골흡수 기전에 관한 연구 : 파골세포의 활성화 기전 MECHANISM OF OSTEOCLAST ACTIVATION

정동균,고재승,김관식,김각균,민병무,김세원 대한구강생물학회 1989 International Journal of Oral Biology Vol.13 No.1

Although the osteoclast has long been recognized to be the cell responsible for bone resorption, little is known of the mechanisms by which its activity is controlled. Recently, it has been suggested that osteoblasts ─ the bone-forming cells ─ seem to be the target cells of PTH, the bone-resorbing hormone, and mediate osteoclastic bone resorption by producing the coupling factor(s). Because bone tissue consists of several types of cells, isolation of distinct bone cell populations is prerequisite for studying the mechanism of bone resorption in cellular level. This experiment was performed ⅰ) to isolate the metabolically distinct bone cell populations from fetal rat calvaria by sequential enzyme digestion and biochemical characterization and ⅱ) to identify the factor(s) produced by osteoblast that stimulate resorption employing organ culture of bone. Calvaria from rat fetus at 19 day of gestation, were sequentially digested by enzyme solution consisted of collagenase, trypsin and EDTA for 10 (population I), 10(II), 10(III), 20(IV) and 20 minutes (V). Each bone cell population was primarily cultured for 6-7 days and effects of PTH, calcitonin and PGE_2 on acid and alkaline phosphatase activity and cAMP level were determined. Basal level of acid phosphatase in populations released early were higher than late population. In contrast, basal level of alkaline phosphatase was reversed. PTH(0.4 unit/ml) increased the acid phosphatase activity only in population I with no effect on alkaline phosphatase. Calcitonin(150ng/ml) had no effect on acid and alkaline phosphatase activity in all bone cell populations. cAMP level of population IV and V were increased by PTH significantly while CT had no effect in all bone cell populations at all. PGE_2 increased cAMP in all populations, the acid phosphatase activity in population I and alkaline phosphatase activity in population IV and V. Taken together, these results indicate that population IV and V express typical osteoblastic phenotype while population I revealed some characteristics of osteoclast. Bone cell population IV and V were incubated with fresh MEM or MEM containing 0.4U/ml PTH for 2 hours. After 2 hour-incubation, both the control-conditioned media(control-CM) or PTH-conditioned media(PTH-CM) were collected. Both conditioned media were lyophyllized and redissolved as 2 fold concentrate. Ulnae and radii were removed from 19-day old fetal rats, prelabelled by subcutaneous injection of 200μCi ^45CaCl_2 into their mothers on the 17th day of gestation. After 24 hours, media was changed with fresh BGJb media or BGJb media containing 300μl of control-CM or PTH-CM and cultured for 5 days. Effects of control-CM or PTH-CM were observed by the ratios of %-release of ^45Ca between paired control and experimental group. Control-CM obtained from population IV and V had no or very little effect on bone resorption but PTH-CM obtained from population IV and V increased the ^45Ca release significantly after 3 and 5 days of culture. This result provides the evidence indicating that osteoblastic cells mediate osteoclastic bone resorption stimulated by PTH.

