Aging Leads to Disturbed Homeostasis of Memory Phenotype CD8+ Cells

Examining the rate of in vivo T cell turnover (proliferation) in aged mice revealed a marked reduction in turnover at the level of memory-phenotype CD44hi CD8+ cells relative to young mice. Based on adoptive transfer experiments, the reduced turnover of aged CD44hi CD8+ cells reflected an inhibitory influence of the aged host environment. Aged CD44hi CD8+ cells also showed poor in vivo responses to IL-15 and IL-15–inducing agents, but responded well to IL-15 in vitro. Two mechanisms could account for the reduced turnover of aged CD44hi CD8+ cells in vivo. First, aging was associated with a prominent and selective increase in Bcl-2 expression in CD44hi CD8+ cells. Hence, the reduced turnover of aged CD44hi CD8+ cells may in part reflect the antiproliferative effect of enhanced Bcl-2 expression. Second, the impaired in vivo response of aged CD44hi CD8+ cells to IL-15 correlated with increased serum levels of type I interferons (IFN-I) and was largely reversed by injection of anti–IFN-I antibody. Hence the selective reduction in the turnover of aged CD44hi CD8+ cells in vivo may reflect the combined inhibitory effects of enhanced Bcl-2 expression and high IFN-I levels

気分状態に依存しない双極性障害と大うつ病性障害における脳梁の白質微細構造の差異

OBJECTIVE: It is difficult to distinguish between bipolar disorder and major depressive disorder (MDD) in patients lacking a clear history of mania. There is an urgent need for an objective biomarker for differential diagnosis. Using diffusion tensor imaging, this study investigated the differences in the brain white matter microstructure between patients with bipolar disorder and MDD. METHODS: Participants included 16 patients with bipolar disorder and 23 patients with MDD having depressed or euthymic states based on DSM-IV-TR criteria and 23 healthy volunteers. Whole-brain voxel-based morphometric analysis was used to detect any significant differences in fractional anisotropy between patients with bipolar disorder and MDD. The study was conducted between August 2011 and July 2015. RESULTS: We found a significant decrease in fractional anisotropy values in the anterior part of the corpus callosum in patients with bipolar disorder compared with MDD (P < .001), which did not depend on the patients' affective state. This decrease was associated with increased radial diffusivity values (P < .05), which was also found in patients with bipolar disorder when compared with healthy volunteers (P < .05). We predicted bipolar disorder and MDD in all patients using the fractional anisotropy values, with a correct classification rate of 76.9%. CONCLUSIONS: The present study revealed that patients with bipolar disorder have microstructural abnormalities in the corpus callosum during depressed or euthymic states, which may deteriorate the exchange of emotional information between the cerebral hemispheres, resulting in emotional dysregulation. Our results indicate the possible use of diffusion tensor imaging as a differential diagnostic tool.博士（医学）・甲第662号・平成29年3月15日© Copyright 2017 Physicians Postgraduate Press, Inc.発行元の規定により、本文の登録不可。本文は以下のURLを参照 "http://dx.doi.org/10.4088/JCP.15m09851" （※全文閲覧は学内限定

Development of Near Infrared-Fluorescent Nanophosphors and Applications for Cancer Diagnosis and Therapy

The use of near infrared (NIR) light for biomedical photonics in the wavelength region between 800 and 2000 nm, which is called “biological window”, has received particular attention since water and biological tissues have minimal optical loss due to scattering and absorption as well as autofluorescence in this region. Recent development of InGaAs CCD enables observations in this wavelength region. In the present paper, we report development of Yb and Er-doped yttrium oxide nanoparticles (Y2O3:YbEr-NP) which show strong NIR emission under NIR excitation (NIR-NIR emission). We also demonstrate that NIR emission can be observed through swine colon wall. Based on these results, we propose a possible application of Y2O3:YbEr-NP for cancer diagnosis and therapy using NIR-NIR imaging system. Our results also suggest potential applications of Y2O3:YbEr-NP for noninvasive detection of various diseases