• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.187-193
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• 2015

Deleterious effects of high dose radiation exposure with high-dose-rate are unarguable, but they are still controversial in low-dose-rate. The regulator of G-protein signaling (RGS) is a negative regulator of G protein-coupled receptor (GPCR) signaling. In addition, it is reported that irradiation stress led to GPCR-mediated mitogen-activated protein kinase (MAPK) and phosphotidylinositol 3-kinase (PI3-k) signaling. The RGS mRNA expression profiles by whole body radiation with low-dose-rate has not yet been explored. In the present study, we, therefore, examined which RGS was modulated by the whole body radiation with low-dose-rate ($3.49mGy{\cdot}h^{-1}$). Among 16 RGS expression tested, RGS6, RGS13 and RGS16 mRNA were down-regulated by low-dose-rate irradiation. This is the first report that whole body radiation with low-dose-rate can modulate the different RGS expression levels. These results are expected to reveal the potential target and/or the biomarker proteins associated with male testis toxicity induced by low-dose-rate irradiation, which might contribute to understanding the mechanism beyond the testis toxicity.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.5
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• pp.1-9
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• 1981

Experimental results on a 4-bit charge-coupled A/D converter are described. Major operations in the successive approximation algorithm are implemented in a monolithic chip, CCADC, which was fabricated usir p-channel CCD technology, with its die size of 4,200 mil2 Typical operating frequency range has been found out to be from 500Hz to 200kHz. In that frequency range, no missing code has been found in the whole signal range of 2.4 volts for ramp signal slewing at 1 LSB/(sampling time). A discussion is made on several layout techniques to conserve the nominal binary ratio of (8:4:2:1) among the areas of four adjacent potential wells (M wells), whose charge storing capacities correspond to each bit magnitude - 3.6 pC, 1.8 pC, 0.9 pC, and 0.45 pC nominal in the order of MSB to the LSB. The effect of 'dump slot', which is responsible for the excessive nonlinearity (2$\frac{1}{2}$LSB) in the A/D converter, is explained. A novel input scheme called 'slot zero insertion' to circumvent the deleterious effects of the dump slot is described with the experimental results.

• Biomedical Science Letters
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• v.12 no.3
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• pp.281-287
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• 2006

Cigarette smoke causes atypical structure of pulmonary and oxidative damage. Therefore, we carried out to determine if exposure to cigarette smoke alters pulmonary structure and anti-oxidant related enzyme in a animal model, when natural product extracts using by Nebulizer. The rat were divided into four groups: $H_2O-treated$ (Control), natural product (Camellia sinensis) extracts-treated (CS), natural product extracts-treated with cigarette smoke-exposed (CS+SM) and cigarette smoke-expose (SM). All groups are similar to Control group in weight, but SM group is lower than the other groups. Microscopic image of the pulmonary structure in SM group showed deleterious alterations in the morphology, but the other groups are maintained in normal structure. In anti-oxidant related enzymes, SOD (superoxide dismutase) and catalase, SM group represents the lowest enzyme activity among all groups. But G6PD (glucose-6-phosphate dehydrogenase) and LPO (lipid peroxidation) is SM group represents the highest enzyme activity among all groups. These result indicate that the natural product extracts is an efficient tissue protective substance against smoke-induced lung injury.

• Biomedical Science Letters
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• v.15 no.3
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• pp.249-255
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• 2009

All living things have been developed efficient strategies to cope with external and internal environmental changes via a process termed 'homeostasis'. However, chronic prenatal maternal stress may significantly contributes to pregnancy complications by disturbing hypothalamic-pituitary-adrenal (HPA) axis and the automatic nervous system (ANS), and results in unfavorable development of the fetus. Dysregulation of these two major stress response systems lead to the increased secretion of the glucocorticoids (GCs) which are known to be essential for normal development and the maturation of the central nervous system. As Hox genes are master key regulators of the embryonic morphogenesis and cell differentiation, we aimed to determine the effects of dexamethasone, a potent synthetic glucocorticoid, on gene expression in mesenchymal stem cell C3H10T1/2. Analysis of 39 Hox genes based on reverse transcription PCR (RT-PCR) method revealed that the expression patterns of Hox genes were overall upregulated by long dexametasone treatment. These results indicate that maternal stress may have a deleterious effect on early developing embryo through the stress hormone, glucocorticoid.

• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.427-433
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• 2017

Previously, we demonstrated that galangin (3,5,7-trihydroxyflavone) protects human keratinocytes against ultraviolet B (UVB)-induced oxidative damage. In this study, we investigated the effect of galangin on induction of antioxidant enzymes involved in synthesis of reduced glutathione (GSH), and investigated the associated upstream signaling cascades. By activating nuclear factor-erythroid 2-related factor (Nrf2), galangin treatment significantly increased expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS). This activation of Nrf2 depended on extracellular signal-regulated kinases (ERKs) and protein kinase B (AKT) signaling. Inhibition of GSH in galangin-treated cells attenuated the protective effect of galangin against the deleterious effects of UVB. Our results reveal that galangin protects human keratinocytes by activating ERK/AKT-Nrf2, leading to elevated expression of GSH-synthesizing enzymes.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.99-104
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• 2007

Studies were conducted to evaluate spent bleaching clay as a feed resource. Raw spent bleaching clay from the soybean refining process in a rotary reactor is rich in crude fat (26.0%) and crude ash (68.3%) but low in moisture (5.2%) and crude protein (0.5%). The peroxide value of spent bleaching clay was significantly higher than soybean oil (P<0.05). Also the acid value of spent bleaching clay and soybean oil were 9.72 and 0.001, respectively, it was significantly different(P<0.01). It is possible that the acidification of spent bleaching clay was prevented by artificial method. On the feeding experiment, 2.0 to 4.0% of dietary spent bleaching clay were improve body weight gain, feed intake and feed/ gain. Results indicate that spent bleaching clay may be used at 2.0 to 4.0% for broiler diets without deleterious effects on performance.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.125-131
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• 2010

