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.     

Effect of Lincocin Treatment on the Greening Process in Bean (Phaseolus vulgaris) Leaves

The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –¹⁴CO₂ fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes.     

Lecithotrophic development and metamorphosis in the Indo-West Pacific brittle star Ophiomastix venosa (Echinodermata: Ophiuroidea)

Summary

The larval development of the ophiocomid ophiuroid Ophiomastix venosais described using SEM. The gastrula transforms into a uniformly ciliated early larva which progressively changes into a lecithotrophic late premetamorphic larva with a continuous bilateral ciliated band. This stage is short-lived and equivalent to a highly reduced ophiopluteus. Comparisons between O. venosa and other ophiuroid species whose development has been investigated suggest that, whatever the developmental mode (lecithotrophic or planktotrophic), a pluteus stage always occurs in ophiuroids with planktonic development. Two metamorphic stages were identified, the late metamorphic larva differing from the early one by the closure of the larval mouth. The appearance of the permanent mouth marks the end of the metamorphosis. The postlarva still possesses remnants of larval features. The transformation of the reduced ophiopluteus into a barrel-shaped metamorphic larva with transverse ciliated bands, a vitellaria larva, is followed. The possible occurrence of a unique type of metamorphic larva in non-brooding ophiuroids is discussed. Verification of this, however, needs further SEM investigations on metamorphic larva from species having “regular” planktotrophic development.     

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.