• 제목/요약/키워드: In-vitro techniques

검색결과 347건 처리시간 0.03초

The Transport of Organic Cations in the Small Intestine: Current Knowledge and Emerging Concepts

  • Kim, Moon-Kyoung;Shim, Chang-Koo
    • Archives of Pharmacal Research
    • /
    • 제29권7호
    • /
    • pp.605-616
    • /
    • 2006
  • A wide variety of drugs and endogenous bioactive amines are organic cations (OCs). Approximately 40% of all conventional drugs on the market are OCs. Thus, the transport of xenobiotics or endogenous OCs in the body has been a subject of considerable interest, since the discovery and cloning of a family of OC transporters, referred to as organic cation transporter (OCTs), and a new subfamily of OCTs, OCTNs, leading to the functional characterization of these transporters in various systems including oocytes and some cell lines. Organic cation transporters are critical in drug absorption, targeting, and disposition of a drug. In this review, the recent advances in the characterization of organic cation transporters and their distribution in the small intestine are discussed. The results of the in vitro transport studies of various OCs in the small intestine using techniques such as isolated brush-border membrane vesicles, Ussing chamber systems and Caco-2 cells are discussed, and in vivo knock-out animal studies are summarized. Such information is essential for predicting pharmacokinetics and pharmacodynamics and in the design and development of new cationic drugs. An understanding of the mechanisms that control the intestinal transport of OCs will clearly aid achieving desirable clinical outcomes.

Methods for Determination of Amino Acids Bioavailability in Pigs - Review -

  • Zebrowska, T.;Buraczewski, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제11권5호
    • /
    • pp.620-633
    • /
    • 1998
  • Methods developed for measuring digestibility and availability of amino acids in feedstuffs used in pig nutrition are reviewed. Digestibility is a proportion of an amino acid in a feed that is absorbed from the digestive tract and should be determined from the difference between the amount of amino acid consumed and passing the distal ileum. Techniques for ileal digesta sampling including various types of cannulas: a re-entrant, T-piece, IPV, IPVC and ileaorectal anastomosis are described and comparisons amongst these methods are presented. Other methodologies like mobile bag technique, in vitro assays and mathematical prediction method are also described. Significance and methodologies for measurement of endogenous nitrogen and amino acids losses at the distal ileum and their effect on the apparent and true nitrogen and amino acid digestibilities in feeds are discussed. Factors influencing the apparent and true amino acid digestibilities such as dry matter intake, protein, fibre and antinutritive compounds content in the diet are discussed. Amino acid bioavailability -the proportion of the total amino acid digested and absorbed in a form utilized in metabolism - measured by the growth assay may differ from its ileal digestibility. Chemical methods for determination of available lysine content in heat treated feeds are evaluated.

마우스 핵이식란의 동결에 관한 연구 (Studies on cryopreservation of nuclear transplanted mouse embryos)

  • 이병천;조충호;황우석
    • 대한수의학회지
    • /
    • 제33권1호
    • /
    • pp.171-178
    • /
    • 1993
  • The present study was carried out to investigate the developmental potency to blastocyst after freezing and thawing of nuclear transplanted 2-cell embryos. The nuclei from 2-, 4- and 8-cell mouse embryos were transferred into enucleated 2-cell embryos, and the reconstituted embryos were submitted to direct current(DC) pulse at output voltage of 2.0 kV/cm for $100{\mu}$ sec to induce cell fusion. The recovery rate and developmental potency to blastocyst after freezing and thawing of nuclear transplanted 2-cell embryos was investigated. 1. The recovery rate of nuclear transplanted 2-cell embryos in normal morphology after freezing and thawing was significantly higher in rapid freezing(DMSO 4.5M) than in slow cooling(p<0.01). 2. When the recovered embryos in normal morphology were cultured in vitro, there were no significant differences in the developmental potency to blastocyst between the freezing methods and the concentrations of cryoprotectant. In summary, these experiments have proved that rapid freezing method(DMSO 4.5M) is effective in nuclear transplanted 2-cell mouse embryos. If improved micromanipulation techniques and freezing are combined, nuclear transplantation technique will contribute to the improvement of productivity in livestock animals.

  • PDF

In vitro and in vivo antidiarrhoeal activity of epigallocatechin 3-gallate: a major catechin isolated from indian green tea

