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Biomedical subjects

R Baumal

Publications and source records attributed to R Baumal.

At least 73 records · Page 4Linked to original sources
PubMed1986

Production of a monoclonal antibody specific for seminomas and dysgerminomas.

A monoclonal antibody (M2A, IgG2a) was produced against a cultured human ovarian epithelial adenocarcinoma cell line, HEY. Monoclonal antibody M2A reacted with a glycoprotein of molecular weight 40,000 on the surface of HEY cells. The affinity constant of the monoclonal antibody M2A for HEY cells was 10(9) M-1, and the number of binding sites on HEY cells was 2 X 10(4) per cell. The monoclonal antibody produced positive immunoperoxidase staining of fetal (but not adult) testis and of seminomas and dysgerminomas but did not stain various normal adult tissues or other gonadal or extragonadal tumors. Monoclonal antibody M2A may be useful for confirming a histological diagnosis of seminoma and dysgerminoma.

Antibodies, Monoclonal↗
PubMed1986

Production of a monoclonal antibody against a human osteosarcoma xenograft.

Monoclonal antibodies (MAbs) against a human sarcoma xenograft carried in BALB/c nu/nu mice were produced by immunizing BALB/c mice with tumor cells and fusing their spleens with the SP2/O-Ag 14 mouse myeloma cell line. Hybridoma supernatants were screened using cryostat tissue sections and an immunoperoxidase reaction for ability to stain osteosarcoma xenograft tumor cells but not tonsil lymphocytes. Of 73 supernatants tested, 19 reacted with both osteosarcoma tumor cells and lymphocytes, while three reacted only with osteosarcoma. One of the latter hybridomas was cloned by limiting dilution to establish a line producing an IgG1 MAb (OS-1). By immunoperoxidase, this MAb stained tumor cells in surgical biopsies of primary (6 of 7) and metastatic (1) osteosarcomas and showed limited cross-reactivity with other tumors. It also cross-reacted with some basement membranes, endothelium and muscular media of blood vessels, and smooth muscle, but not with parenchymal cells of various normal tissues. This MAb may prove useful for the immunohistochemical confirmation of a diagnosis of osteosarcoma in surgical pathology.

Animals↗
PubMed1986

Distinct keratin patterns demonstrated by immunoperoxidase staining of adenocarcinomas, carcinoids, and mesotheliomas using polyclonal and monoclonal anti-keratin antibodies.

The authors assessed whether distinct patterns for keratin could be demonstrated in 10 adenocarcinomas, 10 carcinoids, and 4 mesotheliomas by an immunoperoxidase reaction using 3 polyclonal and 3 monoclonal antibodies to keratin. When color development in diaminobenzidine (DAB) was allowed to proceed for less than 2 minutes, distinct patterns for keratin could be demonstrated using two polyclonal and two monoclonal antibodies; these were plasma membrane and/or web-like in the adenocarcinomas, punctate or crescentic in the carcinoids, and perinuclear in the mesotheliomas consisting of tumor cells with abundant cytoplasm. Immunoelectron microscopy using protein A colloidal gold confirmed these results. When color development in DAB was allowed to proceed for more than 2 minutes, only diffuse staining was seen. The distinct patterns of immunostaining for keratin obtained with the shorter color development were helpful in differentiating adenocarcinomas, carcinoids, and mesotheliomas.

Adenocarcinoma↗
PubMed1986

The use of cytoskeletal characteristics of tumor cells for the diagnosis of colon and breast adenocarcinomas.

The cytoskeleton of colon (11 cases) and breast adenocarcinomas (9 cases) was characterized with the use of immunohistochemistry on tissue sections and one- and two-dimensional (2-D) gel electrophoresis of cytoskeletal extracts of tumor cells. By immunofluorescence, antibodies to epidermal cytokeratin (CK) and Mallory body CK recognized cytoplasmic filaments +/- desmosomal contacts, respectively, in both colon and breast adenocarcinomas. In addition, cytoskeletal extracts of both tumors showed similar CK polypeptides by 2-D gel electrophoresis. By immunoperoxidase, anti-actin antibody stained the apical margin of tumor cells in eight (73%) colon adenocarcinomas and four of five metastases, while diffuse cytoplasmic staining was seen in only one (9%) breast adenocarcinoma and not in five metastases. With 2-D gel electrophoresis, a cytoskeletal-associated doublet polypeptide was found in seven (64%) colon adenocarcinomas but not in the breast adenocarcinomas. By immunoblotting, the doublet did not consist of CK polypeptides, vimentin, or type IV collagen. These findings may facilitate the differentiation of colon and breast adenocarcinomas.

