The Ds(2317) and Ds(2463) Mesons as Scalar and Axial-Vector Chiralons in the Covariant Level-Classification Scheme

The new narrow mesons observed recently in the final states Ds+ pi0 and Ds*+ pi0 are pointed out to be naturally assigned as the ground-state scalar and axial-vector chiralons in the c sbar system, which would newly appear in the covariant hadron-classification scheme proposed a few years ago.Comment: 8 pages, 1 figure, uses ptptex.st

Synthesis and physical properties of (Pb0.5M0.5)(Sr,La)2CuOz (z~5; M = Fe, Co, Cu, and Zn)

(Pb0.5Cu0.5)(Sr0.5La0.5)2CuOz (abbreviated as (Pb,Cu)-"1-2-0-1") with superconducting transition temperature (Tc) of 25 K is a member (n = 1) of one of the homologous series of cuprate superconductors, (Pb4+,Cu2+)(Sr2+,Ln3+)2(Y3+,Ca2+)n-1Cu2+nO2-2n+3 (n = 1-4; Ln: lanthanoid elements). For the (Pb,Cu)-"1-2-0-1", substitution effects of 3d transition metal elements M (M = Fe, Co, and Zn) for the Cu site in the (Pb,Cu)-O charge-reservoir layer (labelled as Cu(1)) are systematically investigated. Because Fe, Co and Ni ions exist as divalent or trivalent in ionic crystals, the Sr2+/La3+ ratio in the (Sr,Ln) site is adjusted to satisfy charge neutrality, assuming that they are in a trivalent state. This results in the successful synthesis of new materials with nominal compositions of (Pb0.5M0.5)(Sr0.75La0.25)2CuOz (M = Fe and Co). This observation suggests that Fe and Co are trivalent in "1-2-0-1". For M = Zn, the nominal composition of (Pb0.5Zn0.5)(Sr0.5La0.5)2CuOz was found to yield a nearly single "1-2-0-1" phase. Temperature dependence of electrical resistivity and magnetization were measured, and superconductivity was confirmed only for the case of M = Zn with a Tc of 19.7 K. For these three materials, the distribution of Fe, Co and Zn between Cu(1) and another Cu site in the Cu-O2 plane labelled as Cu(2) was investigated employing transmission electron microscopy, which showed that Fe, Co, and Zn occupy both the Cu(1) and Cu(2) sites.Comment: 26 pages, 10 figure

Cloning of an isoform of mouse TGF-β type II receptor gene

AbstractA variant of transforming growth factor-β type II receptor (TGF-βRII) cDNA was isolated from a mouse brain cDNA library. The predicted receptor is identical to previously reported mouse TGF-βRII except that the isoform has an insertion sequence of 25 amino acids in the predicted ligand-binding domain. By the use of reverse transcription-polymerase chain reaction (RT-PCR), transcripts for both isoforms were detected in all tissues and developing embryos examined. The isoform transiently expressed in COS cells showed a similar ligand-binding specificity to authentic TGF-βRII. These results suggest that the mouse TGF-βRII gene generates multiple isoforms, possibly by alternative splicing, as reported for activin type IIB receptor; and an isoform which has the extra sequence in the ligand-binding domain is also involved in the TGF-β signal transduction

Presenilin-2 Mutation Causes Early Amyloid Accumulation and Memory Impairment in a Transgenic Mouse Model of Alzheimer's Disease

In order to clarify the pathophysiological role of presenilin-2 (PS2) carrying the Volga German Kindred mutation (N141I) in a conventional mouse model of Alzheimer's disease (AD) expressing amyloid precursor protein (APP) with the Swedish mutation (Tg2576 line), we generated a double transgenic mouse (PS2Tg2576) by crossbreeding the PS2 mutant with Tg2576 mice. Here, we demonstrate that the PS2 mutation induced the early deposition of amyloid β-protein (Aβ) at 2-3 months of age and progressive accumulation at 4-5 months of age in the brains of the mutant mice. The PS2 mutation also accelerated learning and memory impairment associated with Aβ accumulation at 4-5 months of age in Tg2576 mice. These results suggest that the PS2 mutation causes early cerebral amyloid accumulation and memory dysfunction. PS2Tg2576 mice are a suitable mouse model for studying amyloid-lowering therapies

Conformational differences among metarhodopsin I, metarhodopsin II, and opsin probed by wide-angle X-ray scattering

Among the photoproducts of vertebrate rhodopsin, only metarhodopsin II (Meta-II) preferentially adopts the active structure in which transmembrane helices are rearranged. Light-induced helical rearrangement of rhodopsin in membrane-embedded form was directly monitored by wide-angle X-ray scattering (WAXS) using nanodiscs. The change in the WAXS curve for the formation of Meta-II was characterized by a peak at 0.2 Å⁻¹ and a valley at 0.6 Å⁻¹, which were not observed in metarhodopsin I and opsin. However, acid-induced active opsin (Opsin*) showed a 0.2 Å⁻¹ peak, but no 0.6 Å⁻¹ valley. Analyses using the model structures based on the crystal structures of dark state and Meta-II suggest that the outward movement of helix VI occurred in Opsin*. However, the displaced helices III and V in Meta-II resulting from the disruption of cytoplasmic ionic lock were restored in Opsin*, which is likely to destabilize the G-protein-activating structure of opsin

Reactions of 6-metheoxy-3-azabicyclo[4.2.0]octan-2-one and its 7-substituted derivatives

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学

Lumbar Spondylolysis and vascular supply

INTRODUCTION : The pathology of lumbar spondylolysis is generally thought to begin with a stress fracture in adolescence. Stress fractures of the lower extremities occur in watershed areas with a poor vascular supply because of an inability to respond to stress and heal. This pathology has not been well researched in the lumbar spine. The aim of this study was to evaluate the distribution of the spinal arteries in patients with lumbar spondylolysis. METHODS : The extraosseous distribution of the arteries around the pars interarticularis was retrospectively investigated in 14 patients with colon cancer who underwent abdominal contrast-enhanced computed tomography (CE-CT) as part of a preoperative assessment at our hospital and were found to have spondylolysis at L5. RESULTS : All patients were found to have terminal-stage spondylolysis at L5 (1 unilateral, 13 bilateral). L5 segmental artery was absent in all cases. However, separate spinal arteries supplying the pars interarticularis at L5 were found above and below the transverse process at this level. CONCLUSION : All the patients had two separate arteries originating from the cranial and caudal sides that distributed to the superior and inferior articular processes, suggesting that the pars interarticularis is a posterior element containing a vascular watershed area

Hemangioblastoma of Cauda Equina

Introduction : Hemangioblastoma in the spine mainly occurs at the cervical and thoracic levels and is often associated with von Hippel-Lindau (VHL) syndrome. Here, we reported a quite rare case of spinal sporadic hemangioblastoma arising from the cauda equina. Case presentation : A 66-year-old woman presented with a 5-year history of low back and leg pain. Imaging revealed a hypervascular intradural extramedullary tumor in the lumbar region. Preoperative angiography helped to identify the feeding arteries and draining vein, and so facilitated subsequent tumor resection. The pain was dramatically improved but weakness of the left tibialis anterior and left extensor hallucis longus muscles persisted. Discussion : We reported a rare case of spinal hemangioblastoma arising from the cauda equina. Preoperative angiography may be useful for diagnosis and understanding of the anatomy of feeding veins