中水技术污水处理工艺去除病毒的效果

中水技术开发既可缓解水资源的紧缺,又能改善城市环境。本文报道用石英粉吸附/洗脱和浓缩棒脱水的二步浓集水病毒技术(回收率为25.4～37.3％),研究中水技术不同处理工艺去除病毒的效果。结果,二级处理可去除掺入病毒的98.9％,结合三级处理的混凝沉淀和过滤,可去除99.976％,再加活性炭吸附或加氯消毒,所得中水分别去除掺入病毒的99.986％和99.991％。经首都机场中水道试验厂水样检测表明,中水中未检测到病毒(<0.23PFU/L)。     

光敏亲和标记试剂8-N_3-5′-ATP的合成

<正> 近年来,光敏亲和标记技术已被广泛应用于激素及共受体,蛋白和核酸的相互作用、酶的结构与功能、膜蛋白结构、tRNA同共合成酶的识别等研究上,鉴于ATP是某些酶的底物,因此合成光敏的ATP底物类似物将有助于国内对达些酶的结构与功能进行深入研究,为此我们合成了8-N_8-5′-ATP,现将实验结果报道如下:     

Signal peptidase I of Bacillus subtilis: patterns of conserved amino acids in prokaryotic and eukaryotic type I signal peptidases.

Signal peptidases (SPases) remove signal peptides from secretory proteins. The sipS (signal peptidase of subtilis) gene, which encodes an SPase of Bacillus subtilis, was cloned in Escherichia coli and was also found to be active in E.coli. Its overproduction in B.subtilis resulted in increased rates of processing of a hybrid beta-lactamase precursor. The SipS protein consisted of 184 amino acids (mol. wt 21 kDa). The protein showed sequence similarity with the leader peptidases of E.coli and Salmonella typhimurium, and the mitochondrial inner membrane protease I of Saccharomyces cerevisiae. Patterns of conserved amino acids present in these four proteins were also detected in the Sec11 subunit of the SPase complex of S.cerevisiae and the 18 and 21 kDa subunits of the canine SPase complex. Knowledge of the sequence of SipS was essential for the detection of these similarities between prokaryotic and eukaryotic SPases. The data suggest that these proteins, which have analogous functions, belong to one class of enzymes, the type I SPases.     

Induction of interdigitating reticulum cell-like differentiation in human monocytic leukemia cells by conditioned medium from IL-2-stimulated helper T-cells

Monocytic leukemia (MoL) cells were obtained from the peripheral blood of a patient in whom the leukemic cells infiltrating various lymphoreticular organs exhibited features intermediate between interdigitating reticulum cells (IDC) and ordinary phagocytic macrophages, whereas the leukemic cells in the peripheral blood were essentially monocytic and lacked such features. Peripheral blood CD4+ T-cells were established as an interleukin-2-dependent T-cell line. When the MoL cells were exposed for a few days to conditioned medium from the T-cell line, they extended several dendritic cytoplasmic projections and became intensely positive for HLA-DR antigen, cytoplasmic S-100β protein, and CD1 antigen. Functionally, the conditioned medium significantly down-regulated Fc-mediated and Fc-independent phagocytic activities, and the levels of lysosomal enzymes such as lysozyme and nonspecific esterase in the MoL cells. Moreover, the conditioned medium significantly up-regulated the accessory cell function of the MoL cells as measured by the primary allogenic mixed leukocyte reaction (MLR). Furthermore, the conditioned medium significantly down-regulated the expression of CD14 antigen. Biochemical analysis indicated that the factor responsible for these changes is a protein which is distinct from known human cytokines and whose molecular weight is approximately 31 kDa. These findings suggest that IDC are closely related the monocytic lineage and that helper T-cells play an important role in constructing the microenvironment of T-lymphoid tissues which is necessary for the differentiation and maturation of IDC.     

Genotype of Yupik Eskimos with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Summary An A-to-G transition in the second intron was the sole mutation detected in four Yupik Eskimo patients with salt-wasting congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency. Allele-specific hybridization should be an efficient means of performing prenatal diagnosis of the disease in this highly inbred population.     

柴达木盆地荒漠土壤蓝藻群落的初步研究

本文分析了柴达木盆地东部和中部具有代表性地区的丘陵、戈壁和沙丘的蓝藻种类组成、生物量及主要的土壤化学成分;采用了模糊聚类、系统聚类及多元线性回归等方法分析藻类的群落及其与环境因子的关系。共鉴定出21种蓝藻,其中6种为国内首次报道。研究表明:土壤含磷量、总盐量及与粘性和湿度有关的土壤结构是决定柴达木盆地蓝藻群落组成的重要因素。     

Signal peptidase I overproduction results in increased efficiencies of export and maturation of hybrid secretory proteins in Escherichia coli

Summary The effects of 25-fold overproduction ofEscherichia coli signal peptidase I (SPase I) on the processing kinetics of various (hybrid) secretory proteins, comprising fusions between signal sequence functions selected from theBacillus subtilis chromosome and the mature part of TEM-β-lactamase, were studied inE. coli. One precursor (pre[A2d]-β-lactamase) showed an enhanced processing rate, and consequently, a highly improved release of the mature enzyme into the periplasm. A minor fraction of a second hybrid precursor (pre[Al3i]-β-lactamase), which was not processed under standard conditions of SPase I synthesis, was shown to be processed under conditions of SPase I overproduction. However, this did not result in efficient release of the mature β-lactamase into the periplasm. In contrast, the processing rates of wild-type pre-β-lactamase and pre(A2)-β-lactamase, already high under standard conditions, were not detectably altered by SPase I overproduction. These results demonstrate that the availability of SPase I can be a limiting factor in protein export inE. coli, in particular with respect to (hybrid) precursor proteins showing low (SPase I) processing efficiencies.     

Determination for inflorescence development is a stable state,separable from determination for flower development in Pisum sativum L. buds

Terminal meristems of Pisum sativum (garden pea) transit from vegetative to inflorescence development, and begin producing floral axillary meristems. Determination for inflorescence development was assessed by culturing excised buds and meristems. The first node of floral initiation (NFI) for bud expiants developing in culture and for adventitious shoots forming on cultured meristems was compared with the NFI of intact control buds. When terminal buds having eight leaf primordia were excised from plants of different ages (i.e., number of unfolded leaves) and cultured on 6-benzylaminopurine and kinetin-supplemented medium, the NFI was a function of the age of the source plant. By age 3, all terminal buds were determined for inflorescence development. Determination occurred at least eight nodes before the first axillary flower was initiated. Thus, the axillary meristems contributing to the inflorescence had not formed at the time the bud was explanted. Similar results were obtained for cultured axillary buds. In addition, meristems excised without leaf primordia from axillary buds three nodes above the cotyledons of age-3 plants gave rise to adventitious buds with an NFI of 8.3 ±0.3 nodes. In contrast seed-derived plants had an NFI of 16.5 ±0.2. Thus cells within the meristem were determined for inflorescence development. These findings indicate that determination for inflorescence development in P. sativum is a stable developmental state, separable from determination for flower development, and occurring prior to initiation of the inflorescence at the level of meristems.     

Supplement of nutrients for effective cultivation of hepatitis B surface antigen-producing recombinant yeast

Summary In the hepatitis B surface antigen (HBsAg)-producing recombinant yeast culture medium, the supply of Bacto-yeast nitrogen base without amino acids was found to be inadequate due to the lack of the several kinds of vitamins and trace elements. When the culture medium for this recombinant yeast was supplemented with sufficient vitamins and trace elements, its growth, HBsAg production and the stability of plasmid were improved.