Gastrointestinal Segments Research Articles

287 Small Bowel Ischemia Without Rash: A Very Unusual Presentation of Henoch-Schönlein Purpura

Henoch-Schönlein purpura (HSP) is an acute IgA-mediated vasculitic disorder of predominantly pediatric population. It is characterized by generalized small vessel vasculitis involving the skin, gastrointestinal (GI) tract, kidneys, joints, and rarely other organ system. Skin rash is usually the first sign of HSP and is almost always present. While GI symptoms such as abdominal pain and vomiting are seen in approximately 60% of patients, histologic documentation of the affected GI segment is rare. Moreover, HSP presenting as bowel ischemia without rash is exceedingly rare. An 8-year-old girl presented with abdominal pain and diarrhea following recent upper respiratory tract infection. Upper GI obstruction was suspected, thus laparotomy was performed and ischemic portion of jejunum was resected. Within two weeks of her small bowel resection, she developed malignant hypertension, hematuria, and proteinuria. No skin rash was noted. Kidney biopsy was performed for definitive diagnosis. The resected bowel specimen showed ischemic necrosis and patchy leukocytoclastic vasculitis of small submucosal vessels. A suspicion of primary vasculitis was raised, but serological markers were inconclusive for specific diagnosis. Kidney biopsy revealed diffuse proliferative glomerulonephritis. No vasculitis, necrotizing lesion or crescent was seen. Immunofluorescent study showed predominantly mesangial IgG (3+), IgA (3+), C3 (2+), and C1q (2+) deposits. Predominance of IgA deposits was consistent with HSP. Electron microscopy showed scattered glomerular deposits. Additional serologic studies for lupus were negative. Patient was treated with anti-hypertensive and steroids following which the patient recovered. We report a rare initial presentation of HSP without skin rash. While the presence of mesangial C1q deposits raise the possibility of coexisting autoimmune component, its significance or association with clinical presentation remains unknown. This case underscores the significance of high index of suspicion for primary vasculitic process in pediatric population with GI symptoms.

Bioartificial Esophagus: Where Are We Now?

The current treatments for esophageal diseases, such as carcinomas, trauma or congenital malformations, require surgical intervention and esophageal reconstruction using redundant parts of the gastrointestinal tract. However, the use of gastrointestinal segments can cause various surgical morbidities and mortality because additional abdominal surgery may be required at the expense of other anatomic structures. Therefore, tissue engineering using various biomaterial or cell sources has emerged as an alternative strategy of biomimicking the native esophageal tissue that could be implanted as an artificial graft. Although tissue engineering techniques have promise as an effective regenerative strategy, no functional solution currently exists for esophageal reconstruction. Here, we present a review of the progress made in the field of regenerative medicine for esophageal reconstruction from bench to bedside.

Intestinal overexpression of interleukin (IL)-15 promotes tissue eosinophilia and goblet cell hyperplasia.

Interleukin (IL)-15 overexpression in eosinophilic gastrointestinal disorders is reported, but IL-15's role in promoting eosinophilic gastroenteritis is largely unknown. Therefore, we generated enterocyte-overexpressed IL-15 transgenic mice using Fabpi promoter. The Fabpi-IL-15 (iIL-15) transgenic mice showed induced IL-15 levels in the jejunum with a marked increase in jejunum eosinophils. However, no induction of eosinophilia in the blood or any other gastrointestinal segment was observed. Eosinophilia in the jejunum villus was substantially higher in iIL-15 mice compared to wild-type mice. In addition, goblet cell hyperplasia was also observed in the jejunum of iIL-15 mice. Furthermore, a significant correlation between induced IL-15 transcript and the IL-18 transcripts was observed. Therefore, to further understand the role of IL-18 in IL-15 mice associated gastrointestinal disorders, we generated iIL-15/IL-18Rα-/- mice. Using these mice, we found that IL-18 has an important role in promoting IL-15-induced eosinophilia. As intestinal IL-15 overexpression is reported in food intolerance, we examined OVA intolerance in iIL-15 mice. The OVA-sensitized and challenged iIL-15 mice experienced weight loss, diarrhea and eosinophilia in the jejunum. Taken together, our findings demonstrate that intestinal IL-15 overexpression induces IL-18-dependent eosinophilia and immunoglobulins in the intestine that promotes food allergic responses.

