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        검색결과 481

        241.
        2013.10 구독 인증기관·개인회원 무료
        The genus Diadegma is a well known parasitoid group and some are known to have symbiotic virus, PDV. A novel IV was discovered from the calyx of D. fenestrale female. D. fenestrale has more than two hosts, including PTM and DBM. The oviposition and survival rate results showed that D. fenestrale preferred PTM to DBM as hosts. Nevertheless, the developmental period and morphology of D. fenestrale were not significantly different between PTM and DBM. To identify these phenomena, DfIV genome expression patterens were compared between PTM and DBM under various conditions. DfIV genes were more widely expressed in PTM than in DBM after parasitized by D. fenestrale, particularly at the initial point. In addition, large numbers of DfIV genes were expressed only in PTM and they showed differential expression patterns between two lepidopteran hosts. This DfIV genome expression plasticity showed a dependency on the lepidopteran host species and parasitization time, suggesting that it may contribute to the parasitoid survival rate increase. This may be one of the key elements that determine the symbiotic relationship between PDV and parasitoid.
        242.
        2013.06 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to examine the effects of high concentrations of glucose on porcine parthenotes developing in vitro. Addition of 55 mM glucose to the culture medium of embryos at the four-cell-stage significantly inhibited blastocyst formation, resulting in fewer cells in blastocyst-stage embryos and increased levels of apoptosis and autophagy compared to control. Quantitative reverse transcriptase (RT) PCR analysis revealed that the expression of pro-apoptotic genes (Caspase 3, Bax and Bak) and autophagy genes (Atg6 and Atg8/Lc3) were increased significantly by the addition of 55 mM glucose to the culture medium compared to control. MitoTracker Green fluorescence revealed a decrease in the overall mitochondrial mass compared to control. However, the addition of 55 mM glucose had no effect on mRNA expression of the nuclear DNA-encoded mitochondrial-related genes, cytochrome oxidase (Cox) 5a, Cox5b and Cox6b1. These results suggest that hyperglycemia reduced the mitochondrial content of porcine embryos developing in vitro and that this may hinder embryonic development to the blastocyst stage and embryo quality by increasing apoptosis and autophagy in these embryos.
        4,000원
        243.
        2012.12 구독 인증기관 무료, 개인회원 유료
        Fraxinus rhynchophylla (Oleaceae), a deciduous tree, is known to have properties that include anti-inflammatory, convergence, febricide, antiblenophthalmia, antidiarrhea, antileukorrhea, and so forth. In addition, it has been used for traditional herbal medicine in East Asian countries, including Korea. In this study, we investigated the antioxidant and anti-inflammatory effects of Fraxinus rhynchophylla ethanol extract (FRE) in lipopolysaccharide (LPS)-induced murine macrophage Raw 264.7 cells with FRE pretreatment. We performed DPPH-assay, Western blot, and Reverse Transcription-Polymerase Chain Reaction (RT-PCR). FRE showed 85% free radical scavenging activity at concentrations of 80 µg/ml. Results of this study also showed that FRE down-regulates Cox-2 and iNOS expression in mRNA and protein level. In conclusion, crude ethanol extract of Fraxinus rhynchophylla exhibited antioxidant and anti-inflammatory activities, and it may potentially provide a valuable source of natural herbal agent to inhibit inflammation.
        4,000원
        244.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Salmonellosis is a widespread bacterial zoonosis that commonly causes enterocolitis and foodborne poisoning leading to an extensive economic loss in domestic animal industry. Considerably, the emergence of multidrug resistant strains of Salmonella spp. induces further severe problems affecting public health. The present report was designated to investigate the antibacterial efficacies of three common disinfectants including an oxidizing compound disinfectant (OXC), a triple salt (TS) and a quaternary ammonium compound (QAC) against Salmonella typhimurium subjected to the preliminary changes of drug temperature. All solutions of three disinfectants were pre-incubated at different temperature (22, 37 and 63°C) for 1 h prior to exposure to bacteria. The disinfectants and bacteria were diluted with distilled water (DW), hard water (HW) or organic matter suspension (OMS) according to treatment condition. Under the DW condition, the disinfectant efficacy of the QAC at 63°C was higher than that of 22°C. Furthermore, under HW diluent the disinfectant efficacy of the TS pre-warmed at both of 37 and 63°C were increased compared to that of 22°C. Considerably, the efficacy of pre-warmed QAC at both of 37 and 63°C under the OMS diluent were higher than that of 22°C. Conclusively, prewarming at higher temperatures have positive effects on the stability of the antibacterial efficacies of TS and QAC.
