Recent Updates in Gastrointestinal Stent Placement from the Esophagus to the Colon: A Radiological Perspective

Fluoroscopic-guided stent placement has become an advantageous treatment option for diverse gastrointestinal disorders. In addition to palliative stent placement in patients with inoperable cancers, stenting has gradually expanded to other conditions, including as a bridge to surgery, as well as in patients' benign lesions and anastomotic strictures or leaks. This narrative review describes the indications, efficacy and safety of stent placement from the esophagus to the colon, including current recommendations, recent updates, and novel stents.

A rapid diagnostic approach for gastric and colon cancers via Fourier transform mid-infrared spectroscopy coupled with chemometrics from paraffin-embedded tissues

This paper describes the feasibility of Attenuated total reflection-Fourier transform mid-infrared (ATR-MIR) spectroscopy method coupled with chemometrics for the rapid diagnostic approach and screening spectral changes for gastric and colon cancers from paraffin-embedded tissues. A total number of 82 tissue samples were analyzed by a simple ATR-MIR method combined with PCA, HCA, SIMCA and LDA methodologies. Spectral analyses showed significant differences for the molecular contents particularly about the lipid, nucleic acid, protein and other biomolecules in the samples of gastric cancer (GC) and colon cancer (CC) groups from their control/healthy groups. Significant changes in the characteristic of these molecules were only observed for cancer groups based upon the increment in their biosynthesis, and they could be utilized as diagnostic spectral biomarkers. Under the optimum conditions, SIMCA provided excellent classification for diseased and control groups, with 5% significance level. As well, 97.75% of the studied tissue samples were correctly discriminated on the basis of their origin by LDA. Consequently, the findings of this study highlighted the rapid diagnosis of gastric and colon cancer cases from paraffin-embedded tissues via ATR-MIR spectroscopy complemented with chemometrics.

Sessile Serrated Adenoma With Dysplasia of the Colon

OBJECTIVES

Sessile serrated adenomas with dysplasia (SSADs) of the colon are transitional lesions between sessile serrated adenomas (SSAs) and a subset of colorectal adenocarcinomas. We wished to gain insight into the relative percentages and significance of SSAD subtypes.

METHODS

Retrospective (2007-2012) clinicopathologic review of colorectal polyps initially regarded as having mixed serrated and dysplastic elements. SSADs were subdivided into those with cap-like adenomatous dysplasia (ad1), non-cap-like adenomatous dysplasia (ad2), serrated dysplasia (ser), minimal dysplasia (min), and dysplasia not otherwise specified (nos). MLH1 immunostaining was performed on many.

RESULTS

SSADser (7.7%) had a greater propensity for right colon, women, and MLH1 loss vs the entire cohort. SSAad1 (11.6%) had the least female preponderance, was least likely to have MLH1 loss, and was most likely to affect the left colorectum. SSAD with MLH1 loss was associated with an increased burden of SSAs in the background colon (P = .0003) but not tubular adenomas or hyperplastic polyps. Most SSADs (ad2 and nos groups, 80% combined) showed difficult-to-classify dysplasia, intermediate MLH1 loss rates, and intermediate clinical features.

CONCLUSIONS

While some trends exist, morphologically subclassifying SSADs is probably not justified in routine clinical practice. MLH1 loss portends a greater burden of SSAs in the background colon.

Colonic stent as a bridge to surgery versus emergency resection for right-sided malignant large bowel obstruction: a meta-analysis

BACKGROUND

Preoperative colonic stenting for malignant large bowel obstruction (MLBO), also called bridge to surgery (BTS), is considered a great substitute treatment for emergency resection (ER) in the left-sided colon. However, its efficacy in the right-sided colon remains controversial. This systematic review and meta-analysis aimed to compare the postoperative short-term outcomes between BTS and ER for right-sided MLBO.

METHODS

A comprehensive electronic literature search throughout December 2020 was performed to identify studies comparing short-term outcomes between BTS and ER for right-side MLBO. The main outcome measures were postoperative complications and mortality rates. A meta-analysis was performed using a fixed-effect or a random-effect method to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs).

RESULTS

Seven studies were included in this meta-analysis, comprising 5136 patients, of whom 1662 (32.4%) underwent BTS and 3474 (67.6%) underwent ER. This meta-analysis demonstrated that BTS resulted in reductions in postoperative complications (OR = 0.78; 95% CI: 0.66-0.92) and mortality (OR = 0.51; 95% CI: 0.28-0.92) than ER.

CONCLUSION

The results of this meta-analysis indicate that BTS for right-sided MLBO confers preferable short-term outcomes as well as for left-sided. This suggests that BTS results in a reduction of postoperative complications and mortality for right-sided MLBO than ER.

Exercise alleviated intestinal damage and microbial disturbances in mice exposed to fluoride

Gastrointestinal reaction is an important symptom of fluorosis and is associated with intestinal morphological and functional impairment. Regular moderate exercise may reduce the incidence of infection and contribute to the maintenance of intestinal mucosal function and immune homeostasis. In this study, the mice were randomly divided to four groups: control group (C, distilled water), exercise group (E, distilled water and treadmill exercise), fluoride group (F, 100 mg/L NaF), and exercise plus fluoride group (EF, 100 mg/L NaF and treadmill exercise). The treadmill exercise was performed as 5 m/min, 5 min; 10 or 12 m/min, 20 min; 5 m/min, 5 min, with 5 consecutive days per week. After 6 months, exercise alleviated the intestinal morphological structure damage and restored the villus height (VH) and VH/crypt depth (VH/CD) in the duodenum of fluoride-exposed mice. Exercise decreased the mRNA expressions of IL-1β, IL-6, TNF-α, TLR2 and NF-κB (p65) in fluoride-exposed mice, and restored the gene levels of Occludin and ZO-1 in the duodenum, as well as Occludin, ZO-1, and Claudin-1 in the colon. Although there were no significant differences in the Occludin and ZO-1 protein expressions between F and EF, two proteins in EF presented statistical homogeneousness when compared with the C. The 16S rDNA high-throughput sequencing found that exercise restored the variations in intestinal microbiota composition and the abundances of specific bacteria in fluoride-exposed mice, including increasing the abundances of Epsilonbacteraenta and Firmicutes, reducing the Bacteroidetes abundance at the phylum level, and restoring the abundances of 13 bacterial genera. In conclusion, exercise improved intestinal morphological structure damage in fluoride-exposed mice, inhibited the secretion of duodenal inflammatory factors, increased the expression of tight junctions, and alleviated the microbial disorder in mice caused by fluoride exposure for 6 months through actively regulating the composition of intestinal microorganisms and the abundance of specific bacteria.

Stentless repair of left urethral defect with appendiceal interposition: A case report

INTRODUCTION AND IMPORTANCE

Various methods have been described in the repair of ureteral defects. Here, it is aimed to present the repair performed with appendiceal interposition without any double J stent for the left ureteral defect in a patient who was operated on urgently due to obstruction with metastatic and locally advanced colon tumor.

CASE PRESENTATION

An 82-year-old male patient was taken to an emergency operation with the diagnosis of ileus. A tumor involving the left ureter was detected in the sigmoid colon, and a 6 cm defect occurred in the left ureter after resection. This defect was repaired with appendiceal interposition without double J stent placement. Hydroureteronephrosis and stricture were not observed in the patient's 2nd and 8th-month follow-up imaging.

CONCLUSION

The appendix interposition for left ureter reconstruction is a safe and feasible option. Also, this procedure can be done without any ureteral stent.

Schwannoma of the Rectosigmoid Colon

Schwannoma is a rare tumor in the colon which originates from the peripheral nerve plexus. Most of the cases have been asymptomatic but occasionally present as an obstructive mass. Abdominal investigations are effective in some cases, but usually, they are not informative. A significant number of cases have been detected after their operation by histopathology examination. Immune and histochemical staining shows the spindle cells that have been positive for S-100 and vimentin, but negative for CD34 and smooth muscle actin. If the diagnosis of Schowannoma is confirmed preoperatively, segmental resection is recommended. In this case report, we presented a 58-year-old woman with pelvic mass and normal colonoscopy that mimic extramural large uterine myoma with extraluminal pressure effect on the rectosigmoid.

