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The gastric biomechanics influences digestive function as well as a range of topics of medical and scientific interests such as interaction between the stomach and gastric devices. Hence, the mechanical properties are essential for understanding gastric tissue and function in health and disease, and for the development of diagnostic or therapeutic devices. A key characteristic to be characterized is the time dependent mechanical tissue properties. The aim of this study was to characterize viscoelastic properties of the stomach across a frequency range. Longitudinal and circumferential stomach samples from the porcine fundus, corpus and antrum were pre-stretched 10 % and sinusoidally loaded with 10 % dynamic strain. The viscoelastic properties were assessed from 0.01 − 15 Hz using dynamic mechanical analysis. The storage moduli, loss moduli and tan δ had a significant second-order polynomial trend with increasing frequency. For the loss moduli, significant differences were observed between 0.01 and 15 Hz and between 0.05 and 15 Hz (p = 0.023 to 0.041). Significant differences were not found for storage moduli. Tan δ was frequency-independent, indicating that the two moduli varied proportionally. Fundus had significantly smaller storage moduli for longitudinal samples compared to corpus (p = 0.034) and antrum (p = 0.014) but was not significantly different for circumferential samples. Analysis of direction-dependency showed significant differences between longitudinal and circumferential samples (p = 0.002 to 0.042). The presented work provides insight into tensile viscoelastic properties of gastric tissue, which is useful for developing biomaterials, devices and computational models for device development specification calibrations.

Jens Sundbøll,1 Sandra Kruchov Thygesen,1 Katalin Veres,1 Donghua Liao,2 Jingbo Zhao,2 Hans Gregersen,3 Henrik Toft Sørensen11Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2GIOME Academia, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; 3GIOME, Department of Surgery, Chinese University of Hong Kong, Shatin, Hong KongBackground: It remains unclear whether constipation is associated with cancer. We evaluated the risk of malignancies in patients with constipation requiring hospitalization.Methods: Using Danish medical registries, we calculated cumulative incidences and standardized incidence ratios (SIRs) for cancer. SIRs were computed as the observed number of gastrointestinal (GI) cancers and selected non-GI cancers in patients with constipation compared with the expected number based on national incidence rates by sex, age, and calendar year (1978–2013).Results: We identified 1,75,901 patients with constipation (59% females, median age 54 years). The cumulative incidences of GI cancers and non-GI cancers after 15 years of follow-up were 2.5% and 2.6%, respectively. During the first year of follow-up, the SIR for any GI cancer was 5.0 (95% confidence interval (CI): 4.8–5.3), driven by colon and pancreas cancers and higher for younger age groups. Beyond 1 year of follow-up, the risk declined to near unity for colorectal cancer. The risk of other GI cancers (including cancers of the esophagus, stomach, small intestine, liver, and pancreas) remained moderately increased (overall SIR =1.3, 95% CI: 1.2–1.4). Except for ovarian cancer (SIR =7.3, 95% CI: 6.3–8.4), the risk of non-GI cancers was only slightly increased during the first year of follow-up and declined to unity thereafter.Conclusions: Patients with constipation had increased short-term risk of a diagnosis of GI cancer. Beyond 1 year of follow-up, a moderately elevated risk persisted only for GI cancers other than colorectal cancer. The risk of non-GI cancers was elevated only during the first year of follow-up, particularly for ovarian cancer.Keywords: constipation, cancer, cohort study

Esophageal diseases are highly prevalent and carry significant socioeconomic burden. Despite the apparently simple function of the esophagus, we still struggle to better understand its physiology and pathophysiology. The assessment of large data sets and application of multiscale mathematical organ models have gained attention as part of the Physiome Project. This has long been recognized in cardiology but has only recently gained attention for the gastrointestinal(GI) tract. The term "esophagiome" implies a holistic assessment of esophageal function, from cellular and muscle physiology to the mechanical responses that transport and mix fluid contents. These anatomical, mechanical, and physiological models underlie the development of a "virtual esophagus" modeling framework to characterize and analyze function and disease. Functional models incorporate anatomical details with sensory-motor responses, especially related to biomechanical functions such as bolus transport. Our review builds on previous reviews and focuses on assessment of detailed anatomical and geometric data using advanced imaging technology for evaluation of gastro-esophageal reflux disease (GERD), and on esophageal mechanophysiology assessed using technologies that distend the esophagus. Integration of mechanics- and physiology-based analysis is a useful characteristic of the esophagiome. Experimental data on pressures and geometric characteristics are useful for the validation of mathematical and computer models of the esophagus that may provide predictions of novel endoscopic, surgical, and pharmaceutical treatment options.