Transition to adulthood with a bladder augmentation: histopathologic concerns.

ABSTRACTAim:To investigate the histopathologic changes in native bladder and gastrointestinal segment, the relation between histopathologic changes, type of operation and the period passed over operation in patients with bladder augmentation.Materials and methods:Twenty consecutive patients were enrolled in this study. Histopathologic evaluation of the cystoscopic mucosal biopsies from native bladder and enteric augment was performed in all patients.Results:Active or chronic non-specific inflammation of various degrees was found in all specimens except two. Metaplastic changes were detected in 3 patients. Two patients had squamous metaplasia (one focal, one extensive) and one patient had intestinal metaplasia. All metaplastic changes were found in native bladder specimens. The type of augmentation in patients with metaplastic changes were ileocystoplasty and sigmoidocystoplasty. No signs of malignancy were detected in any patient.Conclusion:The complexity of the disorders requiring bladder augmentation does not let the surgeons to draw a clear line between different groups of complications including malignancy formation. However, due to challenging course of the augmentation procedure itself, surgeons should be well aware of the possibility of malignancy development.

Urinary Bladder vs Gastrointestinal Tissue: A Comparative Study of Their Biomechanical Properties for Urinary Tract Reconstruction

To evaluate the mechanical properties of gastrointestinal (GI) tissue segments and to compare them with the urinary bladder for urinary tract reconstruction. Urinary bladders and GI tissue segments were sourced from porcine models (n = 6, 7 months old [5 male; 1 female]). Uniaxial planar tension tests were performed on bladder tissue, and Cauchy stress-stretch ratio responses were compared with stomach, jejunum, ileum, and colonic GI tissue. The biomechanical properties of the bladder differed significantly from jejunum, ileum, and colonic GI tissue. Young modulus (kPa-measure of stiffness) of the GI tissue segments was on average 3.07-fold (±0.21 standard error) higher than bladder tissue (P < .01), and the strain at Cauchy stress of 50 kPa for bladder tissues was on average 2.27-fold (±0.20) higher than GI tissues. There were no significant differences between the averaged stretch ratio and Young modulus of the horizontal and vertical directions of bladder tissue (315.05 ± 49.64 kPa and 283.62 ± 57.04, respectively, P = .42). However, stomach tissues were 1.09- (±0.17) and 0.85- (±0.03) fold greater than bladder tissues for Young modulus and strain at 50 kPa, respectively. An ideal urinary bladder replacement biomaterial should demonstrate mechanical equivalence to native tissue. Our findings demonstrate that GI tissue does not meet these mechanical requirements. Knowledge on the biomechanical properties of bladder and GI tissue may improve development opportunities for more suitable urologic reconstructive biomaterials.

Butyrate presence in distinct gastrointestinal tract segments modifies differentially digestive processes and amino acid bioavailability in young broiler chickens.

