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Biomedical subjects

M Mirowski

Publications and source records attributed to M Mirowski.

At least 37 records · Page 2Linked to original sources
PubMed1998

A 65 kDa oncofetal protein (p65), proliferating cell nuclear antigen (PCNA) and Ki67 expression in breast cancer patients.

Paraffin-embedded tissue slides from 89 infiltrating ductal breast carcinoma, 10 fibrocystic disease and 10 fibroadenoma were assessed immunohistochemically using monoclonal antibodies against human p65 antigen and polyclonal antibodies against p65-like protein present in fetal bovine serum. We did not find any evident differences in p65 detection by polyclonal and monoclonal antibodies, however, monoclonal antibody seems to be more specific. This factor is not induced by cellular proliferation associated with nonneoplastic diseases what was confirmed by immunohistochemical analysis of expression of p65 protein and well know markers of proliferation (proliferating cell nuclear antigen--PCNA and Ki67). It was established that there is no correlation between p65 and PCNA or Ki67 expression. High proliferating indexes (PI) for PCNA (PI-PCNA) or Ki67 (PI-Ki67) may help in selection of tumors with high proliferating activity independently from histological grade of malignancy established by routine methods. The estimation of p65 protein may be useful in the selection of precancerous changes and more differentiated ductal cancer of the breast what raises the possibility that p65 antigen may be helpful in the screening examination of women with high risk for cancer development.

Animals↗
PubMed1997

Expression of 65-kDa oncofetal protein in experimental hepatoma after anticancer therapy.

We have tested the expression of a 65-kDa oncofetal protein (p65) after combined treatment with menadione and methotrexate in hamsters transplanted with Kirkman-Robins hepatoma. The treatment of tumor-bearing animals with these compounds significantly inhibited both the tumor development and the expression of p65. This inhibition in tumor tissue was calculated from densitograms of Western blots. The inhibition of p65 expression was also confirmed in the serum of hepatoma bearing animals by using solid-phase radioimmunoassay (RIA) to quantify the specificity of polyclonal antibodies to fetal p65 molecules. Additionally, p65 was shown to localize both in cytoplasm and in the nuclear extracts prepared from hepatoma tissue.

Animals↗
PubMed1996

Expression of an oncofetal 65-kDa phosphoprotein in lymphocytic and granulocytic leukemias.

We examined the expression of an oncofetal 65-kDa phosphoprotein, termed p65, in patients with lymphocytic and granulocytic leukemia. This protein was previously identified in rat fetal tissues and in epithelial cancers of rat and human origin. Using the anti-p65 monoclonal antibodies MB2 and MF11 in a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA), we analyzed the expression of the protein in sera of 80 normal, healthy controls and in 61 patients with benign, nonneoplastic diseases. We established that the upper level of normal p65 concentration is 115 U/ml p65 (mean plus two standard deviations above the mean in a control group). We also analyzed p65 levels in sera of 71 patients with leukemia in different stages of development. The level of p65 was well above normal in 95% of acute lymphocytic leukemia (ALL; 19 cases), 83% of acute myeloblastic leukemia (AML; 23 cases), 37% of chronic lymphocytic leukemia (CLL; 19 cases), and 30% of chronic myelogenous leukemia (CML; 10 cases). MB2 monoclonal antibodies were used for immunocytochemical staining of isolated lymphocytes from normal peripheral blood and from blood of leukemic patients (in 12 CLL patients, the p65 positivity was 83%, in 2 ALL patients, 100%, and in 4 AML patients, 75%). Our data suggest that p65 protein may be of use as a tumor marker in leukemia.

Adult↗
PubMed1996

Characterization of proteins from chronic lymphocytic leukaemic cells: electrophoretic and immunological approach.

The protein composition of cellular fractions (nuclear, mitochondrial, microsomal and cytosolic) from normal and B-chronic lymphocytic leukaemia (CLL) cells isolated by differential centrifugation was analysed by SDS-polyacrylamide gel electrophoresis. Some diversities in electrophoretic characteristics of proteins from various compartments of normal and leukaemic cells were observed, mainly among nuclear proteins. Comparison of nuclear proteins from CLL cells of patients with different stages of the disease revealed that an expression of some specific for leukaemic cells components, especially a polypeptide (MW 46 kD) might be correlated with a stage of CLL. Immunoblotting analysis in the presence of antiserum raised against cancer-associated antigen, described as p65 indicated the association of this particular antigen with a nuclear fraction of leukaemic cells.

