Abstract:Apoptosis, an intrinsic cell death model which is regulated by organisms, is essential for the maintenance of tissue homeostasis in multicellular organisms. Recently, researchers on cell apoptosis have paid more attention on mitochondrion than on nucleus. Different death stimulus induces opening of PT pore, degradation of mitochondrial transmembrane potential, activation of caspase and inducing cell apoptosis. Bcl-2 and Bcl-X_L inhibit cell apoptosis via mitochondrion while Bax, Bak and Bad induce apoptosis by means of regulation of mitochondrion.

Abstract:The differentiating of neurons and other distinct cell types during embryonic development requires the selective activation or repressing of many different sets of genes. Gene expression patterns in neurons are modulated by multiple extracellular and intracellular stimuli. The transcriptional regulation of individual gene is mediated by small DNA sequences such as silencer and enhancer, and the expression pattern can be determined by the integration of the effects of a very large number of these cis-acting elements. These DNA elements either activate or repress promoter activity depending upon the nature of the transcription factors that bind to them . It is possible that there are different regulatory mechanisms of gene expression in the nerve system.

Abstract:Implantation window is the transient period when the embryos develop into blastocysts and the uterus differentiates into the receptive state synchronically. Estrogen and progesterone are the comprehensive regulating molecules during this process. They influence the proliferation and differentiation of multiple cell types in the uterus through the modulation of various local-signaling molecules. Uterus and blastocyst interact by the paracrine effects of prostaglandin, histamine, calcitonin, cytokines and growth factors at implantation window. This molecular cross-talk modulates the interaction between trophectoderm and uterine luminal epithelium. Once the implantation window is open, it then switches into unreceptive state spontaneously.

Abstract:Defensin is a kind of antimicrobiol and cytotoxic peptides which have been found in a large range of living organisms. The mammal defensins have the most wide range antimicrobiol spectrum. The distribution, structure, gene expression regulation of mammal defensins in China and abroad were summarized. Its application on medicine and plant resistant gene engineering were prospected.

Abstract:Focal adhesion kinase is a non-receptor protein tyrosine kinase with molecular weight 125 ku and regarded as the foundmental molecule of integrin-dependent signal transduction pathway. Active focal adhesion kinase regulates cell adhesion, migration, proliferation and differentiation by interacting with Src family kinase, phosphatidylinositol-3 kinase, cytoskeletal proteins, Graf and adoptor proteins through the phosphorylated tyrosines and the proline-rich sequences.

Abstract:The trophoblast is fetal-derived and in direct contact with maternal tissues. The expression of the various types of MHC antigen in trophoblast cells is very important for successful pregnancy. Among nonclassical MHC class Ⅰ antigens, HLA-G is expressed specifically on cytotrophoblast cells and its expression protects the fetal from maternal immune attack. The expression of the distinct subtypes of classical MHC class Ⅰ antigen is different in different subtypes of trophoblast cells. The expression of MHC class Ⅱ antigen is inhibited in trophoblast during pregnancy. It is suggested that CⅡTA plays an important role in regulation of MHC class Ⅱ gene expression.

Abstract:Gene therapy of spinal cord injury (SCI) is the most promising method compared with the others, because it doesn't involve the problems of resource and higher exclusion which respectively exists in fetal nerve transplantation and peripheral nerve transplantation. There are two ways of gene therapy to be chosen: one is to transfer objective genes to the target-cells in vivo directly; the other is to transfer objective genes to one proper kind of transplantable cells firstly, then graft the highest expressing cells to the target-cells in vivo. To realize the transfer of genes to cells, two measures are used in common: physical or chemical measure such as micro-infection et al and biochemical measure i.e. gene modified defective virus. Although there are some questions unresolved in this field, the clinical value of gene therapy of SCI in the future is depended.

Abstract:Cloning and identification of differentially expressed genes or proteins is helpful not only for finding the functions of genes and proteins, but also for discovery of the mechanism of some diseases. Some methods have been developed for screening differentially expressed genes, such as differential display RT-PCR (DDRT-PCR), subtractive hybridization (SH), DNA chip technique, and serial analysis of gene expression (SAGE). In subtractive hybridization, there have advanced three improved methods which include representational difference analysis (RDA), suppression subtractive hybridization (SSH), and full-length-gene-obtainable subtractive hybridization. For obtaining differentially expressed proteins, scientists have only two choices so far. One is two-dimentional gel electrophoresis. The other is phage display antibody repertoire library technique. Since all of the methods above have their own advantages and disadvantages, they should be used according to different needs.

