The effect of protein-energy malnutrition on appositional bone growth in the rat.

During protein-energy malnutrition appositional bone growth in the seventh caudal vertebra of the rat slows and finally ceases. During rehabilitation appositional growth begins agains and attains a rate in excess of that of the controls. This may account for alterations in skeletal proportions resulting from malnutrition.     

Cytokinin ocntents and cAMP metabolism during growth of Escherchia coli.

During Escherichia coli growth, we found an inverse correlation between free cytokinin content and cAMP level. The rates of synthesis of adenylate-cyclase and cAMP-phosphodiesterase were practically constant.     

Mutants of Bacillus thuringiensis with altered sporulation: morphologic responses to several treatments applied in the exponential phase]

During log-phase of growth, wild strain and and oxytetracycline-resistant mutants with altered sporulation exhibit distinct responses to some treatments, autolysis, osmotic pressure, ultraviolet irradiation and bacteriophage infection.     

Growth metabolism of diaphragm in Swiss albino mice

During the postnatal growth of diaphragm in swiss albino mice, a continuous decline in glycogen content reciprocates with the increasing SDH-activity and protein accumulation. An inverse relationship between DNA-contents and the basic protein levels points towards the regulatory behaviour of the latter during protein synthesis. While the variations in the contents of DNA and RNA speak of a feedback mechanism operative between the 2 nucleic acids during the postnatal growth, the fluctuations in RNA appear to be significant in determining the amount of acidic proteins, in this muscle.     

Growth metabolism of diaphragm in Swiss albino mice

Summary During the postnatal growth of diaphragm in swiss albino mice, a continuous decline in glycogen content reciprocates with the increasing SDH-activity and protein accumulation. An inverse relationship between DNA-contents and the basic protein levels points towards the regulatory behaviour of the latter during protein synthesis. While the variations in the contents of DNA and RNA speak of a feedback mechanism operative between the 2 nucleic acids during the postnatal growth, the fluctuations in RNA appear to be significant in determining the amount of acidic proteins, in this muscle.     

Sur l'apogéotropisme du Phycomyces

Summary Under definite conditions of culture, growth of sporangiophore of Phycomyces has been investigated by Shadowgraphic method. During sporange formation, the rate of growth is the smallest (Fig. 1). The apogeotropic sensitivity of sporangiophores is the greatest before sporange formation; presentation and reaction times increase with age and strongly with light pre-treatment (Fig. 2, 3). Auxin could be responsible for apogeotropic reactions of Phycomyces.     

The generation of new ‘white’ muscle fibers by budding in the lateral musculature of elversAnguilla anguilla (L.) during normal development

Summary The elver is a developmental stage of the European eel Anguilla anguilla (L.). During its growth, relatively large numbers of new muscle fibers are formed in the lateral musculature. We investigated the origin of these fibers. They proved to originate from already existing fibers by budding.     

Incorporation of 32P into renal phospholipids of mice during postnatal growth

During the first 40 days of life the rate of incorporation of 32P into total phospholipids and into phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, diphosphatidylglycerol, phosphatidic acid and phosphatidylinositol of mouse kidney was by some 25-35% higher than in older animals. Results suggest a different involvement of cellular membranes during of normal and compensatory renal growth.     

Monoamine oxidase activity in rat erythrocytes: Evidence for its localization in reticulocyte mitochondria

Summary During growth of young rats, monoamine oxidase activity in erythrocyte membrane preparations decreases more rapidly than reticulocyte concentrations in the respective blood samples. Since reticulocytes lose their mitochondria prior to the substantia reticulo-filamentosa, the non-linear correlation between monoamine oxidase activity and reticulocyte counts indicates that erythrocyte monoamine oxidase is located in reticulocyte mitochondria.This work was supported by a grant from the Deutsche Forschungsgemeinschaft.     

Physical growth and brain development of captive-bred male and female squirrel monkeys, Saimiri sciureus.

The physical growth and brain development of the captive bred male and female squirrel monkeys have shown that the male grows at a significantly faster rate with respect to these parameters in the postnatal life, starting from preweaning stage as compared to the female infant. During the prenatal life the male and the female fetuses grow at similar rates and show comparable brain development as indicated by its weight.     

Incorporation of32P into renal phospholipids of mice during postnatal growth

Summary During the first 40 days of life the rate of incorporation of³²P into total phospholipids and into phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, diphosphatidylglycerol, phosphatidic acid and phosphatidylinositol of mouse kidney was by some 25–35% higher than in older animals. Results suggest a different involvement of cellular membranes during of normal and compensatory renal growth.     

