动态

第三届北京生命科学领域 联合年会在京召开 1月15日,由北京生理科学会、北京生物化学与分子生物学会、北京免疫学会、北京遗传学会、北京神经学会、北京实验动物学学会、北京环境诱变剂学会、北京微生物学会、北京生物工程学会及中华医学会北京消化分会等10个学会共同发起召开的第三届北京生命科学领域联合年会在中关村生物医药园举行。     

第四届北京生命科学领域联合年会举行

为了更好地促进生命科学领域跨学科的合作与交流,在北京市自然科学基金委员会和北京市科技协会的支持下,北京生理科学会、北京生物化学与分子生物学会、北京免疫学会、北京遗传学会、北京神经科学学会、北京实验动物学学会、北京环境诱变剂学会、北京微生物学会、北京生物工程学会、中华医学会北京消化分会、北京中关村生物工程和新医药企业协会等机构于2006年2月25日在首都医科大学召开第四届北京生命科学领域联合年会(北京·2006)。会议主题是“生命科学与人类健康”。自2003年以来,北京生命科学领域联合年会已成功举办了三届。会议围绕国…     

与自然的“较量”

在不同的自然环境中运动,身体会出现不同的反应。如果自然环境适于运动,那么心情会舒畅,运动效果也好。对运动员来讲也是这样,如果自然环境糟糕,将会影响比赛成绩。2008年8月北京奥运会如期举行的时候,北京的天气会是怎么样？如果下雨或有其他异常天气出现,对运动员又有哪些影响呢？     

北京·2002-2003·生命科学国际研讨会

生命科学是 2 1世纪的朝阳学科 ,北京作为我国生命科学研究最活跃和最重要的地区 ,近年来在各个分支领域开展着丰富而有建设性的工作。各类生命科学、医学及生物工程类的专业学会成为各领域优秀科学家碰撞科学灵感的一个交流平台。而当今生命科学发展的重要趋势之一就是不同学科、不同领域的科学家坐在一起 ,互相从新的视角和不同学科中汲取新的营养 ,互相交流 ,互相融合。因此 ,北京生物工程学会、北京生物化学与分子生物学会、北京神经科学学会、北京免疫学会、北京实验动物学会等共同召开“北京· 2 0 0 2 - 2 0 0 3·生命科学国际研讨会…     

北京九代医药研究所简介

北京九代医药研究所是在中国科协、中国科技发展基金会、中国微生物学会、中国免疫学会的大力支持下成立并发展起来的。该所人员脱％以上具有医学本科或专科学历,其中硕士以上学位4名,所长李求是教授是新中国第一界免疫学博士。北京九代医药研究所的宗旨是从事医药科学研究、     

机体的免疫状态与细菌感染的关系

机体的免疫状态与细菌感染的关系北京３０９医院检验科北京１０００９１李洪敏,杨丽珍,匡铁吉人类机体免疫状态是处在一定相对恒定的范围,保护着人体内的微生态平衡。如果免疫状态过高,会引起过敏反应等疾病,过低的免疫状态也容易引起疾病,而以患有慢性疾病的机体免...     

中国生理学会第22届会员代表大会纪要

中国生理学会第22届全国会员代表大会于2006年11月4-6日在北京京丰宾馆顺利召开,应到代表307人,实际到会222人。     

火炬树未对北京地区的自然生态系统构成威胁

2005年10月25日北京生态学学会《新世纪北京生态论坛》在中国科学院植物研究所召开。张新时院士主持了这次研讨会,北京师范大学生命科学学院刘全儒教授、北京市林业局植物保护站陶万强高级工程师、中国科学院植物研究所蒋高明研究员和王光美博士、中国老年科学家协会植物学分会陈佐忠研究员、董保华研究员和杨宗贵副研究员分别做了题为“北京外来物种入侵的现状与对策”.     

关于召开中国遗传学会第九届全国遗传学教学会议的通知

中国遗传学会第九届全国遗传学教学研讨会筹备会于2006年1月19日在北京召开。参加会议的有北京大学生命科学院戴灼华教授,张博教授,武汉大学生命科学院丁毅教授;北京农学院刁福山教授;北京师范大学张根发教授;南开大学陈德富教授及北京大学医学部吴白燕教授。中国遗传学会副秘书安锡培主持会议。     

简讯二则

1991年北京生物教学研究会年会于1991年11月27-29日在北京大兴县召开。会上表扬了教研活动先进个人、先进集体,向获优秀论文奖的同志颁了奖,参观了留民营生态农业,听了生物乡土教材课。     

Regulation and Control of Multiple Pathways of Respiratory Metabolism in Relation to Other Physiological Functions in Higher Plants

