The mechanism of hepatitis B virus entry is an interesting area in HBV research but still enigmatic.The difficulties in HBV entry research were primarily caused by the lack of easily accessible in vitro infection models.Recent years,primary hepatocytes from Tupaia belangeri has been substituted for primary human hepatocytes and upon induction of differentiation in vitro.A human hepatoma cell line named HepaRG has been found to be susceptible for HBV infection too.The two cell models enabled researchers to obtain a number of important discoveries for HBV entry.This article are focusing on these discoveries,including the domains of HBV surface proteins involved in HBV entry,potential HBV receptor candidates and the questions to be resolved in future years.

Since last century, drug discovery efforts mostly focus on searching for chemicals which can inhibit some specific steps in a well-described disease pathway. However, this kind of highly specific inhibitors can not be effective for complex diseases, like cancer, diabetes, schizophrenia and mental illness. Therefore, we need to rethink the drug discovery and therapeutic strategies. In this review, the strategies of selection of cellular signal transduction networks and their dynamics as the targets for drug discovery and pharmacological treatments will be discussed. The properties and analytical methods of these signal transduction networks, internet sources and software tools for performing these strategies will be described. Strategies and procedures of using network-based drug discovery will be emphasized, including multi-targets drug design and network-based drug discovery.

The reversed pH gradient across the cell membrane on account of intracellular alkalinization and extracellular acidosis is an importart characteristic of tumor microenvironment.Sodium hydrogen exchanger isoform 1 (NHE1) is ubiquitously expressed at the plasma membrane of many types of cells,which plays a critical role in intracellular pH and cell volume homeostasis.NHE1 plays an important role in the regulation of tumor microenvironment and involves in tumor migration and invasion,which may be a potential new target in anti-cancer therapy.

Objective To evaluate the application of MSCT in diagnosing the injury of atlantoaxial joint.Methods MSCT data of 20 cases of traumatic atlantoaxial joints were analyzed,the ability of different reconstruction methods in showing the traumatic aspects were evaluated.Results Axial MSCT and in combination with reconstruction methods such as MPR and Direct 3D could distinctly depict atlantoaxial joint in full view.Conclusion MSCT plays an important role and could be the first choice of imaging examination in the detection of injury of atlantoaxial joint.

Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous disease first named by Anhalt, et al. in 1990. The disease is characterized by such distinctive clinical symptoms and signs as severe, painful mucosal erosions, polymorphous skin lesions, histopathology hallmarks, and immunological findings. The situation typically presents in patients with lymphoproliferative diseases and primarily malignancies. A main challenge of the study is the relationship between the existence of associated tumors and the autoimmune reaction to the skin. Some researchers suspected that the possible expression of foreign antigens on the tumor can cross react with epidermal antigens inducing the auto-reactive clones of T-lymphocytes. Some speculated that the type of tumors associated with PNP may produce plakin proteins that result in initiation of the immune response. Other reports believed the autoimmune reaction is related to the epitope spreading or to the changing of cytokines. We analyzed 12 PNP patients diagnosed in our department in the past few years. An intensive study to the B cells in the PNP associated with tumors demonstrated that the tumors have structural basis to produce antibody. The similar immunoglobulin heavy chain genes of tumor B-cells in 7 patients strongly suggested that the B cell clones were functional and recognized the same antigen epitope. The autoantibodies secreted by the tumor can react against specific plakin proteins in epidermis, lead to the impairment of cell-cell adhesion, and cause the mucocutanous lesions. The clinical significance of the results indicates the importances of early finding and total resection of the associated tumors, and the usage of IVIG pre or during operation to prevent Bronchitis Obliterans. The new finding is also important for the study of other antibody mediated autoimmune diseases.