Observation of the drainage process of the residual lipoma after endoscopic unroofing technique during colonoscopic evaluation of post-procedural hematochezia

A 57-year-old man was referred to our hospital for further management of a subepithelial lesion noted on colonoscopy. He underwent endoscopic treatment of unroofing technique, in which the protruding portion of the tumor was partially resected. Due to a small amount of hematochezia, colonoscopy was performed to re-evaluate the lesion post-treatment. This enabled the observation of the drainage process of the residual lipoma. Remission was achieved and confirmed 8 months after the treatment. Endoscopic unroofing technique has been reported as a safe and effective method of treating lipomas, particularly large ones. To the best of our knowledge, this is the first endoscopic unroofing case in which the drainage process of the residual lipoma was observed and the remission of the lesion was confirmed.

Gastrointestinal Kaposi Sarcoma Involving Stomach and Colon: Diagnostic Pitfall for Pathologists with Expression of CD117

Kaposi sarcoma (KS) is a low-grade vascular tumor caused by human herpes virus type 8 (HHV8). Gastrointestinal involvement of KS is rare and most commonly clinically silent. Gastrointestinal KS may mimic gastrointestinal stromal tumors (GISTs) histologically as the tumor formed by morphologically spindle-shaped cells, which is mostly located in the mucosa and submucosa. In the present study, we describe a case of Kaposi sarcoma that was first diagnosed in the gastrointestinal tract of a 73-year-old female patient who presented to the clinic with nausea and diarrhea. Immunohistochemical staining showed cytoplasmic CD117 expression both in stomach and colon biopsies. Although involvement of KS is rarely seen in the gastrointestinal tract (GIT), the differential diagnosis of low-grade spindle cell lesions without significant pleomorphism, KS should definitely be considered, and it should be known that CD117 positivity is also present in these neoplasms.

Seasonal expression of extracellular signal regulated kinases in the colon of wild ground squirrels (Spermophilus dauricus)

BACKGROUND

The purpose of the experiment was to explore the localization and seasonal expression of extracellular signal regulated kinase (ERK) in the colonic tissue of wild ground squirrels (Spermophilus dauricus).

METHODS AND RESULTS

Hematoxylin-eosin staining, immunohistochemistry, real-time quantitative PCR and Western blotting were used in this experiment. The histological results showed that the diameter of the colon lumen enlarged and the number of glandular cells increased in the non-breeding season. It was found in the immunochemical results that both ERK1/2 and pERK1/2 were expressed in the cytoplasm of goblet cells and intestinal epithelial cells, while pERK1/2 was also expressed in the nucleus of them. The immune localization of both was more obvious in the non-breeding season, especially in intestinal epithelial cells. Real-time quantitative PCR and Western blotting showed that ERK1/2 and pERK1/2 were seasonally highly expressed in the non-breeding season.

CONCLUSIONS

The expression of ERK1/2 and pERK1/2 was seasonal changes and had significant increases in the non-breeding season. This study revealed that ERK1/2 had potential roles in the colon to the adaptation of seasonal changes in wild ground squirrels.

Emerging effects of tryptophan pathway metabolites and intestinal microbiota on metabolism and intestinal function

The metabolism of dietary tryptophan occurs locally in the gut primarily via host enzymes, with ~ 5% metabolized by gut microbes. Three major tryptophan metabolic pathways are serotonin (beyond the scope of this review), indole, kynurenine and related derivatives. We introduce the gut microbiome, dietary tryptophan and the potential interplay of host and bacterial enzymes in tryptophan metabolism. Examples of bacterial transformation to indole and its derivative indole-3 propionic acid demonstrate associations with human metabolic disease and gut permeability, although causality remains to be determined. This review will focus on less well-known data, suggestive of local generation and functional significance in the gut, where kynurenine is converted to kynurenic acid and xanthurenic acid via enzymatic action present in both host and bacteria. Our functional data demonstrate a limited effect on intestinal epithelial cell monolayer permeability and on healthy mouse ileum. Other data suggest a modulatory effect on the microbiome, potentially in pathophysiology. Supportive of this, we found that the expression of mRNA for three kynurenine pathway enzymes were increased in colon from high-fat-fed mice, suggesting that this host pathway is perturbed in metabolic disease. These data, along with that from bacterial genomic analysis and germ-free mice, confirms expression and functional machinery of enzymes in this pathway. Therefore, the host and microbiota may play a significant dual role in either the production or regulation of these kynurenine metabolites which, in turn, can influence both host and microbiome, especially in the context of obesity and intestinal permeability.

Spindle Variant Primary Diffuse Large B Cell Lymphoma of the Colon: Case Report and Literature Review

Diffuse large B cell lymphoma (DLBCL) with spindle cell morphology is a rare variant that can be seen in extranodal regions. Because the spindle cell dominant morphology in lymphoma is extremely unusual, the diagnosis can easily be missed in many organ systems. We present a case of an 82-year-old male patient with complaints of abdominal pain and swelling. He operated with the preliminary diagnosis of cecum tumor and ileum perforation. Tumoral proliferation was observed originating from the submucosa and infiltrating the muscularis propria, with the features of mostly spindle-shaped, having round-shaped nuclei in some of the cells, and having relatively narrow cytoplasm. A panel of immunohistochemical stains were performed to rule out the possibilities of sarcoma, carcinoma, or melanoma. Diffuse strong positive reaction was observed for CD45, CD20, CD19, CD22, Pax5, and CD30. The case was reported as spindle cell variant of DLBCL based on the present findings. As far as we know, this is the first case described in the colon. We emphasize that pathologists should be reminded of lymphoma as a differential diagnosis of spindle cell tumors.

The in vitro digestion and fermentation characteristics of feedstuffs inoculated with cecal or colic fluid of Dezhou donkey

The present study was conducted to evaluate the in vitro dry matter disappearance (IVDMD) and fermentation characteristics of 6 fibrous feedstuffs incubated with donkey cecal or colic microorganisms. The fibrous feeds were corn straw (CS), wheat straw (WS), peanut vine (PNV), peanut shell (PNH), wheat shell (WH) and wheat bran (WB), which are commonly applied in large-scale donkey farms in China. After 48 h fermentation, the highest IVDMD occurred in WB, and the lowest occurred in PNH (P<0.05) regardless what inoculum applied. The IVDMD was positively correlated with OM (R=0.42, P<0.01), CP (R=0.76, P<0.01) and EE (R=0.56, P<0.01), while it was negatively correlated with NDF (R=0.75, P<0.01) and ADF (R=0.79, P<0.01). In terms of volatile fatty acids (VFAs), the greatest net VFA production also occurred in WB (P<0.05). The acetate and branched-chain volatile fatty acid (BCVFA) proportions were greater in the colon culture fluids than in caecum (P<0.05), but the propionate proportions were lower in colon than in caecum (P<0.05). This resulted in an increase in the ratio of acetate to propionate in colon culture fluids. In summary, based on the highest IVDMD, net VFA production and CP content occurring with the lowest contents of both NDF and ADF, WB had the highest nutritive value compared to other fibrous substrates. The extent of feed degradation and fermentation depended mainly on the nature of the incubated feedstuffs. Nevertheless, further study is required to investigate these fibrous feeds on hindgut fermentation and in vivo nutrient digestibility.

