Alarm features and age for predicting upper gastrointestinal malignancy in Chinese patients with dyspepsia with high background prevalence of Helicobacter pylori infection and upper gastrointestinal malignancy: an endoscopic database review of 102,665 patients from 1996 to 2006.

OBJECTIVE: Patients with dyspepsia with alarm features are suspected of having upper gastrointestinal (GI) malignancy; however, the true value of alarm features in predicting an underlying malignancy for patients with dyspepsia with high background prevalence of Helicobacter pylori infection and upper GI malignancy is uncertain. The aim of the present study was to determine the diagnostic accuracy of alarm features in predicting upper GI malignancy by reviewing an endoscopic database consisting of >100,000 Chinese patients. METHODS: A retrospective analysis of prospectively collected data was conducted in a single tertiary medical centre. Consecutive patients who underwent oesophagogastroduodenoscopy (OGD) for dyspepsia in 1996-2006 were enrolled. The data including gender, age, symptoms, and endoscopic and pathological findings were analysed. The main outcome measure was the diagnostic accuracy of individual alarm feature. RESULTS: 102,665 patients were included in the final analysis. Among all the 4362 patients with malignancy, 52% (2258/4362) had alarm features. Among 15 235 patients who had alarm features, 2258 (14.8%) were found to have upper GI malignancy. The pooled sensitivity and specificity of the alarm features were 13.4% and 96.6%, respectively. Only the feature of dysphagia in patients between 36 and 74 years old had a positive likelihood ratio (PLR) >10 for malignancy prediction, while all other alarm features in other age groups had a PLR <10. CONCLUSIONS: For uninvestigated Chinese patients with dyspepsia with high background prevalence of H pylori infection and upper GI malignancy, alarm features and age, except for dysphagia in patients between 36 and 74 years old, had limited predictive value for a potential malignancy; therefore, prompt endoscopy may be recommended for these patients. However, less invasive, inexpensive screening methods with high diagnostic yield are still needed to reduce unnecessary endoscopy workload.

Metformin induces apoptosis of pancreatic cancer cells.

AIM: To assess the role and mechanism of metformin in inducing apoptosis of pancreatic cancer cells. METHODS: The human pancreatic cancer cell lines ASPC-1, BxPc-3, PANC-1 and SW1990 were exposed to metformin. The inhibition of cell proliferation and colony formation via apoptosis induction and S phase arrest in pancreatic cancer cell lines of metformin was tested. RESULTS: In each pancreatic cancer cell line tested, metformin inhibited cell proliferation in a dose dependent manner in MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays). Flow cytometric analysis showed that metformin reduced the number of cells in G1 and increased the percentage of cells in S phase as well as the apoptotic fraction. Enzymelinked immunosorbent assay (ELISA) showed that metformin induced apoptosis in all pancreatic cancer cell lines. In Western blot studies, metformin induced poly-ADP-ribose polymerase (PARP) cleavage (an indicator of caspase activation) in all pancreatic cancer cell lines. The general caspase inhibitor (VAD-fmk) completely abolished metformin-induced PARP cleavage and apoptosis in ASPC-1 BxPc-3 and PANC-1, the caspase-8 specific inhibitor (IETD-fmk) and the caspase-9 specific inhibitor (LEHD-fmk) only partially abrogated metformin-induced apoptosis and PARP cleavage in BxPc-3 and PANC-1 cells. We also observed that metformin treatment dramatically reduced epidermal growth factor receptor (EGFR) and phosphorylated mitogen activated protein kinase (P-MAPK) in both a time- and dose-dependent manner in all cell lines tested. CONCLUSION: Metformin significantly inhibits cell proliferation and apoptosis in all pancreatic cell lines. And the metformin-induced apoptosis is associated with PARP cleavage, activation of caspase-3, -8, and -9 in a time- and dose-dependent manner. Hence, both caspase-8 and -9-initiated apoptotic signaling pathways contribute to metformin-induced apoptosis in pancreatic cell lines.

Esophageal motility in patients with sliding hiatal hernia with reflux esophagitis.