Yuelian Sun,1 Hans Gregersen,2 Wei Yuan3 1Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2GIOME, Department of Surgery, Chinese University of Hong Kong, Hong Kong, 3Key Laboratory of Reproduction Regulation of NPFPC, SIPPR, IRD, Fudan University, Shanghai, People’s Republic of China Abstract: China has gone through a comprehensive health care insurance reform since 2003 and achieved universal health insurance coverage in 2011. The new health care insurance system provides China with a huge opportunity for the development of health care and medical research when its rich medical resources are fully unfolded. In this study, we review the Chinese health care system and its implication for medical research, especially within clinical epidemiology. First, we briefly review the population register system, the distribution of the urban and rural population in China, and the development of the Chinese health care system after 1949. In the following sections, we describe the current Chinese health care delivery system and the current health insurance system. We then focus on the construction of the Chinese health information system as well as several existing registers and research projects on health data. Finally, we discuss the opportunities and challenges of the health care system in regard to clinical epidemiology research. China now has three main insurance schemes. The Urban Employee Basic Medical Insurance (UEBMI) covers urban employees and retired employees. The Urban Residence Basic Medical Insurance (URBMI) covers urban residents, including children, students, elderly people without previous employment, and unemployed people. The New Rural Cooperative Medical Scheme (NRCMS) covers rural residents. The Chinese Government has made efforts to build up health information data, including electronic medical records. The establishment of universal health care insurance with linkage to medical records will provide potentially huge research opportunities in the future. However, constructing a complete register system at a nationwide level is challenging. In the future, China will demand increased capacity of researchers and data managers, in particular within clinical epidemiology, to explore the rich resources. Keywords: China, health care, insurance, registry, clinical epidemiology

The esophagus is functionally subjected to dimensional changes. The peristaltic motion that propels the food through the esophagus is a result of the interaction between the passive and active tissue forces and the hydrodynamic forces in the food bolus. Hence, the biomechanical behaviors of the esophageal wall, such as stress-strain relationships, are of particularly importance for maintaining the esophageal physiological function. The biomechanical properties of the esophagus remodel in response to growth, aging, and disease, hence, assessment of the muscle and connective tissue mechanics of the esophagus is fundamental for advancing the understanding of esophageal pathophysiology related esophageal function disorder. However, to better understand physiological and pathophysiological functions of the esophagus, the integration of knowledge on coordination of food movement, secretion, muscle contraction, and circulation is required. Hence, the integrated mathematical model is needed in the field of esophageal physiology and diseases to integrate current models and to further develop more advanced multiscale models that integrate the different anatomical components and functions.

Esophageal disorders are common in diabetes mellitus (DM) patients. DM induces mechanostructural remodeling in the esophagus of humans and animal models. The remodeling is related to esophageal sensorimotor abnormalities and to symptoms frequently encountered by DM patients. For example, gastroesophageal reflux disease (GERD) is a common disorder associated with DM. This review addresses diabetic remodeling of esophageal properties and function in light of the Esophagiome, a scientifically based modeling effort to describe the physiological dynamics of the normal, intact esophagus built upon interdisciplinary approaches with applications for esophageal disease. Unraveling the structural, biomechanical, and sensory remodeling of the esophagus in DM must be based on a multidisciplinary approach that can bridge the knowledge from a variety of scientific disciplines. The first focus of this review is DM-induced morphodynamic and biomechanical remodeling in the esophagus. Second, we review the sensorimotor dysfunction in DM and how it relates to esophageal remodeling. Finally, we discuss the clinical consequences of DM-induced esophageal remodeling, especially in relation to GERD. The ultimate aim is to increase the understanding of DM-induced remodeling of esophageal structure and sensorimotor function in order to assist clinicians to better understand the esophageal disorders induced by DM and to develop better treatments for those patients.

Objective:The former research demonstrated that the high dosage of Changruntong(CRT) could partly restore the morphological and biomechanical reconstruction of colon in diabetic rats.In this study,the correlation between biomechanical reconstruction and expression of advanced glycation end products(AGEs) of colon in the diabetic rats was analyzed,in order to investigate the intervention mechanism of CRT. Methods:Forty SD rats were randomly divided into normal group,diabetes mellitus group,high(50g/kg) and low(25g/kg) dosage of CRT groups,and with 10 rats in each group.Rats in high and low dosage of CRT groups received gavage administration with CRT daily,and the modeling process lasted for 60 days.Blood glucose level and body weight of rats were measured termly.The expression of AGEs and RAGE in colon bowel layers was detected by using immunohistochemistry and analyzed quantificationally by using imaging analysis software.The morphological and biomechanical parameterssuch as wet weight,thickness,opening angle,residual strain and stress-strain of colonic wall were referenced to the former research reports.The correlation between the above two groups of parameters was analyzed by using linear regression analysis. Results: The expression of AGEs and RAGE in colon bowel layers of rats in DM group was higher than that of normal group(P

