Biomedical subjects

A A Pal'tsyn

Publications and source records attributed to A A Pal'tsyn.

At least 55 records · Page 3Linked to original sources

PubMed1988

[Autoradiographic research on RNA biosynthesis in renal tissue in the early period of corrosive sublimate-induced necronephrosis].

Study of 3H-uridine autoradiographs in semithin methacrylate renal sections of white rats showed pronounced decrease of uridine mark in all cellular types of renal tissue following 24 hours after the administration of 0.5 mg corrosive sublimate per 100 g bw. The period was marked by the development of anuria in animals. 48 hours later increase of uridine mark level in renal cortical substance was observed. Epithelial cells being contiguous with necrosed zone of non- and partially damaged but kept-alive urinary small canals became hypertrophic and synthesized RNA actively preceding their mitotic division.

Animals↗

PubMed1988

[Problems of the current theory of polymorphonuclear leukocytes].

Neutrophil is an effector cell capable of intra- and extracellular secretion of biologically active substances which produce a variety of effects on the course of inflammation, stop or inhibit multiplication of bacteria, fungi, viruses, transformed or affected cells of the macroorganism. A wide spectrum of neutrophil functions, recorded both in aerobic and anaerobic conditions, is furnished by previously synthesized and accumulated substances which provide the neutrophil with functionally essential components as early as its entrance into tissues from blood. Being a potent killer of biological objects, neutrophil acts with rapid loss of component substances and eventually destroys itself. Enhanced RNA synthesis proceeding in affected cells and thought to provide their reparative capacity, in neutrophils is denied of this compensatory function for reasons still awaiting clarification. Once stimulated for a specific function, neutrophil reduces or loses its capacity for response to additional stimuli.

Animals↗

PubMed1988

[Effect of serum on the intra- and extracellular bactericidal capacity of neutrophils].

Donors' neutrophils are capable for inhibiting the growth of and killing staphylococci both intra- and extracellularly. In the absence of serum the rate of extracellular killing of microbes by donors' neutrophils is reaching that of killing phagocytized bacteria, while in the serum introduction the rate of intracellular killing overwhelms that of extracellular. Burnt patients' neutrophils fail to control the microbes multiplication either intra- or extracellularly without serum, while in combination with it both intra- and extracellular killing activity of neutrophils of the burnt sharply increases being superior to relevant combination of healthy subjects.

Blood Bactericidal Activity↗

PubMed1988

[Vascular changes in maturing granulation tissue].

Granulation tissue was examined in rats on the 20th and 40th day after wounding of the back. It was shown that by both the 20th and the 40th day the vessels with impaired typical structure could be revealed together with the normal ones in the granulation tissue. Specific rearrangement was observed in the structure of these vessels, consisting in the impairment of their wall integrity, separation of the constituent cells and their free position among the other cells and fibrous structures. This process is especially marked by the 40th day. 3H-thymidine was actively incorporated by some fibroblasts and rather often by the cells of both normal and degenerating vessels. The authors suggest the existence of an earlier unknown phenomenon of transformation of capillary vessels, common for both normal dermal and reparative processes after injury. The essence of the phenomenon consists in the fact that small dermal vessels get permanently disintegrated and are included into the composition of cellular elements of the interstitial tissue, and form again, providing for the physiological regeneration of dermal cells and fibrous structures.

Animals↗

PubMed1987

[Structural transformations of the vascular system of the connective tissue layer of the skin].

Electron microscopic radioautography was performed in skin biopsies obtained from six surgical patients without skin lesions. It has been discovered that besides typical vessels--arterioles and venules--there are vessels with damaged structure in connective tissue of skin basis. On serial electron microscopic sections vascular wall thinning and gradual disconnection of wall-forming cells can be visualized. The authors suggest that structural changes in connective tissue vessels of skin basis are the physiological phenomenon. As a result of such changes pericytes may separate from the vascular wall and initiate new populations of fibroblasts.

Adolescent↗

PubMed1987

[Electron microscopic and radioautographic study of DNA synthesis in kidney tubule epithelial cells in white rats with sublimate-induced necronephrosis].

Electron microscopic analysis of 3H-thymidine radioautographs of ultrathin sections from the white rat kidney has revealed that 72 hours after subcutaneous injection of 0.5 mg per 100 g body weight of mercury bichloride, the damaged and partially necrotized epithelial cell became capable of DNA synthesis. However, due to the reduction of cellular organelle count the process was less intensive, as compared to that in insignificantly damaged cells. The presence in the cytoplasm of many damaged epithelial cells capable of DNA synthesis and free ribosomes demonstrates that the RNA and free ribosome biogenesis is an earlier cell regenerative reaction than DNA synthesis.

