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Biomedical subjects

M Bhattacharya

Publications and source records attributed to M Bhattacharya.

At least 91 records · Page 5Linked to original sources
PubMed1985

Immunoperoxidase localization of a high-molecular-weight mucin recognized by monoclonal antibody 1D3.

The distribution of an antigen recognized by murine monoclonal antibody 1D3 (Bhattacharya, M., Chatterjee, S.K., Barlow, J. J., and Fuji, H. Cancer Res., 42: 1650-1654, 1982) was investigated in various types of human malignant and normal adult tissues by indirect immunoperoxidase assay in fixed paraffin-embedded sections. One hundred percent of ovarian mucinous cystadenocarcinomas expressed high levels of the antigen with intense staining of 80 to 100% of the tumoral area, thus confirming our previous finding with radioimmunoassay and absorption analyses. About 51% of colonic carcinomas, 33% of gastric carcinomas, and 22% of pancreatic carcinomas were also positive for this high-molecular-weight mucoprotein antigen. All other ovarian and nonovarian carcinomas tested including carcinoma of lung, breast, endometrium, cervix, and prostate were not stained by 1D3. In addition, sarcomas, melanomas, and lymphomas also did not express any detectable level of the antigen. When surveyed against various normal adult tissues, 1D3 had reactivity limited to the colon. Normal colon, however, exhibited reduced staining intensities compared to tumors or to the apparently normal colon adjacent to tumors. The antigen thus appears to be a colorectal tissue-specific antigen showing increased levels in ovarian mucinous cystadenocarcinomas and in some gastrointestinal tumors. 1D3 antigen is a potential tumor marker for mucinous ovarian and colonic tumors.

Animals↗
PubMed1985

Biochemical and immunologic characterization of galactosyltransferase purified from the ascites of ovarian cancer patients.

Galactosyltransferase appears to be a promising marker for ovarian carcinoma. For an understanding of its role in this cancer, the enzyme was purified from the ascites of ovarian cancer patients, and its biochemical and immunologic properties were studied. For adequate recovery and stability, Triton X-100 (0.01%) was necessary in all the buffers used for the purification of this enzyme. Immunoglobulins were not detectable in this preparation, which showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Electrophoresis under nondenaturing conditions resolved the enzyme into two to three active components. An antiserum in rabbits, however, produced a single precipitin line suggesting a single determinant. By chromatography in concanavalin A-Sepharose 4B, the enzyme can be resolved into two components (F-1 and F-2). Purified galactosyltransferase and components F-1 and F-2 all catalyzed the transfer of galactose from UDP-galactose to alkali-stable beta-N-glycosidic acceptors, as well as to alkali-labile beta-O-glycosidic mucin-type acceptors. In addition, they catalyzed the N-acetyllactosamine synthetase reaction and, in the presence of alpha-lactalbumin, the lactose synthetase reaction. Galactosyltransferase and components F-1 and F-2 differed in their sensitivity to alpha-lactalbumin-induced inhibition of N-acetyllactosamine synthesis. Galactosyltransferase in the malignant ascites exists as different isoforms, which do not differ significantly in major biochemical and immunologic properties.

Amino Sugars↗
PubMed1984

Histoenzymic studies on phosphatases in the uterine wall of the goat (Capra hircus).

The uteri of 8 goats (2 each at pregnancy, estrus, diestrus, and prepubertal periods) were used for histoenzymic localization of alkaline phosphatase (AKP), acid phosphatase (ACP), glucose-6-phosphatase (G6P), and adenosine triphosphatase (ATPase). In the surface and glandular epithelia of endometrium, all the enzymic reactions showed no appreciable change during pregnancy as compared with diestrus, except that the G6P activity was reduced. At estrus, the AKP reaction in the surface as well as glandular epithelia and ATPase in the glandular epithelium did not change, the ACP decreased and G6P increased in both epithelia but ATPase decreased in surface epithelium. Caruncular tissue showed increased AKP and decreased ACP and ATPase reactions at estrus, all being maximum during pregnancy. No specimen showed G6P reaction in the caruncular tissue. In prepubertal uteri, all the enzymes studied were localized in the same locations as in diestrus uteri except that ACP and G6P were not localized in the caruncular tissue. The myometrium of all the samples demonstrated only ATPase.

