Biomedical subjects
Publications and source records attributed to D L Mirkin.
It is essential to recognize radiation pneumonitis after whole lung irradiation, or nodular changes in response to chemotherapy, so that such conditions are not mistaken for tumor metastases, causing grave error in patient management and the possibility of further lung damage.
Intranuclear filaments aggregating into rodlike structures were found in cells of an undifferentiated soft tissue sarcoma in a child. Similar structures have been uncommonly described in human neoplasms, and uncertainties exist concerning the nature of the inclusion bearing cells in previous reports. The filaments were found to be resistant to mild trypsin digestion. Review of the pertinent literature indicates that these structures may represent the structural manifestation of a highly specialized functional state, rather than a degenerative phenomenon or an artifact. A certain selectivity of occurrence has also been noted. It is therefore plausible to speculate that intranuclear filaments may eventually constitute a morphologic criterion of interest for new tumor classifications.
Histological grading of teratomas is a useful method for evaluating patient prognosis. Although this has been repeatedly shown with ovarian teratomas, those of the sacrococcygeal area have not been scrutinized to a comparable extent. We believe that histologic grade and clinical behavior correlate closely in congenital sacrococcygeal teratomas. Correlation with clinical staging is less clear. There are some taxonomical and conceptual problems posed by the congenital nature of these tumors. The worst prognosis is dictated by the presence of yolk sac tumor areas, which was seen in seven of 40 teratomas examined. Although a neuroectodermal component is common, and was here proved to have metastasizing capacity, its inherent tendency may be toward spontaneous self-limiting differentiation. Vitelline differentiation, however, seems to imply irreversible progression and a uniformly bad prognosis.
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Each of seven 19-nor steroids exhibited the capacity to facilitate the binding of carbon monoxide (CO) to human placental microsomal cytochrome P-450 although quantitative differences were shown to exist. In every case the facilitation was antagonized by androstenedione. 19-Norandrostenedione produced the most pronounced effect followed by 19-nortestosterone, nandrolone decanoate, norethandrolone, norgestrel, norethynodrel and norethindrone in that order. All steroids investigated produced typical type I binding spectra when added to placental microsomes. Scatched plots also indicated binding of each steroid to two sites--a high-affinity, low-capacity binding site and a low-affinity, high-capacity binding site. Correlations between affinity for either site and capacity to facilitate binding of CO to the cytochrome were not observed nor were there good correlations between maximal absorbance differences (approximately390-420 nm) producible and facilitation capacity. It was therefore concluded that no definitive relationships existed between facilitation capacity and qualitative or quantitative aspects of the steroid-binding spectra. The capacity to facilitate CO binding appeared to reside in the absence of a chemical group substituted at the 10 position on molecules of androgenic steroids since all investigated steroids possessing 10-methyl or other 10-substituted groups either had no effect on the CO-binding spectrum or caused a displacement of CO from ferrous heme. In contrast, all steroids studied that lacked a substitution at C-10 (19-nor steroids) produced a facilitating effect on heme-ligand binding.