• Applied Microscopy
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• v.29 no.3
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• pp.383-403
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• 1999

This study was performed to investigate the immunohistochemical and ultrastructural characterization of the choline acetyltransferase (ChAT)-immunoreactive nerve cells in the diagonal band of Broca of the rat basal forebrains, utilizing techniques of immunohistochemical and immunocytochemical microscopy. The ChAT-immunoreactivities were shown within neuronal cell bodies and processes by the light micoscope. According to cell shape and ratio of long axis vs short axis of cell body, the ChAT-immunoreaclive nerve cells in both vertical and horizontal limbs of the diagonal band of Broca were classified into 6 types. at the light microscopic level; round, oval, elongated, fusiform, triangular and polygonal types. As a result of the electron microscopic observation, the ChAT-immunoreactivated products appeared on the outer nuclear envelope, membranes of rough endoplasmic reticula (rER), free ribosomes and polysomes. Each cell type was subdivided into subtype I and II according to the several criteria such as volume of cell body, nuclear size relative to the cytoplasm, kinds and distribution of cell organelles and numbers and sorts of synapses. The subtype I of immnunoreactive nerve cells had large cell body and a small nucleus showing shallow indentations of nuclear evelope. In this subtype I with abundant cytoplasm, rER were well differentiated. Their long cisternae were parallelly ditributed and lamellated. One or two lamellar bodies and nematosomes were observed. The subtype II cell had small cell body and a large nucleus with deep indentations of nuclear envelope. In this subtype II with small cytoplasm, the rER were irregularly distributed and the lamellar body and nematosome were not found. A few axosomatic synapses in the subtype I and II were shown to be symmetric or asymmetric. The ratios of the symmetric synapse to the asymmetric one were investigated to be 1 : 2 and 1 : 4 in the subtype I and II, respectively. The axodendritic ones were almost asymmetric. But, the fusiform and triangular immunoreactive nerve cells were shown only to be subtype I. According to observations in this study, it is considered that the ultrastructural characterization in the 2 subtypes of each cell type may reflect the differences of the metabolic activities and projecting distances to the target cells.

• Applied Microscopy
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• v.29 no.3
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• pp.303-313
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• 1999

In this paper, five kinds of neurosecretory cells-light green (LG) cell, dark green (DG) cell, caudo-dorsal (CD) cell, blue green (BG) cell, and yellow (Y) cell- and neuropils in the cerebral ganglion of the African giant snail, Achatina fulica, were observed with an electron microscope. The following results were obtained. The LG cells are circular or ovoid in shape, and about $60{\mu}m$ in size. The nucleus and cytoplasm of the LG cell look light due to their electron-low density. Large granular chromatins are evenly developed in the karyolymph, where round nucleoli are also found. In the cytoplasm, electron -high dense round granules of $0.4{\mu}m$ in average size are crowded. The DG cells are ovoid in shape, and $50\sim20{\mu}m$ in size. These relatively electron-high dense cells were rarely found. In their cytoplasm, cell organelles such as rough endoplasmic reticulum and mitochondria are found together with electron -high dense round granules of $0.2{\mu}m$ in average size. The CD cells are ellipsoidal cells densely distributed in caudo-dorsal parts of the cerebral ganglion. They have large nuclei compared with the cytoplasm. The developed granular heterochromatins are observed in the karyolymph, and lots of small round granules of $0.12{\mu}m$ in average size in the cytoplasm. The 3G cells, rarely found around endoneurium of the cerebral ganglion, take the shapes of long ellipses. They look dark due to their electron -high density. In the cytoplasm, small round granules of $0.1{\mu}m$ in average size are found. The Y cells are the smallest among the neurosecretory cells($9\times6.6{\mu}m$ in size). They are found mostly between the medio-dorsal parts and the caudo-dorsal parts of the cerebral ganglion. In the cytoplasm, tiny round granules of $0.08{\mu}m$ in average size form a group. The neuropils are found in the middle of the cerebral ganglion. In the axon ending, round granules with electron -high density ($0.07\sim0.03{\mu}m$ in diameter) and lucent vesicles ($0.03{\mu}m$ in diameter) are found in large quantities. They are excreted in the state of exocytosome formed by the invagination of the limiting membrane of the axon ending.

