Tumor neuroendocrino en recto simulando una neoplasia benigna: reporte de caso y revisión de a literatura / Neuroendocrine tumor in the rectum simulating a benign neoplasm: case report and literature review

Los tumores neuroendocrinos se definen como un grupo heterogéneo de neoplasias de origen epitelial, provenientes de células enterocromafines diseminadas por todo el organismo, y representan alrededor del 1 al 4 % de todas las neoplasias. Su mayor distribución se encuentra en el tracto gastrointestinal, donde se localiza el 75 % de los tumores neuroendocrinos, siendo los ubicados en el recto, el 27 % de todos los que afectan el tracto gastrointestinal. A propósito de esta revisión de tema, presentamos el caso de un paciente de 71 años de edad, que consultó por sangrado rectal rojo rutilante, sin otra sintomatología asociada, y se le diagnosticó un tumor neuroendocrino grado 1, que se comportaba como una lesión benigna del recto

Neuroendocrine tumors are defined as a heterogeneous group of neoplasms of epithelial origin from enterochromaffin cells disseminated throughout the body, and represent about 1% to 4% of all neoplasms. Its largest distribution is found in the gastrointestinal tract, where 75% of neuroendocrine tumors are located, being 27% of those in the rectum. We present the case of a 71-year-old patient who consulted for bright red blood per rectum, with no other associated symptoms, and was diagnosed with a grade 1 neuroendocrine tumor, which behaved as a benign lesion of the rectum

The Ultra Structural Studies of Duodenum of Goat (Capra hircus)

The tissues from small intestine containing duodenum were collected from six young goats and processed for scanning and transmission electron microscopic studies. The villi of the duodenum varied in shape and size. The duodenal mucosal surface showed leaf shaped villi along with scanty population of goblet cells on the villi surface. The mucosal surface was having very faint corrugations and dense mat of microvilli. The basal surface of the villi, the number of goblet cells was more. The crypts openings were evident at some places. The transmission electron microscopic studies revealed the presence of different cell population which included columnar or absorptive cells and goblet cells in surface epithelium of the duodenum. The columnar cells were having many uniform regularly spaced microvilli. The goblet cells were very few in the villus epithelium and were interspersed in between the columnar cells and their cytoplasm was distended with mucus granules. The crypt region or glandular epithelium was consisted of polymorphic cell population which included the Paneth cells, enterochromaffin cells and goblet cells

Role of Nav1.3 in control of excitability of RIN-14B cells / 上海交通大学学报（医学版）

Objective: To provide electrophysiological evidence for RIN-14B cells as an useful model of enterochromaffin cells (EC) and to study the role of Nav1. 3 channel in the control of its excitability. Methods: Resting membrane potential was recorded and the effects of TTX and ICA-121431 were examined by current-clamp in cultured RIN-14B cells. The effects of TTX and ICA-121431 on Na+ current of RIN-14B cells were examined by voltage-clamp. Results: RIN-14B cells had a resting potential around -60 mV and fired action potentials when stimulated with depolarizing current pulses. The action potential was completely blocked by TTX and inhibited by ICA-121431 in a dose-dependent manner. TTX blocked activation and inactivation of sodium current. In addition ICA-121431 dose-dependently inhibited activation of Na+ current. Conclusion: The action potential of RIN-14B cells is induced by TTX-sensitive sodium channel and the excitability is controlled by Nav1.3. These results suggest RIN-14B cells are similar to EC and it may be a good model of EC.

Mechanism of Interdigestive Migrating Motor Complex

Migrating motor complex (MMC) is well characterized by the appearance of gastrointestinal contractions in the interdigestive state. This review article discussed the mechanism of gastrointestinal MMC. Luminal administration of 5-hydroxytryptamine (5-HT) initiates duodenal phase II followed by gastrointestinal phase III with a concomitant increase of plasma motilin release in conscious dogs. Duodenal 5-HT concentration is increased during gastric phase II and phase III. Intravenous infusion of motilin increases luminal 5-HT content and induces gastrointestinal phase III. 5-HT4 antagonists significantly inhibits both of gastric and intestinal phase III, while 5-HT3 antagonists inhibited only gastric phase III. These suggest that gastrointestinal MMC cycle is mediated via the interaction between motilin and 5-HT by the positive feedback mechanism. Gastric MMC is regulated via vagus, 5-HT3/4 receptors and motilin, while intestinal MMC is regulated via intrinsic primary afferent neurons and 5-HT4 receptors. Stress is highly associated with the pathogenesis of functional dyspepsia. Acoustic stress attenuates gastric phase III without affecting intestinal phase III in conscious dogs, via reduced vagal activity and increased sympathetic activity. It has been shown that subset of functional dyspepsia patients show reduced vagal activity and impaired gastric phase III. The physiological importance of gastric MMC is a mechanical and chemical cleansing of the empty stomach in preparation for the next meal. The impaired gastric MMC may aggravate dyspeptic symptoms following a food ingestion. Thus, maintaining gastric MMC in the interdigestive state is an important factor to prevent the postprandial dyspeptic symptoms.