Colonic expression of calcium transporter TRPV6 is regulated by dietary sodium butyrate

Dietary fibers have been shown to increase the intestinal absorption of calcium (Ca²⁺) and magnesium (Mg²⁺). However, the mechanisms that explain the enhanced electrolyte absorption remain unknown. Therefore, this study aims to investigate the short-term and long-term effects of 5% (w/w) sodium butyrate (Na-butyrate), an important end-metabolite of bacterial fermentation of dietary fibers, on Ca²⁺ and Mg²⁺ homeostasis in mice. Serum Ca²⁺ levels were only significantly increased in mice treated with Na-butyrate for 1 day. This was associated with a twofold increase in the mRNA expression levels of Trpv6 in the proximal and distal colon. Contrary, Na-butyrate did not affect serum Mg²⁺ concentrations at either of the intervention periods. However, we observed a reduction in urinary Mg²⁺ excretion, although not significantly, after 1 day of treatment. A significant reduction of 2.5-fold in urinary Mg²⁺ excretion was observed after 14 days of treatment. Indeed, 14-day Na-butyrate supplementation increased colonic Trpm7 expression by 1.2-fold compared to control mice. In conclusion, short-term Na-butyrate supplementation increases serum Ca²⁺ levels in mice. This was associated with increased mRNA expression levels of Trpv6 in the colon, suggesting that Na-butyrate regulates the expression of genes involved in active intestinal Ca²⁺ absorption.

Clinicopathologic Findings in Patients With Initial Diagnosis of Extranodal Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue (MALT) in Colorectal Mucosa

OBJECTIVES

To evaluate clinicopathologic features, management, and behavior of colorectal extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT).

METHODS

Clinical data, laboratory studies, and radiographic records were reviewed (2005-2018), and fluorescence in situ hybridization studies were performed.

RESULTS

Eleven patients were identified, six of whom were discovered as an incidental finding on endoscopy. Morphologic and immunophenotypic features were similar to MALT lymphomas at other sites except that lymphoepithelial lesions were uncommon. Three of nine patients were positive for BIRC3/MALT1 fusions, two of whom had identical B-cell clones identified in subsequent gastric biopsy specimens. Eight of 10 patients had no clinically evaluable disease after observation (±antibiotics; n = 4) or radiation/chemotherapy (n = 4).

CONCLUSIONS

Patients with incidental and localized colonic MALT lymphoma demonstrated an excellent prognosis with conservative management, although longer follow-up and data based on consistent staging and surveillance methods (including gastric evaluation) are necessary for informed management.

Immunotherapy in Gastrointestinal Malignancies

Gastrointestinal (GI) cancers represent a heterogeneous group of malignancies, each with a unique tumor biology that in turn affects response to treatment and subsequent prognosis. The interplay between tumor cells and the local immune microenvironment also varies within each GI malignancy and can portend prognosis and response to therapy. Treatment with immune checkpoint inhibitors has changed the treatment landscape of various solid tumors including (but not limited to) renal cell carcinoma, melanoma, and lung cancer. Advances in the understanding between the interplay between the immune system and tumors cells have led to the integration of immunotherapy as standard of care in various GI malignancies. For example, immunotherapy is now a mainstay of treatment for tumors harboring defects in DNA mismatch repair proteins and tumors harboring a high mutational load, regardless of primary site of origin. Data from recent clinical trials have led to the integration of immunotherapy as standard of care for a subset of gastroesophageal cancers and hepatocellular carcinoma. Here, we outline the current landscape of immunotherapy in GI malignancies and highlight ongoing clinical trials that will likely help to further our understanding of how and when to integrate immunotherapy into the treatment of various GI malignancies.

Spectrum of bowel wall thickening on ultrasound with pathological correlation in children

Applications for bowel US in children have been well described; however, less focus has been placed on patterns of bowel wall architectural change in specific disease states. This pictorial essay reviews normal bowel wall architecture and covers a variety of inflammatory, infectious, vascular and neoplastic disorders outside the neonatal period as seen on US, with illustrative pathological correlation. A thorough understanding of normal and abnormal bowel wall architecture can enrich sonographic interpretation and provide a valuable adjunct to appropriate clinical investigation.

Identifying Types of Neurons in the Human Colonic Enteric Nervous System

Distinguishing and characterising the different classes of neurons that make up a neural circuit has been a long-term goal for many neuroscientists. The enteric nervous system is a large but moderately simple part of the nervous system. Enteric neurons in laboratory animals have been extensively characterised morphologically, electrophysiologically, by projections and immunohistochemically. However, studies of human enteric nervous system are less advanced despite the potential availability of tissue from elective surgery (with appropriate ethics permits). Recent studies using single cell sequencing have confirmed and extended the classification of enteric neurons in mice and human, but it is not clear whether an encompassing classification has been achieved. We present preliminary data on a means to distinguish classes of myenteric neurons in specimens of human colon combining immunohistochemical, morphological, projection and size data on single cells. A method to apply multiple layers of antisera to specimens was developed, allowing up to 12 markers to be characterised in individual neurons. Applied to multi-axonal Dogiel type II neurons, this approach demonstrated that they constitute fewer than 5% of myenteric neurons, are nearly all immunoreactive for choline acetyltransferase and tachykinins. Many express the calcium-binding proteins calbindin and calretinin and they are larger than average myenteric cells. This methodology provides a complementary approach to single-cell mRNA profiling to provide a comprehensive account of the types of myenteric neurons in the human colon.

Fluoride exposure cause colon microbiota dysbiosis by destroyed microenvironment and disturbed antimicrobial peptides expression in colon

Colon microenvironment and microbiota dysbiosis are closely related to various human metabolic diseases. In this study, a total of 72 healthy female mice were exposed to fluoride (F) (0, 25, 50 and 100 mg/L F^-) in drinking water for 70 days. The effect of F on intestinal barrier and the diversity and composition in colon microbiota have been evaluated. Meanwhile, the relationship among F-induced colon microbiota alterations and antimicrobial peptides (AMPs) expression and short-chain fatty acids (SCFAs) level also been assessed. The results suggested that F decreased the goblet cells number and glycoprotein expression in colon. And further high-throughput 16S rRNA gene sequencing result demonstrated that F exposure induced the diversity and community composition of colonic microbiota significantly changes. Linear Discriminant Analysis Effect Size (LEfSe) analysis identified 11 predominantly characteristic taxa which may be the biomarker in response to F exposure. F-induced intestinal microbiota perturbations lead to the significantly decreased SCFAs levels in colon. Immunofluorescence results showed that F increased the protein expression of interleukin-17A (IL-17A) and IL-22 (P < 0.01) and disturbed the expression of interleukin-17 receptor A (IL-17RA) and IL-22R (P < 0.05 or P < 0.01). In addition, the increased expression of IL-17A and IL-22 cooperatively enhanced the mRNA expression of AMPs which response to F-induced microbiota perturbations. Collectively, destroyed microenvironment and disturbed AMPs are the primary reason of microbiota dysbiosis in colon after F exposure. Colonic homoeostasis imbalance would be helpful for finding the source of F-induced chronic systemic diseases.

Volcanic ash-driven worsening of mucosal inflammation in an experimental colitis model

Particulate matter exposure and related chemical changes in drinking water have been associated with health problems and inflammatory disorders. This study aimed to examine the effect of orally administered ash-water dilution on the gut of mice under normal and inflammatory conditions. Balb/c mice received ash-released soluble and dust-suspended components in the drinking water for 14 days. On day 7, animals were intrarectally instilled with TNBS in ethanol or flagellin from Salmonella typhimurium in PBS. At sacrifice, colon segments were collected and histologic damage, mRNA expression and cytokine levels in tissue were evaluated. In addition, these parameters were also evaluated in IL-10 null mice. We found that mice that received 5% w. fine-ash dilution in the drinking water worsened colitis signs. Weight loss, shortening of the colon, tissue edema with mucosa and submucosa cell infiltration and production of pro-inflammatory cytokines and chemokines were enhanced compared to control mice. A more pronounced inflammation was observed in IL-10 null mice. In addition, markers of NLRP3-dependent inflammasome activation were found in animals exposed to ash. In conclusion, ingestion of contaminated water with dust-suspended particulate matter enhanced the inflammatory response in the gut, probably due to alteration of the gut barrier and promoting an intense contact with the luminal content. This study critically appraises the response for fine particulate matter in uncommon illnesses reported for volcanic ash pollution. We suggest actions to enable better prediction and assessment the health impacts of volcanic eruptions.

