검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 103

        61.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Brucellosis is a notorious zoonotic disease with global implications. Efforts to control the spread of the disease have been restricted to the agricultural livestock. Increasing incidences of accidental human infection have motivated researches to start working on alternative vaccines. At present, live attenuated vaccines are the only accepted type of vaccines used in developed countries for the prevention of brucellosis. Although serodiagnosis is occasionally unreliable, some countries have already claimed to have eradicated the disease, based on this testing. Live attenuated vaccines are not suitable for use in pregnant and immune-depressed animals. Moreover, these vaccines are not tolerated in humans. Therefore, many researches have been striving to discover alternative methods of vaccination. Most research has focused on the generation of subcellular, subunit, and DNA vaccines that are as efficient as the live attenuated vaccines. At present, none of the available vaccines has been able to replace the live attenuated vaccines. Therefore, additional research is necessary in order to discover a new brucellosis vaccine that is suitable for human use.
        4,000원
        62.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Brucellosis is an important bacterial zoonotic infection worldwide responsible for economic losses in livestock industries which represents a considerable and increasing public health burden. The disease is caused by Brucella which possess the ability to invade and replicate within phagocytes and may result to chronic infection, leading to difficulty in medical therapy of the disease. The treatment for brucellosis employs conventional principles that have been applied for a long time and a combination of antibiotics is currently used due to low efficacy of monotherapies. However, vital effects with respect to health and safety are neglected. Nevertheless, the preventive methods and treatments for brucellosis using traditional medicine have not yet been thoroughly studied, hence, alternative therapies such as the use of natural plant extracts as traditional medicine that are safe, efficient and economical should be explored in order to identify candidates that eliminate complications due to brucellosis. Coptis chinensis Franch (Huanglian) is a traditional Chinese medicinal herb and its extract has been known to possess strong antibacterial activity. In this study, the antibacterial effects of C. chinensis Franch extracts, and the major components of the herb namely berberine and palmatine, were investigated on B. abortus. The C. chinensis Franch ethanol extracts (CCFE) showed bactericidal effects at 1,000 μg/ml concentration and berberine at 100 μg/ml concentration. However, C. chinensis Franch and its components did not affect invasion and intracellular growth of B. abortus in RAW 264.7 cells. In conclusion, C. chinensis Franch ethanol extracts, water extract and its major components such as berberine and palmatine would be a beneficial antimicrobial agent without affecting phagocytic pathway within macrophages, and further study for the precise mechanisms of antibacterial effect would be necessary.
        4,000원
        63.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional and nonprofessional phagocytes and cause abortion in domestic animals and undulant fever in humans. Brucella species can survive in a variety of cells, including macrophages and their virulence and chronic infections are thought to be due to their ability to avoid the killing mechanisms within macrophages. Inhibition of phagosome-lysosome fusion has been proposed as a mechanism for intracellular survival of Brucella in professional and nonprofessional phagocytes. Toll-like receptors (TLRs) are part of a skillful system for detection of invasion by microbial pathogens. Recognition of microbial components by TLRs triggers signaling pathways that promote expression of genes and regulate innate immune responses. Recent studies for the interaction between TLRs-Brucella have indicated the importance of control of Brucella infection. Here, we review selected aspects of TLRs-Brucella interaction, which may be helpful to understanding the mechanism of Brucella pathogenesis.
        4,000원
        64.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fact that flip-flops, one of many different types of unstable shoes, are light and relatively easy to put on, accounts for their popularity among people. But because flip-flops rely heavily on the support of a single thong between your first and second toes, they impose a huge amount of pressure onto lower leg. Thus in the following experiment we tried to examine the different effects of flip-flops and running shoes in terms of their effect on muscle activity and fatigue of tibialis anterior and gastrocnemius during walking. In order to measure an electromyogram we used Free EMG system. 10 men and 10 women in running shoes ran on treadmills for 15 minutes at 4.8km/h, 2 days later the same experiment was carried out, but this time, in flip-flops. p value turned out to be greater than .05 and thus there was no considerable difference between the effects of flip-flops and running shoes on muscle activity and fatigue during walking. Therefore we conclude that despite the fact that flip-flops are considered unstable, their effects on muscle activity and fatigue of tibialis anterior and gastrocnemius are negligible.
        3,000원
        65.
