• Title/Summary/Keyword: in vitro techniques

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Multi-resistance strategy for viral diseases and in vitro short hairpin RNA verification method in pigs

  • Oh, Jong-nam;Choi, Kwang-hwan;Lee, Chang-kyu
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.4
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    • pp.489-498
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    • 2018
  • Objective: Foot and mouth disease (FMD) and porcine reproductive and respiratory syndrome (PRRS) are major diseases that interrupt porcine production. Because they are viral diseases, vaccinations are of only limited effectiveness in preventing outbreaks. To establish an alternative multi-resistant strategy against FMD virus (FMDV) and PRRS virus (PRRSV), the present study introduced two genetic modification techniques to porcine cells. Methods: First, cluster of differentiation 163 (CD163), the PRRSV viral receptor, was edited with the clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 technique. The CD163 gene sequences of edited cells and control cells differed. Second, short hairpin RNA (shRNAs) were integrated into the cells. The shRNAs, targeting the 3D gene of FMDV and the open reading frame 7 (ORF7) gene of PRRSV, were transferred into fibroblasts. We also developed an in vitro shRNA verification method with a target gene expression vector. Results: shRNA activity was confirmed in vitro with vectors that expressed the 3D and ORF7 genes in the cells. Cells containing shRNAs showed lower transcript levels than cells with only the expression vectors. The shRNAs were integrated into CD163-edited cells to combine the two techniques, and the viral genes were suppressed in these cells. Conclusion: We established a multi-resistant strategy against viral diseases and an in vitro shRNA verification method.

In vitro Selection of the 2'-Fluoro-2'-Deoxyribonucleotide Decoy RNA Inhibitor of Myasthenic Autoantibodies

  • Seo, Hwa-Seon;Lee, Seong-Wook
    • Journal of Microbiology and Biotechnology
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    • v.10 no.5
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    • pp.707-713
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    • 2000
  • Myasthenia gravis (MG) is caused mainly by autoantibodies directed against acetylcholine receptors located in the postsynaptic muscle cell membrane. Using in vitro selection techniques, we isolated an RNA containing 2'-fluoro pyrimidines that can specifically and avidly ($K_d$ ~25 nM) bind rat monoclonal antibody called mAb198, which recognizes the main immunogenic region on the acetylcholine receptors. This RNA can act as a very effective decoy and block mAb198 binding to the receptors in vitro. Furthermore, this RNA decoy can prevent the antigenic modulation of the acetylcholine receptor caused by mAb198 in human muscle cell cultures with and $IC_{50} $of approximately $2.4{\mu}M$. These results indicate that the RNA selected in this study is a more potent decly inhibitor of myashthenic antibodies than the previously identified RNA with 2'-amino pyrimidines [11]. Moreover, this RNA cross-reacts with autoantibodies from patients with MG and can protect human cells from the effects of these antibodies. These observations have important implications for developing an antigen-specific treatment of autoimmune diseases including MG, which is based on decoy RNAs selected in vitro.

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Effects of Sperm Activators on Sperm Penetration of Hanwoo Oocytes Following In Vitro-Inseminationi II. Effects of Sperm Activators on Sperm Penetration, In Vitro Development and Offspring Production in Hanwoo Oocytes (정자활성물질의 첨가가 한우난자의 체외수정율에 미치는 영향 II. 정자침입, 체외발육율 및 산자생산에 미치는 영향)

  • 이병천;김정태;김계성;황우석
    • Journal of Embryo Transfer
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    • v.15 no.1
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    • pp.95-102
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    • 2000
  • Techniques for manipulation of spermatozoa and oocytes have been widely used for in vitro production(IVP) of Hanwoo. This study was conducted to examine the effects of theophylline and heparin on frozen-thawed Hanwoo sperm for enhancing the efficiency of IVP technique. Oocytes were inseminated with forzen bull semen treated with either theophylline or heparin for examining the effect of each substance on fertilization and subsequent development. More (P<0.05) oocytes formed pronucleus and develop to the morula and blastocyst stages after inseminated with sperm treated with heparin than after inseminated with sperm treated with theophylline. The pregnancy rate after embryo transfer was higher after heparin treatment than after theophylline treatment, but did not differ significantly. There was no significant difference of offspring delivery between two groups. In conculsion, theophylline and heparin can be used for enhancing the efficiency of IVP system for Hanwoo. Considering characteristics of these substance, theophylline may be useful in the artificial insemination system, which requires vigorous sperm motility. While, heparin supporting sperm viability in vitro can be effectively used for improving in vitro-fertilization system.

