COMPARATIVE HYDROLYSIS OF GELATIN BY PEPSIN,TRYPSIN, ACID,AND ALKALI

A comparison has been made of the relative velocity of hydrolysis of the various peptid linkings of the gelatin molecule when hydrolyzed by acid, alkali, pepsin or trypsin. It has been found that: 1. Those linkages which are most rapidly split by pepsin or trypsin are among the more resistant to acid hydrolysis. 2. Those linkages which are hydrolyzed by pepsin are also hydrolyzed by trypsin. 3. Trypsin hydrolyzes linkages which are not attacked by pepsin. 4. Of the linkages which are hydrolyzed by both enzymes, those which are most rapidly hydrolyzed by pepsin are only slowly attacked by trypsin. 5. Those linkages which are attacked by trypsin or pepsin are among the ones first (most rapidly) hydrolyzed by alkali. In general it may be said that the course of the early stages of hydrolysis of gelatin is similar with alkali, trypsin, or pepsin and quite different with acid.     

STIMULATION OF FUNDULUS BY HYDROCHLORIC AND FATTY ACIDS IN FRESH WATER,AND BY FATTY ACIDS,MINERAL ACIDS,AND THE SODIUM SALTS OF MINERAL ACIDS IN SEA WATER

1. Fundulus heteroclitus was found to be a reliable experimental animal for studies on chemical stimulation in either fresh or sea water. 2. The response of Fundulus to hydrochloric, acetic, propionic, butyric, valeric, and caproic acids was determined in fresh water, while the same acids plus sulfuric and nitric, as well as the sodium salts of the mineral acids, were tested in sea water. 3. Stimulation of Fundulus by hydrochloric acid in fresh water is correlated with the effective hydrogen ion concentration. Stimulation by the n-aliphatic acids in the same environment is correlated with two factors, the effective hydrogen ion concentration and the potential of the non-polar group in the molecule. However, as the number of CH₂ groups increases the stimulating effect increases by smaller and smaller amounts, approaching a maximum value. 4. Stimulation of Fundulus by hydrochloric, sulfuric, and nitric acids in sea water is correlated with the forces of primary valence which in turn are correlated with the change in hydrogen ion concentration of the sea water. The n-aliphatic acids increase in stimulating efficiency in sea water as the length of the carbon chain increases, but a limiting value is not reached as soon as in fresh water. 5. Only a slight difference in stimulation by hydrochloric acid is found in sea water and in fresh water. However, there is a significant difference in stimulation by the fatty acids in fresh and in sea water, which is partly explained by the different buffering capacities of the two media. It is to be noted that in the same environment two different fish, Fundulus and Eupomotis, give different results, while the same fish (Fundulus) in two different environments responds similarly to mineral acids but differently to fatty acids. These results illustrate that stimulation is a function of the interaction between environment and receptors, and that each is important in determining the response. 6. Stimulation by sodium chloride, nitrate, and sulfate is correlated with equivalent concentrations of the salts added to sea water, or with the forces of primary valence. Although the threshold for stimulation by the salts is considerably higher than for the acids, the efficiency of stimulation by the salts is greater.     

特效黄杆菌对蒽菲芘的降解性能研究*

采用定时、定量、逐步提高驯化所用碳源物浓度的方法 ,以萘为唯一碳源驯化长期被焦化废水污染的泥土浸出液 ,7周后 ,平板划线分离出两株黄杆菌FCN1及FCN2。并对这两株菌降解多环芳烃的特性及无机离子对反应的刺激作用进行了研究。结果表明 ,FCN1及FCN2能降解转化蒽、菲、芘。加入FCN1 ,反应 1 0h后 ,蒽、菲、芘去除率分别为84%、69%、 80 % ,而加入FCN2 ,各物质的去除率分别为 76%、 40 %、 71 %。反应进行1 0 6h,FCN1对蒽、菲、芘所产生的总有机碳 (TOC)的     

POTENCY OF SWEETNESS OF ASPARTAME, D-TRYPTOPHAN AND THAUMATIN EVALUATED BY SINGLE VALUE AND TIME-INTENSITY MEASUREMENTS

Perceived sweetness of sucrose, aspartame, D-tryptophan and thaumatin in a sour, citric acid background was analyzed in terms of the potency of these compounds relative to sucrose-water combinations. Potencies of the sweeteners were determined from (1) maximum intensity using single value and time-intensity (T-I) measurements and (2) average intensity calculated as the ratio of area under the T-I curve and total perceived time. Stevens' law was applied to sweet responses, either in static or dynamic conditions. It was found that the exponent of the concentration-response function reflected the relative capacity of a compound to sweeten a given food and stressed differences of potency among sweeteners. Aspartame, D-tryptophan and thaumatin exhibited a decrease in sweetness potency relative to sucrose as sweetness increased from 10 to 100% of the full scale of response. Across the entire sweetness range, thaumatin showed the greatest potency but its long persistence time led to differentiate this intense sweetener from the other sweeteners evaluated.     

