STUDIES ON ENZYME ACTION : XXXIX. LIPASE ACTIONS OF EXTRACTS OF THE WHOLE MOUSE AT DIFFERENT AGES.

The ester-hydrolyzing or lipase actions of extracts of whole mice whose ages ranged from approximately 6 days before birth to 1 year 8 months 21 days were tested on ten simple esters by the method described in previous papers. The "pictures" of the relative enzyme actions changed from a type approaching the "embryonic" as found with embryo rats and a number of tissues of rabbit embryo, to a type characteristic of the adult mouse. The mouse embryos corresponded to the rat embryos in type and differed markedly from the mouse carcinomas which have been studied. The relative and absolute enzyme actions are discussed in some detail, and the results compared with the results obtained for the life cycle of the rat.     

STUDIES ON ENZYME ACTION : XXXIII. LIPASE ACTIONS OF EXTRACTS OF THE WHOLE RAT AT DIFFERENT AGES.

The ester-hydrolyzing or lipase actions of extracts of whole rats whose ages ranged from 3 days before birth to 3 years 15 days were tested on ten simple esters by the method described in previous papers. The results are presented in the form of curves, both as absolute actions and as relative actions on the different substrates. The "pictures" of the relative actions changed progressively with increasing age of the rat. For the embryo and the youngest rats, the curves approached those given by the Flexner-Jobling rat carcinoma and by a number of tumors of human origin, changing to a type characteristic of the adult rat, and appearing to revert again to some extent to the embryonic type for the oldest rats. The changes in the actions on individual esters and the relative changes in the actions on different esters are discussed in detail. The greatest increases in actions as the rats became older were found with methyl and ethyl butyrates; at the same time that the actions on some of the other esters were also found to change in characteristic ways. Similar experiments with the protease actions of the extracts of whole rats of different ages on three protein preparations did not give differences similar to those found for the lipase actions. The probable reasons for these observed differences in the two sets of enzyme actions are discussed.     

STUDIES ON ENZYME ACTION : XLV. LIPASE ACTIONS OF THE WHOLE TROUT AT DIFFERENT AGES.

The ester-hydrolyzing or lipase actions of extracts and whole solids of trout eggs and whole trout of different ages were tested on ten simple esters by the method described in previous papers. Differences in solubility of the enzyme materials of the eggs were found. The "pictures" of the relative enzyme actions changed from a type found with immature eggs to a type which became constant for the fish after they had eaten for 2 weeks. After this, the type did not change up to the age of 4 to 5 years (the oldest trout studied). The absolute ester-hydrolyzing actions of the materials were also presented and discussed.     

STUDIES ON ENZYME ACTION : XIX. THE SUCROLYTIC ACTIONS OF BANANAS.

A number of different methods of treatment of unripe and ripe bananas for the purpose of obtaining and studying sucrolytic and amylolytic enzymes are described. No conclusive evidence of the presence of an amlyase could be obtained in any of the preparations. The sucrase of unripe and ripe bananas was studied more extensively. With ripe bananas, both soluble and insoluble sucrase preparations were obtained. Conditions for converting the soluble into an insoluble form were found. The actions of the sucrase preparations as far as the hydrogen ion concentration for maximum action and the time-action relation are concerned are similar to the behavior of the yeast and the potato sucrase.     

STUDIES ON ENZYME ACTION : XVIII. THE SACCHAROGENIC ACTIONS OF POTATO JUICE.

The saccharogenic enzymes present in potato juice were studied. The actions were followed upon the substances present in the juice and upon added sucrose, maltose, and soluble starch. Sucrase and amylase were found to be present in the juice. No indication of a maltase was obtained. The sucrase showed optimum conditions for action at pH 4 to 5, the amylase at pH 6 to 7, both upon the starch present in the juice and upon added soluble starch. The action of a yeast sucrase preparation upon the juice showed the presence of sucrose (or raffinose) in a concentration of the order of magnitude of 1 per cent.     

