• Title/Summary/Keyword: cell-based assay

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Statistical Optimization of the Lysis Agents for Gram-negative Bacterial Cells in a Microfluidic Device

  • Kim, Young-Bum;Park, Ji-Ho;Chang, Woo-Jin;Koo, Yoon-Mo;Kim, Eun-Ki;Kim, Jin-Hwan
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.4
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    • pp.288-292
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    • 2006
  • Through statistically designed experiments, lysis agents were optimized to effectively disrupt bacterial cells in a microfluidic device. Most surfactants caused the efficient lysis of Gram-positive microbes, but not of Gram-negative bacteria. A Plackett-Burman design was used to select the components that increase the efficiency of the lysis of the Gram-negative bacteria Escherichia coli. Using this experimental design, both lysozyme and benzalkonium chloride were shown to significantly increase the cell lysis efficiency, and ATP was extracted in proportion to the lysis efficiency. Benzalkonium chloride affected the cell membrane physically, while lysozyme destroyed the cell wall, and the amount of ATP extracted increased through the synergistic interaction of these two components. The two-factor response-surface design method was used to determine the optimum concentrations of lysozyme and benzalkonium chloride, which were found to be 202 and 99 ppm, respectively. The lysis effect was further verified by microscopic observations in the microchannels. These results indicate that Gram-negative cells can be lysed efficiently in a microfluidic device, thereby allowing the rapid detection of bacterial cells using a bioluminescence-based assay of the released ATP.

Sexing of Sheep Embryos Produced In vitro by Polymerase Chain Reaction and Sex-specific Polymorphism

  • Saravanan, T.;Nainar, A. Mahalinga;Kumanan, K.;Kumaresan, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.5
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    • pp.650-654
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    • 2003
  • The accuracy of Polymerase chain reaction (PCR) assay in sexing of sheep embryos was assessed in this study. A total of 174 ovine embryos produced in vitro at different stages of development (2, 4-8 cell stages, morula and blastocyst) were sexed. The universal primers (P1-5EZ and P2-3EZ) used in this assay amplified ZFY/ZFX-specific sequences and yielded a 445 bp fragment in both sexes. Restriction enzyme analysis of ZFY/ZFX-amplified fragments with Sac I exhibited polymorphism between sexes, three and two fragments in males and in females, respectively. For verification of accuracy, blood samples of known sex were utilized as positive controls in each test. The mean percentages of sex identification by this method at 2 cell, 4-8 cell, morula and blastocyst were $73.00{\pm}5.72$, $89.77{\pm}3.79$, $3.33{\pm}8.08$ and $79.6{\pm}9.09$, espectively with the over all male to female ratio of 1:0.87. It is concluded that the ZFY/ZFX based method is highly reliable for the sexing of sheep embryos.

Biological Effects of Vinca minor extract; Tyrosinase inhibition, stimulation of ROS generation and increasement of cell migration activity in keratinocytes

  • Kim, Jun-Sub;Yu, Il-Hwan;Joo, Ji-Hye;Nam, Gyeong Hoe;Jung, Kyung-Hwan;Chung, Young Soo;Lee, Hyang-Yeol
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.4
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    • pp.788-794
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    • 2016
  • Vinca alkaloids from plant Vinca minor have been investigated for their effects of tyrosinase inhibition, stimulation of ROS generation and increasement of cell migration activity. The methanolic crude extract and the water-soluble fraction exhibited $IC_{50}$ value of 3.1 mg/mL and 2.1 mg/mL. Vinca minor extract treatment significantly increased ROS levels in HaCaT cells, in a concentration-dependent manner. Treatments of Vinca minor extract led to increase wound closure when compared with non-treatment. Low dose (0.1% or 0.3%) of extracts have not significantly affected, compared with that in controls. By contrast, 0.5% extract have dramatic effect on wound healing activity of keratinocytes. Effects of Vinca minor extract in a filter-based cell mobility assay appear similar to that of wound closure assay, which suggests that the Vinca minor extract have wound healing effects on skin.

Non-B, Non-T Acute Lymphoblastic Leukemia in a Cat

  • Sumin Cha;Hyunwoo Kim;Hyeona Bae;Minjeong Kang;Rankyung Jung;Minji Kim;DoHyeon Yu
    • Journal of Veterinary Clinics
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    • v.40 no.4
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    • pp.298-302
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    • 2023
  • A 7-year-old neutered male, domestic shorthair cat presented anorexia and lethargy. The complete blood cell count revealed severe non-regenerative anemia, lymphocytic leukocytosis, neutropenia, and thrombocytopenia. On the peripheral blood smear examination, medium to large lymphoblastic cells with moderate amounts of basophilic cytoplasm were observed in up to 70% of peripheral leukocytes. Feline leukemia and immunodeficiency viruses were not detected using a commercial diagnostic kit. While splenomegaly and blunt margins of the caudoventral liver were observed in abdominal radiography, changes in the intra-abdominal lymph nodes were not remarkable. Ultimately, flow cytometric immunophenotyping from the peripheral blood revealed a negative for B-cell markers (CD21-/CD79a-) and T-cell markers (CD3-/CD4-/CD5-/CD8-). Based on the hematological examination and the immunophenotyping assay, the cat was diagnosed with non-B, non-T acute lymphoblastic leukemia. Here, we report a rare case of non-B, non-T acute lymphoblastic leukemia to raise awareness and provide information on clinical symptoms and laboratory test and immunophenotyping analysis results.

