• Applied Microscopy
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• v.20 no.1
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• pp.77-89
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• 1990

The ultrastructures of the hemal node and the hemolymph node in the Korean native goat were observed by transmission and scanning elelctron microscopies for their morphological features. The sinus of hemal node was lined by endothelial-like reticular cells that had an euchromatin-rich nucleus and many cytoplasmic processes by which reticular fibers were surrounded. In the hemolymph node, the mast cell and the plasma cell were closely contact each other by the cytoplasmic process. The hemal node had venous sinusal-like vessels which were different from the deep sinus, and the hemolymph node had lymph capillaries. The lymph vessels with valves were observed in the capsule of the hemolymph node.

• Applied Microscopy
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• v.8 no.1
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• pp.23-31
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• 1978

An electron microscopical study on hemocytes of last instar larvae of Orthoptera (Acrida cinerea Thunberg, Paratenodera sinensis De Saussure, Atractomorpha lata Hotschulsk was performed to observe cell types, structures and their origins. Prohemocytes are the smallest round cells with large, nucleus, poorly developed cytoplasmic organelles and lower composition ratio, accouting for less than 1% of all cell types. Little remarked differences were revealed among different species. Plasmatocytes are relatively large cells with higher composition ratio, accounting for 5 to 20%. The majority of the plasmatocytes are oval forms with numerous external cytophismic projections., relatively well developed cytoplasmic organelles. Granular cells are characterized by various granules in cytoplasm. Some considerable remarked differences were revealed among different species. Furthermore the granules themselves differ in fine structures. Adipohemocytes were found only in Acrida cinerea Thunberg.

• Applied Microscopy
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• v.26 no.2
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• pp.137-155
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• 1996

The development of the ganglia of the trachea was studied by electron microscopy in human fetuses ranging from 40 mm to 260 mm crown rump length. At 40 mm fetus, the tracheal ganglia was observed in the submucosa of the trachea. The primitive ganglia consisted of neuroblasts, undifferentiated cells, and unmyelinated nerve fibers. At 50 mm fetus, the neuroblast and their processes in the tracheal ganglia ware ensheathed by the bodies or processes of satellite cells. The cytoplasm of the neuroblast contained rough endoplasmic reticulum, mitochondria, Golgi complex, and ribosomes. At 70 mm fetus, cholinergic and adrenergic axon terminals were observed. Cholinergic axon terminals with agranular vesicles were abundant in the tracheal ganglia with increasing age. During next prenatal stage from 100 mm fetus, the ganglion cells and its processes were completely covered by a thin processes of the satellite cells. Unmyelinated nerve fibers were also completely ensheathed by processes of Schwann cell. Synaptic contacts between the cholinergic axon and dendrite of ganglion cells and a few dendrodendritic synapses were first observed at 100 mm fetus. The granule-containing cells were first identified in the tracheal ganglia at 200 mm fetus. These findings indicate that tracheal ganglia of human fetus resembles other parasympathetic and sympathetic ganglia, but not the enteric ganglia.

• Applied Microscopy
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• v.26 no.2
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• pp.157-175
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• 1996

The development of flexor digital tendon of the hand was studied by electron microscopy in human fetuses ranging from 9 mm to 260 mm crown rump length. The primordium of tendons was first identified as discrete collection of mesenchymal cells at 25 mm fetus. Synovial sheath formation had commenced by 40 mm fetus and was complete by 70 mm fetus. Cell junction or adhesion sites at all ages were noted between the tendon cells. When dilatation of the synovial cavity occurred, two types of synovial cells were observed. A-type cells had numerous vesicles and large vacuoles. In contrast, B-type cells were characterized by abundant rough endoplasmic reticulum and well-developed Golgi complex. By $150mm{\sim}260mm$ fetuses, a mojority of the synovial cells were type B. The most remarkable difference between the synovial cells of full-term fetus and adult was the larger amount of collagen fibers in the latter. The vascular buds were first observed between the individual fibril bundles in the interfascicular space at 150 mm fetus. At 25 mm fetus, collagen fibrils were first noted within narrow cytoplasmic recesses which were continued with the extracellular space. Collagen fibrils were filled in almost entire extracellular space at 150 mm fetus. Besides collagen fibrils in the extracellular space small elastic fibers were also identified and followed in their development.

