Biomedical subjects

A Gangopadhyay

Publications and source records attributed to A Gangopadhyay.

At least 19 recordsLinked to original sources

PubMed2003

Lack of enhancement of caprine arthritis encephalitis virus infection in monocyte-derived macrophage cultures by sera from goats that developed severe arthritis after vaccination and virus challenge.

We examined sera from goats that developed more rapid and severe clinical disease after vaccination with inactivated caprine arthritis encephalitis virus (CAEV) and virus challenge for CAEV infection-enhancing antibodies. Sera from one control and two vaccinated goats were examined for neutralization or enhancement of virus infection in caprine macrophages. Macrophage cultures were incubated with virus-serum mixtures, then washed and fed with fresh media and incubated. Culture fluid was collected at days 2,4 and 8 post-infection and assayed for reverse transcriptase (RT) activity. Serum from one of the vaccinated goats neutralized virus at 10(-2) and 10(-3) dilutions (p = 0.045 and p = 0.020, respectively). The neutralizing effect was lost at higher dilutions (10(-4) and 10(-5)) of the serum, but no enhancement of infection was seen. Serum from the other vaccinated goat did not show any significant neutralizing effect at either 10(-2) or 10(-3) dilutions and increased infection (40% or greater) at higher dilutions, but the increases were not statistically significant. Therefore, there was no evidence of virus infection-enhancing activity in these sera that would suggest that the severe disease experienced by the vaccinated animals was due to serum enhancement of infection. Alternately, the severe arthritis observed could have resulted from the pro-inflammatory activities of cytokines and chemokines produced by macrophages upon phagocytosis, or receptor-mediated uptake of CAEV-antibody complexes.

Animals↗

PubMed2001

Paraoxonase-2 is a ubiquitously expressed protein with antioxidant properties and is capable of preventing cell-mediated oxidative modification of low density lipoprotein.

The oxidation of apolipoprotein B-containing lipoproteins and cell membrane lipids is believed to play an integral role in the development of fatty streak lesions, an initial step in atherogenesis. We have previously shown that two antioxidant-like enzymes, paraoxonase (PON)-1 and PON3, are high density lipoprotein-associated proteins capable of preventing the oxidative modification of low density lipoprotein (LDL) (Reddy, S. T., Wadleigh, D. J., Grijalva, V., Ng, C., Hama, S., Gangopadhyay, A., Shih, D. M., Lusis, A. J., Navab, M., and Fogelman, A. M. (2001) Arterioscler. Thromb. Vasc. Biol. 21, 542-547). In the present study, we demonstrate that PON2 (i) is not associated with high density lipoprotein; (ii) has antioxidant properties; and (iii) prevents LDL lipid peroxidation, reverses the oxidation of mildly oxidized LDL (MM-LDL), and inhibits the ability of MM-LDL to induce monocyte chemotaxis. The PON2 protein was overexpressed in HeLa cells using the tetracycline-inducible ("Tet-On") system, and its antioxidant capacity was measured in a fluorometric assay. Cells that overexpressed PON2 showed significantly less intracellular oxidative stress following treatment with hydrogen peroxide or oxidized phospholipid. Moreover, cells that overexpressed PON2 were also less effective in oxidizing and modifying LDL and, in fact, were able to reverse the effects of preformed MM-LDL. Our results suggest that PON2 possesses antioxidant properties similar to those of PON1 and PON3. However, in contrast to PON1 and PON3, PON2 may exert its antioxidant functions at the cellular level, joining the host of intracellular antioxidant enzymes that protect cells from oxidative stress.

Antioxidants↗

PubMed2001

Human paraoxonase-3 is an HDL-associated enzyme with biological activity similar to paraoxonase-1 protein but is not regulated by oxidized lipids.

