刺果番荔枝中的番荔枝内酯

从刺果番荔枝（Ａｎｎｏｎａ ｍ ｕｒｉｃａｔａ Ｌ．）的种子中分离到３ 个单四氢呋喃型番荔枝内酯类化合物,用波谱方法鉴定为海南哥纳香甲素（ｈｏｗ ｉｉｃｉｎ Ａ, Ｓ１３）、乙素（ｈｏｗ ｉｉｃｉｎ Ｂ, Ｓ５）和新化合物４－去氧海南哥纳香乙素（４－ｄｅｓｏｘｙｈｏｗ ｉｉｃｉｎ Ｂ, Ｓ２）。     

大血藤科植物的分类学研究

作者对大血藤科植物的花性、叶片内部结构形态、花粉形态、染色体核型及过氧化物酶和脂酶同工酶进行了比较研究,结果表明：１）大血藤科植物外形上的两性花,其雄蕊的形态退化、花药始终不开裂,为功能上的雌花,因此其花为单性,同株,同序或异序;１２）首次指出大血藤属植物的染色体数为２ｎ＝２ｘ＝２２,属小型染色体,与木通科植物２ｎ＝２ｘ＝３２、３０、２８的染色体数明显不同,支持Ｓｔａｐｆ（１９２６）将其从木通科分出另立为科的观点;３）单叶和复叶可出现于同一植株上,而且在叶片内部结构、花粉形态、染色体核型、过氧化物酶及脂酶同工酶等性状上,大血藤与单叶血滕间均无实质性的差异,因此将单叶血藤归并于大血藤中。     

甘肃稀有濒危植物的地理分布和区系特征

分析了甘肃稀有濒危植物５１个种的地理分布和４８个属的分布区类型及其区系特征。     

The loss of culturability by Escherichia coli cells in seawater depends on availability of phosphate ions and phosphate transport systems

Using strains with or without the PhoE porin or different components of the phosphate regulon, we determined that maintenance of the culturability of Escherichia coli in seawater depended significantly on the presence of structures allowing access of phosphate ions to the periplasm, then to the cytoplasm of cells. Cells totally deprived of the two main phosphate transport systems (Pit, Pst) exhibited the highest loss of culturability. Most of this effect resulted from the loss of the high-affinity Pst system, and more specifically that of the periplasmic phosphate-binding protein PhoS. Survival was enhanced in seawater supplemented with phosphate (0.5 mm), whether or not these structures were present. From an ecological point of view, it is assumed that the presence of phosphate ions, even at low concentrations, can influence the behavior of E. coli cells in seawater. Offprint requests to: M.J. Gauthier     

豇豆单孢锈菌中病毒样颗粒中双链RNA的存在

从北京西郊清华园附近田间豇豆上采集的豇豆单孢锈菌(Uormyces vignal Barcl)夏孢子。萌发后提取双链RNA,电泳分析可测出300—8000碱基对的三组双链RNA。从萌发的孢子中通过差迷离心提取病毒样颗粒,可获得二种类型的病毒样颗粒,一种直径为35—40nm的等轴颗粒。另一种为长短不等的棒状颗粒,用提纯物提取核酸电泳分析与直接从孢子中提取的双链RNA有相同的核酸带,从而证明这些双链RNA存在于病毒样颗粒中。     

空篷和正常板栗果实发育过程中氨基酸、碳水化合物变化规律的回归分析

本文研究了空篷和正常板栗果实发育过程中的氨基酸和碳水化合物的含量变化,并运用回归分析的方法探讨两者的变化规律及其差异．结果表明：在板栗不同发育时期,子房内氨基酸和淀粉含量变化具有规律性,并得到相关极显著的回归方程,空篷与正常栗具明显示的差异;总苞内除正常栗氨基酸含量得到相关极显著的回归方程外,其它的含量变化回归分析均未得到显著水平,空篷栗与正常栗的差异亦不显著．     

异质性荧光染色的巨噬细胞功能研究I．异质性荧光染色的巨噬细胞吞噬活性

利用淀粉多糖和免疫促进剂（白喉类毒素和卡介苗）诱导和活化小鼠腹腔巨噬细胞,观察了四种异质性荧光染色的巨噬细胞非特异性和特异性吞噬活性。实验证明,深蓝色和淡蓝色荧光的巨噬细胞是分化程度低的幼稚细胞,非特异性吞噬功能较弱,但在特异性吞噬过程中呈现了活跃的吞噬活性,特别是在免疫促进剂的活化下,它们的特异性吞噬功能显著增强、淡蓝绿色荧光的巨噬细胞是分化程度较高、非特异性和特异性吞噬功能最旺盛的巨噬细胞,而黄色荧光的巨噬细胞是分化程度最高、特异性吞噬功能较减退的巨噬细胞。     

新生儿接种小剂量乙肝疫苗后3-5年随访观察

本文对９３８例初生婴儿接种小剂量（１０ｕｇ×３）乙肝疫苗后３－５年的预防效果进行了随访观察,并以２５３例初生儿未接种疫苗者作为对照,结果表明,接种组３－５年后抗－ＨＢｓ阳性率显著高于对照组,ＨＢｓＡｇ阳性率则较对照组显著为低。感染保护率８６．７％。结果还表明,接种乙肝疫苗３年后加强１次,比不加强者Ｐ／Ｎ均值显著增高。文章认为初生儿接种小剂量乙肝疫苗有长期免疫效果;接种后３年加强接种１次,可保持较高免疫力。     

硅藻土在青霉素G酰化酶提纯中的应用

国产硅藻土经氢氧化铵处理后可用于从发酰液中直接取青霉素Ｇ酰化酶,平均吸附量为９０Ｕ／ｇ。吸附的酶可用２２％硫酸铵－０．３ｍｏｌ／ＬＰＢＳ（ｐＨ８．０）溶液洗脱。平均比１８Ｕ／１８Ｕｍｇ蛋白（ＮＩＰＡＢ法）。硅藻土可反复使用。苯乙酰胺－Ｓｅｐｈａｒｏｓｅ４Ｂ树脂可对酶作进一步的纯化。     

Casein Kinase II Activity in the Postischemic Rat Brain Increases in Brain Regions Resistant to Ischemia and Decreases in Vulnerable Areas

Abstract: Casein kinase II (CKII) is a protein kinase acting in the intracellular cascade of reactions activated by growth factor receptors, and that has a profound influence on cell proliferation and survival. In this investigation, we studied the changes in the activity and levels of CKII in the rat brain exposed to 10. 15 and 20 min of transient forebrain ischemia followed by variable periods of reperfusion. The cytosolic CKII activity decreased during reperfusion by ∼ 30 and ∼ 50% in the selectively vulnerable areas, striatum and the CA1 region of the hippocampus, respectively. In the resistant CA3 region of hippocampus and neocortex, the activity increased by ∼ 20 and ∼ 60%, respectively. The postischemic changes in CKII activity were dependent on the duration of the ischemic insult. The levels of CKII did not change after ischemia, suggesting that the enzyme is modulated by covalent modification or is interacting with an endogenous inhibitor/activator. Treatment of the cytosolic fraction from cortex of rats exposed to ischemia and 1 h of reperfusion with agarose-bound phosphatase decreased the activity of CKII to control levels, suggesting that CKII activation after ischemia involves a phosphorylation of the enzyme. The correlation between postischemic CKII activity and neuronal survival implies that preservation or activation of CKII activity may be important for neuronal survival after cerebral ischemia.