Abstract:Haptoglobin, belonging to the group of acute phase reactant proteins in the serum, is an acidoglycoprotein, and exhibits genetic polymor-phism by the difference inthe types of light chains it contains. The biosynthesis and degradation of haptoglobin are mainly carried out in the liver and regulated by some cytokines, prostaglandins and hormones. Haptoglobin has multifaceted biological activities, so it is believed that haptoglobin may be an iniportant regulating protein to be present in the serum.

Abstract:The chemical structures and physiological functions of spider pepude neurotoxins have been reviewed and introduced. These neurotoxins can be classified briefly, into two groups according to their size. The short spider neurotoxins contain 33 to 40 amino acids residues, whereas the long ones have 66 to 77 residues. The homologies of the neurotoxins from different species are not evident and the physiological activities are quite difftirent. Some spider neurotoxins were found to selectively affect the sodium or calcium channels of the neuro-muscular system of the insect and vertebrate and were believed to be useful as tools in neurophysiology and pharmacology studies.

Abstract:Glutathione is the major nonprotein sulfhydryl present in cells and plays an important role in the deactivation of oxygen radicals, organic hydroperoxides and electrophiles. However, recent studies show that conjugation of glutathione with some vicinal dihaloalkanes,haloalkenes. quinoid compounds, isocyanates,isothiocyanates aldehydes, α, β-unsaturated aldehydes etc, will lead to the formation of toxic metabolites.

Abstract:A family of POU-domain proteins is a class of DNA specific transcription factors that contain homeodomains (HD) . During development of the central nervous system (CNS) , the spatial and temporal expression for the POU-domain proteins may play a crucial role in the appearance of neuronal phenotypes via both homodimeric and heterodimeric protein-protein interactions and DNA-protein interactions in qene requlation.

Abstract:In the myofibril of striated muscle, there are three myofilaments thick, thin, and fine myofilaments. Titin (connectin) is a giant elastic contractile protein, with molecular weight of 3000 kD and length of 0.9pm, and forms fine myofilament extended from M-line to Z-line in the myofibril. It may play roles in maintaining thick myofilament in the middle of sarcomere, acting as molecular template for assembly of thick myofilament, and modulating the myosin activity.

Abstract:More and more foreign genes have been expressed in the silkworm larvae or silkworm cell lines using the Bombyx mori nuclear polyhedrosis virus (BmNPV) as a expression vector.The expressed products involve in many fields such as pharmaceutics, medical diagnosis, vaccine production and biological control. The characteristics of BmNPV and its genome structure,characteristics of polyhedrin gene,construction of recombinant BmNPV and its expression in the silkworm larvae and cell line, and efficiency of production for the foreign gene products expressed in the silkworm-BmNPV system and application of the expressed product were described systematically in the review.

Abstract:V-ATPases are present in large numbers of organelles including lysosomes, endosomes, golgi complex and several secretory granules in animal cell. The function of V-ATPase is to generate protonmotive force and to cause limited acidification of the internal space of vacuolar system and extracellular compartments at the expense of ATP. The acidification and the electrochemical H^＋ gradient formed by V-ATPase serve an improtant function in endocytosis , exocvtosis, membrane traffic and transport systems of cells. In the families of H^＋-ATPases, increasing attention is being given to V-ATPase, about which much has been learned in recent years.

Abstract:Interferon-stimulated genes (ISGs) is the central part of the research on interferon (IFN) function mechanism. After IFN binds to its receptor, through signal transducing in cytoplasm, activates the special transcription factors to attach the ciselements existing on the uostream of ISGs in nucleus and then induces gene expression. The paper reviewed mainlyon the signalling pathway and the products which play antiproliferative action of ISGs expression.

Abstract:Molecular cloning studies on five types of dopaniine receptors were summarized. The five types of dopamine receptors are members of family of the G protein-coupled receptors,and divided into two classes by pharmacologic and biochemical criteria (a) D₁R and D₅R mediating the activation of adenylyl cyclase through G protein (G_s) and (b) D₂R, D₃R, D₄R, inhibiting the activation of adenylyl cyclase through the G protein (G_i) . The gene structure, distribution of their mRNA in the brain and location on chroniosomes between the two classes of dopamine receptors were compared.

Abstract:A system, using a cooled slow-scan charge coupled device camera attached to a fluorescence microscope, allows a series of images to be stored, up to 500 fluorescent spots (labelling particles) per image can be identified by position and intensity. The movement of the spots can be traced. The tracking method allows the mobility to be analysed. The receptors of influenza virus and low density lipoprotein on fibroblast have three different types of motion: random motion, directed motion and motion limited to a domain. The high sensitivity of the system leads to short exposures and little photobleaching during the observations. The measurement principle of this system and its biological applications were described.

