• Pediatric Infection and Vaccine
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• 제22권2호
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• pp.97-105
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• 2015

목적: 폐구균의 혈청형 분석은 백신의 효능을 평가하고 감시하는데 매우 중요하다. 그러나 폐구균의 혈청형 분석이 힘들기 때문에 최근 라텍스 구슬과 흐름세포측정기를 이용한 다중구슬 혈청형 분석법이 소개되었다. 이 연구에서는 새로운 혈청형 분석법을 이화백신연구센터에서 구축하고 실제 임상 검체들에 적용해보았다. 방법: 라텍스 구슬 3종과 폐구균 피막다당 특이 단클론항체 1가지, 시동체 2종을 Univerisity of Alabama at Birmingham에서 제공 받았다. 이 시료들을 이용하여 단클론항체와 wzy 다중 PCR을 이용한 다중구슬 혈청형 분석법을 확립하였다. 그리고 75개의 혈청형이 알려져 있는 검체를 이용하여 이화백신효능연구센터에 확립된 다중구슬 혈청형 분석법의 정확도를 보았고 이를 토대로 528개의 임상 검체를 분석해 보았다. 결과: 다중구슬 혈청형 분석법은 이화백신효능연구센터에 안정적으로 확립되었다. 75종의 이미 혈청형이 알려져 있는 검체를 암호화하여 분석한 결과 전부 일치하여 정확도가 높음을 보여 주었고 실제 임상 검체에도 적용한 결과 94.3% (498/528)에서 혈청형을 확인할 수 있었다. 결론: 다중구슬 분석법은 다수의 혈청형을 쉽고 빠르게 한번에 많은 수의 검체를 확인할 수 있는 객관적인 검사 방법으로 향후 임상적 진단과 역학연구 등의 폐구균의 혈청형 분석에 유용하게 사용될 수 있을 것이다.

• Pediatric Infection and Vaccine
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• 제13권2호
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• pp.99-105
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• 2006

목 적 : 현재 폐구균 혈청형 분석을 위해 사용중인 Quellung 반응과 비교하여, multiplex assay 방법에 의한 폐구균 혈청형 분석의 유용성을 확인하고, Quellung 반응에 의한 혈청형 분석의 정확성을 검증하였다. 방 법 : 연세 의료원 신촌 세브란스 병원에서 폐구균 감염이 확인된 환자로부터 분리된 35주의 검체를 이용하였다. Quellung 반응을 통한 혈청형 분석과 multiplex latex bead를 이용한 유세포 분석기기법을 통한 혈청형 분석을 시행한 후 양 방법간의 혈청형 분석을 비교하였다. 결 과 : Multiplex assay 방법에 제시된 대로 각각의 혈청형에서 평균 형광치 값의 감소를 확인할 수 있었다. 비교를 위해 시행한 14개 혈청형 중 11개 혈청형에서 비교가 가능했으며, 분석 비교가 가능했던 27검체 중 17검체에서 혈청형이 일치하는 결과를 보였다. 결 론 : 기존의 Quellung 반응의 경우 혈청형 분석에 많은 시간과 노력이 소요되며 일정량의 오차가 발생하는 문제가 있어, 이를 보완하기 위한 새로운 방법들이 시도되고 있다. 향후 보다 많은 혈청형을 대상으로 multiplex latex bead를 이용한 혈청형 분석을 시행할 필요가 있으며 이를 통해 multiplex assay와 Quellung 반응을 비교하며, Quellung 반응의 정확도를 올리기 위한 노력이 함께 수반되어야 할 것이다. 현재까지의 예비 결과로 볼 때 새로운 방법의 적용 가능성은 매우 높다고 할 수 있다.

• Toxicological Research
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• 제35권1호
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• pp.37-44
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• 2019

A major predictor of the efficacy of natural or synthetic cannabinoids is their binding affinity to the cannabinoid type I receptor ($CB_1$) in the central nervous system, as the main psychological effects of cannabinoids are achieved via binding to this receptor. Conventionally, receptor binding assays have been performed using isotopes, which are inconvenient owing to the effects of radioactivity. In the present study, the binding affinities of five cannabinoids for purified $CB_1$ were measured using a surface plasmon resonance (SPR) technique as a putative non-isotopic receptor binding assay. Results were compared with those of a radio-isotope-labeled receptor binding assay. The representative natural cannabinoid ${\Delta}^9$-tetrahydrocannabinol and four synthetic cannabinoids, JWH-015, JWH-210, RCS-4, and JWH-250, were assessed using both the SPR biosensor assay and the conventional isotopic receptor binding assay. The binding affinities of the test substances to $CB_1$ were determined to be (from highest to lowest) $9.52{\times}10^{-3}M$ (JWH-210), $6.54{\times}10^{-12}M$ (JWH-250), $1.56{\times}10^{-11}M$ (${\Delta}^9$-tetrahydrocannabinol), $2.75{\times}10^{-11}M$ (RCS-4), and $6.80{\times}10^{-11}M$ (JWH-015) using the non-isotopic method. Using the conventional isotopic receptor binding assay, the same order of affinities was observed. In conclusion, our results support the use of kinetic analysis via SPR in place of the isotopic receptor binding assay. To replace the receptor binding affinity assay with SPR techniques in routine assays, further studies for method validation will be needed in the future.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권2호
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• pp.132-136
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• 2004

