[Selective inhibition by chloramphenicol of protein biosynthesis in ascites tumor cells]. / Izbiratel'noe podavlenie khloramfenikolom biosinteza belkov v kletkakh astsitnykh opukholei.

Chloramphenicol in a dose of 50-200 micrograms/ml sharply inhibits the incorporation of 14C-labelled amino acids into proteins of ascites Zajdela hepatoma cells while it has no effect on protein biosynthesis in rat liver cells. In vivo chloramphenicol selectively inhibits this process in ascites tumour cells of rat Zajdela hepatoma and mouse Ehrlich carcinoma and hepatoma 22a, without inhibiting the process in various organs of tumour-bearing animals. The inhibition of labelled amino acid incorporation into nuclear and especially nuclear matrix proteins is more pronounced than into the whole tissue. A certain degree of inhibition was revealed in liver cells as well.

[Repair of mitochondrial DNA after x-ray irradiation of teleost fish loach Misgurnus fossillis eggs]. / Reparatsiia mitokhondrial'noi DNK posle rentgenovskogo oblucheniia iaitsekletok v'iuna Misgurnus fossilis.

X-ray irradiation of loach Misgurnus fossilis mature eggs induces breaks in mtDNA molecules with efficiency about 100 ev per break. The yield of damaged molecules of mtDNA reduces after fertilization or activation of irradiated eggs and subsequent incubation. Two-fold reduction in the relative amount of broken DNA molecules in mitochondria is observed after an 6-7 hour incubation. X-ray irradiation largely accelerates mtDNA synthesis in eggs. Activation of mtDNA synthesis is observed in whole irradiated eggs and in mitochondria isolated from them as well. Appearance of nascent DNA in the broken mtDNA molecules indicates the repair nature of mtDNA synthesis induced by X-irradiation.

[Effect of colostrum polypeptide on structure and lipid peroxidation in liver nuclei of rats late after gamma-irradiation]. / Vliianie molozivnogo polipeptida na strukturu i perekisnoe okislenie lipidov iader pecheni krys v otdalënnye sroki posle gamma-oblucheniia.

Rats were irradiated by 8Gr in a doze power of 2.33 R per second. A portion of animals were injected subcutaneously with a cow colostrum polypeptide (CP) in a doze of 1 mg per g of body weight before the irradiation and daily after the irradiation during 4 days. In irradiated rat liver nuclei injected with CP the lipid peroxide oxidation was restored. At 90th day after the irradiation the production of dienes and dieneketones in liver nuclei oscillated in normal limits. The structure and cytochrome-c-oxidase activity of the nuclei was restored to 60-90th day after the irradiation.

[Semi-centennial history of the nuclear matrix at the turn of the 21st century]. / Poluvekovaia istoriia iadernogo matriksa na poroge 21-go veka.

In 1974, Berezney and Coffey described what they called the nuclear matrix (NM), thus ignoring our priority, since we had isolated and characterized virtually the same skeletal structure 25 years before this discovery. The presence of NM in the live cell was doubted, because of unsuccessful attempts to recognize it in vivo. NM comprises the lamina, extracted nucleoli and an intranuclear fibrogranular network. The internal matrix is very labile, its presence and abundance depending on methods of isolation, whereas the isolated NM can be revealed as granules 25-30 nm in diameter. As the state of the interchromatin space changes with varying in vivo conditions, temperature and methods of isolation, doubts cast upon the very existence of NM are to be regarded as hardly valid, and new progress in its study may be expected in the XXI century.

[Karyosphere and nuclear envelope ultrastructure of oocytes of the common frog Rana temporaria after nuclease treatment and extraction of chromatin and alkali-soluble proteins]. / Ul'trastruktura kariosfery i iadernoi obolochki ootsitov travianoi liagushki Rana temporaria posle obrabotki nukleazami i ékstraktsii khromatina i shchelocherastvorimykh belkov.

The late oocyte karyosphere of Rana temporaria consists mainly of fibrillar nucleoli and micronucleoli, Fibrillar material containing the pore complexes (pseudomembranes) and modified synaptonemal complexes. Nuclease treatment of the karyosphere reveals regularly repeating bands in the nuclei and micronuclei, the fibrillar material associated with the nuclei being attenuated. After a subsequent treatment with DNase-1, RNase A and 1.5 M Nacl and karyosphere is disintegrated to involve remains of extracted nucleoli and fibrillar material containing pore complexes. 0.025 N NaOH extracted the bulk of the karyosphere and left only the islets if fibrillar material. The nuclear envelope proved to be far more stable to the above treatments. It retained its structure and was loosened partly only after 1.5 M NaCl or 0.025 N NaOH extraction, the pore complexes disappearing only after alkaline extraction. It is assumed that the karyosphere represents a skeletal structure (matrix) of the oocyte nucleus.

[Localization of high-molecular alkali-insoluble polypeptides of rat liver cell nuclear matrix revealed by immunological methods]. / Lokalizatsiia vysokomolekuliarnykh shchelochenerastvorimykh polipeptidov iadernogo matriksa kletok pecheni krysy, vyiavliaemaia s pomoshch'iu immunologicheskikh metodov.

