To investigate the effects of Baicalein (BAI) on the proliferation and differentiation of pig preadipocytes, and elucidate its potential mechanism. Primary preadipocytes of pig were cultured in vitro. The morphologic changes of preadipocytes differentiation were observed by Oil Red O staining. Status of cell proliferation was detected by MTT assay. The degree of adipogenesis and differentiation were measured by Oil Red O staining extraction assay. The activity of fatty acid synthase (FAS) was detected by spectrophotometry. The mRNA expression of special peroxisome proliferation activated receptor-gamma2 gene (PPARgamma2) was detected by reverse transcriptase polymerase chain reaction (RT-PCR). When preadipocytes differentiated into adipocytes, the preadipocytes were changed from shuttle shape to oval or round, in which big and small lipid droplets were filled. The proliferation of preadipocytes was inhibited by the treatment of 160-640 micromol/L BAI (P < 0.05). The mRNA expression of PPARgamma2 and FAS activity and the differentiation of preadipocytes was repressed by 40-320 micromol/L BAI treatment (P < 0.05). It is concluded that the proliferation and differentiation of preadipocytes is inhibited by BAI in some degree. The effect of BAI on differentiation of preadipocytes may be resulted from inhibiting the mRNA expression of PPARgamma2 and reducing FAS activity.

Bone morphogenetic protein 2(BMP-2) is a member of the of BMPs family, its osteoinductive capacity has already been demonstrated. We tried to express hBMP-2 in CHO cell. In this study, we inserted hBMP-2 cDNA into vector pCDNA3.1(+) to construct hBMP-2 eukaryotic expression vector pCDNA3.1(+)-hBMP-2. Recombinant Chinese hamster ovary (rCHO) cell line expressing high-level recombinant human bone morphogenetic protein 2(rhBMP-2) was constructed by co-transfecting the expression vectors pCDNA3.1(+)-hBMP-2 and plasmid pSV2-dhfr into dihydrofolate reductase (dhfr)-deficient CHO cells and the subsequent gene amplification in medium containing stepwise increments in methotrexate level such as 0.1 and 1 micromol/L. Western blot analyses showed a specific band of about 18 kD in reduced sample lane and a specific band of about 32 kD in non-reduced sample lane, this indicated that rCHO cells secret rhBMP-2 as a homodimeric glycoprotein form. Finally, we obtained a single clone cell strain expressing a high level (7.83 microg/24 h/10(6) cells) of rhBMP-2 tested by ELISA. Biological activity of rhBMP-2 was tested by the induction of alkaline phosphatase(ALP) activity in C2C12 cells. We treated C2C12 with different concentration of rhBMP-2 condition medium(CM) for 5d. The results showed that the rhBMP-2 could significantly increase the ALP activity of C2C12.

Under phosphate deficiency stress, the mRNA levels of PLDalpha and PLDbeta in tobacco older leaves were higher while in rapid developing ones were lower than those in controls. In addition, changes in PG hydrolase activity were positively correlated with the alternation of transcript levels of PLDalpha and PLDbeta genes in both types of leaves. Phosphate deficiency resulted in decreases in PG content in both older and rapid developing leaves, and that the extent of decrease in older leaves was much larger than that in rapid developing ones. Phosphatidic acid (PA) is one of the main hydrolysis product of PG. Its production was restricted by adding n-butanol, an inhibitor of PA formation via PLD pathway, to the in vitro enzyme reaction mixture. These results suggest that the enhanced PG hydrolase activity is one important cause of the decrease in PG content in older leaves, and the activity of PG hydrolase is regulated at the transcriptional level.

To investigate the anti-tumor effect and the mechanism of down-regulation of HER - 2 by cabamazepine in SKBR - 3 cells , a breast cancer cell line with HER - 2 over - expression.

To investigate the function and mechanism of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) on activity of VEGF and GPI genes in human pancreatic cancer PC-3 cells incubated under hypoxic conditions.

