• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.405-410
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• 2016

Auxins are essential in plant growth and development. The auxin-stimulated elongation of plant cells has been explained by the "acid-growth theory", which was proposed forty years ago. According to this theory, the auxin activates plasma membrane $H^+-ATPase$ to induce proton extrusion into the apoplast, promoting cell expansion through the activation of cell wall-loosening proteins such as expansins. Even though accepted as the classical theory of auxin-induced cell growth for decades, the major signaling components comprising this model were unknown, until publication of recent reports. The major gap in the acid growth theory is the signaling mechanism by which auxin activates the plasma membrane $H^+-ATPase$. Recent genetic, molecular, and biochemical approaches reveal that several auxin-related molecules, such as TIR1/AFB AUX/IAA coreceptors and SMALL AUXIN UP RNA (SAUR), serve as important components of the acid-growth model, phosphorylating and subsequently activating the plasma membrane $H^+-ATPase$. These researches reestablish the four-decade-old theory by providing us the detailed signaling mechanism of auxininduced cell growth. In this review, we discuss the recent research progress in auxin-induced cell elongation, and a set of possible future works based on the reestablished acid-growth model.

• Journal of Nutrition and Health
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• v.30 no.6
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• pp.639-647
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• 1997

The effect of excess L-ascorbic acid(AsA) in blood, liver lipid levels and peroxidation status were investigate . Ten Sprague-Dawley male rats weighing 150-200g were fed 300mg AsA/100g body weight/day, mixed into ground chow diet, for 4 weeks. And another set of then rats were fed only chow diet as the control. Average body weight gain was slightly lowered by AsA feeding without food intake change. The AsA group showed higher AsA levels in plasma and liver than the control group. In addition, the AsA group showed a higher plasma TBARS value. Liver TBARS seemed to be elevated in the AsA, but not significantly. The hemolysis of red cells tended to increase with excess AsA, accompanied by a raised GSH-Px activity and lowered total GSH levels. Plasma HDL-Chol level was increased while the levels of total Chol, LDL-plus VLDL-Chol , and triglyceride were unchanged . Atherogenic index decreased. Hepatic TG levels were also decreased, but the total amount of Chol increased slightly . Platelet TXA$_2$ production was inhibited by excess AsA feeding. Above results indicafe that oral feeding of excess AsA may be beneficial in reducing the risk of atherosclerosis ; however such practice may be detrimental for tissue lipid peroxidation and weight gain.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.271-277
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• 1988

In order to study the marked variation of red blood cell sedimentation rate in some species of animals, the packed cell volume, volume percentage of erythrocytes in whole blood, was reshuffled of 20%, 40% and 60% using heteroplasma of chicken and goat, and the red blood cell sedimentation rate was measured in Westergren tubes at $27{\pm}1^{\circ}C$ and $8{\pm}1^{\circ}C$. The results obtained were summarized as follows: 1. The values of packed cell volume(PCV) of goat and chicken were $40.7{\pm}4.1%$ and $30.2{\pm}2.2%$ respectively. 2. The sedimentation rates of reshuffled red blood cell were settled faster at lower PCV than higher PCV, i.${\acute{e}}$. there was a reverse relationship between the sedimention rate and PCV. 3. Red blood cells of chicken settled quickly, where as those of goat settled very slowly. Chicken red blood cell sedimented rapidly even in goat plasma, and goat red blood cell sedimented slowly in chicken plasma. These findings indicate that the plasma is not the only factor determining the rapid red blood cell sedimentation rate of chicken. 4. The sedimentation rate of reshuffled red blood cell of chicken and goat were accelerated at higher temperature than lower temperature.

• The Korean Journal of Nuclear Medicine
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• v.7 no.1
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• pp.31-38
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• 1973

The blood glucose and plasma immunoreactive insulin(IRI) levels were measured glucose tolerance test in 7 healthy subjects and 6 patients with chronic liver diseases. The glucose tolerance was impaired in 5 of the 6 patients and normal in 1. Plasma IRI responses were markedly increased and delayed in all patients, suggesting insulin resistance. Patients with more glucose intolerance showed less increase in plasma IRI than the group with less intolerance. It is suggested that some insulin antagonists may decrease the peripheral insulin sensitivity and stimulate compensatory hyperactivity of pancreatic islets. If the compensatory hyperactivity is inadequate due to genetic predisposition to diabetes mellitus or exhaustion of ${\beta}$-cells of pancreatic islsts, the glucose intolerance and overt diabetes mellitus may ensue.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.433-433
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• 2013

