[Langerhans cell histiocytosis of the stomach with BRAF-V600E-mutation: case report and review of the literature]. / Langerhans-Zellhistiozytose des Magens mit BRAF-V600E-Mutation: Fallbericht und Literaturübersicht.

Langerhans cell histiocytosis is a disease with different clinical presentations and a wide spectrum of organ involvements. Rarely Langerhans cell histiocytosis can involve the gastrointestinal tract of adult patients. A case of infiltration of gastric mucosa by Langerhans cell histiocytosis is presented. The neoplastic nature of this infiltrate is underlined by the detection of a BRAF-V600E-mutation. Additionally, an overview of the so far 5 cases published in the English literature is provided. The published clinical experience indicates a benign curse of the disease.

Multi-colour FISH in oesophageal adenocarcinoma-predictors of prognosis independent of stage and grade.

BACKGROUND: Oesophageal adenocarcinoma or Barrett's adenocarcinoma (EAC) is increasing in incidence and stratification of prognosis might improve disease management. Multi-colour fluorescence in situ hybridisation (FISH) investigating ERBB2, MYC, CDKN2A and ZNF217 has recently shown promising results for the diagnosis of dysplasia and cancer using cytological samples. METHODS: To identify markers of prognosis we targeted four selected gene loci using multi-colour FISH applied to a tissue microarray containing 130 EAC samples. Prognostic predictors (P1, P2, P3) based on genomic copy numbers of the four loci were statistically assessed to stratify patients according to overall survival in combination with clinical data. RESULTS: The best stratification into favourable and unfavourable prognoses was shown by P1, percentage of cells with less than two ZNF217 signals; P2, percentage of cells with fewer ERBB2- than ZNF217 signals; and P3, overall ratio of ERBB2-/ZNF217 signals. Median survival times for P1 were 32 vs 73 months, 28 vs 73 months for P2; and 27 vs 65 months for P3. Regarding each tumour grade P2 subdivided patients into distinct prognostic groups independently within each grade, with different median survival times of at least 35 months. CONCLUSIONS: Cell signal number of the ERBB2 and ZNF217 loci showed independence from tumour stage and differentiation grade. The prognostic value of multi-colour FISH-assays is applicable to EAC and is superior to single markers.

Foveolar gastric metaplasia of the duodenum: a frequent, so far neglected type of duodenal polyp.

Foveolar gastric metaplasia of the duodenum (FGM) is considered as imperfect mucosal healing in the context of H. pylori gastritis and intake of NSAIDs or ASS.  Typical endoscopic findings are redness of the mucosa, erosion/ulcer and loss of mucosal folds. During diagnostic histological examinations we observed a frequent so far not described association of FGM with endoscopically observed duodenal polyps. The archives of two institutes of pathology with high gastroenterological workload (approximately 100 000 patients per year) were investigated for an association between "duodenal polyp" and "foveolar gastric metaplasia". In Institute 1, of 481 duodenal polyps 41 % were classified as FGM, 9 % as adenoma and 2 % as heterotopic gastric mucosa. In 48 % no histological correlate was present. In Institute 2, 217 cases of FGM were diagnosed. Of these, in 69 cases the endoscopic finding was "polyp" (32 %). In the other cases, the endoscopic findings were mucosal defect (18 %), redness/inflammation (16 %), suspicion for gastric heterotopia (5 %) and scar (3 %). In 26 % of cases no pathologic endoscopic finding was reported. Both groups of patients with FGM showed a similar distribution of age ranges (24 - 83 years and 16 - 88 years), median age (62 years and 61 years, respectively) and a dominance of male sex (both 1.5:1). In conclusion, foveolar gastric metaplasia is a frequent, so far neglected correlate of endoscopically detected duodenal polyps.

[Serrated polyps of the duodenum. Three cases with immunohistological and molecular pathological findings]. / Serratierte Polypen des Duodenums. Drei Fälle mit immunhistologischen und molekularpathologischen Befunden.

We report on three cases of serrated polyps of the duodenum which were incidental endoscopic findings in three male patients with a median age of 70 years (range 63-84 years). Architecturally the histological findings in cases 1 and 2 were similar to hyperplastic polyps of the colon. In case 3 there was a low grade intraepithelial neoplasia which covered the whole polyp. This polyp relapsed after 2 years with similar histological findings. Immunohistochemically an increased proliferative activity was found in case 3 as well as associated overexpression of p16 (INK4a) and p53. No abnormal expression of MLH1 and ß-catenin was found in any of the polyps. Molecular pathological analysis showed a BRAF mutation (V600E) in case 3. A wild type sequence in the KRAS gene was found in all polyps. In conclusion, serrated polyps should be included in the diagnostic spectrum of benign duodenal polyps.

