钠离子对仔猪小肠刷状缘膜囊二肽跨膜转运的影响

为研究Na 在仔猪小肠Gly-Pro跨膜转运中的作用,采用同位素示踪及体外孵育技术,观察在不同Na 浓度梯度条件下Gly-Pro在仔猪小肠刷状缘膜囊(brush border membrane vesicles,BBMV)的跨膜转运量。结果表明:(1)用K 替代Na ,并没有降低Gly-Pro在BBMV中的转运量,在孵育前20min时间内,Gly-Pro的转运量稍稍提高;(2)Na 可使BBMV对L-丙氨酸的转运量提高到4.6倍,但不影响Gly-Pro的转运;二氢骆驼蓬碱显著地降低L-丙氨酸的转运,但对Gly-Pro的转运无影响。研究提示,Gly-Pro在仔猪小肠BBMV体系中的转运与Na 不存在依赖性的关系。     

Changes in antioxidative system and membrane damage of lettuce in response to salinity and boron toxicity

Individual and combined effects of salinity and B toxicity on growth, the major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX) activities, ascorbic acid, proline, and H₂O₂ accumulation, and stomatal resistance (SR), malondialdehyde (MDA), membrane permeability (MP) and the concentrations of sodium (Na), chloride (Cl) and boron (B) of lettuce were investigated. Boron toxicity and salinity reduced growth of lettuce plants. Under B toxicity, B concentration of the plants was increased, but in the presence of NaCl, the concentration of B was significantly reduced. Sodium and Cl concentrations were increased in B + NaCl and NaCl treatments. Membrane damage was more pronounced in NaCl and B + NaCl treatments. Stomatal resistance of the plants was significantly increased by salinity treatments. The accumulation of proline and ascorbic acid was the highest in the B + NaCl treatment. In general, stress conditions significantly increased H₂O₂ and antioxidant enzyme (SOD, CAT and APX) activities. The present results indicate that stomatal closure is an important response of lettuce against NaCl and B + NaCl stress. Furthermore NaCl and B + NaCl toxicity-induced oxidative stress in lettuce resulting in lipid peroxidation and membrane damage. Increased antioxidant enzyme activities and also accumulation of ascorbic acid and proline are involved in order to overcome B- and NaCl-induced oxidative stress.     

The latent gene expression of Epstein-Barr virus in nasopharyngeal carcinoma

AIM: To examine the latent membrane protein 1(LMP1)-DNA sequence in nasopharyngeal carcinoma(NPC) and detect mRNA expression of LMP1,EBNA1,EBNA2,and to explore the relationship between EBV infectious status,expression products and NPC carcinogenesis.METHODS: LMP1 DNA was detected in NPC by PCR.Direct sequence was applied to analyze the difference between NPC-LMP1-DNA and B95-8- LMP1-DNA.mRNA expressions of LMP1,EBNA1,EBNA2 in NPC were detected by nested RT-PCR.RESULTS: LMP1 DNA existed in all 47 NPC tissues.Several single nucleotide variations were found between NPC-LMP1-DNA and B95-8- LMP1-DNA.The notable variation was the lost of XhoⅠrestriction site in NPC.Direct sequence showed 30 bp deletion in NPC.The mRNA expressions of LMP1,EBNA1 and EBNA2 in NPC were 76.6%,80.0% and 74.5% respectively by nested RT-PCR.The expression of EBNA1 in NPC was promoted by Q promoter while the expression of EBNA1 in B95-8 was promoted by C promoter.CONCLUSION: The way of EBV involved in NPC is complex.Latent genes such as LMP1,EBNA1 and EBNA2 as well as early lytic gene BARF1 may all play certain roles in NPC carcinogenesis.     

Antiproliferation effects of 188Re labeled monoclonal antibody on prostate cancer cells in vitro

AIM: To investigate the effect of 188Re labeled monoclonal antibody on prostatic specific membrane antigen 7E11C5.3,radioimmunotherapy for the treatment of human prostate cancer cell line LNCaP in vitro.METHODS: 188Re-7E11C5.3 was prepared by direct 2-mercaptoethanol reduction method.Labeling efficiency and radiochemical purity was measured by paper chromatography.Immunoreactive fraction was determined by linear extrapolation.Cytotoxicity to LNCaP cells was determined by MTT assay.RESULTS: The labeling yield of 188Re-7E11C5.3 was (93.16±2.18)%,the radiochemical purity was (95.62±0.48)%,and the immunoreactive fraction was (74.86±1.86)%.The inhibitory effect of 188Re-7E11C5.3 on cell proliferation of LNCaP cells was significantly higher than that of 188Re-mIgG or 188ReO-4.The 50% inhibitory doses (IC50) of 188Re-7E11C5.3,188Re-mIgG,and 188ReO-4 were (23.38±3.73)×107 Bq/L,(59.21±8.02)×107 Bq/L and (68.89±10.91)×107 Bq/L,respectively.CONCLUSION: 188Re-7E11C5.3 can effectively inhibit the growth of in vitro cultured prostate cancer cells and shows much potential for prostate cancer radioimmunotherapy.     

