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V S Poltoranina

Publications and source records attributed to V S Poltoranina.

At least 19 recordsLinked to original sources
PubMed1998

Inducible protein in rat hepatomas with expression alternative to alpha-fetoprotein.

The rat hepatoma cell line McA RH7777 was cloned into alpha-fetoprotein-producing (AFP+) and non-producing (AFP-) sublines. A monoclonal antibody (MAb A2/3) reacting with an antigen (Ag A2/3) present only in AFP- clones or AFP- cells in mixed clones was obtained. Ag A2/3 was absent from the liver of embryonic, fetal, newborn and adult rats, but it was present in gastric and intestinal mucosa of adult rats. Ag A2/3 was found to be a heavy metal-inducible protein: Cd2+ and Pb2+ strongly induced the expression of Ag A2/3 in vivo in the liver of adult rats, while xenobiotics and CCl4 were not active in this respect. In vitro Cd2+ and Pb2+ induced Ag A2/3 expression in several AFP+ clones, leading to a simultaneous marked decrease of AFP+ cells from such clones. The effect of Cd2+ in the induction of Ag A2/3 and suppression of AFP was reversible. SDS PAGE revealed one protein band with an m.w. close to 45,000, which was not sensitive to mercaptoethanol. Despite its inducible properties, Ag A2/3 was shown not to belong to metallothioneins, cytochrome P-450, glutathion-transferase or heat shock proteins families, well-known as being inducible cell stress proteins. Expression of Ag A2/3 could be one of the factors determining the high amplitude of AFP production by individual liver tumors. The nature of Ag A2/3 and its alternative expression with respect to AFP remain to be studied.

Animals↗
PubMed1996

Reactivity of anti-macrophage monoclonal antibody D11 in human leukemia and malignant lymphoma.

We have studied the reactivity patterns of a previously described pan-macrophage monoclonal antibody (MAb) D11 in 324 cases of acute leukemia and malignant lymphoma (ML). Reaction of D11 in tissue sections was restricted to histiocytes and macrophages. In non-Hodgkin's ML, D11 helped to confirm or to establish the histiocytic nature in 8 of 96 cases, i.e., in 4 of 6 histiocytic MLs; 2 of 13 anaplastic large-cell lymphomas; 1 of 4 large-cell immunoblastic clear-cell MLs; and 1 of 2 histiocytosis X cases. Positive reaction of D11 in acute lymphoblastic leukaemia (ALL) was found in 9 of 86 cases (all belonging to early B-lineage leukemia), of which 4 were CD34-positive and 5 co-expressed 1 or more myeloid/monocytic antigens. MAb D11 did not react in 42 cases of acute-myeloblastic-leukemia (AML) FAB variants M0-M5, except 1 acute mixed-lineage leukemia M1/pre-pre-B. Comparative study of the MAb D11 and a standard CD68 MAb KP- 1 showed that the antigens belong to different epitopes of different molecules.

Acute Disease↗
PubMed1993

Common antigen of oval and biliary epithelial cells (A6) is a differentiation marker of epithelial and erythroid cell lineages in early development of the mouse.

The A6 antigen--a surface-exposed component shared by mouse oval and biliary epithelial cells--was examined during prenatal development of mouse in order to elucidate its relation to liver progenitor cells. Immunohistochemical demonstration of the antigen was performed at the light and electron microscopy level beginning from the 9.5 day of gestation (26-28 somite pairs). Up to the 11.5 day of gestation A6 antigen is found only in the visceral endoderm of yolk sac and gut epithelium, while liver diverticulum and liver are A6-negative. In the liver epithelial lineages A6 antigen behaves as a strong and reliable marker of biliary epithelial cells where it is found beginning from their emergence on the 15th day of gestation. It was not revealed in immature hepatocytes beginning from the 16th day of gestation. However weak expression of the antigen was observed in hepatoblasts on 12-15 days of gestation possibly reflecting their ability to differentiate along either hepatocyte or biliary epithelial cell lineages. Surprisingly, A6 antigen turned out to be a peculiar marker of the crythroid lineage: in mouse fetuses it distinguished A6 positive liver and spleen erythroblasts from A6 negative early hemopoietic cells of yolk sac origin. Moreover in the liver, A6 antigen probably distinguishes two waves of erythropoiesis: it is found on the erythroblasts from the 11.5 day of gestation onward while first extravascular erythroblasts appear in the liver on the 10th day of gestation. Both fetal and adult erythrocytes are A6-negative. In the process of organogenesis A6 antigen was revealed in various mouse fetal organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

D11, a novel monoclonal antibody specific for human mature macrophages and peripheral blood monocytes.

