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Biomedical subjects

J H Adams

Publications and source records attributed to J H Adams.

At least 127 records · Page 7Linked to original sources
PubMed1982

Diffuse axonal injury and traumatic coma in the primate.

Traumatic coma was produced in 45 monkeys by accelerating the head without impact in one of three directions. The duration of coma, degree of neurological impairment, and amount of diffuse axonal injury (DAI) in the brain were directly related to the amount of coronal head motion used. Coma of less than 15 minutes (concussion) occurred in 11 of 13 animals subjected to sagittal head motion, in 2 of 6 animals with oblique head motion, and in 2 of 26 animals with full lateral head motion. All 15 concussioned animals had good recovery, and none had DAI. Conversely, coma lasting more than 6 hours occurred in one of the sagittal or oblique injury groups but was present in 20 of the laterally injured animals, all of which were severely disabled afterward. All laterally injured animals had a degree of DAI similar to that found in severe human head injury. Coma lasting 16 minutes to 6 hours occurred in 2 of 13 of the sagittal group, 4 of 6 in the oblique group, and 4 of 26 in the lateral group, these animals had less neurological disability and less DAI than when coma lasted longer than 6 hours. These experimental findings duplicate the spectrum of traumatic coma seen in human beings and include axonal damage identical to that seen in sever head injury in humans. Since the amount of DAI was directly proportional to the severity of injury (duration of coma and quality of outcome), we conclude that axonal damage produced by coronal head acceleration is a major cause of prolonged traumatic coma and its sequelae.

Acceleration↗
PubMed1981

Acceleration induced head injury in the monkey.I. The model, its mechanical and physiological correlates.

A system has been developed which is capable of inducing brain injuries of graded severity from mild concussion to instantaneous death. A pneumatic shock tester subjects a monkey to a non-impact controlled single sagittal rotation which displaces the head 60 degrees in 10-20 msec. Results derived from 53 experiments show that a good correlation exists between acceleration delivered to the head, the resultant neurological status and the brain pathology. A simple experimental trauma severity (ETS) scale is offered based on changes in the heart rate, respiratory rate, corneal reflex and survivability. ETS grades 1 and 2 show heart rate or respiratory changes but no behavioral or pathological abnormality. ETS grades 3 and 4 have temporary corneal reflex abolition, behavioral unconsciousness, and post-traumatic behavioral abnormalities. Occasional subdural haematomas are seen. Larger forces cause death (ETS 5) from primary apnea or from large subdural haematomas. At the extreme range, instantaneous death (ETS 6) occurs because of pontomedullary lacerations. This model and the ETS scale offer the ability to study a broad spectrum of types of experimental head injury and underscore the importance of angular acceleration as a mechanism of head injury.

Acceleration↗
PubMed1981

Acceleration induced head injury in the monkey. II. Neuropathology.

A comprehensive neuropathological study has been undertaken in 53 adult subhuman primates subjected to a single sagittal plane angular acceleration impulse. The types of injury produced correlated well with the input force and were very similar to those seen in fatal nonmissile head injuries in man. There was a fracture of the skull in 14 animals. Subdural haematoma occurred in 33 animals, contusions in the frontal and temporal regions of the brain in 39, and discrete intracerebral haematoma in 4. Brain shift and tentorial herniation were also seen. There was evidence of hypoxic brain damage in 22 animals, and central chromatolysis in Betz cells and in the motor nuclei of the brain stem in 16.

Acceleration↗
PubMed1981

Eimeria and sarcocystis in raccoons in Illinois.

Eimeria nuttalli oocysts were found in 58% (21/36) and E. procyonis oocysts in 25% (9/36) of raccoons Procyon lotor in Illinois, and sporocysts of Sarcocystis sp. in 17% (2/12) of other raccoons in Illinois. The oocysts of E. nuttalli were ellipsoidal to ovoid, 15-21 X 12-17 micrometer, with a one-layered, smooth, colorless wall. The oocysts of E. procyonis were 22-28 X 18-22 micrometer, with a rough, striated, brownish, two-layered wall. The sporulated sporocysts of Sarcocystis sp. were 11-13 X 8-10 micrometer. Attempts to infect baby pigs by feeding them sporocysts of Sarcocystis sp. from the reaction failed.

Animals↗
PubMed1980

Diffuse involvement of the leptomeninges by tumour--a clinical and pathological study of 63 cases.

The clinical and pathological features of 63 cases of post-mortem-proved diffuse infiltration of the leptomeninges by tumour are presented. A wide variety of tumours of the nervous system, both primary and secondary, was found to give rise to such involvement, with adenocarcinoma having a particular propensity to behave in this manner. Dysfunction of cranial and spinal nerves, a confusional state and headache were prominent clinical features. Examination of the cerebro-spinal fluid was found to be less useful diagnostically in cases of primary tumours of the nervous system with leptomeningeal involvement than in cases of diffuse infiltration of the meninges by carcinoma.

Adult↗
PubMed1979

The effect of agents which modify platelet behaviour and of magnesium ions on thrombus formation in vivo.

The ability of potential anti-thrombotic agents to modify platelet-thrombus formation in injured cerebral arteries in the rabbit was tested. Low doses of heparin were without effect, while higher doses produced variable suppression of white body formation but at the expense of bleeding. Aspirin did not inhibit white body formation but another non-steroid anti-inflammatory agent, flurbiprofen was able to do so, as was the anti-gout agent, sulphinpyrazone. Magnesium salts both topically and parenterally, suppressed thrombus formation and increased the concentration of ADP which was required to initiate thrombus production at minor injury sites.

Animals↗
PubMed1979

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↗
PubMed1978

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↗
PubMed1978

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↗
PubMed1977

Aortic size and aortic calcification. A necropsy Study.

Measurements of aortic length and circumference in 336 post-mortem specimens confirm earlier, neglected observations on the progressive increase in aortic size which occurs with advancing years. The increase is not related to atherosclerosis , or to hypertension and seems to be part of a true ageing process. The value of measurement of aortic size in body age determination merits exploration by forensic pathologists. Aortic calcification is found in raised and complicated atherosclerotic plaques and its prevalence and severity closely follows the accepted pattern of plaque severity, occurring earlier and more severely in men, in the abdominal aorta and in patients with overt vascular disease in other territories such as patients with cardiac infarcts. No association was found between the amount of calcification and the presence of hypertension, diabetes or neoplasia.

Adolescent↗