Sadao Sugiyama

Distribution of apoptosis-mediating Fas antigen in human skin and effects of anti-Fas monoclonal antibody on human epidermal keratinocyte and squamous cell carcinoma cell lines

Fast antigen is a cell surface protein that mediates apoptosis. Using immunohistological, flow cytometry and electron microscopic analyses, we investigated the expression of Fas antigen on various skin tissues, and on cultured SV40-transformed human epidermal keratinocyte cell line KJD and human skin squamous cell carcinoma cell line HSC. The Fas antigen was widely distributed in skin components such as the keratinocytes in the lower portion of the epidermis, epidermal dendritic cells, endothelial cells, fibroblasts, apocrine glands, eccrine sweat glands, sebaceous glands, some normal melanocytes and infiltrating lymphoid cells. It was also strongly expressed on the keratinocytes of lichenoid eruptions seen in lupus erythematosus and lichen planus, and on the spongiotic or acanthotic epidermis seen in chronic eczema, adult T-cell leukaemia/lymphoma (ATLL) and atopic dermatitis. Its expression was closely correlated with lymphoid infiltrating cells and it was strongly expressed in lymphoid neoplastic cells, particularly ATLL cells, and fibroblasts seen in dermatofibroma. However, the antigen was not detected on basal cell epithelioma cells, some malignant melanomas or any junctional naevi. The cell lines KJD and HSC strongly expressed the Fas antigen, and crosslinking of the Fas antigen by an anti-Fas monoclonal antibody induced apoptosis of these cell lines. These results indicate that the apoptosis-mediating Fas antigen may play an important role in normal skin turnover and cell differentiation, in immune regulation of skin tumours, and in the pathogenesis of various skin diseases.

Mode of redifferentiation and melanogenesis of melanocytes in mouse hair follicles. An ultrastructural and cytochemical study.

The mode of redifferentiation and melanogenesis in melanocytes was studied by ultrastructural cytochemistry in C57/6J mouse hair follicles. Melanocytes in telogen revealed a few DOPA reaction-positive cisternae of poorly developed Golgi complexes, with a few small unmelanized melanosomes. During anagen I–III, melanocytes were redifferentiated. DOPA reaction-positive cisternae of Golgi complexes were well developed, forming an anastomosing structure. Thiamine pyrophosphatase-positive or osmium-reducing Golgi elements were not developed. DOPA reaction-positive small vesicles (700 A in diameter) increased along with the increase in melanized melanosomes. These vesicles appeared to be budding off from the DOPA reaction-positive cisternae. Fusion of the vesicles to melanosomes was frequently found. Rough endoplasmic reticulum (RER) was well developed. Direct continuity of the limiting membrane of melanosomes to the short distal agranular portion of the RER was found. This portion of the RER was DOPA reaction negative. A decrease in heterochromatin of nuclei occurred. These findings suggest that the internal structural units and limiting membrane of melanosomes may be formed from dilatation of the agranular portion of the RER, and that tyrosinase may be transferred to the melanosomes by the DOPA reaction-positive small vesicles.

Comparison of macromelanosomes and autophagic giant melanosome complexes in nevocellular nevi, lentigo simplex and malignant melanoma

This study compared the fine structure of macromelanosomes with that of giant melanosome complexes formed through melanosomal autophagocytosis in nevocytes and melanocytes of nevocellular nevi, lentigo simplex and malignant melanoma. While macromelanosomes were found only on rare occasions in these pigmentary disorders [2 of 79 nevocellular nevi (2 junctional nevi), 3 of 12 lentigo simplex and 2 of 93 malignant melanoma], the giant autophagic melanosome complexes were always present, indicating that macromelanosomes are not synthesized simply through melanosomal autophagocytosis. Although both macromelanosomes and giant melanosome complexes exhibited acid phosphatase activity similar to melanosomes, they showed many different ultrastructural features. Characteristically, macromelanosomes contained numerous vesiculoglobular bodies, whereas these bodies were absent in giant melanosome complexes. In those tissues where the presence of macromelanosomes had been ruled out by light microscopy, none of the giant melanosome complexes revealed ultrastructural features indicative of macromelanosomes. Various phases of melanosomal degradation were seen, indicating that they were not simply end‐products of lysosomal degradation of melanosomes. It was thought that the key process in the development of macromelanosomes was the accumulation of vesiculoglobular bodies.

The ultrastructure of the hair follicles in early and late catagen, with special reference to the alteration of the junctional structure between the dermal papilla and epithelial component

The morphology of mouse hair follicles in the catagen stage was examined under an electron microscope. In the early and late catagen stage, compact fine fibrils (120–130 A in diameter) with a hollow profile and a beaded pattern along their long axis were found throughout the dilated intercellular spaces in dermal papilla. These fibrils were not only contiguous to papilla cell membranes but were also attached, and prepared to be inserted into the basal lamina-like structure that protruded from the basal lamina into the dilated intercellular spaces at the upper portion of the papilla. In the late catagen stage, hemi-desmosomes were found along the keratinocyte membranes adjacent to the basal lamina at the papilla—epithelial junction. Both the fine fibrils and hemidesmosomes, which were characteristic structures in hair follicles in the catagen stage, seem to act mechanically, in cooperation with the basal lamina, to form a firm adhesion structure between the papilla and the epithelial column during this stage.

Immunohistochemical and electron microscopic characterization of lymphomatoid papulosis. Review of Japanese literature, histopathological distinction from PLEVA and nature of infiltrating cells.

