• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.1
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• pp.36-48
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• 2008

To repair bone defects in the oral and maxillofacial field, bone grafts including autografts, allografts, and artificial bone are used in clinical dentistry despite several disadvantages. The purpose of this study was to evaluate new bone formation and healing in rat calvarial bone defects using hydroxyapatite (HA, $Ca_{10}[PO_4]_6[OH]_2,\;Bongros^{(R)}$, Bio@ Co., KOREA) and tricalcium phosphate (${\beta}-TCP,\;Ca_3[PO_4]_2$, Sigma-Aldrich Co., USA) mixed at various ratios. Additionally, this study evaluated the effects of type I collagen (Rat tail, BD Biosciences Co., Sweden) as a basement membrane organic matrix. A total of twenty, 8-week-old, male Sprague-Dawley rats, weighing 250-300g, were divided equally into a control group (n=2) and nine experimental groups (n=2, each). Bilateral, standardized transosseous circular calvarial defects, 5.0 mm in diameter, were created. In each experimental group, the defect was filled with HA and TCP at a ratio of 100:0, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, and 0:100 with or without type I collagen. Rats were sacrificed 4 and 8 weeks post-operation for radiographic (standardized plain film, Kodak Co., USA), histomorphologic (H&E [Hematoxylin and Eosin], MT [Masson Trichrome]), immunohistochemical staining (for BMP-2, -4, VEGF, and vWF), and elementary analysis (Atomic absorption spectrophotometer, Perkin Elmer AAnalyst $100^{(R)}$). As the HA proportion increased, denser radiopacity was seen in most groups at 4 and 8 weeks. In general radiopacity in type I collagen groups was greater than the non-collagen groups, especially in the 100% HA group at 8 weeks. No new bone formation was seen in calvarial defects in any group at 4 weeks. Bridging bone formation from the defect margin was marked at 8 weeks in most type I collagen groups. Although immunohistochemical findings with BMP-2, -4, and VEGF were not significantly different, marked vWF immunoreactivity was present. vWF staining was especially strong in endothelial cells in newly formed bone margins in the 100:0, 80:20, and 70:30 ratio type I collagen groups at 8 weeks. The calcium compositions from the elementary analysis were not statistically significant. Many types of artificial bone have been used as bone graft materials, but most of them can only be applied as an inorganic material. This study confirmed improved bony regeneration by adding organic type I collagen to inorganic HA and TCP mixtures. Therefore, these new artificial bone graft materials, which are under strict storage and distribution systems, will be suggested to be available to clinical dentistry demands.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.424-430
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• 2002

Vas deferens is a long tube and could be divided into four regions as its morphological characters: a short and slender proximal region, a convoluted region, a straight and more thick distal region, and an ejaculatory duct, It is connected with the posterior outer horns of the testis and runs to the gonopores opened on the coxa of the fifth walking legs, The proximal region consists almost entirely of simple cuboidal epithelial cells, $12\~28{\mu}$m in height, surrounded by a thin basal membrane. A small aggregation of high cuboidal epithelium is obsened from one side of the proximal region. The convoluted and distal region is composed of two kinds of epithelial cells; high cuboidal epithelial cells, $40\~120{\mu}m$ in height located in dorsal portion and simple cuboidal epithelial cells of $12\~28{\mu}$m in height located in ventral and lateral portion. The ejaculatory duct is surrounded with two kinds of muscle layers, inner longitudinal and outer circular muscle fibers, The lumen is lined with high and simple cuboidal epithelium in almost equal proportions. The proximal region contains mature sperm and basophilic substances. The eosinophilic substances appeared newly going toward the convoluted region and are laid along simple cuboidal epithelial cell layer. Tube-like content (spermatophore) of the vas deferens is ejaculated from a pair of genital pores at mating. Two masses of the content fuse together side by side and are usually deposited on the female thorax between the second and fourth or fifth pereiopods, The spermatophore formed measures $2.7\~4.0$ mm in length and $1.5\~2.7$ mm in width.

