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Biomedical subjects

I Király

Publications and source records attributed to I Király.

16 recordsLinked to original sources
PubMed2000

[Percutaneous gallbladder puncture and drainage].

The authors present their experience and results of 88 percutaneous cholecystostomies performed on 72 high-risk patients suffering from acute cholecystitis during the last 11 years. The local and general treatment resulted in total recovery in 24 cases, surgery could be abandoned. In 37 patients the improvement of their general condition made elective cholecystectomy possible. In 4 cases urgent operation became necessary because of reappearance of acute symptoms after a temporary relief. 7 patients died during the acute phase. In 51 patients out of all cases treated with long-term drainage, the gallbladder was washed out with cooled saline 2-3 times daily.

Acute Disease↗
PubMed2000

New non competitive AMPA antagonists.

New halogen atom substituted 2,3-benzodiazepine derivatives condensed with an azole ring on the seven membered part of the ring system of type 3 and 4 as well as 5 and 6 were synthesized. It was found that chloro-, dichloro- and bromo-substitutions in the benzene ring and additionally imidazole ring condensation on the diazepine ring can successfully substitute the methylenedioxy group in the well known molecules GYKI 52466 (1) and GYKI 53773 (2) and the 3-acetyl-4-methyl structural feature in 2, respectively, preserving the highly active AMPA antagonist characteristic of the original molecules. From the most active compounds (3b,i) 3b (GYKI 47261) was chosen for detailed investigations. 3b revealed an excellent, broad spectrum anticonvulsant activity against seizures evoked by electroshock and different chemoconvulsive agents indicating a possible antiepileptic efficacy. 3b was found to be highly active in a transient model of focal ischemia predictive of a therapeutic value in human stroke. 3b also reversed the dopamine depleting effect of MPTP and antagonized the oxotremorine induced tremor in mice indicating a potential antiparkinson activity.

Animals↗
PubMed1995

Separation of dihydroxybenzoates, indicators of in-vivo hydroxyl free radical formation, in the presence of transmitter amines and some metabolites in rodent brain, using high-performance liquid chromatography with electrochemical detection.

Based on a detailed study of retention parameters, reversed-phase ion-pair chromatographic methods were developed for the simultaneous determination of dihydroxybenzoates, indicators of in-vivo hydroxyl free radical formation, transmitter amines and some metabolites to facilitate neurochemical investigations in rodent brain. Coupling of the separation methods with electrochemical detection and the use of short-chain perfluorinated carboxylic acids for ion-pairing, allowed for a fast and sensitive determination of salicylate-derived 2,3- and 2,5-dihydroxybenzoic acids and the major electroactive, hydroxylated aromatic compounds present in brain samples. Detection limits for the dihydroxybenzoates (signal-to-noise ratio = 2) were 18-22 fmol injected on the column. Basal levels of 2,3-dihydroxybenzoate and 2,5-dihydroxybenzoate in the the striatum of mice treated with salicylate were 72 +/- 13 and 94 +/- 11 ng/g wet tissue, respectively.

Animals↗
PubMed1989

Antipsychotic substances and dopamine in the rat brain; behavioral studies reveal distinct dopamine receptor systems.

Graded doses of apomorphine were injected into terminal areas of the nigrostriatal, mesolimbic and mesocortical dopamine (DA) systems of the rat brain. Injection of high doses of apomorphine into the nucleus caudatus elicited stereotyped sniffing, but did not affect the motility of the rat. Low and high doses of apomorphine injected into the nucleus accumbens decreased and increased motility, respectively, without changing sniffing behavior. Injection of both low and high doses of apomorphine into the pyriform cortex increased sniffing behavior, but did not affect motility. All these apomorphine-induced behavioral responses were antagonized by local pretreatment with the typical neuroleptic, haloperidol, and the atypical neuroleptic, sulpiride, albeit with different potencies as revealed from the calculated ED50 values (ranging from 0.18-20,462 fmol). Local pretreatment with the antipsychotic peptide, des-enkephalin-gamma-endorphin (DE gamma E), antagonized the behavioral changes induced by injecting low and high doses of apomorphine into the pyriform cortex and low doses into the nucleus accumbens (ED50: 0.22-20.6 fmol), but did not affect the behavioral effects elicited by injecting high doses of apomorphine into the nucleus caudatus or the nucleus accumbens. It is proposed that two distinct types of DA receptor systems are present in the rat brain. These are characterized by the slope of the dose-response curve for the substances to antagonize the apomorphine-induced behavioral effects and by the effectiveness of DE gamma E in this respect. The antipsychotic effects of these compounds may be mediated by DA systems in the nucleus accumbens or in the pyriform cortex; this last system is especially sensitive to the three antipsychotic substances and is equally affected by them (ED50 value for the antagonism of the apomorphine-induced effects: 0.18-0.71 fmol).

