Search PubMed⌕ Search

Biomedical subjects

M Antal

Publications and source records attributed to M Antal.

At least 91 records · Page 5Linked to original sources
PubMed1986

Distal dendrites of frog motor neurons: a computer-aided electron microscopic study of cobalt-filled cells.

With the aid of the cobalt labelling technique, frog spinal cord motor neuron dendrites of the subpial dendritic plexus have been identified in serial electron micrographs. Computer reconstructions of various lengths (2.5-9.8 micron) of dendritic segments showed the contours of these dendrites to be highly irregular, and to present many thorn-like projections 0.4-1.8 micron long. Number, size and distribution of synaptic contacts were also determined. Almost half of the synapses occurred at the origins of the thorns and these synapses had the largest contact areas. Only 8 out of 54 synapses analysed were found on thorns and these were the smallest. For the total length of reconstructed dendrites there was, on average, one synapse per 1.2 micron, while 4.4% of the total dendritic surface was covered with synaptic contacts. The functional significance of these distal dendrites and their capacity to influence the soma membrane potential is discussed.

Animals↗
PubMed1986

Introduction of anaesthesia in caesarean section by using ketamine and fazadinium.

The evaluated data of the anaesthesia protocols of 91 caesarean sections are presented. The narcosis of caesarean sections was introduced by using 1 mg/kg ketamine. Relaxation was achieved by administration of 1 mg/kg fazadinium. To maintain anaesthesia, fentanyl or repeated doses of histamine, were used after removal of the fetus. Anaesthesia was adequate in each case, the patients were amnesic concerning the operation. They recovered well. During anaesthesia, circulation was characterized by the elevation of pulse rate and of systolic pressure. The mean value of the above parameters kept on differing significantly from the initial values throughout the anaesthesia. However, the extent of increase had not reached the difference observed by other authors. The method is considered to be safe and easy to perform since ketamine and fazadinium are anaesthetics well adaptable for use just in this sort of patient material. The analgetic, anaesthetic and amnestic effect of ketamine is fairly good. It does not generally produce circulatory depression rather acts inversely. It does not depress the vital functions of the fetus either and, at the same time, due to its long action, it provides adequate anaesthesia for prolonged removals as well. The rapidly acting fazadinium produces fast relaxation similar to that produced by succinylcholine, while its effect is not associated with the side-effects of the former agent, i.e. hyperkalaemia, fasciculations. As a result of the latter, it is a useful aid in preventing the always threatening aspiration in the anaesthesia of caesarean sections.

Adolescent↗
PubMed1986

Transferable resistance to cephalosporins, ureidopenicillins and trimethoprim.

Transferable resistance to classical Cephalosporins emerged three years ago among Enterobacteriaceae simultaneously in several hospitals and was associated with resistance to other betalactam drugs, i.e. with a transmissible TEM-like betalactamase. A systematic survey of incidence of R plasmids in Proteus sp. lead, in two district PHLs, to demonstration of transferable Azlocillin resistance. This resistance was most frequently associated with that for Carbenicillin, but also strains susceptible to CAR but resistant to AZL have been isolated. Trimethoprim resistance was in this country first described by Schŏn, but, since then, it is now frequently found transferable in polyresistant strains from hospitals, resistant also to betalactam antibiotics, Gentamicin and other drugs.

Azlocillin↗
PubMed1985

Rapid changes in growth hormone regulation and hypothalamic somatostatin after transection of anterolateral pathways to the medial-basal hypothalamus in the rat.

Plasma and pituitary GH content, in-vitro GH release and somatostatin-like immunoreactivity (SLI) in the stalk-median eminence were studied up to 7 days after making an anterolateral cut (ALC) around the medial-basal hypothalamus. Plasma GH concentration increased within 15 min to a very high level, then fell to a high level which was unchanged for several hours. The GH concentration then steadily decreased between days 2 and 7. The SLI content in the stalk-median eminence decreased to 3.5% of the control value within 3 days. The GH content of the anterior pituitary gland was 58.8% of the control value by 1 week after the operation but the in-vitro sensitivity to somatostatin of the GH cells failed to change. Pentobarbitone injection stimulated GH release in the sham-operated controls but decreased it in the rats with an ALC. These findings suggest that transection of somatostatin-containing fibres is followed by a rapid rise and a lasting high concentration of plasma GH which slowly returns towards lower levels in parallel with a marked depletion of pituitary GH content. In rats with transected somatostatin innervation of the median eminence, sodium pentobarbitone probably decreases GH secretion by depressing the secretion of GH-releasing hormone.

Animals↗
PubMed1985

Cefamandole resistance transfer in bacterial strains from two newborn units.

