Guo-Ming Xu

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.

Quantitative assessment and characterization of visceral hyperalgesia evoked by esophageal balloon distention and acid perfusion in patients with functional heartburn, nonerosive reflux disease, and erosive esophagitis.

Background and ObjectivesThe role of esophageal hypersensitivity in functional heartburn (FH) with negative pH test, negative symptom index, and the proton pump inhibitor (PPI) failure has not been established. The aim of this study was to investigate the characterization of visceral hyperalgesia evoked by esophageal balloon distention and acid perfusion in patients with FH, nonerosive reflux disease, and erosive esophagitis and further characterize the pathophysiologic mechanism of FH. MethodsA total of 21 FH patients (with esophageal acid exposure <3.1% and a symptom index<50% and nonresponse to a therapeutic trial with proton pump inhibitors, 25 Nonerosive reflux disease (NERD) patients (with esophageal acid exposure>4%), 23 erosive esophagitis (EE) patients (LA grade B to D), and 18 healthy controls were recruited in the study. Mechanosensitivity including the initial perception threshold (IPT) and pain threshold (PT) was evaluated by using a Barostat with a double-random staircase distension protocol. Chemosensitivity was graded along a visual analog scale after perfusion of saline and 0.1 N HCl. ResultsThe baseline IPTs and PTs were all lower in patients with FH, NERD, and EE than in the controls (all P<0.01). In addition, the baseline PT in FH patients was significantly lower than those in NERD (P=0.015) and EE patients (P<0.001). After acid perfusion, the mean symptom intensity scores were significantly greater in patients with FH, NERD, and EE than those in the controls (all P<0.001). The postacid perfusion IPTs in patients with FH, NERD, and EE were all significantly lower than the corresponding baseline values (all P<0.01). The PTs in FH (P=0.026) and EE patients (P<0.001) were significantly lower than the corresponding baseline values. Moreover, the postacid perfusion PT was significantly lower in FH patients than in NERD patients (P<0.001). ConclusionsFH patients are more sensitive to mechanical or chemical stimuli than NERD patients. Sensitization of esophageal acid-sensitive chemoreceptors may exert a significant influence on the pressure-sensitive mechanoreceptors, and there is the cooperative interaction in the process of esophageal visceral hyperalgesia.

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 Barretts 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.

Effect of esomeprazole and rabeprazole on intragastric pH in healthy Chinese : An open, randomized crossover trial

Background and Aim:  Esomeprazole is the S‐isomer of omeprazole, with a stronger acid suppressive effect than omeprazole. This open, randomized crossover study was designed to evaluate the effect of esomeprazole and another proton‐pump inhibitor, rabeprazole, on intragastric pH in healthy Chinese.

Upregulated histone deacetylase 1 expression in pancreatic ductal adenocarcinoma and specific siRNA inhibits the growth of cancer cells.

Objectives: So far, there are no investigations about the role of histone deacetylase 1 (HDAC1) in tumorigenesis of pancreatic ductal adenocarcinoma. This study was designed to elucidate the roles and mechanisms of HDAC1 in tumorigenesis of pancreatic ductal adenocarcinoma. Methods: Real-time reverse transcription-polymerase chain reaction and immunohistochemistry techniques were adopted to detect the expression of HDAC1 in human pancreatic ductal adenocarcinoma tissues and paired paracancerous tissues. The roles of HDAC1 in human pancreatic cell line PaTu8988 were investigated using siRNA. Results: Histone deacetylase 1 mRNA in pancreatic cancer tissues were significantly higher than in paracancerous tissues (P < 0.05). Immunohistochemistry showed that the indices of HDAC1 in pancreatic cancer tissues and paracancerous tissues were 56.4% (SD, 23.1%) and 6.7% (SD, 5.0%), respectively (P < 0.001). Knockdown of HDAC1 can generate a remarkable defect in proliferation and also can significantly induce apoptosis and S-phase arrest in PaTu8988 cells (P < 0.05). The Bcl-2 mRNA expression was significantly downregulated, whereas the p21 and Bax mRNA expression were significantly upregulated. Conclusions: The HDAC1 overexpression might play an important role in tumorigenesis of pancreatic cancer. Our data support the development of selective inhibitors targeting HDAC1 for the treatment of pancreatic ductal adenocarcinoma. Histone deacetylase 1 could be a new gene therapy target in pancreatic ductal adenocarcinoma.

Clinical significance of PCR in Helicobacter pylori DNA detection in human gastric disorders.

AIM To investigate the clinical significance of the PCR assay in the diagnosis of gastric Helicobacter pylori (Hp) infection. METHODS Hp infection in gastric antral biopsied specimens was identified by using the polymerase chain reaction (PCR) to amplify the specific Hp urease gene fragments (PCR-Hp-DNA) in 154 patients with gastrointestinal disorders. Hp urease gene oligonucleotide primers specific for Hp (16s rRNA) were used. Urease test and enzyme-linked immunosorbent assay (ELISA) for anti Hp-IgG serum were also used as controls. RESULTS PCR-Hp-DNA was detected in 140 (91%) of the 154 patients, where patients 114 and 125 were found infected with Hp by urease test and ELISA Hp IgG, respectively. There was a marked difference in the Hp-positive rate between the PCR-Hp-DNA and the urease test or ELISA-Hp-IgG (P < 0.05). The Hp infection rate increased with age, although a minority of infected people developed signs and symptoms of gastric disorders. Hp infection is closely related to adenocarcinoma in both the gastric antrum as well as the down body of the stomach. CONCLUSION PCR is a sensitive and specific method for the detection of Hp in human gastric tissues. Detection of Hp DNA in vivo using this approach might improve the clinical diagnosis and epidemiological research related to H. pylori infection.