This account presents the views of the author on the functional and regulatory aspects of respiratory metabolism in higher plants: Control of metabolism (by enzymes) and the interaction of respiration with the other physiological functions in the living plant (metabolic control). This concept, formulated in the early fifties (ref. 47), was presented in part in 1965 (ref. 2) based on experiments performed mostly by the author and his colleagues and by his co-workers in this country. After an interruption of a decade, during which his work was discontinued, a more complete formulation of his views are given here based on results reported by workers in this field in other countries during that period. The more complete view can now be 'summarized as follows: Respiratory metabolism is the process whereby a part of the material stored in the plant (organism) is converted into biological work (function) for maintaining its state of being alive, while the other part of the same material is converted into substances of higher degrees of orderliness (negative entropy) in the form of structure and organization. Within limits imposed by the genetic potential, these processes are controlled by enzymes which in turn are regulated by internal and external factors. The above statement is essentially a special expression of a general view on the functional aspects of living organisms given in the author’s earlier book, Green Thral- dom (Alien & Unwin, London, 1949). If the above theme finds acceptance, it follows, as stated earlier (ref. 14), that: 1. Respiratory metabolic pathways must be multiple ("multilineal") and multi- directional; 2. They must be interacting, not only with themselves, but also with other functions in the plant, alternatingly in time and separately in space (compartmentation); 3. There must be mutual interactions among the pathways and func- tions regulated by enzymes which in turn are regulated through external and internal factors. This functional and regulatory concept of respiratory metabolism in higher plants are now summarized by the following expressions: 1. CH2O + O2→>Xl→X2→H2O + CO2 + E ↓↓ Y1 Y2 in which E = Energy, X1, X2 etc. represent intermediate products, and Y1, Y2 etc. represent anabolic products of different composition and different degrees of complexity. 2. Borrowing from the second law of thermodynamics, the free energy △G deri- ved from process 1 is used for performance of physiological work (function) during which part of the energy is given off in the form of heat (△H), and the other part is concerned with the change of materials of lower orderliness into form and structure with a decrease in entropy (△S): △G = △H - T△S in which T is temperature (in K). This equation may or may not be directly applicable without qualifications in our case. But the decrease in entropy with the change of degree of orderliness in the process of tissue and organ formation from formless materials holds true. 3. The third expression presents the fundamental aspects of our concept of control of metabolism by enzymes and metabolic control of physiological functions. This may be given as: Fuction Gene→ Enzymes→Metabolism→ Structurc State→ Time cource (Solid arrows denote Control) .Experimental evidences selected from the numerous published experimental results, mostly from those of our own, in support of the above scheme at the substrate level oxidation in addition to those given in an earlier account (ref. 2) are presented here. Evidences based on experiments during the past decade on multiple pathways in NADH oxidation through the electron transport chain gathered in the literature (ref. 37) during the period when our work was interrupted completes the formula- tion of our concept on respiratory metabolism at both the substrate and terminal oxidation levels. The use of this generalized concept on the functional and regulatory aspects of respiratory metabolism in higher plants for guiding further research on plant respiration and on other physiological processes, as well as the application of this concept to practical physiological and biological problems are discussed.     

Enzymaktivitätsmuster und Stoffwechselwege in der frühen Embryogenese vonAcheta domesticus L.

Summary To analyse the main pathways of energy supplying metabolism, the following ratios of enzyme activities are measured in different developmental stages and in isolated embryos: GAPDH/CE, GAPDH/HOADH and HOADH/CE. The ratios show that the early stages are equally capable to metabolize carbohydrates and fat, but the enzyme activity pattern resembles more that of exclusively fat consuming insect tissues. Special features of the pattern are the very high ratio of HOADH/CE, as yet not observed in other tissues, and the ratio GAPDH/TIM of 11 differing from the enzyme group of constant proportion. Generally the enzymes of intermediary metabolism exhibit low activities.The eggs contain a considerable supply of fat and a small one (0.1% of fresh weight) of glycogen, which begins to increase during the formation of the germlayer.The respiratory quotient of 0.6–0.7 mounts to 0.8, when the Körpergrundgestalt is formed.From the properties of the enzyme activity pattern, the early beginning gluconeogenesis and the height of the respiratory quotient it follows, that during early embryogenesis the break down of fat is realized as the main pathway of energy supplying metabolism.     

