A tissue-selective prostaglandin E2 analog with potent antifertility effects

Summary N-methanesulfonyl 16-phenoxy--tetranor PGE₂ is a prostaglandin analog which is markedly more tissue selective than PGE₂. This compound is 10–30 times more potent than PGE₂ in animal models which are considered relevant to antifertility effects in humans. In pharmacological tests which are believed to be predictive for side effects in humans, the compound has potency either equal to or less than that of PGE₂.     

Paleotemperature changes ver the past 3000 years in eastern Beijing, China:A reconstraction based on Mg/Sr records in a stalagmite

The Mg/Sr ratio in a stalagmite, which is directly proportional to DMg/Ca, the solid-liquid distribution coefficient of Mg, is proposed as a geochemical thermometer to estimate paleotemperature changes. The paleotemperature changein eastern Beijing over the past 3000 years has been reconstructed by using this thermometer in the stalagmite ZFFS-1 from Jingdong Cave. The records can be divided into two periods: 3000-2000 aBP, cool and wet, the air temperature averaging 9.8℃; and 2000 aBP-present, hot and dry, the air temperature being 1℃ higher than the mean value (11.7℃) of the past 3000 years. During 500-200 aBP, the air temperature was about 1.2℃ lower than that of the present, corresponding to the Little Ice Age in Europe. Like δ18O and δ13C, Mg/Sr (or DMg/Ca) reflects an obviously warming trend of the past 200 years. These results are supported by historic records.     

Requirements for leukocyte transmigration via the transmembrane chemokine CX3CL1

The surface-expressed transmembrane CX3C chemokine ligand 1 (CX3CL1/fractalkine) induces firm adhesion of leukocytes expressing its receptor CX3CR1. After shedding by the disintegrins and metalloproteinases (ADAM) 10 and 17, CX3CL1 also acts as soluble leukocyte chemoattractant. Here, we demonstrate that transmembrane CX3CL1 expressed on both endothelial and epithelial cells induces leukocyte transmigration. To investigate the underlying mechanism, we generated CX3CR1 variants lacking the intracellular aspartate-arginine-tyrosine (DRY) motif or the intracellular C-terminus which led to a defect in intracellular calcium response and impaired ligand uptake, respectively. While both variants effectively mediated firm cell adhesion, they failed to induce transmigration and rather mediated retention of leukocytes on the CX3CL1-expressing cell layer. Targeting of ADAM10 led to increased adhesion but reduced transmigration in response to transmembrane CX3CL1, while transmigration towards soluble CX3CL1 was not affected. Thus, transmembrane CX3CL1 mediates leukocyte transmigration via the DRY motif and C-terminus of CX3CR1 and the activity of ADAM10.     

台湾在二氧化碳捕获及再利用中的技术研究状况

二氧化碳减量技术包括捕获、封存及再利用技术,是目前国际上亟待发展的减量技术的研究状况.阐述了近年来台湾致力于研发各项减量技术的研究状况,希望通过能源计划将针对化学吸收法、物理吸附法、超重力旋转填充床技术、化学循环程序、CO2转化技术等对台湾未来CO2减量提出一整合性技术.除了基础减量技术的研发之外,国科会通过能源计划整合产学研各界资源,共同开发CO2补获及再利用技术,并建立示范工厂,成为台湾CO2减量的重点技术平台.     

Permeation of purine derivatives into the cerebrospinal fluid of dogs

Zusammenfassung Der Übertritt verschiedener Purinderivate in den Liquor cerebrospinalis nach i.v. Injektion wurde an Hunden untersucht. Coffein permeiert sehr schnell, Theobromin und Theophyllin ungleich langsamer. Dies steht in Einklang mit der unterschiedlichen Lipoidlöslichkeit dieser Substanzen. AAT hingegen tritt nur in geringer Konzentration in den Liquor über, obwohl es die höchste Lipoidlöslichkeit aufweist.     

Pharmacological studies with some new antihypertensive aminoquinazolines

Zusammenfassung 4 neue Aminoquinazolin-Derivate, die den Blutdruck von Hunden und Katzen herabsetzen, werden beschrieben. Ihre wirksamen Dosen liegen im Bereiche von 20 bis 300µg/kg peroral. Diese Substanzen setzen den peripheren Widerstand herab und reduzieren die blutdrucksteigernde Wirkung von Adrenalin, unterscheiden sich aber von den typischen-Sympatholytika.     

LDL-receptor-related proteins in Wnt signal transduction

The Wnt family of secreted signalling molecules are essential in embryo development and tumour formation. The Frizzled (Fz) family of serpentine receptors function as Wnt receptors, but how Fz proteins transduce signalling is not understood. In Drosophila, arrow phenocopies the wingless (DWnt-1) phenotype, and encodes a transmembrane protein that is homologous to two members of the mammalian low-density lipoprotein receptor (LDLR)-related protein (LRP) family, LRP5 and LRP6 (refs 12-15). Here we report that LRP6 functions as a co-receptor for Wnt signal transduction. In Xenopus embryos, LRP6 activated Wnt-Fz signalling, and induced Wnt responsive genes, dorsal axis duplication and neural crest formation. An LRP6 mutant lacking the carboxyl intracellular domain blocked signalling by Wnt or Wnt-Fz, but not by Dishevelled or beta-catenin, and inhibited neural crest development. The extracellular domain of LRP6 bound Wnt-1 and associated with Fz in a Wnt-dependent manner. Our results indicate that LRP6 may be a component of the Wnt receptor complex.     

A novel type of cardiac calcium channel in ventricular cells

Calcium influx is vital for several aspects of cardiac activity, so it is important to ask if heart cells possess a single or multiple types of Ca channel. Only one Ca channel type has been identified in patch-clamp studies of unitary current, despite suggestions to the contrary from whole-cell recordings in heart cells and unitary recordings from other cells. Here we describe a novel type of cardiac Ca channel with several properties that distinguish it from the hitherto-identified Ca channel in heart cells. Its conductance in isotonic Ba is small (8 pS), and is no larger in Ba than in Ca. It activates and inactivates at relatively negative potentials and remains functional long after patch excision. It is insensitive to dihydropyridines such as nimodipine and the Ca agonist Bay K 8644, and is more resistant to block by external Cd than the previously described type of cardiac Ca channel.