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Biomedical subjects

I Graham

Publications and source records attributed to I Graham.

At least 55 records · Page 3Linked to original sources

Hyperhomocysteinemia in premature arterial disease: examination of cystathionine beta-synthase alleles at the molecular level.

Hyperhomocysteinemia occurs in approximately 30% of the patients with premature occlusive arterial disease (POAD). Some of these exhibit significantly reduced fibroblast cystathionine beta-synthase (CBS) activities, suggesting that they may be heterozygous for CBS deficiency. To test this possibility, we studied cDNA derived from four well characterized patients with POAD, exhibiting hyperhomocysteinemia and reduced CBS activities, from four normal controls, and from four obligatory heterozygotes for CBS deficiency. Lysates of individual colonies of E.coli, containing full-length PCR-amplification products in the expression vector, pKK388.1, were tested for CBS activity. cDNA from at least seven of the eight possible independent POAD alleles encoded catalytically active, stable CBS which exhibited normal response to both PLP and AdoMet. The sequences of all 3'-untranslated regions of all seven isolated POAD alleles were identical to the normal, 'wild-type' CBS sequences. The results of the expression studies were confirmed for one POAD patient by determining the full-length cDNA sequences for both alleles; these were entirely normal over the complete length of the cDNA. In contrast, the screening method correctly distinguished mutant from normal alleles in all four obligatory heterozygotes studied. We conclude that CBS mRNAs from POAD individuals are free from inactivating mutations, including all 33 previously identified in heterozygous carriers and homocystinuric patients.

Alleles↗

How do registered nurses think and experience nursing. A phenomenological investigation.

This research adopts a phenomenological approach to investigate how registered nurses think and experience nursing. Findings from the study highlighted the dynamic nature of how nurses think and experience nursing. This dynamic nature demonstrates the often vulnerable and stressed position nurses find themselves in today when trying to meet their professional aspirations within a medically dominated, bureaucratic health-care system. The findings suggest that not only is educational reform required, but nurses need skills to enable them to form change strategies so that their paradigm of health care can be established. This study represents the very beginning of trying to create that paradigm inductively.

Adult↗

Percutaneous balloon pericardiotomy in the treatment of malignant pericardial effusion.

Recurrent pericardial effusion can be a manifestation of metastatic malignant disease. Repeated catheter drainage or surgical pericardial window are two common treatment modalities. We report a case of recurrent malignant pericardial effusion treated successfully with percutaneous balloon pericardiotomy, a relatively new technique avoiding the need for surgery.

Catheterization↗

Predicting operative mortality after coronary artery bypass surgery in males.

The general practitioner often requires a simple and reliable method of determining the potential risks of surgical intervention. We derived and tested a simple clinical scoring system for the preoperative prediction of 30-day mortality after coronary artery bypass surgery. From a national register of all open heart operations in the Republic of Ireland 1984-1989, we identified 4276 male patients who had primary isolated non-emergency coronary artery bypass surgery. Using logistic regression, we derived a clinical scoring system to predict operative (30-day) mortality in patients operated on between 1984 and 1987. We then prospectively evaluated the score on patients seen over the next two years. Variables identified for our scoring system were age, recent myocardial infarction, left ventricular failure, extensive distal coronary artery disease and body surface area. Five risk categories were defined; mortality in the high-risk group was 9.7-fold (95% CI: 4.6-20.7) greater than in the low-risk group. When tested on new patients, the relative mortality between the two risk groups was 15.2 (4.6-50.5). The observed and predicted mortalities in each risk group showed close agreement. This clinical scoring system, easily used by a general practitioner, can predict operative mortality in males for whom primary isolated coronary artery bypass surgery is contemplated.

Adult↗

The role of free radicals as mediators of endothelial cell injury in hyperhomocysteinemia.

Hyperhomocysteinemia has been suggested as a potent new risk factor for premature cardiovascular disease. Homocsyteine can induce endothelial cell injury but the mechanism is not understood. The purpose of this study was to evaluate the role of free radicals as potential causes of endothelial cell injury in a case-control study of obligate heterozygotes for cystathionine beta-synthase deficiency. Firstly, free radical production as measured by neutrophil chemiluminescence in obligate heterozygotes for cystathionine beta-synthase deficiency was compared with age- and sex-matched normal subjects. Secondly, the response of the cellular antioxidant system was examined by measuring the enzymes superoxide dismutase and glutathione peroxidase, their cofactors (selenium, copper), vitamin E and vitamin A in heterozygotes and normal subjects. Analyses of neutrophil chemiluminescence, vitamin A and E, glutathione peroxidase, selenium and copper showed no difference between heterozygotes and controls. While superoxide dismutase activity was higher in heterozygotes than normal subjects, the difference did not reach statistical significance and the hypothesis of excess free radical production as a mechanism of injury was not confirmed. However, further examination of superoxide dismutase activity in a larger number of subjects would be of interest.

Adult↗