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Biomedical subjects

M D Shaw

Publications and source records attributed to M D Shaw.

At least 73 records · Page 4Linked to original sources
PubMed1981

Generation of the ocular motor nuclei and their cell types in the rabbit.

Autoradiography of 3H-thymidine incorporation was combined with horseradish peroxidase (HRP) transport to distinguish the birthdates of motoneurons and internuclear neurons of the abducens nucleus, and of specific motor pools within the oculomotor nucleus. Motoneurons were identified by their retrograde transport of HRP from the extraocular muscles. In other experiments, internuclear neurons of the abducens nucleus were identified by their retrograde transport of HRP from the oculomotor nucleus. We found that motoneurons and internuclear neurons are generated simultaneously in the abducens nucleus, and suggest that the differentiation of these two neuron types may be controlled by the local environment. The motor pools of the oculomotor nucleus are generated sequentially. This may reflect the mechanism whereby nuclei are constructed.

Abducens Nerve↗
PubMed1981

The natural history of postoperative seizures.

The risk of developing postoperative seizures decreases with the passage of time after surgery. In the majority of cases it has fallen to less than 10% by six months but in some specific groups this risk is not reached until much later. Patients who had abscesses were however the only group with a continuing risk after five years. Late epilepsy occurred in 41% of patients suffering early epilepsy. The question of prophylactic anticonvulsant drugs is discussed.

Anticonvulsants↗
PubMed1981

The incidence of postoperative seizures.

Overall, supratentorial neurosurgical procedures are associated with a 17% risk of developing postoperative seizures. The incidence varies, but treatment of an arteriovenous malformation, an intracerebral haematoma, a middle cerebral artery aneurysm, an abscess, and meningiomas carry the highest risk. The role of prophylactic anticonvulsant therapy is discussed.

Brain↗
PubMed1980

Metastatic extradural malignancy of the spine.

One hundred and twenty cases of malignant extradural spinal compression have been reviewed. It is essential to treat such patients early whilst their neurological defects are minimal. When useful function has been lost, it is rarely regained postoperatively, irrespective of the rate of onset, and particularly if the duration of the fixed deficit exceeds 24 hours.

Adolescent↗
PubMed1980

The effect of sodium salicylate on cerebral blood flow and metabolism.

1 The effect of intravenous sodium salicylate on cerebral oxygen consumption and cerebral blood flow and its response to hypercapnia was measured by the 133Xenon intracarotid injection technique in ten baboons. 2 After an initial peak, the plasma salicylate level maintained a stable value for 2 h of 1 mmol/l with 50 mg/kg sodium salicylate and 2.5 mmol/l with 200 mg/kg sodium salicylate. 3 Sodium salicylate (50 mg/kg) produced no change in baseline cerebral blood flow (CBF) or cerebral oxygen consumption (CMRO2) but the CBF response to hypercapnia was reduced by 41% during the first hour. During the second hour after salicylate administration, CMRO2 increased by 26%, CBF at normocapnia increased by 31% and the CBF response to hypercapnia was 67% of the baseline value. 4 Sodium salicylate (200 mg/kg) increased CMRO2 by 65%. There was no significant change in CBF at normocapnia or hypercapnia. 5 These results confirm that inhibitors of prostaglandin synthesis, which can cross the blood brain barrier in sufficient quantity, reduce the response of the cerebral circulation to hypercapnia. The difficulties in interpreting changes in the CBF CO2 response in the presence of increases in CMRO2 are discussed. It is suggested that the respiratory stimulation seen in salicylate intoxication is the result of a central metabolic stimulation.

Animals↗
PubMed1978

The changing pattern of spinal arachnoiditis.

Spinal arachnoiditis is a rare condition. Eighty cases, diagnosed during a period when 7600 spinal contrast investigations were undertaken, have been reviewed. The majority had suffered a previous spinal condition, the most common being lumbar disc disease. There has been a change in the distribution of arahnoiditis with the lumbar region now most frequently involved. This accounts for the persistence of radicular symptoms and the relatively low incidence of paraplegia when compared with earlier series. Surgery does not appear to have any role in the treatment.

Adolescent↗
PubMed1977

Modification of tyrosine residues of the lactose repressor protein.

