Strongyloides stercoralis: a rare cause of obstructive duodenal stenosis.

BACKGROUND: Strongyloidiasis is a rare helminthic infection in Europe, and it may cause duodenal obstruction. METHODS: We report a patient who was admitted to our Medical Department with nausea and repeated vomiting since 10 years until food intake became impossible. Subsequent investigations revealed a duodenal obstruction at the upper third of the duodenum, as well as enterocolitis of the terminal ileum with eosinophils dispersed throughout the mucosa. Since food intake was still not possible after treatment with a course of i.v. PPI and prokinetic applications, we decided to perform a resection of the upper duodenum with Y-Roux reconstruction. RESULTS: The histopathological examination of the resected specimen revealed strongyloidiasis. CONCLUSION: Parasite infections such as strongyloidiasis represent a rare differential diagnosis of duodenal obstruction especially if patients originate from endemic regions.

Endotoxemia and endotoxin tolerance in patients with ARDS.

BACKGROUND: The significance of endotoxemia in man is controversial, induces cytokine release and stimulates the immune system. Exaggerated cytokine release of mononuclear cells was observed in acute lung injury/acute respiratory distress syndrome (ALI/ARDS). However, repetitive administration of endotoxin can cause tolerance. OBJECTIVE: To investigate endotoxemia, plasma TNFalpha, IL-1beta, IL-6, the liberation capacity of those cytokines from mononuclear cells after LPS challenge (Delta values), and plasma antibodies to endotoxins and alpha-hemolysin of Staphylococcus aureus in ALI/ARDS. DESIGN: A prospective clinical study was conducted. SETTING: The study was carried out at the University Hospital Ulm, Ulm, Germany. SUBJECTS: The respondents were 23 patients with ALI/ARDS. INTERVENTIONS: ALI/ARDS was defined according to the American-European Consensus Conference on ARDS. Blood was collected periodically. Parameters were measured by LAL or ELISA. RESULTS: ARDS (P(a)O(2)/F(i)O(2) < 200) revealed higher endotoxemia (0.22-0.46 [0.06-1.15] EU/mL vs 0.05-0.14 [0.02-0.63] EU/mL) than ALI (P(a)O(2)/F(i)O(2) > 200) but lower DeltaIL-6 (124-209 [10-1214] pg/mL vs 298-746 [5-1797] pg/mL), DeltaTNFalpha (50-100 [6-660] pg/mL vs 143-243 [12-2795] pg/mL), and DeltaIL-1 (2-3 [0-26] pg/mL vs 2-14 [0-99] pg/mL). Endotoxemia correlated negative with P(a)O(2)/F(i)O(2) (r, -0.44 to -0.50). All patients presented antibodies to lipopolysaccharides and alpha-hemolysin, but the level did not correlate with P(a)O(2)/F(i)O(2). CONCLUSIONS: ALI/ARDS is associated with endotoxemia. The more severe the disease, the more intense is endotoxemia but the lower is the capacity of mononuclear cells to release cytokines (tolerance). Antibodies against Gram-positive and Gram-negative bacteria are detectable in the plasma but without relation to P(a)O(2)/F(i)O(2).

The tobacco carcinogen NNK is stereoselectively reduced by human pancreatic microsomes and cytosols.

BACKGROUND/AIMS: Cigarette smoking increases the risk of cancer of the pancreas. The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the only known environmental compound that induces pancreatic cancer in laboratory animals. Concentrations of NNK are significantly higher in the pancreatic juice of smokers than in that of nonsmokers. The chiral NNK metabolite, (R,S)-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is itself a potent pancreatic carcinogen in rats. The carcinogenicity of NNAL is related to its stereochemistry; (S)-NNAL is a more potent lung tumorigen in the A/J mouse than is (R)-NNAL. In this study, we determined the potential of the human pancreas to convert NNK into NNAL. MATERIALS AND METHODS: Human pancreatic microsomes and cytosols were incubated with [5-(3)H]NNK, and the metabolic products were determined by high-performance liquid chromatography (HPLC). RESULTS: (S)-NNAL was the predominant isomer formed in all cytosolic incubations. In ten microsomal samples, NNAL was formed at an average rate of 3.8 +/- 1.6 pmol/mg/min; (R)-NNAL was the predominant isomer in this group. The average rate of NNAL formation in 18 other microsomal samples was significantly lower, 0.13 +/- 0.12 pmol/mg/min (p < 0.001); (S)-NNAL was the predominant isomer formed in this group. CONCLUSION: In human pancreatic tissues, there is intraindividual variability regarding the capacity for, and stereoselectivity of, carbonyl reduction of NNK.