Effect of Oral Administration of Korean Red Ginseng on Influenza A (H1N1) Virus Infection

  • Kim, Jin-Young;Kim, Hyoung-Jin;Kim, Hong-Jin
    • Journal of Ginseng Research
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    • v.35 no.1
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    • pp.104-110
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    • 2011
  • Korean red ginseng (RG), which is a ginseng treated by heating and steaming, has biological activity similar to Panax ginseng. The effect of ginseng on influenza infection has not been studied although it is known to have a broad range of biological activities. The aim of the study is to investigate the effect of RG extract on influenza A (H1N1) virus infection. We investigated the inhibitory effect of RG extract on plaque formation by influenza A virus in a cell-based plaque assay, and the effect of orally administered RG on influenza A virus infection in mice. RG extract, which was applied at a non-cytotoxic concentration, inhibited plaque formation by influenza A virus in the cell-based plaque assay. The orally administered RG extract ameliorated body weight loss and significantly increased survival in mice infected with influenza A virus. Our results suggest that RG extract has components that reduce the severity of infection by influenza A virus and could potentially be used as a complement to treatment of influenza A virus infections.

Human sebocyte-based assay system for the screening of compounds to lower the lipid synthesis in sebaceous gland

  • Mun, Yeun-Ja;Lee, Seung-Yon;Im, Sook-Jung;Ahn, Sung-Hun;Lee, Jason;Woo, Won-Hong
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.508-518
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    • 2003
  • SZ95 cell is an immortalized human sebaceous gland cell line that shows the morphologic, phenotypic and functional characteristics of normal human sebocytes. Sebocytes may play crucial parts in the pathophysiologic processes and disorders of the pilosebaceous unit. The secretory activity of the sebaceous gland is remarkably species-specific and acne is an exclusively human disease. Thus, this SZ95 cells offer possibilities for investigations on the physiology of the sebaceous gland and its role in sebum-associated skin disease such as acne. In this study, we investigated the effects of 13-cis-retinoic acid (13-cis-RA) and spironolactone, frequently used as therapeutic agents of acne, on the lipid synthesis and proliferation of human sebocytes. Cell proliferation was determined by MTT assay and cytoplasmic lipid droplets was shown by Oil-red a staining. Total lipid levels were biochemically estimated by the sulfo-phospho-vanilline reagent. 13-cis-RA and spironolactone significantly inhibited proliferation and lipid levels in a dose-dependent manner. Combined treatment with testosterone and 13-cis-RA or spironolactone resulted in a lower total lipid levels than that with androgen alone. These observations indicate that 13-cis-RA and spironolactone are potent inhibitors of both cell proliferation and lipid synthesis in human sebocytes. We will provide experimental evidence that this human sebocyte cell line serves as an adequate tool for evaluating the anti-lipogenic activity of various compounds potentially useful for the bioactive cosmeceutical ingredients on acne skin, and studying the intracellular biochemical markers depending on the types of compounds from various sources.

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Cytotoxic Effect of Korean Traditional Prescriptions on the Human Gastric Cancer Cell Lines (한약처방제의 인체 위암 세포주에 대한 세포독성 효과에 관한 연구)

  • Kim, Eun-Hae;Eun, Young-Ah;Kang, Bong-Joo;Sung, Hyun-Jae;Park, Kap-Joo
    • Korean Journal of Pharmacognosy
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    • v.28 no.4
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    • pp.233-238
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    • 1997
  • ln order to search for antigastric cancer agents from Korean traditional prescriptions. We selected 41 traditional prescriptions, based on a review of the Korean traditional medicine books. Both boiling water and methanol extracts were tested, by means of the Sulforhodamine B (SRB) protein assay. Six of the 41 water extracts; #3, #34, #35, #38, #40, #41 showed efficacy against gastric cancer cell (AGS: Human gastric carcinoma, ATCC HTB 103). #3 inhibited 50% cancer cell growth1 at the concentration of $152\;{\mu}g/ml$, #34, #35, #38, #40 and #41 inhibited 50% cancer cell growth at the concentration of $145\;{\mu}g/ml$, $129\;{\mu}g/ml$, $173\;{\mu}g/ml$, $10\;{\mu}g/ml$ and $19\;{\mu}g/ml$ respectively. Ten of the 41 methanol extracts; #1, #3, #32, #33, #35, #36, #37, #38, #41 were active. #1 inhibited 50% cancer cell growth at the concentration of $206\;{\mu}g/ml$, #3, #32, #33, #35, #36, #37, 738, #40, #41 inhibited 50% cancer cell growth at the concentration of $133\;{\mu}g/ml$, $159\;{\mu}g/ml$, $199\;{\mu}g/ml$, $147\;{\mu}g/ml$, $113\;{\mu}g/ml$, $187\;{\mu}g/ml$, $130\;{\mu}g/ml$, $9\;{\mu}g/ml$, $15\;{\mu}g/ml$ respectively. Prescription #3, #35, #38, #40, #41 were also interesting because both methanol and water extracts were active.

