Nifedipine induces overgrowth of gingival tissues in some patients. However, other collagenous tissues in their body do not overgrow. The purpose of this study was to compare effects of serial dilutions of nifedipine on the in vitro metabolism of fibroblasts derived from normal gingiva, nifedipine-induced hyperplastic gingiva, knee capsular ligament, and dermis. The data suggested that nifedipine affects the metabolism of fibroblasts derived not only from gingiva, but also from other collective connective tissues. Thus, nifedipine-responder cells are present in tissues other than gingiva. There was an inverse relationship between in vivo tissue levels of IL-1-beta and in vitro responsiveness to nifedipine of fibroblasts derived from that tissue. Nifedipine-induced overgrowth of connective tissues, other than gingiva, probably does not occur either because of the relatively slow rate of collagenous protein synthesis by resident fibroblasts or because of alterations in collagen deposition/resorption within susceptible tissues produced by nifedipine on collagenase synthesis.
Marrow transplantation was attempted in a 13-yr-old boy with congenital hypoplastic anemia who had never responded to corticosteroid therapy. Prior to the transplant, he had received 238 transfusions, at least 12 of which were from his father. He was prepared for grafting with antilymphocyte globulin, procarbazine, and total body irradiation (1000 rads). The patient, whose red cells were Group B, then received marrow cells from his Group O, histocompatible, sister. Thereafter, reticulocytes, Group O erythrocytes, and female leukocytes appeared in the peripheral blood. Erythroid precursors were seen in the patient's marrow for the first time in his life, and all lacked fluorescent Y chromosomes. Dividing cells were all female. After initially progressing well, the patient developed interstitial pneumonia and died 55 days after the transplant. The successful erythroid graft suggested that this patient's failure to produce red blood cells was due to a defective stem cell rather than to a humoral defect, plasma inhibitor, or abnormal marrow microenvironment. It suggested further that sibling marrow may be engrafted in patients who have received multiple transfusions, even from a parent.
When all aberrations are absent other than third-order astigmatism and Petzval, it is demonstrated that selection of a flat tangential astigmatic field is optimum if the smallest maximum spot size is desired over the entire field of view. With balanced sagittal and tangential fields the spot size is observed to be smaller than the flat-tangential-field case until the field angle reaches √? of the full-field angle. Comparisons of the spot sizes and shapes for these cases and the flat-sagittal-field case are made for flat and optimally curved image surfaces.
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