Biomedical subjects

A Meenakshi

Publications and source records attributed to A Meenakshi.

At least 19 recordsLinked to original sources

PubMed2006

Cervical ectopic thymus in an infant.

Cervical ectopic thymus, a common embryological anomaly detected incidentally at autopsy, is rarely described in clinical patients. About 100 cases have been described in the literature, ten percent of which occurred in neonates. We report a case of solid cervical ectopic thymus in a three-month-old male infant presenting as a neck lump and snoring at sleep. The embryopathogenesis, clinical features, diagnostic modalities and management options are discussed, together with a review of the literature.

Choristoma↗

PubMed2005

Fetus-in-fetu in the pelvis: report of a case and literature review.

INTRODUCTION: Fetus-in-fetu is an extremely rare condition in which a malformed fetus is found in the body of its twin. To our knowledge, fewer than 100 cases have been reported. Wide variations of presentation have been described, although its embryo-pathogenesis and differentiation from a teratoma have not been well established. CLINICAL PICTURE: We describe a male neonate with a fetoid-like mass in his pelvis associated with bilateral undescended testes. The mass was detected on prenatal ultrasound scans. The diagnosis of fetus-in-fetu was considered prenatally and confirmed on a computed tomography scan after birth. OUTCOME: The mass was successfully excised. Histological examination, accompanied by a review of the literature, confirmed that the mass had features consistent with a fetus-in-fetu. CONCLUSIONS: Although an extremely rare clinical entity, fetus-in-fetu can be diagnosed prior to surgery with current imaging modalities. When it arises in the retroperitoneum of a male infant, it can hinder the descent of the testes. Complete excision is curative.

Cryptorchidism↗

PubMed2003

Radioimmuno targetting (99m)technetium labeled anti-epidermal growth factor receptor monoclonal antibodies in experimental tumor models.

AIM: Monoclonal antibodies (MAb) directed at the extra cellular domain (ECD) of epidermal growth factor receptor (EGFR) offer a promising strategy for diagnosis and therapy of cancers that over-express EGFR. Radiolabelled MAbs against cell surface antigens have improved in vivo tumor diagnosis and treatment. EGFR over-expression has been reported in a wide range of carcinomas especially of the head and neck, breast, etc., and is associated with poor prognosis and resistance to therapy. CIBCNSH3 is a murine MAb generated to the ECD of EGFR in our laboratory and has been extensively characterized and has proven antitumor activity. The tumor targeting potential of (99m)Tc labelled CIBCNSH3 in an experimental tumor model is discussed in this paper. METHODS: A431, an epidermoid carcinoma cell line with overexpression of EGFR, SUDHLH, a lymphoma cell line was used to induce xenografts in inbred adult female BALB/C mice and used for the study. A reduction mediated method of (99m)Tc labelling was adopted to label the MAb. Scintiscan pictures were taken at different time intervals after i.v. administration of the (99m)Tc labelled MAb using a gamma camera and results were correlated with those of biodistribution studies. RESULTS: Immunoscan pictures taken at different time periods showed high uptake of the radioimmunoconjugate by the tumor providing clear tumor images and no uptake in control animals with lymphoma xenografts. Results of scan pictures correlated well with the biodistribution studies. CONCLUSION: The radioimmunoconjugate (99m)Tc-CIBCNSH3 appears to be a promising tool in identifying any early recurrence and micro-metastasis of lesions that overexpress EGFR.

Animals↗

PubMed2003

Immunohistochemical assay (IHC) to study C-erbB-2 status of breast cancer using monoclonal antibody CIBCgp185.

The C-erbB-2 proto-oncogene encodes a 185KD glycoprotein with tyrosine kinase activity. Overexpression of this gene either due to gene amplification and/or increased transcription has been observed in a variety of cancers and has been associated with more aggressive disease and a poor clinical prognosis in 20-30% of patients with breast cancer. Besides several prognostic factors like tumor size, histologic grade, steroid hormone receptor status, DNA ploidy, lymph node status etc which are significant in the management of breast cancer, C-erbB-2 status might also serve as an additional parameter. Immunohistochemistry is the most widely used method to study the expression of C-erbB-2 in breast cancer. The very low levels of expression of C-erbB-2 by normal tissues makes this receptor, a potential target for diagnosis and therapy with monoclonal antibodies raised against its extracellular domain. One such monoclonal antibody designated as CIBCgp185 of IgG2a isotype has been generated in our laboratory and extensively characterized. In the present study, an indirect immunohistochemical assay was carried out on frozen tumor tissue sections of 127 malignant breast tumor specimens of various histological types using monoclonal antibody CIBCgp185, which revealed intense staining of tumor cell membrane in 32 specimens, indicating overexpression of C-erbB-2. In the case of 53 benign breast tissues and 24 normal breast tissues studied, this MAb did not exhibit any reactivity. These results suggest that MAb CIBCgp185 might prove useful to identify tumors with overexpression of C-erbB-2 which are often associated with poor prognosis and early recurrence and might have future therapeutic application in the treatment of these cancers.

