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Biomedical subjects

K Warecka

Publications and source records attributed to K Warecka.

At least 19 recordsLinked to original sources
PubMed1993

Visual evoked potentials in multiple sclerosis: frequency response shows reduced alpha amplitude.

Visual evoked potentials were measured in a group of 16 multiple sclerosis (MS) patients and in a control group of 20 subjects. With respect to vertex and occipital recordings, latencies of main peaks were prolonged and response amplitudes were reduced in the MS group. As a result of frequency domain analysis we found that the amplitude reduction was not uniform in all frequency ranges: alpha (7-12 (Hz) components of EPs were markedly reduced whereas theta (4-7 Hz) responses were not altered. It is remarkable that the frequency components were altered to a different degree--this may shed some light on the physiological roles of the frequency components: As MS is frequently associated with optic neuritis, our interpretation of this frequency-dependent pattern is based on regarding MS as a model of impaired sensory input to the brain: the fact that in this situation alpha responses are markedly reduced hints at a link between alpha responses and primary sensory processing. Theta responses turned out to be unaltered--i.e., less dependent on sensory inputs--and might thus reflect associative sensory processing. This conclusion for functional roles of EP frequency components has also been drawn from previous investigations of topographic differences of EP frequency components.

Adult↗
PubMed1993

Auditory evoked potentials in multiple sclerosis: alpha responses are reduced in amplitude, but theta responses are not altered.

Auditory evoked potentials (EPs) were measured in a group of 16 multiple sclerosis (MS) patients and in a control group of 20 subjects. In vertex recordings, response amplitudes were reduced in the MS group. Remarkably, EP frequency components computed from the averaged EPs showed different degrees of amplitude reduction in different frequency channels: alpha (7-12 Hz) components were reduced whereas theta (4-7 Hz) responses were not altered. Our interpretation takes into account results of our companion paper (Başar-Eroglu et al., this issue) on similar results in the visual modality and is based on considering MS as a disease with disturbed sensory input to the brain. The fact that in this disorder alpha responses are reduced while theta responses are not altered can be interpreted as follows: alpha components might be mainly dependent on sensory input and thus reflect primary sensory processing. Theta responses, being unaltered in MS, might mainly reflect associative processing. The results are in accordance with conclusions drawn from investigations of topographic differences of evoked electric and magnetic brain responses.

Acoustic Stimulation↗
PubMed1989

[Cerebrospinal fluid parameters in Guillain-Barré polyradiculitis. Importance of barrier disorder and intrathecal immunoglobulin synthesis].

With routine CSF determination of 21 patients with GBS the BBB and the intrathecal IgG synthesis was investigated when calculated CSF/serum albumin ratio and CSF IgG-index respectively. Only in 2 of 21 patients (9.5%) an intrathecal IgG synthesis and in 14 of 21 patients (67%) a BBB damage was found. The BBB was considered as an important pathogenetic factor in GBS. A hypothesis for the development of the albumino-cytological dissociation is presented.

Adult↗
PubMed1986

Expression of alpha 2-glycoprotein by glial precursor cells: an immunocytochemical study with glial cultures.

Studies on the presence of the brain-specific alpha 2-glycoprotein in cultures of newborn rat brain cells revealed that a population of glial precursor cells expressed this antigen at an early stage of development. This cell population consisted of small, phase-dark cells that proliferated in culture and occupied the surface of a layer of flat epithelial-like astrocytes. The latter cell type did not react with the antibodies. The number of alpha 2-glycoprotein positive cells gradually decreased from a high concentration of 88% of the total overlying cells at 6 days of culture to 44% at 23 days. The morphological heterogeneity of the overlying cells was noticeable after 10 days in culture as clusters of cells with elaborate processes started to develop. alpha 2-Glycoprotein was found to be concentrated in these structures. A glioma cell line (C-6 glia) which represents a unique in vitro model for the glial progenitor cells, was also found to express this glycoprotein antigen.

Animals↗
PubMed1985

Thiamine deficiency and nervous system function disturbances.

