• 한국군사과학기술학회지
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• 제27권2호
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• pp.304-310
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• 2024

Ricin is a highly toxic protein which is produced in the seeds of the castor oil plant. Ricin toxin A chain has ribosomal RNA N-glycosylase activity that irreversibly hydrolyses the N-glycosidic bond of the adenine residue at position 4324 within the 28S rRNA. In this study, we developed non-toxic recombinant ricin vaccine(R51) in E. coli expression system, and evaluated efficacy of the R51 according to adjuvants. When the R51 was administered using aluminum hydroxide as an adjuvant, the vaccine efficacy was higher than that of TLR agonists or aluminum phosphate. Because it is time-consuming to administer the vaccine three times at three-week intervals, we investigated the survival rate and antibody titer of mice according to the change of time interval of vaccination. Interestingly, there was no difference in survival rate and antibody titer when R51 was administered at 0, 1, and 3 weeks or 0, 2, and 4 weeks compared to when administered at 0, 3, and 6 weeks. Therefore, the developed R51 vaccine is promising to protect soldiers from Ricin attack.

• The Korean journal of internal medicine
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• 제39권4호
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• pp.659-667
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• 2024

Background/Aims: Sensitization to staphylococcal superantigens (SAgs) could contribute to asthma severity. However, its relevance with eosinophilic phenotype has not yet been clarified. This study aimed to investigate associations between serum specific IgE levels to SAg and eosinophilic airway inflammation in adult asthmatics. Methods: The serum specific IgE levels to 3 SAgs, including staphylococcal enterotoxin A (SEA) and B (SEB), and toxic shock syndrome toxin-1 (TSST-1) were measured by ImmunoCAP in 230 adult asthmatic patients and 50 healthy controls (HCs). Clinical characteristics and laboratory parameters, including serum total/free IgE, and 2 eosinophil-activation markers, eosinophil cationic protein (ECP), and eosinophil-derived neurotoxin (EDN), were analyzed according to blood eosinophil counts (BEC; 150 cells/µL) and serum specific IgE levels to 3 SAgs (0.35 kU/L). Results: Asthmatic patients showed higher serum specific IgE levels to 3 SAgs than HCs (p < 0.05 for all). The serum total/free IgE levels were significantly higher in asthmatics with positive IgE responses to 3 SAgs than those without (p < 0.05 for all). There were no significant differences in clinical parameters including age, asthma severity, comorbidities, or smoking according to IgE responses to 3 SAgs. Patients with positive IgE responses to SEB (not to SEA/TSST-1) had higher serum specific IgE levels to house dust mites and ECP/EDN as well as higher BEC with positive correlations between serum SEB-specific IgE levels and BEC/ECP/EDN (p < 0.05 for all). Conclusions: These findings suggest that serum SEB-specific IgE levels could contribute to eosinophil activation as well as IgE production in adult asthma.

• Tuberculosis and Respiratory Diseases
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• 제43권2호
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• pp.210-220
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• 1996

식세포인 호중구나 단핵세포는 생체외실험에 사용하기 위한 세포분리법인 플라스틱 표면부착만으로도 세포활성화가 일어나 이후의 실험결과에 영향을 주고 이 과정에 부착분자가 연관되어 있는 것으로 알려져 있다. 폐의 주된 면역세포인 폐포대식세포도 대부분 플라스틱 표면부착에 의해 세포를 분리하므로 사람의 폐포대식세포가 표면부착 자체에 의해 활성화되는지 알아보고 세포활성회에 부착분자와 같은 기전이 관여하는지 밝히기 위해 적어도 한 쪽 폐가 정상인 사람에서 기관지폐포세척술을 통해 얻은 폐포대식세포를 대상으로 표면 부착이 미치는 영향을 과산화수소 분비량 측정으로 분석하여 다음과 같은 결과를 얻었다. 1) 폐포대식세포는 플라스틱 표면에 부착되면 부착 자체에 의해 과산화수소 분비능이 증가하고 이런 상태에서는 PMA나 fMLP와 같은 추가적인 화학자극물질에 의해 과산화수소 분비가 증가되지 않았다. 2) 여러가지 표면중 A549세포단층에 부착될 경우에만 이후의 PMA와 fMLP자극 모두에 의해 과산회수소 분비가 증가하였다. 3) PMA는 세포 부착여부에 관계없이 과산화수소 분비를 자극하지만 fMLP는 폐포대식세포가 표면에 부착된 상태에서만 자극효과가 나타났고 이런 부착세포에서의 fMLP에 의한 과산회수소 분비 효과는 단백합성억제제인 cycloheximide, G단백차 단제인 일해독소와 $\beta_2$ integrin 부착분자에 대한 항체인 항CD18 단세포항체 3가지 모두의 의해 차단되었다. 이상의 결과로 사람의 폐포대식세포는 플라스틱 부착자체에 의해 활성화되므로 부착 이후의 자극물질에 대한 효과가 반감되지만 폐포상피세포와 같은 생물학적 표면에 부착될 경우에는 이후의 세포자극에 민감하게 반응한다는 것을 알 수 있었고, PMA는 세포 부착여부에 관계없이 세포를 자극하는 반면 fMLP는 세포 부착상태에서만 자극효과가 나타나며 이런 부착세포에서의 fMLP에 의한 산소유리기 자극효과는 G단백결합 수용체를 통한 새로운 단백합성 과정으로 이루워지면서 $\beta_2$ integrin을 통한 폐포대식세포와 폐포상피세포의 부착에 의존하는 것으로 사료된다.