CHLOROPHYLL-SENSITIZED REDUCTION OF PLASTOQUINONE BY ASCORBIC ACID AND QUENCHING OF CHLOROPHYLL-FLUORESCENCE BY PLASTOQUINONE

1. Photochemical reduction of plastoquinone by ascorbic acid inethanol was sensitized with some derivatives of chlorophyll.The order of effectiveness was as follows: allomerized chlorophylla > chlorophyllin a > chlorophyll a > chlorophyll b> pheophytin a.
2. Quenching of the fluorescence of chlorophylla by plastoquinonewas observed. The quenching constant calculatedwas 71 litreper mole.

¹Contribution No. 159 from the Department of Biology, Facultyof Science, Kyushu University. Supported in part by a grant-in-aidfor Fundamental Scientific Research from the Ministry of Education. ²Present address: Biological Laboratory, General Education Department,Kyushu University, Ropponmatsu, Fukuoka. ³Present address: Biological Institute, Daiichi College of PharmaceuticalSciences, Tamagawa-machi, Takamiya, Fukuoka.     

hTERT基因片段的克隆、表达和抗hTERT抗体用于端粒酶及hTERT检测的研究

端粒酶是一种重要的肿瘤生物学标志,其活性在生殖细胞、绝大多数肿瘤细胞和体外培养的永生细胞可以测知,但在大多数体细胞中不易测出。人端粒酶由两部分组成,包括hTERC和hTERT,hTERC在正常细胞和肿瘤细胞中均有表达,而hTERT的表达似乎受到严格的调控且和端粒酶活性一致。为了检测肿瘤细胞中端粒酶及hTERT的表达,我们制备了抗hTERT蛋白的特异性多克隆抗体。首先用RT-PCR方法克隆了hTERTcDNA的一个片段,将其连接到GST融合表达载体pGEX-5X-3后在大肠杆菌中融合表达。将纯化的融合蛋白抗原免疫动物,制备抗hTERT蛋白的多克隆抗体。不同的细胞抽提物用该抗体进行了Westernblot分析,结果表明该抗体可特异识别端粒酶阳性细胞株中的hTERT及端粒酶,为端粒酶及hTERT的检测初步提供了一个简单有效的检测手段。     

牧效黄杆菌对蒽菲芘的降解性能研究

采用定时、定量、逐步提高驯化所用碳源物浓度的方法,以萘为唯一碳源驯化长期被焦化废水污染的泥土浸出液,7周后,平板划线分离出两株黄杆菌FCN1及FCN2。并对这两株菌降解多环芳烃的特性及无机离子对反应的刺激作用进行了研究。结果表明,FCN1及FCN2能降解转化蒽、菲、芘。加入FCN1,反应10h后,蒽、菲、芘去除率分别为84％、69％、80％,而加入FCN2,各物质的去除率分别为76％、40％、71％。反应进行106h,FCN1对蒽、菲、芘所产生的总有机碳（TOC）的去除率分别为70％、54％、69％,而FCN2对相应物的TOC去除率分别为63％、50％、46％。Fe^3 、Mg^2 的加入对FCN1降解多环芳烃有促进作用。     

MORPHOLOGY AND HISTOLOGY OF TUMOR TYPES INDUCED BY X,GAMMA, AND BETA IRRADIATION OF A TOBACCO HYBRID

Hagen , George L. (The Institute for Cancer Research, Philadelphia, Pa.), James E. Gunckel , and Arnold H. Sparrow . Morphology and histology of tumor types induced by X, gamma and beta irradiation of a tobacco hybrid. Amer. Jour. Bot. 48(8): 691–699. Illus. 1961.—Radiation-induced tumors of an interspecific hybrid, Nicotiana glauca × N. langsdorffii, were of 6 morphological types: white-smooth; green-smooth; green-tomentose; purple-pigmented; green-leafy and stalked, although all intergrades could be found in 1 tumor mass. The morphological responses were essentially the same after treatment with acute X rays, chronic gamma or beta rays. Gamma rays were from an external cobalt-60 source and beta rays from internally deposited P³². The histology of the 6 morphological tumor types was not distinctive in terms of meristem, vascular and surface development, but rather followed an ontogenetic series from non-organoid to organoid. The results are discussed in terms of abnormal genome and physiological imbalances, and are compared to similar responses from infection with crown gall and wound-tumor virus.     

