MECHANISM OF INTERFERON ACTION Ⅹ——ANTAGONISTIC EFFECT OF ATP ON pppA2''''p5''''A2''''p5''''A RECEPTOR

pppA2'p5'A2'p5'A (2'-5'P_3A_3) receptor may be the first one in the oligonucleotide field.But ATP can compete with 2'-5'P_3A_3 for the receptor. This raises a question whether this is anATP receptor. If not, what is the role of ATP for this receptor? Data available in this arti-cle show that ATP can bind to macrophages with saturability and reversibility. So ATPappears to be also a ligand of the receptor for 2'-5'P_2A_3. But the binding of ATP did notdevelop phagocytic effect as mentioned before~([11]). Moreover, ATP inhibited the enhancementof phagocytosis of macrophages by 2'-5'P_3A_3 when it acted together with 2'-5'P_3A_3 on mac-rophages at the same time. It is concluded that ATP is an antagonist of 2'-5'P_3A_3 receptor.When macrophages were treated with ATP prior to 2'-5'P_3A_3 and the binding sites for 2'-5'P_3A_3P were first occupied by ATP, both the binding ability and the biological effect of2'-5'P_3A_3 were all markedly blocked. The above data convincingly show that the action of2'-5'P_3A_3 is     

干扰素作用机理的研究——Ⅺ.2′-5′三腺苷酸对巨噬细胞中cAMP和cGMP含量的影响

本研究首次证实了干扰素的作用介质pppA 2'p5'A2'p5'A(2'-5'P_3A_3)能引起巨噬细胞中cGMP,cAMP含量的变化。发现不同浓度的2'-5'P_3A_3和同一浓度的不同作用时间,对细胞内两种环核苦酸的含量有不同的影响。2'-5'P3_A_3的最终浓度在1×10~(-7)—1×10~(-6)mol/L时,可以引起细胞内cGMP显著升高,而使cAMP达到高峰的2'-5'P_3A_3浓度则为1×10~(-7)mol/L。细胞中cGMP与cAMP出现高峰的时间也显著不同,cGMP出现高峰的时间是在加入2'-5'P3_A_3以后15min,而cAMP出现高峰时间则在保温2h之后。上述结果提示,cGMP与cAMP可能与2'-5'P_3A_3受体发挥作用有某种关系。     

MECHANISM OF INTERFERON ACTION——ACTIVATION OF MACROPHAGES AND ANTAGONISM TO a-FETO-PROTEIN BY _(ppp)A_(2'p5')A_(2'p5')A

_(ppp)A_(2'p),'A_(2'p,)'A(2'-5'P_3A_3) activates macrophages and increases the phagocytosis of macrophages from different species including human beings. This indicates that the activation of macrophages may be a general action of 2'-5'P_3A_3. This discovery broadens the effect of 2'-5'P_3A_3 beyond the antiviral field.α-Feto-protein (AFP) inhibits the phagocytosis of macrophages and may be involved in the development of hepatoma. Data presented here show that 2'-5'P_3A_3 can antagonize this suppressive effect of AFP.Methods used so far for introducing 2'-5'P_3A_3 into the cells were made with the aid of CaCl_2, etc. under conditions which may not be the same as those used clinically. It was found that 2'-5'P_3A_3 can develop its biological effect without the aid of CaCl_2, etc.     

MECHANISM OF INTERFERON ACTION——THE DISCOVERY OF pppA2'p5'A2'p5'A RECEPTOR

In this paper it is demonstrated that (~3H)2'-5'P_3A_3 can bind to the peritoneal macrophages from Wistar rat. This binding is strongly inhibited by cold 2'-5'P_3A_3 while the inhibiting capacity of 2'-5'P_3I_3 and 2'-5'A_3 is very small, showing that this binding is highly specific. And the binding of (~3H)2'-5'P_3A_3 is reversible, saturable and with high affinity. A Scatchard analysis of the binding data gives a linear plot, an apparent dissociation constant (Kd) about 1.3×10~(-7) M and binding sites per cell about 2.1×10~7. The above evidence shows the existence of the 2'-5'P_3A_3 receptor, a fact which, to our knowledge, has not been reported before.     