        4,000원
        251.
        2012.10 구독 인증기관·개인회원 무료
        Lepidopteran pests monitoring in adult stage was generally performed using delta or corn typed trap including rubber septa impregnated sex pheromone (lure). Sometimes, unfortunately trapped samples were severly damaged because of biotic and/or abiotic environments such as micro-organism, predator and rain, sticky material, respectively. In our case, we monitored potato tuber moth, PTM, Phthorimaea operculella distribution during 2009~2012 in Korea. However, we encountered unexpected problem, another species can be trapped in species specific sex pheromone trap. Therefore, species confirmation was needed in trapped samples. Here we developed confirmation method by direct PCR (without DNA extraction) or sequencing methods which trapped samples that cannot identified by morphologically. We designed multi-plex PCR universal primers and species specific primers in rRNA region because to check the success of PCR and species identification. This direct PCR method can be applied in other species confirmation which monitored using pheromone trap.
        252.
        2012.10 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii (Glover) (Hemiptera:Aphididae), is a highly polyphagous pest that directly or indirectly damages cultivated plants. Six field-collected populations of cotton aphid, A. gossypii (BY-A, BY-B, YJ-A, YJ-B, CJ-A, and CJ-B) were tested for susceptibility to 14 different insecticides. Most population exhibited high to very high levels of resistance to neonicotinoid. Among them, a strain showing resistance to imidacloprid were selected and showed 1,543-fold in resistance as compared with susceptible strain. Piperonyl butoxide (PBO), diethyl maleate (DEM), and S,S,S tributyl-phosphorothiolate (DEF) failed to synergize imidacloprid in this resistant population. In addition, the activity of detoxification enzymes (P450, EST, GST) were no differences between susceptibility and imidalcoprid resistance strain. However, by analyzing the nicotinic acetylcholine receptor β1 subunit loop D, R81T point mutation was detected in BY-A, BY-B, YJ-A, and YJ-B strain.
        253.
        2012.10 구독 인증기관·개인회원 무료
        The green peach aphid, Myzus persicae (Sulzer), is one of the most serious pests in cabbage cultivation. Field survey was carried out to know the insecticide resistance levels and to develop the applicable insecticide resistant markers in five main cabbage cultivation regions (Pyeong-chang, Hong-cheon, Bong-wha, Mu-ju and Je-ju) during 2009 to 2011. M. persicae can resist a wide range of insecticides in five surveyed local populations. Therefore multi resistant (MR) strain was selected from these five local populations and esterase over-expression, modified AChE (MACE) and mutation(s) in para-type sodium channel were analyzed using native IEF and quantitative sequencing with five local populations. Esterase over-expression and MACE (StoF mutation) were observed in all populations including MR strain. LtoF mutation is well known as a kdr mutation in para-type sodium channel. However, even though LC50 values of MR strain noted over 2,000 times higher than that of susceptible strain against bifenthrin, LtoF mutation was not detected in para type sodium channel and also local populations. We found another mutation (MtoL) in para and that mutation highly correlated between mutation ratio and bioassay data. For preliminary resistance monitoring, we developed quantitative sequencing (QS) to detect the frequencies of point mutation as a population genotyping. These methods can apply to manage M. persicae resistant populations in field.
        254.
        2012.10 구독 인증기관·개인회원 무료
        Agroecosystem is a concurrence of highly complicated interaction such as crop and pest. An agroecosystem can be viewed as a subset of a conventional ecosystem, for example, to identify the pest distribution or seasonal population fluctuations etc. These are really important investigation to set the IPM strategy. With these study, now we focused on sophisticated interaction between pest and their parasite in genome and transcriptome level. We studied these interesting interaction between diamondback moth Plutella xylostella which major pests in cabbage and Diadegma fenestrale as a model endoparasitic wasp. Actually, D. fenestrale was NOT alone because it has symbiotic virus, D. fenestrale Ichnovirus (DfIV). We will deeply discussed these interaction between P. xylostella and D. fenestrale with DfIV.