        2013.06 구독 인증기관 무료, 개인회원 유료
        An efficient plant regeneration protocol is developed for a standard-type chrysanthemum. When petal segments derived from flower buds (4 or 8cm in diameter) were used as the culture material, the highest shoot regeneration frequency (96%) was obtained on a Murashige and Skoog (MS) medium supplemented with 0.5 mg/L IAA, 2 mg/L BA, 3% sucrose, and a 0.8% agar. Pre-culturing the explants under dark conditions for 14 days produced better results for the shoot regeneration frequency than the explants cultured under a continuous 16 h photoperiod (40 μmolm-2 s -1 ). The shoot regeneration frequency ranged from 19.0% for the Shinmato cultivar to 89.1% for the Baeksun cultivar. Activated charcoal (0.2%) enhanced the root formation of the regenerated shoots in a hormone-free MS medium. The rooted plantlets were acclimatized and successfully established in a greenhouse.
        4,000원
        66.
        2013.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to examine the influences of chronic shoulder pain on the muscle tone in trunk muscles. The study's subjects were 40 men and women in their 30 to 50s, which were divided into two groups. A chronic shoulder pain group consisted of 20 subjects who had been diagnosed with chronic shoulder pain by doctors, and a painless group consisted of 20 subjects who had experienced no such pain. An analysis was performed using electromyography on the muscle tone in the rectus abdominalis, external oblique, internal oblique, and erector spinae muscles under the same conditions between the two groups. The analysis results were as follows. The chronic shoulder pain group exhibited an overall high level of trunk muscle tone than the painless group, along with a statistically significant difference in the rectus abdominalis(p<.05). Moreover, the chronic shoulder pain group showed differences in the trunk muscle tone depending on the affected side. The chronic left shoulder pain group yielded higher levels of muscle tone in the right-side trunk muscles. In particular, the group revealed statistically significant differences in the rectus abdominalis and internal oblique(p<.05). The chronic right shoulder pain group exhibited higher levels of muscle tone in the left-side trunk muscles with a statistically significant difference in the internal oblique(p<.05). The above results suggested that chronic shoulder pain influences increases in the muscle tone in the trunk muscles on the opposite side to the affected shoulder.
        4,000원
        67.
        2013.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Brucellosis is an important bacterial zoonosis in humans and domestic animals. Brucella spp. are taken up, and survive within non-professional and professional phagocytes. In common belief, diabetes mellitus increases susceptibility to pathogenic infection. In this study, Brucella (B.) abortus was inoculated into a diabetic animal model, db/db mice, in order to show the course of brucellosis in diabetic state. The liver proliferation, bacterial burden of the liver, level of cytokines in serum and macrophage migration into liver, were investigated at 14 days post-infection. In comparison with the uninfected control mice, the results revealed that the weight of the liver of infected db/db mice was higher but with lower bacterial load in this organ. The level of MCP-1 mRNA expression in the liver was lower, the levels of IL-12p70, IL-10, TNF-α and IFN-γ in serum was significantly higher and the macrophages migration was significantly lower in infected mice than in the control group. In conclusion, this present study suggested that MCP-1 suppression by B. abortus infection may inhibit the macrophages migration, and consequently may induce to abrogate the bacterial survival in db/db mouse liver. Furthermore, the increased inflammatory cytokines may contribute to inhibition of B. abortus proliferation in diabetic mice.
        4,000원
        68.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the increase of chrysanthemum demand on chrysanthemum increases in Korea, the production of high quality chrysanthemum is needed. Chrysanthemum stunt viroid (CSVd) is one of the important viroid, which infects chrysanthemum and induces diseases that affects the decrease of quality and yield. To solve this problem, we used different size of meristem of chrysanthemum ‘Ency’ for shoot tip culture and also that of combined with heat treatment at 37οC. The efficiency of CSVd elimination was influenced by the size of shoot tip. The small-sized of meristems with 1 or 2 leaf primodia were regenerated into the highest number of CSVd-free plantlets. By RT-PCR, the 214-bp band corresponding to CSVd was not detected in 22.2% of the total number of tested regenerants from shoot tips with 2 leaf primordia. While, shoot tip culture combined with heat treatment of one-month-old in vitro shoots was not effective for CSVd-elimination. The CSVd-free plants grew more vigorously than CSVd-infected plants in the greenhouse.
        4,000원
        70.
