• Applied Microscopy
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• 제16권2호
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• pp.49-60
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• 1986

Ultrastructures of the large and elongated cells (idioblasts) in the haustorium of a parasitic angiosperm, Cuscuta australis R. Brown growing on the host plant, Trifolium repens L. were investigated by the electron microscopy. The idioblasts were characterized by the presence of a large nucleus, small vacuoles, and dense cytoplasm including a number of various cell organelles such as ribosome, rough endoplasmic reticulum(r-ER), mitochondrion, dictyosome, proplastid, multilamellar structure(MLS), microfilament bundle(MFB), and cytosegresome. Therefore, it is suggested that the idioblasts are metabolical1y very active. Particularly, MLS, MFB, and cytosegresome observed in this study did not appear in the haustorial cells of the other parasitic angiosperms. MLS was transformed into vacuole and also incorporated with cell wall. MFB composed of microfilaments, about each 7.5 nm in diameter, was observed in nucleus and also cytoplasm. Some types of MFB were distinguished on the basis of arrangement of microfilaments. A part of cytoplasm sequestered by stacked cisternae of smooth ER(s-ER), cytosegresome, was altered into a vacuole which was formed by digestion of the sequestered cytoplasm and of cisternae of s-ER. Cell organelles such as MLS, MFB, and cytosegresome were discussed in relation to the metabolic control of the idioblasts.

• Applied Microscopy
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• 제8권1호
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• pp.23-31
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• 1978

방아깨비, 사마귀, 섬서구메뚜기의 종령유충을 재료로 하여 전자현마경적 관찰을 하였다. Prohemocyte는 세포중 가장 작고 구성비도 낮으며 그 구조상 다른 혈구의 기원이 되는것 같다. Plasmatocyte는 나비류에서 와는 달리 그 형태가 대부분 난형이고 허족과 소기관을 가장 많이 가진다. Granular Cell은 종에 따라 그 형태가 뚜렷이 구분되며 어느 경우나 구성비는 높았다. 같은 세포의 과립이라 할지라도 그 미세구조가 몇 가지로 구분되고 이것은 아마도 축적단계에서 오는 결과인듯 하다. Adipohemocyte 는 방아깨비에서만 나타났고 구성비는 대단히 낮았다.

• 대한방사선기술학회지:방사선기술과학
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• 제18권1호
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• pp.97-110
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• 1995

This study was undertaken to investigate ultrastructural changes according to the radiosensitivity in the spermatogenic cells and Sertoli cell of the seminiferous tubules in Korean native pheasants. During spermatogenetic period, testes were collected from male adult Korean native pheasant and they were used as experimental and control birds. The experimental group was divided into a single-dose whole body irradiation group (400, 600, 800 and 1,000 rads) and a split-dose whole body irradiation groups(400/2, 600/2, 800/2 and 1,000/2 rads). The experimental birds were sacrificed at 24 and 72 hrs after irradiation and the control pheasants were sacrificed at the same time. Ultrastructural changes of Sertoli cells and spermatogonia were investigated by ultrathin section with electron microscope. The results obtained are summarized as follows; 1. The apoptosis was observed after 72 hrs group of the single-dose irradiation of 400 rads. 2. The cytoplasmic organelles of spermatogonia were severely damaged more than that of sertoli cell in 72 hours group of split-dose irradiation of 800 rads. 3. The cytoplasmic organelles of Sertoli cell were severely damaged except the nuclear membrane of Sertoli cells in 72 hrs group of split-dose irradiation of 1,000 rads.

• Applied Microscopy
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• 제17권1호
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• pp.131-160
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• 1987

