Biomedical subjects
Publications and source records attributed to J H Adams.
Two women are described in whom adenoid cystic carcinoma of upper respiratory tract origin presented as a large intracranial tumour with involvement of cranial nerves. Smears of the neurosurgical biopsies were distinguished by abundant metachromatic mucin.
The principal clinical and pathological findings in 16 fatal cases of human African trypanosomiasis caused by T.b. Gambiense are described. The changes in the brain took the form of a non-specific lymphoplasmacytic meningo-encephalitis of varying intensity. Other features included morular cells, diffuse microglial hyperplasia, and large reactive astrocytes in the white matter. Carditis was identified in 10 cases. Acute reactive arsenical encephalopathy appeared to be the principal cause of death in 10 patients. Convulsions figured prominently in this type of encephalopathy in seven patients and were sufficiently severe to produce hypoxic brain damage. In three cases of acute reactive arsenical encephalopathy the structural changes in the brain were those of acute haemorrhagic leucoencephalopathy.
A comprehensive neuropathological analysis was undertaken on 434 patients who died as a result of a non-missile head injury in order to determine the frequency and extent of brain damage secondary to high intracranial pressure (ICP) in head injury. Using the criterion of pressure necrosis in the parahippocampal gyrus as evidence of high ICP due to a supratentorial expanding lesion, it was established that the ICP had been high in 324 cases. In 42 of these there was no other brain damage attributable to a high ICP. There was evidence of secondary brain stem damage in 221 cases and in 44 of these the damage could be seen only microscopically. In 54 cases there was a contralateral peduncular lesion. Other abnormalities were infarction in the territories of various arteries and in the anterior lobe of the pituitary. There was a supracallosal hernia in 80 cases and haemorrhage in the oculomotor nerves in 48 cases. These results further emphasise the frequency and range of brain damage due to secondary vascular factors brought about by high ICP in a patient who has sustained a head injury.
A retrospective clinical and pathological analysis has been performed of 24 cases of herpes simplex virus encephalitis (HSE) seen at the Institute of Neurological Sciences, Glasgow, between 1972 and 1985. All patients had been diagnosed on the basis of isolation of herpes simplex virus (HSV) from, and/or the demonstration of characteristic histological changes of acute necrotizing encephalitis (ANE) in brain biopsy and/or autopsy tissue. Clinical presentation on admission included a prodromal influenza-like illness (46%), sudden onset of headache and confusion (54%), meningism (38%), deep coma (42%), aphasia (54%) and focal neurological signs (79%). Seizures occurred in 46% of cases during the course of the illness. Of the 24 cases, 14 (58%) died and 10 (42%) survived. Intravenous acyclovir treatment was associated with the best prognosis. Cerebral biopsy of one temporal lobe was performed in 22 cases and in 19 of these a positive histological diagnosis of HSE could be made. HSV was isolated from 15 of the 19 (79%) biopsied cases in whom virus isolation was attempted. Only seven out of the 15 cases (47%) in which immunofluorescence assays for HSV antigens were performed were unequivocally positive. Herpes simplex virus was isolated in culture from all cases which were negative by immunofluorescence. Immunocytochemical analysis on tissue sections of five representative brain biopsies demonstrated the presence of HSV antigens in some astrocytes, neurons and macrophages especially within areas of inflammatory infiltration. In situ hybridization experiments with a cloned HSV DNA probe demonstrated viral RNA in astrocytes, neurons and macrophages in two human biopsies and mouse brains in areas broadly corresponding to the distribution of viral antigen labelling. The combined immunocytochemical and in situ hybridization procedure showed that many but not all of the cells containing viral RNA also contained HSV antigens, indicating a productive infection in these double-labelled cells.
Epithelial-type (PK-15) and fibroblast-type (MDBK) mammalian cell cultures were inoculated with purified Eimeria vermiformis sporozoites. Matched samples from 0 to 93 h after inoculation (HAI) were processed for electron microscopy; half of the sample preparations were extracted with non-ionic detergent prior to fixation. Specimens were examined by both transmission and scanning electron microscopy. Numerous sporozoites were attached to the cultured cells from 2 to 93 HAI, usually near the cell periphery. Some host cell microvilli extended up and appeared attached to the sporozoites. Sporozoites fixed during the penetration process were markedly constricted at the site of entry; however, no noticeable changes occurred in the host cell membrane or surface microvilli during sporozoite invasion or in sporozoite-infected cells. In cells extracted with 1% Triton X-100, the host cytoskeleton was progressively reorganized about the parasites but changes were limited to the immediate area of the sporozoite. Around resident sporozoites, the cytoskeleton became less dense but also more ordered, which contrasted with adjacent cell areas. Cytoskeletal elements passed both over and under the parasites. The appearance of the cytoskeleton suggested that the host cell formed a loose, basket-like net of cytoskeletal elements about the parasite.
The charged-particle telescope (CPT) onboard the Clementine spacecraft measured the fluxes of energetic protons emitted in solar energetic particle events. Protons in the energy range from 10 to 80 MeV were of greatest interest for radiation effects such as total dose and single event upsets. Energetic electrons were also of interest for spacecraft charging and their contribution to total dose. The lower-energy CPT electron channels (25-500 keV) were mainly of geophysical interest. While orbiting the moon, the CPT observed the wake created by the moon when it blocked the flow of energetic particles in the magnetotail region. The CPT provided opportunities to observe energetic electron bursts during magnetic storms and magnetospheric substorms. CPT data are particularly useful in multispacecraft studies of interplanetary disturbances and their interaction with the magnetosphere. The proton channels on the CPT provided data on solar energetic protons and storm-time protons associated with the passage of an interplanetary shock at 0903 UT on Feb. 21, 1994. Results are compared with those from GOES-7, SAMPEX, and GEOTAIL.
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