BACKGROUND: Patients with sliding hiatus hernia (HH) and reflux esophagitis (RE) usually suffer from esophageal dysmotility. The aim of the present study was to investigate the role of acid reflux and duodenal gastroesophageal reflux (DGER), esophageal manometry, and esophageal dysmotility by applying the barium meal examination. METHODS: RE with HH was initially diagnosed using the reflux disease questionnaire, and was further confirmed by a barium meal examination and an endoscopy. The radiographic technique was used to test for spasms, strictures, and the coarseness of the mucosa, also was to study the types of reflux and clearance. Then, the esophageal manometry, the esophageal 24-hour pH, and the bilirubin monitoring were observed. RESULTS: Fifty-five patients were diagnosed as HH combined with RE and divided into two groups according to the severity of their esophagitis: group HH1 (grades A and B) and group HH2 (grades C and D). The barium meal examination revealed that the mucosa was either granular or nodular in all cases. The dump reflux and delayed clearance were more significant in patients in the HH2 group than those in the HH1 group (P < 0.05). The percentages of total, supine, and upright acid exposure time were greater in patients with HH than those in the control group (P < 0.01), but the differences between the HH1 and the HH2 groups were not significant. Lower esophageal sphincter pressure (LESP) was lower in the HH group than in the control group (P < 0.05). Three DGER parameters: the percentage of time with absorbance greater than 0.14, the number of bile reflux episodes, the number of bile refluxes lasting longer than 5 minutes were (28.43 +/- 23.34), (40.57 +/- 31.30), and (15.15 +/- 8.72), respectively in the HH2 group; these statistics were significantly higher than those for the HH1 (P < 0.05). The frequency and amplitude of peristalsis were all lower in HH patients than in the control (P < 0.05). Of all the patients, 54.3% (30 of 55) with acid reflux and DGER simultaneously in the HH group exhibited refluxes of barium from the stomach to the esophagus in the recumbent position, and 29.4% (5 in 17) with delayed clearance in the HH group were correlated with esophageal body peristalses. The result was that the frequency and amplitude of peristalsis were less and the duration of esophageal peristalsis was longer than those of control group. CONCLUSIONS: Esophageal dysmotility may play an important role in the severity of RE combined with HH. Esophageal motility results on a barium examination may coincide with esophageal manometry, 24-hour pH, and bilirubin monitoring in the RE and HH, but the radiologic method was the simplest to apply.

[Characteristics of cortical mapping in response to acid exposure in non-erosive reflux disease and erosive esophagitis using functional magnetic resonance imaging].

OBJECTIVE: To investigate the brain mechanisms for esophageal visceral hypersensitivity. METHODS: Thirty-one non-erosive reflux disease (NERD) patients, 21 in the group of NERD with esophageal hypersensitivity (NERD-H) and 10 in the group of NERD with normal esophageal sensation (NERD-N), 13 patients with erosive esophagitis (EE), and 12 healthy volunteers, all sex- and age-matched, underwent whole brain blood oxygenation level dependent (BOLD) fictional magnetic resonance imaging (fMRI) to record the cortical fMRI response to intraesophageal perfusion of normal saline or dilute hydrochloric acid. RESULTS: The main centers affected in the NERD-H patients included the secondary somatosensory cortex (SII), primary somatosensory cortex (S1), right prefrontal cortex (PFC), right orbitofrontal cortex (OFC), insular cortex, amygdala, striatum, motor cortex and its supplementary area, and cerebellum cortices, which form part of the matrix controlling emotional, autonomic modulatory responses to pain. The peak fMRI signal intensity and average maximum percent signal increase in the regions of interest (ROI) at above-mentioned brain areas of the NERD-H group were significantly stronger than those of the NERD-N and control groups (all P < 0.01). The peak image intensity of the anterior cingulate gyrus (ACC) of NERD-H group was 562 +/- 104, significantly lower than that of the control group (587 +/- 126, P < 0. 05), but significantly higher than that of the EE group (535 +/- 91, P < 0.05). The timeline of activation and deactivation events of particular ROI differentiate the four groups. The initial image latency and peak fMRI latency after hydrochloric acid perfusion of the NERD-H patients were 1.7 min +/- 0.9 min and peak 4. 5 min +/- 1.3 min respectively, both significantly shorter than those of the NERD-N group (4.0 min +/- 1.1 min and 6.8 min +/- 1.6 min respectively, both P < 0.01) and those of the control group (5. 4 min +/- 1.7 min and 7.2 min +/- 1.5 min respectively, both P < 0.01). The range of deactivation of SII and R-PFC of the NERD-H group were 26.5% +/- 5.4% and 20.3% +/- 3. 0% respectively, both significantly greater than those of the NERD-N group (8.2% +/- 2.2% and 16.4% +/- 3.6% respectively, both P < 0.05) and those of the EE group (11.9% +/- 4.8% and 11.7% +/- 3.1% respectively, both P < 0.01). The range of deactivation in ACC of the control group was 16.9% +/- 2.5%, significantly greater than those of the NERD-H and EE groups (11.8% +/- 2.8% and 6.4% +/- 1.0% respectively, both P < 0.05). CONCLUSION: The function of central nervous system to integrate and manage the convergence information becomes abnormal under the status of esophageal visceral hypersensitivity.

