• Fisheries and Aquatic Sciences
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• 제5권4호
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• pp.311-313
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• 2002

Proteolytic activity of live Uronema manum was analyzed by fluorescence polarization (FP) technique. Protease activity was measured by a decrease in FP value using fluorescein isothiocynate (FITC)-casein as a protein substrate. The results demonstrated an inverse linear relationship between fluorescence polarization (FP) values and live ciliate concentration over the range $1\times10^4\;to\;2\times10^5$ cells/well. However, the FP values of $10-10^3$ live parasites were not different significantly from that of control. Time-dependent decrease in FP value was shown in the wells containing live U. marinum. In the present study, FP assay had the benefit to provide measurements of substrate hydrolysis by live parasites in real-time, and did not require separations, precipitations, or transfers of reaction mixture.

• Macromolecular Research
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• 제16권8호
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• pp.695-703
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• 2008

Nanoparticles have tremendous potential in cancer prevention, detection and augmenting existing treatments. They can target tumors, carry imaging capability to document the presence of tumors, sense pathophysiological defects in tumor cells, deliver therapeutic genes or drugs based on the tumor characteristics, respond to external triggers to release an appropriate agent, document the tumor response, and identify the residual tumor cells. Nanoparticles < 30 nanometers in diameter show unexpected and unique properties. Furthermore, particles < 5 nanometers in size can easily penetrate cells as well as living tissues and organs. This study evaluated the safety of nano materials in a living body and the relationship between the living tissue and synthetic nano materials by examining the in-vitro cytotoxicity of poly(lactic-co-glycolic) acid (PLGA) nano-spheres and fluorescein isothiocynate(FITC)-labeled dendrimers as polymer nanoparticles. PLGA was chosen because it has been used extensively for biodegradable nanoparticles on account of its outstanding bio-compatibility and its acceptance as an FDA approved material. The dendrimer was chosen because it can carry a molecule that recognizes cancer cells, a therapeutic agent that can kill those cells, and a molecule that recognizes the signals of cell death. Cytotoxicity in L929 mouse fibroblasts was monitored using MTT assay. Microscopic observations were also carried out to observe cell growth. All assays yielded meaningful results and the PLGA nanoparticles showed less cytotoxicity than the dendrimer. These nano-particles ranged in size from 10 to 100 nm according to microscopy and spectroscopic methods.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.80-88
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• 2002

Recent studies demonstrate that collagen IV selectively pro-motes the repair of physiological processes in sublethally injured renal proximal tubular ceils (RPTC). We sought to further define the mechanisms of cell repair by measuring the effects of toxicant injury and stimulation of repair by L-ascorbic acid-2-phosphate (AscP), exogenous collagen IV, or function-stimulating integrin antibodies on the expression and subcellular localization of collagen-binding integrins (CBI) in RPTC. Expression of CBI subunits ${\alpha}_1$, ${\alpha}_2$, and ${\beta}_1$ in RPTC was not altered on day 1 after sublethal injury by S-(1,2-dichlorovinyl)-L-cysteine (DCVC). On day 6, expression of ${\alpha}_1$ and ${\beta}_1$ subunits remained unchanged, whereas a 2.2-fold increase in ${\alpha}_2$ expression was evident in injured RPTC. CBI localization in control RPTC was limited exclusively to the basal membrane. On day 1 after injury, RPTC exhibited a marked inhibition of active $Na^+$ transport and a loss of cell polarity characterized by a decrease in basal CBI localization and the appearance of CBI on the apical membrane. On day 6 after injury, RPTC still exhibited marked inhibition of active $Na^+$ transport and localization of CBI to the apical membrane. However, DCVC-injured RPTC cultured in pharmacological concentrations of AscP (500 ${\mu}$M)or exogenous collagen IV (50 ${\mu}$g/ml) exhibited an increase inactive $Na^+$ transport, relocalization of CBI to the basal membrane, and the disappearance of CBI from the apical membrane on day 6. Function-stimulating antibodies to CBI ${\beta}_1$ did not promote basal relocalization of CBI despite stimulating the repair of $Na^+$/$K^+$-ATPase activity on day 6 after injury. These data demonstrate that DCVC disrupts integrin localization and that physiological repair stimulated by AscP or collagen IV is associated with the basal relocalization of CBI in DCVC-injured RPTC. These data also suggest that CBI-mediated repair of physiological functions may occur independently of integrin relocalization.

