Abstract:Interleukin-15 is a kind of formally recognized new cytokine, its cDNA sequence,function and molecular structure have been elucidated. IL-15 is similar to IL-2 in biological properties and three-dimensional configuration and its receptor utilizes the β and γchains of IL-2 receptor. Further investigation should be done on whether other unknown components participate in IL-15 receptor complexes, its detailed signaling pathway and other unknown biological activities etc.

Abstract:The Ras and JAKs-STATs signaling pathways after growth factors and cytokines activating their receptors respectively are briefly reviewed. The signal transduction of most growth factors' receptors with intrinsic tyrosine kinase activities is achieved through Ras protein pathway.Otherwise, members of JAKs and STATs superfamilies mediate the signaling process of cytokines' receptors lacking intrinsic tyrosine kinase activities. Studies on the signal transduction of growth factors and cytokines are becoming the important subjects in researches of life sciences.

Abstract:The adenovirus vectors have begun to show importance in the researches of gene therapy, and have therefore attracted the attention of public. A fuller description is given on the basic structure of adenovirus genome, the classification and the construction of the adenovirus vectors, the applications of the recombinant adenovirus, as well as their advantages and disadvantages in use of gene therapy.

Abstract:Apoptosis is a common mode of cell death occurring during development as well as in many pathological conditions, such as in tumor, aged and degenerative diseases. However, some experimental results recently demonstrate that free radicals involve in apoptosis. In apoptosis cells, the reactive oxygenspecies (ROS) production increases and the ability to metabolize ROS declines. The ROS in most disabled apoptosis cells is lower and the mortality of this kind of cells can be changed according to the amount of ROS in cells. Irradiation can result in apoptosis damaged by hydroxyl free radical，the apoptosis phenomena in some cells come from with drawing growth factor and medium may becaused by change of the free radical metabolic enzyme activity，such as peroxide hydrogen enzyme. The research summarized collectively suggest that free radical plays an important role in regulation of apoptosis.

Abstract:TATA box binding protein (TBP),a component of RNA polymerase Ⅱ transcriptional factor TFⅡD, binds to TATA box specifically. The co-crystal structure of TBP/TATA-box complex is introduced and its role in the initiation of transcription is discussed.

Abstract:A modified mechanism of 2-step-ATP-driven electron transport is proposed, it can reasonably explain the change of EPR signal in the two components of nitrogenase when the supply of reductant (S₂O₄^2- ) and MgATP are enough or only one is enough.

Abstract:Several enhancing proteins (enhancins) were isolated from the inclusion bodies of some insect viruses. The proteins can enhance the infection of NPV both in vitro and in vivo. There are two hypotheses about the mechanism of enhancement: disrupting the peritrophic membrane (PM ) and facilitating the penetration of virions or increasing the attachment and fusion between the virion envelope and the midgut cell membrane. The proteins are encoded by virus. The first enhancin gene has been cloned and sequenced.Since enhancins can shorten the life-span of infected larvae and increased the effectiveness of biopesticides，it will stimulate the widespread application of viral pesticides.

Abstract:Great progress has been made in therapeutic virus for cancer. The development of molecular biology techniques has greatlyenhanced research on some properties of virus in host-specific, in gene site-specific integration and in oncolysis. It is possible to build up an engineering virus which will be safer and more efficient as an anticancer agent bymodification of virus surface proteins to get strong affinity to cancer cell, by deletion of oncogene from oncogenic virus or of special pathogenic gene to reduce pathogenicity of virus，and by inserting certain anticancer gene such as a silencer to centain gene site based on specificity of target cell and certain virus species. Besides，compared with other gene therapy，another special advantage is that virus DNA can automultiply replicate itself in host，which has a characteristic of cascade amplification for compensating primary dosage when the dosage is deficient.

Abstract:Homeodomain proteins are very important regulation factors in eukaryotic transcription and development. They are classified into many families according to structure of homeobox genes and homeodomain peptide chains. The interaction of homeodomain and DNA was characterized. How the Antp andPOU homeodomains recognized the binding sites of DNA sequences was explained. The function of HTH structure and other proteins in recognition were also described.

Abstract:Calcitonin and calcitonin gene related peptide (CT/CGRP) are coded by a commensal gene, of which the structure and 5＇ flanking sequence make the differential expressive products from thyroid C cell or nerve cell. The regulation of alternative expression determines the growth, sexual differentiation and evolution in multicellular animals. The medullary thyroid carcinoma (MTC) or osteoporosis would arise supposing that the abnormal expressive regulation occurs.

Abstract:Diacylglycerol (DG), a product of the hydrolysis of some phospholipids, isthought to play important functions as a second messenger. DG can activate intracellular protein kinase C (PKC), which in turn phophorylates a variety of proteins and generates cellular effects. On the other hand,as an important intermediate of lipid metabolisms, DG in vivo is also involved in regulating lipid metabolisms and hormone cycles. The present researches on the mechanisms of the modulation of cellular functions by DG, are mostly concentrating on its effects on cellular signalling transduction.

