• 제목/요약/키워드: selective action

검색결과 216건 처리시간 0.03초

치은 Arachidonic acid 대사산물의 억제약물에 관한 실험적 연구 (EFFECTS OF INHIBITORY DRUGS ON THE ARACHIDONIC ACID METABOLISM OF PERIODONTAL TISSUE)

  • 한세희;오귀옥;김형섭
    • Journal of Periodontal and Implant Science
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    • 제23권2호
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    • pp.243-259
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    • 1993
  • The bone resorbing activity of $PGE_2$ and elevated level of prostaglandins(PGs) and thromboxanes (TXs) in inflamed gingiva which are cyclooxygenase(C) metabolites have been well documented. Nonsteroidal anti-inflammatory drugs(NSAIDs) have been known to suppress gingival inflammation and bone resorption through the specific inhibitory action on the C pathway thereby decrease of various C metabolites. Recent studies provide unequivocal results that gingival tissue metabolizes arachidonic acid(AA) mainly through lipoxygenase(L) pathway. And the results of our previous experiments suggest that indomethacin may have inhibitory action on L as well as C. Thus we started this study to show the influences of several C inhibitors on the L activity at therapeutic and toxic dosage. Periodontal tissue samples were obtained from patients with advanced periodontitis and incubated with $^{14}C-AA(0.2{\mu}Ci)$ and various enzyme inhibitors. The tissue lipid extracts were separated by means of thin layer chromatography(TLC) and analyzed by means of autoradiography and TLC analyzer. Our results showed that aspirin inhibited C more selectively than L, however at higher concentration it also decreased HETEs production significantly. Indomethacin showed dose-dependent inhibition of L as well as C and all of the L metabolites were decreased to the same degree by high concentration of indomethacin. AA-861, which is an experimental tool of selective L inhibitor, showed inhibition of HETEs production but no effect on the production of $TXB_2$, PGs and $LTB_4$. Various propionic acid derivatives NSAIDs(ibuprofen, flurbiprofen, naproxen) showed the same patterns of effect on AA metabolism each other that was profound inhibition of PGs production, to the less degree HETEs and $TXB_2$ production, and of no effect on the $LTB_4$ production.

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광치료의 기본원리와 임상 실제 (Light Therapy : Basic Principle and Clinical Practice)

  • 조숙행
    • 수면정신생리
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    • 제5권2호
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    • pp.170-176
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    • 1998
  • Nowadays light therapy is accepted practice in the treatment for Seasonal Affective Disorder. The author reviewed the practical aspects of light therapy, latest treatment research on optimal parameters of light therapy and the mechanisms of action of light therapy. Therapeutic efficacy of light therapy using light visors & dawn simulators has been suggested but further studies are needed to clarify the efficacy. The treatment most strongly supported by research studies is light therapy using a light box to administer bright white light (2500 lux for 2 hours or 10000 lux for 30 minutes). Although some patients may be selective responders to morning light exposure, the optimal timing of light exposure still remains controversial. In practice, generally the duration of exposure can be increased or decreased as necessary and also the timing of exposure can be splitted (e.g. AM/PM usage) if optimal response is obtained. For most, a positive response of light therapy is usually noted within $4{\sim}5\;days$ and optimal response is obtained within 2 weeks. Generally the relapse of symptom occurs within days of discontinuation of light therapy, so to prevent relapse, light therapy should be continued throughout the winter season for typical seasonal affective disorder. Side effects of light therapy appear to be mild and well tolerated. Several theories for the mechanisms of action of light therapy at the basis of seasonal affective disorder had been suggested but remain still controversial. Further studies on the optimal parameters and the mechanisms of light therapy help us to better understand and treat not only seasonal affective disorders but also chronobiological disorders and nonseasonal affective disorders.

