Optical Properties, Electronic Structure and Magnetism of α′-Na x V2O5

The optical properties of sodium-deficient α′-Na _x V₂O₅ (0.85 ≤ x ≤ 1.00) single crystals are analyzed using ellipsometry, and infrared reflectivity techniques. In sodium deficient samples, the optical absorption peak associated to the fundamental electronic gap develops in the middle of the pure α′-NaV₂O₅ gap at ～0.44 eV, and the material remains insulating up to the maximal achieved hole concentration of about 15%. Nonmetallic behavior under hole doping provoked reinterpretation of the α′-NaV₂O₅ optical spectra. We argue that the absorption peak at about 0.9 eV corresponds to the photoionization energy of a large polaron.     

New approaches to the management of acute and chronic cardiac allograft rejection

There are still many problems to be faced in the field of heart transplantation. Acute and chronic rejection are still the major medical obstacles. In this review, we describe recent research in this field undertaken in our laboratory. The induced intercellular adhesion molecule-1 (ICAM-1) and MHC class II antigen resulting from rejection can be visualized in vivo by radioimmunoscintigraphy. This non-invasive method is sensitive for detecting early rejection and allows quantitative assessment of rejection. Short-term administration of monoclonal antibodies to ICAM-1 and leukocyte function-associated antigen-1 (LFA-1) results in an indefinite acceptance of cardiac allografts by induction of antigen-specific tolerance, as evidenced by acceptance of the secondary skin allografts. The characteristics and possible mechanisms of this tolerance induction are discussed. Immunohistopathologic features of graft coronary arteriopathy are shown. Adhesion molecules, cytokines, and growth factors are associated with intimal hyperplasia and phenotypic transformation of smooth muscle cells in the allograft coronary arteries. Dramatic reduction in this intimal hyperplasia was demonstrated by antisense gene therapy targeting cyclin-dependent kinase 2 kinase. We hope that these investigations will contribute to the improvement of the management of patients who undergo heart transplantation.     

Differential display analysis of murine collagen-induced arthritis: cloning of the cDNA-encoding murine ATPase inhibitor

Perforin-deficient (-/-) mice were used as T-cell donors for infusion into irradiated major histocompatibility complex (MHC)-disparate recipients to investigate the requirement for perforin-mediated cytolysis during graft-versus-host disease (GVHD) generation. Administration of 5x10(6) C57BL/6 (H2b) perforin -/- splenocytes was significantly less effective in inducing GVHD lethality when given to MHC class I + II disparate B10.BR (H2k) recipients, as compared with wild-type (+/+) controls. Perforin expression by donor T cells was not required for GVHD induction because recipients given fivefold higher numbers of perforin -/- donor splenocytes uniformly succumbed to lethal GVHD. Because both CD4+ and CD8+ donor T cells are required for optimal GVHD lethality in this strain combination, to discern the relative contribution of perforin-mediated cytolysis by CD4+ and CD8+ T cells, additional studies were performed. For these latter studies, we used a sensitive assay involving the infusion of highly purified CD4+ or CD8+ T cells into sublethally irradiated MHC class II or I disparate recipients, respectively. As compared with recipients of perforin +/+ T cells, recipients of either CD4+ or CD8+ perforin -/- T-cell subsets had a significant reduction in GVHD-mediated lethality at T-cell doses that were uniformly lethal. T-cell dose titration studies established that GVHD lethality in recipients of perforin -/- CD4+ or CD8+ T cells was reduced by approximately threefold. These data are the first to indicate that approaches to limit perforin-mediated cytolysis should be similarly effective in situations in which CD4+ or CD8+ T cells dominate the GVHD response.     

Carcinoid tumor occurring in cystic teratoma of the kidney: a case report

Although carcinoid tumors have occurred rarely in benign teratomas of the ovary and the testis, we believe this case is the first reported of carcinoid arising in a benign cystic teratoma of the kidney. The patient was admitted to the Tagawa Hospital with a left abdominal mass and severe epigastric pain. Retrograde and intravenous pyelograms revealed marked dilatation of the left kidney; a renal tumor was diagnosed clinically. At operation, a polycystic tumor weighing 1400g was removed. Histologically, a carcinoid tumor was evident among teratoid tissues, such as columnar epithelium, cartilage, smooth muscle, and mucous secretory glands. The patient did not have a carcinoid syndrome and had an uneventful recovery.