Abstract:Senescence is one of the most important phenomena in cells' life. It is hold by one of hypothesis for cell senescence that residue DNA damages of a cell will accelerate its senescence. The normal function of surveillance and repair system for DNA damage is highly related with the senescence regulation of a cell. As a result, research of senescence regulation role of enzymes related for surveillance and repair of DNA damage, such as PARP, DNA-PK, ATM, p53, etc., will discover the inner relation between stress response of cell to DNA damage, regulation of DNA damage repair and cell senescence. That may be helpful for research of anti-aging and treatment of tumor by regulation of senescence of tumor cells.

Abstract:Great efforts have been done to reveal the secretary pathway of protein in the recent years. And RTN (reticulon) is a gene family localized on the membrane of endoplasmic reticulum. Up to now RTN1,RTN2,RTN3,RTN4 in this family have been found. While further studies to dissect the concrete function of these genes in the protein secretary pathway and to identify the RTN1 as a marker of specificity of neuroendocrine secretion and its relation to the differentiation of neurons have been doing.

Abstract:Recent research has revealed that scorpion venom contains short-chain peptides with the specificity on K⁺ or Cl^－ channels, in addition to the knowledge of many kinds of long-chain peptides with the specificity on Na⁺ channels. According to the similarity of molecular structure and/or function, they have been classified into several groups. These short-chain scorpion peptides are playing more and more important role in studying the structure and function of K⁺ or Cl^－ channels. The advance of structure and function of short-chain scorpion peptides in recent years was briefly introduced.

Abstract:During recent years, some new methods for phage display panning have been developed by using complex biological systems instead of purified antigens, antibodies or receptors as selector targets. These complex biological systems include living cells, viruses, mouse tissues and tumors etc. The peptides identified by using tumors as selector molecules can selectively home to blood vessels of experimental tumors and may have potential applications in targeted anti-tumor treatment.

Abstract:A variety of extra-cellular signals could activate the target molecules and induce the associated biological effects depended on different signal pathways. Apoptosis,or programmed cell death, is a conservation process essential for normal development and homeostasis of biologist. It's known that a number of factors and pathways can lead to apoptosis. Specific phosphorlipids and proteins of biomembrane could activate the signal cascades of apoptosis. The interaction of caspases, bcl-2 family and mitochondria play an essential role in regulation of apoptosis.

Abstract:although there are many repair pathways in cells, some lesions still escape repair inevitably and remain in genome. In cells, the molecular mechanism of translesion DNA synthesis has been one of the major unsolved problems in DNA repair for a long time. Recently, it was found that the members of a structurally related UmuC/DinB protein superfamily have DNA polymerase function. Unlike the classical replicative DNA polymerases, these newly identified DNA polymerases can carry out translesion DNA synthesis in both error-prone/mutagenic and/or error-free ways. It was also found that their functions are conserved from bacteria to human.

Abstract:24 new cDNA sequences encoding cytochrome P450 were amplified respectively from deltamethrin-susceptible and -resistant strains of the mosquito, Culex pipiens pallens, with a pair of degenerate primers according to the conservative amino acid sequences of CYP4 in insects by RT-PCR. Studies of molecular systematics show that the 24 new genes (alleles) belong to CYP4C,CYP4D,CYP4H and CYP4J subfamilies of the CYP4 family, and they were named by Cytochrome P450 Nomenclature Committee. Among the new genes(alleles),CYP4C23 may be a pseudogene, CYP4H13 has a retained intron 58 nucleotides in length, and CYP4J4V1 has a stop coden(TAG) in frame near the 3′-end.

Abstract:The chimeric gene of ACTH(4-10) with GDNF was constructed by PCR amplification. The fused gene was inserted into the expression vector pET-28a(+) and expressed in E.coli. with a level of 30% of the total bacterial proteins. The expressed product was purified by Ni²⁺-NTA resin, up to 85% purity. The results of activity assays showed that the chimeric protein could significantly promote the survival of spinal cord neurons and had a higher neurotrophic activity than ACTH(4-10) and GDNF respectively.

Abstract:To look for new genes from human brain，get a fragment was obtained using adaptor primer and 3′anchor polymerase chain reaction (PCR) with the human adult whole brain cDNA as template. The fragment was cloned into T easy vector and automatically sequenced with 310 Genetic Analyzer. Later the whole length cDNA of this novel gene was got with the method of 3′rapid amplification of cDNA end (RACE). The whole length of cDNA of this novel gene is 2 024 bp. Chromsome location is at 14q11.2 including 16 extrons and 15 introns. After scanning the sequence against GenBank it is proved that the sequence is a new one. ORF analysis showed that there is a complete coding region in it,it can interprate a protein containing 357 amino acid residules. ProDom analysis result showed that there is an acyl carrier protein (ACP) like domain in it. The gene was banked into GenBank.Then, a pare of primers were designed and were used to amplify the coding region and cloned into pGEX-4T1 expressing vector to express it in E.coli. The Dot blotting and Northern blot showed that this novel gene is highly expressed in the normal adult human brain.