The Importance of the ileocecal valve and colon in achieving intestinal independence in infants with short bowel syndrome

PURPOSE

Infants with short bowel syndrome (SBS) wean from parenteral nutrition (PN) support at variable rates. Small bowel length is a predictor, but the importance of the ileocecal valve (ICV) and colon are unclear. We aim to determine if the ICV and/or colon predict enteral autonomy.

METHODS

Infants from a single intestinal rehabilitation program were retrospectively reviewed. Etiology of SBS, intestinal anatomy, and duration of nutritional support were collected for three years. The primary outcome was time to full enteral nutrition. ANCOVA and Cox proportional hazards model were used, with p < 0.05 significant.

RESULTS

55 infants with SBS were included. After accounting for the effect of small bowel, PN duration was shorter for infants with the ICV compared to those without (mean 218 vs. 538 days, p = 0.003), and had a more significant effect on infants with ≤50% of small bowel. Increased small bowel length was a positive predictor of weaning. Patients with ≤50% of colon spent less time on PN with the ICV, compared to without (mean 220 vs 715 days, p = 0.009).

CONCLUSIONS

Preservation of the ICV was associated with shorter duration of PN support, while colon was not. Small bowel length is a positive predictor of enteral autonomy.

LEVEL OF EVIDENCE

Level III retrospective comparative study TYPE OF STUDY: Retrospective review.

Rhythmicity in the Enteric Nervous System of Mice

The enteric nervous system (ENS) is required for many cyclical patterns of motor activity along different regions of the gastrointestinal (GI) tract. What has remained mysterious is precisely how many thousands of neurons within the ENS are temporally activated to generate cyclical neurogenic contractions of GI-smooth muscle layers. This has been an especially puzzling conundrum, since the ENS consists of an extensive network of small ganglia, with each ganglion consisting of a heterogeneous population of neurons, with diverse cell soma morphologies, neurochemical and biophysical characteristics, and neural connectivity. Neuronal imaging studies of the mouse large intestine have provided major new insights into how the different classes of myenteric neurons are activated during cyclical neurogenic motor patterns, such as the colonic motor complex (CMC). It has been revealed that during CMCs (in the isolated mouse whole colon), large populations of myenteric neurons, across large spatial fields, coordinate their firing, via bursts of fast synaptic inputs at ~2 Hz. This coordinated firing of many thousands of myenteric neurons synchronously over many rows of interconnected ganglia occurs irrespective of the functional class of neuron. Aborally directed propulsion of content along the mouse colon is due, in large part, to polarity of the enteric circuits including the projections of the intrinsic excitatory and inhibitory motor neurons but still involves the fundamental ~2 Hz rhythmic activity of specific classes of enteric neurons. What remains to be determined are the mechanisms that initiate and terminate the patterned firing of large ensembles of enteric neurons during cyclic activity. This remains an exciting challenge for future studies.

Concurrent Collagenous Gastritis and Collagenous Colitis: A Case Presentation and Review of the Literature

Collagenous gastritis is a rare gastrointestinal condition, and its presence with collagenous colitis may be an exception. We describe a 31-year-old man with simultaneous collagenous gastritis and collagenous colitis. The patient initially presented with dyspepsia, anemia, and weight loss. Endoscopy assessment revealed irregular gastric atrophy with the normal colon. Gastric biopsies illustrated increased thickness and subepithelial collagen band.

Chemoprevention with a tea from hawthorn (Crataegus oxyacantha) leaves and flowers attenuates colitis in rats by reducing inflammation and oxidative stress

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A tea from the leaves and flowers of hawthorn is rich in flavonoids, especially vitexin-2-O-rhamnoside.

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Mesalamine and hawthorn tea have positive healing effects in rats with colitis.

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Hawthorn tea reduces the length and area of the brownish necrotic lesions.

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Hawthorn tea diminishes the levels of the inflammatory markers MPO and IL-1β.

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Hawthorn tea regulates the activity of the oxidative stress enzymes CAT and GR.

The purpose of the study was to determine the effects of a tea from the leaves and flowers of Crataegus oxyacantha in rats with colitis. Colitis was induced by administration of 2,4,6-trinitrobenzene sulfonic acid. Hawthorn tea (HT) (100 mg/kg) was given via gavage for 21 days and the mesalamine drug (100 mg/kg) was administrated during the period of disease onset. HT was rich in total phenolic compounds (16.5%), flavonoids (1.8%), and proanthocyanidins (1.5%); vitexin-2-O-rhamnoside was the main compound detected. Mesalamine and the HT diminished the length of the lesions formed in the colon, in addition to reducing the levels of myeloperoxidase and interleukin-1β. Mesalamine was able to significantly reverse the body weight loss, while HT improved the activity of glutathione reductase and catalase. Histological scoring was not changed by the interventions, but it was highly correlated with the necrotic area. HT given at 100 mg/kg can be effective against colitis.

Ischemic Conditioning in the Right Colon and Terminal Ileum: An Experimental Rat Model

INTRODUCTION

Preoperative gastric ischemic conditioning (IC) improves the outcome of esophageal replacement gastroplasty and is associated with low morbidity. However, when the stomach cannot be used for esophageal replacement, a colonic replacement is required. The study aim was to assess the viability of right colon and terminal ileum IC in a rat model and the histological damage/recovery sequence and determine if neovascularization is a potential adaptive mechanism.

METHODS

The study was conducted in Rattus norvegicus with ileocolic vascular ligation. Seven groups of animals were established (6 rats per group) with groups defined by the date of their post-IC euthanasia (+1, +3, +6, +10, +15, and +21 days). Comparisons were made with a sham group. Viability of the model was defined as <10% of transmural necrosis. The evaluation of histological damage used the Chiu score in hematoxylin and eosin sections of paraffin-embedded specimens with CD31 immunohistochemical assessment of neovascularization by the median of submucosal vessel counts in 5 high-magnification fields.

RESULTS

Transmural colon necrosis occurred in 1/36 animals (2.78%) with no animal demonstrating transmural ileal necrosis. The maximum damage was observed in the colon on +1 day post-IC (average Chiu score 1.67, p = 0.015), whereas in the ileum, it was on days +1, +3, and +6 (average Chiu score 1.5, 1.3, and 1.17; p = 0.015, 0.002, and 0.015, respectively). In the +21-day group, histological recovery was complete in the colon in 4 (66.7%) of the 6 animals and in the ileum in 5 (83.3%) of 6 animals. There were no significant differences in quantitative neovascularization in any of the groups when compared with the sham group or when comparisons were made between groups.

CONCLUSIONS

The tested animal model for IC of the colon and terminal ileum appeared to be feasible. Histological damage was maximal between the 1st and 3rd day following IC, but by day 21, recovery was complete in two-thirds of the rats. There was no evidence in this preliminary IC model that would suggest neovascularization as an adaptive mechanism.

The final fate of food: On the establishment of in vitro colon models

The search for life/health quality has driven the search for a better understanding of food components on the overall individual health, which turns to be intrinsically related to the digestive system. In vitro digestion models are considered an alternative for the in vivo studies for a variety of practical reasons, but further research is still needed concerning the colon model establishment. An effective in vitro colon model should consider all unit operations and transport phenomena, together with chemical and biochemical reactions, material handling and reactor design. Due to the different techniques and dependence on the donor microbiota, it is difficult to obtain a standard protocol with results reproductible in time and space. Furthermore, the colon model should be fed with a representative substrate, thus what happens in upper digestion tract and absorption prior to colon is also of crucial importance. Essentially, there are two ways to think about how to achieve a good and useful in vitro colon model: a complex biomimetic system that provides results comparable with the in vivo studies or a simple system, that despite the fact it could not give physiologically relevant data, it is sufficient to understand the fate of some specific components.

