Search Results (71)

Neuroimmune interactions in the intestine are essential for maintaining tissue homeostasis, yet they remain poorly understood in teleost fish. This study investigated the structural and cellular organization of enteric neurons and immune cells in the intestine of goldfish (Carassius auratus) using semithin histology, transmission electron microscopy (TEM), and confocal immunofluorescence. Histological observations revealed a well-organized epithelium composed of enterocytes and goblet cells, with numerous lymphocytes located in the basal epithelium. Prominent gut-associated lymphoid tissue (GALT) was identified in both scattered and aggregated forms within the lamina propria and submucosa. Macrophages were widely distributed throughout all intestinal layers and were consistently found in close proximity to enteric neurons and nerve fibers. Ultrastructural analysis confirmed direct contacts between macrophages and neuronal elements. These macrophages exhibited typical phagocytic features, including lysosomes, vacuoles, and engulfed material, particularly in association with myenteric nerve fibers. Immunofluorescence analysis revealed strong expression of toll-like receptor 2 (TLR2) and major histocompatibility complex class II (MHC II) in macrophages and enterocytes, suggesting an active role in antigen recognition. Langerin-positive dendritic-like cells were identified in the submucosa, while CD4-positive lymphocytes showed partial colocalization with serotonin (5-HT). S100-positive cells also exhibited partial overlap with 5-HT, and goblet cells demonstrated serotonin immunoreactivity. In addition, inducible nitric oxide synthase (iNOS) colocalized with TLR2 in submucosal immune cells. These findings demonstrate a close structural and functional association between enteric neurons and immune cells, highlighting an integrated neuroimmune network in the goldfish intestine. Full article

Background/Objectives: Colorectal cancer is a leading cause of cancer-related mortality worldwide, and early detection of gastrointestinal (GI) polyps through endoscopy is critical for improving patient outcomes. However, access to specialist gastroenterology care remains severely limited in Federal Health Professional Shortage Areas (HPSAs), particularly for high-acuity geriatric patients. This study proposes GeriAIGastroNet, a clinically oriented deep learning framework designed to support AI-assisted tele-gastroenterology workflows in resource-limited settings, with the primary objective of enabling AI-powered risk stratification and colonoscopy referral triage for elderly patients who lack on-site gastroenterology access. Methods: The framework integrates an EfficientNet-B4 backbone with multi-scale attention fusion and a geriatric severity-aware classification head to enable accurate GI polyp segmentation and automated clinical risk stratification from endoscopic images. Patients identified as high-risk are referred to colonoscopy-capable centers; such centers typically offer diagnostic colonoscopy with polypectomy capability for smaller and intermediate-complexity polyps, while patients with larger, sessile, or morphologically complex lesions requiring advanced endoscopic resection (e.g., endoscopic mucosal resection or endoscopic submucosal dissection) are further referred to tertiary endoscopy centers with specialized expertise. The model was trained and evaluated on the publicly available HyperKvasir dataset (1000 annotated polyp images). Results: GeriAIGastroNet achieved a classification accuracy of 96.77%, F1-score of 96.90%, Dice coefficient of 89.18%, and Intersection over Union (IoU) of 80.80%, outperforming established baselines, including U-Net, Attention U-Net, TransUNet, and Hybrid CNN-Transformer architectures. The integrated tele-gastroenterology decision support layer enables severity-based patient triage and automated referral triggering. Conclusions: These results demonstrate the potential of AI-powered polyp analysis to strengthen equitable access to GI care by facilitating risk stratification and specialist referral in HPSAs where direct endoscopy is unavailable, making the system deployable in telehealth infrastructures serving underserved elderly populations. Full article

