Role of carbohydrate moiety of IL-5. Effect of tunicamycin on the glycosylation of IL-5 and the biologic activity of deglycosylated IL-5

IL-5 is a T cell-derived lymphokine that induces B cell growth and differentiation in murine systems. In this study, we examined the role of carbohydrate moiety of IL-5 in the expression of biological function. IL-5 polypeptides translated in Xenopus oocytes were heterogeneous in terms of isoelectric point (pI 4.7 to 8.0) and m.w. (45,000 to 60,000 under nonreducing conditions) and yielded m.w. of 25,000 to 30,000 under reducing conditions. Treatment of rIL-5 with N-glycanase under reducing conditions yielded an IL-5 monomer of m.w. 12,000 to 14,000. Furthermore, deglycosylated rIL-5 that had been translated in the presence of tunicamycin showed very limited heterogeneity by two-dimensional gel electrophoresis (first dimension, nonequilibrium pH gradient electrophoresis; second dimension, SDS-PAGE). The m.w. was 27,000 to 28,000 under non-reducing conditions and migrated to m.w. 13,000 to 14,000 under reducing conditions. These results indicate that IL-5 is a glycoprotein carrying the N-glycosidically-linked carbohydrates. Treatment of IL-5 with sialidase caused the decrease in the heterogeneity in isoelectric point of IL-5. Deglycosylated rIL-5 that had been obtained from tunicamycin-treated oocytes could bind to IL-5-responding cells (T88-M), which express both high- and low-affinity IL-5 receptors, as efficient as intact rIL-5 under high-affinity conditions. Scatchard plot analysis of equilibrium binding of 35S-labeled rIL-5 to T88-M cells revealed that the dissociation constants (Kd) of glycosylated rIL-5 and deglycosylated rIL-5 were 127 pM and 110 pM, respectively. IL-5 activities determined by both B cell growth and differentiation assays were not affected by deglycosylation. These results indicate that N-linked glycoside moiety of IL-5 molecules may not play an essential role in the expression of its activity.     

Evolutionarily stable stalk to spore ratio in cellular slime molds and the law of equalization in net incomes

The evolutionarily stable stalk ratio (ESSR) in the cellular slime molds is studied when the fruiting body is formed by multiple clones of various size. The survival probability of a spore cell is assumed to depend on the stalk ratio and the fruiting body size. ESSR is obtained as the non-co-operative equilibrium (Nash solution) that maximizes the fitness of each clone. The following two predictions are obtained: (1) the number of spore cells produced by each clone forming a fruiting body tends to be equalized, even if a variation in clone size exists. As a result, the larger clones do not necessarily enjoy higher fitness than the smaller ones. (2) The stalk ratio and the overall fitness of the fruiting body decrease as the genetic diversity in the fruiting body increases. A condition for the stalk to spore ratio to be invariant of overall fruiting body size is also investigated. Finally, "the law of equalization in net incomes" is proposed, extending result (1) into the broader range of resource allocation problems.     

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.     

Protection of OK-432, a Streptococcus pyogenes preparation, against lethal infection of mice with herpes simplex virus

We have studied the protective effect of OK-432, a biological response modifier (BRM) of Streptococcus pyogenes origin, on the lethal infection of mice with herpes simplex virus (HSV)-1. A single intraperitoneal (i.p.) injection of more than 10 micrograms of OK-432, when given at least two days before the infection, gave a marked effect yielding nearly 100% protection against ordinarily lethal infection. The protection was independent of the amount of infected virus inoculated. When given after the infection, the agent even at the maximal dose (100 micrograms), produced only a marginal effect. A single i.p. administration of OK-432 augmented the natural killer (NK) activity of peritoneal exudate cells and spleen mononuclear cells in mice 2 to 3 days after injection of OK-432, coinciding with the times when it induced a survival effect on HSV-infection. Treating OK-432-treated mice with a combination of an anti-macrophage agent, silica, and an anti-NK cell agent, anti-asialo GM1 serum, before infection diminished the antiviral effect of OK-432. The OK-432 protection against HSV infection was also markedly diminished in athymic nude mice. Thus, the protective effect of OK-432 on lethal HSV infection seems to be based on the activation of NK cells, macrophages, and T lymphocytes.     

我国特有植物银杉的资源、分布及其环境

我国银杉自1955年发现以来,陆续发现了它的新分布,至今已知在四省、区7个分布区的30多个分布点上,自然生长着银杉3200余株。它们是:广西花坪林区(越城岭南部)6个点有银杉1040抹,其中高5米以上的68株,1～5米的49株,1米以下的923株,最高21.1米,最大胸径83厘米;广西大瑶山4个点有银杉143株,其中高10米以上的94株,1～3米的3株,1米以下的46株,最高30米,最大胸径79.2厘米;湖南罗汉洞(越城岭北部)2个点有银杉58株,5米以上的有45株,最高18米,最大胸径43厘米;湖南罗霄山脉八面山有银杉707株,高1米以上的334株,最高24米,最大胸径46厘米;四川南川金佛山(大娄山东段北部)6个点有银杉527株,其中成年树400余株,最高17米,最大胸径50厘米;百枝山有银杉52株,最高8米,最大胸径27厘米;贵州道真沙河林区(大娄山东段南部)3处12个点有银杉729株,其中高5米以上的105株,2～5米的209株,1～2米的111株,1米以下的304株,最高18.8米,最大胸径48厘米;贵州桐梓白菁有银杉10株,高4～5米的2株,1～3米的6株,1米以下的2株。 银杉分布区范围自北纬24°5′～29°13′14″,东经107°10′～113°40′。其垂直分布自海拔940～1840米,金佛山银杉分布最高,为1600～1840米;罗汉洞银杉分布最低,为940～1060米。分布区内,年均温8.2°～17℃,绝对最低温     