Actins↗
PubMed1986

Protection of adult BALB/c mice against MOPC 315 myeloma by neonatal administration of monoclonal anti-idiotypic antibody to MOPC 315 IgA.

Ascitic fluid containing monoclonal anti-idiotypic antibody (AIA) to MOPC 315 IgA was administered to newborn BALB/c mice, and the mice were challenged in adulthood with IgA-producing MOPC 315 myeloma cells. Administration of AIA D10 (a hybrid molecule containing IgG1 and IgG2a heavy chains), G3 (IgG2b), and A2 (IgG1), all of which reacted with MOPC 315 cells in a cell-binding radioimmunoassay, prolonged survival and reduced the percentage of IgA-producing spleen fragments derived from mice challenged with MOPC 315 myeloma cells, but not with cells of a related IgA-producing myeloma, MOPC 460. Reduction in the percentage of IgA-producing spleen fragments was prevented by treatment of spleen cells prior to culture with anti-Thy 1.2 antibody and complement. Administration of AIA F1 (IgG2a), which did not react with MOPC 315 cells in vitro, or of an antibody with no AIA activity did not produce a similar protection. These results suggest that administration of AIA to MOPC 315 IgA to neonatal BALB/c mice induces idiotype-specific T-lymphocytes that protect these mice against a challenge with MOPC 315 myeloma cells in adulthood.

Animals↗
PubMed1986

Cyclosporine and experimental renal ischemic injury.

To investigate the interaction of cyclosporine nephrotoxicity and renal ischemia, an animal model in rats with bilateral renal artery clamping was used. Rats given cyclosporine had a lower rate of recovery from ischemia. However, the percentages of reduction in glomerular filtration rate in vehicle and cyclosporine groups were the same in sham-operated or ischemically treated group. This suggests a superimposition of cyclosporine nephrotoxicity on the recovering kidneys rather than synergistic potentiation between ischemia and cyclosporine nephrotoxicity.

Animals↗
PubMed1986

Correlations between the 44D7 antigenic complex and the plasma membrane Na+-Ca2+ exchanger.

The exchange of Na+ for Ca2+ across the plasma membrane is mediated by a carrier transport system known as the Na+-Ca2+ exchanger. We have recently reported the specific inhibition of Na+-Ca2+ exchanger activity in cardiac and skeletal muscle sarcolemmal vesicles by monoclonal antibody 44D7. In this review, we summarize the properties of the 44D7 monoclonal antibody and the antigenic complex reacting with this antibody. The 44D7 antibody was produced against human acute lymphocytic cells and recognizes a molecular complex composed of two subunits of the apparent molecular weights 95 000 and 38 000, linked by disulfide bonds. Two other monoclonal antibodies react with the same complex:4F2 which binds to the same epitope as 44D7 and specifically inhibits the Na+-Ca2+ exchanger activity, and 44H7 which reacts with a distinct epitope and does not inhibit exchanger activity. The 44D7 antibody reacts with nerve fibers in brain and proximal convoluted tubules of kidney, both known to possess Na+-Ca2+ exchanger activity. Reactivity of 44D7 antibody with tonsil and thymus sections is restricted to certain subpopulations of cells. The reactivity of the antibody is very weak with resting lymphocytes in suspension; however, activated T lymphocytes and leukemic cells show increased binding to 44D7 antibody. Several malignant cell lines express high levels of the 44D7 antigen. The reactivity of a human hepatoma with 44D7 antibody is much greater than that observed with normal hepatocytes. The inhibition by monoclonal antibody 44D7 of the Na+-Ca2+ exchanger activity and the similarity in tissue distribution of the 44D7 antigenic complex and the exchanger system suggests that these two molecules might be related.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Animal model of grain worker's lung.

We examined the light microscopic changes in the lungs of rabbits exposed to grain dust for variable periods of time, to determine whether an animal model of grain worker's lung could be developed. Experimental animals were exposed to grain dust at a concentration of 20 mg/m3 for 7 hr/day, 5 days/week, for up to 6 months. The lungs of these rabbits demonstrated a granulomatous interstitial pneumonitis associated with exudation of mononuclear cells into the alveoli and conducting airways. These changes appeared within 5 days of the onset of exposure and reached a peak at 3 weeks but were sustained through the longest exposure interval. No abnormalities were observed in the lungs of control rabbits. These results show three points of consistency with those obtained in epidemiologic studies of grain elevator workers. First, the rapid appearance of the experimental changes suggests that the mechanism of tissue injury may not be immunologic. Second, the occurrence of the histopathologic alterations in the interstitium, alveoli, and airways corresponds with the combined restrictive and obstructive ventilatory defect described in the human epidemiologic studies. Third, the absence of lung fibrosis in rabbits exposed to dust for 6 months suggests that the pneumonitis is reversible. Thus this experimental model shows promise of helping to clarify the nature and mechanism of the adverse pulmonary effects of grain dust.

