Correlation of H2O2 production and liver catalase during riboflavin deficiency and repletion in mammals

A substantial decrease in liver peroxisomal catalase was found during riboflavin deficiency in rats. This decrease is greater than that found among other hemoproteins and seems to follow decrease in flavin-dependent peroxisomal oxidases. This is not due to a general depression of peroxisomal enzymes, since Cu-dependent urate oxidase activity was not changed. Furthermore, the level of catalase activity as well as flavin-dependent oxidases was restored by riboflavin repletion. These results suggest that hydrogen peroxide, the substrate for catalase produced by several flavoprotein oxidases, induces catalase in mammals as has been indicated for certain bacteria.     

小麦再生植株的变异研究 Ⅱ.再生植株当代(R_1代)的细胞学和形态学变异

再生植株具有高频率的染色体异常,其中有20.61％表现为染色体数量变异,最常见的为2n—1类型,其次为2n—2类型,也有2n 1、2n—3个体以及染色体数嵌合株。再生植株减数分裂各期均有染色体异常行为,可以见到的有落后染色体、染色体桥、断片、二分体延迟、微核,还有粗线期十字型配对等结构变异,以及五分体、六分体和畸型四分体等异常现象。微核率随培养时间延长而增加,可用作染色体伤害的一个指标。再生植株R_1代存在着许多形态学变异。性状变异与染色体数目变异没有明显关系。     

Virological survey of rhesus monkeys in China

A virological survey of rhesus monkeys captured in China for 13 viruses and/or antibodies was performed. Antigens used were SFV, SF40, HSV-1, Sa11, measles, vaccinia, epidemic or simian hemorrhagic fever, Langat, Kunming, poliomyelitis, HIV, SV41 and rubella. Monkeys were from Sichuan, Hunan, Guizhou, Yunnan and Guangxi provinces. Antibody was detected to all the listed viruses except HIV, SV41 and rubella. Both SFV and SV40 were recovered from monkeys, but H. simiae, LCM and coxsackieviruses were not.     

Hybrid genes in the analysis of transformation conditions: II. Transient expression vs stable transformation—analysis of parameters influencing gene expression levels and transformation efficiency

Reports on direct gene transfer have dealt with either the obtention of stable transformants and transgenic plants, or described the use of reporter genes to analyse different aspects of gene expression in plant protoplasts and conditions for their use in transient gene expression assays.
In this paper we present comparisons between several transformation techniques, show species-specific differences in efficiencies of stable transformants and in the levels of transient gene expression, and report on the identification of major parameters responsible for DNA uptake as judged from transient chloramphenicol acetyl transferase (CAT) expression levels and from efficiencies of transformation based on kanamycin-resistance. The described procedures have been simplified, optimized and standardized and should allow routine use with a great variety of plant species.     

Optimization of delivery of foreign DNA into higher-plant chloroplasts

We report here an efficient and highly reproducible delivery system, using an improved biolistic transformation device, that facilitates transient expression of -glucuronidase (GUS) in chloroplasts of cultured tobacco suspension cells. Cultured tobacco cells collected on filter papers were bombarded with tungsten particles coated with pUC118 or pBI101.3 (negative controls), pBI505 (positive nuclear control) or a chloroplast expression vector (pHD203-GUS), and were assayed for GUS activity. No GUS activity was detected in cells bombarded with pUC118 or pBI101.3. Cells bombarded with pBI505 showed high levels of expression with blue color being distributed evenly throughout the whole cytosol of the transformants. pHD203-GUS was expressed exclusively in chloroplasts. We base this conclusion on: i) the procaryotic nature of the promoter used in the chloroplast expression vector; ii) delayed GUS staining; iii) localization of blue color within subcellular compartments corresponding to plastids in both shape and size; and iv) confirmation of organelle-specific expression of pHD203-GUS using PEG-mediated protoplast transformation. Chloroplast transformation efficiencies increased dramatically (about 200-fold) using an improved helium-driven biolistic device, as compared to the more commonly used gun powder charge-driven device. Using GUS as a reporter gene and the improved biolistic device, optimal bombardment conditions were established, consistently producing several hundred transient chloroplast transformants per Petri plate. Chloroplast transformation efficiency was found to be increased further (20-fold) with supplemental osmoticum (0.55 M sorbitol and 0.55 M mannitol) in the bombardment and incubation medium. This system provides a highly effective mechanism for introducing and expressing plasmid DNA within higher-plant chloroplasts, and the fact that GUS functions as an effective marker gene now makes many genetic studies possible which were not possible before.     

