[Effectiveness of the use of solcoseryl after surgery of acute hemorrhage in gastroduodenal ulcer].

The experience of solcoseryl application in 70 patients, operated on for an acute hemorrhage from gastroduodenal ulcer, was summarized. The preparation was injected intravenously in the dose of 10 ml in 5% solution of glucose every other day during 6 days and then in the dose of 5 ml intramuscularly during 4-5 days. High efficacy of solcoseryl, manifesting by more earlier elimination of pain and oedema, healing of mucosa by first intention, shortening of the treatment duration in stationary by 3-5 days, was established.

Viral Myc oncoproteins in infected fibroblasts down-modulate thrombospondin-1, a possible tumor suppressor gene.

We are interested in identifying the transcriptional targets of the Myc oncoproteins. To this end, we have fused Myc of the MC29 retrovirus with the rat glucocorticoid receptor. This chimeric protein requires dexamethasone to undergo nuclear translocation and achieve an active conformation.

v-Myc is invariably required to sustain rapid proliferation of infected cells but in stable cell lines becomes dispensable for other traits of the transformed phenotype.

The v-myc-containing retrovirus MC29 induces neoplastic transformation of avian embryo cells. To determine which traits of the transformed phenotype are directly controlled by v-Myc, we engineered a conditional MC29 mutant (GRIM) expressing v-Myc as a fusion protein with the glucocorticoid receptor and the retroviral Gag polyprotein. Only in the presence of glucocorticoids such as dexamethasone is GRIM capable of transforming embryo cells, from which six stable GRIM-lines have been derived.

[Study of the quaternary structure of glutamate carboxylase from Escherichia coli].

It was shown by electron microscopy, that the native molecule of glutamate decarboxylase is a hexamer with dihedral symmetry; the subunits are situated at the apices of an octahedron. Apoenzyme at pH 6.0 is dissociated form.

[Electron-microscopic study of the morphology of scaffold-like structures in chromosomes, formed by formamide].

Isolated human metaphase chromosomes treated with formamide and prepared for electron microscopy by protein monolayer technique have an appearance of loop-shaped chromatin fibers coming off the central scaffold-like structures, such chromosomes having approximately the same histone content as those before treatment. The morphology of scaffold-like structures at different formamide concentrations is described. It is shown that during formamide treatment the protein-protein and/or protein-DNA interactions are weakened because of disruption of hydrogen bonds.

Overproduction of v-Myc in the nucleus and its excess over Max are not required for avian fibroblast transformation.

The cellular proto-oncogene c-myc can acquire transforming potential by a number of different means, including retroviral transduction. The transduced allele generally contains point mutations relative to c-myc and is overexpressed in infected cells, usually as a v-Gag-Myc fusion protein. Upon synthesis, v-Gag-Myc enters the nucleus, forms complexes with its heterodimeric partner Max, and in this complex binds to DNA in a sequence-specific manner.

Transforming variants of the avian myc-containing retrovirus FH3 arise prior to phenotypic selection.

The avian retrovirus FH3, which encodes a Gag-Myc fusion protein, transforms chicken macrophages but not fibroblasts. However, passage of FH3 viral stock in fibroblasts leads to emergence of a virus capable of fibroblast transformation. This virus has not acquired myc mutations; instead, it carries internal gag deletions which confer the ability to transform fibroblasts.

gag as well as myc sequences contribute to the transforming phenotype of the avian retrovirus FH3.

The avian retrovirus FH3, like MC29 and CMII, encodes a Gag-Myc fusion protein. However, the FH3-encoded protein is larger, about 145 kDa, and contains almost the entire retroviral gag gene. In contrast to the other gag-myc avian retroviruses, FH3 fails to transform fibroblasts in vitro, although macrophages are transformed both in vitro and in vivo (C.

Long terminal repeats of dwarf hamster endogenous retrovirus are highly diverged and do not maintain efficient transcription.

Recently we described a new endogenous proretrovirus of dwarf hamster Phodopus sungorus (MRS-Ps). Its sequence possesses evident homology with the endonuclease domain of the mouse mammary tumor virus pol gene. Here we present nucleotide sequence data on three clones of retroviral long terminal repeats.

Distribution of mouse mammary tumor virus-related sequences does not correlate with the taxonomic position of their hosts.

Sequences (MRS) distantly related to mouse mammary tumor virus (MMTV) were found in genomes of a wide range of mammalian species using blot hybridization. The number of MRS copies and the degree of their homology with the hybridization probe varied and did not correlate with the taxonomic position of the species. Nevertheless, within a genus the set of MRS was species specific and reflected the taxonomic relation between the species.

Avian endogenous provirus (ev-3) env gene sequencing: implication for pathogenic retrovirus origination.

The avian endogenous env gene product blocks the surface receptor and, as a result, cells become immune to related exogenous retroviruses. On the other hand, the same sequence can be included in the pathogenic retrovirus genome, as shown by oligonucleotide mapping. However, since the complete env gene sequence was not known, the comparison of genomic nucleotide sequences was not possible.

[Sequences homologous to mouse mammary cancer virus are common in mammalian and avian genomes].

Sequences distantly related to mouse mammary tumor virus (MRS) were found in a wide range of mammalian genomes using blot hybridization. The number of MRS copies and the degree of their relationship with the hybridization probe varied and did not correlate with the evolutionary similarity of the species. Nevertheless, within a genus the set of MRS was species-specific and reflected the degree of relationship between species.

[Cloning and analysis of the primary structure of an element, related to the murine mammary cancer virus, from the genome of the Djungarian hamster].

