Functional magnetic resonance imaging(fMRI) has been widely applied in many fields,such as neurology,psychology,etc.Recently it has also been used to study the visceral hypersensitivity of the gut.This review gives an overview of the basic principle of fMRI and its application in the visceral sensitivity of esophagus and rectum.

Chronic active Epstein - Barr virus infection(CAEBV) is an uncommon outcome of EBV infection and may present as severe of fulminant syndrome with high- mortality. It is characterized by chronic or recurrent infectious mononucleosis-like symptoms persisting over a long time and by an unusual pattern of anti-EBV antibodies. Although it occurs in immunocompetent individuals, a number of subtle immunologic defects have been reported in patients with CAEBV. Up to now, there are still no diagnostic criteria of CAEBV in China,so the author introduce it with respect to its diagnosis,history,pathogenesis and therapeutic approaches.

Objective To study the role of esophagogastric junction contractile index (EGJ-CI) in evaluating the function of anti-reflux barrier,and in differentiating patients with gastroesophageal reflux disease (GERD) from those with functional heartburn (FH).Methods A total of 115 patients presenting heartburn were enrolled in the study from January 2012 to June 2015.All subjects had completed Gerd-Q questionnaire and undergone gastroscopy,24-hour pH-impedance monitoring and esophageal high-resolution manometry.GERD patients were divided into as reflux esophagitis,acid-nonerosive reflux disease (NERD) and weakly acid-NERD groups.Patients with normal esophageal mucosa,normal acid exposure and negative proton pump inhibitor test were enrolled in FH group.EGJ-CI (mmHg · cm) as well as EGJ rest pressure and 4s integrated relaxation pressure (IRP 4s) were measured.Results Among the 115 patients,18 were reflux esophagitis [(49.0 ± 18.9) years,M ∶ F =10 ∶ 8],25 were acid-NERD [(48.7 ± 14.4) years,M∶F=13∶ 12],37 were weakly acid-NERD [(52.0 ±14.8) years,M∶F=15∶22] and 35 were FH [(53.6 ± 14.8),M∶ F =8∶27].No differences of Gerd-Q scores were noticed between the four groups.(1) Negative correlations were demonstrated between EGJ-CI and esophageal acid exposure time (r =-0.283,P =0.002),EGJ-CI and acid reflux events (r =-0.233,P =0.012),EGJ-CI and weakly acid reflux events (r =-0.213,P =0.022),EGJ-CI and non-acid reflux events (r =-0.200,P =0.032).(2)The value of EGJ-CI was significantly higher in FH patients than in the three subgroups of GERD(all P ＜ 0.01).EGJ rest pressure of FH group was higher than that of acid-NERD (P ＜ 0.01).IRP 4s in acid-NERD group was lower than that of FH and weakly acid-NERD (P ＜ 0.05).(3) The area under curve (AUC) of EGJ-CI was higher than that of EGJ-CIT,EGJ rest pressure or IRP 4s (0.686 vs 0.678,0.641 and 0.578).The cut-off value of EGJ-CI to differentiate GERD from FH was 9.74 mmHg · cm with sensitivity 82.86％ and specificity 51.52％.Conclusions The EGJ-CI values are negatively correlated with esophageal acid exposure time,weakly acid reflux events and non-acid reflux events.Thus it might be used as a metric to reflect the anti-reflux function of EGJ.According to the cut-off value of EGJ-CI 9.74 mmHg · cm,patients with GERD can be sensitively differentiated from patients with FH.

