Xiaohua Hou

Epidemiology of uninvestigated and functional dyspepsia in Asia: facts and fiction.

Dyspepsia is a syndrome consisting of epigastric pain, burning, fullness, discomfort, early satiety, nausea, vomiting and belching. Functional dyspepsia (FD) is diagnosed if upper gastrointestinal endoscopy does not show structural abnormality explaining these symptoms. 8%-30% and 8%-23% of Asian people suffer from of uninvestigated dyspepsia and FD, respectively. Most patients with uninvestigated dyspepsia are found to have FD. Patients with FD are usually young and there is no predilection to any gender. Overlap of FD with other functional bowel diseases such as irritable bowel syndrome and gastroesophageal reflux disease is common in Asia. Cultural difference in reporting of symptoms of dyspepsia is well-known. Moreover, dietary factors, socio-cultural and psychological issues, gastrointestinal infection including that caused by Helicobacter pylori, frequency of organic diseases such as peptic ulcer and gastric cancer responsible for dyspeptic symptoms in the study population may also influence epidemiology of dyspepsia. There is considerable heterogeneity in the above issues among different Asian countries. More studies on epidemiology of FD are needed in Asia.

A comparative study of sequential therapy and standard triple therapy for Helicobacter pylori infection: a randomized multicenter trial.

OBJECTIVES:Studies conducted in large populations of patients and providing full information on Helicobacter pylori (H. pylori) antibiotic resistance are needed to determine the efficacy of sequential therapy (SQT) against this pathogen. This study compared eradication rates with SQT and standard triple therapy (STT), and evaluated the impact of antibiotic resistance on outcomes.METHODS:The study population included adults with positive H. pylori culture presenting at four centers in China between March 2008 and December 2010. Patients were randomly assigned to 10 days of treatment with esomeprazole, amoxicillin, and clarithromycin (STT; n=140) or to 5 days of treatment with esomeprazole and amoxicillin, followed by 5 days of esomeprazole, clarithromycin, and tinidazole (SQT; n=140). Eradication was assessed 8–12 weeks after treatment.RESULTS:There was no significant difference between the eradication rates achieved with STT (66.4% (95% confidence interval (CI) 59.3–74.3)) and SQT (72.1% (65.0–79.3); P=0.300) in either the intention-to-treat analysis or the per-protocol analysis (72.7% (65.6–79.7) and 76.5% (69.7–83.3), respectively; P=0.475). Clarithromycin resistance (CLA-R, odds ratio (OR)=8.34 (3.13–22.26), P<0.001) and metronidazole resistance (MET-R, OR=7.14 (1.52–33.53), P=0.013) both independently predicted treatment failure in the SQT group. Patients in the SQT group with dual CLA-R and MET-R had a lower eradication rate (43.9%) than those with isolated CLA-R (88.9%, P=0.024) or isolated MET-R (87.8%, P<0.001).CONCLUSIONS:H. pylori eradication rates with STT and SQT were compromised by antibiotic resistance. SQT may be suitable in regions with high prevalence of isolated CLA-R, but it is unsatisfactory when both CLA-R and MET-R are present.

Are There Any Different Effects of Bifidobacterium, Lactobacillus and Streptococcus on Intestinal Sensation, Barrier Function and Intestinal Immunity in PI-IBS Mouse Model?

