Acetylcholine releasing effect of laser irradiation on Auerbach's plexus in guinea-pig ileum

Summary An increased acetylcholine release could be produced by ruby laser from the Auerbach plexus of the guinea-pig ileum.     

Evidence of the modulatory role of serotonin in acetylcholine release from striatal interneurons

The release of acetylcholine was studied in isolated striatal slices of the rat. The spontaneous and ouabain-stimulated release of acetylcholine was higher in those slices where serotonergic input was somehow impaired: raphe nuclei lesion orp-chlorophenylalanine pretreatment or 5,7-dihydroxytryptamine pretreatment resulted in a higher release.l-(m-chlorophenyl)-piperazine, a pure serotonin receptor stimulant andd-fenfluramine, a serotonin releaser significantly reduced the release of acetylcholine evoked by ouabain. Serotonin antagonists (cyproheptadine, mianserine and methysergide) prevented the effect of serotonin agonists. When the serotonergic neurons were destroyed either byp-chlorophenylalanine or by 5,7-dihydroxytryptamine pretreatmentd-fenfluramine had no inhibitory action; however, the effect ofl(m-chlorophenyl)-piperazine was not affected.It is suggested that there is a link between serotonergic and cholinergic neurons in the striatum: serotonin released from raphe-striatal neurons is able to inhibit the release of acetylcholine from striatal interneurons.     

Mediastinal and hilar fibrosis

A case is described of mediastinal and hilar fibrosis in a woman aged 22 years. The fibrotic mass compressed the lobar arteries as well as the veins of various lobes of both lungs. These large vessels as well as numerous smaller arteries and veins were to a large extent obstructed by organized thrombi. It seems likely that 3 years after the beginning of symptoms the fibrosing process was still active. The case provides some support for an immunopathological aetiology of this condition.     

Comments on the EszCsM (Ministry of Health, Welfare and Family) decree No. 60/2004. (VII. 6.) about the rules of admission of psychiatric patients to mental health facilities and the restraints applicable in their care

The authors compare the human right and medical aspects of the restraints which can be used in care of psychiatric patients. They outline the legislation in force and legislative objectives which were taken into consideration when codifying the ESzCsM (Ministry of Health, Welfare and Family) decree No. 60/2004. (VII. 6.) about the rules of admission of psychiatric patients to mental health facilities and the restraints applicable in care of them. The legal problems of the admission and its connection with the restraints and with the judicial review are summed up. Aspects for interpretation are given for the regulations of the decree which supposedly can prove to be most problematic in practice. Suggestions are made for the standpoints of legislative objectives which may seem necessary in the future.     

Reversal of neuromuscular effects of adenosine by specific adenosine A1-receptor antagonist in live rats

Intravenous adenosine in-vivo was shown to potentiate the effects of non-depolarizing neuromuscular blocking agents. This study aimed to determine whether adenosine A1-receptors mediated this potentiation. The authors investigated the effects of intravenous adenosine, N6-cyclopentyladenosine, specific A1-receptor agonist, and 8-cyclopentyl-1,3-dipropylxanthine, specific A1-receptor antagonist, on neuromuscular block by vecuronium, in in-vivo rat sciatic nerve-tibialis anterior preparations. In the presence of 50% steady state block by vecuronium, adenosine, and N6-cyclopentyladenosine caused similar degree of depressions of twitch tension. Twitch tension returned to its pre-injection value more rapidly when 8-cyclopentyl-1,3-dipropylxanthine was given at the maximal block than when it was allowed to recover spontaneously. It was concluded that in in-vivo adenosine potentiated the neuromuscular effects of vecuronium through adenosine A1-receptors in rats.     

