Abstract:Tumor antigen is the substance which gives tumor cell antigenicity and make it to be recognized by the immune system. The discovery of tumor antigen is the basis of the development of tumor vaccine. Until now, there is great progress in tumor antigen. Meantime, along with the new understanding of tumor antigen, the development of tumor vaccine has got into a new stage.

Abstract:Interleukin-17 receptor (IL-17R) has been recently identified, which exhibits no homology to any known family of receptors. Studies show that soluble mouse IL-17R (smIL-17R) can not only inhibit T-cell activation, but also suppress the response to alloantigen in established allograft transplant models.

Abstract:Gene silencing is one of the important factors of transgene inactivation. The main mechanisms, including postion effects, transcriptional silencing and post-transcriptional silencing was presented, the means of stabilizing gene expression in transgeneic plants was discussed.

Abstract:Alzheimer's disease(AD) is a primary neurodegenerative disorder mainly affecting aged people over 60 years old. It is characterized by extracellular senile plaques(SPs) and intracellular neurofibrillary tangles(NFTs)in patients' brains. The major component of SP is β-amyloid peptide(βA) with molecular weight of about 4 ku which is a neurotoxic derivative of β-amyloid precursor protein(APP) and can cause cell damage mainly through oxidative stress and being able to form calcium channels in lipid bilayers. The precursor, APP, whose function is not yet elucidated in detail but evidence exists that it may mediate cell adhesion, maintain synaptic plasticity and so on, can be processed in conventional secretary way by several putative secretases and alternatively in endosomal/lysosomal way. Longer βA is more predisposed to aggregate to form SP than its shorer counterpart, so some APP mutants may cause familial AD through producing more longer βAs or increasing the production of shorter ones. The changes of some factors which are important for the metabolism of APP, for example, mutations of presenilins, may also cause AD by increased generation of βA.

Abstract:lanosterol 14α-demethylase, the target enzyme of the azole antifungals,is the only known member of the P450 superfamily to be expressed in higher plant, fungi, and mammals.Amino acid sequences from higher plant,fungi and mammals have been characterized.Oxidative removal of the 14α methyl group from lanosterol by the enzyme includes three steps and the free radicals are involved in the scheme of the catalytic reaction.The active site of lanosterol 14α-demethylase appears to be open above heme prosthetic group pyrrole ring C.Pyrrole ring A,B and D are occluded by active site residues;3β-hydroxyl group,Δ⁸⁽⁹⁾-double bond and 17-side chain of the substrate lanosterol are the key functional groups for the correct enzyme-substrate interaction and high catalytic turnover. The discussion about the structure-activity relationship (SAR) of two series inhibitors of the enzyme, substrate analogues and azole antifungals, provides the better basis for further high potent inhibitors design.

Abstract:POU domain proteins contain tow high conserved subdomains ( POU_H and POU_S) and variable linker between them. POU proteins interact with DNA by POU_H and POU_S. In aid of the domain flexibility and requirement of cofactors, POU proteins exhibit very complicated ability to bind and recognize DNA in function of regulator and transcription factors. In vertebrate and invertebrate, POU proteins take part in early embryogenesis, exert much regulation in cell lineage differentiation and neural development.

Abstract:The Wnt genes belong to an ever-expanding family of proto-oncogenes that express in species ranging from Drosophila to man. Wnt proteins, as well as other growth factors or signaling molecules, have the characteristics of secreted growth factors. As recently, a group of proteins in Frizzled (Fz) family have been identified as the putative receptors of Wnt family,several components are implicated in the downstream of Wnt/Fz signaling pathway, such as Dishevelled, GSK3 (glycogen synthase kinase 3), APC (adenomatous polyposis coli) and β-catenin.This signal transduction pathway plays a pivotal role not only in the formation and organization of developing organs, but also in biological tumorigenesis.

Abstract:RNA-protein interactions play crucial roles in many fundamental cellular processes. Recently studies on RNA-protein interactions are getting considerable progress with the improvement of techniques and the appearance of new methods. Many protein-binding sites of RNAs have been characterized, some RNA-binding domains of proteins have been found, and the structural features of them have been investigated in detail. The results from above work can provide important information to understand the molecular mechanism of RNA-protein interactions and the related cellular processes.