Adult↗
PubMed1996

Presence in bovine fetal serum of the protein antigenically related to p65-tumor associated antigen: its isolation and polyclonal antibody production.

Monoclonal antibodies raised to the 65-kDa tumor-associated protein (p65) isolated from a human breast cancer cell line have been used to detect an antigenically related protein (p65-like) present in fetal bovine serum (FBS) by Western blot analysis. We have isolated the p65-like protein from FBS by isoelectrofocusing (IEF) on native gels followed by electrophoresis in 12.5% polyacrylamide gel containing 0.1% SDS (SDS-PAGE). Immunostaining with anti-p65 monoclonal antibody of fetal bovine serum fractions separated by electrophoresis on cellulose acetate membrane revealed that the p65-like protein had a location similar to one of gamma-globulin. This protein migrates as a single band upon electrophoresis in SDS-PAGE and had four isoforms which migrate as two doublets with pI's of approximately 5.0 and 5.3.

Animals↗
PubMed1994

Serological and immunohistochemical detection of a 65-kDa oncofetal protein in breast cancer.

Sera from 132 breast cancer patients and 112 healthy female controls were tested with a double-antibody sandwich ELISA using two different monoclonal antibodies against the 65-kDa oncofetal protein, termed p65. Of cancer sera, 90.2% were positive for p65. The average level of p65 was 466.5 +/- 243.8 ng/ml (mean +/- S.D.) in carcinomas and 37.4 +/- 29.5 ng/ml (mean +/- S.D.) in controls (P < 0.0005). A selected group (n = 15) of these 132 patients were needle-biopsied and assessed immunohistochemically using monoclonal antibodies against p65. Nucleocytoplasmic expression was found in 12 patients (80%) using monoclonal antibodies. Expressions of p65 were concordant in 13 (86%) cases between serum and tumour tissues, but did not correlate with tumour DNA ploidy, histological grade or hormone receptors levels. Sera were also tested for CA 15-3 with the average value in cancer serum being 132.4 +/- 14.0 U/ml; there was no significant concordance between the two markers. Thus, p65 may be a potential serum and/or immunohistochemical marker for breast carcinoma.

Adult↗
PubMed1993

Comparative structural analysis of human and rat 65 kDa tumor-associated phosphoproteins.

1. A 65 kDa-tumor-associated protein (p65) was isolated from human and rat carcinoma cell culture media. Antibodies raised to the rat protein recognized an antigenically related protein in human cancer cell line. 2. Amino acid composition, N-terminal and internal sequence as well as peptide map and western blot analysis of the p65 strongly suggest a high degree of homology between the human and rat p65 proteins. 3. Homology searches indicated that p65 was not homologous to previously sequenced proteins, but that it may be related to proteins of the steroid receptor superfamily of genes, especially c-erb A gene.

Amino Acid Sequence↗
PubMed1993

Monoclonal antibodies against a 65-kDa tumor-associated phosphoprotein: development and use in cancer detection.

Five hybridoma cell lines secreting monoclonal antibodies (MAbs) to a 65-kDa tumor-associated phosphoprotein (p65) were established. Purified to homogeneity, p65 was used as an immunogen to induce immune response in C57BL/6N mice. Splenocytes were fused with mouse myeloma cells and hybridoma lines were selectively subcloned. A rapid and sensitive sandwich type ELISA, using purified MAbs was established to measure markedly elevated amounts of p65 in sera obtained from both tumor-bearing rats and from cancer patients. The p65 from rat and human sources was added quantitatively to normal sera to construct standard curves. The average level of p65 in normal rat sera was 38 ng/ml +/- 13 ng/ml (mean +/- SD), and in sera from rats bearing mammary adenocarcinomas, the average value was 1005 +/- 140 ng/ml. In normal human sera the mean level of p65 was 34 +/- 35 ng/ml (mean +/- SD) and sera of patients with variety of cancers had an average p65 value of 344 +/- 57 ng/ml. More than 80% of tested sera from adenocarcinoma-bearing rats (20/24) as well as from cancer patients (82/98) had p65 levels elevated two standard deviations above the mean. Overall the assay had a sensitivity of 80.9% and specificity of 85%. The purified IgG1 MAbs, with high titers and strong anti p65 specificities were also used to develop an immunohistochemical method to visualize the expression of p65 in rat tumor tissue sections. The HB2, HF11 and RE6 cell lines have proved to be quite stable in the ability to secrete anti-p65 MAbs.