Application of CRISPR-Cas9 based gene editing to study the pathogenesis of colon and liver cancer using organoids

Two breakthrough techniques that have totally revolutionized biology in last 1 decade are the discovery of genome editing tools and growing the stem cells/primary tissue explants in defined 3D culture. In this regard the discovery of CRISPR-Cas9 as a specific gene editing tool and organoid culture from adult stem cell has provided easy handy tools to uncover the process of organ development and also modeling cancer. Genetically modified organoids have been developed by sequential knockout and knockin of driver mutations by genome editing followed by niche-based selection. The modified organoids when xenotransplanted in animal models faithfully recapitulate the neoplastic events of human tumors. The present review focuses on the merging of these two powerful technologies in understanding the complexities of colon and liver cancer.

Lower Gastrointestinal Functional and Motility Disorders in Children

Functional and motility gastrointestinal disorders are the most common complaints to the pediatric gastroenterologist. Disorders affecting the small intestine carry a significant morbidity and mortality due to the severe limitation of therapeutic interventions available and the complications associated with such interventions. Congenital colorectal disorders are rare but also carry significant morbidity and poor quality of life plus the social stigma associated with its complications. In this review, we summarize the clinical presentation, diagnostic evaluations, and the therapeutic interventions available for the most common and severe gastrointestinal functional and motility disorders of the small bowel, colon, and anorectum.

L-cell Arntl is required for rhythmic glucagon-like peptide-1 secretion and maintenance of intestinal homeostasis

OBJECTIVE

Recent studies using whole-body clock-disrupted animals identified a disruption in the circadian rhythm of the intestinal L-cell incretin hormone, glucagon-like peptide-1 (GLP-1). Although GLP-1 plays an essential role in metabolism through enhancement of both glucose-stimulated insulin secretion and satiety, recent evidence has also demonstrated its importance in regulating intestinal and microbial homeostasis. Therefore, using in vivo and in vitro models, this study assessed the role of the core circadian clock gene Arntl in the regulation of time-dependent GLP-1 secretion and its impact on the intestinal environment.

METHODS

Oral glucose tolerance tests were conducted at zeitgeber time 2 and 14 in control and inducible Gcg-Arntl knockout (KO) mice. Colonic intraepithelial lymphocytes were isolated, mucosal gene expression analysis was conducted, and 16S rRNA gene sequencing of colonic feces as well as analysis of microbial metabolites were performed. Time-dependent GLP-1 secretion and transcriptomic analysis were conducted in murine (m) GLUTag L-cells following siRNA-mediated knockdown of Arntl.

RESULTS

Gcg-Arntl KO mice displayed disrupted rhythmic release of GLP-1 associated with reduced secretion at the established peak time point. Analysis of the intestinal environment in KO mice revealed a decreased proportion of CD4+ intraepithelial lymphocytes in association with increased proinflammatory cytokine gene expression and increased colonic weight. Moreover, increased Actinobacteria within the colonic microbiome was found following L-cell Arntl disruption, as well as reductions in the microbial products, short chain fatty acids, and bile acids. Finally, siRNA-mediated knockdown of Arntl in mGLUTag L-cells resulted in both impaired time-dependent GLP-1 secretion and the disruption of pathways related to key cellular processes.

CONCLUSIONS

These data establish, for the first time, the essential role of Arntl in the intestinal L-cell in regulating time-dependent GLP-1 secretion. Furthermore, this study revealed the integral role of L-cell Arntl in mediating the intestinal environment, which ultimately may provide novel insight into the development of therapeutics for the treatment of intestinal and metabolic disorders.

Inflammatory response in the mid colon of ICR mice treated with polystyrene microplastics for two weeks

Background

The oral administration of polystyrene-microplastics (PS-MPs) causes chronic constipation of ICR mice, but there are no reports on their effects on the inflammatory response in the colon. To determine if the oral administration of MPs causes inflammation in the colon, the changes in the apoptosis-associated speck like protein containing a caspase recruitment domain (ASC)-inflammasome pathway, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway, and inflammatory cytokine expression were evaluated in the mid colon of ICR mice treated with 0.5 μm size PS-MPs for two weeks.

Results

The thicknesses of the mucosa, muscle, flat luminal surface, and crypt layer were decreased significantly (p < 0.01) in the mid colon of the MPs treated group compared to the Vehicle treated group. On the other hand, a remarkable increase in the expression levels of NOD-like receptor pyrin domain-containing protein (NLRP) 3, ASC, and Cleaved Caspase (Cas)-1 protein was observed in the MPs treated group. In addition, similar increasing pattern in the levels of p-NF-κB and phospho-inhibitory subunit of NF-κB (p-IkB) α protein was detected. Four inflammatory cytokines, including NF-κB, interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β, showed an increased expression level after the MPs treatment.

Conclusions

Therefore, the present study suggests that PS-MPs can be a novel cause of an inflammatory response in the mid colon of ICR mice.

The sulfiredoxin-peroxiredoxin redox system regulates the stemness and survival of colon cancer stem cells

Cancer stem cells (CSCs) initiate tumor formation and are known to be resistant to chemotherapy. A metabolic alteration in CSCs plays a critical role in stemness and survival. However, the association between mitochondrial energy metabolism and the redox system remains undefined in colon CSCs. In this study, we assessed the role of the Sulfiredoxin-Peroxiredoxin (Srx-Prx) redox system and mitochondrial oxidative phosphorylation (OXPHOS) in maintaining the stemness and survival of colon CSCs. Notably, Srx contributed to the stability of PrxI, PrxII, and PrxIII proteins in colon CSCs. Increased Srx expression promoted the stemness and survival of CSCs and was important for the maintenance of the mitochondrial OXPHOS system. Furthermore, Nrf2 and FoxM1 led to OXPHOS activation and upregulated expression of Srx-Prx redox system-related genes. Therefore, the Nrf2/FoxM1-induced Srx-Prx redox system is a potential therapeutic target for eliminating CSCs in colon cancer.

Comparison of bacterial community profiles from large intestine specimens, rectal swabs, and stool samples

The human gastrointestinal tract contains a complex and dynamic population of microorganisms, known as the gut microbiota. Although interest in the role of the gut microbiota in human health has increased in recent years, there remains no standard sampling protocol for analyzing these organisms. Here, we aimed to characterize the microbial composition of distinct segments of the large intestine and to determine whether rectal swabs are suitable for identifying colon microbiota. A total of 100 participants who underwent screening colonoscopy from October 2019 to October 2020 were included in this study. Large intestinal samples (ascending colon, descending colon, sigmoid colon, and rectum) were aspirated by colonoscopy. Rectal swabs were collected before colonoscopy, and stool samples were collected before patients began colonoscopy preparation. All samples were subjected to 16S ribosomal RNA gene sequencing. We identified differences in the number of phylum-level operational taxonomic units among large intestinal samples, rectal swabs, and stool. Five major phyla were detected in all samples (Firmicutes, Bacteroides, Proteobacteria, Actinobacteria, Fusobacteria), although their relative abundances varied. Notably, we found that the microbial compositions of rectal swabs were most similar to those of the sigmoid colon and rectum, whereas the microbiota in stool were relatively different than those from the large intestine and rectal swabs. Our results reveal the existence of microbial heterogeneity within different large intestinal compartments and further suggest that rectal swabs are an acceptable and practical tool for gut microbiota analysis. KEY POINTS: • Our findings highlight local microbiome variations within different regions of the large intestine. • Stool samples do not appear to fully recapitulate the gut microbiome. • Our data from a large population-based cohort indicate that rectal swabs can be used to study the gut microbiome.