Lung and chest wall mechanics in rabbits during high-frequency body-surface oscillation

In eight anesthetized and tracheotomized rabbits, we studied the transfer impedances of the respiratory system during normocapnic ventilation by high-frequency body-surface oscillation from 3 to 15 Hz. The total respiratory impedance was partitioned into pulmonary and chest wall impedances to characterize the oscillatory mechanical properties of each component. The pulmonary and chest wall resistances were not frequency dependent in the 3- to 15-Hz range. The mean pulmonary resistance was 13.8 +/- 3.2 (SD) cmH2O.l-1.s, although the mean chest wall resistance was 8.6 +/- 2.0 cmH2O.l-1.s. The pulmonary elastance and inertance were 0.247 +/- 0.095 cmH2O/ml and 0.103 +/- 0.033 cmH2O.l-1.s2, respectively. The chest wall elastance and inertance were 0.533 +/- 0.136 cmH2O/ml and 0.041 +/- 0.063 cmH2O.l-1.s2, respectively. With a linear mechanical behavior, the transpulmonary pressure oscillations required to ventilate these tracheotomized animals were at their minimal value at 3 Hz. As the ventilatory frequency was increased beyond 6-9 Hz, both the minute ventilation necessary to maintain normocapnia and the pulmonary impedance increased. These data suggest that ventilation by body-surface oscillation is better suited for relatively moderate frequencies in rabbits with normal lungs.     

以融合蛋白形式在大肠杆菌中表达人MCP－1

将编码人单核细胞趋化蛋白－１（ＭＣＰ－１）的基因亚克隆到大肠杆菌表达载体ｐＥＸ３１Ａ中,在大肠杆菌中表达出ＭＳ２／ＭＣＰ－１融合蛋０白,该表达产物约占菌体总蛋白的１５％左右,Ｗｅｓｔｅｒｎｂｌｏｔ检测表明,表达产物可与ＭＣＰ－１抗体特异反应。采用琼脂糖平板法进行活性测定表明,表达产物具有明显的单核细胞趋化活性,说明Ｎ端融合一段细菌蛋白对ＭＣＰ－１有无趋化活性可能没有影响。     

A simple and efficient method for DNA extraction from grapevine cultivars andVitis species

A quick, simple, and reliable method for the extraction of DNA from grapevine species, hybrids, andAmpelopsis brevipedunculata (Vitaceae) has been developed. This method, based on that of Doyle and Doyle (1990), is a CTBA-based extraction procedure modified by the use of NaCl to remove polysaccharides and PVP to eliminate polyphenols during DNA purification. The method has also been used successfully for extraction of total DNA from other fruit species such as apple (Malus domestica), apricot (Prunus armeniaca), cherry (Prunus avium), peach (Prunus persica), plum (Prunus domestica), and raspberry (Rubus idaeus). DNA yield from this procedure is high (up to 1 mg/g of leaf tissue). DNA is completely digestible with restriction endonucleases and amplifiable in the polymerase chain reaction (PCR), indicating freedom from common contaminating compounds.     

骨缘当归的化学成分

骨缘当归Angellica cartilaginomarginata var.foliata Yuan et Shen,别名:山藁本、野芹菜（江苏）,仅分布于江苏和浙江。在江苏镇江等地用干燥全草作山藁本入药,其化学成分未见报道。 样品采自江苏省句容县。将干根磨粉,提取物经中性氧化铝层析,根据色谱及光谱鉴定为两种脂肪酸、四种已知香豆素和一种植物甾醇即:正葵酸（n-capric acid）、月桂酸（lauric acid）、骨缘当归素（cartilaginomarginadin）、蝉翼素（pteryxin）、白花前胡素F（praeruptorin F）、佛手柑内酯（bergapten）及β-谷甾醇（β-sitosterol）。     

稻田两种狼蛛种间相互作用及对白背飞虱复合捕食作用的研究

室内研究结果表明,拟水狼蛛对白背飞虱的捕食作用小于拟环纹豹蛛,两种狼蛛种内种间均存在干扰作用,且主要表现为残杀作用,狼蛛密度越高,干扰作用越大;拟环纹豹蛛对拟水狼蛛的残杀作用大于对其身的残杀作用,拟水狼蛛只存在自相残杀作用,对拟环纹豹蛛无残杀作用。