MAPkinase gene expression, as determined by microarray analysis, distinguishes uncomplicated from complicated reconstitution after major surgical trauma.

Microarray expression analysis was performed in patients with major surgical trauma to identify signaling pathways which may be indicative for complicated versus uneventful reconstitution post trauma. In addition to a generalized upregulation of nonspecific stress response genes in all patients, a remarkable number of differences in gene expression patterns were found in individual patients. Some of the differing genes were associated with uncomplicated convalescence such as upregulation of both the ERK5 pathway (MAPK7 [mitogen-activated protein kinase-7]) and transcription factors which stimulate hematopoiesis and tissue reconstitution (MEF2, BMP-2, TNFRSF11A [RANK], and RUNX-1). Chemokine genes active in stem cell recruitment from the bone marrow as well as dendritic cell and natural killer (NK) cell maturation (SCYA14 [HCC-1]), and activators of the lymphoid compartment (TNFRSF7 [CD27], CD3zeta and perforin [PRF1]) were increased. In contrast, all these transcripts were downregulated in complicated reconstitution and later development of septic shock. Moreover, p38 kinase (MAPK14), S100 molecules, and members of the lipoxygenase pathway were associated with a more eventful outcome. Microarray expression studies are a promising tool for screening and then selecting differentially regulated genes in favorable as compared to complicated reconstitution post trauma.

Specialized DNA arrays for the differentiation of pancreatic tumors.

PURPOSE: Malignant tumors of the pancreas are frequently indistinguishable from inflammatory tumors arising in the context of a chronic pancreatitis with the use of conventional imaging techniques. Thus, cytologic analysis of cells obtained by abdominal ultrasound, computed tomography, or endoscopic ultrasound-guided fine needle aspiration biopsy is required for diagnosis. However, the reliability of cytologic analyses of pancreatic fine needle aspirates remains unsatisfactory, with a diagnostic accuracy of < or =80%. The purpose of the current study was therefore to develop a novel diagnostic approach based on expression profiling of biopsy material using a specialized diagnostic cDNA array. EXPERIMENTAL DESIGN: Previous gene expression profiling studies were reevaluated to design a 558-feature diagnostic array. Minimal amounts of residual material from pancreatic cytology samples as well as surgically resected tumor and control tissue specimens were analyzed using the diagnostic array and a newly developed statistical classification system. RESULTS AND CONCLUSIONS: Our diagnostic approach resulted in 95% accurate differentiation between ductal adenocarcinomas and nonmalignant tumors of the pancreas. The diagnostic array, in conjunction with conventional diagnostic procedures, is thus suitable to significantly improve the reliability of pancreatic cancer diagnostics and can be expected to become a valuable new tool in the routine workup of suspect masses in the pancreas.

Claudin-4 expression decreases invasiveness and metastatic potential of pancreatic cancer.

