栀子苷对小鼠急性肺损伤保护机制的研究

为了探究栀子苷能否对脂多糖(LPS)致小鼠急性肺损伤发挥保护作用及其潜在的作用机制。雄性Balb/c小鼠,于鼻腔滴注LPS前1 h腹腔注射栀子苷(50 mg/kg)或者地塞米松注射液(5 mg/kg),滴注LPS 24 h后,采用酶联免疫吸附法(ELISA)测定小鼠支气管肺泡灌洗液(BALF)中肿瘤坏死因子-α(TNF-α)、白介素(IL)-6和IL-10的浓度。通过细胞分类计数法分析BALF中细胞总数、巨噬细胞和中性粒细胞的变化。采用蛋白印迹法(Western-blot)分析核转录因子-κB（NF-κB）信号转导通路激活的程度。腹腔注射栀子苷可降低小鼠肺干湿比（W/D值）;改善肺组织病理学结构,减少肺泡出血和炎性细胞浸润且伴有髓过氧化物酶活性下降;抑制促炎性细胞因子TNF-α和IL-6分泌,促进抗炎性细胞因子IL-10生成。栀子苷通过缓减炎症反应保护LPS致小鼠急性肺损伤,其机制可能与阻止NF-κB信号转导通路的激活有关。     

Mapping Slight and Moderate Saline Soils in Irrigated Agricultural Land Using Advanced Land Imager Sensor (EO-1) Data and Semi-Empirical Models

Around the world, especially in semi-arid regions, millions of hectares of irrigated agricultural land are abandoned each year because of the adverse effects of irrigation, mainly secondary salinity and sodicity. Accurate information about the extent, magnitude, and spatial distribution of salinity and sodicity will help create the sustainable development of agricultural resources. In Morocco, south of the Mediterranean region, the growth of the vegetation and potential yield are limited by the joint influence of high temperatures and water deficit. Consequently, the overuse of surface and ground water, coupled with agricultural intensification, generates secondary soil salinity. Knowing when, where, and how salinity may occur is very important to the sustainable development of any irrigated production system. Remedial actions require reliable information to help set priorities and to choose the type of action that is most appropriate in each situation. Ground-based electromagnetic measurements of soil electrical conductivity (EC) are generally accepted as the most effective method for quantification of soil salinity. Unfortunately, these methods are expensive, time consuming, and need considerable human resources for land surveying. Moreover, the dynamic nature of soil salinity in space and time makes it more difficult to use conventional methods for comparisons over large areas. A major challenge of remote sensing, as a potential alternative technique, is to detect different levels of soil salinity. The main aim of this research is to assess the potential of the Advanced Land Imager (ALI) sensor on board the Earth Observing-1 (EO-1) satellite, with its rich infrared bands, for the discrimination and mapping of slight and moderate soil salinity in the Tadla’s irrigated agricultural perimeter in Morocco. To achieve this goal, semi-empirical predictive models developed in a previous study using second order regression analysis between the EC of salt-affected soils and different spectral salinity indices were applied to the ALI image. This was atmospherically corrected and the radiometric sensor drift was calibrated. Visual comparisons and statistical validation of these models using ground truth were undertaken in order to identify the best semi-empirical model for slight and moderate salinity mapping. The obtained results show that the model based on the Normalized Difference Salinity Index (NDSI) does not give any results. The model based on the Salinity Index-1 (SI-1) and the SI-Advanced Space-borne Thermal Emission and Reflection Radiometer (SI-ASTER) confuses vegetation with high soil salinity, although the model does bring out areas of lower salinity. Both R² of 0.67 for the SI-1 and 0.65 for the SI-ASTER further reinforce that these models cause too much confusion to be used with accuracy for salt-affected soil detection. The semi-empirical model based on Soil Salinity and Sodicity Index-1 (SSSI-1) performs better than the two last models. However, there is a relative confusion between the classes in the slight and moderate salinity and in areas that are shown by the validation map; the higher class of salinity does not appear to contain higher levels of salinity. The statistical validation of this model reinforces what is seen on the derived map with only an R² = 0.68. The model based on the SSSI-2 clearly provides the best results in comparison to the ground truth. Its derived map gives the closest overall visual approximation of the EC map, with a whole range of values. With a statistical validation of R² = 0.97 to the ground truth, it is by far the best performance of any of the other models, and the different classes are statistically well separated, which further reinforces the accuracy of the visual analysis.     

参麦注射液对大鼠急性肺损伤保护作用及机制的研究

试验旨在探讨参麦注射液对大鼠肺组织的保护作用及可能机制,为临床治疗急性肺损伤(acute lung injury,ALI)提供理论依据。将Wister大鼠随机分为模型组、参麦治疗组和空白对照组,每组采用经典尾静脉注射油酸方法建立急性肺损伤模型。观察肺体系数、病理切片、超微结构及肺组织匀浆中TNF-α、ICAM-1的含量变化,探讨参麦注射液对大鼠肺组织急性肺损伤的保护作用。结果发现,与模型组相比参麦治疗组可以明显改变大鼠急性肺损伤的肺体系数,减轻肺组织形态学及超微结构的病理改变,同时降低肺组织匀浆中TNF-α、ICAM-1的表达。证实参麦注射液对大鼠急性肺损伤具有保护作用,其机制可能通过降低肺组织匀浆中TNF-α、ICAM-1的含量,而发挥抗炎作用。     