Objective To investigate the relationship of body mass index with hiatal hernia (HH) and reflux esophagitis (RE).Methods Two hundreds and twenty seven gastroesophageal reflux disease (GERD) patients with typical acid regurgitation and heartburn were enrolled and categorized into three groups according to body mass index (BMI, kg/m2) as normal weight (18.5≤BMI ＜24), overweight (24≤BMI＜28), and obesity (BMI≥28).RE, non-erosive reflux disease (NERD) and HH were diagnosed by gastroscopy.All the patients underwent ambulatory 24-hour pH monitoring and the pathological acid reflux was considered when the DeMeester score≥15.Effects of BMI on RE and HH were estimated by using logistic regression analysis.Results The percentages of RE and HH were 30.0%(68/227) and 5.7%(13/227), respectively.76.9% (10/13) HH patients had RE. Proportions of RE and HH increased significantly with increasing BMI (P＜0.05), so was that of RE above grade B in three groups (6.4%, 16.9% and 31.6%,P=0.003).DeMeester scores of the three groups were 15.9, 19.8 and 36.9, respectively (P＜0.05).The average 24-hour intra-esophagus pH value of overweight group, was significantly lower than that of normal weight patients in the afternoon and midnight (P＜0.01).Multivariate analysis showed obesity was a risk factor for HH with OR 7.058 (95% CI: 1.294～38.488, P=0.024), male (OR: 2.537, 95% CI: 1.350～4.766, P=0.004), overweight (OR: 1.921, 95% CI: 1.005～3.670, P=0.048), obesity (OR: 3.305, 95% CI: 1.123～9.724, P=0.030) and HH (OR: 6.879, 95% CI: 1.695～27.913, P=0.007) were risk factors for RE.Conclusion BMI has a significant association with HH and RE, obesity is a common risk factor for both HH and RE, HH may induce the development of RE.

Objective To investigate the relationship between HBV genotypes and YMDD motif mutations or BCP mutations in Xiangtan of Hunan Province. Methods HBV genotypes, YMDD motif mutations and BCP mutations were analyzed in 952 HBV infected patients. Results HBV genotyping showed that 698 HBV type B patients and 115 HBV type C patients accounted for 73.32% and 12.08% respectively of all the participants. The rest 139( 14.60% )were genotype B and C mixed infection( B + C ). The analysis of YMDD motif mutations showed that 844 YMDD wild-type which accounted for 88.66% of all the subjects and the remainder were YMDD mutation types, of which 54( 5.67% ) carried YVDD, 53( 5.57% ) YIDD,and 1 YVDD and YIDD mixed infection. Basic Core Promoter mutations showed that 1762A/1764G ( wild type )accounted for 70.59% and 1762T/1764A( mutant ) accounted for 19.75%. The rest 92 patients were 1762T/1764A and 1762A/1764G mixed infection. This study showed no significant difference in the rate of YMDD mutation( 10.04% vs 10.43% ,χ2 =0.017,P＞0.05 ) ,but a significant difference in the types of YMDD mutation(χ2 = 4.836, P ＜ 0.05 )between HBV types B and C. The YVDD mutation was more commonly seen in genotype C( 9.57% ) than in genotype B( 5.88% ). The BCP mutation rate showed a significant difference( 27.36% vs 46.09%, χ2 = 16.478, P ＜ 0.01 ). Genotype C was more frequent than genotype B. The BCP mutation rate showed no significant difference between YMDD Wild-type and YMDD mutation types( 28.67% vs 35.51%, χ2 = 2.139, P ＞ 0.05 ), but most of BCP mutations happened in YVDD mutant type( 61.11% ). Conclusions ( 1 ) The predominant HBV genotypes in Xiangtan were genotype B and genotype C, the major genotype was type B, which display the characteristics of epidemiology in Southern China. ( 2 ) Determination of HBV genotypes before lamivudine therapy was probably not an important pretreatment investigation to predict antiviral responses. ( 3 ) Detection of HBV genotypes, YMDD motif mutations and BCP mutations will contribute to the correct evaluation of prognosis and timely proper management of HBV patients.

Objective To explore the diet features of diarrhea predominant irritable bowel syndrome (IBS-D) with small intestinal bacterial overgrowth (SIBO).Methods IBS-D patients were enrolled in outpatient department of Peking University Third Hospital from March 2015 to April 2016.Healthy volunteers were recruited as controls (HC).All the subjects completed screening examinations,clinical and food investigation,and lactulose methane and hydrogen breath test (LMHBT).The high fat diet is defined as the daily total calories supplying from fat is more than 50％.Results Eighty-eight IBS-D patients and 32 HC were finally enrolled.The positive rate of LMHBT in IBS-D was significantly higher than that of HC [39.8％ (35/88) vs 12.5％ (4/28),P=0.005].The 28 HC with negative LMHBT were enrolled in the follow-up analysis.(1) The BMI of IBS-P (IBS-D with positive LMHBT) was significantly lower than IBS-N (IBS-D with negative LMHBT) [(21.57 ±0.54) vs (23.30 ±0.53) kg/m2,P=0.032].IBS-D patients with SIBO had higher scores of abdominal pain assess.(2) The proportion of dietary protein and carbohydrate in IBS-D was significantly higher than that of HC (14.39％ vs 12.22％,P =0.001;53.94％ vs 46.25％,P =0.003,respectively).The proportion of diet fat was significantly higher in IBS-P than IBS-N[(47.19 ± 2.62) ％ vs (40.74 ± 1.66) ％,P =0.038].(3) The baseline of breath methane in IBS-P was significantly higher than that of in IBS-N [(8.69 ± 0.39) × 10-6 vs (6.39 ± 0.47) × 10-6,P =0.002].IBS-D patients with high fat diet had higher LMHBT positive rate than that of non-high fat diet patients[54.2％ (13/24) vs 17.2％ (11/64),P =0.001].Breath methane peak value was positively correlated with the fat proportion of diet (r =0.413,P =0.022).Conclusions About 39.8％ IBS-D patients diagnosed by Rome 11Ⅲ are combined with SIBO.SIBO may affect IBS-D patients' nutritional status.High fat diet might be one of the risk factors for IBS-D with SIBO.Proper diet structure might reduce the prevalence of IBS-D,especially for IBS-D with SIBO.