Transfer of Cefamandole resistance was demonstrated from strains of Citrobacter freundii as well as from individual strains of Enterobacter cloacae, Acinetobacter anitratus and Klebsiella pneumoniae isolated from patients in two newborn units. In Citrobacter freundii, Cefamandole resistance was transferred always with Cephalotin resistance as well as with a TEM-like beta lactamase (conferring resistance to Ampicillin, Carbenicillin and Azlocillin). Citrobacter freundii strains from Hospital I were completely susceptible to gentamicin, while strains of other species, resistant to Cefamandole plus Cephalotin, were resistant to Gentamicin as well, and transferred this resistance, too. In one Enterobacter cloacae strain from Hospital I, Cefamandole resistance could be separated from resistance to Cephalotin, but only in clones selected with gentamicin and not with any of the cephalosporins. Acinetobacter anitratus strain was also resistant to Cefotaxime, but did not transfer this resistance. It might be concluded that special nosocomial bacteria may carry plasmids conferring a transferable type of resistance to Cefamandole together with resistance to classical cephalosporines. Second cycle of transfers, i.e. between two variants of E. coli K-12 strains confirmed the contransferability of Cefamandole and Cephalotin resistance.

Acinetobacter↗
PubMed1985

Transferable amikacin and cefamandole resistance: Pseudomonas maltophilia and Acinetobacter strains as possible reservoirs of R plasmids.

Three strains belonging to gramnegative non-fermenting rods, i.e. a Pseudomonas maltophilia strain and two strains of Acinetobacter, were tested, as representatives of different types of nosocomial strains, for transferability of their multiple drug resistance. As all of them posed difficulties in demonstrating the transferability of their resistance by conventional methods, a three-step procedure was developed that includes a transfer to rifampicin-resistant P. aeruginosa recipients, then to susceptible P. aeruginosa intermediate strains, and, finally, from these strains to rifampicin-resistant Enterobacteriaceae. In three strains studied three genetically different types of R plasmids have been demonstrated. P. maltophilia transferred Amikacin resistance, as well as resistance to other antibiotics, to P. aeruginosa and then to Enterobacteria. In contrast, an Amikacin-resistant Acinetobacter with quite identical multiple drug resistance spectrum transferred its resistance to P. aeruginosa only, but not to Enterobacteria. Finally, another Acinetobacter strain, resistant to Gentamicin but susceptible to Amikacin transferred this resistance directly to Enterobacteria (and, separately, to P. aeruginosa, too). All three strains transferred Cefamandole resistance together with other resistances. Non-fermenting rods, thus, might be a source of transmissible resistance to reserve antibiotics as Amikacin, and advanced-type Cephalosporins.

Acinetobacter↗
PubMed1985

Ultrastructural changes of the rabbit retina following methohexital anaesthesia.

The effect of methohexital on retinal ultrastructure was studied. In spite of the negligible decrease in arterial blood pressure and the significant decrease in intraocular pressure, retinal cells showed hypoxic alterations after anaesthesia. This indicates that the protective effect of barbiturates against brain hypoxia fails to manifest in the retina. Therefore, in ophthalmological patients, application of methohexital without O2 inhalation and respiratory stimulation, is not recommended. Numerous reports have been published on the ophthalmological complications of anaesthesia. These were thought to be due to hypoxic cerebral lesions. In our previous studies almost all intravenously applied anaesthetics were found to produce fine structural changes in the retina which appeared to be independent of the general effect. As barbiturates are the most frequently used intravenous anaesthetics, the effects of these compounds have been studies. This paper is an account of retinal alterations observed after the application of methohexital, an anaesthetic of ultrashort action.

Anesthesia, Intravenous↗
PubMed1984

Effect of soya consumption on hepatic monooxygenase enzyme system and some lipid parameters in rats.

Young male rats were fed with diets containing Hungarian soya products (extruded or granulated soya preparates) as the only source of protein for four weeks. The weight gain of the animals, the cholesterol and triglyceride content of liver and the activity of the hepatic monooxygenase system were studied. 20% soya protein in the diet (either from extruded or from granulated soya products) supplemented with sulphur containing amino acids met the protein requirement of the young growing rats. In a separate experiment the protein depletion-repletion method was used to investigate the effect of Purina 500 E soya protein isolate on the above mentioned parameters. The results indicate that diets containing 20% soya protein are satisfactory for the regeneration of the protein depleted animals.

Animals↗
PubMed1984

The application of cobalt labelling to electron microscopic investigations of serial sections.

The cobalt labelling technique can be applied to ultrathin serial sections and subsequent electron microscopical investigations with the following modifications: a prolonged, up to 12 h, fixation of the tissue in aldehydes; a shortened, 15 min, postfixation in OsO4; embedding in soft resin block by using a higher proportion of plasticizer in the polimerizing mixture; mounting of 5 micrometers thick serial sections between two layers of Agar-Agar coatings; performing the intensification of the Agar section-Agar sandwich with a physical developer containing a low percentage of the reductive agent; reembedding selected thick sections for ultrathin serial sectioning and staining with uranile acetate and lead citrate. The technique unambiguously shows all labelled profiles, and preserves the fine structural details of the surrounding tissues.

Animals↗