• Journal of Korean Neurosurgical Society
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• v.49 no.6
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• pp.351-354
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• 2011

Objective : This investigation was conducted to evaluate a new, safe entry point for the C2 pedicle screw, determined using the anatomical landmarks of the C2 lateral mass, the lamina, and the isthmus of the pars interarticularis. Methods : Fifteen patients underwent bilateral C1 lateral mass-C2 pedicle screw fixation, combined with posterior wiring. The C2 pedicle screw was inserted at the entry point determined using the following method : 4 mm lateral to and 4 mm inferior to the transitional point (from the superior end line of the lamina to the isthmus of the pars interarticularis). After a small hole was made with a high-speed drill, the taper was inserted with a 30 degree convergence in the cephalad direction. Other surgical procedures were performed according to Harm's description. Preoperatively, careful evaluation was performed with a cervical X-ray for C1-C2 alignment, magnetic resonance imaging for spinal cord and ligamentous structures, and a contrast-enhanced 3-dimensional computed tomogram (3-D CT) for bony anatomy and the course of the vertebral artery. A 3-D CT was checked postoperatively to evaluate screw placement Results : Bone fusion was achieved in all 15 patients (100%) without screw violation into the spinal canal, vertebral artery injury, or hardware failure. Occipital neuralgia developed in one patient, but this subsided after a C2 ganglion block. Conclusion : C2 transpedicular screw fixation can be easily and safely performed using the entry point of the present study. However, careful preoperative radiographic evaluation, regardless of methods, is mandatory.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.9-13
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• 2015

Objective : To improve pedicle screw placement accuracy with minimal radiation and low cost, we developed specially designed K-wire with a marker. To evaluate the accuracy of thoracolumbar pedicle screws placed using the novel guide-pin and portable X-rays. Methods : Observational cohort study with computerized tomography (CT) analysis of in vivo and in vitro pedicle screw placement. Postoperative CT scans of 183 titanium pedicle screws (85 lumbar and 98 thoracic from T1 to L5) placed into 2 cadavers and 18 patients were assessed. A specially designed guide-pin with a marker was inserted into the pedicle to identify the correct starting point (2 mm lateral to the center of the pedicle) and aiming point (center of the pedicle isthmus) in posteroanterior and lateral X-rays. After radiographically confirming the exact starting and aiming points desired, a gearshift was inserted into the pedicle from the starting point into the vertebral body through the center of pedicle isthmus. Results : Ninety-nine percent (181/183) of screws were contained within the pedicle (total 183 pedicle screws : 98 thoracic pedicle screws and 85 lumbar screws). Only two of 183 (1.0%) thoracic pedicle screws demonstrated breach (1 lateral in a patient and 1 medial in a cadaver specimen). None of the pedicle breaches were associated with neurologic or other clinical sequelae. Conclusion : A simple, specially designed guide-pin with portable X-rays can provide correct starting and aiming points and allows for accurate pedicle screw placement without preoperative CT scan and intraoperative fluoroscopic assistance.

• Korean Journal of Veterinary Pathology
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• v.7 no.1
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• pp.63-65
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• 2003

A 10-year-old Korean native female Jin-do dog revealed two growing subcutaneous masses measuring 7.0 ${\times}$ 7.0 ${\times}$ 2.5 cm and 5.0 ${\times}$ 4.0 ${\times}$ 2.0 cm in the left shoulder and lower part of chest, respectively. Grossly tumor masses were well-circumscribed and exhibited ulcerated surface and purulent exudate on the cut surface. Histologically tumor masses were characterized by cystic structures some of which were fused together. Although the cells of cyst wall differentiated to those similar to infundibulum, isthmus, inferior segment of hair follicles, respectively, the most cyst wall consisted of cells similar to infundibulum The luminal content of cysts depended on the cells of cysts; infundibulum-like cyst contained lamellar keratin, isthmus-like cyst was amorphous keratin, and inferior segment-like cyst had shadow cells. From these results, these tumor masses were diagnosed as multiple trichoepithelioma. To our knowledge, this is the first report of canine multiple trichoepthelioma in a dog in Korea.