Metabolism of bilirubin by a clonal strain of rat hepatoma cells

These studies demonstrate that the MH₁C₁ strain of rat hepatoma cells has the ability to take up and conjugate bilirubin and then excrete the conjugated pigment into the culture medium. On incubation with unconjugated bilirubin, the average rate of appearance of conjugated bilirubin in the medium was 4.4 ± 0.20 µg per mg of cell protein per hour (mean ± SE). The products formed from bilirubin by MH₁C₁ cells were chromatographically identical to those found in normal rat bile. Assay of bilirubin UDP glucuronyl transferase activity in homogenates of MH₁C₁ cells gave a value of 3.3 ± 0.50 µg of conjugated pigment formed per mg protein per hour, only moderately less than the enzyme activity of liver from normal rats. Rat fibroblasts in culture did not conjugate bilirubin, nor did they contain bilirubin UDP-glucuronyl transferase activity. As in living animals, flavaspidic acid inhibited bilirubin metabolism by MH₁C₁ cells, suggesting that the mechanism for bilirubin uptake is similar to that of normal liver. In contrast to the findings in animals, however, preincubation of MH₁C₁ cells with phenobarbital led to only minimal enhancement of pigment conjugation. MH₁C₁ cells represent the first example of a clonal strain of cells in culture in which many of the pathways of hepatic bilirubin metabolism remain intact. They should, therefore, serve as a useful model for studies of bile pigment metabolism which are not easily performed in the living animal.     

The history of algology, algotherapy, and the role of inhibition

Cephalalgia (1st century AD), nostalgia (1678), neuralgia (18th century), causalgia (1872) were terms followed in the 1950's by Bonica's 'algology... a disease state of its own', addressed by ever-growing numbers of pain clinics, strongly foreshadowed by Leriche's douleur maladie in the 1930's. (Hence also 'algotherapy'). Philosophers first, then early academic physiologists began to exhibit interest in pain, that all too common phenomenon, only too often unyielding to theoretical as well as practical efforts. Was it, after all, an instance of built-in self-preservation, a reflex? Identification of the nervous energy and its anatomical pathways in the 19th century, endless arguments as to their 'specificity', led to new surgical attempts to control and interpret pain, by now supported by general, then local anesthesia. Early in this century Henry Head's much-discussed notion of 'epicritic' sensation exerting some control over 'protopathic' pain was soon followed by Otfried Foerster's insistence on a central role of inhibition providing pain relief. Almost forgotten, Foerster's idea found expression in Melzack and Wall's 'gate control theory' of 1965. Gasser and Erlanger's classification of sensory nerve fibers began to dominate research in the 1930's thanks to the cathode ray oscillograph invented in 1897. The pain inhibition concept was given another boost in the seventies when the role of the midline mesencephalic and oblongata nuclei was established as both opium receptors and producers of opioids. Finally, inhibition may also be seen as the principle underlying the age-old therapeutic effect of 'counter-irritation', mostly in the form of electrical stimulation.     

Comparative Studies on the Metabolic Function of Differentiated Xylem and Living Bark of Wintering Perennials

Metabolic function of differentiated xylem cells of winteringplants was compared with that of living bark. The differentiatedxylem cells generally contained the enzyme activity of the pentosephosphatase cycle, glycolytic pathway and organelles such asNADPH-linked glyoxylate reductase and NADH-linked hydroxypyruvatereductase. They also contained a NADPH-linked glutathione reductase.Thus, it was shown that the required metabolism of the differentiatedxylem cells continued to function in wintering perennials. In contrast, 12 out of 34 samples of the living bark containedvery low levels of glucose-6-phosphate dehydrogenase activity,and another group of 8 samples exhibited low levels of dehydrogenaseactivity. The remaining 11 samples exhibited various but distinctlevels of enzyme activities. With the exception of Ginkgo biloba L., both the xylem and livingbark of wintering twigs contained almost the same levels ofATP, and both tissues exhibited enzyme activities in sucrosesyntheses. The occurrence of NADPH-linked glyoxylate reductasein xylem tissue indicated that the plastids function in thedifferentiated xylem cells throughout the year. The general occurrence of substantial levels of enzyme activityand ATP in the differentiated xylem cells indicated that thexylem tissues as well as the living bark basically support thestem function in wintering stage of perennials until the timeof the following onset of cambial differentiation. ¹ Contribution No. 2162 from the Institute of Low TemperatureScience, Hokkaido University, Sapporo, Japan. (Received August 2, 1982; Accepted September 20, 1982)     

