• Title/Summary/Keyword: Biological science

Search Result 14,673, Processing Time 0.05 seconds

Microfluidic Control for Biological Cell Orientation

  • Namkung, Young-Woo;Park, Jung-Yul;Kim, Byung-Kyu;Park, Jong-Oh;Kim, Jin-Oh
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.2457-2460
    • /
    • 2003
  • There is a great demand to manipulate biological cell autonomously since biologist should spend much time to obtain skillful manipulation techniques. For this purpose, we propose a cell chip to control, carry, fix and locate the cell. In this paper, we focus on the cell rotator to rotate individual biological cell based on a micro fluidics technology. The cell rotator consists of injection hole and rotation well to rotate a biological cell properly. Under the variation of flow rate in injection hole, the angular velocity of a biological cell is evaluated to find the feasibility of the proposed rotation method. As a practical experiment, Zebrafish egg is employed. Based on this research, we find the possibility of non-contact rotation way that can highly reduce the damage of the biological cell during manipulation. To realize an autonomous biological cell manipulation, a cell chip with manipulation well and micro channel in this research will be utilized effectively in near future.

  • PDF

Herbal extract THI improves metabolic abnormality in mice fed a high-fat diet

  • Han, So-Ra;Oh, Ki-Sook;Yoon, Yoo-Sik;Park, Jeong-Su;Park, Yun-Sun;Han, Jeong-Hye;Jeong, Ae-Lee;Lee, Sun-Yi;Park, Mi-Young;Choi, Yeon-A;Lim, Jong-Seok;Yang, Young
    • Nutrition Research and Practice
    • /
    • v.5 no.3
    • /
    • pp.198-204
    • /
    • 2011
  • Target herbal ingredient (THI) is an extract made from two herbs, Scutellariae Radix and Platycodi Radix. It has been developed as a treatment for metabolic diseases such as hyperlipidemia, atherosclerosis, and hypertension. One component of these two herbs has been reported to have anti-inflammatory, anti-hyperlipidemic, and anti-obesity activities. However, there have been no reports about the effects of the mixed extract of these two herbs on metabolic diseases. In this study, we investigated the metabolic effects of THI using a diet-induced obesity (DIO) mouse model. High-fat diet (HFD) mice were orally administered daily with 250 mg/kg of THI. After 10 weeks of treatment, the THI-administered HFD mice showed reduction of body weights and epididymal white adipose tissue weights as well as improved glucose tolerance. In addition, the level of total cholesterol in the serum was markedly reduced. To elucidate the molecular mechanism of the metabolic effects of THI in vitro, 3T3-L1 cells were treated with THI, after which the mRNA levels of adipogenic transcription factors, including C/$EBP{\alpha}$ and $PPAR{\gamma}$, were measured. The results show that the expression of these two transcription factors was down regulated by THI in a dose-dependent manner. We also examined the combinatorial effects of THI and swimming exercise on metabolic status. THI administration simultaneously accompanied by swimming exercise had a synergistic effect on serum cholesterol levels. These findings suggest that THI could be developed as a supplement for improving metabolic status.

Gene Expression Profiling of the Rewarding Effect Caused by Methamphetamine in the Mesolimbic Dopamine System

  • Yang, Moon Hee;Jung, Min-Suk;Lee, Min Joo;Yoo, Kyung Hyun;Yook, Yeon Joo;Park, Eun Young;Choi, Seo Hee;Suh, Young Ju;Kim, Kee-Won;Park, Jong Hoon
    • Molecules and Cells
    • /
    • v.26 no.2
    • /
    • pp.121-130
    • /
    • 2008
  • Methamphetamine, a commonly used addictive drug, is a powerful addictive stimulant that dramatically affects the CNS. Repeated METH administration leads to a rewarding effect in a state of addiction that includes sensitization, dependence, and other phenomena. It is well known that susceptibility to the development of addiction is influenced by sources of reinforcement, variable neuroadaptive mechanisms, and neurochemical changes that together lead to altered homeostasis of the brain reward system. These behavioral abnormalities reflect neuroadaptive changes in signal transduction function and cellular gene expression produced by repeated drug exposure. To provide a better understanding of addiction and the mechanism of the rewarding effect, it is important to identify related genes. In the present study, we performed gene expression profiling using microarray analysis in a reward effect animal model. We also investigated gene expression in four important regions of the brain, the nucleus accumbens, striatum, hippocampus, and cingulated cortex, and analyzed the data by two clustering methods. Genes related to signaling pathways including G-protein-coupled receptor-related pathways predominated among the identified genes. The genes identified in our study may contribute to the development of a gene modeling network for methamphetamine addiction.

Polyamine Stimulation of arcA Expression in Escherichia coli

  • Rhee, Mun-Su;Kim, Young-Sik;Park, Seon-Young;Park, Myung-Hun;Kim, Bo-Min;Kang, Seong-Uk;Lee, Kui-Joo;Lee, Jong-Ho
    • Journal of Microbiology
    • /
    • v.40 no.4
    • /
    • pp.305-312
    • /
    • 2002
  • The effects of two natural polyamines (putrescine and spermidine) on the synthesis of ArcA, a response regulator of the Arc two-component signal transduction system, were studied using an E. coli mutant deficient in polyamine biosynthesis. Endogenous polyamine deficiency of the mutant resulted in marked reduction in the ArcA level determined by Western blot analysis. Putrescine supplement to the growth medium effectively increased the ArcA level of the mutant in a concentration-dependent manner. Spermidine also stimulated the ArcA level in the mutant to a greater degree than putrescine. Expression of arcA'::lacZ operon fusion in the mutant was stimulated 6-fold and 10-fold by putrescine and spermidine at a 1mM concentration, respectively, indicating that the stimulatory effect of the polyamines on ArcA synthesis is due to transcriptional induction, and that spermidine is a more potent arcA inducer than putrescine. The polyamine-dependent arcA'::lacZ induction was growth-phase-dependent and independent of either arcA or fnr which are two regulators involved in anaerobic stimulation of the Arch level. These results suggested that putrescine and spermidine polyamines may be potential intracellular signal molecules in the control of arcA expression, and thereby may play an important role in cellular metabolism.