PBL(Problem-Based Learning, PBL) is a problem-oriented and effective supplementary teaching method. PBL is giving a great help to improve self-learning, communication and cooperation, thinking and problems solving abilities for the students. In the process of PBL teaching, attention should be paid to two important items. One item is the role transfer for the teacher. Teacher is only a guider in PBL teaching, teacher should avoid excessive interfere of the process for keeping the passion and enthusiasm of the students. Meanwhile, students should always be realized that they are the main part in PBL teaching, they should not depend on their teacher too much. Another important item is how to find and solve the frequently encountered problems, in order to avoid students wandering from the subject, and lead them toward the main goal to get effective teaching and learning.

In the present study, a new compound named 17-(6-cinnamamido-hexylamino-)-17-demethoxygeldanamycin (CDG) was obtained by introducing the cinnamic acid (CA) group into the 17-site of geldanamycin (GDM). The anti-cancer effects of CDG in vitro and in vivo were evaluated. MTT assay was used to examine the inhibitory effect of CDG on the proliferation of MCF-7, HepG2, H460 and SW1990 cells. Immunofluorescent staining flow cytometry combined with Annexin V-FITC/PI staining were used to detect apoptotic cells. Transwell assay was used to analyze the effect of CDG on cell invasion and migration ability. Western blotting was used to detect the expression levels of RAF-1, EGFR, AKT, CDK4 and HER-2 of MCF-7, HepG2 and H460 cells. The toxicities of CDG and GDM were evaluated in mice. Using the subcutaneously transplanted MCF-7 xenograft in nude mice, inhibitory effect was evaluated in vivo. The results showed that CDG inhibited the proliferation of cancer cells (IC50: 13.6-67.4 microg.mL-1). After exposure to CDG for 48 h, most cells presented typical morphologic changes of apoptosis such as chromatin condensation or shrunken nucleus. The rates of apoptosis of MCF-7, HepG2, H460 and SW1990 cells incubated with 10 microg.mL-1 CDG were 23.16%, 27.55%, 22.21%, 20.47%, respectively. A dose-dependent reduction of migration of four cell lines was found after exposure to CDG. The decreased levels of RAF-1, EGFR, AKT, CDK4 and HER-2 showed that CDG possessed HSP90 inhibitory effect. The result of animal toxicity test on the mice suggested that CDG had lower toxicity than GDM. Meanwhile, CDG inhibited the growth of MCF-7 xenografts of athymic mice.
Animals ; Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Apoptosis ; drug effects ; Benzoquinones ; chemical synthesis ; chemistry ; pharmacology ; Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Cyclin-Dependent Kinase 4 ; metabolism ; Female ; HSP90 Heat-Shock Proteins ; antagonists & inhibitors ; Humans ; Lactams, Macrocyclic ; chemical synthesis ; chemistry ; pharmacology ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Invasiveness ; Neoplasm Transplantation ; Proto-Oncogene Proteins A-raf ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Random Allocation ; Receptor, Epidermal Growth Factor ; metabolism ; Receptor, ErbB-2 ; metabolism ; Tumor Burden ; drug effects ; Xenograft Model Antitumor Assays

The experiment included three potassium levels (K0 0 g x kg(-1), K1 0.33 g x kg(-1), K2 0.67 g x kg(-1)) and two water gradients (well watered and drought stress), then measured growth indicators, SOD, POD, CAT activities and concents of osmotic regulation substances. To explore the effects of K fertilizer and water on growth and physiological characteristics of Isatis indigotica, providing reference for improving drought resistance of I. indigotica. The result showed drought stress inhibited the growth and decreased the biomass of I. indigotica but K fertilizer can alleviate the drought stress. Compared with K0 treatment, K1, K2 treatment increased the biomass of overground part of by 89. 13% ,60. 87% under drought stress. The corresponding increase in soluble sugar content was 16.67%, 5.00%, and in proline content was 42.41%, 65.62%, respectively. SOD,POD and CAT activities was significantly improved in K1, K2 treatment in comparison with K0 treatment under drought stress, but soluble protein content significantly reduced. The conclusion is that appropriate amount of K fertilizer can increase the activities of antioxidase and the content of osmoregulation substance under drought stress, and improve drought resistance of I. indigotica.
Fertilizers ; analysis ; Isatis ; chemistry ; enzymology ; growth & development ; metabolism ; Peroxidase ; metabolism ; Plant Proteins ; metabolism ; Potassium ; analysis ; metabolism ; Seedlings ; chemistry ; enzymology ; growth & development ; metabolism ; Superoxide Dismutase ; metabolism ; Water ; analysis ; metabolism

Objective To explore the inter-regional,base-like and informatized support of the field medical station during rotational training.Methods The field medical station information system developed by the hospital was introduced,which had the working mode involving in a set of system and two kinds of terminals.The problems of the information system were analyzed during iner-regional,base-like rotational training.Results The information system had its functions realized,and stills had to be improved in casualty information input flow,precision materials management and allocation standard of operating terminal.Conclusion The field medical station information system contributes to enhancing its service efficiency and informatization.

