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Lipid-binding proteins function to transport lipids across membranes and aqueous phases and act to solubilise their cargo, protect it from chemical damage and probably also to define its destination. As such, they have been adapted to carry out a broad spectrum of biological functions in addition to their classical roles in energy metabolism and the transmission or blocking of retinoid-based signalling. The set of reviews in this issue of CMLS is designed to draw attention to some newly understood aspects and principles of their biology and structure, and concentrates on the proteins involved in transport of fatty acids and retinoids.  相似文献   

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The purpose of this study is to examine the monthly volume series of the New York Stock Exchange (NYSE) during the January 1965-December 1987 period. The NYSE volume series follows a random walk with drift process; however, the events of October 1987 give rise to the application of outlier analysis.  相似文献   

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Like eukaryotes, bacteria possess complex developmental programs that drive environmental adaptation and morphological differentiation. In some species, these morphological changes are quite elaborate and result in major changes in cell appearance, including the formation of ornate appendages. The ease with which some bacteria can be manipulated makes them highly attractive model systems for developmental analysis. In this set of reviews, we tackle the best studied of these systems, spore formation in Bacillus subtilis. Construction of a spore initiates in response to starvation, takes each cell about 8 h and is directed by a tightly controlled genetic program. First, the cell creates an internal protoplast with its own copy of the chromosome. Over the next several hours, development continues as proteins synthesized within the protoplast as well as in the surrounding cell cytoplasm coalesce into the various complex structures that comprise the spore. The resulting cell is metabolically dormant and as close to indestructible as any cell found on earth. Nonetheless, the spore retains the ability to revive almost immediately when nutrient returns to the environment. Here, we review the genetic control of spore formation, the structure and assembly of several major spore components, the process of germination, and the environmental and disease implications of spores. As these reviews document, spore formation in B. subtilis has been among the most productive systems for understanding both the broad themes and the molecular basis of development. Not only does this system continue to add to our understanding of these questions, but it provides a particularly powerful means to address the cell biological dimension of development.  相似文献   

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Zusammenfassung Chromosomenanalyse von 3 asiatischen Säugetieren:Meriones meridianus (2n=50),Ochotona rufescens (2n=60) undSpermiophilopsis lepto-dactylus (2n=38), Deren 2n's und Karyotypen wurden mit verwandten Formen ninsichtlich der Geschlechter und Gattungen verglichen und zur Klassifizierung diskutiert.  相似文献   

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Microautophagy: lesser-known self-eating   总被引:1,自引:1,他引:0  
Microautophagy, the non-selective lysosomal degradative process, involves direct engulfment of cytoplasmic cargo at a boundary membrane by autophagic tubes, which mediate both invagination and vesicle scission into the lumen. With its constitutive characteristics, microautophagy of soluble substrates can be induced by nitrogen starvation or rapamycin via regulatory signaling complex pathways. The maintenance of organellar size, membrane homeostasis, and cell survival under nitrogen restriction are the main functions of microautophagy. In addition, microautophagy is coordinated with and complements macroautophagy, chaperone-mediated autophagy, and other self-eating pathways. Three forms of selective microautophagy, including micropexophagy, piecemeal microautophagy of the nucleus, and micromitophagy, share common ground with microautophagy to some degree. As the accumulation of experimental data, the precise mechanisms that govern microautophagy are becoming more appreciated. Here, we review the microautophagic molecular machinery, its physiological functions, and relevance to human diseases, especially in diseases involving multivesicular bodies and multivesicular lysosomes.  相似文献   

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Selenium: an insulin-mimetic   总被引:17,自引:0,他引:17  
Insulin or agents that can mimic its action (insulin-mimetics) are necessary to promote the entry of glucose into tissues where the glucose can either be converted into energy or stored for later use. In recent years, selenium has been shown to mediate a number of insulin-like actions both in vivo and in vitro. These insulin-like actions include stimulating glucose uptake and regulating metabolic processes such as glycolysis, gluconeogenesis, fatty acid synthesis and the pentose phosphate pathway. The mechanism by which selenium is capable of mimicking insulin is not clear; however, reports indicate that selenium does activate key proteins involved in the insulin-signal cascade. Various proteins in the insulin-signal cascade have been shown to be necessary for different insulin-regulated events, and presumably data will be forthcoming soon that illustrate this similarly for selenium. This review compares the action of selenium to that of insulin and discusses the available evidence in support of selenium as an insulin-mimetic.  相似文献   