        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
        76.
        2012.06 구독 인증기관·개인회원 무료
        The aim of this study was to examine the effect of acteoside (the cyclin-dependent kinase inhibitor) on the SCNT efficiency with adult fibroblasts in dog. Canine adult fibroblasts were obtained from muscle and cell cycle of fibroblasts was synchronized by culturing to confluency, serum starvation and treating with 30 μM acteoside for 48 h. Cell cycle stages, cell cytotoxicity (apoptosis) and, prduction of reactive oxygen species (ROS) were analyzed using flow cytometry. The canine cells, prepared by confluent-cell culture or treating with 30 μM acteoside for 48 h, were injected into enucleated in vivo matured oocytes, the couplets were electrical fused and activated by calcium ionomycin. SCNT embryos using acteoside-treated fibroblasts were surgically transferred into oviducts of estrus cycle synchronized recipient dogs. In cell cycle synchronization (G0/G1), there was no significant difference between serum starvations (83.9%) and acteoside treated groups (81.3%) that were higher than confluent group (78.5%). In production of apoptosis, confluent and acteoside treated groups (4.3 and 4.5%, respectively) were generated less than serum starvation group (21.8%). In case of ROS, serum starvation group was induced a significantly higher than other groups. After synchronization of the donor cell cycle, either confluent or acteoside treated, cells were placed with enucleated in vivo-matured dog oocytes, fused by electric stimulation, activated, and transferred into naturally estrus-synchronized surrogates. Fusion and cleavage rate of acteoside treated group were 64.1 and 41.5%, which were higher than those of confluent group (53.9 and 20.6%, respectively). The reconstructed embryo development rates to 4-cell and 8-cell in acteoside treated group were 29.5 and 14.8%, respectively, while confluent group showed 11.1 and 3.2%, respectively. Total 54 SCNT embryos using acteoside-treated fibroblasts were transferred into oviducts of 2 recipient dogs and one recipient finally delivered one puppy, whereas din`t detected pregnancy on transfer of cloned embryos reconstructed with confluent cells in 6 surrogate dogs. In conclusion, the results of the current study demonstrated that canine fibroblasts could be successfully arrested at the G0/G1 stage with reduced the formation of ROS and apoptosis after acteoside treatment. This results may contribute to improve the effi-ciency of canine SCNT. * This research was supported by iPET (Grants 110056-3), Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
        77.
        2012.06 구독 인증기관·개인회원 무료
        Acteoside acts as an anti-oxidative activity and anti-apoptosis in the cells. But, it has been not studied on maturation and development of porcine oocytes. The aims of the present study were to examine the effects of acteoside on the morphological progress of meiosis, developmental competence, and ROS in porcine oocytes. Oocytes were matured in tissue culture medium-199, supplemented with acteoside at various concentrations: 0 (control), 10, 30 and 50 μM. The oocytes maturation rates of groups supplemented with acteoside were no significantly different (81.13, 85.96, 82.95 and 83.68%, respectively). Level of ROS was significantly decreased in acteoside treated group. Furthermore, the parthenogenetic blastocyst rate was significantly improved in 10 μM acteoside treated group compared with control group (44.83 vs. 27.75%). And we investigated effect of acteoside on the oocytes condition represented by cytoplasmic maturation by homogeneous distribution and formation of cytoplasmic organelles and regulation of apoptosis-related genes. In the results. during IVM, 10 μM acteoside treated oocytes showed that the mitochondria and lipid droplet were smaller and homogeneous distribution in cytoplasm compare with control oocytes. And reverse transcription polymerase chain reaction (RTPCR) of parthenogenetic blstocysts revealed that acteoside increased the anti-apoptotic genes (Mcl-1, Bcl-2 and Bcl-xL), whereas reduced the expression of pro-apoptotic genes (Bax and Bak). In conclusion, based on the results, the effect of acteoside on IVM was not attractive. However, in acteoside treated group, cytoplasmic maturation seemed to be improved with morphologically uniform distribution of cytoplasmic organelles. Furthermore, embryonic development in acteoside treated group was significantly highly increased than that of non-treated group. Our results represents that addition of acteoside to the IVM medium has a beneficial effect in physiology of porcine oocytes, providing a improved method for porcine oocytes in vitro. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.
        78.
