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T Stange
Publications and source records attributed to T Stange.
[Hyperacusis after tympanoplasty].
A case of hyperacusis after tympanoplasty is presented. A 62-year-old woman experienced unilateral conductive hearing loss for about 60 years after antrotomy in infancy. Neurological or otoneurological symptoms were not evident. Tympanotomy showed a missing incus with discontinuity of the chain. Reconstruction was performed by interposition of a partial ossicular replacement prosthesis (PORP). The postoperative audiogram revealed minimal perceptive hearing loss in the high-frequency field in the operated ear. Several weeks after middle ear surgery, the patient complained of hyperacusis on the operated side, which persisted for more than 2 years. To alleviate the unpleasant sensations, an ear plug was used by the patient. In spite of the asymmetric hearing loss, no late onset auditory deprivation could be diagnosed. The pathophysiological causes of the hyperacusis have not yet been clarified. Possible reasons are discussed.
Audiometry, Pure-Tone↗
[Electron microscopic studies of the rabbit nasal mucosa after short-term application of naphzoline nitrate].
BACKGROUND: Vasoconstricting nasal drops are applied frequently. Especially early ultrastructural alterations of the vessels were not examined up to now in animal models. Our goal was the systematic investigation of the submucosal vessels and the epithelium after topic application of naphazoline nitrate (Privin) in an animal model. METHODS: Three times daily over 6 days 3 ml of 0.1% naphazoline nitrate solution (Privin) were instilled into the right nasal cavity of 5 rabbits. At the 7th and 14th day an incisional biopsy of the lower nasal turbinate was carried out in ketamine/rompun anesthesia. RESULTS: In the naphazoline group the capillaries showed an edematous endothelium with narrowed lumina. Thrombosis of the arterioles were frequently observed. The more cubic epithelial cells had deciliated areas with microvilli. Venules, submucosal glands and the surrounding connective tissue was normally configurated. Analogous findings were also observed after 2 weeks. CONCLUSIONS: The disturbance of the microcirculation shows impressive endothelial alterations. These structural changes can result in nonreversible mucosal damages. A regeneration time of more than 1 week is assumable. Our results should be considered critically in order to prevent damages of the nasal mucosa.
Administration, Topical↗
Immunoelectron microscopic demonstration of the membrane proteases aminopeptidase N/CD13 and dipeptidyl peptidase IV/CD26 in normal and neoplastic renal parenchymal tissues and cells.
Aminopeptidase N (APN, CD13) and dipeptidyl peptidase IV (DPP IV, CD26) are transmembrane ectoenzymes occurring in a wide variety of cells. They are involved in tumour cell invasion and the formation of metastases. A basis for further information about these enzymes is the exact ultrastructural localization in normal and malignant cells. In this paper, we demonstrate the precise subcellular localization of the membrane peptidases APN and DPP IV on the cell surfaces in renal tissues, renal cell carcinoma, cultured renal parenchymal cells and cultured renal carcinoma cells. Using cryo-ultramicrotomy of weakly fixed tissues and cells in combination with indirect immunogold labelling, both membrane peptidases were detectable on the external cell surfaces. They showed different ultrastructural expression patterns. Both membrane peptidases were abundantly labelled on the external cell surfaces of human kidney proximal tubular cells. The expression pattern of APN/CD13 and DPP IV/CD26 in single labelling was confirmed by a successive double labelling technique. The immunolabelling of CD13 on cultured renal parenchymal cells showed a stronger expression then in cells in vivo, but CD26 could not be found. In renal cell cancer (mixed clear cell/chromophilic, poorly differentiated and clear cell type, moderately differentiated) CD13 and CD26 were labelled as in benign renal tissue, but CD26 appeared overexpressed. On the renal carcinoma cells Caki-1 and Caki-2, only one of the two peptidases could be found. CD13 was present non-homogeneously in Caki-1, where the enzyme appeared to form clusters. When CD26 on the cultured renal carcinoma cells Caki-2, is compared with renal proximal tubular cells and renal carcinoma cells in tissue sections, a reduced expression is observed. CD13 was not detected in Caki-2, and CD26 was not found in Caki-1. These small changes on the cell surfaces can only be detected by electronmicroscopic methods. The differences in the distribution of APN/CD13 and DPP IV/CD26 in normal and malignant cells are discussed in connection with literature. Further investigations, especially labelling studies on other neoplastic tissues and cells, will be necessary in order to explain the precise role these membrane peptidases in malignancies.
CD13 Antigens↗
Expression patterns of the ectopeptidases aminopeptidase N/CD13 and dipeptidyl peptidase IV/CD26: immunoultrastructural topographic localization on different types of cultured cells.
Aminopeptidase N/CD13 and dipeptidyl peptidase IV/CD26 are widespread membrane-bound peptidases involved in fundamental biological processes. Using cryo-ultramicrotomy of cultured cells followed by indirect immunogold labelling, both enzymes appeared to be strongly and regularly labelled on the cell surfaces of human synovial fibroblasts, T-lymphocytes and colon carcinoma cells Caco-2. In the cytoplasm of the synovial fibroblasts gold-labelled vesicle-like structures were found, which we consider to be potential transport vesicles. An abundant and regular expression of CD13 was detected on cultured renal parenchymal cells. On the renal carcinoma cell line Caki-1 cells we found a low, non-homogeneous and clustered CD13-labelling. On cultured renal parenchymal cells and the Caki-1 cells CD26 could not be observed. The expression pattern of CD26 on renal carcinoma cell line Caki-2 cells showed also a slightly clustered distribution. A low density CD26-labelling was present on the squamous cell carcinoma cell line UM-SCC-22B. CD13 was absent in Caki-2 and UM-SCC-22B cells. The presence of both enzymes on the cultured cells enables their ultrastructural investigation under different growth conditions and their involvement in cell-cell interactions. For this purpose, however, further investigations are necessary.
CD13 Antigens↗
Immunoelectron microscopic single and double labelling of aminopeptidase N (CD 13) and dipeptidyl peptidase IV (CD 26).
Using ultrathin cryosections and immunogold labelling, aminopeptidase N (CD 13) and dipeptidyl peptidase IV (CD 26) were localized on the luminal side of the brush border membrane of proximal tubular cells in human kidney as well as of enterocytes from rat small intestine. Furthermore, both enzymes could be detected on the cell surface of human T lymphocytes and especially aminopeptidase N on human synovial fibroblasts. Gold labelled vesicular structures were also found in the cytoplasm in the apical part of renal proximal tubular cells and synovial fibroblasts. In human kidney the colocalization of the two membrane antigens was possible by using several double labelling methods.
Animals↗