Antibodies, Monoclonal↗

PubMed2002

ELISA for quantitation of serum C-erbB-2 oncoprotein in breast cancer patients.

C-erbB-2 is a protooncogene that is overexpressed in various cancers, either due to its amplification and/or increased transcription, and has been associated with more aggressive disease and a poor clinical prognosis in 20-30% of patients with breast cancer. Besides the prognostic factors such as tumor size, tumor grade, lymph node status, etc., which are significant in the management of breast cancer, C-erbB-2 level might also serve as an additional factor. Immunohistochemistry is the most frequently used method to study the expression of C-erbB-2 in breast cancer. We have generated a panel of monoclonal antibodies against C-erbB-2 oncoprotein with a view to evaluate their application for the diagnosis and therapy of breast cancer. In the present study, a simple, quantitative sandwich ELISA has been developed that uses two monoclonal antibodies directed against the extracellular domain of C-erbB-2 product, designated as CIBCgp185 as the capture antibody and CIBCHER-2 as the detector antibody. C-erbB-2 protein, isolated from BT474 cells, a human breast carcinoma cell line with high expression of C-erbB-2 and purified by Concanavalin A-Sepharose 4B affinity chromatography and HPLC has been used to develop the ELISA procedure. Sera samples of 150 healthy women donors and of 300 breast cancer patients with different histological types of malignancies have been analysed. The control women had serum C-erbB-2 in the range of 4.0-13.2 ng/mL, whereas the 300 breast cancer patients studied had a range of 4.8-75.2 ng/mL with a cut off value of 13.8 ng/mL. Our study showed that 18.6% of breast cancer patients had elevated levels of circulating C-erbB-2. These results might suggest that the serum C-erbB-2 level can be used as a potential tumor marker for breast cancer and that the Sandwich ELISA procedure might serve as an excellent alternative to immunohistochemistry in the near future.

Adult↗

PubMed2002

Immunofluorescent localization of C-erbB-2 oncoprotein in breast cancer: a preliminary study.

Monoclonal antibody CIBCgp185 of IgG2a isotype has been generated against C-erbB-2 oncoprotein using BT474 breast carcinoma cell line as immunogen. Earlier studies have revealed that this MAb has potential application as diagnostic tool in the detection of breast cancers overexpressing C-erbB-2. In the present study, the reactivity pattern of this MAb was studied on frozen sections of 28 malignant and 15 normal breast tissues and on cultured mammary tumor cell lines by indirect immunofluorescent staining. Results indicated that gp185C-erbB-2 was overexpressed in 6 malignant specimens, indicating correlation with immunohistochemical analysis studied previously. These results indicate that immunofluorescence might also be used to study C-erbB-2 overexpression in breast cancers and could serve as a confirmatory test for IHC. However, further studies with large number of cases are needed to confirm these results.

Breast Neoplasms↗

PubMed2001

Generation of monoclonal antibody CIBCgp185 against C-erbB-2 oncoprotein and its clinical evaluation.

The C-erbB-2 proto-oncogene encodes the production of a cell surface receptor protein, with tyrosine kinase activity. Over expression of this gene either due to gene amplification and/or increased transcription has been observed and has been correlated with poor prognosis in patients with Breast (10-33%) and ovarian (20-33%) cancers. The very low levels of expression of C-erbB-2 by normal tissues makes this receptor a potential target for diagnosis and therapy with Monoclonal antibodies raised against its extracellular domain. One such monoclonal antibody designated as CIBCgp185 of IgG2a isotype has been generated in our laboratory using BT474 breast carcinoma cell line as immunogen. This monoclonal antibody immunoprecipitated a 185 KD glycoprotein. The specificity of this antibody was confirmed by the formation of a single discrete band and positive reaction with BT474 antigen in Western blot and Dot blot respectively. Flowcytometric analysis performed using various cancer cell lines revealed that this Monoclonal antibody exhibited high binding affinity with BT474 and SKBR3 cells whichoverexpresses C-erbB-2. By immunoperoxidase test, this antibody stained specifically the tumor cell membrane in frozen tissue sections of breast and ovarian tumors indicating overexpression of the C-erbB-2 product. All these results well correlated with those obtained using a control antibody ICR12, an anti-C-erbB-2 antibody. These studies clearly indicate that Monoclonal antibody CIBCgp185 might prove useful to identify tumors with over expression of C-erbB-2 which are often associated with poor prognosis and early recurrence.