A new monoclonal antibody designated Mab D11 is described, which shows a restricted reactivity to cells of the monocyte/macrophage system. When tested by light and electron microscopic immunoperoxidase methods, Mab D11 specifically reacts with blood monocytes and stains resident macrophages in a wide variety of human tissues; it does not mark the macrophages of other species, i.e., rat, swine and mouse. Antigen-presenting cells, e.g., Langerhans cells, are Mab D11 negative. Mab D11 reveals the antigen on cryostat and paraffin tissue sections. Ultrastructurally the antigen recognized by Mab D11 in all macrophage types studied is located on the plasma membrane and within cytoplasmic structures including lysosomes. On immunoblotting, Mab D11 detects the 125-kDa antigen in human liver and the 135-kDa protein in tumours of histiocytic origin. The similarity of Mab D11 to known "pan-macrophage" monoclonal antibodies is discussed.

Animals↗
PubMed1992

[Histogenesis of experimental renal tumors in mice].

Epithelial kidney tumours induced in CBA male mice by 1,2-dimethylhydrazine were studied histochemically and immunohistochemically. Histologically, 48 tumours studied were diagnosed as clear-cell, acidophilic or mixed adenomas located in the renal cortex. Gamma-glutamyl transpeptidase (GGT) was strongly positive in normal proximal convoluted tubules, slightly positive in the cells of Bowman capsule and negative in 47 of 48 tumours examined. Antibodies against the new antigen obtained from the mouse liver oval cells and called A6 antigen were also used. This antigen in normal kidney is negative in proximal tubules but always positive in distal tubules and collective ducts. It was also positive in all 47 GGT-negative tumours. One tumour was GGT-positive and A6 antigen-negative. The conclusion is made that the majority of renal cell adenomas in mice most likely originate from the collective duct system and not from the proximal tubules.

Adenoma↗
PubMed1991

[Mouse hepatoblastoma: comparative aspects].

The structure of 12 spontaneous hepatoblastomas found in old (average age 26.5 months) male mice is described. There were considerable strain differences in their incidence: 0.5% (1/194), 0.5% (1/194) and 5% (10/198) in strain C57B1, CBA and F1 (CBA X C57B1), respectively. This proves the importance of genetic factor the role of which in the development of human hepatoblastoma is not established so far. Mouse hepatoblastoma develops almost invariably within or adjacent to liver cell tumours (adenoma or carcinoma). There was a correlation between the incidence of liver cell tumours within a given strain treated with different doses of carcinogen but such correlation was absent in mice of different strains. Histologically and ultrastructurally, mouse hepatoblastoma corresponds to the anaplastic variant of human hepatoblastoma. As distinct from human tumour, mouse hepatoblastoma does not contain alpha-fetoprotein. One tumour was transplanted to the syngeneic host and passed 30 transplant generations retaining the structure of a primary tumour with areas of osteoid tissue and foci of squamous cell metaplasia. Mouse hepatoblastoma may be induced by carcinogens. Likewise, according to the literature, risk of hepatoblastoma is higher in children whose mothers were exposed to the potential carcinogens before or during the pregnancy.

Animals↗
PubMed1990

Human alpha-fetoprotein epitopes as revealed by monoclonal antibodies.