Animals↗
PubMed1986

Differential localization within human kidney of five membrane proteins expressed on acute lymphoblastic leukemia cells.

The reactivity of a panel of monoclonal antibodies (MAb) produced against non-T, non-B acute lymphoblastic leukemia cells was investigated by immunoperoxidase staining of sections of normal human kidney. The antigens of kidney reactive with the MAb were isolated by immunoaffinity chromatography and were purified further by immunoprecipitation. Two MAb, 44D7 and 44H9, reacted with determinants found exclusively on the basolateral membranes of proximal convoluted tubules. The 44D7 antigen isolated from kidney was biochemically similar to that isolated from leukemic cells. It was resolved as a multimeric complex with an apparent m.w. of 120,000 when analyzed by SDS-PAGE under nonreducing conditions. The 44H9 antigen has not yet been purified from kidney. MAb 50B4 reacted with components of the interstitium and with the mesangium of glomeruli. It immunoprecipitated a polypeptide chain of apparent m.w. 85,000, similar to that of the 50B4 antigen isolated from leukemic cells. MAb 44G4 also reacted with the mesangium of glomeruli and with the interstitium of the kidney. However, the endothelium of glomerular capillaries and of interstitial blood vessels has also reacted with MAb 44G4. The kidney antigen recognized by MAb 44G4 was characterized as a major polypeptide band, 95,000 m.w. (reduced) and 125,000 m.w. (nonreduced), a subunit structure analogous to the 44G4 antigen isolated from leukemic cells. MAb 44E3 reacted with all cellular elements of glomeruli, tubules, blood vessels, and interstitium. Two polypeptide chains of apparent m.w. 94,000 and 90,000 were immunoprecipitated from kidney by MAb 44E3, while a single polypeptide chain of 94,000 m.w. was precipitated from leukemic cells. Our results describe five new antigens with distinctive cellular distributions within kidney.

Animals↗
PubMed1986

Mode of inheritance of Samoyed hereditary glomerulopathy: an animal model for hereditary nephritis in humans.

The pedigree of a line of Samoyed dogs with Samoyed hereditary glomerulopathy (SHG) was investigated to determine the mode of inheritance. Sixty percent of males were affected with severe renal disease that progressed to renal failure before 15 months of age. In contrast, female carriers showed less severe involvement and their disease did not progress to renal failure. This pattern is consistent with the inheritance of an X-linked dominant gene. A similar mode of inheritance has been postulated in some families with hereditary nephritis. Further similarities between SHG in dogs and hereditary nephritis in humans have been demonstrated previously in clinical and renal morphologic studies. The present study supports the view that this line of Samoyed dogs would be an appropriate model for studying the human disease.

Animals↗
PubMed1986

Monoclonal antibodies to an epithelial ovarian adenocarcinoma: distinctive reactivity with xenografts of the original tumor and a cultured cell line.

Four monoclonal antibodies (mAb) (8C, 10B, M2A, and M2D) were produced against the human epithelial ovarian adenocarcinoma cell line, HEY. The affinity constants of binding of the mAb to cultured HEY cells were 8 X 10(8) M-1 (M2D) and 10(9) M-1 (8C and 10B). mAb 8C reacted with a major glycoprotein of Mr 90,000 on the surface of HEY cells. The four mAb differed from previously reported mAb to epithelial ovarian adenocarcinomas on the basis of their reactivity with cultured ovarian adenocarcinoma cell lines using a cell-binding radioimmunoassay, and their staining of cryostat sections of various human normal and tumor tissues using an immunoperoxidase reaction. All four mAb reacted with s.c. tumors derived by injecting cultured HEY cells into thymectomized CBA/CJ mice. However, only two of the four mAb (8C and 10B) also reacted with s.c. tumors of the original HEY xenograft from which the cultured cell line was derived. In addition, mAb 8C and 10B reacted by immunoperoxidase staining with 2 and 4 different cases, respectively, of 11 epithelial ovarian adenocarcinomas examined. Cultured HEY cells were adapted to grow i.p. in BALB/c-nu/nu mice and the i.p. tumors retained their reactivity with the monoclonal antibodies. These tumor-bearing mice offer a useful model system for studying the potential of mAb, especially 8C and 10B, for the diagnosis and treatment of patients with peritoneal extension of epithelial ovarian adenocarcinomas.