Ethical regulation of biomedical research in Hungary

Hungary joined the Ovideo Treaty (a bioethical health agreement signed by EU countries in 1997), as declared by Law Nr. VI in 2002. In July 1 2002 two departmental orders were enacted: departmental order Nr. [23/2002 (V. 9.)] about the biomedical research in humans and departmental order Nr. [24/2002 (V. 9.)] about the human use and clinical trials of investigational products and the adaptation of Good Clinical Practice (GCP). Both were based on the Health Law. The departmental order on the Medical Research Council [(16/2001 (IV. 28.)] together with these two orders contains the national rules of biomedical research performed in Hungary and also the Hungarian adaptation of various, bioethical principles and directives published by EU or other internationally accepted organisations. According to these regulations from 2002 biomedical research in Hungary could be in agreement with the Oviedo Treaty. Ethical approval and supervision can be obtained from research ethical committees of three types: central, regional and local superimposed upon one another. There are three, central, ethical committees within the frames of the Medical Research Council with national responsibility: Scientific and Research Ethical Committee, Clinical Pharmacological Ethical Committee, Human Reproduction Committee. In some cases regional research ethical committees are entitled to hand out ethical approval and ethical supervision. In those research sites, where the regional research ethical committee is not existent a local committee should be organized for the local ethical control of the research investigations and experiments. This way the ethical requirements and clinical practice by the GCP can be performed in clinical research in Hungary with a special respect to the vulnerable persons possibly involved. The paper gives an overview on recent developments and major ethical principles of the Hungarian biomedical research.     

Veratridine-evoked release of dopamine from guinea pig isolated cochlea

Dopamine released from the lateral olivocochlear efferent system is thought to inhibit the toxic effect of the extreme glutamate outflow from the inner hair cells during ischemia or acoustic trauma. Using in vitro microvolume superfusion, we have studied the release of [(3)H]dopamine from the lateral olivocochlear efferent bundle of guinea pig in response to accumulation of [Na(+)](i), under condition characteristics of ischemia. Veratridine, that acts only on excitable membranes as a specific activator of voltage-sensitive sodium channels, significantly increased the electrically evoked release of [(3)H]dopamine, which was completely inhibited by tetrodotoxin. Dizocilpine (MK-801), a non-competitive NMDA-receptor antagonist, and GYKI-52466, a selective non-NMDA-receptor antagonist, had no effect on veratridine-induced [(3)H]dopamine release. Our data provide further evidence that the cochlear release of dopamine is of neural origin and possibly independent on a local effect of glutamate. The veratridine-induced transmitter release in the cochlea will be a very useful method in studying the effect of drugs on ischemic injury.     

Unexplained diarrhoea and failure to thrive in 2 siblings with unusual facies and abnormal scalp hair shafts: a new syndrome

A family is described in which 2 siblings born to healthy parents presented with abnormal facies, persistent diarrhoea, and early death. Exhaustive pathological and biochemical investigations failed to find a cause. The scalp hair of both babies had an abnormal amino-acid composition, and presented an appearance that was unique on scanning electron microscopical examination; this fact and the clinical picture probably represents a new syndrome.     

Effects of intracerebroventricular AF64A administration on cholinergic, serotoninergic and catecholaminergic circuitry in rat dorsal hippocampus

Five nmol ethylcholine mustard aziridinium ion, a potential cholinotoxin was administered bilaterally into the cerebral ventricles of male rats at coordinates A -1.5, L +/- 1.5 and V -4.0 mm. The dorsal hippocampi were processed for choline acetyltransferase, serotonin or tyrosine hydroxylase immunocytochemistry 7 days after the injection to determine the specificity of the effect of the drug. Intrinsic choline acetyltransferase positive cells were also found after treatment, while the overall staining of fibres decreased. No change was observed in staining for either serotonin or tyrosine hydroxylase. Using the electron microscope, degenerating nerve terminals, with recognizable synaptic specializations were encountered, most frequently in stratum oriens and occasionally, degenerated CA3 pyramidal cells were observed. These findings are consistent with the neurochemical data obtained in parallel experiments with the morphological study in which it was found that acetylcholine content of the hippocampus was reduced by 73.4% 7 days after ethylcholine mustard aziridinium ion treatment, while dopamine, noradrenaline and serotonin levels were unaffected. Furthermore, the morphological studies indicate that ethylcholine mustard aziridinium ion can exert selective effects on the cholinergic system of dorsal hippocampus without significantly altering its cytoarchitecture.