抗菌免疫核糖核酸组份的分离及其活性测定

<正> 抗菌免疫核糖核酸(iRNA)已用于条件致病菌感染的临床治疗,并对其免疫活性做了全面的研究。现已证实iRNA能够诱导特异性抗体的产生和传递特异性的细胞免疫,并能诱生干扰素和白细胞间素Ⅰ、Ⅱ等淋巴因子和单核因子。但制备的iRNA是含有多种RNA种类的混合物,为明确各组份的免疫学功能,我们对iRNA进行了分离,并测定不同组份的免疫活性。     

Mapping of B-cell epitopes of the human hepatitis B virus X protein.

The immune response to the X protein of human hepatitis B virus (HBV) was studied by epitope mapping by using a set of MS2-HBx fusion proteins and synthetic peptides. Antibodies in sera of patients with acute and chronic HBV infection showed a multispecific immune response. Each serum contained antibodies to a different set of epitopes, which taken together cover most of the HBx sequence. Some of the epitopes were detectable only by immunoblotting with fusion proteins; others were detectable only by an enzyme-linked immunosorbent assay (ELISA) with synthetic peptides. The carboxy-terminal half of the HBx protein was preferentially recognized by antibodies from patients with chronic hepatitis and contained a short immunodominant antigenic region with at least two major nonoverlapping epitopes. Anti-HBx antibody titers as revealed by peptide ELISAs were highest and most frequent in patients with chronic hepatitis and usually low in acutely infected patients and asymptomatic carriers. The data demonstrate a remarkable qualitative and quantitative heterogeneity of the humoral HBx immune response which can be monitored by HBx-specific peptide ELISAs. Such tests may become useful diagnostic tools.     

Two new loci for hybrid sterility in cultivated rice (Oryza sativa L.)

Female gamete abortion in Indica-Japonica crosses of rice was earlier identified to be due to an allelic interaction at the S-5 locus on chromosome 6. Recently, in other crosses of rice, similar allelic interactions were found at loci designated as S-7 and S-8, located on chromosomes 7 and 6 respectively. All of them are independent of each other. At the S-5 locus, Indica and Japonica rice have S-5 ⁱ and S-5 ^j alleles respectively and Javanicas, such as Ketan Nangka, have a neutral allele S-5 ⁿ .The S-5 ⁱ /S-5 ^j genotype is semi-sterile due to partial abortion of female gametes carrying S-5 ^j , but both the S-5 ⁿ /S-5 ⁱ and S-5 ⁿ /S-5 ^j genotypes are fertile. The S-5 ⁿ allele is thus a wide-compatibility gene (WCG), and parents homozygous for this allele are called wide-compatible varieties (WCV). Such parents when crossed with Indica or Japonica varieties do not show F₁ hybrid sterility. Wide-compatible parents have been used to overcome sterility barriers in crosses between Indica and Japonica rice. However, a Javanica variety, Ketan Nangka (WCV), showed typical hybrid sterility when crossed to the Indian varieties N22 and Jaya. Further, Dular, another WCV from India, showed typical hybrid sterility when crossed to an IRRI line, IR2061-628-1-6-4-3(IR2061-628). By genetic analyses using isozyme markers, a new locus causing hybrid sterility in crosses between Ketan Nangka and the Indicas was located near isozyme loci Est-1 and Mal-1 on chromosome 4, and was designated as S-9. Another new locus for hybrid sterility in the crosses between Dular and the IR2061-628 was identified and was found linked to four isozyme loci, Sdh-1, Pox-2, Acp-1 and Acp-2, on chromosome 12. It was designated as S-15. On the basis of allelic interactions causing female-gamete abortion, two alleles were found at S-9, S-9 ^kn in Ketan Nangka and S-9 ⁱ in N22 and Jaya. In the heterozygote, S-9 ^kn /S-9 ⁱ , which was semisterile, female gametes carrying S-9 ^kn were aborted. The hybrid of Dular and IR2061-628, with a genetic constitution of S-15 ^Du /S-15 ⁱ , was semi-sterile and the female gametes carrying S-15 ^Du were aborted. A Japonica tester variety, Akihikari, and an Indica variety, IR36, were found to have neutral alleles, S-9 nand S-15 n, at these loci, in addition to S-7 nand at S-7. The accumulation of three neutral alleles into a breeding line should help solve the hybrid sterility problem in wide crosses of rice.     