Paraoxonase-1 (PON1) is a secreted protein associated primarily with high density lipoprotein (HDL) and participates in the prevention of low density lipoprotein (LDL) oxidation. Two other paraoxonase (PON) family members, namely, PON2 and PON3, have been identified. In this study, we report the cloning and characterization of the human PON3 gene from HepG2 cells. Tissue Northern analysis identifies an approximately 1.3-kb transcript for PON3 primarily in the liver. PON3-specific peptide antibodies detect an approximately 40-kDa protein associated with HDL and absent from LDL. Pretreatment of cultured human aortic endothelial cells with supernatants from HeLa Tet On cell lines overexpressing PON3 prevents the formation of mildly oxidized LDL and inactivates preformed mildly oxidized LDL. In contrast to PON1, PON3 is not active against the synthetic substrates paraoxon and phenylacetate. Furthermore, PON3 expression is not regulated in HepG2 cells by oxidized phospholipids and is not regulated in the livers of mice fed a high-fat atherogenic diet.

Animals↗

PubMed2000

Characterization of an oligopeptide transporter in renal lysosomes.

Renal lysosomes play a major role in catabolism of plasma proteins. Final products of this catabolism include dipeptides and tripeptides that must be exported to the cytosol for hydrolysis. The aim of the present study was to determine whether an oligopeptide transporter is present in the renal lysosomal membrane that could mediate this export. The existence of an oligopeptide transporter was probed with the uptake of glycylglutamine (Gly-Gln) by membrane vesicles prepared from renal lysosomes. Kinetic analysis showed the presence of a single transporter with a K(m) of 8.77 mM for the uptake of Gly-Gln. The Gly-Gln uptake was energized by the imposition of an inwardly directed proton gradient (pH(out) 5.0/pH(in) 7.3) and membrane potential (outside positive/inside negative) resulting in overshoot. The Gly-Gln uptake was inhibited by the presence of dipeptides and tripeptides, but not amino acids. Western blot analysis of lysosomal membrane proteins with Pept-1 (an oligopeptide transporter) antibody as the probe showed the presence of an immunoreactive protein. This immunoreaction was abolished when the antiserum was preabsorbed with the Pept-1 epitope (0.5 microg/ml). In conclusion, the present data show the existence of a low-affinity dipeptide transporter in the renal lysosomal membrane that appears to belong to the Pept family of transporters. The function of this transporter appears to be to prevent accumulation of dipeptides in renal lysosomes.

Amino Acid Sequence↗

PubMed2000

Cancer surveillance using data warehousing, data mining, and decision support systems.

This article discusses how data warehousing, data mining, and decision support systems can reduce the national cancer burden or the oral complications of cancer therapies, especially as related to oral and pharyngeal cancers. An information system is presented that will deliver the necessary information technology to clinical, administrative, and policy researchers and analysts in an effective and efficient manner. The system will deliver the technology and knowledge that users need to readily: (1) organize relevant claims data, (2) detect cancer patterns in general and special populations, (3) formulate models that explain the patterns, and (4) evaluate the efficacy of specified treatments and interventions with the formulations. Such a system can be developed through a proven adaptive design strategy, and the implemented system can be tested on State of Maryland Medicaid data (which includes women, minorities, and children).

Database Management Systems↗

PubMed1999

Tyrosine kinase activation in LPS stimulated rat Kupffer cells.

