Pollen-specific expression of theArabidopsis thaliana α1-tubulin promoter assayed by β-glucuronidase,chloramphenicol acetyltransferase and diphtheria toxin reporter genespromoter assayed by β-glucuronidase,chloramphenicol acetyltransferase and diphtheria toxin reporter genes

We have characterized the promoter specificity of theArabidopsis thaliana α₁-tubulin (α ₁-tub) gene by studying expression patterns of gene fusions between the 2.2 kbp 5′ upstream region of theα ₁-tub gene and each of three different reporters: chloramphenical acetyltransferase, β-glucuronidase or the diphtheria toxin chain A gene. Analysis of transgenic tobacco andArabidopsis plants carrying the transgene showed that the chloramphenicol acetyltransferase and β-glucuronidase activities were not detected in any vegetative or reproductive organs except mature pollen. Transgenic tobacco plants carrying the diphtheria toxin chain A gene under the control of theα ₁-tub promoter were of normal phenotype but seed fertility was drastically reduced. Furthermore, the transgene could not be transmitted to the next generation through pollen, supporting the observation that theα ₁-tub promoter is active only in pollen. It was observed that the promoter activity was most active in mature pollen and decreased significantly duringin vitro pollen germination, indicating that the promoter is inactive or subdued in germinating pollen. The promoter activity was not affected by various plant growth hormones during pollen maturation.     

毛枝南蛇藤根皮中南蛇藤素的分离鉴定及含量测定

从卫矛科南蛇藤属植物毛枝南蛇藤(Celastrus hookeri Prain)根皮中首次分离出一个红色立方体形结晶,经紫外、红外、高分辨质谱和~(13)C核磁共振谱分析,并与有关文献数据对照,确认是南蛇藤素。作者用薄层扫描和高效液相两种方法初步测定了毛枝南蛇藤根皮和根的木栓化表皮的南蛇藤素含量,结果表明南蛇藤素主要集中在根的木栓化表皮,含量在12%以上,而在整个根皮中的含量大约为1%。     

The effect of 4-week streptozotocin-induced diabetes on responses to endothelin-1 in rat isolated atria

The effect of endothelin-1 has been examined on isolated spontaneously beating right atria and electrically driven left atria from diabetic rats and age-matched controls. Diabetes was induced by a single i.v. injection of streptozotocin (65 mg/kg) 4–5 weeks before the experiments. Endothelin-1 (0.01–100 nM) caused concentration-dependent increases in atrial rate and force; the increases were not different between atria from diabetic and control rats. The ability of endothelin-1 to reduce chronotropic and inotropic responses to noradrenaline was also not different between the two groups. Endothelin-1 (10 nM) decreased the chronotropic response to sympathetic nerve stimulation (2 Hz, 10 s) in atria from control rats by 68 ± 5% (n = 8), but this decrease was slightly smaller (45 ± 6%, N = 8) in atria from diabetic rats.

The results provide no evidence to suggest that the diabetic state markedly alters cardiac responses to endothelin-1.     

Reversal of chloroquine resistance in falciparum malaria independent of calcium channels

Racemic verapamil and close structural derivatives gallopamil and devapamil completely reverse chloroquine-resistance in falciparum malaria at 1-2 micromolar concentrations. If the R-(+) isomers of these calcium channel inhibitors are used, chloroquine-resistance is again completely reversed at similar doses. However, these R-(+) isomers do not bind to cardiovascular calcium channels which are stereospecific for the S-(-) isomer of the drugs. Further since calcium channel inhibition is not involved, toxicity associated with this activity can be avoided. Therefore it is possible that a series of R-(+) isomers could be found that alter the resistant state without possessing significant toxicity. It is postulated that these lipophilic drugs are interacting with the mechanism of resistance, possibly a multidrug resistance glycoprotein pump.     

Transformation of Tobacco, Tomato, Potato, and Arabidopsis thaliana Using a Binary Ti Vector System

Using a binary tumor-inducing (Ti) plasmid vector system, several plant species were transformed with a kanamycin resistance marker (neomycin phosphotransferase gene). Four Nicotiana species, seven tomato cultivars, two potato cultivars, and Arabidopsis thaliana were transformed by the binary vector transformation method. In this method, various plant organ pieces were co-cultivated with Agrobacterium tumefaciens cells carrying the binary vector, pGA472, and a helper Ti plasmid. We have also demonstrated that a wild type Ti plasmid can be used as a helper to obtain a transformed plant.     

蝮蛇毒抗凝血活酶组份及几种蛇毒粗毒对人红细胞和血小板的作用

蝮蛇毒抗凝血活酶组分及蝗蛇毒、圆斑蝰蛇毒和眼镜蛇毒粗毒,不仅能够水解血浆中的磷脂,而且还能水解完整人红细胞膜和完整人血小板膜上的磷脂。但是五步蛇毒和金环蛇毒粗毒却不能水解完整人血小板膜上的磷脂。 扫描电镜观察表明,由于抗凝血活酶组份和几种蛇毒粗毒的作用,人红细胞和人血小板的形态发生了巨大的变化;人红细胞由正常的双圆盘形变成带刺的小球,人血小板的外形变成蜂窝状。     

The use of microcomputers for the quantitation of light intensity patterns using digitized video signals

We have developed an inexpensive yet versatile microcomputer-basedsystem for quantitating light intensity levels in autoradiographs.This system employs a standard video camera interfaced to ananalog-to-digital convertor. A program has been written forthis system which can measure intensities within a defined regionof an autoradiograph, permitting an easy and accurate quantitationof spots or bands of irregular shape. Received on June 18, 1985; accepted on September 3, 1985     

金丝猴(RHINOPITHECUS)脑的外部形态

本文是对三种金丝猴脑的外部形态的观察结果表明:金丝猴的大脑皮层除存在猴科固有的全部沟裂外,还较其他猴科动物具有更多的副沟。大脑的沟型与疣猴亚科的特征完全吻合,但是很多特点都较叶猴更近似于长臂猿。另外,除了蚓叶和蚓结节较小,四叠体的下丘较猕猴发达以外,金丝猴的小脑和脑干均与猴科的一般特征无明显差异。