Diet derived polycyclic aromatic hydrocarbons and its pathogenic roles in colorectal carcinogenesis

Polycyclic aromatic hydrocarbon (PAHs) are molecules that contaminate meat products during the high-temperature cooking of meat. This study reviewed the pathogenic roles of meat derived polycyclic aromatic hydrocarbons in the carcinogenesis of colorectal cancer (CRC). Ingested PAHs undergo xenobiotic metabolism resulting in the activation of genotoxic metabolites that can induce DNA damage in the colorectum. Genetic polymorphisms in PAH xenobiotic enzymes are linked to the risk of CRC and suggest a role for PAH-meat ingestion in carcinogenesis of colorectal malignancies. Furthermore, PAH specific DNA adducts have been identified in colorectal cancer tissue and linked to high meat intake. DNA adduct resolution is mediated by the nucleotide excision repair, and polymorphisms within genes of this repair pathway and high meat intake are associated with increased CRC risk. In the literature, there is evidence from metabolic enzyme gene variants, DNA repair genes, PAH metabolites, and epidemiological studies suggesting PAH involvement in CRC.

Analysis of the proximal promoter of the human colon-specific B4GALNT2 (Sda synthase) gene: B4GALNT2 is transcriptionally regulated by ETS1

BACKGROUND

The Sda antigen and corresponding biosynthetic enzyme B4GALNT2 are primarily expressed in normal colonic mucosa and are down-regulated to a variable degree in colon cancer tissues. Although their expression profile is well studied, little is known about the underlying regulatory mechanisms.

METHODS

To clarify the molecular basis of Sda expression in the human gastrointestinal tract, we investigated the transcriptional regulation of the human B4GALNT2 gene. The proximal promoter region was delineated using luciferase assays and essential trans-acting factors were identified through transient overexpression and silencing of several transcription factors.

RESULTS

A short cis-regulatory region restricted to the -72 to +12 area upstream of the B4GALNT2 short-type transcript variant contained the essential promoter activity that drives the expression of the human B4GALNT2 regardless of the cell type. We further showed that B4GALNT2 transcriptional activation mostly requires ETS1 and to a lesser extent SP1.

CONCLUSIONS

Results presented herein are expected to provide clues to better understand B4GALNT2 regulatory mechanisms.

In vitro models to evaluate ingestible devices: Present status and current trends

Orally ingestible medical devices offer significant opportunity in the diagnosis and treatment of gastrointestinal conditions. Their development necessitates the use of models that simulate the gastrointestinal environment on both a macro and micro scale. An evolution in scientific technology has enabled a wide range of in vitro, ex vivo and in vivo models to be developed that replicate the gastrointestinal tract. This review describes the landscape of the existing range of in vitro tools that are available to characterize ingestible devices. Models are presented with details on their benefits and limitations with regards to the evaluation of ingestible devices and examples of their use in the evaluation of such devices is presented where available. The multitude of models available provides a suite of tools that can be used in the evaluation of ingestible devices that should be selected on the functionality of the device and the mechanism of its function.

Rectosigmoid transition perforation by ingá (Inga laurina) seeds in the Brazilian amazon: Case report and surgical treatment

Introduction

Foreign body ingestion is a common clinical scenario found in clinical practice. Perforations related to foreign bodies are rare, but they can present as a serious condition in emergency surgery services. The most common sites of perforation are angled areas, such as: ileocecal valve, sigmoid colon, duodenojejunal flexure and small intestine. We are going to describe a rare case of extensive perforation of rectosigmoid transition, without associated obstructive clinical picture, related to voluntary ingestion of foreign body caused by multiple seeds of a typical amazon fruit.

Presentation of case

This case report describes the presentation and management of a 46-year-old man who presented signs of acute perforating abdomen, without obstructive condition, after ingestion of foreign body. Imaging examination revealed the presence of foreign bodies with signs of intestinal perforation. Exploratory laparotomy was performed to treat the lesion and remove foreign bodies.

Discussion

Bowel perforation by a non-sharp foreign body is a rare complication of object ingestion. Object shape, quantity, narrowing of gastrointestinal tract are factors that can favor perforation. The clinic is not very specific, usually preceded by when obstructive or sub occlusive, and the clinical history is relevant for diagnostic formulation. Regions and cultures with a high intake of food with seeds may constitute an extra risk factor.

Conclusion

The importance of alerting surgical teams to the possibility of bowel perforation without associated occlusive conditions caused by multiple non-sharp seeds is highlighted, as well as the need for early treatment aiming at favorable clinical outcome.

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Intestinal perforation by multiple non sharp fruits seeds is rare

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It is possible that there is no intestinal obstruction before perforation

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The use of protective terminal colostomy as described is an option

Beyond Ca2+ signalling: the role of TRPV3 in the transport of NH4. Pflugers Arch 2021;473:1859-1884. [PMID: 34664138 PMCID: PMC8599221 DOI: 10.1007/s00424-021-02616-0]

Mutations of TRPV3 lead to severe dermal hyperkeratosis in Olmsted syndrome, but whether the mutants are trafficked to the cell membrane or not is controversial. Even less is known about TRPV3 function in intestinal epithelia, although research on ruminants and pigs suggests an involvement in the uptake of NH₄⁺. It was the purpose of this study to measure the permeability of the human homologue (hTRPV3) to NH₄⁺, to localize hTRPV3 in human skin equivalents, and to investigate trafficking of the Olmsted mutant G573S. Immunoblotting and immunostaining verified the successful expression of hTRPV3 in HEK-293 cells and Xenopus oocytes with trafficking to the cell membrane. Human skin equivalents showed distinct staining of the apical membrane of the top layer of keratinocytes with cytosolic staining in the middle layers. Experiments with pH-sensitive microelectrodes on Xenopus oocytes demonstrated that acidification by NH₄⁺ was significantly greater when hTRPV3 was expressed. Single-channel measurements showed larger conductances in overexpressing Xenopus oocytes than in controls. In whole-cell experiments on HEK-293 cells, both enantiomers of menthol stimulated influx of NH₄⁺ in hTRPV3 expressing cells, but not in controls. Expression of the mutant G573S greatly reduced cell viability with partial rescue via ruthenium red. Immunofluorescence confirmed cytosolic expression, with membrane staining observed in a very small number of cells. We suggest that expression of TRPV3 by epithelia may have implications not just for Ca²⁺ signalling, but also for nitrogen metabolism. Models suggesting how influx of NH₄⁺ via TRPV3 might stimulate skin cornification or intestinal NH₄⁺ transport are discussed.

Primary hydatid cyst of the left-sided colon presenting with lower gastrointestinal bleeding; an extremely rare location of extrahepatic hydatid disease

Hydatid cyst is an endemic disease especially in underdeveloped and developing countries, affecting mostly the liver and lungs. However, a wide range of unusual anatomical sites in the abdomen have been reported, including the spleen, pancreas, kidney, and ovaries as well as dissemination within the abdominal and pelvic cavities. The location of hydatid disease in the colon is very infrequent, and very few cases have been presented so far. The hydatid cysts located in other sites are mostly due to rupture or extrusion of primary liver or splenic cysts. In this article, we present a case of primary left-sided colon hydatid cyst, resected laparoscopically with the affected intestinal segment. The diagnosis of hydatid cyst was made by macroscopic and microscopic examinations.

Combination of neutrophil gelatinase-associated lipocalin and matrix metalloproteinase-9 are biomarkers for the detection of colon tubular adenocarcinoma

BACKGROUND

Tubular adenocarcinoma of the colon, which originates from the epithelium of the glands, is a major health concern worldwide. However, it is difficult to detect at an early stage. The lack of biomarkers is a main barrier to the diagnosis and treatment of tubular adenocarcinoma. Neutrophil gelatinase-associated lipocalin (NGAL) is a secreted protein that induces the expression of matrix metalloproteinase-9 (MMP-9) and is involved in various tumors. NGAL and MMP-9 have been reported to be associated with tumorigenesis and development. They may have potential as biomarkers for diagnosis of tubular adenocarcinoma of the colon.

AIM

To determine whether NGAL and MMP-9 can be used as potential biomarkers to indicate the progression of tubular adenocarcinoma of the colon.