Abstract:Leukemia inhibitory factor (LIF), mainly secrected by endometrium gland during peri-implantation, is a glycoprotein with pleiotrophic activity on a wide variety of cell types. The principal function of LIF in vivo may be to regulate the growth and to initiate implantation of blastocyst. LIF expression is under maternal control, which is influenced by steroid hormones and cytokines. Gp130, a signal transducer receptor component shared by the cytokines such as LIF, IL-6, OSM and CNTF,can convert the low affinity LIFRβ into a high affinity form, and its homodimerization (in the case of IL-6) or heterodimerization (in the case of LIF,OSM and CNTF) can activate tyrosine kinases, which further regulate expression of target genes by some kinds of pathway.

Abstract:In the progress of the genome projects, the most important purpose of molecular biology of the gene is to investigate the structure and function of not only single important gene but also the whole genome, that is the gene transcription and expression patterns of the whole cell. In order to resolve such complex problem, revolutionary research methods must be developed. Serial analysis of gene expression(SAGE), cDNA microarray, DNA microchip are the novel methods for fast and quantitative analysis of gene characteristics which are recently advanced in this background.

Abstract:The androgen receptor(AR) belongs to the steroid hormone receptor superfamily that is a ligand-dependent transcription factor. It can regulate gene transcription through binding to specific DNA element. The action mechanism of androgen receptors is summarized with a special emphasis on the specificity of the function of androgen receptors.

Abstract:Therapy of hepadnvirus infection is still one of the most difficult problems for human beings.At present few drug can be used for therapy.Antisense strategies against hepadnviral infections gives a new hope for patients.A lot of study was carried out in vitro, and very good results were shown. Some investigation have been done in vivo. These results demonstrate the potential clinical use of antisense nucleotides for hepadnavirus infection.

Abstract:As a translator factor, CREB takes part in the transformation process from short term memory to long term memory, which has been evidenced in several different kinds of animals. In addition, its two forms as both activator and inhibitor with high conservation in their gene structures can mediate this transformation process in a more precise manner. Researches having been conducted so far and the recent progressed in this field were reviewed; the issues to be researched and addressed in future were also pointed out.

Abstract:Recently, several bone morphogenetic protein (BMP) receptors (ⅠA, ⅠB and Ⅱ) have been cloned and characterized. BMP receptors belong to the TGFβ receptors family of serine/threonine kinases. Both typeⅠ and typeⅡ BMP receptors bind BMP ligands, in order to elicit a signal, heteromeric complexes of typeⅠ and typeⅡ receptors are required. Using truncated and constitutively active BMP receptors, it has been shown that type ⅠA BMP receptor plays important role in mesoderm formation in vivo. Type ⅠB BMP receptor plays major roles in chondrogenesis, osteoblast differentiation and programmed cell death in vivo and in vitro. BMP receptor signaling molecules Smad1 and Smad5 are also cloned and characterized. They also play important roles in BMP receptor mediated function.

Abstract:A triglyceride enzyme sensor has been prepared by immobilizing lipase on pH glass electrode. The immobilized methods of lipase and the response characteristics of the sensor were studied.The linear range of detection is 3.09×10^－6～1.91×10^－3 mol/L for triglyceride with a slope of 32.7 mV/pC in the pH 8.5 Tris-HCl buffer solution at 37℃. The response time is 5～10 min. The sensor is relatively stable for 25 days.The sensor has been applied to the determination of triglyceride in serum with satisfactory results.

