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Biomedical subjects

E V Kiseleva

Publications and source records attributed to E V Kiseleva.

At least 37 records · Page 2Linked to original sources
PubMed1991

[The interaction of growth hormone secretion and gonadal function in adolescents with delayed physical development].

The studies conducted in adolescents with physical underdevelopment allowed a conclusion on reduced anabolic processes particularly growth process at the expense of both STH and sex steroids: T and E2. Studies of sex steroid and gonadotrophic hormone concentrations in blood serum revealed dysfunction of the hypothalamo-hypophyseal-gonadal system in this group of patients. Evaluation of androgen receptor level in protein cytosol fraction from the pubic skin of undersized youths with delayed sexual development demonstrated its significant reduction against the control group that may be explained by incomplete ability for androgen receptor synthesis due to relatively low T-level and its biologically active free fraction and low sensitivity of target tissues to androgens as a result of dissociation between functional activity of STH and T.

Adolescent↗
PubMed1991

[Study of unsaturated plasma lipids in children with diabetes mellitus].

The determination of unsaturation of lipids contained by the blood serum and cell plasma membranes, which depends on the total amount of double bonds (DB) in unsaturated fatty acids is a new and promising method of estimating lipid metabolism in diabetes mellitus. Unsaturation was determined by ozonization. 91 children aged 7 to 15 years were examined. The control group included 10 healthy children of the same age. The standardized values of unsaturation were delimited in the healthy children, which amounted to 260 +/- 20 conventional units. A relationship was discovered between DB and the degree of compensation together with the disease standing. Comparative analysis of blood DB and the lipid spectrum demonstrated that the high values of unsaturation correlate with elevated concentrations of free cholesterol, nonesterified fatty acids, cholesterol esters, pre-beta-LP, beta-LP and triglycerides.

Adolescent↗
PubMed1989

Secretory protein synthesis in Chironomus salivary gland cells is not coupled with protein translocation across endoplasmic reticulum membranes. Electron microscopic evidence.

Fragments of rough endoplasmic reticulum containing polysomes bound to the membranes only at the 5 end were visualized in electron microscopic spreads from Chironomus thummi salivary gland cells. The length of the nascent protein molecules in the polysomes increased from the 5 to the 3 (free) polysome end. The data obtained disagree with the generally accepted model according to which synthesis of secretory proteins is concomitant with the protein transport across the endoplasmic membrane.

Animals↗
PubMed1986

[Electron microscopic research on the extrachromosomal genetic elements of Escherichia coli].

The structural organization of extrachromosomal genetic elements were studied in a subfraction obtained after centrifugation of the lysate of E. coli spheroplasts. With this method of isolation, the tertiary structure of the extrachromosomal genetic elements was preserved. The majority of DNA macromolecules were released in the form of single and connected rosettes. Typical rosettes composed of radial loops of DNA clustered around the central dense core (the diameter is about 60 nm). The mean length of the rosette loops was 1.06 +/- 0.4 micron. Both relaxed folded and supercoiled folded forms of DNA were observed on the preparation. Sometimes the rosettes were connected with large aggregates of DNA (possibly the material of bacterial chromosomes) and had the appearance of thick fibers with numerous lateral loops. Linear, cyclic and various replicative forms of DNA have also been observed. It is assumed that rosettes of the extrachromosomal elements of E. coli reflect one of the levels of organization of prokaryotic genetic material.

DNA, Bacterial↗
PubMed1985

Reverse transcriptase of rat liver associated with the endogenous retrovirus related to the mouse intracisternal A-particles.

Reverse transcriptase activity was found in rat liver enclosed in virus-like particles. Through hybridization with DNA probes of A- and C-type retroviruses and with the help of electron microscopy the virus-like particles have been identified as endogenous retroviruses related to the mouse intracisternal A-particles. Blot hybridization revealed the provirus DNA in the rat genome. The enzyme was isolated from the virus-like particles, purified and characterized. The main properties of the enzyme resemble those of the mammalian retrovirus reverse transcriptase.

Animals↗
PubMed1985

Membrane-mediated changes in the structure of chromosomes.

In the present paper the interaction of metaphase chromosomes and chromatin with model and natural lipid membranes was studied. It was shown that chromatin and chromosomes are able to form complexes with membranes in the presence of divalent cations. In such complexes, the typical structure of chromosomes is altered. The character of this alteration in chromosomal structure was investigated with the use of electron microscopy and chemical modification with dimethylsulphate (DMS). The latter is possible because, according to the presented data, the condensation of chromatin into chromosomes is associated with a decrease in accessibility of N-3 in adenine (the protection of the minor groove of DNA) to modifications, and with an increased methylation of N-1 in adenine (the disarrangement of the secondary structure of DNA). It was shown that the interaction of chromosomes with liposomes provides various levels of unfolding up to the appearance of chromatin-like structures. The secondary DNA structure of decondensed chromosomes coincides with the secondary structure of chromosomal but not chromatin DNA, whereas the extent of shielding of the minor groove of DNA in such decondensed structures typical for chromatin DNA. It is possible to suggest that the chromosomal decondensation in telophase of mitosis is initiated by the action of a membrane component of the developing nuclear envelope.

Adenosine Triphosphate↗
PubMed1985

[Quantitative analysis of the ultrastructure of gastric mucocytes in the rat after prostaglandin treatment].

Effect of prostaglandin E2 (PGE2) on mucus secretion by mucocytes of the fundal part of the rat stomach has been studied electron microscopically, morphometrically and biochemically. PGE2 is found to stimulate synthesis of glycoproteins and their secretion by the mucocytes that results in increasing the relative volume of Golgi complex and in decreasing that of secretory granules. Actinomycin does not affect and cycloheximide blocks the stimulating activity of prostaglandin. This demonstrates that prostaglandin produces its action at the posttranscriptional (translational) level controlling mucus secretion of mucocytes. Owing to the results of the investigation and of those previously obtained on incorporation of 3H-pentagastrin and 3H-histamine into the cells of the mucous tunic, at least two mechanisms are supposed to control the gastric mucus secretion.

Animals↗
PubMed1985

[New method of encapsulating isolated nuclei into a lipid membrane].

A new method of the coating of isolated cell nuclei with additional phosphatidylcholine membranes is described. The additional membrane was visualized under the electron microscope using ferritin as a label. The coating diminished leakage of the content of the nuclei and restricted permeability of the nuclei for exterior macromolecules.

Animals↗
PubMed1984

[Electron microscopic analysis of the structure of metaphase chromosomes after liposome treatment].

The fine structure of the methaphase chromosomes from the Chinese hamster cell culture was studied after the incubation with lyposomes isolated from hen egg yolk phosphatidilcholine, or from the total rat liver phospholipid. It has been found that during incubation lyposomes surround chromosomes, form a multifold covering considerably decondensing the chromosome matrix. The data obtained indicate that the analogues of cell membrane - lyposomes - may be involved in the regulation of the structural organization of metaphase chromosomes.

Animals↗