• Applied Microscopy
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• v.42 no.1
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• pp.49-52
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• 2012

For TEM study of biological samples or polymers that are contained in organic structure, it is often required that the sample is prepared by using ultramicrotome and stained with proper agents to increase the contrast of organic structure. In this study, we investigated an efficient TEM sample preparation method for ductile heterogeneity material by using ultramicrotomy. Cryo-ultramicrotomy is a suitable method that is capable of rendering sample hardness for various ductile materials. However, it has several factors to consider, such as experimental cost, working time and finding the optimal staining conditions. To satisfy these considerations, we prepared TEM sample by using ultramicrotome without cryofunction, and secured the sample hardness by applying the staining process prior to ultrathin sectioning. The cross-linked polyethylene structure in the sample was stained with the 2% $RuO_4$ solution in a sealed test tube for 24 hours at $4^{\circ}C$. After the sample staining, ultrathin sections of sample were prepared using ultramicrotome. As a result, it was revealed that the difficulties associated with staining of ultrathin sections prepared by low-temperature conditions were improved. In addition, appropriate staining depth of sample could be selected for sectioning process. The quality of TEM sample obtained by using this method was better than that of cryo-ultramicroscopy. Finally, it is expected that our method could be effectively applied in TEM sample preparation for a variety of nano-bio convergence materials.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2900-2904
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• 2013

We present the synthesis and characterization of DTPA-bis(histidylamide) (1a), DTPA-bis(aspartamide) (1b), and their gadolinium complexes of the type $[Gd(L)(H_2O)]$ (2a:L = 1a; 2b:L = 1b). Thermodynamic stabilities and $R_1$ relaxivities of 2a-b compare well with Omniscan$^{(R)}$, a well-known commercial, extracellular (ECF) MRI CA which adopts the DTPA-bis(amide) framework for the chelate: $R_1$ = 5.5 and 5.1 $mM^{-1}$ for 2a and 2b, respectively. Addition of the Cu(II) ion to a solution containing 2b triggers relaxivity enhancement to raise $R_1$ as high as 15.3 $mM^{-1}$, which corresponds to a 300% enhancement. Such an increase levels off at the concentration beyond two equiv. of Cu(II), suggesting the formation of a trimetallic ($Gd/Cu_2$) complex in situ. Such a relaxivity increase is almost negligible with Zn(II) and other endogenous ions such as Na(I), K(I), Mg(II), and Ca(II). In vivo MR images and the signal-to-noise ratio (SNR) obtained with an aqueous mixture of 2b and Cu(II) ion in an 1:2 ratio demonstrate the potentiality of 2 as a copper responsive MRI CA.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1073-1080
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• 1999

Previous studies suggested that the inhibition of thyroxine ($T_4$) release by ${\alpha}_1$-adrenoceptor and muscarinic receptor stimulation results in activated protein kinase C (PKC) from mouse and guinea pig thyroids. In the present study, the effect of carbachol, methoxamine, phorbol myristate acetate (PMA), and R59022 on the release of $T_4$ from the mouse, rat, and guinea pig thyroids was compared to clarify the role of PKC in the regulation of the release of $T_4$. The thyroids were incubated in the medium containing the test agents, samples of the medium were assayed for $T_4$ by EIA kits. Forskolin, an adenylate cyclase activator, chlorophenylthio-cAMP sodium, a membrane permeable analog of cAMP, and isobutyl-methylxanthine, a phosphodiesterase inhibitor, like TSH (thyroid stimulating hormone), enhaced the release of $T_4$ from the mouse, rat, and guinea pig thyroids. Methoxamine, an ${\alpha}_1$-adrenoceptor agonist, inhibited the TSH-stimulated release of $T_4$ in mouse, but not rat and guinea pig thyroids. In contrast, carbachol, a muscarinic receptor agonist, inhibited the release of $T_4$ in guinea pig, but not mouse and rat thyroids. These inhibition were reversed by prazosin, an ${\alpha}_1$-adrenoceptor antagonist or atropine, a muscarinic antagonist or $M_1$- and $M_3$-muscarinic antagonists, in mouse or guinea pig thyroids. In addition, staurosporine, a PKC inhibitor, reversed methoxamine or carbachol inhibition of TSH stimulation. Furthermore, PMA, a PKC activator, and R59022, a diacylglycerol (DAG) kinase inhibitor, inhibited the TSH-stimulated release of $T_4$ in mouse, rat, and guinea pig thyroids. These inhibition were blocked by staurosporine. These findings suggest that the activation of receptor or DAG inhibits TSH-stimulated $T_4$ release through a PKC-dependent mechanism in thyroid gland.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.463-471
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• 1999

