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921.
Antifungal properties of pristimerin and celastrol isolated from Celastrus hypoleucus 总被引:4,自引:0,他引:4
Pristimerin and celastrol isolated from the roots of Celastrus hypoleucus (Oliv) Warb f argutior Loes exhibited inhibitory effects against diverse phytopathogenic fungi. Pristimerin and celastrol were found to inhibit the mycelial growth of Rhizoctonia solani Kuhn and Glomerella cingulata (Stonem) Spauld & Schrenk in vitro by 83.6 and 62.6%, respectively, at 10 microg ml(-1). Pristimerin showed good preventive effect (96.7% at 100 microg ml(-1)) and curative effect (66.5% at 100 microg ml(-1)) against wheat powdery mildew in vivo. For celastrol, the preventive and curative effects against wheat powdery mildew were 80.5 and 45.4%, respectively, at 100 microg ml(-1). 相似文献
922.
Duck enteritis virus (DEV) is a herpesvirus that causes an acute, contagious, and fatal disease. In the present article, we introduce a quantitative real-time polymerase chain reaction (PCR) assay for DEV DNA using TaqMan technology and a two-step protocol. It was confirmed to be rapid, sensitive, and specific for DEV detection. The primers and probe were designed and directed to the DNA polymerase gene of DEV. The method will provide a valuable tool for rapid laboratory diagnosis of DEV infection. By virtue of its high-throughput format and its ability to accurately quantify the viral DNA, the method may be useful for large epidemiological surveys and clarification of pathogenesis, such as latency and reactivation of the virus. 相似文献
923.
Protective immunity induced by a recombinant pseudorabies virus expressing the GP5 of porcine reproductive and respiratory syndrome virus in piglets 总被引:18,自引:0,他引:18
Qiu HJ Tian ZJ Tong GZ Zhou YJ Ni JQ Luo YZ Cai XH 《Veterinary immunology and immunopathology》2005,106(3-4):309-319
Pseudorabies virus (PRV) has been developed as a vaccine vector for expressing foreign immunogens. Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), continues to be a major problem to the pork industry worldwide. Many vaccine strategies have been developed to control the disease but most of them turn out to be unsuccessful. The objective of this research was to explore the feasibility of PRV-based vector vaccine in protection against PRRSV. A live attenuated vaccine-based PRV recombinant expressing the envelope protein GP5 of PRRSV was generated using recombinant DNA techniques. The Bartha-K61-derived recombinant virus, named rPRV-GP5, was shown to express PRRSV GP5 efficiently. Sixteen healthy piglets were assigned to one of four groups (one to four, four pigs per group). Animals in Groups 1 and 2 were each inoculated intramuscularly and intranasally with 10(7.0) PFU of rPRV-GP5 and its parent Bartha-K61, respectively; Group 3 were vaccinated intramuscularly with one-dose of PRRS inactivated vaccine; Group 4 was served as non-vaccinated control. One month later, all animals were all challenged with 10(6.5) TCID(50) of virulent PRRSV CH-1a. All animals in Groups 1 and 3 remained clinically healthy before and after challenge, with only a short period of fever (no more than 41 degrees C and 3 days), mild and gradually improving lung and kidney lesions, and short-term viremia (2 and 3 week, respectively) in spite of no detectable anti-PRRSV antibody before challenge. On the other hand, all animals in the other two groups showed evident clinical signs with higher temperatures (more than 41 degrees C) after challenge, and severe lung, kidney and spleen lesions and extended viremia (4 weeks). The results indicate that the rPRV-GP5 is safe for vaccinates and able to confer significant protection against clinical disease and reduce pathogenic lesions induced by PRRSV challenge in vaccinated pigs. 相似文献
924.
ABSTRACT Several wheat lines and cultivars of wheat (Triticum aestivum) originating from the southwestern region of China were found to be highly resistant to stripe rust by inoculation with the prevalent races (CYR30, CYR31, and CYR32) and newly emerged races (H46-4, SY11-4 and SY11-14) of the pathogen. An inheritance study of the resistance to stripe rust was carried out by crossing resistant AIM6 with susceptible BeiZ76. Results indicated that the resistance to stripe rust was controlled by a single dominant gene. The 112 F(2) plants chosen from the cross BeiZ76/ AIM6 were analyzed with 218 pairs of microsatellite primers to determine the map location of the resistance gene. A simple sequence repeat marker on chromosome arm 2BS, Xgwm410, showed polymorphism and co-segregation between stripe rust resistant and susceptible plants. From the pedigree, inheritance, molecular marker, and resistance response, it is concluded that the stripe rust resistance gene in wheat cv. Chuan-nong19 (CN19) and wheat lines AIM5 and AIM6 is a novel gene, designated YrCN19. The microsatellite primer Xgwm410 is a diagnostic marker of the resistance gene YrCN19, which has potential for application in the marker-assisted breeding of wheat. 相似文献
925.
