Dithiols and monothiols are linked with GABA transport in membrane vesicles of rat brain synaptosomes.

The properties of gamma-aminobutyric acid (GABA) transport into membrane vesicles derived from synaptosomes of rat brain have been studied using membrane-permeable and -impermeable sulfhydryl reagents, dithiol-specific reagents and oxidizing reagents. GABA transport is inhibited, reversibly, by very low concentrations of the membrane-permeable trivalent arsenical, phenylarsine oxide. Preincubation with this reagent only partially protects GABA transport from inactivation by N-ethylmaleimide (NEM). Thorin, a negatively charged trivalent arsenical, has no influence on GABA transport at concentrations 100-fold higher than that of the inhibitory phenylarsine oxide. The impermeant oxidizing agent, potassium ferricyanide, did not inhibit transport whereas the permeant reagent, diamide, was inhibitory. These data indicate that the GABA transporter possesses an activity-linked dithiol in a hydrophobic region of the carrier not accessible to charged, polar reagents. p-Chloromercuribenzenesulfonate (PCMBS) also inhibits but does not protect against NEM inactivation, suggesting the occurrence of an activity-linked monothiol in a polar region of the carrier.

Homovanillic acid and 5-hydroxyindoleacetic acid cerebrospinal fluid levels. A study with and without probenecid administration of their relationship to the state of consciousness after head injury.

Homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were measured in the lumbar cerebrospinal fluid of 98 patients after closed head injury. The HVA levels decreased in patients, whether or not they were given the drug probenecid, which inhibits the active transport of these acids from the brain. The decline of HVA was more notable in patients with the longest duration of unconsciousness. The HVA levels showed no correlation with the state of consciousness at the moment of the lumbar puncture. The 5-HIAA levels were below normal in the conscious patients, but paradoxically, at about normal levels in unconscious patients. The overall results suggest a decreased cerebral dopamine and serotonin metabolism after head injury.

Gamma-aminobutyric acid and homovanillic acid concentration in the CSF of patients with senile dementia of Alzheimer's type.

The investigation of enzyme and neurotransmitter levels and/or their metabolites in the CSF of patients with senile dementia of Alzheimer's type (SDAT) could become a promising approach for a clinical research and diagnostic procedure. To learn more about the metabolic reflections of central metabolism in the CSF of patients with SDAT, we measured CSF levels of gamma-aminobutyric acid (GABA) and homovanillic acid (HVA), the dopamine metabolite. In 16 female patients with SDAT and in eight matched control patients, CSF GABA levels were measured by ion exchange with fluorimetric detection, and HVA levels were measured fluorimetrically. The GABA content of the CSF was significantly reduced in patients with SDAT, whereas the HVA level was unchanged.

In vivo phosphorus magnetic resonance spectroscopy in multiple sclerosis.

Localized phosphorus magnetic resonance spectroscopy at 1.5 T was performed in 39 patients with multiple sclerosis and in 15 healthy controls. The multiple sclerosis spectra showed increased creatine phosphate levels. This increase was correlated with the severity of the handicap and was greater in patients with a progressive course of the disease than in patients with relapsing-remitting disease. No clear abnormalities were observed in the spectra of patients with multiple sclerosis regarding the phosphomonoesters, phosphodiesters, inorganic phosphate, and beta-adenosine triphosphate or with respect to pH values. There was an increased creatine phosphate level in the spectra in relation to a low metabolic state of the brain.

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.

An improved, ultrasensitive method for the detection of IgM oligoclonal bands in cerebrospinal fluid.

A new, 10-fold more sensitive method, based on an improved immunofixation technique, has been devised to detect oligoclonal IgM bands in unconcentrated cerebrospinal fluid (CSF). Using agarose gel electrophoresis, 5 microliters of an unconcentrated sample containing oligoclonal bands was separated and blotted on to a polyvinyldifluoride membrane. To visualise the pattern, a peroxidase-labelled double-antibody technique was used. No prior concentration of CSF was needed and the process required only 5 h. The technique may prove very useful in diagnosing an early intrathecal immune response.

A specific and sensitive determination of gamma aminobutyric acid in CSF and brain tissue by gas chromatography-mass spectrometry.

The determination of gamma-aminobutyric acid (GABA) in cerebrospinal fluid and brain extracts is described. Its heptafluorobutyryl-isobutanol derivative was measured both by electron impact and chemical ionization mass fragmentography using GABA-d6 as internal standard. The derivatization product is stable for several days. The method is sensitive (1 ng absolute in cerebrospinal fluid and 30 pg in standard GABA solutions) and specific, when chemical ionization mode is applied. Normal values of GABA are in rat brain extracts (1.40 +/- 0.32 mumol/g fresh weight) and human CSF (18.3 +/- 10.0 ng/ml).

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.

Comparison of serum S-100 protein levels following stroke and traumatic brain injury.

