Galaxy clusters enveloped by vast volumes of relativistic electrons.

The central regions of galaxy clusters are permeated by magnetic fields and filled with relativistic electrons1. When clusters merge, the magnetic fields are amplified and relativistic electrons are re-accelerated by turbulence in the intracluster medium2,3. These electrons reach energies of 1-10 GeV and, in the presence of magnetic fields, produce diffuse radio halos4 that typically cover an area of around 1 Mpc2. Here we report observations of four clusters whose radio halos are embedded in much more extended, diffuse radio emission, filling a volume 30 times larger than that of radio halos. The emissivity in these larger features is about 20 times lower than the emissivity in radio halos. We conclude that relativistic electrons and magnetic fields extend far beyond radio halos, and that the physical conditions in the outer regions of the clusters are quite different from those in the radio halos.

Initial Characterization of Transgenic Mice Overexpressing Human Histamine H2 Receptors.

In an integrative approach, we studied the role of histamine H2 receptors in the mouse heart. We noted that histamine, added cumulatively to the organ bath, failed to affect the force of contraction in left atrial preparations and did not change spontaneous heart rate in right atrial preparations from wild-type mice. By contrast, in the same preparations from mice that overexpressed the human H2 receptor in a cardiac-specific way, histamine exerted concentration- and time-dependent positive inotropic and positive chronotropic effects. Messenger RNA of the human H2 receptor was only detected in transgenic mice. Likewise, immunohistology and autoradiography only gave signals in transgenic but not in wild-type cardiac preparations. Similarly, a positive inotropic and positive chronotropic effect was observed with histamine in echocardiography of living transgenic mice and isolated perfused hearts (Langendorff preparation). Phosphorylation of phospholamban was increased in atrial and ventricular preparations from transgenic mice, but not in wild-type animals. The effects of histamine were mimicked by dimaprit and amthamine and antagonized by cimetidine. In summary, we generated a new model to study the physiologic and pathophysiologic cardiac role of the human H2 receptor.

[Psychosomatic aspects of diabetes mellitus in adolescence--a case report]. / Psychosomatische Aspekte des Diabetes mellitus im Jugendalter--eine Falldarstellung.

A case is reported of a 15-year-old girl with insulin-dependent diabetes mellitus and neurotic development. Emphasis is placed on psychosomatic considerations in the discussion of the disease in general and of crisis management and course of treatment in this particular case.