Kupffer cells, a majority of the body's fixed macrophages, are a major site of bacterial lipopolysaccharide (LPS) metabolism and are mediators in the body's response to sepsis. Uptake of LPS is different in Kupffer cells than other macrophages. Signal transduction in other macrophages in response to LPS involves phosphorylation of proteins in the 50-60 kDa range. We hypothesized that Kupffer cells may have unique signal transduction pathways in response to LPS. Rat Kupffer cells were exposed to LPS (1 microgram/mL) for varying times ranging from 15 to 90 min. Cell lysates were Western blotted using an anti-phosphotyrosine antibody. The blots showed an increase in the amount of tyrosine phosphorylation on two proteins of 119 kDa and 83 kDa. The effects of varying LPS concentration (1 ng/mL-1 microgram/mL) showed an increasing amount of phosphorylation with increasing LPS concentration. To associate the importance of tyrosine phosphorylation in the response of Kupffer cells to LPS, the tyrosine kinase inhibitors, tyrphostin, lavendustin, and genisten were used to study the effects of inhibiting phosphorylation on TNF-alpha production. Kupffer cells were preincubated in the presence of the inhibitor and exposed to LPS (1 microgram/mL). TNF-alpha was measured in the conditioned media by ELISA. A 70% or greater decrease in TNF-alpha production was observed. When phagocytosis of latex beads by rat Kupffer cells was measured in vivo using intravital video microscopy, LPS treatment significantly increased uptake. This increase in phagocytosis was inhibited by tyrphostin. These results show what may be unique phosphorylation events in Kupffer cells that are related to LPS induced production of TNF-alpha.

Animals↗

PubMed1999

A decision technology system for health care electronic commerce.

Mounting costs have escalated the pressure on health care providers and payers to improve decision making and control expenses. Transactions to form the needed decision data will routinely flow, often electronically, between the affected parties. Conventional health care information systems facilitate flow, process transactions, and generate useful decision information. Typically, such support is offered through a series of stand-alone systems that lose much useful decision knowledge and wisdom during health care electronic commerce (e-commerce). Integrating the stand-alone functions can enhance the quality and efficiency of the segmented support, create synergistic effects, and augment decision-making performance and value for both providers and payers. This article presents an information system that can provide complete and integrated support for e-commerce-based health care decision making. The article describes health care e-commerce, presents the system, examines the system's potential use and benefits, and draws implications for health care management and practice.

Commerce↗

PubMed1998

Adhesion of colorectal carcinoma cells to the endothelium is mediated by cytokines from CEA stimulated Kupffer cells.

We hypothesize that a major factor regulating hepatic metastasis is the ability of CEA (carcinoembryonic antigen) producing colorectal carcinomas to activate Kupffer cells. CEA and NCA (nonspecific cross-reacting antigen) bind to an 80 kDa Kupffer cell receptor by the peptide sequence PELPK and stimulate cytokine production. Cytokines induce sinusoidal endothelial cells to express intercellular adhesion molecules and increase adhesion of the tumor cells and retention in the liver. In this study human Kupffer cells were activated in vitro with CEA, NCA, and the peptide PELPK. This resulted in release of IL-1beta, TNF-alpha and IL-6. CEA non-producing MIP-101 colon carcinoma cells labeled with 51Cr were incubated on monolayers of ECV-304 human umbilical vein endothelial cells treated with these Kupffer cell derived cytokines or with comparable recombinant human (rH) cytokines. Specific antibodies to the adhesion molecules ICAM-1, VCAM-1, E-selectin and beta2integrin were used to block their functions. A significant enhancement in the adhesion of colorectal carcinoma cells occurred when endothelial cells were stimulated with a very low concentration of Kupffer-cell derived cytokines. Activated endothelium demonstrated significant up-regulation primarily of ICAM-1. The adhesion was blocked by an antibody to ICAM-1. A combination of Kupffer-cell derived cytokines was more effective than IL-1beta or TNF-alpha alone. IL-6 alone did not influence adhesion under our conditions. Our results suggest a mechanism for CEA in the modulation of colorectal carcinoma adhesion to the hepatic endothelium and its enhancement of metastatic potential.

Carcinoembryonic Antigen↗

PubMed1998

Differential expression of alpha2,6-sialyltransferase in colon tumors recognized by a monoclonal antibody.