• Journal of fish pathology
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• v.19 no.2
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• pp.99-108
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• 2006

Diseased tiger puffer (Takijugu rubripes) showed anorexia and severe anemia in the gills. In wet mount preparations Heterobothrium sp. with 4 sets of clamps on the opisthohaptor attached to the gill filaments of the diseased fish. From the drum-shaped filter for filtration of the culturing water and the sediment of aquarium held the diseased fish in the laboratory, their eggs forming long strings through connection of the bipolar filaments could be easily collected. The parasites with 4 pairs of clamps on the opisthohaptor were 2.38mm in length and 0.71 mm in width, but had no isthmus which was separated the opisthohapor from the body proper. The parasites could be easily distinguished from Heterobothrium tetrodonis and H. okamotoi in the absence of distinct isthmus, and resembled H. yamagutii described from the gills of Takifugu xanthopterus in Japan. Their eggs were yellowish spindle in shape and 180-200 x 5-6 Iffil in size, which were pointed at both ends. The eggs were linked to adjacent egg shells like a string of beads by the filaments. Onchomiracidia, ciliated larvae spawned from the eggs were 133 Iffil (120-146 Iffil) x 751ffil (68-80 Iffil) in size. The length of the ciliates was 12 Iffil in the anterior part of the larvae and 14 Iffil in the posterior part. Round or leaf-shaped young parasites attached on the secondary gill lamellae. There was a tendency that most of round smaller parasites without an opisthohaptor were found in the middle part of the gill lamellae while leaf-shaped larger ones with a opisthohaptor attached on the distal part of the gill filaments. Each clamp of mature parasites grasped one secondary gill filament which resulted in bending of the filaments and hyperplasia of the epithelium and mucous cells. In the branchial cavity around the pseudobranch, mature parasites grasped the adjacent ones by means of the clamps, and the epithelia of the branchial cavity around the parasites showed severe irregular hyperplasia and erosion with strongly PAS-positive mucous cells.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.220-225
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• 1999

The aim of these experiments was to investigate the effects of bovine oviduct epithelial cells (OEC) derived from different segments to bind sperm binding and maintain their motility in vitro. In experiment 1, the number of sperm attached to OEC derived from isthmus or ampulla, the motility of unattached sperm during co-culture and fertilizing ability were assessed. In experiment 2, heparin treated sperm (hsp) or no treated sperm (nsp) were used to evaluate OEC binding ability of capacitated sperm. In experiment 1, regardless of their origin, approximately 65% of the sperm were attached to OEC within 2h. From 6h of co-culture, the numbers of unattached sperm on ampullary OEC were significantly higher than those on isthmic OEC (p<0.005). From 12h of co-culture, the motility of unattached sperm on isthmic OEC were significantly higher than those on ampullary OEC(p<0.05). The cleavage rate of oocytes inseminated on OEC derived from isthmic segment was also significantly higher than those from ampullary segment (p<0.01). In experiment 2, the numbers of unattached hsp on OEC were significantly higher than those of controls (p<0.01), between 2-24h examination. From 12h of co-culture, the motility of unattached nsp were significantly greater than those of hsp (p<0.01). These results show that bovine OEC derived from the isthmus play more important role(s) for sperm binding, maintaining motility and fertilization in vitro than those from the ampulla, and heparin induced capacitation may change sperm binding ability on OEC in vitro.

• Korean Journal of Animal Reproduction
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• v.14 no.4
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• pp.253-261
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• 1990

This study was carried out to investigate the factors affecting development in vitro of follicular oocytes fertilized in vitro in Korean Native Cattle. The bovine ovaries were obtained at a slaughter house and the follicular oocytes were recovered by aspirating the follicular fluid from the visible follciles of 3~6mm. The bovine oocytes were matured in vitro for 20~24 hours in TCM0-199 containing 10% FCS and hormones (0.02AU/ml FSH, 10$\mu\textrm{g}$/ml LH, 1$\mu\textrm{g}$/ml estradiol-17$\beta$). The matured oocytes were fertilized in vitro using Percoll-separated frozen-thawed spermatozoa in BO solution containing caffeine(5mM) and heparin(10$\mu\textrm{g}$/ml). Twenty-four hours after insemination, the oocytes were cultured in vitro and then the effects of cumulus cell layer, co-culture with cumulus cells, bovine oviduct epithelial cells from ampulla or isthmus on development of ova, were studied. The results obtained are summarized as follows : 1. The in vitro development degree of oocytes attached with compact and dense layered cumulus cells was higher than that with 3~4 layered cumulus cells to be 9~16cells(P<0.01). 2. When the in vitro fertilized oocytes were co-cultured with bovine oviduct epithelial cells or cumulus cells, the development rate to be morula was 20.2% and 12.7%, respectively and the rates were higher than that of control, 2.1%(P<0.05). 3. The development rate to be morula was 15.8% and 23.8%, respectively when the in vitro fertilized oocytes were co-cultured with bovine oviduct epithelial cells from ampulla or isthmus, and the rates were higher than that of control, 0%(P<0.05%).