The hypothesis was tested that butyrate presence in the digesta of distinct gastrointestinal tract (GIT) segments of broilers leads to differential effects on digesta retention time, gut morphology, and proteolytic enzymatic activities, ultimately resulting in differences in protein digestibility. A total of 320 male day-old Ross 308 broilers were randomly assigned to 5 dietary treatments: 1) control (no butyrate), 2) unprotected butyrate (main activity in the crop and gastric regions), 3) tributyrin (main activity in the small intestine), 4) fat-coated butyrate (activity in the whole GIT) and 5) unprotected butyrate combined with tributyrin, each replicated 8 times. Rapeseed meal was used in combination with a fine dietary particle size in order to challenge the digestive capacity of young broilers. Birds were dissected at 22, 23, and 24 d of age and samples of digesta at various GIT locations as well as tissues were collected. Butyrate concentration varied significantly across GIT segments depending on treatment, indicating that the dietary contrasts were successful. The apparent ileal digestibility of methionine tended to increase when butyrate and/or propionate was present in colonic and cecal contents, possibly due to modifications of GIT development and digesta transit time. Butyrate presence in the digesta of the crop, proventriculus and gizzard, on the contrary, decreased the apparent ileal digestibility of several amino acids (AA). In addition, butyrate presence beyond the gizzard elicited anorexic effect that might be attributable to changes in intestinal enteroendocrine L-cells secretory activities. The present study demonstrates that, in broilers, effects of butyrate on digestive processes are conditioned by the GIT segment wherein the molecule is present and indicates its influence on digestive function and bioavailability of AA.

Influence of feeding crimped kernel maize silage on the course of subclinical necrotic enteritis in a broiler disease model.

This experiment was carried out with 375 male broilers (Ross 308) from days 1 to 28 to evaluate the influence of crimped kernel maize silage (CKMS) on the manifestation of subclinical necrotic enteritis, microbiota counts, organic acid production and relative weights of gastrointestinal segments. A necrotic enteritis disease model was applied. Birds were allocated into 3 different dietary treatments: a maize-based feed (MBF, control diet), and 2 diets supplemented with 15% (CKMS15) or 30% (CKMS30) of crimped ensiled kernel maize. The disease model involved a 10-time overdose of an attenuated live vaccine against coccidiosis given orally on day 17, followed by oral inoculation of Clostridium perfringens Type A (S48, 108 to 109 bacteria/bird) twice daily on days 18, 19, 20 and 21. Scoring of intestinal lesions was performed on days 22, 23, 25 and 28. Ileal and caecal digesta samples were collected for the quantification of selected bacterial groups and organic acids. The results showed that there was no effect of dietary treatments on small intestinal lesion scores (P > 0.05). Lesions scores peaked on days 23 and 25 and decreased again on day 28 (P = 0.001). No effect of age on microbiota counts was observed, but feeding of CKMS30 reduced the number of coliforms in ileal contents (P = 0.01). Dietary treatments did not affect organic acid concentrations in ileum and caeca, but there was an effect of age; butyric acid was higher on days 22, 23 and 25 than on day 28 (P = 0.04). Acetic acid and propionic acid concentrations in caeca were the highest on days 22 and 28 but the lowest on days 23 and 25. Relative gizzard and caeca weights were increased, and relative ileum weights were decreased when birds were fed CKMS30 (P < 0.05). In conclusion, the inclusion of CKMS in broiler diets had no effects on the course of necrotic enteritis but had potential benefits in terms of inhibition of potentially harmful microorganisms.

Comparison of segmental-dependent permeability in human and in situ perfusion model in rat

Nowadays, alternative methods have been developed to predict intestinal permeability values in human as in vitro, in situ or ex vivo methods. They were developed by the necessity to avoid the problems of the human permeability experiments. However, determination of human permeability is needed to properly validate the alternative methods. For this reason, recently, Dahlgren et al. published an indirect method based on a deconvolution technique to estimate the human permeability in different gastrointestinal segments (jejunum, ileum and colon). Therefore, the objective of this research was to demonstrate that Doluisio technique is a useful method to predict the human permeability in different gastrointestinal segments. To achieve this goal, the rat permeability in different segments, of the same drugs studied by Dahlgren et al. (atenolol, metoprolol and ketoprofen), have been compared with the human data obtained by the deconvolution method. The results obtained in this work show that the Doluisio method is a reliable tool to predict segmental human permeability. Consequently, the deconvolution method can be employed to build an extensive database of human permeability, overall from ileum and colon, because there is a lack of human permeability data of these distal segments. Once there are enough human data available, the Doluisio technique will be a valuable alternative method to predict the permeability of new molecules with therapeutic activity without the requirement of human experiments.

