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Biomedical subjects

N Nikolov

Publications and source records attributed to N Nikolov.

At least 73 records · Page 4Linked to original sources
PubMed1980

Changes in the number of EEG-paroxysms, and in the ongoing and instant frequencies of neurones from one population under the effect of a series of interoceptive stimuli.

The changes in the number of EEG-paroxysms and in the average ongoing and instant frequencies of the neuronal discharges from one population (GS or VPL) under the effect of series of mechanoreceptor stimulations of the stomach, are studied simultaneously in acute experiments on cats. The application of a large number of interoceptive stimuli is found to increase the after-effect and the cumulative effect at macro- and micro-levels. The changes in the ongoing and instant frequencies, accompanying the rise in number of the EEG-paroeysms suggest increased excitation of the neurones under the effect of the interoceptive stimulations. No qualitative changes characteristic of the pathologic epileptic neurones are observed. The result obtained give evidence that the paroxysms formed under the effect of adequate interoceptive stimuli, are a manifestation of changes in the excitability of the nervous system, which do not exceed the limits of pysiological homeostasis.

Animals↗
PubMed1980

[Antiexudative effect of naringin in experimental pulmonary edema and peritonitis].

The authors examined antiexudative activity of bioflavonoids naringin and rutin in comparative aspect in two models of acute inflammation. The experiments were carried out on 180 male white rats and 24 guinea pigs. The two flavonoids manifested marked antiexudative effect in rats with experiments peritonitis, induced by the model of U. M. Teotino et al. ED50 of naringin was 200 mg per kg after oral administration, but of rutin-260 mg per kg. In the same model ED50 of naringin was 67 mg per kg of body weight after intramuscular administration. In rats and guinea pigs with experimental lung oedema naringin, used in a dose of 200 mg per kg intraperitoneally two hours before injection of edemogenous substance (a water solution of ammonium chloride), reduced lethality with 57,4% in rats and with 37% in guinea pigs, but rutin-with 50% and 25% respectively. The examined substances were used in doses, presenting 10% of DL50. There was no statistically significant difference in respect to their antiexudative activity.

Animals↗
PubMed1977

[Pathomorphology of infectious bursitis in chicks].

Morphologic studies were carried out on birds aged 17 to 90 days, affected with Gumboro disease and occasionally died from the same disease (infectious bursitis). Established were hemorrhages in the leg and breast musculature, substantial enlargement of the bursa of Fabricius, and lesions in the kidneys. In some cases hemorrhages were also found on the serous membrane of the parenchymal organs. The histologic investigation of the involved parenchymal organs revealed necrobiotic changes (karyopycnosis, karyorrhexis) in the cellular elements, which were evaluated as a possible diagnostic symptom. Discussed is the problem of the dynamics of the morphologic changes observed in the bursa of Fabricius in view of their differential-diagnostic value.

Animals↗
PubMed1977

[Study of gastric secretion in white rats with a chronic gastric fistula on endotoxin exposure].

The author carried out a study on the stomach secretion in white rats endotoxin shock, induced by venous adminsitration of endotoxin, obtained from Escherichia coli. Stomach fistula was made on the rats in advance and the stomach juice was collected under the condition of chronic experiment. The amount of stomach juice was estimated in mililiter per hour as well as the content of free hydrochloric acid, total aidity and electrophoresis of proteolytic enzymes. There was a statistically significnat lowering of the amount of stomach juice, diminuation of free hydrochloric acid and of total acidity acidity as well as diminution of complete disappearence of its proteolytic activity in the rats after endotoxin action.

Animals↗
PubMed1975

Hemoglobin-Strumica or alpha 2 112(G19) His replaced by Arg beta 2. (With an addendum: hemoglobin-J-Paris-I, alpha 2 12(A10) Ala replaced by Asp beta 2, in the same population).

Hemoglobin-Strumica has been observed in five members of a Macedonian family. Histidyl residue in position 112 of the alpha chain of this variant is replaced by an arginyl residue. Two other variants (hemoglobin-Dakar and hemoglobin-Hopkins-2) in which this histidyl residue has been replaced by a glutaminyl and by an aspartyl residue, respectively, have been described (Rosa et al. (1968) 12 thCongr. Int. Soc. Haematol. New York, abstract, p. 73 and Charache, S. and Osterag, W. (1970) Bloodt 36, 852). The hemoglobin-Strumica heterozygotes have minimal hematological changes although this may not necessarily be associated with the hemoglobinopathy. Subjects heterozygous for hemoglobin-Dakar have a mild hemolytic anemia and hemoglobin-Hopkins-2 heterozygotes exhibit minimal hematological changes.

Adolescent↗
PubMed1975

Delta Beta-Thalassaemia in two yugoslavian families.

Members of two Yugoslavian families were found to have delta-beta-thalassaemia. Interaction of beta-thalassaemia with delta-beta-thalassaemia occured in two young children producing a clinical condition which is somewhat less severe than that of homozygous beta-thalassaemia. Results from biosynthetic analyses indicate that the degree of globin chain imbalance in double heterozygotes for beta- and delta-beta-thalassaemia is similar to that in homozygous beta-thalassaemia. Fetal haemoglobin of all heterozygotes contained G-gamma and A-gamma chains in an average ratio of about 2:3 whereas that in the two double heterozygotes had G-gamma and A-gamma chains in a ratio of 3:2.

Adolescent↗
PubMed1975

[Dipeptidase activity in the small intestine of patients with chronic nonspecific enteritis].

Dipeptidase activity in homogenate from small intestinal mucosa is determined according to the method of Josefsson (1965) in 45 patients with chronic non-specific enteritis. The majority of the enzymes are of the endopeptidase group, degrading the dipeptides of the neural aminoacids; glycyl-alanine, alanyl-l-valine, glycyl-l-isoleucine, analyl-glycine, leucyl-l-leucine, alanyl-l-leucine, alanyl-l-proline, glycyl-l-glutamic acid; only one enzyme-glycyl-l-leucine dipeptidase belongs to the enzymes of the brush-like zone of the enterocyte. The glycyl-l-alanine dipeptidase enzyme activity was established to be decreased with 49,2 per cent, glycyl-l-leucine--with 33,2 per cent, glycyl-l-valine with 19,6 per cent, glycyl-l-isoleucine--with 61 per cent, etc. The diminished enzyme activity corresponds, in the majority of the cases, to the severity of the disease and to the degree of the histological changes. It does not reach the decreased degree, found in the patients with coliac sprue. In a series of cases the enzymatic activity does not correspond to the morphological changes: "normal activity" and decreased peptidase activity were found in six cases and in two cases--"partial mucosal atrophy" and normal or elevated peptidase activity. Very likely, the pointed out enzymes, are of a substantial importance for the pathogenetic digestive and resorbtive disturbances in chronic non-specific enteritis, especially protein disturbances.

Adult↗