• 대한치과교정학회지
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• 제13권2호
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• pp.155-163
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• 1983

Many different appliances have been used to move teeth or to attempt to inhibit or stimulate growth of the jaws. Especially, Orthopedic force was used to apply a constant force on the mandible. Various orthopedic forces bring the changes of surrounding tissue, growth and development on the mandibular joint. Author carried out this study to find the histological changes of the mandibular joint in rats when the mandible applied posterior displacement. For the purpose of this study, $009\times036inch$ closed coil spring and 030inch orthopedic wire were used between the post occipital region and the chin region in order to render the orthopedic forces, posteriorly. The experimental animals vu. used 1 month old (GroupI), 3 months old (Group II), and 12 months old (Group III) rats. Following results were obtained; 1. At the beginning of the experimental Group I, there were predominant increment of Cartilage layer in the posterior parts of condylar head. Especially, the mature chondrocyte zone was increased. 2. In the experimental Group II, the chondroblastic zone was decreased while it showed slightly increased mature cartilage zone. 3. In the experimental Group III, the mature chondrocyte zone was disappeared gradually and there was a tendency to reduce the endochondral bone formation in condylar head. 4. After 30 days of experimental Group I and in experimental Group II, there was a tendency to decrease the immature cellular zone in the glenoid fossa by pressure. 5. There were no histological changes in the articular disc by pressure.

• Fisheries and Aquatic Sciences
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• 제12권3호
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• pp.209-218
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• 2009

We examined physiological and histological responses related to the survival, oxygen consumption, excretion, and O/N ratio of the ark shell, Scapharca subcrenata, as a result of salinity changes. The 20-day $LS_{50}$ (median lethal salinity) at $15^{\circ}C$ was 13.87 practical salinity units (psu; confidence limits 10.30-18.74 psu), whereas the 14-day $LS_{50}$ at $25^{\circ}C$ was 12.59 psu (confidence limits 8.03-18.16 psu). In conditions of decreasing salinity, the osmolarity of individuals acclimated within 5 h above 26.4 psu but required more than 60 h below 13.2 psu. Oxygen consumption and ammonia excretion rates varied irregularly as salinity decreased. The O/N ratio was 19 and 27 at water temperatures of $15^{\circ}C$ and $25^{\circ}C$, respectively, but decreased to 1-10 as salinity declined. The effects of decreasing salinity were observed in the histological changes to each organ of S. subcrenata. As salinity decreased, cilia fell off, the epithelial layer underwent necrosis and vacuolation, the connective tissue layers of the mantle and visceral mass were destroyed, and hemocytes increased in the gills. The results of this study could prove important in investigating causes of mass mortality and managing shellfish aquaculture farms.

• Journal of Korean Biological Nursing Science
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• 제2권1호
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• pp.20-33
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• 2000

The author was used for the ICR mouse and induced diabetes with the streptozotocin(50mg/kg)and alloxan(40mg/kg). After the testing and the identifying the diabetes, the histological changes of the glomerulus, blood test for the values of blood sugar, and urine test for the values of urine protein were investigated. The results are as follows : 1. The values of high blood sugar appeared from the 2 group were about $378mg/d{\ell}{\sim}709mg/d{\ell}$, in the treated groups with the streptozotocin and alloxan. The glycosuria were obviously continued from the 2 weeks to the 12 weeks of the streptozotocin and the alloxan treated groups and the proteinuria was ${\pm}{\sim}+$ in the 4 weeks and 8 weeks of streptozotocin treated group and were + in all the 12 weeks. The ketonuria were generally negative. 2. In the view of the light microscope, there was no significant histological changes until the 8 weeks. However, in the 12 weeks group treated with the streptozotocin, the mesangial matrix of glomerulus increased Bowman's capsules adhered to each other and changed them to the crescence shapes because of increasing the exothelial cells.

