• 치과방사선
• /
• 제22권2호
• /
• pp.315-327
• /
• 1992

The purpose of this study was to evaluate the utilization of the orthopantomograph as a diagnostic aid to observe maxillary sinus and adjacent structures. For achieving this goal. the lead plates were attached to the five walls of the maxillary sinus of a human dry skull. The dry skull was placed in fourteen different positions; standard. 20mm forward. 20mm backward. 10 degree upward. 10 degree downward. 20mm lateral. forward & upward, forward & downward. forward & lateral. backward & upward. backward & downward, backward & lateral. upward & lateral. downward & lateral position. The obtained results were as follows: 1. The image of the medial wall was observed very differently according to the head positions. 2. The image of the anterior wall was observed at medial third to half of the maxillary sinus in each head position. 3. the image of the posterior wall was always observed at lateral third of the maxillary sinus in all head positions and more obviously in the downward-lateral position. 4. The image of the superior wall was observed at the inferior third to half of the orbit in each head position. 5. The image of the inferior wall was always observed at the inferior third of maxillary sinus in all head positions and observed more obviously in the standard and downward-lateral positions. 6. The images of the zygomatic process. zygomatic arch and zygomaticotemporal suture were observed very well in the downward-lateral position.

• 한국산업보건학회지
• /
• 제23권3호
• /
• pp.273-286
• /
• 2013

Objectives: The present study was conducted in order to investigate the reproductive toxicity in rats exposed to 1,4-dichlorobutane. Methods: The test chemical was administered orally at 0, 8.3, 50 and 300 mg/kg/day. Males were administered daily for 10 weeks prior to the mating period. Females were administered from between two weeks before mating to the 21stday of lactation. Results: In both sexes, a decrease in body weight and an increase in the weights of the liver and kidneys were observed. In males, discoloration of the liver, hepatocyte hypertrophy and mineralization in the kidneys were observed. In females, animal deaths, dystocia and pup deaths due to maternal dysfunction were observed. In F1 animals of both sexes, a decrease in body weight was observed at 300 mg/kg/day. An increase in the weights of the liver in both sexes, mineralization in the kidneys of males, animal deaths, hepatocyte hypertrophy and pup deaths due to maternal dysfunction were observed at 50 mg/kg/day. Mineralization in the kidneys of males was observed at 8.3 mg/kg/day. Therefore, the no-observed-adverse-effect levels (NOAELs) of 1,4- dichlorobutane were considered to be under 8.3 mg/kg/day for males, 8.3 mg/kg/day for females, more than 300 mg/kg/day for fertility in both sexes, 8.3 mg/kg/day for maternal functions and 50 mg/kg/day for F1 offspring. The absolute toxic dose was believed to be 8.3 mg/kg/day for males, 50 mg/kg/day for females, 50 mg/kg/day for maternal functions and 300 mg/kg/day for F1 offspring. However NOAEL for fertility could not be determined since there were no treatment-related changes. Conclusions: Under the present experimental conditions, 1,4-dichlorobutane is a Category 1B Reproductive Toxicant (presumed human reproductive or developmental toxicant).

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제22권2호
• /
• pp.133-141
• /
• 2000

Purpose : The purpose of this study is to estabilish clinical guidance of microvascular anastomosis in diabetic patients. This study was performed with experimental microvascular anastomosis in streptozotocin induced diabetic rats and observed histopathologic change and endohelial healing process. Materials and Methods : 70 Sprague-Dawley rats, weighting 200 to 250grams, were used for the experiment. 35 induced diabetic rats with streptozotocin and 35 control group were selected. After end-to-end carotid artery microvascular anastomosis was done, the experimental rats were sacrificed at different time interval (1st day, 3rd day, 1st week, 2nd, 4th, 6th and 8th week) for histologic examination. Light microscope observation was used in this study. Results : 1. Histopathologic changes are nearly the same healing process in two groups. But period of tissue reaction was faster in the control than diabetic group. 2. In endotheliall healing, control group started at 1 week after and completed at 4 weeks after, but diabetic group was observed partially at 4 weeks after and complete healing was not observed still at 8 weeks after. 3. In subintimal hyperplasia, control group was observed at 6 weeks after but diabetic group was observed at 6 weeks after and partially at 8 weeks after. 4. All groups showed severe inflammatory response in the early period. This respond is decreased at 2 weeks after in control group but still remained at 8 weeks after in the diabetic group. 5. In media, inflammatory response and degeneration were observed in early period. Regeneration of smooth muscle cell was observed at 1 week after in control group but 4 weeks after in the diabetic group. Conclusions : As the results of study, it could be thought that vascular regeneration process was not failured but delayed in the diabetes. It was considered that diabetes mellitus was not absolute contraindication of microvascular anastomosis.

