• Journal of KIISE:Information Networking
• /
• v.28 no.4
• /
• pp.559-569
• /
• 2001

With the growth of the Internet, applications using the reliable multicast protocol are increasing. Two important requirements of reliable multicasting are reliability and scalability. To enhance scalability, many methods have been proposed. A typical method is a local recovery scheme. This paper proposes a new stable and effective protocol with the following features. The first is to apply the discipline of the separations of concerns to NAK message. By dividing the functions of the NAK message into the error recovery request and the NAK-suppression, each function can be optimized. Second, a local representative, which is selected gradually and distributively, executes error recovery in somewhat deterministic manner. Finally, by dynamically adjusting the TTL value of the control message, the error recovery domain can be optimized. The proposed scheme has been implemented and experimented on Network Simulator. Compared to the existing schemes, the performance results show that scalability has not only been enhanced but also error recovery time and network overhead have been reduced.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.12
• /
• pp.1381-1387
• /
• 2001

Objective : Endodermal sinus tumor or yolk sac tumor is an uncommon malignant germ-cell neoplasm. This tumor was originally described as a germ cell tumor of the ovary or the testis. Intracranial endodermal sinus tumor is extremely rare and usually develop in the pineal or suprasellar regions. The authors evaluated the effect of adjuvant therapy(chemotherapy combined with radiotherapy) and radical removal of intracranial endodermal sinus tumors. Material and Methods : Between 1996 and 2001, four patients of intracranial endodermal sinus tumor were diagnosed with tumor marker(AFP) and biopsy. Three patients were treated with surgical removal and chemotherapy with cisplatin($20mg/m^2$), etoposide($100mg/m^2$) and bleomycin($15mg/m^2$) as well as external beam radiation therapy. We compared the management problems for these tumors. Result : In all three patients the tumor size and the level of tumor marker decresed during initial adjuvant therapy. However, Tumors showed regrowth with elevated AFP of serum and CSF possibly related to delayed chemotherapeutic treatment or inadequate administration of chemotherapeutic drugs due to severe bone marrow suppression. An additional chemotherapy and external radiation therapy were given, but tumors could not be controlled with leptomeningeal seeding. Conclusion : Radiotherapy is considered to be less effective. The combination chemotherapy with PVB(cisplatin, vinblastine, bleomycine) or PE(cisplatin, etoposide) is considered to be value in prolongation of the survival rate. But the role of chemotherapy in this tumor has not yet been clarified due to bone marrow suppression and drug resistance. Further study with large series of this tumor is necessary to establish the optimal management.

• The Journal of Korean Medicine
• /
• v.39 no.2
• /
• pp.92-105
• /
• 2018

Objectives: This aim of this study is to compare the reflux esophagitis improvement effects of Sepiae Os, Arcae Concha, Ostreae Concha, and Proton Pump Inhibitor(esomeprazole) through rat experiments. Methods: NO production inhibitory effect was measured by NO production amount and iNOS mRNA expression level in cell lines. iNOS, $TNF-{\alpha}$ and $p-I{\kappa}B$, and serotonin were compared using immunohistochemistry at the rat reflux esophagitis. Reflux esophagitis connection external form, lower esophageal sphincter, and gap were observed and an esophageal inflammatory indicator, IL-6 activity was also evaluated by immunohistochemistry. Results: NO production and iNOS mRNA expression was showed concentration dependent decrease in cell lines treated with Sepiae OS, Arcae Concha, and Ostreae Concha at the experiments of cell lines. In the suppression of iNOS and $p-I{\kappa}B$ at the rat reflux esophagitis, Sepiae Os treat group(SOT) and Ostreae Concha treat group(OCT) were more effective. In the increase of serotonin at the rat reflux esophagitis, ACT, MT and OCT were more effective. Damage of lower esophageal sphincter, and gap between esophageal keratin and mucosa were observed less at the SOT, ACT, OCT. In the suppression of IL-6 at the rat reflux esophagitis, SOT and OCT were more effective than GE and, SOT was more effective than MT significantly. Conclusions: The anti-inflammatory effect was the best in the SOT and lower esophageal sphincter muscle contraction was the best in the ACT at the rat reflux esophagitis. Sepiae OS was more effective than esomeprazole in the suppression of iNOS, $TNF-{\alpha}$, and IL-6.