Background and aim: Diabetic colon dysfunction is common in longstanding diabetes. Previously the histomorphological and biomechanical remodeling of colon has been demonstrated in the diabetic rat model (1). However, the molecular mechanisms are not well understood. It was reported that advanced glycation end product (AGE) and AGE receptor (RAGE) were up-regulated in the diabetic colon wall (2). However, it lacks data in relation to the association between AGE, RAGE, transforming growth factor- b1 (TGF-b1) and TGFb1 receptor expressions with colon morphological and biomechanical remodeling in the diabetes. The aim of the present study was to investigate the expression of those proteins in the colon wall and the association with STZ-induced diabetic colon remodeling. Materials and methods: Diabetes was induced by a single tail vein injection 40mg/kg of STZ. The experimental period was 60 days. Blood glucose level was measured. The parameters of morphometric and biomechanical properties of colonic segments were obtained from diabetic (DM) and normal (Con) rats. The expressions of AGE, RAGE, TGF- b1 and TGF- b1 receptor were detected in different layers of the colon by immunohistochemistry. In order to determine the expressions of AGE, RAGE, TGF- b1 and TGF- b1 receptor in association with other parameters, and to see interrelation among AGE, RAGE, TGF- b1 and TGF- b1 receptor expressions, the multiple linear regression analysis was done. Results: The expressions of AGE, RAGE, TGF-b1 and TGF- b1 receptor in different layers were up-regulated in the DM group (Figure 1). Glucose level and wall area mainly correlated with AGE and RAGE expressions. Outer residual strain correlated with all proteins expressions in the mucosa layer and with RAGE expressions in the muscle and submucosa layers. Opening angle was mainly determined by RAGE in mucosa layer, AGE in muscle layer and TGF- b1 receptor in muscle and submucosa layers. Circumferential material constant was more related to TGF- b1 in mucosa, AGE in muscle and submucosa layers, whereas longitudinal material constant was more related to AGE in mucosa, TGF- b1 in muscle and RAGE in submucosa layers. AGE and TGF- b1 in different layers mostly correlated with RAGE and TGF- b1 receptor respectively. Conclusions: STZ-induced diabetes up-regulated the expression of AGE, RAGE, TGF- b1 and TGF- b1 receptor in different colon layers of rats. The expressions of those proteins were highly associated with histomorphometric and biomechanical parameters of colon

The nervous innervation and complex mechanical function of the esophagus make sensory evaluation difficult. However, during the last decades, several new techniques have made it possible to gain insight into pain processing of nociceptive signals. The current review highlights the sensory innervation and possibilities for quantitative sensory testing, the mechanosensory properties, the potential of high-resolution manometry and imaging, and the sensory system in special conditions, such as Barrett's esophagus. It is mandatory to understand the complex pathophysiology of the esophagus to enhance our understanding of esophageal disorders, but it also increases the complexity of future experimental and clinical studies. The new methods, as outlined in the current review, provide the possibility for researchers to enhance the quality of interdisciplinary research and to gain more knowledge about sensory symptoms and treatment possibilities.

Background/Aims: Impaired esophageal acid clearance may be a contributing factor in the pathogenesis of Barrett's esophagus. However, few studies have measured acid clearance as such in these patients. In this explorative, cross-sectional study, we aimed to compare esophageal acid clearance and swallowing rate in patients with Barrett's esophagus to that in healthy controls.Methods: A total of 26 patients with histology-confirmed Barrett's esophagus and 12 healthy controls underwent (1) upper endoscopy, (2) an acid clearance test using a pH-impedance probe under controlled conditions including controlled and random swallowing, and (3) an ambulatory pH-impedance measurement.Results: Compared with controls and when swallowing randomly, patients cleared acid 46% faster (P = 0.008). Furthermore, patients swallowed 60% more frequently (mean swallows/minute: 1.90 ± 0.74 vs 1.19 ± 0.58; P = 0.005), and acid clearance time decreased with greater random swallowing rate (P < 0.001). Swallowing rate increased with lower distal esophageal baseline impedance (P = 0.014). Ambulatory acid exposure was greater in patients (P = 0.033), but clearance times assessed from the ambulatory pH-measurement and acid clearance test were not correlated (all P > 0.3).Conclusions: More frequent swallowing and thus faster acid clearance in Barrett's esophagus may constitute a protective reflex due to impaired mucosal integrity and possibly acid hypersensitivity. Despite these reinforced mechanisms, acid clearance ability seems to be overthrown by repeated, retrograde acid reflux, thus resulting in increased esophageal acid exposure and consequently mucosal changes.

