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완전뇌허혈후 재관류시에 국소뇌혈류, 체성감각유발전위 및 신경학적 회복에 대한 Mannitol과 Thiopental의 효과
박춘근,이상원,박영섭,최승진,허필우,정동섭,강준기,최창락 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.2
The cardiopulmonary bypass or cerebral circulation arrest is often used in the treatment of complex aneurysm or of arteriovenous malformation to decrease the risk of intraoperative aneurysm rupture. Although experimental studies have suggested that some drugs may protect the brain from ischemic injury, there are limitations in maintaining cerebral perfusion arrest without incurring neurologic deficits due to the initiation of detrimental processes including excitotoxic neuronal injury, activation of phospholipases, influx of calcium, and generation of damaging free radicals. The purpose of this study is to determine wheter mannitol or thiopental has any favorable effects on the recovery of neurologic deficits and on the regional cerebral blood flow(rCBF), somatosensory evoked potential(SEP) and electroencephalogram(EEG) in cats which underwent 15 minutes-complete global ishcemia-reperfusion. The complete global ischemia was produced in 38 cats by temporary intrathoracic occlusion of the innominate artery and the subclavian artery following ligation of bilateral mammary arteries and simultaneous induction of hypotension. The cats were allocated randomly to one of 4 treatment groups : (1) control group, 8 cats received equal volume of saline solution : (2) thiopental group, 10 cats received 45㎎/㎏ thiopental intravenously, (3) mannitol group, 10 cats received 2g/㎏ mannitol intravenously, (4) combined mannitol and thiopental group, 10 cats received equal dose of mannitol and thiopental intravenously. The drugs were administrated in a equally divided dosage before and after the ischemic episode. The results were as follos : 1) Eight animals which received saline showed the severe postischemic hypoperfusion and poor recovery of SEP and EEG, and 6 of them died within 6 hours after the ischemia. 2) Ten thiopental-treated animals also showed the severe postischemic hypoperfusion and poor recovery of SEP and EEG, and 6 of them died within 6 hours the ischemia. 3) Both mannitol-and combined treated groups showed early recovery of EEG, good recovery of SEP and EEG without the severe postischemic hypoperfusion, and 7 of 10 mannitol-treated animals and 8 of 10 combined treated animals were significantly recovered in all parameters. There were not significant differences in all parameters between the mannitol-and combined treated groups. 4) Thirty-four of 38 animals involved in this 15 minutes-ischemia resulted in the severe neurologic deficits inspite of treatment with mannitol, thiopental or both of them. These results suggest that, in cats, mannitol treatment is effective but not thiopental in preventing severe neurologic injury following complete global ischemia and the duration of complete ischemia should be far less than 15 minutes.
배준우,황재근,박경흠,양희준,이춘열 嶺南大學校 工業技術硏究所 2004 工業技術硏究所論文集 Vol.32 No.1
Recently, force measurement systems are commonly used in many industrial fields and the precision of the measurement system is getting more important as the industry needs more precise tools and instruments to make high quality products. However, a high precision force measurement system is hard to make unless we know precisely the causes, quality and quantity of measurement errors in advance. In this work, many possible mechanical causes of measurement errors are reviewed including ratio of length to diameter of sensing part, radius of contact area, radius of bearing part, ratio of material properties and change of boundary conditions. Also, the measurement errors are analyzed by nonlinear finite element method and the nonlinear behavior of the errors are investigated. The results can be used to design force measurement systems and expected to be very useful especially for compact type load cells.
안형수,장안수,이준혁,박성우,고은석,백상현,박재성,허균,신화균,박춘식 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2
We report a case of a sclerosing hemangioma of the lung with increased size during follow up, a rare benign neoplasm of the lung. A 32-year-old woman had round increased opacity in right upper lobe on posteroanterior chest radiograph. That lesion has grown slowly over four years. Computed tomographic scan showed a well circumscribed lung mass in medial aspect of right upper lobe. Radiological differential diagnosis for the lesion included inflammatory pseudotumor, atypical carcinoid, lung cancer and localized fibrous tumor of pleura. Nonspecific findings were shown by the bronchoscopy and percutaneous transthoracic needle aspiration. Anterior and apical segmentectomy was carried out and the lesion was pathologically diagnosed as sclerosing hemangioma of lung.
Park, Joo-Hee,Choi, Yong-Lak,Kwon, Dae-Jin,Hwang, In-Sun,Park, Choon-Keun,Yang, Boo-Keun,Cheong, Hee-Tae The Korean Society of Animal Reproduction 2009 Reproductive & developmental biology Vol.33 No.4
We attempted to control the maturation promoting factor (MPF) activity and investigated the subsequent reprogramming of bovine somatic cell nuclear transfer (SCNT) embryos. Serum-starved adult skin fibroblasts were fused to enucleated oocytes treated with 2.5 mM caffeine or $150\;{\mu}M$ roscovitine. The MPF activity, nuclear remodeling patterns, chromosome constitutions and development of SCNT embryos were evaluated. Methylated DNA of embryos was detected at various developmental stages. The MPF activity was increased by caffeine treatment or reduced by roscovitine treatment (p<0.05). Blastocyst development was higher in the caffeine-treated groups (27.6%) than that of the roscovitine-treated group (8.3%, p<0.05). There was no difference in the apoptotic cell index among the three groups. However, the mean cell number of blastocysts was increased in the caffeine-treated group (p<0.05). Higher methylation levels were observed in the Day 3 embryos of the roscovitine-treated group (50.8%), whereas lower methylation levels were noted at Day 5 in the caffeine-treated group (12.5%, p<0.05). These results reveal that the increase in MPF activity via a caffeine-treatment creates a more suitable condition for nuclear reprogramming after SCNT.
