Obscure gastrointestinal bleeding is often a diagnostic challenge for the primary care physician, but with improvements in diagnostic testing the cause of such blood loss is determined in most patients. However, in approximately 5% of the cases, the source of bleeding is not identifiable. One common etiology in patients younger than 40 years of age is Meckel’s diverticulum. Technetium-99m perte...

Heterotopic pancreas (HP) is typically an asymptomatic malformation that can present anywhere along the gastrointestinal tract. It is often found incidentally as a single focal mass in patients with abdominal complaints undergoing routine diagnostic testing. HP occasionally presents symptomatically, and the manifestations vary depending on the location of the lesion. We describe the first repor...

Gastric heterotopia occurs throughout the entire gastrointestinal tract, from the oral cavity to the anorectum, and also involves the gallbladder, biliary tract, umbilicus and scrotum [1-10]. The presence of this lesion beyond the ligament of Treitz with recurrent intestinal subocclusive episodes is uncommon [1-10]. We report a case of a 21-year-old woman who had a oneyear history of intermitte...

Bone morphogenetic protein (BMP) signaling is known to suppress oncogenesis in the small and large intestine of mice and humans. We examined the role of Bmpr1a signaling in the stomach. On conditional inactivation of Bmpr1a, mice developed neoplastic lesions specifically in the squamocolumnar and gastrointestinal transition zones. We hypothesized that the regulation of epithelial cell fate may ...

The interaction between signaling pathways is a central question in the study of organogenesis. Using the developing murine tongue as a model, we uncovered unknown relationships between Sonic hedgehog (SHH) and retinoic acid (RA) signaling. Genetic loss of SHH signaling leads to enhanced RA activity subsequent to loss of SHH-dependent expression of Cyp26a1 and Cyp26c1. This causes a cell identi...

BACKGROUND & AIMS The gastrointestinal syndrome is an illness of the intestine caused by high levels of radiation. It is characterized by extensive loss of epithelial tissue integrity, which initiates a regenerative response by intestinal stem and precursor cells. The intestine has 24-hour rhythms in many physiological functions that are believed to be outputs of the circadian clock: a molecula...

Gastric heterotopia is very rare in the rectum - less than 50 cases have been reported so far. Only in six of them Helicobacter pylori has been observed in heterotopic mucosa. We report a case of a 58-year-old woman with asymptomatic gastric heterotopia in the rectum, incidentally revealed during colonoscopy as a small, sessile polyp. The presence of H. pylori was confirmed by immunohistochemis...

A 25-year-old male was referred to the Radiology Department with new onset of right upper quadrant and epigastric abdominal pain. He had no past medical or surgical history. Physical exam was unremarkable. The patient underwent computed tomography (CT), fluoroscopic upper gastrointestinal (GI) evaluation, endoscopic ultrasound (EUS), and positron emission tomography (PET) evaluation, revealing ...

CD200R is an inhibitory receptor expressed on myeloid cells and some lymphoid cells, and plays important roles in negatively regulating immune responses. CD200 is the only known ligand of CD200R and broadly distributed in a variety of cell types. Here we identified novel CD200 homologues, designated iSEC1 and iSEC2, that are expressed exclusively by secretory cell lineages in the gastrointestin...

Gastrointestinal cell proliferation plays an important role in the maintenance of the integrity of the gastrointestinal system. The study of gastrointestinal proliferation kinetics allows a better understanding of the complexity of the system, and also has important implications for the study of gastrointestinal carcinogenesis. Gastrointestinal stem cells are shown to be pluripotential and to g...