Acid Phosphatase↗
PubMed1984

Murine monoclonal antibodies against galactosyltransferase from the ascites of ovarian cancer patients.

Glycoprotein:galactosyltransferase is a promising enzyme marker for ovarian carcinoma. Five stable murine hybridoma monoclones that produce homogeneous antibodies against galactosyltransferase from the ascites of ovarian cancer patients have been established. Three of the monoclonal antibodies produced were immunoglobulin G1 isotype, while two were immunoglobulin M. All the antibodies showed linear Scatchard binding plots and had very high affinity for galactosyltransferase with equilibrium dissociation constants (Kd) ranging between 0.16 X 10(-9) M and 0.97 X 10(-9) M. Two of the monoclonal antibodies recognized adjacent epitopes on the enzyme molecule, two antibodies recognized two other unique epitopes, while the epitope recognized by the fifth was uncertain. Following polyacrylamide gel electrophoresis of the purified enzyme, in the presence of sodium dodecyl sulfate, the separated proteins were transferred to nitrocellulose filters (transblotting) and galactosyltransferase was detected on the filters by immunoperoxidase staining after treatment with monoclonal antibodies. A band at Mr 47,000 was detected by all of the monoclonal antibodies. One of them can detect, in addition, two bands at Mr 52,000 and Mr 54,000. Purified galactosyltransferase catalyzed the transfer of galactose to four types of acceptors: (a) alkali-stable N-glycosidic glycoproteins; (b) alkali-labile mucin-type acceptors; (c) N-acetylglucosamine; and (d) glucose in the presence of alpha-lactalbumin. All these transfer activities of the enzyme were present in the immunoprecipitates of the monoclonal antibodies. Transblotting of the enzyme from nondenaturing slab gels produced diffused stain patterns. Assay of the enzyme using the four types of acceptors in gel slices showed overlapping activity profiles, which coincided with the stained area on the filters, suggesting that the reactions are catalyzed by the same protein.

Animals↗
PubMed1984

Identification of a human cancer-associated antigen defined with monoclonal antibody.

Splenic lymphocytes of BALB/c mice immunized with a glycoprotein-enriched fraction of human ovarian adenocarcinoma were fused with the mouse myeloma cell line P3/NS1/1-Ag4 in the presence of polyethylene glycol (Mr 4,000). The hybrid cultures were screened in an indirect solid-phase radioimmunoassay for the production of relevant antibodies. Hybrids that produced antibodies which bound to the glycoprotein-enriched fractions of ovarian tumors but not to the similar fractions prepared from pooled normal ovary or sera were cloned twice by the limiting dilution method. Two such clones designated 4F4 and 7A10 were expanded in culture and also were grown in mice as ascitic tumors. The immunoglobulin isotype of the clones was of immunoglobulin G1 subclass with kappa light chains. Immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to detect the target antigen in 125I-labeled glycoprotein-enriched fractions of ovarian tumors. A single-chain Mr 48,000 peptide was identified by both clones 4F4 and 7A10. This antigen, which showed binding to concanavalin A-Sepharose, was designated gp48. Monoclonal antibodies against gp48 reacted significantly in radioimmunoassay to approximately 90% of human ovarian tumors and 60% of other tumors, both benign and malignant, but not to normal adult tissues or sera. Quantitative absorption analyses indicated that although the antigen was present in small amounts in some normal adult tissues such as cervix and intestine, it was present in much higher concentrations in most ovarian tumors, in some other tumors, and in fetal intestine and liver. Immunoperoxidase staining of formalin-fixed paraffin-embedded sections of solid ovarian adenocarcinomas revealed strong epithelial reactivity. Monoclonal antibodies to gp48 may be of value for the follow-up and immunotherapy of a variety of human tumors.