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Guidelines for Manufacturing and Application of Organoids: Skin

  • Seunghee Lee;Yeri Alice Rim;Juryun Kim;Su Hyon Lee;Hye Jung Park;Hyounwoo Kim;Sun-Ju Ahn;Ji Hyeon Ju
    • International Journal of Stem Cells
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    • v.17 no.2
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    • pp.182-193
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    • 2024
  • To address the limitations of animal testing, scientific research is increasingly focused on developing alternative testing methods. These alternative tests utilize cells or tissues derived from animals or humans for in vitro testing, as well as artificial tissues and organoids. In western countries, animal testing for cosmetics has been banned, leading to the adoption of artificial skin for toxicity evaluation, such as skin corrosion and irritation assessments. Standard guidelines for skin organoid technology becomes necessary to ensure consistent data and evaluation in replacing animal testing with in vitro methods. These guidelines encompass aspects such as cell sourcing, culture techniques, quality requirements and assessment, storage and preservation, and organoid-based assays.

The Study of MHC class I Restricted CD8+ T Cell Mediated Immune Responses against Mycobacterium tuberculosis Infection: Evidence of M. tuberculosis S pecific CD8+ T Cells in TB Patients and PPD+ Healthy Individuals (MHC class I 분자들에 의해 제시되는 Epitope을 인지하는 CD8+ T 림프구의 결핵균 감염에 대한 면역반응의 연구: 결핵 환자와 PPD+ 건강개체에 존재하는 결핵균 항원에 특정한 CD8+ T세포)

  • Cho, Jang-Eun;Lee, Kyung Wha;Park, Seung Kyu;Cheon, Seon-Hee;Cho, Sang-Nae;Cho, Sungae
    • IMMUNE NETWORK
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    • v.3 no.3
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    • pp.235-241
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    • 2003
  • Background: The protective immunity against tuberculosis (TB) involves both CD4+ T cells and CD8+ T cells. In our previous study, we defined four Mycobacterium tuberculosis derived peptide epitopes specific for HLA-$A^*0201$ restricted CD8+ T cells ($ThyA_{30-38}$, $RpoB_{127-135}$, $85B_{15-23}$, $PstA1_{75-83}$). In this study, we investigated the immune responses induced by these peptide specific CD8+ T cells in latently and chronically infected people with TB. Methods: We characterized these peptide specific CD8+ T cell population present in PBMC of both TB patients and PPD+healthy people using IFN-${\gamma}$elispot assay, intracellular staining and HLA-A2 dimer staining. Results: The frequency of peptide specific CD8+ T cell was in the range of 1 to 25 in $1.7{\times}10^5$ PBMC based on ex vivo IFN-${\gamma}$ elispot assay, demonstrating that these peptide specific CD8+ T cell responses are induced in both TB patients and PPD+ people. Short term cell lines (STCL) specific for these peptides proliferated in vitro and secreted IFN-${\gamma}$ upon antigenic stimulation in PPD+ donors. Lastly, HLA-$A^*0201$ dimer assays indicated that $PstA1_{75-83}$ specific CD8+ T cell population in PPD+ healthy donors is heterogeneous since approximately 25~33% of $PstA1_{75-83}$ specific CD8+ T cell population in PPD+ healthy donors produced IFN-${\gamma}$ upon peptide stimulation. Conclusion: Our results suggest that MHC class I restricted CD8+ T cell mediated immune responses to M. tuberculosis infection are induced in both TB patients and PPD + people; however, the CD8+ T cell population is functionally heterogeneous.

Virus-Cell Fusion Inhibitory Compounds from Ailanthus altissima Swingle (저근백피의 Virus-Cell Fusion 저해활성 성분)

  • Chang, Young-Su;Moon, Young-Hee;Woo, Eun-Rhan
    • Korean Journal of Pharmacognosy
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    • v.34 no.1 s.132
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    • pp.28-32
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    • 2003
  • In order to search for the anti-HIV agents from natural products, eighty MeOH extracts of medicinal plants were applied to a syncytia formation inhibition assay which is based on the interaction between the HIV-1 envelope glycoprotein gp120/gp41 and the cellular membrane protein CD4 of T lymphocytes. Among them, Ailanthus altissima showed a potent virus-cell fusion inhibitory activity. Repeated column chromatoghaphy of the methylene chloride fraction of A. altissima afforded compounds 1$({\beta}-sitosterol-3-O-{\beta}-D-glucoside)$, 2(tetramethoxycoumarin), and 3(ocotillone). Virus-cell fusion inhibitory activity of compound 3(ocotillone) was $70.76{\pm}4.09%$ at the concentration of $100\;{\mu}g/ml$.