[Paraneoplastic acanthosis nigricans of the esophagus: a case report]. / Acanthosis nigricans als paraneoplastische Erkrankung des Ösophagus: ein Fallbericht.

A 69-year-old man presented for endoscopic examination of the upper gastrointestinal tract because of dysphagia for solid food and unintended weight loss. Several months before, he had noticed brownish-gray skin lesions in the neck, in the thorax and in both axillae. A dermatological consultant expressed the suspicion of a paraneoplastic disease. Endoscopic examination revealed an adenocarcinoma of the esophagogastric junction as well as multiple small polyps in the middle and the lower thirds of the esophagus. Histological examination showed papilloma-like proliferations without atypia, which were diagnosed as acanthosis nigricans of the esophagus. After completion of the staging investigation regarding the cardiac carcinoma, combination chemotherapy was started because of the presence of liver metastases. Subsequently, partial regression of the carcinoma as well as of the dermal and esophageal lesions was noted. Acanthosis nigricans is a rare paraneoplastic disease of the esophagus. As an indicator lesion, its detection should prompt a search for a malignant tumor in the gastrointestinal tract.

Differential regulation of hyaluronic acid synthase isoforms in human saphenous vein smooth muscle cells: possible implications for vein graft stenosis.

Autologous saphenous vein bypass grafts (SVG) are frequently compromised by neointimal thickening and subsequent atherosclerosis eventually leading to graft failure. Hyaluronic acid (HA) generated by smooth muscle cells (SMC) is thought to augment the progression of atherosclerosis. The aim of the present study was (1) to investigate HA accumulation in native and explanted arterialized SVG, (2) to identify factors that regulate HA synthase (HAS) expression and HA synthesis, and (3) to study the function of the HAS2 isoform. In native SVG, expression of all 3 HAS isoforms was detected by RT-PCR. Histochemistry revealed that native and arterialized human saphenous vein segments were characterized by marked deposition of HA in association with SMC. Interestingly, in contrast to native SVG, cyclooxygenase (COX)-2 expression by SMC and macrophages was detected only in arterialized SVG. In vitro in human venous SMC HAS isoforms were found to be differentially regulated. HAS2, HAS1, and HA synthesis were strongly induced by vasodilatory prostaglandins via Gs-coupled prostaglandin receptors. In addition, thrombin induced HAS2 via activation of PAR1 and interleukin 1beta was the only factor that induced HAS3. By small interfering RNA against HAS2, it was shown that HAS2 mediated HA synthesis is critically involved in cell cycle progression through G1/S phase and SMC proliferation. In conclusion, the present study shows that HA-rich extracellular matrix is maintained after arterialization of vein grafts and might contribute to graft failure because of its proproliferative function in venous SMC. Furthermore, COX-2-dependent prostaglandins may play a key role in the regulation of HA synthesis in arterialized vein grafts.

Critical reappraisal of current surveillance strategies for Barrett's esophagus: analysis of a large German Barrett's database.

Endoscopic surveillance is recommended for patients with Barrett's esophagus (BE). Based on a large database, gathered from predominantly community-based practices in Germany, we aimed to investigate the time-course of malignant progression and apply these findings to current clinical practice. Data of 1438 patients with BE from a large German BE database were analyzed. Patients with at least one follow-up endoscopy/biopsy were included. Detection of 'malignant Barrett' (either high-grade intra-epithelial neoplasia or invasive adenocarcinoma) was considered as study end-point. Of 1438 patients with BE, 57 patients had low-grade intra-epithelial neoplasia (LG-IN) on initial biopsy and 1381 exhibited non-neoplastic BE. 'Malignant Barrett' was detected in 28 cases (1.9%) during a median follow-up period of 24 months (1-255), accounting for an incidence of 0.95% per patient year of follow-up. The frequency of 'malignant Barrett' was significantly higher (P < 0.001, chi(2)-test) in the LG-IN group (n = 11, 19.3%) compared with the non-neoplastic BE group (n = 17, 1.2%). In the non-neoplastic BE group, 'malignant Barrett' was predominantly found during re-endoscopy within the first year of follow-up (12 of 17; 70.6%), in contrast to the LG-IN group, in which 'malignant Barrett' was observed predominantly after a time exceeding 12 months (8 of 11, 72.7%; P = 0.05, Fisher's exact test). Initial endoscopic evaluations seem to play the most crucial role in managing BE. After 1 year of follow-up, endoscopic surveillance should be focused on patients with LG-IN. In patients with repeatedly proven non-neoplastic BE, elongation of the follow-up intervals to the upper limit of current guidelines, that is, 5 years, might be justified.