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Cloning and Gene Targeting in Domestic Species

  • Piedrahita, Jorge A.
    • Proceedings of the KSAR Conference
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    • 2001.10a
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    • pp.48-49
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    • 2001
  • While transgenic manipulation in mice have been very successful the same is not true for cattle and pigs. The inability to isolate ES cells from the bovine and porcine has precluded the utilization of the gene targeting technology in these species. Fortunately new advances in cloning by nuclear transfer have opened up a unique opportunity to undertake precise genetic modification in cattle and pigs. The ability of a number of different laboratory groups to successfully clone cattle is due to numerous research programs focused on nuclear transfer in cattle, and the enormous base of knowledge developed over the last 20 years involving the application of assisted reproductive techniques in cattle. Successful and repeatable procedures for in vitro oocyte maturation, in vitro fertilization, and in vitro embryo culture are now well established for cattle. In our laboratory we have utilized nuclear transfer to reproduce the genotypes of several animals, selected for cloning based on their inherent genetic value. Results that we have obtained to date are similar to those reported by other laboratories. (omitted)

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Technical Trends of In Vitro Exposure System (전자파 세포노출장치 기술 동향)

  • Lee, Y.S.;Jeon, S.B.;Choi, H.D.
    • Electronics and Telecommunications Trends
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    • v.37 no.3
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    • pp.33-40
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    • 2022
  • Communication technologies are evolving to meet the ever-increasing demand for fast transmission speeds and large capacity. However, the introduction of new mobile networks, such as 5G, should be accompanied by changes in corresponding frequency and modulation techniques to enable the commercialization of its services. Hence, investigating the human health effects of electromagnetic exposures used in these new communication systems is crucial. Since in vitro electromagnetic experiments can provide essential information on important mechanisms of exposure effects, this article presents in vitro exposure systems necessary for reliable experiments. Moreover, the fundamental requirements for system implementation and the features of various systems are discussed.

Improvement of Nutritive Value and In vitro Ruminal Fermentation of Leucaena Silage by Molasses and Urea Supplementation

  • Phesatcha, K.;Wanapat, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.8
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    • pp.1136-1144
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    • 2016
  • Leucaena silage was supplemented with different levels of molasses and urea to study its nutritive value and in vitro rumen fermentation efficiency. The ensiling study was randomly assigned according to a $3{\times}3$ factorial arrangement in which the first factor was molasses (M) supplement at 0%, 1%, and 2% of crop dry matter (DM) and the second was urea (U) supplement as 0%, 0.5%, and 1% of the crop DM, respectively. After 28 days of ensiling, the silage samples were collected and analyzed for chemical composition. All the nine Leucaena silages were kept for study of rumen fermentation efficiency using in vitro gas production techniques. The present result shows that supplementation of U or M did not affect DM, organic matter, neutral detergent fiber, and acid detergent fiber content in the silage. However, increasing level of U supplementation increased crude protein content while M level did not show any effect. Moreover, the combination of U and M supplement decreased the content of mimosine concentration especially with M2U1 (molasses 2% and urea 1%) silage. The result of the in vitro study shows that gas production kinetics, cumulation gas at 96 h and in vitro true digestibility increased with the increasing level of U and M supplementation especially in the combination treatments. Supplementation of M and U resulted in increasing propionic acid and total volatile fatty acid whereas, acetic acid, butyric acid concentrations and methane production were not changed. In addition, increasing U level supplementation increased $NH_3$-N concentration. Result from real-time polymerase chain reaction revealed a significant effect on total bacteria, whereas F. succinogenes and R. flavefaciens population while R. albus was not affected by the M and U supplementation. Based on this study, it could be concluded that M and urea U supplementation could improve the nutritive value of Leucaena silage and enhance in vitro rumen fermentation efficiency. This study also suggested that the combination use of M and U supplementation level was at 2% and 1%, respectively.