Objective To confirm the distribution of high arsenic drinking water and the situation of endemic arsenism in Hubei Province, to provide reference basis for prevention and control of endemic arsenic disease. Methods Using typical investigation and sample investigation in 2006 and 2007, the arsenic content of water was detected sampled from 19 counties(cities or communities). And those water samples which were close to or exceeded the stipulated standard were rechecked by the national standard method. Furthermore, the situation of endemic arsenism was investigated in the cities having high arsenic contents of water. Results In 2006,10 028 water samples of 446 villages in 6 counties (cities or communities) were tested, the wells of high arsenic (> 0.05 mg/L) were found in 5 counties (cities or communities) and the proportion of the well that exceeded stipulated standard was 5.29%(530/10 028); In 2007,19 086 water samples of 1282 villages in 17 counties(cities or communities) were tested, the wells of high arsenic were found in 11 counties(cities or communities), and the proportion of the well that exceeded stipulated standard was 1.74%(333/19 086). In these two years, 29 114 water samples were tested, in which 863 water samples were exceeding the stipulated standard. The 2.96% of total wells exceeded stipulated standard and mainly distributed in 179 villages of 12 counties(cities or communities). And the highest arsenic content of water sample was 2.012 mg/L. In the endemic arsenism area, 2 critical, 1 moderate and 1 mild arsenism patients had been found. Conclusions The water of high arsenic content are scattered in Hubei Province and the situation of endemic arsenism disease is mild. Improving water aiming at decreasing arsenic and establishing patient files should be carried out immediately.

OBJECTIVETo obtain streptavidin-tagged human interleukin-15 (SA/hIL15) fusion protein and evaluate its bioactivity.

METHODSpET24a-6His-SA-hIL-15 and pET32a-hIL-15-SA-6His plasmids were constructed and expressed in BL 21(DE3) host bacteria to generate the fusion protein. The recombinant fusion protein IL-15/SA was purified using Ni-NTA affinity chromatography and refolded, and the efficiency of surface modification of the fusion protein on biotinylated cells was examined by fluorescence-activated cell sorting. CCK-8 method was used to evaluate the effect of IL-15/SA fusion protein in inducing the proliferation of human peripheral-blood lymphocyte (PBL) cells stimulated by PHA.

RESULTSThe recombinant SA-hIL-15 and hIL15-SA fusion proteins were highly expressed in BL21(DE3) at about 20% of the total bacterial proteins. The purified hIL15-SA fusion protein exhibited a bifunctionality by promoting the proliferation of PBL cells activated by PHA and high-affinity binding to biotinylated cell surface mediated by SA, with a cell surface modification efficiency exceeding 95%. SA-hIL-15 showed a 4-fold higher hIL15 bioactivity than hIL15-SA.

CONCLUSIONSA/hIL-15 bifunctional fusion protein has been successfully obtained to facilitate the future development of hIL-15-surface-modified cancer cell vaccine.

Cancer Vaccines ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Humans ; Interleukin-15 ; biosynthesis ; genetics ; Lymphocyte Activation ; drug effects ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Streptavidin ; biosynthesis ; genetics

AIMTo investigate the inhibitory activity of salvianolic acid A (SAA) on nucleoside transport in cancer cells and its antitumor effect.

METHODS[3H] thymidine and [3H] uridine transport assays were used to determine the inhibitory activity on nucleoside transport in Ehrlich carcinoma cells. The cytotoxicity to cultured cancer cells was examined with clonogenic assay. The antitumor effect in vivo was evaluated with transplantable tumor model in mice.

RESULTSSAA was shown to inhibit thymidine and uridine transport in Ehrlich carcinoma cells with IC50 values of 18.1 and 17.1 micromol x L(-1), respectively. By clonogenic assay, the IC50 of SAA for KB cells was 44.7 micromol x L(-1). SAA markedly potentiated the cytotoxicity of 5-FU and mitomycin C in KB cells as well as the cytotoxicity of MTX in human hepatoma BEL-7402 cells. For in vivo experiment, sarcoma 180 cells were transplanted sc in mice and tested drugs were administered ip. When administered separately, SAA at 200 mg x kg(-1) and 5-FU at 10 mg x kg(-1) inhibited tumor growth by 41% and 27%, respectively. Combination of the two drugs inhibited tumor growth by 63% (CDI = 0.86).