Anatomical features of the renal papilla and pelvis and ultrastructures of the epithelium covering these areas in four species of mammals were studied by means of light, scanning and transmission electron microscopy. In terms of the morphology of mammalian kidney types distinguished by Sperber(1944), Pfeiffer(1968) and Schmidt-Nielsen(1977), the kidneys of animal species used in this experiment were; 1) the mouse kidney with the fornix between a long conical papilla and the funnel-shaped pelvis, 2) the guinea pig kidney with the peripelvic column and pelvic pouch between a short conical papilla and the funnel-shaped pelvis, 3) the dog kidney with the peripelvic column and pelvic pouch between the crest-shaped papilla and the funnel-shaped pelvis, and 4) the cattle kidney which is divided into multiple renculi with minor and major calyces and pelvis. The renal papilla was lined with the simple or pseudostratified columnar epithelium which covered the inner zone of the renal medulla. The epithelial cells with numerous short microvilli on the surface contained a few organelles. In the mouse, the fornix was lined with one to two cell-layered cuboidal epithelium which covered the outer zone of the renal medulla and a part of the cortex. The epithelial cells of the fornix with numerous short microvilli or microridges on the surface had well-developed organelles. In the guinea pig, the peripelvic column was lined with the simple cuboidal or low columnar epithelium which covered the outer zone of the renal medulla. The epithelial cells with numerous short microvilli on the surface contained well-developed organelles. The pelvic pouch was lined with the pseudostratified columnar epithelium which was composed of four kinds of cells; the secretory cell with small electron-dense granules (310 nm), the secretory cell with large granules (720 nm) showing various electron densities, the mitochondria-rich cell with a single cilium, and the basal cell. Pelves of the mouse and guinea pig, peripelvic column, pelvic pouch and pelvis of the dog, and minor and major calyces and pelvis of the cattle were lined with the transitional epithelium. The fusiform vesicles in the superficial cells of the epithelium were highly developed in the dog, relatively well developed in the mouse and guinea pig, and poorly developed in the cattle. From the above findings, it is suggested that the transport of solutes and water of the urine in the pelvic cavity can take place through the epithelia covering the renal papilla and fornix of the mouse, papilla and peripelvic column of the guinea pig, and papillae of the dog and the cattle. And specialized cell types in the epithelium of the guinea pig pelvic pouch, two kinds of secretory cells and mitochondria-rich cell with a single cilium, could have peculiar functions in the renal pelvis, respectively.

• 대한치과교정학회지
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• 제24권2호
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• pp.331-348
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• 1994

The purpose of this study was to investigate changes in the shape and ultrastructure of the articular disc of the rat mandibular joint with aging. Mechanical stress applied to the articular disc changes during neonatal, suckling, juvenile, adult and senile stages. Mandibular joints of 6 groups of rats(1-, 7-, 17-, 27-, 55-day and over-1-year groups) were removed en bloc and processed for light and electro microscopic study. The changes in the shape of articular disc were examined by light microscope in each group. Structural and ultrastructural changes in the articular disc were examined by light and electron microscope in each group. The results were as follows : In the 1-day and 7-day groups, the articular disc was long and slender in shape and the articular disc was not fitted with the shape of the mandibular fossa and condyle. However' after that time, the anterior and posterior portions of the articular disc were more bulged and the middle portion was shorter and biconcave. Thus the articular disc was well fitted with the shape of the mandibular fossa and condyle. The cell density decreased with aging. In the l -day and 7-day groups, the Golgi apparatus, rough endoplasmic reticulum and free ribosome, which are involved in the synthesis of intracellular and extracellular matrix, were developed. In the 17-day, 27-day and 55-day groups, not only the cell organelles involved in the synthesis of the intracellular and extracellular matrix but also the cell organelles involved in the remodeling of the extracellular matrix(i.e., finger-like cell process, lysosome and mitochondria)were well developed. With advancing age, intracytoplasmic microfilaments were more accumulated and condroid cells increased. In the over-1-year group, the majority of cells of the articular disc were chondroid cells. The majority of cytoplasmic compartment were filled with intracytoplasmic microfilaments and cell organelles were not developed. Therefore, metabolic activities of the cell was markedly reduced and cells contained structures enduring mechanical stress, and cells which were in the process of degeneration were observed occasionally.

• The Korean Journal of Physiology and Pharmacology
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• 제8권3호
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• pp.167-172
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• 2004

The kinesin proteins (KIFs) make up a large superfamily of molecular motors that transport cargo such as vesicles, protein complexes, and organelles. KIF5 is a heterotetrameric motor that conveys vesicles and plays an important role in neuronal function. Here, we used the yeast two-hybrid system to identify the neuronal protein(s) that interacts with the tail region of KIF5 and found a specific interaction with ${\beta}III$ spectrin. The amino acid residues between 1394 and 1774 of ${\beta}III$ spectrin were required for the interaction with KIF5C. ${\beta}III$ spectrin also bound to the tail region of neuronal KIF5A and ubiquitous KIF5B but not to other kinesin family members in the yeast two-hybrid assay. In addition, these proteins showed specific interactions, confirmed by GST pull-down assay and co-immunoprecipitation. ${\beta}III$ spectrin interacted with GST-KIF5 fusion proteins, but not with GST alone. An antibody to ${\beta}III$ spectrin specifically co-immunoprecipitated KIF5s associated with ${\beta}III$ spectrin from mouse brain extracts. These results suggest that KTF5 motor proteins transport vesicles or organelles that are coated with ${\beta}III$ spectrin.