To evaluate the chemopreventive effect of celecoxib, a specific cyclooxegenease-2 (COX-2) inhibitor, on chemically induced breast cancer of rats and its effect on COX-2 expression.

To construct eukaryotic expression vectors by using the pSilencer3. 1-H1 neo vector for inhibiting human survivin gene by RNA interference, and to detect the effect of the silenced survivin gene on PC-3 cells.

The potential ecological risk by wastewater or reclaimed water for irrigation is of great concerns in recent years, but little work was done on the chronic toxicities through long term accumulation of persistent organic chemicals in soil. In present work, concentration of Ah-receptor agonists in soil organic extract was measured by an ethoxyresorfin O-deethylase (EROD) bioassay, which was calibrated and expressed by the 2, 3, 7, 8-tetrachlorodibenzo- p-dioxin (2, 3, 7, 8-TCDD) toxic equivalent (TEQbio). Simultaneously, 16 PAHs in soil were analyzed and their TEQs (total as TEQ(PAHs)) were calculated according to their toxic equivalent factors (TEFs) cited from literature. By bioassay, it was found that the concentration level of Ah-receptor agonists in soil irrigated using reclaimed water could be as high as 97.4 ng/kg, which was obviously higher than that in background soil using ground water irrigation regime (56.0 ng/kg). In comparing the results from bioassay and chemical analysis, the percentage of TEQ(PAHs) in TEQbio increased from 10.3% in background soil to 78.6% in the soil irrigated by reclaimed water. Use of reclaimed water for irrigation could result in the accumulation of Ah-receptor agonists in soil,and a major part of them in this case could be attributed to the accumulation of 16 priority PAHs in soils.

To investigate the gene expression changes in the degenerated cervical intervertebral discs of rats, and to study the function of Yiqi Huayu Bushen Recipe, a compound Chinese herbal medicine, and its discomposed formulas in regulating gene expressions in the degenerated cervical intervertebral discs.

To observe the effect of survivin gene repression by RNA interference (RNAi) on the radiosensitivity and the chemosensitivity to cisplatin of cervical cancer cell HeLa.

To find out a possible approach to improve the effectiveness of radiotherapy and chemotherapy for Ewing's sarcoma by constructing a eukaryotic expression vector expressing herpes simplex virus-thymidine kinase (HSV-TK) regulated by hypoxia responsive element (HRE) under hypoxia and to evaluate the effects of this HRE regulated HSV-TK system on killing effect of gancyclovir (GCV) on Ewing's sarcoma cell line SK-ES under hypoxic condition.

To investigate the cytotoxic action and its mechanism of a novel anti-human DR5 monoclonal antibody (mAb mDRA-6).

To explore the effect of calpain inhibitor I(CI-I) on ikappaBalpha expression and cytokine secretion in RAW264.7 cells after LPS attack.

To investigate the effects on protein expression of big-conductance Ca(2+)-sensitive K(+) channel (BKca) beta1 subunit caused by high cholesterol in Rabbit Oddi's sphincter (SO) cells.

To investigate the role of ZmPIP1-1 and ZmPIP1-2 in water uptake of roots and drought resistance of crops, semi-quantitative PCR was used to examine the expression of ZmPIP1-1 and ZmPIP1-2 in root systems of different maize genotypes under water deficit. These genotypes showed different resistance to water shortage under field conditions. The reference gene to target genes was tubulin. Maize seedlings were grown by hydroponics in a growth chamber. Water deficit was imposed on the seedlings with PEG-6000. The result showed that ZmPIP1-1 was up-regulated under water deficit in root systems of plants of the filial generation 'Hudan 4' and the mother line 'Tiansi', which were resistant to water shortage, but there was no noticeable up-regulation of ZmPIP1-1 in the root systems of the father line '803', which was sensitive to water deprivation. The result also showed that the extent of up-regulation was positively correlated with drought resistance of maize (Fig.3). On the other hand, the expression of ZmPIP1-1 showed different degrees of tendency after different duration of water stress in the root systems of the maize seedlings of different genotypes. The result showed that ZmPIP1-2 was identically expressed in three different species of maize and under different water conditions. The results support the theory that the intercellular water transport contributes to increased water uptake in root systems under water deficit by up-regulating the number of some kinds of aquaporins. The increases amount of transcripts of aquaporins is positively correlated to drought resistance of plant varieties. But not all kinds of number of aquaporins is up-regulated during water shortage, some kinds of aquaporins are identically expressed under water deficit conditions and well watered conditions.