棉铃虫致病菌BT—931菌株的应用研究

１９９２－１９９３年,作者从菏泽、聊城棉田采集的自然罹病死亡棉铃虫幼虫体内,分离到２个较高毒效的Ｂｔ菌株,编号为ＢＴ—９３１和ＢＴ—０２１,经室内毒力测定和田间药效试验表明,防效及保蕾效果接近或超过化学农药,菌药混剂３—５天平均防治效果达８７．０－９１．６％,增效作用显著。经１９９４年大田防治示范表明,利用ＢＴ—９３１菌剂。配合化学农药防治棉铃虫,具有成本低、保护天敌、持效期长、增产效益高等优点。本研究对菌剂的田间应用技术进行了试验示范。     

Effect of vertebrate predation on the spatio-temporal distribution of cladocerans in a temperature eutrophic lake

We analysed the spatio-temporal distribution of zooplankton along a profile of 10 stations from the shore to the pelagic zone from April to September 1988, the period when the larvae and juveniles Rutilus rutilus, the most abundant species in the Lake, are in the littoral zone. The digestive tracts of the young roach were analysed. They fed essentially on rotifers and on cladocerans. For comparison, zooplankton was also analysed at one littoral area without fish fry. There was an increase of cladoceran density from the vegetated nearshore zone to the offshore zone. Considering the density of Bosmina longirostris, Daphnia longispina, Chydorus sphaericus and Ceriodaphnia quadrangula, we observed a different distribution pattern in the course of the year. In the nearshore zone, the relative abundance of small species, Bosmina and Chydorus, was much higher than that of the larger Daphnia. From April to September, predation pressure mainly affected the smallest species: in contrast to the inshore station without fish fry, the density of Bosmina decreased in May in the littoral with fish. Chydorus was concentrated in the littoral between February and April, then grew into the pelagic zone, where predation pressure obviously was low during the warm season. The number of Daphnia, which was eaten by the fish fry at any time, remained low in the nearshore zone, which suggests that the presence of fish may cause Daphnia to avoid this zone. Ceriodaphnia which was not affected by this predation, was scarce in the nearshore zone during mid-summer. The low density of the cladocerans in the nearshore zone is likely associated with vertebrate predation by roach fry and juveniles, the result of such a process being either a depletion in density of the prey, or an avoidance behaviour.     

Chromosome 4 controls potential water use efficiency ({delta}13C) in barley

By combining the approaches of whole-shoot carbon discriminationand genetic analysis, we found that chromosome 4 controls potentialwater use efficiency (     

Expression and secretion of human lipocortin-1 by promoter and signal sequence of STA1 from Saccharomyces diastaticus

Summary For the secretion of human lipocortin-1 (LC-1) in yeast, a expression and secretion vector was constructed by using the promoter and signal sequence of glucoamylase gene (STA1) of Saccharomyces diastaticus. After the cDNA of human LC-1 was ligated with the secretion vector, the resulting hybrid plasmid was transformed into S. diastaticus. When the recombinant S. diastaticus was cultivated in YPD medium, LC-1 was expressed and secreted into the extracellular medium, yielding LC-1 protein at a concentration of 2.5 g/mL.     

Selection of fatty acid auxotrophs from the oleaginous yeast Cryptococcus curvatus and production of cocoa butter equivalents in batch culture

Summary A search was carried out for mutants, defective in the conversion of stearic acid to oleic acid in effort to improve the quality of lipids produced by Cryptococcus curvatus ATCC, 20509. Mutants were selected as unsaturated fatty acid (Ufa) auxotrophs. After treatment of parent organism with Ethyl methanesulfonate (EMS), 11 oleate-requiring auxotrophs were isolated. Only 3 of them were real unsaturated fatty acid (Ufa) mutants, while the other 8 were designated as fatty acid synthetase (Fas) mutants. The amount of saturated fatty acid (SFA) was about 65.2 % in the lipids extracted from an Ufa mutant named UfaM3 and it was significantly higher than that of the wild-type (WT) (46.6 %) and similar to that of cocoa butter (60.4 %).     

Investigation of the enantioselectivity and enantiomeric elution order of some piperidine-2,6-dione drugs on chiralcel OD column

The enantioselectivity and enantiomeric separation of five racemic piperidine-2,6-dione compounds, on the cellulose tris(3,5-dimethylphenyl carbamate) chiral stationary phase Chiralcel OD-CSP were investigated under the same chromatographic conditions. This class of drugs includes glutethimide, aminoglutethimide, cyclohexylaminoglutethimide, pyridoglutethimide, and phenglutarimide. The results revealed that chiral recognition and the binding sites of these drugs on the Chiralcel OD column are similar, regardless of the absolute configuration of the individual enantiomers. A possible chiral recognition mechanism(s) for this class of drugs and the CSP is presented. © 1994 Wiley-Liss, Inc.     

磁水对蕃茄酯酶同工酶的影响

蕃茄（ＬｙｃｏｐｅｒｓｉｃｏｍｅｓｃｕｌｅｎｔｕｍＭｉｌｌ）在各生长发育期酯酶同工酶谱带无明显变化,但经磁水处理后各生长发育阶段功能叶中酯酶同工酶酶谱及磷素含量与对照组相比存在显著差异,且具有酶谱负极端带数增加,正极端带数减少的趋势。总磷含量测定结果表明处理组均比对照组显著提高。这些变化在磁水处理著前后代中不存在,故认为磁水只是致使非编码顺序局部复制引起ＤＮＡ分子高级结构改变或是通过活化调节基因来调控酯酶同工酶,活化磷代谢,达到促进生长和增产的效果,而并非导致可遗传变异的结果。