Reaction of the lactose repressor protein from Escherichia coli with high molar excesses (up to 800 fold) of tetranitromethane resulted in modification of tyrosine residues in the amino-terminal and core regions of the molecule. Tyrosines 7 and 17 exhibit significant reactivity at low levels (5-10 fold molar excess) of tetranitromethane. The loss of operator binding activity upon nitration at these low concentrations of reagent indicates involvement of these two tyrosines in the binding process. Inducer binding activity was maintained at approx. 90% of unreacted repressor for all excesses of reagent studied. Addition of inducer to the repressor prior to reaction resulted in decreased modification of tyrosines in the core region, but anti-inducers did not affect the reaction significantly. The effect of inducers on the pattern of reaction apparently reflects the conformational change which occurs upon binding of these ligands. Acetylation of the repressor protein with N-acetylimidazole modified lysines and tyrosines with complete loss of operator binding activity and retention of 75-80% of inducer binding activity.

Bacterial Proteins↗
PubMed1977

Penetrating airgun injuries of the head.

Five cases of intracranial airgun injuries are presented. The accepted principles of treatment of a compound depressed fracture of the skull are easily overlooked in these patients because of the rarity of the injury and the apparent well-being of the patient, who is usually fully conscious with only a small scalp laceration.

Adolescent↗
PubMed1977

Value of computed tomography in the diagnosis of intracranial abscess.

The computed tomography (CT) scans of 60 patients with intracranial infection have been reviewed. Computed tomography, particularly if used with contrast enhancement, is a valuable adjunct to the investigation of patients with suspected intracranial abscess. The false negative rate is 1%, but despite this, mortality from intracranial abscess remains unchanged.

Adolescent↗
PubMed1977

Chronic abscess of the brain stem.

The incidence of solitary brain stem abscess is less than 4% of all posterior fossa abscesses, and probably less than 1% of all intracranial abscesses. Two cases are reported, both presenting as chronic progressive clinical problems and initially diagnosed as gliomas. It is suggested that aspiration is a more suitable treatment than excision, and that in cases secondary to otogenic disease, radical mastoidectomy might have been an adequate method of prophylaxis.

Brain Abscess↗
PubMed1977

Spinal subdural haematoma: an unusual complication of lumbar puncture.

A case in which a spinal subdural haematoma obscured the diagnosis of spinal stenosis is described. The haematoma resulted as a complication of the lumbar puncture necessary for the myelogram. No other aetiological factors were found, but it is suggested that this condition may become more frequent as the result of iatrogenic haemostatic defects.

Hematoma, Subdural↗
PubMed1976

Intracranial pressure during ventriculography using meglumine iothalamate.

A small increase in ventricular fluid pressure (1.3 +/- 0.3 mm Hg) occurs on isovolumetic addition of meglumine iothalamate to the lateral ventricle. A marked increase (46.3 +/- 3.2 mm Hg: P less than 0.001) in pressure occurs on passage of the contrast medium into the posterior part of the third ventricle; the aqueduct and the fourth ventricle. Theoretical mechanisms are discussed.

Aged↗
PubMed1976

Computed tomography in the diagnosis of colloid cyst.

The diagnosis of colloid cyst of the third ventricle is notoriously difficult and contributes significantly to the high mortality. Three cases are presented in which computed tomography has contributed to the diagnosis by showing (1) the dilatation of the lateral ventricles without dilatation of the midline ventricular system, and (2) the lesion as an area of increased density within the third ventricle. Computed tomography may reduce the overall mortality in this condition by reducing the number of patients who succumb undiagnosed during an acute phase of raised intracranial pressure.

Adult↗
PubMed1975

Cerebellar abscess. A review of 47 cases.

Forty-seven cases of cerebellar abscess have been reviewed, 93% of which were secondary to otogenic disease. There has been little change in the annual incidence during the period of time under review. The overall mortality was 41%, but with successive decades the mortality has increased. Three factors appear to be of importance in determining survival: the patient's ability to control his infection; reduction of the effect of the posterior fossa mass, preferably by complete excision of the abscess under antibiotic cover; and, in the case of otogenic abscess, an adequate radical mastoidectomy with bone removal to the site of attachment of the abscess to the dura mater.

Adolescent↗