Interleukin-5 induces tumor suppression by peritoneal exudate cells in mice

The antitumor activity of peritoneal exudate cells (PEC) induced by murine interleukin-5 (mIL-5) was examined using Meth-A sarcoma cells transplanted into the peritoneal cavity of mice. Although in vitro treatment of Meth-A sarcoma cells with mIL-5 did not result in inhibition of their growth, treatment of mice intraperitoneally with mIL-5 (1 g/day) from day –5 to +5 (tumor cells were inoculated on day 0) led to a significant increase in survival or even rejection of tumor cells. This antitumor effect depended on the dose of mIL-5. Interestingly, there was identical therapeutic activity when the protocol of days –10 to –1 was used as opposed to –5 to +5. In addition, post-treatment with mIL-5 from day +1 to +10 was ineffective. This suggests that the therapeutic activity of IL-5 is largely prophylactic. Under the former condition, the number of PEC was found to increase over 50-fold when compared to levels in control mice. Moreover, the antitumor effect of mIL-5 was completely abolished by subcutaneous injection of anti-mIL-5 monoclonal antibodies. The treatment of mice injected intraperitoneally with human IL-2 also resulted in an increase in survival. Winn assay experiments using PEC recovered from mIL-5-treated mice (1g/day, from day –10 to –1) revealed that these PEC could mediate antitumor activity against Meth-A sarcoma cells. Furthermore, when the cured mice were re-injected with Meth-A sarcoma cells or syngeneic MOPC 104E cells, they could reject Meth-A sarcoma cells but not MOPC 104E cells, indicating that immune memory had been generated. These results suggest that IL-5 augumented the PEC tumoricidal activity but we have no indication that the tumoricidal activity was mediated through a mIL-5-dependent mechanism.     

植物标本标签的计算机印制数据系统

本文讨论了主要用以印制标本采集记录标签的数据系统及其数据库建库方案与编程原理。该系统可在ＩＢＭ及其兼容系列个人计算机上使用,适合用于个人或科研与教学机构中小型标本采集信息管理;可用以数据的检索、标本标签的印制和植物名录的打印;也可用以地区性的植物区系与生态学研究。     

Organic acid exudation as an aluminum-tolerance mechanism in maize (Zea mays L.)

In this study, the role of root organic acid synthesis and exudation in the mechanism of aluminum tolerance was examined in Al-tolerant (South American 3) and Al-sensitive (Tuxpeño and South American 5) maize genotypes. In a growth solution containing 6 M Al³⁺, Tuxpeño and South American 5 were found to be two- and threefold more sensitive to Al than South American 3. Root organic acid content and organic acid exudation from the entire root system into the bulk solution were investigated via high-performance liquid chromatographic analysis while exudates collected separately from the root apex or a mature root region (using a dividedroot-chamber technique) were analyzed with a more-sensitive ion chromatography system. In both the Al-tolerant and Al-sensitive lines, Al treatment significantly increased the total root content of organic acids, which was likely the result of Al stress and not the cause of the observed differential Al tolerance. In the absence of Al, small amounts of citrate were exuded into the solution bathing the roots. Aluminum exposure triggered a stimulation of citrate release in the Al-tolerant but not in the Al-sensitive genotypes; this response was localized to the root apex of the Al-tolerant genotype. Additionally, Al exposure triggered the release of phosphate from the root apex of the Al-tolerant genotype. The same solution Al³⁺ activity that elicited the maximum difference in Al sensitivity between Al-tolerant and Al-sensitive genotypes also triggered maximal citrate release from the root apex of the Al-tolerant line. The significance of citrate as a potential detoxifier for aluminum is discussed. It is concluded that organic acid release by the root apex could be an important aspect of Al tolerance in maize.Abbreviations SA3 South American 3, an Al-tolerant maize cultivar - SA5 South American 5, an Al-sensitive maize cultivar The authors would like to express their appreciation to Drs. John Thompson, Ross Welch and Mr. Stephen Schaefer for their training and guidance in the use of the chromatography systems. This work was supported by a Swiss National Science Foundation Fellowship to Didier Pellet, and U.S. Department of Agriculture/National Research Initiative Competitive Grant 93-37100-8874 to Leon Kochian. We would also like to thank Drs. S. Pandey and E. Ceballos from the CIMMYT Regional office at CIAT Cali, Colombia for providing seed for the maize varieties and inbred line.     