It has been reported that alpha2,6-sialyltransferase (alpha2,6-ST; E.C. 2.4.99.1) activity is associated with cellular differentiation. To define its role in colon carcinoma differentiation, we have generated murine monoclonal antibodies (MAb) against alpha2,6-sialyltransferase. The MAb, designated 6B9 of IgM isotype, showed strong reactivity with the purified and crude alpha2,6-ST by ELISA and dot blot assays. Western blotting with MAb 6B9 identified purified alpha2,6-ST of MW 47 kDa and the same MW protein from rat and human liver extracts. The MAb also reacted with two other liver proteins of approximate MW 65 and 100 kDa. Immunoperoxidase studies with formalin-fixed paraffin-embedded tissues showed that MAb 6B9 reacts with liver tissues, the staining of hepatocytes was granular and cytoplasmic. There was a distinct pattern of zonal distribution of this enzyme in hepatocytes located particularly in the portal areas of the liver corresponding to zone 1. Normal colon (100%) and hyperplastic polyps (100%) showed very weak to no reactivity. Adenomas (100%) demonstrated moderate reactivity, while the poor (33%), moderate (100%) and well-differentiated (80%) colon adenocarcinomas showed strong reactivity. Results suggest that alpha2,6-ST is associated with the differentiation state of colon tumors.

Animals↗

PubMed1997

In vivo induction of murine cytokine production by carcinoembryonic antigen.

Carcinoembryonic antigen (CEA) may promote experimental metastasis through production of cytokines. The effect of systemic CEA on the production of proinflammatory cytokines was investigated in mice and compared to levels induced by lipopolysaccharide (LPS). Serum concentrations of interleukin (IL)-6 peaked 1 h after an i.v. CEA injection of 40 microg/mouse to 37-54% of the maximal level induced by a 1 microg/mouse injection of LPS in both normal and immunoincompetent mice. The CEA induction of IL-6 was a specific response, because the peptide PELPK (the pentapeptide on CEA that is the ligand for the CEA receptor on Kupffer cells) conjugated to albumin induced 30% of the maximal CEA response for IL-6, whereas the specificity control PELGK-conjugated albumin did not. IL-1alpha and tumor necrosis factor (TNF)-alpha levels after i.v. injection of CEA were only 3-5% of those induced by LPS. The IL-6 responses of mice pretreated with 100 microg/kg genistein were decreased by more than 40%. However, genistein inhibited the TNF-alpha response to LPS by 46% but increased the CEA-induced response by 300%. When murine Kupffer cells were stimulated with LPS or CEA in vitro, LPS increased tyrosine phosphorylation of a Mr 30,000 protein, whereas CEA decreased phosphorylation of a Mr 60,000 protein and did not increase phosphorylation of the Mr 30,000 protein. Thus, i.v. CEA stimulates production of IL-6 and TNF-alpha after binding to Kupffer cells through signal transduction pathways that appear to be different from those stimulated by LPS.

Animals↗

PubMed1997

Carcinoembryonic antigen induces signal transduction in Kupffer cells.

Carcinoembryonic antigen (CEA), an intercellular adhesion molecule and a mediator of hepatic metastasis, is processed by an 80 kDa receptor on murine and human Kupffer cells in the liver. Activation of rat Kupffer cells in vitro by CEA via the 80 kDa receptor produced cytokines IL-1alpha and TNF-alpha which involved tyrosine phosphorylation. The peak response of TNF-alpha was 5.6 times greater than the corresponding IL-1alpha response and was associated with enhanced tyrosine phosphorylation of 108 and 125 kDa proteins. Lipopolysaccharide (LPS) treatment, on the other hand, phosphorylated two major proteins with MW of 93 and 119 kDa associated with the loss of phosphorylation from a 125 kDa protein. Results demonstrate that CEA-induced IL-1alpha and TNF-alpha production involves tyrosine phosphorylation and the signaling in CEA treated cells is different than that seen with LPS stimulation.

Animals↗

PubMed1997

Changes in the leukocyte phenotype profile of goats infected with the caprine arthritis encephalitis virus.