        2012.06 구독 인증기관·개인회원 무료
        The objective of the current study was to describe in vitro embryo production in Hanwoo, analyzing oocytes yield and embryo production. The effects of oocytes production and the number of OPU procedures per animal on embryo production were also evaluated. OPU was done every 3~4 days during experimental period and collected oocytes were fertilized in vitro in both OPU and needle puncture groups. First, we compared the recovery rate of oocytes based on OPU session (Experiment 1). The average of collected oocytes was calculated from every 10 session. The average number of total oocytes recovered per animalonsessionwas 5.16 (mean). Second, we compared the recovery rate base on collection period of OPU (Experiment 2). The following results show the difference of the number of recovered oocytes in every month during the procedure between the months of session. Every animal shows the constant number of recovered oocytes for the first 5 months. However, the recovery rate of oocytes was decreased from month 6 to 8. Third, we compared the developmental rate to blastocyst in two groups (Experiment 3). Oocytes by needle puncture were fertilized with frozen-thawing semen; the cleavage rate 24~48 h after in vitro fertilization (IVF) was 75.8% and blastocyst development rate was 18.8% in needle puncture group. Even though there is lower cleavage rate after IVF in OPU group (61.1%), blastocyst development rate was higher compared with needle puncture group (28.4%). In conclusion, Blastocyst developmental rate could be increased by OPU than classical method of needle puncture. Improvement of bio- technique in collecting oocytes could be applied to understand the reproductive physiology in cattle, expecially Hanwoo. Therefore, further investigation should be done to clarify the efficiency and advantage of OPU involved in reproduction in animals and human being.
        79.
        2011.10 구독 인증기관·개인회원 무료
        The objective of this study was to evaluate in vitro production of bovine embryos in Hanwoo. Oocytes were collected by ovum pick up (OPU) from ovaries of genetically high-value Hanwoo or by needle puncture from ovaries of slaughtered cattle. OPU was done every 3 4 days duing experimental period and collected oocytes were fertilized in vitro in both OPU and needle puncture groups. First, We compared the in vitro maturation rate in two groups (Experiment 1). 545 oocytes were recoverd from 4 females by 32 trials of OPU and then 433 oocytes were shown MⅡ stage after in vitro maturation (79.4%). In case of needle puncture group, 1905 oocytes were collected and then 1420 oocytes were matured to MⅡ stage during in vitro culture(74.5%). Second, we compared the developmental rate to blastocyst in two groups (Experiment 2). 1420 oocyte by needle puncture were fertilized with frozen-thawing semen; the cleavage rate 24 48 h after in vitro fertilization (IVF) was 88.6% and blastocyst development rate was 20.5% in needle puncture group. Even though there is lower cleavage rate after IVF in OPU group (84.8%), blastocyst development rate was higher compared with needle puncture group (26.4%). In conclusion, Blastocyst developmental rate could be increased by OPU than classical method of needle puncture. Improvement of bio-technique in collecting oocytes could be applied to understand the reproductive physiology in cattle, expecially Hanwoo. Therefore, further investigation should be done to clarify the efficiency and advantage of OPU involved in reproduction in animals and human being. This research was suppoted by Imsil-gun agricultural technology service center.
        80.
        2011.03 구독 인증기관 무료, 개인회원 유료
        Teeth develop via a reciprocal induction between the ectomesenchyme originating from the neural crest and the ectodermal epithelium. During complete formation of the tooth morphology and structure, many cells proliferate, differentiate, and can be replaced with other structures. Apoptosis is a type of genetically-controlled cell death and a biological process arising at the cellular level during development. To determine if apoptosis is an effective mechanism for eliminating cells during tooth development, this process was examined in the rat mandible including the developing molar teeth using the transferase-mediated dUTP-biotin nick labeling (TUNEL) method. The tooth germ of the mandibular first molar in the postnatal rat showed a variety of morphological appearances from the bell stage to the crown stage. Strong TUNEL-positive reactivity was observed in the ameloblasts and cells of the stellate reticulum. Odontoblasts near the prospective cusp area also showed a TUNEL positive reaction and several cells in the dental papilla, which are the forming pulp, were also stained intensively in this assay. Our results thus show that apoptosis may take place not only in epithelial-derived dental organs but also in the mesenchyme-derived dental papilla. Hence, apoptosis may be an essential biological process in tooth development.
        4,000원
        1 2 3 4 5