Receptor-mediated endocytosis and nuclear transport of a transfecting DNA construct

A soluble construct consisting of a plasmid carrying the gene of the SV40 large T-antigen and an insulin-poly-L-lysine conjugate is able to selectively transfect PLC/PRF/5 human hepatoma cells which possess insulin receptors. Transfection can be efficiently competed by excess free insulin. To examine intracellular transport of the construct, it was fluorescently labeled and its accumulation on and in cells visualized by video-enhanced microscopy and quantitative confocal laser scanning microscopy. After 2 h at 37 degrees C, the labeled construct was found predominantly in intracellular acidic compartments, with a substantial portion of fluorescence localized both near and in the cell nucleus. Binding, endocytosis, and nuclear localization of the labeled conjugate could all be competed by excess free insulin, thus indicating that entry of the conjugate into cells was specifically mediated by the insulin receptor.     

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.     

Convergent Synthesis of the Rat Galanin and Study of Its Biological Activity

Russian Journal of Bioorganic Chemistry - The full-length rat galanin (GWTLNSAGYLLGPHAIDNHRSFSDKHGLT-NH2, G29) was prepared by the solid phase peptide synthesis using the Fmoc-strategy. The peptide...     

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.     

Apoptosis-inducing action of antituberculosis drugs of the main group in vitro

The influence of the main antituberculosis drugs (isoniazid, rifampicin, ethambutol) on in vitro apoptosis of peripheral blood lymphocytes from patients with pulmonary tuberculosis was researched. It was shown that all the investigated drugs induced apoptotic death of the lymphocytes in vitro, that could result in disturbance of antigen-specific response formation in pulmonary tuberculosis.     

Proteomic characterization of <Emphasis Type="Italic">Mycoplasma gallisepticum</Emphasis> nanoforming

The goal of this work was to create a model for the long persistence of Mycoplasma gallisepticum in depleted medium and under low growth temperature followed by proteomic study of the model. Nanoforms and revertants for M. gallisepticum were obtained. Proteomic maps were produced for different stages of the formation of nanoforms and revertants. It is shown that proteins responsible for essential cellular processes of glycolysis, translation elongation, and DnaK chaperone involved in the stabilization of newly synthesized proteins are crucial for the reversion of M. gallisepticum to a vegetative form. Based on the current data, it is assumed that changes in the metabolism of M. gallisepticum during nanoforming are not post-mortal, thus M. gallisepticum does not transform to uncultivable form, but remains in a reversible dormant state during prolonged unfavorable conditions.     

Chimeric Agonist of Galanin Receptor GALR2 Reduces Heart Damage in Rats with Streptozotocin-Induced Diabetes

Biochemistry (Moscow) - Neuropeptide galanin and its N-terminal fragments reduce the generation of reactive oxygen species and normalize metabolic and antioxidant states of myocardium in...