The proportions of different sub-populations of leukocytes in five healthy goats and five goats infected with the caprine arthritis encephalitis virus (CAEV) were examined using immunofluorescence and flow cytometry. A panel of monoclonal antibodies that identified a monocytegranulocyte marker (GMI); the CD4, CD8, IgM, MHC Class I, MHC Class II and T19 antigens, and the gamma delta (gamma delta) T cell receptor was used. We observed a significant (P = 0.016) reduction in the proportion of monocytes in the peripheral blood of infected (5.98%) compared with healthy control goats (9.92%). There was also a decrease in the proportion of CD4+ T lymphocytes that approached significance (P = 0.076) accompanied by a slight increase in the proportion of CD8+ T lymphocytes, in infected compared with uninfected animals. Consequently, three of the five infected animals had lower CD4:CD8 ratios than any of the healthy animals and two of these three ratios were inverted. Approximately 14% of T cells in the peripheral blood of healthy goats was identified as gamma delta T cells and all expressed the T19 antigen. A significantly elevated level of gamma delta T cells (P = 0.030) and an elevated level of T19 cells were observed in infected, compared with healthy animals. The proportion of leukocytes expressing surface IgM (B cells) was also elevated, although not significantly, in CAEV-infected compared to healthy controls. The changes in peripheral blood leukocyte subsets in infected goats suggest that immune responses to the infection are probably altered in these animals with eventual progression to severe disease and death.

Animals↗

PubMed1996

Carcinoembryonic antigen induces cytokine expression in Kuppfer cells: implications for hepatic metastasis from colorectal cancer.

The mechanism by which carcinoembryonic antigen (CEA) causes enhancement of hepatic metastasis from colorectal cancer is not defined. We hypothesize that binding of CEA to an 80-kDa Kupffer cell receptor by the peptide sequence Pro-Glu-Leu-Pro-Lys (PELPK) induces cytokine production in the hepatic microenvironment, which then impacts on the formation of hepatic metastasis from colorectal cancer. We have, therefore, isolated Kupffer cells and treated them in vitro with CEA, its gene family member nonspecific cross-reacting antigen, PELPK-albumin conjugate, and lipopolysaccharide as a positive control. Spent media was examined for the content of cytokines interleukin (IL) 1alpha, IL-1beta, IL-6, and tumor necrosis factor alpha using the ELISA. Simultaneously, mRNA was extracted from the same cells and amplified using reverse transcription-PCR to evaluate the induction of specific cytokine transcripts. As expected, lipopolysaccharide stimulated cytokine production. CEA, nonspecific cross-reacting antigen, and PELPK-albumin induced secretion of all of the cytokines tested; the response was higher in general with PELPK-albumin. The levels of cytokine mRNA showed a similar profile. These responses were not seen when a similar but irrelevant peptide conjugate PELGK-albumin was used. These results demonstrate that binding of the peptide PELPK to the 80-kDa receptor results in the release of a series of cytokines that have the potential to activate hepatic sinusoidal endothelium. This may explain CEA-induced enhancement of experimental hepatic metastasis.

Animals↗

PubMed1996

Processing of carcinoembryonic antigen by Kupffer cells: recognition of a penta-peptide sequence.