METHODS

Samples were collected from surgically excised tissue from various patients. The content of pro-gastrin-releasing peptide (pro-GRP) in the serum was measured by an electrochemiluminescence immunoassay. The expression patterns of NGAL and MMP-9 and the relationship between NGAL and MMP-9 were examined by quantitative real-time PCR, Western blotting and immunohistochemical analysis.

RESULTS

In this study, we found that NGAL and MMP-9 can be used as biomarkers for the detection of tubular adenocarcinoma of the colon and that their combination improved diagnostic accuracy. By analyzing the expression of NGAL in tubular adenocarcinoma at different levels, we found that NGAL expression was significantly upregulated in primary tubular adenocarcinoma tissues compared with normal tissues. The upregulation of NGAL expression was strongly correlated with both the degree of differentiation and the disease stage (I–III), indicating that NGAL could serve as a diagnostic biomarker for tubular adenocarcinoma. When using NGAL as a biomarker for diagnosis, the accuracy was similar to that achieved with the widely used biomarker pro-GRP, suggesting that NGAL is reliable. Moreover, the expression of MMP-9 was also strongly correlated with the differentiation stage, demonstrating that MMP-9 could be used as a biomarker to indicate the progression of tubular adenocarcinoma of the colon. More importantly, the combination of NGAL and MMP-9 produced a more accurate diagnosis of tubular adenocarcinoma, and these results were further confirmed by immunohistochemical analysis of tissue sections.

CONCLUSION

Our study demonstrated that both NGAL and MMP-9 can be used as biomarkers for the diagnosis of colon tubular adenocarcinoma and that the results could be further improved by combining them.

A longer interval after stenting compromises the short- and long-term outcomes after curative surgery for obstructive colorectal cancer

PURPOSE

Intestinal decompression using self-expandable metallic colonic stents (SEMSs) as a bridge to surgery is now considered an attractive alternative to emergency surgery. However, data regarding the optimal timing of surgery after stenting are limited.

METHODS

We investigated the impact of the interval between stenting and surgery on short- and long-term outcomes in 92 obstructive colorectal cancer (OCRC) patients who had a SEMS inserted and subsequently received curative surgery.

RESULTS

The median age of the patients was 70.5 years, and the median interval between SEMS insertion and the surgery was 17 (range 5-47) days. There were 35 postoperative complications, including seven major postoperative complications. An interval of more than 16 days was an independent predictor of a poor relapse-free survival (hazard ratio [HR] = 3.12, 95% confidence interval [CI] 1.24-7.81, p = 0.015). An interval of more than 35 days was independently associated with major postoperative complications (HR = 16.6, 95% CI 2.21-125, p = 0.006).

CONCLUSION

A longer interval between stenting and surgery significantly compromised the short- and long-term outcomes. Surgery within 16 days after stenting might help maximize the benefit of SEMS without interfering with short- and long-term outcomes.

Ultrasound and contrast enhanced CT imaging of a colon mesentery leiomyosarcoma

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Primary mesenteric leiomyosarcoma is a very rare, aggressive neoplasm.

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Tumour recurrence and metastatic spread is a significant risk following surgical treatment.

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Follow-up is warranted and likely improves patient survival rates.

Primary leiomyosarcoma of the colon mesentery is an extremely rare neoplasm, and only a small number of cases have been reported. We describe a case of leiomyosarcoma originating in the colonic mesentery, in a 68-year-old woman. Ultrasound showed a heterogeneous mass with varying vascularization in the left fossa. Central areas of the mass were hypoechoic, without detectable vascularization. Contrast enhanced computed tomography (CECT) of chest and abdomen showed a contrast enhanced tumour, with central non-enhanced areas. The tumour was radically resected and histopathology showed primary leiomyosarcoma. Two years after primary surgery, follow-up CECT revealed a local recurrence, which was re-resected. Subsequent follow-up CECT since have shown no sign of recurrence.

Ablation of liver Fxr results in an increased colonic mucus barrier in mice

Background & Aims

The interorgan crosstalk between the liver and the intestine has been the focus of intense research. Key in this crosstalk are bile acids, which are secreted from the liver into the intestine, interact with the microbiome, and upon absorption reach back to the liver. The bile acid-activated farnesoid X receptor (Fxr) is involved in the gut-to-liver axis. However, liver-to-gut communication and the roles of bile acids and Fxr remain elusive. Herein, we aim to get a better understanding of Fxr-mediated liver-to-gut communication, particularly in colon functioning.

Methods

Fxr floxed/floxed mice were crossed with cre-expressing mice to yield Fxr ablation in the intestine (Fxr-intKO), liver (Fxr-livKO), or total body (Fxr-totKO). The effects on colonic gene expression (RNA sequencing), the microbiome (16S sequencing), and mucus barrier function by ex vivo imaging were analysed.

Results

Despite relatively small changes in biliary bile acid concentration and composition, more genes were differentially expressed in the colons of Fxr-livKO mice than in those of Fxr-intKO and Fxr-totKO mice (3272, 731, and 1824, respectively). The colons of Fxr-livKO showed increased expression of antimicrobial genes, Toll-like receptors, inflammasome-related genes and genes belonging to the ‘Mucin-type O-glycan biosynthesis’ pathway. Fxr-livKO mice have a microbiome profile favourable for the protective capacity of the mucus barrier. The thickness of the inner sterile mucus layer was increased and colitis symptoms reduced in Fxr-livKO mice.

Conclusions

Targeting of FXR is at the forefront in the battle against metabolic diseases. We show that ablation of Fxr in the liver greatly impacts colonic gene expression and increased the colonic mucus barrier. Increasing the mucus barrier is of utmost importance to battle intestinal diseases such as inflammatory bowel disease, and we show that this might be done by antagonising FXR in the liver.

Lay summary

This study shows that the communication of the liver to the intestine is crucial for intestinal health. Bile acids are key players in this liver-to-gut communication, and when Fxr, the master regulator of bile acid homoeostasis, is ablated in the liver, colonic gene expression is largely affected, and the protective capacity of the mucus barrier is increased.

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Fxr ablation in the mouse liver has a major impact on colonic gene expression.

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Fxr signalling is induced in the colons of liver Fxr knockout (Fxr-livKO) mice.

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In Fxr-livKO colons, expression of antimicrobial and mucus genes is increased.

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Microbiome of Fxr-livKO mice is indicative of enhanced mucus barrier function.

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Fxr-livKO mice have an increased mucus barrier.

Treatment with a spore-based probiotic containing five strains of Bacillus induced changes in the metabolic activity and community composition of the gut microbiota in a SHIME® model of the human gastrointestinal system

MegaSporeBiotic™ is an oral, spore-based probiotic comprised of five Bacillus spp. (Bacillus indicus HU36, Bacillus subtilis HU58, Bacillus coagulans SC208, Bacillus licheniformis SL307, and Bacillus clausii SC109). The effects of MegaSporeBiotic™ on gut microbiota activity and community composition were evaluated for the first time using an in vitro model of the human gastrointestinal tract, the simulator of the human intestinal microbial ecosystem (SHIME®), under healthy conditions. Following a stabilization period and a control period (2 weeks each), the reactor feed was supplemented with daily MegaSporeBiotic™ for 3 weeks (treatment period). Changes in microbial community activity and composition between the control and treatment periods were evaluated for each colon compartment (ascending [AC], transverse [TC], and descending colon [DC]). Propionate levels increased significantly in the TC (week 2, P = 0.02; week 3, P = 0.0019) and DC (week 2, P = 0.03) with treatment while lactate levels significantly decreased in the TC (week 3, P = 0.03). Ammonium levels were significantly decreased during the final week of treatment (TC, P = 0.02; DC, P = 0.03). Overall, Akkermansia muciniphila, Bifidobacteria spp., and Firmicutes increased with treatment while Lactobacillus spp. and Bacteroidetes decreased. The Firmicutes:Bacteroidetes ratio increased with treatment in the AC compartment. MegaSporeProbiotic™ treatment resulted in changes in metabolism and increased bacterial diversity.

