Bibliothek

Notizen: InSb films have been deposited directly by rf sputtering on sapphire substrates. X-ray diffraction and scanning electron microscopy data are presented to show that the InSb layer on sapphire (0001) is epitaxial and grows with (111) parallel to the substrate surface. Optical absorption studies of the epitaxial film also reveal distinct spectral features which resemble these from bulk, single-crystal InSb.

Notizen: We observed a 61-year-old woman, presenting with deeply infiltrating, erythemato-cyanotic, sometimes ulcerated or crusted plaques and nodules, mainly located on the lower limbs. Similar lesions had been present for more than 4 years, with a typical evolution: fast growth, followed by ulceration and necrosis, resulting in hyperpigmented, atrophic patches. The patient had had Rx-confirmed, symptomatic lung sarcoidosis for 5 years. Histological examination of skin lesions showed diffuse dermal and hypodermal lympho-histiocytic infiltrate, mainly composed of pleomorphic cells. On immunohistochemistry, the infiltrate was mainly composed of CD2 ±, CD3 ±, CD45RO ±, CD4 ±, CD30 ±, CD25 - T-cells, with sparse CDla ± dendritic cells. The typical clinical evolution (relapsing, self-regressing plaques and nodules), morpho-immuno-logical features of skin lesions, and strong expression of CD30 antigen by neoplastic T-cells suggest the possible classification of this case as CD30 ± (Ki-1 ±) cutaneous T-cell lymphoma. The association with systemic sarcoidosis, together with a down-regulated cell-mediated immune response, suggests the possibility that this latter may be a common denominator in the development of the two diseases.

Notizen: AlGaAs graded-index separate-confinement heterostructure lasers with lateral mode confinement are realized by one time metalorganic chemical vapor deposition with silicon dioxide stripes as selective masks and current blocking layers. The effect of the active region width on lasing characteristics is investigated. The threshold current and external quantum efficiency are around 12 mA and 70%, respectively, for narrow lasers. Elevated waveguide structure formed by the growth-rate difference between (100) and sidewall planes was effective for stable lateral mode characteristics.

Notizen: Parameter dependence of the radial structure of edge poloidal rotation is studied with spectroscopic measurements for L- and H-mode plasmas in the JFT-2M tokamak [Y. Miura et al., in Plasma Physics and Controlled Nuclear Fusion Research, Proceedings of the 13th International Conference, Washington 1990 (IAEA, Vienna, 1991), Vol. 1, p. 325]. The poloidal flow is in the electron diamagnetic direction and appears suddenly near the plasma edge at the H-mode transition. The poloidal rotation velocity profile in the H mode has a peak at the separatrix. No critical normalized ion collisionality, ν*i, for the transition of the L to the H mode is observed. The size of the poloidal flow in the H mode has no dependence on the poloidal gyroradius.

Notizen: Immunohistochemical distribution of carbonic anhydrase II (CA) in mixed tumours and adenomas of sweat gland origin and in sebaceous adenomas was demonstrated by the PAP method. Normal sweat glands, both eccrine and apocrine, clear cells of the secretory coils, and ductal epithelial cells all showed conspicuous staining for CA, and sebaceous glands were also positive. Mixed tumours of the skin indicated strongly positive staining for CA in the luminal cells of tubular and duct-like or cystic structures, while most of the other tumour cells were negative. In solid or massive foci, CA positive cells were found scattered among the cellular mass. Sebaceous adenomas were usually moderately positive for CA throughout the tumour.

