流感病毒的检测和分型技术研究进展

近年来,病毒性流感的不断流行和暴发已引起世界范围的广泛关注。为了更好地对流感病毒进行检测和分型,我们对目前流感病毒常用的血清学检测和分型方法、免疫荧光法、PCR方法、多重RT-PCR法、实时RT-PCR法、依赖核酸序列的扩增法、环介导等温扩增法、焦磷酸测序法、基因芯片技术分别进行了描述,并阐述了其优缺点。     

Nature of the mutation in adult beta-galactosidase deficient patients.

Fibroblasts from three chronically affected, beta-galactosidase deficient adults were shown to synthesize nearly normal quantities of immunologically reactive catalytically deficient beta-galactosidase, indicating that they are CRM + structural mutants.     

A rapid technique to predict malting quality in barley prior to harvest

Samples of grain from three spring barley cultivars of differing malting quality were collected at regular intervals during four weeks prior to harvest. The samples were dried, then assessed for relative grain hardness using the "Milling Energy" test. Ranking order of the cultivars for this character, which relates strongly to malting quality, was unaltered throughout. In a further experiment, it was demonstrated that selection for milling energy could be successfully practised on oven-dried grain collected six weeks after ear emergence.     

Analysis of insulin-receptor phosphorylation sites in intact cells by two-dimensional phosphopeptide mapping.

Insulin stimulates the autophosphorylation of the partially purified insulin receptor initially on tyrosine residues 1146, 1150 and 1151. This is followed by increased autophosphorylation of tyrosine residues 1316, 1322 and two further residues, possibly tyrosine residues 953 and 960 or 972 [Tavaré & Denton (1988) Biochem. J. 252, 607-615]. In the present paper we have used two cell lines transfected with insulin-receptor cDNA (CHO.T and NIH 3T3 HIR3.5 cells) to assess which tyrosine residues are phosphorylated on the insulin receptor within intact cells. We show that: (1) insulin causes a rapid increase in phosphorylation of tyrosine residues 1146, 1150 and 1151 in both cell types; tyrosine residues 1316 and 1322 are also phosphorylated, but apparently to a lesser extent in NIH 3T3 HIR3.5 cells; (2) the sites that may correspond to tyrosine residues 953 and 960 or 972 appear to be very poorly phosphorylated in both intact cell types; (3) insulin also promotes a substantial and rapid increase in the phosphorylation of serine and threonine residues on insulin receptors on CHO.T cells; this results in the appearance of two phosphopeptides not evident in the maps of the solubilized receptor preparations autophosphorylated in vitro.     

Synergistic enhancement of type I and III collagen production in cultured fibroblasts by transforming growth factor-β and ascorbate

Transforming growth factor-β (TGF-β) is a prototype of a family of polypeptides that regulates cellular growth and phenotypic differentiation [(1986) Science 233, 532-534; (1987) Cell 49, 437-438]. TGF-β injection induces angiogenesis and fibrosis locally [(1986) Proc. Natl. Acad. Sci. USA 83, 4167-4171; (1987) Science 237, 1333-1336] and stimulates the synthesis of extracellular matrix proteins, fibronectin, collagens, and proteoglycans in vitro in many cell types [(1986) J. Biol. Chem. 261, 4337-4345; (1987) Biochem J. 247, 597-604]. Ascorbate is also known to induce collagen synthesis and to promote wound healing [(1988) J. Invest. Dermatol. 90, 420-424; (1986) Coll. Rel. Res. 6, 455-466]. We report that in cultured human skin fibroblasts, ascorbate and TGF-β synergistically enhance the biosynthesis of type I and III collagens and their steady-state mRNAs. TGF-β alone has no enhancing effect on type III collagen synthesis. The cooperation between ascorbate and TGF-β may be of significance in wound healing and in disorders of fibrosis.     

Microbial Transport, Survival, and Succession in a Sequence of Buried Sediments

Abstract Two chronosequences of unsaturated, buried loess sediments, ranging in age from <10,000 years to >1 million years, were investigated to reconstruct patterns of microbial ecological succession that have occurred since sediment burial. The relative importance of microbial transport and survival to succession was inferred from sediment ages, porewater ages, patterns of abundance (measured by direct counts, counts of culturable cells, and total phospholipid fatty acids), activities (measured by radiotracer and enzyme assays), and community composition (measured by phospholipid fatty acid patterns and Biolog substrate usage). Core samples were collected at two sites 40 km apart in the Palouse region of eastern Washington State, near the towns of Washtucna and Winona. The Washtucna site was flooded multiple times during the Pleistocene by glacial outburst floods; the Winona site elevation is above flood stage. Sediments at the Washtucna site were collected from near surface to 14.9 m depth, where the sediment age was approximately 250 ka and the porewater age was 3700 years; sample intervals at the Winona site ranged from near surface to 38 m (sediment age: approximately 1 Ma; porewater age: 1200 years). Microbial abundance and activities declined with depth at both sites; however, even the deepest, oldest sediments showed evidence of viable microorganisms. Same-age sediments had equal quantities of microorganisms, but different community types. Differences in community makeup between the two sites can be attributed to differences in groundwater recharge and paleoflooding. Estimates of the microbial community age can be constrained by porewater and sediment ages. In the shallower sediments (<9 m at Washtucna, <12 m at Winona), the microbial communities are likely similar in age to the groundwater; thus, microbial succession has been influenced by recent transport of microorganisms from the surface. In the deeper sediments, the populations may be considerably older than the porewater ages, since microbial transport is severely restricted in unsaturated sediments. This is particularly true at the Winona site, which was never flooded.     

The α-Glycerophosphate in DROSOPHILA MELANOGASTER II. Genetic Aspects

Seven alleles of the alpha-Glycerophosphate dehydrogenase-1 (alphaGpdh-1) locus of Drosophila melanogaster have been described. These include two naturally occurring electrophoretic variants, one EMS-induced electrophoretic variant, and four EMS-induced "null" or "zero" mutants. With the electrophoretic variants, the locus was mapped to II-20.5 +/- 2.5. A complementation matrix was prepared utilizing the null mutants. Three of the four mutants and a deletion of the locus (Grell 1967) exhibit dosage dependency. The dosage independent mutant exhibits complementation with two of the other null alleles. Flies genetically deficient in alpha-glycerophosphate dehydrogenase are fertile, but their relative viability is severely diminished. Such flies also lose the ability to sustain flight, an observation consistent with the enzyme's function in energy production. The levels of mitochondrial alpha-glycerophosphate oxidase, measured in flies genetically deficient in the cytoplasmic enzyme, were normal.