Abstract:Vascular endothelial growth factor (VEGF) is a specific mitogen on endothelial cells and promotes angiogenesis. It has been identified that VEGF is very closely linked to the growth of solid tumors. With Dot blot technique, expression of the VEGF mRNA in cancers of stomach, kidney, bladder and colon are investigated. The results showed that the expression of the VEGF mRNA is higher in tumors than in peritumors. There is significant expression of VEGF mRNA in SGC-7901 cells after adding TPA 4h. Human bladder carcinoma cell line BIU-87 transfected with antisense N-ras exon 1 DNA fragment inhibit VEGF mRNA expression.

Abstract:Two 23-mer unmodified oligodeoxynucleotides have been synthesized, one to hybridize with the region across the transcription initiation site of TGFa cDNA called antisense, and the second with an identical base composition, but the nucleotide sequence randomized. The random oligodeoxynucleotide was used to control for any non-specific effects of the oligodeoxynucleotides. TGFα antisense inhibited cell proliferation and DNA synthesis from 31% to 44% and 25.8% to 88.0% respectively. This effect is specific and dose-responded. However, at the same condition, the inhibition by random is only 10% to 17% and 17% to 27%.This effect is not dose-responded. By RNA dot blot analysis，the addition of 3μmol/L TGFa antisense and random upon BIU87 cells resulted in 61.4% and 42.5% inhibition in TGFa mRNA expression respectively. These results suggested that TGFa may play an important role in the proliferation of BIU87 cell line and provide a rational basis for the development of selective cancer therapeutical approaches.

Abstract:The expressed CH925 was aggregated into inclusion bodies (IB) in E.coli cytoplasm. The IBs were isolated by centrifugation and sonication. CH925 were refolded and reoxidateo in a glutathione redox system following denaturation of the IBs in 7mol/L guanidine hydrochloride. The specificactivities of IL2 and IL6 assayed by CTLL-2 and 7TDl cell line were 2.2×10⁶U/mg and 2.3×10⁸U/mg, respectively,following renaturation. The renatured CH925 was chromatographed through DEAE-Sepharose 6B column and Sephacryl and column. The active fractions were pooled and applied to HPLC with reversed-phase C-18 column, while CH925 was eluted through 10%-70% acetonitrile gradient. It showed only one pratein peak and SDS-PAGE confirmed that the purified CH925 was almost homogeneous.

Abstract:The C : G base-pair at position -17 in the spacer of β-lactamase gene promoter was removed by restriction with BspH Ⅰ. partial filling-in with Klenow fragment, and trimming with niung bean nuclease. The β-lactamase activities of both bacteria harboring the wildtype and C-17 deleted plasmids were determined using ampicillin as substrate, and the tolerances of the bacteria to ampicillin were tested. The results indicate that the C-17 deletion increases the promoter strength by about 60%. The mutant has more resistance to ampicillin. The half-inhibition concentration of ampicillin for the mutant growth is 280μg/ml. At the same concentration, the wild-type cell density is only about half as much as that of the mutant. The causes for the promoter-up mutation were discussed.

Abstract:Maleinimide was used as spin label for studying the effect of metallothionein (MT) on the conformation of erythrocyte membrane by ESR technique. The results show that the presence of different MTs resulted in considerable changes of the ESR parameters. W/S and τ_e. implying that MT can interact strongly with membrane. The experiments carried out in vitro demonstrated that MT could be absorbed on the surface of erythrocytes. In addition, rab-hits were in Jected s. c. with CdCl₂ to induce the biosynthesis of MT, the presence of MT mainly in the erythrocyte is first suggested after chromatographic separation of plasma and blood haemolysates from Cd-loaded rabbits. It is claimed that a dynamic equilibrium could be established between MT absorbed on the surface of erythrocytes and presence in plasma. The significance of the above findings is disscussed in brief.

Abstract:Sephadex LH-20 and silica gel centrifugal liquid chromatography were applied to isolation and purification of gangliosides from the pig brain. The highly purified gangliosides were obtained. The concentration of lipid-bound sialic acid determined is 30.1% (W/W). The results determined by silica gel G-60 HPTLC and 580nm scanning were GM1 19.5%. GD3 13.8%, GD1a 27.8%, GD1b 14.2% and GT1b 19.3%.

Abstract:An affinity chromatography column for isolation and purification of metallothionein (MT) was prepared with Chelating Sepharose Fast Flow gel bound with bivalent copper. Zinc-induced rabbit liver, or cadmium-induced mouse liver was homogenized and precipitated with ethanol. The sample was applied on the column and equilibrated with pH4.0 acetic acid buffer. Then pH5.2 of different concentration acetic acid buffers were used for elution of MT. Two eluted peaks were obtained and identified as MT-2 and MT-1. Comparing with the traditional method——gel filtration and ion exchange chromatography, this method is simple and time-saving in laboratory-scale.