Background/Objectives: Ulcerative colitis (UC)-associated neoplasia (UCAN) often presents as flat lesions with indistinct margins, and biopsy sensitivity is limited. Therefore, we evaluated endoscopic criteria to distinguish UCAN from sporadic neoplasia, assessing the accuracy of endoscopic ultrasonography (EUS) for invasion depth and the role of endoscopic submucosal dissection (ESD) as a “total biopsy.” Methods: We reviewed 212 endoscopically treated neoplastic lesions in UC-affected mucosa (April 2016–January 2025). We compared preoperative diagnoses using macroscopic type, pit pattern, and the Japan Narrow-Band Imaging Expert Team classification with final histology. We compared depth estimates with pathology in 10 UCAN-suspected lesions undergoing EUS. Lesions < 2 cm underwent conventional endoscopic resection, whereas those ≥ 2 cm underwent ESD. Results: No UCAN was found in 189 lesions < 2 cm. Among 23 ESD lesions, 8 suspected sporadic lesions were non-UCAN. Of 15 UCAN-suspected lesions, 8 were UCAN, 6 sporadic, and 1 inflammatory. For positive T1b or deeper invasion, the sensitivity, specificity, positive and negative predictive values, and overall accuracy of EUS were 50.0%, 100%, 100%, 88.9%, and 90.0%, respectively. EUS depth assessment agreed with pathology in 9/10 cases; nine lesions were T1a or shallower, and one was T1b. Third-layer thickening occurred in two lesions—both UCAN—including the T1b cancer. In ESD cases, redness and a VI pit pattern were independent predictors of UCAN. Conclusions: EUS-based depth assessment is useful for determining optimal treatment strategies. Beyond therapy, ESD enables comprehensive histologic assessment of the entire lesion, functioning as a total biopsy to guide management while preserving bowel function. Full article

Miniprobe endoscopic ultrasonography (mEUS) combines high-resolution imaging of the gastrointestinal (GI) wall and bile ducts with ease of applicability during routine endoscopy. This narrative review aims to provide an overview of known and emerging fields of application for mEUS in gastrointestinal endoscopy. After its initial development in pancreatobiliary scenarios in the early 1990s, mEUS has been recently reconsidered a third-space endoscopic technique that is progressively developing and spreading for the treatment of early gastrointestinal neoplastic lesions. The high spatial resolution of mEUS provides an accurate assessment of the degree of submucosal invasion in early esophageal, gastric, and colorectal neoplasia, while the small caliber of catheters allows for mEUS employment in settings where standard echoendoscopes are impractical (e.g., severe stenoses or proximal colonic lesions). Beyond cancer staging, mEUS offers point-of-care characterization of subepithelial lesions by defining the layer of origin and echo-pattern, eventually defining endoscopic resectability, but definitive diagnosis remains histological. In pancreatobiliary diseases, miniprobe intraductal ultrasonography (IDUS) shows its strongest application for indeterminate biliary strictures when endoscopic retrograde cholangiopancreatography (ERCP)-based sampling strategies and brushing cytology show inconclusive diagnoses, and in choledocholithiasis, particularly for the detection of small stones/sludge and confirmation of duct clearance. IDUS is also valuable for the staging of ampullary tumors, for longitudinal extension mapping in hilar cholangiocarcinoma and for selected portal biliopathy scenarios. Overall, mEUS and IDUS are high-resolution adjuncts that can meaningfully refine local decision-making in the treatment of superficial epithelial/subepithelial tumors or lesions involving the bile ducts. Limitations include shallow penetration, lack of tissue acquisition capability, a relative increase in post-ERCP pancreatitis risk for intraductal use, and substantial cost with limited availability in lower-volume centers. Full article

Background and Clinical Significance: Angiotensin-converting enzyme inhibitors (ACE-Is) are commonly used for treatment of hypertension and are well known among primary care specialists. ACE-I-induced angioedema is a rare, yet possible side effect. It should not be taken lightly, as it can be life-threatening. It is characterized by erythematous or skin-coloured, self-limiting, localized, non-pitting swelling of the submucosal and/or subcutaneous layers of tissue. Usually, it develops in the first year of using the medication, although it can also start several years after using it. Herein, we describe a late-onset ACE-I-induced angioedema, which developed 7 years after using the ACE-I. This case report depicts the challenges of diagnosing ACE-I-induced angioedema, especially if it is late-onset. It highlights the importance of actively asking patients questions about possible side effects of medication even several years after using it and the patients themselves not having any complaints. Case Presentation: We present a 61-year-old Caucasian male with recurring swelling of the lips, tongue and an uncomfortable feeling in the throat, which started 7 years after using an ACE-I: perindopril. There was no airway obstruction or urticaria in any of the episodes. Hereditary angioedema was ruled out by blood analysis. Based on the clinical presentation, images and blood analysis, it was diagnosed as late-onset ACE-I-induced angioedema. After discontinuing the ACE-I, there were two more episodes of angioedema reported, which were a lot milder in symptoms and lasted a shorter time period. Since then, there have been no other episodes of angioedema. Conclusions: It is important to keep in mind angioedema as a possible side effect for patients on ACE-Is. Patients should be regularly and actively questioned about side effects, even if the medication has been started several years ago and no complaints are brought up by the patient. Full article

