植物营养活力素对小鼠生长及耐受能力的影响

以不同剂量的植物营养活力素（ＰＶＮ）喂饲小鼠，对小鼠的体重增长、耐寒、耐热、耐力等进行了观测。结果：用药后实验小鼠的体重和胸脾系数明显增加；耐寒、耐热及持续游泳时间明显延长。表明ＰＶＮ可明显提高小鼠的体重增长和对应激的耐受能力，提示其营养作用不仅适用于植物，而且适用于动物。     

植物抗体及其应用

20世纪80年代末科学家将抗体基因转入烟草表达,标志着植物抗体的诞生.人类既可以以植物为生物反应器异源表达和生产具有药用及商业价值的蛋白质;也可用抗体在植物体中进行免疫调节,以研究植物生理代谢机制,或增加植物抵抗病虫害的能力.本文旨对植物抗体的优越性、表达生产及其在医药学、植物抗病及代谢等领域的进展进行综述和讨论.     

12种中草药的乙醇提取液对印鼠客蚤的毒效研究

目的:探讨中草药灭蚤的可行性。方法:用乙醇提出12种中草药的可溶成分,以瓶膜法测定其对印鼠客蚤的毒力。结果:在0.5g/ml(生药)的浓度下,10种中草药对印鼠客蚤有速效击倒作用,其中鸡血藤、巴豆仁、除虫菊花的10min击倒率大于50％;5种中草药的KD_(50)小于15min,比2％DDVP为优;巴豆仁接触30min恢复24h死亡率为70％。结论:除虫菊花、黎芦、鸡血藤、巴豆仁、贯众用于杀蚤有一定价值。     

Screening 34 Peanut Introductions for Allergen Content Using ELISA

Peanut is one of the most allergenic foods and reports of accidental ingestion of peanuts in unsuspected food are increasing. No information is available on the allergen content of peanut germplasm grown commercially and used in the food and confectionery industry. The objectives of this study were: (1) to determine the allergen contents of 34 peanut introductions (PI); and (2) to identify naturally occurring allergen-free and/or low or hypoallergenic peanuts germplasm. A basic ELISA protocol was utilized to detect the presence of antigens in the peanut lines using a pool of human sera from patients with documented history of peanut allergy. Two naturally occurring low, or hypo-allergenic germplasm were identified as PI 261942 and PI 338386. Both are Valencia market types with total allergen content significantly lower (P ≤0.05) than that of PI 119880 (0.550), PI 119876 (0.415) and PI 118991 (0.410) three Valencia market types and PI 262111 (0.485), a Virginia market type. No allergen-free PI was found. Allergen content of peanut lines from Bolivia and Paraguay were significantly (P ≤0.05) different to those from Venezuela. No significant difference was observed in the allergen content of the four market types.     

Antimicrobial Activity of Various Extracts of Ocimum Basilicum L. and Observation of the Inhibition Effect on Bacterial Cells by Use of Scanning Electron Microscopy

The antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of Ocimum basilicum L. were studied. These extracts were tested in vitro against 10 bacteria and 4 yeasts strains by the disc diffusion method. The results indicated that the methanol extracts of O. basilucum exhibited the antimicrobial activity against tested microorganisms. While the chloroform and acetone extracts had no effect, the methanol extracts showed inhibition zones against strains of Pseudomonas aeruginosa, Shigella sp., Listeria monocytogenes, Staphylococcus aureus and two different strains of Escherichia coli. The cells of microorganisms, which were treated and untreated with plant extracts, were observed by using the scanning electron microscope. It was observed that the treated cells were damaged.     

Size distribution and In vitro translation of the RNAs isolated from turnip yellow mosaic virus nucleoproteins

Purified preparations of TYMV contain a number of minor nucleoprotein components distinguishable on the basis of their density in CsCl gradients (R. E. F. Matthews, Virology12, 521–539, 1960). When analysed by polyacrylamide-gel eletrophoresis, the RNA from each of these various components was found to consist of a characteristic set of molecular-weight species. Full-size RNA (2 × 10⁶ daltons) was present only in nucleoproteins B₁ and B₂. Nucleoproteins B₀, B₀₀, and B₀₀₀ contained RNAs ranging in size from approx 1.3 to 0.28 × 10⁶ daltons. The 0.28 × 10⁶-dalton RNA species was detectable in all nucleoprotein fractions, but was a significant proportion of the RNAs of B₀₀₀ and B₀₀. Translation of the RNA from each of the nucleoproteins in the wheat germ cell-free protein synthesizing system yielded essentially similar patterns of polypeptides which ranged in size from 5000 to 70,000 daltons. The major radioactive product migrated on SDS-polyacrylamide gels to the same position as TYMV coat protein. The data suggest that the 0.28 × 10⁶-dalton RNA component is the cistron for coat protein, and that it and other RNAs associated with TYMV infection are encapsidated.     