Bilayer silk fibroin grafts support functional oesophageal repair in a rodent model of caustic injury.

Surgical repair of caustic oesophageal injuries with autologous gastrointestinal segments is often associated with dysmotility, dysphagia and donor site morbidity, and therefore alternative graft options are needed. Bilayer silk fibroin (BLSF) scaffolds were assessed for their ability to support functional restoration of damaged oesophageal tissues in a rat model of onlay oesophagoplasty. Transient exposure of isolated oesophageal segments with 40% NaOH led to corrosive oesophagitis and a 91% reduction in the luminal cross-sectional area of damaged sites. Oesophageal repair with BLSF matrices was performed in injured rats (n = 27) as well as a nondiseased cohort (n = 12) for up to 2 months after implantation. Both implant groups exhibited >80% survival rates, displayed similar degrees of weight gain, and were capable of solid food consumption following a 3-day liquid diet. End-point μ-computed tomography of repaired sites demonstrated a 4.5-fold increase in luminal cross-sectional area over baseline injury levels. Reconstructed oesophageal conduits from damaged and nondiseased animals produced comparable contractile responses to KCl and electric field stimulation while isoproterenol generated similar tissue relaxation responses. Histological and immunohistochemical evaluations of neotissues from both implant groups showed formation of a stratified, squamous epithelium with robust cytokeratin expression as well as skeletal and smooth muscle layers positive for contractile protein expression. In addition, synaptophysin positive neuronal junctions and vessels lined with CD31 positive endothelial cells were also observed at graft sites in each setting. These results provide preclinical validation for the use of BLSF scaffolds in reconstructive strategies for oesophageal repair following caustic injury.

Gastrointestinal complications induced by sevelamer crystals.

BackgroundSevelamer is a phosphate binder widely used in chronic kidney disease (CKD) patients. Sevelamer, as well as other resin-based binders, can crystallize leading to the formation of concretions. Sevelamer crystals (SC) have been associated with gastrointestinal (GI) mucosal injury. We describe three new cases of GI lesions associated with SC and review previously reported cases.MethodsWe describe three new cases of GI lesions associated with SC and review previously reported cases.ResultsWe found 16 previously reported cases of SC-induced GI lesions. The mean patient age was 61 years (interquartile range 51.5–71.75), 62.5% were females and 10 patients were diabetic. In 13 cases, SC was found inside the GI mucosa. Six patients had history of major abdominal surgery. GI bleeding was the most common clinical symptom (n = 7), with three patients presenting with acute abdomen requiring surgical intervention. Although, SC-induced lesions were observed in all GI segments, intestine was involved in 81% of the cases. Endoscopic examination revealed mainly erosions and ulcerations (n = 7) and pseudoinflammatory polyps (n = 5). No association between sevelamer doses and the severity of GI lesions was found. However, diabetics patients seemed to develop GI lesions with smaller doses of sevelamer as compared with non-diabetic patients, in spite of their fewer GI comorbidities.ConclusionsSC-induced GI lesions should be considered in CKD patients treated with sevelamer who present GI symptoms, especially lower GI bleeding, once other causes have been ruled out. Diabetics seem more prone to develop SC- associated GI lesions. Sevelamer therapy should be avoided if possible in patients with a history of major abdominal surgery or chronic constipation, because of the high risk of serious GI complications.

Effect of Gastric By‐pass on Dietary Protein Bioavailability and Protein Anabolism in Rats