The epitope specificity of 12 anti-human alpha-fetoprotein monoclonal antibodies (Mabs) was estimated in an enzyme-linked immunosorbent assay (ELISA). A combination of two different approaches: (i) Mabs binding to heterologous alpha-fetoprotein (AFP); and (ii) cooperative Mabs binding to human AFP (hAFP) when tested in pair mixtures; was used. This double-approach methodology was found to be more reliable for the definition of Mab specificities than either method alone. The anti-hAFP Mabs studied recognised eight unique non-repeated epitopes on hAFP. Two of the epitopes were specific for humans, whereas six were common to other species (mouse, rat, calf, dog, pig and cat) with a characteristic species distribution for each epitope. All epitopes were present on hAFP synthesised by hepatoma, yolk sac tumour and embryo.

Animals↗
PubMed1990

Transplantable mouse hepatoblastoma: histologic, ultrastructural and immunohistochemical study.

Hepatoblastoma found adjacent to a liver cell adenoma in an aged (CBA x C57Bl/6)F1 male mouse was transplanted to the syngeneic host and passed through 30 generations. Histologically, tumours that grew on transplantation retained principal morphological features of the primary tumour. Transplanted tumours were negative for AFP and for antigen A6. This antigen in the normal mouse liver is found in epithelial cells lining bile ducts and ductules including the terminal Hering canals. Some of the Hering cells were consistently A6 negative under normal conditions, and the suggestion is made that these A6 negative cells might be the cells of hepatoblastoma origin.

Adenoma↗
PubMed1990

Common antigens of mouse oval and biliary epithelial cells. Expression on newly formed hepatocytes.

Two antigens - A6 and G7 - shared by mouse biliary epithelial and oval cells were revealed by monoclonal antibodies raised in rat immunized with oval-cell-enriched liver fraction. Oval cells were induced in CBA or F1 (CBA x C57BL6) mice by a combination of a single injection of the alkylating drug Dipin with partial hepatectomy. In normal liver A6 antigen was localized, using light and electron microscopy, in biliary epithelial cells of all ducts including Hering canals. Some bile ductal and Hering cells were A6-negative. Occasionally, A6 antigen was present in single hepatocytes forming the periportal ends of hepatic cords. In preneoplastic and tumorous liver A6 antigen was present in bile ductal and oval cells and in a fraction of newly formed hepatocytes and tumor cells. G7 antigen was revealed in normal, precancerous and tumorous liver in biliary epithelial and oval cells but not in hepatocytes. A6 and G7 antigens were not liver-specific: they were expressed in various normal organs and tissues, especially in epithelia. In studies of mouse liver lineages A6 antigen can be used as a common marker of biliary epithelial and oval cells and hepatocytes at certain stages of differentiation. G7 antigen is a marker of oval and biliary epithelial cells. There was a striking similarity in A6 antigen localization to that of human blood group antigens in normal liver and liver tumors. A6 antigen may thus provide a useful tool for the study of neoexpression of human blood group antigens in liver tumors.

Animals↗
PubMed1987

Mixed precipitation in gel: a new method of identification and characterization of monoclonal antibodies.

A mixed precipitation in the gel (MPG) technique is suggested for detection and characterization of monoclonal antibodies (MAbs). The MPG is based on the formation of a mixed precipitate composed of an antigen, the corresponding MAb and precipitating polyclonal antiserum. MAb incorporated into the precipitate is revealed by Fab'-peroxidase conjugate added to polyclonal antiserum. The MPG technique was applied to hybridoma screening as well as for the antigen and epitope specificity analysis of different MAbs. The MPG is a one-step, simple, inexpensive technique and valuable for the study of any antigen which could be revealed by immunodiffusion.

Agar↗
PubMed1987

[Mixed gel precipitation in the analysis of monoclonal antibodies against determinants of the carcinoembryonic antigen].

Mixed gel precipitation technique was used in the study of 5 monoclonal antibodies (MA) to carcinoembryonic antigen (CEA). The method is based on specific inclusion of MA into the precipitate formed by the antigen and polyclonal antibodies to it. The test-system for the determination of nonspecific cross-reacting antigen (NCA) has demonstrated that MA 2D10 are directed to the determinant, common for CEA and NCA, whereas MA 3C12 and 2G10 give no reaction with NCA. The specificity of MA 192 and 35 correlated with the previously established one. Mixed gel precipitation technique is recommended for primary screening and study of MA specificity to any precipitating antigen.