Objective To evaluate the protective value of cardioplegia solution plus metformin in different cardiac arrest time and concentration of metformin in isolated rat hearts .Methods There were 36 male Sprague–Dawley rats divided into six groups randomly, according to the duration of cardioplegic arrest(30 min or 60min) and the concentrations of metformin(50μmol/L or 100 μmol/L) .Langendorff-perfused Sprague-Dawley rat hearts were perfused for 20 minutes with Krebs-Henseleit buffer followed by 30 or 60 minutes of crystalloid cardioplegia or plus metformin (50 or 100 μmol/L) and 60 minutes of reperfu-sion.The left ventricular performance was recorded at 5 time points.The expressions of AMPKαand phosphorylation of AMPKαwere detected by western Blot.The changes of myocardial mitochondria were observed under transmission electron mi-croscope.Results There were no significant differences in Con(A), 50(A) and 100(A) groups in LVDP, ±dp/dtmax and HR.Compared with Con(B) group subjected to 60 minutes of ischemia followed by 60 minutes of reperfusion, the 100(B) group significantly improved myocardial performance , and the ratio of p-AMPKα/AMPKαwas the highest in all 6 groups.The structure of myocardial mitochondria in 100(B) group was better protected than that of Con(B) group.Conclusion These findings suggested that the left ventricular performance was protected in rat heart perfused by cardioplegia plus 100 μmol/L after 60 minutes cardioplegic arrest .The mechanism may be the activation of AMPK and the protection of structures of myocardial mitochondria.

Objective　To establish the animal model of denervation of sympathetic nerve and to explore the effects of denervation of the sympathetic nerve on liver regeneration after partial resection. Methods　The animal model of denervation of sympathetic nerve was made with 6-OHDA. A total of thirty male Wistar rats were divided equally into experimental and control group. The left and middle lobe of liver were resected with improved Higgins and Anderson's method. Meanwhile, denervation was made in the experimental group. All the rats were killed by haemospasia on the 7 th day after operation. HMI, RLR and MI were measured. The rates of DNA synthesis were detected by 3H-TdR method. Results　The concentration of NE decreased extremely on day 3 to day 14 after administration of 6-ONDA. No death happened in all the rats 7 days after liver resection. HMI, RLR, MI and 3H-TdR incorporation significantly decreased in experimental group compared with that in control (P<0.01). Conclusion　The chemical denervation of sympathetic nerve can be aroused by administration of 6-OHDA. Regeneration of the liver is inhibited by the denervation of sympathetic nerves.