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Tetrodotoxin 중독가토(中毒家兎)의 심전도학적(心電圖學的) 연구(硏究) (An Electrocardiographic Study on Tetrodotoxin Intoxicated Rabbits)

  • 박용국;신홍기;김기순
    • The Korean Journal of Physiology
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    • 제10권1호
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    • pp.41-48
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    • 1976
  • Tetrodotoxin (TTX) is the purified active principle responsible for tetrodon (Puffer-fish) poisoning which has long been known in the Orient. The pharmacological actions of TTX have been rather extensively investigated. Two of the most prominent effects of intravenousely administered TTX are severe hypotension and respiratory paralysis resulting from its depressant actions on tissues. This depressant actions of TTX in turn result from the selective inhibition of sodium-carrying mechanism which is essential to generation of the action potential. TTX differs from local anesthetics in that it does not affect potassium conductance. Although the mechanism of the hypotensive action of TTX remains a subject of controversy, most investigator agree that TTX-induced hypotension is caused by alteration in the blood vessels rather than the heart. Not only the study on the effects of TTX on cardiac function is meager but the results of reported works are often contradictory. The present study was undertaken to investigate the effect of TTX on the electrocardiogram of the rabbit and to compare them with well known electrocardiographical characteristics found in digitalis and quinidine intoxicated animals. The results obtained from the present study are summarized as follows. 1. No changes were found in P-R interval and QRS duration after i.v. administration of $1.0\;{\mu}g/kg\;to\;1.5\;{\mu}g/kg$ TTX to the animals. It is obvious that there were no conduction disturbance between atria and ventricles as well as in the ventricular tissue. 2. In $1.0\;{\mu}g/kg$ TTX group, S-T interval and T-P segment were not changed whereas marked changes were observed in $1.5\;{\mu}g/kg$ TTX group. 3. The first and second degree A-V blocks appeared in the $2.0\;{\mu}g/kg$ TTX group. 4. TTX differs from digitalis and quinidine in that it does not cause S-T interval depression and T-wave inversion. In contrast with digitalis, TTX caused Q-T interval prolongation.

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근거이론을 활용한 담양 삼다리마을 지역주민의 파트너십 갈등 연구 - 국가중요농업유산 제 4호, 담양 대나무밭을 중심으로 - (A Study on the Partnership Conflict of Damyang Samdari Village Using the Grounded Theory - For Damyang Samdari Village, No.4 National Important Agriculture Heritage -)

  • 김영랑;김은솔;이태겸
    • 농촌계획
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    • 제26권4호
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    • pp.41-52
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    • 2020
  • The purpose of this study is to identify the conflict between residents and governments in partnership arising from the designation of National Important Agricultural Heritage for Damyang Samdari village and to suggest directions for improvement. To this end, residents of Samdari Village in Damyang, designated as an important national agricultural heritage, were interviewed. Interviews were analyzed through grounded theory, categorized into open coding, axial coding, and selective coding, and a paradigm model was constructed. Through this, the central phenomena of resident participation patterns currently appearing in the village were identified, and causal, contextual, and intervening conditions were analyzed. Causal conditions were analyzed as one-sided administrative treatment, assortment matching project, one-time plan, excessive dependence of residents and economic damages of residents at the beginning of the designation of national important agricultural heritage. As a result, conflict between residents and local governments occurred as a central phenomenon, and contextual conditions such as decline in the competitive of bamboo resources and frequent change in managers were also affecting the central phenomenon. As intervening conditions to alleviate the central phenomenon, there are local government's purchase of bamboo fields and fragmentary business effects. The action taken by the residents and officials in response to a fixed conflict is called an action-interaction strategy. Residents refused to change and settled in reality, and local governments avoided conflict. From the beginning of the designation to the present, the villagers gradually lost interest in the National Important Agricultural Heritage due to problems and conflicts that occurred in the process of forming a partnership in the National Important Agricultural Heritage project. Based on the analyzed model, a plan to build the partnership standards on Damyang bamboo field to secure the sustainability of the field and increase the practicality of resident participation, that is partnership, was suggested.

Reaction of Bis(diethylamino)aluminum Hydride in Tetrahydrofuran with Selected Organic Compounds Containing Representative Functional Groups