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.655-669
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• 1995

Restorative procedures can lead to weakening tooth due to reduction and alteration of tooth structure. It is essential to prevent fractures to conserve tooth. Among the several parameters in cavity designs, cavity isthmus is very important. In this study, amalgam 0 cavity was prepared on maxillary first premolar. Two dimensional finite element models were made by serial photographic method and isthmus(1/4, 1/3, 1/2, 2/3 of intercuspal distance) were varied. Three or four-nodal mesh were used for the two dimensional finite element models. The periodontal ligament and alveolar bone surrounding the tooth were excluded in these models. 1S model was sound tooth with no amalgam cavity. B model was assumed perfect bonding between the restoration and cavity wall. Both compressive and tensile forces were distributed directly to the adjacent regions. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed von Mises stress, 1 and 2 directional normal stress and Y and Z axis translation with FEM software Super SAPII Version 5.2 (Algor Interactive System Co.) and hardware 486 DX2 PC. The results were as :follows : 1. 1S model was slightly different with 1B model in stress distibution. 1S, 2B, 3B, 4B models showed similiar stress distribution. 2. 1S model and four B models showed similiar pattern in Y axis and Z axis translation. 3. 1S model and four B models showed the bending phenomenon in the translation. 4. As increasing of the width of the cavity, experimental group was similiar with the control group in stress distribution. 5. As increasing of the width of the cavity, experimental group was similiar with the control group in Y and Z axis tranlation.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.487-501
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• 1998

In the case of CAD/CAM ceramic inlay restorations, if isthmus width is widened too much, it may cause fracture of remaining tooth structure or loss of bonding at the luting interface because of excessive displacement of buccal or lingual cusps under occlusal loads. So to clarify the criterior of widening isthmus width, this study was designed to test the tensile bond strength and bond failure mode between dentin and ceramic cemented with luting composite resin cements. Cylindrical ceramic blocks(Vita Cerec Mark II, d=4mm) were bonded to buccal dentin of 40 freshly extracted third molars with 4 luting composite resin cements(group1 : Scotchbond Resin Cement/Scotchbond Multi-Purpose, group2 : Duolink Resin Cement/ All-Bond 2, group3: Bistite Resin Cement/Ceramics Primer, and group4:Superbond C&B). Tensile bond test was done under universal testing machine using bonding and measuring alignment blocks(${\phi}ilo$ & Urn, 1992). After immersion of fractured samples into 1 % methylene blue for 24 hours, failure mode was analysed under stereomicroscope and SEM. Results: The tensile bond strength of goup 1, 2 & 4 was $13.97{\pm}2.90$ MPa, $16.49{\pm}3.90$ MPa and $16.l7{\pm}4.32$ MPa, respectively. There was no statistical differences(p>0.05). But, group 3 showed significantly lower bond stregnth($5.98{\pm}1.l7$ MPa, p<0.05). In almost all samples, adhesive fractures between dentin and resin cements were observed. But, in group 1, 2 & 4, as bond strength increased, cohesive fracture within resin cement was observed simultaneously. And, in group 3, as bond strength decreased, cohesive fracture between hybrid layer and composite resin cement was also observed. Cohesive fracture within dentin and porcelain adhesive fracture were not observed. In conclusion, although adhesive cements were used in CAD/CAM -fabricated ceramic inlay restorations, the conservative priciples of cavity preparation must be obligated.

• Journal of Chest Surgery
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• v.13 no.3
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• pp.269-273
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• 1980

The rupture of the aorta commonly follows major blunt trauma to the thorax. It has markedly increased in recent years, paralleling the rising number of vehicular accidents. The most frequent site of rupture is the area of the isthmus, with the ascending aorta second. The diagnosis of the condition from clinical data is difficult, and aortography is used whenever aortic tear is suspected. We are presenting a case of patient who had intimal tearing of the thoracic aorta with multiple injuries. The patient underwent surgical repair 28 days after injury with left heart [LA-Femoral artery] bypass.

• Korean Journal of Poultry Science
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• v.26 no.1
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• pp.27-33
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• 1999

The distribution of oviductal vessels of eight Korean native pheasants was observed after Latex casts of vessels. Latex was injected into thoracic aorta and posterior vena cava of these birds for cast preparation. The results were as follows: 1. The arteries suppling oviduct of the Korean native pheasants contained A. oviductalis cranialis, media, caudalis and vaginalis. The veins drainaging oviduct were stretched along the following ateries and all of the oviductal vessels were situated on the left side of the body. 2. The anterior oviductal artery arose from the pubic artery of the left external iliac artery and distributed to the infundibulum and the magnum of the oviduct. 3. The middle oviductal artery arose from the left sciatic artery and distributed to the isthmus and shell gland of the oviduct. 4. The caudal artery arose from the left internal pudendal artery of the median sacral artery and distributed to the caudal part of uterus and the cranial part of vagina. 5. The vaginal artery arose from the left internal pudendal artery of median sacral artery and distributed to the caudal part of vagina.