STUDIES ON ENZYME ACTION : XXXVIII. THE ESTER-HYDROLYZING ACTIONS OF THE WHOLE EEL.

The hydrolyzing actions of various preparations of the adult eel were studied on ten esters in the usual way. The results are presented in the form of curves for the relative actions and in a table for the absolute actions obtained in one complete experiment. The separation of the enzyme material in some cases into an active portion and a co-enzyme, the mixture showing greater actions on some esters than the sums of the individual actions, is described and discussed.     

STUDIES ON ENZYME ACTION : XLVI. THE ESTER-HYDROLYZING ACTIONS OF WHOLE TROUT PREPARATIONS UNDER VARIOUS CONDITIONS.

The ester-hydrolyzing actions of trout extracts at different hydrogen ion concentrations were studied. It was pointed out that the behavior was similar to that found with various tissue and tumor materials and that similar relations hold. Glycerol solutions extracted somewhat larger amounts of active enzyme material from trout than did water and sodium chloride solutions, although the differences were not large. Evidence was presented for the existence of a so called "coenzyme."     

液化沙雷氏菌胞外脂肪酶产生条件的研究

新分离的一株液化沙雷氏菌（Ｓｅｒｒａｔｉａｌｉｑｕｅｆａｃｉｅｎｓ）能产生大量胞外碱性脂肪酶,本文在摇瓶发酵水平上考察了培养基组成、培养条件等因素对其生成脂肪酶的影响。在优选条件下,即培养基组成为（％）玉米油１．２５,豆饼粉２．０,蛋白胨１．０,酵母膏０．２,Ｋ_２ＨＰＯ_４０．２,ＭｇＳＯ_４·７Ｈ_２Ｏ０．１,初始ｐＨ为７．２５时,２８℃,１５０ｒ／ｍｉｎ旋转摇床振荡培养４０ｈ,该菌株的发酵液酶活达到４３ｕ／     

3-脱氧葡糖松代谢酶产生菌的筛选及产酶条件

从霉菌和酵母中筛选到一株酵母（Saccharomycescerevisiae231）,该菌株具有能够代谢3-脱氧葡糖松（3－deoxyglucosone）的酶,且活性较高。研究了该菌株的最适产酶条件：培养温度28℃,培养基起始pH7.0,培养时间12h,碳源、氮源分别为蔗糖、牛肉膏,添加KH₂PO₄、Ca（H₂PO₄）₂·H₂O能促进产酶。     

不同年龄大鼠主动脉壁凝集素组织化学的图像分析研究

本文利用凝集素组织化学的方法,结合应用ＩＢＡＳ图像分析系统对不同年龄（１０天,６个月及２年）大鼠主动脉壁的凝集素受体进行研究。在所采用的六种生物素化凝集素中（ＣｏｎＡ、ＲＣＡＩ、ＵＥＡ－Ｉ、ＰＮＡ、ＳＢＡ及ＷＧＡ）,ＣｏｎＡ、ＲＣＡ－Ｉ及ＷＧＡ在大鼠主动脉壁呈阳性反应,它们在各年龄组大鼠主动脉壁内膜及外膜均表现出强阳性反应,而在中膜反应较弱。ＵＥＡ－Ｉ、ＰＮＡ和ＳＢＡ表现出无明显反应。此外,三种阳性反应凝集素在主动脉壁的反应产物随增龄而减少,图像分析结果显示其灰度值随增龄的变化趋势是逐渐增加。上述结果提示,大鼠主动脉壁含α－Ｄ－Ｍａｎｎｏｓｅ、β－ＤＧａｌａｃｔｏｓｅ、ｓｉａｌｉｃａｃｉｄ或Ｎ－ａｃｅｔｙｌ－Ｄ－Ｇｌｕｃｏｓａｍｉｎｅ残基的糖复合物含量随增龄而减少,可能使ＬＤＬ易于通透而致脂质在动脉壁沉积,加速脂纹病变的形成,从而易于导致动脉粥样硬化。     

