精密组织切片的制备及其应用

精密组织切片是被研究人员广泛使用的器官体外模型,它保持了体外系统的主要优点,弥补了细胞系所缺失的功能,能充分维持组织活性、功能活性以进行毒性、诱导和感染研究.本文简要介绍了精密组织切片技术的发展进程、优点以及应用前景,对精密组织切片的制备方法、培养体系和活性测定指标,以及精密组织切片技术作为一种新型的离体模型应用于各个...     

MyD88抑制剂ST2825对丝状支原体山羊亚种 感染宿主细胞的影响

为分析MyD88在丝状支原体山羊亚种(Mmc)感染肺泡上皮细胞中的分子机制。以山羊肺泡上皮细胞为材料,用不同浓度的MyD88抑制剂(ST2825)与细胞孵育,MTT法检测细胞活性,试剂盒检测caspase-3的活性,以及实时定量PCR检测MyD88和TNF-a mRNA的表达水平,试剂盒检测H_2O_2浓度和NO浓度。当ST2825浓度为5、10和20μmol·L~(-1)不影响细胞活性,而浓度为40μmol·L~(-1)时细胞活性显著降低;感染比例(MOI)为10,感染时间为8、12和24 h,Mmc可以显著提高MyD88 mRNA的表达水平(P0.01);可显著提高caspase-3的活性,而ST2825能够显著降低caspase-3(P0.05);感染时间为24 h,Mmc可显著提高TNF-a mRNA的表达水平、H_2O_2浓度和NO浓度(P0.05),而ST2825在10和20μmol·L~(-1)的浓度时,可显著降低Mmc介导的caspase-3活性、H_2O_2浓度以及LDH水平(P0.05),ST2825在5、10和20μmol·L~(-1)浓度时可显著降低TNF-a mRNA的表达水平和NO浓度(P0.05)。     

Lechiguana (Focal Proliferative Fibrogranulomatous Panniculitis) in Cattle

Lechiguana is a disease of cattle characterized by large, hard, subcutaneous swellings that grow rapidly and result in death after 3–11 months in untreated animals. Cattle treated with antibiotics recover. The disease has been reported from five states in south and southeastern Brazil. Histologically, the lesion consists of focal proliferation of fibrous tissue infiltrated by plasma cells, eosinophils, lymphocytes and sometimes neutrophils. The primary lesion is an eosinophilic lymphangitis, which results in eosinophilic abscesses, with occasional rosettes containing bacteria in their centres. Much experimental and epidemiological evidence, reviewed in this article, supports the suggestion that lechiguana is caused by an association of Pasteurella granulomatis (syn: Mannheimia granulomatis) and Dermatobia hominis.     

Ultrastructural and cell wall modifications during infection of <Emphasis Type="Italic">Eucalyptus viminalis</Emphasis> roots by a pathogenic <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> strain

Fusarium species are soil-borne fungal pathogens that produce a variety of disease symptoms when attacking crop plants. The mode of root colonization of Eucalyptus viminalis seedlings by a pathogenic F. oxyporum strain (Foeu1) at the ultrastructural level and changes in cell wall pectin during host pathogen interactions are described. Root systems of E. viminalis plants were inoculated with F. oxysporum in an in vitro model system. Hyphae of F. oxysporum adhered to the outer epidermal cell walls through fibrillar material, and after penetration they spread into the internal tissues. They developed intercellularly and intracellularly in the root cortex and invaded vascular tissues. Papillae were induced, and the host plasma membrane ruptured in colonized cells, causing rapid host tissue and cell damage. Changes in distribution and occurrence of nonesterified and methyl-esterified pectins were evaluated after root colonization by F. oxysporum using two monoclonal antibodies, JIM 5 and JIM 7, respectively. Nonesterified pectin in control roots was mainly localized in the epidermal cell walls and middle lamellae in parenchymal cortex, whereas methyl-esterified pectin accumulated more in primary cell walls of the cortex and phloem. Decreases in immunodetected nonesterified and methyl-esterified pectins were associated with extensive plant tissue degradation after root colonization by the pathogenic fungus.     

禽流感病毒的致病性和免疫性研究进展

介绍了禽流感病毒的病原、基因结构及其对禽类、人类的致病机理和危害，探讨了感染病毒后宿主的反应、机体的体液免疫和细胞免疫，在一定程度上概述了禽流感病毒的固有特点和规律，为进一步研究打下了基础。     

Research Advances on Porcine Epidemic Diarrhea and New Vaccine

Porcine epidemic diarrhea (PED) is one of the important diseases that endanger the healthy development of the pig industry.It has acute and highly infectious characteristics,causing severe economic losses to the pig industry.Porcine epidemic diarrhea virus (PEDV) infection could destroy the animal's digestive system,cause the appetite of sick pigs to decline,vomit,and severe diarrhea.And the piglets cured by drugs will also have a serious impact on production due to factors such as poor growth and development,which will bring huge problems to the farmers.The outbreak of PEDV highly pathogenic mutant strains in China in 2010 led to a significant increase in the incidence and mortality of PED,which severely affected pig production in China.The outbreak of PED has drawn close attention from the pig industry.Scholars in related research fields have conducted more in-depth research on the pathogenic mechanism of PEDV and the new PED vaccine.Five new types of PED vaccines,including subunit vaccine,virus live vector vaccine,bacterial live vector vaccine,transgenic plant vaccine and nucleic acid vaccine,have been developed successively,and new breakthroughs and progress have been made.Compared with the traditional PED inactivated vaccine and PED attenuated vaccine,the new PED genetically engineered vaccine has the advantages of good safety,simple preparation,and good immune effect.This article focuses on the pathogenesis of PEDV and the research progress of five new PED vaccines,so as to deepen our understanding of new PEDV and PED vaccines,in order to provide references for prevention and control measures of PEDV infection.     

