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Biomedical subjects

L D Papsidero

Publications and source records attributed to L D Papsidero.

At least 37 records · Page 2Linked to original sources
PubMed1983

Monoclonal antibody (F5) to human prostate antigen.

Hybridoma culture F5 has been developed which secretes monoclonal antibody (McAb) directed to an epitope of a prostatic glycoprotein of Mr 34 kD (Prostate Antigen, PA). Tissue levels of PA have been evaluated using a competitive-binding enzyme-immunoassay based upon the inhibition of McAb binding activity to purified antigen. Results indicated the specific occurrence of high antigen concentrations in extracts prepared from prostatic tissues. The antigenicity of epitope F5 is resistant to tissue fixation and embedding protocols, and has been demonstrated upon immunoperoxidase staining procedures. Immunoperoxidase data strongly indicate that McAb F5 possesses a singular specificity towards prostatic epithelial cells. Other tissues, whether normal or cancerous, fail to express this determinant. Specimens examined included epithelial and nonepithelial tissues along with a panel of carcinomas and sarcomas. The antibody was able to detect tumor cells at extra-prostatic sites and represents a powerful probe for the detection and differential diagnosis of metastatic cancer of the prostate.

Animals↗
PubMed1983

Circulating antibody to prostate antigen in patients with prostatic cancer.

A reverse enzyme-linked immunosorbent assay (ELISA) modified from a prostate antigen (PA) assay previously reported has been developed to measure circulating PA-binding globulin (PABG). Serum specimens taken from normal males, normal females, male patients with nonprostatic cancers, patients with benign prostatic hypertrophy, and patients with various stages of prostate cancer were analyzed for PABG. Results revealed that only patients with an advanced stage of prostatic cancer exhibited an elevated level of PABG. PABG was then isolated from prostatic cancer patients' serum by PA affinity chromatography. Upon immunodiffusion and immunoelectrophoresis, this PABG preparation reacted with purified PA, anti-PA xenoantibodies and anti-human IgG. By the immunoperoxidase technique, PABG stained positively in prostatic ductal epithelial cells and negatively in all other tissues examined. An additional PABG preparation, which reacted with anti-PA and anti-human IgG and not with purified PA, was also isolated by an anti-PA affinity chromatography. These PABG preparations were separately subjected to high-performance liquid chromatography for further purification. Three major protein peaks at Mr of greater than 240K, 150K, and 34K were obtained. These results demonstrated that circulating IgG antibody reactive with PA was present in patients with metastatic cancer of the prostate, and this in part was in complexed form with PA and was specifically reactive with ductal epithelial elements of the prostate.

Animals↗
PubMed1983

Monoclonal antibodies (F36/22 and M7/105) to human breast carcinoma.

Cloned hybridoma cell lines were obtained from fusions of murine myeloma cells with lymphocytes of mice immunized against human breast cancer cells. Hybridomas F36/22 and M7/105 produced antibodies whose binding to breast cancer cells could not be inhibited by prior absorptions with fibroblasts, lymphoblastoid cells, or erythrocytes. Results from cell surface binding assays using a panel of tumor cell lines indicated that antibodies F36/22 and M7/105 recognized determinants expressed maximally on breast cancer cells. Antibody F36/22 reacted with normal mammary epithelial membranes and milk fat globule membranes, whereas antibody M7/105 produced no detectable binding to these specimens. Antigens carrying these epitopes each showed reactivity with concanavalin A lectin. The determinant corresponding to antibody F36/22 was detectable in histological sections of a subset of breast tumors obtained at surgery.

Adenocarcinoma↗
PubMed1983

Tissue distribution of an epithelial and tumor-associated antigen recognized by monoclonal antibody F36/22.