  • Bandyopadhyay, Durba;Dutta, Pradeep Kumar;Dastidar, Sujata G;Chatterjee, Tapan Kumar
    • Advances in Traditional Medicine
    • /
    • 제8권2호
    • /
    • pp.171-177
    • /
    • 2008
  • Epigallocatechin 3-gallate (EGCG), one of the major catechins of tea, was isolated from the decaffeinated, crude methanolic extract of Indian green tea (Camellia sinensis L. O. Kuntze) using chromatographic techniques. EGCG was then screened for antidiarrhoeal activity against 30 strains (clinical isolates) of V. cholerae, which is a well known Gram negative bacillus functioning as the pathogen of cholera. V. cholerae strains like V. cholerae 69, 71, 83, 214, 978, 1021, 1315, 1347, 1348, 569B and ATCC 14033 were inhibited by EGCG at a concentration of $25\;{\mu}g/ml$ whereas V. cholerae 10, 522, 976 were even more sensitive, being inhibited at $10\;{\mu}g/ml$ level. However, V. cholerae DN 16, DN 26, 30, 42, 56, 58, 113, 117, 564, 593, 972 and ATCC 14035 were inhibited at $50\;{\mu}g/ml$ level of EGCG. Only four strains were inhibited at $100\;{\mu}g/ml$. In this study the isolated compound was found to be bacteriostatic in its mechanism of action. In the in vivo experiment using the rabbit ileal loop model two different dosages of EGCG ($500\;{\mu}g/ml$ and $1,000\;{\mu}g/ml$) were able to protect the animals when they were challenged with V. cholerae 569B in the ileum.

Porcine growth hormone induces the nuclear localization of porcine growth hormone receptor in vivo

  • Lan, Hainan;Liu, Huilin;Hong, Pan;Li, Ruonan;Zheng, Xin
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제31권4호
    • /
    • pp.499-504
    • /
    • 2018
  • Objective: Recent studies have challenged the traditional paradigm that growth hormone receptor (GHR) displays physiological functions only in the cell membrane. It has been demonstrated that GHR localizes to the cell nucleus and still exhibits important physiological roles. The phenomenon of nuclear localization of growth hormone (GH)-induced GHR has previously been described in vitro. However, until recently, whether GH could induce nuclear localization of GHR in vivo was unclear. Methods: In the present study, we used pig as an animal model, and porcine growth hormone (pGH) or saline was injected into the inferior vena cava. We subsequently observed the localization of porcine growth hormone receptor (pGHR) using multiple techniques, including, immunoprecipitation and Western-blotting, indirect immunofluorescence assay and electronmicroscopy. Results: The results showed that pGH could induce nuclear localization of pGHR. Taken together, the results of the present study provided the first demonstration that pGHR was translocated to cell nuclei under pGH stimulation in vivo. Conclusion: Nuclear localization of pGHR induced by the in vivo pGH treatment suggests new functions and/or novel roles of nuclear pGHR, which deserve further study.

Generation of Full-Length Infectious cDNA Clones of Middle East Respiratory Syndrome Coronavirus

  • Lee, Jeong Yoon;Bae, Sojung;Myoung, Jinjong
    • Journal of Microbiology and Biotechnology
    • /
    • 제29권6호
    • /
    • pp.999-1007
    • /
    • 2019
  • Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in Saudi Arabia in 2012 and related infection cases have been reported in over 20 countries. Roughly 10,000 human cases have so far been reported in total with fatality rates at up to 40%. The majority of cases have occurred in Saudi Arabia with mostly sporadic outbreaks outside the country except for the one in South Korea in 2015. The Korean MERS-CoV strain was isolated from the second Korean patient and its genome was fully sequenced and deposited. To develop virus-specific protective and therapeutic agents against the Korean isolate and to investigate molecular determinants of virus-host interactions, it is of paramount importance to generate its full-length cDNA. Here we report that two full-length cDNAs from a Korean patient-isolated MERS-CoV strain were generated by a combination of conventional cloning techniques and efficient Gibson assembly reactions. The full-length cDNAs were validated by restriction analysis and their sequence was verified by Sanger method. The resulting cDNA was efficiently transcribed in vitro and the T7 promoter-driven expression was robust. The resulting reverse genetic system will add to the published list of MERS-CoV cDNAs and facilitate the development of Korean isolate-specific antiviral measures.

Influence of Autophagy Induction after Hormone Treatment on Oocytes Maturation of Porcine

  • Kim, Sang Hwan;Yoon, Jong Taek
    • 한국수정란이식학회지
    • /
    • 제33권4호
    • /
    • pp.271-280
    • /
    • 2018
  • Here, we evaluated the mode of programmed cell death during porcine oocyte maturation by comparing the two major pathways associated with programmed cell death, apoptosis (type I), and autophagy (type II). We investigated the expression and localization of major genes involved in autophagy and apoptosis at mRNA and protein levels. Furthermore, the effect of hormonal stimulation on autophagy and apoptosis was analyzed. We found that the activity of autophagy-associated genes was increased in the cumulus-oocyte complexes (COCs) following follicle-stimulating hormone (FSH) treatment, while the addition of luteinizing hormone (LH) reversed this effect. The expression of proteins associated with autophagy was the highest in FSH-treated COCs. On the other hand, caspase-3 protein level was maximum in COCs cultured with LH. The treatment with rapamycin resulted in the effect similar to that observed with FSH treatment and increased autophagy activity. Thus, hormonal stimulation of pig oocytes resulted in distinct patterns of maturation. The high-quality oocytes majorly relied on the type II pathway (autophagy), while the type I pathway (apoptosis) was more prominent among poor-quality oocytes. Further investigation of this distinction may allow the development of techniques to produce high-quality oocytes in porcine in vitro fertilization.