LSTM 인공신경망을 이용한 자동차 A/S센터 수리 부품 수요 예측 모델 연구

정동균,박영식 한국정보시스템학회 2022 情報시스템硏究 Vol.31 No.3

Purpose The purpose of this study is to identifies the demand pattern categorization of repair parts of Automotive After-sales Service(A/S) and proposes a demand prediction model for Auto repair parts using Long Short-Term Memory (LSTM) of artificial neural networks (ANN). The optimal parts inventory quantity prediction model is implemented by applying daily, weekly, and monthly the parts demand data to the LSTM model for the Lumpy demand which is irregularly in a specific period among repair parts of the Automotive A/S service. Design/methodology/approach This study classified the four demand pattern categorization with 2 years demand time-series data of repair parts according to the Average demand interval(ADI) and coefficient of variation (CV2) of demand size. Of the 16,295 parts in the A/S service shop studied, 96.5% had a Lumpy demand pattern that large quantities occurred at a specific period. lumpy demand pattern’s repair parts in the last three years is predicted by applying them to the LSTM for daily, weekly, and monthly time-series data. as the model prediction performance evaluation index, MAPE, RMSE, and RMSLE that can measure the error between the predicted value and the actual value were used. Findings As a result of this study, Daily time-series data were excellently predicted as indicators with the lowest MAPE, RMSE, and RMSLE values, followed by Weekly and Monthly time-series data. This is due to the decrease in training data for Weekly and Monthly. even if the demand period is extended to get the training data, the prediction performance is still low due to the discontinuation of current vehicle models and the use of alternative parts that they are contributed to no more demand. Therefore, sufficient training data is important, but the selection of the prediction demand period is also a critical factor.

한국인의 치아우식 조절에 관한 연구 : Ⅲ. 만경강 유역 주민의 뇨중 불소농도, 반상치 지수에 관한 연구 STUDY ON THE RELATION BETWEEN THE URINARY FLUORIDE CONCENTRATIONAND THE FLUOROSIS INDEX OF RESIDENTS IN MANKYUNG RIVER VALLEY

정동균,정태영,이종흔,김중수,오귀옥,이효재 대한구강생물학회 1980 International Journal of Oral Biology Vol.4 No.1

This experiment was conducted to elucidate the relation between the urinary fluoride concentration and the fluorosis index of residents in Mankyung River valley, especially in 3 areas (Yookang-ri, Koje·Yoochun, Shinbok·Yongkang) with high fluoride concentration in drinking water. The urinary fluoride concentration was measured by fluoride ion electrode, and dental fluorosis was surveyed and analysed by Dean and McKay's and Horowitz's method. 1. There was no reletionship between the urinary fluoride concentration and age. 2. 11-20 years age groups has revealed the highest fluofosis index. In this group : 3. There showed a parallel relationship between the fluorosis index and the urinary fluoride concentration. 4. DMF rates of residents in Yookang-ri, Koje and Shinbok are 59.2, 48.4 and 47.1%, respectively. 5. There showed a parallel relationship between the years of residence within 8 years after birth and the fluorosis index.

한국인의 치아우식 조절에 관한 연구 : Ⅱ.흰쥐 치아우식 이환율에 미치는 수종 양념의 영향에 관한 추가연구 Ⅱ. ADDITIONAL STUDIES ON THE EFFECTS OF THE SEVERAL SPICES ON THE CARIES RATE IN RATS

정동균,이종흔,김각균,이공훈,오귀옥,정태영 대한구강생물학회 1980 International Journal of Oral Biology Vol.4 No.1

Those studies were performed to elucidate the effects of several dietary spices on dental caries and to determine which component of spices induced the change of incidence of dental caries in Sprague-Dawley rats which were supplied from SNU animal house. For this study, 132 rats (rats weighing 90-140 gm) were chosen at random with the same number of both sexes and divided into eleven experimental groups which contained the differential components of drinking water and diets for control and experimental group. Control group was fed standard cariogenic diet and tap water. In experimental groups, rats were fed standard cariogenic diet supplemented with capsicum (10%), ash capsicum (1, 10%), garlic (5%), common salt (3%), and analytical salt (3%) for 80 days. Drinking water was tap water containing water extract of capsicum (1, 10%), water extract of garlic (1.1%), and fluoride (50ppm). The results were as follows. 1. 54.6 in caries score was recorded in control group. 2. Rats which drank water containing 50ppm of fluoride showed 18.4% decrease in caries score. 3. Capsicum-fed rats showed 10.7% (capsicum 10%) increase in caries score and rats which drank water containing water extract of capsicum (1, 10%) showed 14.1% (w.e. capsicum 1%) and 0.16% (w.e. capsicum 10%) increase in caries score. But ash capsicum-fed rats showed 18.7% (ash capsicum 1%) and 7.3% (ash capsicum 10%) decrease in caries score. 4. Garlic-fed rats showed 22.1% (garlic 5%) decrease in caries score. But rats which drank water containing 1.1% of water extract of garlic showed 24.1% increase in caries score. 5. 58.4% and 68.0% increase in caries score were recorded in rats which were fed diet containing common salt (3%) and analytical NaCl (3%), respectively.