Abstract:Glutathione S-transferase P1-1(GSTP1-1) is expressed at a different level in tumor cell and drug resistant neoplastic cell.It is suggested that GSTP1-1 can serve as a marker for malignant transformation and drug resistance. On the study upstream regulatory sequence of rat glutathione S-transferase P1(rGSTP1) gene, it is found that two enchancing elements named GPE Ⅰ and GPE Ⅱ arelocated in - 2. 5 kb, - 2. 2 kb respectively.A silencer locates at-400 bp. Both of GPE Ⅰand silencer bind at least three kinds of transacting factors. Although any enhancer or silencer has not been found in human glutathione S-transferase P1 (hGSTP1) gene so far, but insulin and retinoic acid (RA) responsive sequences have been identified. The regulatory mechanism of hGSTP1 gene in tumor cells and antidrug tumor cells is different from normal cells.

Abstract:The effects of electric and magnetic fields on single intact and chemically skinnedmuscle fibres of frog are comparativelystudied. The results show that alternative pulse electric field obviously decreases the depolarization ratio of the diffracted light from intact fibers but it does not change that from skinned fibres. Static magnetic field does not affect the depolarization ratio from either intact or skinned fibers. It is suggested that changes of spatial disposition but not conformation of the contractile proteins take place during muscle contraction caused by electric field and that during the transition from weakly-binding state to strongly-binding state the crossbridges (particularly subsegment-2) move towards actins，thus the average tilt of crossbridges relative to the backbone of thick filaments is increased. It is also shown that static magnetic field with field strength could not exert apparent influence on both the electric properties of cell membrane and the contractile protein movement within skeletal muscle fiber.

Abstract:Aged rats were divided into aged memory-impaired rats and normal aged rats based on their behaviour in the Moms water maze. Brain synaptosomal membrane fluidity and the effect of GM1 on it was evaluated by fluorescence polarization technique. The results showed that statistically significant decreases of the synaptosomal membrane fluidity in the neocortex and hippocampal formation were found in the aged memory-impaired rats compared with the young and normal aged rats, and that GM1 could ameliorate the abnormal membrane fluidity. Correlation analysis indicated that the brain synaptosomal membrane fluidity was closely related to aged learning and memory impairment. It was suggested that GM1 has a potential therapeutic value for aged memory impairment through altering neuronal membrane structure.

Abstract:Protein kinase C (PKC) and its inhibitor activities were measured in human coloretal cancer cell line CCL₂₂₉ induced by retinoic acid (RA) and 1, 25-dihydroxyvitamin D₃ (1, 25 (OH)₂VD₃) both for two days and phorbol 12-myristate 13-acetate (PMA ) for six hours. The results showed that total PKC activity was markedly increased after treatment with three inducers (P< 0. 05 ). The cytosolic PKC activities were significantly increased in RA and 1, 25 (OH)₂VD₃ treated CCL₂₂₉ cells (P< 0. 05 ). In PMA-treated cells，the membrane ratio(membrane activity/total activity) was significantly increased (P<0. 01).The levels of PKC inhibitor in cytosolic membrane supernatants after treatment with three inducers were all decreased. Among these three inducers，1，25 (OH)₂VD₃ caused significantly difference compared with control. The results implied that PMA translocates PKC from the cytosolic to membrane fraction，PKC and its inhibitor in RA，1，25 (OH)₂VD₃ and PMA-induced cells are in different relatively parralel relationship.

Abstract:The high level secretive expression of hGM-CSF in streptomyces was obtained.The factors, which can influence the exogenous expression in prokaryoties, such as the distance between SD and ATG, and the features of expression induction in streptomyces,etc. were studied. Then the secreted hGMCSF protein in streptomyces using the signal peptide MEL were obtained. One third of the expression products were secreted. By the experiment of clony stimulating factor formation and cell culture of TF-1 (hGM-CSF dependent cell line)，its biological activity determined is 5 MU/L.

Abstract:Pulsed field gel electrophoresis (PFGE) was used to quantitatively measure the double-strand breaks (dsbs) of DNA damage in human lymphocytes induced by hydroxyl radicals generated from H₂O₂－Fe³⁺ system.It was shown that there was a significant dose-dependent relationship between concentration of H₂O₂－Fe³⁺ and the content.of DNAdsbs occuring in cells. Moreover, the DNA damage in terms of dsbs became heavier as the time of incubating cells with H₂O₂－Fe³⁺ was extended but could be inhibited by catalase considerably.The sensitivity of PFGE was estimated by the concentration of H₂O₂－Fe³⁺ which were 0.3 mmol/L and 6 pmol/L, respectively.