Carcinoembryonic antigen (CEA) binds to an 80-kDa cell surface receptor on Kupffer cells via the peptide sequence PELPK (residues 108-112) located at the hinge region between the N and Al immunoglobulin-like domains. This study is aimed at analyzing the specificity of the peptide binding, determining biodistribution of 80-kDa receptor, and processing of CEA by this receptor. We synthesized a number of bovine serum albumin (BSA) derivatives carrying PELPK and related sequences. A series of peptides (YPELPK, YPDLPK, YPDLPR, and YPELGK) were conjugated to bovine serum albumin using N-hydroxysuccinimidyl-4-azidobenzoate. When 125I peptide conjugates, CEA, and BSA were injected intravenously into rats CEA and the PELPK-albumin conjugate were cleared rapidly. The other peptide conjugates and BSA cleared at a much slower rate. Activity of 125I-labeled CEA and PELPK-albumin conjugate per gram of tissue was highest for the liver and spleen. Clearance of 125I-CEA was inhibited by the presence of higher concentrations of the PELPK-albumin conjugate. With isolated rat Kupffer cells, only CEA and the PELPK-albumin conjugate were bound and internalized in vitro and CEA binding was inhibited by higher concentrations of the PELPK-albumin conjugate. Similarly, binding of the PELPK-albumin conjugate was inhibited by the presence of unlabeled CEA. Use of a heterobifunctional cross linking agent demonstrated reaction of the PELPK-albumin with an 80-kDa protein on the Kupffer cell surface by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). This semisynthetic ligand (PELPK-albumin) allows us to examine the function of the 80-kDa receptor without interference due to other properties of CEA including its ability to bind lectins and to cause homotypic aggregation of cells. The consequences of CEA binding to the 80-kDa receptor may have implications in the development of hepatic metastasis from colorectal cancer.

Amino Acid Sequence↗

PubMed1996

Purification and analysis of an 80-kDa carcinoembryonic antigen-binding protein from Kupffer cells.

The receptor-mediated interaction of Kupffer cells with carcinoembryonic antigen (CEA) has led to the identification of an 80-kDa CEA-binding Kupffer cell protein. This study is aimed at the isolation and analyses of this protein from rat Kupffer cells. The binding protein was purified using a combination of gel filtration, preparative polyacrylamide gel electrophoresis (PPAGE), and affinity chromatography using a CEA-Sepharose column. Fractions obtained from the gel filtration produced two major and few minor peaks with CEA-binding activity. Maximum reactivity was detected in the first major peak. The first major peak protein was partially precipitated following fractionation with 30% loss of activity in the precipitate. Fractions with CEA-binding activity were pooled and separated on the basis of molecular weight (MW) in PPAGE. The fractions between MW 70 and 90 kDa were pooled and affinity purified using CEA-Sepharose affinity chromatography. The purity of the 80-kDa protein was demonstrated by a single protein band on SDS-polyacrylamide gel. The protein was further identified by an anti-80-kDa binding protein antibody in Western blot analysis. The pI of the 80-kDa protein is 4.95. Amino acid analysis demonstrated no histidine; higher percentages of glutamine (13.3%), leucine (11.2%), asparagine and alanine (10.4%), and lysine (9.2%) were observed. Protein microsequencing revealed two unique sequences, one with 16 amino acids and the other with 11 amino acids. The 16-amino-acid sequence has less than 50% homology with a large sample of unrelated proteins, whereas the sequence containing 11 amino acids has 60-70% homology with the alpha chain of collagen from a variety of species but no significant homology with other known proteins, suggesting the presence of collagen-like domains in the 80-kDa receptor.

Amino Acid Sequence↗

PubMed1996

Modification of antibody isoelectric point affects biodistribution of 111-indium-labeled antibody.

We evaluated the influence of changes in charge on the biodistribution of 111In-labeled purified rabbit antihuman serum albumin (R-HSA) IgG conjugated to diethylenetriaminepentaacetic dianhydride (DTPA). Optimization of isoelectric point (pI) may influence the biodistribution profile, especially retention in vital organs, which ultimately affects radioimmunoimaging. Experiments were designed to modify the pI of R-HSA by conjugating various molar ratios of DTPA (DTPA:R-HSA ratios 5:1 to 100:1). The pI of the conjugates was determined by isoelectricfocusing (IEF). 111In-labeled DTPA:R-HSA with known pI range was injected intraperitoneally into BALB/c mice to evaluate biodistribution. There was a proportional relationship between the molar ratio of DTPA to R-HSA IgG and the number of DTPA substituted. Molar ratios of 5, 10, 20, 50 and 100 gave, on average, 2.0, 3.6, 5.1, 9.5 and 16.0 DTPA per R-HSA IgG, respectively. An anodal shift in the pI of 111In-labeled R-HSA IgG was noted with increased number of DTPA conjugation. Biodistribution studies at both 4 and 24 h showed sequential increase in the liver activity with increasing number of DTPA per antibody, whereas colon and small intestine showed a decrease in the activity at 4 h. The organ-specific increase (e.g., liver) or decrease (e.g., colon and small intestine) in the activity may depend on a critical balance of charge of a particular organ and its interaction with the amount of negative charge carried by the antibody conjugate. The results suggest that pI optimized 111In-labeled antibody could be used to increase or decrease colon and hepatic retention for more efficient radioimmunoimaging of colon tumors and their hepatic metastasis.

