• Fisheries and Aquatic Sciences
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• v.5 no.4
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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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• v.16 no.8
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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.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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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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• v.29 no.2
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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.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.25-31
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• 2001

The purpose of this study was to investigate the distribution and fluorescence intensity of vasoactive intestinal polypeptide immunoreactive (VIP-IR) cells in rat trigeminal ganglion following pulp extirpation of rat mandibular molar. The animals were divided into control group(n=6) and experimental group(n=6). The experimental animals were sacrificed at 14 days after pulp extirpation. The trigeminal ganglion was removed and immersed in the 4% paraformaldehyde in 0.1M phosphate buffer. Serial frozen sections about $20{\mu}m$ in thickness were cut with a cryostat. The immunofluorescence staining was performed. The rabbit anti-VIP(1 : 8,000) was used as primary antibody and fluorescene isothiocynate(FITC) conjugated anti-rabbit IgG(1 : 80) as secondary antibody. The slides were observed under confocal laser scanning microscope (CLSM). Unprocessed optical sections were obtained and stored on a optical disk. Color pictures were printed by a video copy processor. The results were as follows; 1. The positive ratio of VIP-IR cells in mandibular part of trigeminal ganglion were 7.40% in control group and 28.42% in experimental group(14 days after pulp extirpation). 2. The relative fluorescence intensity of VIP-IR cells in mandibular part of trigeminal ganglion were 87.78 in control group and 138.65 in experimental group. The relative fluorescence intensity of experimental group was 58% higher than that of control group. 3. In optical serial section analysis of VIP-IR cells of experimental group, most of the 9 sections showed high fluorescence intensity. At high magnification, axons of the experimental group displayed greater VIP-IR than in the control group, and the positive cells were mainly of medium size. The result indicate that number and fluorescence intensity of VIP-IR cells were increased in the mandibular part of trigeminal ganglion following pulp extirpation of mandibular molar, and it suggests that VIP could play a role in processing of nociception.