• 대한수의학회지
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• 제43권1호
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• pp.31-39
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• 2003

We have investigated the effect of extracellular $Mg^{2+}$ ($[Mg^2+]_o$) on action potential duration (APD) in guinea pig papillary muscles by using microelectrodes. Increasing $[Mg^2+]_o$ resulted in progressive negative inotropic effect, progressive ascending depolarization of membrane potential, and increase in intracellular $Mg^{2+}$ concentration. In addition, increase in $[Mg^2+]_o$ from 1.1 to 3, 6, 10, and 20 mM produced a reversible dose-dependent shortening of both APD at 30% ($APD_{30}$) and 90% repolarization ($APD_{90}$), especially showing a tendency towards more remarkable prominent shortening in $APD_{30}$ than $APD_{90}$. Cooling from 37 to 33 and $27^{\circ}C$ diminished the $[Mg^2+]_o$-induced APD shortening. Increase in extracellular $Ca^{2+}$ concentration from 1.8 to 3.6 and 5.4 mM caused a significant depressed effect on the increasing $[Mg^2+]_o$-induced APD shortening. Furthermore, increase in $[Mg^2+]_o$ from 1.1 to 10 and 20 mM produced a significant depressed effect on the APD shortening induced by extracellular $Ca^{2+}$. Pretreatment of verapamil and imipramine significantly attenuated the increasing $[Mg^2+]_o$-induced APD shortening in both $APD_{30}$ and $APD_{90}$, whereas the $[Mg^2+]_o$-induced APD shortening was not affected by strophanthidin, glibenclamide and tetrabutylammonium. These findings suggest that the effects of $[Mg^2+]_o$ on APD are probably due to a decrease in ionic transport across plasma membrane. In conclusion, the present study indicates that $[Mg^2+]_o$ exerts antiarrhythmic activities by antagonistic actions on intracellular $Ca^{2+}$.

• Tuberculosis and Respiratory Diseases
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• 제76권3호
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• pp.114-119
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• 2014

Background: Epigallocatechin-3-gallate (EGCG), a major biologically active component of green tea, has anti-cancer activity in human and animal models. We investigated the schedule-dependent effect of EGCG and paclitaxel on growth of NCI-H460 non-small cell lung cancer cells. Methods: To investigate the combined effect of EGCG (E) and paclitaxel (P), combination indices (CIs) were calculated, and cell cycle analysis was performed. For the effect on cell apoptosis, western blot analysis was also performed. Results: CI analysis demonstrated that both concurrent and sequential E ${\rightarrow}$ P treatments had antagonistic effects (CIs >1.0), but sequential P ${\rightarrow}$ E had synergistic effects (CIs <1.0), on the growth inhibition of NCI-H460 cells. In the cell cycle analysis, although paclitaxel induced $G_2/M$ cell cycle arrest and increased the sub-G1 fraction, concurrent EGCG and paclitaxel treatments did not have any additive or synergistic effects compared with the paclitaxel treatment alone. However, western blot analysis demonstrated that sequential P ${\rightarrow}$ E treatment decreased the expression of Bcl-2 and procaspase-3 and increased poly(ADP-ribose) polymerase (PARP) cleavage; while minimal effects were seen with concurrent or sequential E ${\rightarrow}$ P treatments. Conclusion: Concurrent or sequential E ${\rightarrow}$ P treatment had opposite effects to P ${\rightarrow}$ E treatment, where P ${\rightarrow}$ E treatment showed a synergistic effect on growth inhibition of NCI-H460 cells by inducing apoptosis. Thus, the efficacy of EGCG and paclitaxel combination treatment seems to be schedule-dependent.

• 생물정신의학
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• 제4권2호
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• pp.198-210
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• 1997

