PubMed Health⌕ Search

Biomedical subjects

E V Kiseleva

Publications and source records attributed to E V Kiseleva.

At least 55 records · Page 3Linked to original sources
PubMed1976

Integration of biochemical functions of different cells of rat gastric mucosa for hydrochloric acid secretion.

The regulation patterns of gastric acid secretion in rats were investigated. Pentagastrin and histamine stimulate gastric acid secretion, but the inhibitors of DNA-dependent synthesis of RNA and of proteins prevent only the pentagastrin action. It has been found that pentagastrin induces histidine decarboxylase in gastric mucosa, ensuring local accumulation of histamine. The latter activates adenylate cyclase and results in 3',5'-AMP accumulation in gastric tissues. The administration of pentagastrin, histamine or 3',5'-AMP enhances the activity of gastric carbonic anhydrase, the enzyme which takes part in HCl formation. The data suggest that these three compounds act sequentially (pentagastrin leads to histamine leads to3',5'-AMP) and the effect of the last one could be mediated through 3',5'-AMP dependent protein kinase. The experiments in vitro demonstrated that gastric carbonic anhydrase can be separated into two isoenzymes and thephosphorylation of one of them by the 3',5'-AMP dependent protein kinase sharply increases its activity. The findings raise the possibility that histamine and 3',5'-AMP, mediating gastrin action, form together with enzymes (histidine decarboxylase, adenylate cyclase, protein kinase, carbonic anhydrase) a caascade of amplifiers. Autoradiographic studies have shown that [3H]-pentagastrin is not bound by oxyntic cells but adheres preferentially to histamine-producing alpha-like endocrine cells and to the chief cells, while 3H-histamine adheres preferentially to oxyntic and to chief cells. Electron microscopy indicates that only pentagastrin (but not histamine) initiates in alpha-like endocrine cells ultrastructural changes characteristic for induction. Pentagastrin, histamine and 3',5'-AMP administration produces in oxyntic cells ultrastructural changes typical for the secretion processes. These results lead to assumption that pentagastrin (gastrin) induces histidine decarboxylase in alpha-like endocrine cells of gastric glands. Histamine which is secreted enhances adenylate cyclase activity in the neighbouring oxyntic cells where 3',5'-AMP dependent protein kinase activates carbonic anhydrase by means of phosphorylation. These different cells form, probably, a multicellular functional unit for gastric acid secretion.

Adenosine Triphosphatases↗
PubMed1975

[An electron microscopic and morphometric study of the gastric parietal cells of rats following administration of gastrin, histamine and cyclic 3',5'-adenosine monophosphate].

The ultrastructure of the gastric parietal cells was studied in rats affected by a genetic inductor of the hydrochloric acid secretion and its mediators in this process - histamine and cyclic 3', 5'-adenozinemonophosphate playing the role of the enzyme activators. All these stimulators caused similar changes in the cell structure. The square surface of the intracellular secretory tubules was shown to become 2,5 times larger, and that of the canaliculi - vesiculoid elements which seemed to be the cell membrane depot became 2,5 times less. It may be supposed that the gastric mucosa parietal cells are not the target-cells for pentagastrine (gastrine).

Animals↗
PubMedDate not supplied

[Self-similarity in variability of human heart variability at various stages of ontogenesis].

We consider the potential of applying wavelet analysis to fluctuations found in physiological systems. We focus on cardiac interbeat interval time series (RR-intervals) from a group of young adults and children and fetus heart beat rate time series (antepartum cardiotocography), because the wavelet analysis of these heart rate dynamics may provide important practical diagnostic and prognostic information not obtainable with current approaches. We show that all the signals analyzed are self-similar and propose a method for estimating this scaling feature.

Adolescent↗
PubMedDate not supplied

[Structural organization and distribution of the symbiotic bacteria Wolbachia during spermatogenesis of Drosophila simulans].

Electron microscopy and morphometric analysis have shown that the symbiotic bacteria Wolbachia occur the testis cells during spermatogenesis and are absent in mature spermatids. Bacteria did not affect the structural organization of testis cells, which have a typical morphology during morphogenesis. Bacteria were distributed along the meiotic spindle microtubules near the mitochondria. They increased in number in spermatids at the stage of elongation. Endosymbionts aggregated at the spermatid distal end and contained many vacuoles but were absent at the spermatid proximal end near the nuclei. It was shown for the first time that the diameter of spermatids in a strongly infected line was two of three times that in a noninfected line. We hypothesize that the increase in the number of endosymbionts during spermatid elongation can affect the chromatin condensation in the spermatozoon.

Animals↗
PubMedDate not supplied

[The indices of the lipid peroxidation and desaturation of the blood serum in diabetes mellitus in children].

Comparative investigation of indices of lipid peroxidation and blood lipid unsaturation was carried out in 91 pediatric inpatients (aged 7 to 15) with type I diabetes mellitus and in 10 controls of the same age. Activation of free radical lipid peroxidation was shown to occur in children with diabetes mellitus. A degree of compensation of diabetes did not influence the level of hydroxyperoxides (HP) and final decay products (FP) of lipid peroxidation. In ketoacidotic decompensation HP and FP concentrations in the patients were increased as compared to those in the controls by 284 and 255%, respectively. At the same time children who were admitted in coma, demonstrated low values of blood lipid unsaturation. Insulin therapy (irrespective a drug dose) was accompanied by a 1.8-2-fold increase (p less than 0.05) in a HP level as compared to control values. Change in the level of lipid unsaturation depended upon a daily dose of insulin. In diabetes over 1 year different types of changes in lipid peroxidation and unsaturation were detected, and individual differences in their levels required a differentiated approach to therapeutic tactics.