Abstract:Irradiated cells express DNA structural damages. such as DNA double-strand break. DNA-DNA crosslink and DNA-protein crosslink etc. These damages result to changes of DNA supercoil state, which trigger a series changes of DNA replication and expression. Many methods to test DNA damages have been established, roughly can be devided into two kinds according to the DNA materials used. The first use the naked DNA extracted from cells and free from DNA-binding materials existed in cell. The second one uses nucleoid for research, here the detergents and hypertonic salt buffers were used to remove nuclear envelope and a part of nuclear proteins, nuclear DNA remains appropriate tangled loop and binds to residual nucle-arskeleton. This DNA structure is beneficial to research damage effects on DNA structure, single cell gel electrophoresis belongs to the latter. It also named comet assay because its cell electrophoresis shape looks like a comet. It can test not only DNA stand break but also measure DNA structure changes resulted from stand bleak. According to oversea reports, with slight modification, single cell gel electrophoresis assay has been established Employing image analysis system. fast quntitative measurement of DNA structure changes of single cell irradiated as low as 0.1Gy can be given with a well correlated dose-respones relationship. After further study, the method might be developed as a kind of biodosimeter for application of monitoring enviromental low level irradiation.

Abstract:Soluble proteins mainly containing G_s (stimulatory GTP-binding protein) and adenylate cyclase (AC) from cell membranes of bovine brain cortex were extracted with 1% sodium cholate and 15% saturated ammonium sulfate. Separation of G_s and AC was carried out by Sepharose 6B gel filtration. Purifiled G_s can be obtained by passing the fractions containing G_s from Sepharose 6B column through a heptylaminc Sepharose 4B hydrophobic column. The purity of G_s was identified by its highly stimulated activity to AC and SDS PAGE which showed two bands of 45kD and 36kD. The procedure described above is characterized by simplicity, rapidity, repeatability and high yield.At the same time,AC,a by-product which was not contaminated by G_s, can be used for assay of G_s, activity after reconstituting it into asolectin vesicls. This method of assaying Gs activity has been proved to be simple, reliable and sensitive.

Abstract:Gel shift of electrophoresis and Northern and Western blotting analysis were used to detect the effect of c-iun antibody on the interact between AP-1 site of ET-1 gene and nuclear proteins as well as the effect of TPA on c-fos/c-jun gene expression. The results showed that AP-1 binding activity in vascular endothelial cells was stimulated by c-fos/c-jun, whose expression was induced by TPA, and that the electrophoretic mobility of band of DNA-protein complexes was altered by the antibody against c-jun. These results suggest that ET-1 gene expression induced by TPA is mediated by c-fos/c-jun.

Abstract:A simple, rapid and reliable sequencing method for double stranded PCR products is described. This method presented utilizing the unique property of T7 DNA polymerase which remains active at low temperature to allow the sequencing reaction performed at low temperature. Excellent sequencing results have been obtained by this method for various PCR products .

Abstract:The contents of AchE in plasma and erythrocyte membrane of patients with PNH were determined by ELISA. The results show that the content of AchE is low in PNH erythrocyte membrane but high in plasma when it is compaired with that in normal.

Abstract:With computer analysis of the adenosine deaminase (ADA) mRNA, which included cleavage site selection, secondary structure analysis, biological function and homology analysis of the gene fragment around the cleavage site，four hammerhead ribozymes were designed. These ribozymes targeted sequence around the cleavage site have hairpine structure in which the cleavage site is in the ring part. This gene fragment is of biological importance in ADA gene. No homologies were found between these gene fragments and other murine genes. These characteristics of the gene fragment make them easy to be paired and cleaved by their respective ribozymes.

Abstract:Increased expression of the glutathione Stransferase (GST: E, C, 2, 5, 1, 18) π class isoenzyme is associated with both tumor and preneoplastic tissues. In order to further characterize the alteration of GST-π gene expression during progression of carcinoma, both the levels of GST-π DNA in one normal gastric tissue and 20 gastric tumor with perineo-plastic normal tissue，and the GST-π RNA in the normal gastric tissue and 12 gastric poorly differiented adenoearcinomas with corresponding perineoplastic normal tissues were tested using Dig-GST-π cDNA probe by Dot blot hybridization.No significant change of GST-π DNA level, but the expression level of GST-π RNA in 6 of eight gastric tumors was higher than in normal gastric tissue，and in 7 perineoplastic normal tissue of twelve poorly differentiated adenocarcinoma was higher than that in its corresponding tumor. This suggests that the elevation of GST-π gene expression is related to gastric tumor, and earlier than the changes of cell morphology.

Abstract:The various differences of the hydrodynamic behavior of bovine serum albumin in NaCl,KSCN and KI solutions were evidenced by viscosimetry. Based on the empirical formula and viscosity data, the apparent axial ratios and apparent molecular volumes were calculated，which were also affected by the salt properties，correspondingly.

Abstract:Some ways are introduced to enhance the cloning efficiency of PCR amplification produts. The purification of PCR products，the speciality of PCR amplification, the remainder of Tag polymerase, the 3′-end projection of PCR products and the blunt end ligation are the main factors to affect the cloning efficiency.