Expression of prostaglandin E synthase in Barrett's cancer.

Expression of prostaglandin E synthase (PGES) - an enzyme of the prostaglandin biosynthetic pathway with suspected impact on carcinogenesis--was studied in Barrett's cancer to determine its pathogenetic role and prognostic impact in this entity. Expression analysis of PGES was performed on mRNA level (quantitative reverse transcription polymerase chain rection [RT-PCR]) in a large surgical series of 123 primary resected adenocarcinomas of the distal esophagus (Barrett's cancer). Gene expression results were correlated with clinical parameters, overall survival and expression levels of previously analyzed target genes of the cyclooxygenase (COX) pathway (COX-1, COX-2) and mediators of angiogenesis (vascular endothelial growth factor [VEGF]-A) and lymphangiogenesis [VEGF-C]. Expression of PGES was demonstrated in all 123 tumors (100%) on mRNA level (quantitative RT-PCR). Relative mRNA expression levels were highly variable between different cases. Gene expression showed a strong positive correlation with both COX isoforms (COX-1: r = 0.502, P < 0.001; COX-2: r = 0.679, P < 0.001), with the angiogenetic VEGF-A (r = 0.583, P < 0.001) and with the lymphangiogentic VEGF-C (r = 0.465, P < 0.001). PGES mRNA expression showed no significant correlation with clinicopathologic parameters (i.e. pTNM categories, UICC stage, survival). Variable overexpression of PGES seems to be potentially implicated in Barrett's carcinogenesis. Gene expression of PGES is strongly correlated with other mediators of the prostaglandin biosynthetic pathway, that is both COX isoforms (COX-1 and COX-2). However, no impact on patients' outcome in relation to PGES expression was found.

Analysis of the E-cadherin repressor Snail in primary human cancers.

Epithelial-mesenchymal transition (EMT), a normal developmental process, is known to play a crucial role in tumor progression. Molecules involved in this process, such as the E-cadherin repressor Snail, facilitate migration and invasion of carcinoma cells. A growing number of studies addressing the expression of Snail in clinical samples have been reported and are discussed in this review. A total of 2,112 cases from 9 different tumor types were evaluated. So far, a clear picture has emerged only in some cancer types analyzed with regard to overexpression of Snail and clinical-pathological parameters. Currently, it seems that Snail may play a role in hormone-dependent carcinomas but may be of minor importance in gastrointestinal cancers for tumor dedifferentiation and the maintenance of the invasive phenotype. It should be kept in mind, however, that the threshold for Snail activity does not have to be the same in every tumor type analyzed. The recent introduction of well-characterized novel monoclonal antibodies reacting with the short-lived nuclear Snail protein may help to establish a potential clinical usefulness for this master molecule of EMT, at least for certain types of cancer.

Prognostic significance of expression patterns of c-erbB-2, p53, p16INK4A, p27KIP1, cyclin D1 and epidermal growth factor receptor in oesophageal adenocarcinoma: a tissue microarray study.

