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Biomedical subjects

I K Ross

Publications and source records attributed to I K Ross.

33 records · Page 2Linked to original sources
PubMed1980

Coronary artery surgery in South Australia: second report.

This is the second report on the results of coronary artery grafting in South Australia. Symptomatic relief after grafting has continued at a high level (at five years, the conditions of 90.3% of surviving patients are improved as assessed by their cardiologists), and, in patients with significant symptoms, the operation can be recommended with a high degree of safety on these grounds alone. In addition, an attempt has been made to ascertain whether grafting alters longevity and, although more information is required on this point, the initial results are most encouraging with the five-year survival rate for operated patients being 92%, a figure which compares favourably with any large, medically treated group of patients. The operative mortality rate has continued to fall and is 2.2% for the entire series.

Adult↗
PubMed1980

Surgery for left main coronary artery disease.

The early and late results of the first 103 patients with left main coronary obstruction submitted to bypass grafting in South Australia are presented. A satisfactory hospital mortality of 2.9% and a surprisingly low late mortality of 2.9% (at an average follow-up time of 30 months), were obtained, and these figures, when taken in conjunction with a symptomatic relief rate of 83% at 24 months, have encouraged us to continue to recommend coronary artery grafting as the treatment of choice of left main stem disease.

Adult↗
PubMed1978

The effect of proteases on plasmodium formation in Didymium iridis.

An improved assay for quantitatively measuring the number of plasmodia formed with time is presented. Using this assay we have investigated the effects of three proteases, subtilisin PBN', subtilisin carlsberg and alpha-chymotrypsin. We have shown that 1) plasmodium formation is sensitive to protease treatment only during the first 2 h after mixing amoebae of compatible mating type but not after, 2) amoebae are protease sensitive when treated 1 h prior to mixing, 3) the two clones used have different sensitivities to protease treatment and 4) these effects are due to enzymatic activity and have little effect on viability. The meaning of these results in relation to recent evidence for a diffusible inducer of plasmodium formation is discussed.

Cell Fusion↗
PubMed1977

Coronary artery surgery in South Australia 1970-1976.

The South Australian population of approximately 1,245,000 is 9.2% of the total Australian population. The Cardio-Thoracic Surgical Unit of the Royal Adelaide Hospital is the only one such unit in the State which is equipped for open heart surgery, and coronary artery grafting was first undertaken there in December, 1970. From that time until the end of December, 1976, 701 patients underwent coronary artery grafting with an overall hospital mortality of 3.0%, and a late mortality of 3.2%. The principal indication for operation was incapacitating angina, and of the 628 patients who have been followed-up after operation for a minimum period of six months, 78.6% were judged by their cardiologist to be completely relieved of this symptom. A further 8.9% of patients were considered to be significantly improved. Coronary artery surgery has rapidly assumed a dominant role in our Unit so that, in 1976, of the 435 open heart operations which were performed, 267 (61%) were procedures which necessitated coronary artery grafting. The rate of increase has slowed considerably over the past 18 months, and it is expected that, with current operative indications, the proportion of coronary artery cases will not rise much above 60% of the open heart work load of the Unit.

Adult↗
PubMed1976

A highly infectious 'mycoplasma' that inhibits meiosis in the fungus Coprinus.

We have discovered a cytoplasmically inherited infectious agent that inhibits meiosis in a species of Coprinus, a basidiomycetous fungus. From infectivity, filtration, centrifugation and ultrastructural studies we believe the agent to be a mycoplasma. The agent is highly infectious to several strains of the host species and is capable of spreading rapidly through infected hosts. No pathological effect has been seen on any aspect of growth or differentiation of the fungus except for the inability of infected strains or undergo meiosis. The failure of meiosis results in mushrooms that do not produce the normal black spores and are therefore pale in colour. The paleness represents a simple assay for the presence and activity of the infectious agent. Infected hosts do not display any ultrastructural abnormalities in the vegetative stages, only in the cells in which meiosis should occur. In the meiotic cells, at the time when normal cells are undergoing synapsis and synaptinemal complexes are forming, the vacuoles of the infected cells become occupied with vesicular, membrane-bound bodies resembling in shape and form mycoplasmas. Extracts from infected clones may be filtered through 0.2-mum filters and retain full infectivity. The infectious material may be pelleted from such extracts at only 10 000g. Migration experiments, as well as the filtration studies, rule out involvement directly of nuclei. The high rate of infection and spread of the mycoplasma through the host, combined with the anatomical simplicity of the host, make this an ideal system in which to study the basis of infection. The singularity of the pathological effect make this host-parasite association useful in studying both the underlying mechanisms of mycoplasma pathogenicity and to investigate the regulation of meiosis. This is only the second report of mycoplasmas in fungi.

Agaricales↗
PubMed1975

Appendicitis and mimicking conditions. A prospective study.

A prospective study of 444 consecutive patients diagnosed as having acute appendicitis was carried out in a district general hospital. The appendix was acutely inflamed, gangrenous, or perforated in 346 patients. Diagnostic error, 22% overall, was twice as common in females as in males. Organisms were isolated from the outer appendix wall in 117 patients, isolation increasing with the severity of inflammation. 12% of children under 11 had mesentric adenitis, 10% of all females had gynaecological lesions, and 14% of patients over 50 had acute diverticulitis. In only 6% of patients was no abnormality found at operation, and in every case the disorder was dealt with through the gridiron incision.

Abdomen, Acute↗
PubMed1973

Changes in isozyme patterns between monokaryons and dikaryons of a bipolar Coprinus.

Proteins and isozymes of several different classes of enzymes in partially purified protein extracts of monokaryons, dikaryons, and monokaryon mixtures of a bipolar Coprinus sp. were separated on polyacrylamide gels by slab electrophoresis. Differences in protein and isozyme spectra were correlated with the operation of the incompatibility factors and with the results of Wang and Raper on Schizophyllum. It was concluded that the shift from monokaryon to dikaryon mediated a major change in the nature, quantity, or distribution of the proteins of this Coprinus sp.

Aminopeptidases↗
PubMedDate not supplied

The costs of coronary artery surgery to the community.

The possible benefits obtained both for the community and patients following coronary artery bypass grafting (CABG) have been examined in 4001 patients (mean age 54 years, 14.8% female) who underwent CABG from 1971 to 1982 in the Cardiothoracic Surgical Unit of the Royal Adelaide Hospital. Assessment followed a fixed response format questionnaire sent to all patients with a total follow-up of 98.8%. The hospital mortality was 1.4% for the 10 year period with a fall from 4% in 1973 to 0.9% in 1981. Shifts in employment were assessed in survivors. At follow up, 548 patients who were previously employed had ceased full-time or part-time employment. This decrease in employment was attributed mainly to age. Analysis of retirement curves for the general male population and male patients showed a similar pattern but downward translation of 4% for the pre-operative group. A similar downward shift occurred following surgery. For female patients, performance of home duties improved from 159 patients on full home duties pre-operatively to 292 post-operatively. Visits to the doctor dropped in 50% of surviving patients. CABG has a low mortality. The community benefits by helping to maintain productivity and decreased cost for ongoing medical care.

Australia↗