Per-oral flexible endoscopy has expanded minimally invasive options for the management of gastric subepithelial tumors (G-SETs). This narrative review appraises conventional and advanced endoscopic resections alongside hybrid laparoscopic–endoscopic procedures, within a size- and layer-based clinical framework. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) achieve high en bloc resection rates for small, intraluminal tumors arising from mucosa or submucosa. Traction strategies and dedicated traction devices may improve submucosal exposure, shorten procedure time, and reduce adverse events. Submucosal tunneling endoscopic resection (STER) has been developed to enucleate tumors originating from the muscularis propria while preserving mucosal integrity. However, tunnel creation and specimen retrieval become challenging for large tumors or for those located in the cardia or fundus. Endoscopic full-thickness resection (EFTR) enables controlled transmural excision of G-SETs arising from deeper wall layers. Exposed EFTR, combined with secure endoscopic closure, provides high en bloc and complete (R0) resection rates. Closure options range from through-the-scope clips—for small defects—to over-the-scope clips, endoloop-clip purse-string methods, reopenable-clip over-the-line techniques and endoscopic suturing systems—for larger defects. Non-exposed EFTR and device-assisted systems reduce the risk of peritoneal contamination, although complete resection rates are more variable. Hybrid approaches, including classical laparoscopic–endoscopic cooperative surgery (LECS) and non-exposure variants, combine endoscopic precision with the safety and closure capabilities of laparoscopic surgery, minimizing the amount of resected gastric wall. They are particularly suited to larger, awkwardly located or ulcerated G-SETs. Emerging traction platforms, flexible robotic systems, and AI-based tools may further broaden the role of per-oral flexible endoscopy for the treatment of G-SETs. However, evidence remains preliminary, and surgery continues to play a key role for large, extraluminal or anatomically prohibitive G-SETs. Full article

Intestinal emphysema is a rare pathological condition observed in humans and animals, characterized by the presence of multiple gas-filled cysts within the intestinal wall. In pigs, it is occasionally observed at slaughter, without affecting carcass suitability for human consumption or impairing farm profitability. Despite investigations, the etiology and pathogenesis of intestinal emphysema remain poorly understood. Therefore, this study aimed to provide further morphological insights into porcine intestinal emphysema through histopathological, histochemical and immunohistochemical methods. A total of ten slaughtered heavy pigs were examined, showing gross lesions consistent with intestinal emphysema. Gaseous cysts were predominantly located in the submucosal and mesenteric layers, at least partially lined by lymphatic endothelial cells. The cysts were separated by fibrous connective septa and were almost invariably associated with granulomas, consisting of epithelioid macrophages and multinucleated giant cells. Overall, the immunohistochemical patterns of porcine intestinal emphysema overlap with those described in humans and support the hypothesis that lesions likely originate within the lymphatic vessels. Full article

Background/Objectives: Zenker’s diverticulum (ZD) is a rare but clinically relevant condition. It is a false, pulsion-type diverticulum due to the protrusion of mucosal and submucosal layers through the Killian’s Triangle. Its pathogenesis is multifactorial and entails cricopharyngeus muscle dysfunction and age-related tissue degeneration. This review addresses the current evidence regarding the anatomy, pathophysiology, clinical presentation, diagnostic approach, and therapeutic management of ZD. Methods: For this literature review, we searched the PubMed and Scopus databases using combinations of keywords relevant to Zenker’s diverticulum, including “Zenker’s diverticulum,” “esophageal diverticula,” “diagnosis,” “endoscopic treatment,” and “surgery”. We included articles published in recent decades, with a focus on most recent ones regarding clinical studies, systematic reviews, meta-analyses, and descriptions of new diagnostic and therapeutic techniques. Results: Characteristic symptoms comprise progressive dysphagia, regurgitation of undigested food, halitosis, and, in advanced cases, aspiration-related respiratory complications. Diagnosis of ZD is primarily based on barium swallow esophagography and endoscopic evaluation, complemented by other imaging techniques. Current therapeutic options include traditional open surgery and endoscopic procedures, including newer minimally invasive techniques. Conclusions: ZD is the most common type of esophageal diverticulum and can have a disabling impact on a patient’s quality of life. It is commonly underdiagnosed or misdiagnosed as another condition, and prevalence is expected to increase with the growing population ageing. Improved understanding of its pathophysiology is needed to refine diagnostic and therapeutic strategies and minimize recurrences and risks. Full article