        255.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A drug delivery system (DDS) was prepared with a temperature and pH-responsive hydrogel. Poly(vinyl alcohol) (PVA)/poly(acrylic acid) (PAAc)/poly(N-isopropylacrylamide) (PNIPAAm)/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by radical polymerization for the temperature and pH-responsive hydrogels. MWCNTs were employed to improve both the thermal conductivity and mechanical properties of the PVA/PAAc/PNIPAAm/MWCNT nanocomposite hydrogels. Various amounts of MWCNTs (0, 0.5, 1 and 3 wt%) were added to the nanocomposite hydrogels. PVA/PAAc/PNIPAAm/MWCNT nanocomposite hydrogels were characterized with a scanning electron microscope. The mechanical properties were measured with a universal testing machine. Swelling and releasing properties of nanocomposite hydrogels were investigated at various temperatures and pHs. Temperature and pH-responsive release behavior was found to be dependent on the content of MWCNTs in nanocomposite hydrogels.
        4,000원
        256.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to examine the effect of dietary n-3/n-6 fatty acid (FA) ratio on in vitro dry matter digestibility (IVDMD), fermentation indices and FA profile. Rice bran was mixed with oil sources (cotton seed oil and linseed oil) to make the diets at 0.02, 0.29 and 0.61 of dietary n-3/n-6 FA ratio. These diets (0.5g) were placed into the incubation bottles with 40 ml of anaerobic culture medium, which contained rumen fluid and Van Soest medium at 1:2 ratio. Five replicates of each diet and two blanks were incubated at 39℃ for 48 hours. After incubation, the incubated contents were centrifuged. The residues were freeze-dried for DMD and FA analyses. The supernatant was used for pH, NH3-N and volatile fatty acid analyses. The concentrations of lactate (p<0.001) and iso-valerate (p<0.001) decreased linearly with increasing dietary n-3/n-6 FA ratio, but acetate concentration (p=0.056) and the ratio of acetate to propionate (p=0.005) was increased linearly. The concentrations of n-3, n-6 FA and the ratio of n-3/n-6 FA in residues increased (p<0.001) linearly with increasing dietary n-3/n-6 FA ratio, but C18:1n-9 FA concentration was decreased (p<0.001) linearly. With these results, it could affect fermentation characteristics and FA profile of rumen content by dietary n-3/n-6 FA ratio.
        4,000원
        257.
        2012.06 구독 인증기관 무료, 개인회원 유료
        Tooth development involves bud, cap, bell and hard tissue formation stages, each of which is tightly controlled by regulatory molecules. The aim of this study was to identify genes that are differentially expressed during dental hard tissue differentiation. Sprague-Dawley rats at postnatal days 3, 6 and 9 were used in the analysis. Differential display RT-PCR (DD-PCR) was used to screen differentially expressed genes between the 2nd (root formation stage, during mineralization) and 3rd (cap stage, before minerali-zation) molar germs at postnatal day 9. The DNA detected in the 2nd molar germs showed homology to osteonectin only (GenBank accession no. NM_012656.1). The level of osteonectin mRNA expression was much higher in the 2nd molar germs than in the 3rd molar germs and was found to increase in a time-dependent manner from the early bell stage to the root formation stage in the 2nd molar germs. The pattern of osteonectin protein expression was consistent with these RT-PCR results. Osteonectin protein was found by immunofluorescent analysis to localize in odontoblasts and preodontoblasts rather than the dentin matrix itself. Further studies are needed to validate the involvement of osteonectin in mineralization and root formation.
        4,000원
        258.
        2012.06 구독 인증기관·개인회원 무료
        The objective of this study was to investigate the effects of NEAA and leptin supplemented to in vitro culture medium on the developmental competence of porcine embryos after intracytoplasmic sperm injection (ICSI), and to modify the culture condition to improve the quality and the development of ICSI-derived porcine embryos in vitro. After ICSI, the putative zygotes were then cultured in PZM-3 medium with/without NEAA or leptin. The proportion of embryos that developed to the blastocyst stage significantly increased when 1% NEAA (24.62%) was added to the medium compared with 2% NEAA and no NEAA group (17.24% and 20.24%, respectively, p<0.05). The effect of different concentration of leptin (0, 10, 100, 500 ng/ml) was evaluated on the development of porcine ICSI embryos cultured in vitro. In case of blastocyst formation, 100 ng/ml group (27.05%) showed significantly higher rate than 10, 500 ng/ml, and control group (23.45%, 17.99%, and 19.68%, respectively, p<0.05). We also evaluated the effects of different NEAA and leptin treatment time on the development of porcine embryos after ICSI. Among groups of embryos cultured in the presence of NEAA or leptin for whole 7 days (D 1-7), first 4 days (D 1-4), the subsequent 3 days (D 5-7), both NEAA (27.13%, 21.17 %, and 17.56%, respectively, p<0.05) and leptin (25.60%, 20.61%, and 16.53%, respectively, p<0.05) showed that supplementation for whole 7 days significantly increased the blastocyst formation rate compared with the other groups of D1-4 and D5-7. We further evaluated the combination effect of 1% NEAA and 100 ng/ml leptin compared with the effect of each supplementation with 1% NEAA or 100 ng/ml leptin or no supplementation on development of embryos. For blastocyst formation, combination group of NEAA and leptin (24.78%) showed significantly higher rate than other three groups (18.37%, 20.44 %, and 13.27%, respectively, p<0.05). We further evaluated the expression of proapoptosis genes such as BAX and BAK and anti-apoptosis genes, BCL-XL and BCL-2 in blastocysts cultured in the presence of 100 ng/ml leptin. RT-PCR analysis revealed that leptin supplementation significantly decreased the expression of pro-apoptosis genes as well as increased the expression of anti-apoptosis genes. These results of present study demonstrate that NEAA and leptin could improve the in vitro development of ICSI- derived porcine embryos with optimal concentration of each reagent. Furthermore, the optimal culture condition could increase the quality of ICSI-derived embryos in vitro.