  • Jin Soon Cha;Oh Oun Kwon;Jong Mi Kim
    • Bulletin of the Korean Chemical Society
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    • 제15권2호
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    • pp.132-138
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    • 1994
  • Bis(diethylamino)aluminum hydride was utilized in a systematic study of the approximate rates and stoichiometry of the reaction of excess reagent with 55 selected organic compounds containing representative functional groups under standardized conditions (THF, $0^{\circ}C$, reagent to compound=4 : 1) in order to define the characteristics of the reagent for selective reductions. The reducing action of BEAH was also compared with that of the parent aluminum hydride. The reducing action of the reagent is quite similar to that of aluminum hydride, but the reducing power is much weaker. Aldehydes and ketones were readily reduced in 1-3 h to the corresponding alcohols. However, unexpectedly, a ready involvement of the double bond in cinnamaldehyde was realized to afford hydrocinnamyl alcohol. The introduction of diethylamino group to the parent aluminum hydride appears not to be appreciably influential in stereoselectivity on the reduction of cyclic ketones. Both p-benzoquinone and anthraquinone utilized 2 equiv of hydride readily without evolution of hydrogen, proceeded cleanly to the 1,4-reduction products. Carboxylic acids and acid chlorides underwent reduction to alcohols slowly, whereas cyclic anhydrides utilized only 2 equiv of hydride slowly to the corresponding hydroxylacids. Especially, benzoic acid with a limiting amount of hydride was reduced to benzaldehyde in a yield of 80%. Esters and lactones were also readily reduced to alcohols. Epoxides examined all reacted slowly to give the ring-opened products. Primary and tertiary amides utilized 1 equiv of hydride fast and further hydride utilization was quite slow. The examination for possibility of achieving a partial reduction to aldehydes was also performed. Among them, benzamide and N,N-dimethylbenzamide gave ca, 90% yields of benzaldehyde. Both the nitriles examined were also slowly reduced to the amines. Unexpectedly, both aliphatic and aromatic nitro compounds proved to be relatively reactive to the reagent. On the other hand, azo- and azoxybenzenes were quite inert to BEAH. Cyclohexanone oxime liberated 1 equiv of hydrogen and utilized 1 equiv of hydride for reduction, corresponding to N-hydroxycyclohexylamine. Pyridine ring compounds were also slowly attacked. Disulfides were readily reduced with hydrogen evolution to the thiols, and dimethyl sulfoxide and diphenyl sulfone were also rapidly reduced to the sulfides.

Ononis spinosa alleviated capsaicin-induced mechanical allodynia in a rat model through transient receptor potential vanilloid 1 modulation

  • Jaffal, Sahar Majdi;Al-Najjar, Belal Omar;Abbas, Manal Ahmad
    • The Korean Journal of Pain
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    • 제34권3호
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    • pp.262-270
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    • 2021
  • Background: Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel implicated in pain sensation in response to heat, protons, and capsaicin (CAPS). It is well established that TRPV1 is involved in mechanical allodynia. This study investigates the effect of Ononis spinosa (Fabaceae) in CAPS-induced mechanical allodynia and its mechanism of action. Methods: Mechanical allodynia was induced by the intraplantar (ipl) injection of 40 ㎍ CAPS into the left hind paw of male Wistar rats. Animals received an ipl injection of 100 ㎍ O. spinosa methanolic leaf extract or 2.5% diclofenac sodium 20 minutes before CAPS injection. Paw withdrawal threshold (PWT) was measured using von Frey filament 30, 90, and 150 minutes after CAPS injection. A molecular docking tool, AutoDock 4.2, was used to study the binding energies and intermolecular interactions between O. spinosa constituents and TRPV1 receptor. Results: The ipsilateral ipl injection of O. spinosa before CAPS injection increased PWT in rats at all time points. O. spinosa decreased mechanical allodynia by 5.35-fold compared to a 3.59-fold decrease produced by diclofenac sodium. The ipsilateral pretreatment with TRPV1 antagonist (300 ㎍ 4-[3-Chloro-2-pyridinyl]-N-[4-[1,1-dimethylethyl] phenyl]-1-piperazinecarboxamide [BCTC]) as well as the β2-adrenoreceptor antagonist (150 ㎍ butoxamine) attenuated the action of O. spinosa. Depending on molecular docking results, the activity of the extract could be attributed to the bindings of campesterol, stigmasterol, and ononin compounds to TRPV1. Conclusions: O. spinosa alleviated CAPS-induced mechanical allodynia through 2 mechanisms: the direct modulation of TRPV1 and the involvement of β2 adrenoreceptor signaling.

