PubMed Health⌕ Search

Biomedical subjects

L Kerényi

Publications and source records attributed to L Kerényi.

11 recordsLinked to original sources

Acetazolamide as a vasodilatory stimulus in cerebrovascular diseases and in conditions affecting the cerebral vasculature.

Pathologic processes affecting the brain vessels may damage cerebral vasodilatory capacity. Early detection of cerebral dysfunction plays an important role in the prevention of cerebrovascular diseases. In recent decades acetazolamide (AZ) has frequently been used for this purpose. In the present work the mechanism of action and the previous studies are reviewed. The authors conclude that AZ tests are useful in cerebrovascular research. Further investigations are recommended to prove how impaired reserve capacity and reactivity influence the stroke risk in patients and whether these tests may indicate therapeutic interventions.

Acetazolamide↗

[The effect of a single-dose intravenous vinpocetine on brain metabolism in patients with ischemic stroke].

The effect of a single-dose i.v. infusion of vinpocetine on the cerebral blood flow (CBF) and glucose metabolism of post-stroke patients was studied by measuring the regional and global cerebral metabolic rates of glucose (CMRglu) and the corresponding kinetic constants before and after treatment. Transcranial Doppler (TCD) and single photon emission tomography (SPECT) measurements were also performed. The cerebral glucose metabolism was significantly higher in the contralateral hemisphere than in the affected one before therapy. In the affected hemisphere the regional glucose metabolism was inhomogenous: relatively low values were measured in the stroke region, whereas it was increased in the peristroke region. Although a single-dose vinpocetine treatment did not affect significantly the regional or global metabolic rates of glucose, the glucose transport (both intracellular up-take and release) was strongly affected in the whole brain, in the contralateral hemisphere and in the peri-infarct area of the symptomatic hemisphere. A slightly increased (not significant, N. S.) cerebral blood flow could be observed in the contralateral and a decreased flow (N. S.) in the symptomatic hemisphere.

Aged↗

Cerebral effects of a single dose of intravenous vinpocetine in chronic stroke patients: a PET study.

The effects of vinpocetine (Cavinton) on the cerebral glucose metabolism of chronic stroke patients are studied with positron emission tomography. The regional and global cerebral metabolic rates of glucose (CMRglu) and the kinetic constants related to them are quantified before and after single-dose intravenous vinpocetine treatment. These measurements are completed with transcranial Doppler sonography and single photon emission computed tomography to explore the possible mechanisms underlying the resulting changes in glucose uptake and metabolism in the brain. The authors' findings indicate that a single-dose vinpocetine treatment, although it does not affect significantly the regional or global metabolic rates of glucose, improves significantly the transport of glucose (both uptake and release) through the blood-brain barrier in the whole brain, the entire contralateral hemisphere, and in the brain tissue around the infarct area of the symptomatic hemisphere. These changes are in accord with increased blood flow in the entire contralateral hemisphere as well as decreased blood flow velocity and increased peripheral vessel resistance in the entire symptomatic hemisphere.

Aged↗

Cerebrospinal fluid (CSF) investigations in migraine.

A normal cell count as well as normal CSF pressure levels were found in both classic and common migraine patients during and between attacks. Total protein content was significantly lower in the migraine patients than in the controls, but no changes were found in the CSF protein fractions. The CSF 5-hydroxyindoleacetic acid level of the migraine patients proved to be higher than in the controls, whereas the homovanillic acid concentration was within the control limits.

Adult↗

CSF transferrins characterized by the transferrin/albumin index.

Unconcentrated CSF and 200 times diluted serum samples from 192 patients were examined by agar electrophoresis; their albumin and transferrin content were determined simultaneously by radial immunodiffusion. Using the data on transferrin and albumin concentrations in serum and cerebrospinal fluid, the transferrin/albumin index was calculated in a similar way to the IgG/albumin index. Normally the transferrin/albumin index is 1.68 (n = 77; S.D. = 0.22). If the permeability of the blood-CSF barrier increases, the transferrin/albumin index gradually decreases to 1. If the tau-globulin fraction is increased on the agar pherogram, the transferrin/albumin index will be greater than 2.34 (mean + 3 S.D.).

Electrophoresis, Agar Gel↗

Determination of the minimal amount of IgG synthesized within the central nervous system in different neurological diseases.

The albumin and the IgG were determined in cerebrospinal fluid (CSF) and serum samples from 312 patients by radial immunodiffusion. The correlation between the CSF/serum ratio of IgG and the CSF/serum ratio of albumin was determined by regression analysis in three groups of patients with no signs of IgG synthesis within the central nervous system. The patients were selected on the basis of the state of the blood-CSF barrier, as indicated by the ratio of serum/CSF of albumin. Using the +2 S.D. regression borderlines, the maximal amount of IgG derived from the blood and the minimal amount of IgG synthesized within the central nervous system can be calculated in CSF samples of patients with acute infections and chronic inflammatory diseases.

Albumins↗

[EEG-restitution and brain metabolism during electroconvulsive treatment in relaxation (author's transl)].

Blood-gas (pO2, pCO2) and pH-changes of venous (v.jugularis interna) and arterial (A.femoralis) blood samples, furthermore glucose utilization and lactate-, pyruvate-production of brain were investigated during electroconvulsive treatment in relaxation of 45 psychotic patients. The blood-gas values and substrate concentrations were statistically evaluated and represented in a function of the characteristic phases of the postconvulsive EEG-activity. A correlation was found between the glucose metabolism of the brain and the postconvulsive recovery of EEG. The restitution of postconvulsive brain metabolism runs discontinuously in the first 12 minutes of postconvulsive state. In the phase of electric silence and periodic delta-waves the brain metabolism was shifted to anaerobic direction. During the treatment no anoxic anoxia or acidosis takes place during the seizure activity and restitution, the measurable metabolic changes are moderate and supposedly play no important role in the "effect" of treatment.

Blood↗