• Applied Microscopy
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• v.41 no.1
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• pp.1-11
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• 2011

This experiment was performed to evaluate the morphological responses of the gastric epithelial cells of the mouse, inoculated with Ehrlich carcinoma cells in the inguinal area, following administration of 5-fluorouracil, mitomycin C or Acriflavine-Guanosine compound (AG60). In this study, each mouse was inoculated with $1{\times}10^7$ Ehrlich carcinoma cells subcutaneously in the inguinal area. From next day after inoculations, 0.2 mL of saline, 5-fluorouracil (30 mg/kg), mitomycin C ($400{\mu}g/kg$) or AG60 (30 mg/kg) were injected to the animals every other day, respectively. Each animals were sacrificed after 7th injection and tissue were taken from the gastric mucosa. Thereafter, the ultrathin sections were stained with uranyl acetate and lead citrate. In the 5-fluorouracil-, mitomycin C- or AG60-treated mice, myelin figures and multivesicular bodies within the gastric mucous epithelial cells were observed more frequently than those of the normal control. In the 5-fluorouracil-treated mice, membrane structures containing a few mucous granules in the luminal space were observed. Indeed, bulging cytoplasmic process containing mucous granules protruding into the gastric lumen were observed in the mitomycin Ctreated mice. Therefore, this study suggested that AG60 as compared with 5-fluorourail and mitomycin C may effective medicine without damage to the secretion ability of gastric mucous epithelial cells.

• Applied Microscopy
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• v.38 no.4
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• pp.307-314
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• 2008

Hydrophytes such as Spirodela polyrhiza form dormant turions to withstand cold winters. The turion is an anatomically distinct structure from which a vegetative frond arises later during germination. The turions sink to the bottom of the pond when temperatures drop and remain there throughout the winter. In the spring, they float to the surface and germinate into a new frond from the turion primordium. Unlike fronds, turions are known to possess small aerenchyma, starch grains, and relatively dense cytoplasm. These features allow the turions to survive the cold winter season at the bottom of the pond. Spirodela polyrhiza has been investigated previously to a great extent, especially in its physiological, biochemical and ecological attributes. However, a little is known about the structural features of the frond and turion during turion development. Thus, the aim of the present study was to reveal the structural characteristics of the frond and turion with regard to tissue differentiation, aerenchyma development, starch distribution, and ultrastructure, with the use of electron microscopy. A moderate degree of mesophyll tissue differentiation was found in the frond, whereas the turion did not exhibit such differentiation. Within the frond tissue, approximately $37{\sim}45%$ of the cellular volume was occupied by a large aerenchyma, but only $9{\sim}15%$ was taken up by the aerenchyma in the turion. The turion cells, especially those of the turion primordium, were derived from frond cells, and contained cytoplasm. Their cytoplasm was densely packed with plastids, mitochondria, endoplasmic reticulum, Golgi bodies, and microtubules. Plasmodesmata were also well developed within these cells. The most striking feature observed was the distribution of starch grains within the plastids of turion cells. Before the turion sank to the bottom of the pond, a considerable amount of starch accumulated in the plastid stroma. The starch grains dissolved when temperatures rose in the spring, and this promptly provided the nutrients which the primordium needed for turion germination. The turion therefore, was an appropriate dormant structure for free-floating, reduced hydrophytes like Spirodela polyhriza due to its small aerenchyma and large starch grains that aided in the purpose of sinking below the surface of the water to survive cold winters. The new fronds that arose from such turions grew rapidly in the spring, beginning the new life cycle.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.512-522
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• 1999

Background: Due to the paucity of suitable donor organs for lung allotransplantation, a number of techniques have been developed to improve the lung preservation. Ultrastructural studies of the morphologic changes of the flushing, preservation and reperfusion injury in donor lungs have rarely been reported. Methods: Adult dogs (n=46) were matched as donors and recipients for the single lung transplantation. The donor lungs were preserved after flushing with preservation solution and transplanted after 20-hours of preservation at $10^{\circ}C$. Ultrastructural features of the lung were examined after flushing, preservation and 2 hours after lung transplantation (reperfusion) respectively. Results: Electron microscopy after flushing showed focal alveolar collapse and mild swelling of type I epithelial cells. After preservation both type I epithelial cells and endothelial cells were swollen and destroyed focally. The endothelial cells showed protrusion of tactile-like structures into the lumina, blebs or vacuoles of the cytoplasm After reperfusion the lung tissue showed fibrin material in the alveoli, prominent type I epithelial cell swelling with fragmented cytoplasmic debris and marked endothelial cell swelling with vacuoles or tactile-like projections. The alveolar macrophages showed active phagocytosis. Scanning electron microscopic examination of the pulmonary parenchyma showed focally alveolar collapse and focal consolidation after the preservation and more prominent changes after the reperfusion procedure. The lungs preserved with low potassium dextran glucose solution, with additional prostaglandin $E_1(PGE_1)$ and verapamil(VP) showed relatively well preserved ultrastructures compared with those which were preserved with modified Euro-Collins or University of Wisconsin, and with additional $PGE_1$ and/or VP. Conclusion: The ultrastructural changes associated with flushing were mild in severity, the donor lungs were injured during the preservation, and further damage was occurred during the reperfusion. The reperfusion injury resulted in prominent pulmonary parenchymal alterations with a pattern of acute lung injury.