高三尖杉酯碱、血栓通与地塞米松联合对翼状胬肉成纤维细胞的抑制效果 总被引:2,自引:0,他引:2
用中药高三尖杉酯碱(Homoharringtonine)及血栓通(XueShuanTong)与地塞米松(Dexamethasone)联合应用,对体外培养的人翼状胬肉成纤维细胞抑制的结果表明:前两药的给药浓度分别在10-6M/L及3g/L时,抑制率为50.4%及64.3%,均有明显的抑制作用及相应的细胞形态学改变。当高三尖杉酯碱给药浓度为10-4M/L时.其细胞增殖抑制率达91.8%,镜下基本见不到正常细胞。而当两药分别与地塞米松联合应用时,呈现比单一药物应用时的药量减少而药效增强。 相似文献
926.
先兆子痫及子痫并发HELLP综合征的诊断与治疗(附4例报告) 总被引:1,自引:0,他引:1
先兆子痫及子痫并发HELLP综合征的典型症状为上腹部疼痛、恶心、呕吐及出血倾向等,以溶血性贫血、红细胞压积降低、外周血涂片见到异形红细胞、肝酶及胆红素升高,血小板减少等为主要诊断依据。小剂量阿斯匹林和潘生丁联合应用以抗血小板凝聚和及时终止妊娠是最为有效的治疗手段。 相似文献
927.
体外开花的研究已取得一些重大进展,这些研究所采用的外植体不同,体外诱导花芽分化的难易、分化速度及分化细胞的起源都不同,其中细胞薄层培养以其外植体体积小,内源营养物质和生长物质含量少,对外界刺激反应敏感,易于分化成为研究花芽分化的理想体系。但此法的外植体是花梗上离体的表皮和表皮下的几层薄壁细胞,其与内部组织的联系隔 相似文献
928.
荔枝叶瘿蚊的研究 总被引:1,自引:0,他引:1
荔枝叶瘿蚊(Mayetiola sp)是国内首次报导的荔枝新害虫。在广州一年发生6代,以幼虫在被害叶上越冬。蛹期11—14天,成虫寿命1—2天,卵期2—4天,幼虫期14—39天。越冬幼虫期可达240余天。成虫产卵于嫩叶背面,幼虫孵出后侵入叶肉并发育形成疱状突起的虫瘿,通常一叶多瘿。幼虫老熟后离瘿入土化蛹,大多数是被蛹,但也有围蛹。本文描述了各期虫态的形态特征。温湿度及荔枝品种对叶瘿蚊种群数量影响极大,“三月红”对其幼虫有高度的生理抗性。目前已发现5种瘿内幼虫的寄生蜂。每年春天,于越冬幼虫离瘿入土或成虫羽化出土前用辛硫磷进行土表施药,对压低第一代虫口密度效果显著;氧化乐果或喹硫磷、杀虫双、杀虫单、敌杀死等与敌百虫混合喷雾对卵及初孵幼虫均有明显的防效。 相似文献
929.
贝斯莉斯克旗草引种栽培试验初报 总被引:3,自引:0,他引:3
斯莉斯克旗草引种栽培试验结果表明,该草适应性强、耐瘠、耐酸、耐旱、抗病虫害,终年保持青绿,生长速度快,产草量高,质量好。是一种优良牧草,具有推广利用前景。 相似文献
930.
Effects of mushroom and herb polysaccharides, as alternatives for an antibiotic, on growth performance of broilers 总被引:1,自引:1,他引:0
Guo FC Kwakkel RP Williams BA Li WK Li HS Luo JY Li XP Wei YX Yan ZT Verstegen MW 《British poultry science》2004,45(5):684-694
(1) This in vivo trial was conducted to study the effects of polysaccharide extracts of two mushrooms, Lentinus edodes (LenE) and Tremella fuciformis (TreE), and a herb, Astragalus membranaceus (AstE) on growth performance, and the weights of organs and the gastrointestinal tract (GIT) of broiler chickens. (2) Three extracts (LenE, TreE and AstE) were supplemented at inclusion rates of 0.5, 1, 2, 3 and 4 g/kg from 7 to 14 d of age and compared with an antibiotic treatment group (20 mg/kg, virginiamycin (VRG) as well as a group of non-supplemented birds. (3) Body weight (BW) gain, feed intake and feed conversion ratio (FCR) of the extract-supplemented groups were not significantly different from those of the antibiotic group. Significant effects of type of extract and concentration on growth performance were found from 7 to 28 d of age. Generally, birds fed with LenE showed higher BW gain and lower FCR from 7 to 28 d of age than those fed with TreE and AstE and 2 g/kg LenE was considered the optimal inclusion rate for enhanced broiler growth. However, the extracts had no significant effect on the relative weights of organs and GIT compared with the antibiotic group. (4) The birds fed the extracts showed better growth performance than the non-supplemented birds, but were not significantly different from those fed VRG. Of the three extracts, LenE appeared to be a potential growth promoter. Future studies are needed to investigate whether the extracts can be used as alternatives for antibiotic growth promoters in challenged birds, and to elucidate the mechanisms for potentially enhanced growth performance in poultry. 相似文献