11 recombinant bacteriophages from the genomic library of Djungarian hamster genome, that carry MMTV-related sequences (MRS-Ps), have been cloned with the murine mammary cancer virus (MMTV) as a hybridization probe. The sequences are repeated 50 times in the genome. MRS-Ps contain the tracts of homology with the long end repeat MMTV, the genes pol and, possibly, env, but not with the gag gene.

[Detection of viral proteins during synthesis of defective phage of Proteus mirabilis D52 using the immunocolloid gold method].

We have applied the method of immunocolloidal gold in order to label the ribonuclear proteins of prokaryotic cells on isolated bacterial chromatosomes. In the process of protein synthesis it was possible to visualize a definite protein of defective phage D52 of Proteus mirabilis.

[Endogenous proretroviruses and other autonomous retroposons: traces of viral origin or decay?].

Origin of viruses is considered to be a fundamental trend in biology. In 1970 H. Temin proposed that some of them (namely, retroviruses) could originate from preexisting transcriptional units of cell genome.

[The genome of chickens free of endogenous avian leukosis-sarcoma proviruses contains sequences distantly related to Rous sarcoma virus].

Line of Brown leghorn chickens free of RAV-O-type endogenous proviruses was obtained by selection under blot hybridization control. A set of dispersed sequences distantly related to avian leukosis virus genome was found in DNA of these chickens by means of hybridization in non-stringent conditions. Different restriction fragments were detected by gag, pol and env hybridization probes.

Methylation of endogenous proviruses of Brown Leghorn chickens.

Among the 7 endogenous proviruses we have detected in Brown Leghorn chickens none encodes the production of virions and only one, ev-3, expresses the gag gene. To study the possible role of DNA methylation in the inhibition of provirus expression, we performed blot hybridization and restriction endonuclease analysis with EcoRI and SmaI, is sensitive to methylation. Of the six endogenous proviral loci examined (ev-3, ev-6,, ev-22, ev-23, ev-24, ev-25), two loci, ev-23 and ev-24, were methylated at all SmaI restriction sites, in both the DNA from erythrocytes of adult chickens and the DNA from 10-day embryos.

Genetic structure of the endogenous proviruses and expression of the gag gene in Brown Leghorn chickens.

Seven loci of endogenous proviruses were detected in the genome of Brown Leghorn chickens. Sets of endogenous proviruses in DNA of the chicken embryos examined were identified by blot hybridization with 32P-labelled DNA of RSV and EcoRI restriction endonuclease digestion. Comparison of the results showed that only one locus (A) of endogeneous provirus was associated with a gs+ phenotype as determined by the immunoperoxidase reaction and antibodies against gag gene products of RSV.

[Immune electron microscopy in the study of biological matter].

A brief review of literature data and our investigations on the antibodies used for specific labeling in electron microscopy is presented. Considered are the problems connected with structure and function of separate components of bacterial viruses revealed by means of specific antibodies. The results of fine differentiation of antigenic components in the case of phages of the colidysentery group allowed to elucidate the functional role of the adsorption apparatus in the course of phage interaction with the bacterial cell.

[Electron microscope study of changes in the chromatin structure in different functional states of nuclei of a ciliate Bursaria truncatella and a myxomycete Physarum polycephalum].

Chromatin structural organization was studied by means of electron microscopy in the macronuclei of ciliate Bursaria truncatella at various stages of the life cycle (at different time intervals after cell division, in resting cysts and at excysting) and in the nuclei of myxomycete Physarum polycephalum during the mitotic cycle. Inactive chromatin was shown to be organized in compact clumps 100-300 nm in diameter linked with each other, their loop organization being convincingly demonstrated. Upon activation chromatin decompacts and is represented by nucleosomal fibres with a lot of replicationally and transcriptionally active regions.

[Changes in the ultrastructure of subcomponent C1q of human complement during spontaneous inactivation in diluted solutions].

Dilution of human serum or solutions of highly purified subcomponent C1q of human complement results in the drop of C1q activity. Electron microscopy of highly purified subcomponent C1q revealed that a certain part of molecules has a changed ultrastructure and C1q subunits are dissociated. As the preparations for electron microscopy have been obtained from dilute solutions, the changes in the ultrastructure and C1q inactivation should be interrelated phenomena.

[Study of the effect of different concentrations of a detergent on the chromatin structure of Physarum polycephalum during the mitotic cycle].

The influence of different concentrations of detergent Joy on the chromatin structure of Physarum polycephalum in the process of mitotic cycle was studied electronmicroscopically. The investigations showed that at Joy concentrations less than 0,01% a small part of nuclei disrupt and, as a rule, chromatin is insufficiently dispersed; at concentrations more than 0,1% the detergent may influence the chromatin structure of Physarum polycephalum. Based on the data obtained we consider that the optimal detergent concentrations that practically do not influence the chromatin structure and lead to disruption of the majority of nuclei and to the proper dispersion of chromatin is 0,1-0,01%.

[Structure of the macronucleus chromatin of the ciliate Bursaria truncatella. III. Chromatin organization in resting cysts and during excysting].

Structural organization of macronuclear chromatin of a ciliate Bursaria truncatella was studied electronmicroscopically by means of Miller's technique and negative staining of resting cysts and at excysting. In resting cysts practically all the macronuclear chromatin was shown to be organized into compact chromatin clumps 100-300 nm in size. At excysting a natural decompactization of the chromatin clumps occurred and radial loop-shaped chromatin fibres appeared around the clumps.