AIMS: To correlate immunohistochemical expression patterns and prognosis in oesophageal adenocarcinoma. METHODS: The expression of c-erbB-2, p53, p16INK4A, p27KIP1, cyclin D1 and epidermal growth factor receptor (EGFR) was studied in a series of 137 primarily resected oesophageal adenocarcinoma samples. The expression analysis on protein level was performed on routine paraffin wax-embedded material, with immunohistochemical staining of the samples, assembled on a tissue microarray. The results were correlated with clinicopathological features (pT, pN and G) and survival. RESULTS: 22 (16%) tumours showed an overexpression of the c-erbB-2 oncoprotein. Expression of EGFR was observed in 72 (55%) cases, accumulation of p53 in 68 (52%) cases and of cyclin D1 in 102 (77%) cases. Loss of p16INK4A expression was observed in 101 (76%) cases and low expression of p27KIP1 in 91 (71%) cases. Expression of these proteins did not correlate with tumour stage, grade, Lauren's or World Health Organization classification or lymph node status. On univariate survival analysis, more advanced tumour stage (p = 0.002), lymph node involvement (p = 0.003), high tumour grade (p = 0.017) and lack of EGFR expression (p = 0.034) were found to be associated with poorer survival. On multiple regression analysis, only tumour stage (p = 0.03) and lymph node involvement (p = 0.004) were shown to have an association with the survival of the patient. CONCLUSION: The immunohistochemical expression of c-erbB-2 oncoprotein, cylin D1, p16INK4A, p27KIP1, p53 and EGFR in most oesophageal adenocarcinomas suggests their implication in the pathogenesis of this entity. None of the molecular markers assessed, however, was of prognostic value. Identification of any marker superior to or even approaching the prognostic value of conventional histopathological markers (pT and pN) was therefore not possible.

Induction of hyaluronic acid synthase 2 (HAS2) in human vascular smooth muscle cells by vasodilatory prostaglandins.

Hyaluronic acid (HA) is a prominent constituent of the extracellular matrix of atherosclerotic vascular lesions in humans known to modulate vascular smooth muscle phenotype. The regulation of HA synthesis by vasodilatory prostaglandins was analyzed in human arterial smooth muscle cells (SMCs). The prostacyclin analogue, iloprost (100 nmol/L), markedly increased pericellular formation of HA coats and HA secretion into the cell culture medium in human arterial SMCs (8.7+/-1.6-fold). Expression of HA synthase 2 (HAS2) was determined by semiquantitative RT-PCR and found to be strongly upregulated at concentrations of iloprost between 1 and 100 nmol/L after 3 hours. Furthermore, endogenous cyclooxygenase-2 (COX2) activity was required for basal expression of HAS2 mRNA in SMCs in vitro. Total HA secretion in response to iloprost was markedly decreased by RNA interference (RNAi), specific for HAS2. In addition, siRNA targeting HAS2 strongly increased the spreading of human SMCs compared with mock-transfected cells. HAS2 mRNA levels were also stimulated by a selective prostacyclin receptor (IP) agonist, cicaprost (10 nmol/L), prostaglandin E(2) (10 nmol/L), and the EP(2) receptor agonist, butaprost (1 micromol/L). Induction of HAS2 mRNA and HA synthesis by prostaglandins was mimicked by stable cAMP analogues and forskolin. In human atherectomy specimens from the internal carotid artery, HA deposits and COX2 expression colocalized frequently. In addition, strong EP(2) receptor expression was detected in SMCs in HA-rich areas. Therefore, upregulation of HAS2 expression via EP(2) and IP receptors might contribute to the accumulation of HA during human atherosclerosis, thereby mediating proatherosclerotic functions of COX2.

Cyclooxygenase-2 expression in human esophageal carcinoma.

On the basis of epidemiological observations that nonsteroidal antiinflammatory drugs reduce the risk of esophageal carcinoma, we studied the expression of cyclooxygenase-2 (COX-2) in esophageal squamous cell carcinomas (SCCs; n = 172) and in esophageal adenocarcinomas (ADCs; n = 27). Using immunohistochemistry, we observed COX-2 expression in 91% of the SCCs and in 78% of the ADCs. Western blot analysis showed enhanced expression of the COX-2 protein in some tumors as compared with normal esophageal squamous epithelium, whereas similar amounts of the COX-1 protein were found in normal and cancerous tissues. COX expression was also studied in two esophageal cancer cell lines (OSC-1 and OSC-2) to evaluate the functional relevance of COX-2-derived prostaglandins (PGs). OSC-2 cells expressed COX-2 but not COX-1, whereas OSC-1 cells expressed high levels of COX-1 but showed only a very weak COX-2 expression. Accordingly, PGE2 synthesis was 600 times higher in the OSC-2 cells as compared with the OSC-1 cells. Treatment of OSC-2 cells with the selective COX-2 inhibitors flosulide and NS-398 concentration dependently suppressed PGE2 synthesis and proliferation and also induced apoptosis. In contrast, no effect of the COX-2 inhibitors was seen in OSC-1 cells. Our data demonstrate that COX-2 is expressed in the majority of esophageal SCCs and ADCs and that COX-2-derived PGs play an important role in the regulation of proliferation and apoptosis of esophageal tumor cells. It is concluded that inhibition of COX-2 may be useful in the therapy of esophageal cancer.

