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P Svec

Publications and source records attributed to P Svec.

At least 37 records · Page 2Linked to original sources
PubMed1996

Synthesis and local anesthetic activity--lipophilicity relationships for a homological series of phenylcarbamic acid esters. Note II.

A homological series of new esters of 2-alkoxyphenylcarbamic acid and one ester of 2,6-dimethylphenylcarbamic acid were synthesized and assayed for surface local anesthetic activity. All compounds were isolated as hydrochlorides and their structure proved by IR and for one homologue also by 1H and 13C NMR spectroscopy. A parabolic relationship was found between log activity and molecular lipophilicity (as measured by RM) and the number of carbons in the alkoxy group, thus confirming the results obtained in previous works.

Anesthetics, Local↗
PubMed1996

[The effect of piperazine analogs of aryloxyaminopropanol (IIIq and IIIb) on the occurrence of reperfusion dysrhythmias in an in vivo experiment on rats].

The present experimental study reports the beneficial effects of newly synthetized substances IIIq and IIIb in vivo. These aryloxyaminopropanol drugs have been shown to antagonize the contraction caused by calcium comparable to verapamil and flunarizine in the model of the isolated guinea pig terminal ileum. Effects of substances on both the incidence of arrhythmias during ischemia and the reperfusion period and mortality were investigated in the rat model ischemia-reperfusion injury. We can conclude that compound IIIq in a dose of 10(-6) mol/kg is effective in reducing the incidence of reperfusion-induced arrhythmias. Substance IIIb (10(-6) mol/kg) administered before ischemia was not able to suppress arrhythmias in the rat model of myocardial infarction and reperfusion.

Animals↗
PubMed1996

Lipid peroxidation during acute stress.

Lipid peroxidation (LPO) is one of the main events induced by oxidative stress. The aim of our study was to investigate the influence of 30 min cold-immobilization (model of acute stress used in this experiment) on LPO in the brain, heart, liver and stomach homogenates of the rats. LPO was determined by measuring of the contents of thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and sulfhydryl groups (SH). Experimental stress induced enhancement of TBARS formation in the liver and increased level of the CD in the heart, stomach and liver, while in the brain both parameters were found to be decreased. The levels of TBARS were not changed in the heart and in the stomach, too. The concentrations of SH-groups were decreased in the heart, brain and stomach, while in the liver the parameter was found to be not changed. The results of this study showed the increase of LPO in the heart, stomach and liver under stress conditions. It could be supposed that LPO may be involved in mechanisms of stress injury in different tissues.

Alkenes↗
PubMed1996

[Use of the Streptotest kit for identification of enterococci isolated from human clinical material].

Enterococci are part of the common microflora of man and are isolated in large numbers also from the environment. Recently their presence in clinical material is increasing and they have become an important causal agent of nosocomial infections. From human clinical material (urine, vaginal smears, wounds) a total of 164 strains of enterococci was isolated. Identification of these isolates by means of the commercial STREPTOtest kit was not very successful (71.3%). The use of several supplementary tests and evaluation by the TNW programme improved successful identification (98.8%). The dominating species in clinical material was E. faecalis (94.5%), the second most frequent isolated species was E. faecium (3%). To achieve better identification of enterococci the authors recommend to supplement the kit by further tests (acidification of arabinose, ribose and pyruvate assimilation).

Bacteriological Techniques↗
PubMed1995

Localization, interaction, and RNA binding properties of the V(D)J recombination-activating proteins RAG1 and RAG2.

The RAG1 and RAG2 gene products are indispensable for activating somatic rearrangement of antigen receptor gene segments. The two proteins form a stable complex in primary thymocytes as well as when expressed in adherent cells. In both cell types, most cells localize RAG proteins at the periphery of the nucleus. However, when overexpressed in fibroblast cells, RAG1 is found largely in the nucleolus. Nucleolar localization of RAG1 is mediated by several domains containing stretches of basic amino acids, indicating that RAG1 has affinity for RNA or ssDNA. The RAG1 interacting proteins SRP1 and Rch1 directly bind to the nuclear localization signals of RAG1, which mediate the nuclear and nucleolar translocation of the protein. RAG1 appears to have a binary structure, each half containing multiple regions that can act as NLSs, binding sites for the SRP1/Rch1 family, and RNA binding domains.

3T3 Cells↗
PubMed1995

[Antiexsudative activity of (methylsalicylate)copper-water compounds].

Using rat paw dextran edema, the antiexudative activity of the complexes of the composition Cu(RCOO)2.nH2O--R represents 2-hydroxy-Y-phenyl: Y = 3 (n = 1,5), Y = 4 (4), Y = 5 (2) or 2-hydroxy-3,6-dimethylphenyl (n = 4)--and of the corresponding uncomplexed acids was assayed. Salicylic and acetylsalicylic acids and their Cu(II) salts were used as standards of comparison. The compounds were administered i.p. in a single dose of 10 mg/kg body weight. In general, the acids were more effective than their copper(II) salts except for the pair m-cresotic acid--Cu(II) complex. Only p-cresotic acid (mean edema reduction 56%) and copper(II) m-cresotate tetrahydrate (43%) exhibited a biological activity comparable to those of salicylic acid (62%) and copper(II) salicylate tetrahydrate (70%). The observed activities of complexes are discussed in relation to their proposed structures.

Animals↗
PubMed1995

[Pharmacologic control of reperfusion dysrhythmias].

