• Applied Microscopy
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• v.25 no.3
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• pp.20-32
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• 1995

Ultrastructural aspects on the production of the duct cuticle and formation of cuticular precursors within silk glands of the orb web spider, Nephila clavata L. Koch(Araneae: Araneidae), were studied using transmission electron microscope. Four kinds of silk glands(ampullate glands, tubuliform glands, flageliform glands, and aggregate glands), which connected with large spinning tubes(spigots) of the spinnerets, were examined and discussed in terms of cuticle precursor production. Inner cuticular intima which composed of three layers of cuticles-subcuticle, endocuticle and exocuticle- were commonly originated from duct epithelial cells surrounding the cuticle. The morphology and internal textures of each cuticle precursors were very diverse according to the types of silk glands. However several common features were observed. These cuticle precursors were first produced from the rough endoplasmic reticulum and next concentration was accomplished through the Golgi complex. After this step, cuticle precursors were released to the cuticle layer as a form of secretory granule by the mechanism of merocrine secretion commonly.

• Applied Microscopy
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• v.19 no.1
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• pp.49-58
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• 1989

Ultrastructure of the excretory duct of the small ampullate gland in the orb web spider, Nephila clavata L. Koch are studied with light and electron microscopes. The small ampullate glands, located near the midline portion of the abdominal cavity, are connected with the spigots(large spinning tubes) on the middle spinnerets and composed of three parts which are the excretory duct, the storage sac and the convoluted tail. The excretory duct of this gland is enclosed by a thin layer of the outer connective tissues. By the morphology of the apical cuticles and internal textures of the epithelial cells, the duct is subdivided into two regions which are proximal duct region near the sac and distal duct region near the spinnerets. At the distal region of the ducts, the subcuticle which had the function of water removal form the progenetive silk material is well developed, whereas at the proximal region this cuticle disappeared and instead of these, endocuticle is developed. Moreover the epithelium of the distal duct region is composed of columnar epithelial cells, but at the proximal region the epithelium is changed to squamous or cuboidal forms. In the cytoplasm of the epithelial cells, rough endoplasmic reticula, Golgi comlexes and large secretory vesicles related to the production of the cuticular materials are well developed. And between the adjacent epithelial cells, specialized septate junction and desmosomes are formed along the plasma membrane.

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.71-74
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• 1993

A 43-year-old Korean woman with billary ascariasis accompanied by cholellthiasis is reported. Her chief complaints were abdominal pain, nausea, and vomiting. She had the past history of several attacks of abdominal pain in her childhood. ciliary stones were recovered from the left hepatic duct after cholecystectomy, which contained degenerated cuticle or body wall, and numerous eggs of Ascaris lumbriooides. It is strongly suggested that the ciliary stones were formed from the dead Ascmis worm(s). This is a rare case of biliary ascariasis during the recent 5 years in Korea.

• Parasites, Hosts and Diseases
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• v.47 no.1
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• pp.65-68
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• 2009

Excretory-secretory products of Toxocara canis larvae have been considered as a major functional antigen in immune responses against toxocariasis. We studied ultrastructural localization of T. canis second-stage larval antigen using a seropositive human serum under immunogold electron microscopy. High-density gold particles were observed in the secretory cells, excretory duct, intestinal epithelium, and cuticle of the larval worm sections. The distribution of the positive reactions in the larval worms suggests that the nature of the antigen is excretory-secretory antigen including waste metabolites and secretory enzymes.

• Applied Microscopy
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• v.42 no.2
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• pp.67-76
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• 2012

The biomimetic approach on the cuticular spinning nozzles of the major ampullate silk glands in the golden-web spider Nephila calvata has been attempted using various visualizing techniques of light and electron microscopes to improve the design of spinning nozzle for producing synthetic nanofibers spun from electrospinning apparatus. The major ampullate spigot which has the most effective nozzle system to produce nanofibers for dragline silk with high strength and elasticity is connected via the bullet type spigot on anterior spinneret with flexible terminal segment. The excretory duct which transports the liquid silk feedstock from ampulla to spigot is divided into 3 limbs by loops back on itself to form an S-shape morphology that is bundled in connective tissue. Final diameter of the nanofibers at nozzle was dramatically reduced by gradual narrowing of duct cuticle less than 10 times comparing to its original size of funnel region. Moreover, the funnel has a characteristic cuticular organization with porous microstructure which seems to be related to water removal from feedstock of silk precursors. High magnification electron micrographs also reveal the presence of the spiral grooves on the surface of the cuticular intima near the valve which presumed to reduce friction during rapid flow of liquid silk.