• Title/Summary/Keyword: early-late phase

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A Case of Chronic Monocular Solar Retinopathy (만성 단안 일광망막병증 1 예)

  • Chang, Woo-Hyok
    • Journal of Yeungnam Medical Science
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    • v.24 no.2
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    • pp.329-332
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    • 2007
  • Solar retinopathy is a rare but well-recognized clinical entity of macular damage, caused by viewing a solar eclipse or direct sun gazing. A 21-year-old man gazed at the sun for approximately thirty seconds at noon using a monocular telescope with his left eye. Forty-eight hours after sun gazing, the patient experienced symptoms of blurred vision and central scotoma in the left eye. Eight months after sun gazing, the visual acuity decreased from 1.0 to 0.1 in the left eye and the fundus examination showed a round, yellowish-white discoid lesion at the left fovea. Fluorescein angiography showed an early window defect in the fovea of the left eye, that persisted without size change during the late phase resulting from atrophy of the retinal pigment epithelium. A small, central scotoma of the left eye was also found in the visual field test. The visual acuity was unchanged at the end of a one-year follow-up period.

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Studies on Genetics and Breeding in Rainbow Trout, Oncorhynchus mykiss Ⅷ. Ultrasturctural Changes of Oocytes in Reproductive Cycles (무지개 송어의 유전육종학적 연구 Ⅷ. 난모세포의 고아학 및 미세구조적 변화)

  • 윤종만;김영곤;박홍양
    • Korean Journal of Animal Reproduction
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    • v.15 no.3
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    • pp.207-220
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    • 1991
  • This study was carried out to investigate the ultrastructural changes of ooplasm and follicular membrane of oocytes, obtained from 150 of 3-year-old female rainbow trout(Oncorhynchus mykiss). All data were collected from March in 1989 to February in 1990, and from August to October in 1991. The size of the nucleoli and number of the yolk granules increased as the oocyte growed. Yolk granules were deposited in the oocyte as crystalline granules. Due to the presence of large early and late maturing oocytes, their ovaires were enlarged, transparent and granular. The lattice was broken down at hydration, leaving the egg transparent. As thepercentages of fish in LPO and EMO stage increased from September to October, Mean GSI values increased. Follicle cells such as granulosa cell and thecal cell change a squamous into cuboid shape in LPO and EMO stage. Seasonal changes in the microscopic appearance of the ovaries were well correlated with those in bothgonadosomatic index and macroscopic apearance. Under the natural conditions,t he ovarian follicle influences the histological development and periodical secretion of the hormones, sufficient for a oogenesis and gonadal steroid production. The electrophoretic pattern of major band in mature stage was much thicker(70∼110k dalton) than that in previtellogenic phase.

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Eddy Formation Near the Izu-Ogasawara Ridge and its Link with Seasonal Adjustment of the Subtropical Gyre in the Pacific

  • Ihara, Chie;Kagimoto, Takashi;Masumoto, Yukio;Yamagata, Toshio
    • Journal of the korean society of oceanography
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    • v.37 no.3
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    • pp.134-143
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    • 2002
  • Using OGCM results, we have shown that the ring-like cold baroclinic eddies associated with cyclonic circulation are shed from late summer to early fall near the Izu-Ogasawara Ridge from the Kuroshio Extension owing to baroclinic instability. On the other hand, warm baroclinic eddies are generated by the intensified western boundary current associated with the warm anomaly accumulated near the Ridge in winter, which corresponds to the basin-wide barotropic intensification of the wind-driven gyre in winter. We are successful in reproducing the behavior of those meso-scale eddies using a simple two-layer primitive equation model driven by seasonal winds associated with the positive curl. Those eddies carry barotropic seasonal signals originated in the Pacific Basin quite slowly west of the ridge; this process introduces a phase lag in the timing of the seasonal maximum transport in the Philippine Basin west of the ridge. It Is demonstrated that the existence of bottom topography, baroclinicity, and nonlinearity due to advection are three necessary elements for the generation of these eddies south of Japan.

