Differences in the isoelectric focusing patterns of serum and cerebrospinal fluid transthyretin.

Transthyretin isolated by polyacrylamide gel electrophoresis from human serum and cerebrospinal fluid, dissociated into its subunits, was subjected to isoelectric focusing in polyacrylamide gels containing 8 mole/L urea. The isoelectric focusing multi-component patterns of serum and cerebrospinal fluid transthyretin differ in a characteristic way, having only one main protein zone in common. Double diffusion immunotest and immunoblotting revealed the immunological identity of serum and cerebrospinal fluid transthyretin and of the main components separated by isoelectric focusing. The different isoelectric focusing zones can be consistently explained when they are ascribed to structurally identical transthyretin subunits associated with different ligands specifically occurring in either serum or cerebrospinal fluid. Only the protein zone located at the same pI in serum and cerebrospinal fluid transthyretin patterns may be assigned to ligand-free subunits. Thus, the typical differences in isoelectric focusing patterns may point to different carrier functions of transthyretin in serum and cerebrospinal fluid.

Serum and CSF cholinesterase activity in various kinds of dementia.

The activity of acetyl- and butyrylcholinesterase was determined in serum and CSF of controls and patients suffering from different types of dementia. A statistically significant decrease in the activities of both esterases was observed in CSF of demented patients, however, primary degenerative and vascular dementia did not differ in their CSF cholinesterase levels. Compared to age-matched controls the serum butyrylcholinesterase activity was also significantly lowered in the overall dementia group. No typical serum and CSF cholinesterase isoenzyme pattern was found for dementia or any of its subgroups. It is concluded that the cholinesterase levels reflect metabolic alterations associated with dementia as a collective group but cannot be used for differential diagnosis of subgroups.

[Function of the blood-cerebrospinal fluid barrier and selected biochemical cerebrospinal fluid components in senile dementias of various types]. / Blut-Liquor-Schrankenfunktion und ausgewählte biochemische Liquor-komponenten bei Altersdemenzen verschiedenen Typs.

Some selected CSF and serum components were determined in demental patients classified by the Hachinski test into vascular and primary-degenerative groups. As for the vascular group, the frequency distribution of the serum/CSF albumin ratios characterizing the barrier function corresponds to that of controls, in primary-degenerative cases, however, it is shifted to higher values. In vascular dementia higher CSF LAP activities pointing to actual cell damaging processes in the CNS were found. The concentrations of lactate and some trace metals in CSF and serum are not suitable for differential diagnostic purposes.

Comparative study of the proteinase inhibitor pattern in serum and cerebrospinal fluid.

After concentration the alpha 1-proteinase inhibitors (Pi) of cerebrospinal fluid (CSF) were separated by isoelectric focusing. The relative amounts of the different Pi components in the CSF were compared with those in the serum of the same donor. The Pi components were identified by crossed isoelectric focusing. Most of the serum Pi components could be detected in the CSF but their relative proportions in serum and CSF differed considerably. The typical serum Pi patterns observed for different phenotypes were not reflected in the CSF. In cases when CSF protein levels were abnormally high alterations of the CSF Pi pattern were observed, i.e. the proportions of at least some of the Pi components approached those in serum. It is concluded that CSF Pi components originate from the serum and that a highly selective blood-CSF barrier function results in a considerable alteration of the concentration pattern. It has been shown by crossed isoelectric focusing technique that at least two proteins acting as Pi in serum do not exert antiproteolytic activity in CSF. Consequently, in CSF these Pi components may have been chemically modified, resulting in an alteration of the acceptor sites but not of the isoelectric point of the inhibitor molecule.

Study of the free amino acid pattern in human cerebrospinal fluid along the cerebrospinal axis.

The concentration of the free amino acids in CSF of patients whose pneumoencephalogram was pathological (cerebral atrophy) showed a caudocranial decrease along cerebrospinal axis, while in borderline cases or if pneumoencephalogram was normal, an increase of the amino acid concentration could be observed.