[Changes in adhesive interactions of keratinocytes during regeneration of the rat skin]. / Izmeneniia adgezivnykh vzaimodeistvii keratinotsitov v protsesse regeneratsii kozhi krys.

The values of adhesion between keratinocytes as dermo-epidermal junction in the skin decreased after UV-irradiation, heating to 60 degrees C or sodium dodecyl sulfate action. The results suggest the existence of nonspecific adaptive reactions of keratinocytes adhesive interactions in response to different irritative stimulants.

[Effects of inflammation on adhesive interactions of keratinocytes]. / Vliianie vospaleniia na adgezivnye vzaimodeistviia keratinotsitov.

The reversible prolonged increase of intercellular adhesion in the epidermis along the margins of the wound as well as in the scar epidermis during the full-thickness skin wound healing was found. This effect must have adaptive significance.

[Stimulation of skin wound contraction and epithelialization by soluble collage]. / Stimuliatsiia kontraktsii i épitelizatsii kozhnykh ran rastvorimym kollagenom.

It is found that local applications of the unguent with soluble collagen, but not solution of the collagen, stimulate healing of erosions and full-thickness excision wounds in the rat skin. Not all the stages of healing were stimulated, but only two of them--contraction and epithelialization.

[The anti-inflammatory activity of structural analogs of the platelet-activating factor]. / Protivovospalitel'naia aktivnost' strukturnykh analogov faktora aktivatsii trombotsitov.

The pro- and anti-inflammatory activity of new structural analogues of the platelet-activating factor (PAF) was studied. It was found that three PAF analogues inhibit PAF-induced rat paw edema in a dose-dependent manner. The anti-inflammatory activity of one of the PAF analogues upon PAF- or carrageenan-induced inflammation was comparable or in some extent exceeded that of dexamethasone.

[Platelet activating factor inhibits irritant-induced leukocyte migration into mouse peritoneal cavity]. / Faktor aktivatsii trombotsitov ingibiruet migratsiiu leikotsitov v briushnuiu polost' myshei, indutsirovannuiu irritantami.

The effect of platelet-activating factor (PAF) on the leucocytes accumulation into mouse peritoneal cavity, that induced by high-molecular irritants carrageenan and polyacrylic acid pentaerytritol (carbopol) was studied. It was found that injection of PAF into peritoneal cavity one hour before i.p. injection of the irritants did not change their effects. On the contrary the injection of PAF simultaneously with the irritants or 3 and 6 hours after these injections inhibited the leucocyte accumulation into the peritoneal cavity and/or these injections increased the leucocyte adhesion to the peritoneal covering. It was supposed that finding effects are mediated by the change of leucocytes adhesion under action of PAF.

[Vitamin A prevents an increase in epitheliocyte adhesion induced by carcinogens in the epidermis of rats and the large intestine of mice]. / Vitamin A prepiatstvuet uvelicheniiu stsepleniia épiteliotsitov, indutsiruemomu kantserogenami v épidermise krys i tolstoi kishke myshei.

The data obtained suggest that high doses of vitamin A may prevent from the carcinogen-induced increase in adhesion between mature cells in the rat epidermis and murine colon.

[Effect of vitamin A on the adhesive interaction of cells in epithelial tissue]. / Vliianie vitamina A na adgezivnye vzaimodeistviia kletok v épitelial'nykh tkaniakh.

Both the increasing and decreasing contents of vitamin A in rats induced a lowering of cell adhesion in the skin multilayer epithelium, and that of their packing density. However, the same stimulus did not alter cell adhesion in the small intestinal monolayer epithelium. The data obtained show that vitamin A may serve as a factor modulating intercellular adhesive interactions with tissue specificity.

[Changes in the mechanical properties of the epidermis during chemical carcinogenesis]. / Izmeneniia mekhanicheskikh svoistv épidermisa pri khimicheskom kantserogeneze.

Effects of the long-term and the short-term action of N-methylurea and 9,10-dimethyl-1,2-benzanthracene on the mechanical properties of the rat epidermis were studied. Both long term and short-term applications were shown to increase the strength of mechanical friction between corneocytes during the whole period of observation, i.e. six and two months, respectively. The increase in the intercellular adhesion in the stratum corneum was proposed to promote the decrease in the cell loss and the tumor growth in the epidermis.

[Changes in the cytoskeleton and surface charge as a possible cause of the increased mechanical binding between enterocytes in the small intestine epithelium induced by 1,2-dimethylhydrazine]. / Izmeneniia tsitoskeleta i zariada poverkhnosti kak vozmozhnaia prichina povsyheniia mekhanicheskoi sviazi mezhdu énterotsitami v épitelii tolstoi kishki, indutsirovannogo 1,2-dimetilgidrazinom.

