Abstract:The principle of surface plasmon resonance and the applications of this theory,particularly in biological fields are reviewed.Using this technique,the experimental system can be directly probed and followed in real time and in situ without the requirement for additional parameters, such as labelled moleculars.With high sensitivity,the sequential reactions during adsorption or desorption can be monitored. So far, the applications are involved in biological binding analysis, kinetics, affinity measurement, immuno-distinguish, structure-actmty study and nucleic acid research, etc.

Abstract:In situ PCR is a novel technique in the field of molecular biology.It combied advantages of both PCR and in situ hybnridiztion(ISH).Its origin, development and methodology are intoduced.Its application and prospect are also discribed briefly.

Abstract:One of the most important mechanisms to regulate DNA replication in eukaryotic cells is to regulate the initiation of the replication. Investigations into SV40(simian 40)and Saccharomyces cerevisiae systems provide instructive suggestions to the mechanisms of replication initiation in eukaryotic systems and maneuvers with which the initiation are concerted with cell cycle. Many functions of protein factors involved in initiation of replication in eukaryotic cells are being clarified. And the cycle-dependent regulatory pattern is gaining experimental supports. Two regulation points in cell cycle for DNA replication initiation and the roles played by cyclins are mainly introduced. The relationship between carcinogenesis and the disturbance of replication-cycle is also discussed at appropriate point, which hints at the significance of initiation regulation.

Abstract:Apoptosis is a programmed cell death which can be triggered off by cells in response to variuos physiological and pathological stimuli. Recently;studies on apoptosis of tumour cells have attracted much attention.Some methods to detect apoptotic cells have been developed on bases of the typical morphological and biochemical changes during apoptosis.The application of flow cytometry(FCM)in the study of cell apoptosis. especially the value of some new methods based on FCM is described in detail.

Abstract:In living cells,exploiting homologous recombination between sequences both from genomic DNA and extracellular DNA to accomplish site-modification in a certain gene on chromosome,is a method called gene targeting.Although the molecular mechanism of DNA homologous recombination is far from being elucidated, it is a common biological phenomenon.It is true that in cells there is an enzyme system that plays the role to make recombination of homologous DNAs, which is the theoretical foundation of gene targeting. The technology of gene targeting has been fully developed. The key step for operation is to construct a recombinant carrier including one or two genes for selection and to transfer it into the nucleus effectively. The targeted cells can be inherited stably. Gene targeting has promising prospects in production of new strains of living things, in clinical usage and in theoretical research of some complicated biological phenomena such as the molecular mechanism of development.

Abstract:Protein-protein interaction is the basis of many phenomena including replication,transcription, secretion, signal transduction,metabolism et al. Designed genetically,twohybrid system can be used to detect protein-protein interaction in vivo. An unknown protein which interacts with certain target protein can also be found by using this method.Consequently, the DNA sequence encoding the unknown protein can be cloned,the key amino acids involved in the interaction can also be decided. Drawing protein linkage map is its another application. Being used in drug design, two-hybrid system will have a more practical value in future.

Abstract:In recent years PCR technique has shown its advantages and flexibility with the development of its methodology.This not only extended its application, but also promoted therapid development of molecular biology.The advances of PCR used in gene and protein engineering are reported here,including ligationindependent cloning, random- primed/ anchored PCR, random rapid amplification of cDNA ends, recombinant PCR and megaprimer PCR.

Abstract:Shortening of the chromosome caused by DNA incompleted replication of chromosome end (telomeres) at each cell division leads the cells to lose proliferative capacity and senescence.Telomerase elongates telomeric DNA.And the unlimted cell proliferation needs telomerase activation. About 85% of malignacy express positive for telomerase.The formations and functions of telomeres and the effects of telomerase on the telomere synthessis are reviewed.The measuring of telomerase and the relationship between cancer cell and activation of telomerase are also introduced. The possibility of the cancer treatment by the telomerase inhibition is discussed.

