六味地黄汤对5/6肾切除大鼠肾组织中细胞外基质的影响

目的观察六味地黄汤对慢性肾衰大鼠肾组织细胞外基质的影响,探讨其防治肾间质纤维化的可能机制。方法用5/6肾切除大鼠复制慢性肾衰模型,分空白对照组、假手术组、模型组和六味地黄汤组。术后8周,检测各组肾功能指标;HE染色观察肾脏组织病理变化,Masson染色检测肾脏中胶原纤维沉积;免疫组化法检测ColⅠ、ColⅢ、FN在肾组织中的表达;Western blot法检测PDGF-A、PDGF-B在肾组织中的蛋白表达水平。结果与假手术组比较,模型组24 h尿蛋白、血尿素氮和血肌酐明显升高(P<0.01);与模型组比较,六味地黄汤组24 h尿蛋白(P<0.01)、血尿素氮(P<0.01)和血肌酐(P<0.05)均明显降低。模型组HE和Masson染色显示大鼠肾间质纤维化明显,大量胶原纤维沉积,六味地黄汤组肾间质纤维化程度明显减轻,少量胶原纤维沉积。免疫组化法显示,与假手术组比较,模型组肾组织中ColⅠ、ColⅢ、FN蛋白水平均明显升高(P<0.01);与模型组比较,六味地黄汤组肾组织中ColⅠ、ColⅢ、FN蛋白水平均明显降低(P<0.05)。Western blot法显示,与假手术组比较,模型组肾组织中PDGF-A、PDGF-B蛋白水平均明显升高(P<0.01);与模型组比较,六味地黄汤组肾组织中PDGF-A、PDGF-B蛋白水平均明显降低(P<0.01)。结论六味地黄汤可能通过下调PDGF-A、PDGF-B表达,从而减少肾组织中细胞外基质的积聚而抑制肾间质纤维化。     

原料奶生产环节微生物污染分析及防控措施研究

【目的】研究原料奶生产环节微生物菌落总数的变化规律,确定防控微生物污染的有效措施。【方法】通过测定原料奶生产各环节微生物菌落总数,分析微生物污染的变化规律,在此基础上研究不同奶牛乳房清洗消毒方式、舍弃奶量、贮存温度、运输条件等对原料奶中微生物菌落总数的影响,进而获得有效防控微生物污染的措施。【结果】奶站设备的卫生状况是造成不同奶站原料奶中微生物菌落总数存在明显差异的原因,奶牛乳房卫生状况、设备的卫生状况及贮存运输条件是造成同一奶站不同环节微生物存在明显差异的原因。温水清洗后擦干再用质量分数0.1% KMnO₄溶液消毒奶牛乳房并擦干后,原料奶中菌落总数由未清洗时的2.65×10⁴ cfu/mL降低到2.56×10³ cfu/mL。舍弃奶量超过40 mL时,原料奶菌落总数小于1.00×10³ cfu/mL,并趋于稳定。相同贮存时间下于0～4 ℃条件下贮存奶样中的微生物菌落总数增长较缓慢。4 927次收奶记录中的1 054 次微生物抽检记录显示,奶温越高、运输距离越长原料奶中微生物菌落总数越多。【结论】采取改善奶站设备卫生水平、温水清洗擦干后消毒奶牛乳房并擦干、机械挤奶前舍弃多于40 mL奶、将原料奶快速冷却至0～4 ℃贮存以及缩短运输距离、减少贮运温度波动等措施,均可有效控制原料奶的微生物污染。     

降低畜禽对环境磷污染的一些措施

People have paid more and more attention to the environment contamination, especially the contamination of phosphorus excreted by livestock in resent years. This paper reviewed some measures to reduce the phosphorus contamination covering molecular biological technology, nutrition regulation, feed processing and feces treatment.     

Decreasing eel stocks: survival of the fattest?