Temporal changes in serum S-100 protein levels were compared between patients with ischemic stroke, transient ischemic attack (TIA) and traumatic brain injury (TBI). In addition, S-100 levels were correlated with clinical severity and outcome. Measurements were done with a LIA-mat((R)) Sangtec((R)) 100 using an automated immunoluminometric assay. Serum S-100 was measured in 21 stroke patients, 18 TIA patients and ten TBI patients on days 1 (0-24 h), 2, 3, 4, 5 or 6 and 8 or 9. In a control group of 28 healthy volunteers one measurement was done. For the stroke and TIA patients, National Institutes of Health Stroke Scale (NIHSS) scores were obtained on admission and on day 10. For the TBI patients, Glasgow Coma Scale (GCS) scores were obtained on admission and Glasgow Outcome Scale (GOS) scores were obtained after 6 months. Changes in serum S-100 levels over the first 3 days were significantly different between stroke and TBI patients (P=0.014) and between stroke and TIA patients (P=0.006). Peak concentrations of S-100 were most often observed on day 3 or 4 after stroke and on day 1 or 2 after TBI. In the stroke patients individual S-100 peak levels correlated well with the NIHSS score on admission (r=0.58 P=0.014) and the change in NIHSS score between day 10 and day 1 (r=0.65, P=0. 005). In the TBI patients a good correlation between individual peak levels of S-100 and the GCS score on admission (r=-0.81, P=0.010) and the GOS score 6 months after the trauma was found (r=-0.87, P=0. 004). We conclude that there is a significant difference in temporal changes of S-100 levels between ischemic stroke and TBI patients. This suggests different pathophysiological mechanisms. The results of this study further confirm that peak levels of serum S-100 correlate with neurological deficit resulting from either stroke or TBI.

Determination of polyamines and metabolites in cerebrospinal fluid by isotope dilution mass fragmentography, and a clinical application.

Capillary gas chromatography and mass fragmentography was used to determine simultaneously 1,3-diaminopropane, putrescine, cadaverine, spermidine, spermine, isoputreanine and putreanine in cerebrospinal fluid. After addition of deuterium labelled analogs and acid hydrolysis, the compounds were isolated by adsorption onto silica and converted into their N-heptafluorobutyryl-methylesters. Quality control data and an application of the method are given. A patient harbouring an astrocytoma was monitored during chemotherapeutic treatment.

The pathogenesis of cerebral gliomatous cysts.

In this study, the authors have examined the mechanism of the formation of tumor cysts. Cyst fluid samples were obtained during surgery and by percutaneous aspiration from 22 patients with cystic cerebral gliomas. The concentration of protein was measured in the cyst fluid and blood plasma. Analysis of brain tumor cyst fluids revealed that plasma proteins constituted a major fraction (92%) of cyst fluid proteins; moreover, the protein fractions occurred in concentrations (relative to the plasma concentrations) that were around 50-fold of those in cerebrospinal fluid. This strongly indicates blood-brain barrier disruption. Evidence from computed tomographic and magnetic resonance imaging scans as well as from electron microscopy of tumor cyst walls suggests the transition of spongy edematous tissue in or around tumors into the contents of associated cysts. Pathophysiologically, blood-brain barrier breakdown is inherent to the occurrence of vasogenic brain edema. It is therefore plausible that the development of cysts is related to peritumoral vasogenic edema.

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.

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.

T-lymphocyte subpopulations in peripheral blood of patients with multiple sclerosis, patients with other neurological diseases and healthy controls.

We report our results in profiling peripheral blood lymphocyte subpopulations with monoclonal antibodies in 17 multiple sclerosis (MS) patients, 22 patients with other neurological diseases (OND), and 11 healthy controls, using a blind experiment. Untreated patients with a chronic progressive MS have higher T-helper cell (OKT4+) counts and a higher ratio OKT4+/OKT8+ than other MS patients, OND or healthy controls. Two weeks after the onset of a relapse of MS there is a decreased T-helper and an increased T-suppressor cell percentage. Treatment with ACTH results in a significant increase of helper cells after 4 weeks of therapy. Patients with the lowest helper cell counts and the lowest helper/suppressor ratio show the best clinical improvement by ACTH. High OKT4+ cell percentages make a chronic progressive course of MS more probable.

The effect of gonadectomy on the clinical course of chronic experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE) is an animal model for the human neurological disease multiple sclerosis (MS). Upon immunization with guinea pig spinal cord under a low dose of Cyclosporin A, male Lewis rats develop a severe chronic (relapsing) course of EAE (CR-EAE). By contrast, female Lewis rats develop a more mitigated course of EAE: only half of the female rats develop relapses. To further analyze factors determining this sexual dimorphism in the course of EAE, in the present study male and female Lewis rats were gonadectomized before induction of CR-EAE. Now both male and female rats all developed a severe chronic course of EAE, showing extensive pathological changes in the CNS. In the female sham-gonadectomy (control) group only one third of the rats developed relapses. These female rats only showed mild pathological changes in the CNS. In the male sham-gonadectomy (control) group all rats developed relapses of EAE and showed extensive pathological changes in the CNS. From these data we conclude that the presence of the ovaries (partially) protects female rats against relapses of EAE and CNS injury. Presence or absence of the testes apparently makes no difference on the course of EAE. We propose that sex hormones produced in the ovaries protect female rats against relapses of EAE and underlying CNS injury.