Acute Kidney Injury↗

PubMed1987

[Electron-autoradiographic demonstration of intra- and extracellular bactericidal activity of polymorphonuclear leukocytes].

A technique for the determination of intra- and extra-cellular bactericidal activity of neutrophils has been suggested. A mixture of neutrophils and bacteria was incubated for 30 min and subsequently 3H-uridine was added to the incubated mixture. If phagocytized and extracellularly located bacteria remain alive they incorporate 3H-uridine. Killed bacteria fail to incorporate 3H-uridine. Intra- and extracellular killing capacity of neutrophils is determined by the content of labelled and unlabelled bacteria in radioautographs.

Autoradiography↗

PubMed1986

[RNA synthesis during neutrophil activation].

By means of electron-microscopic radioautography RNA synthesis in blood neutrophils of burn patients was studied. Activation by phagocytic subjects was found to increase overall level of RNA synthesis in blood neutrophils either by increasing the number of cells capable of synthesis, or increasing their number in line with the intensification of the process in each of these cells. Alteration of activation conditions influences the degree of RNA synthesis by both of these means. Wound neutrophils are activated cells with a high level of RNA synthesis and low compared to blood cells, level of protein synthesis and increased capability of adhesion as well. They contain in their numerous phagosomata tissue detritus more frequently than bacteria do. Wound neutrophils are subjected to rapid destruction; it is not possible to stimulate in them phagocytic activity by means of opsonized Pseudomonas aeruginosa.

Autoradiography↗

PubMed1986

[Method of treating leukocytes for electron microscopic research].

A technique of pretreatment of leukocytes and other cellular suspensions for the electron microscopic studies in suggested. Cells fixed in a suspension are embedded in a warm gelatine solution. Upon cooling, a gelatinous block that can be cut into small pieces is formed. These pieces are fixed in glutaraldehyde solution and used thereafter as pieces of dense tissues. The technique provides a better preservation of leukocyte structure, considerably facilitating ultratomy.

Animals↗

PubMed1986

[Osteogenic precursor cells in repair osteogenesis].

Histological and electron-microscopic radioautographic investigations of regenerating medullar tissue were performed in rabbits following curettage. Low differentiated connective tissue cells were shown to possess the highest proliferative activity. DNA synthesis mainly took place in low differentiated, endothelial and osteogenic cells. It is suggested that low differentiated cells take part in histogenesis of regenerating medullar tissue, including osteo- and angiogenesis.

Animals↗

PubMed1985

[Bone formation after graded distraction in patients with open fractures of the long tubular bones complicated by purulent infection].

Osteogenesis under the above conditions is studied on the material of biopsies from 22 men with the open fractures of long bones complicated with a purulent infection. The increasing space between the edges of the fractured bone is filled with an osteoid tissue and subsequently a normal bone tissue is formed. The cells with a high proliferative activity (an intense DNA synthesis) are localised exclusively or predominantly in the wall of the capillary type vessels or in their vicinity. This indicates a close link between angiogenesis and osteogenesis. It is possible that the undifferentiated precursor cell which is the main source of the formation of all components of a new bone is localised in the wall of small vessels as a pericyte or adventitial cell. The method of graded distractional osteosynthesis in combination with the use of a controlled abacterial medium gives a possibility to replace without a free bone transplant big bone defects in open fractures complicated with a purulent infection.

Fractures, Open↗

PubMed1985

[Autoradiographic study of DNA synthesis in epithelial cells of albino rat kidney tubules as affected by corrosive sublimate nephrosis].

The analysis of 3H-thymidine radioautographs of semithin (0.5 micron) methacrylate sections of white rat kidney has shown that 72 h after corrosive sublimate injection in a dose of 0.5 mg/100 g bw, pronounced heterogeneity of impulse thymidine mark distribution stipulated by asynchronous DNA replication in damaged nephrocytes was noted. Thymidine mark is to be observed in some heavily damaged nephrocytes, retaining around the nucleus a negligible amount of cytoplasm. Thymidine mark concentration in the peripheral zone of nuclei typical only of nephrocytes with increased cytoplasm amount testifies to the fact that during S-period repairing processes take place in the damaged nephrocytes, leading to normalization of nuclear-cytoplasmic shifts.

Animals↗

PubMed1984

[Electron microscopic and radioautographic study of nucleic acid synthesis in normal fatty tissue and lipomas].

Electron microscopic radioautography was used to study nucleic acid synthesis in the normal fatty tissue and lipomas of different degree of maturity. Destroyed adipocytes were found in the investigated varieties of the fatty tissue. In a slow-growing Madelung's lipoma such adipocytes occurred in a greater amount than in the normal fatty tissue and nongrowing lipomas. 3H-Thymidine was mainly incorporated by endotheliocytes and pericytes, whereas Madelung's lipoma contained a greater number of labeled cells. Based on the data obtained it is suggested that the replenishment of adipocytes occurs at the expense of the proliferation of vascular wall cells.

