• Title/Summary/Keyword: Lateral inhibition

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Effect of Brushing on the Growth, Yield, and Starch Contents of Spring Planted Potato(Solanum tubersoum L.) (Brushing 처리가 봄감자의 생육ㆍ수량 및 전분 함량에 미치는 영향)

  • 박용봉;문창준;김용덕
    • Journal of Bio-Environment Control
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    • v.13 no.2
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    • pp.120-123
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    • 2004
  • This study was conducted to investigate the effect of brushing on overgrowth inhibition, growth, yield and starch content in spring-grown potato in the netted house. The plant growth of aerial parts was inhibited with growth stage and brushing duration. Especially, The number of lateral branches decreased greatly with brushing duration. The stem length and stem diameter were not different significantly between brushing and non-brushing on May 6. But the stem length was long in later growth stage but short in longer brushing duration. Chlorophyll content by SPAD increased with growth stage regardless of non-brushing duration and ranged from 30 to 36 mg/$\textrm{cm}^2$. The fresh and dry weight of aerial part and tuber were heavy in longer brushing duration. Starch content was higher in brushing treatment as compared to non-brushing and increased with brushing duration.

Studies on the mechanism of the cardiovascular effect of intraventricular 5-hydroxytryptamine in rabbit

  • Lim, Dong-Yoon;Kim, Young-Rae;Kim, Won-Sik;Kim, Kyoon-Hong;Yoo, Ho-Jin;Choi, Hee-Woong;Kim, Soo-Bok
    • Archives of Pharmacal Research
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    • v.13 no.1
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    • pp.55-63
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    • 1990
  • An attempt was made to investigate the effect of intracerebroventricular 5-hydroxytrypatamine (5-HT) on the cardiovascular system in urethane-anesthetized rabbit and to elucidate the mechanism of its action. 5-HT given into a lateral ventricle caused clearly a dose-dependent decrease inboth arterial blood pressure and in heart rate. The bradycardia and hypotension induced by 5-HT were significantly attenuated by the prior injection of ketanserin, cyproheptadine or clonidine. Pretreatment of atropine with bilateral vagotomy did not affect both bradycardia and hypotension. Propranolol weakened markedly the breadcardia of 5-HT but did not influence the depressor response of 5-HT. These experimental results suggest that intraventricular 5-HT cause the hypotension and bradyardia in rabbits through the stimulation of serotonergic receptors in brain, which is seemed to be associated to inhibition of sympathetic tone.

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Inhibition of Metastatic Lung Cancer in C57BL/6 Mice by Marine Mangrove Rhizophora apiculata

  • Prabhu, V. Vinod;Guruvayoorappan, C.
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1833-1840
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    • 2013
  • Metastasis is one of the hallmarks of malignant neoplasms and is the leading cause of death in many cancer patients. A major challenge in cancer treatment is to find better ways to specifically target tumor metastasis. In this study, the anti-metastatic potential of the methanolic extract of Rhizophora apiculata (R.apiculata) was evaluated using the B16F-10 melanoma induced lung metastasis model in C57BL/6 mice. Metastasis was induced in C57BL/6 mice by injecting highly metastatic B16F-10 melanoma cells through the lateral tail vein. Simultaneous treatment with R.apiculata extract (10 mg/kg b.wt (intraperitoneal) significantly (p<0.01) inhibited pulmonary tumor nodule formation (41.1 %) and also increased the life span (survival rate) 107.3 % of metastatic tumor bearing animals. The administration of R.apiculata extract significantly (p<0.01) reduced biochemical parameters such as lung collagen hydroxyproline, hexosamine, uronic acid content, serum nitric oxide (NO), ${\gamma}$-glutamyl transpeptidase (GGT) and sialic acid levels when compared to metastasis controls. These results correlated with lung histopathology analysis of R.apiculata extract treated mice showing reduction in lung metastasis and tumor masses. Taken together, our findings support that R.apiculata extract could be used as a potential anti-metastasis agent against lung cancer.

The Effects of Iridoid Compounds on Wound Healing (Iridoid 화합물이 창상 치유에 미치는 영향)

  • Lee, Sung-Woo;Kho, Hong-Seop;Lee, Sang-Goo
    • Journal of Oral Medicine and Pain
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    • v.24 no.2
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    • pp.137-143
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    • 1999
  • Aucubin, the natural product, which is isolated from Aucuba japonica, has a variety of pharmacological effects such as liver-protective function, inhibition of liver RNA and protein biosynthesis, hypotensive activity and antimicrobial effect, etc. This study was performed to investigate the effects of iridoid compounds on wound healing. The author prepared 0.1% aucubin solution and 0.1% aucubin ointment as an active form, aucubigenin to which aucubin was converted by ${\beta}$-glucosidase. Artificial surgical wound was made on either 1cm lateral side of the dorsal midline along the axis of spine of Sprague-Dawley rats under sterile technique. Application of 0.1% aucubin solution or 0.1% aucubin ointment to surgical wound was done daily. Light microscopic examination was performed on the postsurgical 3 days, 5 days, and 9 days. The 0.1% aucubin solution group epithelialized earlier than the control group and the fibrosis of granulation tissue of both aucubin groups were more prominent than the control group. Collectively, this study suggests the possibility of aucubin as a topical agent. Further research should be performed on the mechanism of aucubin on wound healing and proper formulation for effective topical agents.