Abstract:The recombinant pro-urokinase expressed in CHO cells was purified. The purification procedure was based on the following steps: micro-pore glass chromatography, CM-15HR chromatography, Sephacryl S-200 gel filtration. The yield was 46% and the purification factor was 700-fold. Small amounts of contaminating urokinase were removed by Benzamidine-Sepharose 6B affinity chromatography. Analysis by SDS-PAGE showed that the purity of pro-urokinase was 90% and the molecular weight was 52 ku.The specific activity of the purified pro-UK was 51 220 U/mg of protein. The characters of the recombinant pro-UK were consistent with that of the natural pro-UK.

Abstract:Using the mRNA prepared from hybridoma DW₁₀ secreted monoclonal antibody against human D-dimer as a template, the cDNA fragment encoding the V_k domain was amplified by reverse transcription and polymerase chain reaction (RT-PCR) with a set of universe primers that were on the FR1 region and FR4 region of V_k domain respectively.The RT-PCR product was ligated with pUC18. The result obtained from the restriction enzyme fragments and DNA sequencing showed that the length of the V_k was 330 bp, and the distinctive structures of the immunoglobin CDR1，CDR2 and CDR3 bf V_k gene appeared.

Abstract:The detection of DNA contents and ds-DNA cross-link in HeLa line, HL-60 line,proliferative and non-proliferative T lymphocytes with EB-fluorescence assay was investigated, and study on the correlation of cell proliferative activity with its ds-DNA cross-link was carried out as well. The results show that the percentages of ds-DNA cross-link in HeLa, HL-60 line, proliferative and nonproliferative T lymphocytes were 36.5, 22.2,20.2 and 0 respectively, and that the proliferative activity of cells has a relationship with their ds-DNA cross-link，and nonproliferative or G₀ phase cells do not produce ds-DNA cross-link.

Abstract:The 5, 10, 15, 20-tetrakis (3methoxy-hydroxyphenyl) porphyrin cobalt is absorbed on the surface of the glassy carbon electrode to make a CoTMHPP modified electrode.The modified electrode has high sensitivity and good electrocatalytic oxidation towards catechols for each range of their responses, and the response time is less than 10 s. The electrode possesses characteristics of high catalytic activity, fast response, good stability and a long lifetime under the optimal operations.

Abstract:A modified method of preparing chromatin is introduced here, which omits the procedure of glass-homogenization. It is easy to operate, to reproduce and has high yield.With this method, chromatin in different size can be obtained.

Abstract:Analysis of all of the PI cycle phospholipids is usually performed by twodimensional thin-layer chromatography. A simple and rapid method for analyzing the phosphoinositides by one-dimensional thinlayer chromatography has been developed.The non-polyphosphoinositides in cells were first extracted with chloroform: methanol:water (8: 4: 3), and then the polyphosphoinositides were extracted with chloroform:methanol: water: concentrated HCI (100:100: 50: 1). Each part of phospholipids were further separated by one-dimensional thin-layer chromatography with different developing systems，i. e.，chloroform，methanol，acetic acid:formic acid:water(70:30:12:4:2) for non-polyphosphoinositide phos-pholipids and chloroform:methanol:water: NH₄OH(40:48:10:5) for polyphospho-inositides. The method can be used for comparative analysis of phosphoinositides in small samples，and also for the extraction，separation and quantitation of polyphospho- inositides. separation and quantitation of polyphosphoinositides in samples which are not labelled with isotope.

Abstract:In order to evaluate the effect of ribozymes on suppressing BmNPV, triplet ribozyme (R426) targeting the BmNPV immediate early gene (IE) was designed. In vitro cleavage experiment showed that R426 transcript was able to cleave the target sequence specifically. Expression experiment indicated that R426 extracted from Bm-N cell can also cleave the target specifically and cause about 30% reduction of BmNPV polyhedra in transfected cell.

Abstract:Incorporating biotin-11-dUTP, the rearranged fragment Vδ2-Dδ3 of T cell receptor gene has been amplified by nest PCR from bone marrow DNA of acute lymphoblastic leukemic patients to get biotin-labeled leukemic clonospecific probe for detection of minimal leukemic cells. The initial results of dot hybridization show that the clonospecific probes are sensitive and specific for identifying residual leukemic clone in clinical practice.

Abstract:An iron staining method for the determination of catalase activity based on the polyacrylamide gel electrophoresis technique was established. The results indicated thatboth bacterial catalase and bovine livercatalase showed unique band in the gel. This staining method was convenient, quick and sensitive for the measurement of catalase activity.

Abstract:A very simple method to determine the activity of AST isoenzymes by using the AST inhibitor AMANO-3 has been developed. This inhibitor is a protease which selectively proteolyzes m-AST in the sample and no influence to the activity of c-AST. The coefficient of variation. of the proteolytic method is among 3.5%～7.9%. Resultsobtained by the present method correlated with those by the electrophoresis method. In the present assay system, reference values for mitochondrial AST activity in healthy people ranges from 1.64～9.64 U/L and the reference values for cytosolic AST activity in healthy people range from 5.55～16.85 U/L. The study showed that the selective measurement of AST isoenayme method is a rapid and accurate method. It has great clinical significance.