水稻叶片对模拟酸雨伤害的生理反应

水稻暴露于ｐＨ２．５～４．２的模拟酸雨中２个月后测定表明：叶片叶绿素含量下降,细胞液离子外渗率增加,气孔阻抗增高,蒸腾速率降低。不同叶位的水稻叶片对模拟酸雨的敏感性不同,杂交稻（汕优６３）对模拟酸雨的敏感性较粳稻（中粳８６４）高     

慢性心功能不全大鼠心脏和血淋巴细胞β-肾上腺素受体的改变

在主动脉与肾动脉缩窄造成的慢性心功能不全大鼠,血浆儿茶酚胺浓度增高;心脏β-肾上腺素受体(β-AR)数量增加,其中β_1-AR及其mRNA增加,而β_2-AR及其mRNA不变;左心房异丙基肾上腺素(ISO)浓度-收缩效应曲线右移;而心肌ISO浓度-cAMP蓄积曲线无显著改变;血淋巴细胞β-AR数量显著减少.结果提示心功能不全时心脏β_1-AR数量增多,但其介导的正性变力效应反而降低,在cAMP生成以后的信号转导过程或心肌收缩成分功能存在障碍,而血淋巴细胞β-AR的改变与心脏β-AR的功能改变平行.     

硬脂酸修饰超氧化物歧化酶的制备及其性质研究

报道了一种修饰ＳＯＤ的方法。所得硬脂酸修饰ＳＯＤ比活力为每毫克蛋白１００００单位,经鉴定已达均一程度。测得其分子量为３５０００．修饰ＳＯＤ和天然ＳＯＤ在紫外光区的最大吸收均在２６５ｎｍ。修饰ＳＯＤ对温度、ｐＨ、蛋白酶水解的稳定性比天然ＳＯＤ增强,且免疫原性消除。在低浓度的某些有机介质中活性比在水中高。     

毛细管水解及反相高效液相色谱分析蛋白质的氨基酸组成

 毛细管水解及反相高效液相色谱分析蛋白质的氨基酸组成陈平,梁宋平（湖南师范大学生物研究所,长沙４１０００６）氨基酸组成的分析是阐明蛋白质和多肽化学特性的基础,在蛋白质与多肽的氨基酸组成分析中,常采用对水解管反复充氮并抽真空的方法使蛋白质和多肽在隔绝氧气...     

链霉菌酪氨酸酶基因的克隆与表达

本文综述了近年来对链霉菌酪氨酸酶基因的研究。由酪氨酸酶合成黑色素是链霉菌属各个种的共同特性,并受到酪氨酸酶基因的控制。链霉菌几个种的酪氨酸酶基因已克隆到,其产黑色素的特性使之作为重要的标记基因得以广泛应用,同时,该基因在链霉菌的不同种及不同属的微生物中得到了高水平的表达。链霉菌酪氨酸酶基因表达调控的分子机制也得到较深入的研究。     

The mechanism for the effect of selenium supplementation on immunity

Lipid peroxide (LPO) in lymphocytes from mice was evaluated by measuring substances reactive to thiobarbituric acid (TBA). The product resulting from the reaction of TBA with lymphocytes was extracted with n-butyl and fluorescence intensity was determined. The degree of lipid peroxidation, expressed as fluorescence intensity f547, was assessed for stimulation of lymphocytes with concanavalin A (Con A), and was related to lymphocyte proliferation in response to Con A if Se was administered. The lymphocyte proliferation was determined by [³H]thymidine incorporation, expressed as cpm. The effect of superoxide dismutase (SOD), added to cell culture on lymphocyte proliferation was also evaluated. It was found that LPO in lymphocytes before Con A stimulation was significantly less than that after stimulation (p<0.001), and that SOD promoted lymphocyte proliferation dose dependently. The addition of Na₂SeO₃ to lymphocyte culture or supplementation in drinking water to mice decreased the produced LPO in lymphocyte in response to Con A. In the presence of Se, there is an inverse correlation between the levels of LPO in lymphocyte and the stimulated proliferation (r=−0.8902,r=−0.9439). In conclusion, active oxygen species scavenging was proposed as one of the mechanisms for Se to promote immunity.     

龙血树真菌群及其对血竭形成的影响

从柬埔寨龙血树（Ｄｒａｃａｅｎａｃｏｃｈｉｎｃｈｉｎｅｎｓｉｓ）茎杆中分离到３０３株真菌,其中镰刀菌属（Ｆｕｓａｒｉｕｍ）菌株占总分离频率的５２％,其次是短梗霉（Ａｕｒｅｏｂａｓｉｄｉｕｍ）和枝孢霉（Ｃｌａｄｏｓｐｏｒｉｕｍ）。通过活体接种对血竭产生的影响试验表明,对血竭形成起重要作用的真菌主要是禾谷镰刀菌龙血树变种（Ｆ．ｇｒａｍｉｎｕｍｖａｒ．ｄｒａｃａｅｎａ）等４株红色镰刀菌,可使血竭形成量提高６６％－１２０％。     

Nanosecond optical rotatory dispersion spectroscopy: application to photolyzed hemoglobin-CO kinetics.

A standard technique for static optical rotatory dispersion (ORD) measurements is adapted to the measurement of ORD changes on a nanosecond (ns) time scale, giving approximately a million-fold improvement in time-resolution over conventional instrumentation. The technique described here is similar in principle to a technique recently developed for ns time-resolved circular dichroism (TRCD) spectroscopy, although the time-resolved optical rotatory dispersion (TRORD) technique requires fewer optical components. As with static ORD, TRORD measurements may be interpreted by empirical comparisons or may be transformed, via the Kramers-Kronig relations, to more easily interpreted TRCD spectra. TRORD can offer experimental advantages over TRCD in studying kinetic processes effecting changes in the chiral structures of biological molecules. In particular, the wider dispersion of ORD bands compared with the corresponding CD bands means that ORD information may often be obtained outside of absorption bands, a signal-to-noise advantage for multichannel measurements. Demonstration of the technique by its application to ns TRORD and the transform-calculated TRCD of carboxy-hemoglobin (Hb-CO) after laser photolysis is presented.     

人Ⅳ型胶原的提纯及其抗血清制备

采用胃蛋白酶限制性消化,NaCl分级盐析,还原和烷基化反应,纤维素离子交换层析从人胎盘组织分离纯化Ⅳ型胶原.经SDS-PAGE电泳鉴定符合Ⅳ型胶原α肽链电泳带.用纯化的Ⅳ型胶原免疫兔制备出高效价的特异抗血清.