EGFR expression and EGF stimulation of proliferation in human liver carcinoma cells

Epidermal growth factor receptor (EGFR) gene expression and growth stimulation of EGF on human hepatoma cells of cell lines BEL-7404 and SMMC-7721 were studied. 125I-EGF binding assay was used to measure the binding characteristics and the amounts of EGFR on these cells. The binding time course and the binding competition assay showed that the binding of 125I-EGF to 7404 cells was saturable and specific. Scatchard analysis of EGF binding curve indicated that 7404 and 7721 cells expressed approximately 1.1 x 10(5) and 0.7 x 10(5) EGFRs per cell with binding affinity (Kd) 2.1 nM and 1.8 nM respectively. Northern hybridization and immunoblotting analysis showed the EGFR gene expression products in 7404 and 7721 cells were 5.6 Kb mRNA and 170 Kilo-dalton glycoprotein. Anchorage-dependent growth of 7404 and 7721 cells was stimulated in the presence of nanogram quantities of EGF in medium containing 10% calf serum or 0.5% calf serum. The factors in serum appeared to act synergitically in stimulating of cell proliferation. EGF also stimulated the anchorage-independent growth of 7404 and 7721 cells in soft agar. The results suggest that EGFR is actively expressed in human hepatoma 7404 and 7721 cells and EGF may be one of the mitogens needed for the growth of hepatoma cells.     

Inheritance of mitochondrial aldehyde dehydrogenase: genotyping in Chinese,Japanese and South Korean families reveals dominance of the mutant allele

Summary Genotyping of mitochondrial aldehyde dehydrogenase (ALDH I) was performed in enzymatically amplified DNA of 20 Chinese, Japanese and South Korean families (85 individuals) and in 113 unrelated persons by employing allele-specific oligonucleotide probes and dot blot hybridization. Genotyping individuals with phenotypic deficiency of ALDH I activity always showed the presence of at least one mutant allele. The data are compatible with a model assuming dominant inheritance of the mutant allele, which we have previously suggested on the basis of a population study.     

千金藤属植物小叶地不容中的生物碱(Ⅷ)

从小叶地不容(Steghania succitera Lo.et Tsoong)的块根中分得11种生物碱,根据理化性质及波谱测定,鉴定为克班宁(crebanine)(Ⅰ),四氢巴马汀(tetrahydropalmatine)(Ⅱ),去氢克班宁(dehydrocrebanine)(Ⅲ),巴马汀(palmatine)(Ⅳ),去氢紫堇单酚碱(dehydro-corydalmiae)(Ⅴ),克班宁硝酸盐(Ⅵ),氧代克班宁(oxocrebanine)(Ⅶ),紫堇单酚碱(corydalmine)(Ⅷ),phanostenine(Ⅸ),离木明碱 discretamine(Ⅹ),及 corypalmine(Ⅺ),化合物(Ⅳ)、(Ⅴ)、(Ⅵ)、(Ⅶ)、(Ⅸ)、(Ⅹ)和Ⅺ为首次报道从该植物中分得。     

甘蔗叶不同部位ATP酶活性细胞化学定位

甘蔗叶片,叶鞘和肥厚带韧皮部 ATP 酶活性定位于筛管、伴胞的质膜、内质网和某些伴胞细胞基质、小囊泡和发育成熟的液泡上;叶片韧皮部薄壁细胞、厚壁细胞和厚壁通道细胞质膜及小囊泡中亦显示有 ATP 水解产物;维管束鞘细咆与厚壁细胞或厚壁通道细胞所构成的细胞间隙上也存在有 ATP 酶活性反应产物沉淀。甘蔗叶片大、中、小三种维管束,从小维管束到大维管束,面向细胞间隙的细胞表面上的 ATP 酶活性逐渐增强,而维管束鞘细胞质膜上的 ATP 酶活性则趋于减弱;同一维管束内则以韧皮部细胞的 ATP 酶活性最强。维管束鞘细胞与叶肉细胞之间存在很多的胞间连丝,并表现出高的 ATP 酶活性。讨论了 ATP 酶活性的分布状态与叶肉细胞的光合产物向韧皮部运输的关系。     

瓜子金皂甙丙和丁的化学结构研究

自草药瓜子金(Polygala japonica Houtt)地上部分又分离得到两种皂甙,即瓜子金皂甙丙和皂甙丁,它们的分子式均为 C_(42)H_(68)O_(15),为同分异构物。两者酸水解均得瓜子金皂甙元和 D-葡萄糖,但碱水解时,只有皂甙丁可被水解,产物和酸水解相同。经~1HNMR,~(13)CNMR,MS 推定它们的结构式,瓜子金皂甙丙为3-O-[β-D-葡萄吡喃糖(1→2)-β-D-葡萄吡喃糖]瓜子金皂甙元;而瓜子金皂甙丁为28-O-[β-D-葡萄吡喃糖(1→2)-β-D-葡萄吡喃糖]瓜子金皂甙元。上述两种皂甙均为新化合物。     