Animals↗
PubMed1986

Elimination of murine erythroleukemic stem cells with a novel anti-erythroid antibody conjugated to ricin A-chain: a model for studies of bone-marrow transplantation therapy.

We have produced a rat monoclonal antibody (MAb) MAE15 (IgG), specific for murine erythroid cells, using a murine erythroid cell line as immunogen. This MAb specifically binds to the surface of normal and neoplastic murine erythroid cells. Murine mature erythrocytes and non-erythroid cells as well as rat and human erythroid and non-erythroid cells are not recognized by MAb MAE15. Immunoblotting analysis and mixed precipitation in agar gel showed MAb MAE15 to be specific for murine epitope of 69 kDa antigen of erythroblasts (Ag-Eb), an interspecies antigenic marker of nucleated red cells and reticulocytes. A conjugate (immunotoxin) was prepared, comprising ricin A-chain and MAb MAE15. The immunotoxin inhibited protein synthesis of murine erythroleukemic Ag-Eb-positive K-2 cells and completely inhibited (at the concentration of 2 X 10(-7) M) spleen colony formation by erythroleukemic stem cells of the Ag-Eb-positive RAL cell line. Approximately 35% of the murine normal stem-cell (CFU-S) population was not affected by the immunotoxin at the concentration of 2 X 10(-7) M. This experimental system may be a convenient model for studies of bone marrow transplantation therapy of erythroleukemias.

Animals↗
PubMed1986

[Intralobular distribution of albumin synthetic activity in the hepatocytes of the normal and regenerating mouse liver].

Immunolocalization of albumin was investigated in normal and regenerating adult mouse liver after perfusion fixation with saponin. Light and electron microscopy have demonstrated that in normal liver the intralobular activity of albumin synthesis was distributed along the gradient decreasing from the portal tract to central vein. The uniform intensive staining of all hepatocytes was observed in regenerating liver. In addition, albumin synthesis was expressed in the epithelial cells of portal bile ducts.

Animals↗
PubMed1985

[Determination of monoclonal antibody specificity by mixed precipitation ingel].

The enzyme-immunodiffusion technique is advanced which permits testing monoclonal antibodies included in the precipitate line formed in gel by polyclonal antibodies with the corresponding antigen. Rat or mouse monoclonal antibodies were mixed with polyclonal rabbit antiserum to the antigen at issue. The precipitate formed by immunogen and rabbit polyclonal antibodies included monoclonals.

Animals↗
PubMed1982

[Changes in the nature of the hepatocyte proliferation in the liver and adenomatous nodes of mice in CC14-induced carcinogenesis].

A study was made of cell proliferation and DNA content in the liver of SWR mice after 1, 7, 41 and 52 administrations of CCl4 made at 3-4 daily intervals. After 41 and 52 administrations of CCl4 the liver of all the animals demonstrated multiple small nodules and single large nodes. Cell proliferation in liver and large nodes was analyzed by cytophotometry and radioautography with the use of double isotopic label. The proliferation pattern in the liver was shown to change during cancerogenesis. Unlike normal, a great number of cells were not polyploidized but were reproduced. As regards the cell content, the three adenomatous nodes examined differed from the surrounding parenchyma and from each other. On the whole, the degree of polyploidy in the nodes was much lower despite the fact that the population contained all the cell types, uni- and binuclear cells, up to those with the DNA content of 32c. All these cells and those from the surrounding liver were involved in proliferation. The cellular sources of nodular formations are discussed.

Animals↗
PubMed1981

[Induction of alpha-fetoprotein synthesis in nonproliferating hepatocytes].

The localization of alpha-fetoprotein (alpha-FP) and the proliferative activity of hepatocytes were studied after an insignificant liver damage. On the 3rd--6th day after the operation alpha-FP was detectable in hepatocytes localized on the boundary with the zone of damage. The most intensely stained cells were found adjacent to some vessels lying near this zone. The overwhelming majority of alpha-FP-containing hepatocytes did not incorporate 3H-thymidine. The data obtained allow a conclusion that the synthesis of alpha-FP is not related to cell proliferation.

Animals↗