• 대한수의학회지
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• 제49권4호
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• pp.345-349
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• 2009

Polychlorinated biphenyls (PCBs) are synthetic organic compounds with two benzene rings and well known environmental pollutants. This study examined the effect of persistent exposure to 2,$3^{\prime}$,4,$4^{\prime}$,5-pentachlorobiphenyl (PCB118) on the proinflammatory and proapoptotic factors in male rats. Male Sprague Dawley rats were administered weekly intraperitoneal injections of either PCB118 (20 mg/kg) dissolved in corn oil or corn oil alone. One week after 2 and 5 administrations, the rats were sacrificed by a pentobarbital injection. The effect of PCB118 on the expression of cyclooxygenase 2 (COX-2), cytosolic phospholipase A2 (cPLA2), peroxisome proliferator-activated receptor gamma, Bcl and Bcl-2-associated X protein (BAX) was investigated. The level of COX-2 and cPLA2 expression was higher in the PCB118-treated rats than the control. These results suggest that PCB118 has a proinflammatory effect in rats.

• Structural Engineering and Mechanics
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• 제40권2호
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• pp.215-231
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• 2011

The axial compressive strength of unidirectional FRP is generally quite lower than its axial tensile strength. This fact decreases the advantages of FRP as main load bearing member in engineering structure. In order to restrain the lateral expansion and splitting of GFRP, and accordingly heighten its axial compressive bearing capacity, a project that to confine GFRP pole with surrounding CFRP sheet is suggested in the present study. The Experiment on the CFRP sheet confined GFRP poles showed that a combined structure of high bearing capacity was attained. Basing on the experiment research a theoretical iterative calculation approach is suggested to predict the ultimate axial compressive stress of the combined structure, and the predicted results agree well with the experimental results. Then the influences of geometrical parameters on the ultimate axial compressive stress of the combined structure are also analyzed basing on this approach.

• 소성∙가공
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• 제31권2호
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• pp.89-95
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• 2022

3D printing products manufactured by material extrusion are used in many industrial fields recently. However, these products are difficult to use in the field due to their low tensile strengths. In order to solve this problem, research on improving the tensile strength of the output using a 3D printer has been continuously conducted. In this study, we performed a tensile test using Universal Testing Machine according to infill pattern, nozzle temperature, bed temperature, and printing speed conditions. Results revealed that tensile specimen of concentric shape had the highest tensile strength in infill pattern condition and that the tensile strength increased linearly with increasing nozzle and bed temperatures. However, the tensile strength decreased with increasing printing speed. Consequently, we confirmed that tensile strength could be increased and decreased depending on output conditions of 3D printing.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4777-4781
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• 2012

Objective: To investigate the relationship between the efficacy and safety of different doses of thalidomide (Thal) plus dexamethasone (Dex) as the initial therapy in elderly patients with newly diagnosed multiple myeloma (MM). Methods: Clinical data of 28 elderly patients with newly diagnosed MM who underwent the TD regimen as the initial therapy were analyzed retrospectively. The patients were divided into two groups according to the maximal sustained dose of Thal: lower dose (group A) and higher dose (group B). The overall response rate (ORR), progression free survival (PFS), overall survival (OS), and adverse events (AES) were compared between the two groups. Results: A total of 28 patients were followed up with a median of 18 months. The ORR was 60.1%. The median response time and PFS were 2.0 and 17.0 months, respectively. The mean sustained dose of Thal in group B was significantly higher than group A (292.9 mg v 180.4 mg, P=0.01). There was no significantly difference in ORR (57.1% v 64.3%, P=1.00) and PFS (9.63months v 17.66 months, P=0.73) between groups A and B. During the follow up, only five patients died (<40%) and, therefore, median OS values were not available. It is estimated, however, that the mean survival time in the two groups was 35.6 and 33.4 months (P>0.05), respectively. All of the patients tolerated the treatment well. The incidence of AES in patients with a grading above 3 in group B was significantly higher than in group A (P=0.033). Conclusions: The TD regimen results in a high response rate and manageable AES as the initial therapy in elderly patients with MM. TD should be considered as the front line regimen for the treatment of elderly patients with MM in areas with financial constraints. The clinical response can be achieved at a low dose Thal with minimal toxicity.

• The Korean Journal of Physiology and Pharmacology
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• 제2권2호
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• pp.251-260
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• 1998

Cromakalim (BRL 34915), known as an airway smooth muscle relaxant, inhibited the releases of mediators in the antigen-induced mast cell activation. It has been suggested that cromakalim, in part, inhibited mediator releases by inhibiting the initial increase of 1,2-diacylglycerol (DAG) produced by the activation of the other phospholipase system which is different from phosphatidylcholine-phospholipase D pathway. The aim of this study is to further examine the inhibitory mechanism of cromakalim on the mediator release in the mast cell activation. Guinea pig lung mast cells were purified by using enzyme digestion and percoll density gradient. In purified mast cells prelabeled with $[^3H]PIP_2$, phospholipase C (PLC) activity was assessed by the production of $[^3H]$insitol phosphates. Protein kinase C (PKC) activity was assessed by measuring the protein phosphorylated from mast cells prelabeled with $[{\gamma}-32P]ATP$, and Phospholipase $A_2\;(PLA_2)$ activity by measuring the lyso-phosphatidylcholine produced from mast cell prelabeled with 1-palmitoyl-2-arachidonyl $phosphatidyl-[^{14}C]choline$. Histamine was assayed by fluorometric analyzer, and leukotrienes by radioimmunoassay. The PLC activity was increased by activation of the passively sensitized mast cells. This increased PLC activity was decreased by cromakalim pretreatment. The PKC activity increased by the activation of the passively sensitized mast cells was decreased by calphostin C, staurosporine and cromakalim, respectively. The $PLA_2$ activity was increased in the activated mast cells. The pretreatment of cromakalim did not significantly decrease $PLA_2$ activity. These data show that cromakalim inhibits histamine release by continuously inhibiting signal transduction processes which is mediated via PLC pathway during mast cell activation, but that cromakalim does not affect $PLA_2$ activity related to leukotriene release.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4711-4715
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• 2013

