Monitoring hairy-root growth by image analysis

Hairy roots, incited byAgrobacterium rhizogenes, form a useful system for analysing the expression and phenotypic effects of foreign genes in plant root tissue. Image analysis offers a non-invasive method of describing their growth in culture. Images of pea (coarse) andBrassica (fine) hairy roots were captured, processed and analysed without difficulty using a commercially available image analysis system. The value of this method in monitoring intermediate changes in growth pattern was illustrated by following the changes in five putatively chlorsulfuron-resistantBrassicc hairy-root lines cultured with and without a selective level of chlorsulfuron. Areas of hairy-root research where this technique will be particularly useful are discussed.     

Investigation of inanimate objects by the greater bushbaby (Otolemur garnettii)

Investigatory behavior with novel, inanimate objects by two groups of four juvenile greater bushbabies (Otolemur garnettii) was examined in the laboratory. Substantial investigatory behavior was shown by all subjects. In the first study, subjects showed interest in a wide variety of nonfood stimulus objects. In the second, subjects displayed sustained interest in and investigation of non-food stimulus objects over three sessions. Bushbabies showed preferences for larger, more manipulable objects and variations in total contact over days. Individual differences were observed in the duration and types of contact with objects. These observations contradict earlier reports that prosimians show little interest in inanimate, non-food objects.     

Angiogenesis in the mouse retina: a model system for experimental manipulation

The vascular system of the mouse retina provides a useful model for analyzing the molecular and cellular mechanisms regulating angiogenesis because (1) hierarchical vascular networks are newly formed only after birth, (2) the cellular components involved in angiogenesis are well characterized, and (3) all the processes are accessible for monitoring and manipulation. In this article, we present an overview of our current understanding of the process of retinal angiogenesis and describe a number of methodologies applicable to experimental manipulation of the retinal vascular system.     

H－ras在颊粘膜正常、良性、癌前及恶性变上皮中的表达：免疫组织化学定量研究

本文通过建立图象分析方法对免疫组织化学反应结果进行定量,检测观察Ｈ－ｒａｓ在口腔颊粘膜上皮在正常（Ｎ）、慢性炎症（ＩＦ）、癌旁上皮（ＥＡＣ）和鳞癌（ＳＣＣ）的变化过程中的表达并进行分析。结果显示Ｈ－ｒａｓ在ＳＣＣ组中,以中等分化的ＳＣＣ无论是Ｈ－ｒａｓ表达的量还是细胞阳性率都较高。此外,组织学观察显示,Ｈ－ｒａｓ在处于分化末期但尚未角化的正常上皮细胞中有较高的表达。本文结果显示了Ｈ－ｒａｓ的过表达与上皮细胞的会化程度密切相关。本研究还显示,所采用的阳性区域透光值、平均总透光值及阳性反应区域与阴性反应区域比值可靠并有相关性。这进一步说明了用免疫组化定量方法检测Ｈ－ｒａｓ癌基因表达的精确和可靠性。     

New anatomical method of grain angles measurement using confocal microscopy and image cross-correlation

Some tropical trees with indistinct growth rings have a distinct interlocked grain that reveals their internal growth rhythm. To determine their growth rhythm, it is necessary to accurately measure the wood grain angle. The usual methods for grain angle measurement are radial splitting using wood disks, which occasionally provides inaccurate data, and serial tangential sectioning, which requires preparation and analysis of many sections. The present report proposes an easier but accurate method to measure grain angle using a single xylem transverse section. A confocal microscope was used to obtain two optical sections of different depths from a transverse section of a 7-year-old Hopea odorata Roxb. The tangential lag between the optical images was then calculated using image cross-correlation and transformed into grain angle. Radially consecutive sampling revealed distinct radial fluctuations in the grain angle. The fluctuation data were compared to data obtained by radial splitting and serial tangential sectioning. There was a strong correlation between grain angle using the three methods. In the region close to the cambium, however, the present method revealed an abrupt change in the grain angle, although radial splitting showed a smooth undulation throughout the radius. Using the present method, the analysis of a radial range of 5 cm required a single transverse section compared to 1,000 tangential sections 50-m thick. In conclusion, the present method using a single transverse section, confocal microscopy, and image cross-correlation analysis provides more accurate data than radial splitting, and is less time-consuming than serial tangential sectioning.