Objective: Acute mesenteric ischemia (AMI) accounts for 1–2% of gastrointestinal illnesses. This study investigated changes of intestinal motility in relation to time-dependent exposure to AMI. Methods: After anesthesia with Hypnorm and Dormicum, a midline laparotomy incision was made in 40 male Wistar rats. A segment of middle jejunum was made ischemic by ligating five mesenteric arterial branches to the segment. The ischemic period lasted for 15, 30, 60, and 120 min with 10 rats in each group. Another 10 rats were used as normal controls. The motility experiments were carried out in an organ bath containing physiological Krebs solution. Luminal pressure and intestinal diameter changes were obtained for (i) basic contractions, (ii) flow-induced contractions with different outlet resistance pressures, and (iii) contractions induced by ramp distension. Contraction frequency and amplitude were analyzed from the pressure-diameter curves. Distension-induced contraction thresholds and maximum contraction amplitude of basic and flow-induced contractions were calculated in terms of mechanical stress and strain. Differences among different groups were analyzed using t-test and ANOVA . Results: After ischemia for 60 and 120 min, the intestinal wall thickness and wall area were significantly smaller (p < 0.05); the maximum stresses of flow- induced contractions were lower at low outlet resistance pressures (p < 0.05); the maximum pressures and strain was lower at all outlet resistance pressures (p < 0.05 and p < 0.01); the pressure and stress thresholds to induce phasic contraction were significantly higher during ramp distension (p < 0.05, p < 0.01). These abovementioned changes were not significant after ischemia for 15 and 30 min (p > 0.05). Conclusion: The intestinal contractility was significantly disturbed with hypocontractility and hyposensitivity after AMI for 60 min. This indicates that AMI affects both muscle and nerve functions. In the future, it is important to investigate whether intestinal motility can be recovered after re-establishing circulation from AMI.

Objective: It has been documented that the Chinese medicine Chang Run Tong (CRT) has a positive effect on constipation which is a prominent symptom in diabetic patients. This present study investigated the effect and the possible mechanism of CRT on colonic remodeling in streptozotocin (STZ) induced diabetic rats. Methods: Morphomechanical properties were studied in colonic segments from diabetic (DM), CRT-treated diabetic (T1, high dosage: 50 g/kg; T2, low dosage: 25 g/kg) and normal (Con) rats. Morphomechanical data such as the circumferential length, wall thickness, opening angle and residual strain were obtained from segments in the no-load and zero-stress states. Circumferential and longitudinal stress-strain and stiffness were computed from length, diameter and pressure data. Expressions of TGF-b and its receptor were detected using immunohistochemistry in the colonic wall layers. Results: The wet weight, wall thickness, wall area, opening angle, and absolute value of residual strain were highest in the DM group (p < 0.05). The circumferential and longitudinal wall stiffness was highest in the DM group (p < 0.01). In the T1 group these parameters were lower than those in DM group (p < 0.05). No difference was found between the T2 and DM groups. Expression of TGF-b and its receptor in the colon layers was highest in the DM group (p < 0.05). In general the parameters are lower in the T1 group compared to the DM group (p < 0.05) whereas the T2 group did not differ from DM (p > 0.05). Using a linear regression model, we found that the TGF-b and its receptor expressions were highly correlated to most morphomechanical remodeling parameters. Conclusion: CRT treatment dose-dependently partly restored the morphomechanical remodeling of the diabetic colon. Down-regulation of the expression of TGF-b and TGF-b receptors in the diabetic colon seems to be an important mechanism.

Background & aims: Stress softening is a feature of mechanical preconditioning in soft tissue. Previously, we demonstrated that esophageal stress softening is reversible by muscle activation with KCl. Since the esophagus consists of muscle and mucosa-submucosa layers, the aim was to study the stress softening behavior in these layers in normal and diabetic rat esophagus and how diabetes affect the reversibility of esophageal stress softening.Methods: Ten Wistar rats were injected with STZ and the average blood glucose level reached 25 mmol/L after 8 weeks. Ten rats were used as the normal group. The distal three cm of the esophagus were used in this study. Each esophagus segment was separated into muscle tubes and mucosa-submucosa tubes using a microscope. The muscle and mucosa-submucosa tubes were placed in a double-channel organ bath where the two tubes could be distended simultaneously with the same loading rate. First, the tubes were immersed in Ca2+-free solution with EGTA for 30min to eliminate spontaneous contractions and then stretched to in vivo length. Five repeated pressure controlled ramp distensions were done synchronously in both tubes with distension pressures up to 0.5, 1.0 and 2.0kPa. After 10min rest in the Ca2+-free solution, the tubes were subjected to a second series of five cyclic loadings at each of the three pressure levels. Then the tubes were immersed in Ca2+-containing solution for 1h. Subsequently they were distended to 1.0kPa pressure where 110mM KCl was added for maximum contraction for 3min. KCl was washed out to permit relaxation and contractions were eliminated by immersion into Ca2+-free solution. After 1h rest, the tubes were exposed to five repeated ramp distensions conformed to the aforesaid two series. Stress-strain curves were used to analyse the viscoelasticity and stress softening.Results: For normal and diabetic esophageal muscle layer, the energy loss due to viscoelasticity was partially reversible whereas the energy loss due to stress softening was irreversible. For the normal esophageal muscle layer, the energy and stiffness losses due to stress softening were recovered by KCl-induced contraction. Such losses could not be recovered by KCl in the diabetic esophageal muscle layer. The normal esophageal mucosa-submucosa layer obtained extra energy gain by KCl activation whereas the diabetic mucosa-submucosa layer became softer even after KCl treatment.Conclusion: The stress softening behavior in normal and diabetic esophageal tissue is different. We demonstrated reversible mechanical properties in the normal muscle layer after KCl activation. These adjustable passive mechanical properties may serve as a kind of 'self-protection' in the normal oesophagus whereas this property seems to be lost in diabetes.

