The origin of MeV gamma-ray diffuse emission from the inner Galactic region

The origin of the inner Galactic emission, measured by COMPTEL with a flux of $\sim ~ 10^{-2}$ MeV cm$^{-2}$ s$^{-1}$ sr$^{-1}$ in the 1-30 MeV range, has remained unsettled since its discovery in 1994. We investigate the origin of this emission by taking into account individual sources which are not resolved by COMPTEL and the Galactic diffuse emission. The source contribution is estimated for sources crossmatched between the Swift-BAT and Fermi-LAT catalogs by interpolating the energy spectra in the hard X-ray and GeV gamma-ray ranges, as well as unmatched sources. This results in a flux of $\sim$20% of the COMPTEL excess. The Galactic diffuse emission is calculated by GALPROP to reconcile the cosmic-ray and gamma-ray spectra with observations by AMS-02, Voyager, and Fermi-LAT, resulting in a flux of $\sim$30-80% of the COMPTEL emission. Thus, we show that the COMPTEL emission could be roughly reproduced by a combination of the sources and the Galactic diffuse emission. Furthermore, combined with the extragalactic emission, we construct all-sky images in the MeV gamma-ray range to pinpoint some potential interesting targets for future missions, which would be critical for bridging the MeV gap in the spectra of gamma-ray sources.Comment: Proceedings of Science; 7th Heidelberg International Symposium on High-Energy Gamma-Ray Astronomy (Gamma2022), 4-8 July 2022, Barcelona, Spai

胆管細胞特異的PDC-E2発現マウスを用いたPBCモデルの作製およびその解析

金沢大学附属病院我々のグループはヒトPBC肝組織にて、病期の進展に伴い発現遺伝子群が変化していくことを、cDNAマイクロアレイを用いた多数遺伝子発現をもとに解析した。これから、臨床的にPBCが顕性化した病期を解析するだけでは、PBCの病態を理解するためには不十分である事が判明している。本研究においては、自己免疫反応の生じ始めた段階に遡り、更にどのようなカスケードにて免疫現象が進行し、胆管の消失に至るかの解明を試みた。このためにPBCに必須ともいえるという2つの条件をみたしたCK19-PDCE2 Tg miceの作製に成功した。蛋白の発現はmRNA及び蛋白発現にて証明された。また、系統の掛け合わせにより、発現量を更に多いdouble transgenic miceの系を確立した。これらCK19-PDCE2 Tg miceにおける発現形質の解析を行った。自然発症の有無が今回の実験目的の大きな課題の一つであったが、通常のTg mice50匹を生後1年の時点でsacrificeしたが、組織学的に胆管障害は認めなかった。また、肝機能検査にて血清ALT, ALPは正常範囲内であり、PBC診断の血清学的マーカーの一つとされている抗ミトコンドリア抗体も陰性であった。Double Tg miceについては、現在長期観察中だが、生後24週の時点でのsacrificeでは陽性所見は認めなかった。PBCの病因として、PDC-E2の胆管細胞細胞質での異所性発現が原因か結果かについて、以前より議論のあるところであった。本研究で作製したマウスにおいて、PDC-E2異所性発現のみではPBCを惹起し得なかったことは、今後の病態機序解明において有用であった。(2004年アメリカ肝臓病学会にて口演発表)今後何らかのsecond hitが必要なのかについて更に検討を加え、PBCの発症機序を包括的に解析し、それを踏まえて効果的な治療法の開発に繋げることが可能である。研究課題/領域番号:15790341, 研究期間(年度):2003 – 2004出典：「胆管細胞特異的PDC-E2発現マウスを用いたPBCモデルの作製およびその解析」研究成果報告書　課題番号15790341（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-15790341/)を加工して作

Human RAD18 is involved in S phase-specific single-strand break repair without PCNA monoubiquitination

Switching from a replicative to a translesion polymerase is an important step to further continue on replication at the site of DNA lesion. Recently, RAD18 (a ubiquitin ligase) was shown to monoubiquitinate proliferating cell nuclear antigen (PCNA) in cooperation with RAD6 (a ubiquitin-conjugating enzyme) at the replication-stalled sites, causing the polymerase switch. Analyzing RAD18-knockout (RAD18−/−) cells generated from human HCT116 cells, in addition to the polymerase switch, we found a new function of RAD18 for S phase-specific DNA single-strand break repair (SSBR). Unlike the case with polymerase switching, PCNA monoubiquitination was not necessary for the SSBR. When compared with wild-type HCT116 cells, RAD18−/− cells, defective in the repair of X-ray-induced chromosomal aberrations, were significantly hypersensitive to X-ray-irradiation and also to the topoisomerase I inhibitor camptothecin (CPT) capable of inducing single-strand breaks but were not so sensitive to the topoisomerase II inhibitor etoposide capable of inducing double-strand breaks. However, such hypersensitivity to CPT observed with RAD18−/− cells was limited to only the S phase due to the absence of the RAD18 S phase-specific function. Furthermore, the defective SSBR observed in S phase of RAD18−/− cells was also demonstrated by alkaline comet assay

Suppressive effects of transforming growth factor-beta1 produced by hepatocellular carcinoma cell lines on interferon-gamma production by peripheral blood mononuclear cells.