• 대한치과교정학회지
• /
• 제24권4호
• /
• pp.969-982
• /
• 1994

This study was designed to investigate the stress distribution, intensity and force mechanism derived from the MEAW by photoelastic stress analysis of the artificial teeth and surrounding bone composed of photoelastic material(PL-3) The findings of this study were as follows, 1. In case of no elastic on the MEAW with tip back, the moderate stress was observed on the molar and canine area, and the light stress was observed on the other area. 2. In case of the vertical elastic on the plain A.W, and the MEAW without tip back, the great stress was observed on the lateral incisor area, but on the MEAW with tip back, the moderate stress was observed on the anterior area and molar area. 3. In case of the C III elastic on plain A.W., the stress was concentrated on the anterior area hanged by elastic but on the MEAW without tip back, the stress was transmitted equally from the anterior area to the posterior teeth area. On the MEAW with tip back, the great stress was observed on the anterior and molar area. 4. In case of the C III elastic on the plain A.W., the stress was concentrated on the posterior area hanged by elastic but on the MEAW without tip back, the stress was transmitted equally from the posterior area to the anterior area. On the MEAW with tip back, the great stress was observed on the posterior area and the moderate stress was observed on the anterior area.

• 한국농공학회지
• /
• 제34권2호
• /
• pp.73-84
• /
• 1992

The TIDE, finite element model for the simulation of tidal flow in shallow sea was tested for its applicability at the Saemangeum area. Several pre and post processors were developed to facilitate handling of the complicated and large amount of input and output data for the model developed. Also an operation scheme to run the model and the processors were established. As a result of calibration test using the observed data collected at 9 points within the region, linearlized friction coefficients were adjusted to be ranged 0.0027~0.0072, and water depths below the mean sea level at every nodes were changed to be increased generally by 1 meter. Comparisons of tidal velocities between the observed and the simulated for the 5 stations were made and obtained the result that the average relative error between simulated and observed tidal velocities was 11% for the maximum velocities and 22% for the minimum, and the absolute errors were less than 0.2m/sec. Also it was found that the average R.M.S. error between the velocities of observed and simulated was 0.119 m/sec and the average correlation coefficient was 0.70 showing close agreement. Another comparison test was done to show the result that R.M.S. error between the simulated and the observed tidal elevations at the 4 stations was 0.476m in average and the correlation coefficients were ranged 0.96~0.99. Though the simulated tidal circulation pattern in the region was well agreed with the observed, the simulated tidal velocities and elevations for specific points showed some errors with the observed. It was thought that the errors mainly due to the characteristics of TIDE Model which was developed to solve only with the linearized scheme. Finally it was concluded that, to improve the simulation results by the model, a new attempt to develop a fully nonlinear model as well as further calibration and the more reasonable generation of finite element grid would be needed.

• Applied Microscopy
• /
• 제28권1호
• /
• pp.21-38
• /
• 1998

The present study was performed to determine the effect of cold stress on myocardium of aging rat. Control groups, which aged 6, 12 and 24 months, were compared with age-matched experimental groups that were exposed to moderate cold stress for a hours daily in a week at laboratory cold room $(4{\pm}1^{\circ}C)$. The histological, histochemical and ultrastructural changes of myocardium were observed. The results were summarized as follow: 1. Age-dependent histological change of control groups was observed the formation of contraction band in 24months aged group. The experimental groups submitted to cold stress showed a similar change pattern as seen in control groups. However, the degree of change in the experimental groups was significantly larger than that of control groups. In the 34 months aged group the formation of hypercontraction band was observed. 2. Regarding age-dependent histochemical changes of control groups, we observed the increase activities of PAS and Masson's trichrome. In experimental groups the activities of PAS and Masson's trichrome were also increased with age. Compare with control group, the activities of PAS was increased but the activities of Masson's trichrome was decreased. 3. Age-dependent ultrastructural changes on vacuolization, lysosome were observed. In control groups the structural changes occur at 12 months. The accumulation of lipofuscin, contraction band, hypercontraction band and a component of connective tissue were observed in 24 months. However, the degree of change in the experimental groups was significantly larger than that of control groups. In contract, the myelin body in intercalated discs was observed in 24 months of experimental groups.

• 대한치과교정학회지
• /
• 제21권3호
• /
• pp.603-614
• /
• 1991

To study the possibility of attraction magnetic forces to expand maxillary arch, we used 2 big adult dogs, 2 small puppies, 1 small adult dog as experiments, and 1 small adult dog as a control. We measured the intercanine width and intermolar width and histologically observed in the suture and cervical and apex region of teeth and took occlusal X-rays to observe separation of suture line in the maxilla. The results were as follows: 1. Expansion velocities of intercanine (0.25mm/day) and intermolar widths (0.23mm/day) in puppies were faster than those (0.135mm/day, 0.09mm/day) in adults. 2. In all experiments in adults (0.135mm/day) and puppies (0.25mm/day), expansion velocity of intercanine widths were faster than those (0.09mm/day, 0.23mm/day) of intermolar width. 3. In all experiments ectatic changes were observed and cellularities of fibroblast increased in the suture line. Only in adults dogs the separations of palatal suture were observed in the occlusal X-ray view. 4. In the puppies bony deposition was particularly observed in the suture line and micro-bony fragments were often observed. 5. In the all experiments no root resorption was observed in the cervical and root area, but normal root resorption due to eruption of permanent teeth was observed in the puppies.