Graphene, $sp^2$-hybridized 2-Dimension carbon material, has drawn enormous attention due to its desirable performance of excellent properties. Graphene can be applied for many electronic devices such as field-effect transistors (FETs), touch screen, solar cells. Furthermore, indium tin oxide (ITO) is commercially used and sets the standard for transparent electrode. However, ITO has certain limitations, such as increasing cost due to indium scarcity, instability in acid and basic environments, high surface roughness and brittle. Due to those reasons, graphene will be a perfect substitute as a transparent electrode. We report the graphene synthesized by inductive coupled plasma enhanced chemical vapor deposition (ICP-PECVD) process on Cu substrate. The growth was carried out using low temperature at $400^{\circ}C$ rather than typical chemical vapor deposition (CVD) process at $1,000^{\circ}C$ The low-temperature process has advantage of low cost and also low melting point materials will be available to synthesize graphene as substrate, but the drawback is low quality. To improve the quality, the factor affect the quality of graphene was be investigated by changing the plasma power, the flow rate of precursors, the scenario of precursors. Then, graphene film's quality was investigated with Raman spectroscopy and sheet resistance and optical emission spectroscopy.

• Archives of Pharmacal Research
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• v.26 no.1
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• pp.64-69
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• 2003

To analyze vasopressin-induced $Ca^{2+}$ increase in liver cells, rat hepatocytes were isolated and attached to collagen-coated cover slips. Using fura-2, a $Ca^{2+}$-sensing dye, changes in intracellular $Ca^{2+}$ concentration by vasopressin were monitored. Results in this communication suggested that vasopressin-induced $Ca^{2+}$ increase were composed of both $Ca^{2+}$ release from internal $Ca^{2+}$ stores and influx from the plasma membrane. The $Ca^{2+}$ influx consisted of two distinguishable components. One was dependent on the presence of vasopressin and the other was not. SK＆F96365 blocked vasopressin-induced $Ca^{2+}$ influx in a dose-dependent manner. Vasopressin-induced $Ca^{2+}$ release from internal stores diminished in a primary culture of hepatocytes according to the culture time. However, changes in vasopressin-induced $Ca^{2+}$ influx across the plasma membrane differed from changes in the $Ca^{2+}$ release from internal stores, suggesting two separate signalings from receptor activation to internal stores and to the plasma membrane.

• Current Research on Agriculture and Life Sciences
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• v.2
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• pp.109-114
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• 1984

Eight Korean native black goats were used, $10m{\ell}$ of blood was collected from the Jugular vein into heparinized tubes a week interval. The heparinized blood was centrifuged for separation to blood plasma and corpuscles. The hematocrit, per centage of blood that is red blood cells, was reschuffuled of 10 %, 20 %, 30 %, 40 % and 50 % using blood plasma, 0.9 % NaCl solution and 5.4 % dextrose solution. The sedimentation rates of red blood cell obtained at $7^{\circ}C{\pm}1^{\circ}C$ and $27^{\circ}C{\pm}1^{\circ}C$ are summarized as follows. 1) The sedimentation rates of red blood cell were more increased by lower PCV%, i.e. there was a reverse relationship between the sedimentation rates and PCV% at any condition of these experiments. 2) The RBC were sedimented the most quickly in the NaCl solution and slower in the plasma compare with the dextrose solution at the same PCV%. 3) There was no temperature effect on the sedimentation rates between the two groups of $7^{\circ}C{\pm}1^{\circ}C$ and $27^{\circ}C{\pm}1^{\circ}C$(at PCV 20% and 10%), even though the temperature difference is $20^{\circ}C$.