Comparison of complication rates after transvaginal ultrasound-guided oocyte pick-up procedures with respect to ovarian response

  • Gungor, Nur Dokuzeylul;Gurbuz, Tugba;Onal, Murat
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제49권2호
    • /
    • pp.142-148
    • /
    • 2022
  • Objective: The aim of this study was to compare the complication rates of oocyte pick-up (OPU) procedures via transvaginal ultrasonography in patients with different levels of ovarian reserve. Methods: In total, 789 patients who underwent OPU procedures for in vitro fertilization (IVF) were included in the study. Results: Individuals with normal ovarian reserve had a 2.947-fold higher risk of complications in OPU procedures than individuals with low ovarian reserve, and individuals with high ovarian reserve had a 7.448-fold higher risk of complications than individuals with low ovarian reserve. In addition, a higher number of IVF trials was associated with an increased risk of complications. Conclusion: The results of this study show that OPU has a higher risk of complications, particularly severe pain, in patients with high ovarian reserve. It is thought that complications can be reduced by preferring mild stimulation in patients with high ovarian reserve. Collecting fewer oocytes is also associated with a lower risk of complications from OPU. Even if a patient's reserve is very good, fewer and higher-quality oocytes should be targeted with the use of the lowest possible dose of drugs.

소폐동맥 내피세포를 이용한 인조혈액접촉표면의 혈액 접합성 (Blood Compatibility of Artificial Blood-Contacting Surface Seeded with Cultured Bovine Endothelial Cells)

  • 김원곤;곽영태;유세영
    • Journal of Chest Surgery
    • /
    • 제26권2호
    • /
    • pp.80-85
    • /
    • 1993
  • Synthetic and biosynthetic vascular grafts of small diameter have long been considered to be prone to thrombosis, ultimately leading to the complete graft occlusion. Endothelial cell seeding onto synthetic blood-contacting surfaces has been suggested to be an ideal means to solve this problem. This study described a culture method of bovine endothelial cells and evaluated blood-compatibility and seeding efficiency of cultured endothelial cells. Bovine pulmonary artery endothelial cells were harvested enzymatically and grown to confluence on polystyrene culture flask surfaces using established techniques. The identification of endothelial cells was made through the demonstration of expression of factor VIII R:Ag by immunofluorescent technique. To quantitate the effect of improvement in blood-compatibility of viable endothelial cells, endothelial monolayers were exposed to blood containing $\^$111/In-oxine labeled platelets. Viable endothelial monolayers retained less labeled platelets than control surfaces. The Indium-labeled endothelial cells were seeded onto three different blood-contacting surfaces of Dacron vascular graft immobilized in specially equipped wells and incubated for specific time intervals (t=15, 30, 60, 120 minutes). Longer incubation times showed improved cell adherence in collagen-coated and fibrin-coated Dacron vascular graft groups. However in untreated Dacron grafts, no direct relationship was observed between incubation time and endothelial cell seeding efficiency. This may be due to leakage of endothelial cells through porosity of Dacron grafts in this in-vitro experimental condition.

  • PDF

Could Natural Products Confer Inhibition of SARS-CoV-2 Main Protease? In-silico Drug Discovery

  • Mohamed-Elamir F Hegazy
    • 한국자원식물학회:학술대회논문집
    • /
    • 한국자원식물학회 2020년도 추계국제학술대회
    • /
    • pp.14-14
    • /
    • 2020
  • In December 2019, the COVID-19 epidemic was discovered in Wuhan, China, and since has disseminated around the world impacting human health for millions. Herein, in-silico drug discovery approaches were utilized to identify potential candidates as Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro) inhibitors. We investigated several databases including natural and natural-like products (>100,000 molecules), DrugBank database (10,036 drugs), major metabolites isolated from daily used spices (32 molecules), and current clinical drug candidates for the treatment of COVID-19 (18 drugs). All tested compounds were prepared and screened using molecular docking techniques. Based on the calculated docking scores, the top ones from each project under investigation were selected and subjected to molecular dynamics (MD) simulations followed by molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations. Combined long MD simulations and MM-GBSA calculations revealed the potent compounds with prospective binding affinities against Mpro. Structural and energetic analyses over the simulated time demonstrated the high stabilities of the selected compounds. Our results showed that 4-bis([1,3]dioxolo)pyran-5-carboxamide derivatives (natural and natural-like products database), DB02388 and Cobicistat (DB09065) (DrugBank database), salvianolic acid A (spices secondary metabolites) and TMC-310911 (clinical-trial drugs database) exhibited high binding affinities with SARS-CoV-2 Mpro. In conclusion, these compounds are up-and-coming anti-COVID-19 drug candidates that warrant further detailed in vitro and in vivo experimental estimations.

  • PDF