To investigate the changes in mitochondrial permeability transition, DNA degradation and cell death, seedling roots of Malus hupehensis Rehd. were treated directly with exogenous H(2)O(2). The results showed that mitochondrial permeability increased obviously by 0.024% (V/V) H(2)O(2) treatment for 30 min and increased continuously during the time of H(2)O(2) treatment (Fig.1). At the time of mitochondrial permeability increasing, mitochondrial membrane potential (Delta psi m) decreased (Fig.2). In addition, the ratio of Cyt c/a became lower (Fig.3) when mitochondrial permeability increased and Delta psi m decreased. DNA fragments were detected at the 60 min of H(2)O(2) treatment, the number of fragments increased after 60 min of H(2)O(2) treatment (Fig.4). Granular nuclei stained irregularly were evident in root slices stained by acridine orange (Fig.5). This indicates H(2)O(2) can induce programmed cell death by increasing mitochondrial permeability and decreasing Delta psi m in the root of Malus hupehensis Rehd.

To investigate the molecular mechanism of epidermal growth factor (EGF) signal pathway on the expression of integrin alpha5 beta1 in prostate cancer cell line DU145.

To establish a sensitive and efficient reporter gene-based screening model for finding agonists of estrogen receptor beta subtype.

Continuing depletion of the stratospheric ozone layer by atmospheric pollutants, in particular chlorofluorocarbons (CFCs), has resulted in an increasing incidence of solar UV-B (280-320 nm) at the Earth's surface. Enhanced UV-B radiation has been considered as important global environmental problem and results in important effects to mankind and the entire global ecosystem. Nitric oxide (NO) is not only a toxic molecule, one of reactive nitrogen species (RNS), but also an important redox-active signaling molecule. NO is really a double-edged sword, it can be either beneficial and activate defense responses in plants and animals or toxic, together with ROS. Besides those, NO can also act as a signal molecule and play very important roles in life of organisms. To study the effects of NO on the biological specific property of enhanced UV-B stressed Spirulina platensis, the chlorophyll-a, protein contents and biomass were investigated under enhanced UV-B radiation and its combination with different chemical treatment. The changes of chlorophyll-a, protein contents and biomass confirmed that 0.5 mmol/L sodium nitroprusside (SNP), a donor of nitric oxide (NO), could markedly alleviate the biological damage of cyanobacteria-Spirulina platensis 794 caused by enhanced ultraviolet-B. Further results proved that NO significantly increase the content of protein and proline. Meanwhile, the accumulation of reduced glutathione (GSH) in S. platensis cells were raised under normal growth condition. But exogenous NO could decrease the increasing of reduced glutathione (GSH) in enhanced UV-B stressed S. platensis cells. These results suggest that NO has protective effect and can strongly alleviate biological damage caused by UV-B stress in S. platensis 794 cells. For the first time, reported the effect of NO on the regulating ability of biological damage of S. platensis induced by enhanced UV-B. Therefore, further investigations will be necessary to inquire into the interaction and inter-correlation of signal molecules and the mechanism in cyanobacterium under enhanced UV-B stress.

To study the expression and localization of nuclear transcription factor Sp1 in macrophages after stimulated by silicon dioxide in vivo and in vitro.