• Molecules and Cells
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• v.26 no.2
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• pp.113-120
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• 2008

Laser light microscopy enables observation of various simultaneously occurring events in living cells. This capability is important for monitoring the spatiotemporal patterns of the molecular interactions underlying such events. Two-photon excited fluorescence microscopy (two-photon microscopy), a technology based on multiphoton excitation, is one of the most promising candidates for such imaging. The advantages of two-photon microscopy have spurred wider adoption of the method, especially in neurological studies. Multicolor excitation capability, one advantage of two-photon microscopy, has enabled the quantification of spatiotemporal patterns of $[Ca^{2+}]_i$ and single episodes of fusion pore openings during exocytosis. In pancreatic acinar cells, we have successfully demonstrated the existence of "sequential compound exocytosis" for the first time, a process which has subsequently been identified in a wide variety of secretory cells including exocrine, endocrine and blood cells. Our newly developed method, the two-photon extracellular polar-tracer imaging-based quantification (TEPIQ) method, can be used for determining fusion pores and the diameters of vesicles smaller than the diffraction-limited resolution. Furthermore, two-photon microscopy has the demonstrated capability of obtaining cross-sectional images from deep layers within nearly intact tissue samples over long observation times with excellent spatial resolution. Recently, we have successfully observed a neuron located deeper than 0.9 mm from the brain cortex surface in an anesthetized mouse. This microscopy also enables the monitoring of long-term changes in neural or glial cells in a living mouse. This minireview describes both the current and anticipated capabilities of two-photon microscopy, based on a discussion of previous publications and recently obtained data.

• Journal of Nutrition and Health
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• v.40 no.2
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• pp.138-146
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• 2007

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades. Harmful contaminants naturally occurred from foods which contain high levels of unsaturated fatty acids that are easily oxidized can affect the human anti-oxidation system through the generation of free radicals. Moreover, previous studies proved that ${\gamma}$-irradiation may cause production of free radicals in food. We investigated the effect of ${\gamma}$-irradiated soybeans in relation to oxidative stress in mice. Oxidative index of mice was evaluated by TBARS, DNA fragmentation in various organs such as blood lymphocytes, liver and kidney. Forty male ICR mice were equally divided into 4 groups and fed control diet or ${\gamma}$-irradiated diet containing 50% soybeans (5, 10, and 20 kGy, respectively) for 8 weeks. Peroxide values of the irradiated diets were higher than that of the non-irradiated one and increased according to the storage period. There was no significant difference in weight gain as well as in TBARS value in plasma and kidney of all groups. Liver TBARS value of the group fed with irradiated diet at 20 kGy increased significantly compared with the control group (p < 0.05). DNA oxidative damage as measured by alkaline comet assay showed that % tail DNA in the blood lymphocytes of 5 kGy and 10 kGy groups increased significantly over the control group (p < 0.05). Also, tail moments of 5 kGy and 10 kGy groups were higher than that of the control group. Ultrastructural examination shows myeline figures and swollen mitochondria in parietal and intestinal epithelial cells of the group fed with irradiated diet. Therefore, considering unsaturated fatty acid content, consumption of soybeans ${\gamma}$-irradiated with over 20 kGy or repeatedly may decrease the body's antioxidant mechanism.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.7-8
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• 2000

Transgenic animals are very useful for scientific, pharmaceutical, and agricultural purposes. In livestock, transgenic technology has been used forthe genetic alteration of farm animals, the production of human proteins inlarge quantities in the milk of transgenic farm animals, and the generation of animals with organs suitable for xenotransplantation. To date, the transfer of foreign genes into farm animals has been performed mainly by microinjection of DNA into the pronuclei of fertilized eggs. However, the overall success rate of transgenic animals in livestock so far has been disappointingly low, eg., the efficiency is 0∼5% in swine, and less than 1% in sheep and cattle, compared with the rate in mice where 5% microinjected develop into transgenic animals. Recently, McGreath et al. (2000) have succeeded in producing the gene targeted sheep by the use of nuclear transfer from cultured somatic cells transfected with a foreign gene in vitro. However, we may need plenty of time until currently employ this method for gene transfer to farm animals. We have been studying to exploit the method for improving production efficiencies of transgenic animals with emphasis of its application to farm animals. The present paper describes three approaches that we have made in our laboratory to improve production efficiencies of transgenic animals, based on the DNA microinjection method. 1. Co-injection of restriction enzyme with foreign DNA into the pronucleus for elevating production efficiencies of transgenic animals. 2. Efficient selection of transgenic mouse embryos using EGFP as a marker gene. 3. Phenotypes of tansgenic mice expressing WAP/hGH-CAG/EGFP fusion gene produced by selecting transgenic embryos. 4. Efficient site-specific integration of the transgene targeting an endogenous lox like site in early mouse embryos.