Prognostic significance of urokinase-type plasminogen activator expression in squamous cell carcinomas of the esophagus.

In the present study, urokinase-type plasminogen activator (uPA) expression in 150 potentially curatively resected SCCs of the esophagus was analyzed immunohistochemically by means of a murine monoclonal antibody (American Diagnostica, Greenwich, CT) and correlated with survival. Altogether, 122 of the 150 tumors (81.3%) expressed different levels of uPA. Among the 122 uPA-positive tumors, 104 (85.2%) showed a weak staining intensity, and 18 (14.8%) showed a strong staining intensity. Among the uPA-positive tumors, 29 (23. 8%) tumors showed a uPA immunoreactivity in 6-25% of all tumor cells, 30 (24.6%) showed a uPA immunoreactivity in 26-50% of all tumor cells, 41 (33.6%) showed a uPA immunoreactivity in 51-75% of all tumor cells, and 22 (18.0%) showed a uPA immunoreactivity in 76-100% of all tumor cells. No significant correlation could be shown between the different patterns of uPA expression and various clinicopathological parameters, such as pT category, pN category, tumor size, histological grade, blood vessel invasion, lymphatic vessel invasion, and inflammatory response. Concerning the overall postoperative survival, no significant differences between uPA-positive and uPA-negative tumors could be verified. This also held true when different cut points in the percentage of uPA-positive tumor cells were used. In contrast, the intensity of uPA staining provided significant prognostic information in that patients with strongly uPA-positive tumors had a poorer outcome than patients with weakly uPA-positive or uPA-negative tumors. Moreover, as shown by stepwise multivariate Cox regression analysis, the intensity of uPA expression was an independent prognostic factor.

Expression of apoptosis-regulating proteins and outcome of esophageal cancer patients treated by combined therapy modalities.

The present study retrospectively examines the correlation between the outcome of patients with locally advanced esophageal squamous cell carcinoma (LAEC) after multimodal treatment (radiochemotherapy +/- surgery) and the expression of apoptosis-regulating proteins in pretherapeutic biopsies. Thirty-eight patients with LAEC who took part in a prospective multicentric trial received radiochemotherapy, optionally followed by surgery. Pretreatment tumor biopsies were immunohistochemically investigated for expression of p53, Bcl-2, Bax (bcl-2-associated X protein), and Bcl-X(L) (bcl-2-related X protein). The overall expression of p53, Bcl-2, Bax, and Bcl-X(L) was 52.6, 57.9, 100, and 97.4% respectively. Tumors without p53 expression and tumors with weak Bcl-X(L) expression showed response to chemotherapy more frequently (55.6 and 52.6%, respectively) than tumors positive for p53 expression and tumors with strong Bcl-X(L) expression (30.0 and 31.6%, respectively); however, these differences did not attain statistical significance. No correlations were found between the expression of Bcl-2 and Bax and the response to chemotherapy. In patients treated by radiochemotherapy and surgery, p53-negative tumors showed a significantly better outcome than p53-positive tumors (mean survival, 31.1 months versus 11.3 months; P = 0.0378). Additionally, a more favorable outcome was observed in tumors positive for Bcl-2 (not significant), whereas no differences in survival were observed in relation to the expression of Bax or Bcl-X(L). No differences in survival were observed in patients treated by radiochemotherapy without subsequent resection therapy in relation to the expression of apoptosis-regulating proteins. Immunohistochemical examination of pretherapeutic tumor biopsies for expression of apoptosis-regulating proteins may help to identify patients with LAEC who may benefit from multimodal treatment and those who may not.

Expression of Bcl-X(L), an antiapoptotic member of the Bcl-2 family, in esophageal squamous cell carcinoma.