Thiamine is important for oxidative metabolism, and B1 deficiency is thought to give rise to polyneuropathies. A group of male Wistar rats (n = 15) received a vitamin B1 deficient diet (group-a), and the pair fed control group (n = 20, group-b) received a normal diet with no vitamin deficiency. A second control group (group-c) was fed unrestrictedly with a standard diet (n = 19). All animals were examined for 25 weeks. The sensory nerve conduction velocity, the compound radicular, spinal and brain stem responses and the SEP were derived for tail and hind paw stimulation. The examination was repeated at 6-week intervals. There was no difference in nerve conduction between group-a and -b, but for both groups the conduction velocity was significantly slower than in group-c. The SEP latencies were significantly increased in group-a compared with group-b and also with group-c. The spinal and cerebral latencies were delayed in group-a. The diameters of myelinated nerve fibres were decreased in group-a compared with group-b, and in group-b compared with group-c. The results indicate that a specific polyneuropathy exists as a result of B1 deficiency, and that the sequelae of the lack of thiamine are pronounced in the CNS.

Afferent Pathways↗
PubMed1985

[Sporadic and familial-occurring multiple sclerosis. HLA typing and study of chromosomal sister chromatid exchange rate].

HLA and sister chromatid exchange (SCE) has been investigated in 17 multiple sclerosis cases and 10 controls. While the HLA showed no differences between familial cases of MS and the control group, in sporadic cases of MS the occurrence of the antigen A3 and B7 have been confirmed. The study showed a significant increase of the SCE-rate in sporadic cases of multiple sclerosis, in the contrary, in those cases with familial occurrence no changes in the SCE-rate could be found. A different etiology for sporadic and familial cases of multiple sclerosis is assumed.

Gene Frequency↗
PubMed1985

Ethanol and polyneuropathy.

Two groups of alcoholics (30 patients each)--identified by the MALT score--were examined. Clinical and laboratory investigations showed no connection between thiamine, riboflavin, or Vitamin B6 deficiency and development of the polyneuropathy. Neither the polyneuropathy nor the diminished sensory conduction velocity were related to malnutrition. The relation between the duration of alcoholism and symptoms of polyneuropathy was highly significant in one group. The neurotoxicity of ethanol was confirmed in an experiment with rats.

Adult↗
PubMed1984

The influence of vitamin B6 deficiency on somatosensory stimulus conduction in the rat.

Whilst 22 male Wistar rats were fed on a pyridoxine-deficient diet for 26 weeks, 22 controls received a normal diet. The vitamin B6 deficient animals lost no weight but they developed symptoms of rat pellagra. The sensory nerve conduction velocity, the compound radicular, spinal and brain stem responses and the SEP were derived following tail and hind paw stimulation. The examination was repeated at 6 week intervals. A disturbed central stimulus conduction was indicated by the delayed SEP and intracerebral conduction times. An impairment of neurotransmitter metabolism may be of importance in this case. Considering related data the results implicate the importance of vitamin B6 substitution in the case of CNS disturbances due to malnutrition, e.g., chronic alcoholism. The nerve conduction velocity decreases subsequently. A disturbance of myelin function is indicated in adult rats under conditions of pyridoxine deficiency.

Afferent Pathways↗
PubMed1982

Immunoelectron microscopy of alpha 2-glycoprotein. An astrocyte-specific antigen.

The cellular and fine structural localization of the soluble brain-specific acidic alpha 2-glycoprotein was investigated using the indirect immunohistochemical method. The electron microscope was used to unambiguously identify cells containing the antigen. A single type of cell, the astrocyte, was found to be labelled with specific antisera directed against alpha 2-glycoprotein. Immunoperoxidase reaction product was found in astrocyte perikarya, their processes and perivascular end feet. It was found to be apparently associated with the cytoplasmic surface of mitochondria, reticular membranes and the plasma membrane. No specific labelling of neurones, oligodendrocytes, myelin or capillary endothelial cells was observed. The data is discussed in relation to the immunological properties of alpha 2-glycoprotein already reported.

Animals↗
PubMed1982

Cellular localization of the brain specific alpha 2-glycoprotein in rat cerebellum: an immunohistological study.

The cellular localization of the brain-specific, soluble, acidic alpha 2-glycoprotein was studied in rat cerebellum by using the immunoperoxidase technique at the light-and electron-microscopy levels with monospecific immune serum directed against this glycoprotein. Only astrocytes, their processes, and their end feet (subpial or perivascular) contained heavy immunoperoxidase reaction product. Cerebellar neurones, oligodendrocytes, myelin and blood vessel endothelia did not stain. Thus it appears that alpha 2-glycoprotein is an astrocyte marker.

Animals↗
PubMed1981

[Psychotic disturbance and epilepsy as principal signs of arteriovenous angioma of the brain--described on case history basis (author's transl)].

