Changes of L-selectin expression on peripheral blood polymorphonuclear leukocytes and their significance in rats with acute lung injury

AIM:To explore the changes of L-selectin expression on peripheral blood polymorphonuclear leukocytes (PMNs) and their significance in rats with acute lung injury (ALI). METHODS:ALI model in rat was established by intravonous injection of E. coli endotoxin (ET). The expression of L-selectin on peripheral blood PMNs was measured by immunofluorescence and flow cytometry.RESULTS:The contribution of L-selectin fluorescence signal was on the surface of PMNs membrane. The expression of L-selectin on poeripheral blood PMN was significantly lower at 5 min after injection of ET and the lowest during 15 min to 30 min, then gradually increased, but the expression of L-selectin on PMN was lower at 60 min after injection of ET than that of control animal.CONCLUSION:In physiological state, L-selectin were expressed on the surface of PMN membrane. The protein expression of L-selectin on PMNs reduced rapidly after injection of ET and the lowest at 15 min, then gradually increased. L-selectin may play a role in the development of ALI.     

Effects of temperature on ascospore germination and penetration of oilseed rape (Brassica napus) leaves by A- or B-group Leptosphaeria maculans (phoma stem canker)

Ascospores of both A-group and B-group Leptosphaeria maculans germinated at temperatures from 5 to 20°C on leaves of oilseed rape. Germination of ascospores of both groups started 2 h after inoculation and percentage germination reached its maximum about 14 h after inoculation at all temperatures. Both the percentage of A-/B-group ascospores that had germinated after 24 h incubation and germ tube length increased with increasing temperature from 5 to 20°C. Germ tubes from B-group ascospores were longer than those from A-group ascospores at all temperatures, with the greatest difference at 20°C. Hyphae from ascospores of both groups penetrated the leaves predominantly through stomata, at temperatures from 5 to 20°C. A-group ascospores produced highly branched hyphae that grew tortuously, whereas B-group ascospores produced long, straight hyphae. The percentage of germinated ascospores that penetrated stomata increased with increasing temperature from 5 to 20°C and was greater for A-group than for B-group L. maculans after 40 h incubation.     

Further Contributions to the Development of a Differential Set of Pea Cultivars (Pisum sativum) to Investigate the Virulence of Isolates of Aphanomyces euteiches

Common root rot (Aphanomyces euteiches Drechs.) has become a very destructive disease in the French pea crops since 1993. For an accurate investigation of the virulence variability among French A. euteiches populations and between French and foreign populations, a new set of differential pea genotypes was developed. Thirty-three American and European pea lines, displaying different levels of resistance, were screened in a growth chamber against two French isolates. Symptoms (disease severity from 0 to 5, evaluating symptom surface on roots and epicotyl) and percentage of top fresh weight (inoculated/uninoculated top fresh weight ratio) were measured. From this screening 12 relatively resistant lines, from various genetic backgrounds, were identified along with a highly susceptible control. This set of 13 genotypes was inoculated under controlled conditions with 14 isolates from France, Sweden, USA, Canada and New Zealand, to investigate genotype–isolate interactions. Root symptoms were rated (disease severity), and a susceptibility/resistance threshold was established at disease severity = 1. Significant quantitative interactions were observed, and five 'resistance patterns' were identified, leading to a set of six pea genotypes: Baccara (susceptible), Capella, MN313, 902131, 552 and PI180693. Fields trials of this set in 1999 and 2000 gave the same resistance rankings than in growth chamber conditions. This set will allow more accurate assessments of the variability in virulence/aggressiveness of A. euteiches isolates from France and foreign countries, and further investigations of the epidemiological and genetic basis of pea–A. euteiches interactions.     

Leafhopper and planthopper vectors of rice viruses and their management in Nepal

Research on insect pests (including leafhoppers and planthoppers) in Nepal was initiated in 1956 by the Entomology Division and Plant Protection Units of the Department of Agriculture. More systematic work began after the establishment of a Rice Improvement Programme in 1972. Because of poor documentation and publication of research findings, it is difficult to assess the research efforts and achievements to date. The available research reports are mostly published in the proceedings of national seminars/workshops. They are used here to assess the current status of research on the occurrence and damage caused, distribution and composition, relative abundance, biology and management through chemicals. Much of past research has focused on insect surveys by light traps and sweep nets and the evaluation of insecticides and, since early 1990, some research on rice green leafhoppers (Nephotettix virescens and Nephotettix nigropictus) has begun to determine their relative abundance and population characteristics in relation to their potential as vectors of rice viruses. The challenges to pest management in general and some suggestions for future research needs are discussed, based on the present standing of agricultural research in the country     