PRODUCTION OF VITAMIN B12, THIAMINE,AND BIOTIN BY PHYTOPLANKTON1

Some ecologically important phytoplankters released vitamins into culture medium during growth. Skeletonema costatum and Stephanopyxis turris (vitamin B₁₂-requirers) produced both thiamine (vitamin B₁) and biotin when growing with either 12 or 2 ng vitamin B₁₂/liter. Gonyaulax polyedra (vitamin B₁₂-requirer) produced thiamine with 12 ng vitamin B₁₂/liter, and Coccolithus huxleyi (thiamine-requirer) produced vitamin B₁₂ and biotin with 120 ng thiamine/liter, but only biotin with 10 ng thiamine/liter. The amount of vitamin produced by an alga and rate at which it was produced varied with the phytoplankter, the concentration of the required vitamin, and incubation time. Vitamins produced during early and exponential growth were due to excretions, and those produced at stationary growth resulted from excretion and release due to cell lysis. Uptake of the required vitamin by all phytoplankters was greatest during the first few days of incubation. On continued incubation the rate of uptake/cell decreased. In the sea phytoplankters may contribute a major portion of the amount of dissolved vitamins.     

THE BIOTRANSFORMATION,BIODEGRADATION, AND BIOREMEDIATION OF ORGANIC COMPOUNDS BY MICROALGAE1

Rapid growth in the biotechnological industry and production has put tremendous pressure on the biological methods that may be used according to the guidelines of green chemistry. However, despite continuing dramatic increases in published research on organic biotransformation by microorganisms, more research exists with microalgae. Our efforts in transforming chemicals such as organic compounds for the production of functionalized products help to lessen the environmental effects of organic synthesis. These biotransformations convert organic contaminants to obtain carbon or energy for growth or as cosubstrates. This review aims to focus on the potential of microalgae in transformation, conversion, remediation, accumulation, degradation, and synthesis of various organic compounds. However, these technologies have the ability to provide the most efficient and environmentally safe approach for inexpensive biotransforming of a variety of organic contaminants, which are most industrial residues. In addition, the recent advances in microalgal bioactivity were discussed.     

THE DEPRESSION OF PHAGOCYTOSIS BY EXOGENOUS CYCLIC NUCLEOTIDES, PROSTAGLANDINS, AND THEOPHYLLINE

The effects of agents that elevate intracellular cyclic adenosine 3',5'-monophosphate (cAMP) have been studied with respect to phagocytosis by guinea pig polymorphonuclear leukocytes. The investigation depends upon the use of a precise method for following ingestion. Theophylline, dibutyryl cAMP, and prostaglandins inhibited the phagocytosis of starch particles. The inhibitions caused by prostaglandins E₁, E₂, and F_2α (PGE₁, PGE₂, and PGF_2α) were synergistic with that due to theophylline. Inhibition by PGA₁ and PGA₂ was not. At equal concentrations the order of increasing inhibition of phagocytosis (assayed at 10 min) by the prostaglandins was PGE₁ < PGF_2α < PGE₂ < PGA₁ = PGA₂. Our results are consistent with the hypothesis that increased intracellular levels of cAMP impair the phagocyte's ability to ingest particles. The mechanism of the inhibition has not been defined. The increment in oxidation of [1-¹⁴C]glucose to ¹⁴CO₂ that normally accompanies phagocytosis was found to be depressed in the presence of PGE₁ or theophylline, together or individually as expected from the inhibition of phagocytosis. Paradoxically, oxygen consumption although depressed by theophylline or PGE₁ plus theophylline, was stimulated by PGE₁ alone.     

生长素、细胞分裂素和三十烷醇对米兰空中压条生根的影响

采用滤纸法经对比试验及正交设计试验研究了混合生长素(萘乙酸和吲哚丁酸等量混合物)单用或与苄基腺嘌呤及三十烷醇相配合,对小叶米兰(Aglaia odorata Lour. var. microphyllina DC.,)空中压条生根的影响。发现三类生长物质适当配合或仅用混合生长素,都能大大改善米兰空中压条生根的质量,对加速繁殖有肯定作用。三因素最佳配合每枝压条的用量是:混合生长素3.0,苄基腺嘌呤0.075,三十烷醇10~(-4)毫克。在生产上每枝压条单用混合生长素1.5—3.0毫克亦可获得增加生根数目与根总长度以及提早生根的效果。 讨论了生长物质作用的可能原因,滤纸法及正交设计用于农业生物学试验的优点。