Adipose Tissue↗

PubMed1984

[RNA synthesis in the polymorphonuclear leukocytes of a suppurative wound].

RNA synthesis in biopsy specimens of burn or traumatic wounds and in blood leukocytes was investigated in 11 patients by electron microscopic radioautography. Experiments with leukocytes were carried out in two variants: 1) incubation with 3H-uridine; 2) incubation with 3H-uridine in the presence of Staphylococcus aureus of Staphylococcus epidermidis suspensions. It was detected that neutrophils incubated without bacteria did not contain the label. Neutrophils incubated with bacteria and phagocytizing them could incorporate 3H-uridine. The label was insignificant in this case and the number of labeled cells did not exceed 18%. The majority of neutrophils (70-90%) in pus accumulations from burn and traumatic wounds contained the label in a higher concentration than neutrophils that phagocytize bacteria in test-tubes.

Autoradiography↗

PubMed1984

[Electron radioautographic study of a human infected wound].

Biopsies from burn (IIIa-IV degree, 20-55% of body surface) and large traumatic wounds of 18 patients were studied. The use of electron-microscopic radioautography made it possible to determine the viability and functional activity of bacteria and host cells in various wound areas. In the necrotic area, apart from a number of viable bacterial cells (intensely labelled with 3H-uridine), unlabelled bacterial cells with various structural alterations were found. Bacteria were found less frequently in the demarcation area; they were detected occasionally in the granulation tissue and only in macrophages. Phagosomes with viable or dead bacteria were observed in few neutrophils of the demarcation area. Here, the majority of neutrophils did not contain bacteria, but degranulation and many phagosomes with tissue detritus were observed. Correlation between the rate of RNA synthesis and functional activity of neutrophils was observed. In the blood neutrophils the RNA synthesis was not detected at all. In the blood neutrophils which were cultivated in vitro with staphylococci and in the wound neutrophils phagocytizing bacteria, the RNA synthesis became evident but slow. The authors established that a sharp increase of the RNA synthesis rate occurs in the neutrophils phagocytizing the dead tissues.

Adult↗

PubMed1984

[New data on the histogenesis of connective tissue tumors].

The normal skin and adipose subcutaneous tissue, desmoid fibroma, lipomas with varying proliferative activity, fibrosarcoma, malignant fibrous histiocytoma, epithelioid leiomyoma are studied by means of electron microscopy and electron microscopical radioautography. It was found that the walls of the smallest vessels contain cells which are the source of a permanent physiological renewal of a different type of the connective tissue. In proportion to differentiation and gradual removal of these cells from the vascular wall their proliferative and metabolic activity is more and more decreasing. Thus, the vessels represent not only the transport-nutritive system but the central generative structure of the connective tissue as well. Pluripotential mesenchymal cell of the vascular wall which under physiological conditions is differentiating in the direction of fibro-, angio-, lipo- or osteogenesis, due to the influence of oncogenic factors gives rise to the development of benign and malignant tumours of fibrous, vascular (angiomas), smooth muscle, adipose and bone structure. This can be most demonstratively checked using electron-radioautography of tumourlike conditions and relatively slow growing tumours.

Adipose Tissue↗

PubMed1984

[Electron radioautographic study of osteogenesis during distraction osteosynthesis].

Electron microscopic radioautography was used to study the osteogenesis during the replacement of bone tissue defects by graded distraction osteosynthesis in 12 patients with open fractures of the tibia. In the early stages of reparative tissue formation, the cells that intensely synthesized DNA and DNA were located exceptionally in the vascular walls or near them. The authors assume that vascular cells, most probably pericytes, are a basic source of the origin of the reparative tissue, turning firstly to fibroblast-like cells and then to osteoblasts.

Autoradiography↗

PubMed1983

[Electron-radioautographic study of the effect of potassium orotate on RNA and protein synthesis in fibroblasts during experimental wound healing].

Electron microscopic radioautography with the use of the double-labeling technique was applied to study potassium orotate influence on RNA and protein synthesis in fibroblasts of intact mouse skin and in granulation tissue on days 3 and 7 of the healing of a musculocutaneous wound. Experimental animals received potassium orotate per os in a daily dose of 0.2 g/kg immediately after operation. Intact animals received the drug for 3 days. According to the assay data potassium orotate did not potentiate the protein-synthesizing activity of an individual cell but apparently activated the proliferation of wound fibroblasts.

Animals↗