寡聚糖素诱导植物抗病性反应研究进展

阐述了寡聚糖素作为诱导植物抗病性反应的重要信息分子，它们的来源、活体生成机制及可能的信息传递机理。评述了结构与诱导活性的相关性以及将寡聚糖素推广应用于植物病害防治的可能性。提出了进一步研究所存在的问题及可能解决的途径。

安徽茶种资源抗茶轮斑病初步鉴定研究

本文就安徽省培育出的部分茶树品种进行茶轮斑病(Pestalotiopsis theae Sawada)抗性的鉴定。两年的试验结果表明,鉴定的18份材料中,高抗型的有2份,属高抗与中抗之间的有2份,中抗型的有9份,介于中抗与感病之间的有4份,感病型的有1份。

Avr/Cf Interaction Induce the Expression of Ptis, Genes Encoding Pto-interactors

Products of plant resistance ( R ) genes Pto and Cf contain distinct domains, and have different cellular localization. It is intriguing to compare the development mechanisms of resistance conferred by the two R genes. In the present report, two hypersensitive response (HR) initiation systems were employed to study the time_course expression induced by Avr / Cf interaction of the genes encoding Pti4, Pti5 and Pti6 which interact directly with Pto: (1) Seeds of tomato (Lycopersicon esculentum Mill.) containing complementary gene pairs Avr 4/ Cf _4 and Avr 9/ Cf _9 were obtained through crossing. Their seedlings developed HR under room temperature. (2) Avr / Cf seedlings grew normally at 33 ℃. When the temperature was shifted down to 25 ℃, HR occurred within hours in the seedlings. Results of both experiments showed that expression of Pti4, Pti5 and Pti6 was induced upon development of hypersensitive necrosis in Avr / Cf seedlings. However, the expression levels and patterns of these Pti s differed. This finding indicated that these Pti s function complementarily, and might be involved in regulation of both Pto and Cf _conferred resistance.

Insulin resistance and hepatitis C

Insulin resistance is the major feature of the metabolic syndrome and depends on insulin secretion and insulin sensitivity. In chronic hepatitis C, insulin resistance and type 2 diabetes mellitus are more often seen than in healthy controls or chronic hepatitis B patients. Hepatitis C virus （HCV） infection promotes insulin resistance, mainly by increased TNF production together with enhancement of suppressor of cytokine （SOC-3）; both events block PI3K and Akt phosphorylation. Two types of insulin resistance could be found in chronic hepatitis C patients＇. ＂viral＂ and ＂metabolic＂ insulin resistance. Insulin resistance in chronic hepatitis C is relevant because it promotes steatosis and fibrosis. The mechanisms by which insulin resistance promotes fibrosis progression include： （1） steatosis, （2） hyperleptinemia, （3） increased TNF production, （4） impaired expression of PPARy receptors. Lastly, insulin resistance has been found as a common denominator in patients difficult-to-treat like cirrhotics, overweight, HIV coinfected and Afro-American. Insulin resistance together with fibrosis and genotype has been found to be independently associated with impaired response rate to peginterferon plus ribavirin. Indeed, in genotype 1, the sustained response rate was twice （60%） in patients with HOMA ≤ 2 than patients with HOMA 〉 2. In experiments carried out on Huh-7 cells transfected by full length HCVRNA, interferon alpha blocks HCV replication. However, when insulin （at doses of 128 μU/mL, similar that seen in the hyperinsulinemic state） was added to interferon, the ability to block HCV replication disappeared, and the PKR synthesis was abolished. In summary, hepatitis C promotes insulin resistance and insulin resistance induces interferon resistance, steatosis and fibrosis progression.

Alpha-picolinic acid,a fungal toxin and mammal apoptosis-inducing agent,elicits hypersensitive-like response and enhances disease resistance in rice

Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistant mutants. Here,we report that PA is an efficient apoptosis agent triggering cell death of hypersensitive-like response in planta. Confirmed by Fluorescence Activated Cell Sorter (FACS),rice suspension cells and leaves exhibited programmed cell death induced by PA. The PA-induced cell death was associated with the accumulation of reactive oxygen species that could be blocked by diphenylene iodonium chloride,indicating that the generation of reactive oxygen species was NADPHoxidase dependent. We also demonstrated the induction of rice defense-related genes and subsequent resistant enhancement by PA against the rice blast fungus Magnaporthe grisea. Hence,it was concluded that the PA-stimulated defense response likely involves the onset of the hypersensitive response in rice,which also provides a simple eliciting tool for studying apoptosis in the plant cell.