Murine monoclonal antibody F36/22 was derived by immunizing BALB/c mice with human breast cancer cells. This antibody reacts with an antigen located both on differentiated mammary ductal epithelia and on breast carcinomas, as examined by indirect immunoperoxidase techniques. Although the expression of this antigen correlated with estrogen receptor levels of breast tumors, antibody F36/22 did not directly react with estrophilin. In contrast to the expression of classical differentiation antigens, this antigen was found in a high percentage of poorly differentiated carcinomas of the breast. Staining intensities were similar for well- and poorly differentiated tumors; thus, antigen expression was not related to tumor grade. Intratumoral heterogeneity of antigen expression was observed in the majority of tumors. Since a subset (64 of 80) of the breast carcinomas examined have expressed the antigen, McAb 36/22 was of use for the immunological subclassification of tumors which were indistinguishable by conventional histopathological staining techniques. The antigen was also present on other adenocarcinomas (ovary, colon, stomach, pancreas, and prostate); however, these tumors usually exhibited reduced staining intensity compared with that observed in breast cancer. The normal counterpart tissues at these histotypes contained no detectable levels of the antigen, and increased expression of the antigen was associated with tumorigenesis at these sites. Tumors of mesenchymal origin and carcinomas other than adenocarcinomas exhibited undetectable levels of the antigen. Therefore, depending on the organ site, McAb F36/22 recognizes an epithelial and/or tumor-associated antigen.

Animals↗
PubMed1982

Hybridoma antibody to breast cancer immune complexes.

Hybridoma clones were established by fusing spleen cells from mice immunized with purified breast cancer-related immune complexes to drug-resistant nonproducing myelomas. Hybridoma cultures were evaluated for antibody production using immunofluorescence, radioimmunoassay and immunoperoxidase techniques. One antibody demonstrated strong reactivity against breast tumor cells (BT-20) in culture and also was found to bind ductal epithelial cells within sections of human mammary tissue. Antigen was detected within the soluble fraction of breast tumors with molecular weight greater than 500 K. The possible relationship between antigen detected in breast tumor cells and in immune-complexed form is discussed.

Antibodies, Monoclonal↗
PubMed1982

Multiple marker evaluation in human prostate cancer with the use of tissue-specific antigens.

Serum prostate-specific antigen and prostatic acid phosphatase were simultaneously evaluated in 22 healthy males, 29 patients with benign prostatic hypertrophy, and 192 patients with prostate cancers at various stages as well as in 30 patients with cancers other than prostate cancer. Both markers were quantitated by specific sandwich-type, enzyme-linked, immunosorbent assays with the use of specific antiserum reagents. Serum assays revealed a discordance between these two markers; thus expressions of these two biochemically and immunologically distinct prostate-specific proteins may reflect different aspects in the biology of prostate cancer. A combination test with the use of 7.5 ng of prostate antigen and 15.5 ng of prostatic acid phosphatase/ml of serum, respectively, as cutoff values resulted in a positive detection rate of 58% for prostate cancers of stages A (7/12) and B (21/36) each, 68% for prostate cancer of stage C (19/28), 92% for prostate cancer of stage D (106/116), and only 10% for benign prostatic hypertrophy (3/29). None of 52 other cancers or healthy controls was registered as positive. This study demonstrates that a multiple marker test of tissue-specific antigens can be of an additive value in the immunodiagnosis of cancer and may be a logical and effective approach at this time, in light of the unavailability of human tumor-specific markers.

Acid Phosphatase↗
PubMed1981

Purification and characterization of a human pancreas-specific antigen.

A pancreas-specific antigen was identified by immunologic techniques and purified from saline extract of human pancreas. The purified pancreas-specific antigen was shown to be homogeneous by polyacrylamide gel electrophoresis under both denaturing and non-denaturing conditions. It had a molecular weight of 44000 as estimated by gel filtration or sodium dodecyl sulfate-gel electrophoresis, and a sedimentation coefficient of 3.4 S as analyzed by sucrose gradient centrifugation. Pancreas-specific antigen possessed an isoelectric point of 4.9 and migrated to alpha-beta region upon immunoelectrophoresis. By colorimetric assay procedures, pancreas-specific antigen exhibited no enzyme activity, such as amylase, protease, esterase, lipase, acid phosphatase, alkaline phosphatase peroxidase, deoxyribonuclease or ribonuclease. Immunoreactivity of pancreas-specific antigen was sensitive to proteolytic enzymes, perchloric acid and high temperature (70 degrees C, 10 min); but insensitive to neuraminidase or beta-glucosidase. Immunohistochemical staining revealed that pancreas-specific antigen was located in acinar cells of human pancreas. In addition, a higher concentration of pancreas-specific antigen was detected in pancreatic juice than in the saline extract of pancreas. This newly identified pancreas-specific antigen, therefore, may be a useful marker protein in physiological studies of pancreas and pancreatic secretion.

