Deep learning reconstruction for brain diffusion-weighted imaging: efficacy for image quality improvement, apparent diffusion coefficient assessment, and intravoxel incoherent motion evaluation in in vitro and in vivo studies

PURPOSEDeep learning reconstruction (DLR) to improve imaging quality has already been introduced, but no studies have evaluated the effect of DLR on diffusion-weighted imaging (DWI) or intravoxel incoherent motion (IVIM) in in vitro or in vivo studies. The purpose of this study was to determine the effect of DLR for magnetic resonance imaging (MRI) in terms of image quality improvement, apparent diffusion coefficient (ADC) assessment, and IVIM index evaluation on DWI through in vitro and in vivo studies.METHODSFor the in vitro study, a phantom recommended by the Quantitative Imaging Biomarkers Alliance was scanned and reconstructed with and without DLR, and 15 patients with brain tumors with normal-appearing gray and white matter examined using IVIM and reconstructed with and without DLR were included in the in vivo study. The ADCs of all phantoms for DWI with and without DLR, as well as the coefficient of variation percentage (CV%), and ADCs and IVIM indexes for each participant, were evaluated based on DWI with and without DLR by means of region-of-interest measurements. For the in vitro study, using the mean ADCs for all phantoms, a t-test was adopted to compare DWI with and without DLR. For the in vivo study, a Wilcoxon signed-rank test was used to compare the CV% between the two types of DWI. In addition, the Wilcoxon signed-rank test was used to compare the ADC, true diffusion coefficient (D), pseudodiffusion coefficient (D*), and percentage of water molecules in micro perfusion within 1 voxel (f) with and without DLR; the limits of agreement of each parameter were determined through a Bland–Altman analysis.RESULTSThe in vitro study identified no significant differences between the ADC values for DWI with and without DLR (P > 0.05), and the CV% was significantly different for DWI with and without DLR (P < 0.05) when b values ≥250 s/mm2 were used. The in vivo study revealed that D* and f with and without DLR were significantly different (P < 0.001). The limits of agreement of the ADC, D, and D* values for DWI with and without DLR were determined as 0.00 ± 0.51 × 10-3, 0.00 ± 0.06 × 10-3, and 1.13 ± 4.04 × 10-3 mm2/s, respectively. The limits of agreement of the f values for DWI with and without DLR were determined as −0.01 ± 0.07.CONCLUSIONDeep learning reconstruction for MRI has the potential to significantly improve DWI quality at higher b values. It has some effect on D* and f values in the IVIM index evaluation, but ADC and D values are less affected by DLR

Production of IFN- by CD4+ T cells in response to malaria antigens is IL-2 dependent

T-cell immune responses are critical for protection of the host and for disease pathogenesis during infection with Plasmodium species. We examined the regulation of CD4+ T-cell cytokine responses during infection with Plasmodium berghei ANKA (PbA). CD4+ T cells from PbA-infected mice produced IFN-γ, IL-4 and IL-10 in response to TCR stimulation at levels higher than those from uninfected mice. This altered cytokine response was dependent on parasitemia. To examine the specificity of the response, mice were adoptively transferred with CD4+ T cells from OT-II TCR transgenic mice and were infected with PbA expressing OVA. Unexpectedly, CD4+ T cells from the OT-II-transferred wild-type PbA-infected mice showed high levels of IFN-γ production after stimulation with OVA and the cells producing IFN-γ were not OT-II but were host CD4+ T cells. Further investigation revealed that host CD4+ T cells produced IFN-γ in response to IL-2 produced by activated OT-II cells. This IFN-γ response was completely inhibited by anti-CD25 mAbs, and this effect was not due to the block of the survival signals provided by IL-2. Furthermore, IFN-γ production by CD4+ T cells in response to PbA antigens was dependent on IL-2. These findings suggest the importance of IL-2 levels during infection with malaria parasites and indicate that CD4+ T cells can produce IFN-γ without TCR engagement via a bystander mechanism in response to IL-2 produced by other activated CD4+ T cells

Separated Transcriptomes of Male Gametophyte and Tapetum in Rice: Validity of a Laser Microdissection (LM) Microarray