To examine the double-faced thymoleptic(antidepressant and antimanic) effects of risperidone in mood disorders, this article reviews the psychotropic-induced mania, thymoleptic effects of antipsychotics, therapeutic effects of risperidone and risperidone(RIS)-induced mania(RIM) in mood disorders, risk factors of RIM, possible neurochemical mechanism of these thymoleptic effects, pathophysiological and clinical significance of thymoleptic effects, and suggestive clinical guideline of RIS in mood disorders. RIS appeared effective for bipolar disorder at a lower dose than that recommended for schizophrenia, especially in the cases of maintenance of mood stabilizers, and gradual titration from low doses. Manic induction/exacerbation can occur by chance during RIS treatment in mood disorders, schizoaffective disorders, and schizophrenias. The possible risk factors for RIM are refractory mood disorder, especially in bipolar I disorder with poor initial response ; refractory schizoaffective disorders, especially in bipolar type with poor initial response ; refractory chronic schizophrenias, especially with initial responses ; psychotic features ; higher initial doses ; rapid titration ; combined therapy with antidepressants in refractory depression ; and RIS monotherapy in mania/hypomania. RIS is a drug that preferentially block 5-HT2 receptors. The effects of low dose are due mainly to the blockade of 5-HT2 receptors. There are more gradual increase in D2 blockade with increasing dose and this D2 blocking properties become apparent at higher doses. This may be related to a modulation of dopaminergic transmission by 5-HT2 antagonism at lower doses with the direct action of RIS on DA receptors coming into play at higher dose. The serotonergic antagonistic effect may be important for its effects on depressive symptoms. This, together with adequate blo-ckade of D2 receptors, may not necessarily lead to destabilization of mood disorder, but rather to more therapeutic effects. Therefore, this dose-receptor affinity relationship with both antidepressant and antimanic effects according to treatment duration can explain a continuum of antidepressant effect, antimanic effect, behavioral stimulation, and manic/hypomanic induction/exacerbation. It was the recognition of a useful psychiatric side effects by a thoughtful observer with fertile minds that led to their ultimate utilization as psychotropic drugs, i.e., phenothiazine, MAOI, TCA, and lithium. And, in vivo pharmacological challenge by novel psychotropics, as a neurochemical probe, with more specific actions is a useful tool to select pharmacologically homogeneous subgroup of the same phenotypical(clinical) condition, to further study the unknown underlying pathogenesis of various mental illnesses. Finally, RIS may be a useful alternative or adjunctive drug for patients with mood disorders without psychotic features or refractory to treatment with standard antipsychotic drugs. The more conservative doses(tirated slowly from 1-3 mg/d) of RIS, and maintenance of mood stabilizer in the cases with risk factors of RIM are recommended in mood disorder.

• 대한환경공학회지
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• 제36권2호
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• pp.119-126
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• 2014

본 연구에서는 과불화합물(PFOA, PFOS)과 수계에 보편적으로 존재하는 중금속(Cu, Zn, Cr, Cd, Pb, Hg)의 복합독성을 Vibrio fischeri를 이용하여 평가하였다. PFOA와 PFOS의 경우, 30 min-$EC_{50}$값이 각각 134.21 (119.54-150.68)와 235.97 (180.96-307.70) mg/L로 PFOS 보다는 PFOA의 독성이 높은 것으로 나타났다. 한편 중금속류의 독성은 $Hg^{2+}$의 독성이 가장 높았으며, 이어서 $Pb^{2+}$, $Cr^{6+}$, $Cu^{2+}$, $Zn^{2+}$, $Cd^{2+}$ 순으로 높은 독성민감도를 나타냈다. 과불화합물류와 중금속류의 복합독성의 경우, PFOA와 PFOS 모두 $Cr^{6+}$과 공존할 시 상승효과가 나타났으며, PFOA + $Zn^{2+}$, PFOS + $Zn^2$, PFOA + $Cd^{2+}$, PFOS + $Cd^{2+}$의 조합은 상가 효과를 나타냈다. 이외의 복합물질은 모두 길항작용을 하는 것으로 확인되었다. 본 연구에서는 과불화합물인 PFOA, PFOS와 중금속 복합물질들의 조합에 따른 상호작용이 상이함을 확인하였고 이 결과로부터 과불화합물과 중금속 공존할 때 수환경에 야기할 수 있는 잠재적 위해성을 예측할 수 있다.

• 한국잡초학회지
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• 제4권2호
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• pp.188-193
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• 1984

우리나라 논에 우점(優占)하고 있는 대표적(代表的) 일년생잡초(一年生雜草)인 피와 올챙이 고랭이, 다년생잡초(多年生雜草)인 올미와 너도방동산이를 공시(供試)하여 Butachlor와 Pyrazolate, Bifenox와 Bromobutamide의 혼합처리(混合處理)에 의한 상호작용(相互作用)을 특효과선법(特效果線法)에 의해 평가(評價)하였다. 1. Butachlor는 피와 너도방동산이에 대해서, Pyrazolate는 올미와 올챙이고랭이에 대한 방제효과(防除效果)가 높았고, 두 약제(藥劑)의 혼합처리(混合處理)의 경우 올미에 대해서는 상승효과(相乘效果), 피, 올챙이고랭이와 너도방동산이에는 상가적(相加的) 효과(效果)를 나타냈다. 2. Bifenox는 피와 올챙이고랭이에 대해서, Bromobutamide는 올챙이고랭이, 피와 너도방동산이에 대해서 방제효과(防除效果)가 높았고 올미에는 효과(效果)가 낮았다. 두 제초제(除草劑)의 혼합처리(混合處理)의 경우 피와 너도방동산이에는 상승효과(相乘效果), 올미에 대해서는 길항적(拮抗的) 반응(反應)을 보였다. 3. 공시(供試)한 4초종(草種)의 90% 등효과선(等效果線)에 의하면 Butachlor와 Pyrazolate의 혼합처리(混合處理)에서는 높은 상승효과(上乘效果)를 나타냈고 가장 높은 효과(效果)를 보인 혼합조합(混合組合)은 Butachlor : Pyrazolate가 89%:41g/10a인 경우 였으며 상가적(相加的) 효과(效果)를 나타내는 경우보다 Butachlor는 75g/10a, Pyrazolate는 28%/10a이 적은 약량(藥量)이 요구되었다. 4. 공시(供試)한 4초종(草種) 전체(全體)에 대한 Bifenox와 Bromobutamide의 상호작용(相互作用)은 매우 낮은 상승효과(上乘效果)를 보였으며 이는 올미에 대한 효과(效果)가 낮기 때문이었고 가장 높은 상승효과(上乘效果)는 Bifenox : Bromobutamide가 208 : 22g/10a인 경우에 나타났다. 5. 따라서 이상의 결과(結果)를 검토(檢討)하여 보면 같은 혼합처리(混合處理)에서도 초종별(草種別)로 상호작용(相互作用)은 다르며 혼합제(混合劑)를 사용(使用)하고자 하는 지역(地域)의 우점초종(優占草種)에 따라 혼합제(混合劑)의 사용여부(使用與否)와 혼합비율(混合比率)이 결정(決定)되어야 할 것으로 사료(思料)된다.

• 한국잡초학회지
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• 제16권4호
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• pp.317-326
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• 1996

Sulfonylurea계 제초제 pyrazoslulfuron-ethyl과 imidazolinone계 제초제 imazaquin을 대상으로 약해발생양상, dymron에 의한 약해경감효과, butachlor와의 상호작용성, ALS에 대한 혼합작용 등을 조사한 결과는 다음과 같다. 1. 제초제에 의한 벼(동진)의 생장저해증상은 pyrazosulfuron-ehtyl 처리구에서 시간이 경과되면서 회복되었지만 imazaquin 처리구에서는 회복되지 않았다. 2. 높은 농도의 pyrazosulfuron-ehtyl에 의한 벼의 약해는 dymron 혼합처리에 의하여 크게 감소되었지만, IMA에 대해서는 약해경감효과가 나타나지 않았다. 3. 혼합처리에 의한 강피의 생장억제효과는 동시 또는 체계처리 모두 동일한 경향으로 pyrazosulfuron-ehtyl과 butachlor은 길항적이었지만 imazaquin과 butachlor은 상가적이었다. 4. Pyrazosulfuron-ehtyl과 imazaquin의 ALS 효소활성 50% 저해농도는 각각 $4{\times}10^{-7}$M, $2.8{\times}10^{-6})$M 이었고 혼합처리할 경우 butachlor은 두 제초제의 ALS 저해작용에 영향을 주지 않았다. 이상의 결과를 보면 pyrazosulfuron-ethyl과 imazaquin이 공통적으로 ALS를 저해하지만 살초기작은 서로 다른 것으로 생각되었다.

• 생명과학회지
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• 제20권7호
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• pp.969-976
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• 2010

피리딜 이미다졸 시리즈의 비펩타이드 안지오텐신 수용체 리간드로 새롭게 개발된 KR-31125에 대한 생체 내활성을 동물모델에서 검증하였다. 척수장애 동물모델에서 KR-31125는 비대칭 농도의존적으로 로자탄보다 18배 이상의 경쟁적인 혈압강하 효과를 나타내었으며, 기타 수용체 촉진제들의 영향을 받지 않았다. 안지오텐신으로 유도된 정상혈압 쥐모델에서는 대조화합물인 로자탄과 비교하여 경구효과는 동등하였으나 더 빠른 초기효과가 관찰되었다. 또한 신성고혈압 쥐모델에서 KR-31125는 로자탄보다 3배 이상의 지속형 혈압강하 효과를 나타내었고, 이뇨제를 투여하여 레닌을 활성화시킨 개실험 모델에서 KR-31125는 로자탄보다 20배 이상의 지속적인 경구혈압강하 효과를 나타내었다. 이러한 KR-31125의 생체 내 활성특징은 대사물질을 통하여 효과를 발휘하는 로자탄과 달리 동일물질의 효과에 의한 것으로 고혈압 및 혈관질환과 깊은 관련이 있는 안지오텐신 조절시스템에 대한 세포영상, 비침투성 진단등의 도구물질로서 가능성이 높을 것으로 판단된다.

• Environmental Engineering Research
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• 제12권1호
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• pp.16-20
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• 2007

Toxicity of metal plating wastewater was evaluated by using acute toxicity tests on Daphnia magna. To identify toxicants of metal plating wastewater, several manipulations such as solid phase extraction (SPE), ion exchange and graduated pH adjustment were used. The SPE test had no significant effect on baseline toxicity, suggesting absence of toxic non-polar organics in metal plating wastewater. However, anion exchange largely decreased the baseline toxicity by 88%, indicating the causative toxicants were inorganic anions. Considering high concentration of chromium in metal plating wastewater, it is thought the anion is Cr(VI) species. Graduated pH test showing independence of the toxicity on pH change strongly supports this assumption. However, as revealed by toxicity confirmation experiment, the initial toxicity of metal plating wastewater (24-h TU=435) was not explained only by Cr(VI) (24-h TU = 725 at $280\;mg\;L^{-1}$). Addition of nickel($29.5\;mg\;L^{-1}$) and copper ($26.5\;mg\;L^{-1}$) largely decreased the chromium toxicity up to 417 TU, indicating antagonistic interaction between heavy metals. This heavy metal interaction was successfully predicted by an equation of 24-h $TU\;=\;3.67\;{\times}\;\ln([Cu]\;+\;[Ni])\;+\;79.44$ at a fixed concentration of chromium.

• 대한약리학회지
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• 제17권1호
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• pp.41-46
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• 1981

Eighty of Sarcoma 180 bearing mice, averaging 30 gm of body weight, were divided into eight groups of animals receiving Saline as the control, Corynebacterium parvum, Tubercin-3 and Cyclophosphamide alone and Cyclophosphamide combined with C. parvum, with Tubercin-3 and with both C. parvum and Tubercin-3 and Tubercin-3 combined with C. parvum respectively. Treatment was initiated 4.8 hours after tumor implantation and repeated three times once a day. Doses were suspended or dissolved in 0.2 ml of Saline: 1.4 mg of C. parvum: 0.5 micrograms of Tubercin-3; and 2.7 mg of Cyclophosphamide either in alone or in combination. All the agents given were administered subcutaneously but Cyclophosphamide was given intraperitoneally. The observation on the general conditions of animal took place twice a day following the treatment until the time of death after tumor implantation was determined. Average survival days in each group were as follows: In Control, Saline (11.2 days), C. parvum (14.8 days), Tubercin-3 (16.7 days), Cyclophosphamide(18.7 days). In combination therapy, Cyclophosphamide with C. parvum(22.8 days) with Tubercin-3 (26.9 days). Cyclophosphamide with both C. parvum an Tubercin-3, however, was somewhat longer than in Cyclophosphamide alone but shorter than in combined with either one of C. parvum or Tubercin-3. Finally, in combination with immunotherapeutic agents, Tubercin-3 and C. parvum each other it (8.2 days) was shorter even than Control. Life span of host is, in generally, inversely related to the number of malignant cells and conclusively, the therapeutic potentiation was reflected to be extended survival in combined treatment of a chemotherapeutic Cyclophosphamide with either one of immunotherapeutics, Tubercin-3 or C. parvum. Tubercin-3 and C. parvum in combination, however, appeared to be antagonistic each other.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.103.1-103
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• 2003

An antagonistic bacteria, Stenotrophomonas maitophilia BW-13 strain which was effectively inhibited mycerial growth of Bottom rot pathogen, Rhizoctonia solani PY-1 strain was isolated from the rhizosphere of the lettuce in Uiryeong-Gun, Gyeongsangnam-Do from 2002 to 2003. For the biological control, the most suitable inoculum and its density of pathogen, PY-1 strain ware tested prior biological control test, For the pathogenicity test, A inoculum (wheat bran)sawdust+rice bran+PDB) showing disease incidence of 100％ was selected as the most suitable inoculum, which showed more effective than B inoculum (sawdust＋rice bran＋DW) and mycelial disc. also, In selection of the amount of inoculum (40g, 50g, 60g, 70g, 80g), most suitable amount of inoculum of pathogen determined as 40g showing disease incidence of 80％. For the selection of effective microorganism to control bottom rot on lettuce, about 200 isolates were isolated from the diseased soil and lettuce leaves, and examined their antifungal activity to the pathogen on PDA. As the pots assay, BW-13 strain showed the highest control value as 90％, and followed by R-13 and R-26 strain as 80％ and 60％, respectively. Selected BW-13 isolates identified as 5. maltophilia (GeneBank accession no. AJ293473.1, 99％) by 16S rRNA sequencing. This is the first report on the biological control using by S. maltophilia to the bottom rot pathogen, Rhizoctonia solani PY-1 strain.