Mapping of gene encoding mouse placental alkaline phosphatase to chromosome 4

The gene encoding the mouse placental alkaline phosphatase (ALP; orthophosphoric-monoester phosphohydrolase, alkaline optimum, EC 3.1.3.1) is mapped to chromosome 4, based on Southern blot hybridization of the mouse cDNA with DNAs from mouse-Chinese hamster somatic cell hybrids. This assignment is consistent with the genetic analysis of theAkp-2 locus, which is responsible for the genetic variation of alkaline phosphatase enzyme in placenta as well as in liver, kidney, and bone.     

The effect of noradrenaline on the end-plate potential in twitch fibres of the frog

1. The action of noradrenaline in increasing the amplitude of the end-plate potential (e.p.p.) has been studied in magnesium-blocked frog skeletal muscle.2. Noradrenaline (10(-5)M) increased the e.p.p. by about 20% without causing any comparable change in the amplitude of the miniature end-plate potentials (m.e.p.p.s). It was concluded that noradrenaline acts by potentiating the release of acetylcholine by the nerve impulse, rather than by increasing the sensitivity of the end-plate.3. In support of this, it was found that the increase in e.p.p. amplitude was associated with a reduction in the variability of successive e.p.p.s, as is to be expected if the quantal content of the e.p.p. became larger. Further, noradrenaline was without effect on the response to iontophoretically-applied acetylcholine, although it potentiated depolarizations elicited by acetylcholine applied for much longer periods in the bathing fluid.4. Noradrenaline increased the frequency of occurrence of m.e.p.p.s, and unusually large m.e.p.p.s. were occasionally observed.     

Quartz glass pipette puller operating with a regulated oxy-hydrogen burner

Quartz glass electrodes are superior to conventional glass electrodes for low-noise recording. They have better electrical characteristics and hydrophobic surfaces which resist creeping of salt solutions. We used oxy-hydrogen heating with program-controlled gas pressure to melt quartz glass capillaries. Usually, the relative wall thickness (the quotient of the outer and inner diameters do/di) of capillaries is, at best, maintained up to the electrode tip. If tips with thicker walls can be produced, coating and other surface treatments can be avoided. We found that programmed heating periods without pull allowed an fivefold increase of do/di in the tip region. Since do/di is inversely proportional to input capacity, the recording noise was minimized and became insignificant relative to amplifier and holder noise. A sample patch-clamp recording is shown.     

Hydrops des Cavum Septi Pellucidi

Zusammenfassung Beschrieben wird ein Fall von in vivo diagnostiziertem Hydrops des Cavum septi pellucidi mit schizophrener Psychose, welche nach zweimaliger Encephalographie zur Rückbildung kam. Das klinisch-röntgenologische Pellucidum-Syndrom wird erörtert.     

Angiogenic response induced by acellular aortic matrix in vivo

In this study, we investigated the angiogenic response induced by acellular aortic matrices implanted in vivo onto the chick embryo chorioallantoic membrane (CAM), a useful model for such investigation. Results showed that acellular matrices were able to induce a strong angiogenic response comparable to that of fibroblast growth factor 2 (FGF-2), a well-known angiogenic cytokine. The angiogenic response was further increased when exogenous FGF-2 or transforming growth factor beta 1 (TGF-beta1) were added to the matrices and inhibited by the addition of an anti-FGF-2 or anti-TGF-beta1 antibodies. The response may be considered dependent on a direct angiogenic effect exerted by the matrices and in part also by the presence of FGF-2 and TGF-beta1 in the acellular matrices.     

Current perspectives on HER2 testing: a review of national testing guidelines.

Knowledge of HER2 status is a prerequisite when considering a patient's eligibility for Herceptin (trastuzumab) therapy. Accurate assessment of HER2 status is essential to ensure that all patients who may benefit from Herceptin are correctly identified. There are several assays available to determine HER2 status: the most common in routine clinical practice are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Various factors can affect the results achieved with these assays, including the assay antibody/probe, the methodology and the experience of personnel. Many countries have implemented national testing guidelines in an attempt to standardize testing procedures and make results more accurate. These guidelines vary in the level of detail and the number of recommendations. This review looks at areas of consensus between the different national testing guidelines and highlights where errors may arise during the testing procedure. The key point underlined by this review is that whatever method is used to test for HER2 status, the technology must be validated first, and there must be regular internal and external quality control and quality assurance procedures.     

C3d binding to the circumsporozoite protein carboxy-terminus deviates immunity against malaria

The immunogenicity of recombinant protein or anti-viral DNA vaccines can be significantly improved by the addition of tandem copies of the complement fragment C3d. We sought to determine if the efficacy of a circumsporozoite protein (CSP)-based DNA vaccine delivered to mouse skin by gene gun was improved by using this strategy. Instead, we found that C3d suppressed the protective immunity against Plasmodium berghei malaria infection and deviated immunity, most notably by suppressing the induction of antibodies specific for the CSP C-terminal flanking sequence and by suppressing the induction of CSP-specific IL-4-producing spleen cells. We further showed that C3d bound to the C-terminal flanking sequence of the CSP, which may explain the immune deviation observed in CS/C3d chimeric antigen. We have thus identified C3d-mediated epitope masking and shifting of both the humoral and cellular immune responses as a potential novel escape mechanism, which plasmodia may use to divert the induction of protective immunity.     

Tolerance in mixed chimerism – a role for regulatory cells?

The establishment of mixed hematopoietic chimerism induces life-long donor-specific organ graft tolerance while obviating the need for chronic immunosuppression. Recent advances have dramatically reduced the conditioning toxicity required to achieve mixed chimerism. We argue that the achievement of high levels of donor chimerism ensures life-long deletion of donor-reactive T cells, precluding and obviating the need for regulatory mechanisms in the maintenance of tolerance. However, in situations where high levels of donor chimerism cannot be established or sustained, control of immune responsiveness can be achieved through additional mechanisms, including regulatory T cells.     

New x-ray tube performance in computed tomography by introducing the rotating envelope tube technology

The future demands of computed tomography imaging regarding the x-ray source can be summarized with higher scan power, shorter rotation times, shorter cool down times and smaller focal spots. We report on a new tube technology satisfying all these demands by making use of a novel cooling principle on one hand and of a novel beam control system on the other hand. Nowadays tubes use a rotating anode disk mainly cooled via radiation. The Straton x-ray tube is the first tube available for clinical routine utilizing convective cooling exclusively. It is demonstrated that this cooling principle makes large heat storage capacities of the anode disk obsolete. The unprecedented cooling rate of 4.8 MHU/min eliminates the need for waiting times due to anode cooling in clinical workflow. Moreover, an electronic beam deflection system for focal spot position and size control opens the door to advanced applications. The physical backgrounds are discussed and the technical realization is presented. From this discussion the superior suitability of this tube to withstand g-forces well above 20 g created by fast rotating gantries will become evident. Experience from a large clinical trial is reported and possible ways for future developments are discussed.