Animals↗

PubMed2001

Enzyme immunoassay of human epidermal growth factor receptor (hEGFR).

Overexpession of EGFR has been reported in a variety of human cancers and serves as a target for diagnosis and therapy. In the case of breast cancer, about 48% EGFR and have poor clinical prognosis. Besides the prognostic factors like tumor size, nodal status, histological grade etc., which are significant in the management of breast cancer, EGFR level might also serve as an additional parameter. Immunocytochemical assay has been extensively used to study the expression of EGFR in various cancers. We have generated a panel of monoclonal antibodies against human EGFR with a view to evaluate their application for the diagnosis and therapy of these cancers. In the present study, an EIA has been developed using 2 monoclonal antibodies against hEGFR designated as CIBCNSH3 as the capture antibody and CIBCRGC1 as the detector antibody. EGFR isolated from MDA MB 468, a human breast carcinoma cell line, with high expression of EGFR and purified by conA affinity chromatography and HPLC has been used to develop the EIA procedure. Sera samples of 150 healthy women donors, of 300 breast cancer patients with different histological types of malignancies and of various other types of cancers have been analyzed. The control women had a range for serum EGFR level of 7-162 fmol/ml, whereas the 300 breast cancer patients studied had a range of 126-1587 fmol/ml with a cut off value of 180 fmol/ml. It is interesting to note that 67.5% of breast cancer patients had elevated levels of circulating EGFR. These results might suggest that serum EGFR level can be used as prognostic marker for breast cancer. The serum EGFR level will be compared with disease free interval and patient survival.

Breast Neoplasms↗

PubMed2000

Monoclonal antibody CIBCHTB1 defining an epitope on carcinoembryonic antigen (CEA).

Carcinoembryonic antigen (CEA) is an oncofoetal protein first identified by Gold and Freedman (1965) in colorectal cancer. It is a cell surface tumor marker which has been characterised as a heterogenous group of glycoproteins. It is also present in a variety of benign and non-neoplastic diseases like ulcerative colitis, Adenomatous polyp, Liver cirrhosis and other cancers like GI tract tumors, Cancer of the breast, lung, ovary, pancreas, prostate, hepatoma etc. Elevated CEA levels serve as clinical tool in the diagnosis, monitoring, detecting early any recurrence or metastasis and in prognostication for confirmed colorectal cancers. In order to develop an Enzyme Immuno Assay and immunocytochemical assay for CEA, an MAb designated as CIBCHTB1 has been generated using CEA isolated from a cell line HT115, human adenocarcinoma of the colon, as immunogen by the conventional Hybridoma technology. This MAb of IgG1 isotope was selected by screening of culture supernatents by ELISA and then by its high binding affinity with HT115 cells as revealed by flowcytometric analysis. By ABC method of immunocytochemical assay, this Ab exhibited strong staining of cells in frozen tissue sections of normal colon and malignant colorectal lesions and various other types of human cancers. This MAb has useful application to study the expression of CEA in human cancers. Serum CEA levels of patients with colorectal cancers and other CEA producing cancers and controls determined by EIA using this MAb were in good correlation with the results obtained using commercial kit. The diagnostic potential of this Mab in the management of colorectal cancers is discussed.

Adenocarcinoma↗

PubMed1999

Morphologic and imaging studies of duplicate optic canals in dry adult human skulls.

Three dry adult human skulls, two with bilateral and one with unilateral duplication of the optic canal were found. Their gross morphologic features were studied. Optic canals were separated by a septum of variable thickness dividing the posterior part of the canal into a large canal in the usual position and a smaller one inferior to it. The skull with unilateral duplication of the right side had a bony bar forming the carotico-clinoid canal. One of the skulls was disarticulated and its sphenoid had bilaterally duplicated optic canals divided by thin septa, both having a slit. Conventional radiography and CT scans for the optic canal were performed on two of these skulls but not on the disarticulated bone, and the imaging representations of these features were correlated with the anatomic findings on the dry skull.

Adult↗

PubMed1999

Characterization of monoclonal antibody CIBCNSH3 generated to the human EGF receptor.