高效液相色谱法测定氟甲喹可溶性粉含量

采用高效液相色谱法测定氟甲喹可溶性粉的含量,采用C 18 色谱柱(150 mm×4.6 mm,5μm),以乙腈-水-磷酸(35∶65∶0.5,V/V)为流动相,柱温25 ℃,流速1.0 mL/min,检测波长248 nm.方法的线性范围 100～400 μg/mL,线性方程A=2.455×104C 28 111,r=0.999 9,平均回收率100.3%,RSD= 0.74%.本法具有专属性,可将氟甲喹与已知的杂质进行有效分离.     

草莓摘叶处理对果实芳香物质的影响

 对草莓(Fragaria×ananassa Duch．)‘哈达’品种坐果后植株进行摘叶处理，对成熟果实的糖类和芳香物质含量进行了测定分析，结果表明：不摘叶、摘1/3叶和摘2/3叶3个处理果实GC/MS分析分别检测出43、33和37种芳香物质成分。随摘叶程度加重，芳香物质成分中酯类的相对含量呈下降趋势，而醛类的相对含量呈上升的趋势；2，5-二甲基-4-甲氧基-3(2H)-呋喃酮的相对含量明显降低；果糖和总糖含量显著降低。     

Effect of insulin on the secretion of VEGF and its receptor in serum-free cultured bovine thoracic aortic endothelial cells

AIM: This study was designed to investigate the secretion of VEGF and its receptor (flt-1 or flk-1/KDR) protein by cultured bovine thoracic aortic endothelial cells treated with various insulin concentrations. METHODS: Endothelial cells was isolated from bovine thoracic aorta, and cultured in serum-free medium, then incubated with different insulin concentrations (30 mU/L, 300 mU/L, 3 000 mU/L). The level of VEGF and its receptor (flt-1 or flk-1/KDR) protein were detected by immunohistochemical staining. RESULTS: As compared with no insulin group, the expression of VEGF protein in low insulin concentration (30 mU/L and 300 mU/L) groups were significantly increased (P＜0.01). The expression of VEGF protein in high insulin concentration (3 000 mU/L) group was significantly decreased (P＜0.05). Howerer, no difference of the expression of VEGF receptor (flt-1 or flk-1/KDR) protein among all groups (P＞0.05) was observed. CONCLUSION: Low concentration insulin up-regulates the VEGF protein expression while high concentration insulin down-regulates the VEGF protein expression in bovine thoracic aortic endothelial cells, but insulin had no directly effect on the VEGF receptor (flt-1 or flk-1/KDR) protein expression in bovine thoracic aortic endothelial cells.     

两种一步法RNA提取试剂的比较

RNA的提取在生物医学研究和临床检测上应用广泛。本文分别用进口Invitrogen公司生产的以及我们自己研制的一步法RNA提取试剂，提取大肠杆菌RNA、鸡肌肉组织RNA和尿囊液RNA，通过核酸电泳和荧光定量RT-PCR进行比较。结果表明用我们自己研制的和进口的试剂提取的RNA都不含有DNA；这些RNA都可以作为模板进行RT-PCR检测，并且在数量上相互之间没有明显差异。说明我们自己研制的一步法RNA提取试剂可以取代进口试剂。此外，本文还讨论了此类试剂一些评定方法。     

实时荧光定量PCR构建绵羊PrP基因标准品质粒和标准曲线

羊痒病是一种传染性的致死性神经退行性疾病,常引起绵羊和山羊发病,该病在欧洲流行了大约250年,但是它的流行病学和传播机制还不是很清楚.正常的朊蛋白（PrPc）不能引起神经退行性病变,虽然目前已经对许多组织的PrP mRNA进行了检测,但是对它的生物学功能还知之甚少,对PrP基因表达的机制尚不清楚.研究显示,不同组织来源的细胞中朊蛋白的表达程度差异很大,主要出现于神经细胞中.PrPc在细胞中的高水平表达可促使PrPc向PrPsc转变,目前的研究中,对绵羊PrP mRNA的转录机制尚未阐释清楚.因此,对绵羊外周和中枢系统PrP mRNA的表达进行定量,有助于探讨各组织器官中的PrP在羊痒病的发生过程中的作用.