[Enucleation, formation of cyto- and karyoplasts, and their fusion with neuronal body].

In this research that was performed on isolated neurons of mollusk Lymnaea stagnalis, using neuron enucleation, the cytoplast was obtained which was then fused with another neuron resulting in cybrid formation. The experiments performed have shown that the isolated neurons are able to fuse with each other, forming binuclear neurons; also, like all other cells, they could be enucleated with the formation of cyto- and karyoplasts and, after fusion, they can form cell body-cytoplast, cytoplasts-karyoplast, and other complexes. This is associated with the appearance of all doubtless indicators of fusion described for fusion of nerve cell bodies. This work demonstrates the possibility to artificially fuse the amputated neuroplasm fragment with neuronal cell body--the metabolic center of another cell. Theoretically, this means that in vivo amputated neuronal process also can be fused with a novel cell.

[Glio-neuronal and glio-glial syncytial cytoplasmic connections in peripheral nerve trunks of the crayfish Astacus leptodactylus].

The paper considers various aspects of glial sheaths of neuritis in the crayfish peripheral nerve trunks and roots. There are revealed dotted glio-neurite tight junctions and a varicose deformation of the intercellular glio-neurite cleft. Rupture of membranes in the area of contact leads to formation of the glio-neurite pore (less than 10 nm) that is enlarged and forms wide (up to 240 nm) syncytial perforations. At the edge of perforation, either remnants of tight junctions are present or damaged membranes that fuse and are rounding. The lumen of perforations always contains residual membranous bodies in the form of vesicles. Their deviation from the median line can indicate a mutual translocation of substances of the glio- and neuroplasm. In the adjacent layers of the multilayer glial sheath there is noted a similar phenomenon of formation of the glio-glial syncytial connection terminating by fusion of neighbor glial layers, which is terminated by fusion of neighbor glial layers into the single lamina. The process begins from the varicose deformation of interglial clefts, which appears as a result of massive formation of dotted and expanded tight membranous contacts. As a result of transformation of ellipsoid varicose deformations into the spherical ones, syncytial pores (less than 10 nm) between them are formed, which are enlarged and break the paired gliolemmas into fragments. As a result, the adjacent glial layers are united. Since this process in intact animals occurs on the background of undamaged nerve structures, a suggestion is put forward about its reversibility and the functional nature.

Neuron division or enucleation.

The classical Bielschowsky-Gross neurohistological method was used to reproduce all the morphological phenomena interpreted by many authors as signs of neuron division, budding, and fission. It is suggested that these signs are associated with the effects of enucleation, which occurs in many cells of other tissue types in response to a variety of chemical and physical treatments. Studies were performed using neurons isolated from the mollusk Lymnaea stagnalis and exposed in tissue culture to the actin microfilament inhibitor cytochalasin B. Phase contrast time-lapse video recording over periods of 4-8 h demonstrated nuclear displacement, ectopization, and budding, to the level of almost complete fission of the neuron body. This repeats the pattern seen in static fixed preparations in "normal" conditions and after different experimental treatments. Budding of the cytoplasm was also sometimes seen at the early stages of the experiments. Control experiments in which cultured neurons were exposed to the solvent for cytochalasin B, i.e., dimethylsulfoxide (DMSO), did not reveal any changes in neurons over a period of 8 h. We take the view that the picture previously interpreted as neuron division and fission can be explained in terms of the inhibition of actin microfilaments, sometimes developing spontaneously in cells undergoing individual metabolic changes preventing the maintenance of cytoskeleton stability.

Neuron changes in a mollusk in response to proteolytic enzymes.

The aims of the present work were to investigate the structure of neurons after treatment with proteases and to identify possible recovery of interneuronal syncytial connections. In the first series of experiments, phase-contrast microscopy studies of live dissociated neurons from ganglia of the mollusk Lymnaea stagnalis treated with 0.4% pronase solution demonstrated retraction of nerve processes and biphasic changes in cell body volume. At stage I, at an average of 82.5 min, neuron body volume decreased by 12.1%, after which it increased by a mean of 14.1%. Signs of neuron viability in Ringer's solution were seen for an average of 828 min; survival time in pronase solution was 1.4 times shorter. In the second series of experiments, studies of neuron ultrastructure showed many cases of persistence of mitochondria, the rough and smooth endoplasmic reticulum (ER), Golgi complex, light and granular vesicles, nuclear structure, and neuroplasm optical density. Cells coming close together after centrifugation formed intracellular clefts of uniform width (about 20 nm). There were very rare cases of points at which membranes came into contact. There were no signs of syncytial connections. Lengthening and fusion of smooth ER cisterns separated fragments of neuron bodies from relatively undamaged cells. Some neurons were damaged, with multiple vacuoles formed form swollen mitochondria and ER cisterns. Fragments of nerve processes formed on dissociation were surrounded by a normal outer cell membrane.