Objective To explore the clinical characteristics in twin premature infants in order to provide some guidance for clinical work in future.Methods The clinical data of 593 premature infants hospitalized in Department of Pediatrics,the Affiliated Hospital of Kunming Medical University were collected from June 2010 to June 2012,in terms of gestational age,birth weight and neonatal complications.A retrospective analysis was performed for the data.The premature infants were divided into 2 groups:study group of 131 twin premature infants and control group of 462 singleton premature infants.The 131 twin premature infants in study group were divided into large double group(n =64) and small double group(n =67) according to delivery time.The clinical data of premature infants in each group were statistically analyzed.Results The gestational age of study group was (34.23 ± 1.90) weeks,which in control group was (33.91 ± 1.82) weeks,and there was no significant difference between the 2 groups(t =1.689,P =0.092).The birth weight in study group [(1 921.64 ± 414.05)g] had statistically significant difference compared with control group [(2 164.98 ± 495.85) g] (t =-5.209,P =0.000).The study group of incidence of premature rupture of membranes was 16.79％ (22/131 cases)and which in the control group was 32.68％ (151/462 cases),and there was statistically significant difference between the 2 groups (x2 =12.472,P =0.000) ;the incidence of neonatal asphyxia of study group was 9.92％ (13/131 cases) and that of the control group was 17.10％ (79/462 cases),there was statistically significant difference between the 2 groups (x2 =4.010,P =0.045) ; the incidence of respiratory distress syndrome in study group was 6.87％ (9/131 cases) and that in the control group was 3.03 ％ (14/462 cases),the difference was statistically significant between the 2 groups (x2 =4.037,P =0.045) ; the incidence of apnea in study group was 4.58％ (6/131 cases) and that in the control group was 0.65％ (3/462 cases),the difference was statistically significant between the 2 groups(x2 =8.085,P =0.004) ; the incidence of meconium aspiration syndrome of study group was 0 and that of the control group was 3.90％ (18/462 cases),there was statistically significant difference (P =0.018) ;the incidence of neonatal hypoglycemia of study group was 27.48％ (36/131 cases) and that of the control group was 16.67％ (77/462 cases),the difference was statistically significant between the 2 groups (x2 =7.738,P =0.005) ;the incidence of sepsis of study group [16.79％ (22/131 cases)] was significantly higher than that of the control group [8.44％ (39/462 cases)],and the difference was statistically significant between the 2 groups (x2 =7.715,P =0.005) ;the incidence of extrauterine growth retardation of study group was 6.10％ (8/131 cases) and that of the control group was 2.38％ (11/462 cases),the difference was statistically significant between the both groups (x2 =4.568,P =0.033).In the study group,the incidence of neonatal sepsis in big double group was 29.68％ (19/64 cases),and that in small double was 14.93％ (10/67 cases),there was statistically significant difference between the 2 groups(x2 =4.138,P =0.042).The other complications between the big double group and small double group had no significant difference.Conclusions The incidence rates of acute respiratory distress syndrome,apnea,neonatal hypoglycemia,sepsis and extrauterine growth retardation of twin premature infants are higher than the singleton premature infants in the neonatal period.But the incidence rate of meconium aspiration syndrome is a higher in singleton premature infants.

Objective To estimate the prevalence and risk factors for irritable bowel syndrome (IBS) in China.Methods Cross-sectional studies relevant to IBS conducted among Chinese were identified through the databases including PubMed,Web of Science,the Cochrane Library,CBM,CNKI,Wanfang data and VIP.Quality of studies was assessed according to the criteria for cross-sectional studies recommended by Agency for Healthcare Research and Quality(AHRQ).Analysis of data,publication bias and sensitivity were performed with Stata (Version 12.0).Results A total of twenty-three studies were extracted.No obvious publication bias was detected in all analysis except the effect of depression on IBS prevalence.Pooled prevalence of IBS in China was 6.5％.IBS was more common in women than in men (8.1％ vs 6.8％;OR=1.23,95％CI 1.09-1.38) and high rate in age group between 30 to 59 years (6.9％ ; OR =1.22,95％ CI 1.12-1.32).Intestinal infection history(OR =2.39,95％ CI 1.69-3.38),anxiety (OR =2.95,95 ％ CI 1.94-4.49),depression (OR =1.85,95 ％ CI 1.11-3.09),food allergy (OR =2.80,95％ CI 2.12-3.67) and alcohol consumption (OR =1.15,95％ CI 1.07-1.24) might increase the risk for IBS.There were no significant difference of IBS prevalence between urban and rural areas (OR =0.97,95％ CI 0.72-1.29),neither in different education classes (OR =0.85,95％ CI 0.70-1.03).Sub-group analysis showed IBS prevalence varied apparently with different diagnostic criteria:prevalence defined by Manning was 11.8％ and by Rome Ⅱ and Rome Ⅲ prevalence values were 4.4％ and 8.9％ respectively.Conclusions Pooled prevalence of IBS in China was 6.5％.IBS is more common in age group between 30 to 59 years.Female,history of intestinal infection,anxiety,depression,food allergy and alcohol consumption were risk factors for IBS in Chinese population.