BACKGROUND AND AIM: The Chinese medicine Chang Run Tong (CRT) effectively improved senile constipation in the clinics. The aims of the present study were to investigate the effect of CRT on colonic remodeling in streptozotocin (STZ) induced diabetic rats and to explore the mechanisms of the CRT effects. Meterials and METHODS: Morphometric properties, residual strains and stress-strain of the wall were studied in colonic segments obtained from diabetic (DM), CRT treated diabetic (T1, high dosage: 50g/kg; T2, low dosage: 25g/kg) and normal (Con) rats. Diabetes was induced by a single tail vein injection 40mg/kg of STZ. CRT was poured directly into the stomach by gastric lavage once daily. The experimental period was 60 days. Blood glucose level, serum insulin level and body weight were measured. At the end of the experiment, morphometric data such as the circumferential length, the wall thickness and the opening angle were measured from the digitized images of the segments in the no-load state and zero-stress state. The residual strain was computed from the morphometry data. Step-wise distension was done (from 0 to 20 cmH2O). Circumferential and longitudinal stresses and strains were computed from the length, diameter and pressure data and from the zero-stress state geometry. The expression of advanced glycation end products (AGE) and receptor of AGE (RAGE) were detected in different layers by using immunohistochemistry method and quantitatively analyzed by using imaging analysis software. Linear regression analysis was done to study association between AGE/RAGE expression with the histomorphometric and biomechanical parameters. RESULTS: The wet weight per unit length to body weight ratio, wall thickness, the cross-sectional wall area,opening angle and absolute values of inner and outer residual strain of colonic segments in the DM group were significantly higher than those in Con group (P0.05). CONCLUSIONS:CRT (high dose) treatment could partly restore the morphometric and biomechanical remodeling of colon in diabetic rats. One mechanism for CRT to improve colon remodeling is down-regulation of the expression of AGEs and RAGE in the diabetic colon wall.

Background and aim: Previously we demonstrated pronounced morphometric and biomechanical remodeling in the rat intestine during physiological growth up to 32 weeks of age. The aim of the present study is to study intestinal geometric and biomechanical changes in aging rats. Materials and methods: Twenty-four male Wistar rats, aged from 6 to 22 months, were used in the study. The body weight and the wet weight per length of duodenal and ileal segments were measured at the termination of experiment. Morphometric data were obtained by measuring the wall thickness and wall cross-sectional area. The mechanical test was performed as a step-wise distension experiment. The intestinal diameter and length were obtained from digitized images of the segments at pre-selected pressures and at no-load and zero-stress states. Circumferential and longitudinal stresses (force per area) and strains (deformation) were computed from the length, diameter and pressure data and from the zero-stress state geometry. Results: The duodenal and ileal dimensions increased slightly from 6 to 22 months, e.g. the weight per unit length, the wall thickness and the wall cross-sectional area increased 20%, 4% ,and 25% for duodenum and 12%, 5%, and 8% for ileum, respectively. The opening angle gradually decreased from 154 to 117 degrees for duodenum and from 144 to 87 degrees for ileum as function of aging. The circumferential stress-strain curves shifted to the left after 22 months (p

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the methods and characteristics of esophageal afferents in humans; the pitfalls in characterization of mechanosensitive afferents; the sensitization of esophageal afferents in human studies; the brain source modeling in the understanding of the esophagus-brain axis; the use of evoked brain potentials in the esophagus; and measuring descending inhibition in animal and human studies.

