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Biomedical subjects

B Kiss

Publications and source records attributed to B Kiss.

96 records · Page 6Linked to original sources
PubMedDate not supplied

Pharmacokinetics and pharmacodynamics of the novel H1-receptor antagonist emedastine in healthy volunteers.

OBJECTIVE: Emedastine is a novel H1-receptor antagonist with pre-clinically well-documented anti-allergic effects. Here, we set out to study the relationship between emedastine pharmacokinetics and the suppressive effect on histamine-induced wheals and flares, and to compare these effects to placebo and cetirizine. METHODS: Emedastine (4 mg q.d.), emedastine (2 mg b.i.d.), cetirizine (10 mg q.d.) and placebo were administered to healthy volunteers in a double-blind, cross-over fashion. On day 1 and day 5 (steady state) following drug administration, wheals and flares were induced by skin-prick testing with 1 mg ml(-1) or 10 mg ml(-1) histamine. RESULTS: Following the administration of 4 mg emedastine q.d., mean area under the concentration-time curve (AUC)0-24 values of 34.49 +/- 24.07 ng h ml(-1) and 47.05 +/- 36.12 ng h ml(-1) were attained on day 1 and day 5, respectively. Following the administration of emedastine (2 mg b.i.d.) mean AUC0-24 values were 29.75 +/- 19.92 ng h ml(-1) and 46.13 +/- 38.50 ng h ml(-1) on day 1 and day 5, respectively. Histamine-induced wheals and flares were significantly more effectively suppressed by emedastine and cetirizine than placebo. At pharmacokinetic steady-state levels, no significant difference could be found in the potency between cetirizine and emedastine (2 mg b.i.d.). CONCLUSION: Emedastine displays pharmacodynamic properties comparable with cetirizine and therefore qualifies as a safe and alternative compound with H1-receptor antagonist properties. Additional larger studies may be needed to substantiate potential benefits of cetirizine over emedastine after single-dose administration.

Adult↗
PubMedDate not supplied

Response of retinal blood flow to CO2-breathing in humans.

PURPOSE: To investigate the effect of systemic hypercapnia on retinal hemodynamics in humans. METHODS: We studied the effect of breathing a mixture of normal air with 5% CO2 for 13 minutes in ten healthy young male volunteers, using the Zeiss retinal vessel analyzer for continuous measurement of retinal vessel diameter and the blue-field entoptic technique to quantify retinal white blood cell flux. In eight other subjects the effect of hypercapnia was measured with the Zeiss retinal vessel analyzer and by laser Doppler velocimetry to establish retinal blood flow velocity. RESULTS: Retinal arterial and venous vessel diameters increased by a maximum of 4.2% and 3.2%, respectively. Peak effect was observed after 3 minutes of breathing the mixture of normal air with 5% CO2. During hypercapnia red blood cell velocity increased 11.7% and, accordingly, retinal blood flow increased 19.1%. White blood cell density and velocity rose significantly during hypercapnia, resulting in an increase in white blood cell flux (19.2%). CONCLUSIONS: Our data indicate that CO2 induces vasodilation in retinal arteries and retinal veins. Retinal blood flow and perimacular white blood cell flux increased to the same extent in subjects breathing a mixture of normal air with 5% CO2.

Adult↗
PubMedDate not supplied

[Clinical aspects of gastro-esophageal reflux in children].

In 20 children hospitalized in the age range from 2 months to 7 years the clinical manifestations caused by radiologically demonstrated gastro-oesophageal reflux were analysed. The main symptoms were from the digestive tract and respiratory system. In this group of children this reflux was also the cause of deficient body weight and attacks of apnoea with cyanosis.

Apnea↗
PubMedDate not supplied

Substituted ergolines: potential antipsychotics with unique profile. II. Neurochemical characterization.

A series of lumilysergol and lysergol derivatives were studied with a number of neurochemical methods. The compounds investigated showed heterogenous profiles on receptor binding tests. They were mostly active on D-2 receptors, but some alpha-1, alpha-2 and 5-HT-2 affinity could also be demonstrated. None of the drugs showed remarkable D-1 activities tested on basal and DA-stimulated adenylate cyclase (AC) enzyme in vitro. On the basis of the effects of the drugs on the mouse whole brain monoamine neurotransmitter and metabolite levels and neurotransmitter biosynthesis rates along with the receptor binding data we conclude that their actions are mainly related to the central dopaminergic system(s). The 2-halo-lumilysergole derivatives were less potent than the 2-halo-lysergoles with respect to their dopaminergic actions. We found the substitution at position 8 to be substantial to achieve agonistic or antagonistic properties, and, interestingly, 2,8-dihalo-lysergoles have proven to be DA agonists. The neurochemical findings are in good agreement with the behavioral results presented in the accompanying paper. We confirmed the behavioral data in that there are two subgroups among 2-halo-lysergoles possessing antipsychotic activity with opposite effects on DA receptors.

Adenylyl Cyclases↗
PubMedDate not supplied

Inhibition of dopamine uptake by a new psychostimulant mesocarb (Sydnocarb).

The effect of a new psychostimulant, mesocarb was determined on the in vitro uptake of biogenic amines into synaptosomes prepared from whole rat brain and various cerebral regions. Amphetamine was also examined as reference compound. On the other hand, the effects of mesocarb and amphetamine were compared in vivo on the uptake of catecholamines (CA) using an indirect method based on the inhibiton of cerebral CA depletion caused by intraventricularly injected 6-hydroxydopamine (6-OHDA). Mesocarb was found to block the synaptosomal uptake of dopamine (DA) in the striatum and whole brain more effectively than amphetamine, but inhibited the noradrenaline (NA) uptake into hypothalamus much less than amphetamine. The effect of mesocarb on 5-hydroxytryptamine (5HT) uptake was not significant, similarly as that of amphetamine. On the other hand, mesocarb inhibited the decrease of brain DA levels but had no protecting effect against NA depletion caused by 6-OHDA, in vivo. Amphetamine dose-dependently inhibited NA depletion caused by 6-OHDA but did not inhibit DA depletion. These findings indicate that mesocarb is a specific inhibitor of in vitro synaptosomal CA uptake, with an activity for striatal and whole brain DA uptake blockade much higher than that of amphetamine. The results also show that mesocarb is a selective inhibitor of DA uptake in vivo, in contrast to amphetamine, which preferentially blocks the uptake of NA in the brain. This difference may presumably be responsible for the different psychostimulatory action of the two compounds.

Amphetamine↗