线粒体膜通透性变化与细胞凋亡的关系

线粒体膜通透性转换孔是一种位于线粒体内膜的非选择性孔道,它的开放引起线粒体膜通透性改变,导致细胞色素C、凋亡诱导因子和Ca²⁺及膜间隙中的胱冬肽酶原等凋亡因子释放到细胞质中,致使细胞整体结构破坏、功能紊乱,发生凋亡。以前普遍认为线粒体膜通透性改变(mitochondrial permeability transition,MPT）是导致细胞凋亡的关键点,但一些新的研究结果表明,MPT与细胞凋亡并不存在必然的联系。作者结合细胞凋亡方面的研究着重就线粒体膜通透性转换的生物学功能和腺嘌呤核苷酸转位子、环孢素A 结合蛋白D及Bcl-2家族蛋白定位、转位在通透性转换中的作用及其与细胞凋亡的关系进行概括性论述与分析。     

水分胁迫下墨西哥羽毛草耐旱生理

本研究以一年生墨西哥羽毛草(Nassella tenuissima)为试验材料,采用盆栽控水法对墨西哥羽毛草进行水分胁迫,测定其各项指标,以期为墨西哥羽毛草的养护管理与在园林中的合理应用提供理论基础。结果表明,土壤水分为田间最大持水量的20%、40%、60%处理(D20、D40、D60)的植株株高生长速度和叶片相对含水量随干旱胁迫时间的延长而大幅度地降低,复水后D₂₀、D₄₀、D₆₀各处理的叶片含水量与对照(土壤水分为田间最大持水量的80%)相差7.11%、2.68%、0.80%,只有D₂₀处理与对照差异显著(P<0.05)未恢复到对照水平;相对电导率和丙二醛(MDA)含量随各处理水分胁迫时间的延长而呈逐步增加的趋势,复水后,D₂₀、D₄₀、D₆₀各处理相对电导率分别比对照高12.1%、5.92%、2.42%,D₂₀、D₄₀、D₆₀处理MDA含量分别为对照的152.18%、151.92%、133.97%,与对照差异显著(P<0.05);在水分胁迫下的超氧化物歧化酶(SOD)和过氧化酶(POD)活性均呈先上升后下降的变化趋势,复水后,D₂₀、D₄₀、D₆₀各处理SOD活性恢复到对照的82.65%、90.68%、97.13%,只有D₂₀处理与对照差异显著(P<0.05),其余处理均恢复到对照水平,D₂₀、D₄₀、D₆₀处理POD活性与对照相差7.54%、5.55%、11.73%,D₂₀、D₄₀处理与对照差异显著(P<0.05)。通过本研究可以得出,墨西哥羽毛草具有较强的抗旱性,能够适应40%田间持水量的土壤水分条件,是干旱地区优良的园林地被植物。     

In vitro Inhibition of Canine Complement‐Mediated Hemolysis

Background

Immune‐mediated hemolytic anemia (IMHA) is the most common hematologic immune‐mediated disease in dogs. Complement fixation on erythrocytes causes hemolysis. Complement inhibition decreases hemolysis in people with the hemolytic disease and also may prove effective in treating IMHA in dogs.

Hypothesis/Objectives

Evaluate the in vitro efficacy of 2 complement inhibitors used in humans against canine complement.

Methods

The inhibitory activity of the C3‐inhibitor compstatin and recombinant human C1‐esterase inhibitor (C1‐INH) was evaluated using an in vitro hemolytic assay and spectrophotometric measurement of released hemoglobin. Dose‐response curves for each inhibitor were generated.

Results

Compstatin decreased approximately 50% of canine complement‐mediated hemolysis in initial experiments. This inhibition largely was lost when a new lot of drug was purchased. C1‐INH showed a dose‐dependent inhibition. The highest concentration of C1‐INH tested (500 μg/mL) decreased >80% of canine complement‐mediated hemolysis, and the lowest concentration tested (31.25 μg/mL) decreased hemolysis >60%.

Conclusions and Clinical Importance

Human C1‐INH is a robust inhibitor of canine complement‐mediated hemolysis, whereas compstatin was minimally and variably effective. Human C1‐INH may substantially decrease complement‐mediated hemolysis in dogs with IMHA and warrants further investigation.     