IntroductionBariatric surgery is an efficient treatment of massive obesity but it can trigger nutritional deficiencies, especially regarding vitamins and proteins. Protein wasting may be observed although there are large prevalence variations in the literature. Additionally to a low protein intake, protein malabsorption logically appears as a risk factor of protein wasting. However, there is little data on protein digestion after bariatric surgery. Our study aimed to assess the effect of gastric‐bypass (RYGB) on dietary protein bioavailability and protein status in rats.MethodsRats were fed for 3 months an obesogenic diet. Eighteen rats underwent RYGB surgery (survival: n=9) and 10 Sham (survival: n=10) served as control that were pair‐fed. For 15 d post‐surgery, dietary intake, weight and body composition were measured. After 15 d, rats were given a test meal containing 15N labeled proteins. They were sacrificed 6 h after the meal and dietary proteins were quantified in gastrointestinal segments (stomach, duodenum, jejunum, ileum, caecum and colon) by elemental analyzer coupled to isotope ratio mass spectrometer. Small intestine morphology was studied by histology. The protein Fractional Synthesis Rate (FSR) was measured in the liver, kidney, muscle and skin using a 13C valine flooding dose before sacrifice. Results (means ± SEM) were analyzed using a t test (P&lt;0.05).ResultsCompared to baseline, RYGB decreased dietary intake by 49%. Despite pair‐feeding, weight loss was higher in RYGB than in Sham (14±2 % vs 7±0.8 %, P= 0.002), as well as fat mass loss (33±5 % vs 20±1 %, P=0.03). Lean mass loss was 7±1.5 %. in both groups. Six hours after the meal test, there was more dietary nitrogen in the caecum of Sham than RYGB but no difference was detected in other intestinal segments. Real protein digestibility was lower in Sham than RYGB (93.1±0.6 % vs 95.2±0.7%, P=0.03). Histology revealed a hypertrophy of jejunum mucosa in RYGB. The FSR of kidney protein was strongly decreased (P&lt;0.001) in RYGB (72.2±3.2 %/j) compared to sham (98.4±3.3 %/j). Protein anabolism was similar between groups in other tissues.ConclusionWe showed that dietary protein bioavailability was paradoxically improved in RYGB, an effect that can be attributed to the jejunum mucosa hypertrophy. We also revealed that RYGB markedly lowered protein anabolism in the kidney. It will be interesting to identify which protein are involved in this effect.

Microbial Biogeography and Core Microbiota of the Rat Digestive Tract

As a long-standing biomedical model, rats have been frequently used in studies exploring the correlations between gastrointestinal (GI) bacterial biota and diseases. In the present study, luminal and mucosal samples taken along the longitudinal axis of the rat digestive tract were subjected to 16S rRNA gene sequencing-based analysis to determine the baseline microbial composition. Results showed that the community diversity increased from the upper to lower GI segments and that the stratification of microbial communities as well as shift of microbial metabolites were driven by biogeographic location. A greater proportion of lactate-producing bacteria (such as Lactobacillus, Turicibacter and Streptococcus) were found in the stomach and small intestine, while anaerobic Lachnospiraceae and Ruminococcaceae, fermenting carbohydrates and plant aromatic compounds, constituted the bulk of the large-intestinal core microbiota where topologically distinct co-occurrence networks were constructed for the adjacent luminal and mucosal compartments. When comparing the GI microbiota from different hosts, we found that the rat microbial biogeography might represent a new reference, distinct from other murine animals. Our study provides the first comprehensive characterization of the rat GI microbiota landscape for the research community, laying the foundation for better understanding and predicting the disease-related alterations in microbial communities.

Foetal Intraperitoneal AAV8 Injections as a Valid and Promising Tool to Specifically Target Neuronal Subpopulations Within the Gastrointestinal (GI) Tract