[The clinical value of endoscopic ultrasonography in early diagnosis of pancreatic tumor].

OBJECTIVE: To investigate the clinical value of endoscopic ultrasonography (EUS) and intraductal ultrasonography (IDUS) compared with the other imaging examination in the early diagnosis of pancreatic tumor. METHODS: Retrospect studied of 188 cases of small pancreatic lesions (less than 3 cm in diameter) detected by EUS, IDUS and the other imaging examination at Changhai hospital from October 1992 to September 2006. RESULTS: (1) The accurate rate of small pancreatic cancer diagnosed by EUS was 95.6%, and it is better compared with US (58.6%), CT (77.4%), MRI (76.2%) and ERCP (85.3%). The most common endosonographic features of small pancreatic cancer were alike round, irregular edge, hypoechoic mass with uniformity internal echo. (2) IDUS was performed in 25 cases of small pancreatic lesions, the accurate rate of diagnosis was 100% (25/25), and it is better compared with US 32.0% (8/25), CT 52.9% (9/17) and MRI 57.9% (11/19). (3) EUS guided FNA (EUS-FNA) was performed in 18 cases of small pancreatic lesions, the accurate rate of diagnosis was 66.7% (12/18). (4) The accurate rate of pseudocyst diagnosis by EUS was 100.0% (27/27), it is better compared with US 52.0% (13/25), CT 66.7% (12/18), MRI 82.4% (14/17) and ERCP 78.9% (15/19); and the overall accurate rate of diagnosis of cystic pancreatic tumors by EUS was 57.7% (15/26), it is better compared with US 19.2% (5/26), CT 36.4% (8/22), MRI 37.5% (6/16) and ERCP 50.0% (7/14). CONCLUSIONS: EUS and IDUS were better than the other imaging examinations in the detection of small pancreatic tumors.

Construction of an oral recombinant DNA vaccine from H pylori neutrophil activating protein and its immunogenicity.

AIM: To construct a live attenuated Salmonella typhimurium (S. typhimurium) strain harboring the H pylori neutrophil activating protein (HP-NAP) gene as an oral recombinant DNA vaccine, and to evaluate its immunogenicity. METHODS: By genetic engineering methods, the genomic DNA of H pylori was extracted as a template. The total length of the HP-NAP gene was amplified by polymerase chain reaction (PCR) and cloned into pBT vector for sequencing and BLAST analysis, then subcloned into a eukaryotic expression vector pIRES followed by PCR identification and restriction enzyme digestion. The identified recombinant plasmid pIRES-NAP was transfected into COS-7 cells for target fusion protein expression, and its antigenicity was detected by Western blotting. Then the recombinant plasmid was transformed into a live attenuated S. typhimurium strain SL7207 as an oral vaccine strain, and its immunogenicity was evaluated with animal experiments. RESULTS: A 435 bp product was cloned using high homology with HP-NAP gene in GenBank (more than 98%). With identification by PCR and restriction enzyme digestion, a recombinant eukaryotic expression plasmid pIRES-NAP containing the HP-NAP gene of H pylori was successfully constructed. The expressed target protein had a specific reaction with H pylorii whole cell antibody and showed a single strip result detected by Western blotting. Oral immunization of mice with recombinant DNA vaccine strain SL7207 (pIRES-NAP) also induced a specific immune response. CONCLUSION: The successful construction of HP-NAP oral DNA vaccine with good immunogenicity may help to further investigate its immunoprotection effects and develop vaccine against H pylori infection.

Role of duodenogastroesophageal reflux in the pathogenesis of esophageal mucosal injury and gastroesophageal reflux symptoms.