Monoclonal antibody CIBCNSH3 of IgG1 isotype has been generated against human epidermal growth factor receptor (EGFR) using MDA MB 468 breast carcinoma cell line as immunogen. Earlier studies have revealed that this MAb blocked growth factor-receptor interaction and thus inhibited cell proliferation and tumor growth. In the present paper, this MAb has been extensively characterized to evaluate its application in the study of human cancers. The results were compared with those obtained using a control MAb ICR 62 specific to EGFR. Competitive assay showed that this MAb bound to an epitope in the extracellular domain of the EGFR to which MAb ICR 62 also bound. This MAb immunoprecipitated the 170 kD glycoprotein. The specificity was further confirmed by the formation of a single discrete band in western blot analysis. By flow cytometric analysis this monoclonal antibody revealed high binding affinity with MDA MB 468 cells. By immunocytochemical assay, out of 35 breast tumors studied, 40% were found to exhibit strong cell membrane staining and in the case of 25 oral cancers studied, 56% were strong positive. High expression of EGFR was observed in MDA MB 468 cells and HN 5 cells. These studies clearly indicate that MAb CIBCNSH3 might prove useful to identify tumors with high level of expression of EGFR associated with poor prognosis.

Antibodies, Monoclonal↗

PubMed1999

Studies on p53 immunolocalisation in breast cancer and its prognostic significance.

Immunocytochemical localisation of mutant p53 in breast tumours serves as a potential prognostic molecular marker. In order to study the expression of p53 protein in breast cancer which constitutes the second most common malignancy in the South Indian female population, MAb CIBCVMC12 has been generated against human p53 protein isolated and purified from bacterial cell lysate of E.coli carrying the plasmid T 7-7 Hup53 grown in Luria broth to induce the expression of p53. The positive clones selected by ELISA were found to exhibit strong staining of nuclear p53 in both fresh and archival paraffin embedded breast tumour tissue sections. Commercial MAb D 07 against p53 was used as control. In immunoprecipitation, this MAb of IgG2b isotype was found to bind specifically to a protein of 53 kD. Immuno cyto chemical assay of normal, benign and malignant breast tissues of different histological types revealed that the majority of tumour cells were strong positive in the case of infiltrating ductal and lobular carcinomas, the staining being less intense for in situ carcinoma. The test for normal and benign tissues was negative. The staining patterns were comparable with those of control antibody. These results suggest that the MAb generated is specific to p53. The p53 protein expression was compared with the estrogen receptor (ER) status for 50 breast tumours which revealed that 38% of these were p53 positive and of these two were ER+. Among the p53 negative tumours, 48% were found to be ER+. A comparison of the p53 expression for 100 breast cancer patients indicated that 57% of the tumours were p53 negative and these patients had a longer overall 5 year survival rate and recurrent free interval which is statistically very significant. These results might suggest that p53 positive tumours are more aggressive biologically with poor prognosis.

Antibodies, Monoclonal↗

PubMed1997

Detection of breast tumor associated mucin epitope on CAMA cell line using monoclonal antibody G3F1 generated against HMFG membrane.

The expression of breast tumor associated mucin epitope on CAMA cell line was detected employing the mouse MAB G3F1 generated against HMFG membrane. Immunocytochemical studies revealed that MAB G3F1 strongly reacted with 85% of breast cancer tissue sections with specific staining of apical cell membrane of malignant epithelial cells. The mucin antigen recognised by MAB G3F1 was detected by selectively extracting high molecular weight glycoprotein antigen from HMFG membrane using lectin affinity chromatography and gel filtration chromatography. Immunoprecipitation studies revealed that MAB G3F1 recognized a high molecular weight glycoprotein with an approximate molecular weight of 300kd. The expression of MAB G3F1 reactive antigen on CAMA cells was detected by immunocytochemistry and by immumoprecipitating 300kd antigen from 125I labelled Tx100 solubilized extract of CAMA cells. The results from these investigations suggest that CAMA cells express MAB G3F1 reactive antigen with tumor associated epitope, similar to tumor associated mucin epitope of HMFG membrane.

Animals↗

PubMed1994

Immunoscintigraphy of MCF7 rat mammary tumour xenograft using monoclonal antibody.

A transplantable, ER+ mammary carcinoma has been induced in virgin female Wistar rats by an 'air-pouch' technique by xenografting MCF7 cells. An air pouch induced by injecting sterile air subcutaneously into the mammary fat pad was primed with pristane and 17 beta estradiol (10 micrograms) in peanut oil prior to injection of 2-5 x 10(7) MCF7 cells fresh from culture. Solid tumours developed within 1-3 months (0.5-3.4 cm diam.) well encapsulated, pediculated tumours with histology of adenocarcinoma (> 80%) and fibroadenoma (< 10%), the former tumour being estrogen-dependent and transplantable. Monoclonal antibody 15C3 generated against MCF7 cells in this laboratory has been used for Tc-99m immunoscintigraphic studies by "SPECT" analysis of this mammary carcinoma and revealed selective localization of Tc-99m resulting in highly distinct tumour images.