Claudin-4 has been identified as an integral constituent of tight junctions and has been found to be highly expressed in pancreatic cancer. The aim of the present study was to elucidate the effect of claudin-4 on growth and metastatic potential in pancreatic cancer cells, as well as the regulation of claudin-4 by oncogenic pathways. Claudin-4 was stably overexpressed in SUIT-2 pancreatic cancer cells, and its effect on invasion and growth in vitro was examined by using two-chamber invasion assays, soft agar assays, and fluorescence-activated cell sorter analysis. Claudin-4 localization was characterized by light and electron microscopy, and pulmonary colonization was analyzed in vivo after injection of claudin-4 overexpressing cells into the tail vein of nude mice. Overexpression of claudin-4 was associated with significantly reduced invasive potential in vitro and inhibited colony formation in soft agar assays. In vivo, tail vein-injected claudin-4 overexpressing cells formed significantly less pulmonary metastases in comparison with mock-transfected cells. These effects were not caused by changes in proliferation, cell cycle progression, or matrix metalloproteinase gelatinolytic activity, but were paralleled by increased cell contact formation. Moreover, proinvasive transforming growth factor beta was able to down-regulate claudin-4 in PANC-1 cells. Inhibition of Ras signaling by using dominant-negative Ras and specific inhibitors of both downstream effectors mitogen-activated protein/extracellular signal-regulated kinase kinase and phosphatidylinositol 3'-kinase also decreased claudin-4 expression. Our findings identify claudin-4 as a potent inhibitor of the invasiveness and metastatic phenotype of pancreatic cancer cells, and as a target of the transforming growth factor beta and Ras/Raf/extracellular signal-regulated kinase pathways.

SERPINE2 (protease nexin I) promotes extracellular matrix production and local invasion of pancreatic tumors in vivo.

In large-scale expression profiling analyses, we have previously identified genes differentially expressed between subclones of the pancreatic cancer cell line SUIT-2. One of the genes most strongly overrepresented in the highly metastatic subclone S2-007 as compared with the rarely metastatic subclone S2-028 was the serine proteinase inhibitor SERPINE2 (protease nexin I), suggesting that this protein may play an important part in the process of metastasis. The aim of this study was to functionally characterize SERPINE2 for its potential to influence the invasive and metastatic phenotype of cancer cells in vitro and in vivo. SERPINE2 expression was weak or absent in all normal pancreas and chronic pancreatitis tissue samples examined. In contrast, it was strongly overexpressed in the majority of pancreatic carcinoma as well as gastric and colorectal cancer samples. [(3)H]Thymidine incorporation, soft agar, two chamber migration, Matrigel invasion, and zymography assays of SERPINE2-transfected S2-028 cells revealed no significant effects on metastasis-related cellular characteristics of isolated cancer cells. Although overall metastatic activity of the transfected cells in vivo was also unaltered, SERPINE2 overexpression greatly enhanced the local invasiveness of the s.c. xenograft tumors, accompanied by a massive increase in extracellular matrix (ECM) production in the invasive tumors. ECM deposits were positive for type I collagen, fibronectin, and laminin, thus resembling the desmoplastic reaction commonly observed in pancreatic cancer. Moreover, cancer cells in invasive SERPINE2-expressing tumors tended to adopt a spindle-shaped morphology and strongly expressed the mesenchymal intermediate filament marker vimentin. We propose that SERPINE2 overexpression enhances the invasive potential of pancreatic cancer cells in nude mouse xenografts by altering ECM production and organization within the tumors. Thus, our experimental system for the first time provides the opportunity to effectively model the desmoplastic reaction of pancreatic cancer and represents a valuable new tool for the study of tumor-stroma interactions.

Evaluation of pyrimidine metabolising enzymes and in vitro uptake of 3'-[(18)F]fluoro-3'-deoxythymidine ([(18)F]FLT) in pancreatic cancer cell lines.