Background and Aims Research has increasingly suggested that gut flora plays an important role in the development of post-infectious irritable bowel syndrome (PI-IBS). Studies of the curative effect of probiotics for IBS have usually been positive but not always. However, the differences of treatment effects and mechanisms among probiotic stains, or mixture of them, are not clear. In this study, we compared the effects of different probiotics (Befidobacterium, Lactobacillus, Streptococcus or mixture of the three) on intestinal sensation, barrier function and intestinal immunity in PI-IBS mouse model. Methods PI-IBS model was induced by Trichinella spiralis infection in mice. Different probiotics were administered to mice after 8 weeks infection. Visceral sensitivity was measured by scores of abdominal withdrawal reflex (AWR) and the threshold intensity of colorectal distention. Colonic smooth muscle contractile response was assessed by contraction of the longitudinal muscle strips. Plasma diamine oxidase (DAO) and d-lactate were determined by an enzymatic spectrophotometry. Expression of tight junction proteins and cytokines in ileum were measured by Western blotting. Results Compared to control mice, PI-IBS mice treated either alone with Befidobacterium or Lactobacillus (but not Streptococcus), or the mixture of the three exhibited not only decreased AWR score and contractile response, but also reduced plasma DAO and D-lactate. These probiotic treatments also suppressed the expression of proinflammatory cytokine IL-6 and IL-17 and promoted the expression of major tight junction proteins claudin-1 and occludin. The mixture of the three probiotic strains performed better than the individual in up-regulating these tight junction proteins and suppressing IL-17 expression. Conclusions Bifidobacterium and Lactobacillus, but not Streptococcus, alleviated visceral hypersensitivity and recovered intestinal barrier function as well as inflammation in PI-IBS mouse model, which correlated with an increase of major tight junction proteins. In addition, Mixture of three species was indicated to be superior to a single one.

Treatment of high-frequency gastric electrical stimulation for gastroparesis

Background and Aims:  The aim of this study was to assess the effects of gastric electrical stimulation (GES) on symptoms and gastric emptying in patients with gastroparesis, and the effects of GES on the three subgroups of gastroparesis.

Prevalence of irritable bowel syndrome and its relationship with psychological stress status in Chinese university students

Background and Aims:  Although irritable bowel syndrome (IBS) is a common disorder in the West, information on the prevalence of IBS in university students is relatively scant, especially in Asia. The aims of the present study were to investigate the prevalence and pattern of symptoms of IBS and its relationship with psychological stress status in Chinese university students.

Two-Channel Gastric Electrical Stimulation Accelerates Delayed Gastric Emptying Induced by Vasopressin

The aim of this study was to investigate the effects of two-channel gastric electrical stimulation (GES) on delayed gastric emptying, gastric dysrhythmias, and motion sickness-like symptoms induced by vasopressin. Seven dogs implanted with four pairs of gastric electrodes and a duodenal cannula were studied in four randomized sessions (saline, vasopressin, single-channel GES, and two-channel GES). The experiment in each session was conducted sequentially as follows: 30-min baseline, ingestion of a liquid meal, 30-min iv infusion of vasopressin or saline, and two 30-min postprandial recordings. In the GES sessions, GES was applied via the first pair of electrodes for single-channel GES or the first and third pairs of electrodes for two-channel GES. Gastric emptying was collected every 15 min via the cannula for a period of 90 min. Results were as follows. (1) Vasopressin induced gastric dysrhythmias, motion sickness-like symptoms, and delayed gastric emptying (P < 0.01, ANOVA). (2) GES normalized gastric dysrhythmias (P < 0.01) but showed no effects on vasopressin-induced emetic response. (3) Two-channel GES improved delayed gastric emptying induced by vasopressin. In comparison with the vasopressin session, two-channel GES, but not single-channel GES, significantly increased gastric emptying at 30 min (43.9 ± 12.6 vs. 27.5 ± 7.7%; P < 0.03), 60 min (75.3 ± 15.1 vs. 54.0 ± 17.8%; P < 0.05), and 90 min (91.6 ± 9.8 vs. 80.3 ± 9.0%; P < 0.05). GES with long pulses is able to normalize gastric dysrhythmias. Two-channel GES improves delayed gastric emptying induced by vasopressin.

Gastric Electrical Stimulation Using Endoscopically Placed Mucosal Electrodes Reduces Food Intake in Humans

BACKGROUND:Implantable gastric stimulation (IGS) has been proposed for treating obesity. The aim of this study was to investigate the effects of temporary mucosal electrical stimulation on water and food intake as well as gastric emptying in healthy humans.METHODS:The study was designed to study the effects of temporary gastric electrical stimulation (GES) on symptoms, gastric accommodation, food intake, and gastric emptying. It was performed in 12 healthy volunteers on 3 consecutive days. GES was performed using mucosal electrodes endoscopically placed in the fundus.RESULTS:The amount of maximum water intake was reduced with GES (894 ± 326 mL) compared with sham-GES (1,093 ± 417 mL, p= 0.01). The food intake was also reduced with GES (p= 0.012). In comparison with sham stimulation, GES delayed gastric emptying during the first 45 min after the meal but not during the remaining time. GES with parameters effective in reducing water and food intake and delaying gastric emptying did not induce significant dyspeptic symptoms, compared with sham stimulation.CONCLUSIONS:GES using temporary mucosal electrodes decreases food intake as well as maximum intake of water, and has a tendency of delaying gastric emptying. It may have a potential application for the treatment of obesity.