The parturition season of grazing Tibetan ewes spans from October to March, a period that exacerbates the adverse impacts of nutrient-deficient herbage on milk yield, body condition, and postpartum recovery. To alleviate the weight loss of ewes during the cold seasons, we provided concentrate supplements at four levels (dry matter (DM) basis), 260 g (C1), 440 g (C2), 520 g (C3), and 610 g (C4), alongside a basal diet of grazed pasture. A total of 96 multiparous Tibetan ewes (third parity, body weight: 45.17 ± 3.69 kg (body weight (BW) were enrolled within 12–18 h postpartum and randomly allocated to four dietary groups (n = 24 ewes per group). We measured growth performance, ruminal histomorphology, fermentation parameters, and digestive enzymes. A multi-omics technique (16S rRNA gene sequencing and RNA-seq) was employed to investigate the mechanisms underlying alterations in ruminal function. The results showed that increasing the concentrate level decreased body weight loss and increased average dry matter intake (p < 0.05). Rumen morphology was significantly altered: papilla width and muscle layer thickness were greatest in the C4 group, whereas submucosal thickness was highest in the C1 group (p < 0.05). Cellulase activity was lowest in the C1 group (p < 0.05). Papilla width of lactating Tibetan ewes in the C4 group was higher (p < 0.05) than that in the C1 and C3 groups. Concentrate supplementation altered ruminal microbiota composition and diversity. Each group exhibited a distinct microbial signature: the C1 group was characterized by Lachnospiraceae_XPB1014_group, Candidatus_Omnitrophus, Paenibacillus, and unclassified_Oligoflexaceae; the C2 group was enriched in Papillibacter, Anaerovibrio, V9D2013_group, and unclassified_Peptococcaceae; the C3 group was characterized by unclassified_Bacteroidales_RF16_group; and the C4 group was characterized by Ruminococcus, Pseudobutyrivibrio, and Mitsuokella (p < 0.05). Transcriptomic analysis identified differentially expressed genes (TRPA1, EPHB1, GATA3, C4, ABCG2, THBS4, and TNFRSF11B) that are predominantly involved in immune regulation, signal transduction, and nutrient digestion. The results of Spearman correlation analysis showed that Anaerovibrio was negatively correlated with propionate (r = −0.565, p < 0.05). However, it was positively correlated with the ratio of acetate and propionate (r = 0.579, p < 0.05). Moreover, Lachnospiraceae_XPB1014_group was negatively correlated with cellulase (r = −0.699, p < 0.05) and α-amylase (r = −0.514, p < 0.05). These findings suggest that the increasing concentrate supplementation alleviates body weight loss in lactating Tibetan sheep by orchestrating improvements in rumen histomorphology, digestive function, altering bacteria composition, and ruminal immune and modulating host epithelial gene expression. Full article