The present study aims to investigate the effects of the lipophilic antioxidant Trolox C (a vitamin E analogue) and stobadine, a scavenger of free oxygen radicals, on reperfusion dysrhythmias. Experiments were performed on isolated perfused rat hearts subjected to global stop-flow ischaemia followed by reperfusion. Trolox C (10(-4 mol.l-1) and stobadine (10(-5) mol.l-1) were infused immediately prior to ischaemia. Trolox C (10(-4) mol.l-1) and stobadine (10(-5) mol.l-1) decreased the incidence and duration of reperfusion-induced dysrhythmias (quantified by the dysrhythmia score) in comparison to the ischaemic-reperfusion damaged hearts. There was an improvement in the recovery of contraction force and left ventricular diastolic pressure in Trolox or stobadine pretreated hearts. No significant changes in coronary flow resistance were observed. The results suggest that both substances protect the myocardium during ischaemic-reperfusion injury probably by affecting the generation and activity of reactive oxygen species.

Animals↗
PubMed1995

[Free oxygen radicals in the pathogenesis of ischemic-reperfusion heart damage and possibilities of its pharmacologic control].

Due to their molecular configuration, most free radicals are highly reactive and can cause cell injury. The present review deals with the role of oxygen-free radicals (OFR) in the pathogenesis of the heart disease and reperfusion injury. Cellular protection against deleterious effects of OFR is organized at multiple levels. Regulation of the antioxidant capacity includes not only the maintenance of adequate levels of antioxidants but the localisation of antioxidant compounds and enzymes as well. Synthetic antioxidants may mimic biological defence mechanisms.

Animals↗
PubMed1994

Carbamate analogues of tocainide.

A series of the new aminoalkyl esters of chlor-, methyl- and alkoxy carbanilates was synthesized. All the compounds prepared were found to exhibit antiarrhythmic activities comparable with those of mexiletine.

Aconitine↗
PubMed1994

Partially phosphorylated phosphorylase in the rat heart after beta-receptor stimulation in vivo.

The formation of the phosphorylase ab hybrid and its further transformation into phosphorylase a has been demonstrated in the rat heart after different periods of i.v. isoproterenol administration. Phosphorylase ab hybrid was determined in the presence of AMP and/or caffeine. Only the partially phosphorylated phosphorylase was found in the control rat hearts and its activity was 30% of the total phosphorylase. The phosphorylase ab hybrid was disclosed particularly after small isoproterenol doses (0.031-0.062 microgram.kg-1) and at short time interval (15 s) after its administration. Higher isoproterenol doses (0.25-0.5 microgram.kg-1) changed the partially phosphorylated phosphorylase to phosphorylase a (58%) after a longer time interval (40 s). The phosphorylase ab hybrid was revealed even at the maximal rate of stimulation. The formation of the phosphorylase ab hybrid in the rat heart in vivo appears to be of physiological significance. Our results confirmed the earlier suggestion that the -AMP/+AMP activity ratio reflects the percentage proportion of the phosphorylated subunits of phosphorylase but not of the activated phosphorylase molecules.

Adenosine Monophosphate↗
PubMed1994

[Radioprotective effects of basic copper carboxylate complexes].

The radioprotective activity of eight selected copper (II) carboxylates--Cu (RCOO)2.nL (R = alkyl, aryl, 2-furyl and 2-thienyl; L usually represents water)--was assayed in a model of lethally gamma-irradiated (9 Gy, 0.97 Gy/min) mice. The compounds tested were applied (as solutions in saline) s.c. in three single doses of 20 mumol/kg 48.24 and 6 h before irradiation. The highest radioprotective effects were measured by survival of mice achieved after premedication of animals with copper (II) 2-thenoate monohydrate (77%), copper (II) acetylsalicylate (64%), copper (II) 2-methoxybenzoate monohydrate (62%) and copper (II) acetate monohydrate (54%). On the other hand, survival of vehicle-pretreated mice was only 10%. The observed biological properties of complexes are discussed in relation to their structures.

Animals↗
PubMed1994

[The effect of butylhydroxyanisole, an antioxidant, on oxidative phosphorylation of myocardial mitochondria in experimental ischemia].

The present paper evaluated the effect of the antioxidatively acting agent butylhydroxyanisole (BHA) on the oxidative and energetic processes in the mitochondria of the myocardium, both normal and damaged with isoprenaline. BHA was administered for 20 days in a daily dose of 10 mg.kg-1. Experimental necrosis of the myocardium was induced by a single-dose administration of a dose of 25 mg.kg-1 s.c. The results shown in Graphs 1-7 indicate that BHA in the above-mentioned concentration did not act protectively on the metabolic processes taking place in the mitochondria during experimentally induced necroses of the myocardium.

Animals↗
PubMed1993

[Development of a withdrawal syndrome in a neonate after long-term therapy of the mother with metipranolol during pregnancy].

The authors describe the withdrawal syndrome of a beta-adrenolytic in neonates manifested above all 10-16 hours after delivery by alternating bradycardia and marked tachycardia independently on the infant's activity. The withdrawal syndromes correlate with the increased heart rate of the mother after delivery. The authors draw attention to the fact that the withdrawal syndrome in the neonate may develop after delivery if the mother used during pregnancy not only addictive drugs affecting the central nervous system but also drugs affecting the cardiovascular system such as the beta-adrenolytic metipranolol.

Adult↗
PubMed1993

[Anti-ulcer effectiveness of mono- and dibasic carbamates with local anesthetic effects].

An evaluation of anti-ulcer effects of mono- and dibasic carbamate local anaesthetics was performed using two experimental models of gastric ulcers, i.e. those induced by stress, or by ligation of the pylorus. These models have been found not to be identical. In the case of stress-induced ulcers, no experimental animal died as compared to the second experimental group with a 30% mortality rate due to the more frequent occurrence of ulcer perforations. Result similarities of both models could only be found with respect to the range of damage of the mucous membrane of the stomach. A premedication with a majority of basic carbamates decreased the incidence and range of ulcer lesion. The anti-ulcer activity of monobasic carbamates was more significant when compared with dibasic compounds.

Anesthetics, Local↗