短尾猴（Macaca arctoides）和猕猴跟骨的功能形态研究

本文从形态描述和统计入手,对短尾猴(macaca arctoides)和猕猴的跟骨进行了比较研究。结果表明,所研究的跟骨变量无论数值大小还是几何图形结构都存在一定差异。特别是跟骨最大宽、跟长、后距骨连结面长、跟骨高度及相对跟长存在显著性差异水平。猕猴跟骨变量间的相关关系比短尾猴的表现得更为紧密。据其形态与功能的关系,我们认为:与猕猴相较,短尾猴更适应于地栖生活。这似乎与短尾猴具更大的体重有关。     

Identification and nucleotide sequence of the Leptospira biflexa serovar patoc trpE and trpG genes.

Leptospira biflexa is a representative of an evolutionarily distinct group of eubacteria. In order to better understand the genetic organization and gene regulatory mechanisms of this species, we have chosen to study the genes required for tryptophan biosynthesis in this bacterium. The nucleotide sequence of the region of the L. biflexa serovar patoc chromosome encoding the trpE and trpG genes has been determined. Four open reading frames (ORFs) were identified in this region, but only three ORFs were translated into proteins when the cloned genes were introduced into Escherichia coli. Analysis of the predicted amino acid sequences of the proteins encoded by the ORFs allowed us to identify the trpE and trpG genes of L. biflexa. Enzyme assays confirmed the identity of these two ORFs. Anthranilate synthase from L. biflexa was found to be subject to feedback inhibition by tryptophan. Codon usage analysis showed that there was a bias in L. biflexa towards the use of codons rich in A and T, as would be expected from its G + C content of 37%. Comparison of the amino acid sequences of the trpE gene product and the trpG gene product with corresponding gene products from other bacteria showed regions of highly conserved sequence.     

皖南、赣北奥陶纪笔石立体标本形成环境的初步研究*

皖南、赣东北和赣西北地区奥陶纪笔石地层发育良好,笔石化石丰富。宁国组和胡乐组均为笔石相地层,但笔石的保存特点并不相同。立体保存的黄铁矿化笔石标本主要见于宁国组,而胡乐组的笔石几乎均为薄膜标本。在比较宁国组和胡乐组在岩性、颜色、化石、矿物和元素等方面的特点后发现,两者有较明显的差异。这表明宁国组和胡乐组形成时的环境是不同的,前者为弱还原环境,后者为较强的还原环境,而在研究区内影响笔石体立体保存的主要因素为还原环境和较高的铁含量。在还原环境下,铁可呈Fe~(2+)存在,笔石体内含有硫,死亡后经降解作用可生成H_2S;H_2S和Fe~(2+)结合可使笔石体黄铁矿化,从而使笔石体硬化而呈立体保存下来。宁国组的铁含量明显高于胡乐组,这似可以解释宁国组产有较多笔石立体标本的原因。     

Immobilization of enzymes with polyaziridines.

A novel method of enzyme immobilization using a low molecular weight prepolymer of tri-functional aziridines which can immobilize enzymes both by covalent attachment and entrapment within a gel matrix is described. The enzymes are immobilized on a solid support and exhibit an excellent retention of enzymatic activity. The immobilization procedure is essentially a single step process which can be easily performed at room temperature or 4 degrees C in either aqueous solution or in an inert organic solvent. The polyaziridines used in the immobilization are nontoxic, available in bulk at low cost and completely miscible with water and many organic solvents, thus providing one of the most satisfactory methods of immobilization available.     

Scanning electron microscopic observation of the pretarsal suckers of the honey-bee ectoparasite,Varroa jacobsoni (Gamasida: Dermanyssina)

The pretarsus of the female miteVarroa jacobsoni Oudemans (1904) consists of two main parts, a cuticular basal stalk and an extrudable, membranous ambulacral pad, the caruncle. The caruncle, when fully extruded and expanded, becomes a bilobed sucker, and when deflated, the entire caruncle is retracted into the basal stalk. The basal stalk of the pretarsus with the sucker fully retracted into it resembles an inverted cone with its narrow portion attached to the apex of the tarsus. The basal stalk consists of three large plates; two lateral and one median. The proximal end of each lateral plate bears a sclerotized claw-like structure which functions to support the expanded caruncle. The median plate possesses a long, narrow ridge process connecting the basal stalk with the caruncle, and functions to control retraction and protraction of the caruncle. The morphology and function of the basal stalk suggest that the claw-like structure are the ungues; the median plate is the unguifer, and the median ridge is the tendon of the retractor/depressor muscles of the pretarsus. The significance of the pretarsal suckers to the control of the mite is also discussed.