Animals↗
PubMed1981

Isolation, characterization and clinical evaluation of a pancreas cancer-associated antigen.

A pancreas cancer-associated antigen (PCAA) was identified and isolated from ascites fluid of human pancreatic cancer. Purified PCAA was homogeneous as determined by polyacrylamide gel electrophoresis. PCAA was a glycoprotein with a molecular weight of approximately 1,000,000 and consisted of 20% carbohydrates and 80% peptides, had an isoelectric point of 4.7, and migrated to alpha 2-beta region. It possessed a sedimentation coefficient of 14S and appeared to be a fibrous or fibroglobular protein. Immunoreactivity of PCAA was sensitive to proteolytic enzymes, perchloric acid, KSCN, glycine-HCl at pH 2.5, urea and lithium diiodosalicylate; and insensitive to neuraminidase or beta-glucosidase. Immunohistochemical technique revealed that PCAA was located in the cytoplasm of ductal epithelial cells of malignant pancreas. Using heteroantiserum raised against purified PCAA, horseradish peroxidase and CNBr-activated Sepharose 4B, an enzyme-immunoassay (EIA) for circulating PCAA has been developed. From a group of 40 healthy blood donors, an upper limit of 16.2 micrograms of PCAA/ml of serum has been tentatively determined. An elevated PCAA was shown in 67% (29/43) of patients with pancreas cancer, as well as in 30% (11/36) of lung cancer patients, 27% (10/37) of colonic cancer patients, and in 16% (6/36) of breast cancer patients. The reactive antigen in sera of these cancers was shown to be immunologically identical. PCAA also was detected in extracts of various human tissues, particularly pancreatic tumors, colonic tumors, and in a normal colon. Further, PCAA exhibited heterogeneity in molecular weight, isoelectric point, and electrophoretic mobility.

Animals↗
PubMed1981

Prostate antigen: a new potential marker for prostatic cancer.

A prostate-specific antigen, distinct from acid phosphatase, was identified by immunologic procedures in prostate tissues (normal, benign hypertrophic, and cancerous) and seminal plasma, as well as in sera of patients with prostatic cancer and of nude mice bearing human prostatic tumor. This antigen was shown by immunoperoxidase staining to be confined to epithelial cells comprising the prostatic ductal elements. Prostate antigen was purified from prostatic tissue and seminal plasma, and it was shown to have a molecular weight of 33,000-34,000 with no subunit component. The isoelectric point of purified antigen was around 6.9, though several unpurified isomers with different isoelectric points also were observed. Serum-borne prostate antigen showed a molecular weight of 90,000-100,000 but it exhibited a molecular weight of 36,000 in the presence of sodium dodecyl sulfate. A sandwich-type, peroxidase-linked immunosorbent assay capable of detecting 0.1 ng of the antigen per milliliter of blood was developed. With this technique, serum level of the antigen was found to increase in patients with prostatic cancer as compared with normal males. The prostate-specific antigen can be a useful marker for detection of prostatic cancer.

Antigens↗
PubMed1981

Purification of a human pancreas-specific antigen.

Using an antibody reagent, an organ-specific antigen has been purified from human pancreas. Purification was achieved using ammonium sulfate and ethanol precipitations, concanavalin A-Sepharose affinity chromatography, anion-exchange chromatography and gel filtration. The antigen had a molecular weight of approximately 68,000 as determined by gel filtration, was not dissociated into subunits by sodium dodecyl sulfate, and did not bind to immobilized concanavalin A. The biological significance of this antigen in pancreatic cancer is being studied.

Animals↗
PubMed1981

Prostate antigen: a marker for human prostate epithelial cells.

Specificity of a previously reported prostate antigen (PA) was assessed by several immunologic procedures. This antigen, restricted in distribution to the prostate gland, was detected within ductal epithelial cells. Continuous established cell lines LNCaP and PC-3 of malignant prostate origin retained the expression of PA. Tumor cells released the antigen in vitro into the culture fluid and also in vivo into the circulation of nude mice preinoculated with LNCaP cells. Prostate cells in culture also specifically accreted immunoglobulin fragments of PA antiserum.