Abstract:The method of hight performance liquid chromatography(HPLC) was used to analyse the dynamic rule about accumulating β-carotene isomers in Dunaliella salina under the special stress conditions.The results show:1.The strength of stress conditions is advantageous to accumulate trans-isomer, otherwise,decreasing the stress conditions advantage to accumulat cis-isomers. For example, under the conditions of 32℃ with light intensity 10 000 lx, salinity 18%, the amount of trans-isomeris most (2.593 mg/L), but the cis-isomers amount is most (0.630 mg/L) under 25℃, indoornature light and salinity 24%.2.The kind and amount of cis-ismoers are different when the stress conditions are changed.After being cultured 30 days,trans-isomer and two cis-isomers were obtained under 25℃,indoor nature light salinity 24%,but only trans-isomer and one cis-isomer were obtained,when 32℃ with 10 000 lx light intensity and salinity 18%.3.Eventhongh the stress conditions is the same, it is different of the isomers'kind and amount only when culturing time is changed.For example: under the conditions of 25℃ 10 000 lx,18% salinity, only trans-isomer was found before culturing,after 8 days and 19 days,trans-isomer and two cis-isomer, after 34 days,trans-isomer and one cis-isomer were found.

Abstract:Epatein-Barr Virus(EBV) is isolated from B95-8 cell line, the primary B lymphocytes from human blood and tonsil tissue are transfected with EBV in order to gain immortalized lymphoblastoid cell lines(LCLs) and tonsil lymphoblastoid cell lines(TLCL). The LCLs and TLCL contain wt p53 gene, and do not express p53 proteins before treatment with cisplatin. Cell viability are decreased, p53 proteins are accumulated,and DNA ladders appear in LCLs and TLCL with time extension after treating with 10 mg/L. Lymphoma cell lines(BJAB, Raji, Ramos, Molt4) carring mutant p53 gene show accumulation of p53 protein before treatment with cisplatin. In paralleled experiment, the lymphoma cell lines appear relatively resistant to the doses of cisplatin. The results suggest that cisplatin cause DNA damage of LCLs and TLCL, activate wt p53 expression, and cells with DNA damage enter the pathway of apoptosis induced by wt p53.

Abstract:Both soluble abnormally phosphorylated tau and tau in paired helical filaments are abnormally glycosylated. Abnormally modified tau is incompetent in promoting the assembly of microtubules. Dephosphorylation of insoluble tau with various phosphatases restores differentially the biologic activity of tau in promoting the assembly of microtubules. Deglycosylation of tau enhances the above-mentioned activity caused by dephosphorylation although deglycosylation alone has no significant effect on restoring the biological activity of tau. These data suggest that abnormal phosphorylation of tau might be the direct factor for its deficient function whereas glycosylation might be an indirect one by affecting the structure of tau; that protein phosphatases might arrest and reverse the lessions in Alzheimer brain.

Abstract:Patch clamp is a useful method to study ion channels in cell membrane. By means of repatched whole cell, it becomes available to monitor the long term effect of some kinds of reagents on ion currents of a single cell without wash-out problem. After the cell was whole cell patched, drugs can be conveniently dialyzed into the cell from the pipette. The neurotoxicity of MPP⁺ in dopaminergic neuronal cell line (MN9D) was investigated with repatched whole-cell method. It was found that the voltage dependent calcium current (I_Ca) was significantly suppressed in differentiated cells and I_Ca induced by high depolarizing pulse decreased earlier than that induced by low depolarizing pulse during MPP⁺ treating for up to 1 h. In undifferentiated cells, no apparent change happened under the same condition.

Abstract:The influence of sulfated polysaccharide from brown seaweed Laminaria Japonica(SPS) on the respiratory burst of polymorphonuclear neutrophils(PMN) induced by phorbol myristate acetate(PMA) was investigated with the techniques of ESR，spin trap and oxygen spin probe.The results showed that SPS inhibited the respiratory burst of PMN significantly.10 g/L and 5 g/L SPS almost completely scavenged superoxide anion (O-·2) from the respiratory burst while 10 g/L SPS inhibited the oxygen consumption of PMN markablely， and 1 g/L SPS scavenged 53.2% O-·2.