A case of a seven year old boy with lymphomatoid papulosis is presented in terms of (a) clinical and histopathological distinction from pityriasis lichenoides et varioliformis acuta (PLEVA), and (b) immunohistochemical and electron microscopic characterization of infiltrating cells in skin lesions. Our case showed recurrent episodes of high fever and skin eruptions similar to those seen in the ulceronecrotic form of PLEVA for three years. However, the case has been differentiated from PLEVA by showing (a) recurrent episodes of skin eruptions, (b) spontaneous remission of these eruptions, (c) presence of numerous eosinophils in the infiltrates, (d) dense aggregation of atypical lymphohistiocytic cells with the membrane marker of T‐lymphocytes, and (e) various, ultrastructural features similar to those seen in lymphoblastogenesis. Our immunohistochemical and electron microscopic studies suggest that the infiltrating cells in lymphomatoid papulosis are primarily derived from variants of T‐lymphocytes which are in the process of reactive lymphocytic hyperplasia.

Proliferating Activity of the Hair Follicular Melanocytes at the Early and Anagen III Stages in the Hair Growth Cycle: Detection by Immunocytochemistry for Bromodeoxyuridine Combined with DOPA Reaction Cytochemistry

In order to demonstrate the existence of proliferating activity in hair follicular melanocytes during the early and anagen III stages, immunocytochemistry for bromodeoxyuridine (BrdU) incorporated in the nuclei of the melanocytes for 1 hr was undertaken at the light and electron microscopic levels in combination with DOPA reaction cytochemistry.

Occurrence of actinlike microfilaments in the outer root sheath cells of the hair follicle: a possible role of a cytoskeleton.

Broad bundles of actinlike microfilaments are found in the basal cells of the outer root sheath of the hair follicle. The filaments react specifically with heavy meromyosin to form a fuzzy structure, and disappear from the cells after the actin depolymerization treatment. An array of the filament bundles alters along with the cell shape changes of the basal cells. In the flattened cells of the hair follicle bulb, the bundles appear to run parallel to the long axis of the cells, and are present in the basal cytoplasm. In the cuboidal cells of the suprabulbar and the more superficial portion of the follicle, the bundles are perpendicular to the basal plasma membrane, and are disposed mainly in the basal cytoplasm. The microfilaments are associated with the basal plasma membrane directly or via insertion into the plaque of the membrane, where filamentous or amorphous materials link the membrane and the basal lamina. In vitro treatment of cytochalasin B for up to 8 hr causes no visible change in the distribution pattern of the bundles nor abnormal changes in the cell shape. Thus, the actinlike microfilament bundles appear to provide a cytoskeletal system responsible for the maintenance of the cell shape change, since they are disposed in the direction and area in which a maintenance force for the cell shape change may be required, and other cytoskeletal systems of the cells such as microtubules and tonofilament-desmosome complexes are poorly developed, and no hemidesmosomes are present in the cells.

Cytochemistry of Trichohyalin Granules: A Possible Role for Cornification of Inner Root Sheath Cell in the Hair Follicle

We studied ultracytochemically how trichohyalin granules (TGs) were involved in the cornification of the inner root sheath (IRS) cells in the hair follicle. After storing unfixed mouse skin samples in glycerol and then low ionic strength salt solution (G‐LISS), the TGs reduced electron‐dense amorphous material (EDM) to various degrees, with the appearance of filamentous material in routine staining. As the IRS cells were differentiating, these changes in the TGs became successively prominent; Some TGs consisted of the filamentous material and residual granular EDM, showing a “filamentogranular structure”. In the cells in transition to cornified cells, or transitional cells, the EDM of the TGs disappeared and consisted of only filamentous material which was intertwined with keratin filaments (KFs). The internal substructure of the TGs induced by the G‐LISS treatment stained well with ethanolic phosphotungstic acid, which reacts with basic proteins, and the KFs associated with the TGs also stained well. In skin samples not treated with G‐LISS, the TGs of the transitional cells often exhibited fibrogranular structure after PTA staining to detect tissue basic proteins, suggesting a release of PTA stainable proteins(s) by the TGs in living transitional cells. The KFs of the cornified cells were more intensively stained and thicker (about 20 nm wide) than those of the differentiating IRS cells. These findings suggest that the TGs may contain at least two kinds of basic proteins; One is G‐LISS‐soluble, and the other is a very insoluble filamentous protein. These protein materials may be added to or incorporated into the KFs in the cornified cells with the disappearance of the TGs, since the KFs are markedly thick with PTA staining.

A case of trichilemmal carcinoma.

91歳女子の左足背に生じたtrichilemmal carcinomaについて報告した。病理組織学的に狭義のclear cell, すりガラス様細胞, trichilemmal keratinizationおよびsquamous eddiesが認められ, 多彩な組識像を呈した。いわゆる明調な細胞のうち, すりガラス様細胞が主体を占めたので, 主に毛包峡部, 一部毛包下部への分化を示し, 真皮内浸潤を認めたtrichilemmal carcinomaであった。

A case of malignant trichilemmoma accompanied by lymph node metastasis.

84歳男性の左大腿外側に発生し, 左鼠径リンパ節に転移を生じたmalignant trichilemmomaの1例を報告した。組織学上, 腫瘤辺縁の局面部ではtrichilemmoma様の構築を示していたが, 原発巣腫瘤部や転移巣では大小の分葉状構造や嚢腫形成傾向を示し, malignant proliferating trichilemmal cystの構築に類似していた。光顕的に, 中心部の角化様構造を思わせた好酸性物質は, 電顕的にtrichilemmal keratinizationによるものではなく,壊死の所見であった。