• 대한본초학회지
• /
• 제25권2호
• /
• pp.41-54
• /
• 2010

Objectives : This study was carried out to investigate the anti-toxicity effect of Hwangryunhaedoktang on the dried Mylabris phalerata extract containing cantharidin in ICR mouse. Methods : Dried Mylabris phalerata extracts were orally administered at dosage level 2000, 1000, 500, 250 and 125mg/kg, respectively with and/or without administration of Hwangryunhaedoktang 200mg/kg. During 2 weeks, the changes of body weight, mortality, $LD_{50}$, macroscopic changes of gastrointestinal tract and liver, changes of serum gastrin and somatostatin levels were observed. Results : Decrease of body weight gains was observed in dried Mylabris phalerata extract-dosing groups, but it was significantly developed in Hwangryunhaedoktang extract-dosing groups after dosaging. Increase of mortality rates was observed in dried Mylabris phalerata extract-dosing groups, but it was significantly developed in Hwangryunhaedoktang extract-dosing groups after dosaging. The $LD_{50}$ of dried Mylabris phalerata extract in male mice significantly increased in a case of concomitant used of Hwangryunhaedoktang 268.86 vs 662.05mg/kg. Clinical signs were observed in dried Mylabris phalerata extract-dosing groups, but it was significantly developed in Hwangryunhaedoktang extract-dosing groups after dosaging after dosaging. Increase of number of hemorrhagic and/or erythematous spots in the gastrointestinal tracts, enlargement and congestion in the liver were observed in dried Mylabris phalerata extract-dosing groups, but it was significantly developed in Hwangryunhaedoktang extract-dosing groups after dosaging. Increase of serum gastrin level was observed in dried Mylarbis phalerata extract-dosing groups, these state of abnormal increase was significantly developed in Hwangryunhaedoktang extract-dosing groups after dosaging. Decrease of serum somatostatin level was observed in dried Mylabris phalerata extract-dosing groups, these state of abnormal decrease was significantly developed in Hwangryunhaedoktang extract-dosing groups after dosaging. Conclusions : We could conclude that the Hwangryunhaedoktang has anti-toxicity effect on the dried Mylabris phalerata extract containing cantharidin.

• Plant Resources
• /
• 제3권3호
• /
• pp.163-172
• /
• 2000

We compared microstructural features of the ordered cell and disordered leaves in Citrus junos Sieb. by electron microscopy. In the cell of the ordered leaves, many chloroplasts and large vacuoles were particularly observed. Also a lot of vessel, companion cell and big nucleus were presented in vascular bundle regions. The mitochondria and the other organelles were interspersed among the chloroplasts in a thin, peripheral layer of cytoplasm. The chloroplast possessed typical grana and intergranal lamellae, numerous starch grains and a few small osmophilic globules. Besides, microbodies were closely associated with the mitochondria and the chloroplast. The process of the formation of the secondary cell wall from primary cell wall was observed the vessel elements, the tonoplast wall and the secondary cell wall. It was observed that the oil sac with the unique perfume distributed the adjacent cell wall. In the cell of disordered leaves, the all of the organelles were thrust toward the cell wall due to the fusion of vacuoles in the cells. It was observed that a lot of the very small particles spreaded in the cytoplasm. The loss of unique perfume of the leaves was resulted in the destruction of the oil sac. Also, there was not observed grana, lamellae, starch and osmophillic globules in the chloroplast. The small distributed organelles was not observed but the elongation of the cell wall was proceed no longer. Therefore, the plasma membrane diverged from the cell wall. All of organelles in the cell had poor function and deformation. A massive vacuole was fulfilled in single cell and the vacuole contains a lot of large and small particles. The organelles were presented on the side of the cell wall according to the enlargement of vacuole and they were observed to be breakdown.

• Journal of Korean Neurosurgical Society
• /
• 제30권sup1호
• /
• pp.61-67
• /
• 2001

Objectives : To demonstrate the preventive effect on post-operative spinal deformity of the laminoplasty compared with laminectomy for spinal cord tumor. Methods : Sixteen patients who underwent laminoplasty and 89 patients who underwent lamenectomy were reviewed retrospectively after removal of spinal cord tumors between February 1981 and December 1999. The mean follow-up period after laminoplasty and laminectomy were 29 months(range, 12-49 months) and 66 months(range, 6-120 months) respectively. Patients were observed neurologically and radiologically. Results : Postoperative kyphosis was observed 17 patients(19%) in the laminectomy group, but was not observed in the laminoplasty group. Postoperative slipping was observed 16 patients(18%) in the laminectomy group, but was not observed in the laminoplasty group. Complications such as postoperative scoliosis, rotation, and swan-neck deformity were observed in the laminectomy group, but were not observed in the laminoplasty group. Conclusions : Laminoplasty prevented postoperative spinal deformities after removal of spinal cord tumors, and afforded anatomic reconstruction of the vertebral arch. Additionally, appropriate patient selection maximizes the chance of optimal neurologic outcomes and minimizes complications. Laminoplasty appears to warrant further evaluation as an alternative to wide laminectomies for exposure of intraspinal tumors.