The genus Metastelma (Asclepiadoideae-Asclepiadeae-Metastelmatinae) in South America

Molecular and morphological analyses are used to circumscribe the genus Metastelma in South America. In northem South America, fourteen species are identified, nine o f them new; and two species are found in Southern South America, one o f them new. The northem South American lineage is retrieved as sister to a clade comprising the type species of Metastelma, M. parviflorum, one o f several Caribbean lineages. The Southern South American lineage remains unresolved. The Central American lineage remains poorly supported monophyletic, but ineludes a species from Jamaica, M. priorii. Several specimens from the Andes o f Argentina and Bolivia are retrieved in a well-supported clade outside Metastelma s.s. For these specimens, a new genus is described comprising presently seven species. Four o f these species are transferred from Metastelma, one from Ditassa, and two species are described as new Stelmation E.Foum. is resurrected, comprising presently a single species, S. myrtifolium from Brazil. Metastelma giuliettianum and M. harleyi, also from Brazil, are excluded from Metastelma, but cannot yet be transferred to another genus, because the taxonomy o f Metastelmatinae is still in flux. Thus, Metastelma s.s. is absent from Brazil

Regulatory Roles of IL-2 and IL-4 in H4/Inducible Costimulator Expression on Activated CD4+ T Cells During Th Cell Development

AbstractWe found a tight correlation among the levels of H4/inducible costimulator (ICOS) expression, IL-4 production, and GATA-3 induction, using activated CD4+ T cells obtained from six different murine strains. BALB/c-activated CD4+ T cells expressed ∼10-fold more H4/ICOS on their surfaces and produced ∼10-fold more IL-4 upon restimulation than C57BL/6-activated CD4+ T cells. BALB/c naive CD4+ T cells were shown to produce much higher amounts of IL-2 and IL-4 upon primary stimulation than C57BL/6 naive CD4+ T cells. Neutralization of IL-4 with mAbs in culture of BALB/c naive CD4+ T cells strongly down-regulated both H4/ICOS expression on activated CD4+ T cells and IL-4 production upon subsequent restimulation. Conversely, exogenous IL-4 added to the culture of BALB/c or C57BL/6 naive CD4+ T cells up-regulated H4/ICOS expression and IL-4 production upon restimulation. In addition, retroviral expression of GATA-3 during the stimulation of naive CD4+ T cells from C57BL/6 or IL-4−/− mice increased H4/ICOS expression on activated CD4+ T cells. A similar effect of IL-2 in the primary culture of BALB/c naive CD4+ T cells appeared to be mediated by IL-4, the production of which was regulated by IL-2. These data suggest that IL-4 induced by IL-2 is critical to the maintenance of high H4/ICOS expression on BALB/c-activated CD4+ T cells

DNA diagnosis in the NF2 gene

Neurofibromatosis 2 (NF2) is a genetic disorder characterized by the develop-ment of multiple tumors in the central nervous system. Recently, the NF2 gene has been cloned and found to encode a novel member of the protein 4.1 family which is thought to link integral membrane proteins to the cytoskeleton. The identification of the NF2 tumor suppresser gene has allowed us to screen for pathological mutations in the gene. We have studied germline mutations in the NF2 gene by direct sequence analysis of genomic DNA from blood samples of NF2 patients. In the present report, we demonstrate a novel pathological missense mutation in a patient with NF2, which reveals that the variant observed may affect important functional regions or alter the protein on a larger scale by affecting conformation or degradation

Development of high current vapor-cooled current leads for large superconductor critical current measuring

Several programs to develop superconducting magnets for the Large Helical Device (LHD) are under way at the National Institute for Fusion Science in Japan. The development of large-scale superconductors for use in superconducting magnets is an important goal of these programs. To measure the critical current of such large-scale superconductors it is necessary to supply a very high current of up to 100 kA. For this purpose, very large current capacity, vapor-cooled current leads have been developed. As a first step in this development, a pair of current leads with a short-time rated current of 30 kA has been made and tested. Also developed was an analytical program to calculate the time-dependent characteristics of vapor-cooled current leads, and the results of calculations with the experimental results obtained with 30 kA current leads were compare

Engineering research and development of magnetically levitated high-temperature superconducting coil system for mini-RT project

A magnetically levitated superconducting coil system is being developed using high temperature superconductors for examining a new magnetic confinement of high-beta plasmas. A miniature double-pancake coil was fabricated with a Bi-2223 Ag-sheathed tape for the purpose of developing a floating control using laser displacement gauges. The coil was inductively excited with liquid nitrogen cooling and successfully levitated in the air. A persistent current switch is also being developed with a Bi-2223 Ag-0.3wt%Mn-sheathed tape, and a prototype model was successfully tested

Stable long-term operation of superconducting current-feeder system for the LHD

A superconducting (SC) current-feeder system is used as the current transmission lines for the experimental fusion device, LRD. It consists of nine flexible SC bus lines with total length of 497 m, and nine pairs of gas-cooled current leads. To avoid the propagation of the ice on the leads, the temperature of the terminals had been kept in the range between 5 and 20 degrees C by the heaters. The measured voltage drops of all leads were less than 20 mV. The liquid helium levels of the leads and the sub-cooler tank will equalize by the siphon method. The total time of the coil excitations exceeds 3000 hours. We have demonstrated successfully that the SC current-feeder system was stable and easy to handle, and is useful for the SC experimental fusion device