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Distribution of chitinases and characterization of two chitinolytic enzymes from one-year-old Korean Ginseng (Panax ginseng C.A. Meyer) roots

  • Moon, Jong-Kook;Han, Beom-Ku;Kim, T. Doo-Hun;Jo, Do-Hyun
    • BMB Reports
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    • v.43 no.11
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    • pp.726-731
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    • 2010
  • We report the tissue-specific distribution of chitinolytic activity in Korean ginseng root and characterize two 31-kDa chitinolytic enzymes. These two enzymes (SBF1 and SBF2) were purified 70- and 81-fold with yields of 0.75 and 1.25%, respectively, and exhibited optimal pH and temperature ranges of 5.0-5.5 and 40-$50^{\circ}C$. With [$^3H$]-chitin as a substrate, $K_m$ and $V_{max}$ values of SBF1 were 4.6 mM and 220 mmol/mg-protein/h, respectively, while those of SBF2 were 7.14 mM and 287 mmol/mg-protein/h. The purified enzymes showed markedly less activity with p-nitrophenyl-N-acetylglucosaminide and fluorescent 4-methylumbelliferyl glycosides of D-N-acetylglucosamine oligomers than with [$^3H$]-chitin. End-product inhibition of both enzymes demonstrated that both are endochitinases with different N-acetylglucosaminidase activity. Furthermore, the $NH_2$-terminal sequence of SBF1 showed a high degree of homology with other plant chitinases whereas the $NH_2$-terminal amino acid of SBF2 was blocked.

Root-Rot Development of 2-Year old Ginseng (Panax ginseng C.A. Meyer) Caused by Cylindrocarpon destructans (Zinssm.) Scholten in the Continuous Cultivation Field (Cylindrocarpon destructans (Zinssm.) Scholten에 의한 연작지 2년근 인삼의 근부병 발병 특성)

  • 조대휘;박규진
    • Journal of Ginseng Research
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    • v.19 no.2
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    • pp.175-180
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    • 1995
  • The disease development of root-rot [pathogen:Cylindrocarpon destruction (Zinssm.) Scholten] occurred in 2-year old ginseng (Panax ginseng C.A. Meyer) was investigated in the continuous (the first cultivation: 1978∼1982, 2nd cultivation: 1990∼1993 and abolished in 1993 due to replanting problem) and replanted cultivation (period of cultivation: 1980∼1984). In the continuous cultivation, incidences of root-rot were 0.7% on May 3, 48.6% on May 24, and 95.8% on June 14, respectively. In the replanted cultivation, no symptom was observed on May 3 and disease incidence was generally lower compared with the continuous cultivation. On the aerial part of the ginseng infected by C. desiccates, the end and/or margin of leaves were changed to dark reddish color that appeared for behind the root-rot symptom. In this field, the longitudinal growth of lateral root was more inhibited than in the case of the replanted cultivation by C. destmctans. The inhibition rate of rootlet growth was 37.3% in the continuous cultivation as compared with that of replanted cultivation at June 14. Though lesions of root-rot were formed all over the roots, 61.2% of the lesions was positioned within 6 cm under the rhizome. Key words Panax ginseng, Cylindrocarpon destmtan, root-rot of ginseng, replanting problem of ginseng.

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Ethylene-Induced Auxin Sensitivity Changes in Petiole Epinasty of Tomato Mutant dgt

  • Chang, Soo Chul;Lee, Myung Sook;Lee, Sang Man;Kim, Jinseok;Kang, Bin G.
    • Journal of Plant Biology
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    • v.37 no.3
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    • pp.257-262
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    • 1994
  • The tomato (Lycopersicon esculentum Mill.) mutant diageotropica (dgt) lacking normal gravitropic response is known to be less sensitive to auxin compared with its isogenic parent VFN8. Straight growth as well as ethylene production in response to added auxin in hypocotyl segments of dgt was negligible. However, there was no significant difference between the two genotypes in auxin transport in petiole segments and its inhibition by the phytotropin N-1-naphthylphthalamic acid(NPA). Kinetic parameters of NPA binding to microsomal membranes were also non-distinguishable between the two. Its petiolar explants treated with ethylene developed epinastic curvature with the magnitude of response increased about 3 folds over non-mutant wild type. Ethylene-induced epinasty in both dgt and VFN8 was nullified by treatment of explants with the ethylene autagonist 2,5-norbonadiene. Lateral transport of 3H-IAA toward the upper side of ethylene-treated petioles in dgt, however, was not significantly more pronounced than in VFN8, the implications being that auxin sensitivity in the mutant was restored, or even rised above the wild type, by ethylene.

