1. |
- Bergquist, Jonas, et al.
(författare)
-
Analysis of human cerebrospinal fluid by capillary electrophoresis with laser-induced fluorescence detection.
- 1994
-
Ingår i: Analytical Chemistry. - 0003-2700 .- 1520-6882. ; 66:20, s. 3512-8
-
Tidskriftsartikel (refereegranskat)abstract
- Capillary electrophoresis with laser-induced fluorescence detection is used to analyze 10 microL samples of human cerebrospinal fluid. Primary amine-containing compounds in untreated cerebrospinal fluid are labeled with 3-(4-carboxybenzoyl)-2-quinolinecarboxaldehyde prior to analysis, producing fluorescent isoindoles. Electropherograms containing approximately 50 peaks are obtained in less than 35 min from cerebrospinal fluid samples. Ten peaks in the electropherograms have been identified and quantitated: arginine, glutamine, threonine, valine, gamma-amino-n-butyric acid, serine, alanine, glycine, glutamic acid, and aspartic acid. Detection limits for these 10 amino acids range from 0.29 nM for gamma-amino-n-butyric acid to 100 nM for threonine, and separation efficiencies as high as 190,000 theoretical plates are obtained for these analytes. Electropherograms of cerebrospinal fluid samples from patients with Alzheimer's disease and from children with different neurological disorders are compared to those of healthy controls. Differences in individual amino acid levels are observed between the patient groups, and these differences appear to be disease and age related. These results indicate that analysis of cerebrospinal fluid by capillary electrophoresis will be useful as a selective, rapid, and sensitive tool for both diagnosis of central nervous system disorders and for study of the mechanisms of these disorders.
|
|
2. |
- Bergquist, Jonas, et al.
(författare)
-
Demonstration of immunoglobulin G with affinity for dopamine in cerebrospinal fluid from psychotic patients.
- 1993
-
Ingår i: Clinica Chimica Acta. - 0009-8981 .- 1873-3492. ; 217:2, s. 129-42
-
Tidskriftsartikel (refereegranskat)abstract
- Using an enzyme-linked immunosorbent assay, significantly raised concentrations of immunoglobulin G with affinity for the neurotransmitter dopamine were demonstrated in cerebrospinal fluid from psychotic patients. We have varied the antigen presentation in order to find a conjugate with low unspecific binding. The conjugation of dopamine to carbodiimide-activated poly-L-glutamic acid and that to activated succinimide ester of biotin are described. The use of glutaraldehyde conjugation is not recommended because of the risk of formation of tetrahydroisoquinolines. A strong correlation (r = 0.94, P < 0.001) between the results obtained with dopamine conjugated to poly-L-glutamic acid and dopamine conjugated to biotin was observed. Forty-two human cerebrospinal fluid samples from 20 psychotic patients, (12 with a bipolar disorder and 8 with schizophrenia) and 22 control patients, with various neurological diseases but no apparent psychiatric diseases were investigated. A significantly higher incidence (P < 0.001) of antibodies with affinity for dopamine were found in the group of psychotic patients compared with the neurological control group.
|
|
3. |
- Bergquist, Jonas, et al.
(författare)
-
Discovery of endogenous catecholamines in lymphocytes and evidence for catecholamine regulation of lymphocyte function via an autocrine loop.
- 1994
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424 .- 1091-6490. ; 91:26, s. 12912-6
-
Tidskriftsartikel (refereegranskat)abstract
- Evidence has been obtained that catecholamines and their metabolites are present in single lymphocytes and extracts of T- and B-cell clones by use of capillary electrophoresis with electrochemical detection. Pharmacological inhibition of tyrosine hydroxylase reduces observed catecholamine levels, suggesting catecholamine synthesis by lymphocytes. Intracellular dopamine levels are shown to be increased by extra-cellular dopamine, suggesting a cellular-uptake mechanism. Furthermore, incubation with either dopamine or L-dihydroxyphenylalanine, a precursor of dopamine, results in a dose-dependent inhibition of lymphocyte proliferation and differentiation. Together, these results suggest the presence of an autocrine loop whereby lymphocytes down-regulate their own activity.
|
|