• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.111-116
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• 2002

This study investigated quantitative changes in the spaces between and within myofibrils and the impact of high and low voltage electrical stimulation on muscle ultrastructure as seen in electron micrographs. In addition, the relationships of these spaces and the impact to meat tenderness were investigated. The degradation of myofibrils during aging appeared to be localized across the muscle fibre. Structural deterioration of muscle fibres was evident 1 day post-mortem, involving the weakening in the lateral integrity of the myofibrils and Z-disc regions. Meat tenderisation, as shown by objective measurements, coincided with these increases in degradation, as assessed by the sum of the gaps between and within myofibrils. The results showed that the total size of gaps between and within myofibrils can be used as an indicator of meat tenderization during aging, but that ultrastructural alteration in electrically stimulated muscle had little relationship with meat tenderness.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.599-605
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• 1995

The ultrastructures of in vitro-derived bovine blastocysts have been compared with those of blastocysts obtained from a superovulated cow. In vivo blastocysts obtained from the uterus showed well-differentiated features, while in vitro-derived embryos, which were developed from in vitro fertilized ovum, showed insufficient cellular organizations. In vitro-derived embryos contained many undefined cellular organizations in the perivitelline spaces compared with in vivo-derived blastocysts. Other features of in vivo and in vitro blastocysts were characterized by differential development of microvilli projection into blastocoele from the surface of the trophoblast cells. The conceivable reason for the difference between in vivo and in vitro developments of bovine embryos is that it is likely that in vitro culture system adopted in the present experiment may not be sufficient for better embryonic development.

• Journal of Plant Biology
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• v.35 no.2
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• pp.173-182
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• 1992

The parasitic flowering plants obtain nutrients and water from their host plants through a parasitic organ, haustorium, which connects both structurally and physiologically host and parasite. The parasitism in angiosperms thus can be understood from the knowledge of the haustorial structure. The haustoria have evolve convergently and independently in several unrelated taxa; therefore, they have similar morphology. Many anatomical studies on the haustoria in several parasites in the pst have been carried out by light microscopy. Ultrastructural studies on the haustoria, which are started from the end of 1060s', have provided new information relating to the phenomenon of parasitism in angiosperms. The purpose of this paper is to introduce and compare the structure of haustoria between parasitic plants. The results may help an understanding of phylogenetic relationships of parasitic angiosperms. The haustoria of some families, such as Santalaceae, Orobancaceae, Scrophulariaceae, Loranthaceae (or Viscaceae), and Convolvulaceae (Cuscuta) will be discussed.

• The Korean Journal of Cytopathology
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• v.1 no.2
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• pp.164-169
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• 1990

Carcinsarcoma is an uncommon pulmonary malignancy characterized by carcinmatous parenchyma and sarcomatous stroma. The cytologic, immunohistochemical and ultrastructural features of a case of pulmonary carcinosarcoma suspected by fine needle aspiration cytology is presented. Only bizarre spindle cells arranged in loose groups, in microtissue fragments and in a dissociate fashion were present on the aspiration smears. They were markedly positive for vimentin. The epithelial component was not found, which was probably due to marked paucity of carcinomatous component that was proved by histologic examination of the resected tumor. The diagnosis of pulmonary carcinosarcoma should be conidered whenever poorly differentiated epithelial ceil groups with a malignant mesenchymal component set in a myxoid background are seen in a pulmonary cytology specimen.

• Applied Microscopy
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• v.25 no.4
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• pp.104-114
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• 1995

The epidermis of scales in the abdominal parts from freshwater- and seawater-adapted guppies(Poecilia reticulatus) were studied respectively by scanning- and transmission- electronmicroscope. In the seawater adapted group, the surface area of pavement cells is increased nearly twice as much as that of freshwater-adapted group, and the pavement cells are relatively flattened. Adaptatoin to seawater causes the increment of the density of glycocalyx in the surface of the microridge of pavement cells, as well as the well developed intercellular junctional complex(desmosome) between neighbouring filament-containing cells. Also, intercellular space between adjacent filament-containing cells is more frequently observed in the epidermis of seawater adapted guppy.

• Applied Microscopy
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• v.25 no.4
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• pp.115-123
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• 1995

This study was carried out to observe the functional ultrastructures of photoreceptor cells in frog(Rana catesbeiana) retina using transmission electron microscope. The photoreceptor cells are divided into two types-rod and cone cells-consist of outer and inner segment. The long outer segment of rod cell contains dense stacks of membrane and formed vertical and horizontal folds. The outer segment of cone cell is small, and vertical and horizontal folds are not exist. The electron dense cytoplasm of rod cell contains compact mitochondria, Golgi complexes, and endoplasmic reticula. The inner segment of cone cell shows low electron density and contains a large lipid droplet in the upper part of inner segment. In addition, cone cell contains many mitochondria, Golgi complexes. rough endoplasmic reticula, ribosomes and numerous glycogen particles. It is believed that these ultrastructural characteristics are closely associated with photoreceptive function of photoreceptor cells in frog retina.

• 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.24 no.4
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• pp.52-60
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• 1994

The developing ovarian oocyte of Dendrolimus spectabilis has been studied by using electron microscopical techniques. After yolk formation the vitelline membrane was laid down in the intercellular space between the follicle cell and the oocyte. But before the vitelline membrane formation the granules with high electron density that the vitelline membrane precusor are observed in the follicle cell. At the late vitellogenesis stage these granules were transported into the intercellular space between the follicle cells and the oocyte. These granules fuse to each other and larger bodies which eventually produce the vitelline membrane. The vitelline membrane was distinguished into the light inner and dark outer membrane. Next the chorion was laid down. It was apparent that the chorion was laid down in the intercellular space immediately adjacent to the vitelline membrane, and that it was formed by the follicle cells only.

• Applied Microscopy
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• v.25 no.3
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• pp.33-39
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• 1995

To compare the quality of ultrastructural preservation of Scanning Electron Microscopic specimens dried with different methods; pure air-drying, air-drying with using Tetramethylsilane(TMS), four kind of air-drying using Hexamethyldisilazane(HMDS) and critical point drying(CPD), we conducted scanning electron microscopic observation on liver, skeletal muscle and intestinal tissues from laboratory rat treated with each method. In pure air drying group, severe distortion of tissue surface was observed, and in HMDS treated group, only liver tissue showed slight distortion. But in TMS treated group, each tissue showed a good presentation comparable to CPD group. The results suggest that the method of air-drying using TMS may be the former is less expensive and simple be and also time-saving.

• Journal of fish pathology
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• v.19 no.2
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• pp.109-117
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• 2006

A new myxosporean species Ceratomyxa oplegnathus n. sp. was found from the gallbladder of cultured rock bream, Oplegnathus fasciatus. Mature spores were 44.14 ± 2.41 (39.04-48.41) ㎛ in length, 8.52 ± 0.36 (7.9-9.26) ㎛ in width in sutural view. Spores contained two spherical polar capsules measuring 3.04 ± 0.2 (2.71-3.37) ㎛ in diameter and a binucleated sporoplasm. Each polar capsule had a 5-6 coiled polar filament, and was situated near the sutural line. In ultrastructural observation, asynchronous divisions of generative cells without pansporoblast formation gave arise to 2 spores within a trophozoite. Sporoplasmic cell in the sporoblast was binucleated, and capsulogenic cells had large amounts of rough endoplasmic reticulum, external tubules, and capsular primordia.