Chemoquiescence with Molecular Targeted Ablation of Cancer Stem Cells in Gastrointestinal Cancers

  • Jong-Min Park;Young-Min Han;Migyeong Jeong;Eun Jin Go;Napapan Kangwan;Woo Sung Kim;Ki Baik Hahm
    • Journal of Digestive Cancer Research
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    • 제4권1호
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    • pp.1-9
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    • 2016
  • The abundance of multi-drug resistance ATPase binding cassette and deranged self-renewal pathways shown in cancer stem cells (CSCs) played a crucial role in tumorigenesis, tumor resistance, tumor recurrence, and tumor metastasis. Therefore, elucidation of CSCs biology can improve diagnosis, enable targeted treatment, and guide the follow up of GI cancer patients. In order to achieve chemoquiescence, seizing cancer through complete ablation of CSCs, CSCs are rational targets for the design of interventions that will enhance responsiveness to traditional therapeutic strategies and contribute in the prevention of local recurrence as well as metastasis. However, current cancer treatment strategies fail to either detect or differentiate the CSCs from their non-tumorigenic progenies mostly due to the absence of specific biomarkers and potent agents to kill CSCs. Recent advances in knowledge of CSCs enable to produce several candidates to ablate CSCs in gastrointestinal (GI) cancers, especially cancers originated from inflammation-driven mutagenesis such as Barrett's esophagus (BE), Helicobacter pylori-associated gastric cancer, and colitis-associated cancer (CAC). Our research teams elucidated through revisiting old drugs that proton pump inhibitor (PPI) and potassium competitive acid blocker (p-CAB) beyond authentic acid suppression, chloroquine for autophage inhibition, sonic hedgehog (SHH) inhibitors, and Wnt/β-catenin/NOTCH inhibitor can ablate CSCs specifically and efficiently. Furthermore, nanoformulations of these molecules could provide an additional advantage for more selective targeting of the pathways existing in CSCs just like current molecular targeted therapeutics and sustained action, while normal stem cells intact. In this review article, the novel approach specifically to ablate CSCs existing in GI cancers will be introduced with the introduction of explored mode of action.

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Inhibitory Mechanism of Polyphenol Compounds Isolated from Red Wine on Catecholamine Release in the Perfused Rat Adrenal Medulla

  • Yu, Byung-Sik;Ko, Woo-Seok;Lim, Dong-Yoon
    • Biomolecules & Therapeutics
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    • 제16권2호
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    • pp.147-160
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    • 2008
  • The present study was designed to examine effects of polyphenolic compounds isolated from red wine (PCRW) on the release of catecholamines (CA) from the isolated perfused model of the rat adrenal medulla, and to clarify its mechanism of action. PCRW (20${\sim}$180 ${\mu}$g/mL), given into an adrenal vein for 90 min, caused inhibition of the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic $N_N$ receptor agonist, 100 ${\mu}$M) and McN-A-343 (a selective muscarinic $M_1$ receptor agonist, 100 ${\mu}$M) in dose- and time-dependent fashion. PCRW itself did not affect basal CA secretion (data not shown). Following the perfusion of PCRW (60 ${\mu}$g/mL), the secretory responses of CA evoked by Bay-K-8644 (a L-type dihydropyridine $Ca^{2+}$ channel activator, 10 ${\mu}$M), cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10 ${\mu}$M) and veratridine (an activator of voltage-dependent $Na^+$ channels, 10 ${\mu}$M) were also markedly blocked, respectively. Interestingly, in the simultaneous presence of PCRW (60 ${\mu}$g/mL) and L-NAME (a selective inhibitor of NO synthase, 30 ${\mu}$M), the inhibitory responses of PCRW on the CA secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclpiazonic acid were recovered to considerable level of the corresponding control release compared with those effects of PCRW-treatment alone. Practically, the amount of NO released from adrenal medulla after loading of PCRW (180 ${\mu}$g/mL) was significantly increased in comparison to the corresponding basal released level. Collectively, these results obtained here demonstrate that PCRW inhibits the CA secretory responses evoked by stimulation of cholinergic (both muscarinic and nicotinic) receptors as well as by direct membrane-depolarization from the isolated perfused adrenal gland of the normotensive rats. It seems that this inhibitory effect of PCRW is mediated by blocking the influx of both ions through $Na^+$ and $Ca^+{2$} channels into the rat adrenomedullary chromaffin cells as well as by inhibiting the release of $Ca^{2+}$ from the cytoplasmic calcium store, which are due at least partly to the increased NO production through the activation of nitric oxide synthase. Based on these data, it is also thought that PCRW may be beneficial to prevent or alleviate the cardiovascular diseases, such as hypertension and angina pectoris.

