Biomedical subjects
Publications and source records attributed to S Kay.
Effective reconstructive techniques are available for immediate, primary repair of surgical defects caused by extensive ablation for malignant conditions of the head and neck. Primary repairs rely heavily on the principle of 'axial-based' skin flaps which can be transposed into the defects without delay. Three cases are presented to illustrate the method.
A case of a paraganglioma located over the thyroid cartilage in the midline is reported. The tumor had all the appearances of a carotid body tumor, but its odd location could not be explained on the basis of previously known areas where paraganglionic tissues have been found. Since a paraganglioma has also hitherto been described within the thyroid gland, clinicians and pathologists alike are cautioned that unusually located paragangliomas may be expected in the future.
A case of mixed hepatoblastoma with osteoid elements was studied by light and electron microscopy. The ultrastructure of the epithelial elements showed a lack of differentiation and simple cytoplasmic organelles. However, an occasional cytoplasmic crystalloid structure were seen. The ultrastructure of the osteoid foci showed fibroblast-like cells capable of collagen formation, clearly distinguishable from the epithelial elements. These cells had neoplastic characteristics of nuclear pleomorphism and high nucleo-cytoplasmic ratio. These findings support the belief that hepatoblastoma arises from a multipotential blastema capable of both epithelial and mesenchymal differentiation, with the osteoid elements being an intrinsic neoplastic component of the tumor.
A case of a functioning interstitial-cell tumor in a 12-year-old Negro boy is reported. The patient manifested precocious puberty, with signs of sexually aggressive behavior. The ultra-structural studies of the tumor showed features similar to those of the few cases previously reported in the literature. One characteristic finding was the presence of numerous membranous whorls within the cytoplasm. The cells grown in tissue culture were maintained for at least 9 weeks and were confirmed as testicular interstitial cells. Ultrastructurally they were similar to the cells in vivo, as evidenced by the finding of cytoplasmic organelles related to steroid synthesis.
Although many investigators have felt that humoral antibody was responsible for chronic rejection, attempts to detect it in the sera of recipients in the presence of functioning renal allografts have been largely unsuccessful. A modification of the mixed antiglobulin reaction has increased its sensitivity so that the development of low titers of immunoglobulin (IgG) antibody antibody specific for donor kidney cells can be detected in renal allograft recipients while renal function is still good. Donor-specific antibody was detected in the sera of 11 of 13 patients whose transplants had ceased to function from 5 to 43 months after transplantation. In five recipients the antibody was present prior to as well as after transplantation and in six recipients antibody developed after transplantation from 3 to 25 months prior to the cessation of function. In the patients with antibody, chronic rejection was characterized by hypertension which required treatment with multiple drugs, by proteinuria of greater than one gram per day, by a gradual, progressively rising serum creatinine, and by an absence of acute ologuric rejection episodes. Pathologically there was extensive intimal proliferation and occlusion of the intrarenal arteris. There also was significant glomerulonephritis which consisted of thickening of the basement membranes, mesangial cell proliferation, simplification of the capillary loops, and in some patients fibroepithelial crescent formation. These findings suggest that IgG antibodies directed against cell-surface antigens of the donor are the chief cause of chronic renal allograft rejection.
Lymphomatoid granulomatosis is a necrotizing arteritis primarily affecting the lungs but also found in the skin, kidneys, central nervous system, and other extra-pulmonary sites. Cutaneous involvement occurred in 45% of the cases described by Liebow in his original series. Light microscopy studies were performed. The IgA and IgG levels were slightly decreased and the IgE level was elevated. Cell-mediated immunity was impaired. No viruses were isolated or identified by immunofluorescence. A man had cutaneous lesions as the first sign of lymphomatoid granulomatosis.
The electron microscopic features of a leiomyosarcoma occurring in the lung, a rare site, were studied; Unusual was the fwnding of extremely electron-dense bands that interrupted the longitudinally-arranged microfilaments and dense bodies of many of the tumor cells. These bands superficially resembled anomalous Z-bands seen in nemalin myopathy and aging rat cardiac muscle, but have not been described to occur in smooth muscle tumors. They are thought to represent condensations of dense bodies in degenerating tumor cells.
The electron microscopic features of a leiomyosarcoma occurring in the lung, a rare site, were studied. Unusual was the finding of extremely electron-dense bands that interrupted the longitudinally-arranged microfilaments and dense bodies of many of the tumor cells. The bands superficially resembled anomalous Z-bands seen in nemalin myopathy and aging rat cardiac muscle, but have not been described to occur in smooth muscle tumors. They are thought to represent condensations of dense bodies in degenerating tumor cells.
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