银杏叶提取物对心肌缺血再灌注微循环的保护作用

复制家兔缺血再灌注模型,采用显微电视和微机图像处理系统对20只家兔球结膜微血管口径、流速、流量等参数进行定量分析.结果:银杏叶提取物(GBE)组在结扎即刻、30分钟、再灌注30分钟等时相,与生理盐水组比较,微动脉、微静脉口径(3、4级)、微静脉流速、流量、毛细血管密度均增加,交换距离缩小(P<0.05).提示:GBE对心肌缺血再灌注微循环有显著的保护作用.其机制可能与扩张微血管口径、改善血流灌注有关.     

3'-Terminal RNA secondary structures are important for accumulation of tomato bushy stunt virus DI RNAs

The plus-strand RNA genome of tomato bushy stunt virus (TBSV) contains a 351-nucleotide (nt)-long 3'-untranslated region. We investigated the role of the 3'-proximal 130 nt of this sequence in viral RNA accumulation within the context of a TBSV defective interfering (DI) RNA. Sequence comparisons between different tombusviruses revealed that the 3' portion of the 130-nt sequence is highly conserved and deletion analysis confirmed that this segment is required for accumulation of DI RNAs in protoplasts. Computer-aided sequence analysis and in vitro solution structure probing indicated that the conserved sequence consists of three stem-loop (SL) structures (5'-SL3-SL2-SL1-3'). The existence of SLs 1 and 3 was also supported by comparative secondary structure analysis of sequenced tombusvirus genomes. Formation of the stem regions in all three SLs was found to be very important, and modification of the terminal loop sequences of SL1 and SL2, but not SL3, decreased DI RNA accumulation in vivo. For SL3, alterations to an internal loop resulted in significantly reduced DI RNA levels. Collectively, these data indicate that all three SLs are functionally relevant and contribute substantially to DI RNA accumulation. In addition, secondary structure analysis of other tombusvirus replicons and related virus genera revealed that a TBSV satellite RNA and members of the closely related genus Aureusvirus (family Tombusviridae) share fundamental elements of this general structural arrangement. Thus, this secondary structure model appears to extend beyond tombusvirus genomes. These conserved 3'-terminal RNA elements likely function in vivo by promoting and/or regulating minus-strand synthesis.     

核电站事故的公众防护行动

随着核能发展不断推进,居住在核电站周围的公众数量越来越多,但是他们普遍缺乏对核辐射的基础知识,对核事故的防护行动也知之甚少。而及时、正确的防护行动可以将核电站事故对公众的健康危害降到最低。本文介绍了核电站事故后,公众的防护行动：隐蔽、体表污染去污、撤离、服用稳定性碘、食品和饮用水控制、个人防护措施、宠物照料、心理援助等,以指导公众在事故后开展正确的自救与互救,提高公众对核电站事故的应急响应能力。     

Plant sterols in vegetables and fruits commonly consumed in Sweden

Summary Plant sterols are known to have serum cholesterol lowering effects. A high dietary intake might therefore have a positive impact on health. All food items of vegetable origin contain some amount of plant sterols. The aim of this study was to analyse the plant sterol content of vegetables and fruits commonly consumed in Sweden, and to compare fresh and cooked samples of the same items. Altogether 20 different vegetables and 14 fruits were analysed. All vegetables and fruits were purchased in two shops in the city of Gothenburg, Sweden. Lyophilization was performed within one month of the items being purchased. The samples were frozen at −20 (C and analysed within six months, with a GLC method after acid hydrolysis, alkaline hydrolysis and silylation with tri-methylsilylether. The acid hydrolysis was done in order to detect the fraction of glycosylated plant sterols, which are split during boiling with HCl. The median plant sterol content of vegetables was 14 (3.8–50) mg/100 g edible portion. The highest concentrations were found in broccoli, Brussels sprouts, cauliflower and olives. The median plant sterol content of fruits was 16 (3–44) mg/100 g edible portion. The highest concentrations were found in oranges and passion fruits. The plant sterol concentrations were thus low in vegetables and fruits commonly consumed in Sweden. A serum cholesterol lowering effect attributed to the plant sterols in vegetables and fruits would therefore be of limited significance. Received: 25 September 1998, Accepted: 10 February 1999