Background and aims The course and outcome of pregnancy is closely correlated to change of biomechanical properties of the uterine cervix. The aim of this study was to build a non-linear, fiber reinforced mechanical model of the cervix for estimation of mechanical characteristics of the cervix in early- and term-pregnant women based on recordings of in vivo pressure and diameter by means of the Functional Luminal Imaging Probe (FLIP) technology. Materials and methods Five early- and six term-pregnant women were examined with a FLIP probe. The bag on the probe was inserted into the cervical canal for concomitant measurement of diameters at 16 serial locations along the canal and the bag pressure. The bag was inflated to a maximum volume of 50 ml. A three-fiber-families model including isotropic elastin-dominated matrix and anisotropic collagen was introduced to describe the mechanical behavior of the cervical canal. The unknown geometric and mechanical parameters were calculated on the basis of the mid-cervical diameters and the intraluminal pressures during the inflation. Results The wall thickness in the unloaded state (zero pressure applied) and mechanical properties of the matrix material ( c ) and collagens ( c 1 , c 2 ) were estimated with good fits of the calculated intraluminal pressures to the FLIP recordings during the cervical canal distension. No significant difference in the wall thickness was found between the early- and term-pregnant women (10.3±0.8 mm vs . 11.7±2.2 mm, p =0.30). The cervical matrix material and the collagen in the early-pregnant women were much stiffer than that in the term-pregnant women ( p Conclusions The cervical mechanical properties can be obtained from recorded pressure and diameter data in vivo via the established mechanical model. Matrix material and collagens of the cervix wall were remodeled during pregnancy. The mechanical model can be applied to other tubular visceral organs where concomitant measures of pressure and diameter can be obtained for better understanding diseases and their evolution or treatment.

AIM: To generate phasic and tonic stress-strain curves for evaluation of intestinal smooth muscle function in type 2 diabetic rats during active and passive conditions.METHODS: Seven diabetic Goto-Kakizaki (GK) male rats, 32-wk old (GK group), and 9 age-matched normal Wistar rats (Normal group) were included in the study. Jejunal segments were distended up to a pressure of 10 cm H2O in an organ bath containing 37 °C Krebs solution with addition of carbachol (CA). The pressure and outer diameter changes were synchronously recorded. Passive conditions were obtained using calcium-free Krebs solution containing ethylene glycol tetraacetic acid and papaverine. Total phasic, tonic and passive circumferential stress and strain were computed from the diameter and pressure data with reference to the zero-stress state geometry. The active phasic and tonic stresses were defined as the total phasic and tonic stresses minus the passive stress.RESULTS: Diabetes increased jejunal mucosa and muscle layer thicknesses compared to the Normal group (mucosa, 755.8 ± 63.3 vs 633.1 ± 59.1 μm, P < 0.01; muscle, 106.3 ± 12.9 vs 85.2 ± 11.7 μm, P < 0.05). The pressure and stress thresholds were decreased in the GK group after CA application compared to distensions without CA application (pressure, 1.01 ± 0.07 vs 1.99 ± 0.19 cmH2O, P < 0.01; stress, 0.11 ± 0.01 vs 0.24 ± 0.02 kPa, P < 0.01). CA application did not change the pressure and stress threshold in the Normal group (pressure, 2.13 ± 0.32 vs 2.34 ± 0.32 cm H2O, P > 0.05; stress, 0.25 ± 0.03 vs 0.35 ± 0.06 kPa, P > 0.05). The amplitude of total phasic, total tonic, active phasic and active tonic circumferential stresses did not differ for the distensions without CA application between the GK group and the Normal group. However, the total phasic and total tonic stresses increased after CA application in the GK group compared those in the Normal group. When normalized to muscle layer thickness, the amplitude of active stresses before CA application was lowest in the GK group compared with the Normal group. No difference was found during CA application.CONCLUSION: The stress generated by intestinal muscle normalized to the muscle layer thickness was lowest in GK rats compared to normal rats whereas the response to CA stimulation was preserved.

This paper presents commentaries on whether Starling's law applies to the esophagus; whether erythromycin affects esophageal motility; the relationship between hypertensive lower esophageal sphincter and vigorous achalasia; whether ethnic- and gender-based norms affect diagnosis and treatment of esophageal motor disorders; health care and epidemiology of chest pain; whether normal pH excludes esophageal pain; the role of high-resolution manometry in noncardiac chest pain; whether pH-impedance should be included in the evaluation of noncardiac chest pain; whether there are there alternative therapeutic options to PPI for treating noncardiac chest pain; and the usefulness of psychological treatment and alternative medicine in noncardiac chest pain.