Adeno‐associated viral vectors (AAV) are a versatile tool for gene transfer to manipulate neuronal function in preclinical research and are potential means for gene therapy. Recent studies showed successful in vivo transduction of the mouse enteric nervous system (ENS) by AAV after neonatal and postnatal injection of the viral vector (1–5). Although the full development of the mouse ENS also continues after birth, the prenatal phase starting from E9,5 till E14 spans the period of the start and complete colonization of the GI tract by neural crest cells. In humans the equivalent period corresponds to week 4–7 of gestation. Defects in ENS development result in congenital gastrointestinal phenotypes, such as Hirschsprung's disease. Therefore, in order to better understand the underlying mechanisms of ENS development and related dysfunctions, genetic studies performed at prenatal stage are essential. To test our transduction technique, AAV8 encoding eGFP driven by the immediately early human cytomegalovirus promoter was injected intraperitoneally into E14 mouse embryos. At postnatal day 35, the transduction of cell types in the gastrointestinal tract was evaluated using fluorescence microscopic imaging of the transgene‐encoded eGFP in combination with a set of neuronal and glial markers. In the distinct gastrointestinal segments, i.e. oesophagus, gastric corpus, ileum and distal colon, eGFP was exclusively found in neurons, stained with HuC/D, indicating a highly cell type specific transduction. Immunostaining revealed viral‐encoded eGFP neurons which were either nitrergic in nature, calbindin‐immunoreactive (ir), calretinin‐ir or CGRP‐ir, indicating that several functional neuronal subpopulations were transduced. A strong eGFP signal was also seen in neuronal fibers, either of intrinsic or possibly also of extrinsic origin as systemic administration of AAVs at foetal stage leads to extrinsic transduction of the nervous system as well (6). eGFP positive glial cells could not be observed. These results demonstrate the specific and successful transduction of the prenatal ENS. However, compared to earlier results from the neonatal and postnatal injections (2–4), the transduction efficiency in the myenteric plexus in prenatal injections is still significantly lower (6% versus 20–30%). Therefore, further research is still indicated to improve the technique (e.g. exploring other AAV serotypes and promoters), but the results presented in this study clearly show the enormous potential of this technique in addition to the transgenic animal breeding.Support or Funding InformationThis project is supported by BOF‐KP grant 32765 of the University of Antwerp.

In Vitro and In Vivo Modeling of Hydroxypropyl Methylcellulose (HPMC) Matrix Tablet Erosion Under Fasting and Postprandial Status

PurposeTo develop a model linking in vitro and in vivo erosion of extended release tablets under fasting and postprandial status.MethodsA nonlinear mixed-effects model was developed from the in vitro erosion profiles of four hydroxypropyl methylcellulose (HPMC) matrix tablets studied under a range of experimental conditions. The model was used to predict in vivo erosion of the HPMC matrix tablets in different locations of the gastrointestinal tract, determined by magnetic marker monitoring. In each gastrointestinal segment the pH was set to physiological values and mechanical stress was estimated in USP2 apparatus rotation speed equivalent.ResultsErosion was best described by a Michaelis–Menten type model. The maximal HPMC release rate (VMAX) was affected by pH, mechanical stress, HPMC and calcium hydrogen phosphate content. The amount of HPMC left at which the release rate is half of VMAX depended on pH and calcium hydrogen phosphate. Mechanical stress was estimated for stomach (39.5 rpm), proximal (93.3 rpm) and distal (31.1 rpm) small intestine and colon (9.99 rpm).ConclusionsThe in silico model accurately predicted the erosion profiles of HPMC matrix tablets under fasting and postprandial status and can be used to facilitate future development of extended release tablets.

IMPROVING CONSPICUITY OF THE CANINE GASTROINTESTINAL WALL USING DUAL PHASE CONTRAST-ENHANCED COMPUTED TOMOGRAPHY: A RETROSPECTIVE CROSS-SECTIONAL STUDY.

