Morphocytochemical and electron microscopic research on murine hybridoma cells producing and not producing monoclonal antibodies

Cytochemical and ultrastructural features of mouse hybridomas and also of the parental cells--myeloma P3-X63-Ag8.653 and spleen cells of the Balb/c mice immunized with cell line RPMI-1788 have been studied. Differences in cytomorphological signs and activity of acid phosphatase, acid nonspecific esterase, nonspecific-alpha-naphthyl acetate esterase were shown in hybrid cell lines secreting and not secreting monoclonal antibodies.     

Minicircular kinetoplast DNA from Trypanosomatidae

Analysis of primary structure and organization of mitochondrial (kinetoplast) DNA of flagellates occupies a prominent place in the studies of eukaryote mitochondrial genomes, owing to its unusual organization and functioning as well as to the epidemiological role of the Trypanosomatidae family. According to contemporary notions, living zooflagellates are direct descendants of the ancestral forms that gave rise to all eukaryotic kingdoms. Hence, comparative mtDNA studies of recent Trypanosomatidae open broad prospects for phylogenetic reconstructions and analysis of presumable routes of eukaryote evolution. The structure, characteristics, and functions of Trypanosomatidae minicircular kinetoplast DNA are discussed here.     

Immunological and morphological properties of fibroblasts transformed in vitro. II. The change in the susceptibility of FC3H3 cells to lymphocytes--natural killers and macrophages during their selection for malignancy

The previous report contained the information on obtaining in vitro continuous cell lines of embryonic fibroblasts of mice of 4 genotypes, including C3H. In this paper, data on the degree of lysis of some derivatives of FC3H3 cells by natural killers and macrophages are given. It was shown that normal cells were not lysed by these effectors unlike cells which overcame Hayflick's limit and got minimum malignancy in vitro. However, it was established that the in vivo selection of cells for high tumorigenicity resulted in the formation of tumor cells resistant to lymphocytes--natural killers and macrophages.     

Redox enzymes in the corneal cells after low-temperature preservation (a cytochemical study)

Activity of LDG, MDG, alpha-GFDG, NAD X H2DG and NADP X H2DG was studied in different type cells of rabbit cornea subjected to cryopreservation (-196 degrees C) in the presence of PEO-400. Fresh cornea was used for comparison. It is revealed that the enzyme activity in the represerved tissue changes: the level of cytochemical reaction increases with MDG and alpha-GFDG detection and decreases with NADP X H2DG detection. The difference in response to cooling may be attributed to unequal sensitivity of structural cell elements to cooling.     

Immunological and morphological properties of in vitro transformed fibroblasts. III. Recognition by macrophages and activated lymphocytes of mouse and rat cells of various degrees of tumorigenicity

Data are provided on the development of tumorigenicity in cells of 6 independently produced lines of mouse and rat embryonic fibroblasts during their prolonged passage in vitro. The data on the development of lysis of these cells by macrophages and activated lymphocytes during the same passage indicate that enhanced cell lysis of cells by natural effectors and, hence, cell recognition by them may be regarded as an obligatory manifestation of cell malignization.     

A karyotype study of the Vero cell line cultured long term in a monolayer by static and roller methods

A cytogenetic investigation of Vero cells, before and after adaptation to the medium containing a cattle serum, was carried out by methods of differential chromosome staining. Under these conditions, both the modal number of chromosomes (from 58 to 55) and the karyotype structure, namely the copy number of normal chromosomes and the marker composition were shown to change. The Vero cell karyotype stability was studied in the continued culture by the static (50 passages) and roll-bottle (37 passages) methods. The quantitative changes (the rising percentage of diploid cells, and the change of cell fraction involving the modal number of chromosomes) were shown to occur in spite of the chromosome composition stability, which limits the time of using Vero cells as a substrate for preparation of vaccines.     

Suppression of translation in vitro of the mRNA of the M1 protein of influenza virus using antisense oligonucleotides]

Effect of antisense oligonucleotides on the in vitro translation of the influenza virus M1 protein mRNA was investigated. The most efficient arrest of mRNA translation was achieved by simultaneous action of two or three oligonucleotides (14-16-mers) complementary to the juxtaposed sequences in the 5'-terminus of the molecule around and upstream of the initiation codon.     

Mechanisms of the interaction of neurotransmitter systems

Interaction between different neurotransmitter systems has been revealed on various objects--the myocardium, identified, intact and internally perfused isolated neurons of molluscs. In frog myocardium, the inhibitory effect of adrenaline on cholinergic response may be simulated by theophylline and cholera toxin, i.e. the substances which indirectly increase intracellular content of cAMP. Another interaction reaction--inhibition of the response to adrenaline by acetylcholine--may be reproduced by imidazole, which decreases cAMP content due to activation of phosphodiesterase. Two types of interaction between serotonin and acetylcholine were revealed in the identified neurons of the snail Helix pomatia. In some of the neurons, serotonin increases acetylcholine depolarization, whereas in other ones decreases the latter. Both the increase and the decrease of responses to acetylcholine may be reproduced by theophylline. On intracellularly perfused neurons of Lymnaea stagnalis, modulation of acetylcholine responses of cell by biogenic amines was observed, the effect being induced by the drugs added not only to the surface membrane, but to intracellular medium as well.