[Transthyretin gene V30M, H90N, and del9 mutations in cardiomyopathy patients from St. Petersburg].

A search of transthyretin (TTP) gene mutations was conducted in patients with cardiomyopathies from St. Petersburg. Mutations H90N, V30M, G47A, and deletion (del9) of nucleotides GACTTCTCC in position 6776 from the start codon of the TTP gene (in position 98782 according to reference sequence AC079096 (NCBI) was found.

[The study of preimplantation development of mice embryos labelled with green fluorescent protein gene (EGFp)].

One of the crucial problems of developmental biology is the study of mechanisms of regulation of gene expression in early embryogenesis. Here we studied dynamics of mosaic appearance of a marker fluorescent protein in in vitro developing mice embryo derived from zygotes after microinjections to male pronuclei of cloned DNA fragment carrying EGFP under control of different promoters. Main attention was paid to initial stages of development, when structural rearrangements and reprogramming of both parental genomes, activation of zygotic genes, and control of development by embryo genome take place.

Role of the C-terminal fragment of human transthyretin in abnormal fibrillogenesis.

Polypeptide chain fragments of recombinant transthyretin (TTR) with leucine-55 substituted by proline (L55P), which are involved in abnormal fibrillogenesis of this protein, were studied. No fibrils were produced in purified preparations of TTR(L55P) under the optimum conditions for fibrillogenesis but in absence of protease inhibitors. The ability of TTR for fibrillogenesis was lost because of a limited proteolysis resulting in detachment of the TTR polypeptide chain C-terminal fragment of approximately 18 amino acid residues in length.

[The role of quarternary structure in fluorescent protein stability].

The stability of fluorescent proteins (FPs) is of great importance for their use as reporters in studies of gene expression, protein dynamics and localization in cell. A comparative analysis of conformational stability of fluorescent proteins, having different association state was done. The list of studied proteins includes EGFP (monomer of green fluorescent protein, GFP), zFP506 (tetramer GFP), mRFP1 and "dimer2" (monomer and dimmer of red fluorescent protein), DsRed1 (red tetramer).

[Expression of marker genes in muscle fibers after transfection in vivo, mediated by lactoferrin].

The capacity of milk iron-transporting human protein lactoferrin (LF) to deliver genetic constructions into cells was studied in an effort to correct hereditary defects. The purified LF and LF conjugates containing either polylysine (C-1) or both polylysine and ficoll (C-2) were bound to plasmid DNA. These complexes were injected into mouse muscles, and the expression of the marker genes was tested immunochemically.

[A comparative study of the transport dynamics of the peptide moiety of the milk ceruloplasmin molecule in the body of rats with embryonic and adult types of copper metabolism].

In chase experiments, we followed the distribution of [125I]-ceruloplasmin prepared from human breast milk orally administered to young rats. Experiments were conducted using six-day-old rat pups (the embryonic type of copper metabolism) or 35-day-old ones (the adult type of copper metabolism). Using the technique of rocket immunoelectrophoresis, we have demonstrated that in six-day-old rats [125I]-ceruloplasmin was transferred from the gastrointestinal tract to the bloodstream and could be detected there over a period of 4 h.

Comparative analysis of the molecular heterogeneity of ceruloplasmin from human blood and breast milk.

The content of ceruloplasmin (Cp) was determined in 96 samples of human breast milk using rocket immunoelectrophoresis and measurement of Cp oxidase activity. The concentration of immunoreactive Cp in milk decreased about 9 times during the first 20 days of lactation while the specific oxidase activity decreased only 4 times. Two-dimensional electrophoresis of purified milk Cp before and after its treatment with chelating agents showed that copper atoms in milk Cp are more sensitive to EDTA treatment that those in blood Cp.

Reconstitution of the intercellular transfer pathway of the peptide moiety of ceruloplasmin in mammals.

According to rocket immunoelectrophoresis, the antigenic properties of the ceruloplasmin (Cp) receptor present on the surface of human fibroblasts are similar to those of the Cp receptor of the erythrocyte plasma membrane. Using antibodies to Cp receptor, it was demonstrated that Cp binds to the surface of fibroblasts only via the Cp receptor. Ceruloplasmin was labelled with radioactive iodine and its binding to cultured human HT-1080 fibroblasts was studied; at saturating concentrations [125I]Cp interacts with cell surface of fibroblasts (but not hepatocytes) with high affinity (Kd = 80 nM).

[Regulation of biosynthesis of molecular forms of ceruloplasmin in rat ontogenesis].

Ceruloplasmin (CP) expression at the level of formation of its molecular forms in the liver and other rat organs during ontogenesis has been studied. The synthesis of CP commenced on day 15th of embryogenesis and coincided in time with the completion of formation of the fetal liver. This period of rat embryo development was marked by the appearance of two molecular forms of newly formed CP, one of which was secreted in vitro by isolated fetal liver, while the other one was found in the membrane fraction of extrahepatic embryonic tissues.