Aim: The aim of this study was to evaluate acute adverse events and efficacy of three-dimensional intensitymodulated radiotherapy (IMRT) combined with endocrine therapy for intermediate and advanced prostate cancer. Methods: Sixty-seven patients were treated with three-dimensional IMRT combined with maximum androgen blockade. The correlation between radiation-induced rectal injury and clinical factors was further analyzed. Results: After treatment, 21 patients had complete remission (CR), 37 had partial remission (PR), and nine had stable disease (SD), with an overall response rate of 86.5%. The follow-up period ranged from 12.5 to 99.6 months. Thirty-nine patients had a follow-up time of ${\geq}$ five years. In this group, three-year and five-year overall survival rates were 89% and 89.5%, respectively; three-year and five-year progression-free survival rates were 72% and 63%. In univariate analyses, gross tumor volume was found to be prognostic for survival ($X^2$ = 5.70, P = 0.037). Rates of leucopenia and anemia were 91.1% and 89.5%, respectively. Two patients developed acute liver injury, and a majority of patients developed acute radiation proctitis and cystitis, mainly grade 1/2. Tumor volume before treatment was the only prognostic factor influencing the severity of acute radiation proctitis (P < 0.05). Conclusions: IMRT combined with endocrine therapy demonstrated promising efficacy and was well tolerated in patients with intermediate and advanced prostate cancer.

• Steel and Composite Structures
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• 제23권2호
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• pp.187-194
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• 2017

To reuse a broken plain concrete (PC) arch, a retrofitting method was proposed to ensure excellent structural performances, in which carbon fiber reinforced polymers (CFRPs) were applied to repair and strengthen the damaged PC arch through bonding and wrapping techniques. Experiments were carried out to reveal the deformation and the load carrying capacity of the retrofitted composite arch. Based on the experiments, repairing and strengthening effects of the CFRP retrofitted broken arch were revealed. Simplified analysing model was suggested to predict the peak load of the CFRP retrofitted broken arch. According to the research, it is confirmed that absolutely broken PC arch can be completely repaired and reinforced, and even behaves more excellent than the intact PC arch when bonded together and strengthened with CFRP sheets. Using CFRP bonding/wrapping technique a novel efficient composite PC arch structure can be constructed, the comparison between rebar reinforced concrete (RC) arch and composite PC arch reveals that CFRP reinforcements can replace the function of steel bars in concrete arch.

• Journal of Acupuncture Research
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• 제29권3호
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• pp.55-65
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• 2012

Objectives : The purpose of this study was find out the therapeutic effects of Ulmus davidiana Planch pharmacopuncture(UPP) on the mice with collagen-induced rheumatoid arthritis. Methods : UPP was prepared and tested for therapeutic potential of rhematoid arthritis by measuring the inhibition of cyc1ooxgenase-2(COX-2) and phospholipase A2(PLA2) activities in mice. Results : UPP showed therapeutic effects on collagen-induced rheumatoid arthritis on week 8 and week 9. UPP also inhibited Freund's complete adjuvant induced chronic rheumatoid arthritis in mice. UPP showed significant inhibition of type I and type II PLA2 activities in a dose dependent manner. However, PGE2 Production was not decreased with UPP and lipopolysaccharide-induced COX-2 protein expression was not inhibited by UPP. Conclusions : These results suggest that UPP has an therapeutic effects on drug induced-rheumatoic arthritis by inhibiting PLA2 activity.

• Reproductive and Developmental Biology
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• 제28권2호
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• pp.89-94
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• 2004

본 연구는 생쥐 자궁에 있어서 아라키돈산으로부터 prostaglandin의 생성에 관여하는 것으로 추측되는 acyl-CoA sytnhetase 4 유전자의 임신단계별 발현을 확인하고자 실시하였다. Acyl-CoA sytnhetase 4 유전자는 착상 전에는 발현이 증가하는 경향을 나타내었으며 착상 후에는 감소하였다. 이러한 발현의 양상은 세포막의 인질로부터 아라키돈산을 유리시키는 cPLA2의 발현과 유리된 아라키돈산으로부터 prostaglandin의 생성에 관여하는 COX1과 COX2의 발현 양상과 일치하였다. 이러한 결과는 세포막에서 유리된 아라키돈산이 무한적으로 COX1과 COX2에 의하여 prostaglandin의 생성에 이용되는 것이 아니라 acyl-CoA sytnhetase 4에 의하여 세포막의 인지질로 되돌려져 prostaglandin의 생성을 조절하는 기능을 세포가 수행하고 있는 것으로 추정된다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.427-433
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• 2010

This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase $A_2$ ($PLA_2$), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and $0.5\;{\mu}M$ melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free $PLA_2$ assay, we failed to observe tbe change of $cPLA_2$ and $sPLA_2$ activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells.