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Biomedical subjects

J Meszaros

Publications and source records attributed to J Meszaros.

14 recordsLinked to original sources
PubMed1986

[Wound healing of the corneal posterior surface in animal experiments].

Autoradiographic studies using tritiated thymidine as a precursor of DNA synthesis show that the process of wound healing of the corneal endothelium in both rhesus monkeys and rabbits following scarification and cryocoagulation takes place for the most part by means of cell proliferation. After injection of tritiated thymidine into the anterior chamber immediately prior to sacrifice, autoradiographically labeled flat mounts and cross-section preparations of the corneas of 7 rhesus monkeys and 14 rabbits were examined at lesion ages ranging from 4 hours to 10 days. In the monkeys scarcely 10% of the endothelial cells in the areas of the corneal lesions or at their borders were in the S-phase in the autoradiographically labeled flat mounts 24 hours to 3 days after injury, whereas up to 39% of those in the rabbits were seen to be so after 18 hours. In the monkeys one could discern mitoses between the 2nd and 5th days, and amitoses (binuclear cells) were found in 1-day and 3-day animals. In rabbits numerous mitoses could be discerned between the 1st and 5st days, but no multinuclear cells were seen. Healing of the corneal endothelium in the monkeys occurred some-what later and was less pronounced than in the rabbits.

Animals↗
PubMed1978

[Mobility measurements and histological studies on endosseous titanium implants under masticatory stress in the mandibles of adult macacas].

Linkow blades were implanted into 5 adult monkeys. Measurements of mobility showed that two weeks after implantation the implant mobility was below the mobility of the control teeth. Fixed bridgework was inserted and after 8-14 months the mobility of implant and control teeth were alike. Inspite of this favourable result, the mobility of the implants, after removal of the bridgework, was higher than that of the controls and of normal values. The histological picture explains this, since all implants showed a sheath of connective tissue which was 5-10 times the dimension of the normal desmodontal space. Inflammatory processes and epithelial growth into depth were observed inspite of the absence of clinical symptoms. There was bony growth through the windows of the implants, but only on two implants could bone sheathing be observed. The conclusion is that Linkow implants should not be used alone for the anchoring of bridgework but only as link supports between long bridge spans or as distal extension of shortened tooth arches. Also, it can be used for the retention of a Dolder bar in mucosa supported dentures.

Animals↗
PubMed1977

Central anticholinergic effects of N-ethyl-2-pyrrolidylmethyl-cyclopentylphenyl glycollate.

The following effects of N-ethyl-2-pyrrolidyl-methyl-cyclopentylphenyl glycollate (PMCG) have been studied: effects on aggressive behaviour in mice and on general behaviour in rats, protective effects against central action of arecoline and nicotine in mice, thermo-regulatory effects in mice, protective action in poisonings with fluostigmine in mice and rats, and effects on bioelectrical activity of the brain in cats. It was stated that PMCG possesses a strong central anticholinergic activity blocking predominantly central muscarinic receptors; PMCG had also strong protective effects in anticholinesterase intoxications. It is suggested that this drug could have antiemotional and antiparkinsonian properties.

Aggression↗
PubMedDate not supplied

Permanent bile duct cannulation in the monkey. A model for studying intestinal absorption.

Our aim has been to obtain an experimental model where the test animal is subjected to the least amount of stress and restraint, and can serve for the repeated sampling of biliary excretion over a prolonged period of time. By using a special end-piece at the outer terminals of the two cannulas the monkeys could be given full freedom after experimentation. During the course of the study it was found that insertion of the cannula into the common bile duct led to the development of collateral pathways for passage of bile around the point of insertion. This adaption reaction for the restoration of a normal bile channel would seem to be characteristic of Rhesus monkeys, for we did not encounter it in similar experiments on dogs and minipigs. The experimental model described is intended to serve for the determination of intestinal absorption of compounds that are mainly excreted via the bile. Results with radioactive ergotamine are presented.

Animals↗
PubMedDate not supplied

[Propionibacterium acnes in the etiology of endocarditis].

Propionibacterium acnes is the gram positive anaerobic bacteria belongs to the normal skin and oral microbial flora. The participation of this microorganism in the infective endocarditis is still controversial. The aim of the study was to perform the diagnostic and therapeutic difficulties in 5 patients with infective endocarditis caused by Propionibacterium acnes. In 3 out of 5 patients the infective endocarditis developed after prosthesis valve replacement, in 2 others on the native valves. The inserted prostheses were mechanical ones, propionibacterium acnes was identified as causative organisms in all of the causes (two positive blood and/or valve culture). The bacterial strains were sensitive to the antibiotics as: penicillins, cephalosporins, clindamycin, and vancomycin, however cephalosporins used at the beginning of the treatment in 3 patients and clindamycin in 1 patient had limited clinical efficacy. Later treatment with timentin, augmentin and tienamycin was successful in 3 patients; one patient was cured with vancomycin. One patient died because of septic, embolic complication in early stage of illness. We conclude the effectiveness of penicillins in combination with clavulanic acid and tienamycin in therapy of infective endocarditis due to Propionibacterium acnes. The treatment should be lasted during 4-6 weeks.

Adult↗
PubMedDate not supplied

[Imipenem in the treatment of patients with severe surgical infection].

The clinical efficacy and safety of intravenously administered imipenem/cilastatin in the treatment of 45 patients with severe bacterial septicemia due to intra-abdominal abscesses, respiratory and urinary tract as well as skin, soft tissue and bone infections was studied in the prospective and open trial. The in vitro antimicrobial activity of imipenem has been assessed on the basis of 909 bacterial strains isolated from patients treated and non-treated with imipenem/cilastatin. Among them were 526 Gram-negative, 370 Gram-positive aerobic bacteria and 13 Gram-negative anaerobic bacteria (Bacteroides sp.). Pathogen susceptibility to imipenem was determined with a disc-diffusion technique using Merck, Sharp Dohme sensitive discs containing 10 mcg of imipenem. Highly sensitive to imipenem were 96.8% of Gram-negative 82.7% of Gram-positive aerobic bacteria and 100% of Bacteroides sp. All patients, in whom evident foci of infection e.g. intra-abdominal abscesses were discovered, were operated on. The dosage of imipenem/cilastatin ranged from 1.5 to 2.0 g/24 h. Clinical cure and bacteriological elimination was achieved in 39 (86.7%) of patients while 6 (13.3%) showed marked clinical improvement. Before and during therapy, aerobic and anaerobic cultures were taken from accessible sites. All specimens were worked up using conventional bacteriological techniques. Before during and after therapy, samples for hematology, biochemistry and urinanalysis were obtained. Adverse clinical effects were noted in 2 (4.4%) patients. One had nausea and vomiting which were probably related to rapid infusion and disappeared after increasing the administration time, and one had transient diarrhea. In conclusion, imipenem/cilastatin was a well tolerated and effective drug in the treatment of life-threatening surgical infections.

Adolescent↗
PubMedDate not supplied

Lesion of locus coeruleus: the effect on pethidine and pentazocine analgesia.

Analgesic activity of pethidine and pentazocine in the locus coeruleus lesioned rats was evaluated. Bilateral destruction of locus coeruleus resulted in a marked decrease in noradrenaline content in forebrain but did not change significantly the levels of dopamine. Lesioned animals showed a marked decrease of predrug pain threshold. However, pethidine increased more effectively the nociceptive threshold in lesioned rats. The effect observed after pentazocine was generally similar but the maximal increase in pain threshold in lesioned animals did not differ significantly from the values observed in sham lesioned rats. The action of both analgesics was markedly prolonged after the lesion of the locus coeruleus.

Analgesics↗