The LAL (Limulus amebocyte lysate) test for the detection and quantification of endotoxin is based on the gelation reaction between endotoxin and LAL from a blood extract of Limulus polyphemus. The test is labor intensive, requiring dedicated personnel, a relatively long reaction time (approximately 1 h), relatively large volumes of samples and reagents and the detection of the end-point is rather subjective. To solve these problems, a miniaturized LOC (lab-on-a-chip) prototype, 62mm (L) ${\times}$ 18 mm (W), was fabricated using PDMS (polydimethylsiloxane) bonded to glass. Using this prototype, in which 2mm (W) ${\times}$ 44.3mm (L) ${\times}$ 100 $\mu\textrm{m}$ (D) microfluidic channel was constructed, turbidometric and chromogenic assay detection methods were compared, and the chromogenic method was found the most suitable for a small volume assay. In this assay, the kinetic-point method was more accurate than the end-point method. The PDMS chip thickness was found to be minimized to around 2 mm to allow sufficient light transmittance, which necessitated the use of a glass slide bonding for chip rigidity. Due to this miniaturization, the test time was reduced from 1 h to less than 10 min, and the sample volume could be reduced from 100 to ca. 4.4 ${\mu}$L. In summation, this study suggested that the LOC using the LAL test principle could be an alternative as a semi-automated and reliable method for the detection of endotoxin.

• 약학회지
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• 제42권3호
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• pp.307-311
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• 1998

This study was carried out to evaluate antitoxic effects Taraxaci Herba extract against Cadium by calorimetric methods. The antitoxic activity of Taraxaci Herba ex tract in NIH 3T3 fibroblasts was evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-phenyl-2H-tetrazoliumbromide), NR (Neutral red) and SRB (Sulforhodamine B protein) assay. The light microscopic study was carried out to observe morphological changes of the treated cells. These results were obtained as follows; The concentration of $10^{-2}mg/ml$ of Taraxaci Herba extract was shown significant antitoxic activity. The number of NIH 3T3 fibroblasts were antitoxic and tend to regenerate. These results suggest that Taraxaci Herba extract retains a potential antitoxic activity.

• Toxicological Research
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• 제16권1호
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• pp.77-82
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• 2000

This study was conducted to assess a possible alternative method as replacements for in vivo test. The human fibroblasts were exposed to several photoxic chemicals (promethazine, neutral red, chlortetracyclone, amiodatone, bithional, 8-methyooxypsorale) and non-phototoxi substance, ammonium laureth sulfate and irradiatied with 5 J/$cm^2$ of UVA (3320~420nm). The cell viability was measured by NRU (neutral red uptake) assay. The photoxic potential of test chemicals in the NRU PT (phototoxicity test) was assessed by determining the PIF (photoirritancy Factor) by using a cut-off value of 5. The NRU PT responses of most chemicals showed a close agreement with in vivo response except bithinol. There was a relatively good agreement between in vitro NRU assay and in vivo data. These results suggest that NRU assay using fibroblast could be used to predict the phototoxicity.

• 대한수의학회지
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• 제54권2호
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• pp.113-115
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• 2014

Salmonella are causative agents of gastroenteritis and systemic disease in animals. The invA gene was selected as a target sequence of loop-mediated isothermal amplification (LAMP) assay for diagnosis of Salmonella infection. The detection limits for broth dilution, spiked feces and enrichment were $10^4$, $10^5$ and $10^2$ CFUs/mL, respectively. The LAMP assay developed in the present study may be a reliable method for detection of Salmonella spp. in pig feces.

• Environmental Analysis Health and Toxicology
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• 제9권1_2호
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• pp.19-23
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• 1994

The tetrazolium dye, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), is reduced by live but not dead cell, and this reaction is used as the end point in a rapid drug screening assay. It can also be used for accurate determinations of drug sensitivity but only if a quantative relationship is established between cell number and MTT-formazan production. Several conditions were examined to devise an in vitro assay method in primary cultured hepatocytes, such as optimum wavelength, optimal MTT concentration, optimal incubation time, and cell density.

• 약학회지
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• 제6권1호
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• pp.28-34
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• 1962

Oxytocin and vasopressin were extracted from bovine posterior pituitaries and assayed, in many ways. On the assay of oxytocic active substance, it was found the depression method of blood pressure in a chicken was the easiest one among possible methods. The potency of oxytocin which was extracted with glacial acetic acid was 14.2 I.U./mg. On the assay of vasopressin for pressor activity. A full grown healthy male rat was used. Applying a simple artificial respiratory apparatus, the assay could be carried out successfully. The potency of vasopressin was 13.2 I.U/mg.

• BMB Reports
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• 제28권1호
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• pp.12-16
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• 1995

The branched-chain ${\alpha}$-keto acid dehydrogenase (BCKAD) complex is a rate limiting enzyme which catalyzes the oxidative decarboxylation of branched-chain ${\alpha}$-keto acids. Numerous studies have suggested that BCKAD is subject to covalent modification in vitro via phosphorylation and dephosphorylation, which are catalyzed by a specific kinase and phosphatase, respectively. The biggest difficulty in the assay of BCKAD activity is to arrest the interconversion between the active and inactive forms. BCKAD activity was determined from fresh rat heart and liver tissues using homogenizing and assay buffers containing inhibitors of phosphatase and kinase. The results suggest that a radiochemical assay using ${\alpha}$-keto[1-$^{14}C$]-isovalerate as a substrate for the enzyme can be applied as a reliable method to determine in vitro enzyme activity with arrested interconversion between the active and inactive forms of the BCKAD complex.