Structure and hydraulic properties of the boreal clay soil under differently managed buffer zones

Vegetated buffer zones (BZs) between arable fields and bodies of water are commonly established to reduce erosion and run‐off of particle‐bound nutrients. Functioning of a BZ depends on soil structure, as it is important for water infiltration. Therefore, it is vital to understand how varying management practices affect soils of BZs. We studied the structural and hydraulic properties of three differently managed BZs established in a boreal Vertic Stagnic Cambisol (clay, 51%). The three management practices for vegetation were as follows: natural with no treatment, harvested yearly and grazed by cattle. We used bulk density and macroporosity, together with a pore geometry index (air permeability per unit air‐filled porosity), to describe the soil structural properties. Hydraulic properties were measured at different length scales by means of an aggregate sorptivity test, saturated hydraulic conductivity of the core samples and field‐saturated hydraulic conductivity. Vegetation management markedly affected the physical properties in the top 5 cm of the soil. Properties were least favourable for infiltration at the grazed site, with the greatest bulk density, least macroporosity and hydraulic conductivity or greatest pore tortuosity. In general, spatial variation in zones with restricted and good hydraulic conductivity together with reduced aggregate sorptivity in the deeper horizons made the soil prone to preferential flow when initially dry. Prolonged wetness, on the other hand, reduced saturated hydraulic conductivity significantly, resulting in surface run‐off. Harvesting was considered the best management practice due to its inherent capacity for reducing the soil nutrient content and because it has minor implications for soil physical properties.     

耐溶剂复合纳滤膜的研究进展

综述了复合纳滤膜的材料和结构,重点概述了复合纳滤膜的溶涨和膜性能下降的机制,并进一步介绍了近年来耐溶剂复合纳滤膜的研究进展。     

超滤技术制备乳铁蛋白制品工艺的研究

本文通过超滤技术从牛初乳中分离乳铁蛋白，然后对浓缩液进行干燥制成乳铁蛋白制品。文中对分离工艺，膜的组件优选及操作参数的影响作了全面论述。     

模拟酸雨对葡萄叶片的生理伤害

研究了模拟酸雨对巨峰葡萄叶片的伤害作用。结果表明：经pH3.5、pH2.5和pH2.0的酸雨处理后叶片在短期内均出现不同程度的伤害斑，叶绿素含量和净光合速率下降。酸雨处理使SOD活性及不饱昨脂肪酸指数（IUFA）下降，同时使MDA含量、细胞膜透性及乙烯生成速度显著增加。     

PVC双壁波纹排水暗管开孔率试验研究

采用一维渗流试验装置研究了ＰＶＣ双壁波纹管用作农田排水时的适宜开孔率，试验表明：ＰＶＣ双壁波纹管用作农田排水暗管时开孔率不必要求过高，控制在２．５％￣３．０％之间即可满足生产要求。     

接装纸涂胶量对卷烟滤嘴通风率的影响

为使接装纸透气度及滤嘴通风率在指标范围内保持稳定,采用单因素试验法,研究接装纸涂胶量对接装纸透气度及滤嘴通风率的影响,以及接装纸涂胶量随接装机运转速度和接装纸包角的变化关系。结果表明,1接装纸涂胶量对接装纸透气度及滤嘴通风率的影响显著;2接装纸涂胶量随接装机运转速度的提高而减少;3接装纸涂胶量随接装纸包角的增大而增加。并建立了接装纸涂胶量与接装机运转速度和接装纸涂胶量与接装纸包角之间的函数关系,经过分析计算得到了接装纸包角与接装机运行速度的数学模型。当接装机运转速度发生变化时,该模型可通过调节接装纸包角使接装纸涂胶量保持稳定,进而使接装纸透气度及滤嘴通风率保持稳定。     

Effect of glucagon-like peptide-1(7-36)NH2 on insulin secretion and membrane potentials of pancreatic islet β-cells

AIM: To observe pathomorphological changes in cerebral cortex and hippocampus in the mouse with synthetic vascular dementia. METHODS: The synthetic vascular dementia model was produced in the mouse. Animals were killed 7 d, 15 d, and 30 d after the operation, brain tissues were removed and embedded in paraffin. Section of 8μm thickness were stained with hematoxylin-eosin(HE) and Nissl methods, and observed with light microscope. RESULTS: The cerebral cortex in the mouse became thinner on the seventh day, karyopyknosis in partial nervous cells was formed, the number of local neurons was reduced, sieve structure was observed, and glial cells proliferated, with the similar results 15 d and 30 d after operation. Model mouses hippocampal cells in CA₁ area were reduced and almost disappeared 30 d after operation. At the same time, glial cells were abundantly proliferated, tubercles were formed. Cells in CA₂, CA₃ area were also reduced and hippocampal sclerosis occurred. CONCLUSION: Delayed necrosis of hippocampal pyramidal cells may be the pathological basis of ischemia cerebral vascular dementia.