A spectral index to monitor the head-emergence of wheat in semi-arid conditions

Harvesting wheat (Triticium aestivum L.) for forage or leaving it for grain is the main decision uncertainty growers face in semi-arid regions during mid-season. To facilitate decision-making, a decision support system (DSS) has recently been proposed that requires information about crop water and nutritional status during spike emergence. Though remote sensing has been used to provide site-specific crop status information, a spectral vegetation index is needed to ensure that the information has been acquired during spike emergence. The objective of this study was to propose a spectral index sensitive to spike emergence and validate its suitability across different commercial farm fields by using ground spectral measurements and multispectral satellite imagery. To develop the index, controlled experiments with commonly grown wheat varieties were conducted during the 2004/2005 and 2005/2006 growing season in the agricultural area of the northern Negev desert of Israel. The experiments showed that spike emergence correlated most strongly (r = 0.7, p < 0.05) with spectral changes near the 1.2 μm water absorption feature in contrast to the band at 1.1 μm which appeared to be only weakly correlated. Thus, the spike emergence sensitive band at 1.2 μm has been combined with the insensitive band at 1.1 μm as reference to form the ratio-based normalized heading index (NHI). Experimental data were then used to establish an index threshold that helps separate data acquired before and after spike emergence. The proposed NHI was able to identify spike emergence with a classification accuracy varying between 53 and 83%. Accuracy was influenced by season, and whether narrow or broad spectral bands were used. Validation of the index in commercial farm fields in Israel and the United States showed that the classification accuracy was similar for ground spectral measurements and the advanced land imager (ALI) satellite imagery. These results suggest that the NHI is suited for identifying the onset of heading throughout wheat-growing areas without the need for characterizing seasonal trends.     

肺表面活性物质相关蛋白A的研究进展

肺表面活性物质相关蛋白A（pulmonary surfactant-associated protein A,SP-A）是肺表面活性物质（pulmonary surfactant,PS）中含量最丰富的蛋白成分,主要分布于支气管表面和肺泡气液界面上,属C-型胶凝素家族的重要成员,在维持PS的正常生物学功能和调节局部免疫及炎症反应方面发挥重要作用。研究结果表明,SP-A质和量的改变与哺乳动物的肺部疾病密切相关,以SP-A作为肺疾病严重程度的指标已日益受到重视。此外,在急性肺损伤/急性呼吸窘迫综合症（ALI/ARDS）的治疗方面,PS替代治疗虽已获得了一定成功,但是,因现有外源性PS制剂中缺乏SP-A,使其疗效大受限制。因此,运用分子生物学手段,研究SP-A的表达调控,大量获取SP-A,将成为PS制剂研发的一个主要方向。     

Identification and examination of a novel 9‐bp insert/deletion polymorphism on porcine SFTPA1 exon 2 associated with acute lung injury using an oleic acid‐acute lung injury model

The pulmonary surfactant‐associated protein (SFTPA1, SP‐A) gene has been studied as a candidate gene for lung disease resistance in humans and livestock. The objective of the present study was to identify polymorphisms of the porcine SFTPA1 gene coding region and its association with acute lung injury (ALI). Through DNA sequencing and the PCR‐single‐strand conformation polymorphism method, a novel 9‐bp nucleotide insertion (+) or deletion (‐) was detected on exon 2 of SFTPA1, which causes a change in three amino acids, namely, alanine (Ala), glycine (Gly) and proline (Pro). Individuals of three genotypes (?/?, +/? and +/+) were divided into equal groups from 60 Rongchang pigs that were genotyped. These pigs were selected for participation in the oleic acid (OA)‐ALI model by 1‐h and 3‐h injections of OA, and there were equal numbers of pigs in the control and injection groups. The lung water content, a marker for acute lung injury, was measured in this study; there is a significant correlation between high lung water content and the presence of the 9‐bp indel polymorphism (P < 0.01). The lung water content of the OA injection group was markedly higher than that of the control group and lung water content for the +/+ genotype was significantly higher than that of the others in the 1‐h group (P < 0.01). No differences in the expression of the SFTPA1 gene were found among individuals with different SFTPA1 genotypes, indicating that the trait is not caused by a linked polymorphism causing altered expression of the gene. The individuals with the ?/? genotype showed lower lung water content than the +/+ genotype pigs, which suggests that polymorphism could be a potential marker for lung disease‐resistant pig breeding and that pig can be a potential animal model for human lung disease resistance in future studies.     

青天葵提取物对小鼠急性肺损伤的保护作用

为探讨青天葵乙酸乙酯提取物对小鼠急性肺损伤(acute lung injury,ALI)的保护作用,本试验选择50只昆明小鼠随机分为模型组、青天葵(高、中、低)治疗组和空白对照组,采用内毒素腹腔注射法建立急性肺损伤模型。观察肺脏湿/干重比(W/D)、病理切片、肺脏组织匀浆中丙二醛(malondialdehyde,MDA)、超氧化物歧化酶(SOD)的含量变化。结果发现,青天葵乙酸乙酯提取物可以明显减轻损伤肺脏组织的形态学变化,肺脏组织匀浆中MDA、SOD与模型组相比差异极显著,证实青天葵乙酸乙酯提取物对小鼠急性肺损伤具有保护作用。