• 생명과학회지
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• 제21권2호
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• pp.183-193
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• 2011

중간엽 줄기세포의 이동과 분화는 손상된 조직의 재생을 위해 필수적이다. Sphingosine-1-phosphate (S1P)는 세포성장, 생존, 분화, 이동성 등 여러 가지 생명현상에 중요한 역할을 하는 생리활성 지질이다. 본 연구에서는 인체 골수유래 중간엽 줄기세포의 이동과 세포분화에 대한 S1P의 영향을 조사하였다. S1P는 중간엽 줄기세포의 이동을 증가시켰으며 pertussis toxin의 전처리는 S1P에 의한 세포이동을 억제하였다. 본 결과는 S1P에 의한 세포 이동과정에 Gi에 연결된 수용체가 관여함을 제시한다. $S1P_1$과 $S1P_3$ 수용체에 대한 길항제인 VPC23019의 전처리나 siRNA를 이용한 $S1P_1$ 수용체의 발현억제는 S1P에 의한 세포 내 칼슘 증가와 중간엽 줄기세포의 이동을 저해 하였다. 또한, S1P의 처리는 중간엽 줄기세포에서 평활근세포의 표지유전자인 $\alpha$-smooth muscle actin ($\alpha$-SMA)의 발현을 증가시켰으며 VPC23019의 전처리는 S1P에 의한 $\alpha$-SMA의 발현증가를 저해하였다. S1P는 중간엽 줄기세포에서 p38 mitogen-activated protein kinase (p38 MAPK)의 인산화를 촉진하였으며 p38 MAPK의 저해제인 SB202190의 전처리 또는 p38 MAPK의 dominant negative mutant의 과발현은 S1P에 의한 중간엽 줄기세포의 이동 $\alpha$-SMA 발현증가를 억제하였다. 본 연구결과는 S1P가 $S1P_1$-p38 MAPK 신호전달기전을 통해 중간엽 줄기세포의 이동과 평활근세포로의 분화를 촉진함으로써 중간엽 줄기세포를 이용한 조직재생에의 활용 가능성을 제시한다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.86-86
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• 2003

Research has been in progress for more than a decade to production of useful proteins by genetic modification in cattle. However, the levels of protein production in transgenic cattle have been reported very low. To enhance protein production in transgenic animal, we tried homologous recombination to donor cells for production of transgenic clone cattle through nuclear transfer procedure. Thus, we constructed the two targeting vectors of human thrombopoietin (TPO) at bovine $\beta$-casein locus using homologous recombination with 13.6 kb and 9.6 kb homology. In two targeting vectors, positive selection was through the neomycin resistance gene and negative selection was by the diphtheria toxin (DT). Gene targeting was attempted in bovine embryonic fibroblasts (bEF) and bovine ear skin fibroblasts (bESF). To determine the most appropriate concentration of neomycin for bEF and bESF, G4l8 resistance was confirmed by culturing the cells in various concentrations of the drug and both of the cells were optimally selected at $900 \mu g/ml$ of neomycin. The transfected bEF and bESF by the targeting vectors were colonized efficiently at the ratio of DNA to transfection reagent such as $4 \mu g$:2 ${mu}ell$ and $1 \mu g$:$2 \mu l$. Comparing number of healthy clones from passage 4 to passage 8, bESF (17%) persist in culture for much longer than bEF (6%). The two gene-targeted bESF clones of 30 random-integrated clones with 9.6 kb homology length were confirmed, however, nothing was out of 72 random integration clones with 13.6 kb homology length, The DT also worked more efficiently in clones transfected with the vector of 9.6 kb homology length. Our data suggests that the choice of donor cell for long culture period should be considered to obtain targeted cell clone, and the gene-targeting frequency and the DT working efficiency are dependent on the length of target homology.