The present study investigates the effect of Chang Run Tong (CRT) on the biomechanical and morphometrical remodeling of colon and rectum in streptozotocin-induced diabetic rats. The colonic and rectal segments were obtained from diabetic (DM), CRT-treated diabetic (T1, high dosage: 50 g/kg/day; T2, low dosage: 25 g/kg/day) and normal (Con) rats. The experimental period was 60 d. The blood glucose level and body weight were measured. The circumferential length, wall thickness, and opening angle were measured from the segments in the no-load and zero-stress states. The residual strain was computed from the morphometry data. The step-wise distension was done on the colonic segment (from 0 to 20 cmH2O). The circumferential and longitudinal stresses and strains were computed. The blood glucose level was significantly higher and the body weight was significantly lower in the DM, T1, and T2 groups compared to those in the Con group (p < 0.01, p < 0.001). The glucose level did not differ among the DM, T1, and T2 groups. The wet weight per unit length to body weight ratio, wall thickness, cross-sectional wall area, opening angle, and absolute value of residual strain of colonic and rectal segments in the DM group were significantly higher than those in the Con group (p < 0.05 and p < 0.01), and those in the T1 group, but not those in the T2 group, were significantly lower than those in the DM group (p < 0.05, p < 0.01). Furthermore, the circumferential and longitudinal stiffness of the colonic wall in the DM group was higher than those in the Con group. T1, but not T2, treatment could significantly decrease the colonic wall stiffness in both directions (p < 0.01). CRT (high dose) treatment could partly restore the morphometric and biomechanical remodeling of the lower gastrointestinal tract in diabetic rats.

The present study investigates the effect of Chang Run Tong (CRT) on the biomechanical and morphometrical remodeling of colon and rectum in streptozotocin-induced diabetic rats. The colonic and rectal segments were obtained from diabetic (DM), CRT-treated diabetic (T1, high dosage: 50 g/kg/day; T2, low dosage: 25 g/kg/day) and normal (Con) rats. The experimental period was 60 d. The blood glucose level and body weight were measured. The circumferential length, wall thickness, and opening angle were measured from the segments in the no-load and zero-stress states. The residual strain was computed from the morphometry data. The step-wise distension was done on the colonic segment (from 0 to 20 cmH2O). The circumferential and longitudinal stresses and strains were computed. The blood glucose level was significantly higher and the body weight was significantly lower in the DM, T1, and T2 groups compared to those in the Con group (p < 0.01, p < 0.001). The glucose level did not differ among the DM, T1, and T2 groups. The wet weight per unit length to body weight ratio, wall thickness, cross-sectional wall area, opening angle, and absolute value of residual strain of colonic and rectal segments in the DM group were significantly higher than those in the Con group (p < 0.05 and p < 0.01), and those in the T1 group, but not those in the T2 group, were significantly lower than those in the DM group (p < 0.05, p < 0.01). Furthermore, the circumferential and longitudinal stiffness of the colonic wall in the DM group was higher than those in the Con group. T1, but not T2, treatment could significantly decrease the colonic wall stiffness in both directions (p < 0.01). CRT (high dose) treatment could partly restore the morphometric and biomechanical remodeling of the lower gastrointestinal tract in diabetic rats.

The work of the expert group was based on peer-reviewed scientific or technical literature, supplemented by peer-reviewed examples of practice. Section II provides an overview of the processes that underpin ecosystem functions in relation to hydrology, and how these support the delivery of ecosystem services. Specific examples of these relationships, and how they can be managed in practice, are elaborated for agricultural systems and cities in section III . Social and economic aspects of this topic are largely self-evident and briefly discussed in section IV. Section V discusses the recent international policy landscape, highlighting the profile of this topic in the outcomes of the United Nations Conference on Sustainable Development 2012 (Rio+20). It also discusses some institutional constraints to managing the biodiversity-water cycle relationship and identifies simple ways of enabling more rapid uptake of biodiversity-based solutions to water-related problems. Section VI identifies the immediate opportunity available to the Conference of the Parties to strengthen cooperation and partnerships on this subject as a means to enhance implementation of the Strategic Plan for Biodiversity (2011-2020).

Sensory nerve endings are widely distributed throughout the body. Neither the nature of the mechanosensitive channels nor the principal mechanical stimulus for these receptors is known. Afferents supplying the gastrointestinal tract responding to distension and contraction are responsible for co-ordinated reflex control, feeding behaviour and sensations, including pain. Different populations of intestinal afferent fibres follow different pathways to the CNS, have different terminal fields and possess different thresholds for activation that may reflect the extent to which mechanical forces are distributed and dissipated by non-neural structures in the bowel wall. In this study, we have characterized the stimulus-response function of afferent fibres innervating the rat jejunum, correlating luminal distensions in the bowel wall with the firing frequency of mesenteric afferent nerve bundles. Combining video imaging with intraluminal pressure recordings and utilizing a strain softening protocol, we have determined whether mechanoreceptors respond primarily to stress or strain. Multiunit afferent recordings were separated using spike discrimination software into low-threshold (LT) and high-threshold (HT) single units. For multifibre afferent recordings and both LT and HT single units, we observed a linear relationship between circumferential stress and mesenteric afferent discharge that was independent of distension-induced tissue softening, with correlation coefficients >0.9. A fivefold change in the rate of applied distension did not significantly alter the magnitude of the afferent response and the linearity of the stress-dependent mechanotransduction in both multifibre preparations and the LT and HT afferent fibres (P > 0.2). Thus, the firing characteristics of intestinal mechanoreceptors are linearly associated with the input in terms of mechanical stress.