• 대한수의학회지
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• 제34권4호
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• pp.665-678
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• 1994

This study was undertaken to investigate histological changes according to the radiosensitivity in the spermatogenic cells in Korean native pheasants. During spermatogenetic period, testes wete 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 1000 rads) and a split-dose whole body irradiation groups(400/2, 600/2, 800/2 and 1000/2 rads). A Henseky's $^{60}Co$ ${\gamma}$-radiotherapy machine was used for this experiment and the dose rate of $^{60}Co$ ${\gamma}$-ray was 104 rads/min. The experimental birds were sacrificed at 24 and 72 hrs after irradiation and the control pheasants were sacrificed at the same time. General histological changes of seminiferous epithelial cells were observed by hematoxylin-eosin stain with light microscope. The results obtained are summarized as follows ; 1. In the single-dose and the split-dose irradiation groups, the average diameter of the seminiferous tubule was decreased compared with control group. 2. Seminiferous epithelial cells were more severely damaged after 72 hrs than after 24 hrs of single-dose irradiation of 400, 600 and 800 rads but the difference of cell injury was almost not observable with the elapsed time in the group of the single-dose irradiation of 1000 rads. 3. The damage of spermatogenic cells were more severe after 24 hrs than after 72 hrs of the split-dose irradiation of 400 rads but the split-dose irradiation of 600, 800 and 1000 rads were more severe after 72 hrs than after 24 hrs.

• 대한수의학회지
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• 제38권2호
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• pp.290-296
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• 1998

Histological changes was investigated in the 4 weeks old rat brain using NMDA (N-methyl-D-asparate) which is capable of mediating excitotoxic events. The changes were occured when the injected NMDA solved in PBS was over $1.0{\mu}g/g$(about 90nM). The necrosis of Purkinje cells in cerebellum and the increasement of coloidal plexus cell number were prevalent. The Purkinje cell number of necrosis were increased according to increasement of amount of injected NMDA. In spite of increasement of degenerated Purkinje cell number, differentiation of new Purkinje cell was not identified because total number of Purkinje cell was not changed. The change of cell number was observed in coloidal plexus cell rather than degeneration of cell. About 5 time increasement was occured. This change may cause increasement of cerebrospinal fluid and the makes mophorogy of brain more round than nomal.

• 한국환경과학회지
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• 제6권1호
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• pp.53-60
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• 1997

The toxicity of purified ricln from Ricinus communis to rats was examined by histological and histochemical methods. Sprague-Dawley rats were injected intraperitoneally with 75$\mu\textrm{g}$/kg body weight of ricin and were sacrified at itntervals of 6, 24, 48 and 120 hours after injectoon. The major morphological changes, such as cloudy swelling, hydropic degeneration, necrosis, fatty change, blood congestion, increase of Kupffer cells in number and extension of sinusoids, were obvious in the liver of experimental group. These morphological changes of hepatic cells were mainly observed in both the periportal and midlobular region of hepatic lobule. The extension of sinusoids was obvious in the controlobular region. And glycogen dlstrlbution of hepatic cells tended to decrease in the same region showing morphlogical changes as compared with the control group.

• Environmental Analysis Health and Toxicology
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• 제12권3_4호
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• pp.55-59
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• 1997

Furfural, an organic solvent, is widely used as synthetic component material in producing chemical products. However, furfural has been reported that it shows strong toxicities to human being showing intense stimulus to skin, eyes, mucous membrane and nerve system. It is also known to cause anemia, liver cirrhosis, kidney failure and genetic toxicity in the human being working in the exposed area. LD$_{50}$ of furfural for peritoneal injected mouse has been known around 20mg/kg, but the acute toxicity on aquatic organisms such as fish, daphnid or algae are not well known, compared to those on rodents. In this experiment, we studied on the fish toxicity of furfural using Japanese Medaka (Orvzias latipes) and Common Carp (Cvprinus carpio). We also observed histological changes in the fish organs. The LC$_{50}$ were 12. Smg/L in Japanese Medaka and 21.8 mg/L in Common Carp, respectively. When Common Carps were exposed to 120mg/L of furfural concentration for 30 minutes, blood congestion in gills and lysis of secondary lamella were shown. Though the muscle of caudal fin was not completely eroded, its epidermic cells were shown to be necrotic in various parts. Tissue atrophy and cell necrosis were also shown in the liver of Common Carps exposed to furfural. From these results, furfural seems to cause histological damages on liver, an internal organ as well as on external organs such as gills and fins eventhough the fish were exposed for a short-term.