Abstract:Random or arbitrary primers, in contrast with common specific primer,refer to the non-specific oligonucleotides used as primers in DNA synthesis.In 1990's several new techniques were developed as a result of combination of random primers and PCR. RAPD, AP-PCR and DAF by random primers with different length were used for DNA fingerprinting. Differential display was used for polymorphism analysis of mRNA.rPCR,T-PCR and so on derived from application of random primers were discussed too.The technique characters and applications in molecular biology research of random primered PCR were introduced particularly in RAPD.

Abstract:The recent advance of the plasmodesma-associated proteins(PAPs) in plants was reviewed. The homologies between plasmodesma-associated protiens and animal gap junction connexins, the localization of PAPs,the phosphorylation of PAPs and the molecular biology of PAPs were included. The research prospects of PAPs were forecasted as well.

Abstract:The biological functions of glial cell line-derived neurotrophic factor purified recently and its distribution in rat embryo were described.The survival-promoting, restoring and regeneration activities of GDNF on injured motoneuron and dopaminergic neuron were emphasized.

Abstract:A new nucleic acid hybridizing assay, piezoelectric quartz-sensor which is capable of quantitative analysis has been established on the basis that the frequency of piezoelectric quartz vibration is the function to its surface sediment. The technique is simple, specific and sensitive up to 100 pg.It uses the rapid,sensitive frequency messages as the demonstration system of nucleic acid hybridization.

Abstract:A simplified procedure for the purification of adenosine deaminase(ADA)from human thymus based on immuno-affinity chromatography of anti-human thymus ADA IgG was described. After ammonium sulfate fractionation, immuno-affinity chromatography and Sephadex G-100 gel filtration. ADA was separated as homogeneity from human thymus.The yield and the specific activity of purified ADA were 34.15% and 14898 U/mg respectively. The purified ADA molecule consists of about 380 amino acid residues giving a Mr of 41.3 ku and pI of 4.9. The optimum temperature is 37～40℃. The optimum pH is 7.0. Using adenosine or 2-deoxyadenosine as substrate the apparent K_m of the enzyme is 83 μmol/ L and 61 μmol/ L respectively. The enzyme activity can be inhibited by p-chloromercuric benzoic acid while partially restored by dithiothreitol. ADA activity was decreased by anti-calf ADA IgG and anti-thymus ADA IgG.

Abstract:After the lysines on the surface of Cu,Zn superoxide dismutase are modified,the enzyme stability increases remarkably.The rearrange of charge structure of the enzyme due to modification results in the change of enzyme electrostatic field.The finite difference solution to the Poisson-Boltzman method is used to calculate the change of electrostatic field and the effect on Cu, Zn ligand structure which play an important role to stabilize the enzyme.The results show the first and second decomposition constants of Cu, Zn ligand complex are reduced by 10³ and 10⁶ after modification respectively.

Abstract:The solubility of the protein can be increased by citraconic anhydride(CT)modification. According to this principle, the effects of the CT modification on the fusion protein using rhGM-CSF as a model which contain thrombin cleavage sites have been studied.The result demonstrated that the process of denature and renature in the modified protein was much easier than that in unmodified counterpart. In addition the modified protein is more sensitive to thrombin digestion, one percent amount of thrombin was enough to achieve the complete digestion. The modification by CT did not effect the bioactivity of rhGM-CSF. A new way was paved in the purification of recombinant protein by CT modification method.