• Applied Microscopy
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• v.37 no.3
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• pp.157-166
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• 2007

This experiment was performed to evaluate the ultrastructural responses of the absorptive cells in the appendix of the mouse, inoculated with Ehrlich carcinoma cells in the inguinal area, following administration of BCG (Bacillus Calmette-Guerin). Healthy adult ICR mice weighing 25 gm each were divided into normal and experimental groups (experimental control group and BCG treated group). In the experimental groups, each mouse was inoculated with $1{\time}10^7$ Ehrlich carcinoma cells subcutaneously in the inguinal area. From next day after inoculations, 0.5mL of saline or BCG (0.5 mL/25gm B.W.: $0.03{\times}10^8{\sim}0.32{\times}10^8CFU$) were injected subcutaneously to the animals every other day. The day following the last injection, each mouse was sacrificed. Pieces of the tissue were taken from the appendix, prefixed with 2.5% glutaraldehyde-1.5% paraformaldehyde solution, followed by post-fixation with 1% osmium tetroxide solution. The ultrathin sections were stained with uranyl acetate and lead citrate. In the normal control, experimental control and BCG treated mice, general morphology of the absorptive cells of appendix were similar. But myelin figures and intramitochondrial dense granules were more frequently observed in the absorptive cells of BCG treated mice than normal control ones. Above results show that BCG did show slight ultrastructural alterations in the absorptive cell of the appendix. These results that BCG may slightly suppress function of the absorptive cells of the appendix.

• Applied Microscopy
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• v.32 no.2
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• pp.131-147
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• 2002

Optic lobes of Todarodes pacificus and Octopus minor are largely divided into cortex and medulla, the cortex being composed of three layers (an outer granule cell layer, a plexiform layer, and an inner granule cell layer). The cortex of Todarodes pacificus is about $420{\sim}450{\mu}m$ thick, being $170{\sim}200{\mu}m$ thicker than that of Octopus minor of which thickness is about $250{\sim}290{\mu}m$. In the outer granule cell layer of Todarodes pacificus, three types of nerve cells (type-A, type-B and type-C) and neuroglial cells that surround or contact with the neurons are observed, while in the outer granule cell layer of Octopus minor, two types of nerve cells (type-A and type-B) and a single type of neuroglial cells are observed. In a plexiform layer, a presynaptic bag and nerve endings are connected to each other, consequently forming various types of synaptosomes. The synaptosomes of Todarodes pacificus contain electron dense vesicles, electron dense-core vesicles and electron lucent vesicles, either individually or in a mixture. On the other hand, three types of synaptosomes a mixture of electron dense-core vesicles and electron lucent vesicles, electron lucent vesicles only, and electron dense-core vesicles only are observed in Octopus minor. The structures of the inner granule cell layer are almost similar in the two species. It is composed of two types of nerve cells (type-A, type-B) and a single type of neuroglial cells. In the medulla of Todarodes pacificus, the cells of $7{\times}5{\mu}m$ are arranged to a line and form the palisade cell layer, but these are not observed in Octopus minor.

• Journal of Plant Biology
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• v.38 no.1
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• pp.95-105
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• 1995

Complete microsporogenesis of Hibiscus syriacus L. were carried out employing LM, TEM, and SEM to investigate the pollen ontogeny that undergoes considerable structural differentiation. The process first began with several cell diYisions in the anther primordium that produces 3 different tissues of epidennal, archesporial, and connective tissues. Only archesporial tissue involved further differentiation into the tapetum and formation of reproductive cells, pollen mother cells (PMC). The tapetum and PMC were closely associated with each other structurally and metabolically by exhibiting numerous plasmodesmata, mitochondria, and many small vacuoles in their dense cytoplasm. A callosic wall began to surround the PMC while meiosis took place in the PMC to produce 4 microspores. When thick callose encircled each microspore as a frame, the sporodenn development initiated from the plasma membrane of a pollen grain in a tetrad. The first fonned sporoderm layer was bacules and tectum of sexine that originated from the plasma membrane. After the dissolution of a callose, further development Qf sporoderm continued in the order of nexine 1, nexine 2, and intine layer. The nexine layer was thicker (ca. $2-3.5\;\mu\textrm{m}$) than the intine layer whose thickness was about $0.9-1.5\;\mu\textrm{m}$. Upon completion of the sporoderm development, that is after intine formation, spines and apertures of pollen surface ornamentation initiated from the tectum. Spines were dimorphic, about $4-9\;\mu\textrm{m}\;an;15-20\;\mu\textrm{m}$ in length, and no basal cushion was detected. The mature pollen grains ranged $100-200\;\mu\textrm{m}$ in diameter, but their average was about $170\;\mu\textrm{m}$. About 120 spines were observed over the spheroidal pollen surface. Apertures were simple punctures of $2-3\;\mu\textrm{m}$ in diameter and about 50 apertures were arranged somewhat helically over the surface. Comparing such features of form and size of the pollen, sporodenn sculpture and structure, and aperture and spine conditions with known evolutionary trends in the genus Hibiscus, Hibiscus syriacus seemed to possess many advanced features in the sporodenn differentiation.iation.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.31-37
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• 2000