Animals↗
PubMed1993

Demonstration of a 65 kDa tumor-specific phosphoprotein in urine and serum of rats with N-methyl-N-nitrosourea-induced mammary adenocarcinomas.

Polyclonal antibodies against a 65 kDa tumor-associated phosphoprotein (p65) were used to develop an ELISA to analyze the presence of p65 in urine and serum of rats bearing N-methyl-N-nitrosourea-induced mammary gland adenocarcinomas. Highly purified rat p65 was added to normal urine and serum to establish a quantitative standard curve with the average correlation coefficient being 0.98 and 0.99 respectively. All samples of urine and serum obtained from different carcinoma-bearing rats showed p65 concentrations above the normal levels found in the control urine and sera. The correlation coefficient between tumor burden and p65 concentration in urine and serum was 0.65 and 0.77 respectively. The average levels of p65 in normal urine and normal serum were 37.0 +/- 32.0 and 48.0 +/- 38.0 ng/ml respectively. In the case of urine obtained from rats bearing mammary adenocarcinomas, the mean p65 level was 119.0 +/- 35.9 ng/ml and their serum level was 225.4 +/- 67.5 ng/ml. Sensitivity, specificity and predictive value for serum and urine marker elevation were 78.5, 70.0 and 78.5% respectively. Following in vitro phosphorylation of concentrated urinary proteins, isoelectrofocusing, SDS-PAGE and autoradiography, a phosphorylated form of the 65 kDa protein with a pI of 5.8 was identified in the urine of tumor-bearing rats. This phosphoprotein bound to an antiphosphotyrosine monoclonal antibody and an anti-p65 polyclonal as determined by Western blot analysis. Using the anti-p65 antibodies in an immunoprecipitation procedure, the main radio- and immunoactive band of 65 kDa and two lower mol. wt bands of 50 and 41 kDa, apparently representing degradation products of p65, were identified after in vitro and in vivo phosphorylation of urinary proteins obtained from mammary carcinoma-bearing rats.

Adenocarcinoma↗
PubMed1993

[Specific inhibitors of plasminogen activators].

The article contains a survey of the recent papers on the fibrinolytic inhibitors which regulate the process of plasminogen activation--PAI-1 and PAI-2. Both of them belong to serine protease inhibitors family and are specific for tPA as well as uPA, forming stable complexes in molar ratio 1:1 with them. PAI-1, secreted mainly by endothelial cells and platelets, is the main plasmic inhibitor of plasminogen activation. PAI-2, originated essentially from placenta, appears in blood during pregnancy.

Animals↗
PubMed1992

The automatic implantable cardioverter-defibrillator. Long-term clinical experience and outcome at a hospital without an open-heart surgery program.

From November 1982 through April 1989, 111 patients with refractory sustained ventricular tachycardia/fibrillation had the automatic cardioverter-defibrillator implanted at our institution, the first community hospital involved in implantation of such a device. We have reviewed our long-term clinical experience to assess the feasibility, learning curve, and efficacy of device implantation in a facility with cardiac electrophysiology expertise but without open-heart surgery facilities. All patients were considered inoperable or at high risk for other concomitant surgery. Eighty-six patients (77%) underwent uneventful implantation. Nine patients (8%) died prior to hospital discharge. Operative mortality declined from 10.9% to 5.4% during the first half (55 patients; November 1982 through September 1986) and second half (56 patients; October 1986 through April 1989) of the experience. Other postoperative complications occurred in 16 patients (14%), 12 of whom experienced complications during the first half of the experience. At 22 +/- 20 (mean +/- SD) months' follow-up, 78 (76%) of 102 patients discharged were alive, and 24 patients (24%) had died. Fifty patients (49%) had experienced at least one automatic cardioverter-defibrillator discharge associated with hypotensive symptoms. The actuarial incidence of sudden death at 1, 2, and 3 years was 1.2%, 5.5%, and 6.2%, respectively. We concluded that the automatic implantable cardioverter-defibrillator is an effective therapy for refractory ventricular tachycardia/fibrillation and that device implantation at community hospitals with an experienced cardiac electrophysiology team is both feasible and practical.