Abstract:The arterial smooth muscle cells (SMC)are the predominant type of cells within atherosclerotic(As)lesions,and their proliferation plays an important role in the process of As genesis.On the basis of the establishment of primary culture and sub-culture method for human arterial SMC,the effects of LDL, VLDL,HDL,OX-LDL,OX-VLDL, OX-HDL on DNA synthesis of cultured human arterial SMC wereobserved.Results are as follows:(1) HDL had no stimulating effect on ³H-TdR incorporation into DNA of SMC (P>0.05),(2) LDL and VLDL showed the obvious stimulating effects (P<0.05);(3) OX-LDL, OX-VLDL and OX-HDL increased siginificantly ³H-TdR incorporation into SMC DNA, respectively (P<0.01). These results suggest that the atherogenic roles of LDL, VLDL, OX-LDL, OX-VLDL, OX-HDL are closely related to their stimulating effects on DNA synthesis and the proliferation of the arterial SMCs.

Abstract:An enzyme reaction system which contains L-Arg、NADPH、FAD、FMN、BH₄、Ca²⁺ etc,has been studied to determine the activity of nitric oxide synthase (NOS) in rats'brain. Alter being incubated at 37℃ for 80 min in dark with samples,the sulfanilic acid and N-(1-naphthyl)-ethylenediammonium was added to the reaction system to measure the concentration of produced nitrite in system.It was found that the optimum pH for the enzyme reaction was 7.4,Km was 0.1 mmol/L.There was a relationship between the amounts of sample and nitrite concentration in the system. This method is simple and convenient. Intra-assay CV value is 3.69% and inter-assay CV value is 5.16%. The specific activity of nitric oxide synthase in ten rats' brains is (39.61±7.64)nmol/(min·g).

Abstract:TAME (N_α-p-tosyl-L-arginine methyl ester) is a specific substrate of trypsin. N_α-p-tosyl-L-arginine is released from TAME after tryptic hydrolysis,which reacts with NaOH in the assay mixture and causes the decrease of pH.Using phenol red as the indicator, the PH change of the solution can be monitored by the decrease of the absorbance at 555 nm. The decrease of A₅₅₅ is directly proportional to the amount of trypsin with a linear range of 0.001～0.3 mg.The method is very convenient to use, highly sensitive and specific.

Abstract:Hydroxyl radical produced by H₂O₂/Fe^2＋ was assayed by the new method.After oxidized by hydroxyl radical the A₅₃₆ of 1, 10-phenanthroline-Fe^2＋ decreased apparently.The △A₅₃₆ was dependent upon the dosage of 1, 10-phenanthroline, FeSO₄ or H₂O₂ individually. The △A₅₃₆ increased as the reaction lasted. It was demonstrated that the hydroxyl radical scanvenge effect of mannitol, ascorbic acid and thiourea was dosedependent by the new method.

Abstract:The coding sequence of glial cell linederived neurotrophic factor (GDNF) was amplified from human genomic DNA by PCR method.Recombinant GDNF was expressed in E. coli and purified.

Abstract:The coomassie brilliant blue (CBB) protein assay first developed by Bradford became an alternative for an ever-increasing number of researchers because of its simplicity, rapidity and being free from interference by some common laboratory reagents which have been shown to affect the lowry assay. Despite all its advantages, many problems have been encountered by researchers in using this procedure. One of the main drawbacks of this procedure is the nonlinearity which has been noted since Bradford developed the CBB-protein assay. The effect of ingredients in color-developing reagent on the absorbances at 465 nm and 595 nm, of free CBB and protein-binding CBB mixture was tested respectively. The results showed that the main factor which affects the linearity of calibration curve is H⁺ concentration. A new color-developing reagent formula which consists of CBB, HCl and NaCl, may improve the nonlinearity.

Abstract:A phosphatase activity assay where p-nitrophenyl phosphate was used as substrate was improved by use of the terminating reagent containing 1 mol/L NaOH-0.2 mol/L EDTA. A better assay result was obtained.

Abstract:The gene transcription induced rapidly in mammalian cells by treatment with ultraviolet light(UV)and other DNA damaging agents is termed UV response and was regarded as the results of DNA damage formerly. Whereas this view is challenged by facts acquired in recent years.There several contradictory evidences were discussed and some proposals about the mechanisms of UV response triggered were brought out.The functions of UV response were also involved.