Animals↗

PubMed1995

The effect of transfection of the CEA gene on the metastatic behavior of the human colorectal cancer cell line MIP-101.

Carcinoembryonic antigen (CEA) has been shown to increase the metastatic potential of some human colorectal cancer cell lines. To investigate further the mechanisms involved we have produced three clones (6, 8 and 17) from the poorly differentiated human colorectal cancer cell line MIP-101 that have been transfected with the full length cDNA encoding for human carcinoembryonic antigen (CEA). They produce CEA with a mol. wt. of 180000 by Western blotting and secrete it into the culture medium. Clone 6 is a high CEA producer, clones 8 and 17 are intermediate producers. The doubling time for clone 8 was similar to that of the parent cell line while clones 6 and 17 had doubling times nearly twice that of the parent cells. These clones are tumorigenic when injected subcutaneously in nude mice are positive for CEA by immunoperoxidase staining and the mice have elevated blood levels of CEA. Clone 6 formed large aggregates in culture while clone 17 formed smaller aggregates. Clone 8 behaved like the parent cell line with rare cell/cell contact. Clones 6 and 17 also adhered to CEA coated plastic while clone 8, a neo-transfected control and the parent cell line did not. A significant increase in the incidence of hepatic tumors was observed with clone 6 (P < 0.01) and clone 17 (P < 0.02) following intrasplenic injection into nude mice. Immunohistopathology of the hepatic tumors showed strong CEA staining from clones 6 and 17 with weak staining from clone 8. The parent cell line was negative for CEA as were the neo-transfected controls. Of the neo controls none of 10 had liver colonies. Mice injected with clone 6 which developed liver metastasis had the highest plasma levels of CEA (37.3 +/- 8.8 ng/ml). We observed strong CEA staining in Kupffer cells in the normal liver adjacent to the CEA producing tumors. This study provides further evidence for the involvement of CEA in the metastatic process.

Adenocarcinoma↗

PubMed1995

Detection of tumor-associated antigens in sera of canine cancer patients by monoclonal antibodies generated against canine mammary carcinoma cells.

Two murine monoclonal antibodies (MAbs), 1A10 and SB2, generated against a canine mammary carcinoma cell line, were used in a competitive enzyme-linked immunosorbent assay (ELISA) to measure tumor-associated antigens (TAAs) in canine serum samples. Sera were tested from disease-free dogs and from dogs diagnosed with mammary carcinoma, non-mammary carcinoma, sarcoma, benign mammary tumor, benign non-mammary tumor, or non-neoplastic disease. Serum antigen concentrations measured by ELISA were expressed as inhibitory units (IU). The upper limit of normal, defined as the mean plus 2 SD of the TAA concentration in disease-free dogs, was 20 IU with antibody 1A10 and 22 IU with antibody SB2. Compared with disease-free dogs, the frequency of TAA-positive sera was significantly greater (P < 0.05) among dogs with mammary or non-mammary carcinoma when tested with MAbs 1A10 or SB2, and also with sarcoma when tested with MAb SB2. Testing a serum sample with both antibodies rather than just one increased the sensitivity of the competitive ELISA for TAA detection. The presence of TAA in serum might serve as a useful marker for certain types of carcinomas or sarcomas in canine cancer patients.

Animals↗