• 한국발생생물학회지:발생과생식
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• 제25권3호
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• pp.157-171
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• 2021

To determine whether the reproductive processes of sea bass, Lateolabrax japonicus, proceed normally after transportation from an outdoor net-cage into indoor tanks, we examined changes in the gonadosomatic index (GSI), histological gonadal tissue, and plasma levels of sex hormones (testosterone and estradiol-17ß) during their annual reproductive cycle. We also measured maturation and spawning across two sea water salinity levels (full and low salinity). Fecundity was estimated by the relationship between egg number and body size in female sea bass. Monthly changes in the GSI, histological gonadal tissues, and oocyte size showed both male and female sea bass reach final maturation in January and February, respectively, indicating that the spermiation of males occurs earlier than the spawning of females. The histological results indicated that the sea bass is a multiple spawner, similar to many marine teleosts, exhibiting group-synchronous oocyte development. Female maturation and spawning were enhanced in lower salinity seawater (29.6-31.0 psu) compared to that of normal salinity (34.5-35.1 psu). These results confirm that sea bass reproduction can occur successfully in captivity and imply that fertilized eggs can be collected from February to March. Additionally, our results show that lower salinity enhances oocyte maturation and spawning of female sea bass.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권5호
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• pp.543-549
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• 2008

Distraction osteogenesis is a commonly used technique for mandibular lengthening, but changes in the temporomandibular joint(TMJ) have not been well documented. The TMJ is one of the most complex joint in the body and is composed of a fibrous surface layer, a proliferative zone, hypertrophic cartilage, and bone. The shape and role of the TMJ change and modify during a person's life-time. Possible complications that can arise after mandibular distraction include failure of the formation, failure of callus, infection, disturbance of TMJ and of occlusion. However, there are only a few reports on changes in the TMJ as a result of distraction osteogenesis. Hence, the goal of this study was to evaluate the change of the TMJ after experimental distraction of mandibular ramus in rabbit. We studied histological changes of mandibular condyle, articular disk and retrodiscal tissue, and also examined the collagen I gene expression and MMP-1 gene expression. The results were as follows. 1. In the histological staining, experimental condylar surface showed more thick fibrous articular layer and proliferative layer, compared with the control condyle and experimental articular disc showed thick and dense collagen fibers compared with the control disc. 2. In the collagen I and MMP-1 gene RT-PCR analysis, experimental discs showed increased collagen I expression compared with the control disc, while MMP-1 gene expression was decreased compared with the control disc. The retrodiscal tissue was almost equal expressions of the collagen I and MMP-1 genes compared with the control retrodiscal tissue. These findings suggest that histological and biomolecular changes occur in condyles and discs after unilateral mandibular distraction osteogenesis.

• Biomolecules & Therapeutics
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• 제1권1호
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• pp.9-19
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• 1993

DA-125, a new anthracycline antibiotic, showed antitumor activity against animal tumors and human tumors. Therefore we studied the cardiotoxic potential of DA-125 in hamsters and rats as a part of safety research, and compared it with that of doxorubicin(DXR). In acute cardiotoxicity test model used hamsters DA-125 was administered intravenously at a dose of 6, 9, 12 mg/kg, and DXR at 3 mg/kg was given. The electrocardiogram(ECG) of hamsters was recorded for 30 minutes after administration. The DA-125 caused slight ECG alterations at a dose of 6 mg/kg. At a dose of 12 mg/kg DA-125 induced moderate to remarkable changes in ECG like decrease of heart rate, widening of PR interval and 07 interval, and A-V block in 3 out of 5 animals. The severity of ECG alteration at 12 mg/kg of DA-125 was similar to that at 3mg/kg of DXR and these changes caused by DA-125 and DXR recovered within 10 minutes after injection. In chronic cardiotoxicity test model used rats, DA-125 was administered intravenously once a week for three weeks at a dose of 6, 9mg/kg and DXR was given at a dose of 6mg/kg. Electrocardiogram was recorded every week from the start of administration to 2 weeks after the last administration and the animals were sacrificed for histological heart examination at 1 week or 2 weeks after the last administration. DA-125 did not cause any abnormal changes in ECG and in histological heart examination due to administration, but DXR caused widening of ST segment, QRS complex, and QT interval from 1 week after administration and these changes were continued to necropsy. These alterations in ECG were accompanied by cardiac histological lesions such as vacuolation in myocardiac cells, interstitial edema and necrosis of myocytes. These results suggest that DA-125 is less cardiotoxic than DXR.