Gastrointestinal (GI) disease is a common clinical complaint in small animal patients; computed tomography (CT) examinations enable a global overview of the GI tract and associated structures. Previously, the GI wall has been reportedly identified from serosa to mucosa in 77% of standard postcontrast CT studies and wall layers seen in ultrasound have not been distinguished. Inconsistent strong contrast enhancement of the inner layer of the GI mucosal surface was noted on dual phase CT studies acquired in our institution, which increased the visibility of the GI tract and disease processes. The aim of this retrospective, observational, cross-sectional study was to determine the optimal portal vein attenuation for maximizing GI wall conspicuity using dual phase contrast-enhanced CT. Patients with abdominal CT for a non-GI related disease were included. In a pilot study, 175 GI segments from 35 CT studies were graded for presence of mucosal surface enhancement (MSE). The strongest mucosal surface enhancement grade correlated with portal vein attenuation of 43-150HU; this value was used as inclusion criterion in the main study. A total of 441 GI segments were evaluated in 42 CT studies postcontrast for GI wall conspicuity. The GI wall was conspicuous in 56.7% precontrast, 84.5% at 30s, and 77.3% late postcontrast; 4.7% of segments were removed due to motion blur. At 30 s distinct mucosal surface enhancement was seen in the small intestine and gastric mucosal surface enhancement was poor. Findings supported the use of dual phase contrast-enhanced CT for improving conspicuity of the GI wall.

Bariatric surgery in morbidly obese patients with inflammatory bowel disease: A systematic review

BackgroundsWith increased prevalence of obesity, the number of inflammatory bowel disease (IBD) patients suffering from morbid obesity has raised. It is not clear yet if bariatric surgery is a safe and effective option in this population. ObjectivesOur systematic review aims to summarize the available literature on the safety and efficacy of bariatric surgery in morbidly obese patients with IBD. SettingUniversity hospital, Iran. MethodsA PubMed/MEDLINE search was performed to identify studies reporting the outcome of morbidly obese IBD patients. Postoperative outcome of IBD patients after bariatric surgery were pooled for early and late complications, change of IBD status, and medication alteration. ResultsA total of 7 studies reported post-bariatric surgery outcomes of 43 morbidly obese IBD patients (31 females, 11 males) with an age ranging from 30 to 64 years and a body mass index from 35.7 to 71 kg/m2. Of these, 25 suffered Crohn’s disease (CD) (58.2%) and 18 were ulcerative colitis (UC) patients (41.8%). The small bowel was the most common involved gastrointestinal segment in 27.3% of patients. CD patients more commonly underwent sleeve gastrectomy (72%), while UC patients similarly underwent sleeve gastrectomy and Roux-en-Y gastric bypass (44.4%). After a follow-up of 8 to 77 months, IBD patients lost up to 71.4%±5.9% of excess weight and 14.3 kg/m2±5.7 kg/m2 of body mass index. There were 9 early (21.4%) and 10 late (23.8%) postoperative complications related to the bariatric procedure. IBD remitted in 20 patients (47.6%), improved in 2 patients (4.8%), but exacerbated in 7 patients (16.7%). ConclusionsAlthough available data on morbidly obese patients with IBD is scarce, bariatric surgery seems to be a safe and effective option for these patients with no added morbidity or mortality. Further studies are necessary to confirm this data.

In Vitro Recording of Mesenteric Afferent Nerve Activity in Mouse Jejunal and Colonic Segments.

Afferent nerves not only convey information concerning normal physiology, but also signal disturbed homeostasis and pathophysiological processes of the different organ systems from the periphery towards the central nervous system. As such, the increased activity or 'sensitization' of mesenteric afferent nerves has been allocated an important role in the pathophysiology of visceral hypersensitivity and abdominal pain syndromes. Mesenteric afferent nerve activity can be measured in vitro in an isolated intestinal segment that is mounted in a purpose-built organ bath and from which the splanchnic nerve is isolated, allowing researchers to directly assess nerve activity adjacent to the gastrointestinal segment. Activity can be recorded at baseline in standardized conditions, during distension of the segment or following the addition of pharmacological compounds delivered intraluminally or serosally. This technique allows the researcher to easily study the effect of drugs targeting the peripheral nervous system in control specimens; besides, it provides crucial information on how neuronal activity is altered during disease. It should be noted however that measuring afferent neuronal firing activity only constitutes one relay station in the complex neuronal signaling cascade, and researchers should bear in mind not to overlook neuronal activity at other levels (e.g., dorsal root ganglia, spinal cord or central nervous system) in order to fully elucidate the complex neuronal physiology in health and disease. Commonly used applications include the study of neuronal activity in response to the administration of lipopolysaccharide, and the study of afferent nerve activity in animal models of irritable bowel syndrome. In a more translational approach, the isolated mouse intestinal segment can be exposed to colonic supernatants from IBS patients. Furthermore, a modification of this technique has been recently shown to be applicable in human colonic specimens.