Abstract:In order to obersve the effect of dexamethasone on the secretion of apolipoproteins AⅠ，AⅡ，CⅢ，B100 and E by cultured HepG2 cells. The apolipoprotiens contents in culture media were measured by radioimmuodiffusion assay (RID) kits developed by authors' research unit. 20-fold lyophilizely condensed culture media were used for the assays.The results showed that dexamethasone can increase the secretion of apoC and E, and inhibit the secretion of apoAⅡ,B100 and CⅢ;and the effect of dexamethasone were strengthened in a dose-dependent manner. When the concentration of dexamethasone was 5.5×10^－5mol/L in the culture media,the secretion of apolipoprotein AⅠand E increased 36.6% and 49.4%（P＜0.01）respectively, while the secretion of apo AⅡ,B100 and CⅢ decreased 38.9%、31.9% and 29.8%（P＜0.01）respectively.

Abstract:With redox-sensitive fluorescene probes DCFH-DA and DHR123, the formation of cytosolic and intramitochondrial reactive oxygen species (ROS) inside immature rat cerebellar granule cells during the apoptosis induced by nitric oxide donor S-nitroso-N-acetyl-pennicillamine (SNAP) was monitored by laser confocal scanning microscopy. The cytosolic and intramitochondrial ROS increase significantly after 0.5 mmol/L SNAP treatment for 1 h. Pre-treatment with the nitric oxide scavenger hemoglobin can effectively inhibit the formation of cytosolic and intramitochondrial ROS and protect neurons from apoptosis. Adding glutathione can also protect neurons from apoptosis, and the cytotoxity of nitric oxide increases significantly while the synthesis of glutathione is inhibited. The results indicated that ROS might be involved in NO-induced apoptosis in neural cells and glutathione might be the endogenesis antioxidant to protect neurons from oxidative injury.

Abstract:Hirudin is one of the most potent anti-coagulant protein ever found, and its C-terminus is a key domain for inhibiting thrombin. In order to enhance its specificity, a novel anti-coagulant protein was constructed via fusing the C-terminus of hirudin to AnnexinⅤ, which was expected to sustain both anti-coagulant activity and phorspholipid affinity. The structure of the designed protein was predicted with both molecular mechanics and dynamics. Molecular dynamics was adopted to simulate the docking interaction between the fusion protein and thrombin. The results showed the inhibitory activity of the fusion protein to thrombin.

Abstract:Synaptosomes were isolated from pig brain by homogenization, differential centrifugation and sucrose gradient centrifugation. After synaptosome lysis in hypoosmotic buffer, the plasma membrane vesicles were collected. Following the solubilization of plasma membrane vesicles in Triton X-100, the solubilized protein was applied to calmodulin affinity chromatography column, and the delipidated plasma membrane Ca²⁺-ATPase was purified to nearly homogeneity. The novel feature of this purification is the use of large affinity column and heavy washing to facilitate the purified Ca²⁺-ATPase with higher activity and protein yield. The specific activity of the purified Ca²⁺-ATPase was recovered to a maximum of 3.32 μmol·mg^－1·min^－1 after incubation with asolectin. Silver staining of SDS-PAGE revealed a single protein band around M_r 140 000, showing the purity was over 90%. Different Ca²⁺ concentrations dramatically affect the specific activity of Ca²⁺-ATPase.

Abstract:The extraction method with organic solvent extraction to detect nitric oxide was improved, and the production of nitric oxide in mice myocardium in vitro was detected with this method. Using organic solvent (DETC)₂-Fe²⁺-NO complex was extracted from water phase into ester phase, and nitric oxide in sample of large volume can be detected by ESR at room temperature. The extracting ability of several organic solvents such as ethyl acetate, butyl acetate, glycerol triacetate, iso-amy lacetate, and n-butanol, was compared, and it was found that ethyl acetate was a good kind of organic solvent. There was a good linear relationship between the concentration of nitric oxide and ESR intensity within concentration of 20 μmol/L, and the detected limit was improved to below 200 nmol/L; (DETC)₂-Fe²⁺-NO complex is easy to decompose in light but it is very stable in dark at 0～4℃ which, there is only a little change after ten days.

Abstract:To clone overexpressed gene from human gastric carcinoma cell SGC-7901, DDRT-PCR technique is used with human gastric epithelial cell GES-1 as control. After cloned into pGEM^?-T vector, YA61,one of the overexpressed genes, was analyzed by dot blot and was sequenced then. The sequence gotten was then compared to GenBank data and analyzed by NCBI ORF Finder. Dot blot results showed that the gene YA61 was overexpressed in human gastric carcinoma cell SGC-7901. NCBI's sequence similarity search indicated that the gene YA61 was a new gene sequence. Open reading frame analysis demonstrated that the gene YA61 had one complete open reading frame. In conclusion, the gene YA61 was a new gene sequence that was overexpressed in human gastric carcinoma cell SGC-7901.