Adult↗
PubMed1992

Purification and characterization of a 65-kDa tumor-associated phosphoprotein from rat transplantable hepatocellular carcinoma 1682C cell line.

We have isolated a homogeneous tumor-associated phosphoglycoprotein of about 65 kDa (p65) by ammonium sulfate precipitation of proteins from conditioned medium containing the rat transplantable hepatocellular carcinoma 1682C cell line, followed by high-performance liquid chromatography on molecular-sieving and phenyl hydrophobic interaction columns. The protein was concentrated in a Rotofor isoelectric focusing cell and finally separated by isoelectrofocusing followed by SDS--polyacrylamide gel electrophoresis. We achieved a purification of approximately 11,000-fold after the Rotofor concentration step. This protein migrated as a single band upon electrophoresis in SDS-PAGE and had a pI of 5.8 in isoelectrofocusing gels. The carbohydrate content of the blotted phosphoglycoprotein was analyzed by probing the blots with biotinylated lectins; a positive reaction was detected with concanavalin A, wheat-germ agglutinine, and Ricinus communis agglutinine. To confirm the tumor origin of this molecule, hepatocellular carcinoma cells were labeled in vivo using [32P]orthophosphate as well as [35S]methionine and cell culture medium was analyzed for the presence of radioactive band that corresponds with our protein. Phosphoamine acid analysis by thin-layer chromatography showed the presence of phosphotyrosine, phosphothreonine, and phosphoserine, which was later confirmed by analysis of the amino acid composition. Using the method described by Marchalonis and Weltman for comparative analysis of protein structure and evolution, we compared the protein isolated by us with other tumor markers and proteins showing similar properties and found no significant similarities.

Animals↗
PubMed1991

[Plasminogen activator inhibitors from neoplastic tissues].

This article contains a survey of works, published in the last few years on plasminogen activators inhibitors in neoplastic tissues. These inhibitors belong to a heterogenous group of proteins, having different molecular weights and specific ways of acting. They exemplify immunological relationship to known inhibitors of fibrinolysis from normal tissues--i.e. the inhibitors from endothelial cells--(PAI-1) and placental inhibitor--(PAI-2). To PAI-1 type belong: acid-stabile inhibitor of fibrinolysis with Mr 50,000 from HTC hepatoma cells in rats, acid-labile inhibitor Mr 42,770 produced by HepG2 human hepatoma cells; the inhibitor with Mr 54,000 from HT 1080 human cells from fibrosarcoma and single-chain acid-stabile inhibitor with Mr 50,000 from MJZJ melanoma cells. In PAI-2 type we can mention the inhibitor with Mr 47,000 from U-937 histiocytic lymphoma cells.

Animals↗
PubMed1990

Fibrinolytic activity of rat plasma during development of Guerin epithelioma.

Fibrinolytic activity in the blood of rats during the development of Guerin epithelioma was studied. It was measured by means of radiometric method, based on the amount of plasmin degradation products released from 125I-fibrin, as well as by means of amidolytic technique with the use of Chromozym PL. During the initial phase of epithelioma development the fibrinolytic activity of plasma, determined after inactivating plasma proteinase inhibitors, increases. It also increases in the euglobulin fraction. Simultaneously, the content of fibrin(ogen) degradation products (FDP) increases in the blood. During the stage of the intensive development of neoplastic disease fibrinolytic activity as well as plasminogen activator activity become inhibited, whereas the concentration of FDP retains the level observed in healthy animals. Inhibition of fibrinolytic activity in the later phase of the disease coincides with the appearance of low-molecular weight antifibrinolytic factor in the blood of rats loaded with epithelioma.

Animals↗