BACKGROUND AND AIM: Patients with gastroesophageal reflux disease (GERD) usually suffer from acid reflux and duodenogastroesophageal reflux (DGER) simultaneously. The question of whether DGER has an important effect on the development of GERD remains controversial. The aim of the present study was to investigate the role of DGER in the pathogenesis of GERD and its value for the diagnosis of nonerosive reflux disease (NERD). METHODS: GERD was initially diagnosed using the reflux disease questionnaire. For further diagnosis, results of the upper gastrointestinal endoscopy (excluding a diagnosis of Barrett's esophagus) were considered in conjunction with simultaneous 24 h esophageal pH and bilirubin monitoring. RESULTS: According to endoscopic findings, 95 patients (43 men, 50+/-10 years of age) were divided into two groups: the reflux esophagitis (RE) group (n=51) and the NERD group (n=44). Three DGER parameters, the percentage of time with absorbance greater than 0.14, the total number of reflux episodes and the number of bile reflux episodes lasting longer than 5 min, were evaluated in the study. For the RE group, the values of the DGER parameters (19.05%+/-23.44%, 30.56+/-34.04 and 5.90+/-6.37, respectively) were significantly higher than those of the NERD group (7.26%+/-11.08%, 15.68+/-20.92 and 2.59+/-3.57, respectively, P<0.05 for all) but no significant difference was found in acid reflux. Of NERD patients, 18.5% were diagnosed with simple DGER. The positive diagnosis rate of NERD could be significantly elevated from 65.9% to 84.1% (P<0.05), if bilirubin monitoring was employed in diagnosis. CONCLUSIONS: DGER may occur independently but plays an important role in the development of RE and GERD symptoms. Simultaneous 24 h esophageal pH and bilirubin monitoring is superior to simple pH monitoring in helping identify patients at risk for NERD.

Construction of a recombinant attenuated Salmonella typhimurium DNA vaccine carrying Helicobacter pylori hpaA.

AIM: To construct a recombinant attenuated Salmonella typhimurium DNA vaccine carrying Helicobacter pylori hpaA gene and to detect its immunogenicity. METHODS: Genomic DNA of the standard H pylori strain 17 874 was isolated as the template, hpaA gene fragment was amplified by polymerase chain reaction (PCR) and cloned into pUCmT vector. DNA sequence of the amplified hpaA gene was assayed, then cloned into the eukaryotic expression vector pIRES through enzyme digestion and ligation reactions. The recombinant plasmid was used to transform competent Escherichia coli DH5alpha, and the positive clones were screened by PCR and restriction enzyme digestion. Then, the recombinant pIRES-hpaA was used to transform LB5000 and the recombinant plasmid isolated from LB5000 was finally used to transform SL7207. After that, the recombinant strain was grown in vitro repeatedly. In order to identify the immunogenicity of the vaccine in vitro, the recombinant pIRES-hpaA was transfected to COS-7 cells using Lipofectamine2000, the immunogenicity of expressed HpaA protein was detected with SDS-PAGE and Western blot. RESULTS: The 750-base pair hpaA gene fragment was amplified from the genomic DNA and was consistent with the sequence of H pylori hpaA by sequence analysis. It was confirmed by PCR and restriction enzyme digestion that H pylori hpaA gene was inserted into the eukaryotic expression vector pIRES and a stable recombinant live attenuated Salmonella typhimurium DNA vaccine carrying H pylori hpaA gene was successfully constructed and the specific strip of HpaA expressed by pIRES-hpaA was detected through Western blot. CONCLUSION: The recombinant attenuated Salmonella typhimurium DNA vaccine strain expressing HpaA protein with immunogenicity can be constructed and it may be helpful for further investigating the immune action of DNA vaccine in vivo.

[A study of cerebral evoked potentials response to esophageal distention in non-erosive gastroesophageal reflux disease].