This study was designed to identify the ultrastructural changes of mouse endometrium during peri-implantation period and obtain the fundamental information for the establishment of 3-dimensional culture system of mouse endometrial cells in vitro. The used female ICR mice ($6{\sim}8$ wks) were conducted on pregnant. The biopsies were obtained from whole uterus at cycle day 1 (D1) and day 5 (D5) after hCG injection and mating. The biopsies materials were fixed 2.5% glutaraldehyde and 1% osmium tetroxide. Subsequently, for observation using light and transmission electron microscopy (LM and TEM), they were dehydrated and embedded in Epon and the embedded biopsies were sectioned and stained. For scanning electron microscopy (SEM), the fixed specimens were dehydrated, dried and coated with gold. 1) For LM, the biopsied materials at D5 (late secretory phase) were appeared the extended stromal layer by increased connective tissues and the fully developed endometrial glands and vessels compared with D1 (early secretory phase). 2) For TEM, the mouse endometrium was consisted of 3-layers, a simple polarized columnar epithelial cells, basement membrane and stromal cells. At D5, the distribution of microvilli, endoplasmic reticulum, Golgi body, lipid and glycogen deposits, secretory granules and surface area of basement membrane were increased. 3) For SEM, the degree of folding and microvilli of surface of mouse epithelial cells was became more and more according to the process of secretory phase, and at D5, implantation time of mouse, the appearance of pinopodes as a specific marker of uterine receptivity was found. The uterine pinopodes of mouse were found in narrow sites at the luminal surface, irregularity and appeared the different stages in the same sample. Therefore, these results indicated that the mouse endometrium was experienced dramatic morphological changes during peri-implantation period.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.925-935
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• 1996

Background : In order to elucidate one of the pathogenic mechanisms of ARDS associated with pulmonary surfactant and oxidant injury, acute lung injury was induced by N-nitroso N-methylurethane (NNNMU). In this model, the role of phospholipase $A_2$ ($PLA_2$), surfactant, gamma glutamyl transferase (GGT) and morphology were investigated to delineate one of the pathogenic mechanisms of ARDS by inhibition of $PLA_2$ with high dose of dexamethasone. Method: Acute lung injury was induced in Sprague-Dawley rats by NNNMU which is known to induce acute lung injury in experimental animals. To know the function of the alveolar type II cells, GGT activity in the lung and bronchoalveolar lavage was measured. Surfactant phospholipid was measured also. $PLA_2$ activity was measured to know the role of $PLA_2$ in ARDS. Morphological study was performed to know the effect of $PLA_2$ inhibition on the ultrastructure of the lung by high dose of dexamethasone. Results : Six days after NNNMU treatment (4 mg/kg), conspicuous pulmonary edema was induced and the secretion of pulmonary surfactant was decreased significantly. In the acutely injured rats' lung massive infiltration of leukocytes was observed. At the same time rats given NNNMU had increased $PLA_2$ and GGT activity tremendously. Morphological study revealed bizarre shaped alveolar type II cells and hypertrophied lamellar bodies in the cytoplasm of the alveolar type II cells. But after dexamethasone treatment (20 mg/kg, for six days) in NNNMU-treated rats, these changes were diminished i.e. there were decrease of pulmonary edema and increase of surfactant secretion from alveolar type D cells. Rats given dexamethasone and NNNMU had decreased $PLA_2$ and GGT activity in comparison to NNNMU induced ARDS rats. Conclusion : Inhibition of $PLA_2$ by high dose of dexamethasone decreased pathological findings caused by infiltration of leukocytes and respiratory burst. Based on these experimental results, it is suggested that an activation of $PLA_2$ is the one of the major factors to evoke the acute lung injury in NNNMU-induced ARDS rats.