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Biomedical subjects

A W Teelken

Publications and source records attributed to A W Teelken.

At least 37 records · Page 2Linked to original sources
PubMed1984

CSF GABA levels in Parkinson's disease.

CSF levels of GABA were investigated in a group of Parkinson patients without drug treatment and a group of Parkinson patients under treatment with L-DOPA or anticholinergics. Probenecid results in an elevation of CSF GABA levels in healthy persons. The results indicate a significant decrease of GABA levels in CSF in untreated Parkinson patients. Parkinson patients treated with L-DOPA or anticholinergics show nearly normal CSF GABA levels. This may suggest that the altered GABA function in Parkinson's disease is secondary to changes in the dopamine system.

Dopamine↗
PubMed1977

Biochemical and ultrastructural aspects of the inhibited phagocytosis by neutrophil granulocytes in acute brain-damaged patients.

In a study of 60 head-injured patients inhibition of phagocytosis by neutrophil granulocytes was observed over a period of up to 5 weeks. This inhibition of phagocytosis could be correlated with the severity of head injury as well as with the state of unconsciousness at the time of the investigation. No correlation was found between neutrophil granulocyte counts and the inhibition of phagocytosis. A good correlation could be demonstrated between the level of lumbar CSF 5-HIAA and the inhibition of phagocytosis. After in vitro incubation with albumin the cells showed a recovery of phagocytosis. Electron micrographs of the cells showed ultrastructural appearances suggesting a changed permeability of the plasma membrane and, in addition, alterations in the cytoplasmic region beneath the plasma membrane. It is suggested that head injury may influence the pituitary-adrenal system and the autonomic nervous system, giving changes of neutrophil function and of neurotransmitter metabolism; these changes may represent an adaptation mechanism.

Adolescent↗
PubMed1977

Cell-mediated hypersensitivity in multiple sclerosis and other neurological diseases.

Using a direct macrophage migration inhibition test the hypersensitivity against encephalitogenic protein and phytohaemagglubinin in normal persons, multiple sclerosis patients and patients with other diseases of the central nervous system were examined. It proved that the vast majority of patients were sensitised to brain antigen. The percentage of positive tests and the percentage of migration inhibition was related to the activity of the disease. No differences were found between lymphocytes of multiple sclerosis patients and of patients with the other neurological diseases patients. Foetal calf serum was proven to depress the hypersensitivity to phytohaemagglutinin as did multiple sclerosis serum on normal lymphocytes. The results did not support the hypothesis that multiple sclerosis is caused by a cell-mediated auto-immune process.

Autoimmune Diseases↗
PubMed1976

On the nature of brain stem disorders in severe head injured patients.

In head injured patients changes were found in the CSF levels of metabolites of the dopaminergic and the serotonergic neurotransmission (HVA and 5-HIAA). After the fifth day following trauma a significant decrease of the HVA levels in the lumbar CSF after probenecid treatment was found. The intensity of this decrease was found to be related to the severity of the trauma (period of unconsciousness), but not to the state of consciousness. Also the probenecid-induced 5-HIAA levels in conscious patients were decreased after the fifth post-traumatic day. In unconscious patients, the period of unconsciousness, particularly in the period of 5-20 days after trauma. Between 21 and 60 days after trauma the 5-HIAA concentrations in unconscious patients decreased remarkably, but they were still significantly higher than in the conscious patients. It can be concluded that during unconsciousness serotonergic neurons have a high rate of turnover, but that both neurotransmitter systems are damaged by the direct or indirect consequences of the injury.

Adolescent↗
PubMed1976

Amino acid abnormalities in cerebrospinal fluid of patients with parkinsonism and extrapyramidal disorders.

Free amino acid determinations in the cerebrospinal fluid of patients with Parkinson's disease or other extrapyramidal disorders showed that in both groups most amino acids were increased. Significantly increased amino acids were neutral and basic amino acids. Amino acid clusters were present and corresponded with the grouping of amino acids in accordance with amino acid transport systems. The amino acids within the clusters showed a remarkable degree of correlation, and there was a notable correlation between the clusters both in the parkinsonian group and in the group of extrapyramidal disorders, but not in a control group. Our data suggest that in a number of extrapyramidal disorders, Parkinson's disease included, a more generalized abnormality exists than neuronal loss only and, in addition, that patients with these neurologic conditions have a common biochemical defect in their amino acid transport systems.

Adult↗
PubMed1976

A direct macrophage migration inhibition test applied in man.

A direct macrophage migration test is described, which proved to be useful for the detection of cellular hypersensitivity in man. We used a modification of the method described by Hughes & Paty (1972). In this method the MLR is abolished by 100 rad gamma-irradiation of the peritoneal exudate cells prior to pooling with human lymphocytes. Experiments with various intensity of irradiation, PPD, muscle antigen and encephalitogenic factor were performed to check this method. In a pilot study lymphocytes of patients with diseases of the central or peripheral nervous system or of muscle were tested. This proved that a hypersensitivity of Ef was present in various diseases of the CNS, while in muscle diseases positive tests were found using muscle antigen.

Antigens↗