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Biomedical subjects

M J Harrison

Publications and source records attributed to M J Harrison.

At least 217 records · Page 12Linked to original sources
PubMed1986

The effect of isovolaemic haemodilution and intravenous glycerol on the sequelae of middle cerebral artery occlusion in the rat.

The therapeutic potential of isovolaemic haemodilution and osmotherapy on the sequelae of middle cerebral artery occlusion has been studied in an animal model. The territory of the middle cerebral artery that failed to fill with a carbon black intravascular marker after intracranial occlusion for 30 minutes in the anaesthetised rat was reduced by 50% by isovolaemic haemodilution to a haematocrit of 30%. An intravenous infusion of 10% glycerol prevented swelling of the ischaemic hemisphere, though it did not further improve vascular perfusion. These findings support the use of isovolaemic haemodilution and osmotherapy in the acute aftermath of stroke.

Animals↗
PubMed1986

An assessment of the possible protective effect of allopurinol in acute stroke.

Allopurinol has been shown to have a protective effect on ischaemic tissue by the indirect prevention of excessive purine loss. This property was tested in the gerbil model of acute stroke. A total of 69 animals were pretreated with an intraperitoneal injection of either allopurinol (50 mg/kg) or sterile water and then subjected to unilateral ligation of the left common carotid artery under general anaesthesia. The clinical effect of the ligation was grouped into three categories of normal, mild to moderate defect (splayed leg, turning behaviour) and severe defect (death, nonresponsiveness and seizures). More normal animals and fewer severely affected animals were present in the allopurinol treated group compared to controls, but only at 2 to 4 hours after carotid ligation (p less than 0.05). Histological examination of brain tissue from the normal category failed to reveal any difference in subclinical ischaemic damage between the two groups. It was concluded that allopurinol may have a protective effect in acute stroke and that this property warrants further elucidation.

Acute Disease↗
PubMed1986

Hypoglossal-facial nerve anastomosis: a clinical and electrophysiological follow-up.

Eight patients with acoustic neuroma and five patients with hemifacial spasm, who had undergone hypoglossal-facial nerve anastomosis 1-14 years previously, were reviewed clinically and electrophysiologically with an electrically elicited blink reflex. Functional recovery from the anastomosis, as rigorously judged on a scale of good, fair and poor, was fair to poor. Electrically it was found that the blink reflex was present in eight patients, suggesting facial nerve re-innervation of the facial musculature. This was confirmed by the mild recurrence of hemifacial spasm in four patients. Implications for the future role of this operative procedure are discussed.

Facial Muscles↗
PubMed1986

Pituitary apoplexy and haemorrhage into adenomas.

A review of 78 cases of surgically managed pituitary adenomas revealed that haemorrhage had occurred in 13. Frank haemorrhage or haemorrhagic infarction caused increasing headache, drowsiness, diplopia and visual failure. The correct diagnosis was suggested by skull X-rays and contrast studies leading to prompt surgical decompression.

Adenoma↗
PubMed1986

Cerebral embolism.

Explore the source record for details and available documents.

Anticoagulants↗
PubMed1985

Clinical diagnosis of intracranial haemorrhage using Guy's Hospital score.

We tested the Guy's Hospital stroke diagnostic score using the clinical data from two independent samples of patients with acute stroke. These were 228 patients from the Oxfordshire community stroke project and 130 referred to the National Hospital for Nervous Diseases in London. The diagnosis was confirmed by computed tomography or necropsy in each case. The optimum cut off point on the clinical score for the differentiation of intracranial haemorrhage from infarction was found to be the same for both the patients in our study and those from whose data the score was derived originally. Set at this level, the score achieved a sensitivity for the diagnosis of haemorrhage of 81% and 88% in the patients from Oxford and London, respectively. In those from Oxford infarction was diagnosed with a sensitivity of 78% with an overall predictive accuracy of 78% with an overall London the sensitivity for infarction was also 78% with an overall predictive accuracy of 82%. When it is essential to exclude intracerebral blood before starting treatment in the small proportion of patients with stroke who require anticoagulation the Guy's Hospital score is not sufficiently accurate to replace computed tomography. The score is, however, the most accurate clinical means of differentiating haemorrhage from infarction as the cause of stroke. It is suggested that it should be used as a screening test in epidemiological studies and in large scale trials of low risk treatment for the secondary prevention of stroke when computed tomography in all cases is impracticable.

Cerebral Hemorrhage↗
PubMed1985

Inhibitors of "spontaneous" platelet aggregation in whole blood.

In vitro 'spontaneous' platelet aggregation has been studied in whole blood. The spectrum of activity of materials known to influence platelet aggregation in platelet-rich plasma proved different in whole blood. Thus dipyridamole and one of its analogues SH1242 had a striking effect in whole blood whilst aspirin, chlorpromazine and K3920 had little or no effect. The combination of aspirin and dipyridamole as currently employed in clinical practice had no greater inhibitory effect than dipyridamole alone. The possible clinical relevance of these findings is discussed.

Aspirin↗
PubMed1985

Successful breast feeding: the mother's dilemma.

A content analysis of 141 articles on breast feeding by discipline revealed differences in the factors considered necessary for breast feeding success and in the criteria used to determine success. Whereas medical articles focused on maternal factors prenatally and infant health post-natally, or the length of time breast feeding was maintained, lay articles focused on the relationship of the mother with her infant (the nursing couple) and the mother's ability to manage breast feeding within the family context. The implications of this discrepancy for nursing practice and research are discussed.

Attitude↗
PubMed1985

Decelerating burst and complex repetitive discharges in the striated muscle of the urethral sphincter, associated with urinary retention in women.

A type of electromyographic activity, formerly referred to as "pseudomyotonia", can be recorded from the striated muscle of the urethral sphincter using a concentric needle electrode. There are two components to this activity, complex repetitive discharges and decelerating bursts. The latter usually dominate recordings and sound very like myotonic discharges. Analysis of these discharges indicates that they are a form of "bizarre repetitive discharge", and as such, result from ephaptic spread of excitation between muscle fibres rather than from excitation arising in the terminal branches of the motor axon. Profuse activity of this type has been found in 15 women with symptoms of urethral dysfunction, including 11 with urinary retention. It is suggested that this activity is associated with a failure of urethral sphincter relaxation.

Adult↗
PubMed1985

How often can an embolic stroke be diagnosed clinically? A clinicopathological correlation.

A retrospective case note survey of 103 autopsy proven cases of cerebral infarction was carried out to assess how often a cardiac source for embolism had been correctly suspected on clinical grounds. Only 61% of 46 patients with cardiac embolic sources were so identified. Cases of rheumatic heart disease and bacterial endocarditis were more frequently identified than cases of mural thromboembolism from ischaemic heart disease. This relative failure of unaided clinical diagnostic criteria probably accounts for the discrepancy between the autopsy evidence of cardiac embolism as a cause of stroke (about 40%), and clinical studies (about 20%).

Cerebral Infarction↗
PubMed1984

Controlled ventilation using the Lack circuit with an injector device.

A Lack breathing system with an injector device has been used for controlled ventilation. Oxygen was delivered through an injector device, which was positioned between the Lack circuit and the catheter mount, whilst nitrous oxide was delivered from the anaesthetic machine. The circuit was fully tested on two model lungs. Satisfactory tidal volumes were obtained and with fresh gas flow rates of about 4 l X min-1, rebreathing was not detected. The circuit was then studied on ten patients undergoing surgery and it was found that an end-tidal carbon dioxide concentration of 5-6% could be maintained. The use of this system during general anaesthesia is discussed.

Anesthesia↗