• BMB Reports
• /
• v.33 no.2
• /
• pp.184-187
• /
• 2000

Prostaglandin $E_2$ ($PGE_2$) plays an important role in the regulation of various gastric functions, and the growth-inhibitory activities on tumor cells are studied in vitro and in vivo. Although the mechanisms have attracted many researchers in the past decade, the molecular mechanisms of cell cycle arrest, or induction of apoptosis by $PGE_2$, is unclear. We investigated the effects of $PGE_2$ on the growth of the human gastric carcinoma cell line SNU1 and genes that are regulated by $PGE_2$ and isolated them using differential display RT-PCR (DD RT-PCR). FACS analysis suggested that SNU1 cells were arrested at the G1 phase by $PGE_2$ treatment. This growth inhibitory effect was in a time- and dose-dependent manner. Treatment of SNU1 cells with $10\;{\mu}g/ml$ $PGE_2$, followed by DD RT-PCR analysis, revealed differently expressed bands patterns from the control. Among the differently expressed clones, we found an unidentified cDNA clone (HGP-27) overexpressed in $PGE_2$-treated cells. The full-length cDNA of HGP-27 was isolated using RACE, which consisted of a 30-nt 5'-noncoding region, a 891-nt ORF encoding the 296 amino acid protein, and a 738-nt 3'-noncoding region including a poly(a) signal. This gene was localized on the short arm of chromosome number 11. Using the Motif Finder program, a myb-DNA binding repeat signature was detected on the ORF region. The COOH-terminal half was shown to have similarity with the $NH_3$-terminal domain of thioredoxin (Trx). This relation between HGP-27 and Trx implied a potential role for HGP-27 in modulating the DNA binding function of a transcription factor, myb.

• BMB Reports
• /
• v.32 no.6
• /
• pp.585-593
• /
• 1999

The water and methanol extracts of Artemisia argyi showed significant cytotoxicities against J774A.1 cells but not so much against normal leukocytes. The cytotoxicities were found to be dependent on the extract concentration and the incubation time. The concentration of water and methanol extracts inhibiting 50% of cell proliferation ($IC_{50}$) were estimated to be 44.2 mg/ml and 71.6 mg/ml, respectively. In the presence of Artemisia argyi water extract, total superoxide dismutase (CuZnSOD and MnSOD) activities of media, cytoplasmic and mitochondrial fractions of J774A.1 cells increased in accordance with cytotoxicity. MnSOD was found to be the main component of enhanced total SOD activities, particulary in the mitochondrial fraction. In contrast to SOD, catalase and glutathione peroxidase (GPx) were not found in any instance of the current investigation. In addition, substantial amount of $O_2^-$ appeared to be generated in the mitochondrial fraction under the influence of Artemisia argyi. All data put together, it is postulated that Artemisia argyi extracts seem to stimulate $O_2^-$ generation in mitochondria of J774A.1 cells with concomitant increases of SODs. Since $H_2O_2$, the reaction product of SOD on $O_2^-$, is known to be readily converted to very toxic $OH{\cdot}$ in the absence of catalase and/or GPx cooperation, toxicity derived from ROS such as $O_2^-$, $H_2O_2$, and $OH{\cdot}$ may be the main cause of necrosis and/or apoptosis of J774A.1 cells.

• Korean Journal of Poultry Science
• /
• v.44 no.4
• /
• pp.283-290
• /
• 2017

Totally, one hundred and sixty 1-day-old Ross 308 broiler chicks were fed with a diet containing 0, 0.5, 1.0, and 2.0 mg of aflatoxin $B_1(AFB_1)/kg$ of feed for 21 days. Body weight was lower for the $AFB_1$-treated broilers than for the control group. At 14 and 21 DPF, the broilers fed with 2.0 mg of $AFB_1/kg$ of feed weighed significantly lower than those of the other groups (p<0.05). Relative liver weights increased significantly in a dose-dependent manner, and relative spleen weights were significantly high in the chicks fed with 2.0 mg of $AFB_1/kg$ of feed at 21 DPF (p<0.001). Biochemical analyses showed that total protein and albumin levels decreased significantly at 7 and 14 DPF for the chicks of the group fed with 2.0 of mg $AFB_1/kg$ of feed, compared with those fed with 0.5 and 1.0 mg of $AFB_1/kg$ of feed (p<0.05). AST and ALT levels increased significantly at 14 and 21 DPF (p<0.05), and the AST levels, particularly, increased dose-dependently (p<0.05). Histopathological analyses showed that the liver tissues of the $AFB_1$-treated chicks showed significant lesions, including hemorrhage, hepatocyte necrosis, inflammatory cell infiltration, and fatty degeneration. The severity of both hepatocyte necrosis and inflammatory cell infiltration appeared to increase dose- and time-dependently. Similarly, hepatic fibrosis increased dose-dependently (p<0.05). The results of this study could improve our understanding of parameters used for evaluating aflatoxicosis in poultry.

