c-FLIP Protects Eosinophils from TNF-α-Mediated Cell Death In Vivo

Understanding the signals that regulate eosinophil survival and death is critical to developing new treatments for asthma, atopy, and gastrointestinal disease. Previous studies suggest that TNF-α stimulation protects eosinophils from apoptosis, and this TNF-α-mediated protection is mediated by the upregulation of an unknown protein by NF-κB. Here, we show for the first time that eosinophils express the caspase 8-inhibitory protein c-FLIP, and c-FLIP expression is upregulated upon TNF-α stimulation. Considering that c-FLIP expression is regulated by NF-κB, we hypothesized that c-FLIP might serve as the “molecular switch” that converts TNFRI activation to a pro-survival signal in eosinophils. Indeed, we found that one c-FLIP isoform, c-FLIP_L, is required for mouse eosinophil survival in the presence of TNF-α both in vitro and in vivo. Importantly, our results suggest c-FLIP as a potential therapeutic target for the treatment of eosinophil-mediated disease.     

The effect of high intensity focused ultrasound treatment on metastases in a murine melanoma model

This study aims to assess the risk of high intensity focused ultrasound (HIFU) therapy on the incidence of distant metastases and to investigate its association with HIFU-elicited anti-tumor immunity in a murine melanoma (B16-F10) model. Tumor-bearing legs were amputated immediately after or 2 days following HIFU treatment to differentiate the contribution of the elicited anti-tumor immunity. In mice undergoing amputation immediately after mechanical, thermal, or no HIFU treatment, metastasis rates were comparable (18.8%, 13.3%, and 12.5%). In contrast, with a 2-day delay in amputation, the corresponding metastasis rates were 6.7%, 11.8%, and 40%, respectively. Animal survival rate was higher and CTL activity was enhanced in the HIFU treatment groups. Altogether, our results suggest that HIFU treatment does not increase the risk of distant metastasis. Instead, HIFU treatment can elicit an anti-tumor immune response that may be harnessed to improve the overall effectiveness and quality of cancer therapy.     

地中海沿岸沙丘土壤种子库的异质性

应用自然萌发法和物理筛选法相结合的方法,调查了地中海沿岸沙丘三种微生境土壤总种子库和永久种子库特征,用功能群的方法分析了微生境之间的土壤总种子库和永久土壤种子库的组成和结构差异,也分析了主要物种土壤种子库的微生境分布格局,分析了种子大小和土壤种子库中的种子永久性关系.发现地中海沿岸沙丘土壤种子库具有明显的空间异质性,即使在相同的微生境内,土壤种子库的分布也不是均匀的,甚至具有很大的差异;微生境对总的土壤种子库和各功能群的土壤种子库的分布格局具有显著的影响,开阔地区域具有最大的种子密度,而灌丛下和路径具有较小的种子密度;在永久土壤种子库中,豆科类植物种子在休眠种子中占有最大的比例,约为76%,而一年生和多年生禾草未发现休眠种子,豆类、伞形科类、多年生阔草、菊科类、一年生阔叶草和十字花科类等种子在土壤中的永久性比例依次下降,分别为50%、46%、41%、6%、6%和1%,微生境影响各功能群种子在土壤中的永久性.微生境显著影响大部分主要物种的土壤种子库分布;种子大小与其在土壤中的永久性为正相关,即大种子具有较高的永久性,小种子具有较低的永久性.     

地中海沿岸沙丘种子大小对植物及其种子多度的影响

分析了地中海沿岸沙丘3种微生境(灌丛下、灌丛之间的开阔地、路径)以及整个沙丘生态系统的种子大小与土壤种子库中休眠种子的数量、土壤种子库中总种子的数量、地上植被中各个植物种的个体数量和幼苗数量、每种植物在小样方中的出现频率等方面之间的关系,也分析了种子尺寸(长、宽、高之和的平均值)与土壤种子的长久性、土壤种子库中休眠种子数量之间的关系;还分析了具有不同种子大小的植物在沙丘生态系统和各微生境的分布比率,验证了生活周期短的植物的种子在土壤中更长久和被干扰的微生境具有更多的休眠种子这种假说。结果发现,在地中海沿岸沙丘生态系统中,具有特别大的种子和特别小种子的植物种类都很少,不同植物种子的大小呈现近正态分布,但绝大多数植物的种子重量都不超过10 mg;微生境影响种子尺寸与种子长久性的关系,在灌丛下、开阔地区域等两个微生境以及整个的沙丘生态系统都呈现显著的正向关系(p<0 .0 5 ) ,而在路径这种关系不很明显;种子多度与植被物种出现频率呈现强烈的正相关(p<0 .0 5 ) ,没有发现种子大小与土壤种子库中休眠种子数量、种子库中总的种子数量、植被物种出现频率、植被的物种多度、幼苗植物多度等方面有显著的关系;具有中度大小种子(0 .1～10 mg)的植物在总的土壤种子库、休     

Role of Ethylene on de Novo Shoot Regeneration from Cotyledonary Explants of Brassica campestris ssp. pekinensis (Lour) Olsson in Vitro

The promotive effect of AgNO₃ and aminoethoxyvinylglycine (AVG) on in vitro shoot regeneration from cotyledons of Brassica campestris ssp. pekinensis in relation to endogenous 1-amino-cyclopropane-1-carboxylic acid (ACC) synthase, ACC, and ethylene production was investigated. AgNO₃ enhanced ACC synthase activity and ACC accumulation, which reached a maximum after 3 to 7 days of culture. ACC accumulation was concomitant with increased emanation of ethylene which peaked after 14 days. In contrast, AVG was inhibitory to endogenous ACC synthase activity and reduced ACC and ethylene production. The promotive effect of AVG on shoot regeneration was reversed by 2-chloroethylphosphonic acid at 50 micromolar or higher concentrations, whereas explants grown on AgNO₃ medium were less affected by 2-chloroethylphosphonic acid. The distinctive effect of AgNO₃ and AVG on endogenous ACC synthase, ACC, and ethylene production and its possible mechanisms are discussed.     

