PubMed Health⌕ Search

Biomedical subjects

Z Farkas

Publications and source records attributed to Z Farkas.

At least 19 recordsLinked to original sources
PubMed1998

Vulnerability of small GABAergic neurons to human beta-amyloid pentapeptide.

beta-Amyloid peptide (A beta), the principal component of senile plaques in Alzheimer's disease, has been found to be neurotoxic. The role of A beta in the deficits of the GABAergic system in patients with Alzheimer's disease is unclear. It has been suggested that the cytotoxic activity of A beta is localized to amino acid residues 25-35 of this peptide, which contains a total of 42 amino acid residues. We now report that the short amyloid peptide fragments corresponding to amino acids 31-35 (A beta 31-35) and 34-39 (A beta 34-39) are also toxic in vitro to the small GABAergic neuron population of basal forebrain cultures. Morphological changes were accompanied by an increased number of varicosities localized on the processes of the GABA-immunoreactive neurons and by the appearance of round cells without processes. The neurodegeneration was confirmed by means of scanning electron microscopy. Quantification of the morphological findings by image analysis demonstrated a size-related dependence of the degeneration of GABAergic neurons. The results suggest that fragments of A beta shorter than A beta 25-35 may exert cytotoxic action and demonstrate the toxicity of these A beta fragments in decreasing the number of small GABAergic neurons.

Amyloid beta-Peptides↗
PubMed1998

[Management of hydatid disease of the lung].

Cystic echinococcosis is a worldwide zoonose which is not infectious from man to man occurring seldom in our country. The diagnosis and the treatment of a case of a 4-year-old girl with large left-sided lung cyst were presented. Diagnosis was based on history, clinical findings, imaging techniques (conventional X-ray examination, ultrasonography, computer tomography), eosinophilia (7-50%) in blood smear, leucocytosis (28,000), increased sedimentation of blood (85 mm/hour), significantly elevated antibody against of Echinococcus in immunodiagnostic test (passive haemagglutination) with high sensitivity and specificity, light microscopic radiological and scanning electronmicroscopic analysis of cyst content. Continuous thoracic drainage, twice percutan drainage under CT guidance and a new technique for treatment as Puncture-Aspiration-Injection-Respiration and lavage with hypertonic sodium chlorate, long-term chemotherapy with benzimidazole-carbamates (Vermox: 20 mg/kg/day, Zentel: 30-50 mg/kg/day) were reported. The cyst was grown down into a solid mass as large as 4 cm. The body-weight of this child has grown 6 kilograms and laboratory parameters were normalized.

Albendazole↗
PubMed1996

The structural localization of galanin, and its function in modulating acetylcholine release in the olfactory bulb of adult rat.

The localization of galanin immunoreactivity was analyzed within the olfactory bulb of adult rats. Galanin-positive neurons were differentially distributed among the bulb layers. The density of stained neurons was highest in the glomerular and external plexiform layers. According to morphology, size, location and arrangement, a large proportion of galanin-immunoreactive neurons corresponds to external tufted cells and short-axon neurons in the superficial part of the external plexiform and glomerular layers. A smaller number were middle tufted cells and short-axons neurons while only a few short-axon neurons were labeled in the granule cell layer. Galanin-stained nerve fibers had different structures (thick fibers with or without varicosities, and thin fibers with or without varicosities). Among them were afferent immunoreactive nerve fibers entering the bulb through the olfactory nerve layer, but penetrating superficial layers. Correspondingly, a large number of galanin-positive axons (with or without varicosities) were observed in the olfactory nerve layer. A number of galanin-positive nerve fibers was also present in the glomerular and internal plexiform layers, while these fibers were scarce in the granule cell layer, their density was lowest in the external plexiform layer. These results suggest that galanin-positive axons present in the olfactory bulb originate from at least four different sources. From the periphery axon bundles enter the bulb together with olfactory nerve fibers from the rostral direction and with a fiber bundle from the ventral posterior surface, i.e. at the border between the olfactory tract and the main olfactory bulb along a large blood vessel. Central sources are local interneurons in the olfactory bulb and some extrabulbar brain regions. Double-labeling experiments combining acetylcholinesterase histochemistry with galanin immunocytochemistry did not show any co-localization of acetylcholinesterase and galanin in nerve cell perikarya or nerve fibers. Synthetic porcine galanin (1-29) promoted acetylcholine release in olfactory bulb tissue slices, suggesting that galanin can effectively modulate cholinergic transmission and perhaps other forms of neuronal transmission. It is concluded that galanin may be significantly involved in olfactory processing at cellular and synaptic levels.