Adenocarcinoma↗
PubMed1983

Insect sex chromosomes. VIII. Identification of active/inactive X-chromosomes in Gryllotalpa fossor by 5-BrdU/AO fluorescence.

By employing 5-BrdU/AO fluorescence technique to distinguish active from inactive X-chromosomes, we have, for the first time, provided evidence in support of the validity of this technique for a non-mammalian system Gryllotalpa fossor (Orthoptera). In the female somatic cells of Gryllotalpa, it is only in the active (euchromatic) arm of X-chromosome that the fluorescence is bright, whereas it is dull in the facultative and constitutive heterochromatic arms. In tetraploid spermatogonial cells one of the two X-chromosomes is inactive, suggesting that this phenomenon is probably a random one and that the inactivation process is independent of the imprinting mechanism.

Acridine Orange↗
PubMed1983

Tumour-associated antigens for cystadenocarcinoma of the ovary.

This chapter summarizes the various epithelial ovarian cancer markers which have been termed cystadenocarcinoma 'antigens'. Virtually every reported antigen has been demonstrated by raising antibodies to tumour extracts injected into heterologous animals. As yet, despite numerous attempts, no heterologous antiserum has been demonstrated to have the requisite sensitivity and specificity for the immunodiagnosis of early ovarian cancer. However, some of the antigen markers may prove useful in monitoring the response to therapy. Hybridoma-generated monoclonal antibodies could prove to be the means by which the immunodiagnosis of early ovarian cancer will be achieved. That the abnormal antigens reflect altered glycoprotein metabolism is suggested by the findings of elevated serum galactosyltransferase, which in itself is a good ovarian cancer tumour marker, and a genetic serum deficiency of alpha-L-fucosidase, which appears to identify a high risk population for the development of ovarian cancer.

Animals↗
PubMed1982

Beta-hexosaminidase activities and isoenzymes in normal human ovary and ovarian adenocarcinoma.

Levels and isoenzyme profiles of beta-hexosaminidase were compared in extracts from normal ovarian and ovarian epithelial tumors. The specific activities of beta-hexosaminidase were significantly (P less than 0.001) higher in malignant than in normal ovarian tissues. The enzyme levels of the tumors depended on their degree of differentiation. Well-differentiated tumors had activities in the normal range, while poorly differentiated ones had values higher than the normal mean +/- 2 SD. The moderately and moderately to poorly differentiated tumors had intermediate levels. DEAE-cellulose chromatography was used to resolve the isoenzyme of beta-hexosaminidase. Two major forms, beta-hexosaminidase A and beta-hexosaminidase B, were detected in all the preparations. In one tumor specimen, a component eluting slightly ahead of beta-hexosaminidase A was also detected. For quick separation, a batch-wise procedure using DEAE-cellulose was adapted. Proportions of the isoenzymes A and B separated by batch-wise procedure were similar to those obtained by column chromatography. Heat stability, optimum pH, acid stability and substrate specificity of the beta-hexomsaminidase isoenzymes from ovarian tissues were similar to those from other human sources. Isoenzymes from tumor extracts were more labile to heat and acid pH compared with those from normal source. Slight differences in the affinity for the substrate p-nitrophenyl-beta-N-acetyl-galactosaminidase between the isoenzymes from normal and malignant ovaries were noted.

Acetylgalactosamine↗
PubMed1982

Monoclonal antibodies recognizing tumor-associated antigen of human ovarian mucinous cystadenocarcinomas.