MECHANISM OF INTERFERON ACTION Ⅲ——SIGNIFICANCE OF _(ppp)A_(2'P5')A_(2'P5')A IN THE ANTIVIRAL ACTION OF INTERFERON

This paper is to evidence that the antiviral effect of _(ppp)A_(2'p5')A_(2'p5')A(2'-5'P_3A_3) could cover a wide spectrum of viruses, the RNA viruses such as influenza H_3N_2/77, influenza H_1N_1/77, ECHO_(11), rhino, Sendai, Sindbis and VSV, and the DNA viruses such as herpes (type Ⅰ). In addition, the antiviral effect of 2'-5'P_3A_3 on ECHO_(11) virus, as compared with other viruses, is more efficient than that of IFN itself. It seems likely that 2'5'P_3A_3 plays an important role in the antiviral action of IFN. After comparing the action of 2'-5'P_3A_3 with interferon (IFN), it has appeared that the action of 2'-5'P_3A_3 is something parallel to that of IFN for most viruses. For a few viruses, however, considerable differences have been observed.     

MECHANISM OF INTERFERON ACTION——STRUCTURAL REQUIREMENT OF LIGAND AND CELLULAR SPECIFICITY

We had reported the existence of 2'-5'P_3A_3 receptor on the peritoneal macrophages from Wistar rat. In this paper data are given to demonstrate that the ligand, for binding with 2'-5'P_3A_3 receptor and enhancing the phagocytosis of macrophages, must have a three-phosphate radical on its 5'-terminus and at least three adenylate residues in 2'-5'oligoadenylate. (~3H)-2'-5'P_3A_3 can also bind on macrophages from other animals; and the binding of (~3H)-2'-5'P_3A_3 on Hepatoma cell line 7402 is lower than that on macrophages; whereas it is very low (binding ratio less than 1%) on erythrocytes (from rabbit, rat and mouse) or human embryo lung fibroblast cells. The binding conditions of the ligand with 2'-5'P_3A_3 receptor have also been investigated.     

A NEW METHOD ON THE CHEMICAL SYNTHESIS OF DOPED POLYPYRROLE INITIATED BY CuCl_2-C_2H_5OH SYSTEM

Our objectives were to develop a new chemical method for the polymerization of pyrrole. CuCl_2 dissolved in C_2H_5OH solvent is primarily used for the initiation polymerization of pyrrole. The polymers with different yield and conductivity were obtained by raring the initial concentration of Cu~(2+). The initial concentrations of Cu~(2+) varied from 1.2 ×10~(-4) mole to 6.48 ×10~(-3) mole Cu~(2+) with 2.16 ×10~(-2) mole pyrrole. The polypyrrole obtained was characterized with elemental analyzer, XPS, IR spectroscopy, Four-point probe and SEM.     

STUDY OF THE FLUORESCENCE ENHANCEMENT IN THE SYSTEM OF EUROPIUM-OR SAMAR-IUM-TERBIUM-DIBENZOYLMETHANE-CETYLTRIMETHYLAMMONIUM BROMIDE-TRITON X-100 AND ITS APPLICATION

A fluorescence enhancement phenomenon on adding terbium to the Eu or Sm-DBM-CTMAB-Triton X-100 fluorescence system was observed. The fluorescence intensity of this system was 50 times greater than that of the system without terbium at pH 9.0. The fluorescence intensity is a linear function of the concentration of europium or samarium in the range of 1.0×10~(-10)-8.0×10~(-6) mol/L and 1.0×10~(-7)-8.0×10~(-6) mol/L, respectively. The deteetion limits for them were 1.0×10~(-12) mol/L and 1.0×10~(-9) mol/L, respectively. This system was used for the determination of europium or samarium in rare earth samples with satisfactory results.     

Determination of chloride ion by electrochemiluminescence and investigation of the mechanism

The electrochemiluminescence (ECL) of luminol in aqueous alkaline solution was studied.Trace amounts of chloride showed significant effect on the efficiency of light emission of luminol as a posi-tive trigonometrical wave pulse was exerted on the solution. The detection limit for the chloride is5.0 ×10~(-6) mol/L and the linear calibration range extends up to 1.0 ×10~(-2) mol/L; the relative standarddeviation for 1.0 ×10~(-5) mol / L chloride is 5%. The influencing factors for chloride determination arealso discussed. The possible mechanism for the electrochemiluminescence reaction may be due to theoxidation of chloride ion in the solution to ClO~-, and the latter acts on luminol and then gives outluminescence. The method has been applied to determine the total chloride in tap water with satisfactoryresults.     

THE STIMULATORY EFFECT OF HEAVY METAL CATIONS ON PROLIFERATION OF AORTIC SMOOTH MUSCLE CELLS

Heavy metal cations Cd~(2+), Pb~(2+), and Hg~(2+)were added to substitute for Ca~(2+)in culture media to study their effect on the relationship between CaM and the proliferation of cultured rabbit aortic smooth muscle cells (ASMC). It was found that all the heavy metal cations studied stimulated the proliferation of ASMC in varying degrees, increased the CaM content in cells at late G_1 stage and decreased the activity of cAMP PDE. These results suggest that the adverse effect of heavy metals may be related to the pathogenesis of atherosclerosis and hypertensive disease.     