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Riassunto Si è studiato sperimientalmente la tossicologia acuta e subacuta dell'adriamicina, un nuovo antibiotico antitumorale con struttura simile a quella della daunomicina, rilevandone l'attività depressiva sulla riproduzione cellulare.  相似文献   

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Histamine: entering physiology   总被引:4,自引:0,他引:4  
G Kahlson  E Rosengren 《Experientia》1972,28(9):993-1002
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Résumé L'acide cétonique deSamuel etManasse obtenu par la transformation du quinone camphorique a été déjà réduit par l'auteur avec formation d'un acide saturé, C10H18O2, dont la constitution est maintenant prouvé par sa synthèse. L'auteur a trouvé aussi que l'éther méthylique de l'acide 2-méthylcyclopentan-1-ol-1-carboxylique fournit par transformation pinacolique un mélange de 2:2:3-triméthyl- et 2:2:6-triméthylcyclohexanones.  相似文献   

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Adriamycin: toxicity data   总被引:1,自引:0,他引:1  
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It is argued that Hugo de Vries's conversion to Mendelism did not agree with his previous theoretical framework. De Vries regarded the number of offspring expressing a certain character as a hereditary quality, intrinsic to the state of the pangene involved. His was a shortlived conversion since after the ‘rediscovery’ he failed to unify his older views with Mendelism. De Vries was never very much of a Mendelian. The usual stories of the Dutch ‘rediscovery’ need, therefore, a considerable reshaping.  相似文献   

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Aspirin exerts anti-thrombotic action by acetylating and inactivating cyclooxygenase-1, preventing the production of thromboxane A 2 in platelets. Through this inhibition of platelet function, aspirin is considered as a preventative of ischemic diseases such as coronary and cerebral infarction. However, many studies have revealed that aspirin has other beneficial actions in addition to its anti-platelet activity. For example, aspirin may confer some benefit against colorectal cancer. Here, we discuss the involvement of inflammation in atherosclerosis and how aspirin exerts its beneficial actions in atherosclerotic diseases and cancer. Received 30 September 2007; received after revision 31 October 2007; accepted 6 November 2007  相似文献   

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Zusammenfassung Die hier geschilderte Periode der Histaminforschung ist durch die Erkenntnis gekennzeichnet, dass grosse Veränderungen in der Geschwindigkeit der Histaminbildung unter physiologischen Verhältnissen vorkommen. In der Magenmucosa bedingen Gastrin und Nahrungszufuhr eine Mobilisierung von Histamin und eine Erhöhung der Aktivität der Histidindecarboxylase. Bei verschiedenen Formen von normalem und malignem Wachstum wird in den Geweben «Nascent-Histamin» gebildet, dessen Wirkung exogenes Histamin nicht ausüben kann und auch nicht mit Antihistaminen antagonisiert wird65.  相似文献   

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Laminin, one of the most widely expressed extracellular matrix proteins, exerts many important functions in multiple organs/systems and at various developmental stages. Although its critical roles in embryonic development have been demonstrated, laminin’s functions at later stages remain largely unknown, mainly due to its intrinsic complexity and lack of research tools (most laminin mutants are embryonic lethal). With the advance of genetic and molecular techniques, many new laminin mutants have been generated recently. These new mutants usually have a longer lifespan and show previously unidentified phenotypes. Not only do these studies suggest novel functions of laminin, but also they provide invaluable animal models that allow investigation of laminin’s functions at late stages. Here, I first briefly introduce the nomenclature, structure, and biochemistry of laminin in general. Next, all the loss-of-function mutants/models for each laminin chain are discussed and their phenotypes compared. I hope to provide a comprehensive review on laminin functions and its loss-of-function models, which could serve as a reference for future research in this understudied field.  相似文献   

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