Abstract:Using cDNA from normal human primary cultures of nasopharyngeal epithelial cells as tester amplicon and cDNA from nasopharyngeal carcinoma(NPC) cell line HNE1 as driver amplicon, four differential cDNA fragments were isolated by cDNA representational difference analysis(RDA).While these differential cDNA fragments were hybridized to amplicons by DNA blot, it was found that they really came from the tester amplicon.In addition,RNA blot also revealed that the differentially expressed fragments were not expressed or down-regulated in the NPC HNE1 cells;and sequence analysis also indicated that those differentially expressed fragments may include tumor suppressor gene relative to NPC. Therefore,it shows that the cDNA RDA is an effective，sentitive and specific method for screening the candidates of tumor supressor gene.

Abstract:Purification and refolding of bacterially expressed anti HBsAg ScFv by means of in situ refolding on column were investigated. Three refolding approaches were adopted: dialysis, in situ refolding via metal chelated chromatography and via gel filtration chromatography. The relative refolding index and relative recovery of the ScFv inclusion body were compared using the three procedures. The results showed that the refolding on gel filtration column(sephacryl S-200) was far more efficient than the other two approaches, with relative refolding index of 98% and relative recovery of 81%, illustrating the potential of this technique in production of recombinant ScFv.

Abstract:Human immunoglobulin heavy chain and light chain genes were separately amplied by PCR with cDNA as templates from human peripheral lymphocytes，using four 5′-primers and four 3′-primers corresponding to heavy chain, eight 5′-primers and two 3′-primers corresponding to light chain. At different annealing temperature, using the primers described above, all the light chain PCR products and 80% heavy chain PCR products were yielded. When signal sequences of immunoglobulin were used as 5′ primers, all remain heavy chain products were obtained by this half-nested PCR. This results indicate that more immunoglobulin variable region genes can be obtained by PCR through changed of procedures and reaction conditions, which can increased the diversity of antibody library.

Abstract:Three monoclonal antibodies against tumuor necrosis factor(TNF-α) were selected to biopan a 6-mer phage-displayed random peptide library. After biopannings, the enrichment of binding phages were estimated using a dot blot, ELISA, DNA sequence methods.These results showed that three to four rounds of biopanning could be enriched enough and the results also revealed that the screening of epitope would be easier with an antibody recognized a conformation-independent antigen than conformation-dependent one. Competitive ELISA assay and homological comparasion between the original antigen and the motifs were helpful to identification of epitopes.

Abstract:A spectrophotometer method was used to test oxygen radicals produced by a system of ammonium persulphate and tetramethylethylenediamine(AP-TEMED).The reaction of hydroxylamine and O-·2 produced NO-2 and then developed by sulphanilic acid and α-naphthylamine.The results indicated that there was a special absorption at 530 nm when the sample was tested by spectrophotometer, and its color responsiveness showed a quantitative relation to O-·2.Otherwise, ascorbic acid as a matter deleted oxygen radicals had a significantly quantitative relation too.

Abstract:Intact goat small antral follicles were dissected from ovaries by a micro-surgical method. The follicular DNA content was estimated by a fluorometric method using the fluorochrome, 4,6-diamidino-2-phenylindol-2HCl(DAPI).Significant positive correlations were found between the follicular diameters and follicular DNA contents in follicles smaller than 3 mm (r=0.9824＞0.7800=r_0.001,n=12). It suggested that this method of DNA assay would have great application value in study on follicular gowth and development.

Abstract:Fluorescence quenching method was to measure the proton pumping activity of tonoplast H^＋-ATPase from higher plants. The sensitivity of two common fluorescent dyes was compared. Acridine orange is better than quinacrine with the initial slope and maximum quenching. The optimim for the fluorescence measurement of acridine orange dye were:5 μmol/L acridine orange, 200～250 μg protein, Hepes-Tris of Hepes-BTP(pH 7.0). Initiating with ATP or Mg^2＋ was both valid.

Abstract:A new method for PCR products cloning——T-A cloning technique is introduced. pBluescript SK(+) plasmid was extracted by modified alkali lysis method. A blunt ends was generated using restriction enzyme EcoRⅤ, then T-A cloning vector was prepared in the presence of Taq DNA polymerase and dTTP. β-actin cDNA fragment was cloned into the above T-A cloning vector. After the recombinant plasmids were digested by EcoRⅠ and HindⅢ, an expected size of β-actin cDNA fragment was obtained.