Animals↗

PubMed1989

Tumor imaging of Dalton's lymphoma using antibody-desferal-Ga-67 complex.

Using desferal, a bifunctional chelating agent, Ga-67 was conjugated to the antibody, anti DLAA, specific for a 80 KD antigen associated with Dalton's lymphoma (DLAA) and was used for imaging of murine lymphomas induced by an 'air-pouch' technique. Scintiscan studies were carried out at 24 hr, 48 hr, 72 hr, after i.v. administration of Ga-67-anti DLAA-DF complex and compared with scintigrams obtained after administration of free Ga-67 citrate and suspension of Ga-67, DF, anti DLAA to different batches of tumor bearing mice. The study was also carried out using mouse IgG, a non-specific antibody, instead of anti DLAA. The results were compared with biodistribution studies. Scintigrams demonstrated that with anti DLAA there was maximum uptake of Ga-67 by the tumor providing the best images.

Animals↗

PubMed1988

Generation of monoclonal antibodies against human carcinosarcoma cell line for identification of myoepithelium and basement membrane.

An immunohistochemical method is described for identification of myoepithelial cells and basement membrane for cryostat tissue sections of normal, benign, and in situ carcinomas of the breast using two monoclonal antibodies 155C1 and 155D10 generated against human breast carcinosarcoma cell line HS578T. In the majority of infiltrating ductal carcinomas of the breast, there was a discontinuity in the myoepithelial cell layer, as a result an intact basement membrane could not be visualized. The reactivity of these two monoclonal antibodies might prove useful in the study of myoepithelial differentiation antigens and in the delineation of basement membrane. Among the other types of tissues studied, prominent staining was present with soft tissue tumors like leiomyosarcoma and synovial sarcoma.

Antibodies, Monoclonal↗

PubMed1987

Tumor targeting potential of liposomes encapsulating Ga-67 and antibody to Dalton's lymphoma associated antigen (anti-DLAA).

Dalton's lymphoma (solid tumor) was induced in Swiss mice by an 'Air-pouch' technique using ascites cells. A liposomal technique for radioimmunodetection and localization using Ga-67 and antibody has been developed. Dalton's lymphoma associated antigen (DLAA) was isolated and purified by ammonium sulfate fractionation and chromatography. The antibody to this antigen, anti-DLAA, was prepared by immunization of rabbits and purified by CNBr activated chromatography. The specificity of this antibody to the solid tumor antigen was ascertained by agar gel diffusion. Scintiscan studies were carried out using controls and Dalton's lymphoma bearing mice at various time intervals after i.p. administration of 10-20 mu ci of Ga-67, Ga-67 Ga-67 as liposomes and Ga-67 incorporated with antibody to DLAA as liposomes. Extensive studies carried out using liposomes of different sizes and charges revealed that anti-DLAA significantly improved the tumor uptake of Ga-67, thereby facilitating better visualization of the tumor. Negative and neutral liposomes delivered maximum radioactivity at the target tissue, whereas positive liposomes did not cause significant tumor accumulation of 67Ga. Biodistribution studies showed maximum tumor-associated activity that is 15.43% of the injected dose per gram tumor tissue was achieved with Ga-67 anti-DLAA liposomes compared to 6.6% with Ga-67 administered as such. Injection of Ga-67 liposome resulted in minimum tumor-associated activity that is 5.33%, with maximum uptake by liver and spleen. This might be caused by accumulation of liposomes in these organs. Incorporation of anti-DLAA might significantly improve uptake of Ga-67 by target tissue, due to the specificity of the antigen antibody reaction.

Animals↗

PubMed1984

7,12-Dimethylbenzanthracene induced mammary tumours in Wistar rats by 'air pouch' technique--a new approach.

An 'air pouch' technique of inducing highly localized, transplantable, estrogen-dependent adenocarcinomas of the mammary gland in Wistar rats with 7,12-dimethylbenzanthracene (DMBA) is described. The induction time was 67-80 days compared to 150-180 days by the conventional technique. Using this model estrogen receptor status, transplantation and effect of exogenous hormones on tumour growth have been studied. It is felt that this model might be a useful one for studying the biochemical mechanisms involved in hormone-dependent experimental mammary cancers.

9,10-Dimethyl-1,2-benzanthracene↗