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Biomedical subjects

G Copeland

Publications and source records attributed to G Copeland.

9 recordsLinked to original sources
PubMed1999

A comparison of the codeswitching patterns of aphasic and neurologically normal bilingual speakers of English and Spanish.

Conversational discourse samples were obtained from four aphasic and four neurologically normal Hispanic bilinguals in monolingual English, monolingual Spanish, and bilingual contexts to identify codeswitching patterns. Analysis of the samples based on the Matrix Language Frame (MLF) Model (Myers-Scotton, 1993a) revealed consistent matching of the language context by the aphasic and normal subjects. The aphasic subjects demonstrated a greater frequency of MLF constituents and codeswitching patterns not evident in the speech samples of the normal subjects. Results suggest an increased dependence on both languages for communication following neurological impairment.

Adult↗
PubMed1996

Octreotide in the control of post-sclerotherapy bleeding from oesophageal varices, ulcers and oesophagitis.

Bleeding from oesophageal varices, oesophageal ulcers or oesophagitis is occasionally massive and difficult to control. Octreotide, a synthetic analogue of somatostin lowers portal pressure and collateral blood flow including that through varices, increases lower oesophageal sphincter pressure, and inhibits the gastric secretion of acid as well as pepsin. Our current experience suggests it is effective in controlling acute variceal haemorrhage. Therefore we have examined the efficacy of octreotide in the control of post-sclerotherapy bleeding from oesophageal varices, oesophageal ulcers and oesophagitis. During the study period 77 patients experienced a significant gastrointestinal bleed (blood pressure < 100 mm Hg, pulse > 100 beats per min or the need to transfuse 2 or more units of blood to restore the hemoglobin level) following injection sclerotherapy of oesophageal varices. The source of bleeding was varices in 42 patients, oesophageal ulcers in 31 and oesophagitis in 4. All patients received a continuous intravenous infusion of octreotide (50 micrograms/h) for between 40-140h. If bleeding was not controlled in the first 12h after commencing octreotide hourly bolus doses (50 micrograms) for 24h were superimposed on the continuous infusion. Haemorrhage was successfully controlled by an infusion of octreotide in 38 of the 42 patients with bleeding from varices, in 30 of 31 patients with oesophageal ulceration, and all patients with oesophagitis. In the 1 patient with persistent bleeding from oesophageal ulceration and in 2 of the 4 with continued haemorrhage from varices, haemostasis was achieved by hourly boluses of 50 micrograms octreotide for 24h in addition to the continuous infusion. No major complications were associated with octreotide administration. The results of this study clearly indicate that octreotide is a safe and effective treatment for the control of severe haemorrhage after technically successful injection of sclerotherapy.

Adult↗
PubMed1994

A ten-year study of the Ionescu-Shiley low-profile bioprosthetic heart valve.

Seven hundred and eight adults (age > or = 16 years) with isolated aortic (n = 433) or mitral (n = 275) Ionescu-Shiley Low-Profile (ISLP) pericardial valves were followed at 14 implanting centres in Canada, the United Kingdom, and the United States for a mean of 6.7 years, providing 4,729 patient-years of clinical data. The operative mortality rate was 3.0% for aortic valve replacement (AVR) and 5.5% for mitral valve replacement (MVR) (p = ns). Actuarial patient survival following AVR at 5 years was 81.6%, and 62.9% at 10 years; for MVR patients it was 78.1% at 5 years and 59.6% at 10 years. The ISLP valve appears to have durability comparable to other contemporary bioprosthetic valves. For aortic prostheses, the freedom from structural deterioration was 96.5% at 5 years and 73.7% at 10 years, and 89.7% at 5 years and 62.4% at 10 years for mitral prostheses. Structural deterioration was significantly more frequent following MVR than after AVR (p < 0.05). Structural deterioration was the principal cause for reoperation, but sudden deterioration precluding safe reoperation was not a dominant feature of this series. The ISLP valve appeared to engender more thrombo-embolic events than would be anticipated from earlier studies of pericardial bioprostheses, but was indistinguishable from other tissue valves in its incidence of other valve-related complications. We conclude that ISLP valves now implanted for 7 years or more are entering a phase of increasing structural deterioration, indicating the need for regular clinical and echocardiographic surveillance, and that long-term anticoagulation should be instituted for relatively minimal indications in these patients.

Adolescent↗
PubMed1981

Trends in tar, nicotine, and carbon monoxide yields of UK cigarettes manufactured since 1934.

The tar, nicotine, and carbon monoxide yields of cigarettes manufactured in the United Kingdom between 1934 and 1979 were studied. Over this period the average tar yield decreased by 49%, the nicotine yield by 31%, the carbon monoxide yield by 11%, all estimated on a sales-weighted basis. The average tar yield decreased progressively after the second world war, owing both to the introduction of filter cigarettes and to changes in the manufacture of plain cigarettes. The average nicotine yield increased initially, decreased by 43% from about 1950 to 1974, but increased again by 9% between 1974 and 1979. The average carbon monoxide yield started to decrease after about 1961; while it decreased substantially in plain cigarettes, the rapid increase in sales of filter cigarettes at this time, at the expense of plain cigarettes, largely offset the reduction in carbon monoxide yield that would otherwise have occurred. As with nicotine, carbon monoxide yield showed a small rise in later years (4% between 1976 and 1979). The trends in tar yield may well explain the reduction in lung cancer in the UK better than has been suspected hitherto. The trends in nicotine and carbon monoxide yields are probably not sufficiently different to distinguish which of them might be the more likely cause of cardiovascular disease.

Carbon Monoxide↗
PubMed1980

Alpha 2-macroglobulin in patients with inflammatory bowel disease.

Alpha 2-macroglobulin (alpha 2-M) has been investigated in patients with ulcerative colitis and Crohn's disease and compared with normal control subjects. During an active phase of either disease, serum concentrations of alpha 2-M fall but no other relationship with clinical features was found. The proportion of circulating mononuclear cells bearing alpha 2-M on their surface in patients with inflammatory bowel disease did not differ from normal controls. Alpha 2-M was not detected in rectal tissue from either the patients or control subjects. The fall in alpha 2-M in patients with active disease was unexpected. Protein loss from the inflamed intestine is unlikely to be the cause and metabolic studies will be needed to elucidate synthetic and catabolic rates.

Colitis, Ulcerative↗