        259.
        2012.06 구독 인증기관·개인회원 무료
        It is well established that mitochondrial genome is strictly maternally inherited in mammalian, despite the fact that paternal mitochondria enter into oocyte during fertilization. To date, although some mechanisms have been extrapolated to interpret the elimination of paternal mitochondria, the exact mechanism still is unclear. Recent studies suggest that autophagy process and the ubiquitin-mediated degradation pathway may be involved in elimination of paternal mitochondria. However, the dynamic profiles of autophagy and ubiquitination associated with paternal mitochondria degradation have not been determined in mouse model. Through immunostaining with specific antibody LC3 and Ubiquitin and confocal microscopy, we investigated the dynamic profiles of LC3 and Ubiquitin signals in mouse embryos during preimplantation development. In addition, embryos were stained with MitoTracker Red for tracking the degradation process of paternal mitochondria. Our results showed that paternal mitochondria gradually degraded during postfertilization development, and sporadic paternal mitochondria were found at least in 16 cell embryos. LC3 and Ubiquitin signals appeared in the midpiece of sperm at 3 h postfertilization, and they were strictly colocalizated with paternal mitochondria from zygote to 2 cell embryo. Nevertheless, the colocalization became loose at 4 cell embryos, and gradually disappeared beyond 4 cell embryos. Our results confirmed that autophagy process and the ubiquitin-mediated degradation pathway may take part in the postfertilization remove of paternal mitochondria.
        260.
        2012.06 구독 인증기관·개인회원 무료
        Superovulation, or ovarian stimulation is a commonly used ART for treatment of human infertility/subfertility. Recent studies suggest that superovulation unaffects methylated imprints acquisition in mouse oocytes during oogenesis, whereas disrupts DNA methylation maintenance in embryos during preimplantation development. However, the mechanisms of defects in methylation maintanence caused by superovulation remain largely unclear. We hypothesized that superovulation may disrupt the expression of DNA methyltransferases (Dnmts), the enzymes which catalyze DNA methylation acquisition and maintenance. The mice were subjected to superovulate with low (6 IU) and high (10 IU) dosage hormone. We examined the global DNA methylation levels in zygotes and DNA methylation of repeated sequences (IAP and Line 1) in blastocyst stage embryos. In addition, we investigated the expression of Dnmts (Dnmt3a, Dnmt3b, Dnmt3l and Dnmt1o) in ovulated oocytes and zygotes. Through staining with antibody 5mC and Di-H3K9 coupled with confocal microscopy, we found that global methylation profiles in zygotes derived from females after low or high dosage hormone treatment were not affected when compared to control counterpart. Moreover, methylation at IAP in blastocysts also was unaffected by superovulation, irrespective of hormone dosage. In contrast, methylation level at Line 1 decreased when the females were administered by high dosage hormone. Furthermore, expression of de novo DNA methyltransferase Dnmt3a, Dnmt3b, Dnmt3L, as well as maintenance Dnmt1o in MII oocytes and zygotes was not disrupted by superovulation. Given superovulation adversely affected methylation maintenance in blastocysts during preimplantation development but with normal expression of Dnmts in oocytes and zygotes, it is indicated that defects of embryonic methylation didn’t originate from abnormal expression of Dnmts.