• Biomolecules & Therapeutics
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• 제26권6호
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• pp.546-552
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• 2018

A comprehensive collection of proteins senses local changes in intracellular $Ca^{2+}$ concentrations ($[Ca^{2+}]_i$) and transduces these signals into responses to agonists. In the present study, we examined the effect of sphingosine-1-phosphate (S1P) on modulation of intracellular $Ca^{2+}$ concentrations in cat esophageal smooth muscle cells. To measure $[Ca^{2+}]_i$ levels in cat esophageal smooth muscle cells, we used a fluorescence microscopy with the Fura-2 loading method. S1P produced a concentration-dependent increase in $[Ca^{2+}]_i$ in the cells. Pretreatment with EGTA, an extracellular $Ca^{2+}$ chelator, decreased the S1P-induced increase in $[Ca^{2+}]_i$, and an L-type $Ca^{2+}$-channel blocker, nimodipine, decreased the effect of S1P. This indicates that $Ca^{2+}$ influx may be required for muscle contraction by S1P. When stimulated with thapsigargin, an intracellular calcium chelator, or 2-Aminoethoxydiphenyl borate (2-APB), an $InsP_3$ receptor blocker, the S1P-evoked increase in $[Ca^{2+}]_i$ was significantly decreased. Treatment with pertussis toxin (PTX), an inhibitor of $G_i$-protein, suppressed the increase in $[Ca^{2+}]_i$ evoked by S1P. These results suggest that the S1P-induced increase in $[Ca^{2+}]_i$ in cat esophageal smooth muscle cells occurs upon the activation of phospholipase C and subsequent release of $Ca^{2+}$ from the $InsP_3$-sensitive $Ca^{2+}$ pool in the sarcoplasmic reticulum. These results suggest that S1P utilized extracellular $Ca^{2+}$ via the L type $Ca^{2+}$ channel, which was dependent on activation of the $S1P_4$ receptor coupled to PTX-sensitive $G_i$ protein, via phospholipase C-mediated $Ca^{2+}$ release from the $InsP_3$-sensitive $Ca^{2+}$ pool in cat esophageal smooth muscle cells.

• The Korean Journal of Physiology and Pharmacology
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• 제2권1호
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• pp.101-108
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• 1998

We investigated the effect of ${\alpha}-subunit$ of the stimulatory GTP-binding protein ($G{\alpha}_s$) gene mutation on the expression of the thyrotropin-releasing hormone (TRH) receptor (TRH-R) gene in GH3 cells and in growth hormone (GH)-secreting adenomas of acromegalic patients. In the presence of cyclohexicmide, forskolin and isobutylmethylxanthine, cholera toxin, and GH-releasing hormone (GHRH) decreased rat TRH-R (rTRH-R) gene expression by about 39%, 43.7%, and 46.7%, respectively. Transient expression of a vector expressing mutant-type $G{\alpha}_s$ decreased the rTRH-R gene expression by about 50% at 24 h of transfection, whereas a wild-type $G{\alpha}_s$ expression vector did not. The transcript of human TRH-R (hTRH-R) gene was detected in 6 of 8 (75%) tumors. Three of them (50%) showed the paradoxical GH response to TRH and the other three patients did not show the response. The relative expression of hTRH-R mRNA in the tumors from patients with the paradoxical response of GH to TRH did not differ from that in the tumors from patients without the paradoxical response. Direct PCR sequencing of $G{\alpha}_s$ gene disclosed a mutant allele and a normal allele only at codon 201 in 4 of 8 tumors. The paradoxical response to TRH was observed in 2 of 4 patients without the mutation, and 2 of 4 patients with the mutation. The hTRH-R gene expression of pituitaty adenomsa did not differ between the tumors without the mutation and those with mutation. The present study suggests that the expression of TRH-R gene is not likely to be a main determinant for the paradoxical response of GH to TRH, and that $G{\alpha}_s$ mutation may suppress the gene expression of TRH-R in GH-secreting adenoma. However, a certain predisposing factor(s) may play an important role in determining the expression of TRH-R.

