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Biomedical subjects

D I Graham

Publications and source records attributed to D I Graham.

At least 289 records · Page 16Linked to original sources

Brain damage complicating septic shock: acute haemorrhagic leucoencephalitis as a complication of the generalised Shwartzman reaction.

The neuropathological findings in six patients who developed neurological signs after the onset of "septic shock" caused by Gram-negative septicaemia are described. The changes in the brains were characteristic of acute haemorrhagic leucoencephalitis, and there was evidence, particularly in the kidneys, of disseminated intravascular coagulation with tubular necrosis and, in some, appearances indistinguishable from membrano-proliferative glomerulonephritis. It is agreed that acute haemorrhagic leucoencephalitis is another manifestation of a generalised Shwartzman reaction, and it is suggested that activation of complement is the final common pathway that produces tissue damage in the brain and kidney.

Adult↗

Delayed effects of subarachnoid haemorrhage on cerebral metabolism and the cerebrovascular response to hypercapnia in the primate.

A technique is described for the production of subarachnoid haemorrhage in baboons and their subsequent recovery for chronic study of cerebrovascular reactivity. The baboons make complete neurological recoveries but the response of their cerebral circulation to hypercapnia is impaired one week later. Baseline values of cerebral blood flow and of cerebral oxygen consumption are unaffected at this time. There is no evidence of hypoxic brain damage.

Animals↗

Late effects of subarachnoid haemorrhage on the response of the primate cerebral circulation to drug-induced changes in arterial blood pressure.

The ability of the cerebral circulation to maintain a constant level of cerebral blood flow with halothane-induced hypotension and angiotensin-induced hypertension was found to be impaired one week after subarachnoid haemorrhage in the baboon. No evidence of hypoxic brain damage was found. The clinical significance of these findings is discussed.

Angiotensin II↗

Computerised tomography after recent severe head injury in patients without acute intracranial haematoma.

Sixty patients with severe head injury who did not have an acute intracranial haematoma on CAT scanning are reviewed. The scans are correlated with the level of consciousness at the time of scanning and with the outcome six months after injury. The initial scan was interpreted as being normal in 38% of the cases. In the remainder the most common abnormalities were small ventricles and areas of mixed increased and decreased density interpreted as contusions. All the patients with small ventricles were under 20 years of age. Postmortem examinations were undertaken on 15 of the 19 fatal cases. There was evidence of a high intracranial pressure in 12, cerebral contusions were absent or minimal in 10, there was diffuse immediate impact damage to white matter in six, and there was moderate or severe hypoxic damage in four.

Adult↗

The smear technique in the diagnosis of neurosurgical biopsies.

This paper reviews 216 consecutive neurosurgical biopsies examined by the immediate smear technique, and the smear diagnoses are compared with the final diagnoses made on paraffin processed sections of the same material. Ninety three percent (93%) of the diagnoses were correct. The majority of errors were due to the incorrect classification of malignant tumours. The diagnosis of malignancy, however, was clearly established in all of these cases. The smear technique is suitable for application to material obtained at craniectomy, laminectomy, and also the small, soft pieces of tissue obtained by needle biopsy through a burr hole.

Biopsy↗

Ischaemic brain damage in fatal non-missile head injuries.

The incidence and distribution of ischaemic brain damage in a consecutive series of 151 patients who died as a result of a non-missile head injury in the Institute of Neurological Sciences was determined on the basis of a comprehensive neuropathological and neurohistological examination. Ischaemic damage was identified in 138 cases (91%) even after excluding cases who only had necrosis and infarction related to contusions or fat embolism, and infarction in the brain stem of the type conventionally associated with raised intracranial pressure. The ischaemic damage was assessed as severe in 37 (27%), moderately severe in 59 (43%) and mild in 42 (30%), and in the 138 cases with ischaemic brain damage it was found more frequently in the hippocampus (122 cases; 81%), and in the basal ganglia (119 cases; 79%) than in the cerebral cortex (70 cases; 46%) and in the cerebellum (67 cases; 44%). There were statistically significant correlations between ischaemic brain damage and either an episode of hypoxia or of raised intracranial pressure. From the nature of the brain damage it seems likely that much of it was due to a reduction in the cerebral perfusion pressure. This study has shown that ischaemic brain damage is common after head injury, that at least a proportion of it is probably avoidable, and that it is more important as a cause of mortality and morbidity after head injury than has been hitherto realised.

