• 제목/요약/키워드: Potentiation

검색결과 207건 처리시간 0.027초

급성 일산화탄소 중독 후 해마에서 Parvalbumin 양성 중간뉴론의 변화에 대한 N-acetylcystein의 효과 (Effects of N-acetylcystein on changes in parvalbumin-positive interneurons in the hippocampus after carbon monoxide poisoning)

  • 김선태;유수진
    • 대한임상독성학회지
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    • 제19권2호
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    • pp.100-109
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    • 2021
  • Purpose: The purpose of this study was to investigate effect of N-acetylcysteine (NAC) on the injury of putative parvalbumin positive interneurons defined by molecular marker and hippocampal long-term potentiation (LTP), a marker of neural plasticity following acute carbon monoxide (CO) poisoning. Methods: Adult Sprague-Dawley rats were exposed to 1100 ppm CO for 40 minutes followed by 3000 ppm CO for 20 minutes. Animals received daily intraperitoneal injection of NAC (150 mg/kg) for 5 days after CO exposure. Changes in learning and spatial memory were evaluated by Y-maze test 5 days after the poisoning. In vivo LTP in hippocampal CA1 area was evaluated by using extracellular electrophysiological technique. Immunohistochemical staining were adopted to observe expressional damages of parvalbumin (PV) immunoreactive interneurons in the hippocampus following the poisoning. Results: Acute CO intoxication resulted in no changes in memory performance at Y-maze test but a significant reduction of LTP in the in hippocampal CA1 area. There was also a significant reduction of PV (+) interneurons in the hippocampal CA1 area 5 days after CO poisoning. Daily treatment of NAC significantly improved hippocampal LTP impairment and reduced immunoreactivity for PV in the hippocampus following the acute CO poisoning. Conclusion: The results of this study suggest that reduction of hippocampal LTP and PV (+) interneurons in the hippocampus is sensitive indicator for brain injury and daily NAC injections can be the alternative therapeutics for the injury induced by acute CO poisoning.

Partial Purification and Characterization of a Glycoprotein Factor from Fresh Ginseng

  • Kong, Yun-Cheung;Fong, Wing-Ping;Song, Myung-Eun;Ng, Kam-Hung;Ho, Dan-Dan;Ng, Ping-Chung
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1990년도 Proceedings of International Symposium on Korean Ginseng, 1990, Seoul, Korea
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    • pp.79-85
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    • 1990
  • The aqueous extract of fresh ginseng (Panax ginseng C.A. Meyer) contains a macromolecular fraction that showed mitogenic and comitogenic activities in human peripheral blood Iymphocytes. Purification of the crude extract by size (ultrafiltration, Sephadex G-200) and charge (DEAE-cellulose. DEAE-Sepharose) yielded a semi-purified fraction (DS-3). This fraction contains at least three subgroups of anionic macromolecules with apparent molecular weight greater than 600 kilodaltons. It is a glycoprotein with a large amount of glucuronic acid. It acts as a mitogen in both T and B cells of human peripheral blood lymphocytes. It could also potentiate the mitogenic action of Concanavalin A in Iymphocyte T cells. Such potentiation is not due to increased binding of Concanavalin A to the cell surface. Its mitogenic and co-mitogenic effects do depend on the presence of extracellular Ca2+.

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Spatial Information Processing between Hippocampus and Prefrontal cortex: a Hypothesis Based on Anatomy and Physiology