초등학교 5, 6학년 과학교과서 집필자가 겪은 어려움과 대처 방법 : 근거이론을 중심으로 (Difficulties and Coping Methods Encountered by Authors of 5th and 6th Grade Science Textbooks: Based on Grounded Theory)

  • 채동현;양일호;정성안
    • 한국과학교육학회지
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    • 제31권8호
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    • pp.1121-1144
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    • 2011
  • 본 연구의 목적은 초등학교 5, 6학년 과학교과서 집필자 겪은 어려움과 그 해결방법을 조사하여 다음 초등학교 과학교과서 개발 및 초등학교 과학교과서의 인식에 도움을 주고자 하는 것이다. 이를 위해 연구자는 초등학교 5, 6학년 과학교과서 집필에 참여한 교사 6명을 대상으로 심층면담을 실시하였다. 기록된 면담 내용은 Strauss와 Corbin(1998)이 제시한 개방코딩, 축코딩, 선택코딩에 따라 분석이 이루어졌다. 연구결과는 다음과 같다. 개방코딩에서는 관련 개념을 추출하고 이를 다시 46개의 하위범주와 15개의 상위범주로 범주화 하였다. 축코딩에서는 상위범주들을 분석하여 근거이론의 패러다임의 흐름에 따라 인과적 조건, 중심현상, 맥락, 중재적 조건, 작용/상호작용 전략, 결과로 구분하고 일관성 있게 연결하였다. 마지막으로 선택코딩에서는 핵심범주를 찾아내고 이것을 중심으로'초등 과학교과서 질 향상을 위한 집필자의 집필과정 유형'을 보수형, 진보형, 혁신형으로 분류하여 그 의미를 해석하였다.

제초제(除草劑) Cyhalofop-butyl ester의 벼와 피간(間)의 선택성기작(選擇性機作) - III. 흡수(吸收), 전이(轉移) 및 대사(代謝) (Selective Mechanism of Cyhalofop-butyl ester between Rice(Oryzae sativa L.) and Echinochloa crus-galli - III. Uptake, Translocation, and Metabolism, of 14C-cyhalofop-butyl ester)

  • 김길웅;박재읍
    • 한국잡초학회지
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    • 제17권2호
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    • pp.185-191
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    • 1997
  • 벼와 피의 속간(屬閒) 선택성(選擇性)을 구명(究明)하기 위해 $^{14}C$-cyhalofop-BE를 이용(利用)하여 피와 벼의 흡수정도(吸收程度) 및 전이(轉移)의 차이(差異)와 대사작용(代謝作用)의 기작(機作)을 구명(究明)한 시험결과(試驗結果)를 요약(要約)하면 다음과 같다. 1. $^{14}C$-cyhalofop-BE를 줄기 에 처리(處理)할 경우 벼와 피 모두 체내(體內) 흡수(吸收) 및 이행(移行)이 잘 되었으나 벼 보다 피가 흡수량(吸收量)이 높았고 체내(體內) 이행(移行) 정도(程度)가 높은 양상(樣相)을 보여 주였다. 2. $^{14}C$-cyhalofop-BE의 피 체내(體內) 흡수시간(吸收時間)은 흡수(吸收) 30분후(分後)부터 급격(急激)히 증가(增加)하기 시작하여 흡수(吸收) 12시간(時閒) 후(後)에 최대(最大)를 보여 주었으나 벼는 흡수(吸收) 30분후(分後)부터 증가(增加)하다가 시간(時間)이 지나면서 큰 변화(變化)를 보이지 않아 흡수량(吸收量)에서도 벼가 현저(顯著)히 낮았고, 줄기로부터 상방(上方) 및 하방(下方) 이동(移動)도 피가 훨씬 높은 경향(傾向)을 보였다. 3. $^{14}C$-cyhalofop-BE가 피 체내(體內)에 흡수후(吸收後) 활성물질(活性物質)인 acid 화합물(化合物)로 전환(轉換)이 높았으나 벼는 현저(顯著)히 낮은 경향(傾向)을 보였다.

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