Takuo Tsuji

Light and scanning electron microscopic studies on wrinkles in aged persons' skin

Wrinkles in six aged persons (67–82 years of age) have been investigated by light microscopy (LM) and scanning electron microscopy (SEM). There are two types of wrinkles. One is a deep wrinkle which develops on the sun‐exposed skin and does not disappear on stretching (permanent wrinkle). The LM and SEM showed less elastotic change in the upper dermis in the area of wrinkle than in that of the surroundings. The other type is a shallow wrinkle which develops on sun‐protected skin and disappears on stretching (temporary wrinkle). The LM and SEM showed the decrease or loss of the elastic fibres in the papillary dermis as seen in ageing skin.

Age‐related changes in human dermal elastic fibres

Age‐related changes in the human dermal elastic fibres were studied by scanning (SEM) and transmission (TEM) electron microscopy. The SEM findings showed an increase in the complexity of shape and arrangement of the fibres including flattening and branching, an increase in the roughness of the surface, and a decrease in interfibrillar areas. The TEM findings showed a decrease in microfibrils and amorphous material, and an increase in electron dense inclusions followed by the appearance of vesicular structure.

Elastic fibers in striae distensae.

Eight cases with striae distensae associated with obesity or prolonged corticosteroid intake were examined by light and scanning electro microscopy. Fine elastic fibers predominated in early lesions, while thick elastic fibers predominated in older lesions. In early lesions the periphery showed thick and tortuous elastic fibers, but in older lesions it was of normal appearance. It is suggested the elastic fibers in striae were newly synthesized and gradually increased and thickened with age.

Elastic fibers in scar tissue: scanning and transmission electron microscopic studies

Cutaneous scar tissue (atrophic and hypertrophic) and normal dermis were examined using scanning (SEM) and transmission electron microscopy (TEM) as well as light microscopy (LM). Although LM revealed only a few Weigert stain‐positive elastic fibers in scar tissue, SEM and TEM disclosed the presence of a large number of fine elastic fibers which was not present in normal dermis. Atrophic scar tissue contained more Weigert stain‐positive fibers and fewer fine elastic fibers than hypertrophic scar tissue. In addition, findings suggestive of newly synthesized elastic fibers were seen in some hypertrophic scar tissue. These results indicate that there is elastogenesis in scar tissue.

Subcutaneous fat necrosis of the newborn: Light and electron microscopic studies.

Specimens from two cases of subcutaneous fat necrosis of the newborn were studied by light and electron microscopy. Crystallization of the fat cell started with clearing of the central fat droplet, followed by the appearance of cylindrical crystals. The fat crystals were phagocytoscd by cytoplasmic projections of macrophages as well as by foreign body giant cells. Calcium deposits were demonstrated within the central fat droplet of the degenerated fat cell of Case 2.

Secondary localized cutaneous amyloidosis in solar elastosis

A case of secondary localized cutaneous amyloidosis in solar elastosis was studied by light and electron microscopy. Amyloid deposition was restricted to areas with elastotic changes, and in some areas both changes were intermingled with each other. The amyloid was permanganate‐sensitive, and proved to be protein AA. Ultrastructurally it was composed of fine tubular filaments. It is suggested that the amyloid deposition in this case was related to sunlight damage of the skin.

Marfan syndrome: demonstration of abnormal elastic fibers in skin

The back skin of a 15‐year‐old girl with Marfan syndrome has been investigated using scanning (SKM) and transmission (TEM) electron microscopy. The SEM showed that admixed with normal‐looking portions, there were abnormal portions of the elastic fibers which were composed of many unusual fine fibers (5‐22 nm in diameter), and had a cobweb‐like appearance. The TEM showed that these fine fibers were substructures of the amorphous material and were surrounded by micro‐fibrils. It is suggested that the fine fibers could be abnormal elastic fibers resulting from the incomplete fusion of the elastic units.

Ultrastructure of deep wrinkles in the elderly

Deep wrinkles of 6 elderly people were investigated using electron microscopy. There were ultrastructural differences in the elastotic changes between the area of the wrinkle and the surrounding areas. Elastic fibers containing electron‐dense inclusions were mostly seen in the upper dermis of the wrinkled area and were considered to be an early event of the elastotic changes. The elastotic changes showing net‐like structures were seen in the areas surrounding the wrinkle and were considered to be a more advanced event. Another form of elastotic change was the presence of thickened elastic fibers with many holes containing round bodies, which were scattered in the deep dermis of the wrinkled area, and increased and packed in the middle and deep dermis of the surrounding areas. In one case subepidermal amyloid deposits were seen in the areas surrounding the wrinkle, suggesting a close relationship between amyloid and sun‐light exposure.

Elastic fibres in the dermal papilla. Scanning and transmission electron microscopic studies.

The straight elastic fibres aligned perpendicularly to the dermo‐epidermal junction have been examined by transmission and scanning electron microscopy. We found that these fibres connect the basal lamina to the underlying dermal elastic tissue, and it seems likely that they are involved in dermoepidermal adhesion.

Focal dermal hypoplasia syndrome

An 11‐month‐old female with focal dermal hypoplasia syndrome is described. Historically, the skin lesions were characterized by a marked decrease in dermal connective tissue. Ultrastructurally, there were a number of fine filamentous structures measuring 5 to 70 mn within and between the bundles of collagen; most of the dermal fibroblasts of the lesions possessed no remarkably developed rough endoplasmic reticulum and Golgi complex. Multilocular fat cells which are regarded as young fat cells were often seen. It is suggested that this disease may be characterized by a decreased rate of collagen synthesis by fibroblasts and an overgrowth of adipose tissue.