Acetylcholine↗
PubMed1996

Cochlear implants in children.

The authors give an account of their experiences with cochlear implants on the basis of 10 years' work. Preoperative evaluation, operating methods and postoperative rehabilitation are presented. During a decade 56 operations were performed, 11 of them on children. Results with prelingually deaf children are demonstrated together with the phenomenon of hearing improvement observed on the contralateral side of the operation.

Child, Preschool↗
PubMed1993

[Hearing loss resulting from purulent meningitis in the light of adjuvant dexamethasone therapy].

Results of objective audiometry of 109 infants and children after purulent meningitis are presented. Among them 17 patients got dexamethasone as a supportive therapy. There was no statistically significant difference in hearing loss between the dexamethasone-treated and the control group. (41 vs 43% sensorineural hearing loss respectively). Authors do not contraindicate the dexamethasone therapy in purulent meningitis because of its harmlessness and useful effect to the course of the disease but further investigations are needed for avoidance of hearing loss following meningitis.

Chemotherapy, Adjuvant↗
PubMed1993

Transitory evoked otoacoustic emission (TEOAE) in a child with profound hearing loss.

The case of a 3-month-old, prematurely born boy with auditory brainstem response (ABR), verified profound hearing loss and normal transitory evoked otoacoustic emission is presented. Isolated retrocochlear deafness which did not influence TEOAE is hypothesised as a possible cause. The critical evaluation of results when using TEOAE as a screening method is suggested.

Deafness↗
PubMed1989

[Follow-up studies of patients with neonatal icterus using acoustic evoked potential audiometry].

Neonatal hyperbilirubinaemia is a common cause of sensorineural hearing loss. There is no exact method to detect the neurotoxicity of bilirubin. On the other hand the auditory pathway is known to be one of the most sensitive part of the CNS to this toxic agent. 39 one-year-old children were examined by BERA, who had had hyperbilirubinaemia in the newborn period. According to the risk factors the patients were divided into two groups but there was no significant difference in BERA changes. Two infants were found suffering serious hearing loss, who required hearing aids. Five more had some subclinical BERA changes. The authors emphasize the value of acoustic evoked potentials in evaluation infants after neonatal jaundice.

Audiometry↗
PubMed1986

Promotion by sodium bromide of functional synapse formation from foreign nerves in the superior cervical ganglion of adult rat with intact preganglionic nerve supply.

The possible effect of sodium bromide (NaBr) (a substance with known inhibitory action on synaptic transmission) was studied on synapse formation with foreign nerves, implanted into the superior cervical ganglion of adult rats. It was found that in spite of the presence of preganglionic nerve supply, both implanted nerves (n.XII and n.X, respectively) were enabled to establish functional synapses with the principal ganglion cells in NaBr-treated animals. In contrast, synapse formation was almost absent in ganglia of sodium chloride drinking (control) rats with intact preganglionic nerve supply. This effect of NaBr is considered to be analogous to that of GABA, whose promoting action on synaptogenesis in adult rat superior cervical ganglion has been previously described.

Animals↗
PubMed1985

Tracheal substitution in dogs with reinforced Gore-Tex prosthesis.

Reinforced Gore-Tex prostheses were implanted into the trachea, above the bifurcation, in 11 dogs. The first 3 animals died within a few days, due to an inappropriate surgical technique. The remaining animals were subjected to an adequate surgical procedure and all survived for a period of at least several months, except one which died of an esophago-tracheal fistula after 6 weeks. Ingrowth of respiratory epithelium into the prostheses was observed 5 to 7 weeks postoperatively.

Animals↗