Abstract –  Since the 1980s, the European eel Anguilla anguilla stock is in steep decline. Lipid reserves are essential to cover energetic requirements for silver eel migration and reproduction. Two large and independent data sets from Belgium and The Netherlands show an average one-third decrease in fat contents of yellow eels over the past 15 years. Also Le Cren's relative condition factor decreased. On the basis of the somatic energy reserves, reproductive potential of eels from various latitudes over Europe was estimated, assuming fat levels in yellow eel are indicative of those in silver eels. Only large individuals, females as well as males, with high lipid content seem to be able to contribute to the spawning stock. The decrease in fat content in yellow eels may be a key element in the stock decline and raises serious concerns about the chances of the stock to recover.     

Low rates of pollen contamination in a Scots pine seed orchard in Sweden: the exception or the norm?

We investigated mating structure and gene flow in a clonal seed orchard of Scots pine (Pinus sylvestris L.) over three consecutive pollination seasons (2010–2012) with nine nuclear microsatellite markers. The paternity of 1991 offspring from four maternal parents was assigned to 28 candidate fathers using an exclusion procedure and a likelihood-based method implemented in the program CERVUS. Relative reproductive success was highly variable among pollen parents but consistent across years and ranged from 0.1% to 18.3%. Consequently, the seed crops’ effective number of fathers was reduced to 52.9%, 48.8%, and 45.7% of the census in the three seasons, respectively. Self-fertilization fluctuated around the orchard's expected value of 5.1%, reaching 4.05%, 7.71%, and 6.61%, respectively. Pollen contamination was estimated to be 5.64%, 7.29%, and 4.89%, respectively, after correction for cryptic gene flow. CERVUS provided similar results as the exclusion method, but estimates greatly varied depending on the input parameters, mainly the proportion of fathers sampled. These results indicate the studied seed orchard is a well-functioning production population with only minor negative effects of self-fertilization and pollen contamination on the quality of seed crops. Genotyping issues associated with microsatellites as a potential source of false paternity assignment and exclusion are discussed.     

Multi-method assessment of nitrate and pesticide contamination in shallow alluvial groundwater as a function of hydrogeological setting and land use

In this study deterministic, multivariate and stochastic methods are applied to a combined temporal and spatial monitoring data set, in order to assess nitrate and pesticide levels and contamination risk in shallow groundwater. The case study involves an area in the Mondego River alluvial body in central Portugal, where agriculture is the main land use, with predominantly maize, rice and some vegetable crops supported by river water irrigation. Factorial correspondence analysis (FCA), reducing the original data matrix to a small number of independent orthogonal factors, is applied to detect associations between nitrate levels, land use (crop type), lithology and groundwater depth. Indicator-geostatistical techniques are used to create maps indicating the probability of nitrate concentrations in groundwater exceeding predetermined threshold values, including the drinking water standard (98/83/EC) and vulnerable zone designation criterion (91/676/EEC) of 50 mg/l NO₃⁻. For pesticides the leaching potential is determined by calculating the Groundwater Ubiquity Score (GUS), based on the sorption coefficient and soil half-life for each pesticide compound. Results for nitrate show an overall very low risk of exceeding 50 or 25 mg/l, whereas the risk of exceeding 9.5 mg/l (third data quartile) is particularly high in areas where FCA shows correlation of nitrate contamination with vegetable and maize crops, aerobic conditions, lower groundwater levels and to some extent, coarser grained sediments. On the contrary, nitrate levels under rice are lowest and correlated to a reduced environment, finer-grained sediments and a higher water table. Denitrification is found to be an important attenuation process, as well as dilution by surface water irrigation and precipitation. Crop type and irrigation source are seen to have a large influence on the nitrate contamination potential of groundwater. Total concentrations of the analysed pesticide compounds above the regulatory limit of 0.5 μg/l are observed in 32% of the analysed water samples, with a maximum value of 16.09 μg/l. The probability maps provide a particularly interesting example of how multiple-well monitoring results over a certain period can be condensed into single maps and used by water engineers, managers and policy-makers.     