By means of chicken immunization, antibodies were obtained to two high molecular weight polypeptides of an alkali-insoluble highly dispersed fraction of rat liver cell nuclear matrix. Using methods of indirect immunofluorescence these antibodies were seen fixed selectively on the periphery of the cell nuclei of rat liver, cultured human fibroblasts and of cultured human fibrosarcoma 8387 cells. The same pattern of antibody fixation, with non-specific net-like staining in the cytoplasm, was observed in the light microscope after the immunoperoxidase staining. Using the similar peroxidase staining with electron microscopy, antibody fixation was recorded with nuclear pore complexes, ribosomes, fibrous lamina and intranuclear granular structures in isolated rat liver cell nuclei and in the nuclear matrix. In mitotic cells the cytoplasm displayed a bright fluorescence, whereas the condensed chromosomes showed a fainter fluorescence. Thus, the examined high molecular weight antigens revealed no organ or species specificity. They appear to be constituents of nonmembraneous structures of the nuclear envelope, more likely of the pore complexes.

[Action of x-ray irradiation on the nuclear envelope of rat liver cells]. / Deitsvie rentgenovskogo oblucheniia na iadernuiu obolochku kletok pecheni krysy.

X-irradiation of isolated nuclear envelopes (NE) has revealed their high radiosensitivity, while irradiation of isolated intact nuclei in vitro, in the doses up to 5000 r 18--20 hours after partial hepatectomy, produced no morphological changes in NE. The damaging effect of irradiation on both nuclei and mitochondria (Mt) was revealed only with a decrease in cytochrome-c-oxidase (CO) activity in parallel with an increase in the radiation dose. One hour after the whole body irradiation of rats in the beginning of S-period, the damaging effect was recorded in both NE and Mt at the doses of 50 and 150 t, and was enhanced with the increase of irradiation dose. Morphological changes were observed mostly in the outer nuclear membrane, which lost its distinct outline and disappeared from some nuclear regions. Lethal radiation doses produced a decrease in the number of pore complexes (PC) with their evident segregation from the membranes. After irradiation in a dose of 1200 r, only the residue or "ghosts" of the PCs remained. After irradiation in doses up to 400 r, the CO-activity recovered during the first hour in Mt and during first two hours in the nuclei.

[Nuclear pore density in rat liver cells during regeneration and x-ray irradiation of the animals]. / Plotnost' iadernykh por v kletkakh pecheni krysy pri regeneratsii i rentgenovskom obluchenii zhivotnykh.

Cytoplasmic as well as nucleoplasmic surfaces of the pore complexes (PC) could be observed using freeze-etching method. The density of PCs per 1 micron2 of nuclear envelope (NE) surface in regenerating liver (9.9) is twice as that in resting liver (5.3). 1 hour after 1200 R X-ray irradiation the pore density in regenerating liver decreases 5.8-fold, consisting only of 1.7 PCs per 1 micron2 of the NE. The structure of the PC after irradiation undergoes degradation and normal PCs practically disappear; only their "ghosts" remain. Peripheral and possibly central granules of the PC appear to consist of some subunits with their diameter of 4--5 nm. The central granule forms a channel through which RNA containing material may be transported from the nucleus to the cytoplasm. The non-uniform state of the PC, observed on platinum-carbon replicas of cleaved nuclei, and the non-altered PC associate with the dense lamina of the NE, after detergent treatment of isolated nuclei indicate that the PC could be formed inside the nuclei and to be "inserted" into the NE membranes in the course of their processing.

[The effect of gamma irradiation on the structure and enzymatic activity of the nuclear membrane of the liver in pregnant rats and their embryos]. / Vliianie gamma-oblucheniia na strukturu i fermentativnuiu aktivnost' iadernoi obolochki pecheni beremennykh krys i ikh émbrionov.

Morphological and biochemical investigations of pregnant rats and embryo liver cell nuclei after in vivo irradiation in the doses of 1 and 2 Gr revealed their high radiosensitivity at all stages of gestation and embryonal development. At damaging effect of radiation, we managed to observe sharp accumulation of products of lipid peroxide oxidation and suppression of the activities of such enzymes as cytochrome-c-oxidase, NAD.N-cytochrome-c-reductase, ATPase and RNAase in liver nuclei of pregnant rats and embryos. The changes of such a kind are shown to intensify with the increasing of irradiation doses. The most profound inhibition of the activities of these enzymes in liver nuclei of embryos irradiated in utero was observed during the period of organogenesis (the 13th day of the development) and in fetal period of embryogenesis (the 17th day of the development), as well as at the 13th and 17th day of gestation. The morphological data also demonstrate the high level of cell nucleus sensitivity to the action of radiation during gestation and embryogenesis.

[Proteins of the nuclear matrix and their phosphorylation in normal and tumor cells]. / Belki iadernogo matriksa i ikh fosforilirovanie v normal'nykh i opykholevykh kletkakh.