• Biomolecules & Therapeutics
• /
• v.22 no.2
• /
• pp.122-128
• /
• 2014

The stiffness of cancer cells is attributable to intermediate filaments such as keratin. Perinuclear reorganization via phosphorylation of specific serine residue in keratin is implicated in the deformability of metastatic cancer cells including the human pancreatic carcinoma cell line (PANC-1). 12-O-Tetradecanoylphorbol-13-acetate (TPA) is a potent tumor promoter and protein kinase C (PKC) activator. However, its effects on phosphorylation and reorganization of keratin 8 (K8) are not well known. Therefore, we examined the underlying mechanism and effect of TPA on K8 phosphorylation and reorganization. TPA induced phosphorylation and reorganization of K8 and transglutaminase-2 (Tgase-2) expression in a time- and dose-dependent manner in PANC-1 cells. These effects peaked after 45 min and 100 nM of TPA treatment. We next investigated, using cystamine (CTM), Tgase inhibitor, and Tgase-2 gene silencing, Tgase-2's possible involvement in TPA-induced K8 phosphorylation and reorganization. We found that Tgase-2 gene silencing inhibited K8 phosphorylation and reorganization in PANC-1 cells. Tgase-2 gene silencing, we additionally discovered, suppressed TPA-induced migration of PANC-1 cells and Tgase-2 overexpression induced migration of PANC-1 cells. Overall, these results suggested that TPA induced K8 phosphorylation and reorganization via Tgase-2 expression in PANC-1 cells.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.24 no.2
• /
• pp.169-181
• /
• 2014

Objectives: The purpose of this study was to obtain information regarding classification and health hazards that may result from a 13-week inhalation exposure to 2-methylpentane by Sprague-Dawley rats. Materials: The testing method was conducted in accordance with OECD guidelines for the testing of chemicals No. 413. The rats were divided into four groups(ten male and ten female rats in each group) and exposed to 0 ppm, 290 ppm, 1,160 ppm, 4,640 ppm 2-Methylpentane in each exposure chamber for six hours per day, five days per week, for 13 weeks. Results: No death or particular clinical presentation including weight change and change of feed rate was observed. The relationships between dose, gender and response were also not significantly changed in urinalysis, hematologic examination, or biochemical examination of blood(except for total cholesterol being up, total protein being up, and chloride ion being down in males), and blood coagulation time. For the relative weight measurement of organs, in the male group the weight change of both kidney and liver were increased in proportion to dose. In histopathological examination, nephropathy in the kidney(cystic change of renal tubules, regenerative tubule, inflammatory cell infiltration and necrosis in the interstitial tissue) was increased in a dose-dependent manner in the male group(290 ppm, 1,160 ppm, 4,640 ppm). However, other organs were not affected by the test substance. Conclusions: 2-methylpentane was estimated as a chemical causing nephropathy in the male group. NOAEL(No Observable Adverse Effect Level) in the female group is more than 4,640 ppm, while inthe male group it is less than 290 ppm.

• Journal of Sericultural and Entomological Science
• /
• v.18 no.1
• /
• pp.27-39
• /
• 1976

In this study several kinds of spun silk yarn-synthetic filament compounded yarn was manufactured, and several fabrics woven from above mentioned silk compound yarn for evaluation of serviceability as clothing materials. The following results were obtained: 1. Degumming agents are in the order of sodium silicate, sodium hydroxide, sodium carbornate, soap and water. 2. When the concentration of sodium hydroxide is exceeded 3%, degradation of floss silk property is resulted because of excessive dissolving out of silk protein. 3. Degumming effect is much improved by concentration of degumming agent and less by its treating time. 4. Simultaneous application of more the 2 kinds of degumming agent is desirable for improvement of floss silk. 5. Application of natural organic acid brings very good results in keeping original scooping and color of the silk. 6. Load and elongation it increased by compound with synthetic filament yarn. 7. Even the evenness of compound yarn is largely dependent on the quality of floss silk and extent of degumming, the C.V.% of silk compound yarn in the experiment was 8-12%. 8. Single bath dyeing technique was impossible for their cloth, and dyeing was performed in 2 bath system separately for silk and synthetic fiber. 9. Shrinkage ratio due to the dyeing of fabric was 23% in case of polyester and spun silk fabric. 10. The final woven cloth can be applicable to (a) Blouse in care of thin cloth (compound silk fabric) (b) Korean costume for women in case of thick cloth. (compound hand spun silk fabric)

• The Korean Journal of Physiology and Pharmacology
• /
• v.9 no.5
• /
• pp.283-289
• /
• 2005

Endothelium, particularly pulmonary endothelium, is predisposed to injury by reactive oxygen species (ROS) and their derivatives. Heme oxygenase (HO) has been demonstrated to provide cytoprotective effects in models of oxidant-induced cellular and tissue injuries. In the present study, we investigated the effects of YS 49 against oxidant [tert-butylhydroperoxide (TBH)]-induced injury using cultured sheep pulmonary artery endothelial cells (SPAECs). The viability of SPAECs was determined by quantifying reduction of a fluorogenic indicator Alamar blue. We found that TBH decreased cell viability in a timeand concentration-dependent manner. YS 49 concentration- and time-dependently increased HO-1 induction on SPAECs. As expected, YS 49 significantly decreased the TBH-induced cellular injury. In the presence of zinc protophorphyrin, HO-1 inhibitor, effect of YS 49 was significantly inhibited, indicating that HO-1 plays a protective role for YS 49. Furthermore, YS 49 showed free radical scavenging activity as evidenced by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and inhibition of lipid peroxidation. However, YS 49 did not inhibit apoptosis induced by lipopolysaccharide (LPS) in SPAECs. Taken together, HO-1 induction along with strong antioxidant action of YS 49 may be responsible for inhibition of TBH-induced injury in SPAECs.