Animals↗
PubMed1987

Behavioral evidence for the involvement of endogenous opioids in the interaction between cholecystokinin and brain dopamine systems.

The hyperactivity induced by injection of the dopamine (DA) agonist apomorphine into the nucleus accumbens of rats was dose dependently inhibited by intra-accumbal pretreatment with cholecystokinin (CCK-8) (ED50, 0.34 ng). Local treatment with the opioid antagonist naloxone antagonized this inhibitory action of CCK-8 (ED50, 18 ng), but did not change the blocking effect of haloperidol on the apomorphine-induced hyperactivity. These data show that endogenous opioids are concerned in certain interactions between CCK-8 and DA systems.

Animals↗
PubMed1986

Behavioral interaction between endogenous opioids, CCK-8 and dopaminergic systems in the nucleus accumbens of rats.

Injection of apomorphine into the nucleus accumbens of rats elicits hypermotility, presumably by activating postsynaptically located dopamine receptor systems. This behavioral response is inhibited by local treatment with CCK-8 or gamma-endorphin. The action of both peptides is antagonized by intra-accumbal treatment with naloxone. These findings suggest that endogenous opioids are implicated in certain neuroleptic-like effects of CCK-8 and that in the nucleus accumbens a functional interaction exists between CCK-8, endogenous opioids and dopaminergic systems.

Animals↗
PubMed1984

Non-opiate beta-endorphin fragments and dopamine--VI. Behavioural analysis of the interaction between gamma-type endorphins and dopaminergic systems in the nucleus accumbens of rats.

Injection of small doses of apomorphine, bromocriptine and the new ergoline compound, GYKI-32887 into the nucleus accumbens decreased locomotor activity when rats were tested in a small open field. This effect was observed following injection of 1 pg of these substances; GYKI-32887 being more potent than bromocriptine. The hypolocomotion induced by the ergoline compound could be prevented by local pretreatment with haloperidol (30 pg), fluphenazine (30 pg), sulpiride (10 pg) or desenkephalin -gamma-endorphin (DE gamma E; 100 pg). Large doses of apomorphine and amphetamine, injected into the nucleus accumbens, increased locomotor activity. This behavioural response was antagonized by pretreatment with haloperidol (30 pg), but not with sulpiride (10 pg) or DE gamma E (100 pg or 10 ng). It is concluded that two dopaminergic receptor systems exist in the nucleus accumbens with different sensitivity to apomorphine. One of these receptor systems, which is activated by small doses of apomorphine and ergoline compounds, can be blocked by classical and atypical neuroleptics and by the neuroleptic-like peptide DE gamma E. This may be of relevance to the antipsychotic action of these substances.

Amphetamine↗
PubMed1981

Further evidence for the neuroleptic-like activity of gamma-endorphin.

gamma-Endorphin inhibits the amphetamine-induced stereotypy in rats with an approximate ED50 of 0.3 mg/kg. SC. The anti-amphetamine effect of gamma-endorphin can be antagonized to a certain extent by both the dopamine receptor stimulant 2-bromo-ergocryptine and the opiate receptor antagonist naloxone.

Animals↗
PubMed1976

Effect of thyrotropin-releasing hormone (TRH) and antidepressant agents on brain stem and hypothalamic multiple unit activity in the cat.

The EEG and MUA (multiple unit activity) of mesencephalic reticular formation (MRF), area hypothalami posterior (PH), and area hypothalami anterior (AH) were studied in chronically implanted freely moving cats. The effects of thyrotropin-releasing hormone (TRH) and some antidepressant agents were tested on neuronal activity. Desipramine and imipramine resulted in a dose-dependent decline of MUA of all structures with the most significant decrease of activity in PH. A single injection of TRH resulted in slight or moderate gross behavioral changes and vegetative excitation lasting for 30-50 min with variable MUA levels. In the course of repetitive TRH treatment on consecutive days the gross behavioral changes and the vegetative symptoms failed to develop by the 3rd or 4th day. By that time the MUA changes of PH and MRF showed similar characteristics in response to TRH administration which was observed following the injection of desipramine and imipramine. The drugs, except for TRH, induced a suppression of paradoxical sleep cycles.

Animals↗