Statistical Analysis of Gene Expression in Innate Immune Responses: Dynamic Interactions between MicroRNA and Signaling Molecules

  • Piras, Vincent;Selvarajoo, Kumar;Fujikawa, Naoki;Choi, Sang-Dun;Tomita, Masaru;Giuliani, Alessandro;Tsuchiya, Masa
    • Genomics & Informatics
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    • v.5 no.3
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    • pp.107-112
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    • 2007
  • MicroRNAs (miRNAs) are known to negatively control protein-coding genes by binding to messenger RNA (mRNA) in the cytoplasm. In innate immunity, the role of miRNA gene silencing is largely unknown. In this study, we performed microarray-based experiments using lipopolysaccharide (LPS)-stimulated macrophages derived from wild-type, MyD88 knockout (KO), TRIF KO, and MyD88/TRIF double KO mice. We employed a statistical approach to determine the importance of the commonality and specificity of miRNA binding sites among groups of temporally co-regulated genes. We demonstrate that both commonality and specificity are irrelevant to define a priori groups of co-down regulated genes. In addition, analyzing the various experimental conditions, we suggest that miRNA regulation may not only be a late-phase process (after transcription) but can also occur even early (1h) after stimulation in knockout conditions. This further indicates the existence of dynamic interactions between miRNA and signaling molecules/transcription factor regulation; this is another proof for the need of shifting from a 'hard-wired' paradigm of gene regulation to a dynamical one in which the gene co-regulation is established on a case-by-case basis.

Study on the medical philosophy of Zheng Zhi Xin Chuan(證治心傳) - based on the theory of acute febrile disease - (≪증치심전(證治心傳)≫의 의학사상 고찰 - 온병이론(溫病理論)을 중심으로 -)

  • Jeong, Chang-hyun
    • Journal of Korean Medical classics
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    • v.28 no.4
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    • pp.139-154
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    • 2015
  • Objectives : Zheng Zhi Xin Chuan(證治心傳) is a compact compilation of 14 discussions on medicine, written by Yuan Ban(袁班) in the late Ming-early Qing period. Methods : To survey the scholarly position of Yuan Ban(袁班) in the history of Wenbing by systematically analyzing and organizing Wenbing related theories in Zheng Zhi Xin Chuan (證治心傳). Results & Conclusions : In his book, YB suggests concepts such as 'mainly attack upper heater(多犯上焦)', 'transmission to the nutrient phase(轉入營分)', 'sequential transmission(順傳)', 'abnormal transmission(逆傳)', 'dryness invasion of human body in autumn(秋傷於燥)'. In the history of Wenbing, it has been widely acknowledged that the concept of weiqiyingxiebianzheng(衛氣營血辨證) and abnormal transmission to the pericardium(逆傳心包) were originally suggested by Ye Tianshi(葉天士). However, according to the findings of this study, these concepts are traced back to the contents of YB's publication, nearly a century before Ye's time. In addition, YB's discussion on '秋燥' was highly advanced than any other scholar of his time, hinting his influence on medicine thereafter.

YlaC is an Extracytoplasmic Function (ECF) Sigma Factor Contributing to Hydrogen Peroxide Resistance in Bacillus subtilis

  • Ryu Han-Bong;Shin In-Ji;Yim Hyung-Soon;Kang Sa-Ouk
    • Journal of Microbiology
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    • v.44 no.2
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    • pp.206-216
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    • 2006
  • In this study, we have attempted to characterize the functions of YlaC and YlaD encoded by ylaC and ylaD genes in Bacillus subtilis. The GUS reporter gene, driven by the yla operon promoter, was expressed primarily during the late exponential and early stationary phase, and its expression increased as the result of hydrogen peroxide treatment. Northern and Western blot analyses revealed that the level of ylaC transcripts and YlaC increased as the result of challenge with hydrogen peroxide. A YlaC-overexpressing strain evidenced hydrogen peroxide resistance and a three-fold higher peroxidase activity as compared with a deletion mutant. YlaC-overexpressing and YlaD-disrupted strains evidenced higher sporulation rates than were observed in the YlaC-disrupted and YlaD-overexpressing strains. Analyses of the results of native polyacrylamide gel electrophoresis of recombinant YlaC and YlaD indicated that interaction between YlaC and YlaD was regulated by the redox state of YlaD in vitro. Collectively, the results of this study appear to suggest that YlaC regulated by the YlaD redox state, contribute to oxidative stress resistance in B. subtilis.

On the Negative Feedback Control Mechanism of the Renin Release in Kidney Slices (신성고혈압 백서의 신장절편에서 Renin 유리의 Negative Feedback 조절기전의 변조)