大菱鲆致病性溶藻弧菌SR1的外膜蛋白及其抗原性分析

用十二烷基肌氨酸钠(Sarkosyl)抽提结合超速离心的方法提取了一株大菱鲆致病性溶藻弧菌(Vibrio alginolyticus)SR1和其他7株弧菌的外膜蛋白。通过SDS-PAGE图谱分析比较了这8株弧菌外膜蛋白的组成,结果表明,8株弧菌的外膜蛋白电泳一般可得到6-12条条带,其分子量多集中在65-106 kD和28-48 kD,其中36 kD的蛋白带为8株弧菌所共有。用兔抗SR1全菌血清进行Western-blot印迹显示,菌株SR1的外膜蛋白条带中有6条发生了阳性反应,其分子量分别为73 kD、48 kD4、5 kD3、9 kD、36 kD和32 kD。而其他7株弧菌的外膜蛋白与兔抗SR1血清也发生程度不等的阳性反应,这些阳性反应条带的分子量集中在65-73 kD、45-48 kD和36-41 kD之间,其中36 kD的外膜蛋白在8株弧菌中均出现明显的阳性反应,说明36 kD的外膜蛋白是这8株弧菌共有的特异性抗原。     

山莨菪碱(654-2)对内毒素诱导山羊红细胞膜损伤过程中膜脂流动性的影响

用1,6-二苯基-1,3,5-己三烯(1,6-diphenyl-1,3,5-hexatriene, DPH)分子荧光偏振技术,研究了内毒素(ET)诱导的山羊红细胞膜(ECM)损伤过程中膜脂的流动性(P)、膜脂区微粘度(-η)、脂双层分子排列有序性系数(A)的变化及山莨菪碱(654-2)对其的影响。结果表明,ET 处理组(Ⅱ组)ECM 的P、-η和A 参数在处理后3、5、7、9、12 h 均显著高于Ⅰ组和Ⅲ组(P< 0.05,P< 0.01);Ⅲ组P、-η和A 参数在处理后3 h 显著低于Ⅰ组(P< 0.01), 5、7 h 高于Ⅰ组(P< 0.05,P < 0.01)。结果显示,ET可使山羊ECM P、-η和A 增加、膜流动性降低,而654-2 能有效地改善ET诱导的这些损伤变化,支持了654-2 具有维护膜结构和功能的理论。     

Calcium Effects on Acetic Acid Toxicity in Rice

Recent soil‐management practices such as no‐tillage and minimal tillage, when applied to the irrigated rice crop, promote changes in soil composition as a result of anaerobic degradation of organic matter. Several short‐chain organic acids are formed, such as acetic acid. The objective of this work was to determine the effect of calcium (Ca) on plant development under stress by acetic acid toxicity. The experiment was conducted in hydroponics by testing different Ca (0.2, 1.0, and 5.0 mmol L^?1) and acetic acid (0 and 2.5 mmol L^?1) concentrations. The variables evaluated were the root system morphological parameters (total length, radius, area, dry‐matter weight, and main root growth), shoot parameters (shoot dry matter, plant height), and concentration and total accumulated nitrogen (N), phosphorus (P), potassium (K), Ca, and magnesium (Mg) in the plants. The growth of the root system and the shoots of rice plants were not affected by the addition of Ca to the treatments containing acetic acid.     

脂肪细胞膜免疫技术研究进展

脂肪细胞膜免疫技术是从以动物脂肪细胞膜分离得到的膜蛋白作为抗原,通过被动免疫或主动免疫来破坏脂肪细胞,使脂肪组织中的细胞数量减少,限制其贮存脂肪的能力,从而达到调控动物生长和降低动物脂肪的目的。本文将对脂肪细胞膜蛋白抗体的制备、作用机制及在动物上的使用效果进行阐述,并对此技术尚需解决的问题和发展方向进行综述。     

Role of outer membrane proteins in immunity against murine salmonellosis--1. Antibody response to crude outer membrane proteins of Salmonella typhimurium

The humoral immune response to crude outer membrane proteins (comp) of S. typhimurium in mice has been characterized. Maximal and quicker antibody response was observed when 50 micrograms of comp was injected intraperitoneally. The comp of smooth C5 strain of S. typhimurium evoked antibody response to both lipopolysaccharide (LPS) and proteins. Absorption of these sera with LPS coated erythrocytes eliminated the antibodies to LPS completely, while the antibody level to protein was left unaltered. The comp from rough mutant (lacking O-specific chain of LPS) of S. typhimurium elicited antibodies to proteins but not to LPS. These results indicate the concomitant production of antibodies to Salmonella outer membrane proteins also. The significance of such antibodies in protection and diagnosis has been discussed.     

鸡肠道抗菌肽的提取及活性研究

取新鲜鸡肠黏膜超声波破碎,乙酸浸提,经Sephadex G-50层析后,收集具有抑菌活性的组分进行超滤离心,抑菌实验表明滤过物具有抑菌活性.滤过物经SDS-PAGE分析为一个条带,分子量约为6.078KD,得到电泳纯的鸡肠道抗微生物肽.该肽具有一定的耐热性,但经90℃以上热处理后活性下降较大;pH值对其活性影响较大,在pH6～8时活性最强.