• Journal of Pharmacopuncture
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• v.16 no.1
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• pp.43-49
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• 2013

Objective: Pyungwi-san (PWS) plays a role in a number of physiologic and pharmacologic functions in many organs. Interstitial cells of Cajal (ICCs) are pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. We aimed to investigate the beneficial effects of PWS in mouse small-intestinal ICCs. Methods: Enzymatic digestion was used to dissociate ICCs from the small intestine of a mouse. The whole-cell patch-clamp configuration was used to record membrane potentials from the cultured ICCs. Results: ICCs generated pacemaker potentials in the GI tract. PWS produced membrane depolarization in the current clamp mode. Pretreatment with a $Ca^{2+}$-free solution and a thapsigargin, a $Ca^{2+}$-ATPase, inhibitor in the endoplasmic reticulum, eliminated the generation of pacemaker potentials. However, only when the thapsigargin was applied in a bath solution, the membrane depolarization was not produced by PWS. Furthermore, the membrane depolarizations due to PWS were inhibited not by U-73122, an active phospholipase C inhibitor, but by chelerythrine and calphostin C, protein kinase C inhibitors. Conclusions: These results suggest that PWS might affect GI motility by modulating the pacemaker activity in the ICCs.

• Journal of the Korean Society of Radiology
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• v.2 no.2
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• pp.23-30
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• 2008

X-ray microscopy with synchrotron radiation(SR) might be a useful tool for novel x-ray imaging in the clinical and laboratory settings. Microscopically, it enables us to observe detailed structure of animal organs samples with a great magnification power and an excellent resolution. The phase contrast mechanisms in image by X-ray are described. The phase-contrast X-ray imaging with SR from in-vivo and in-vitro mouse tail, rat nerve and rat lung were obtained with an 8 KeV monochromatic beam. The visual image was magnified using 10x microscope objective lens and captured using an digital CCD camera. The results showed more structural details and high resolution images with SR imaging system than conventional X-ray radiography system. The SR imaging system may have a potential for imaging in biological researches, material applications and clinical radiography.

• Reproductive and Developmental Biology
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• v.33 no.2
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• pp.93-98
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• 2009

In this study, bovine Dnmt1 cDNA was sequenced and detected Dnmt1 mRNA level in bovine tissues by northern blot, methylation pattern of genome by southern blot, specific localization of Dnmt1 in mouse and bovine preimplantation embryos by immunocytostaining and Dnmt1 protein level in ovary and testis by western blot. Bovine Dnmt1 cDNA sequence showed more homology with that of human than mouse and rat. The RNA level of Dnmt1 was 10 times higher expression in placenta than other tissues. This indicates that placenta was hypermethylated compared to others organs. The genomic DNA could not be cut by a specific restriction enzyme (HpaII) in placenta, lung and liver of bovine. It suggests that Dnmt1 in some somatic cells was already methylated. Dnmt1, which has the antibody epitope 1316~1616, was distributed in nucleus and cytoplasm including the stage of pronuclear stage and maturation of oocyte and gradually weaken to blastocyst stage compare to negative. In addition, Dnmt1 was strongly expressed in tetraploid embryo and cloned 8-cell than IVF 8-cell. An aberrant pattern of DNA methylation in cloned embryo may be abnormal development of fetus, embryonic lethality and placenta dysfunction. The somatic specific band (190kDa) was appeared in ovary and testis, but oocyte specific band (175kDa) was not. Further investigations are necessary to understand the complex links between the methyltransferases and the transcriptional activity of genes in the cloned bovine tissues.

• Journal of Nutrition and Health
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• v.36 no.3
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• pp.255-261
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• 2003

Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.