The kinetic alterations of plasma prekallikrcin(PKA) and antithrombin Ⅲ (AT-Ⅲ) following myocardial infarction induced by 2 injections subcutaneously of 85 mg isoproterenol/kg at 24 hours interval in rats were detected in this study, and the relationship between PKA, AT-Ⅲ and myocardial ischemia induced by isoproterenol were also discussed. It was found that the activity of PKA decreased significantly and AT-Ⅲ tended to decrease at 4 hours after the first injection of isoproterenol, both of the PKA and AT-Ⅲ at 24 hours were lower than those at 4 hours and evidently lower than those of normal control, and at 48 hours after the first injection of isoproterneol the PKA was still maintained at the same level of 24 hours but the AT-Ⅲ almost returned to the normal level.

Since last century, drug discovery efforts mostly focus on searching for chemicals which can inhibit some specific steps in a well-described disease pathway. However, this kind of highly specific inhibitors can not be effective for complex diseases, like cancer, diabetes, schizophrenia and mental illness. Therefore, we need to rethink the drug discovery and therapeutic strategies. In this review, the strategies of selection of cellular signal transduction networks and their dynamics as the targets for drug discovery and pharmacological treatments will be discussed. The properties and analytical methods of these signal transduction networks, internet sources and software tools for performing these strategies will be described. Strategies and procedures of using network- based drug discovery will be emphasized, including multi-targets drug design and network-based drug discovery.

Objective A LC/MS/MS method is developed for determination of paraquat in biological tissue.Methods The samples were pretreated with solid phase extraction using Oasis WCX cartridges and separated with HPLC,paraquat could be identified by LC/MS/MS.Result Calibration curves were linear on injection of amounts ranging from 0.02～20?g/ml and the limit of detection was 10ng/ml(S/N≥3).Conclusion The described menthod was proved to be sensitive,rapid and accurate,it will be applied in identification and determination of paraquat in biological tissues.

A series of paeonol derivatives have been synthesized by simple acylation and etherification of the paeonol. Anti-tumor activities of the synthesized compounds were evaluated against HeLa and MCF-7 cells lines in vitro by the standard MTT assay. It was found that the derivatives were more active against HeLa than MCF-7. The results also indicated that 4-methoxy group is the synergistic group of paeonol's anti-tumor activity and ketone carbonyl side chain is essential functional group of paeonol's anti-tumor activity. Compound 2d had stronger antiproliferative activities than paeonol against HeLa and MCF-7 cell lines with IC50 values of 2.67 and 4.74 micromol x L(-1) respectively. The results showed that paeonol derivatives were worth to be intensively studied further.

Objective To testify the lung injury induced by cardiopulmonary bypass(CPB) in canine model and observe the influence of CPB on the aquaporin-1 ( AQP1 ) mRNA expression in canine lung. Methods 8 mongrel dogs were used to perform the cardiopulmonary bypass. The hearts arrested for 90 minutes with mild hypothermia and rebeated for 6 hours. The hemodynamics, the ratio of lung dry weight and wet weight, the plasmic osmotic pressure, and the characteristics of light and fine structure were analyzed. The retro-transcription polyase chain reaction ( RT-PCR ) was used to measure the expression of AQP1 mRNA during the CPB. Results The hemodynamic data were stable in different time point during the CPB (P ＞0.05 ). The ratio of lung dry weight and wet weight was getting lower ( P ＜0.001) and the plasmic osmotic pressure was getting higher due to the prolongation of the CPB time and reperfusion time ( P ＜0.01). The light and electron microscopy showed the prominent aggregation of the white blood cell, severe interstitial edema and mild tear of respiratory membrane after 3 hour and 6-hour rebeat. AQP1 mRNA expression in lung was downregulated, 78.4% after 3-hour reperfusion and 55.5% after 6-hour reperfusion respectively, comparing to the level before CPB. Conclusion We recognize that the lung injury and lung edema were severe following 3-hour and 6-hour rebeat in CPB and hypothesize that the down-regulation of lung AQP1 mRNA expression may be a sign of pulmonary interstitial capillary injury induced by CPB.