Abstract:An in vitro model was built for researching the effects of strain on vascular smooth muscle cells (VSMCs). The cultured VSMCs was stretched by four-support-bending-beam system, then the project area of cells was measured by computer-image-processing, the adhesion force was measured by micropipette-aspirating system, the α-actin of VSMCs was distinguished by immunocytochemistry and the dynamic of VSMCs was determined by FCM. The results show that: (1) The adhesion force of VSMCs is positively related to time. The adhesion force of unit area is indistinct after stretched for four hour. (2) The amount of α-actin increases with stretching time. (3) The proliferation of VSMCs is a little inhibited by stretched 24 h. These results suggest that the VSMCs in vitro could adjust their behavious to adapt the tension.

Abstract:To compare the luminescent characters in different bacteria of two different recombinant mycobaceriaphages by using biolimenescent methods in order to understand the differences between sensitivity and specificity of these phages, and to set up methods to use recombinant mycobacteriaphages in detecting drug suscepbility of mycobacteria. Result showed that both two phages have high light production in action with mycobacterium selectively and have almost no light production with E.coli, the difference is very obvious. Among different mycobacterium, BCG has the highest light production and mycobacterium tuberculosis has the lowest light production. The sensitivity of Phage 88 is higher than Phage 40, the difference is obviously. It can be considered that both recombinant mycobacteriaphages can detect mycobacterium specifically, but Phage 88 is more suitable for clinical usage.

Abstract:In order to obtain liposomes with properties of heptocyte-specificity and pH-sensitivity, four galactosylated derivatives were synthesized. A series of liposomes were prepared by mixing the galactosylated derivatives with DC-chol/DOPE respectively. The liposome 18-gal was proven to have favorable gene transfer efficiency to human hepatoma HepG2 cells, which was significantly inhibited in the presence of galactose solution, indicating that the liposomal transfection activity was mediated by asialoglycoprotein receptors. The liposome showed prominent pH-sensitivity and low cytotoxicity. Its optimum gene transfer conditions were also determined. The results showed that the liposome may be developed as a potential hepatocyte targeting pH-sensitive delivery system for nucleic acid drugs.

Abstract:The radioassay of glutamic decarboxylase(GAD) was modified by taking NaOH as trapped agent instead of phenylethylamine. The results showed that the coefficient of variation (CV) within same sample was 9.6% and the radioactivity remains stable after 72 hours if use NaOH as trap agent. It is significantly stable than use phenylethylamine as trap agent, which the CV was 31.9% and the radioactivity decreased 47% within the first hour and decreased to background after 6 hours. The reabsorption experiment shows over 80% of ¹⁴CO₂ can be reabsorption by NaOH within 6 hours. It is suggested that NaOH is a much better trap agent than phenylethylamine and the sensitivity can increase 1.66 folds. Using this method the GAD activity in 0.39～17.8 mg of brain tissue can be measured and it is success in determine the GAD activity both in rat brain tissue and cultured neurons.

Abstract:The use of microarrays of oligonucleotides or cDNA is considered to be a promising approach for DNA and RNA sequence analysis, diagnostics of genetic diseases, gene polymorphism studies and analysis of gene expression. To manufacture cDNA microarrays the samples were printed onto glass microscope slides treated with poly-L-lysine, and then the slides were processed by heat and UV light treatment to attach the cDNA sequence to the glass surface. But the immobilization efficiency of cDNA on the glass surface was low. A simple procedure for manufacture cDNA microarrays on a slide treated with 3-aminopropyltrimethoxysilane is described. The efficiency for attaching cDNA to the amino-modified slides is greater than that to the slides treated with poly-L-lysine. The cDNA microarray made by the amino-modified slides is stable for use in 80℃, 75% humidity, 3 600Lx light, exposure in air, respectively.

Abstract:The biosensors based on biocatalytic and immunosensors have gained increasing applications in environmental biomonitoring. Along with the advances in molecular biology and biotechnology, the DNA biosensors, based on DNA interaction and using nucleic acid as recognition element, was developed. They can be used for the hybridization detection of nucleic acid sequences from infectious microorganisms, for monitoring of priority pollutants and for the interacting study of pollutants and DNA. They possess a great potential for environmental monitoring. The principle of nucleic acid hybridization biosensors and their applications for the detection of environmental microorganisms and the priority pollutants was briefly described.