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Development of an Alignment Method for Retarders in isoSTED Microscopy

  • Ilkyu Park;Dong-Ryoung Lee
    • Current Optics and Photonics
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    • v.8 no.4
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    • pp.421-426
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    • 2024
  • The use of stimulated emission depletion (STED) microscopy has significantly improved resolution beyond the limits imposed by diffraction; Furthermore, STED microscopy adopts a 4Pi-geometry to achieve an isotropic improvement in resolution. In isoSTED microscopy, a polarizing beam splitter and retarders are used in a 4Pi cavity to split beams of identical power, generating constructive and destructive interference for lateral and axial resolution improvements, respectively. The precise alignment of the retarders is crucial for optimizing the performance of isoSTED microscopy, because this orientation affects the quality of the depletion focus, necessitating zero intensity at the center. Incomplete destructive interference can lead to unwanted fluorescence inhibition, resulting in degraded resolution and contrast. However, measuring the intensity and polarization state in each optical path of the 4Pi cavity is complex and requires additional devices such as a power meter. Here, we propose a simple and accurate alignment method for the 4Pi cavity in isoSTED microscopy. Our approach demonstrates the equal allocation of power between upper and lower beam paths and achieves complete destructive interference using a polarizing beam displacer and a single CCD camera positioned outside the 4Pi cavity.

Influence of Intracerebroventricular Thiopental Sodium on the Renal Function in Conscious Rabbit (측뇌실내로 투여한 Thiopental Sodium의 가토 신장기능에 미치는 영향)

  • Hong, Ki B.;Cho, Kyung W.
    • The Korean Journal of Physiology
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    • v.19 no.1
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    • pp.35-48
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    • 1985
  • One of most frequently used anesthetic agents is barbiturate derivatives. Pentobarbital or thiopental sodium have been used most frequently in the laboratory or clinical practice. There have been reports on the renal effects of barbiturate anesthesia in human and laboartory animals. Renal effects of thiopental sodium anesthesia, however, are still controversial. One of the discrepancies may be derived from the doses used. It has been reported that subanesthetic small dose of thiopental sodium influences the renal function directly. To clarify possible central effects of very small amounts of thiopental sodium on the renal function, experiments have been done in conscious rabbits. Thiopental sodium was infused into the lateral cerebroventricle for 10 minutes. Intracerebroventricular thiopental sodium induced increased urinary volume, glomerular filtration rate and renal plasma flow by doses of $0.1{\sim}1.0\;mg/10 min/rabbit$. Filtration fractions were not changed. Sodium, chloride and potassium excretions were increased by 0.065 mg/10 min/rabbit of thiopental sodium without significant changes of renal hemodynamics. Higher doses of thiopental sodium $(0.1{\sim}1.0\;mg/10 min/rabbit)$ induced greater increases of electrolytes excretion and renal hemodynamics. Free water clearance was not changed by thiopental sodium, but the fractional excretion of free water showed a tendency of decrease. Fractional excretion of sodium was increased by doses of 0.065 to 1.0 mg of thiopental sodium . Highly significant correlation between the changes of glomerular filtration rate and the changes of sodium excretion were found in the higher doses. Plasma renin concentration (activity) was not changed by the centrally administered thiopental sodium. Intravenous thiopental sodium, 1.0 mg/rabbit, induced no changes of renal function in conscious rabbit. These data suggest that intracerebroyentricular thiopental sodium can increase urinary sodium excretion directly by inhibition of sodium reabsorption in the renal tubules and/or indirectly by increasing the renal hemodynamics.

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Ghrelin Protects Spinal Cord Motoneurons Against Chronic Glutamate Excitotoxicity by Inhibiting Microglial Activation

  • Lee, Sung-Youb;Kim, Yu-Mi;Li, Endan;Park, Seung-Joon
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.1
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    • pp.43-48
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    • 2012
  • Glutamate excitotoxicity is emerging as a contributor to degeneration of spinal cord motoneurons in amyotrophic lateral sclerosis (ALS). Recently, we have reported that ghrelin protects motoneurons against chronic glutamate excitotoxicity through the activation of extracellular signal-regulated kinase 1/2 and phosphatidylinositol-3-kinase/Akt/glycogen synthase kinase-$3{\beta}$ pathways. Previous studies suggest that activated microglia actively participate in the pathogenesis of ALS motoneuron degeneration. However, it is still unknown whether ghrelin exerts its protective effect on motoneurons via inhibition of microglial activation. In this study, we investigate organotypic spinal cord cultures (OSCCs) exposed to threohydroxyaspartate (THA), as a model of excitotoxic motoneuron degeneration, to determine if ghrelin prevents microglial activation. Exposure of OSCCs to THA for 3 weeks produced typical motoneuron death, and treatment of ghrelin significantly attenuated THA-induced motoneuron loss, as previously reported. Ghrelin prevented THA-induced microglial activation in the spinal cord and the expression of pro-inflammatory cytokines tumor necrosis factor-${\alpha}$ and interleukin-$1{\beta}$. Our data indicate that ghrelin may act as a survival factor for motoneurons by functioning as a microglia-deactivating factor and suggest that ghrelin may have therapeutic potential for the treatment of ALS and other neurodegenerative disorders where inflammatory responses play a critical role.