Alterations in the mechanical linkage between the enterocytes in BALB/c mouse colonic epithelium were investigated under the influence of agents affinitable to the cell surface and cytoskeleton. It is found that cytochalasin B (10(-6) - 10(-5) g/ml), low pH (pH 3) and low concentration of colchicine (10(-8) g/ml) increased, but EDTA (5 X 10(-3) g/ml) and high concentration of colchicine (10(-4) g/ml) reduced the magnitude of mechanical linkage between the enterocytes. A comparative analysis of the data obtained with the control and with 1,2-dimethylhydrazine (DMH) treated mice indicates that probable reasons of a DMH-induced rise in the intercellular mechanical linkage may involve the decrease in electrostatic repulsive forces between the cell surfaces, and the weakening of centripetal tensions due to a decrease in negative surface charge and disorganization of the microfilament system, respectively. These alterations of the cell surface negative charge and the cytoskeleton are expressed on day 3 after a single injection of DMH and are seen to persist during repeated carcinogen applications.

[Kinetic characteristics of the normal enterocyte population and in carcinogenesis]. / Osobennosti kinetiki populiatsii énterotsitov v norme i pri kantserogeneze.

A correlation was revealed between the crypt cell proliferation changes and variations in adhesion among mature enterocytes at the extrusion zone: an increase in the proliferative activity is accompanied by a decrease in the cell adhesion, and vice versa. This dependence exists in the normal tissue and possibly serves for the epithelium protection from hypo- and hyperplasia. A distinctive feature of carcinogen treatment is the irreversible disturbance of the dependence.

[Changes in the epithelial permeability of the large intestine of mice in the process of carcinogenesis]. / Izmenenie pronitsaemosti épiteliia tolstoi kishki myshei v protsesse kantserogeneza.

1,2-dimethylhydrazine (DMH), a colon carcinogen, being injected weekly to BALB/c mice, inhibits an active sodium transport, increases the transepithelial passive ion permeation and decreases ion selectivity in the descending colon. A single DMH injection leads to the same alterations, manifested for a month, followed by normalization of all the parameters to the control value. Distinctive, wavy changes in electrophysiological parameters were noted after a single injection of "non-colon" carcinogen 7,12-dimethyl-benz(alpha)antracen. It is supposed that the prolonged drop in active sodium transport, transepithelial resistance and ion selectivity are specific reactions of the colonic epithelium to carcinogenic treatment with DMH.

[Changes in induced cell loss in the intestinal epithelium of mice after a single exposure to 1,2-dimethylhydrazine]. / Izmenenie indutsirovannoi poteri kletok v épitelii kishechnika myshei posle odnokratnogo vozdeistviia 1,2-dimetilgidrazina.

A single subcutaneous injection of 1,2-dimethylhydrazine lowers the induced cell loss from the superficial regions of mucosa in the distal colon of mice which may be revealed on the 3rd day after injection to retain longer than a month. The magnitude of this effect in the different regions of intestine is closely related to the frequency of tumor appearance established under numerous carcinogen injections. Non-carcinogenous analogs of 1,2-dimethylhydrazine and different carcinogens that induce tumors in other organs, but not in intestine, do not lead to the lowering in the induced cell loss. The data obtained indicate that the above effect may be related to carcinogenous properties of 1,2-dimethylhydrasine.

[Assessment of cell losses in the intestinal epithelium]. / Ob otsenke kletochnykh poter' v épitelii kishechnika.

An attempt was made of quantitative evaluation of the epithelial cell separation in vitro from the descending colon of mice (strains A, BALB/C, CBA, C57Bl and random-bred mice) under unified procedure of the tissue desintegration in norm and under carcinogenesis, depending on the age and strain distinctions. The devised method of forced cell isolation enable us to separate single, differentiated enterocytes, being in the stage of desquamation, from intestinal mucose. The cell separation was shown to decrease with age. The BALC/C mice, with high frequency of 1,2-dimethylhydrasine-induced tumor appearance, were characterized by a more decreased cell separation than C57Bl mice, with low sensitivity to the carcinogen. The cell separation from tumor-free mucosal surface in mice with tumors in colon was also seen decreased, as compared with control animals. The data obtained show that the reported approach of forced cell isolation can be useful for the appraisal of cell loss in the intestine, and suggest that the cell loss is decreasing during cancerogenesis.