Definition is a rhetorical mode that can be used in something smaller or shorter than a full paper. You can use extended definition for several paragraphs only in a paper of much greater length. You also can add to a paper a one-paragraph definition--like a brief encyclopedia definition.
The research group, headed by Dr. Lukas Sommer at the Swiss Federal Institute of Technology, has identified a heretofore unknown role for the TGF cell-to-cell signaling pathway in the pathogenesis of DiGeorge syndrome.
Glomerular hypertrophy leads to hemodynamic changes, which lead to hypertension. 3. Mesangial cell hyperplasia with ECM deposition, epithelial and endothelial cell injury occur as consequences of the above. Epithelial and endothelial cell injury lead to proteinuria (nephrotic syndrome).