• Applied Microscopy
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• 제27권1호
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• pp.47-56
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• 1997

The objective of the present study was to investigate the cytotoxicity of adriamycin in liver cells (group A), and the protective effect of squalene to the hepatocytes to which adriamycin-induced cytotcxicity (group B) was examined by transmission electron micro-scope. In the group A, The cisternae of rough endoplasmic reitculum and smooth endoplasmic reticulum are dilated/disoriented at 24 hours and 48 hours. The inner and outer membrane of mitochondria are detached or destructed , and attached ribosomes of rough endoplasmic reticulum are diminished in number. The cisternae of the smooth endoplasmic reticulum are dilated, and the cristae of mitochondria are disrupted at 72 hours and 96 hours. In the group B, the cisternae of the rough endoplasmic reticulum and smooth endoplasmic resticulum are dilated at 24 hours. The cisternae of the smooth endoplasmic reticulum are dilated at 48 hours. The cell organelles of hepatocytes are recovered from cytotoxicity at 72 hours. These results suggest that 50 is not only concerned with composition of the membrane system of the cell organelles but also decreased the cytotoxicity of the hepatocytes.

• Molecules and Cells
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• 제41권12호
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• pp.1000-1007
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• 2018

Mitochondria and endoplasmic reticulum (ER) are essential organelles in eukaryotic cells, which play key roles in various biological pathways. Mitochondria are responsible for ATP production, maintenance of $Ca^{2+}$ homeostasis and regulation of apoptosis, while ER is involved in protein folding, lipid metabolism as well as $Ca^{2+}$ homeostasis. These organelles have their own functions, but they also communicate via mitochondrial-associated ER membrane (MAM) to provide another level of regulations in energy production, lipid process, $Ca^{2+}$ buffering, and apoptosis. Hence, defects in MAM alter cell survival and death. Here, we review components forming the molecular junctions of MAM and how MAM regulates cellular functions. Furthermore, we discuss the effects of impaired ER-mitochondrial communication in various neurodegenerative diseases.

• Applied Microscopy
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• 제10권1_2호
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• pp.1-6
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• 1980

바퀴 (Blattella germanica L.)의 중장 상피내에 있는 분비과립세포를 전자현미경으로 관찰하였다. 직경이 약 $200{\AA}$크기의 분비과립을 가지고 있는 secretory granul cell은 그 형태와 위치 그리고 세포질의 염색성에 따라 3가지 types으로 구별할 수 있다. 1) 세포와 핵의 형태가 구형이면서 세포질 내에는 mitochondria, vacuoles등 세포 소기이관 풍부한 light secretory granul ceil, 2) 세포는 작고 타원형이며 세포질 내에는 세포 소기관들이 발달하지 않았으며, 재생세포 집단의 기부에 위치하는 light secretory granular cell, 3) 세포는 원추형이면서 세포질 내에는 endoplasmic reticulum, ribosomes등이 풍부하며 많은 수의 분비과립을 가지며, 세포질은 짙은 염색성을 나타내는 dark secretory granul cell등인데 이들은 모두 상피조직의 기저막상에 밀착되어 있다.

• Applied Microscopy
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• 제21권2호
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• pp.39-56
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• 1991

The development of notochordal cells of nucleus pulposus was studied with electron microscope in human fetuses ranging from 30 mm to 260 mm crown-rump length. At 30 mm fetus, primitive notochordal cells were large with central nucleus, few organelles, and their cytoplasm usually contained dense glycogen and fine filaments. Notochordal cells at all ages contained bundles of fine filaments of indeterminate nature. One unusual feature of fetal notochordal cells was the consistent presense of rough endoplasmic reticulum surrounding poorly developed mitochondria. At 50 mm fetus, notochordal cells formed dense masses with interdigitating cell membranes connected by a variety of cell to cell junctions. With increasing age, the cell connections became slender threaded cytoplamic extending from cell and enclosed large extracellular space. Chondrocyte-like cells appeared to be separated by large volumes of extracellular matrix. Viable notochordal and condrocyte-like cells existed in specimen from all age. The extracellular spaces were filled with fibrillar and granular material by 90 mm fetus. Necrotic cells were distinguished by loss of their membrane integrity, vacuolization of their organelles, and the presence of dense osmiophilic masses. In adult tissue, notochordal cells became rounded or irregular in shape and developed a pericellular matrix consisting of collagen fibrile, and dense particle. The structure of notochordal cells and their persistance in the nucleus pulposus after fetal life suggested that they may have a significant role in the formation and maintenance of the nucleus pulposus. The presence of Golgi complex and well-developed endoplasmic reticulum in chondrocyte-like cells suggested that they are capable of producing and maintaining the extracellular matrix.