OBJECTIVE: To study the mechanism of visceral hypersensitivity in patients with non-erosive gastroesophageal reflux disease (NERD) and to get further objective evidence in the abnormal alteration of the afferents involved in mediating esophageal sensation by cerebral evoked potentials (CEP). METHODS: We recruited 21 NERD patients and 10 normal healthy volunteers for the study. Mechanical distention stimulation was performed using a balloon-affixed polyvinyl multilumen catheter. First, maximally tolerated pain threshold of all subjects were recorded, then esophageal mechanical stimulation at an intensity of 75% maximum tolerated intensity and a frequency of 0.2 Hz was inflated in a total of 64 times by means of a computer-controlled barostat. The alternation of esophageal CEP was recorded before and after acid perfusion with a multi-channel international 10-20 system of electroencephalograph. RESULTS: Esophageal mucosal distention may evoke recognizable and reproducible multi-peak CEP. CEP morphology of the NERD patients was characterized by randomly distributed patterns and the peak latencies for N1, P1, and N2 were significantly shorter for mechanical stimulation as compared with the control group (respectively, P = 0.016, 0.003, 0.031), and the amplitude of the P1-N2 components was significantly increased in NERD patients (P = 0.03). CONCLUSIONS: Characterization and alternation of CEP morphology and peak latencies and P1-N2 amplitudes elicited by esophageal distention in NERD patients provides evidence for defective hypersensitivity of afferent neural pathways and cortical processing.

Detection of point mutation in K-ras oncogene at codon 12 in pancreatic diseases.

AIM: To investigate frequency and clinical significance of K-ras mutations in pancreatic diseases and to identify its diagnostic values in pancreatic carcinoma. METHODS: 117 ductal lesions were identified in the available sections from pancreatic resection specimens of pancreatic ductal adenocarcinoma, comprising 24 pancreatic ductal adenocarcinoma, 19 peritumoral ductal atypical hyperplasia, 58 peritumoral ductal hyperplasia and 19 normal duct at the tumor free resection margin. 24 ductal lesions were got from 24 chronic pancreatitis. DNA was extracted. Codon 12 K-ras mutations were examined using the two-step polymerase chain reaction (PCR) combined with restriction enzyme digestion, followed by nonradioisotopic single-strand conformation polymorphism (SSCP) analysis and by means of automated DNA sequencing. RESULTS: K-ras mutation rate of the pancreatic carcinoma was 79%(19/24) which was significantly higher than that in the chronic pancreatitis 33%(8/24) (P<0.01). It was also found that K-ras mutation rate was progressively increased from normal duct at the tumor free resection margin, peritumoral ductal hyperplasia, peritumoral ductal atypical hyperplasia to pancreatic ductal adenocarcinoma. The mutation pattern of K-ras 12 codon of chronic pancreatitis was GGT-GAT, GGT and CGT, which is identical to that in pancreatic carcinoma. CONCLUSION: K-ras mutation may play a role in the malignant transformation of pancreatic ductal cell. K-ras mutation was not specific enough to diagnose pancreatic carcinoma.

Detection of K-ras point mutation and telomerase activity during endoscopic retrograde cholangiopancreatography in diagnosis of pancreatic cancer.

AIM: To study the value of monitoring K-ras point mutation at codon 12 and telomerase activity in exfoliated cells obtained from pancreatic duct brushings during endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic cancer. METHODS: Exfoliated cells obtained from pancreatic duct brushings during ERCP were examined in 27 patients: 23 with pancreatic cancers, 4 with chronic pancreatitis. K-ras point mutation was detected with the polymerase chain reaction and restriction fragment-length polymorphism (PCR-RFLP). Telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA). RESULTS: The telomerase activities in 27 patients were measured in 21 exfoliated cell samples obtained from pancreatic duct brushings. D450 value of telomerase activities in pancreatic cancer and chronic pancreatitis were 0.446+/-0.27 and 0.041+/-0.0111, respectively. Seventy-seven point eight percent (14/18) of patients with pancreatic cancer and none of the patients with chronic pancreatitis showed telomerase activity in cells collected from pancreatic duct brushings when cutoff value of telomerase activity was set at 2.0. The K-ras gene mutation rate (72.2%) in pancreatic cancer was higher than that in chronic pancreatitis (33.3%) (P<0.05). In considering of both telomerase activities and K-ras point mutation, the total positive rate was 83.3%(15/18), and the specificity was 100%. CONCLUSION: Changes of telomerase activities and K-ras point mutation at codon 12 may be an early event of malignant progression in pancreatic cancer. Detection of telomerase activity and K-ras point mutation at codon 12 may be complementary to each other, and is useful in diagnosis of pancreatic cancer.

Distribution of cagG gene in Helicobacter pylori isolates from Chinese patients with different gastroduodenal diseases and its clinical and pathological significance.

