Main-duct intraductal papillary mucinous adenoma of the pancreas

<p>Abstract</p> <p>Background</p> <p>The prevalence of carcinoma in main-duct intraductal papillary mucinous neoplasm (IPMN) is high, and surgical resection is recommended for all patients with a main-duct IPMN.</p> <p>Results</p> <p>A main-duct IPMN with typical imagings including protruding lesions in the dilated main pancreatic duct was resected, but the histology was intraductal papillary mucinous adenoma of the pancreas.</p> <p>Discussion</p> <p>It has been reported that the presence of mural nodules and dilatation of MPD are significantly higher in malignant IPMNs. The presented case had protruding lesions in the dilated main pancreatic duct on endoscopic ultrasonography, but the histology was adenoma.</p> <p>Conclusion</p> <p>Preoperative distinction between benign and malignant IPMNs is difficult.</p

Planar CuO_2 hole density estimation in multilayered high-T_c cuprates

We report that planar CuO_2 hole densities in high-T_c cuprates are consistently determined by the Cu-NMR Knight shift. In single- and bi-layered cuprates, it is demonstrated that the spin part of the Knight shift K_s(300 K) at room temperature monotonically increases with the hole density $p$ from underdoped to overdoped regions, suggesting that the relationship of K_s(300 K) vs. p is a reliable measure to determine p. The validity of this K_s(300 K)-p relationship is confirmed by the investigation of the p-dependencies of hyperfine magnetic fields and of spin susceptibility for single- and bi-layered cuprates with tetragonal symmetry. Moreover, the analyses are compared with the NMR data on three-layered Ba_2Ca_2Cu_3O_6(F,O)_2, HgBa_2Ca_2Cu_3O_{8+delta}, and five-layered HgBa_2Ca_4Cu_5O_{12+delta}, which suggests the general applicability of the K_s(300 K)-p relationship to multilayered compounds with more than three CuO_2 planes. We remark that the measurement of K_s(300 K) enables us to separately estimate p for each CuO_2 plane in multilayered compounds, where doped hole carriers are inequivalent between outer CuO_2 planes and inner CuO_2 planes.Comment: 7 pages, 5 figures, 2 Tables, to be published in Physical Review

Novel Calcium-Binding Ablating Mutations Induce Constitutive RET Activity and Drive Tumorigenesis

がんゲノム医療のさらなる拡大へ向けた一歩 --コンピュータ解析で意義不明変異のなかに治療標的となる新たな遺伝子変異を発見--. 京都大学プレスリリース. 2022-09-29.Distinguishing oncogenic mutations from variants of unknown significance (VUS) is critical for precision cancer medicine. Here, computational modeling of 71, 756 RET variants for positive selection together with functional assays of 110 representative variants identified a three-dimensional cluster of VUSs carried by multiple human cancers that cause amino acid substitutions in the calmodulin-like motif (CaLM) of RET. Molecular dynamics simulations indicated that CaLM mutations decrease interactions between Ca²⁺ and its surrounding residues and induce conformational distortion of the RET cysteine-rich domain containing the CaLM. RET-CaLM mutations caused ligand-independent constitutive activation of RET kinase by homodimerization mediated by illegitimate disulfide bond formation. RET-CaLM mutants possessed oncogenic and tumorigenic activities that could be suppressed by tyrosine kinase inhibitors targeting RET. This study identifies calcium-binding ablating mutations as a novel type of oncogenic mutation of RET and indicates that in silico–driven annotation of VUSs of druggable oncogenes is a promising strategy to identify targetable driver mutations