Bcl-X, a Bcl-2-related protein, is a potent antagonist of apoptosis in its long splice variant (Bcl-X(L)). The present study was performed to determine its expression in preneoplastic and neoplastic lesions of the esophagus, its correlation with other members of the Bcl-2 family, and its impact on the outcome of surgically treated esophageal cancer patients. Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasias (n = 19), carcinomas in situ (n = 14), invasive squamous cell carcinomas (n = 172), and lymph node metastases (n = 21) were immunohistochemically analyzed for Bcl-X(L) expression using a polyclonal anti-Bcl-X(L) antibody. The immunostaining was evaluated according to a score system (0-12 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmic staining for Bcl-X(L) protein was invariably found in all cell layers of the normal esophageal squamous epithelium. In contrast, a considerable portion of preneoplastic and neoplastic lesions display a decreased Bcl-X(L) expression as compared with that in the normal esophageal epithelium. On comparison of the amount of Bcl-X(L) expression between the different types of lesions, however, no significant differences were found between severe squamous cell dysplasias (mean immunoreactive score +/- SD, 5.2 +/- 1.8), carcinomas in situ (5.2 +/- 2.2), invasive carcinomas (4.5 +/- 2.8), and lymph node metastases (4.2 +/- 2.6). In invasive carcinomas, Bcl-X(L) expression decreased continuously with decreasing tumor differentiation (P = 0.0001) and was also directly correlated with bcl-2-associated X protein expression (P = 0.0001). On the contrary, an inverse correlation was found between Bcl-X(L) expression and Bcl-2 protein expression (P = 0.0001). No correlation was found between Bcl-X(L) expression and the parameters pT category, pN category, and tumor size. In the univariate survival analysis, patients with low immunoreactive scores (< or = 4) of Bcl-X(L) expression in the tumor tissue showed lower 2-year and 5-year survival rates than patients with high immunoreactive scores (> 4; P = 0.0485). In multivariate survival analysis, however, only the parameters pN category and pT category, but not Bcl-X(L) expression, could be verified as independent prognostic factors. This tendency of decreasing levels of an antiapoptotic protein toward unfavorable outcome is supported by an increasing number of studies on the role of Bcl-2, another antiapoptotic protein, and must be interpreted against the backdrop of apoptosis as a result of the interaction of many cell death-promoting and protecting proteins.

Expression of p21WAF1 predicts outcome of esophageal cancer patients treated by surgery alone or by combined therapy modalities.

The p21WAF1 protein is an important regulator of the cell cycle. Its expression and prognostic significance were investigated immunohistochemically in samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasia (n = 20), carcinoma in situ (n = 14), permanent esophageal squamous cell carcinoma cell lines (n = 3), and invasive squamous cell carcinomas treated either by potentially curative resection (n = 172) or by combined modality therapy (radiochemotherapy +/- surgery; n = 38). Whereas p21WAF1 expression in the normal epithelium was restricted to a few cells adjacent to the basal cell layer, p21WAF1 overexpression was frequently found in preneoplasias and invasive carcinomas. Expression of p21WAF1 in invasive carcinomas was not correlated with tumor differentiation, pT category, or pN category. Among carcinomas treated by potential curative resection, univariate (P = 0.0025) and multivariate (P = 0.0081) survival analysis showed significant correlation of strong p21WAF1 expression (> or =50% p21WAF1-positive tumor cells) with poor overall survival. Univariate survival analysis (P = 0.0006) revealed the same prognostic influence in the group of patients treated by combined modality therapy. We conclude that overexpression of p21WAF1 protein is a frequent event in preneoplasias and neoplasias of the esophagus. Immunohistochemical examination of p21WAF1 expression may provide important prognostic information for decision-making in the treatment of patients with esophageal cancer.

Oxidative injury to isolated rat pancreatic acinar cells vs. isolated zymogen granules.

This study compares the susceptibility of pancreatic acinar cells and zymogen granules against oxidative injury and analyzes the mechanisms involved. Zymogen granules and acinar cells, isolated from rat pancreas, were exposed to a reaction mixture containing xanthine oxidase, hypoxanthine, and chelated iron. Cell function and viability were assessed by various techniques. Trypsin activation was quantified by an Elisa for trypsinogen activating peptide. Integrity of granules was determined by release of amylase. The reaction mixture rapidly generated radicals as assessed by deoxyribose and luminol assays. This oxidative stress caused lysis of granules in a matter of minutes but significant cell death only after some hours. Nevertheless, radicals initiated intracellular vacuolization, morphological damage to zymogen granules and mitochondria, increase in trypsinogen activating peptide, and decrease in ATP already after 5-30 min. Supramaximal caerulein concentrations also caused rapid trypsin activation. Addition of cells but not of granules reduced deoxyribose oxidation, suggesting that intact cells act as scavengers. Caerulein pretreatment only slightly increased the susceptibility of cells but markedly that of granules. In conclusion, isolated zymogen granules are markedly more susceptible to oxidative injury than intact acinar cells, in particular, in early stages of caerulein pancreatitis. The results show that oxidative stress causes a rapid trypsin activation that may contribute to cell damage by triggering autodigestion. Zymogen granules and mitochondria appear to be important targets of oxidative damage inside acinar cells. The series of intracellular events initiated by oxidative stress was similar to changes seen in early stages of pancreatitis.