  • Jung, Min-Whan
    • Animal cells and systems
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    • 제2권1호
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    • pp.65-69
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    • 1998
  • The hippocampus and prefrontal cortex are regarded as the highest-order association cortices. The hippocampus has been proposed to store "cognitive maps" of external environments, and the prefrontal cortex is known to be involved in the planning of behavior, among other functions. Considering the prominent functional roles played by these structures, it is not surprising to find direct monosynaptic projections from the hippocampus to the prefrontal cortex. Rhythmic stimulation of this projection patterned after the hippocampal EEG theta rhythm induced stable long-term potentiation of field potentials in the prefrontal cortex. Comparison of behavioral correlates of hippocampal and prefrontal cortical neurons during an a-arm radial maze, working memory task shows a striking contrast. Hippocampal neurons exhibit clear place-specific firing patterns, whereas prefrontal cortical neurons do not show spatial selectivity, but are correlated to different stages of the behavioral task. These data lead to the hypothesis that the role of hippocampal projection to the prefrontal cortex is not to impose spatial representations upon prefrontal activity, but to provide a mechanism for learning the spatial context in which particular behaviors are appropriate.propriate.

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수삼 고분자 분획의 성장촉진활성 (Growth Promoting Activity of a Macromolecular Fraction from Fresh Ginseng)

  • Eun, Song-Myung;Hung, Ng-Kam;Nam, Leung-Kwok;Cheung, Kong-Yum
    • Journal of Ginseng Research
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    • 제13권2호
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    • pp.215-222
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    • 1989
  • A macromolecular fraction from fresh ginseng root containing mainly polysaccharide showed mild mitogenic activity in human cord blood lymphocytes. 2) When lymphocytes were transformed by Con A or PHA, this fraction could greatly enhance the activity of these lectin mitogens, thus showing a potentiation effect. 3) Although this macromolerular fraction contains saponin and is susceptible to trypsin digestion, it is probably a peptido-glycan in nature on account of its important carbohydrate content and thermal stability. 4) This fraction could not support cancer cell (EAT, K562) growth : its inhibitory effect on these cells remains to be explored.

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Carrageenin으로 흰쥐 발 염증으로 Indomethacin에 의한 유도성 nitric oxide synthase의 발현증가 (Potentiation of Inducible Nitric Oxide Expression by Indomethacin in Carageenin-treated Rat Paw Inflammation)

  • 원혜영;강건욱;김영미;김낙두
    • 약학회지
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    • 제43권2호
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    • pp.214-220
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    • 1999
  • Present study was aimed to examine whether indomethacin affected the production of NO in the rat paw exudate by carrageenin. Paw edema and nitrite/nitrate levels in the paw exudate were maximal after 4 h and remained elevated up to 10 h, whereas indomethacin (10 mg/kg, po) significantly inhibited the carrageenin-induced paw edema and levels of nitrate in the paw exudate. However, paw edema and nitrite/nitrite levels were increased thereafter for 10 h. Indomethacin also enhanced the expression of iNOS mRNA and protein 4 h after carrageenin infection. Indomethacin inhibited the level of $PGE_2$ in the paw exudate in a time-dependent manner. These results suggest the possibility that indomethacin may potentiate expression of iNOS and subsequently increase nitrite/nitrate level in the late phase of carrageenin-induced rat paw inflammation possibly by suppressing cycloxygenase activity.

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알쯔하이머 치매의 동물모형 (Animal Models of Alzheimer's Dementia)

  • 우성일
    • 생물정신의학
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    • 제6권2호
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    • pp.149-152
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    • 1999
  • Transgenic mice models of Alzheimer's disease were produced by overexpressing APP(amyloid precursor protein) mutant and presenilin mutant genes using the promotors that induced neuronal expression. The neuropathologies, electrophysiological changes and behavioral changes that were demonstrated in these transgenic mice models were amyloid changes, gliotic changes, A-beta increases, deficit in LTP(long-term potentiation) and behavioral changes. Some or all of the above changes were found in each transgenic mice model. These models generally showed amyloid neuropathology but they usually lacked the neurofibrillary tangles. So, they can be regarded as partial models of Alzheimer's disease. The development of them is undoubtedly the great progress toward future research.