STUDIES ON THE LOW-TEMPERATURE SYNTHESIS OF METHANOL BY CARBONYLATION AND HYDROGENOLYSIS

The present process may be less energy intensive compared withthe existing processes.A proprietary amide aleohol additive can markedly in-hibit the deactivation of CH_3ONa catalyst for methanol carbonylation.Thespace-time yield(STY)of the methyl formate(MF)is 625g·1 ~1h ~1after 40htime on stream with theadditive,while the yield is only 190g·1 ~1h ~1without the additive at the same reaction conditions.By using four types of tubu-lar reactors without any mechanico-rotary parts and hige speed circulation ofthe reactants for the carbonylation at P_(CO)=5MPa,a 95% single pass conversion of CO and 645g·1 ~1h ~1of STY of MF were obtained.A novel Cu-ZnO/Al_2O_3 catalyst for MF hydrogenolysis to methanol is reported in this pa-per.The Cu-ZnO/Al_2O_3 catalyst is characterized by the resistance to poison-ing of high concentration CO up to 16.2v%.     

STUDIES ON VOLTAMMETRIC BEHAVIOUR OF 2-ANTIEPILEPSIRINE

In a supporting electrolyte containing 0.6mol/L H_2SO_4,asensitivity derivative wave of 2-AES is formed by oscillopolarography.Thepeak potential is-1.01V(vs.SCE),The change of peak height with theconcentration of 2-AES is linear in the range from 3.0×10~(-7) to8.0×10~(-6)mol/L.The detection limit is 1.0×10~(-7)mol/L.The electrodereaction mechanism is discussed.     

STUDIES ON THE POLAROGRAPHIC ADSORP-TIVE COMPLEX WAVE OF RARE EARTH-ERIOCHROME AZUROL B (Ⅱ)

The rare earth ions form complexes with ECAB in 0.1 mol/L NaAc-HAc supporting electrolyte at pH 6. The composition of the complex was determined by spectrophotometric method to be 1: 2. The decrease of SAC peak height of ECAB is proportional to the concentration of rare earth ions in the range of 1×10~(-6)-2×10~(-5) mol/L. The reduction mechanism of ECAB and RE-ECAB is proposed based on the experimental evidence. The complexing group of ECAB with RE ions iust is the redox group, so when RE ions are added, there is no new peak appearing in the polarograms:, the only phenomenon observed is that the peak current of ECAB decreases. The fast protonation of EGAB carbanion formed after the second electron transfer results in the formation of colourless tetrahedral molecules.     

SOLID-PHASE SYNTHESIS OF 2''''—5'''' OLIGOADENYLATE——2''''—5''''A CORE

With phosphotriester approach, the 2'—5' linked oligonucleotide——2'—5'A core was synthesized by using cross-linked polyacrylmorpholide resin as the support and the mesitylene sulfonyl chloride and N-methylimidazole as the condensing agent. Synthesizing the 2'—5'A core with this method has not yet been described. The yields that each of the protected monomers was attached to the polymeric support were satisfactory, i.e., 100%, 60% and 91% respectively.For the synthesis, we improved the methods for preparing the polymeric support and a series of intermediates. For this reason, the yields of the products were markedly increased and the operations to separate the products from the by-products and reagents were simplified.     

ADSORPTION OF SAMARIUM（III） ON DIGLYCOLAMIDIC ACID RESIN

The sorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR), for Sm(lll) were investigated. The optimal sorption condition of DAAR for Sm(lll) is pH=6.0 in HAc-NaAc medium. The statically saturated sorption capacity is 190mg/g resin at 298K. The Sm(lll) adsorbed on DAAR can be eluted reaching 100% by 0.5-2.0mol/L HCI used as eluant. The resin can be regenerated and reused without apparent decrease of sorption capacity. The apparent sorption rate constant is k298= 1.96×10^-5s^-1. The apparent activation energy is 26kJ/mol. The sorption behavior of DAAR for Sm(lll) obeys the Freundlich isotherm. The thermodynamic sorption parameters, enthalpy change ΔH of DAAR for Sm(lll) is 16.9Kl/mol. The molar coordination ratio of the functional group of DAAR to Sin (111) is 3. The sorption mechanism of DAAR for Sm(lll) was examined by using chemical method and IR spectrometry. The coordination bond was formed between oxygen atoms in the functional group of DAAR and Sin(Ill).     