AIM: To determine the distribution of cagG gene of Helicobacter pylori (H pylori) isolates cultured from patients with various digestive diseases and its relationship with gastroduodenal diseases. METHODS: cagG was amplified by polymerase chain reaction in 145 H pylori isolates cultured from patients with chronic gastritis (n=72), duodenal ulcer (n=48), gastric ulcer (n=17), or gastric and duodenal ulcer (n=8), and the relationship between cagG status and the grade of gastric mucosal inflammation was determined. RESULTS: cagG was present in 91.7% of the 145 H pylori isolates, with the rates were 90.3%, 93.8%, 88.2% and 100.0%, respectively, in those from patients with chronic gastritis, duodenal ulcer, gastric ulcer, and gastric and duodenal ulcer. There was no significant difference among the four groups (P>0.05). The average grade of gastric mucosal inflammation in the antrum and corpus was 1.819+/-0.325 and 1.768+/-0.312, respectively in cagG positive patients, whereas the average inflammation grade was 1.649+/-0.297, 1.598+/-0.278 respectively in cagG negative cases (P>0.05). CONCLUSION: cagG gene of H pylori was quite conservative, and most H pylori strains in Chinese patients were cagG positive. cagG status was not related to clinical outcome or the degree of gastric mucosal inflammation. Therefore, cagG can not be used as a single marker for discrimination of H pylori strains with respect to a specific digestive disease.

Lymphoepithelial cyst of the pancreas: a case report.

BACKGROUND: Lymphoepithelial cyst of the pancreas is a rare lesion of undetermined pathogenesis that had been documented almost exclusively in males. The literature on this entity is limited to reports of single or a small number of cases. METHODS: The case we described herein was compared with a total of 36 cases reported elsewhere. RESULTS: The 37 cases of lymphoepithelial cyst of the pancreas including our case were reviewed. Lymphoepithelial cysts have uniform and distinctive clinicopathologic features. Approximately 46% of the reported cases were asymptomatic with the lesions found incidentally, and their symptoms were non-specific. CONCLUSIONS: Lymphoepithelial cyst is a rare benign lesion of the pancreas. Fine-needle aspiration biopsy (FNAB) is a rapid and reliable technique that can be used as the first diagnostic step in cases of cystic lesions of the pancreas.

Killing effects of cytosine deaminase gene mediated by adenovirus vector on human pancreatic cancer cell lines in vitro.

OBJECTIVE: To evaluate the killing effects of the cytosine deaminase (CD) gene mediated by adenovirus vector on human pancreatic cancer cell lines in vitro. METHODS: The CD gene was cloned into pAdTrack-CMV-CD, and pAdTrack-CMV-CD and pAdEasy-1 were recombinated in bacteria. The newly recombinated Ad-CD containing green fluorescent protein (GFP) was propagated in 293 cells and purified by cesium chloride gradient centrifugation. Human pancreatic cancer cell lines Patu8988 and SW1990 were infected with this virus, then 5-FC was added. XTT assay was used to estimate relative numbers of viable cells. RESULTS: The positive clones were selected by using endonuclease to digest the combinatants and the concentration of viral liquids containing the CD gene was 2X10(11) pfu/ml. It was found that significant cytotoxic activities were possessed by 5-FC for the CD gene transduced pancreatic cell lines, but little effects exerted on the nontransduced pancreatic carcinoma cells. CONCLUSIONS: The CD gene mediated by adenovirus with a high infectivity is efficient for gene therapy of pancreatic carcinoma cell lines. These data demonstrate the therapeutic efficacy of an enzyme prodrug strategy in experimental pancreatic cancer.

Detection of K-ras gene mutation at codon 12 by pancreatic duct brushing for pancreatic cancer.

OBJECTIVE: To assess the diagnostic value of endoscopic pancreatic duct brushing in detecting mutation of the K-ras gene at codon 12 in cytologic specimens from patients with pancreatic cancer. METHODS: Thirty-five patients treated at Changhai Hospital, Shanghai between 1999 and 2001 were enrolled. Their cells obtained by pancreatic duct brushing during endoscopic retrograde cholangiopancreatography (ERCP) were suspended with phosphate buffer solution (PBS). DNA of the cells was extracted and mutation of the K-ras gene at codon 12 detected by means of PCR-SSCP. RESULTS: The K-ras gene mutation rate of pancreatic cancer was 70%, which was higher than that of chronic pancreatitis (14%, P<0.05). K-ras gene mutation was not found in patients with pancreatic cystocarcinoma and duodenum carcinoma. As to the location of pancreatic cancer, no significant difference was observed between the head, the body and tail. The sensitivity, specificity, accuracy of pancreatic duct brushing in detecting pancreatic cancer was 70%, 94%, and 83%, respectively. CONCLUSION: K-ras analysis of pancreatic brushing samples is helpful in the diagnosis of patients with early pancreatic cancer.

Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea.

Chronic diarrhea is a common bowel disorder; disturbance of intestinal microorganisms may play a role in its pathogenesis. This study assessed the clinical efficacy of lyophilized, heat-killed Lactobacillus acidophilus LB versus living lactobacilli in the treatment of chronic diarrhea. One hundred thirty-seven patients with chronic diarrhea were randomly allocated to receive either a 4-week course of 2 capsules of Lacteol Fort twice a day (Lacteol group, 69 patients) or a 4-week course of 5 chewable tablets of Lacidophilin three times a day (Lacidophilin group, 64 patients). The frequency of stools was recorded quantitatively, and semiquantitative parameters such as stool consistency, abdominal pain, distention, and feeling of incomplete evacuation were evaluated. At the second and fourth week of treatment, mean bowel frequency was significantly lower in the Lacteol group than in the Lacidophilin group (1.88 +/- 1.24 vs 2.64 +/- 1.12, 1.39 +/- 0.92 vs 2.19 +/- 1.05; P<.05). At the end of the treatment, the clinical symptoms were markedly improved in the Lacteol group, indicating that L. acidophilus LB is more effective than living lactobacilli in the treatment of chronic diarrhea.

Angiotensin II type 1 receptor mRNA and its protein expression in human pancreatic cancer cell lines.

OBJECTIVE: The incidence of pancreatic cancer is increasing in China, and in many patients the surrounding lymphatics have already been invaded and there is blood-borne metastasis at the time of diagnosis. Additionally, pancreatic cancer is largely refractory to conventional therapies. Therefore, to improve its prognosis, it is important to resolve the problem of its growth. Angiotensin II type 1 receptor (AT1) stimulates the growth and angiogenesis of pancreatic cancer and a selective AT1 antagonist could inhibit these effects. The present study aimed to investigate the expression of AT1 in pancreatic cancer cell lines to provide the theoretical basis for its treatment. METHODS: The pancreatic cancer cell lines were SW1990, PaTu8988s and PANC-1. RT-PCR was used to detect the AT1 mRNA expression, and ABC immunocytochemical staining and SDS-PAGE were used to detect the expression of AT1 protein. RESULTS: Both AT1 mRNA and protein were expressed in all three cell lines. The AT1 protein was found on the cell membrane and in the cytoplasm of these cells. The AT1 protein (44 x 10(3)) was also demonstrated by SDS-PAGE. CONCLUSION: The results suggest that AT1 plays an important role in the growth of pancreatic cancer and its inhibition may be a therapeutic strategy.

Dynamic changes of mitogen-activated protein kinase signal transduction in rats with severe acute pancreatitis.

OBJECTIVE: To investigate the dynamic changes of mitogen-activated protein kinase (MAPK) signal transduction in rats with severe acute pancreatitis (SAP). METHODS: The SAP model was induced by infusing the bilio-pancreatic duct of 56 Sprague-Dawley rats with 5% sterile sodium taurocholate solution. The rats were randomly divided into seven groups: control group, 0.5 h postoperative group, 1 h group, 3 h group, 6 h group, 12 h group and 24 h group. Western blot analysis was used to determine the activities of p38 MAPK and c-Jun N-terminal kinase (JNK) in the pancreas and lungs. RESULTS: In the rats of the control group, basal p38MAPK activity could be detected but not that of JNK. After SAP was induced, the p38MAPK activity in the pancreas increased markedly and peaked at 3 h, but in the lung it peaked at 6 h. The p38MAPK activity in the pancreas and lungs was significantly higher than the basal activity at the 24 h time point. The activity of INK was only increased at the 12 h point and was not detectable at 24 h. CONCLUSION: The MAPK signal transduction pathway, in particular p38MAPK, plays an important role in the pathogenesis of SAP.

Changes in endothelin-1 gene expression in the gastric mucosa of rats under cold-restraint-stress.

