异源八倍体小冰麦体细胞无性系的建立及其染色体变异

从５个异源八倍体小冰麦（Ｔｒｉｔｉｃｕｍ －Ａｇｒｏｐｙｒｏｎ）的叶片、幼穗及成熟胚诱导愈伤组织,建立体细胞无性系,获得大量再生植株。附加一个冰草染色体组的异源八倍体小冰麦杂种无性系中３７．５％ 表现变异,其中非整倍体植株变异较多,很多变异的再生植株形态与小麦近似,同时出现一定数量染色体重排、交换、易位、断裂、融合等变异。结果表明,通过杂种无性系变异进行染色体基因转化及遗传修饰是一条可行的途径。实验还观察了小冰麦愈伤组织分化过程中绿点的形成过程,首次提出两种类型绿点,即芽绿点和根绿点,并描述了两者的差异     

Alcohol and aldehyde dehydrogenase genotypes and drinking behavior of Chinese living in Shanghai

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), the principal enzymes responsible for oxidative metabolism of ethanol, exist in multiple, genetically determined molecular forms. Widely different kinetic properties in some of these isozymes account for the individual differences in alcohol sensitivity. In this study we used the polymerase chain reaction/restriction fragment length polymorphism method to determine the genotypes of the ADH2 and ALDH2 loci of alcoholic and nonalcoholic Chinese living in Shanghai. We also investigated the subjects' drinking patterns by means of semistructured interviews. The alcoholics had significantly lower frequencies of the ADH2² and ALDH2² alleles than did the nonalcoholics, suggesting the inhibitory effects of these alleles for the development of alcoholism. In the nonalcoholic subjects, ADH2² had little, if any, effect, despite the significant effect of the ALDH2² allele in decreasing the alcohol consumption of the individual. Taken together, these results fit the proposed hypothesis for the development of alcoholism, i.e., drinking behavior is greatly influenced by the individual's gentoypes of alcohol-metabolizing enzymes, and the risk of becoming alcoholic is proportionate with the ethanol consumption of the individual.     

拉萨郊区藏族的指纹研究

本文报道了拉萨郊区５１７例（男２２６人,女２９１人）藏族健康人的指纹参数正常值、调查分析了指纹类型、指纹组合、指纹指数和指嵴纹计数。比较了藏族不同居群、不同民族和人种间的差异。结果表明,藏族有自己的指纹特点,又显著蒙古人种的一般特征。     

鹅掌楸属植物引导组织和花粉管生长

应用光学显微镜和常规石蜡切片技术研究了鹅掌楸属（ＬｉｒｉｏｄｅｎｄｒｏｎＬ．）两种植物雌蕊引导组织的分布和个体发育,引导组织是由心皮边缘或内表面的表皮细胞层或亚细胞层发育形成,是由一层细胞组成的连续层,覆盖干柱头、花柱道和珠柄的表面,引导组织的细胞形态学因其所在部位不同而有差异。在电境水平上研究了柱头和花柱引导组织的超微结构,引导组织细胞是分泌型的传递细胞,其分泌面发育了明显的壁内突,细胞质中富含内质网、多聚核糖体、各种小泡、高尔基体和线粒体,大液泡通常远离分泌面。文中还探讨了花粉管生长后引导组织的变化。     

The drug metabolism systems of liver and liver tumors: A comparison of activities and characteristics

Summary Transplantable rat liver tumors 5123 t.c., 7288 ct.c., 5123 t.c.(H) and the Novikoff hepatoma have active mixed function oxidase systems capable of metabolizing a variety of drug and polycyclic hydrocarbon substrates. The tumor drug metabolism systems are at best 20% as active as rat liver. The tumor drug metabolism activities are induced by pretreatment with phenobarbital or -naphthoflavone and can be inhibited with specific inhibitors such as carbon monoxide or 7,8-benzoflavone. Tumor drug metabolism systems appear to consist of cytochrome P-450 and cytochrome P-450 reductase. The properties of the two protein components from tumors are highly similar to the corresponding components of the liver drug metabolism system.Cytochrome P-450 reductase has been at least partially purified from the Novikoff hepatoma and hepatoma 5123 t.c.(H). The kinetic and physical properties of the tumor reductases are similar to those of the liver reductase except that the K_m of hepatoma 5123 t.c.(H)     

Effects of enkephalin in analogues on prolactin release in the rat.

The effects of nineteen enkephalin analogues on the circulating levels of prolactin in the male rat following intraventricular injection of the peptides were determined and compared with that of Met- and Leu-enkephalin. Eleven of the 19 analogues stimulated prolactin secretion. It was found, in general, that the structure activity relationship for enkephalin stimulation of prolactin secretion was similar to that for opiate receptor activity. Analogues which contained a [DAla²] substitution were generally effective in stimulating prolonged prolactin release. Some, but not all analogues containing [DTrp²] or [DLeu⁵] were active. Analogues containing the [DTrp¹], [DPhe⁴] or [DMet⁵] substitutions were ineffective. The prolactin releasing effect of intravenous Tyr-DAla-Gly-Phe-DLeu was reversed by naloxone. Naloxone had no effect on the haloperidol- and alpha-methylparatyrosine induced increases in plasma prolactin levels. The results of these studies are discussed in the light of the suggestion that the enkephalins may function as neuroendocrine modulators.     

Estimation of whole-plant resistance to gaseous exchange independent of leaf temperature measurement

For studies into the uptake of mercury vapor by wheat (Triticum aestivum), a simple theory and plant chamber were employed to estimate total leaf resistance of whole plants to water vapor exchange. The estimates were independent of leaf temperature, for which mean values were indirectly determined. The approach involved the measurement, at steady-state conditions, of the net change in water vapor flux per unit of leaf surface (Δq_v) in response to a small induced change in absolute humidity (ΔC_a). Assuming that total leaf resistance (r_l) was constant and that change in leaf temperature (T_l) was negligible, total leaf resistance was calculated from the equation, [Formula: see text]     

小麦根系特征对干旱胁迫的响应

干旱胁迫时, 小麦(Triticum aestivum)根系率先产生应激响应, 同时向地上部发出信号, 诱导地上部发生生理反应, 从而提高植株抗旱能力。根系构型包括平面几何性状和立体几何结构(即拓扑构型), 具有遗传稳定性和可塑性。干旱胁迫影响根系理化特性, 如根源化学信号、根系细胞酶类和根系渗透作用的响应。根系通过调整其解剖学结构和水分吸收动力等来适应干旱胁迫。该文从根系构型、理化特性和解剖学结构3个方面, 系统阐述了小麦根系特征对干旱胁迫的响应, 并探讨了其与干旱胁迫的关系和当前研究中存在的问题, 以期为相关研究提供参考。     

DNA methylation patterns of human pachytene spermatocytes

A study has been made of the possibility that methylation occurs during germ cell production in the human testis. Utilizing the immunoperoxidase method with an antibody to 5-methylcytidine, it has been demonstrated that the number of immunoreactive sites on bivalents increased between early and mid/late pachytene.