Adolescent↗
PubMedDate not supplied

[The drug arginine aspartate (pargin) in the therapy of hyposomal states].

Arginine aspartate (Pargine), a stimulator of endogenous STH, was given to 13 adolescents with retarded growth resulting from a relative deficiency of STH for 6 mos. Two patients discontinued treatment after 3 mos., two others are still on therapy. In 3 adolescents the rate of growth against a background of therapy was insufficient (1.3 cm over 6 mos.). Six patients demonstrated a positive effect: the rate of growth over 6 mos. was 4.13 +/- 0.39 cm, the basal level of STH increased by 6.3 +/- 2.46 ng/ml. The drug use did not accelerate skeletal differentiation in either of the patients. A conclusion is that the drug can be used to influence growth processes in patients with hyposomal conditions.

Adolescent↗
PubMedDate not supplied

[Changes in the RNA-dependent DNA-polymerase activity of retrovirus-like particles in the rat liver during postnatal ontogeny].

The RNA-dependent DNA-polymerase activity was studied in the postmicrosomal fraction and in the microsomal sediment of the liver of the newborn and adult Wistar rats. In the microsomal sediment of 4-6 day old rats the RNA-dependent DNA-polymerase activity was approximately by one order of magnitude higher than in that of 2 week old and adult rats. In the postmicrosomal fraction of 3 day old rats the RNA-dependent DNA-polymerase activity was also higher, but only by 30-35%, than in that of animals of the other age groups. Particles with density of 1.17 g/ml were found in the microsomal sediment of all studied animals. The characteristic morphology, sensitivity of the particle RNA-dependent DNA-polymerase activity to RNAse and the presence of reverse transcriptase allow for these particles to be referred to as retroviruses. A suggestion is put forward that the high intensity of reverse transcription during the early postnatal period can be due to still continuing processes of cell differentiation and enzymatic imprinting.

Animals↗
PubMedDate not supplied

[Relation of RNA-dependent DNA-polymerase from the rat liver with virus-like particles].

RNA-dependent DNA-polymerase activity was found in the 165 000 g supernatant and pellet of the postmitochondrial rat liver fraction. Further fractionation of the 165 000 g pellet in the linear sucrose gradient (20-50%) showed that RNA-dependent DNA-polymerase activity was distributed between fractions with densities 1.18-1.19 g/ml and 1.09-1.1 g/ml. In the fractions with 1.18-1.19 g/ml density the enzymic activity could be detected only after Triton X-100 treatment and disappeared after the incubation with pancreatic ribonuclease A. Triton X-100 treatment of the 165 000 g supernatant and the fractions with density 1.09-1.1 g/ml did not increase further the enzymic activity. Electron microscopy revealed in the 1.18 g/ml fraction virus-like particles resembling retroviruses of A and C type. In the light peak "non-mature" virus-like particles were found. The 165 000 g supernatant devoid of virus-like particles contained free RNA-dependent DNA-polymerase activity. The virus-like particles of both types seem to be endogenous rat retroviruses serving as a source of the particular and free reverse transcriptase in the rat liver.

Animals↗
PubMedDate not supplied

[Biochemical mechanisms of the regulation of gastric mucus secretion in the rat: the role of prostaglandin E2 and histamine].

Both prostaglandin E2 (PGE2) and histamine activated the adenylate cyclase system of rat gastric cells. Parietal acid-producing cells of the stomach were the target-cells for histamine, while PGE2 affected the mucous cells of gastric glands. The stimulating effect of PGE2 on mucus production occurred due to activation of protein synthesis. Electron microscopy of mucous cells detected alterations in structure of cells involved in biosynthesis of mucoids. Histamine appears to cause its effect on secretion of gastric mucus via the activating influence on production of hydrochloric acid.

Adenylyl Cyclases↗
PubMedDate not supplied

[Visualization of DNA segments, interacting with reactive oligonucleotide derivatives in interphase nuclei and metaphase chromosomes].

Reaction of (pdT)16 derivatives, bearing 4-(N-2-chloroethyl-N-methylamino)benzylphosphamide group on its 5' end and biotin on its 3' end with DNA in interphase nuclei and metaphase chromosomes has been investigated by fluorescence and electron microscopy. The result obtained evidence that in interphase nuclei DNA in active chromatin (nucleolus) is the most available for specific modification. In metaphase chromosomes the modified DNA regions are situated on the surface of chromosome.

Animals↗
PubMedDate not supplied

[Distribution of the total quantity of fatty acid double bonds in lipid components of the blood in children with diabetes mellitus].

Children suffering from insulin-dependent diabetes mellitus (IDDM) were examined for unsaturation, that is, total quantity of double bonds in individual fractions of blood serum lipids was assessed. Lipid fractions were isolated by thin-layer chromatography. Unsaturation was assessed by ozonation method. The research was aimed at elucidation of biochemical criteria of the degree of metabolic disorders in children with IDDM and at development of methods for quantitative assessment of such disorders. Thirty-two inpatients with IDDM aged 7 to 15 were examined over time. Control group included 10 healthy age-matched children. Twenty children were examined during compensation stage (group 1), twelve during decompensation with ketoacidosis (group 2). Total unsaturation parameters were found reliably decreased in children with IDDM both during compensation and decompensation stages vs. those in healthy controls. A relative decrease of unsaturated fatty acids in the fraction of unesterified fatty acids (p < 0.05) was characteristic of group 2, with the content of their fragments in triglyceride fraction being the maximal (p < 0.05). The pattern of total unsaturation distribution in serum lipid fractions may serve as an indicator for metabolic disorders and decompensation in IDDM.

Adolescent↗