AIM: The aim of the study was to investigate the biomechanical and morphometrical remodeling of gastrointestinal (GI) tract in streptozotocin (STZ) induced diabetic rats. METERIALS AND METHODS： Eighteen SD male rats of diabetic group（DM, a single tail vein injection 40mg／kg of STZ, 9 rats) and normal group (CON, 9 rats) were used in the study. Blood glucose and body weight was regularly measured. After 60 days of experiment, morphometric properties and residual strains were studied in esophageal, duodenal, jejunal, ileal, colonic and rectal segments. Stress-strain of the wall was also studied in the esophageal, jejunal and colonic segments. RESULTS: The blood glucose level, the wet weight per unit to body weight ratio, wall thickness, opening angle, absolute value of residual strain in DM group were significantly higher than those in C0N group (PCONCLUSION：The experimental diabetes induces morphometric and biomechanical remodeling in the gastrointestinal tract which is likely relate to the gastrointestinal disorders in the diabetic patients.

AIM: The aim of the study was to investigate the effect of TWAJJ on the biomechanical and morphometrical remodeling of colon and rectum in streptozotocin (STZ) induced diabetic rats. METHODS: The colonic and rectal segments obtained from diabetic (DM), TWAJJ treated diabetic (TH, high dosage: 10 g/kg; TL, low dosage: 5 g/kg) and normal (CON) rats were used for the study. Blood glucose and serum insulin levels were measured. At the end of experiment, the circumferential length, the wall thickness and the opening angle were measured from the digitized images of those segments and residual strain was computed. Circumferential and longitudinal stresses and strains were computed from the length, diameter and pressure data and from the zero-stress state geometry for the colonic segment.RESULTS: The glucose and insulin levels did not differ among DM, TH and TL groups. Wet weight, wall thickness, cross-sectional wall area, opening angle, and absolute values of residual strain of colonic and rectal segments in DM group were significantly higher than those in CON group (PCONCLUSION: Although TWAJJ (high dose) treatment could not significantly correct the changes of blood glucose and serum insulin levels in the diabetic rats; it could partly restore the morphometric and biomechanical remodeling of lower GI tract caused by diabetes.

The following contains commentaries on distensibility testing using the functional lumen imaging probe (FLIP); the use of the distention test of the esophageal body in the clinic diagnosis of noncardiac chest pain; the functional lumen imaging in gastroesophageal reflux disease-impaired esophagogastric junction; a multimodal pain model for the esophagus; the rationale for distensibility testing; and further developments in standardized distension protocols.

The focus of this paper is that thecontextual issues influencing the adequacy and appropriateness of opportunity cost as a proxy for payments required to get successful REDD+ can be major ones in most tropical developing countries; and resolving them can be expensive and timeconsuming.

Udgivelsesdato: 2009-Jan-14 This issue presents different new techniques aiming to increase our understanding of the gastrointestinal system and to improve treatment. The technologies cover selected methods to evoke and assess gut pain, new methods for imaging and physiological measurements, histochemistry, pharmacological modelling etc. There is no doubt that the methods will revolutionize the diagnostic approach in near future.

BACKGROUND: No studies have examined the risk of upper gastrointestinal diseases among patients with unexplained chest/epigastric pain (UCEP) and a normal upper endoscopy. AIM: To examine the relative risk of peptic ulcer, oesophagitis, pancreatitis or gallstone in UCEP patients. METHODS: This Danish 10-year cohort study focused on UCEP patients (n = 386), diagnosed in 1992-93. Ten age- and gender-matched controls were selected per patient from Denmark's Civil Registration System (n = 3860). Kaplan-Meier analysis and Cox's regression analysis was used to calculate the risk of hospitalization for peptic ulcer, oesophagitis, pancreatitis or gallstone. RESULTS: Compared with controls, the adjusted relative risks among UCEP patients or = 1 year after upper endoscopy were for peptic ulcer 2.0 [95% confidence interval (CI) 0.2-18.4] and 1.7 (95% CI 0.9-3.4), for oesophagitis 8.2 (95% CI 1.2-59.2) and 1.9 (95% CI 0.7-5.0), for pancreatitis 9.2 (95% CI 2.0-41.8) and 3.9 (95% CI 1.4-10.5), and for gallstone 14.1 (95% CI 5.4-37.2) and 3.3 (95% CI 1.9-5.8). CONCLUSIONS: UCEP is positively associated with all study outcomes especially in the first year after upper endoscopy, indicating that peptic ulcer, oesophagitis, pancreatitis or gallstone could be underlying early UCEP symptoms. However, the long-term association remained strong for pancreatitis and gallstone, suggesting a genuine excess risk.

Udgivelsesdato: MAY 1

Udgivelsesdato: DEC