Bacterial contamination is an unavoidable finding of the semen collection process in boar and can lead in deleterious effects on semen quality and longevity if left uncontrolled. The purpose of this study is to identify the bacteria in extended boar semen and to select the effective antimicrobials to control of the contaminants. Of 116 extended boar semen samples submitted from eight AI centers in Korea, 39 (33.6%) samples were positive for bacterial contamination. Among 39 contaminated semen, most of them (84.6%) were contaminated with one or two bacterial species and there was no significant difference between two age groups $(\leq\;24\;and\;>\;24\;month\;old).$ Stenotrophomonas maltophilia (n = 18) was the most predominant bacterium followed by Elizabethkingia meningoseptica (n = 12), Sphingomonas paucimobilis (n = 12), Myroides spp. (n = 5), Ochrobactrum anthropi (n = 3), and so on. Enrofloxacin (72.9%), florfenicol (72.9%), bacitracin (49.2%) and tylosin (49.2%) showed higher sensitivity compared with penicillin (13.6%) or aminoglycosides (6.8%-18.6%). Brucella spp., Leptospira spp., Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycobacterium tuberculosis complex were not detected in semen by PCR.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1291-1296
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• 2003

Effects of feeding of 9.95 mg free gossypol/kg live weight through cottonseed meal (CSM) were studied in 20 intact male calves fed barley or sorghum as source of cereal during the experimental duration of 210 days. Serum concentration of total protein, albumin, globulin and their ratio did not vary because of protein (gossypol) or cereal sources. Serum level of cholesterol and urea were lower (p<0.05) in sorghum than barley fed calves. Feeding of gossypol through CSM enhanced (p<0.05) serum cholesterol. An interaction between protein and period was observed with respect to serum concentrations of urea, creatinine and alanine transferase. The levels of serum creatinine and alanine transferase increased (p<0.05) following 120 days of experimental feeding in calves fed CSM diets compared to the control animals fed groundnut meal diets. No effect of feeding gossypol was, however, evident on the serum enzymes viz. alanine and aspartate transferases and alkaline phosphatase. Moreover, the source of cereal and protein did not appear to influence the metabolic profile of the calves. Humoral immune response, measured through antibody titre against Brucella abortus S99 innoculation, revealed a delayed and depressed seroreactivity indicative of immunocompromisation because of the phytotoxin gossypol. In conclusion, the feeding of gossypol at the designated levels, although had no deleterious clinico-biochemical manifestations, affected the humoral immune response of the calves.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.9-21
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• 2015

Cancer, a serious public health problem in worldwide, results from an excessive and uncontrolled proliferation of the body cells without obvious physiological demands of organs. The gastrointestinal tract, including the esophagus, stomach and intestine, is a unique organ system. It has the highest cancer incidence and cancer-related mortality in the body and is influenceed by both genetic and environmental factors. Among the various chemical elements recognized in the nature, some of them including zinc, iron, cobalt, and copper have essential roles in the various biochemical and physiological processes, but only at low levels and others such as cadmium, lead, mercury, arsenic, and nickel are considered as threats for human health especially with chronic exposure at high levels. Cadmium, an environment contaminant, cannot be destroyed in nature. Through impairment of vitamin D metabolism in the kidney it causes nephrotoxicity and subsequently bone metabolism impairment and fragility. The major mechanisms involved in cadmium carcinogenesis could be related to the suppression of gene expression, inhibition of DNA damage repair, inhibition of apoptosis, and induction of oxidative stress. In addition, cadmium may act through aberrant DNA methylation. Cadmium affects multiple cellular processes, including signal transduction pathways, cell proliferation, differentiation, and apoptosis. Down-regulation of methyltransferases enzymes and reduction of DNA methylation have been stated as epigenetic effects of cadmium. Furthermore, increasing intracellular free calcium ion levels induces neuronal apoptosis in addition to other deleterious influence on the stability of the genome.

• Journal of Korean Neurosurgical Society
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• v.59 no.5
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• pp.471-477
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• 2016

Objectives : The correction of clinical and radiologic abnormalities in patients with symptomatic ossification of the posterior longitudinal ligament (OPLL) is the current mainstay of treatment. This study aimed to identify radiographic predictors of severity of myelopathy in patients with symptomatic OPLL. Methods : Fifty patients with symptomatic cervical OPLL were enrolled. Based on Japanese Orthopedic Association (JOA) scores, patients were divided into either the mild myelopathy (n=31) or severe myelopathy (n=19) group. All subjects underwent preoperative plain cervical roentgenogram, computed tomography (CT), and MR imaging (MRI). Radiological parameters (C2-7 sagittal vertical axis, SVA; C2-7 Cobb angle; C2-7 range of motion, ROM; OPLL occupying ratio; and compression angle) were compared. Compression angle of OPLL was defined as the angle between the cranial and caudal surfaces of OPLL at the maximum level of cord compression Results : The occupying ratio of the spinal canal, C2-7 Cobb angle, C2-7 SVA, types of OPLL, and C2-7 ROM of the cervical spine were not statistically different between the two groups. However, the OPLL compression angle was significantly greater (p=0.003) in the severe myelopathy group than in the mild myelopathy group and was inversely correlated with JOA score (r=-0.533, p<0.01). Furthermore, multivariate regression analysis demonstrated that the compression angle (B=-0.069, p<0.001) was significantly associated with JOA scores (R=0.647, p<0.005). Conclusion : Higher compression angles of OPLL have deleterious effects on the spinal cord and decrease preoperative JOA scores.