• Applied Microscopy
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• v.24 no.1
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• pp.77-85
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• 1994

In order to investigating the pulmonary toxicity of the O-chlorobenzyledene malononitrile (CS), lacrimating agent, $2.6g/m^3$ of CS was inhalated to Sprague-Dawley rats in the plastic chamber for 20 minutes. The ultrastructural changes of type II pneumocytes in the lung were observed with Hitachi 600 transmission electron microscope. The results obtained were as follows: 1. 3 hours after exposure to CS the fusion of surface microvilli, dilatation of cristernae of the rough endoplasmic reticulum, atrophy of Golgi complex and condensation, deletion of lamellated membranes in lamellar bodies were observed in type II pneumocytes. 2. One and 2 days after CS-exposure, disorganization of mitochondrial double membranes, fragmentations of rough endoplasmic reticulum were found in the great alveolar cells. In addition, decrease in amount of polyribosome granules and deletion or condensation of lamellated membranes in lamellar bodies were also observed. 3. 4 days after exposure to CS, the type II pneumocyte revealed new whorled lamellar membranes in lamellar bodies, a few intact rough endoplasmic reticulum and restoration of polyribosome granules. It is consequently suggested that CS induces degenerative changes of cytoplasmic organelles in the type II pneumocytes.

• Applied Microscopy
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• v.28 no.3
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• pp.399-414
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• 1998

Glandular trichomes present on the leaf surface of Drosera capensis were examined using transmission electron microscopy. A large number of stalked glands exist on the adaxial surfaces of the leaf blade. The secretory head is composed of two layers of secretory cells, one layer of middle cells, and the inner tracheids. The secretory cells contain rough endoplasmic reticulum, mitochondria, plastids, Golgi apparatus, and vacuoles. The secretory cells show prominent cell wall ingrowth, and thick cuticle restricted on the subcuticular wall. Frequently, the cuticle has some pores, canal-like structures, showing electron -dense granules being penetrated through them. Ultrastructural localization using diaminobenzidine showed the electron-dense deposits in the vacuole. No peroxidase activity was seen in the cell wall and cytolasm. The activity of peroxidase (POX) isozymes in Drosera which isoelectric point (pI) is 3.6 and some anionic POX isozymes which pIs are laid between 3.6 and 4.6 were especially increased according to the development and the formation of glandular trichomes. Also, the activity of some POX isozymes which isoelectric points are laid between 4.6 and 5.1 were increased in the regions of leaves which has trichomes.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.07a
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• pp.52-52
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• 2005

Oogenesis, the gonadosomatic index (GSI), reproductive cycle and first sexual maturation of the female Neptunea (Barbitonia) arthritica cumingii have been investigated by light and electron microscope observations. In the early vitellogenic oocyte, the Golgi complex and mitochondria were involved in the formation of glycogen, lipid droplets and yolk granules. In late vitellogenic oocytes, the rough endoplasmic reticulum and multivesicular bodies were involved in the formation of proteid yolk granules in the cytoplasm. In particular, compared with the results of other gastropods, it is a different result that appearances of cortical granules at the cortical layer and microvilli on the vitelline envelope, which is associated with heterosynthetic vitellogenesis, were not observed in vitellogenic oocytes during oogenesis. A mature yolk granule was composed of three components: main body (central core), superficial layer, and the limiting menbrane, Monthly changes in the gonadosomatic index in females were studied in 2002 and 2003 were closely associated with ovarian developmental phases. Spawning occurred between May and August in 2002 and 2003 and the main spawning occurred between June and July when the seawater temperature rose to approximately 18${\sim}$23${\circ}$C. The female reproductive cycle can be classified into five successive stages: early activestage (Septmber to October), late active stage ( November to February), ripe stage (February to June), partially spawned stage (May to Aygust), and recovery stage (June to August).

• Development and Reproduction
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• v.20 no.1
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• pp.11-22
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• 2016

The ultrastructures of germ cells and the functions of Leydig cells and Sertoli cells during spermatogenesis in male Kareius bicoloratus (Pleuronectidae) were investigated by electron microscope observation. Each of the well-developed Leydig cells during active maturation division and before spermiation contained an ovoid vesicular nucleus, a number of smooth endoplasmic reticula, well-developed tubular or vesicular mitochondrial cristae, and several lipid droplets in the cytoplasm. It is assumed that Leydig cells are typical steroidogenic cells showing cytological characteristics associated with male steroidogenesis. No cyclic structural changes in the Leydig cells were observed through the year. However, although no clear evidence of steroidogenesis or of any transfer of nutrients from the Sertoli cells to spermatogenic cells was observed, cyclic structural changes in the Sertoli cells were observed over the year. During the period of undischarged germ cell degeneration after spermiation, the Sertoli cells evidenced a lysosomal system associated with phagocytic function in the seminiferous lobules. In this study, the Sertoli cells function in phagocytosis and the resorption of products originating from degenerating spermatids and spermatozoa after spermiation. The spermatozoon lacks an acrosome, as have been shown in all teleost fish spermatozoa. The flagellum or sperm tail of this species evidences the typical 9+2 array of microtubules.

• Biomedical Science Letters
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• v.10 no.2
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• pp.107-113
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• 2004

This study was conducted to investigate an effect of Mori Cortex in the cardiac injury following dermal scald burn in rats. Sprague-Dawley rats were induced scald bum (15％ of total body surface area). Heart was removed at 5 h postburn and examined with biochemical assay, ultrastructural observations and stereological analysis. The activity of serum aspartate aminotransferase and creatinine was increased at 5 h postburn compared with them of control. Administration of heat extracts of Mori Cortex after scald burn inhibited the production of KC (neutrophil chemoattractant cytokine) and increased the activity of protein kinase C (PKC) in heart tissue. The activity of myeloperoxidase (MPO) in heart tissue was decreased both at 5 h postburn and in case of Mori Cortex administration after scald burn. Ultrastructurally, many contraction bands and separation of intercalated disk induced by scald burn were decreased by administration of heat extracts of Mori Cortex. In stereological analysis, administration of Mori Cortex after scald burn resulted the volume densities of myofibril and mitochondria were increased compared with them of burn control. These data suggest that Mori Cortex may be a useful stuff to the range of available treatments for cardiac injury induced by skin burn.

• Toxicological Research
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• v.14 no.3
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• pp.333-339
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• 1998

Sambutoxin, a newly purified mycotoxin in Koea, caused hemorrhage in the stomach and intestine of rats. To elucidate the mechanism of hemorrhage, effects of sambutoxin on rabbit platelet aggregation were investigated. First of all, the effects of sambutoxin on the platelet aggregation response and ATP release from platelet by various appregating factors were investigated. And then the role of $Ca^{2+}$ on the platelet aggregation was investigated by flow cytometer. Finally, morphological effect of sambutoxin on platelet ultrastructure was examined by transmission electron microscope. Sambutoxin inhibited aggregation induced by ADP, collagen, thrombin, and arachidonic acid and decreased platelet activating factor-induced disaggregation time in a dose dependent manner. Sambutoxin also decreased thrombin and arachidonic acid-induced ATP release, but increased all factors induced $Ca^{2+}$ release. Sambutoxin showed severe ultrastructural changes of platelet such as appearance of disorganization debri of cellular organelle in intercellular space. Our results indicate that sambutoxin inhibitis rabbit platelet aggregation, and it may be party due to the decrease of ATP release. However, it is not clear whether the antiaggregating effect of sambutoxin is related to $Ca^{2+}$ increase.