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Biomedical subjects

M H Ebert

Publications and source records attributed to M H Ebert.

At least 73 records · Page 4Linked to original sources
PubMed1983

Cerebrospinal fluid probenecid studies: a reinterpretation.

Probenecid is used to block the transport of acid monoamine metabolites from cerebrospinal fluid (CSF), on the assumption that the resultant rise in CSF concentrations of the metabolites will reflect presynaptic "turnover" of the parent monoamine. However, CSF levels of probenecid correlate with CSF levels of the metabolite, suggesting that the blockade is incomplete at the probenecid levels obtained in human studies. This article reviews the literature on CSF probenecid-metabolite correlations and presents data demonstrating variations in the correlations across diagnostic groups. These cross-diagnostic variations may be due to group differences in membrane transport characteristics and and confound attempts to "correct for" CSF probenecid concentrations in studies of monoamine turnover.

Biological Transport↗
PubMed1982

Demonstration of conjugated dopamine in monkey CSF by gas chromatography-mass spectrometry.

A method for measuring unconjugated and conjugated dopamine in body tissues and fluids is described. Conjugated dopamine was hydrolyzed in acid to unconjugated dopamine, separated from the sample matrix by alumina chromatography, and assayed by gas chromatography-mass spectrometry. Conjugated dopamine was detected in greater concentrations than unconjugated dopamine in CSF taken from lateral ventricle or thecal sac of the Rhesus monkey. Haloperidol administration did not increase the levels of conjugated dopamine in lumbar CSF.

Animals↗
PubMed1982

Cerebrospinal fluid opioid activity in anorexia nervosa.

The authors found higher levels of CSF opioid activity, determined by radioreceptor assay, in patients with anorexia nervosa who were severely underweight than in 1) the same patients after weight restoration and 2) normal controls. Another group of patients who had chronic anorexia nervosa but were not severely underweight had normal levels of CSF opioid activity. Endogenous opioid systems have been shown to be related to eating behavior and metabolic regulation in animals. The association between decreased weight and increased CSF opioid activity observed by the authors may be a compensatory response to weight loss or may be etiologically related to anorexia nervosa.

Adult↗
PubMed1982

Aggression, suicide, and serotonin: relationships to CSF amine metabolites.

In an earlier, separate study, the authors found that human aggression and suicide (a specific aggression-related behavior) were associated with lower levels of CSF 5-hydroxyindoleacetic acid (5-HIAA), a serotonin metabolite. That study focused on subjects with personality disorders without affective illness. In the present study they examine the life history of aggression and history of suicidal behavior in 12 subjects with borderline personality disorders without major affective disorder. Histories of aggressive behaviors and of suicide attempts were significantly associated with each other, and each was significantly associated with lower 5-HIAA levels. Altered serotonin metabolism may be a highly significant contributing factor to these behaviors in whatever diagnostic group they occur.

Adolescent↗
PubMed1982

d-Amphetamine-induced heterogeneous changes in psychotic behavior in schizophrenia.

In this placebo-paired, double-blind study, 13 of 45 schizophrenic patients showed an acute improvement in schizophrenic symptoms following d-amphetamine infusion (20 mg). The 18 patients who worsened tended to have higher CSF 3-methoxy-4-hydroxyphenylglycol levels than did those who improved. d-Amphetamine blood levels and clinical descriptors of schizophrenic subgroups did not differentiate patients who improved from those who worsened; however, patients who improved had been significantly more psychotic before the infusion. Patients who worsened had been more psychotic than those who did not change. The authors suggest that those who did not change. The authors suggest that sensitivity to dopamine stimulation in schizophrenia is state-dependent rather than trait-dependent and that the simple, undirectional hypothesis of schizophrenia needs to be reformulated.

Adolescent↗
PubMed1982

Lymphocyte proteins in Huntington's disease: quantitative analysis by use of two-dimensional electrophoresis and computerized densitometry.

We used quantitative two-dimensional electrophoresis to study lymphocyte proteins in Hungtington's disease. Three hundred and six polypeptides from 14C-labeled, phytohemagglutinin-stimulated lymphocytes were measured for variation in relative spot density and 186 for variation in spot position by use of a computer program requiring operator interaction. Each polypeptide was measured in a total of 30 electrophoretograms from 28 individuals, including 13 with Huntington's disease, 2 at risk for it, and 13 controls. The study included two sets of identical twins and, as neurological controls, individuals with neurofibromatosis, Alzheimer's disease, or Shy-Drager syndrome. Seven protein polymorphisms were identified among the 186 most dense polypeptides of each gel, corresponding to a minimum average heterozygosity of 1.4%. Stringent criteria were used to define polymorphic proteins, including observation of at least one individual with each of two homozygous phenotypes and one with the heterozygous phenotype, demonstration of the expected gene dosage relationship by quantitative densitometry, consistency with genetic relationships, and reproducibility. One polymorphic protein showed three electrophoretically variant alleles. Our identification of seven polymorphisms among the 186 proteins measured on a single electrophoretogram illustrates the potential of this technique for performing linkage analysis in diseases of genetic origin. However, we observed no quantitative or positional protein variations that were characteristic of (i.e. specific for) Huntington's disease.

Blood Proteins↗
PubMed1981

Ultrasensitive stain for proteins in polyacrylamide gels shows regional variation in cerebrospinal fluid proteins.

A new silver stain for electrophoretically separated polypeptides can be rapidly and easily used and can detect as little as 0.01 nanogram of protein per square millimeter. When employed with two-dimensional electrophoresis, it should permit qualitative and quantitative characterization of protein distributions in body fluids and tissues. It has been used to demonstrate regional variations in cerebrospinal fluid proteins.

Cerebrospinal Fluid Proteins↗
PubMed1981

Essential hypertension: central and peripheral norepinephrine.

The concentration of norepinephrine in cerebrospinal fluid from patients with essential hypertension is higher than that from healthy normal volunteers, but the concentrations of norepinephrine in plasma from these groups are similar. This finding indicates that central nervous system noradrenergic hyperactivity occurs in essential hypertension but apparently is not reflected in abnormal function of the peripheral sympathetic nervous system in these patients.

Adult↗