In flowering plants, the male gametophyte, the pollen, develops in the anther. Complex patterns of gene expression in both the gametophytic and sporophytic tissues of the anther regulate this process. The gene expression profiles of the microspore/pollen and the sporophytic tapetum are of particular interest. In this study, a microarray technique combined with laser microdissection (44K LM-microarray) was developed and used to characterize separately the transcriptomes of the microspore/pollen and tapetum in rice. Expression profiles of 11 known tapetum specific-genes were consistent with previous reports. Based on their spatial and temporal expression patterns, 140 genes which had been previously defined as anther specific were further classified as male gametophyte specific (71 genes, 51%), tapetum-specific (seven genes, 5%) or expressed in both male gametophyte and tapetum (62 genes, 44%). These results indicate that the 44K LM-microarray is a reliable tool to analyze the gene expression profiles of two important cell types in the anther, the microspore/pollen and tapetum

ヌードマウス可移植性ヒト泌尿生殖器腫瘍の胸腺摘出, ATS処理ハムスターへの移植

ヌードマウス可移植性ヒ卜泌尿生殖器腫瘍のうち， われわれが保持している未分佑型前立腺癌，膀胱移行上皮癌，腎細胞癌について胸腺摘出後, ATSを投与した新生児ハムスターにそれぞれ皮下移植をこころみた。これらの腫腫は， ヌードマウスにおける継代移植時におけるときと, (1) やや発育が遅く， (2) 周囲組織との癒着性，が存在しているのが相違点であった。ただし移植時に比して，あきらかに腫瘍の増大が認められ，通常飼育下で実験動物としての使用される可能性があるものと考えられた。Experiments representing an attempt to transplant human urogenital malignant tumors transplantable in nude mice to anti thymocyte serum (ATS)-treated, thymectomized neonatal hamsters were conducted, with the results assessed in comparison with those in nude mice, using specimens from human anaplastic prostatic adenocarcinoma, transitional cell carcinoma of the bladder and renal cell carcinoma. These tumors transplanted grew somewhat slower in hamsters and showed a slightly pronounced tendency of adherence to surrounding tissues, compared to those in nude mice. There was no evidence of metastasis of the tumors transplanted in hamsters and nude mice. The results of the experiments suggest possibilities of development of laboratory animals in which human malignant tumors of the urogenital system may be transplanted under ordinary conditions of feeding

Geology of Ashitaka Volcano, Central Japan

本論はテフロクロノロジーの手法に基づき,特異なテクトニクス場にある火山と考えられている愛鷹火山の発達史について述べると共に,富士・箱根などの周辺火山の活動期との関係を検討した.愛鷹火山の活動は,4噴火ステージに区分され(Fig.23),挟在されるテフラ層との関係より,その活動時代は約40万年前より開始し,10万年前に終了したことが明らかになった.4つの活動期のうち,旧期と中期を境に,一連の分化により形成されたアシディックマグマの活動から再びベーシックマグマの活動へと変化する.また,中期の噴出物は南東側に厚く偏在しており,この成因として25万年前から17万年前までの間に,山体が南東側に傾動したと考えると,うまく説明できる.一方,愛鷹火山の活動期は箱根火山とほぼ同時期であり,古富士火山の活動以前に終了したと考えられる.Ashitaka volcano, situated at the south foot of Fuji volcano, central Japan, is a stratovolcano, dissected intensively. The eruptive products of Ashitaka volcano are divided into four stratigraphica groups: Older group, Middle group, Younger group and Youngest group. The Older group is mainly composed of many thin flows of basaltic lava (SiO2=49-53%) and voluminous tuff breccia. These lava flows are interstratified with Shimowada loam formation. The upper unit of the Older group consists of breccia pipe deposits in Kumagaya crater, and some tephra layers of Mishima loam formation east of Ashitaka volcano are air-fall deposits from the pipe. The middle group is composed of voluminous tuff breccia (Mtb), occupying more than half of the volume of the main body. The volcanic fan deposits are secondary deposits derived from Mtb. It is interstratified with a T-6 tephra layer which erupted from Ashitaka volcano 170,000 y. B. P

Enantioselective Synthesis of Anti Homoallylic Alcohols from Terminal Alkynes and Aldehydes Based on Concomitant Use of a Cationic Iridium Complex and a Chiral Phosphoric Acid

We report a highly diastereo- and enantioselective synthesis of anti homoallylic alcohols from terminal alkynes via (<i>E</i>)-1-alkenylboronates based upon two catalytic reactions: a cationic iridium complex-catalyzed olefin transposition of (<i>E</i>)-1-alkenylboronates and a chiral phosphoric acid-catalyzed allylation reaction of aldehydes