Magnesium($Mg^{2+}$) is one of the most abundant intracellular divalent cation. Although recent studies demonstrate that adrenergic receptor stimulation evokes marked changes in $Mg^{2+}$ homeostasis, the regulation of $Mg^{2+}$ by dopaminergic receptor stimulation is not yet known. In this work, we used dopaminergic agents to identify which type(s) of receptors were involved in the mobilization of $Mg^{2+}$ by dopaminergic receptor stimulation in the perfused rat hearts, isolated myocytes and circulating blood. The $Mg^{2+}$ content was measured by atomic absorbance spectrophotometry. Dopamine(DA), apomorphine(APO) and pergolide stimulated $Mg^{2+}$ efflux in the perfused rat hearts and these effects were inhibited by haloperidol or fluphenazine, nonselective dopaminergic antagonists. SKF38393, a selective doparminergic agonist, increased $Mg^{2+}$ efflux from the perfused hearts in dose dependant manners and SKF38393-induced $Mg^{2+}$ efflux was blocked by haloperidol. However, dopaminergic agonists-induced $Mg^{2+}$ efflux was potentiated in the presence of sulpiride or eticlopride, $D_2$-selective antagonist, from the perfused hearts. This increase of $Mg^{2+}$ efflux was blocked by haloperidol or imipramine. DA or pergolide increased in circulating $Mg^{2+}$ from blood. By contrast, PPHT stimulated $Mg^{2+}$ influx(a decrease in efflux) from the perfused hearts and circulating blood. PPHT-induced $Mg^{2+}$ influx was blocked by fluphenazine in the perfused hearts. DA-stimulated $Mg^{2+}$ efflux was inhibited by dopaminergic antagoinst in the isolated myocytes. In conclusion, the flux of $Mg^{2+}$ is modulated by DA receptor activation in the rat hearts. The efflux of $Mg^{2+}$ can be increased by $D_1$-receptor stimulation and decreased by $D_2$-receptor stimulation, respectively.

• Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.5.1-5.8
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• 2018

Stimulator of interferon gene (STING) is induced by various inflammatory agents, such as lipopolysaccharide and microbial pathogens, including virus and bacteria. In this study, we obtained a full-length cDNA of a STING homolog from olive flounder using rapid amplification of cDNA ends PCR technique. The full-length cDNA of Paralichthys olivaceus STING (PoSTING) was 1442 bp in length and contained a 1209-bp open reading frame that translated into 402 amino acids. The theoretical molecular mass of the predicted protein sequence was 45.09 kDa. In the PoSTING protein, three transmembrane domains and the STING superfamily domain were identified as characteristic features. Quantitative real-time PCR revealed that PoSTING expressed in all the tissues analyzed, but showed the highest level in the spleen. Temporal expression analysis examined the significantly upregulated expression of PoSTING mRNA after viral hemorrhagic septicemia virus (VHSV) stimulation. In contrast, no significant changes in the PoSTING expression were detected in Edwardsiella tarda-challenged group compared to the un-injected control. The expression of P. olivaceus type I interferon (PoIFN-I) was also highly upregulated upon VHSV challenge. These results suggest that STING might be involved in the essential immune defense against viral infection together with the activation of IFN-I in olive flounder.

• International Journal of Oral Biology
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• v.36 no.3
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• pp.155-162
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• 2011

Eugenol (4-allyl-2-methoxyphenol) is a naturally occurring phenolic compound that is widely used in dentistry as a component of zinc oxide eugenol cement that is commonly applied to the mouth environment. Cisplatin is one of the most potent known anticancer agents and shows significant clinical activity against a variety of solid tumors. This study was undertaken to investigate the synergistic apoptotic effects of co-treatments with eugenol and cisplatin on human melanoma (G361) cells. To investigate whether this co-treatment efficiently reduces the viability of G361 cells compared with each single treatment, an MTT assay was conducted. The induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining and an analysis of DNA hypoploidy. Western blot analysis and immunofluorescent staining were also performed to evaluate the expression levels and the translocation of apoptosis-related proteins following this co-treatment. Furthermore, proteasome activity and mitochondrial membrane potential (MMP) changes were also assayed. The results indicated that a co-treatment with eugenol and cisplatin induced multiple pathways and processes associated with an apoptotic response in G361 cells including nuclear condensation, DNA fragmentation, a reduction in MMP and proteasome activity, the increase and decrease of Bax and Bcl-2, a decreased DNA content, the release of cytochrome c into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, and the activation of caspase-9, caspase-7, caspase-3, PARP and DFF45 (ICAD). In contrast, separate treatments of 300 ${\mu}M$ eugenol or 3 ${\mu}M$ cisplatin for 24 h did not induce apoptosis. Our present data thus suggest that a combination therapy of eugenol and cisplatin is a potential treatment strategy for human melanoma.