Increased Immunoendocrine Cells in Intestinal Mucosa of Postinfectious Irritable Bowel Syndrome Patients 3 Years after Acute Shigella Infection: An Observation in a Small Case Control Study

PURPOSE: Postinfectiously irritable bowel syndrome (PI-IBS) develops in 3-30% of individuals with bacterial gastroenteritis. Recent studies demonstrated increases in inflammatory components in gut mucosa of PI-IBS patients even after complete resolution of infection. We aimed to investigate histological changes in colon and rectum of PI-IBS subjects after long term period of infection. MATERIALS AND METHODS: We recruited PI-IBS subjects who had been diagnosed IBS after complete resolution of enteritis caused by shigellosis outbreak 3 years earlier. We compared unmatched four groups, PI-IBS (n = 4), non PI-IBS (n = 7), D-IBS (n = 7, diarrhea predominant type) and healthy controls (n = 10). All of them underwent colonoscopic biopsy at three areas, including descending colon (DC), sigmoid colon (SC) and rectum, which were assessed for 5-hydroxytryptamine (5-HT)/peptide YY (PYY)-containing enterochromaffin (EC) cell, intraepithelial (IEL) and lamina propria T lymphocyte (CD3), CD8 lymphocytes, mast cells and CD68/calprotectin+ macrophages. RESULTS: All subjects had no structural or gross abnormalities at colonoscopy. In PI-IBS, 5-HT containing EC cells, PYY containing EC cells, IELs, CD3 lymphocytes, CD8 lymphocytes, mast cells, and CD68 + macrophages were increased compared to control (p < 0.05). In D-IBS, PYY containing EC cells, IELs, and CD3 lymphocytes were increased compared to control (p < 0.05). In PI-IBS, 5-HT containing EC cells tended to increase and PYY containing EC cells, CD8 lymphocytes, mast cells, and CD68+ macrophages were increased compared to non PI-IBS (p < 0.05). Calprotectin + marcrophages were decreased in PI-IBS, non PI-IBS and IBS compared to control. CONCLUSION: The immunoendocrine cells were sporadically increased in PI-IBS, non PI-IBS and D-IBS compared with control. Our findings in a very small number of patients suggest that mucosal inflammation may play a role in long-term PI-IBS, and that other sub-groups of IBS and larger scale studies are needed to confirm this observation.

Quantity and functional alterations of gastric enterochromaffin cells in patients with functional dyspepsia / 中华消化杂志

Objective To investigate the alteration of serotonin-producing gastric enterochromaffin (EC)cell in patients with functional dyspepsia(FD).Methods Fifteen healthy volunteers and 33 patients with FD were enrolled.Proximal gastric mucosal EC cells were countered after immunohisto- chemistry staining.The ultrastructure of EC cell was observed by electromicroscope.Results The EC cells in proximal gastric mucosa in patients with FD were significant higher than that in controls(12.5?2.1 vs 8.3?1.4,t=2.353,P＜0.05),and the staining intensity of EC cell in patients with FD was also stronger than that in controls(3.72?0.42 vs 2.61?0.57,t=2.078,P＜0.05).The more sever the gastric mucosal inflammation was,the more number of EC cells and the stronger staining intensity were.Under the electromicroscopy,more Golgi apparatus,mitochondria and endoplasmic reticulum were found in EC cells.Special secreting particles were also found in cytoplasm.Conclusions EC cells may be involved in the pathogenesis of FD.The number of EC cell is related with the severity of gastric mucosal inflammation.

Morphological and functional alteration of serotonin-producing intestinal enterochromaffin cells in patients with irritable bowel syndrome / 中华消化杂志

Objective To investigate morphological and synthetic alteration of enterochromaffin(EC) cells of intestinal mucosa in patients with irritable bowel syndrome(IBS). Methods Fifty cases of IBS were classified into diarrhea predominant and constipation predominant in accordance with RomeⅡ criteria. Colon biopsy tissues were stained through Envision immunohistochemistry. Morphological changes of EC cells in intestinal mucosa were also studied by electron microscopy. Results EC cells were seen in the crypt of intestinal mucosa. The shapes and the number of EC cells in diarrhea predominant IBS and constipation predominant IBS increased remarkably, compared with those in controls (15.90 ?5.09, 14.73?2.73 vs. 7.27?2.50). It was shown that EC cells synthesized excessive 5 hydroxytryptamine (5 HT) by immunohistochemistry. The function of EC cells in IBS was active under electron microscopy. Conclusions Active enteral EC cells noticed in IBS indicate that excessive 5 HT may play an important role in the pathogenesis of IBS.