CONCLUSIONSAA is active in blocking nucleoside transport in cancer cells and potentiates the cytotoxicity of chemotherapeutic drugs. As an agent showing moderate antitumor effect in vivo, SAA might be useful in combination cancer therapy.

Animals ; Antineoplastic Agents ; pharmacology ; Antineoplastic Agents, Phytogenic ; isolation & purification ; pharmacology ; Biological Transport ; Caffeic Acids ; isolation & purification ; pharmacology ; Drug Synergism ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Fluorouracil ; pharmacology ; Humans ; KB Cells ; Lactates ; isolation & purification ; pharmacology ; Male ; Methotrexate ; pharmacology ; Mice ; Mitomycin ; pharmacology ; Neoplasm Transplantation ; Plants, Medicinal ; chemistry ; Salvia miltiorrhiza ; chemistry ; Sarcoma 180 ; metabolism ; pathology ; Tumor Cells, Cultured

0.05).(4) Toxicity:Grade Ⅲ-Ⅳ myelosuppression was 60%(18/30)in Tp group,26%(8/31)in TC group and 30%(10/33)in PC group.The TP regimen had the greatest hematologic toxicity(P0.05). Conclusions As first line chemotherapy in epithelial ovarian cancer,TP regimen comparable to the standard chemotherapy regimen.

Objective To investigate the effect of mesenchymal stem cells (MSC) on the activity of nuclear factor (NF)-?B in rats with myocardial infarction.Methods MSC were isolated from SD rats (120—150 g in weight).SD rats (180—200 g in weight) were subjected to MI by left coronary artery occlusion,and were allo- cated into three groups randomly:1)sham group (without ligation of the artery,n=8);2)injection of PBS solu- tion (n=8);3)injection of MSC (n=8).MSC or PBS solution was injected into myocardium from epicardium instantly after MI models were established.Four weeks after transplantation,cardiac function was evaluated u- sing physiological recorder.Western blot were performed to investigate the nuclear factor-? activity.The ex- pressions of tumor necrosis factor (TNF)-? and interleukin (IL)-6 were evaluated by RT-PCR and Western blot. Results 1)Mortality was 20%(2/10) in sham group,33.3%(4/12) in PBS group and 20%(2/10) in MSC group with no statistic differences between them(P=0.646).2) Hemodynamic measurements showed that MSC trans- plantation caused significant improvement in cardiac function,comparing with MI+PBS group.3) MSC inhibi- ted the activities of NF-?B in myocardium and down-regulated the expression of TNF-? and IL-6 in mRNA and protein level.Conclusion Transplantation of MSC improved cardiac function in MI rats,which may partly at- tribute to their immuno-inflammatory regulation mechanism.

OBJECTIVETo evaluate the possible vascular effects of an environment carcinogen benzo(a)pyrene (BaP).

METHODSThe cytotoxicit of BaP and rat liver S9 (0.25 mg/mL)-activated BaP were examined by MTT assay. Thoracic aortic rings were dissected from Sprague-Dawley rats. Contraction of aortic rings was induced by 60 mmol/L KCl or 10(-6) mol/L phenylephrine (PE) in an ex-vivo perfusion system after BaP (100 μmol/L) incubation for 6 h. [Ca(2+)](i) was measured using Fluo-4/AM. For in-vivo treatment, rats were injected with BaP for 4 weeks (10 mg/kg, weekly, i.p.).

RESULTSBaP (1-500 μm) did not significantly affect cell viability; S9-activated BaP stimulated cell proliferation. BaP did not affect the contractile function of endothelium-intact or -denuded aortic rings. BaP did not affect ATP-induced ([Ca(2+)](i)) increases in human umbilical vein endothelial cells. In BaP-treated rats, heart rate and the number of circulating inflammatory cells were not affected. Body weight decreased while blood pressure increased significantly. The maximum aortic contractile responses to PE and KCl and the maximum aortic relaxation response to acetylcholine were significantly decreased by 25.0%, 34.2%, and 10.4%, respectively.

CONCLUSIONThese results suggest, in accordance with its DNA-damaging properties, that metabolic activation is a prerequisite for BaP-induced cardiovascular toxicity.

Animals ; Aorta ; drug effects ; Benzo(a)pyrene ; pharmacology ; Calcium ; metabolism ; Endothelial Cells ; drug effects ; metabolism ; Humans ; Male ; Rats ; Vasoconstriction ; drug effects