인삼(人蔘), reserpine, 및 chlorpromazine이 epinephrine 및 morphine 과혈당(過血糖)에 미치는 영향(影響)

정동균,Cheong, Dong-Kyun 대한약리학회 1965 대한약리학잡지 Vol.1 No.1

Besides it's all important analgesic action, morphine has, among others, hyperglycemic effect, though not important clinically, which is believed to be resulted from augmented glycogenolysis in the liver and muscles due to the increased liberation of epinephrine from the adrenal medulla upon the stimulation of the posterior part of hypothalamus. It is known that adrenergic blocking agents are acting inhibitory to this sort of hyperglycemia. Much, however, should as yet be studied for the drugs which affect central nervous system and release of endogenous catecholamine as far as their effects on hyperglycemia are concerned. Much is still not known about the effect of ginseng, which has been highly regarded in the Herb Medicine, as far as it's influence on the blood sugar is concerned. Author investigated the effects of chlorpromazine, reserpine and ginseng on epinephrine induced, and morphine-induced hyperglycemiae. Animals used in this experiment were healthy albino rabbits weighing approximately 2.0 kg of body weight and were all fasted for 24 hours, before the experiment undertaken. Blood sugar determination was carried out by Nelson-Somogy method. Results obtained are summarized as follows; 1. The groups of rabbits administered intravenously with epinephrine 0.02 mg/kg, and 0.05 mg/kg, showed marked and transient hyperglycemia within 15 minutes after injection. The maximal rate of elevation in blood sugar to the control level, were 28% and 57% respectively. The blood sugar returned to the control level within 3 hours. Thus, the hyperglycemic responses were paralleled with epinephrine doses. 2. The hyperglycemic responses by morphine were different according to the doses. The groups of rabbits in which 4 mg/kg of morphine was administered, did not show any hyperglycemic effect, but, in which 10 mg/kg of morphine administered, showed severe hyperglycemic effect, resulting in the maximal level within 2 hours after injection. The maximal rate of increasing in blood sugar ,level was 88%. Compared .with epinephrine-injected groups, morphjne-injected groups showed more persistent hyperglycemic effect, but returned to control blood sugar .level in 6 hours after injection. 3. The intravenous injection of chlorpromazine 2 mg/kg and 8 mg/kg evoked a slight, and persistent hyperglycemia. The maximal rate of increasing in blood sugar level were 15% and 23% respectively. These hyperglycemia gradually returned to the normal level in 5 or 6 hours after injection. Thus, the intensity of response was paralleled with the dose of chlorpromazine. 4. The intravenous injection of reserpine 0.2 mg/kg and 0.5mg/kg, showed the most persistent but steady elevation of blood sugar level in this experiments, resulting in the maximal level in 5 hours after injection. The maximal rate of increasing of blood sugar level were 18% and 39% respectively. 5. The blood sugar level from 24 hours to 30 hours after intraperitoneal administration of reserpine 1.0mg/kg, did not show statistically significant difference, compared with control groups. 6. The oral administration of ginseng extract 15 ml/kg did not. show any :change in blood sugar level. 7. The intravenous administration of epinephrine 0.05 mg/kg or morphine 4 mg/kg to the group pretreated with ginseng extract 15 ml/kg $20{\sim}30$ minutes before the experiment, evoked more marked hyperglycemic effect than the non-pretreated group. 8. The intravenous administration of epinephrine 0.02 mg/kg, morphine 4 mg/kg, or morphine 10 mg/kg to the groups pretreated with reserpine 0.2 mg/kg or 0.5 mg/kg $20{\sim}30$ minutes before experiment, produced more marked and persistent hyperglycemic effects than the groups injected with single epinephrine or morphine injection. 9. When epinephrine 0.05 mg/kg or morphine 10 mg/kg administered intravenously to the groups pretreated with the intraperitoneal administration of reserpine 1 mg/kg 24 hours before experiment morphine-induced hyperglycemia was i