The protein composition of the nuclear matrix of normal and tumor cells is discussed. A characteristic feature of the latter is the predominance of high molecular weight polypeptides containing mainly glyco- and phosphoproteins. Only few of them are identified. Nuclear matrix preparations from tumors differ by the presence of fibronectin and phosphotyrosine-containing proteins with a molecular mass of nearly 180 and 170 kDa as well as of high turnover of high molecular weight protein group and inhibition of their biosynthesis by chloramphenicol.

[Electrophoretic pattern of the nuclear matrix proteins from rat hepatoma-27, and the effect of various proteinase inhibitors]. / Osobennosti élektroforeticheskoi kartiny belkov iadernogo matriksa gepatomy-27 krys i deistvie na nee nekotorykh ingibitorov proteinaz.

Nuclear matrix preparations of rat hepatoma 27 differed from those of rat liver tissue in predominance of polypeptides with molecular weights of about 220, 160, 100, 45 and 31 kilodaltons. An inhibitor of serine proteinases phenylmethylsulfonyl fluoride did not alter practically the yield or protein pattern of rat liver or hepatoma 27 nuclear matrices. At the same time, thiol reagents mersalyl and 5,5-dithio-bis(2-nitro-benzoic acid) increased 2-3-fold the yield of both rat liver and hepatoma 27 nuclear matrices elevating mainly the content of polypeptides of 34-45 kilodaltons molecular weights.

[Protein kinase activity of proteins extracted by triton X-100 from isolated rat liver cell nuclei and Zajdela hepatoma]. / Proteinkinaznaia aktivnost' belkov, ékstragiruemykh tritonom X-100 iz izolirovannykh kletochnykh iader pecheni krysy i gepatomy Zaidela.

Proteins extracted with Triton X-100 from rat liver tissue and Zajdela hepatoma nuclei exhibited similar electrophoretic properties of both proteins and phosphoproteins if they were separated by means of electrofocusing. Four protein-kinase activity peaks were detected in each of these preparations. Three protein-kinases from rat liver tissue and Zajdela hepatoma were similar in their electrofocusing point and substrate specificity. However, the fourth protein-kinase, which had pI 6.1-6.3 and was activated by rabbit muscle thermostable proteins, was detected only in the preparation of rat liver tissue, while the enzyme with isoelectric point at pH 4.0 was found only in Zajdela hepatoma preparation. All the protein-kinases studied phosphorylated nuclear matrix proteins at higher rate as compared with histones.

[Protein composition and electron microscopy of the residual protein fractions of cell nuclei of certain normal organs and tumors of rats]. / Belkovyi sostav i élektronnaia mikroskopiia fraktsii ostatochnogo belka kletochnykh iader nekotorykh normal'nykh organov i opukholei krys.

A marked difference in polypeptide pattern and electron micrographs of the nuclear residual protein fraction between normal tissues /liver, kidney, spleen/ and tumors /hepatoma 27, Jensen and Yoshida sarcomas/ is revealed. While in normal tissues the polypeptides with molecular weight lower than 26 KD constituted about one half of the total residual protein, in tumors the polypeptides with molecular weight exceeding 100 KD were markedly prevailing. In electron micrographs the uniform filaments with a diameter of 4-5 nm, and periodical structure represented the bulk of the preparation from normal liver, while in the case of hepatoma 27 an amorphous granulated material was predominating.

[Effect of actinomycin D, cycloheximide, puromycin and mitomycin C on the biosynthesis of heat shock proteins in the nuclear matrix of Chinese hamster fibroblasts]. / Vliianie aktinomitsina D, tsiklogeksimida, puromitsina i mitomitsina C na novoobrazovanie belkov teplovogo shoka iadernogo matriksa fibroblastov kitaiskogo khomiachka.

The thermal shock proteins with molecular mass of 86 kD and pI 5.5 as well as of 70 kD and pI 5.2-5.4 were isolated by means of two-dimensional electrophoresis in polyacrylamide gel from nuclear matrix of chinese hamster fibroblasts after heating of the animals. Incorporation of 35S-methionine into the thermal shock proteins was completely inhibited by actinomycin D (2 micrograms/ml), if the antibiotic was added into the cell incubation medium before heating, while the incorporation of methionine was decreased only slightly when the antibiotic was added after heating of the cells. Thus, biosynthesis of mRNA of the thermal shock proteins of 86 and 70 kD in nuclear matrix was induced by means of an increase in temperature during the incubation of the cells. Biosynthesis of the thermal shock proteins in nuclear matrix was distinctly inhibited by cycloheximide (1 microgram/ml) and was not practically inhibited by puromycin (60 micrograms/ml).

[Characteristics of protein metabolism in labyrinthine tissue]. / Osobennosti belkovogo obmena v tkaniakh ushnogo labirinta.

The synthesis of total protein in organic culture of the internal ear was studied in 16-day embryo of CBA mice exposed to altering factors. The experiments showed feasibility of partial recovery for impaired metabolic processes in the labyrinth following phonophoretic introduction of mitochondrial coenzymes and inhibitors of lysosomal activity. Formation of systemic structural trace by modelling of acoustic stress and verification of protein stress agents was tested making it possible to identify an important component in dysadaption mechanism in mature CBA mice labyrinth.