Adenocarcinoma↗
PubMed1986

Samoyed hereditary glomerulopathy (SHG). Evolution of splitting of glomerular capillary basement membranes.

Samoyed hereditary glomerulopathy (SHG) in dogs resembles hereditary nephritis (HN) in man. Affected males and carrier females spontaneously develop proteinuria, but only males progress to renal failure. We examined the evolution of splitting of glomerular capillary basement membranes (GCBM) in affected male and carrier female dogs. At birth, examination by light microscopy (LM) in all dogs showed normal glomerular capillaries, but by electron microscopy (EM), many GCBM showed separation of endothelial from visceral epithelial cell basement membranes. By LM, glomerular capillaries of affected males appeared normal for up to 4 months, but then isolated and eventually all capillaries became thickened and split. However, by EM, a bilaminar appearance of the GCBM was seen within 1 month which evolved into multilaminar splitting that became extensive as renal failure ensued. Carrier females showed mild nonprogressive changes in GCBM. These results with SHG permitted speculation on the evolution of splitting of GCBM in human HN.

Animals↗
PubMed1985

Immunohistochemical staining of macrophages in the skin lesions of leprosy: the role of antibody to mycobacteria in human serum and various polyclonal immune rabbit antisera.

Immunohistochemical staining of tuberculoid and lepromatous leprosy skin lesions was performed using various rabbit antisera. Macrophages in both stained with serum containing antibodies against lysozyme and alpha-1-antitrypsin, while macrophages in lepromatous leprosy also reacted with other antibodies. An immunoglobulin fraction of positive serum stained following pepsin digestion, indicating that reactivity was not Fc dependent. Positive serum contained antibody against Mycobacterium butyricum, which caused macrophage staining, since affinity-purified antibody did not stain and absorption with M. butyricum removed staining. Staining was also produced by serum of subjects with leprosy or a positive tuberculin test. By immunoblotting, the anti-mycobacterial antibody was directed against surface components of M. butyricum of molecular weights 20 000-70 000. Electron microscopy showed M. leprae in phagolysosomes of macrophages, while immunoelectron microscopy demonstrated labelling along bacterial cell membranes. Therefore, macrophages in lepromatous leprosy skin lesions stain because they contain M. leprae, which reacts with antibody to either M. leprae, M. tuberculosis or atypical mycobacteria in human serum and with antibody to M. butyricum in serum from rabbits immunized with various antigens and Freund's complete adjuvant. These results indicate that immunohistochemical studies on leprosy are misleading if performed using intact polyclonal immune sera rather than affinity purified or monoclonal antibodies.

Antibodies, Bacterial↗
PubMed1985

Abnormal mitochondria on a renal biopsy from a case of mitochondrial myopathy.

Mitochondrial myopathy (MM) is reported in a 5-year-old girl with short stature, hypotonia, ptosis, retinal pigmentation, and Fanconi's syndrome. A muscle biopsy showed the characteristic features of MM, and a renal biopsy revealed abnormal mitochondria in tubular cells that were similar to those seen in the muscle. This is the first report of such findings in association with MM.

Child, Preschool↗
PubMed1985

Myoepithelial cells in salivary gland tumors. An immunohistochemical study.

Normal salivary glands and 55 salivary gland tumors were examined by immunostaining (immunoperoxidase [IMP] and immunofluorescence [IMF]) to identify myoepithelial cells (MCs) and speculate on their role in the histogenesis of the tumors. The classic (C) MCs of normal salivary glands stained by IMP with antibodies to cytokeratin and S100 protein and stained by IMF with the same antibodies and with antibodies to vimentin and actin. Modified (M) MCs of pleomorphic adenomas stained positively by IMP and IMF with all of the preceding antibodies. In many mucoepidermoid carcinomas, adenoid cystic carcinomas, and basal cell adenomas, variable numbers of CMCs and MMCs stained positively by IMP with anti-cytokeratin and anti-S100 protein antibodies. No MCs were detected in adenolymphomas or acinic cell carcinomas. We believe that MCs play a major role in the histogenesis of pleomorphic adenomas and may also be important in many mucoepidermoid carcinomas, adenoid cystic carcinomas, and basal cell adenomas.

Actins↗