Park, Sun-Ji,Kim, Tae-Shin,Park, Choon-Keun,Lee, Sang-Hee,Kim, Jin-Man,Lee, Kyu-Sun,Lee, In-kyu,Park, Jeen-Woo,Lawson, Mark A,Lee, Dong-Seok Society for Endocrinology 2013 Journal of molecular endocrinology Vol.50 No.2
<P>Endoplasmic reticulum (ER) stress generally occurs in secretory cell types. It has been reported that Leydig cells, which produce testosterone in response to human chorionic gonadotropin (hCG), express key steroidogenic enzymes for the regulation of testosterone synthesis. In this study, we analyzed whether hCG induces ER stress via three unfolded protein response (UPR) pathways in mouse Leydig tumor (mLTC-1) cells and the testis. Treatment with hCG induced ER stress in mLTC-1 cells via the ATF6, IRE1a/XBP1, and eIF2α/GADD34/ATF4 UPR pathways, and transient expression of 50 kDa protein activating transcription factor 6 (p50ATF6) reduced the expression level of steroidogenic 3β-hydroxysteroid dehydrogenase △5-△4-isomerase (3β-HSD) enzyme. In an <I>in vivo</I> model, high-level hCG treatment induced expression of p50ATF6 while that of steroidogenic enzymes, especially 3β-HSD, 17α-hydroxylase/C17–20 lyase (CYP17), and 17β-hydrozysteroid dehydrogenase (17β-HSD), was reduced. Expression levels of steroidogenic enzymes were restored by the ER stress inhibitor tauroursodeoxycholic acid (TUDCA). Furthermore, lentivirus-mediated transient expression of p50ATF6 reduced the expression level of 3β-HSD in the testis. Protein expression levels of phospho-JNK, CHOP, and cleaved caspases-12 and -3 as markers of ER stress-mediated apoptosis markedly increased in response to high-level hCG treatment in mLTC-1 cells and the testis. Based on transmission electron microscopy and H&E staining of the testis, it was shown that abnormal ER morphology and destruction of testicular histology induced by high-level hCG treatment were reversed by the addition of TUDCA. These findings suggest that hCG-induced ER stress plays important roles in steroidogenic enzyme expression via modulation of the ATF6 pathway as well as ER stress-mediated apoptosis in Leydig cells.</P>
Synthesis and Characterization of Zinc Phosphate Cement Powder and Cement-forming Liquid
Park, Choon-Keun The Korean Ceramic Society 1997 The Korean journal of ceramics Vol.3 No.4
Chemical composition of cement powder influences the setting time and early compressive strength development. The setting time increases as the amounts of zinc oxide and magnesium oxide are increased. For one day compressive strength development, a cement powder with a composition 90% ZnO, 8% MgO and 2% silica resulted in the highest strength (greater than 1, 090 kg/$\textrm{cm}^2$). Cement-forming liquids also need to be buffered, with both aluminum and zinc ions, for a good consistency and a higher strength of the zinc phosphate cement. These liquids control the setting reactions.
Park, Joo-Hee,Kwon, Dae-JinK,Lee, Beom-Ki,Hwang, In-Sun,Park, Choon-Keun,Yang, Boo-Keun,Cheong, Hee-Tae The Korean Society of Animal Reproduction 2009 Reproductive & developmental biology Vol.33 No.1
The aim of this study was to examine the microtubule distributions of somatic cell nuclear transfer (SCNT) and parthenogenetic porcine embryos. Porcine SCNT embryos were produced by fusion of serum-starved fetal fibroblast cells with enucleated oocytes. Reconstituted and mature oocytes were activated by electric pulses combined with 6-dimethlyaminopurine treatment. SCNT and parthenogenetic embryos were cultured in vitro for 6 days. Microtubule assembly of embryos was examined by confocal microscopy 1 hr and 20 hr after fusion or activation, respectively. The proportions of embryos developed to the blastocyst stage were 25.7% and 30.4% in SCNT and parthenogenetic embryos, respectively. The frequency of embryos showing $\beta$-tubulins was 81.8% in parthenogenetic embryos, whereas 31.3% in SCNT embryos 1 hr after activation or fusion. The frequency of the embryos underwent normal mitotic phase was low in SCNT embryos (40.6%) compared to that of parthenogenetic ones (59.7%) 20 hr after fusion or activation (p<0.05). The rate of SCNT embryos with an abnormal mitosis pattern is about twice compared to that of parthenogenetic ones. The spindle assembly and its distribution of SCNT embryos in the first mitotic phase were not different from those of parthenogenetic ones. The result shows that although microtubule distribution of porcine SCNT embryos shortly after fusion is different from parthenogenetic embryos, and the frequency of abnormal mitosis 20 hr after fusion or activation is slightly increased in SCNT embryos, microtubule distributions at the first mitotic phase are similar in both SCNT and parthenogenetic embryos.