Here we report the expression of major pyrimidine metabolising enzymes in pancreatic cancer cell lines, chronic pancreatitis tissue and human pancreatic cancer and the in vitro uptake of 3'-[(18)F]fluoro-3'-deoxythymidine ([(18)F]FLT). The expression of pyrimidine metabolising enzymes was evaluated with real-time PCR, Western blot and immunostaining. Thymidine kinase 1 (TK-1) activity was measured with a fluorocytometric assay. The cellular uptake and intracellular metabolism of [(18)F]FLT were evaluated in pancreatic lobules and in transformed cancer cell lines. TK-1 and thymidine synthetase mRNA were increased in six pancreatic cancer cell lines, while mRNA levels of thymidine kinase 2 and deoxycytidine kinase were down-regulated. High TK-1 activity was confirmed in all cell lines. Furthermore, TK-1 was overexpressed in human pancreatic cancer as compared with normal pancreatic tissue and samples from patients with chronic pancreatitis. The cellular uptake of [(18)F]FLT was 18.4%+/-3.6% and 5.2%+/-1.4% of the applied radioactivity after 240 min in SW-979 and BxPc-3 cells, respectively, while uptake of [(18)F]fluorodeoxyglucose ([(18)F]FDG) was only 0.6%+/-0.04% (SW-979) and 0.3%+/-0.13% (BxPc-3) after 240 min of incubation. In contrast, cellular uptake of [(18)F]FLT in isolated pancreatic lobules and growth-arrested HT1080 cells was lower as compared with the uptake of [(18)F]FDG and with the malignant pancreatic cancer cell lines. HPLC analysis of the perchloric acid-soluble cell fraction demonstrated the phosphorylation of [(18)F]FLT to the respective monophosphate in both cell lines. Furthermore, 0.8%+/-0.12% (BxPc-3) and 1.3%+/-0.38% (SW-979) of the applied radioactivity was detected in the perchloric acid-insoluble cell fraction, indicating the incorporation of [(18)F]FLT into the DNA. Our results demonstrate the cellular uptake, intracellular trapping and incorporation into the DNA of [(18)F]FLT in pancreatic cancer cells in vitro. TK-1, as the rate-limiting enzyme of [(18)F]FLT metabolism, is overexpressed in pancreatic cancer cell lines and in human pancreatic cancer. Thus, we propose [(18)F]FLT as a promising tracer for positron emission tomography that might overcome current limitations in the diagnosis of pancreatic cancer.

Identification of tobacco-derived compounds in human pancreatic juice.

Cancer of the pancreas is the fourth leading cause of cancer mortality in the USA with an estimated 28 900 deaths in 2001. Several factors have been implicated in the etiology of this disease. However, at present, only cigarette smoking has been positively associated with pancreatic cancer. It is our working hypothesis that tobacco-derived compounds can be delivered to the pancreas where, upon metabolic activation, they can initiate carcinogenesis. Our current investigation was conducted to determine whether cotinine and tobacco-specific nitrosamines (TSNA) are present in human pancreatic juice. Smoking status was assessed by the determination of levels of urinary cotinine and was further supported by quantifying nicotine in hair. The TSNA were extracted from the pancreatic juice of 18 smokers and 9 nonsmokers by supercritical carbon dioxide that contained 10% methanol. The extracts were analyzed for TSNA, namely, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN), by gas chromatography with mass spectrometric detection using a selected ion monitoring technique (GC-SIM-MS). Twenty-three extracts of human pancreatic juice were also analyzed for the presence of the NNK metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) by GC-SIM-MS and by gas chromatography interfaced wit a thermal energy analyzer (GC-TEA; TEA, a nitrosamine-specific detector). Cotinine was detected in all analyzed samples of pancreatic juice from smokers (129 +/- 150 ng/mL juice; mean +/- standard deviation) and was present in only two of the nine samples of pancreatic juice from nonsmokers. Its levels in these two samples were 7 and 9 ng/mL juice. NNK was detected in 15 of 18 samples (83%) from smokers at levels from 1.37 to 604 ng/mL pancreatic juice. In nine samples of pancreatic juice from nonsmokers, NNK ranged from not detected (in three samples) to 96.8 ng/mL juice. In pancreatic juice from smokers the mean level of NNK (88.7 +/- 161 ng/mL juice) was significantly higher (p < 0.04) than in that from nonsmokers (12.4 +/- 31.7 ng/mL juice). In addition to NNK, NNN was found in two samples of pancreatic juice of smokers at levels of 68.1 and 242 ng/mL juice; NNN was not detected in any other sample. NNAL was present in 8 of 14 pancreatic juice samples (57%) from smokers and in three of nine samples (33%) from nonsmokers. This research presents preliminary data that supports the hypothesis that pancreatic tissue is exposed to TSNA and that they may be important contributors to pancreatic carcinogenesis in humans.