Animals↗
PubMed1981

Detection of a breast tissue-associated antigen by antiserum to Raji cell-bound circulating immune complexes of human breast cancer.

Rabbits tolerant to human immunoglobulin G were used to raise antisera against the Raji cell-bound circulating immune complexes from human breast cancer sera. After solid-phase adsorption treatment with glutaraldehyde-cross-linked normal human plasma, acetone-extracted normal liver tissue powder, and glutaraldehyde-fixed Raji cells, one antiserum reacted specifically with breast tissue extracts but not with extracts of other tissues, as examined by a counterimmunoelectrophoresis technique. Immunological reactivity of the treated antiserum was removed by incubation with normal, primary, or metastatic breast tumor tissue extracts. Incubation with normal human serum or extracts derived from tissues other than the breast showed no neutralizing effect on the antibodies. This specific antiserum reagent was used in a modification of the Raji cell radioimmunoassay. Raji cells were incubated with sera from cancer patients or normal controls and then reacted with 125I-labeled F(ab')2 fraction of the treated antiserum reagent. The amount of 125I-F(ab')2 bound was then determined. Although all sera exhibited elevated circulating immune complexes by the conventional Raji cell radioimmunoassay, 14 of 18 breast carcinoma sera demonstrated a significant uptake when compared with the normal population group as opposed to five (three lung and two colon) of 29 other cancer sera examined (p less than 0.001). An immunologically reactive breast tissue-associated antigen, purified from malignant breast tumor or normal breast tissue extracts with the use of antiserum reagent, exhibited an apparent molecular weight of 85,000 by sodium dodecyl sulfate; polyacrylamide gel electrophoresis and a pI value of 4.9 +/- 0.2. These results demonstrated that a breast tissue-associated antigen rather than a breast tumor-associated neoantigen, was involved in circulating immune complexes of breast cancer patients as detected by Raji cell immunoassay. It also implied the occurrence of disease-related autoimmunity in human breast cancer.

Antigen-Antibody Complex↗
PubMed1981

Use of human prostate-specific antigen in monitoring prostate cancer.

The newly reported human prostate-specific antigen (PA) is a specific histiotypic product of human prostate. With the use of a sensitive enzyme immunoassay, the circulating PA in prostatic cancer patients has been evaluated clinically. In 96 patients with advanced stage of disease (D2) and receiving chemotherapies, the pretreatment serum PA levels were found to be of prognostic value with regard to the patient survival. Ten patients with metastatic prostate cancer were monitored for more than 32 weeks by 183 serial PA values and were found generally to respond to the treatment. Additionally, in another group of 32 patients who underwent curative therapies for localized prostate cancer, 161 serum samples were evaluated during periods of 12 to 114 weeks (average 56 weeks). Of these patients, five developed metastases during follow-up, and all were shown to exhibit increasingly elevated PA values, either corresponding to or preceding the clinical diagnosis of disease recurrence. These results suggest that PA is a new marker with potential value to merit further clinical study.

Antigens, Neoplasm↗
PubMed1981

Recovery of immunologically reactive antibodies and antigens from breast cancer immune complexes by preparative isoelectric focusing.

A new technique for the recovery of immunologically reactive antibodies and putative antigens from breast cancer-associated immune complexes was described. Soluble immune complexes were isolated from extracellular fluids by 2.5% polyethylene glycol fractionation and affinity chromatography on Protein A:Sepharose CL-4B. The immune complexes bound to immobilized Protein A were then subjected to preparative isoelectric focusing. The dissociated immunoglobulins and putative antigens were recovered from the appropriate pH regions of the preparative isoelectric focusing gel. G-type immunoglobulins recovered from immune complexes isolated from a breast cancer patient bound to the recovered putative antigen(s) and three breast cancer cell culture lines, but these immunoglobulins did not bind to carcinoembryonic antigen or other cancer cell culture lines originating in colon, pancreas, prostate, or lymphoblast. The recovered putative antigens had isoelectric points between pH 3.0 and 5.0 and molecular weights of 20,000 and 42,000.

Antibodies, Neoplasm↗