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Biomedical subjects

G Baker

Publications and source records attributed to G Baker.

At least 109 records · Page 6Linked to original sources
PubMed1982

TSH in the rat and monkey brain. Distribution, characterization and effect of hypophysectomy.

Characterization of the molecular, immunological and biological properties of a thyrotropin-stimulating hormone (TSH)-like peptide in rodent brain tissue showed similarities to its pituitary counterpart. The distribution of immunoreactivity in rodent brain was determined by radioimmunoassay in both intact and hypophysectomized animals. Easily detectable but smaller quantities of immunoassayable TSH were present in formalin fixed, acetone-stored brains from Macaca mullata. No change in the level of this TSH-like peptide was observed in most rat brain parts, although the hypothalamus did show a significant drop in hormone level after removal of the pituitary. Extracts of brain containing TSH-like material restored thyroid histology to normal when administered to hypophysectomized rats. Tissue cultured neural cells from both intact and hypophysectomized rats released a TSH-like material into the medium over a 30-day time period. Sodium l-thyroxine suppressed TSH release from pituitary monolayers but did not alter TSH release from brain derived cells that were similarly cultured. Surgical thyroidectomy resulted in a striking rise in serum TSH concentrations with no alteration in the content of brain TSH.

Animals↗
PubMed1981

The value of postcardiac infarction exercise stress testing: identification of a group at high risk.

We prospectively selected 154 patients who had survived acute myocardial infarction with electrical and/or mechanical complications to undergo an exercise stress test, four to six weeks after discharge from the Coronary Care Unit, Royal Melbourne Hospital. The patients exercised on a bicycle ergometer until they were unable to continue or had reached 70% of their predicted maximum heart rate for their age. Eighteen (11.7%) patients exhibited flat ST-depression of 1 mm or more on exercise. Six of these 18 patients later died (33.3%). Only seven (5.1%) of the 136 patients who exhibited no electrocardiographic change died during follow-up. We conclude that patients recording positive exercise stress test results after acute myocardial infarction, have a poorer prognosis and therefore should be considered for more intensive medical or surgical treatment.

Arrhythmias, Cardiac↗
PubMed1981

Use of lignocaine and atropine autoinjectors for patients at high risk of sudden death and reinfarction after myocardial infarction.

Twenty-five patients entered a prospective study to assess the usefulness of atropine and lignocaine autoinjectors for coronary events after discharge from hospital after a definite, complicated myocardial infarction. They were selected on the basis of being at high risk of sudden death and reinfarction, being less than 70 years of age and being able to maintain a close liaison with the hospital. One or both autoinjectors were used for five reported events (four of collapse, one of chest pain) in four patients, with possible benefit in two instances. Six patients collapsed and died, despite the use of autoinjectors in three of their fatal collapses. In our experience, the use of autoinjectors has been of little observable benefit, perhaps due to the lack of specific warning symptoms preceding the onset of lethal arrhythmias, so that the injectors were often used for unobserved collapses when the chances of survival were remote.

Aged↗
PubMed1979

Predictors of reinfarction and sudden death in a high-risk group of acute myocardial infarction survivors.

75 patients aged under 70 years who had survived acute myocardial infarction complicated by both significant arrhythmias and cardiac failure were followed-up for 1 year in an attempt to identify features which suggest the likelihood of late death or reinfarction. Patients were carefully instructed in the identification and importance of possible prodromal symptoms and the availability of a mobile intensivecare ambulance service and a 24 h hospital control centre. Horizontal ST-segment depression or anginal pain on an exercise test done within 6 weeks of infarction was a useful predictor of late death. Routine twice weekly E.C.G. recordings taken by telephone transmitter at rest and after mild exertion resulted in the identification of significant arrhythmias in only 7 patients. 13 patients (17%) died, 5 of them instantaneously. 4 of the 13 patients and 22 of the 62 survivors reported "prodromal symptoms". Unreported prodromal symptoms were elicited retrospectively in 14 of the 62 survivors and from the relatives of 4 of the 13 patients who died. Thus, 35% of prodromal symptoms were not reported despite intensive patient education and counselling. The incidence of "prodromal symptoms" was no higher in patients who died than in those who did not die.

Acute Disease↗
PubMed1979

Ocular injuries associated with periorbital fractures.

The incidence of serious ocular injuries found in association with periorbital fractures, 10%, was determined through a retrospective review of 230 patient records. Eye injury was most frequently in conjunction with supraorbital fractures. A brief survey of the diagnosis and treatment of the injuries identified, loss of visual acuity, global laceration or rupture, retinal contusion, intraocular hemorrhage, glaucoma, and optic nerve damage, is presented, with special emphasis on the importance of the acute physical examination of the eye and determination of the visual acuity. Use of the recently developed method of diagnosing glaucoma and determining visual acuity, the Arden Sine Wave Grating, is discussed.

Adolescent↗