• Applied Microscopy
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• v.15 no.2
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• pp.111-129
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• 1985

The morphology and histology of the gastrointestinal mucosa of the mole, Talpa micrura coreana (Thomas), were studied using light and scanning electron microscopes. Tissue specimens were taken from body and pyloric portions of the stomach, and from the initial, proximal, middle, distal and terminal portions of the intestine. For light microscopy, tissue blocks were fixed in 10% buffered neutral formalin, embedded in paraffin wax, and sectioned at a thickness of $5{\mu}m$. These sections were stained with hematoxylin-eosin. For scanning electron microscopy, tissue blocks were fixed in 1% glutaraldehyde-1.5% paraformaldehyde, and postfixed in 1% osmium tetroxide, dehydrated in graded alcohol, transferred to isoamylacetate and dried by the critical point drier(Polaron E 3000). Subsequently, specimens were coated with gold and observed with a JSM-35C scanning electron microscope. The results were as follows: The mucous membrane of the body portion of the stomach had numerous irregular folds and the pyloric mucosa formed the strawberry-shaped folds, and general histological structures of each portion were similar to those of man. The intestine could not be differentiated macroscopically and microscopically into small and large intestines. There was no cecum, appendix, taenia coli, haustra coli or appendices epiploicae. In the initial portion (4 mm long), conical or tongue-shaped villi with the height of $143.3{\pm}10.7{\mu}m$ were present, and large mucous glands were seen in the submucosa. In the proximal, middle and distal portions, wavy folds composed of the epithelium and lamina propria were densely and transversely arranged, and their heights were $440.4{\pm}45.5{\mu}m,\;454.4{\pm}19.9{\mu}m\;and\;205.2{\pm}33.5{\mu}m$, respectively. The mucosa of the terminal portion (3 cm long) formed several longitudinal folds, and the intestinal glands were directly opened on the smooth surface of the folds. Aggregated lymphoid follicles were observed in the major portions of the intestine except the initial and terminal portions. There was no circular or semilunar fold throughout the intestine.

• Journal of Periodontal and Implant Science
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• v.49 no.1
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• pp.2-13
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• 2019

Purpose: The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy. Methods: Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses. Results: New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2. Conclusions: HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.86-95
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• 2022

Egg development and morphological change of larvae and juvenile of the Roughscale sole, Clidoderma asperrimum, were investigated in the present study. Adult fishes were collected on the East Sea, Korea, from 2017 to 2018 and reared in a circular water tank (Ø 6×1 m) at water temperature of 12.8±1.9℃. Fertilized eggs ranged from 1.42 to 1.59 mm (mean 1.51±0.04 mm, n=50) in diameter. The eggs were spherical in shape, transparent, floating and colorless. The egg yolk was separated from the egg membrane 60 mins post-fertilization (PF), and an embryo was formed in 62 hrs PF. More than 50% of the eggs hatched within 144 hrs PF in the range of 10.2~11℃(mean 10.8℃). The size of the newly hatched larvae were 4.22~4.64 mm (mean 4.53±0.16 mm) in total length (TL), their mouth and anus were not open yet. At 10 days after hatching, the preflexion larvae reached 5.88~6.62 mm (mean 6.31±0.33 mm) in TL, and the yolk absorption was completed and the mouth began to open. At 55 days after hatching the larvae reached to flexion larvae stage and they were 10.4~13.3 mm (mean 12.7±1.3 mm) in TL, and the tip of notochord was bent upward. At 120 days after hatching the larvae reached to juvenile stage and they were 35.3~40.5 mm (mean 39.5±2.4 mm) in TL. Their all fins had completed set of the fin-rays (D. 79~94: A. 63~75) and the juveniles adopted a benthic life.

• Applied Biological Chemistry
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• v.43 no.2
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• pp.86-94
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• 2000

In order to develop the enzymatic hydrolysis system concerned with taste and flavor, strains having the high hydrolyzing activity on the soy protein were selected from some traditional Mejus. Two molds and one bacterium producing enzymes which were different in character of hydrolysis were isolated and identified. Leucine and azodye enzyme activities of both M4 and M5 were relatively high among in the isolated molds. And, leucine enzyme activity of B16 was the lowest in the isolated bacteria. These strains were isolated as microorganisms having a dissimilar hydrolysis pattern on the soy protein by enzymatic reactions. Mold M4 on the culture solid media was mycelium colors of white and its sclerotia colors were changed from white to black. According to the result of slide culture, radial conidial head, subclavate vesicle, conidia of subglobose, stipes of uncolored with smooth walls and metula and phialides were existed. Because M4 was taxonomically similar to the characteristics of Aspergillus oryzae (ahlburg) species, M4 was identified and named as Aspergillus oryzae M4.Mold M5 showed white and black mycelium on the MEA medium. Mold M5 colony exhibited grayish-green color and have long(7 mm) sporangiophores at slide culture. Sporangia became brownish-gray and the wall of larger sporangia was broken to form small collars, and smaller sporangia were fomed continually from large basal membrane. Columella is globose and hyaline, and sporangiospores are ellipsoidal of small diameter$(80\;{\mu}m)$. Because M5 was taxonomically similar to the Mucor circinelloides of zygomycetes, M5 was was identified and named as Mucor circinelloides M5. Bacteria B16 colony was opaque white, circular and lobate, and had rod shaped endospore. B16 was found positive in stain, catalase, ${\beta}-glucosidse$ and V-P tests. B16 was found to utilize D-fructose, ${\alpha}-D-glucose$, maltose, D-mannose, D-raffinose, stachyose and sucrose. By the morphological and physiological results, the characteristics of B16 was thought to correspond to that of Bacillus megaterium. However, fatty acid composition was similar to Paenibacillus marcerans, requiring further study for the definite identification. Accordingly, Bacteria B16 was provisionally classified and named as Bacillus megaterium B16.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.257-261
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• 1998