  • Kim, Hyun-J.;Cho, Kyung-W.
    • The Korean Journal of Physiology
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    • v.20 no.2
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    • pp.236-248
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    • 1986
  • Alterations of renin-angiotensin system have been suggested as one of the mechanisms increasing arterial blood pressure in experimental and clinical hypertension. But the exact nature of high blood pressure in the early and late phase of renal hypertension is still controversial. To clarify the nature of renin release in both unclipped and clipped kidney of two kidney one clip Goldblatt lypertensive rat, experiments have been done in kidney slices, which were obtained from the rats of 3 and 7 days of operation. Basal rate of renin release was suppressed in unclipped kidney slices compared to clipped kidney Norepinephrine increased renin release from unclipped kidney slices, but not from clipped kidney slices. Suppressions by angiotensin Il and arginine vasopressin of renin release were attenuated in the clipped kidney slices compared to unclipped and sham-operated kidney slices. Increases by verapamil and trifluoperazine of renin release were attenuated in the clipped kidney slices compared to unclipped and sham-operated kidney slices. These results suggest that the negative feedback control mechanism of the renin-angiotensin system by angiotensin Il and arginine vasopressin is attenuated in the clipped kidney of two kidney one clip Goldblatt hypertensive rat, and that one of the altered mechanisms may be caused by certain regulatory changes of intracellular calcium and/or calcium-calmodulin complex in the juxtaglomerular cells.

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Sea Buckthorn (Hippophae rhamnoides L.) Leaf Extracts Protect Neuronal PC-12 Cells from Oxidative Stress

  • Cho, Chi Heung;Jang, Holim;Lee, Migi;Kang, Hee;Heo, Ho Jin;Kim, Dae-Ok
    • Journal of Microbiology and Biotechnology
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    • v.27 no.7
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    • pp.1257-1265
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    • 2017
  • The present study was carried out to investigate the antioxidative and neuroprotective effects of sea buckthorn (Hippophae rhamnoides L.) leaves (SBL) harvested at different times. Reversed-phase high-performance liquid chromatography analysis revealed five major phenolic compounds: ellagic acid, gallic acid, isorhamnetin, kaempferol, and quercetin. SBL harvested in August had the highest total phenolic and flavonoid contents and antioxidant capacity. Treatment of neuronal PC-12 cells with the ethyl acetate fraction of SBL harvested in August increased their viability and membrane integrity and reduced intracellular oxidative stress in a dose-dependent manner. The relative populations of both early and late apoptotic PC-12 cells were decreased by treatment with the SBL ethyl acetate fraction, based on flow cytometry analysis using annexin V-FITC/PI staining. These findings suggest that SBL can serve as a good source of antioxidants and medicinal agents that attenuate oxidative stress.

Timing Synchronization with Channel Impulse Response in OFDM Systems (채널 임펄스 응답을 이용한 OFDM 시스템 시간 동기)

  • Kang, Eun-Su;Han, Dong-Seog
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.7 s.361
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    • pp.53-58
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    • 2007
  • OFDM (orthogonal frequency division multiplexing) is an effective modulation technique for high speed transmission over fading channels. However, it has a high bit error rate in the receiver if there is an error on frame synchronization because of phase rotation. A coherent OFDM system has to acquire exact timing synchronization of fraction and integer sampling positions. When a sampling offset exist the performance of a receiver will be degraded severely. In this paper, we propose an algorithm that acquires the fractional sampling offset in OFDM systems. This scheme compares the channel impulse responses with the early and late sampled signals having 0.5 sample offset from the estimated sampling positions by correlation with the received and training samples. Its performance is verified by computer simulations in multipath channels.

Cudrania tricuspidata Suppresses Mast Cell-Mediated Allergic Response In Vitro and In Vivo (꾸지뽕나무 추출물의 비만세포 억제에 의한 항알레르기 효과 및 기전)

  • Kim, Young-Mi
    • YAKHAK HOEJI
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    • v.56 no.1
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    • pp.26-34
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    • 2012
  • Mast cells play an important role in early and late phase allergic reactions through allergen and IgE-dependent release of histamine, proteases, prostaglandins, and several multifunctional cytokines. In this study, we investigated whether Cudrania tricuspidata extract (CTE) suppresses IgE-mediated allergic responses in mast cells, an allergic animal model, and its mechanism of action in mast cells. We found that CTE inhibited IgE-mediated degranulation and cytokine production in rat basophilic leukemia (RBL)-2H3 mast cells and bone marrow-derived mast cells (BMMC), as well as passive cutaneous anaphylaxis (PCA) in mice. With regard to its mechanism of action, CTE suppressed the activating phosphorylation of spleen tyrosine kinase (Syk), a key enzyme in mast cell signaling processes and that of LAT, a downstream adaptor molecule of Syk in $Fc{\varepsilon}RI$-mediated signal pathways. CTE also suppressed the activating phosphorylation of mitogen-activated protein (MAP) kinases and Akt. The present results strongly suggest that the anti-allergic activity of CTE is mediated through inhibiting degranulation and allergic cytokine secretion by inhibition of Syk kinase in mast cells. Therefore, CTE may be useful for the treatment of allergic diseases.