• Asian-Australasian Journal of Animal Sciences
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• 제29권2호
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• pp.288-298
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• 2016

Resveratrol acts as a free radical scavenger and a potent antioxidant in the inhibition of numerous reactive oxygen species (ROS). The function of resveratrol and resveratrol-loaded nanoparticles in protecting human lung cancer cells (A549) against hydrogen peroxide was investigated in this study. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay was performed to evaluate the antioxidant properties. Resveratrol had substantially high antioxidant capacity (trolox equivalent antioxidant capacity value) compared to trolox and vitamin E since the concentration of resveratrol was more than $50{\mu}M$. Nanoparticles prepared from ${\beta}$-lactoglobulin (${\beta}$-lg) were successfully developed. The ${\beta}$-lg nanoparticle showed 60 to 146 nm diameter in size with negatively charged surface. Non-cytotoxicity was observed in Caco-2 cells treated with ${\beta}$-lg nanoparticles. Fluorescein isothiocynate-conjugated ${\beta}$-lg nanoparticles were identified into the cell membrane of Caco-2 cells, indicating that nanoparticles can be used as a delivery system. Hydrogen peroxide caused accumulation of ROS in a dose- and time-dependent manner. Resveratrol-loaded nanoparticles restored $H_2O_2$-induced ROS levels by induction of cellular uptake of resveratrol in A549 cells. Furthermore, resveratrol activated nuclear factor erythroid 2-related factor 2-Kelch ECH associating protein 1 (Nrf2-Keap1) signaling in A549 cells, thereby accumulation of Nrf2 abundance, as demonstrated by western blotting approach. Overall, these results may have implications for improvement of oxidative stress in treatment with nanoparticles as a biodegradable and non-toxic delivery carrier of bioactive compounds.

• 대한소아치과학회지
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• 제28권1호
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• pp.25-31
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• 2001

말초신경 손상에 의한 VIP의 변화를 연구하기 위해 흰쥐 하악대구치 치수제거 후 삼차신경절에서 VIP의 분포 및 반응강도를 공초점레이저주사현미경을 이용하여 관찰하였다. 체중 200g 내외의 Sprague-Dawley계 흰쥐를 대조군과 하악대구치 치수제거 후 14일군으로 분리하여 희생시켰다. 1차 항체로 rabbit anti-VIP, 2차 항체로 fluorescein isothiocyanate(FITC) conjugated anti-rabbit IgG를 사용하여 면역형광염색을 시행한 후 공초점레이저주사현미경으로 관찰하여 다음과 같은 결론을 얻었다. 1. 삼차신경절 하악부위에서 VIP 양성반응세포의 비율은 대조군에서 7.40%를, 실험군에서는 28.42%를 보였다. 대조군에 비해 실험군에서 양성반응세포의 증가를 보였다. 2. 삼차신경절 하악부위에서 VIP면역반응세포체에 대한 상대성 형광강도는 대조군에서 87.78을, 실험군에서는 138.65를 보였다. 대조군과 비교하였을 때 실험군에서 상대성 형광강도의 증가를 보였다. 3. 실험군의 광연속절편$(1{\mu}m)$ 관찰에서 VIP면역반응세포는 9개의 절편 대부분에서 강하게 나타났다. 축삭의 면역반응을 살펴보면, 대조군의 축삭에서는 약한 반응을 보였으며, 실험군의 축삭에서는 강한 면역반응을 보였다. 또한 양성 반응 세포체의 크기는 $20\sim25{\mu}m$의 중간 크기의 세포체에서 강한 면역반응을 보였다. 위의 결과로 보아 치수제거 후에 삼차신경절 하악부위에서 VIP 면역반응세포의 증가와 함께 상대성 형광강도가 높아졌음을 알 수 있었다.