Some additional morphological and metrical observations on Pan brain casts and their relevance to the Taung endocast

Using an increased sample of chimpanzee brains and brain casts, 32 hemispheres were measured to determine the variability of OP-FP (occipital-pole) and OP-LS (occipital pole-lunate sulcus) arc dimensions and their ratios. The Taung endocast was remeasured to test Falk's assertions that the lunate sulcus is in a pongid position. The average ratio for the chimpanzee brains was 0.218, a value more than 2+ S.D.'s posterior to Falk's placement of the lunate sulcus on the Taung specimen. It is suggested that the chimpanzee and Taung occipital poles have a different morphometric pattern, the former being coincident with the caudal end of the LC (lateral calcarine) fissure. The Taung OP-LS arc consistently measured at least 42 mm, and not 40 mm as claimed by Falk.     

Inhibition of human natural killer cell activity by platelet-derived growth factor

The present report demonstrates that the naturally occurring biologic substance, platelet-derived growth factor (PDGF), substantially inhibits human natural killer (NK) cell activity. More precisely, pretreatment of peripheral blood mononuclear cells for 2 h with nanogram amounts of either partially purified PDGF or highly purified PDGF significantly inhibited peripheral blood NK cell activity (cytotoxicity) in a dose-dependent manner as measured against the NK-sensitive target, K-562. Furthermore, pretreatment of purified NK cells for 2 h with nanogram amounts of purified PDGF also resulted in a significant, dose-dependent inhibition of human NK cell activity (cytotoxicity), as mediated by positively selected, B73.1+ human NK cells sorted on a fluorescence-activated cell sorter. In addition to the inhibition of NK-mediated cytotoxicity, nanogram amounts of purified PDGF also significantly inhibited the single-cell binding of B73.1+ human NK cells to the NK-sensitive target K-562, as determined by routine single-cell-binding assays (i.e. conjugate formation). The implications of these findings are discussed.     

Fine needle aspiration cytology, immunocytochemistry and electron microscopy in a rare case of carcinoma of the breast with malignant epithelial giant cells

The cytohistologic findings in a fine needle aspirate from a case of the rare breast carcinoma with bizarre tumor giant cells are described, along with the results of immunocytochemical and ultrastructural studies. The observations in this case suggest that the bizarre malignant giant cells in this type of breast cancer are of an epithelial origin, rather than a histiocytic-stromal origin. The other conditions that may yield giant cells in needle aspirates of breast masses are briefly discussed.     

Immunocytochemical and ultrastructural study of the rare osteoclast-type carcinoma of the breast in a fine needle aspirate

The cytologic findings in a fine needle aspirate from a case of the rare osteoclastlike carcinoma of the breast are described along with the immunocytochemical and ultrastructural findings. The ultrastructural and immunocytochemical findings suggest that the osteoclastlike giant cells in this type of carcinoma are not of epithelial origin, but rather are reactive and of a histiocytic-stromal origin.     

Mapping Development of the Human Intestinal Niche at Single-Cell Resolution

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