The repeated subcultures of in vitro plant materials in wasabi became highly vitrified and the capacity for multiple shoot formation from the vitrified plant materials was very low. In order to improve the quality of in vitro propagated planting materials, the experiments were carried out using culture vessels capped with membrane filter(MF). When vitrified shoots were cultured on MS medium with 0.2mg/L BA in the vessels with MF or without MF for 60 days, the shoots in the vessels with MF did not vitrified. In contrast, the shoots grown in the vessels without MF vitrified at 65%. The stomates of vitrified leaves were circular and inflated, whereas those of normal leaves acclimatizated in the vessels with MF were ovate in shape. The hardened shoots were also cultured on MS media without sucrose containing 0.01mg/L IBA in vessels with(photoautotrophic culture) or without(control) MF. Sucrose was necessary for survival of the in vitro plantlets in the vessels without MF. After 20 days of culture, the shoots in the vessels without MF on the sucrose-free media turned yellow and died. But the shoots in the vessels with MF in the sucrose-free media produced a lot of roots. When shoots were cultured on MS medium with 2% sucrose containing 0.01mg/L IBA in the vessels with(photomixotrophic culture) or without(heterotrophic culture) MF, best growth occured in photomixotrophic culture.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.457-474
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• 2003

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.259-272
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• 1987

This was study carried out to investigate the effect of calcium on spontaneous contraction and electrical activity induced by ethanol in gastric smooth muscle. After peeling off the mucous membrane from the isolated whole stomach of 102 cats, two kinds of small muscle preparations $(2.0{\times}0.2\;cm)$, one longitudinal and the other circular, were excised from the fundus, the corpus and the antrum portion of each whole stomach specimen. The isometric contraction of the small muscle preparation was measured in a cylinder-shaped chamber filled with Krebs-Ringer-dextrose solution (pH 7.4, temperature $36{\pm}0.5^{\circ}C$) bubbling with 5% $CO_2$ in $O_2$. A large muscle preparation $(5.0{\times}1.2\;cm)$ was excised from the anterior wall of the corpus-antrum portion of the same specimen in 72 of 102 cats. The gastric electrical activity (slow wave and spike potential) was monopolarly recorded by four capillary electrodes (Ag-AgCl), of which two were placed on the corpus and two on the antrum, in a muscle chamber filled with the same solution as described above. Changes in the amplitude of the contraction, frequency of the gastric slow wave and the production of the spike potential were observed after adding ethanol and/or under the treatments with verapamil, $CaCl_2$ and Ca-free Krebs-Ringer-dextrose solution. The results were as follows: 1) After adding ethanol, the spontaneous phasic contraction of the corpus was reduced dose-dependently (0.125-2.0%), which was totally abolished by higher concentrations (2.0-8.0%) of ethanol. 2) The corporal phasic contraction was also completely abolished by verapamil $(3{\times}10^{-5}\;M)$ or Ca-free Krebs-Ringer-dextrose solution. The contraction was increased by $CaCl_2\;(1.8{\times}10^{-3}\;M)$, but the inhibitory effect of ethanol on the contraction persisted even under the treatment with $CaCl_2$. 3) At higher concentrations, ethanol caused tonic contraction of both preparations from the fundus, the corpus and the antrum in a dose-dependent manner. The tonic contraction of the fundus produced by ethanol was not influenced by $CaCl_2$ or verapamil, whereas the tonic contraction was not produced by ethanol in tile Ca-free solution. 4) Frequency of gastric slow wave was decreased dose-dependently by the addition of ethanol (0.25-1.0%), and tile slow wave was not produced by higher concentration of ethanol (2.0%). 5) The frequency of slow wave was significantly reduced by verapamil only and the inhibitory influence of ethanol on the slow wave frequency was reinforced by verapamil. 6) The treatment of $CaCl_2$ increased significantly the slow wave frequency, and attenuated the inhibitory effect of ethanol on the frequency. It is therefore suggested that ethanol regulates the phasic contraction and the production of slow wave by interfering with the transport of calcium in the stomach muscle of the cat.

• 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.