Zenker’s diverticulum (ZD) is an esophageal condition that results in an outpouching of the mucosal layer through a weakened area in the hypopharyngeal wall. This condition can cause symptoms like dysphagia, regurgitation, and aspiration, impacting patients’ quality of life. Historically, open surgery was the primary treatment. Although effective, this method is associated with longer recovery times and risks such as infections, nerve damage, and prolonged hospitalization. Rigid endoscopic stapling emerged as a less invasive alternative, offering high success rates for patients with favorable anatomy. Zenker’s peroral endoscopic myotomy (Z-POEM), adapted from treatments for achalasia, represents the latest advancement in ZD management. It involves creating a submucosal tunnel and precisely dividing the cricopharyngeus muscle. Z-POEM is minimally invasive and often provides quick relief with a high success rate of around 92%, while enabling outpatient treatment or brief hospital stays. However, it requires specialized expertise, and long-term data on recurrence rates are still emerging. This review discusses the evolution of these treatment modalities through comprehensive searches of PubMed, MEDLINE, and ScienceDirect databases. Studies reporting on treatment outcomes, complication rates, operative times, and clinical success associated with open surgery, rigid endoscopic stapling, and Z-POEM were included, with emphasis on meta-analyses, multicenter studies, and large case series highlighting Z-POEM’s comparable success to open surgery and increased patient tolerance. Open surgery achieves long-term symptom resolution rates of 90–95% but is associated with higher complication rates (up to 30%) and prolonged recovery times. Rigid endoscopic stapling offers symptom relief in approximately 90% of cases, with lower morbidity and shorter hospital stays (1–2 days), though anatomical limitations restrict its use. Z-POEM has demonstrated clinical success rates of 85.5–93%, with major complications reported in 4.8–5% of cases and recurrence rates as low as 1.4% at one-year follow-up in larger diverticula. Z-POEM’s minimally invasive nature and suitability for high-risk patients make it increasingly preferred in specialized centers. Management of Zenker’s diverticulum has evolved significantly, with endoscopic techniques, particularly Z-POEM, offering comparable success to open surgery but with fewer complications and faster recovery. Ongoing advances in endoscopic equipment and technique, along with emerging data on long-term outcomes, are likely to further refine treatment algorithms for ZD, especially for elderly and high-risk populations. Future directions in ZD management include ongoing research to enhance the safety and efficacy of endoscopic techniques, with new technologies on the horizon that could further improve outcomes and accessibility. Full article

High viscosity of alginate means a relatively low substrate concentration, which limits the efficiency of hydrolysis, resulting in one of the main challenges for the large-scale production of alginate oligosaccharides (AOS). In this study, a pilot-scale degradation product (PSDP) of the recombinant enzyme 102C300C-Vgb was produced for the first time at a substrate concentration of up to 20% sodium alginate. The optimal conditions for SA digestion were: enzyme dosage of 25 U/g, enzymatic temperature of 45 °C, enzymatic pH of 7.0, and enzymatic time of 24 h. Under these conditions, the yield of enzymatic hydrolysis was consistently in the range of 69% to 70%. The average molecular weight (Mw) of PSDP was 1496.36 Da, mainly containing oligosaccharides with degrees of polymerization ranging from 2 to 4. The low-Mw PSDP was subsequently applied in the diet of sea cucumber Stichopus japonicus. The results showed that the body wall weight of S. japonicus increased significantly after 40 days of feeding with a 0.09% PSDP-supplemented diet. Furthermore, PSDP-supplemented diet significantly increased the thickness of the serosal and submucosal layers and the width folds of mucosa of the sea cucumber gut. The abundance of pathogenic bacteria was reduced effectively, and that of beneficial bacteria increased significantly after being fed with PSDP. The results demonstrated that PSDP can serve as a digestive health enhancer for sea cucumbers, promoting their healthy growth. Full article

Short bowel syndrome (SBS) is characterized by insufficient intestinal length to support absorption causing malnutrition. The bowel adapts to SBS via intestinal dilation and delayed gastric emptying but still often requires long-term parenteral nutrition. Current surgical options to lengthen the bowel pose significant risks and often provide limited expansion. ‘Distraction enterogenesis’ has been proposed as a technique to induce intestinal lengthening for SBS. The deployment of the intestinal expansion sleeve (IES) device is hypothesized to result in significant intestinal lengthening in vivo. A Roux-en-Y was created in the jejunum of seven rats for isolated IES deployment. The IES was precontracted over a Bucatini noodle and inserted into the isolated roux limb. After 4 weeks of deployment, rats were sacrificed, Roux-en-Y length recorded, and histology analyzed. A paired t-test was performed to compare initial and final roux limb lengths and histopathological tissue remodeling. Intestinal distraction evaluated at 4 weeks post deployment of the IES resulted in a significant 30.2% elongation in roux limb length (43.6 ± 14.4 mm to 56.4 ± 20.8 mm (p = 0.043, n = 7). IES samples showed changes in mucosal and submucosal integrity and bowel wall thickness in response to IES lengthening. In samples with partial mucosal erosion, the basal/regenerative layers of the mucosa were preserved. Distraction enterogenesis with significant intestinal lengthening in vivo has been achieved with the IES device. Histologic changes suggest all bowel functional layers and attributes are maintained through distraction enterogenesis. Future constructs of the IES may benefit from the addition of immunomodulators. Increasing intestinal mass with these devices may complement the treatment paradigm for SBS. Full article

