An immunocytochemical analysis of torn rotator cuff tendon taken at the time of repair.

During rotator cuff repairs, it is recommended that the hypovascular tissue edge be resected. To investigate rotator cuff tendon histopathology, we performed immunohistochemistry on 8 surgical and 6 cadaveric specimens. Hoechst nuclear stain and standard hematoxylin-eosin were used for morphologic analysis. Antibody to human von Willebrand factor tagged with fluorescein isothiocyanate, conjugated, was used to visualize vascularity, and antibody to human procollagen type I tagged with Cy3 was used to visualize new procollagen synthesis. There were no significant differences in the vascularity of surgical specimens sectioned near the tear site (<2.5 mm from tear margin) and matched cadaveric controls. However, sections taken 2.5 to 5 mm away from the tear demonstrated more vessels than those taken from either control or surgical specimens within 2.5 mm of the tear (P <.001). There were no differences in nuclear distribution patterns or in procollagen production and distribution between surgical specimens from sites near the tear or away from the tear. On the basis of morphologic architecture, these data suggest that minimal debridement of tendon edges only is required to maximize healing of the rotator cuff tendon at the time of repair.

Memory and growth in the superior temporal gyri.

The superior temporal gyri were measured in 33 infants and in 33 adults. In the adults, most right superior temporal gyri were larger. This asymmetry was not found in infants, a difference which suggests greater growth of the right superior temporal gyri in the population from which our sample was taken. The asymmetry may be related to the functional asymmetry found by Penfield: some of his patients reported re-experiencing of past sensory experiences with electrical stimulation of the temporal lobe. This response was more frequently evoked from the right hemisphere.