Tendency and Problems in Porcine in-vitro Fertilization (돼지체외수정의 연구동향과 문제점)

  • 박춘근;정희태;양부근;김정익
    • Korean Journal of Animal Reproduction
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    • v.20 no.4
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    • pp.413-421
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    • 1997
  • In vitro culture has provided new information on the mechanisms involved in fertilization how sperm and oocyte fuse together. At the same time, results obtained in vitro have led to new questions. Techniques for In vitro maturation of porcine oocytes have progressed such that the problem of the low rate of pronucleus formation with in vitro matured oocytes after in vitro fertilization has been nearly improved. On the other hand, porcine spermatozoa have been shown to be capacitated if the fertilization medium contains caffeine and Ca$^2+$, but the incidence of polyspermy in IVM-IVF oocytes is still high. To prevent polyspermy, co-culture with oviductal cells, sperm preincubation with porcine follicular fluid or control of sperm concentration, have been examined with significant effects but still remarkably high rates of polyspermy. The under standing of these influences is a prerequisite to enhancing in vitro production of porcine em bryos.

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A review on three dimensional scaffolds for tumor engineering

  • Ceylan, Seda;Bolgen, Nimet
    • Biomaterials and Biomechanics in Bioengineering
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    • v.3 no.3
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    • pp.141-155
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    • 2016
  • Two-dimensional (2D) cell culture and in vivo cancer model systems have been used to understand cancer biology and develop drug delivery systems for cancer therapy. Although cell culture and in vivo model studies have provided critical contribution about disease mechanism, these models present important problems. 2D tissue culture models lack of three dimensional (3D) structure, while animal models are expensive, time consuming, and inadequate to reflect human tumor biology. Up to the present, scaffolds and 3D matrices have been used for many different clinical applications in regenerative medicine such as heart valves, corneal implants and artificial cartilage. While tissue engineering has focused on clinical applications in regenerative medicine, scaffolds can be used in in vitro tumor models to better understand tumor relapse and metastasis. Because 3D in vitro models can partially mimic the tumor microenvironment as follows. This review focuses on different scaffold production techniques and polymer types for tumor model applications in cancer tissue engineering and reports recent studies about in vitro 3D polymeric tumor models including breast, ewing sarcoma, pancreas, oral, prostate and brain cancers.

Protein Nutritional Quality of Precooked Seafood as Predicted by the C-PER Assay (C-PER방법(方法)을 이용(利用)한 수산단백질(水産蛋白質) 품질(品質)의 예측(豫測))

  • Ryu, Hong-Soo;Lee, Kang-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.1
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    • pp.13-22
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    • 1985
  • A study was undertaken to evaluate the nutritional quallity of protein from precooked seafoods. Procedures for evaluation included protein efficiency ratio(PER) using the rat, computed PER(C-PER) and discriminant computed PER(DC-PER) techniques. These procedures involve the determination of in vitro digestibility and amino acid composition of the sample prior to computation of C-PER and CD-PER value in laver was higher. For the oyster, the C-PER value was very close to the PER value obtained from the rat assay. The difference between DC-PER value and rat-PER or NPR was slightly lower than that between C-PER and rat-PER except oyster and laver. Seafood samples which posses a high in vitro protein digestibility may need the DC-PER procedure could offer more advantages in predicting the protein quality of seafood samples than the DC-PER procedure which showed poor in vitro digestibility.

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In Vitro Studies on the Release of Intracelluar Prolactin from Lymphocytes Using Strees Related Amines and Hormones

  • Sharma, G.T.;Majumdar, A.C.;Gupta, L.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.7
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    • pp.1031-1034
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    • 1999
  • Circulating lymphocytes collected from control and heat-stressed buffaloes were subjected to in vitro culture with glucocorticoids, epinephrine or serotonin and their effect, if any, on the release of intracellular prolactin (PRL) was studied using ELISA and C-ELISA techniques. It was noted from the study that PRL level was higher in lymphocytes than in plasma of the control and heat-stressed animals, and that the PRL levels increased in the plasma of heat-stressed animals compared to that of non stressed animals with a significant decrease in lymphocytic PRL content by heat stress. Epinephrine and serotonin significantly increased the release of intracellular PRL from the lymphocytes of both in the control and the heat-stressed buffaloes but release of PRL from lymphocyte was not significantly changed by cortisol treatment in both control and heat-stressed buffaloes as compared to epinephrine and serotonin in vitro. When lympocytes were incubated with serotonin, it caused drastic lysis of the lymphocytes but epinephirine and cortisol did not show any lysis. It may be concluded from this study that hormones like epinephrine or serotonin known to increase during stress, release intracellular PRL from lymphocytes, the satellite PRL storage/synthesizing organ of blood, although the mechanism of the release is different.