Enteric Micromotor Can Selectively Position and Spontaneously Propel in the Gastrointestinal Tract.

The gastrointestinal (GI) tract, which hosts hundreds of bacteria species, becomes the most exciting organ for the emerging microbiome research. Some of these GI microbes are hostile and cause a variety of diseases. These bacteria colonize in different segments of the GI tract dependent on the local physicochemical and biological factors. Therefore, selectively locating therapeutic or imaging agents to specific GI segments is of significant importance for studying gut microbiome and treating various GI-related diseases. Herein, we demonstrate an enteric micromotor system capable of precise positioning and controllable retention in desired segments of the GI tract. These motors, consisting of magnesium-based tubular micromotors coated with an enteric polymer layer, act as a robust nanobiotechnology tool for site-specific GI delivery. The micromotors can deliver payload to a particular location via dissolution of their enteric coating to activate their propulsion at the target site toward localized tissue penetration and retention.

A Quantitative Review and Meta-Models of the Variability and Factors Affecting Oral Drug Absorption-Part I: Gastrointestinal pH.

This study aimed to conduct a quantitative meta-analysis for the values of, and variability in, gastrointestinal (GI) pH in the different GI segments; characterize the effect of food on the values and variability in these parameters; and present quantitative meta-models of distributions of GI pH to help inform models of oral drug absorption. The literature was systemically reviewed for the values of, and the variability in, GI pH under fed and fasted conditions. The GI tract was categorized into the following 10 distinct regions: stomach (proximal, mid-distal), duodenum (proximal, mid-distal), jejunum and ileum (proximal, mid, and distal small intestine), and colon (ascending, transverse, and descending colon). Meta-analysis used the "metafor" package of the R language. The time course of postprandial stomach pH was modeled using NONMEM. Food significantly influenced the estimated meta-mean stomach and duodenal pH but had no significant influence on small intestinal and colonic pH. The time course of postprandial pH was described using an exponential model. Increased meal caloric content increased the extent and duration of postprandial gastric pH buffering. The different parts of the small intestine had significantly different pH. Colonic pH was significantly different for descending but not for ascending and transverse colon. Knowledge of GI pH is important for the formulationdesign of thepH-dependent dosage forms and in understanding the dissolution and absorption of orally administered drugs. The meta-models of GI pH may also be used as part of semi-physiological pharmacokinetic models to characterize the effect of GI pH on the in vivo drug release and pharmacokinetics.

Avian Crop Function – A Review

Abstract The aim of this review is to present and discuss the anatomy and physiology of crop in different avian species. The avian crop (ingluvies) present in most omnivorous and herbivorous bird species, plays a major role in feed storage and moistening, as well as functional barrier for pathogens through decreasing pH value by microbial fermentation. Moreover, recent data suggest that this gastrointestinal tract segment may play an important role in the regulation of the innate immune system of birds. In some avian species ingluvies secretes “crop milk” which provides high nutrients and energy content for nestlings growth. The crop has a crucial role in enhancing exogenous enzymes efficiency (for instance phytase and microbial amylase, β-glucanase), as well as the activity of bacteriocins. Thus, ingluvies may have a significant impact on bird performance and health status during all stages of rearing. Efficient use of the crop in case of digesta retention time is essential for birds’ growth performance. Thus, a functionality of the crop is dependent on a number of factors, including age, dietary factors, infections as well as flock management. It is important to expand knowledge about the crop functions to use them effectively in poultry production. Furthermore, more scientific data is needed in the scope of immunological function of the crop as well as its microecosystem for a better understanding of the avian immune system and enhancing the health of the birds.