• Tuberculosis and Respiratory Diseases
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• v.56 no.1
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• pp.85-90
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• 2004

A 69 year-old female was admitted to the hospital due to intermittent hemoptysis for 1 month. Emergent bronchoscopy revealed mass-like lesion almost completely obstructing right intermediate bronchus with multiple hemorrhagic spots. Bronchial arterial angiography was performed but failed to find out actively bleeding vessel. Spiral computerized tomography of the chest showed contrast enhanced bulging of the posterior portion of right main bronchus into the lumen of right intermediate bronchus suggesting Rasmussen aneurysm. The AFB smear of bronchial washing fluid was positive. Pulmonary arterial angiography and embolization were not performed due to improvement of clinical course with medical conservative care. Here we report a case of endobronchial mass-like Rasmussen aneurysm grossly suspected by bronchoscopy and diagnosed by spiral CT, which successfully managed by medical conservative care with antituberculous agents.

• Korean Journal of Clinical Pharmacy
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• v.23 no.3
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• pp.213-222
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• 2013

Purpose: The aim of this study was to investigate the current state of antidepressant prescriptions in breast cancer patients and factors affecting the prescription of antidepressants. Methods: This study targeted female breast cancer patients who were prescribed antidepressants by a psychiatrist at least once between August 2010 and July 2011 at the Asan Medical Center in Seoul. The prescription history of each study subject was investigated to analyze the current state of antidepressant prescriptions in breast cancer patients. Results: The analysis of the prescription histories of 136 subjects in the antidepressant group determined that escitalopram, mirtazapine, and trazodone were the three most commonly prescribed medications with an average of 1.54 antidepressants prescribed per patient. A logistic regression analysis showed a statistically significant increase in antidepressant prescriptions in patients who were divorced or widowed, had sleep disturbances, or had undergone oncologic surgery for the breast cancer (p<0.050). In contrast, the prescription rate was lower for patients with tumour sizes greater than 50 mm (p<0.050). Conclusion: The sociodemographic factor of marital status, clinical factors of sleep disorders and tumour size, and a treatment-specific factor of the use of surgical therapy were identified as affecting the prescription of antidepressants in female breast cancer patients.

• Journal of Technology Innovation
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• v.7 no.1
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• pp.36-59
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• 1999

Fundamental advances in the biotechnologies are exerting a profound influence on the health care, agricultural, industrial chemical, environmental, and other industrial fields. Korean government are now more and more realizing the importance of biotechnology as a main technology for the 21st century. But any technical progress is largely the result of a complex set of relationships among the firms, institutions and others involved in development. So understanding the complexity is very important to make promoting strategies and it is even critical in the field of biotechnology. The reason is that commercialization of research results in biotechnology is strongly related with the national science bases provided by academic and public institutes. And its applicable industrial sectors are very diverse. So it is very important to make a effective collaboration system among many R&D related agents. This article discusses and compares both USA and Japanese framework of national innovation systems in the field of biotechnology. The American Innovation system encourages basic research in the biological sciences, and fosters the creation of small venture firms that focus on the development of novel products. America's peculiar incentive structure, derived from its research and educational system, financial system, and regulatory environment has driven USA labs and firms to the forefront of many biotechnology fields. The Japanese institutional environment in contrast, supported the strategy of building production expertise. Firms were urged to use the new techniques as a way of leapfrogging into a second generation of bio-products, in that cost and production advantages count. But the strategy was not effective as expected and Japanese firms have remained competent but not prominent rivals. The differing situations in USA and Japan with regard to biotechnology have many suggestions for our bioindustry. In the conclusion of this article, we translate USA and Japan's experiences to some suggestions which guide for promoting Korea's biotechnology R&D and commercialization activities.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.90-99
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• 2020

This study aimed to screen for plants with antimicrobial potential among the evergreen woody species of South Korea that are used for horticulture and landscaping and to provide basic information about plants with proven antimicrobial activity to underpin future research. The plant materials were extracted under various conditions, and the antimicrobial activities of the extracts were evaluated by agar diffusion assay. The screening tests demonstrated that the crude extracts of 43 species had inhibitory effects against S. aureus. The inhibitory activities of four species (Elaeocarpus sylvestris, Camellia japonica, Cleyera japonica, and Quercus salicina) were relatively higher than that of the synthetic antimicrobial agents methylparaben and phenoxyethanol. The highest inhibitory activity was observed with the leaf extracts (extracted with methanol for 30 minutes) of E. sylvestris, based on induction of the largest inhibition zone of 23.3 mm in size. In addition, solvent fractions of E. sylvestris were evaluated. The largest inhibitory zone of 23.1 mm was observed for the n-butanol fraction, which is likely to contain effective compounds that exhibit inhibitory activity against S. aureus. In contrast, n-hexane and residual aqueous fractions showed no antimicrobial activity. Overall, our findings confirm that evergreen woody plants native to South Korea have potential antimicrobial activity.