[Neuronal division or enucleation].

In this work,using the classical neurohistological Bielschowsky-Gros method, all the morphological phenomena were reproduced that were earlier interpreted by many authors as the signs of neuron division, budding and fission. It is suggested that these phenomena are associated with the effect of enucleation demonstrated in many cells of other tissue types exposed to different physical and chemical factors. The experiments were conducted in tissue culture, using the isolated neurons of the mollusk Lymnnaea stagnalis, in which the neural cells were treated with actin microfilament inhibitor cytochalasin B. Phase-contrast time-lapse video recording during 4-8 hours demonstrated the effects of nucleus displacement, ectopy and bulging up to almost complete fission of neuronal body. These effects reproduce the images obtained in static fixed preparations under "normal" and various experimental conditions. Sometimes, at the early experimental stages, the bulging of cytoplasm was also detected. Control experiments in which the neurons were treated with the culture medium containing cytochalasin B solvent dimethyl sulfoxide, showed no changes in neurons during 8-hour period. It is suggested that the images, interpreted earlier as neuron division or fission, could be explained by inhibition of actin microfilaments, which sometimes may develop spontaneously in cells experiencing individual metabolic changes compromising the cytoskeleton stability maintenance.

[Changes in molluscan neurons under the influence of proteolytic enzymes].

The goal of the work was to study the structure of neurons treated with proteases and to elucidate if this could lead to the formation of the interneuronal syncytial connections. In the first series of experiments, phase contrast observation of the living dissociated ganglionic neurons of the mollusc Lymnaea stagnalis treated with 0.4% pronase, demonstrated a retraction of nerve processes and a two-phase change of the cell body volume. At the first stage, the soma volume decreased, on the average, for 82.5 min by 12.1%; subsequently, the volume increased, on average, by 14.1%. Signs of neuronal vital activity in Ringer's solution were observed, on the average, for 828 min, while in pronase solution their duration was 1.4 times shorter. In the second series of experiments, the study of neuronal ultrastructure has demonstrated in many cases the integrity of mitochondria, rough and smooth endoplasmic reticulum (ER), Golgi complex, light and granular vesicles, nuclear structure, and the preservation of the optical density of neuroplasm. The cells making contacts after centrifugation form uniform intercellular clefts of about 20 nm. Point approaches of membranes were very rare. No signs of syncytial connections were detected. Elongation and fusion of smooth ER cisterns separated the fragments of soma from relatively undamaged cells. Some neurons were damaged, they contained numerous vacuoles formed by swollen mitochondria and ER cisterns. The nerve process fragments, detached during the dissociation, were surrounded by the normal plasma membrane.

[Sucralfate: the agent of choice in the treatment of peptic ulcer?]. / Sukral'fat: sredstvo vybora v lechenii iazvennoi bolezni?

As many as 72 patients with erosive and ulcerous injuries to the stomach and duodenum were examined for the clinical efficacy of antepsin (sucralfate). Of these patients, 42 were with duodenal ulcer, 10 with gastric ulcer and 20 with erosive gastroduodenitis). Antepsin exerted a beneficial effect on the painful syndrome and on ulcer and erosion healing. The coefficient of the therapeutic efficacy of antepsin in duodenal ulcer patients turned out to be equal to 2.67 that of gastric ulcer to 2.1 and that in patients with gastroduodenitis was 2.6. The drug did not produce any well-defined side effects. In some cases (8.3%), it caused the appearance or enhancement of constipation. Antepsin is indicated not only in ulcer disease but also in duodenogastric reflux, reflux gastritis and reflux esophagitis.

[Treatment of chronic hepatitis patients with catergen]. / Lechenie bol'nykh khronicheskim gepatitom katergenom.

The authors analyse the results of the treatment of patients with chronic active hepatitis of moderate activity with catergen as compared with basic therapy including dietetic management, polyvitamins, and essentiale. The treatment efficacy was evaluated according to the time-course of changes in subjective sensations of the patients, objective data of the clinical and laboratory studies. It was established that catergen produced a beneficial effect on the time-course of both subjective and objective characteristics in patients with chronic active hepatitis, while the drug therapeutic activity was found to be higher as compared with essentiale and basic therapy.