Identification of Brassica oleracea monosomic alien chromosome addition lines with molecular markers reveals extensive gene duplication

Summary Chromosomes of Brassica oleracea (2n=18) were dissected from the resynthesized amphidiploid B. napus Hakuran by repeated backcrosses to B. campestris (2n=20), creating a series of monosomic alien chromosome addition line plants (2n=21). Using morphological, isozyme and restriction fragment length polymorphism markers (RFLPs), 81 putative loci were identified. Of nine possible synteny groups, seven were represented in the 25 monosomic addition plants tested. Sequences homologous to 26% of the 61 DNA clones utilized (80% were cDNA clones) were found on more than one synteny group, indicating a high level of gene duplication. Anomalous synteny associations were detected in four 2n=21 plants. One of these plants showed two markers from one B. oleracea chromosome associated with a second complete B. oleracea synteny group, suggesting translocation or recombination between non-homologous chromosomes in Hakuran or the backcross derivatives. The other three 2n=21 plants each contained two or more B. oleracea synteny groups, suggesting chromosome substitution.     

Expression and transport into mitochondria of bovine cytochrome P-450(SCC) in insect cells using the baculovirus expression system.

Bovine cytochrome P-450(SCC) introduced with the baculovirus host vector system was found to be expressed in Spodoptera frugiperda cells. Cell fractionation analysis indicated that the P-450(SCC) expressed as the precursor form was transported into mitochondria and converted to a mature form. However, this form did not exhibit definite activity for cholesterol side chain cleavage. These findings suggest that most of the P-450(SCC) expressed by this system is an inactive protein within mitochondria that is not folded to the conformation of the active enzyme and/or does not incorporate heme appropriately.     

Intervention trial with selenium for the prevention of lung cancer among tin miners in Yunnan,China

This pilot study evaluated the feasibility and effectiveness of conducting a double-blind clinical trial for the prevention of lung cancer with selenium (Se) in Yunnan Tin Corporation, the People's Republic of China, where the incidence rates of lung cancer are extraordinarily high among the miners. Forty healthy miners were randomized to either 300 μg of Se in high Se malt cakes or an identical placebo of malt cakes daily for one year. Subjects consumed their usual daily diet. The low Se concentrations in plasma (0.05±0.008 μg/mL) and hair (0.442±0.085 μg/g) reflected their low dietary Se intake in the control subjects. In Se-supplemented group, the Se status was increased by 178% for serum and 194.8% for hair. The serum GSHpx activity was increased by 155.7%, whereas the lipid peroxide level was reduced by 74.5% compared to the placebo. The results of UDS assay indicated that the lymphocyte DNA damage induced by ultraviolet irradiation and carcinogen 3,4-benzpyrene could be protected by Se supplementation. Se-supplementation did not affect the liver function test (SGPT), as well as the concentrations of hemoglobin, albumin, and cholesterol. Thus, daily intake of 300 μg Se in form of Se-malt as a chemopreventive measure is safe and effective to humans with low Se status.     

Template-directed oligomerization of 5′-deoxy-5′-nucleosideacetic acid derivatives

5-Deoxy-5-nucleosideacetic acids II–V are isostructural analogues of nucleotides with a carboxylate group in the place of the 5-phosphate group. We have studied their oligomerization in aqueous solution using a water-soluble carbodiimide as the condensing agent in the presence or absence of an appropriate polynucleotide template. Condensation of adenylic acid analogues IIa, IIIa, and Va in the presence of polyuridylic acid were found to be the most efficient reactions. Cyclization of the activated monomers to lactones and the insolubility of the oligomers in aqueous solution were found to be obstacles to the efficient formation of long oligomers.     

小鼠LAK细胞对红系祖细胞及多向造血祖细胞增殖的影响

小鼠脾细胞经重组人白细胞介素-2(rhIL-2)激活后对YAC-1,LP-3和WEHI-164等肿瘤细胞均有很强的杀伤活性。在CFU-E和BFU-E培养体系中,不同浓度LAK细胞与BMC直接加入或预温育4h后再培养,均能加强CFU-E和BFU-E增殖。低浓度LAK细胞(LAK/BMC为0.5)与BMC直接加入或预温育后再加入CFU-mix培养体系中,均能增强CFU-mix增殖,而高浓度LAK细胞和BMC(LAK/BMC=8.0)直接加入培养体系则抑制CFU-mix增殖;若共温育后再培养则非常明显地抑制CFU-mix增殖,CFU-mix仅为对照的17.6％。小鼠LAK细胞对造血祖细胞体外增殖具有调节作用,这种调节可能包括分泌某些细胞因子以及细胞间直接相互作用两种方式。