αvβ6-ERK pathway participates in norcantharidin-induced apoptosis of HT-29 colon cancer cells

AIM: To investigate the pharmacological mechanism of norcantharidin (NCTD)-induced apoptosis of HT-29 colon cancer cells. METHODS: Hoechst 33258 staining was used to analyze the apoptosis of HT-29 cells treated with NCTD. The effects of NCTD on the expression of integrin in HT-29 cells were determined by flow cytometry. The effects of several functional blocking antibodies on HT-29 cells were detected by MTT method. The expression and the phosphorylation of mitogen activated protein kinases (MAPKs) in HT-29 cells were measured by Western blotting. Co-immunoprecipitation assay was used to detect the activity of αvβ6-extracellular signal-regulated kinase (ERK) direct linkage in HT-29 cells.RESULTS: NCTD induced the apoptosis of HT-29 colon cancer cells. The expression of integrin αvβ6 in HT-29 cells treated with NCTD was reduced, but the expression of αvβ3 and αvβ5 was not changed. A function-blocking antibody to αvβ6,10D5,strengthened the growth inhibitory effect of NCTD on HT-29 cells ,but LM609 (a function-blocking antibody to αvβ3) and P1F6 (a function-blocking antibody to αvβ5) did not. The level of phosphorylated ERK (p-ERK) was decreased substantially after treated with NCTD in a dose-and time-dependent manner. NCTD also affected the association of αvβ6 and ERK. CONCLUSION: NCTD decreases the expression of integrin αvβ6 and interferes with the phosphorylation of ERK. As a result, the formation of αvβ6-ERK direct linkage is affected and the signal transduction mediated by αvβ6 is disturbed. The mechanism of NCTD-induced HT-29 cell apoptosis is involved in the αvβ6-ERK signaling pathway.     

Response to drought and salt stress of lemon ‘Fino 49’ under field conditions: Water relations,osmotic adjustment and gas exchange

Drought and salinity are two of the most important factors limiting the lemon yield in south-eastern Spain. The effects of drought and salt stress, applied independently, on water relations, osmotic adjustment and gas exchange in the highest evapotranspiration period were studied to compare the tolerance and adaptive mechanisms of 13-year-old ‘Fino 49’ lemon trees, in immature and mature leaves. The study was carried out in an experimental orchard located in Torre Pacheco (Murcia). Three treatments were applied: Control, well-irrigated; drought-stress (DS), non-irrigated from 15th May to 7th July and salinity, irrigated with 30 mM NaCl from 1st March to 7th July. At the end of the experiment, only DS trees showed a decreased leaf stem water potential (Ψ_md). Under DS conditions, both types of leaf lost turgor and did not show any osmotic or elastic mechanism to maintain leaf turgor. Osmotic adjustment was the main tolerance mechanism for maintenance of turgor under salt stress, and was achieved by the uptake of Cl⁻ ions. Gas-exchange parameters were reduced by DS but not by salinity, stomatal closure being the main adaptive mechanism for avoidance of water loss and maintenance of leaf turgor. Salinity gave rise to greater Cl⁻ accumulation in mature than in immature leaves. The increase of proline in immature leaves due to DS indicates greater damage than in mature leaves.     

土壤铅污染对苋菜生长和矿质元素含量的影响

采用土培试验研究了不同水平铅处理下苋菜生长和矿质元素吸收的相关指标.结果表明:较高浓度(0.4 mol/kg)铅胁迫下苋菜的生长受到明显抑制,其中根受到的抑制程度最高.铅对苋菜第3和第4片成熟叶面积扩展的抑制作用比对叶干物质的积累大,导致单位叶面积干重增大.土壤中过量铅明显增加了苋菜各器官中铅的含量并主要积累在根部,降低了苋菜对铁、钾、钙、镁的吸收和向地上部分运输的速率而导致含量降低.     

6HW-50型车载高射程喷雾机防治杨潜叶跳象试验

报道了使用6HW-50车载高射程喷雾机,采用1.2%苦烟乳油不同施药量进行杨潜叶跳象防治的对比试验的结果,旨在评估这一新药械防治杨潜叶跳象的效果.