Coordinate expression of cytokeratins 7 and 20 in feline and canine carcinomas.
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Forty-seven feline and 60 canine epithelial tumors were studied to test the coordinate expression of cytokeratin 7 (CK 7) and cytokeratin 20 (CK 20) using commercially available monoclonal antibodies and an avidin-biotin immunoperoxidase staining technique. Previously, the distribution of both cytokeratins was examined in normal tissues from 4 cats and 4 dogs. The pattern of distribution of CK 7 in normal tissues was similar, with minor differences, to that described in humans, whereas the reactivity pattern of CK 20 in cats and dogs was wider than that in humans. The subset of tumors strongly expressing CK 7 and CK 20 included pancreatic adenocarcinomas (100%), transitional cell carcinomas (75%), and endometrial carcinomas (67%) in the cat. None of the canine tumors had this immunophenotype. Feline (50%) and canine (56%) mammary gland carcinomas and canine cholangiocarcinomas (67%) were the only tumors presenting the CK 7 +/CK 20- immunophenotype, whereas the CK 7-/CK 20+ immunophenotype included thyroid carcinomas (100%), intestinal adenocarcinomas (60%), bronchioloalveolar carcinomas (50%), and renal carcinomas (50%) in the cat and intestinal adenocarcinomas (56%), gastric adenocarcinomas (50%), and ovarian carcinomas (50%) in the dog. The CK 7-/CK 20- immunophenotype included the rest of the analyzed tumors. The immunohistochemical evaluation of coordinate expression of both CK 7 and CK 20 in feline and canine carcinomas using monoclonal antibodies provides important information that can help to discriminate among carcinomas from different primary sites and could be particularly helpful in the determination of the primary site of origin of carcinomas presenting as metastatic disease. (+info)
Pancreatic insulin-secreting neoplasm (insulinoma) in a West Highland white terrier.
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A West Highland white terrier was evaluated because of persistent hypoglycemia and an acute episode of collapse. A pancreatic insulin-secreting neoplasm (insulinoma) was diagnosed on the basis of clinical signs, serum glucose levels, serum insulin levels, abdominal ultrasonography, and exploratory laparotomy with histologic evaluation of neoplastic tissue. (+info)
Syntactic analysis and languages of shape feature description in computer-aided diagnosis and recognition of cancerous and inflammatory lesions of organs in selected x-ray images.
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We present new algorithms for the recognition of morphologic changes and shape feature analysis, which have been proposed to be used in a diagnosis of pathologic symptoms characteristic of cancerous and inflammatory lesions. These methods have been used so far for early detection and diagnosis of neoplastic changes in pancreas and chronic pancreatitis based on x-ray images acquired by endoscopic retrograde cholangiopancreatography (ERCP). Preliminary processing of x-ray images involves binarization, and, subsequently, pancreatic ducts shown in the pictures are subjected to the straightening transformation, which enables obtaining two-dimensional width graphs that show contours of objects with their morphologic changes. Recognition of such changes was performed using attributed context-free grammars. Correct description and diagnosis of some symptoms (e.g., large cavitary projections) required two-dimensional analysis of width graphs. In such cases, languages of shape feature description with special multidirectional sinquad distribution were additionally applied. (+info)
A new functional Ras antagonist inhibits human pancreatic tumor growth in nude mice.
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Constitutively active Ras proteins, their regulatory components, and overexpressed tyrosine kinase receptors that activate Ras, are frequently associated with cell transformation in human tumors. This suggests that functional Ras antagonists may have anti-tumor activity. Studies in rodent fibroblasts have shown that S-trans, transfarnesylthiosalicylic acid (FTS) acts as a rather specific nontoxic Ras antagonist, dislodging Ras from its membrane anchorage domains and accelerating its degradation. FTS is not a farnesyltransferase inhibitor, and does not affect Ras maturation. Here we demonstrate that FTS also acts as a functional Ras antagonist in human pancreatic cell lines that express activated K-Ras (Panc-1 and MiaPaCa-2). In Panc-1 cells, FTS at a concentration of 25-100 microM reduced the amount of Ras in a dose-dependent manner and interfered with serum-dependent and epidermal growth factor-stimulated ERK activation, thus inhibiting both anchorage-dependent and anchorage-independent growth of Panc-1 cells in vitro. FTS also inhibited tumor growth in Panc-1 xenografted nude mice, apparently without systemic toxicity. Daily FTS treatment (5 mg/kg intraperitoneally) in mice with tumors (mean volume 0.07 cm3) markedly decreased tumor growth (after treatment for 18 days, tumor volume had increased by only 23+/-30-fold in the FTS-treated group and by 127+/-66-fold in controls). These findings suggest that FTS represents a new class of functional Ras antagonists with potential therapeutic value. (+info)
Centrosome abnormalities in pancreatic ductal carcinoma.
