Expression of human fibroblast interferon gene in Escherichia coli

The human fibroblast interferon gene was inserted in a thermoinducible expression plasmid under control of the phage lambda PL promoter. The primary translation products predicted on the basis of the plasmid constructions were hybrid proteins starting with beta-lactamase or phage MS2 polymerase information followed by the total preinterferon. On induction, antiviral activity, whose physico-chemical, immunological and biological characteristics closely corresponded to those of authentic human fibroblast interferon, was synthesized. Processing to a size compatible with mature but unglycosylated authentic product was observed.     

Isolation and structure of a human fibroblast interferon gene

Chimaeric plasmids containing double-stranded cDNA copies of mRNA induced in human fibroblasts by poly I . C were screened by an RNA selection method. A series of clones to which human fibroblast interferon mRNA selectively hybridized was identified. From the nucleotide sequence of the gene, the complete amino acid sequence of human fibroblast interferon was deduced. The protein is 166 amino acids long and is preceded by a 21-amino acid signal sequence.     

富勒烯[4,6]-C32-2x(BN)x(x=1,2)的结构及其稳定性的理论研究

在混合密度泛函B3LYP理论下,用6-31G基函数对[4,6]-C32的单BN取代产物和二BN取代产物进行了几何构型优化和频率分析。计算结果表明,BN取代四六公共边所得C30BN异构体最稳定,异质富勒烯的稳定性受体系共轭性质的影响,主要由环的张力决定;C28（BN）2中两对BN原子首尾相连构成一个四员环是最稳定异构体,体系的稳定性主要由环张力决定。[4,6]-富勒烯C32和C24的取代规则不尽相同。     

Biodistribution of fullerene derivative C60(OH)x(O)y

The biological behavior of fullerene derivatives shows their considerable potential application in medicine field. To understand the biodistribution of C₆₀ derivatives as drugs or drug carriers, a simple water-soluble derivative C₆₀(OH)_x(O)_y was labeled with^99mTc. A γ-counter and a single photo emission computed tomography (SPECT) were used to assess the biodistribution and metabolism of the labeled compound in mice and rabbits, respectively. The results showed that the compound could be absorbed rapidly by tissues, especially by coronal bone, breastbone, backbone, extremity honeycomb, liver and spleen. The clearance was slow from all tissues except for brain. The compound might be excreted through urine and enteron. The biodistribution shows some difference from that of Yamago et al. In this note, we discuss the possible reason leading to the difference. Further study is needed to find out to what extent the C₆₀ itself determines the biodistribution of derivatives.     

Chiral selection in poly(C)-directed synthesis of oligo(G)

Theories of the origin of optical asymmetry in living systems place fundamental importance on the amplification of optical asymmetry by an autocatalytic process. The replication of a polynucleotide is one obvious choice for such an autocatalytic growth mechanism. If an optically homogeneous polynucleotide could replicate by directing the polymerization of monomers of the same handedness, while excluding monomers of the opposite handedness, its chiral descendants would come to dominate what was once an achiral environment. Recently, two highly efficient template-directed reaction systems have been developed for the oligomerization of activated guanosine mononucleotides (Fig. 1) on a poly(C) template. The synthesis of L-guanosine 5'-mononucleotide makes it possible to study chiral selection in these systems. We report here that poly(C)-directed oligomerization of activated guanosine mononucleotides proceeds readily if the monomers are of the same optical handedness as the template, and is indeed far less efficient if the monomers are of the opposite handedness. However, in template-directed reactions with a racemic mixture, monomers of the opposite handedness to the template are incorporated as chain terminators at the 2'(3') end of the products. This inhibition raises an important problem for many theories of the origin of life.     

Selective activation of human beta-but not gamma-globin gene in human fibroblast x mouse erythroleukaemia cell hybrids.

The human alpha- and beta-globin genes have been activated in MEL X human fibroblast cell hybrids. However, even though the human gamma- and beta-globin genes are closely linked and were shown in these hybrid clones to be present in approximately equal numbers, no human gamma-globin mRNA was produced. Thus, the human beta- and gamma-globin genes in these cells are differentially regulated apparently by a positive regulatory factor(s) specific for individual globin genes.     

对于幂指函数y=f(x)~(g(x)~(h(x)))导数的研究

对y=f(x)g(x)h(x)各内函数的取值范围进行了讨论,并利用3种不同的方法来证明幂指函数y=f(x)g(x)h(x)的导数公式,解决了幂指函数y=f(x)g(x)h(x)的求导问题.     

A family of structural genes for human lymphoblastoid (leukocyte-type) interferon

Amino acid sequences of tryptic and chymotryptic peptides from human lymphoblastoid interferon (IFN-alpha) have been determined. The results show that IFN-alpha consists of a family of proteins with at least five different, but homologous, primary structures. There appears to be little, if any, glycosylation of the major components of IFN-alpha.     

Human cytomegalovirus induces alteration of β-actin mRNA and microfilaments in human embryo fibroblast cells

Objective: To investigate the infection of human embryo fibroblast cell line HF cells by CMV as well as the effects of CMV on β-actin mRNA and microfilaments. Methods: HF cells shape was observed after the infection of CMV.RT-PCR assay was used to detect the mRNA expression of CMV immediate early (IE) gene, β-actin and GAPDH genes of HF cells infected by CMV. CMV particles and cell microfilaments were detected with electron microscope. Results: Shape of HF cell changed after the infection by CMV. HF cells infected by CMV could express IE mRNA and the expression of β-actin mRNA decreased in a time-and titer-dependent manner compared with the uninfected HF cells whose expression of GAPDH mRNA did not change much. CMV particles were found with electron microscope in the cells. Microfilaments were ruptured and shortened after the infection of CMV. Conclusion: CMV can not only infect human embryo fibroblast cells line HF cells and replicate in the cells, but can also affect the expression of β-actin mRNA and the microfilaments.     

广义Jacobson-Witt代数W(m;n)的I(x)约化表示(英)

推广了对限制李代数 W(m;1)的研究方法,研究了当特征p>2时的阶化Cartan型李代数W(m; n)的表示.特别地, 把对限制型李代数所用的降秩的方法推广到了非限制的情形. 描述了当x正则半单时W(m;n)的不可约广义x约化表示.