Phytogard® and DL-β-amino Butyric Acid (BABA) Induce Resistance to Downy Mildew (Bremia Lactucae) in Lettuce (Lactuca sativa L)

Downy mildew of lettuce (Bremia lactucae) is a serious disease. An alternative to chemicals is the application of disease resistance inducers. The aim of this study was to test whether DL--amino butyric acid (BABA) and Phytogard® (K₂HPO₃) could induce resistance in downy mildew susceptible plants. Aqueous solutions of BABA (0, 10, 20, 30, 50, 80, 100mM) and Phytogard® (0.0, 5.8, 29.0, 40.6, 58.0 and 87.0ppm) were sprayed on seven-day-old seedlings 0, 3, 7 and 15 days before or 1–3 days after inoculation with B. lactucae. Results obtained showed that Phytogard®- and BABA-induced resistance was dose-dependent. At 40.6ppm for Phytogard® and 10mM for BABA, complete protection was obtained. Both compounds had a curative effect and the induced resistance lasted for at least 15 days. It was also shown that both compounds induced systemic resistance in lettuce against downy mildew. Phytogard® at 40.6ppm completely inhibited spore germination while BABA at 20mM did not. Pathogenesis related (PR) protein analysis showed that BABA induced weak accumulation of PR-2, but not PR-1, PR-5 and PR-9. Phytogard® induced none of these proteins. The use of these two compounds to protect lettuce from B. lactucae is discussed.     

Clinicomorphological Studies in Chicks Fed Ochratoxin A While Simultaneously Developing Coccidiosis

The progression of coccidiosis and the resultant mortality were followed in chicks fed a OTA-contaminated diet. More complex and rapid progress of coccidiosis occurred in OTA-treated chicks than in chicks fed a OTA-free diet. The concentration of total protein in the serum was significantly decreased in the chicks in the OTA-treated group, whereas this was significantly increased in chicks infected with Eimeria tenella, irrespective of additional treatment with OTA. The serum glucose concentration was significantly increased in all the chicks exposed to OTA and/or suffering from coccidiosis, as was serum retention of uric acid in all groups, most notably in those consuming OTA. OTA induced degenerative changes in, and an increase in the weight of the kidneys, liver, heart and ventriculum; there was depletion of lymphoid tissue and a decrease in the lymphoid organs' weight and body weight. Coccidiosis induced only a slight growth depression and a slight increase in the relative weight of the kidneys and liver. The intensity of the clinical signs, the impairment of kidney function, macroscopic and histopathological changes, deviations in the weight of some organs and general depression in growth were greater when chicks infected with E. tenella were also given OTA.     

人工合成高抗菌核病甘蓝型油菜几种关键酶编码基因的表达与其抗性的关系

【目的】研究人工合成高抗菌核病甘蓝型油菜RB165的几种关键酶编码基因与菌核病抗性的关系。【方法】以RB165及其野生甘蓝抗病亲本BP（Brassica incana）和耐、感病甘蓝型油菜为试材,离体鉴定叶、茎菌核病抗性,并用qRT-PCR对4个病程相关基因（OXO、Cu/Zn SOD、PR2和PR3）在叶片接种0、6、12、24、36 h的表达进行检测。【结果】参试材料叶片和茎杆的抗病性达到极显著正相关（r = 0.93）; RB165的抗病性低于RP,但极显著高于耐、感病品（种）系;接种核盘菌后,OXO的表达被抑制,Cu/Zn SOD的表达则先下降后上升,PR2的表达出现2次峰值,PR3的表达被剧烈诱导,4个基因在不同材料间的相对表达量差异极显著,但变化规律相似。【结论】RB165的抗病性强于耐病甘蓝型油菜,但几种酶编码基因受核盘菌的诱导表达与菌核病抗性没有直接关系。     

竹丛枝病病原研究进展

竹丛枝病是竹类植物产生丛枝状病害的总称,是竹林退化最具破坏性的病害之一。大量研究表明:竹针孢座囊菌Aciculosporium take,异香柱菌属Heteroepichloё,竹暗球腔菌Phaeosphaeria bambusae以及植原体（phytoplasma）等均能引起竹丛枝病。长期以来这些病原物所处分类地位的变化较大且它们的致病机制尚不清楚,这对竹丛枝病的防治造成了极大的困难。对上述病原物所处分类地位的演变过程及其致病机制的研究进行了综述,并对竹丛枝病今后的研究方向进行了展望。参26