Adolescent↗

Effects of hypotension induced by halothane, on the cerebral circulation in baboons with experimental renovascular hypertension.

The effect of graded, progressive hypotension on the autoregulation of cerebral blood flow was studied in anaesthetized baboons with experimental renovascular hypertension. Graded hypotension was induced over a period of 5-6 h by the administration of increasing concentrations of halothane. In these chronically hypertensive animals cerebral blood flow remained constant until the mean arterial pressure had decreased to approximately 90 mm Hg. At mean arterial pressures of less than this value cerebral blood flow was pressure passive. At the completion of the investigation the brains were fixed by perfusion and submitted to neuropathological examination. Evidence of chronic hypertension and of ischaemic brain damage was found in every animal.

Animals↗

Remote metastases from intracranial tumours.

A review of the primary tumours of the nervous system encountered over the past 16 years from the population of the west of Scotland uncovered only three tumours in which remote extracranial metastases had developed. In all three, there had been surgical intervention before the appearance of metastases. The findings in these patients are compared with those in other published accounts of this unusual complication.

Adult↗

Correlation between angiographic findings and the ischaemia of head injury.

The carotid angiograms of 96 patients who had died from non-missile head injury were reviewed and assessed for evidence of arterial spasm, slowing of the cerebral circulation, and the presence of intracranial haemotoma. As bilateral angiography had been done in 44 cases the results are based on a correlation between the angiographic appearances and the presence or absence of ischaemic brain damage in the cortex of 140 cerebral hemispheres. There was a significant relationship between spasm alone, the presence of intracranial haematoma alone, or their combination, and ischaemic damage in the ipsilateral cortex. Apart from an association between the more severe grades of spasm and slowing of circulation in the group with ischaemia within arterial territories, there was none between slowing of the circulation or the combination of slowing with either spasm or haematoma and ischaemic brain damage.

Adolescent↗

Effects of dexamethasone and betamethasone on in vitro cultures from human astrocytoma.

Cultures of human astrocytoma have been derived by collagenase digestion and are presumed, from their aneuploid karyotypes, to be predominantly neoplastic. Early passage cultures in proliferative phase have been cloned in the presence of dexamethasone and betamethasone, both commonly used in management of patients with brain tumours. These steroids raise both the cloning efficiency and the proliferative capacity of cells within each clone. Inhibition was detected only in very high steroid concentrations (25-50 microng/ml). Since these concentrations are unlikely to be attained in vivo it is concluded that anticipated physiological levels of these steroids enhance cell survival at low densities in culture. The significance of this in vivo is discussed.

Adult↗

Diffuse brain damage of immediate impact type. Its relationship to 'primary brain-stem damage' in head injury.

In a neuropathological analysis of 151 fatal non-missile head injuries, there were 19 cases with focal lesions in the dorsolateral quadrant of the brain-stem in the corpus callosum, and histological evidence of diffuse damage to white matter. Eight of these cases had not experienced a high intracranial pressure during life. All 19 cases had been rendered unconscious at the moment of impact and had remained so or in the persistent vegetative state until death. It is therefore concluded that diffuse damage to white matter may occur as a primary event at the moment of impact, that is, it is one type of immediate impact damage to the brain. It is also concluded that this type of damage is the pathological basis of 'primary brain-stem injury' since in no patient thought clinically to have sustained 'primary brain-stem injury' were abnormalities confined to the brain-stem. Since no patient with this type of brain damage recovered consciousness after injury, it is probable that diffuse damage to white matter is the most important single factor governing the outcome in a patient who sustains a non-missile head injury.

Adolescent↗