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Biomedical subjects

G A Kovalenko

Publications and source records attributed to G A Kovalenko.

At least 19 recordsLinked to original sources
PubMed2006

[Role of Mg2+-dependent alkaline endodnaase of blood serum in tumorigenesis in A/smail mice].

An enzymoassay of levels of Mg2+-dependent alkaline endoDNAase of protein spectrum of blood serum of noninbred albino mice by SDS-electrophoresis in 10% PAAG established a fairly high heterogeneity of the enzyme. The variety of alkaline endoDNAases must be due to the limited proteolysis of their high-molecular precursor by specific proteases as described in the literature. No alkaline endoDNAase activity was identified by analysis of 10-150 kDa protein spectrum in A/smail line mice without ascites hepatoma. It was detected (pH 8.3) in the 25-45 kDa range on day 10 after tumor transplantation. Considering the gravity of disease (pre-lethal stage), on day 10, it was suggested that the level be accounted for by decay of diseased cells. The lack or extremely low level of endoDNAase activity in original blood serum expressed a mechanism of enhancing sensitivity to tumor cell effects. In mice bearing ascites hepatoma, the enzyme levels (pH 8.3) were much higher on day 10. DNAase activity (pH 7.5) was not induced in response to the heterogenous DNA. Our data point to possible defects in the induction of Mg2+-dependent alkaline endoDNAases (pH 8.3) and DNAses (pH 7.5) as well as their role in raising sensitivity to transplantable ascites hepatoma.

Animals↗
PubMed2000

Time course of serum nuclease activity in mice infected with plasmodium malariae.

Time course of DNase and RNase activities in the sera of random-bred mice infected with Plasmodium malariae (chloroquine-sensitive strain H) was studied. Similarly to viral infection, infection with a protozoa eukaryotic parasite was accompanied by increased DNAse and RNAse activities, though Plasmodium malariae biologically differes from viruses.

Acute-Phase Proteins↗
PubMed1997

[Photosensitive epilepsy].

Photosensitive epilepsy (PE) is the most frequent form of reflex epilepsy. Authors picked out two PE forms based on the analysis of the 16 own observations. The first form is PE with environmental factors of the process' provocation, which is characterised by genuine character of disease, pre- and pubertal period of its beginning, considerable prevalence of males among the patients, rare generalized tonic and clonic fits and favorable prognosis. The second form of PE is significantly rarer PE form -with self-induction of the fits. It is characterized by the beginning of the disease in preschool period, even sex distribution, quite frequent evaluated organic damages of brain, nonconvulsive fits, non-efficiency of antiepileptic drugs. The mechanisms of pathogenesis and the ways of fits' prophylaxis were discussed.

Adolescent↗
PubMed1991

[Angioneurotic edema of the face and upper extremities].

A classification scheme in which the etiology, localization, course and intensity of edemas are reflected has been elaborated on the basis of examining 255 patients with neurovascular edemas of the face and upper limbs. The authors provide a list of the main diagnostic methods, which enables the mechanisms of the development of neurovascular edemas to be specified.

Angioedema↗
PubMed1986

[Results of peridural morphine analgesia in the early postoperative period].

The influence of age, concomitant atherosclerosis and pregnancy on the efficiency of postoperative peridural analgesia with morphine was studied in 2000 patients. It was found that the incidence of adequate analgesia was linearly increased with the age of the patients and the morphine dose. The influence of atherosclerosis and pregnancy manifested itself in the improvement of the analgetic and sedative effect of morphine. The data obtained are thought to be associated with changed permeability of diffuse barriers for the analgetics.

Adult↗
PubMed1985

[Peridural anesthesia with morphine and trimecaine: an analysis of 2000 cases].

Complex investigations of 2000 patients have shown that peridural anesthesia represents an adequate anesthesiologic defense of the patient from the operative stress. The potentiating effect of morphine is greater with greater doses and results in systemic elevation of sensory thresholds, suppression of the emotional component of perception of pain and a prolongation of anesthesia. A conclusion is made that in some patients operations on lower extremities and small pelvis organs should be performed under peridural anesthesia in combination with subnarcotic doses of sedative drugs.

Acetanilides↗
PubMed1984

[Effect of sleep deprivation on visual evoked potentials and brain stem auditory evoked potentials in epileptics].