Small RNA interference-mediated gene silencing of heparanase abolishes the invasion, metastasis and angiogenesis of gastric cancer cells.

BackgroundHeparanase facilitates the invasion and metastasis of cancer cells, and is over-expressed in many kinds of malignancies. Our studies indicated that heparanase was frequently expressed in advanced gastric cancers. The aim of this study is to determine whether silencing of heparanase expression can abolish the malignant characteristics of gastric cancer cells.MethodsThree heparanase-specific small interfering RNA (siRNAs) were designed, synthesized, and transfected into cultured gastric cancer cell line SGC-7901. Heparanase expression was measured by RT-PCR, real-time quantitative PCR and Western blot. Cell proliferation was detected by MTT colorimetry and colony formation assay. The in vitro invasion and metastasis of cancer cells were measured by cell adhesion assay, scratch assay and matrigel invasion assay. The angiogenesis capabilities of cancer cells were measured by tube formation of endothelial cells.ResultsTransfection of siRNA against 1496-1514 bp of encoding regions resulted in reduced expression of heparanase, which started at 24 hrs and lasted for 120 hrs post-transfection. The siRNA-mediated silencing of heparanase suppressed the cellular proliferation of SGC-7901 cells. In addition, the in vitro invasion and metastasis of cancer cells were attenuated after knock-down of heparanase. Moreover, transfection of heparanase-specific siRNA attenuated the in vitro angiogenesis of cancer cells in a dose-dependent manner.ConclusionsThese results demonstrated that gene silencing of heparanase can efficiently abolish the proliferation, invasion, metastasis and angiogenesis of human gastric cancer cells in vitro, suggesting that heparanase-specific siRNA is of potential values as a novel therapeutic agent for human gastric cancer.

Diversity of Duodenal and Rectal Microbiota in Biopsy Tissues and Luminal Contents in Healthy Volunteers

The diverse microbial communities that colonize distinct segments of the gastrointestinal tract are intimately related to aspects of physiology and the pathology of human health. However, most recent studies have focused on the rectal or fecal microbiota, and the microbial signature of the duodenum is poorly studied. In this study, we compared the microbiota in duodenal and rectal samples to illustrate the characteristic microbial signatures of the duodenum in healthy adults. Nine healthy volunteers donated biopsies and luminal contents from the duodenum and rectum. To determine the composition and diversity of the microbiota, 454- pyrosequencing of bacterial 16S rRNA was performed and multiple bioinformatics analyses were applied. The α-diversity and phylogenetic diversity of the microbiota in the duodenal samples were higher than those of the rectal samples. There was higher biodiversity among the microbiota isolated from rectal biopsies than feces. Proteobacteria were more highly represented in the duodenum than in the rectum, both in the biopsies and in the luminal contents from the healthy volunteers (38.7% versus 12.5%, 33.2% versus 5.0%, respectively). Acinetobacter and Prevotella were dominant in the duodenum, whereas Bacteroides and Prevotella were dominant in the rectum. Additionally, the percentage of OTUs shared in biopsy groups was far higher than in the luminal group (43.0% versus 26.8%) and a greater number of genera was shared among the biopsies than the luminal contents. Duodenal samples demonstrated greater biological diversity and possessed a unique microbial signature compared with the rectum. The mucosa-associated microbiota was more relatively conserved than luminal samples.

A review of the irritable bowel syndrome investigation on epidemiology, pathogenesis and pathophysiology in China.

Background and Aim:  Irritable bowel syndrome (IBS) is a highly prevalent functional disorder with poor understanding on its pathogenesis and pathology. China has huge amount of population and have a lot of literatures on IBS in Chinese publications. The aim of this article was to review the reported investigations on IBS in China and discuss the difference between China and other country.