Notizen: In view of the critical role of dendritic cells in immune mediated skin diseases, we have investigated the membrane antigen patterns and ultrastructure of cutaneous dendritic cells in eight patients with chronic discoid lupus erythematosus and five with subacute cutaneous lupus erythematosus. In the lesional epidermis, the expression of HLA-DR antigens by epidermal dendritic cells was reduced, as compared with perilesional, clinically normal skin. In addition, only few CD1a+ dendritic cells (Langerhans' cells), along with some CD11c+ and CD14+ cells (presumable precursors of Langerhans' cells), were found in atrophic areas of lesional epidermis. In contrast, the number of Langerhans' cells in non-atrophic areas of lesional epidermis was similar to that in perilesional skin. On electronmicroscopy, epidermal Langerhans' cells appeared depleted of organelles and dendrites and contained tubuloreticular inclusions. In the lesional dermis, both CD1a+ and CD36+ dendritic cells were found, associated with CD4+ and CD8+ T-cells, respectively. Moreover, CD11c+ and CD14+ cells were found around capillaries in the papillary dermis on electronmicroscopy. Indeterminate cells (dendritic cells with features of Langerhans' cell lineage, but apparently without Birbeck granules) and dendritic macrophages were found, associated with lymphocytes and mast cells. No cells with intermediate/transitional features between these two dendritic cell types were found. Conversely, peculiar dendritic cells—with short and blunt dendrites and cytoplasm containing many flat, rough cisternae, moderately well developed Golgi apparatus and no lysosomes—were found in the same location as the CD11c+ and CD14+ cells identified by light microscopy. These findings might be interpreted as follows: 1 the alterations in cytological differentiation and expression of functionally meaningful molecules by epidermal Langerhans' cells in cutaneous lupus erythematosus lesions suggest an impairment of their immunological efficiency; 2 in the lesional dermis of cutaneous lupus erythematosus, a CD4+ T-cell/CD1a+ dendritic cell-based, delayed-type immune response is possibly modulated by a suppressor T-cell circuit in which CD36+ dendritic cells may act as accessory cells; 3 CD11c+ and CD14+ cells with peculiar ultrastructure are possible precursors of both CD1a+ indeterminate cells and CD36+ dermal dendrocytes in the dermis.

Notizen: Immunohistochemical distribution of human epidermal growth factor (hEGF) was described in 17 cases of mixed tumour of the skin with monoclonal antibody. In normal sweat glands, epithelial cells in the secretory portion and in the transitional area between secretory portion and duct showed prominent staining for hEGF. In the salivary pleomorphic adenoma type of mixed tumour of the skin, luminal tumour cells of tubular and duct-like structures gave a very characteristic hEGF staining reaction. The tumour cells showing strong staining for hEGF were scattered throughout the solid foci in this type of mixed tumour. Tubular epithelial cells in the clear cell adenoma type also displayed a positive hEGF reaction. And apocrine mixed tumours strong staining for hEGF occurred on the apical side of tubular and ductal tumour cells. In view of the immunohistochemical staining patterns for hEGF, the histologic origin of mixed tumours of the skin is suggested to be cells in the secretory portion and (hose in the transitional portion between secretory portion and duct of the sweat gland.

Notizen: Lectin binding sites and immunohistochemically detectable fibronectin and carbonic anhydrase II (CA II) were examined in induced bone structure of calcifying epithelioma of Malherbe. Pathological features of ossification were particularly evident in the border zone between tumor epithelium and stroma, and epithelial foci adjacent to sites of bone formation were conspicuously basophilic. The use of lectin binding in these foci coincided with the basophilic epithelial zones: Con A, RCA-1, PNA, SBA, and WGA bound strongly, indicating thepresence of glucose (Glu), mannose (Man), galactose (Gal), N-acetyl-D-galactosamine (GalNAC), and N-acetyl-D-glucosamine (GlcNAC). Fibronectin was also detected in the same epithclial-mesenchymal interacting layers as the positive lectin-binding sites. Staining for CA II was strongly positive in giant cells and in epithelial zones in the bone-inducting areas. The bond induction mechanism in the stromal tissue of calicifying epithelioma of Malherbe may initially involve the action CA II in the epithelial-mesenchymal interacting zone, which then brings about ossification of the matrix which is fibronectin-positive and rich in lectin-binding sites.

Notizen: Obstructive sialoadenitis was examined by immunohistochemical techniques for keratin (MoAb K.LI, PKK.I and K.8.12) and actin. Electronmicroscopy (EMS) was used to identify ultrastructural changes in myoepithelial cells and ductal basal cells. With immunohistochemistry, actin staining was used as a marker of myoepithelium. MoAbs KL1 and PKK1 for ductal luminal cells, and MoAb K8.12 for ductal basal cells. Histologic features of the lesion usually showed degenerative changes of acinar and duct cells with cell infiltration and fibrous replacement. Immunohistochemical findings indicated that actin staining in the changed myoepithelial cells was irregularly positive or negative, and also keratin staining in luminal and ductal basal cells was reduced or disappeared. Ultra-structural features of the changed myoepithelial cells indicated that these cells appeared less altered than adjacent acinar and ductal cells and showed increased amounts of lipid droplets and lipofuscin granules, and also wrinkled processes filled the prominent myofilamenl material.