不同温度对太湖短吻银鱼秋季孵化的试验研究

太湖短吻银鱼是太湖的主要经济鱼类之一。本文在1975和1981年对不同温度下太湖短吻银鱼秋季人工授精孵化进行了8次试验,胚胎发育和孵化仔鱼均属正常,并得到如下统计分析结果: 1.在试验温度范围内孵化温度与积算温度(A)的相关为A=3441.97-93.41t; 2.孵化温度与孵化时间(H)的相关为logH=4.3615-1.8946logt; 3.孵化温度与初孵仔鱼全长(L)的相关为logL=1.0917-0.5246logt。     

不同叶龄黄瓜叶片叶绿素蛋白质复合物组分的比较研究

用SDS-聚丙烯酰胺凝胶电泳的方法,对比分析了老、嫩黄瓜叶片叶绿素蛋白质复合物之间的差异,发现嫩黄瓜叶片中缺少1条属光系统Ⅰ的CPI_b带。从低温荧光发射光谱观察到,嫩黄瓜的光系统Ⅰ相对高于光系统Ⅱ,而老黄瓜则相反。指出在叶绿体发育过程中首先形式光系统Ⅰ,以后是光系统Ⅱ。我们还注意到,叶片中的F685/F735比值与叶绿素蛋白质复合物中的单体/寡聚体比值之间是正相关关系。     

STUDIES ON THE MECHANISM OF ACTION OF PEDERINE

Pederine, a drug extracted from the coleopter Paederus fuscipes, inhibits the growth of in vitro cultured cell lines at concentrations of the order of 1.5 nanogram/ml. Cytological examination shows a generalized cytotoxic effect. Analysis of macromolecular syntheses by the use of radioactive precursors shows that pederine causes an almost immediate block of protein and DNA synthesis, without affecting RNA synthesis. The effects on the synthesis of the two types of macromolecules remain nearly simultaneous even at the lowest active concentrations of pederine. Studies with cell-free systems show that the drug inhibits protein synthesis, whereas it is ineffective on the DNA-polymerizing activity. It seems, therefore, that the drug acts primarily on the amino acid-polymerizing system, and that the effect on DNA is secondary. This idea is strengthened by the observation that puromycin, a specific inhibitor of protein synthesis, also affects promptly DNA synthesis of in vitro cultured cells. Other authors have shown the same phenomenon with a number of inhibitors of protein synthesis; the properties of pederine support, therefore, the view that continuous protein synthesis is necessary for the maintenance of DNA replication in higher organisms.     

不同日龄小鼠的超排、体外授精及二细胞胚胎移植的比较研究(简报)

小鼠是现代生物医学中应用最为广泛的实验动物,特别是随着基因工程动物的大量开发,对小鼠卵母细胞和小鼠胚胎的需求量将日趋增多。但是如果单纯依靠动物的自然排卵,一方面所得到的卵母细胞数或胚胎数较少,一方面又消耗大量的时间和浪费较多的动物。因此,研究者期望使用较少的动物但仍能得到较多的、正常的卵母细胞或胚胎来满足生命科学研究的需要。Onadera,M等的研究表明,小鼠卵母细胞的发育与年龄有关,同一品系小鼠不同日龄间的自然排卵数差异不显著,出现异常卵的比例有显著性差异。但对不同日龄、不同品系小鼠的超排的效果尚     

百里香提取物抑菌特性的研究

以百里香水和酒精提取物及百里香芳香油作为抑菌剂进行抑菌试验 ,结果表明 ,所用抑菌物对供试菌金黄色葡萄球菌 (Staphalococcusaureus)、枯草芽孢杆菌 (Bacillussubtilis)和大肠杆菌 (Escherichiacoli)均有不同程度的抑制作用 ,可望将其用于食品工业作为防腐和抑菌剂。