• Applied Microscopy
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• v.27 no.3
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• pp.321-332
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• 1997

The dermal papilla is known to playa major role in influencing the form and dynamics of the hair follicle, which probably involves regulatory substances crossing the basal lamina. But little is known about the junctions between the dermal papilla and the surrounding epithelial cells of the hair bulb, or between the connective tissue and the epithelial cells on the outside of the hair follicle. This study was performed to identify the ultrastructural differences between dermoepidermal junction of the skin and connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla of normal anagen hair follicles in the human fetal scalp skin. Electron microscopic findings of dermoepidermal junction in scalp skin showed that basal lamina was very irregular and undulated, and it contained many attachment plaques of hemidesmosomes with sub-basal dense plates, tonofilaments, and anchoring filaments. Also invaginations of plasma membrane of basal keratinocytes were seen. There were clear differences both on the outside of the follicle and around the dermal papilla as compared with similar junction in the skin. In particular, neither hemidesmosomes nor tonofilaments, as seen in dermoepidermal junction, were observed in the dermal papilla. Also attachment plaque, sub-basal dense plate and anchoring filaments were not observed at the junction on the outside of the follicle and the dermal papilla. There were some differences between connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla, ie, smoothness of basal lamina and orthogonal arrangement of collagen fibers were seen in the outside of hair follicle, but not in the dermal papilla. These results indicate that the mechanical connection between the hair follicle and the connective tissue component is much weaker than that between the corresponding components in skin, and it reflects the dynamic processes during the anagen phase of the hair follicle compared to the relatively permanent state of the epidermis.

• Applied Microscopy
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• v.29 no.2
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• pp.223-230
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• 1999

The epithelium of the rectum in the mosquito larvae, Culex pipiens pallens: Culicidae, was observed with electron microscope. The rectum of posterior hindgut was composed of epithelial tissue which were covered with cuticular intima on the luminal side, connective tissue and muscular tissue. The rectal epithelial cells were squamous absorptive cells, and apical plasma membranes were highly folded to form apical infoldings with mitochondria inserted them. The lateral plasma membranes were irregularly infolded and well developed mitochondria were found closely associated with infoldings . And intercellular spaces (or channels) were formed between the epithelial cells, whereas speptate junction was found near the apical zone between them. Also basal plasma membrane were infolded which made basal infoldings ('basal labyrinth'), and were covered with thin basal lamina. Rcetal epithelium was surrounded by the connective tissue which was contained axon and tracheole cells. Connective tissue was covered with the bundles of circular and longitudinal muscles.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.8 no.1
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• pp.28-35
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• 1999

The preservation of a healthy periodontal attachment is the most significant factor in the long-term prognosis of a restored tooth. The 'Biologic Width' is composed of the connective tissue attachment and the epithelial attachment in the dentogingival junction. The violation of the biologic width may result in a progressive inflammatory process and crestal bone loss. So a careful soft tissue management is needed to preserve it for the gingival health and an esthetic restoration. The following clinical cases show the five different situations of the violation of the biologic width and their management.

• The Korean Journal of Zoology
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• v.28 no.1
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• pp.44-59
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• 1985

The epithelium of the hindgut in the german cockroach, Blattella germanica Linne, was observed with electron microscope. The epithelium of the ileum, which is located at the anterior hindgut, is composed of a single layer of squamous and cuboidal cells. The liminal surface of the epithelium is lined with the cuticular intima. The epithelial cells contain cell organelles expected to be found in absorptive cells, and some epithelial cells have numerous lamelated crystals, the "spherites". The rectal epithelium of posterior hindgut is composed of rectal pads which are covered with cuticular intima on the luminal side. The rectal pads are composed of columnar absorptive cells and basal cells. The apical plasma membrane of columnar cell is made of microvilli, where mitochondria associated with some of the microvilli. The lateral plasma membrane is highly infolded and space is an uniform width of approximately 200$\\AA$. Well developed mitochondria are found closely associated with the infoldings and this is referred to as the "mitochondrial-scalariform complex". A septate junction is found near the apical zone between the columnar absorptive cells, whereas many desmosomes and intercellular spaces are formed between the columnar cells. Basal cells are bowl-shaped where the convex surface is inlaid into the basal surface of the columnar cells while the concave surface faces the basal lamina. The cytoplasm of the basal cell is electron dense and contains well developed cell organelles. The basal sheath is located between the basal membrane and basal lamina, providing barrier between the epithelium and the hemolymph. The epithelium is surrounded by the subepithelial space and muscles. The subepithelial space, which is composed of fibrous connective tissue, is innervated by many tracheoles and axons.