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Biomedical subjects

D G Thomas

Publications and source records attributed to D G Thomas.

At least 271 records · Page 15Linked to original sources
PubMed1980

Impaired thymus-derived lymphocyte function in patients with malignant brain tumour.

Cell-mediated immunity was evaluated in 28 patients with malignant glioma, using in vivo and in vitro tests of lymphocyte function. The results were compared to those found in patients with carcinomatosis (11 subjects), benign brain tumours (9), other neurological disorders (20) and normal, healthy controls (21). Significant impairments of delayed hypersensitivity responses to common antigens was found in patients with malignant glioma and in those with generalised malignancy. A less significant depression of lymphocyte responses was also detected in patients with meningioma. The impairment in cell-mediated immunity was shown not be due to a serum blocking factor. Our data indicate that there is defective T cell function in patients with glioma, similar to that reported in cases with malignancies outside the central nervous system. This impaired immunity may have clinical significance.

Adolescent↗
PubMed1980

Urinary incontinence and minimal pyramidal disease.

Nine patients with detrusor instability and minimal pyramidal disease are presented. None had neurological symptoms. All had severe urinary symptoms. These patients may add support to the theory that all detrusor instability has a neurogenic basis.

Adolescent↗
PubMed1979

Radioimmunoassay of serum myelin basic protein and its application to patients with cerebrovascular accident.

Myelin basic protein-like immunoactivity was measured in the serum of patients after cerebrovascular accident (CVA) using a double antibody radioimmunoassay for myelin basic protein with a detection limit of 3 ng/ml serum. For up to 6 days after ictus, serum myelin basic protein levels in patients with severe CVA and patients who died as a result of CVA were significantly greater than those in control patients, patients with moderate CVA and patients surviving CVA. All patients with serum myelin basic protein levels greater than the range found in control subjects subsequently died. Serial dilutions of positive sera suggested that the immunoactivity differs from authentic myelin basic protein and may represent breakdown products of the protein. Serum from some patients with a previous history of moderate CVA had myelin basic protein binding activity consistent with the presence of antibodies to the protein.

Cerebrovascular Disorders↗
PubMed1979

Glial fibrillary acidic protein (GFAP): purification from human fibrillary astrocytoma, development and validation of a radioimmunoassay for GFAP-like immunoactivity.

The extraction and purification of glial fibrillary acidic protein (GFAP) from human fibrillary cerebellar astrocytoma is described. Using an immunoperoxidase method, antisera raised to the protein showed specific staining of astrocytes in normal spinal cord and in tumours of astrocytic origin. A double antibody radioimmunoassay for GFAP in tissue extract was developed, the detection limit of the assay being 360 pg. Extracts of tissues other than brain or spinal cord did not cross-react significantly in the assay, neither did purified preparations of myelin basic and S-100 proteins. Levels of GFAP in normal CNS tissue were higest in spinal cord (1370 microgram/g wet weight) but a level of 3050 microgram/g wet weight was detected in a fibrillary astrocytoma.

Astrocytes↗
PubMed1979

Selective sacral neurectomy in the management of urinary incontinence due to detrusor instability.

Since Torrens (1974) reported on the use of selective sacral neurectomy in the management of bladder instability, the procedure has been used increasingly in specialised centres. We report the clinical and urodynamic findings in 9 patients in whom this procedure has been performed. The results suggest that selective sacral neurectomy is a valuable procedure in a highly selected group of patients with neurogenic bladder dysfunction. Patient selection, contraindications and the choice of which sacral nerves to divide are discussed.

Adolescent↗
PubMed1979

The urological status of 86 females following spinal cord injury.

A review of the urological problems in 86 female spinal cord injury patients is presented. There were no urological or renal deaths. Three urinary diversions were performed. Fifty-five patients are catheter-free and 28 are managed with permanent catheter drainage. The problems of "bladder training" are presented.

Adolescent↗
PubMed1979

Successful removal of an intrapontine haematoma.

A patient with progressive signs and symptoms suggestive of a pontine lesion is described. Intracranial investigations, CAT scan, vertebral angiography, and lumbar pneumoencephalogram revealed a space-occupying lesion of the pons and midbrain. The exact nature of the lesion was not established before the operation. A posterior fossa exploration was performed and a pontine haematoma was discovered and evacuated. The pathological specimen was designated as a cryptic arteriovenous malformation. Preoperative neurological deficits disappeared except for minimal left sixth nerve palsy and mild truncal ataxia.

Adolescent↗
PubMed1978

Serum-myelin-basic-protein assay in diagnosis and prognosis of patients with head injury.

Serum levels of myelin basic protein (M.B.P.), a nervous-system-specific protein, were measured in 157 patients after head injury and related both to the type of brain damage and to the clinical outcome assessed three months after injury. Mean concentrations of M.B.P. in patients with severe intracerebral damage, with or without associated extracerebral haematoma, were significantly raised at the time of admission and remained high for two weeks after injury. In patients with extracerebral haematoma not associated with severe intracerebral damage mean M.B.P. values rose four to six days after injury and were significantly raised only in patients with poor eventual outcome. Mean serum-M.B.P. concentrations in patients with a good outcome after injury were similar to those in controls. In patients with a poor outcome the mean M.B.P. levels between two and six days after injury were significantly higher than in those with a good outcome. The assay of serum-M.B.P. may be valuable in assessment of severity of brain damage in patients after head injury and in prediction of outcome.

Blood-Brain Barrier↗
PubMed1977

Auditory evoked potentials as probes of hemispheric differences in cognitive processing.

The amplitude of auditory evoked potentials recorded from the cerebral hemispheres to pairs of task-irrelevant tones was related to differential hemispheric engagement in ongoing cognitive activity (for example, verbal versus musical). The hemisphere hypothesized to be most engaged in the ongoing cognitive task, as compared to the unengaged hemisphere, produced a greater potential difference between the temporal and reference electrode to the second of the tone pairs. These findings are related to "fast habituation" and "recovery cycle.".

Adult↗
PubMed1977

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↗