Megakaryocytes are depleted and abnormal in ITP SCID mice. Histologic section of (A) healthy bone marrow and (B) bone marrow from a morbid mouse engrafted with 5 × 104 nondepleted splenocytes (40× magnification; numerical aperture, plan apo; objective lens, 0.75). (A) The yellow arrows point to megakaryocytes, and (A-B) each scale bar represents 50 μm. Because of the paucity of megakaryocytes in SCID mouse ITP bone marrows, the marrows were prepared by a cytospin method to concentrate them on a slide and stained with H&E. (C) An example of a megakaryocyte from the bone marrow of a healthy SCID mouse. (D) H&E staining of a rare megakaryocyte found in the bone marrow of a SCID mouse with ITP (60× magnification; numerical aperture, plan apo; objective lens, 1.4). (C,D) Each scale bar represents 10 μm. All pictures were taken with Nikon Eclipse E800 upright microscope.