• The Korean Journal of Physiology
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• v.23 no.2
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• pp.339-350
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• 1989

Electrophysiological effects of ammonia was studied in the isolated superfused sinus node and atrial muscle cells of the rabbit heart. No significant changes were observed in the overshoot potential (05), maximum diastolic potential (MDP), and action potential amplitude (APA) of the sinus node cells following superfusion with 3.0 mM ammonia, fifty times upper limit of the normal human plasma level. However the action potential duration (APD) of sinus node cells were significantly prolonged after superfusion with 0.6 mM ammonia for 20 min or with 1.2 and 3.0 mM ammonia for 5 minutes. Ammonia in all the concentrations tested decreased the rate of spontaneous firing (RSF) from the sinus node cells. After superfusion of sinus node cells with 0.3 mM ammonia for 20 min, the RSF significantly decreased from 20 min to 25 min after onset of superfusion while a significant decrement in the RSF was observed from 7 min to 30 min following superfusion with 3.0 mM ammonia for S min. On the other hand, the effects of ammonia on the action potential of the rabbit atrial muscle cell were much similar to those on pacemaker cells except that the atrial cell was generally less sensitive to ammonia. The results suggest that ammonia may cause changes in the action potential of the rabbit cardiac cells by the direct action, and that the cardiac effects of ammonia are generally opposite to those of glycine.

• Oncology Letters
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• v.17 no.4
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• pp.3981-3989
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• 2019

Tamoxifen (TAM) is the most widely used treatment for estrogen receptor-positive breast cancer patients. Unfortunately, the majority of these patients exhibit TAM resistance following treatment. We previously reported that proliferation and migration were greater in TAM-resistant MCF-7 (TAMR-MCF-7) cells than in parental MCF-7 cells. Janus kinases (JAKs) are cytosolic tyrosine kinases that transduce signals from plasma membrane cytokines and growth factor receptors. JAK2 selectively phosphorylates signal transducer and activator of transcription (STAT)-3, and the JAK2-STAT3 signaling pathway is known as a crucial signaling pathway for the regulation of cancer progression and metastasis. In the present study, basal phosphorylation of STAT3 was revealed to be greater in TAMR-MCF-7 cells than in control MCF-7 cells. Ruxolitinib, a potent JAK2 inhibitor, was demonstrated to attenuate STAT3 phosphorylation and the proliferation of TAMR-MCF-7 cells. Ruxolitinib also suppressed the enhanced cell migration of TAMR-MCF-7 cells through the inhibition of epithelial mesenchymal transition. Vascular endothelial growth factor (VEGF), a representative target gene of the JAK2-STAT3 pathway, functions as a key regulator of invasion and angiogenesis. Ruxolitinib significantly inhibited VEGF mRNA expression and transcriptional activity. The present study also performed a chick embryo chorioallantoic membrane assay to assess tumor growth and angiogenesis in TAMR-MCF-7 cells. Ruxolitinib reduced tumor weight and the number of blood vessels produced by TAMR-MCF-7 cells in a concentration-dependent manner. These results indicated that JAK2 could be a new therapeutic target for TAM-resistant breast cancer.

• Parasites, Hosts and Diseases
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• v.62 no.3
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• pp.281-293
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• 2024

We previously reported that leukotriene B₄ (LTB₄) contained in Trichomonas vaginalis-derived secretory products (TvSP) play an essential role in interleukin-8 (IL-8) production in human mast cell line (HMC-1 cells) via LTB₄ receptor (BLT)-mediated Nuclear Factor-kappa B (NF-κB) activation. Dynamin, a GTPase, has been known to be involved in endocytosis of receptors for signaling of production of cytokine or chemokines. In the present study, we investigated the role of dynamin-mediated BLT1 endocytosis in TvSP-induced IL-8 production. When HMC-1 cells were transfected with BLT1 or BLT2 siRNA, TvSP-induced IL-8 production was significantly inhibited compared with that in cells transfected with control siRNA. In addition, pretreatment of HMC-1 cells with a dynamin inhibitor (Dynasore) reduced IL-8 production induced by TvSP or LTB₄. TvSP- or LTB₄-induced phosphorylation of NF-κB was also attenuated by pretreatment with Dynasore. After exposing HMC-1 cells to TvSP or LTB₄, BLT1 was translocated from the intracellular compartments to the plasma membrane within 30 min. At 60 min after stimulation with TvSP or LTB₄, BLT1 remigrated from the cell surface to intracellular areas. Pretreatment of HMC-1 cells with dynamin-2 siRNA blocked internalization of BLT1 induced by TvSP or LTB₄. Co-immunoprecipitation experiments revealed that dynamin-2 strongly interacted with BLT1 60 min after stimulation with TvSP or LTB₄. These results suggest that T. vaginalis-secreted LTB₄ induces IL-8 production in HMC-1 cells via dynamin 2-mediated endocytosis of BLT1 and phosphorylation of NF-κB.