• 대한약리학회지
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• 제31권3호
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• pp.355-363
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• 1995

Calcium수송에 대한 기전을 추구하기위하여, carbachol을 사용하여 ml muscarinic receptor-transfected RBL-2H3 cell-line에서 다음과 같은 실험결과를 얻었기에 이에 보고한다. 1) Carbachol의 투여로 이들 cell-line에서 $Ca^{2+}$ influx가 농도에 따라 증가하였고, hexosaminidase 분비양도 의의있게 증가하였다. 2) Atropine 투여로 Carbachol의 상승작용이 의의있게 억제되었다. 3) 수종의 금속양이온을 투여하여 carbachol의 $Ca^{2+}$수송에 대한 영향을 관찰한 바, 이들 금속이온들은 $Ca^{2+}$의 influx를 의의있게 억제하였다. 4) PMA(20 nM) 투여로 carbachol의 hexosaminidase의 분비는 억제되지 못했지만 $Ca^{2+}$ influx는 억제되었다. 5) PTx $(0.2\;{\mu}g/ml)$ 투여로 carbachol의 hexosaminidase 분비가 의의있게 억제되었다. 위의 결과로 미루어 보아, 이 세포의 muscarinic receptor가 calcium channel을 통한 calcium수송에 매우 중요한 영향을 나타내는데, 이들 calcium ion channel은 적어도 두 종류가 존재하며, 하나는G-protein-dependent calcium channel에 의하며, 다른 하나는 G-protein-independent calcium channel에 대한 작용에 의한 것으로 생각된다. 또한 이 calcium channel들은 2가 또는 3가의 다른 금속 ion들에 의하여 calcium수송이 억제된다.

• 농약과학회지
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• 제18권4호
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• pp.358-363
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• 2014

신규 병원성세균 Bacillus thuringiensis CAB565, 566균주를 이용한 산업배지에서의 배양조건에 따른 독소단백질의 차이를 확인하였다. 포도당, 효모추출물 등으로 구성된 산업배지의 산소 전달 속도를 확인하고자 소형배양기에서 임펠러와 배지 농도에 따른 산소전달계수(KLa)의 차이를 확인하였다. 교반기의 통기량이 많을수록 그리고 배지 농도가 높아질수록 산소전달계수(KLa) 값이 상승하였다. 하지만 교반속도는 200 rpm에서 가장 효율적이었고, 교반속도가 상승할수록 효과가 떨어졌다. Microsparger를 이용하여 배양 중 단계적으로 통기속도를 높여 배지내 용존산소농도를 50% 이상으로 유지시켜 배양한 결과 생균수는 배양 후 16시간, 포자수는 54시간에 최대의 농도값을 보였다. 그 결과, B.t. CAB565의 생균수는 $2.3{\times}10^{10}cell/ml$, 포자수는 $1.9{\times}10^{10}spore/ml$ 그리고 B.t. CAB566의 생균수는 $1.8{\times}10^{10}cell/ml$, 포자수는 $1.4{\times}10^{10}spore/ml$를 보였다. 탄소원의 농도는 포도당의 농도가 5%일 때, 세포성장에 가장 유리한 것으로 조사되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.103-108
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• 2005

To study the direct effect of somatostatin (SS) on calcium channel current ($I_{Ba}$) in guinea-pig gastric myocytes, $I_{Ba}$ was recorded by using whole-cell patch clamp technique in single smooth muscle cells. Nicardipine ($1{\mu}M$), a L-type $Ca^{2+}$ channel blocker, inhibited $I_{Ba}$ by $98{\pm}1.9$% (n=5), however $I_{Ba}$ was decreased in a reversible manner by application of SS. The peak $I_{Ba}$ at 0 mV were decreased to $95{\pm}1.5$, $92{\pm}1.9$, $82{\pm}4.0$, $66{\pm}5.8$, $10{\pm}2.9$% at $10^{-10}$, $10^{-9}$, $10^{-8}$, $10^{-7}$, $10^{-5}$ M of SS, respectively (n=3∼6; $mean{\pm}SEM$). The steady-state activation and inactivation curves of $I_{Ba}$ as a function of membrane potentials were well fitted by a Boltzmann equation. Voltage of half-activation ($V_{0.5}$) was $-12{\pm}0.5$ mV in control and $-11{\pm}1.9$ mV in SS treated groups (respectively, n=5). The same values of half-inactivation were $-35{\pm}1.4$ mV and $-35{\pm}1.9$ mV (respectively, n=5). There was no significant difference in activation and inactivation kinetics of $I_{Ba}$ by SS. Inhibitory effect of SS on $I_{Ba}$ was significantly reduced by either dialysis of intracellular solution with $GDP_{\beta}S$, a non-hydrolysable G protein inhibitor, or pretreatment with pertussis toxin (PTX). SS also decreased contraction of guinea-pig gastric antral smooth muscle. In conclusion, SS decreases voltage-dependent L-type calcium channel current ($VDCC_L$) via PTXsensitive signaling pathways in guinea-pig antral circular myocytes.