Changes in chorion proteins induced by the exudate released from the egg cortex at the time of fertilization in the teleost, Oryzias latipes

The chorion of unfertilized medaka Oryzias latipes eggs consists of two major proteins (77–73 and 49 kDa) and a minor 150 kDa protein. Upon fertilization, these major chorion proteins are polymerized to insoluble high molecular weight proteins via the temporary formation of several new proteins (132, 114, 62 and 61 kDa). Increasing chorion toughness is closely related to the formation of high molecular weight proteins and the increasing insolubility of the chorion proteins. The changes in chorion proteins and hardening could be induced in vitro in isolated chorions by an egg exudate, which includes cortical alveolar contents. The effects of temperature and pH on the egg exudate-induced changes in chorion proteins were examined in the present study. The major proteins could be digested by proteolytic enzymes. The 49 kDa protein was PAS-positive. Analysis with polyclonal antibodies against the major proteins demonstrated that the temporarily formed 62 and 61 kDa proteins were derived from the 77–73 kDa protein and that higher molecular weight proteins, newly formed in the process of chorion hardening, contained the same epitopes as did the 77–73 and 49 kDa proteins. The results suggest that the changes in chorion proteins of the medaka egg at the time of fertilization can be induced by an enzyme(s) released from the egg cortex into the perivitelline space.     

Identification and characterization of flavonoids in the root exudate of Robinia pseudoacacia

 Eight compounds exuded from young roots of black locust (Robinia pseudoacacia) were separated by two-dimensional HPTLC, by HPLC and GC, and were identified by spectroscopic methods (ultraviolet/visible spectroscopy and mass spectrometry) as 4′,7-dihydroxyflavone, apigenin, naringenin, chrysoeriol and isoliquiritigenin. Structural assignments were confirmed by comparison with authentic standards. The capacity to induce β-galactosidase activity in Rhizobium sp. NGR234 containing a nod box::lacZ fusion on plasmid pA27 identified these flavonoids and the chalcone as nod gene inducers. This indicates the important role of these compounds in nodulation of this legume tree. Received: 26 July 1996 / Accepted: 9 September 1996     

Sex estimation using the first cervical vertebra

The articular surfaces and vertebral foramen area of the first cervical vertebra are sexually dimorphic and can be used to sex complete or fragmentary specimens. Eight measurements were taken from the articular regions (superior and inferior) of 100 first cervical vertebrae from Terry collection specimens housed at the Smithsonian Institution. Seven regression and seven discriminant function equations were created that predict sex with 77–85% and 75–85% accuracy, respectively. In separate control tests, measurements from 100 first cervical vertebrae from Hamann-Todd collection individuals (Cleveland Museum of Natural History) and from 34 archaeological specimens were used with the Terry equations. The control samples were sexed with 60—85% accuracy. © 1995 Wiley-Liss, Inc.     

Oral exudate as a mediator of behavior in larval eastern and western spruce budworms (Lepidoptera: Tortricidae)

The production of oral exudate by larval eastern and western spruce budworms,Choristoneura fumiferana (Clem.) andChoristoneura occidentalis Free., respectively, was investigated in the laboratory. All larvae except those entering into a molt exhibited aggressive behavior and produced exudate in response to handling or intraspecific encounters. Larvae could be induced to produce exudate up to four times over 2–3 min and produced an average of 1.92±0.04 µl (X ± SE) per induction. Larvae on foliage spent much of their time maintaining their silken feeding tunnel, including spinning and combing silk and removing frass. Exposure to conspecific oral exudate deposited inside the tunnel, or released by agitated larvae inside the tunnel, increased the proportion of larvae that dispersed away from the tunnels and, apparently, increased the larval sensitivity to disturbances. The behavior induced by the oral exudate indicates that it acts as an epideictic (spacing) pheromone.     

Phloem unloading and ‘sink strength’: The parallel between the site of attachment of Cuscuta and developing legume seeds

Sink regions play a central role in determining assimilate distribution patterns. Two factors are discussed which have a strong effect on the sink strength of a sink, viz. phloem unloading and turgor-sensitive transport. Sink strength may be defined as the capacity of phloem in the sink region to import assimilates from other parts of the plants and to release the imported substances into the sink apoplast.A stem parasitized by Cuscuta represents a very strong sink. A review is presented of data on enhanced phloem unloading, at the site of attachment of Custuta. Recent data on metabolically controlled sucrose and amino acid unloading into the seed coat apoplast of developing legume seeds show a remarkable parallel with phloem unloading in a parasitized Vicia faba stem. Data on turgor-sensitive sucrose and amino acid transport into developing seeds are presented, which throw new light on the pressure flow theory of phloem transport.