Effect of sodium sulfate on in vitro organogenesis of tobacco callus

Callus of tobacco (Nicotiana tabacum L. cv. Wisconsin 38) was grown on callus-proliferating (CP) and shoot-forming (SF) media with elevated sodium sulfate (Na₂SO₄) concentrations either in the light or dark for more than one year. An increase in Na₂SO₄ concentration resulted in a decrease in callus growth index, an increase in percent dry weight of callus tissues grown on both media, and a decrease in both number of calli forming shoots and number of shoots per callus in SF medium. The CP callus grown in the light spontaneously began to form shoots after the 5th monthly transfer, and spontaneous root formation occured after the 16th transfer in the presence of 0.75 and 1.0% Na₂SO₄. Both water () and osmotic (_s) potentials of the callus increased with increasing Na₂SO₄ concentration; and callus exhibited greater and _s in the light than dark for both CP and SF media.     

Synergistic effect of ethylene inhibitors and putrescine on shoot regeneration from hypocotyl explants of Chinese radish (Raphanus sativus L. var. longipinnatus Bailey) in vitro

Summary The role of ethylene and putrescine on shoot regeneration from hypocotyl explants of Chinese radish (Raphanus sativus L. var. longipinnatus Bailey cv. Red Coat) was investigated. Explants were recalcitrant in culture, but exogenous application of ethylene inhibitor [20–30 M aminoethoxyvinylglycine (AVG) or AgNO₃] enhanced shoot regeneration of explants grown on medium supplemented with 2 mg/l N⁶-benzyladenine and 1 mg/l 1-naphthaleneacetic acid. The best regeneration occurred in the medium containing AgNO₃ in combination with AVG. Culture medium solidified with agarose in the presence of AgNO₃ but not AVG was also beneficial to shoot regeneration. Exogenous putrescine, 2-chloroethylphosphonic acid and 1-aminocyclopropane-1-carboxylate had no effect on shoot regeneration. However, regeneration was greatly promoted by 10–25 mM putrescine in combination with 30 M AgNO₃ or AVG. Explants with high regenerability grown in the presence of AgNO₃ or in combination with putrescine emanated high levels of ethylene throughout the 21-d culture period. By contrast, AVG or putrescine alone resulted in a decrease in ethylene production. For rooting of shoot cuttings, IAA and IBA at 1–5 mg/l were more effective than NAA.Abbreviations ACC 1-aminocyclopropane-1-carboxylate - AVG aminoethoxyvinylglycine - BA N⁶-benzyladenine - CEPA 2-chloroethylphosphonic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - MS Murashige and Skoog (1962) medium - NAA 1-naphthaleneacetic acid - PAs polyamines - SAM S-adenosyl-L-methionine     

Properties of membrane-bound bilirubin UDP-glucuronyltransferase in rough and smooth endoplasmic reticulum and in the nuclear envelope from rat liver.

We examined regulatory properties of bilirubin UDP-glucuronyltransferase in sealed RER (rough endoplasmic reticulum)- and SER (smooth endoplasmic reticulum)-enriched microsomes (microsomal fractions), as well as in nuclear envelope from rat liver. Purity of membrane fractions was verified by electron microscopy and marker studies. Intactness of RER and SER vesicles was ascertained by a high degree of latency of the lumenal marker mannose-6-phosphatase. No major differences in the stimulation of UDP-glucuronyltransferase by detergent or by the presumed physiological activator, UDPGlcNAc, were observed between total microsomes and RER- or SER-enriched microsomes. Isolated nuclear envelopes were present as a partially disrupted membrane system, with approx. 50% loss of mannose-6-phosphatase latency. The nuclear transferase had lost its latency to a similar extent, and the enzyme failed to respond to UDPGlcNAc. Our results underscore the necessity to include data on the integrity of the membrane permeability barrier when reporting regulatory properties of UDP-glucuronyltransferase in different membrane preparations.     

Effect of AgNO3 and aminoethoxyvinylglycine on in vitro shoot and root organogenesis from seedling explants of recalcitrant Brassica genotypes

The presence of 1–10 M aminoethoxyvinylglycine (AVG) or 5–30 M AgNO₃ markedly enhanced shoot regeneration from cotyledon and hypocotyl cultures of eight recalcitrant Brassica campestris and B. juncea genotypes tested. Expiants of B. campestris ssp. chinensis and ssp. parachinensis grown with a high AVG concentration (20 M), regenerated poorly. All cytokinins tested were equally effective in promoting shoot formation, except that kinetin was inhibitory to shoot regeneration from hypocotyls of B. campestris ssp. pekinensis (cv. Wong Bok). Both AgNO₃ and AVG had no effect on percent rooting and number of roots per rooted cutting of Wong Bok, White Sun and Leaf Heading, but AgNO₃ was inhibitory to rooting of India Mustard. However, root elongation of all cuttings was markedly inhibited by AVG at concentrations of 5 and 10 M.Abbreviations AVG aminoethoxyvinylglycine - BA benzyladenine - IBA indole-3-butyric acid - 2ip 6-{ie195-01}-{ie195-02}-dimethylallylamino purine - MS Murashige and Skoog - NAA naphthaleneacetic acid