Biomaterial Database

Inhibitory effects of the graft versus host reaction upon the development of the bursa of Fabricius. Early modifications in the subepithelial mesenchyma. 1981

H Gérard, and A Gérard, and L Marchal

The graft versus host reaction elicited in the chick embryo by lymphoid cells from a homologous adult donor is known to alter the histogenesis of the bursa of Fabricius. This paper reports the first scanning and transmission electron microscope studies of this phenomenon. Of the three main bursal components (lymphoid lineage, endodermic epithelium and mesenchyma), the subepithelial mesenchyma (SEM) exhibits the earliest and the most obvious modifications. There is a concomitant decrease of SEM alkaline phosphatase activity. It is suggested that disorganization of the SEM, which is a normal pathway of migration for the lymphoid precursors, reduces the inflow of these cells into the epithelial compartment.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D002060	Bursa of Fabricius	An epithelial outgrowth of the cloaca in birds similar to the thymus in mammals. It atrophies within 6 months after birth and remains as a fibrous remnant in adult birds. It is composed of lymphoid tissue and prior to involution, is the site of B-lymphocyte maturation.	Fabricius Bursa
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D002642	Chick Embryo	The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.	Embryo, Chick,Chick Embryos,Embryos, Chick
D003094	Collagen	A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).	Avicon,Avitene,Collagen Felt,Collagen Fleece,Collagenfleece,Collastat,Dermodress,Microfibril Collagen Hemostat,Pangen,Zyderm,alpha-Collagen,Collagen Hemostat, Microfibril,alpha Collagen
D006087	Graft vs Host Reaction	An immunological attack mounted by a graft against the host because of HISTOINCOMPATIBILITY when immunologically competent cells are transplanted to an immunologically incompetent host; the resulting clinical picture is that of GRAFT VS HOST DISEASE.	HLA Sensitization,Human Leukocyte Antigen Sensitization,Sensitization, HLA
D000469	Alkaline Phosphatase	An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia