• Toxicological Research
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• 제25권4호
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• pp.175-180
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• 2009

Lead (Pb) is a ubiquitously occurring environmental heavy metal which is widely used in industry and human life. Possibly due to a global industrial expansion, recent studies have revealed the prevalent human exposure to Pb and increased risk of Pb toxicity. Once ingested by human, 95% of absorbed Pb is accumulated into erythrocytes and erythrocytes are known to be a prime target for Pb toxicity. Most of the studies were however, focused on $Pb^{2+}$ whereas the effects of $Pb^{4+}$, another major form of Pb on erythrocytes are poorly understood yet. In this study, we investigated and compared the effects of $Pb^{4+}$, $Pb^{2+}$ and other heavy metals on procoagulant activation of erythrocytes, an important factor for the participation of erythrocytes in thrombotic events in an effort to address the cardiovascular toxicity of $Pb^{4+}$. Freshly isolated erythrocytes from human were incubated with $Pb^{4+}$, $Pb^{2+}$, $Cd^{2+}$ and $Ag^+$ and the exposure of phosphatidylserine (PS), key marker for procoagulant activation was measured using flow cytometry. As a result, while $Cd^{2+}$ and $Ag^+$ did not affect PS exposure, $Pb^{4+}$ and $Pb^{2+}$ induced significantly PS exposure in a dose-dependent manner. Of a particular note, $Pb^{4+}$ induced PS exposure with a similar potency with $Pb^{2+}$. PS bearing microvesicle (MV), another important contributor to procoagulant activation was also generated by $Pb^{4+}$. These PS exposure and MV generation by $Pb^{4+}$ were well in line with the shape change of erythrocyte from normal discocytes to MV shedding echinocytes following $Pb^{4+}$ treatment. Meanwhile, nonspecific hemolysis was not observed suggesting the specificity of $Pb^{4+}$-induced PS exposure and MV generation. These results indicated that $Pb^{4+}$ could induce procoagulant activation of erythrocytes through PS exposure and MV generation, suggesting that $Pb^{4+}$ exposure might ultimately lead to increased thrombotic events.

• Journal of Chest Surgery
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• 제29권7호
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• pp.713-722
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• 1996

폐이식후의 수용자들의 낮은 생존율은 주로 거부반응 또는 면역억제제 사용에 따른 합병증과 관련이 있다. 따라서 이식편에대한 수용자의 관용을 유도해낼 수 있는 더욱 좋은 방법이 절실히 요구된다. 저자 는 동종의 골수간세포가 주입되어진 혼합동종이 인자형 키메라 쥐에서 특정 동종 공여군의 공여 폐이식 편에대한 관용의 초래여부를 연구하였다. Fisher(F344)와 Wistar Forth(WF)종주의 쥐에서 치사량의 (1100c0y) 방사선조사후 T-임파구를 제거한 동일종주와 동종이인자형 골수의 혼합물로 재구성하였다 (F)44+WFIWF, AC1+F3441F3f4).28일후 말초혈액에서 임파구형의 검사로 혼합형 키메리즘이 확 인된 쥐에서 특정 공여군 또는 제3군의 동종 공여폐로 좌측의 동소 폐이식을시행하였다. 이식후 어떠 한 면역억제제도 투여하지 않았다. 이식편의 거부는 흉부 X선검사로 관찰하였고 조직학적으로 확인하 였다. 혼합형 키메라쥐들은 특정 공여군의 폐들을 받아들였으나 종주들 끼리의 특정효과에의한 것은 아 니었고, 이들에서 150일이상 거부반응을 관찰할 수 없었다. 이식편에대한 관용은 키메리즘의 백분율과 는 관계없이 일어났으며 제3군의 공여폐에대해서 \ulcorner정상대조군에서와 마찬가지로 10일내에 이식편에 대한거부반응이 완료되었다. 이 결과들은흔합형 키메라에서 정상적인 면역기전을 유지하면서도,특정 공여군의 폐이식후 안정적이고_1. 지속적 인, 이식 편에대한 관용이 일어난다는 것을 보여준다.

• 한국미생물·생명공학회지
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• 제14권2호
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• pp.145-153
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• 1986

본 연구에서는 토양으로부터 분리한 Aspergillus 속의 한 균주가 Colubridae과 독사의 사독 주성분인 출혈독을 강하게 불찰성화 시키는 물질을 생성하므로 이 물질을 분리한 후 부분적으로 정제하여 결정이 형성됨을 확인하였다. 본 물질은 Colubridae과의 Agkistrodon bromohoffi brevicaudus, A. saxatilis, Trimersurus flavoviridis, A. acutus 사독의 출혈독을 정량적으로 불활성화 시키며, 최대 저해률은 80-90%에 이르며 실험한 대상 동물에 따라 활성차이가 다소 있음이 인정되었다. 예로서 병아리 피하반응에 있어서는 T. flavoviridis 사독을 동량의 시료로서 처리하였을 때 완전히 출혈활성이 저해되나 mouse 족도 조직내 반응에서는 사독의 8배량의 시료로서 출혈활성이 거의 저해되었다. 또 본 시료는 출혈독이 지니고 있는 치사활성에 있어서도 독량의 약 3배량의 시료에 의해서 거의 치사 활성을 저해하며, T. flavoviridis 사독의 HR-I 및 HR-II부종활성에 대해서는 본 물질의 1/2량 이상의 농도에서는 시료농도에 관계없이 약 50% 정도로 저해하는 반면 A. bromohoffi brevicaudus 전독의 부종은 거의 완전히 저해하였다. 사용 균은 2종의 항출혈성 물질을 생성하고 있음이 가면피내 반응에서 확인되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.419-425
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• 2010

Mast cells are activated by specific allergens and also by various nonspecific stimuli, which might induce physical urticaria. This study investigated the functional expression of temperature sensitive transient receptor potential vanilloid (TRPV) subfamily in the human mast cell line (HMC-1) using whole-cell patch clamp techniques. The temperature of perfusate was raised from room temperature (RT, $23{\sim}25^{\circ}C$) to a moderately high temperature (MHT, $37{\sim}39^{\circ}C$) to activate TRPV3/4, a high temperature (HT, $44{\sim}46^{\circ}C$) to activate TRPV1, or a very high temperature (VHT, $53{\sim}55^{\circ}C$) to activate TRPV2. The membrane conductance of HMC-1 was increased by MHT and HT in about 50% (21 of 40) of the tested cells, and the I/V curves showed weak outward rectification. VHT-induced current was 10-fold larger than those induced by MHT and HT. The application of the TRPV 4 activator $3{\alpha}$-phorbol 12,13-didecanoate ($4{\alpha}$ PDD, $1\;{\mu}M$) induced weakly outward rectifying currents similar to those induced by MHT. However, the TRPV3 agonist camphor or TRPV1 agonist capsaicin had no effect. RT-PCR analysis of HMC-1 demonstrated the expression of TRPV4 as well as potent expression of TRPV2. The $[Ca^{2+}]_c$ of HMC-1 cells was also increased by MHT or by $4{\alpha}$ PDD. In summary, our present study indicates that HMC-1 cells express $Ca^{2+}$-permeable TRPV4 channels in addition to the previously reported expression of TRPV2 with a higher threshold of activating temperature.

• Tuberculosis and Respiratory Diseases
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• 제41권5호
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• pp.494-503
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• 1994

연구배경: 기관 및 기관지결핵으로 인한 반흔성 기도협착으로 호흡곤란을 호소하는 환자들을 대상으로 Nd-YAG 레이저치료를 시행하고 그 효과를 조사하였다. 방법: 기관 및 기관지결핵으로 기도내경이 1~4mm로 심한 반흔성 기도협착이 있는 환자들을 대상으로 하였으며, 기도협착을 내시경소견에 따라 횡경막형, 허탈형 및 복합형으로 분류하고 허탈형의 기도협착은 치료대상에서 제외하고 횡경막형과 복합형의 기도협착이 있는 10명의 환자들을 대상으로 굴곡성기관지경을 통해 Nd- YAG 레이저 치료를 시행하였다. 치료효과는 치료 후 1개월에 주관적인 증상의 호전과 객관적인 검사성적의 호전 유무를 조사하여 평가하였다. 결과: 1) 기도협착의 형태는 횡경막형 1예, 복합형이 9예로 대부분 복합형이었다. 2) 기도협착 부위는 기관 2예, 좌주기관지 6예 등이었고 증상발현 기간은 12.7개월이었다. 3) 레이저치료 횟수는 평균 3.3회였고 총조사량은 평균 865 joule이었다. 4) 기도내경은 치료전 평균 1.8mm에서 치료 후 5.5mm로 유의하게 증가되었다(p<0.05). 5) 10예 가운데 8예에서 측정한 노력성폐활량(FVC)은 치료 전 평균 2.62L에서 치료 후 3.04L로 유의하게 증가되었고, 노력성폐활량 1초치도 평균 1.81L에서 치료 후 2.22L로 유의하게 증가되었다(p<0.05). 6) 10예 가운데 8예는 치료 후 호전되었으나 성대 직하방에서 용골까지 심한 기도협착이 광범위하게 있었던 1예와 기관지의 굴곡변형이 심했던 1예는 호전이 없었다. 7) 출혈 및 천공과 같은 레이저치료에 따르는 합병증은 없었으며 치료 후 호전되었던 8예는 평균 31.9개월 간의 추적기간 동안 이러한 호전이 지속되었다. 결론: 이상의 결과로 기관 및 기관지결핵으로 인한 반흔성 기도협착이 있는 환자에서 기관지경적적 Nd-YAG 레이저치료는 기도협착의 개선에 도움이 되는 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제38권3호
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• pp.270-279
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• 1991

It has been well known that the integrity of airway epithelium is important in developing of bronchial hyperreactivity or bronchial asthma. But the mechanisms underlying this nonspecific airway hyperresponsiveness are not yet determined. To evaluate the ability of guinea pig trachea to release an epithelium derived relaxing factor (EpDRF) which relax rat vascular smooth muscle, we performed the coaxial bioassay using guinea pig trachea and rat aorta. And to evaluate the nature of EpDRF we investigate the influence of methylene blue and indomethacin on the coaxial bioassay. Results were as follows. 1) Vascular smooth muscle mounted into the epithelium intact trachea which was precontracted with phenylephrine was relaxed by addition of histamine or acetylcholine. But vascular smooth muscle mounted into epithelium denuded trachea failed to be relaxed. 2) Epithelium dependent relaxation of vascular smooth muscle was not affected by pretreatment of methylene blue or indomethacin. These results strongly suggests that guinea pig tracheal epithelium releases EpDRF which is able to relax rat vascular smooth muscle. And EpDRF released by airway epithelium is not related to endothelium derived relaxing factor (EDRF) or cyclooxygenase products.

• Restorative Dentistry and Endodontics
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• 제20권1호
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• pp.193-213
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• 1995

The purpose of this study is to investigate a possible contribution of nonspecific esterases, which occur in the oral cavity, to the degradation of ester bonds in polymethacrylates. One of the problems connected with the use of composite resins for restorations is their inadequate resistance to wear. It has been shown that methacrylate hydrolysis can be catalyzed by enzymes and that a carboxylic hydrolase (porcine liver esterase) catalyzed the hydrolysis of several mono - and dimethacrylates. The softening effect on a BISGMA/TEGDMA polymer induced by hydrolase will accelerate the in vivo wear of the polymer. Porcine liver esterase (EC 3.1.1.1) 3.2 mol/L $(NH_4)_2$ $SO_4$ was obtained from Sigma Chemical Company. The esterase activity of one unit is defined as the amount of enzyme capable of hydrolyzing $l{\mu}mol$ ethyl butyrate per min at pH 8.0 AT $25^{\circ}C$. Phosphate buffer, 10mmol/L, pH 7.0, was made by adjustment of a solution of $Na_2HPO_4$ with $H_3PO_4$. Composite resins used in this study are Silux Plus, Z-100, Durafil VS, and Prisma APH. Cylindrical specimens, 14mm in diameter and 3mm thick, of Silux Plus, Z-100, Durafil VS, Prisma APH were polymerized under the celluloid strip. 60 specimens were divided into 2 groups. One group was emersed only in buffer solution, the other group was emersed in buffer and enzyme solution. Silux Plus and Z-100 were divided into 2 subgroups, one subgroup was cured only Visilux 2. And the other subgroup was cured Visilux 2 and Triaid II. Thereafter, specimens were polished to its best achievable surface according to manufacture's directions. The Vickers hardness of the specimens was measured after 1, 2, 4, 7, 9, 15, 50 days. The solutions were changed after each measurement. Composite resin surfaces were evaluated for the surface roughness with profilometer (${\alpha}$-step 200, Tencor instruments, USA) after 1 and 50 days. And then surfaces of specimens were pictured with stereosopy after 1 and 50 days. The results were as follows. 1. The surface hardness of Silux plus, durafil VS, and Prisma APH were decreased with time. But, the surface hardness of Z-100 was not decreased. 2. The surface hardness of all composite resins was decreased by esterase. 3. Composite resins, which were light-cured by Visilux 2 and concomitantly baked by oven, showed more hardened surface than light-cured by Visilux 2 only. 4. Significant surface changes were occured in Silux plus after esterase treatment.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.101-109
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• 2016

Reducing $[Mg^{2+}]_o$ to 0.1 mM can evoke repetitive $[Ca^{2+}]_i$ spikes and seizure activity, which induces neuronal cell death in a process called excitotoxicity. We examined the issue of whether cultured rat hippocampal neurons preconditioned by a brief exposure to 0.1 mM $[Mg^{2+}]_o$ are rendered resistant to excitotoxicity induced by a subsequent prolonged exposure and whether $Ca^{2+}$ spikes are involved in this process. Preconditioning by an exposure to 0.1 mM $[Mg^{2+}]_o$ for 5 min inhibited significantly subsequent 24 h exposure-induced cell death 24 h later (tolerance). Such tolerance was prevented by both the NMDA receptor antagonist D-AP5 and the L-type $Ca^{2+}$ channel antagonist nimodipine, which blocked 0.1 mM $[Mg^{2+}]_o$-induced $[Ca^{2+}]_i$ spikes. The AMPA receptor antagonist NBQX significantly inhibited both the tolerance and the $[Ca^{2+}]_i$ spikes. The intracellular $Ca^{2+}$ chelator BAPTA-AM significantly prevented the tolerance. The nonspecific PKC inhibitor staurosporin inhibited the tolerance without affecting the $[Ca^{2+}]_i$ spikes. While $G{\ddot{o}}6976$, a specific inhibitor of $PKC{\alpha}$ had no effect on the tolerance, both the $PKC{\varepsilon}$ translocation inhibitor and the $PKC{\zeta}$ pseudosubstrate inhibitor significantly inhibited the tolerance without affecting the $[Ca^{2+}]_i$ spikes. Furthermore, JAK-2 inhibitor AG490, MAPK kinase inhibitor PD98059, and CaMKII inhibitor KN-62 inhibited the tolerance, but PI-3 kinase inhibitor LY294,002 did not. The protein synthesis inhibitor cycloheximide significantly inhibited the tolerance. Collectively, these results suggest that low $[Mg^{2+}]_o$ preconditioning induced excitotoxic tolerance was directly or indirectly mediated through the $[Ca^{2+}]_i$ spike-induced activation of $PKC{\varepsilon}$ and $PKC{\xi}$, JAK-2, MAPK kinase, CaMKII and the de novo synthesis of proteins.

• 대한미생물학회지
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• 제14권1호
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• pp.89-97
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• 1979

암환자(癌患者)에서 세포성면역반응(細胞性免疫反應)이 대체적(大體的)으로 억제(抑制)되었다는 사실(事實)은 여러 항원(抗原)에 대(對)한 피부반응(皮膚反應)의 감소(減少), 임파구(淋巴球)의 mitogen에 대(對)한 임파아구형성반응저하(淋巴芽球形成反應低下) 및 임파구(淋巴球)와 면양적혈구(緬羊赤血球)(SRBC)와의 자연로젤형성(自然로젤形成)의 감소(減少) 등에 의(依)하여 구명(究明)되었다. 그러나 이와 같은 현상(現象)에 대(對)한 기전(機轉)의 설명(說明)은 많은 연구(硏究)에도 불구(不句)하고 아직 미흡(未洽)하다. 본(本) 실험(實驗)에서 저자(著者)는 간암(肝癌) 및 폐암환자(肺癌患者)로부터 무균적(無菌的)으로 채취(採取)한 복수(腹水) 및 늑막액(肋膜液)을 마우스에 SRBC로 면역(免疫)하기 2일전(日前), 항원조사(抗原注射)와 동시(同時) 또는 항원주사(抗原注射) 2일(日)에 투여(投與)하여 마우스의 SRBC에 대(對)한 세포성(細胞性) 및 체액성면역반응(體液性免疫反應)에 미치는 영향(影響)을 실험(實驗)하였다. 그 결과(結果) SRBC로 면역(免疫)하기 전(前)에 암성삼출액(癌性渗出液)을 투여(投與)받은 마우스군(群)의 면역반응(免疫反應)은 대조군(對照群)의 면역반응(免疫反應)에 비(比)하여 유의성(有意性)있는 감소(減少)를 보인데 비(比)하여, 암성삼출액(癌性渗出液)을 SRBC와 동시(同時) 및 항원주사(抗原注射) 후(後)에 투여(投與)받은 마우스군(群)의 면역반응(免疫反應)은 대조군(對照群)의 그것과 유의(有意)한 차이(差異)가 없었다. 따라서 이상(以上)의 본(本) 실험결과(實驗結果)는 암성삼출액(癌性渗出液)이 면역억제인자(免疫抑制因子)를 가지고 있으며 이 억제인자(抑制因子)는 면역계(免疫系)의 afferent arc을 억제(抑制)함을 강력(强力)히 시사(示唆)한 증거(證據)라고 사료(思料)된다.

• 대한미생물학회지
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• 제21권1호
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• pp.133-144
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• 1986

This study was undertaken to assess the effect of ginseng administration on T lymphocyte induced local xenogenic graft-versus-host(GVM) reactions which were induced with thymocyte, spleen cell and lymph node cell of ICR mice. Mice received daily 10mg of 70% alcohol ginseng extract oral1y for 100days and control mice remained untreated for the same period of time. The cells from donor mice were injected intradermally into the closely shaven abdominal skin of Sprague-Dawley rats for GVH tests. The thymocyte from control(ginseng-untreated) mice showed a negative local GVH reaction, whereas thymocyte from experimental(ginseng-treated) mice showed a positive reaction with the rate of 17.4%. When spleen cells were injected, the incidence of positive local GVH reaction was 66.7% among ginseng-treated mice, as opposed to incidence of 45.5% of positive local GVH reaction among control mice. The incidence of positive local GVH reaction of the lymph node cells when injected into a recipient was 71.4% among ginseng-treated mice as compared with that of 18.9% among control mice. The relationship between spleen cell inoculum and intensity of the local GVH reaction was assessed in ginseng-untreated mice. The intensity of GVH reaction clearly appears to be dose related. In ginseng-treated mice, a minimum of $1{\times}10^7$ spleen cell was required for production of positive local GVH reaction with almost linear relationship up to an inoculum of $5{\times}10^8$ cells. In control mice, however, a minimum of $1{\times}10^8$ spleen cells was required for positive GVH reaction. These results strongly suggest that the ginseng administration augments significantly the local xenogenic GVH reaction which was used to assess T lymphocyte function and immunocompetence of mice and in addition to this, these results appear to support previous suggestions that the local GVH reaction consitutes a qualitative test of the functional activity of T lymphocytes. These results may be the first to induce local GVH reaction, employing rats as recipient and mice as donor. This study was also desingned to investigate some of the effects of ginseng extract on lymphocyte-macrophage interactions. This was accomplished by in vitro quantification of 1) migratory inhibitory factor(MIF) synthetic capacity of splenic lymphocytes in mice previously primed with ginseng 2) MIF responsiveness of mouse peritoneal macrophages or chicken peripheral leucocytes under the presence of ginseng extract 3) migration ability of chicken peripheral leucocytes by direct stimulation of ginseng extract or ginseng saponin and 4) immunosuppressive effects of immunosuppressants such as cyclophosphamide, cyclosporin A or dexamethasone. Mice divided equally into the ginseng and the saline groups, which received intraperitoneally daily 0.2ml of ginseng absolute alcohol-extract(5mg/ml) and same amount of saline for 15 days, respectively. The cellular immune responsiveness of these mice was assayed 15 days after ginseng pretreatment. Splenic lymphocytes of mice treated with ginseng, when stimulated with sensitized specific-antigen such as sheep red blood cells or toxoplasmin, or with polyclonal activator concanavalin A, produced significantly more MIF than those of control saline group. MIF responsiveness of normal mouse macrophages was significantly augmented when assayed under the presence of ginseng extract (1mg/ml). The migratory ability of normal chicken leucocytes in the absence of MIF was significantly decreased by the stimulation of ginseng extract alone. MIF response was significantly decreased by immunosuppressants and this impaired response was not restored by ginseng pretreatment. This study was additionally performed to evaluate the effect of ginseng on the expulsion of adult Trichinella spiralis in mice. ICR mice were infected experimentally by esophageal incubation of 300 T. spiralis infective muscle larvae prepared by acid-pepsin digestion of infected mice. and received oral administration of 70% alcohol ginseng extract(10mg/mouse/day) for the indicated days plus 4 days before infection. At various times after infection, the number of adult T. spiralis worms in small intestines was determined. Interestingly, ginseng-treatment was accompanied by accelerated expulson of T. spiralis. These results led to the conclusion that Panax ginseng caused some enhancing effect on GVH reaction, macrophage migration inhibition reaction and expulsion of T. spiralis. In addition these results suggested that the mechanisms responsible for this enhancement of ginseng may be chiefly or partially due to nonspecific stimulation of cell-mediated immune response.