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Biomedical subjects

J McDonald

Publications and source records attributed to J McDonald.

At least 199 records · Page 11Linked to original sources
PubMed1981

Effect of naturally occurring dietary fibre in Western foods on blood glucose.

The aim of this study is to evaluate the short term effect of naturally occurring dietary fibre (mainly cellulose and hemicelluloses) in the Western diet on carbohydrate absorption. Two equicaloric test meals were designed, each containing the same amount and types of absorbable carbohydrate and similar proportions of fat and protein. One meal was composed of salad vegetables and apple and the other of simple sugars and starch added to a gelatine and cream cheese base. Thirteen normals and 12 maturity onset diabetics consumed both test meals and neither group showed any reduction in the post-prandial blood glucose levels or immunoreactive insulin concentrations on the fibre containing meal. Thus naturally occurring dietary fibre in unrefined foods commonly consumed in Australia does not attenuate carbohydrate absorption in short term studies.

Blood Glucose↗
PubMed1981

Resistance to intravenous tumor metastases in the athymic nude mouse: a paradoxic response.

The role of the host immune response in the abatement or prevention of tumor metastasis is unclear. To investigate possible interaction of lymphocytes with tumor cells, the F10 subline of the B16 melanoma was studied after subcutaneous or intravenous injection in original host C57BL/6 mice, Swiss nude mice, and BALB/c nude mice. The F10 tumor grew rapidly after subcutaneous injection in all strains of mice. Although florid pulmonary metastases were detected in the lungs of C57BL/6 mice after intravenous inoculation, both strains of nude mice were markedly resistant to the development of pulmonary metastases (P less than 0.001). Labeling of the B16 F10 melanoma cells with 3H-thymidine demonstrated that the kinetics of tumor cells after intravenous inoculation were similar in C57BL/6 mice and nude mice. Increased natural killer (NK) activity in the nude mouse play an important role in the prevention of pulmonary metastases.

Animals↗
PubMed1979

Genetic analysis of lines selected for wing vibration in Drosophila melanogaster.

Selection for the wing vibration component of courtship in the Oregon-R stock of D. melanogaster was practiced for 44 generations. Selection was successful, indicating that there is genetic variation for the trait in the Oregon-R stock. The mean realized heritability of the trait, based on the first 11 generations of selection, was 15%. Biometrical analysis showed that there is some additive genetic variance for the trait with the possibility of some ambidirectional dominance. No maternal effects for the trait were found.

Animals↗
PubMed1979

The incidence of divorce within cohorts of American marriages contracted since the Civil War.

The proportion of marriages that end in divorce can be estimated from vital registration or from census data. The former source suggests considerably higher levels of divorce than does the latter. A new series, combinig the two sources, is presented for annual marriage cohorts back to 1867. Actual experience to 1970 is traced and a projection beyond that point is made for cohorts with incomplete divorce histories. The cohort divorce series moves steadily upwards and shows much less variability than an equivalent series of period divorce rates. Factors related to high divorce within a cohort are armed service mobilization and high unemployment rates in the year of marriage, and slow national economic growth between pre- and post-marital periods.

Divorce↗
PubMed1979

A time series approach to forecasting Australian total live-births.

The relationship between classical demographic deterministic forecasting models, stochastic structural econometric models and time series models is discussed. Final equation autoregressive moving average (ARMA) models for Australian total live-births are constructed. Particular attention is given to the problem of transforming the time series to stationarity (and Gaussianity) and the properties of the forecasts are analyzed. Final form transfer function models linking births to females in the reproductive age groups are also constructed and a comparison of actual forecast performance using the various models is made. Long-run future forecasts are generated and compared with available projections based on the deterministic cohort model after which some policy implications of the analysis are considered.

Australia↗
PubMed1978

Immunological and plasma protein changes in cancer patients following a single plasmapheresis.

Serial serum protein determinations and immunological monitoring were performed prior to and following a single 4 to 5 liter plasma exchange in 10 patients with disseminated cancer. The most consistent changes were observed for two initially elevated alpha globulins, acid glycoprotein and haptoglobin, which declined rapidly in all patients 1 hour after plasmapheresis and began to rise again as early as 24 hours post-plasmapheresis to reach initial levels by 72 hours. Among the immunological parameters T and B cell counts, and phytohemaglutinin-induced lymphocyte transformation showed little change. In 4 out of 10 patients C3 levels dropped at 1 hour post-plasmapheresis and continued to decline to 24 hours, suggesting that consumption of C3 possibly by macrophages may have occurred. In view of our earlier reports that repeated plasmapheresis induced partial tumor regressions in patients with disseminated cancer and that these regressions may have been related to depletion of immunosuppressive serum proteins, it is suggested that to maintain levels of these rapidly renewed proteins at a minimum for as long as possible, it is most appropriate to perform plasmapheresis every 48 hours rather than every 72 or 96 hours as was the case in the earlier study.

Adult↗
PubMed1976

Pulmonary bacterial defense. Effect of the burn wound on transfer of alveolar macrophage activation in rats by parabiosis.

The alveolar macrophage was studied in parabiotic rats using an inbred strain. Parabiotic pairs were sutured together at five weeks of age. Rats were subjected to a full thickness cutaneous burn of 20 per cent of the body surface area at seven weeks of age, and alveolar macrophages were washed from the lungs at six days post burn. The number of alveolar macrophages, their per cent of activation, and their ability to phagocytize and kill P aeruginosa in vitro were significantly increased at six days post burn in the burned controls and in both the burned and unburned members of the parabiotic pairs. No change in the alveolar macrophages was found in either unburned parabiotic pairs or in those which were sham-burned. These results indicate that a humoral or cellular agent produced either within the cutaneous burn wound or elsewhere as a response to the injury, traverses the parabiotic cross circulation to stimulate the alveolar macrophages.

Animals↗
PubMed1976

Comparative analysis of the cytotoxicity of substituted (phenylglyoxal bis(4-methyl-3-thiosemicarbazone)) copper (II) chelates.

Seven para-substituted [phenylglyoxal bis(4-methyl-3-thiosemicarbazone)]copper (II) chelates (12-18) have been designed, synthesized, and tested for their ability to inhibit the respiration of rat liver slices as a normal cell model and Ehrlich ascites cells as a tumor cell model. Relationships between chemical structure and respiratory inhibition are described on a quantitative basis using substituent contants (pi, Es, and sigmap) by computerized multiparameter regression analyses. The correlations indicate that changes in Es have the largest effect on liver slice toxicity of chelates while pi and sigmap account for most of the variation in toxicity to ascites cells. A comparative analysis strongly suggests that electron-donating substituents with greater water solubility should increase cytotoxicity to ascites cells at the expense of cytotoxicity to the rat liver cells. The predictions of the equations were checked by synthesizing and testing an additional derivative. The results strengthen the initial predictions.

Animals↗