[Biosynthesis and secretion of ceruloplasmin by rat mammary cells during lactation].

Some peculiarities of rat milk ceruloplasmin (CP) biosynthesis have been analysed. Electrophoretic and immunoelectrophoretic data suggest that rat milk contains up to 20 mg/100 ml of CP. Rat milk CP is represented by a single molecular form whose molecular mass, enzymatic activity and antigenic properties are fully identical with those of serumal CP.

[Biosynthesis of two molecular forms of ceruloplasmin in rat liver and their polar secretion into the blood stream and bile].

Biosynthesis and secretion of ceruloplasmin (CP) in rat liver has been studied in order to elucidate its role in the distribution, transport and excretion of copper in the body. The kinetics and topography of CP synthesis, intracellular transport and secretion were followed using in vivo pulse-chase experiments. It was found that the newly formed CP was firmly bound to endoplasmic reticulum membranes in the hepatocytes.

[Spatial-temporal coding of simultaneously entering information on several visual signal signs by frog brain neurons].

Experiments were performed on frogs. It was shown that 9 neuron types with narrow- and wide-band sensitive characteristics were present in the tectum. These neurons used different modifications of spatio-temporal codes for transfer information about three features of a moving visual object--its orientation, direction and speed.

[Properties of silver-containing rat ceruloplasmin].

Ceruloplasmin (Cp) was isolated from the sera of albino rats fed with silver nitrate (60 mg/kg of body weight). The oxidase activity of the enzyme was sharply decreased, while its concentration in the blood (as assayed immunologically) was slightly lower than in controls. The drop in the oxidase activity was caused by the replacement of several coppers by silver ions in the Cp molecule.

[Etiologic significance of hereditary deficiency of proteinase alpha1-inhibitor in the formation of respiratory diseases].

A study was made of the content of protease alpha 1-inhibitor and of the phenotyping of protease alpha 1-inhibitor subtypes in 666 patients with different chronic non-specific pulmonary diseases. It is concluded that pronounced deficiency of protease alpha 1-inhibitor is of importance in the formation of primary emphysema, chronic obstructive bronchitis and bronchial asthma. The clinical characteristics of obstructive pulmonary diseases marked by protease alpha 1-inhibitor deficiency have been investigated.

[Synthesis and secretion of ceruloplasmin by isolated rat hepatocytes].

The synthesis and secretion of ceruloplasmin (Cp) by isolated rat hepatocytes were investigated. Cp released by liver cells appeared to have properties similar to those of the blood-circulating protein, i. e.

[Neuronal reactions of the hippocampus of the frog in response to visual stimulation].

Histological and electrophysiological studies of the frog primordial hippocampus described coordinates of the hippocampus within the telencephalon. Receptive fields of hippocampal neurons were compared with those of other neurons within the visual system. Neurons with excitatory on-off responses and tonic type of responses were shown to prevail.

Neuronal level of organization of the visual analyzer in frog tectum.

A study of neuronal responses of frog tectum to diffuse light and a moving visual stimulus, in which paired microelectrodes were used, disclosed the excitation-inhibition constructions originating in the midbrain tectum in response to various forms of visual stimulation. It was demonstrated that the dimensions of the excitation zones of these constructions are 100-200 mu in cross section, and are separated by inhibition zones. The dimensions of the excitatory tectal constructions resulting from various kinds of visual stimulation correlated with the width of the branching zones and locations of terminals of the afferents and intratectal fibers.

[Responses and organization of the receptive fields of neurons of the basal optic nucleus of the frog tegmentum during visual stimulation].

Stationary visual stimuli and diffuse light induced mainly excitatory responses of the neurons. Among the neurons responding to visual stimulations many units were the polysensory cells responding also to tactile and sound stimuli. The questions of organization of the tegmental neurons' visual receptive fields, are discussed.

[Morpho-functional organization of the optic thalamic system in the frog].

Histological and electrophysiological studied of the frog thalamus localized more precisely the Bellonci and the posteriorthalamic nuclei in the diencephalon. Responses of the thalamic neurons have been characterized as well as the specifics of their receptive fields as compared with the tectum neurons. Large heterogeneous receptive fields with prevailing excitatory response were shown to predominate in the frog diencephalon.

[Reactions of the tectum neurons of the frog to movement into its field of vision of an object with different velocities].

Neurons with different "velocity selectiveness" and different "velocity sensitivity" were found in the frog midbrain tectum as well as neurons with different types of the firing rate dependence on the velocity of a visual stimulus motion. Visual recognition in frogs seems to proceed with the aid of two systems: the image--detecting and the image--describing those which complement each other.