Periaquenductal gray 와 nucleus raphe magnus 자극이 medullary dorsal horn의 세포 활성도와 serotonin 및 enkephalin 농도에 미치는 영향

정동균,이종흔,김중수 대한구강생물학회 1987 International Journal of Oral Biology Vol.11 No.2

This experiment was carried out to clarify the role of periaqueductal gray (PAG) on the neural activity in medullary dorsal horn (MDH) and influences of PAG or nucleus raphe magnus (NRM) on methionine-enkephalin (MENK) and serotonin which were related to modulation of pain. Rabbits were operated under general anesthesia, and fixed to stereotaxic apparatus. Caudal brainstem and rostral spinal cord were exposed and activity of neurons in MDH were recorded with glass-coated tungsten microelectrode. The cells which were responded to noxious or non-noxious stimuli were classified as low threshold (LT), wide dynamic range (WDR) and nociceptive specific (NS) neuron, and modulatory effects of PAG on these neurons were evaluated. In some animals, brainstem including MDH was removed after PAG or NRM stimulation for quantifying the content of serotonin and MENK by HPLC and RIA, respectively. PAG stimulation modulated activities of LT, WDR and NS neurons in MDH, and mainly produced inhibitory effect. The inhibitory effects of PAG stimulation were significantly greater in NS neurons than in LTneurons (χ^2=3.98, P<0.05). Content of serotonin in MDH was decreased by PAG or NRM stimulation, this effect was greater in NRM stimulation than in PAG stimulation. In MENK content, PAG or NARM stimulation induced only slight decrease. In summary, PAG influenced afferent pathway for central transmission of mechanical stimuli in oro-facial region, and serotonin and MENK were related to descending inhibitory mechanism of PAG and NRM.

동통에 대한 약물요법

정동균 치과연구사 1990 치과연구 Vol.28 No.1

白鼠에 있어 不顎位置變動 및 藥物投與가 顎關節 및 齒牙組織의 組織像 및 數種成分의 變動에 미치는 影響

丁東均(Dong Kyun Cheong) 대한치과의사협회 1977 대한치과의사협회지 Vol.15 No.5

낭창성 신염환자에서 단백뇨의 임상적 의의

정동균,김미림,함영환,최규현,하성규,이호영,한대석 대한신장학회 1988 학술대회및초록집 Vol.7 No.1

Ascorbic acid가 두개관 세포군의 cAMP농도에 미치는 영향

정동균,김관식,김세원 대한구강생물학회 1989 International Journal of Oral Biology Vol.13 No.1

Ascorbic acid has long been known to influence the bone formation by hydroxylating the proline and lysine residues of collagen. Although there were no direct evidences, this effect might be due to the effect on the function of osteoblasts. This study was undertaken to investigate the effect of ascorbic acid on the cAMP accumulation in the calvarial bone cell populations. Fetal rat calvaria at 19th day of gestation were sequentially digested with enzyme mixture of collagenase, trypsin and EDTA for 10, 10, 10, 20 and 20 minutes. Each calvarial bone cell population was primarily cultured for 6-7 days, and then the effects of ascorbic acid, PTH and their combination on the cAMP accumulation were determined. The results were as follows. 1. Ascorbic acid, at concentration of 100㎍/ml, had no effect on the cAMP accumulation in all bone cell populations. 2. PTH, at concentration of 0.4U/ml, increased cAMP in population I, II, IV and V and decreased cAMP in population III, but the effect of PTH was great in population IV and V. 3. Ascorbic acid plus PTH increased the cAMP in population I, II, IV and V, and showed the synergistic effect in population IV.