Novel Superconducting Phases in Copper Oxides and Iron-oxypnictides: NMR Studies

We reexamine the novel phase diagrams of antiferromagnetism (AFM) and high-Tc$superconductivity (HTSC) for a disorder-free CuO$_2$plane based on an evaluation of local hole density ($p$) by site-selective Cu-NMR studies on multilayered copper oxides. Multilayered systems provide us with the opportunity to research the characteristics of the disorder-free CuO$_2$plane. The site-selective NMR is the best and the only tool used to extract layer-dependent characteristics. Consequently, we have concluded that the uniform mixing of AFM and SC is a general property inherent to a single CuO$_2$plane in an underdoped regime of HTSC. The$T$=0 phase diagram of AFM constructed here is in quantitative agreement with the theories in a strong correlation regime which is unchanged even with mobile holes. This {\it Mott physics} plays a vital role for mediating the Cooper pairs to make$T_c$of HTSC very high. By contrast, we address from extensive NMR studies on electron-doped iron-oxypnictides La1111 compounds that the increase in$T_c$is not due to the development of AFM spin fluctuations, but because the structural parameters, such as the bond angle$\alpha$of the FeAs$_4$tetrahedron and the a-axis length, approach each optimum value. Based on these results, we propose that a stronger correlation in HTSC than in FeAs-based superconductors may make$T_c$ higher significantly.Comment: 5 pages, 4 figures, accepted for publication in J.Phys.Chem.Solids (2010

Visualization of murine lymph vessels using photoacoustic imaging with contrast agents

Metastasis frequently occurs even in the early stage of breast cancer. This research studied the feasibility of using photoacoustic (PA) imaging for identifying metastasis in the lymph vessels of mice. The photoacoustic efficiency of various contrast agents was investigated, and the influence of scattered light was evaluated by using a lymph vessel phantom. The lymph vessels of mice were then visualized using the selected contrast agents: indocyanine green (ICG) and gold nanorods (AuNR). The attenuation of the PA imaging was −1.90 dB/mm, whereas that of the fluorescence imaging was −4.45 dB/mm. The results indicate the potential of identifying sentinel lymph nodes by using PA imaging with these contrast agents. Keywords: Photoacoustic tomography, Contrast agents, Lymph vessels, 3D-real-time imaging systems, Ultrasonic transducer arrays, Light wavelength dependence of photoacoustic signal

Effect of Microstructures on Yield Strength in Hot-Stamped Steel Sheet

For automotive structural parts, hot stamping is being increasingly used because of the need for both higher fuel efficiency and crashworthiness. The yield strength of hot-stamped steel sheet is lower than that of water-quenched steel sheet. The microstructure of hot-stamped low-carbon steel sheet comprises lath martensite and retained austenite. Due to the slow cooling rate below the martensite start temperature, the martensite formed by hot stamping is auto-tempered. To clarify the factor dominating the yield strength of the hot-stamped steel, the authors herein investigated the effect of microstructures on the yield strength with heat-treated specimens at various cooling rates and heating temperatures. Consequently, it was clarified that the yield strength of the auto-tempered low-carbon steel depends on grain, dislocation, solute carbon, carbide, and retained austenite. As far as the present experiment is concerned, the retained austenite is the most effective factor on the yield strength

Tumor development in Japanese patients with Lynch syndrome.

Lynch syndrome (LS) patients have a high risk of developing various tumors. This study aimed to clarify the characteristics of tumors developing in LS patients.This is a retrospective review of 55 LS patients treated at Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital.The median age at the diagnosis of the first malignant tumor and first LS-related tumor was 44 (range, 19-65) and 44 (range, 24-66) years, respectively. Of the 55 LS patients with developing malignant tumors, 45 (93.8%) developed an LS-related tumor as the first malignant tumor. Colorectal cancer (CRC) developed in 47 patients (85.4%), followed by endometrial cancer (n = 13, 56.5%) in females and gastric cancer (n = 10, 18.1%). In 6 gastric cancer patients, Helicobacter pylori was detected in resected specimens. Twenty-nine patients (52.7%) developed CRC and extra-colonic tumors; of these, 15 patients (48.3%) had mutations in MLH1, 10 (58.8%) in MSH2, and 4 (57.1%) in MSH6. At the age of 50, the cumulative incidence was 50.9% [95% confidence interval (CI), 36.9-63.3%] for CRC, 17.4% (95% CI, 5.2-35.6%) for endometrial cancer, and 5.5% (95% CI, 1.4-13.8%) for gastric cancer. Eight gastric cancer, one breast cancer patient, five bladder cancer patients, and one prostate cancer patient demonstrated loss of expression of the mismatch repair (MMR) protein; patients with thyroid cancer, spindle cell sarcoma, and giant cell tumors did not demonstrate this.Gastric cancer incidence was high in Japanese patients with LS and associated with H. pylori infection. MMR protein deficiency caused the development of malignant tumors in LS patients