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S Nishida

Publications and source records attributed to S Nishida.

At least 91 records · Page 5Linked to original sources
PubMed2002

Radiative B meson decays into kpigamma and kpipigamma final states.

We report observations of radiative B meson decays into the K+pi(-)gamma and K+pi(-)pi(+)gamma final states. In the B0-->K+pi(-)gamma channel, we present evidence for decays via an intermediate tensor meson state with a branching fraction of B(B0-->K(*)(2)(1430)(0)gamma)=[1.3+/-0.5(stat)+/-0.1(syst)]x10(-5). We measure the branching fraction B(B+-->K+pi(-)pi(+)gamma)=[2.4+/-0.5(stat) +0.4-0.2(syst)]x10(-5), in which the B+-->K(*0)pi(+)gamma and B+-->K+rho(0)gamma channels dominate. The analysis is based on a data set of 29.4 fb(-1) recorded by the Belle experiment at the KEKB collider.

Journal Article↗
PubMed2002

Expression of a p67(phox) homolog in Caco-2 cells giving O(2)(-)-reconstituting ability to cytochrome b(558) together with recombinant p47(phox).

Human normal and transformed (Caco-2) colon tissues as well as guinea pig gastric mucosal cells express Nox1, which is a homolog of the phagocyte NADPH oxidase subunit, gp91(phox) of membrane-bound cytochrome b(558). It was reported that Nox1-transfection to NIH 3T3 cells could provide O(2)(-)-generating ability, independently of regulatory cytosolic factors (Rac2, p67(phox), and p47(phox)) that are obligatory in the phagocyte oxidase system. Here, we detected and sequenced a p67(phox) homolog in Caco-2 almost identical to the neutrophil sequence, except for three nucleotide substitutions, two of which changed lysines 181 and 328 to arginines. Investigation of its ability to support O(2)(-)-generation in cell-free reconstitution experiments combining with neutrophil cytochrome b(558) showed O(2)(-)-generation, provided that recombinant p47(phox) was added. This result demonstrates that the intrinsic p67(phox) homolog of Caco-2 was able to function as a phagocyte p67(phox) for cytochrome b(558). The requirement of p47(phox) addition suggested that this component was absent in Caco-2 cells. Caco-2 membranes, used as a source of Nox1 in place of cytochrome b(558), did not show significant O(2)(-)-generation, which was mainly explained by their very little Nox1 expression.

Caco-2 Cells↗
PubMed2002

Stage-dependent changes in trabecular bone turnover and osteogenic capacity of marrow cells during development of type II collagen-induced arthritis in mice.

Rheumatoid arthritis (RA) is a disease characterized by inflammatory polyarthritis leading to destruction of the joints and reduction in bone mass. However, the relationship between bone mass and turnover is not yet clear in RA patients. To clarify the effect of bone turnover and marrow osteogenic capacity on mass and structure during the development of arthritis, we examined DBA1/J mice for 8 weeks after the first immunization with bovine type II collagen at the age of 9 weeks. Localized arthritis developed at 4 weeks and advanced arthritis at 6 weeks postimmunization. Urinary deoxypyridinoline levels in arthritic mice were significantly higher at 4 weeks, and levels were maintained thereafter. Their serum osteocalcin levels were significantly reduced compared with controls at 2 and 6 weeks, but did not differ significantly from those in the control group at 4 and 8 weeks. Three-dimensional (3D) trabecular bone volume of the proximal tibia measured by 3D microcomputed tomography (micro-CT) in the arthritic mice became significantly lower at 4 weeks and decreased further at 6 weeks compared with controls. Parameters of 3D trabecular bone structure, such as structure model index and trabecular bone pattern factor, were increased at 4 and 6 weeks, respectively. Trabecular osteoclast number increased and bone formation rates decreased at 8 weeks. The number of total bone marrow cells (BMCs), adherent stromal cells, and area of mineralized nodule formation in the tibia of arthritic mice were significantly reduced compared with controls at 6 weeks. Numbers of total fibroblastic colony-forming units (CFU-f) and alkaline phosphatase (ALP)-positive CFU-f colonies also decreased. However, the values of these osteogenic parameters corrected for the total BMCs and/or adherent stromal cells did not differ significantly between the arthritic and control groups. These data indicate that an increase in bone resorption led to the reduction in trabecular bone mass and deterioration of 3D structure during the localized arthritic stage. The reduction in bone marrow osteogenic potential in the advanced arthritic stage was due to the reduction in the number of total bone marrow cells, and differentiation of osteogenic cells was apparently unaffected. The reduction in bone formation may not be substantial in this arthritic model.

Animals↗
PubMed2001

Serum citrulline and rejection in small bowel transplantation: a preliminary report.

BACKGROUND: There is no known serum marker for intestinal rejection. Serum concentrations of the amino acid citrulline arise almost exclusively from the intestinal mucosa. We examined the impact of acute cellular rejection (ACR) of intestinal allografts on serum citrulline levels. METHODS: Citrulline concentrations were assayed in serum samples of healthy volunteers (n=6) and seven patients who underwent small bowel transplants (SBTx). Trends in mean citrulline concentrations versus degree of ACR were assessed by matching posttransplantation citrulline concentrations with patients' grade of ACR at time of serum collection. Rejection was confirmed by biopsy and graded by following standardized criteria. An additional patient had citrulline concentrations determined for 31 sequential specimens 3-60 days posttransplant. RESULTS: Mean citrulline concentrations in controls were significantly higher than posttransplantation samples at any rejection grade. Mean concentrations declined significantly as rejection severity increased. The overall downward trend was statistically significant (P<0.05). In sequential measurements, citrulline levels increased significantly over time with declining severity of rejection. The increase in mean citrulline concentration between posttransplant days 3-16 and 52-60 was significant (P<0.01). CONCLUSIONS: Serum citrulline levels decline with increasing grade of ACR and may be a useful serum marker for intestinal rejection.

Adult↗
PubMed2001

Afterimage of perceptually filled-in surface.

An afterimage induced by prior adaptation to a visual stimulus is believed to be due to bleaching of photochemical pigments or neural adaptation in the retina. We report a type of afterimage that appears to require cortical adaptation. Fixating a neon-color spreading configuration led not only to negative afterimages corresponding to the inducers (local afterimages), but also to one corresponding to the perceptually filled-in surface during adaptation (global afterimage). These afterimages were mutually exclusive, undergoing monocular rivalry. The strength of the global afterimage correlated to a greater extent with perceptual filling-in during adaptation than with the strength of the local afterimages. Thus, global afterimages are not merely by-products of local afterimages, but involve adaptation at a cortical representation of surface.

Adaptation, Ocular↗