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The centrosome plays an important role in microtubule nucleation and organization, ensuring the establishment of cell polarity and balanced chromosome segregation. Recent studies have suggested that the loss of cell polarity and/or chromosome missegregation (aneuploidy) in human malignant tumors could result from defects in centrosome function. Using immunofluorescence analysis with an antibody to gamma-tubulin (a well-characterized centrosomal component), we examined surgically resected human pancreatic tissues for centrosome abnormalities. The tissues included ductal carcinomas (n = 13), adenomas (n = 3), endocrine tumors (n = 3), chronic pancreatitis (n = 5), and normal pancreatic tissues (n = 12). We found that most (85%) carcinomas and some adenomas displayed abnormal centrosome profiles, characterized by an increase in size and number of centrosomes, and by their irregular distribution. In contrast, none of normal ductal and stromal tissues showed these abnormalities. These findings suggest that centrosome abnormalities may develop at a relatively early stage of pancreatic ductal carcinogenesis. (+info)
Detection of mutations of p53 tumor suppressor gene in pancreatic juice and its application to diagnosis of patients with pancreatic cancer: comparison with K-ras mutation.
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Because of the difficulty in obtaining biopsy specimens from pancreatic cancer patients, K-ras mutation analysis in pancreatic juice has been used for specific diagnosis. But recently, false positives have been obtained with this method. To improve the genetic diagnosis of pancreatic cancer, detection of p53 gene mutation in pancreatic juice was studied. Pancreatic juice was sampled endoscopically. Single-strand conformation polymorphism analysis was used for p53 mutation analysis. Furthermore, K-ras mutations at codon 12 were also studied in the same pancreatic cancer patients. Of 26 cases of pancreatic cancer, p53 mutations were detected in 11 (42.3%). No mutations were seen in the cases with mucin-producing adenoma nor with chronic pancreatitis. K-ras mutations were detected in 84.0% of cases by RFLP analysis, which has high sensitivity, and in 65.3% by hybridization protection assay, which has high specificity. Using a combination assay with both genes, genetic abnormalities were detected in 92.0% by RFLP and 73.1% by hybridization protection assay including two cases in which p53 alone was positive by both methods. The specificity of p53 mutation for pancreatic cancer is very high. Therefore, simultaneous analysis of p53 and K-ras mutation is suggested to enhance the genetic diagnosis of pancreatic cancer. (+info)
Fish oil-enriched nutritional supplement attenuates progression of the acute-phase response in weight-losing patients with advanced pancreatic cancer.
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The presence of an acute-phase protein response (APPR) has been suggested to shorten survival and contribute to weight loss in patients with pancreatic cancer. Fatty acids derived from fish oil have been shown to alter proinflammatory cytokine production and acute-phase protein synthesis in vitro. The present study was designed to determine the effects of a fish oil-enriched nutritional supplement on the concentrations of a range of individual acute-phase proteins (APP) in patients with advanced pancreatic cancer. In a sequential series, 18 patients with pancreatic cancer received the supplement (providing 2 g eicosapentaenoic acid and 1 g docosahexaenoic acid/d) for 3 wk while another 18 received full supportive care alone. Six healthy subjects served as additional controls. Acute-phase proteins were measured before and after the 3-wk intervention period in cancer patients. At baseline, albumin, transferrin and pre-albumin were significantly reduced and fibrinogen, haptoglobin, alpha-1-acid glycoprotein, alpha-1-antitrypsin, ceruloplasmin and C-reactive protein (CRP) were significantly elevated in the cancer patients compared with healthy controls, reflecting their roles as negative and positive acute phase proteins, respectively. In the supplemented cancer group, the only significant change in APP concentrations over the 4-wk study period was an increase in transferrin. In the control cancer group there were further significant reductions in albumin, transferrin and pre-albumin, and a significant increase in CRP concentration. These results suggest that many positive and negative APP are altered in advanced pancreatic cancer. The APPR tends to progress in untreated patients but may be stabilized by the administration of a fish oil-enriched nutritional supplement. This may have implications for reducing wasting in such patients. (+info)
Identification of HLA-A2-restricted T-cell epitopes derived from the MUC1 tumor antigen for broadly applicable vaccine therapies.
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The tumor-associated antigen MUC1 is overexpressed on various hematological and epithelial malignancies and is therefore a suitable candidate for broadly applicable vaccine therapies. It was demonstrated that major histocompatibility complex (MHC)-unrestricted cytotoxic T cells can recognize epitopes of the MUC1 protein core localized in the tandem repeat domain. There is increasing evidence now that MHC-restricted T cells can also be induced after immunization with the MUC1 protein or segments of the core tandem repeat. Using a computer analysis of the MUC1 amino acid sequence, we identified two novel peptides with a high binding probability to the HLA-A2 molecule. One of the peptides is derived from the tandem repeat region and the other is derived from the leader sequence of the MUC1 protein, suggesting that, in contrast to previous reports, the MUC1-directed immune responses are not limited to the extracellular tandem repeat domain. Cytotoxic T cells (CTL) were generated from several healthy donors by primary in vitro immunization using peptide-pulsed dendritic cells. The addition of a Pan-HLA-DR binding peptide PADRE as a T-helper epitope during the in vitro priming resulted in an increased cytotoxic activity of the MUC1-specific CTL and a higher production of cytokines such as interleukin-12 and interferon-gamma in the cell cultures, demonstrating the importance of CD4 cells for an efficient CTL priming. The peptide induced CTL lysed tumors endogenously expressing MUC1 in an antigen-specific and HLA-A2-restricted fashion, including breast and pancreatic tumor cells as well as renal cell carcinoma cells, showing that these peptides are shared among many tumors. The use of MUC1-derived peptides could provide a broadly applicable approach for the development of dendritic cell-based vaccination therapies. (+info)