Gastrointestinal submucosal tumors (SMTs) are difficult to diagnose accurately due to their deep location and the limitations of traditional biopsy tools. To address these issues, we propose a multifunctional capsule-shaped puncture biopsy robot (PBR) with capabilities for tissue sampling, thermal hemostasis, and multi-stage drug delivery. The PBR measures 27 mm in length and 13 mm in diameter, integrating a micro-scale electro-permanent magnetic system with a 60-turn dual-layer coil (wire diameter: 0.6 mm) to drive an 8 mm-depth puncture needle. A graphene–carbon nanotube composite heating film enables rapid and safe temperature elevation, achieving effective hemostasis and triggering sequential drug release using paraffin-based phase-change materials. Heating remains within the clinical safety range. Experiments demonstrated successful tissue penetration, precise magnetic control, and reliable staged pigment release simulating drug delivery. Tests on an ex vivo porcine stomach confirmed adaptability to irregular gastric surfaces. This compact PBR provides an integrated and minimally invasive approach to both the diagnosis and treatment of gastrointestinal lesions. Full article

Today, endoscopy plays a crucial role not only in the detection of precancerous and malignant colorectal lesions, but also in the treatment of even widespread adenomas and T1 early cancers. In addition to classic polypectomy and endoscopic mucosal resection (EMR) using a snare, in recent years, endoscopic submucosal dissection (ESD) has become increasingly important. Marking, submucosal injection, circumferential incision of the mucosa around the lesion, tunneling, and submucosal dissection using a short diathermic knife facilitate the ‘en bloc’ resection of lesions larger than 3 cm, difficult to resect in one piece using a snare. Lesions with high-grade dysplasia or mucosal carcinoma are other good candidates aside from widespread adenomata with a high risk of recurrence after piecemeal resection. ESD allows R0 resection rates of more than 90% in specialized centers. Lesions of 20 cm have been removed ‘en bloc’ by expert endoscopists. ESD provides an optimal histopathologic yield and has a risk of recurrence as low as 3%. Endoscopic full-thickness resection using a special device (eFTRD) is another addition to the resection armamentarium. It is especially suitable for circumscribed lesions up to 2 cm in the middle and upper rectum. Endoscopic intermuscular dissection (EID) is a recent modification of ESD primarily in the rectum, including the inner, circular muscular layer into the resection specimen. In this way, it allows a histopathologic analysis of the entire submucosa beyond the mucosal and upper submucosal layer such as in ESD. This is especially important for T1 cancers invading the submucosa without any other risk factors of invasion. Full article

A 78-year-old woman was referred to our hospital for close examination of an extramural submucosal tumor in the gastroesophageal region, suspected based on an imaging test performed for a chief complaint of epicardial pain while eating. Contrast-enhanced computed tomography revealed a 3 cm sized mass with well-defined margins and a homogeneous interior near the gastroesophageal junction. Endoscopic ultrasonography (EUS) revealed a large (28 mm) unilocular cystic lesion with a heterogeneous hypoechoic internal structure. The cyst wall was layered with a hypoechoic layer that appeared to be muscular and continuous with the external longitudinal muscle of the esophagus. Based on the EUS findings, an esophageal duplication cyst was diagnosed. Cystectomy was performed because the patient was symptomatic. Pathological examination revealed that the specimen was covered with columnar and pseudostratified ciliated epithelium without atypia and that the cyst wall comprised two layers of smooth muscle. No cartilaginous tissue was present, which is consistent with esophageal duplication cysts. Retrospectively, the EUS findings were consistent with the pathological findings. Full article