Proteinases in cutaneous wound healing

Cutaneous wound healing is a complex and highly coordinated process where a number of different cell types participate to renew the damaged tissue under the strict regulation of soluble and insoluble factors. One of the most versatile processes involved in wound repair is proteolysis. During cell migration, proteins of extracellular matrix are cleaved, often creating biologically active cleavage products, and proteolysis of cellular contacts leads to increased cell motility and division. Moreover, proteases activate various growth factors and other proteases in wound and regulate growth factor signaling by shedding growth factor receptors on cell surface. Normally, proteolysis is strictly controlled, and changes in protease activity are associated with alterations in wound closure and scar formation. Here, we present the current view on the role of metalloproteinases and the plasmin-plasminogen system in normal and aberrant cutaneous wound repair and discuss their role as potential therapeutic targets for chronic ulcers or fibrotic scars. Received 07 July 2008; received after revision 11 August 2008; accepted 13 August 2008     

Plasma growth hormone in the rabbit fetus. Relation to maturation of the liver and lung]

Day 25 after insemination is a date of peculiar importance in the maturation of several organs in the Rabbit fetus. From day 25 onward the fetal liver stores increasing amounts of glycogen and the lung stores increasing amounts of lecithins, concomitant with sudden rise in the activity of lung phosphatidic-acid phosphohydrolase. Earlier studies on decapitated fetuses established that glycogen storage in the liver is dependent on a dual hormonal control, comprising a pituitary hormone like growth hormone or prolactin (some placental hormones share the same activity) and corticosteroids (Jost, 1961). Since the variations in endogenous corticosteroids do not seem to herald these liver or lung changes (Mulay et al., 1973), a study was made of growth hormone. Plasma immunoreactive growth hormone--determined with a heterologous Rat system (Kervran et al., 1976)--increases eightfold between days 23 and 25. During the same time plasma prolactin does not change according to McNeily and Friesen, 1978, and to unpublished data obtained with Dr McNeilly. In preliminary assays, Rat growth hormone was seen to increase phosphorylase "a" activity in the lung of 18.5 day-old Rat fetuses, thus anticipating normal development. We suggest that growth hormone plays a role in initiating liver and lung maturation.     

Correlation between ovarian growth,vitellogenin titer,and yolk polypeptide pattern in the haemolymph ofCalliphora vicina

Summary During the first egg maturation cycle ofCalliphora vicina changes in the vitellogenin titer and yolk polypeptide pattern of the haemolymph are correlated with the intensity of follicular growth, and the rate of yolk deposition.Acknowledgments. Support from The Danish Natural Science Research Council (grant: 11-0423) and access to facilities at the laboratory of Dr Bente L. Hansen (Institute of Medical Microbiology) is gratefully acknowledged.     

无机功能晶体材料的结晶过程研究

功能晶体材料作为光、声、电等转换的重要介质,已经被广泛应用于能源、信息、航空航天等高新技术领域,是目前国际材料科学与工程学科发展的热点和前沿课题.结晶过程是制备功能材料的核心环节,结晶习性直接影响材料的光、电、磁、催化等功能特性.在无机材料的结晶过程中,晶体组成在微观上经历了从自由态离子到结晶态固体的相变过程.可以借助晶体组成离子的电负性及基团微观对称性的变化,研究结晶过程中聚集体的形成和结构演变规律.利用分子振动光谱能够从分子尺度上揭示非线性光学晶体材料在水溶液结晶过程中结晶学结构的形成过程,克服了传统原位观测手段中缺乏对非长程有序结构的确定.利用结晶生长的化学键合理论从热力学和动力学两个方面指导大块晶体的生长实践,合理调控晶体的生长表/界面热力学和动力学.将结晶生长的化学键合理论应用到大尺寸晶体提拉生长参数的设计和优化,成功搭建了大尺寸晶体智能生长系统,并成功生长了φ2″蓝宝石晶体、φ3″YAG晶体和φ4″铌酸锂晶体.     