• Clinical and Experimental Pediatrics
• /
• v.60 no.2
• /
• pp.45-49
• /
• 2017

Purpose: Serum level of 25-hydroxyvitamin D (25-OHD) is considered as the most appropriate marker of vitamin D status. However, only a few studies have investigated the relationship between 25-OHD and parathyroid hormone (PTH) in children. To this end, this study was aimed at evaluating the lowest 25-OHD level that suppresses the production of parathyroid hormone in children. Methods: A retrospective record review was performed for children aged 0.2 to 18 years (n=193; 106 boys and 87 girls) who underwent simultaneous measurements of serum 25-OHD and PTH levels between January 2010 and June 2014. Results: The inflection point of serum 25-OHD level for maximal suppression of PTH was at 18.0 ng/mL (95% confidence interval, 14.3-21.7 ng/mL). The median PTH level of the children with 25-OHD levels of <18.0 ng/mL was higher than that of children with 25-OHD levels ${\geq}$ 18.0 ng/mL (P<0.0001). The median calcium level of children with 25-OHD levels<18.0 ng/mL was lower than that of children with 25-OHD levels${\geq}18.0ng/mL$ (P=0.0001). The frequency of hyperparathyroidism was higher in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels${\geq}18.0ng/mL$ (P<0.0001). Hypocalcemia was more prevalent in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels${\geq}18.0ng/mL$ (P<0.0001). Conclusion: These data suggest that a vitamin D level of 18.0 ng/mL could be the criterion for 25-OHD deficiency in children at the inflection point of the maximal suppression of PTH.

• Journal of the Korean Society of Safety
• /
• v.32 no.2
• /
• pp.117-123
• /
• 2017

This study was intended to find methods of fire extinguishing system designs that can improve the equipment's usability. In this study, the fire suppression experiment through fire extinguishers and the data drawn through the experiment were analyzed, and then the guideline for the improvement of designs was presented. The procedure is as follows. A fire suppression experiment with the use of fire extinguishers was done by 43 average adults. The whole process of the fire suppression was videotaped, and then captured major scenes were analyzed with the use of RULA, a human engineering measurement tool. The analyzed data were divided into 4 steps, and then the guideline for design improvement was presented. The summary of the study is as follows. Step 1, Fire extinguisher distance step. To reduce overload occurring at the process of holding fire extinguishers suddenly, wheels are attached to the body of extinguishers, or pedestals are installed. Step 2, Fire extinguisher transportation step. The length of hose is extended, or fire fighting water is sprayed far, so that overload of legs occurring at the process of travel can be reduced. In addition, the weight of fire extinguisher shouldn't be over 2 kg. Step 3, Safety pin removal stage. Safety pins should be applied with button type, so that excessive posture of lower limbs and excessive twisting of wrists won't happen during safety pin removal process. Besides, safety pins should be designed for easy identification and operation. Step 4, Fire extinguishing agent spraying step. To reduce overload occurring at sudden spraying of fire fighting water, pressure should be increased gradually until high pressure. With the above study results applied to existing fire extinguisher design, it may contribute to reducing any fire damage.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.16 no.3
• /
• pp.171-177
• /
• 2013

Purpose: This study was aimed to evaluate the frequency and course of adverse events associated with azathioprine treatment in Korean pediatric patients with inflammatory bowel disease. Methods: Total of 174 pediatric patients (age range, 1 to 19 years) with inflammatory bowel disease who received azathioprine in order to maintain remission at Samsung Medical Center (Seoul, Korea) from January 2002 through December 2012 were included in this study. Medical records of these subjects were retrospectively reviewed regarding the development of adverse events associated with azathioprine treatment. Results: Ninety-eight patients (56.3%) of 174 patients experienced 136 episodes of adverse events, requiring dose reduction in 31 patients (17.8%), and discontinuation in 18 patients (10.3%). The mean dose of azathioprine that had been initially administered was $1.32{\pm}0.42$ mg/kg/day. Among the adverse reactions, bone marrow suppression developed in 47 patients (27.0%), requiring dose reduction in 22 patients (12.6%) and discontinuation in 8 patients (4.6%). Other adverse events that occurred were gastrointestinal disturbance (15.5%), hair loss (12.1%), pancreatitis (7.5%), arthralgia (6.9%), hepatotoxicity (2.9%), skin rash/allergic reactions (2.9%), headache/dizziness (2.3%), sepsis (0.6%), and oral mucositis (0.6%). Conclusion: Bone marrow suppression, especially leukopenia was most commonly associated with azathioprine treatment in Korean pediatric inflammatory bowel disease patients. Close observation for possible adverse events is required in this population with inflammatory bowel diseases who are under treatment with azathioprine.

