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 During the same time plasma prolactin does not change according to McNeily and Friesen, 1978, and to unpublished data obtained with Dr McNeilly.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.     

Chemical investigation of hassium (element 108)

The periodic table provides a classification of the chemical properties of the elements. But for the heaviest elements, the transactinides, this role of the periodic table reaches its limits because increasingly strong relativistic effects on the valence electron shells can induce deviations from known trends in chemical properties. In the case of the first two transactinides, elements 104 and 105, relativistic effects do indeed influence their chemical properties, whereas elements 106 and 107 both behave as expected from their position within the periodic table. Here we report the chemical separation and characterization of only seven detected atoms of element 108 (hassium, Hs), which were generated as isotopes (269)Hs (refs 8, 9) and (270)Hs (ref. 10) in the fusion reaction between (26)Mg and (248)Cm. The hassium atoms are immediately oxidized to a highly volatile oxide, presumably HsO(4), for which we determine an enthalpy of adsorption on our detector surface that is comparable to the adsorption enthalpy determined under identical conditions for the osmium oxide OsO(4). These results provide evidence that the chemical properties of hassium and its lighter homologue osmium are similar, thus confirming that hassium exhibits properties as expected from its position in group 8 of the periodic table.     

组织生物学和病理学功能超微结构图谱

图谱当然以图为主，图的选择要精良，不但要显示出正常组织和病理改变的特征，而且最好还能提示这种改变的发生机制。此外，若尚有“余地”的话，除了显示常见的典型结构（无论正常的或是病理的）之外，最好同时展现一点“罕见”的变异之处。若能做到上述要求，则这种图谱是一种“活图谱”而非“死图谱”了。     

The nuclear content of DNA in three different strains ofArtemia salina leach (Phyllopoda,Branchiopodidae)

Zusammenfassung DNS-Messungen an Interphasekernen vonArtemia salina parthenogenetica 2n undArtemia salina anfigonica zeigen ein Mengenverhältnis von 1.21, während zwischenArtemia salina parthenogenetica 4n undArtemia salina anfigonica DNS Werte im Verhältnis 21 gefunden wurden.     

Deterministic quantum teleportation of atomic qubits

Quantum teleportation provides a means to transport quantum information efficiently from one location to another, without the physical transfer of the associated quantum-information carrier. This is achieved by using the non-local correlations of previously distributed, entangled quantum bits (qubits). Teleportation is expected to play an integral role in quantum communication and quantum computation. Previous experimental demonstrations have been implemented with optical systems that used both discrete and continuous variables, and with liquid-state nuclear magnetic resonance. Here we report unconditional teleportation of massive particle qubits using atomic (9Be+) ions confined in a segmented ion trap, which aids individual qubit addressing. We achieve an average fidelity of 78 per cent, which exceeds the fidelity of any protocol that does not use entanglement. This demonstration is also important because it incorporates most of the techniques necessary for scalable quantum information processing in an ion-trap system.     

Role of plasminogen activator-plasmin system in tumor angiogenesis

New blood formation or angiogenesis has become a key target in therapeutic strategies aimed at inhibiting tumor growth and other diseases associated with neovascularization. Angiogenesis is associated with important extracellular remodeling involving different proteolytic systems among which the plasminogen system plays an essential role. It belongs to the large serine proteinase family and can act directly or indirectly by activating matrix metalloproteinases or by liberating growth factors and cytokines sequestered within the extracellular matrix. Migration of endothelial cells is associated with significant upregulation of proteolysis and, conversely, immunoneutralization or chemical inhibition of the system reduces angiogenesis in vitro. On the other hand, genetically altered mice developed normally without overt vascular anomalies indicating the possibility of compensation by other proteases in vivo. Nevertheless, they have in some experimental settings revealed unanticipated roles for previously characterized proteinases or their inhibitors. In this review, the complex mechanisms of action of the serine proteases in pathological angiogenesis are summarized alongside possible therapeutic applications.     

A camelid antibody fragment inhibits the formation of amyloid fibrils by human lysozyme

Amyloid diseases are characterized by an aberrant assembly of a specific protein or protein fragment into fibrils and plaques that are deposited in various organs and tissues, often with serious pathological consequences. Non-neuropathic systemic amyloidosis is associated with single point mutations in the gene coding for human lysozyme. Here we report that a single-domain fragment of a camelid antibody raised against wild-type human lysozyme inhibits the in vitro aggregation of its amyloidogenic variant, D67H. Our structural studies reveal that the epitope includes neither the site of mutation nor most residues in the region of the protein structure that is destabilized by the mutation. Instead, the binding of the antibody fragment achieves its effect by restoring the structural cooperativity characteristic of the wild-type protein. This appears to occur at least in part through the transmission of long-range conformational effects to the interface between the two structural domains of the protein. Thus, reducing the ability of an amyloidogenic protein to form partly unfolded species can be an effective method of preventing its aggregation, suggesting approaches to the rational design of therapeutic agents directed against protein deposition diseases.     

网络 从生物学到理论

后基因组时代的生命科学研究已经不单单只是研究单个基因、蛋白质或细胞的功能，而是更加注重从整体上研究生物体内各个成分问的相互关系和作用机制。因此，如何构建基因、蛋白质及神经细胞间相互作用网络并阐明网络内各成分的动态关系是目前系统生物学研究的一个热点。