The article reports on the first study of the evoked activity of the brain in epileptic patients (n = 20) following sleep deprivation. An analysis of the data obtained has revealed a tendency to the shortening of the peak latent intervals of visual evoked potentials in the range of 100-200 mu sec and the V component and the interpeak interval III-V of evoked auditory trunk potentials in patients with temporal epilepsy. The phenomenon may indicate the elimination of stabilizing control involving the specific conductive pathways and, possibly, an accelerated conduction of a specific sensor signal.

Adolescent↗
PubMed1984

[Electron microscopy study of deoxyribonuclease penetration into chick embryo fibroblasts and the effect of the enzyme on the cells].

Peroxidase labeled DNase (0.25 g/ml) penetrated into the chick fibroblast culture cells by means of pinocytosis to be localized in pinocytotic vacuoles. Within a 24 hour-incubation of the cell culture with DNase a relative volume of vacuoles in cells increased from 4.6 to 19.5 per cent, the majority of pinocytic vacuoles being filled with labeled DNase. The incubation of cells with non-labeled DNase (24 hours) did not damage DNA-containing cell structures. The data obtained permit to explain the selective effect of the enzyme on the viral DNA and the inhibition of reproduction of DNA-containing viruses by the interaction of the viral DNA and DNase inside pinocytic vacuoles which protect the cells from the enzyme damaging effect.

Animals↗
PubMedDate not supplied

[Time course of serum nuclease activity in mice infected with Plasmodium berghei].

The present paper shows that murine serum nuclease activity increases following P.berghei infection. DNA activity begins increasing just 48 hours after infection. Following 78 hours, it achieves the maximum, by exceeding the baseline level by 6 times. Then DNA activity starts decreasing and following 94 hours after infection it is just thrice higher than the baseline. Serum RNA activity shows only 30% increases 72 hours after infection and returns to the baseline following 94 hours. Microscopic monitoring indicates that only single malaria causative agents appear in the red blood cells in this period. The peak increases in nuclease activities after P.berghei infection are assumed to be associated with the induction of serum infection.

Acute-Phase Proteins↗
PubMedDate not supplied

[Dynamic of DNAse activity induction in serum of normal animals after heterogeneous DNA injection and in hereditary pathology].

Studies of reactions in animals with hereditary diseases (Sapphire minks highly sensitive to Aleutian disease virus, ADV; CBA mice with 60-70% incidence of tumors; AKR mice with 90% incidence of leukemia) showed that serum DNAse activity in these animals dropped after injection of a foreign heterogeneous DNA and remained decreased during 72 h. By contrast, serum DNAse activity considerably and persistently increased after injection of DNA in Standard minks resistant to ADV, C57BI/6J mice with 1% tumor incidence, and random-bred albino mice. Presumably the capacity of standard minks to react to a foreign heterogeneous DNA by increase of DNAse activity ensures their resistance to DNA-containing ADV, while incapacity of Sapphire minks to respond to DNA by DNAse activity induction makes them sensitive to ADV. A similar relationship between the capacity to react to DNA by changes in serum DNAse activity and capacity to inherit a disease was detected in mouse strains.

Aleutian Mink Disease↗
PubMedDate not supplied

[Immobilized yeast membranes as biocatalysts for sucrose inversion].

Yeast membranes were obtained by autolysis of various strains with relatively high invertase activity. Heterogeneous biocatalysts for sucrose inversion were made of the yeast membranes and granulated carbon-containing supports made of common natural materials: expanded clay aggregate (ECA), sapropel, and lignin. The properties of these biocatalysts were studied. It was shown that the biocatalyst activity and stability of the immobilized yeast membranes increased with reference to the initial ECA, independent of the structure of the carbon layer synthesized on the support surface. Heterogeneous biocatalysts prepared by adsorption of yeast membranes on sapropel had the greatest activity and stability, whereas lignin-based biocatalysts were relatively unstable.

Adsorption↗
PubMedDate not supplied

[Immobilized glucoamylase: A biocatalyst of dextrin hydrolysis].

Heterogeneous biocatalysts of starch conversion based on glucoamylase and carbon-containing carriers were obtained, and their biocatalytic properties in enzymatic hydrolysis of corn dextrins were studied. It was shown that the morphology of the surface carbon layer of carriers markedly affected the properties of biocatalysts. Glucoamylase that was immobilized by adsorption on the surface of carriers covered with a layer of catalytic fibrous or pyrolytic carbon had the maximum enzymatic activity and stability, whereas the biocatalysts prepared on the basis of carriers that had no carbon layer or were covered with graphite-like surface carbon had a low activity and stability.

Aluminum Oxide↗