OBJECTIVE: To investigate in rats the role of endothelin (ET)-1 gene expression in the development and progression of acute gastric mucosal lesions (AGML) induced by stress, and the effect of BQ-123 (a special ETA receptor antagonist) on the AGML. METHODS: A rat model of gastric ulcer induced by cold-restraint-stress (CRS) was used. ET-1 concentrations in the plasma and gastric mucosa were determined by radioimmunoassay (RIA), gastric mucosa blood flow (GMBF) was measured with a laser Doppler flow meter, the ulcer index (UI) was used to estimate the degree of gastric mucosa damage and the expression levels of ET-1 mRNA in the gastric mucosa were measured using dot blot and reverse transcription polymerase chain reaction (RT-PCR). Different doses of BQ-123 were administered via the left femoral vein prior to the stress in order to observe the effects of BQ-123 on the ET-1 concentrations in the plasma and gastric mucosa, the GMBF and the UI. RESULTS: Compared with the normal controls, the ET-1 concentrations in the plasma and gastric mucosa of the stressed rats were increased significantly (P < 0.05), the GMBF was decreased markedly (P < 0.01), and the UI increased dramatically (P < 0.01). There was a significant positive correlation between the gastric mucosal EF-1 concentration and the UI (r = 0.98, P < 0.01), and a significant negative correlation between the gastric mucosal ET-1 concentration and GMBF (r = -0.89, P < 0.01) and also between the UI and GMBF (r = -0.98, P < 0.01). The expression level of ET-1 mRNA in the gastric mucosa of the stressed rats increased significantly compared with that of the normal controls (P < 0.01), and there was a positive correlation between the expression of ET-1 mRNA and the ET-1 concentration in the gastric mucosa (r = 0.93, P < 0.01). Compared with the untreated animals, the GMBF was increased (P < 0.01) and the UI decreased significantly (P < 0.01) in the BQ-123-treated rats, and the dose of BQ-123 correlated with the degree of change in the GMBF and UI; however, the ET-1 concentrations of either the plasma or the gastric mucosa did not change markedly in the BQ-123-treated animals (P > 0.05). CONCLUSION: The present study showed that the level of expression of ET-1 mRNA and the synthesis of ET-1 in the gastric mucosa both increased significantly, which suggests that the increased concentration of endogenous ET-1 may be involved in the development and progression of stress ulcer (acute gastric mucosa lesion). The mechanism of action may be associated with a reduction of GMBF induced by ETAR-mediated vasoconstriction. BQ-123 can dose-dependently attenuate significantly the degree of damage to the gastric mucosa induced by stress, and may have therapeutic benefits for stress ulcer.

Study of visceral hypersensitivity in irritable bowel syndrome.

OBJECTIVE: Visceral hypersensitivity is highly prevalent in most functional bowel disorders, such as irritable bowel syndrome (IBS), and activation of intestinal mast cells (MC) may play a role because they have been found in close proximity to gastrointestinal mucosal sensory nerve terminals containing neuropeptides and a bi-directional pathway connecting the central nervous system, gut, and MC has been demonstrated. The current study appraised the status of rectal visceral perception, as well as the changes in the MC and substance P (SP) in the intestinal mucosa of patients with IBS. METHODS: The study group comprised 42 patients with IBS and 19 healthy subjects who underwent anorectal manometry and rectal perception thresholds to balloon distension. The MC and the SP-ergic terminals in the mucosa were stained for respective histochemical and immunohistochemical investigations. The results were presented both qualitatively and quantitatively by color image analyzer, based on analysis of the intensity and area of stained fibrils. The structural relationship between the MC and nerve terminals was studied by electron microscopy, using an in situ embedding technique. RESULTS: The anorectal resting pressure, squeezing pressure and relaxation pressure were normal in both groups. The sensation threshold, defecation threshold and pain threshold in diarrhea-predominant IBS and the pain thresholds in constipation-predominant IBS were much lower than in the controls. Rectal compliance decreased in IBS. The number of MC in the terminal ileum, the ileocecal junction and the ascending colon was significantly elevated in IBS (P < 0.01), and the MC showed great variation. A significantly increased concentration of SP was found in the colon of the IBS patients compared with the controls. There was a positive correlation between the profiles of mucosal MC and the SP-ergic terminals, and MC were closely adjacent to SP-ergic terminals in the lamina propria. CONCLUSION: As altered rectal perception is present in almost all patients with IBS, it might be a reliable biological characteristic of the disease. Alterations in the MC and SP of the intestinal mucosa may be important factors in visceral hypersensitivity.