Rearrangement of enzyme patterns in maize callus and suspension cultures

The development of enzyme patterns was followed in the course of: (a) the irreversible cell differentiation via division and expansion to maturity in the root tip and coleoptile of the intact seedlings, (b) the irreversible cell dedifferentation associated with induction and establishment of callus from the growing internodes, and (c) the growth cycle (proliferationstationary phase) in callus and cell-suspension cultures of maize (Zea mays L.). By measuring the activities of glycolytic, mitochondrial, microbody and hydrolytic enzymes cells proliferating in vivo and in vitro could be compared and changes related to cessation or resumption of cell division could be studied.Proliferating cells of callus and suspension cultures maintained by serial culture did not differ from those of the root meristem and coleoptile in the specific activities of hexokinase, phosphoglycerate kinase and phosphopyruvate hydratase. Proliferation in vitro resulted in an enormous increase in the ratio g glutamate-dehydrogenase/cytochrome-oxidase activity and in the level of acid-phosphatase activity, with concomitant drop in galactosidase and xylosidase activity. A 3-5-fold increase of alcohol-dehydrogenase, lactate-dehydrogenase and catalase activities was characteristic of dividing callus cells, while a ca. 100-fold increase in the fructofuranosidase-to-glucosidase activity ratio marked cell proliferation in suspension-cultured cells.Changing enzyme activities after cessation of proliferation were quite similar in root tips and coleoptiles, except those of alcohol dehydrogenase and catalase. The enzyme rearrangement during callus establishment and in the growth cycle of callus cultures was in most cases comparable to that in the intact tissues, while the changes from the dividing to the non-dividing cells in suspension cultures, in contrast, differed widely from those in the intact tissues and callus. Galactosidase and xylosidase were the only activities that showed a similar trend of changes in all the investigated, intact and in-vitro-grown cells.Thus, judged by the pattern of enzyme development, the cell suspension appears to be a unique system, virtually unrelated to the growing cells of the intact tissues. It is also very difficult to draw a definite distinction between the metabolic consequences of cell growth and enzyme modulations in cell suspensions as the cells adapt their metabolism to the environmental changes in liquid medium.     

Human NAD(P)H:quinone oxidoreductase inhibition by flavonoids in living cells

Procedures for assessing enzyme inhibition in living cells are an important tool in the study of the relevance of enzyme-catalyzed reactions and interactions in the human body. This paper presents the effects of flavonoids on NAD(P)H:quinone oxidoreductase 1 (NQO1) activity, by a newly developed method to measure NQO1 inhibition in intact cells. The principle of this method is based on the resorufin reductase activity of NQO1. The change in fluorescence in time was used to determine NQO1 activity in intact Chinese hamster ovary (CHO) cells genetically engineered to overexpress human NQO1. Applying this method to determine the inhibitory effects of reported in vitro NQO1 inhibitors (dicoumarol, 7,8-dihydroxyflavone, chrysin) showed that for all inhibitors tested, the IC50 in intact cells was at least 3 orders of magnitude higher than the IC50 in cell lysates. This result demonstrates that in vitro studies with purified NQO1 or with extracts from disrupted tissues are of limited value for obtaining insight into the situation in living cells. Possible factors underlying this discrepancy are being discussed. For the first time, we determined NQO1 inhibition by flavonoids in cells without disruption of the cells or addition of cofactors, enabling the assessment of enzymatic activity and the interaction of modulators of enzymatic activity in an intracellular situation.     

The problem of the skin derivatives' origin in the amniote evolution. The skin appendages--scale, feather, and hair

Overview of modern data on morphology of the skin derivatives in the higher vertebrates is given. Analysis of convergent similarities between the hair and feathers themselves as well as between their follicles makes it possible to forward a "generative" concept of the evolutionary origin of various ecto-mesodermal derivatives, such as keratinized dermal appendages (scales, feathers, hair). This concept appeared as a result of the author's studies on the skin derivatives, as well as of the data on molecular biology and the tissue engineering showing similar mechanisms of morphogenesis of the dermal appendages. Recurrently published ideas on various heterochronies in generations of the skin derivatives both in the onto- and the phylogeneses are also taken into acount. Various dermal appendages have appeared in the evolution of the higher vertebrates as independent generations of the ecto- and mesodermal tissues. Their parallel origin was caused by similar changes in the metabolism and molecular regulation of morphogenesis.     

Certain Modes of Control of Life Process Operation by Respiratory Metabolism in Plant Cells

A new concept of respiratory metabolism is proposed, which regards this process as anabolism involved in catabolism, and as the basis of self organization in living cells. In addition to furnishing material and energy for the performance of the plant as a living organism, it regulates the other physiological functions via the operation of multiple pathway. Based on the proposed concept, a bioenergetic system in he-erotrophic plant cells is described, which comprises proticity, reducing powers and water motive force, a newly coined term by the authors, generated by respiration. The feed back effects of photorespiration, or in a broad sense, photoxidatlon on photosynthesis are discussed. An analysis of regulatory effects of phytohormones on respiratory pathway is also attempted.