Transforming growth factor-beta1 (TGF-beta1) exerts potent immunosuppressive effects. In this study, we investigated the potential role of TGF-beta1 produced by hepatocellular carcinoma (HCC) cell lines in immunosuppression mechanisms. Using the Mv1Lu cell-growth inhibition assay and an enzyme-linked immunosorbent assay (ELISA), we detected optimal levels of TGF-beta1 in the culture supernatants conditioned by the HCC cell lines PLC/PRF/5, Hep3B, and HepG2. To determine the biological activity of TGF-beta1 in the supernatants, we examined the effects of the culture supernatants on the production of interferon (IFN)-gamma induced during the culture of peripheral blood mononuclear cells (PBMCs) stimulated with interleukin (IL)-12. IFN-gamma production of IL-12-stimulated PBMCs in the 1:1 dilution of the acid-activated conditioned medium of PLC/PRF/5, Hep3B, and HepG2 reduced to 14.7 +/- 0.8, 17.3 +/- 9.0, and 35.9 +/- 14.6%, respectively, compared with the value in the culture with control medium (complete culture medium). These results suggest that HCC cells producing TGF-beta1 may reduce the generation or activation of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, and thus could enhance their ability to escape immune-mediated surveillance.</p

Quantum-grade nanodiamonds for ultrabright spin detection in live cells

Optically accessible spin-active nanomaterials are promising as quantum nanosensors for probing biological samples. However, achieving bioimaging-level brightness and high-quality spin properties for these materials is challenging and hinders their application in quantum biosensing. Here, we demonstrate ultrabright fluorescent nanodiamonds (NDs) containing 0.6-1.3-ppm nitrogen-vacancy (NV) centers by spin-environment engineering via enriching spin-less 12C-carbon isotopes and reducing substitutional nitrogen spin impurities. The NDs, readily introduced into cultured cells, exhibited substantially narrow optically detected magnetic resonance (ODMR) spectra, requiring 16-times less microwave excitation power to give an ODMR depth comparable to that of conventional type-Ib NDs. They show average spin-relaxation times of T1 = 0.68 ms and T_2 = 1.6 us (1.6 ms and 2.7 us maximum) that were 5- and 11-fold longer than those of type-Ib, respectively. The bulk-like NV spin properties and bright fluorescence demonstrated in this study significantly improve the sensitivity of ND-based quantum sensors for biological applications

Glycolysis Inhibition Inactivates ABC Transporters to Restore Drug Sensitivity in Malignant Cells

Cancer cells eventually acquire drug resistance largely via the aberrant expression of ATP-binding cassette (ABC) transporters, ATP-dependent efflux pumps. Because cancer cells produce ATP mostly through glycolysis, in the present study we explored the effects of inhibiting glycolysis on the ABC transporter function and drug sensitivity of malignant cells. Inhibition of glycolysis by 3-bromopyruvate (3BrPA) suppressed ATP production in malignant cells, and restored the retention of daunorubicin or mitoxantrone in ABC transporter-expressing, RPMI8226 (ABCG2), KG-1 (ABCB1) and HepG2 cells (ABCB1 and ABCG2). Interestingly, although side population (SP) cells isolated from RPMI8226 cells exhibited higher levels of glycolysis with an increased expression of genes involved in the glycolytic pathway, 3BrPA abolished Hoechst 33342 exclusion in SP cells. 3BrPA also disrupted clonogenic capacity in malignant cell lines including RPMI8226, KG-1, and HepG2. Furthermore, 3BrPA restored cytotoxic effects of daunorubicin and doxorubicin on KG-1 and RPMI8226 cells, and markedly suppressed subcutaneous tumor growth in combination with doxorubicin in RPMI8226-implanted mice. These results collectively suggest that the inhibition of glycolysis is able to overcome drug resistance in ABC transporter-expressing malignant cells through the inactivation of ABC transporters and impairment of SP cells with enhanced glycolysis as well as clonogenic cells

Significant impact of biochemical recurrence on overall mortality in patients with high-risk prostate cancer after carbon-ion radiotherapy combined with androgen deprivation therapy

BACKGROUNDWhether biochemical recurrence (BR) is a significant predictive factor of mortality after definitive radiation therapy for prostate cancer remains unknown. The aim of the current study was to investigate the relation between BR and overall mortality (OAM) in high-risk prostate cancer patients who were treated with carbon-ion radiotherapy (CIRT) and had long-term follow-up in 2 prospective trials.METHODSIn the 2 phase 2 clinical trials, which involved 466 prostate cancer patients who received 63.0 to 66.0 Gy of CIRT (relative biological effect) in 20 fractions between 2000 and 2007, 324 patients who were deemed to be at high risk on the basis of the modified D\u27Amico classification criteria and received CIRT along with androgen-deprivation therapy (ADT) were examined. The OAM rate was adjusted for the ADT duration, and multivariate analyses using a Cox proportional hazards model were performed for OAM with BR as a time-dependent covariate.RESULTSThe median follow-up period was 107.4 months, and the 5- and 10-year OAM rates after adjustments for the ADT duration were 7.0% (95% confidence interval [CI], 4.0%-9.4%) and 23.9% (95% CI, 16.4%-26.2%), respectively. A multivariate analysis revealed that the presence of BR (hazard ratio, 2.82; 95% Cl, 1.57-5.08; P = .001) was one of the predictive factors for OAM. On the other hand, the duration of ADT had no impact on OAM.CONCLUSIONSBR after CIRT combined with ADT is an independent predictive factor for OAM in high-risk prostate cancer patients. The results of this study could be applied to other high-dose radiation therapies