The article describes the case of a 36-year old female patient with left temporal arteriovenous angioma suffering from psychomotoric epilepsy followed five years later by a symptomatic psychosis (paraphrenia). Basing on the case history of this patient, the phenomenological, neurophysiologico-biochemical and cerebrolocalisatory common features of psychotic disturbance and psychomotoric epilepsy are discussed; the etiologically underlying lesion of the limbic system is described. As far as clinical practice is concerned, the author raises the demand that, to say the least, orientating neurological diagnosis should be included at any early stage into differential diagnostic considerations.

Adult↗
PubMed1980

Quantitation of glial fibrillary acidic protein in human brain tumours.

The glial fibrillary acidic protein (GFA) content of 58 human brain tumours was determined by quantitative immunoelectrophoresis, using monospecific antibody against GFA. Astrocytomas, glioblastomas, oligodendrogliomas, spongioblastomas, ependymomas and medulloblastomas contained relatively high amounts of GFA, up to 85 times the concentration in parietal grey substance of normal human brain. GFA was not found in neurinomas, meningiomas, adenomas of the hypophysis, or in a single case of metastasis of adenocarcinoma. Non-glial tumours of craniopharyngioma and haemangioblastoma were infiltrated by reactive astroglia and showed considerable amounts of GFA.

Albumins↗
PubMed1979

[Nystagmus giratoire and optic nerve hypoplasia in combination with absence of the septum pellucidum (author's transl)].

Septo-optical dysplasia and Optic nerve hypoplasia often are combined with pendular nystagmus in the horizontal, vertikal or rotatory direction. Our patient, 26 year old, showing discret neurological symptoms, added the nystagmus giratoire, perhaps similar to see-saw-nystagmus: Vision was about 0.2. Nystagmus and the whole state did not change within 6 years. The nystagmus was influenced by drugs. There was found also an aplasia of the fovea zentralis. Pneumencephalography revealed in the midline a dilatated single ventricle; the septum pellucidum was absent. Te X-rays of the atlantooccipital axis showed a foramen arcuale atlantis.

Adult↗
PubMed1978

["Slow virus" infections and degenerative diseases of the central nervous system].

Slow virus infections of the central nervous system are produced by both conventional and unconventional viruses. Diseases of the central nervous system which are produced by unconventional viruses are discussed. They are kuru and the Creutzfeldt-Jacob disease. Mention is also made of the fact that these disease may be transmitted to animals which allows an infectious genesis to be assumed. The author also discusses the clinical symptomatology, the results of anatomical and pathological examinations, and the mechanism of transmission of the disease from one human being to another. Slow virus infection as a cause of other neurological diseases is also dealt with by the author in her present paper.

Animals↗
PubMed1976

Primary malignant melanoma of the gallbladder.

A primary malignant melanoma of the gallbladder in a 44-years-old man is presented. The typical pathologic findings in the now eight reported cases are analysed. The clinical course of the present case was determined by multiple metastases to the brain. The histogenesis of these rare tumors of the gallbladder is still obscure.

Adult↗
PubMed1976

[Lymphocyte sensitivity to brain specific glycoprotein in multiple sclerosis].

The lymphocytes of seven out of eight multiple sclerosis patients were sensitized to brain-specific glycoproteins that had been isolated from extracts of human white matter and purified by means of affinity chromatography utilizing specific antibodies as immunoadsorbents. The diagnosis of multiple sclerosis for the eighth patient, whose lymphocytes were not sensitized, was doubtful. A significant correlation between the severity of the disease and degree of lymphocyte sensitization was not obtained, although the most disabled patient showed the greatest sensitization.

Brain↗
PubMed1975

[Quantitative determination of glia-specific proteins in the cerebrospinal fluid of patients with MS (author's transl)].

150 cerebrospinal fluids from MS patients (85 cases) and patients with different neurological diseases (65 cases) were investigated for their glia-specific content. The demonstration was made quantitatively by means of modified passive hemagglutination tests. The brain-specific glycoprotein was examined for its possible endogenous antigen and/or antibody properties in the cerebrospinal fluid (csf). It could only be demonstrated in the CSF as antigen. CSF with a quantitatively detectable glia-specific protein content- recognizable by a significant increase in titer - were set in relation to other CSF parameters such as cell count, total protein and globulin ratio, and investigated for possible relationships to the clinical syndromes mentioned and their development. A firm correlation was found between the glia-specific protein content and the total protein content of the CSF with retained equivalence.

Antigens↗