Paneth Cells: Differentiated epithelial cells of the INTESTINAL MUCOSA, found in the basal part of the intestinal crypts of Lieberkuhn. Paneth cells secrete GROWTH FACTORS, digestive enzymes such as LYSOZYME and antimicrobial peptides such as cryptdins (ALPHA-DEFENSINS) into the crypt lumen.alpha-Defensins: DEFENSINS found in azurophilic granules of neutrophils and in the secretory granules of intestinal PANETH CELLS.Dithizone: Chelating agent used for heavy metal poisoning and assay. It causes diabetes.Intestine, Small: The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.Defensins: Family of antimicrobial peptides that have been identified in humans, animals, and plants. They are thought to play a role in host defenses against infections, inflammation, wound repair, and acquired immunity.Intestinal Mucosa: Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.Muramidase: A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 184.108.40.206.Matrix Metalloproteinase 7: The smallest member of the MATRIX METALLOPROTEINASES. It plays a role in tumor progression.Intestines: The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.Goblet Cells: A glandular epithelial cell or a unicellular gland. Goblet cells secrete MUCUS. They are scattered in the epithelial linings of many organs, especially the SMALL INTESTINE and the RESPIRATORY TRACT.Ileitis: Inflammation of any segment of the ILEUM and the ILEOCECAL VALVE.Ileum: The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.Crohn Disease: A chronic transmural inflammation that may involve any part of the DIGESTIVE TRACT from MOUTH to ANUS, mostly found in the ILEUM, the CECUM, and the COLON. In Crohn disease, the inflammation, extending through the intestinal wall from the MUCOSA to the serosa, is characteristically asymmetric and segmental. Epithelioid GRANULOMAS may be seen in some patients.Protein PrecursorsIntestinal Neoplasms: Tumors or cancer of the INTESTINES.Intestinal Diseases: Pathological processes in any segment of the INTESTINE from DUODENUM to RECTUM.Enteroendocrine Cells: Cells found throughout the lining of the GASTROINTESTINAL TRACT that contain and secrete regulatory PEPTIDE HORMONES and/or BIOGENIC AMINES.beta-Defensins: DEFENSINS found mainly in epithelial cells.Intestine, Large: A segment of the LOWER GASTROINTESTINAL TRACT that includes the CECUM; the COLON; and the RECTUM.Appendix: A worm-like blind tube extension from the CECUM.Cytoplasmic Granules: Condensed areas of cellular material that may be bounded by a membrane.Enterocolitis, Necrotizing: ENTEROCOLITIS with extensive ulceration (ULCER) and NECROSIS. It is observed primarily in LOW BIRTH WEIGHT INFANT.Jejunum: The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.Acrodermatitis: Inflammation involving the skin of the extremities, especially the hands and feet. Several forms are known, some idiopathic and some hereditary. The infantile form is called Gianotti-Crosti syndrome.Nod2 Signaling Adaptor Protein: A NOD signaling adaptor protein that contains two C-terminal leucine-rich domains which recognize bacterial PEPTIDOGLYCAN. It signals via an N-terminal capase recruitment domain that interacts with other CARD SIGNALING ADAPTOR PROTEINS such as RIP SERINE-THEONINE KINASES. The protein plays a role in the host defense response by signaling the activation of CASPASES and the MAP KINASE SIGNALING SYSTEM. Mutations of the gene encoding the nucleotide oligomerization domain 2 protein have been associated with increased susceptibility to CROHN DISEASE.Duodenum: The shortest and widest portion of the SMALL INTESTINE adjacent to the PYLORUS of the STOMACH. It is named for having the length equal to about the width of 12 fingers.