In vivo models to evaluate ingestible devices: Present status and current trends

Evaluation of orally ingestible devices is critical to optimize their performance early in development. Using animals as a pre-clinical tool can provide useful information on functionality, yet it is important to recognize that animal gastrointestinal physiology, pathophysiology and anatomy can differ to that in humans and that the most suitable species needs to be selected to inform the evaluation. There has been a move towards in vitro and in silico models rather than animal models in line with the 3Rs (Replacement, Reduction and Refinement) as well as the better control and reproducibility associated with these systems. However, there are still instances where animal models provide the greatest understanding. This paper provides an overview of key aspects of human gastrointestinal anatomy and physiology and compares parameters to those reported in animal species. The value of each species can be determined based upon the parameter of interest from the ingested device when considering the use of pre-clinical animal testing.

Does intermittent fasting associated with aerobic training influence parameters related to the gut-brain axis of Wistar rats?

BACKGROUND

Intermittent fasting (IF) and aerobic training have demonstrated beneficial effects on intestinal microbiota composition, but little is known about benefits to the brain through the gut-brain axis. The present study aimed to evaluate gut-brain axis parameters in Wistar rats submitted to IF associated or not with aerobic training.

METHODS

Male rats were evaluated for training performance and then randomized into 4 groups of ten: sedentary control (SC), trained control (TC), sedentary intermittent fasting (SIF), and trained intermittent fasting (TIF), and evaluated during four weeks.

RESULTS

The adiposity index was similar among the TC (2.15±0.43%), SIF (1.98±0.69%) and TIF (1.86±0.51%) groups, and differed from SC (2.98±0.80%). TIF had lower counts of lactic acid bacteria, while SIF had higher counts of Bifidobacterium and Enterococcus. TIF had the highest amount of formic acid in faeces (44.44±2.40 μmol/g) and lowest amount of succinic acid in the gut (0.38±0.00 μmol/g), while SIF had the highest propionic acid amount in the faeces (802.80±00.33 μmol/g) and the lowest amount of lactic acid in the gut (0.85±0.00 μmol/g). TIF demonstrated a tendency towards an anxiolytic effect and SIF showed potential antidepressant effect. IF caused different brain and intestinal injuries. TIF rats presented a diffuse and intense marking of IL-1β in the hippocampus.

CONCLUSION

IF and aerobic exercise, associated or not, can modulate parameters related to the gut-brain axis of Wistar rats, and some benefits may be related to the amounts of organic acids.

Regulation of neurotoxicity in the striatum and colon of MPTP-induced Parkinson's disease mice by gut microbiome

Increasing evidence suggests the role of gut-microbiota-brain axis in the pathogenesis of Parkinson's disease (PD). The objective of this study was to examine whether repeated administration of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) can influence the neurotoxicity in the striatum and colon, and the composition of gut microbiota and short-chain fatty acids (SCFAs) in feces of adult mice. MPTP caused the reduction of dopamine transporter (DAT) and tyrosine hydroxylase (TH) in the striatum, and increases in phosphorylated α-synuclein (p-α-Syn) in the striatum and colon. There was a negative correlation between the expression of TH in the striatum and the expression of p-α-Syn in the colon, suggesting a role of gut-brain communication. MPTP caused abnormalities in the α- and β-diversity of gut microbiota in the mice. Furthermore, the relative abundance of the genus Faecalicatena in the MPTP-treated group was significantly lower than that of control group. Interestingly, there was a positive correlation between the genus Faecalicatena and the expression of TH in the striatum. Moreover, MPTP did not alter the levels of SCFAs in feces samples. However, there was a positive correlation between the relative abundance of the genus Faecalicatena and propionic acid. The data suggest that MPTP-induced increases in colonic p-α-Syn expression might be associated with dopaminergic neurotoxicity in the striatum via gut-microbiota-brain axis.

Rectal endometriosis presenting as toxic megacolon

Background

The bowel is the most common site of extragenital endometriosis, with involvement of the locoregional sigmoid colon and anterior rectum seen most often. The clinical presentation varies depending on how soon patients seek medical care, thus requiring changes in management strategies. Endometriosis can cause a life-threatening surgical emergency with progressive obliteration of the bowel lumen leading to obstruction and late complications including toxic megacolon and transmural necrosis.

Case presentation

We report the case of a 41-year-old woman presenting with an acute abdomen and complete large bowel obstruction complicated by sepsis and toxic megacolon. The patient underwent emergency total colectomy with ileostomy. Medical history was significant for chronic, vague, and episodic lower abdominal pain self-medicated with herbal tea and laxatives. Pathologic examination demonstrated colonic endometriosis within the bowel wall as the cause of obstruction, ischemia, and transmural necrosis.

Conclusions

Although a rare clinical entity, this case highlights two important points. First, it demonstrates the value of performing proper and complete clinical work up to rule out or in all possible causes of colonic obstruction, including intestinal endometriosis. Second, it suggests a potential benefit of a formalized multidisciplinary approach, including surgery, in the management of medically unresponsive endometriosis. In conclusion, this case shows that endometriosis can cause life-threatening colonic obstruction in women of childbearing age. Prompt early intervention is warranted, particularly when obstruction is only partial and ischemia has not supervened, to conceivably prevent the development of a toxic megacolon requiring colectomy and avoid late complications.

Diagnosis of Hirschsprung disease by hydrocolonic sonography in children

OBJECTIVES

To compare hydrocolonic sonography with histopathology for diagnosing children with symptoms highly suggestive of Hirschsprung disease (HD).

METHODS

In this prospective study, patients presenting refractory constipation highly suggestive of HD underwent hydrocolonic sonography with retrograde infusion of saline into the colon. The dilated segments, narrowed segments, luminal diameter ratio, transition zone (TZ), thickening, and blood perfusion of the upstream bowel were evaluated. The sensitivity and specificity of combined and single parameters were determined in comparison with biopsy.

RESULTS

One hundred and three children were included in this study; 49 were confirmed to have HD. The luminal diameter ratio showed superiority over other parameters. An area under the curve (AUC) of 0.969 (95% confidence interval [CI]: 0.936-1.000) and a cutoff value of 1.51 were established by receiver operating characteristic (ROC) curve analysis of the luminal diameter ratio (sensitivity: 89.8%; specificity: 96.3%). By combining the luminal diameter ratio as the major criterion with two minor criteria, hydrocolonic sonography showed the same sensitivity (91.8%) and better specificity (96.3% vs 87%) than contrast enema, but this difference was not statistically significant (p = 0.063). Consistency analysis showed a kappa value of 0.825 (p < 0.001), indicating excellent agreement between hydrocolonic sonography and contrast enema.

CONCLUSIONS

Hydrocolonic sonography is a valuable diagnostic tool with both high sensitivity and specificity for HD diagnosis, allowing morphological and vascular assessments of the colon, and correlates well with contrast enema. In the appropriate setting, hydrocolonic sonography may be an alternative screening method for HD in a large group of children with constipation. Key Points • Hydrocolonic sonography is a simple, well-tolerated diagnostic tool with both high sensitivity and specificity for HD diagnosis. • Hydrocolonic sonography allows morphological and vascular assessments of the colon, and correlates well with contrast enema. • Hydrocolonic sonography is a possible alternative modality for paediatric patients highly suggestive of HD.

A large lipoma of the descending colon: A rare case report

Colon lipoma is a rare benign disease in the gastrointestinal tract with an incidence rate of approximately 0.035%-4.4%. The disease is often asymptomatic, so it is frequently discovered incidentally through endoscopy, computed tomography , or autopsy. When the tumor is over 2 cm in size, symptoms such as abdominal pain, bowel disorders, and bowel obstruction are common. Surgery is considered the mainstay of treatment for colonic lipomas. Furthermore, surgical (rather than endoscopic) resection is preferred for lipomas >2 cm to avoid complications such as bleeding and perforation. We report on a 61-year-old female patient who was diagnosed with a 4-cm descending colonic fat tumor detected by endoscopy and computed tomography and confirmed by pathology.