Endoscopic Management of Foreign Bodies in the Gastrointestinal Tract: A Review of the Literature

Foreign body ingestion is a common diagnosis that presents in emergency departments throughout the world. Distinct foreign bodies predispose to particular locations of impaction in the gastrointestinal tract, commonly meat boluses in the esophagus above a preexisting esophageal stricture or ring in adults and coins in children. Several other groups are at high risk of foreign body impaction, mentally handicapped individuals or those with psychiatric illness, abusers of drugs or alcohol, and the geriatric population. Patients with foreign body ingestion typically present with odynophagia, dysphagia, sensation of having an object stuck, chest pain, and nausea/vomiting. The majority of foreign bodies pass through the digestive system spontaneously without causing any harm, symptoms, or necessitating any further intervention. A well-documented clinical history and thorough physical exam is critical in making the diagnosis, if additional modalities are needed, a CT scan and diagnostic endoscopy are generally the preferred modalities. Various tools can be used to remove foreign bodies, and endoscopic treatment is safe and effective if performed by a skilled endoscopist

Chemoreception Regulates Chemical Access to Mouse Vomeronasal Organ: Role of Solitary Chemosensory Cells

Controlling stimulus access to sensory organs allows animals to optimize sensory reception and prevent damage. The vomeronasal organ (VNO) detects pheromones and other semiochemicals to regulate innate social and sexual behaviors. This semiochemical detection generally requires the VNO to draw in chemical fluids, such as bodily secretions, which are complex in composition and can be contaminated. Little is known about whether and how chemical constituents are monitored to regulate the fluid access to the VNO. Using transgenic mice and immunolabeling, we found that solitary chemosensory cells (SCCs) reside densely at the entrance duct of the VNO. In this region, most of the intraepithelial trigeminal fibers innervate the SCCs, indicating that SCCs relay sensory information onto the trigeminal fibers. These SCCs express transient receptor potential channel M5 (TRPM5) and the phospholipase C (PLC) β2 signaling pathway. Additionally, the SCCs express choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) for synthesizing and packaging acetylcholine, a potential transmitter. In intracellular Ca2+ imaging, the SCCs responded to various chemical stimuli including high concentrations of odorants and bitter compounds. The responses were suppressed significantly by a PLC inhibitor, suggesting involvement of the PLC pathway. Further, we developed a quantitative dye assay to show that the amount of stimulus fluid that entered the VNOs of behaving mice is inversely correlated to the concentration of odorous and bitter substances in the fluid. Genetic knockout and pharmacological inhibition of TRPM5 resulted in larger amounts of bitter compounds entering the VNOs. Our data uncovered that chemoreception of fluid constituents regulates chemical access to the VNO and plays an important role in limiting the access of non-specific irritating and harmful substances. Our results also provide new insight into the emerging role of SCCs in chemoreception and regulation of physiological actions