• Korean Journal of Clinical Laboratory Science
• /
• v.43 no.4
• /
• pp.179-187
• /
• 2011

Animal models are important tools in thrombosis research and preclinical drug development. In recent studies, ferric chloride ($FeCl_3$) has been widely used to induce arterial thrombosis in a variety of species. The purpose of this study was to find an optimal concentration of $FeCl_3$ and validate this model suited better for thrombosis research. A small piece of filter paper, soaked in $FeCl_3$ solution (10, 20 or 35%, v/v, in distilled water) was topically applied on the carotid artery of SD rats to measure the time to occlusion (TTO) and thrombus weight (TW) to ascertain 35%, as an optimal $FeCl_3$ concentration ($8.63{\pm}0.92min$; p =0.000, $0.79{\pm}0.03mg/mm$; p =0.000, respectively). To validate this experimental model, Ginkgo biloba special extract EGb761 (5, 10 or 30 mg/kg) as a reference agent administered by peritoneal route for 1h prior to the induction of thrombosis, showed significantly delayed TTO in a dose dependent manner ($18.50{\pm}2.17$, $29.17{\pm}1.83$, and $38.00{\pm}1.79min$, respectively) and significantly reduced TW and repaired collagen fibre in the injured vessel compare to vehicle group. Our results provide a simple, reproducible and well controlled in vivo screening system to induce thrombosis in rats by the topical application of 35% $FeCl_3$ to assess the efficacy of the new anti-thrombotic agents.

• Structural Engineering and Mechanics
• /
• v.63 no.1
• /
• pp.1-9
• /
• 2017

Shot peening is a cold surface treatment employed to induce residual stress field in a metallic component beneficial for increasing its fatigue strength. The experimental investigation of parameters involved in shot peening process is very complex as well as costly. The most attractive alternative is the explicit dynamics finite element (FE) analysis capable of determining the shot peening process parameters subject to the selection of a proper material's constitutive model and numerical technique. In this study, Ansys / LS-Dyna software was used to simulate the impact of steel shots of various sizes on an aluminium alloy plate described with strain rate dependent elasto-plastic material model. The impacts were carried out at various incident velocities. The influence of shot velocity and size on the plastic deformation, compressive residual stress and force-time response were investigated. The results exhibited that increasing the shot velocity and size resulted in an increase in plastic deformation of the aluminium target. However, a little effect of the shot velocity and size was observed on the magnitude of target's subsurface compressive residual stress. The obtained results were close to the published ones, and the numerical models demonstrated the capability of the method to capture the pattern of residual stress and plastic deformation observed experimentally in aluminium alloys. The study can be quite helpful in determining and selecting the optimal shot peening parameters to achieve specific level of plastic deformation and compressive residual stress in the aluminium alloy parts especially compressor blades.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.7
• /
• pp.1156-1168
• /
• 2007

The somatotropic (GH-IGF-I) axis consists of many hormonal and nutritional factors that control GH release from the somatotrophs in the anterior pituitary. The GH-releasing substances are GHRH and GHS (GHRP or ghrelin), while the GH release-inhibiting substances are somatostatin (SRIF), insulin-like growth factor-I (IGF-I), leptin and glucocorticoids. However, there is evidence showing that nutrition is involved in the control of the somatotropic axis. In addition, weaning is a drastic event for neonates because their alimentary and endocrine circumstances are changed due to the switch, even if gradual, from a liquid milk diet to one composed of such solids as hay and grains. The biological role of ghrelin is one of the hormonal factors that have been focused on ever since ghrelin was discovered at the end of the last century. A 27-amino acid peptide that is mainly synthesized and released from the abomasum epithelium, ghrelin has not been fully evaluated in relation to the somatotropic axis of the ruminant. It has also proven difficult even to investigate the cellular mechanisms of ghrelin action, because this hormone exerts animal-species-dependent actions via a complex set of intracellular signaling pathways. This is also the case for the action of leptin. Another substance, IGF-I, shows a partial inhibitory action on GH secretion in the ruminant. The effect of nutrition is also different among animal species. This is evident by the fact that undernutrition suppresses the circulating GH levels in rodents, but increases it in ruminants and humans. Recently, weaning has been shown to change the postprandial GH responses in ruminants; milk feeding increases, but hay and concentrate feeding suppress, the postprandial circulating GH levels. Even if the postprandial GH level is increased, the ghrelin level is decreased by milk feeding. Macronutrients also possess stimulatory and inhibitory actions on GH secretion in vivo and in vitro. These findings indicate the complexity of the control mechanisms of the somatotropic axis. In the present review, we summarize recent findings on the factors controlling the axis of the ruminant.