of social services. As the welfare state has moved toward universal entitlement to social services, a number of contradictions between the theory and practice of universalism in a capitalist society have surfaced. These contradictions lend a degree of support to the resurgence of selectivity which the welfare state is currently experiencing.

Aged↗