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아출(莪朮)의 Sesquiterpene 성분의 약물활성 (Pharmacological Activities of Sesquiterpenes from the Rhizomes of Curcuma zedoaria)

  • 신국현;윤기영;조태순
    • 생약학회지
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    • 제25권3호
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    • pp.221-225
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    • 1994
  • Pharmacological activities of two sesquiterpenes, curzerenone(I), and curcumenol(II) isolated from the rhizomes of Curcuma zedoaria being used as an aromatic stomachic in Chinese medicines were evaluated in rats and mice. Curzerenone (I), at 100mg/kg, p.o. showed a potent protective effect against HCl-ethanol induced gastric lesion in rats, and curcumenol(II), at the same dose level showed a CNS depressant action characterized by a potentiation of hexobarbital(HB)-induced narcosis. Both compounds showed a moderate analgesic action but did not exhibit a hypothermic action even at 200mg/kg dose level.

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Cytotoxic and Cytotoxicity-Potentiating Effects of the Curcuma Root on L1210 Cell

  • Ahn, Byung-Zun;Lee, Jeong-Hyung
    • 생약학회지
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    • 제20권4호
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    • pp.223-226
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    • 1989
  • A cytotoxic sesquiterpene against L1210 cell has been isolated from the root of Curcuma domestica. Its structure was identified as ${\beta}-sesquiphellandrene$. The cytotoxicity-potentiating substance was (+)-ar-turmerone. (+)-ar-Turmerone potentiated the cytotoxicity of ${\beta}-sesquiphellandrene$(5 fold in $ED_{50}$ value) and an unknown sesquiterpene which was isolated from the root as well, and that of aurapten(6.3 fold) isolated from the unripe fruit of Poncirus trifoliata. Moreover, it potentiated the cytotoxic activities of MeCCNU 10 fold and cyclophosphamide 10 fold. Except the fact that all the effective cytotoxic substances possess relatively good lipophilicity, no relationship between structures of the cytotoxic substances and the cytotoxicity-enhancing effect of (+)-ar-turmerone could be observed.

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가미쌍화탕류(加味雙和湯類)의 독성(毒性) 및 약효연구(藥效硏究) (The Acute and Subacute Toxicities and Pharmacological Actions of Gami Ssanghwa Tang Preparations)

  • 신국현;이은방;정명숙;김운자;윤기영
    • 생약학회지
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    • 제21권2호
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    • pp.179-185
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    • 1990
  • The acute and subacute toxicities and pharmacological actions of two preparations of Ssanghwa Tang prescriptions have been evaluated in mice, rats and rabbits. The two prescriptions were found to be safe drugs because those preparations exhibited almost no acute and subacute toxicities even at a high dosage level. The two prescriptions elicited CNS depressant activities characterized by potentiation of hexobarbital-induced narcosis, antipyretic activity in typhoid-vaccinated rabbits and a significant antifatigue effect against cold immobilized stress, the activities of prescription B being more potent.

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외상후 스트레스 장애의 정신생물학적 접근 (Psychobiological Approach for Post-Traumatic Stress Disorder)

  • 박기창
    • 정신신체의학
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    • 제4권1호
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    • pp.124-137
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    • 1996
  • As the society becomes more industrialized and modernized, we have more chances to experience a serious traumatic event. Post-traumatic stress disorder (PTSD) has 3 major categories of symptoms such as memory disturbance, hyperarousal and avoidance or numbness. I reviewed the psychobiological evidences in 3 main categories of symptoms and the biological treatment after a brief review of the epidemiology, psychosocial etiology and diagnosis of PTSD. The memory disturbance of PTSD might be developed by the potentiation of the memory pathway mediated by norepinephrine. PTSD induces HPA axis abnormality, it might also develop hippocampal dysfunction, which might contribute to the memory disturbance. The kindling effect develops desensitization, which might develop reexperiencing of the traumatic events and hyperarousal state. Chronic aroused state of locus ceruleus with resultant chronic maladaptive state of norepinephrine system, might develop hyperarousal state. Social avoidance and physical numbing state in PTSD might be caused by serotnin or opiate system. Stress induced analgesia might be developed by opiate reliesed against the acute stress. The biologic research results would help the selective treatment of PTSD.

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