Effect of Stem Rust Race Ug99 on Grain Yield and Yield Components of Wheat Cultivars in Kenya

Stem rust, caused by Puccinia graminis Pers. f. sp. tritici Eriks ＆ E. Henn., is an important disease of wheat （Triticum aestivum L.） in many countries. To estimate grain yield losses due race Ug99 （TTKSK）, replicated experiments including fifteen wheat cultivars were screened for seedling and adult plant resistance. Greenhouse seedling test was conducted under controlled conditions. Field experiments were set up at two locations, Mau-Narok and KARI-Njoro, during 2008 and 2009 cropping seasons. The stem rust epidemics were created by inoculating spreader rows of a susceptible variety planted perpendicular to rows of non-protected plots. Rust severity and infection response were determined using modified Cobb scale. All the cultivars were susceptible at seedling stage, but some displayed adult plant resistance response despite of the high disease pressure. Mean grain yield losses ranged between 5.6% and 66.3% and were highly correlated to final disease severity （FDS） and the area under disease progress curve （AUDPC）. Genetic studies are needed to characterise the adult plant resistance in tolerant culti（,ars to race Ug99 for exploitation in breeding for resistance.

Screening of genotypes for their resistance againstMeloidogyne incognita and Fusarium chlamydosporum causing wilt complex on Coleusforskohlii Briq.

A pot culture experiment was carried out for the Screening of 11 popular genotypes against to Meloidogyne incognita and Fusarium chlamydosporum wilt complex on Coleus forskohlii. Genotype viz., yellow tubers and Rabakavi local showed resistant reaction, Orange tuber and Nimbanur local showed moderately resistant reaction. Rest of the seven genotvDes showed suscentible reactions.

Gefitinib in the treatment of 41 cases with refractory non-small cell lung cancer

Objective： We observe the curative effect, median survival time, time to progression, quality of life and adverse effect of patients with advanced refractory non-small cell lung cancer （NSCLC） after gefitinib （Iressa） treatment. Methods： Forty-one patients with grade Ⅲb to Ⅳ NSCLC previously treated with two chemotherapy including 85.4% of patients after second line therapy were chosen. The regimen was oral intake of gefitinib 250 mg once daily until the disease progression or toxic reaction has become intolerable. The patients were required to receive tumor evaluation before the treatment, one month, two month and every three months after Iressa administration. Results： All of 41 patients were evaluable for therapeutic effect. Without complete regression being observed, partial response rate （PR）, stable disease （SD） and progression of disease （PD） were 43.9% （18/41）, 34.1% （14/41） and 22.1% （9/41）, respectively. The overall response rate was 43.9% （18141） and disease control rate （PR ＋ SD） was 78% （32/41）. The response rate in male was 42.1%, while it in female was 45.5% （P 〉 0.05）. Twenty-two of them （53.7%, 22/41） were still alive with 10.1 months of MST when the follow-up ended in November 2006. TTP and MST of patients who died was 2.7 and 5.0 months, respectively. The rate of symptom improvement was 78% of all patients with 13 months of MST of PR patients. The Karnofsky enhanced 20 ＋ 5 after 28 days treatment without 3-4 degree of reactive toxicity. Conclusion： Iressa has significant antitumor activity in advanced NSCLC patients who have previously failed in second or third line chemotherapy. Iressa is effective and safe for patients with poor performance status.

B cells biology in systemic lupus erythematosus—from bench to bedside

Systemic lupus erythematosus(SLE) is a debilitating autoimmune disease that can involve multi-organs. B cells play a central role in the immunopathogenesis via antibody-dependent and antibody-independent ways. Excessive autoantibodies production, hyperresponsiveness and prolonged survival of autoreactive B cells are characteristics of SLE. In this article, mechanisms of self-tolerance loss of B cells and promising B cell-targeting therapies in lupus are reviewed and discussed.

Antiviral activity of Jinchai capsule against influenza virus

OBJECTIVE:To evaluate the effect on influenza virus of Jinchai,a capsule made of Traditional Chinese Medicine.METHODS:Madin-darby canine kidney(MDCK) cells were infected with the FM1 strain of influenza virus A(subtype H1N1) in vitro.They were used to explore how Jinchai affected cell adsorption,cell membrane fusion,transcription and replication of the influenza virus.Hemagglutinin(HA) protein,intracellular pH,and influenza virus protein acid(PA) polymerase subunit were detected with confocal microscopy and real-time fluorescent quantitative polymerase chain reaction.RESULTS:Jinchai significantly reduced the expression of HA and PA polymerase subunit mRNA in infected MDCK cells.Jinchai also significantly decreased intracellular pH in infected cells.CONCLUSIONS:Jinchai had strong anti-influenza activity against the influenza virus.It weakened the ability of the influenza virus to adsorb to cell wall and fuse with cell membranes in the early infection stage,and inhibited the transcription and replication of the virus.