STUDIES ON THE TOPOLOGICAL PROPERTY OF POTENTIAL ENERGY PROFILE OF ELEMENTARY REACTIONS

In the present paper cusp catastrophe is used to model the topological property of poten-tial energy profile of elementary reactions, and four typical situations, which can be trans-formed into two types, have been systematically analyzed with 58 independent elementaryreactions. The main results obtained here are (i) the concept of activation energy is brieflydiscussed and extended; (ii) the reaction O+ CO→CO_2 is found to belong to type Ⅳ, not totype Ⅰ;and (iii) there may be some special correlation between α_1 and α_2. Finally the neces-sary discussions are carried out.     

STUDY ON THE TREATMENT AND REUSE OF WASTEWATER FROM THE PRODUCTION OF 2—NAPHTHANOL

Systematic studies on the treatment and reuse of the acid industrial watewater containing sodium 2-Naphthylsulfonate(β-salt)from 2-Naphthanol production process by ND-910 resin (made by self) is reported in this paper.Under the operation conditions of initial β-salt concentration of 10000-25000mg/L and initial CODCr of 20000-40000mg/L,the removal rates of Sodium 2-Naphthylsulfonate and CODCr are over 95% and over 89%,respectively.The effluent can be discharged directly after biological degradation.The working sorption capacity of ND-910 Resin for β-salt is over 230g/kg.An alkali-water wash procedure isutilized to regenerate resin and the reclaiming rate of β-salt is over 98%.     

STUDY ON INDUCTION OF DIFFERENTIATION OF A HUMAN MEGAKARYOBLASTIC LEUKEMIA CELL LINE (HIMeg) BY 1,25-DIHYDROXYVITAMIN D_3

It is reported that 1,25-dihydroxyvitamin D_3(1,25(OH)_2D_3), a physiological factor, has aninductive effect on the differentiation of a novel human megakaryoblastic leukemia cell line(HIMeg) in vitro. At the concentrations ranging from 10~(-9) to 10~(-6) mol/L, 1,25(OH)_2D_3 showedinhibition of proliferation on HIMeg cells which was demonstrated by count of survivalcells and cloning efficiency. Meanwhile, using light/electron microscopy, stain of cytochem-istry (including immunoenzymatic technique) and flow cytometry, we found that HIMeg cellscould be further induced into more mature cells in megakaryocytic lineage confirmed by aseries of evidence, including the changes of cell morphology/structure and cytochemistry,increased expression of differentiation antigens on the cell surface, and polyploidization.So, it is possible for 1,25(OH)_2D_3 to promote the differentiation of the cells in megakaryo-cytic lineage in vivo and to be used to treat acute megakaryoblastic leukemia and other di-seases with mal     

STUDIES ON THE KINETICS OF PROPYLENE POLYMERIZATION WITH THE COMPLEXTYPE TiCl_3 CATALYST

The active center concentration C_p, the rate constant k_p, and the activation energy of chain propagation E_p in the polymerization of propylene with complex-type TiCl_3-(C_2H_5)_2AlCl catalyst system were studied. The Mn was corrected by (?) value determined by GPC. The values thus obtained for C_p, k_p, and E_p at 50℃were 3.01 mol/mol Ti, 6.27 1/mol·sec, and 5.10 Kcal/mol respectively.The kinetic parameters were compared with those obtained from conventional TiCl_3·AlCl_2 catalyst, showing that the higher activity of the complex-type catalyst over the conventional catalyst is not only due to the higher C_p of the former, but to a greater extent due to the increase of the k_p value.     

EFFECTS OF MONOCLONAL ANTIBODY ANTIEGF RECEPTOR ON HUMAN NASOPHARYNGEAL CARCINOMA CELL AND OTHER TUMOR CELLS

Three anti-EGF receptor MoAbs were used in these studies. Administration of MoAbs 3 and 176 inhibited tumor formation in nude mice by CNE-2, a poorly differentiated nasopharyngeal carcinoma cell line and A431, an epidermoid carcinoma cell line. When the same MoAbs were used in treatment against HeLa, a cervical carcinoma, tumor growth was not affected. The number of EGF receptors and apparent dissociation constants for ~(125)I-EGF on CNE-2 and A431 was 1.3×10~(?)/cell (Kd 7.7×10~(-8)mol/L) and 1.4×10~6/cell(Kd 2.4×10~(-9)mol/L), respectively. Both MoAbs 3 and 176, capable of competing with EGF for receptor binding, showed significant tumor growth inhibition. MoAb 101 was incapable of blocking the binding of EGF to its receptor, and not as effective as MoAbs 3 and 176 in tumor growth inhibition. Our observation is that the MoAb anti-EGF receptor is cytostatic rather than cytocidal, in vitro against CNE-2 and A431.