Spleen cells from BALB/c mice immunized with human ovarian cystadenocarcinoma extract were fused with the mouse myeloma cell line P3/NSI/1-Ag 4 in the presence of polyethylene glycol (Mr 4000). Of the 46 hybrids obtained, four secreted antibodies preferentially reactive to the immunizing ovarian tumor extract. Two of these hybrids, which showed no reaction with normal controls, were selected for cloning by the limiting dilution method. The numerous clones obtained from each hybrid were screened against a panel of five ovarian tumor extracts, pooled normal ovary extracts, and pooled normal human sera. One clone from each hybrid that showed specificity for ovarian mucinous cystadenocarcinomas was recloned to assure monoclonality and to establish a permanent hybridoma cell line. The antibodies secreted by these cell lines were of IgG1 subclass with kappa light chains. These antibody-producing hybridomas were selected for further analysis of the antibody specificity by a solid-phase radioimmunoassay and quantitative absorption tests. The monoclonal antibodies recognized an antigenic determinant present only in mucinous cystadenocarcinomas of the ovary. These did not react with any other gynecological or nongynecological tumor thus far tested. The antigen was not demonstrable in any normal adult tissues tested. Among fetal tissues examined, only fetal intestine extract showed a positive reaction. The antigenic determinant recognized by these monoclonal antibodies was unrelated to carcinoembryonic antigen, normal glycoprotein, normal human serum components, or human ABO blood group materials. These antibodies, which have relatively high affinity and can be produced in large amounts, will be useful for the isolation and immunochemical characterization of this antigen. The purified antigen and the specific antibodies could be then combined in a sensitive radioimmunoassay for the early detection of the antigen in the sera and body fluids of patients with ovarian mucinous cystadenocarcinomas.

Animals↗
PubMed1981

Evaluation of 5'-nucleotidase as an enzyme marker in ovarian carcinoma.

A plasma membrane ectoenzyme in mammalian cells, 5'-nucleotidase, was evaluated as a marker for ovarian carcinoma. Activities of this enzyme were determined in homogenates from normal (N = 17) and malignant ovaries (N = 17), as well as in the sera from control women (N = 35), ovarian cancer patients with active disease (N = 24), and those in clinical remission (N = 9). A significant reduction of the activity of 5'-nucleotidase was observed in tumor homogenates compared with homogenates from normal ovaries. Levels of this enzyme in the sera of ovarian cancer patients were higher than in control women, suggesting the possibility of shedding of this enzyme from the tumor cell surface to the systemic circulation of the host. The diagnostic value of serum 5'-necleotidase levels was compared with another enzyme marker for ovarian carcinoma, viz. serum glycoprotein:galactosyltransferase. The upper limit of normal was set at 2 SD higher than the normal mean. Elevation of serum 5'-nucleotidase was observed in 12/24 (50%) patients with active disease, and 1/9 (11%) patients with clinical remission. In contrast, serum glycoprotein:galactosyltransferase was elevated in all the serum samples from patients with active disease and in none of those with clinical remission. There was some correlation between the serum levels of 5'-nucleotidase and those of glycoprotein:galactosyltransferase (0.01 less than P less than 0.05). Elevation of 5'-nucleotidase in the serum of these patients was not due to liver metastasis. Serum 5'-nucleotidase levels seem to correlate with disease status in some ovarian carcinoma patients, but in general it is inferior to serum glycoprotein:galactosyltransferase as a tumor marker.

5'-Nucleotidase↗
PubMed1980

Determination of serum galactosyltransferase levels in ovarian cancer patients for the evaluation of the effectiveness of therapeutic programs.

The activity of galactosyltransferase using endogenous acceptor(s), (GT-En) in the sera of ovarian cancer patients was significantly higher than age and blood-group matched controls. GT-En, and galactosyltransferase activity using an exogenous acceptor (GT-Ex), were assayed in the sera of 30 patients undergoing treatment for ovarian epithelial cancer, at the start of chemotherapy, and after a suitable interval. The direction of the alterations in levels of both these enzymes correctly reflected the clinical response to chemotherapy in most of these patients. The assay of GT-En and GT-Ex in the serum may be useful for the evaluation of the effectiveness of therapeutic programs in these patients.

Female↗