• Toxicological Research
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• v.19 no.4
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• pp.277-283
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• 2003

Polychlorinated biphenyls (PCBs) has been widely used as plasticizer, insulator, lubricant, paint and ink. The persistence of PCBs in the environment and their bioaccumulation in living organism make a raise concerns regarding their toxic effects in immune system and subsequent effects on human health. However little has been known about effect of PCB, an endocrine disrupter, on splenocytes. In this study, for identifying the effect on the organs and immune cell of mice by the concentration and time of commercial PCB mixture (Aroclor 1254), each 3 mice were tested at the concentration of 3, 30, 300, 1,000 mg/kg respectively, and their organ's weight were measured in 4, 7, 14 days, respectively. Also according to concentration and time, PCB was evaluated for the effects on splenocyte viability and lipopolysaccaride (LPS) and concanavaline A (Con A)-induced splenocyte proliferation on mice spleen. In liver and lung, there were significantly defferent by concentration and time of PCB (p < 0.0001). In respect of concentration of PCB, no significant effects on mice's liver by Aroclor 1254 concentration below than 300 mg/kg were observed except at the concentration of 1,000 mg/kg doses (p < 0.0001). But there was not significant different change in mice spleen by concentration and time of PCB (p=0.2206) and the mode of weight change of spleen was different to of liver and of lung. Viabilities of splenocytes were decreased following treatment with high concentration of PCB. Also, LPS and Con A-induced cell proliferations were decreased by Aroclor 1254 at 1,000 mg/kg. These data suggest that Aroclor 1254 is the immunotoxic compound that may have an effect on mouse immune system.

• Applied Microscopy
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• v.39 no.1
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• pp.17-25
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• 2009

This study investigated that exposure of male mice to estrogen receptor $\alpha$-selective agonist, 4,4',4"-(4-propyl-[1H]-pyrazole-1,3,5-triyl)tris-phenol (PPT) induce morphological changes of accessory genital glands. The male reproductive organs were fixed and processed for light microscopy. The PPT induced decreases of ventral prostates, seminal vesicles and preputial glands weights with experimental time. The glandular lumen of ventral prostate was atrophied compared with control group. Type of epithelial tissues in the prostate was changed from simple columnar epithelium to stratified cuboidal or squamous epithelium. Treated group with the agonist showed that increased connective tissue underlying epithelium in the prostate and seminal vesicle. Especially, the glandular lumen of the seminal vesicle was contracted when PPT-treated animals were compared with control group. Secretion cells of preputial gland were smaller than that of control group. On week 8, PPT treatment caused decrease of epithelial cell height lining the lumen of preputial gland. These results provide information useful in researching the physiological function of estrogen mediated by estrogen receptor $\alpha$ in male accessory genital gland.

• Journal of Haehwa Medicine
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• v.29 no.1
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• pp.1-17
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• 2020

Objectives : The objectives of this study is to develop a mouse model similar to Taeeum-type by inducing Lung fibrosis with bleomycin, and to determine adequate concentration of bleomycin. Methods : The subjects were divided into six groups: normal, obesity induced group, and bleomycin administered 0.015U, 0.03U, 0.06U, and 0.09U(U/100g bw) concentrations respectively. Each concentration of bleomycin was dissolved in distilled water, and administered through Intra-Nazal-Trachea injection method. Food intake and body weight were measured at regular time weekly. At the end of the experiment, blood was gathered by cardiac puncture for biochemical examinations, organs were removed for histological examinations, and weigh and mRNA genes was analyzed. Result : Mice administered with bleomycin at 0.015U and 0.03U showed body and fat weight gain, and increased blood total cholesterol, LDL-cholesterol, glucose, and free fatty acid level. Fat related genes also showed higher level than the control group. Obesity was most strongly induced in the mice administered with 0.03U of bleomycin. On the other hand, when bleomycin was administered at concentrations above 0.06U, a model of obesity mouse was not created due to rapid emphysema inflammation and weakness. Conclusions : Mice were most vulnerable to obesity when bleomycin was administered at a concentration of 0.3 to cause liver damage. Bleomycin concentration over 0.06U did not cause obesity-induced mice, due to severe damage in liver.