Antiatherosclerotic effects of oral cicaprost in experimental hypercholesterolemia in rabbits.

The efficacy of the oral prostacyclin mimetic cicaprost in preventing atheromatous plaque formation was studied in an in vivo model of experimental hypercholesterolemia. New Zealand white rabbits were fed either standard chow or a cholesterol-enriched (1%) diet for 12 weeks. Cicaprost was added to the drinking water in a non-hypotensive dose (5 micrograms/kg/day) and withdrawn 3 days prior to studying platelet, leukocyte and endothelial function. In cholesterol-fed rabbits, oral cicaprost reduced the aortic intimal surface covered by atheromatous lesions from 84 to 63% (P < 0.05). There was no major difference in serum lipid composition between cicaprost- and vehicle-treated animals. In hyper-cholesterolemic rabbits there was a significant impairment of endothelium-dependent relaxations. Cicaprost treatment considerably improved this endothelial function but had no effect in rabbits receiving standard diet. In addition, platelet and leukocyte hyperreactivity, as seen in hypercholesterolemic rabbits, were largely reduced by cicaprost treatment. These data are the first to demonstrate marked antiatherosclerotic effects of long-term oral prostacyclin treatment. The mechanism may be related to improved endothelial function and subsequent prevention of secondary platelet and neutrophil hyperreactivity.

The prognostic significance of DNA ploidy in adenocarcinomas of the esophagogastric junction.

DNA aneuploidy, as determined by flow cytometry, was detected in 36 out of 59 adenocarcinomas of the esophagogastric junction (61.0%). DNA aneuploidy was more frequent in tumors with infiltrative growth pattern and in high pT categories. No correlation was found with pN category, grading and Laurén's classification. In contrast to clinicopathological parameters, DNA ploidy has no impact on patients survival in univariate survival analysis.

Differential expression of mucins and trefoil peptides in native epithelium, Barrett's metaplasia and squamous cell carcinoma of the oesophagus.

BACKGROUND AND AIMS: In humans, trefoil peptides (TFF peptides) and some mucins have been reported to be expressed in a cell-specific manner at mucosal surfaces of normal gastrointestinal tissues. Neoplastic conditions cause characteristic changes of these expression patterns. To study such patterns in Barrett's metaplasia and squamous cell carcinoma of the oesophagus (SCC), the distribution of MUC1, MUC2, MUC5AC and the three TFF peptides (TFF1, TFF2 and TFF3) was investigated. METHODS: In 40 archival samples of SCC and in 21 samples of Barret's metaplasia, expression of the three mucins and two TFF peptides (TFF1 and TFF2) was assessed by specific antibodies. Reverse transcriptase/polymerase chain reaction amplification (RT-PCR) was performed on frozen tissue samples from the 11 biopsies of SCC for the three TFF peptides. RESULTS: Immunohistochemical tests for MUC2 and TFF2 were negative both in samples of Barret's metaplasia and in SCC. MUC1 expression was detected in 57.5% of the tumour samples, while TFF1 and MUC5AC were found in 10% and 7.5% of the cases respectively. In Barrett's metaplasia MUC1 was detected in 90.5% of the cases and TFF1 and MUC5AC in all of them. RT-PCR analysis revealed a more complex pattern: TFF1 and TFF3 expressed the corresponding mRNA in all samples investigated; the third member, TFF2, was active in 45.5% of the carcinoma biopsies and not in the corresponding native tissue. CONCLUSIONS: This finding in oesophageal carcinoma contrasts with the situation found in normal and neoplastic stomach epithelium where TFF1 and TFF2 are found co-expressed and TFF3 remains silent. Interestingly, MUC1 is expressed in a significant proportion of SCC. Both in Barett's metaplasia and in SCC the expression of MUC5AC mirrors the TFF1 synthesis in intensity and spatial distribution.