• Korean Journal of Acupuncture
• /
• v.32 no.2
• /
• pp.51-58
• /
• 2015

Objectives : Pinus densiflora gnarl, called Song-Jeol in Korean medicine, has been used to cure inflammatory diseases such as arthritis. In the present study, we evaluated inhibitory property of Song-Jeol pharmacopuncture(SJ) on C6 glioma cell migration. Methods : To evaluate cell viability on C6 glioma cells of SJ, the viability was assessed by using Ez-cytox assay kit. The cell migration was assessed by wound-healing assay and Boyden chamber assay, respectively. LPS-induced NO productions were determined by using the Griess reagent. The expression of iNOS and protein kinase $C(PKC)-{\alpha}$ were estimated by western blotting assay. Results : In the wound-healing assay and Boyden chamber assay, SJ showed a significant inhibition on serum-induced C6 glioma cell migration. In addition, NO production was decreased by SJ through suppression of iNOS expression in LPS-stimulated C6 glioma cell. Futhermore, LPS-induced protein kinase $C(PKC)-{\alpha}$ expression was effectively inhibited by SJ. Conclusions : These results demonstrated that SJ was useful for the suppression of the C6 glioma cell migration.

• Journal of the Korean Magnetic Resonance Society
• /
• v.21 no.4
• /
• pp.131-134
• /
• 2017

Proton detected Heteronuclear Multiple Quantum Coherence (HMQC) and Heteronuclear Single Quantum Coherence (HSQC) essentially provide the same information - correlation of the chemical shift of the proton to J-coupled hetero nuclei such as $^{13}C$ or $^{15}N$ nuclei. This paper is a practical note for the students who ask which one is better and which methods they use routinely. Artifact suppression using phase cycling and gradient pulses are discussed.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.05a
• /
• pp.15-20
• /
• 2003

Molecular immunological methods are extensively applied to toxicological investigations. Furthermore, various immunological markers have been developed to substantiate molecular mechanisms of xenobiotics-mediated immunotoxicities. We discuss molecular immunological approach to evaluate lead (Pb)-induced immune alteration resulting in suppression of IFN${\gamma}$ production, and its value for establishing useful immunotoxicological markers.(omitted)

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.21 no.2
• /
• pp.46-53
• /
• 2008

Background and Objectives : The aim of this study was to investigate the anti-oxidant, anti-allergic and anti-inflammatory ability of the Taglisodog-eum(SHE) extract on the RAW 264.7 and EL4 cells Materials and Methods : Three types of experiments were implemented for this study: first, the experiment to study the anti-oxidant effect of SHE using Riboflavin; second, in vitro experiment to investigate the inhibition of Th 2 cell differentiation by SHE using EL4 cells (IL-4 mRNA expression); third, the suppression of $NF-{\kappa}B$ activation using RAW 264.7 cells (iNOS and COX-2 mRNA expression). Results : The anti-oxidant ability of SHE were dose-dependantly increased. From in vitro, the LPS-induced iNOS and COX-2 mRNA expression were dose-dependantly decreased in the RAW264.7 cells treated with SHE and the PMA-induced IL-4 mRNA expression were also dose-dependantly decreased in EL4 cells. $NF-{\kappa}B$ activation was suppressed, and iNOS & COX-2 production were inhibited by SHE Conclusion : The results suggest that SHE has dose-dependant anti-oxidant ability, and has anti-allergic and anti-inflammatory effects through the suppression of $NF-{\kappa}B$ activation and the inhibition of Th 2 cell differentiation.