Half-life of dehydroepiandrosterone sulfate (DHAS) during pregnancy]

During pregnancy the half-life of DHAS was measured after non tritiated DHAS infusion. At 30 weeks, the mean value obtained for DHAS half-life was 3.64 h +/- 0.74 and it was 3.67h +/- 0.38 at 38 weeks. The half-life of DHAS is shorter in pregnant than in non-pregnant women. Among 14 pathological pregnancies that we studied, 13 cases exhibited a DHAS half-life significantly longer than the average value obtained in normal pregnancies. In retarded fetal growth, the half-life of DHAS was more closely related to fetal than to placental weight.     

Physical growth and brain development of captive-bred male and female squirrel monkeys,Saimiri sciureus

Summary The physical growth and brain development of the captive bred male and female squirrel monkeys have shown that the male grows at a significantly faster rate with respect to these parameters in the postnatal life, starting from preweaning stage as compared to the female infant. During the prenatal life the male and the female fetuses grow at similar rates and show comparable brain development as indicated by its weight.Acknowledgments. This work was supported by USPHS Grants RR-00165 and HD-06087 from National Institutes of Health. The technical assistance of Mrs Judie Wells is greatly appreciated.     

Syndecan family of cell surface proteoglycans: Developmentally regulated receptors for extracellular effector molecules

Syndecans are a family of integral membrane proteoglycans with conserved membrane-spanning and intracellular domains but with structurally distinct extracellular domains (ectodomains). They are known to function as heparan sulphate co-receptors in fibroblast growth factor signalling as well as to link cells directly to the extracellular matrix. These and other biological activities of syndecans involve specific interactions of the heparan sulphate side chains of syndecans with cytokines and extracellular matrix proteins. Four different vertebrate syndecans, designated as syndecans 1–4 (or syndecan, fibroglycan, N-syndecan and amphiglycan, respectively), are known. During embryonic development, syndecans have specific and highly regulated expression patterns that are distinct from the expression in adult tissue, suggesting an active role in morphogenetic processes. The developmental expression of syndecans is particularly intense in mesenchymal condensates and at epithelium mesenchyme interfaces, where a number of heparan sulphate-binding cytokines and matrix components are also expressed in a regulated manner, ofter spatially and temporally co-ordinated with the syndecan expression. Recent evidence indicates that the regulation of heparan sulphate fine structure (mainly the number and arrangement of sulphate groups along the polymer) provides a mechanism for the cellular control of syndecan-protein interactions. Furthermore, morphogenetically active cytokines such as fibroblast growth factor-2 and transforming growth factor-β participate in the regulation of syndecan expression and glycosaminoglycan structure. This review discusses the developmental expression and binding functions of syndecans as well as the molecular regulation of specific heparan sulphate-protein interactions.     

Integrin and microtubule crosstalk in the regulation of cellular processes

Integrins engage components of the extracellular matrix, and in collaboration with other receptors, regulate signaling cascades that impact cell behavior in part by modulating the cell’s cytoskeleton. Integrins have long been known to function together with the actin cytoskeleton to promote cell adhesion, migration, and invasion, and with the intermediate filament cytoskeleton to mediate the strong adhesion needed for the maintenance and integrity of epithelial tissues. Recent studies have shed light on the crosstalk between integrin and the microtubule cytoskeleton. Integrins promote microtubule nucleation, growth, and stabilization at the cell cortex, whereas microtubules regulate integrin activity and remodeling of adhesion sites. Integrin-dependent stabilization of microtubules at the cell cortex is critical to the establishment of apical–basal polarity required for the formation of epithelial tissues. During cell migration, integrin-dependent microtubule stabilization contributes to front–rear polarity, whereas microtubules promote the turnover of integrin-mediated adhesions. This review focuses on this interdependent relationship and its impact on cell behavior and function.     

How plants recognize pathogens and defend themselves

Plants have an innate immunity system to defend themselves against pathogens. With the primary immune system, plants recognize microbe-associated molecular patterns (MAMPs) of potential pathogens through pattern recognition receptors (PRRs) that mediate a basal defense response. Plant pathogens suppress this basal defense response by means of effectors that enable them to cause disease. With the secondary immune system, plants have gained the ability to recognize effector-induced perturbations of host targets through resistance proteins (RPs) that mediate a strong local defense response that stops pathogen growth. Both primary and secondary immune responses in plants depend on germ line-encoded PRRs and RPs. During induction of local immune responses, systemic immune responses also become activated, which predispose plants to become more resistant to subsequent pathogen attacks. This review gives an update on recent findings that have enhanced our understanding of plant innate immunity and the arms race between plants and their pathogens. Received 24 June 2007; received after revision 18 July 2007; accepted 15 August 2007