摘要：
Diallyl disulfide (DADS) is a major constituent of garlic. Previously, we found that DADS both inhibited proliferation in human gastric cancer cells in vitro and in vivo, and induced G2/M arrest. In this study, we investigated whether this differentiation effect was induced by DADS in human gastric cancer MGC803 cells, and whether it was related to an alteration in ERK activity. The results showed that the growth of MGC803 cells was inhibited by DADS. Cells treated with DADS displayed a lower nucleocytoplasmic ratio and tended to form gland and intercellular conjunction structures. The ConA-mediated cell agglutination ratio and cells’ ALP specific activity decreased. In MGC803 cells, dye transfer was limited to a few cells neighbouring the dye-injected cell and to a depth of 1–2 layers beneath the scrape site. However, after treatment with DADS, the LY (Lucifer Yellow) was transferred to several cells immediately neighbouring the microinjected cell and to a depth of 2–4 cell layers from the scrape site. This indicated that DADS induced differentiation in MGC803 cells. Western blot analysis revealed that although DADS did not influence the quantity of ERK1/2 protein expressed, it did decrease its phosphorylation in a concentration-dependent manner, compared with the controls. At 30 mg·L−1, DADS inhibited the activation of ERK1/2 in 15–30 min. These results suggested that the DADS-induced differentiation of MGC803 cells involved an alteration of the ERK1/2 signaling pathway.
作者机构：
[Y, F.; J, Z. S.; W, D. H.; T, Z. Y.; Tu, Y. L.; Y, G. H.; Y, Y. Z.; W, Z.; Lv, Y. C.; Li, G. H.] Nanhua Univ, Inst Cardiovasc Dis, Heng Yang, Peoples R China.
作者机构：
Sun Yat Sen Univ, Zhongshan Med Coll, Dept Physiol, Guangzhou 510080, Peoples R China.;China Three Gorges Univ, Med Coll, Dept Morphol, Hubei 443002, Peoples R China.;Nahua Univ, Med Coll, Dept Physiol, Hunan 421001, Peoples R China.;[Feng, JQ] Sun Yat Sen Univ, Zhongshan Med Coll, Dept Physiol, 74,Zhongshan 2nd Rd, Guangzhou 510080, Peoples R China.
通讯机构：
[Feng, JQ] S;Sun Yat Sen Univ, Zhongshan Med Coll, Dept Physiol, 74,Zhongshan 2nd Rd, Guangzhou 510080, Peoples R China.
关键词：
apoptosis;bcl-2;curcumin;cytoprotection;iNOS
摘要：
The aim of present study is to explore the cytoprotection of curcumin against 1-methyl-4-phenylpridinium ions (MPP+)-induced apoptosis and the molecular mechanisms underlying in PC12 cells. Our findings indicated that MPP+ significantly reduced the cell viability and induced apoptosis of PC12 cells. Curcumin protected PC12 cells against MPP+-induced cytotoxicity and apoptosis not only by inducing overexpression of Bcl-2, but also reducing the loss of mitochondrial membrane potential (MMP), an increase in intracellular reactive oxygen species (ROS) and overexpression of inducible nitric oxide synthase (iNOS). The selective iNOS inhibitor AG partly blocked MPP+-induced apoptosis of PC12 cells. The results of present study suggested that the cytoprotective effects of curcumin might be mediated, at least in part, by the Bcl-2-mitochondria-ROS-iNOS pathway. Because of its non-toxic property, curcumin could be further developed to treat the neurodegenerative diseases which are associated with oxidative stress, such as Parkinson's disease (PD).
作者机构：
[Xu, Z. X.; Sun, Y. H.; Sun, W. Q.; Dong, B. H.; Jin, H. Y.; Tang, Y. L.; Yang, Y. Z.; Ye, X.; Wang, S.] Nanhua Univ, Inst Cardiovasc Dis, Hengyang, Peoples R China.
关键词：
Conditioned place preference;Drug craving;Gamma-band EEG;Manganese-enhanced MRI
摘要：
The orbitofrontal cortex is involved in the reinforcing effects of drugs of abuse. However, how the dynamic activity in OFC changes during opiate administration and withdrawal period has not been investigated. We first tested the effects of opiates and drug craving with the conditioned place preference paradigm, using manganese-enhanced magnetic resonance imaging and traditional electroencephalograph recording techniques in rats. T1-weighted 2D MRI (4.7 T) was used after unilateral injection of MnCl2 (200 nL, 80 mM) into the right orbitofrontal cortex. The manganese-enhanced magnetic resonance imaging data suggested that the OFC activity decreased during the opiate administration period but recovered increasingly during the withdrawal period. Also, we found decreases and increases in gamma-band (20-100 Hz) activity during the opiate administration and withdrawal period, respectively. Our results showed that orbitofrontal cortex activity decreased during morphine administration and then went up progressively over several days during withdrawal. The time course of the recovery of orbitofrontal activity from inhibition during the withdrawal period may be related to the experience of drug craving. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.
摘要：
Accurately measuring exhaled nitric oxide (eNO) is still an unsolved problem. We report the fabrication of a novel nanotube-based gas sensor. The gas sensor consists of a gas-responsive multiwall vanadium oxide nanotube (VO X-NT) layer deposited on a ceramic chip with two Ag-Pd electrodes, a gas sensor signal collecting system and a computer data-processing system. The absorption of different gases in the VOX-NT layer changes the permittivity and conductivity of the material and consequently alters the voltage of the sensor. By measuring the voltage change of the sensor, different gas concentrations can be determined. Our results show that the sensor response to nitric oxide (NO) is both highly sensitive and reversible at room temperature. The VOX-NT-based gas sensor only reponds to NO and water vapor in the exhaled air, and the response is concentration dependent. We suggest that the novel sensor can meet the demands of clinical diagnosis.
