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Biomedical subjects

M J Harrison

Publications and source records attributed to M J Harrison.

At least 253 records · Page 14Linked to original sources
PubMed1982

Red cell deformability is not an independent risk factor in stroke.

Reduced erythrocyte deformability has been implicated in the causation of stroke. We have therefore tested this red cell property by filtration through polycarbonate membranes in 42 patients with either transient ischaemic attacks or completed ischaemic stroke together with age and sex paired controls. We have failed to demonstrate any difference between patients and controls suggesting that reduced red cell deformability is unlikely to be an important independent factor in the production of stroke.

Adult↗
PubMed1982

Haematocrit, hypertension and smoking in patients with transient ischaemic attacks and in age and sex matched controls.

The blood pressure, smoking habit and haemotocrit of 154 patients with transient ischaemic attacks and 191 age-and sex-matched neurological controls were studied. Regression analysis revealed that the haematocrit value was related to both systolic and diastolic blood pressure, and to smoking. Smoking elevated the haematocrit by 1.9 +/- 0.59 in males and by 2.18 +/- 0.68 in females. When these associations were allowed for there was still evidence of a higher haematocrit in patients with transient ischaemic attacks (plus 1.44 +/- 0.56 in males and 0.75 +/- 0.75 in females p less than 0.02). The role of an elevated haematocrit in the pathogenesis of cerebrovascular disease and its management are briefly discussed.

Adult↗
PubMed1982

Tremor after head injury and its treatment by stereotaxic surgery.

Tremor, both postural and kinetic may be a late complication for victims of severe closed head injury, especially in the young, and may add to their disability. The nature of the tremor is described in eight patients. In each a stereotaxic thalamotomy was performed, dramatically relieving or reducing the severity of tremor in each instance, and resulting in improved function of the affected limb and increased independence. The site of the responsible lesion, which is thought to lie in the mid brain, is discussed together with the indications and contraindications for surgical management.

Adolescent↗
PubMed1982

End-to-side vascular anastomosis: a study of technical considerations in the rat.

A study of technical problems in the performance of microvascular anastomosis has been carried out in the rat. A comparison of two types of suture material suggested that handling characteristics had a significant effect on the time taken to complete the anastomosis, and on the accuracy of apposition of the vessel walls. Technical difficulties encountered intraoperatively proved predictive of subsequent compromise of the lumen, shown angiographically and histologically. The optimum conditions are discussed, and it is argued that postoperative antithrombotic medication is indicated when technical problems are encountered.

Animals↗
PubMed1982

The clinical presentation of intracranial abscesses.

A retrospective case note survey of 67 surgically proven cases of intracranial abscess formation has been carried out. Males predominated, especially in the third decade. Only 15 per cent had a predisposing condition such as cyanotic heart disease though the majority had some evidence of a systemic infection or fever. A peripheral leucocytosis and elevated erythrocyte sedimentation rate (ESR) were also more frequently encountered than in a comparable group of cases of cerebral tumour. Despite these pointers to an infective process the correct diagnosis was commonly not considered on admission. Headache, vomiting, drowsiness and focal symptoms sometimes accompanied by focal or generalized seizures remain the classical features in the history, with papilloedema and focal signs commonly found in a drowsy ill-looking patient. Many individuals failed to show all these features however. The progressive nature of the clinical picture should itself be enough to prompt urgent referral for investigation, electro-encephalography, nuclear scanning and CT scanning all being reliable.

Adolescent↗
PubMed1981

Effect of monensin sodium on the performance and proportions of rumen volatile fatty acids of Friesian bulls.

The effect of including monensin sodium at a dose rate of 40 mg/kg in the diet of Friesian bulls (mean initial liveweight 158 kg) fed a barley-based diet ad libitum was assessed in terms of growth rate, feed intake, feed and energy conversion efficiency and the concentration and molar proportions of ruminal volatile fatty acids over a 157-day period. Mean daily feed dry matter intake for the treated group (5.4 kg) was 24 per cent lower than the control group (7.1 kg). The treated group grew at a significantly slower rate than the control animals although feed conversion efficiency was improved by the treatment. A comparison with the results of other workers suggested that the dose rate used had been too high. There were no significant differences in the molar proportions of volatile fatty acids in rumen fluid as a result of monensin usage. While many workers have shown increases in the molar proportions of propionic acid the fact that the control group in this experiment had a very high value (48 per cent) may explain the lack of response.

Administration, Oral↗
PubMed1981

Effect of haematocrit on carotid stenosis and cerebral infarction.

Carotid angiograms in 187 patients presenting with transient ischaemic attacks and minor completed strokes were reviewed. A haematocrit of 50% or more was encountered more frequently in those found to have carotid occlusion. The severity of vessel-wall disease showed no relationship to the level of haematocrit. Computerised axial tomographic to the level of haematocrit. Computerized axial tomographic measurements of the volume of the cerebral infarct seen in 23 patients with carotid occlusion and completed strokes showed a correlation between the size of the infarct and the height of the haematocrit. It is suggested that reduced blood flow resulting from increase blood viscosity associated with a high haematocrit adversely affects collateral flow, thereby increasing the size of the infarct.

Arterial Occlusive Diseases↗
PubMed1981

Codifications of anaesthetic information for computer processing.

In order for any decision-making process to be computer-assisted it is necessary for the information to be encodable in some way so that the computer can manipulate the data using logical operations. In this paper the information used to generate an anaesthetic regiment is examined. A method is presented for obtaining a suitable set of statements to describe the patient's history and surgical requirements. These statements are then sorted by an algorithm which uses standard Boolean operators to produce a protocol for six phases of anaesthetic procedure. An example is given of the system in operation. The system incorporate knowledge at the level of a consultant anaesthetist. The program used 428 statements to encode patient data, and drew upon a list of 163 possible prescriptions. The program ran on an LSI-11/2 computer using one disc drive. The scheme has direct application in training of junior anaesthetist, as well as producing guidelines to application in other areas of medicine where the possibility of a similar codification may exist.

Anesthesia↗
PubMed1981

Role of 5HT in the morbidity of cerebral infarction-a study in the gerbil stroke model.

Cerebral infarction was produced by unilateral carotid ligation in the gerbil, and 5HT levels in the cerebral hemispheres were assayed 3.5 hours later. A bilateral fall as confirmed, with the greatest change occurring on the side of carotid ligation in animals showing the clinical sequelae of infarction. Neither absolute levels nor right left differences in 5HT content related directly to the nature or prevalence of neurological morbidity. Neither putative 5HT receptor antagonists nor agents causing increasing brain 5HT levels produced consistent changes in the prevalence of neurological morbidity. It is argued that the fall in 5HT in a cerebral infarct is more likely to be due to reduced synthesis and turnover than to release of the amine into the synaptic cleft. These findings cast doubt on the hypothesis that a significant part of the morbidity and mortality of cerebral infarction is due to the sequelae of 5HT release.

5-Hydroxytryptophan↗
PubMed1981

Surgery for stroke.

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Carotid Artery Diseases↗
PubMed1981

Nystagmus.

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Caloric Tests↗