浸潤性発育を示した後腹膜孤立線維性腫瘍の1例

56歳女.悪性後腹膜孤立性線維性腫瘍であり, 主訴は腹部腫瘤触知で, 腹部CT及びMRI検査にて左腎下方に接して, Gerota筋膜に沿うように発育する境界不明瞭な腫瘤を認めた.手術所見では後腹膜腔にゼラチン状の腫瘍を認め, 下行結腸周囲の脂肪組織やGerota筋膜周囲の脂肪組織に浸潤していた.Gerota筋膜内への浸潤は認めなかったので左腎は温存した.病理組織像では間質の膠原線維は著明に増殖し, hemangiopericytoma様のくちばし状を呈する血管も豊富に認められた.腫瘍組織内に腫瘍細胞密度の増加しているところや核異型度が強く分裂像を認める組織が混在しており, また周囲脂肪組織内に浸潤している所見を認めた.以上より, 悪性後腹膜孤立性線維性腫瘍と診断した.治療は外科的切除のみを行い, 2年4ヵ月を経過しても再発無く生存中であるSolitary fibrous retroperitoneal tumor is rare. We present a case with infiltrative growth in a 56-year-old female patient whose initial symptom was palpable tumor in the lower abdomen. Computed tomography and magnetic resonance imaging indicated a mass in the retroperitoneum under the left kidney with a poorly demarcated infiltrative growth. Surgical findings revealed a gelatinous tumor in the retroperitoneum, which had invaded up to the fatty tissue surrounding the Gerota's fascia and to the fatty tissue surrounding the descending colon. However, as there was no invasion into the Gerota's fascia, it was possible to preserve the left kidney. Pathohistological examination revealed increased cellularity in the tumor tissues as well as tissues with atypical nuclei of the tumor cells with some cell division. Due to these findings, it was diagnosed as malignant solitary fibrous tumor. Only surgical treatment was performed and the patient is alive without recurrence 2 years and 4 months after surgery

Conformational Study of Polypeptide Chains Grafted on the Surface of Polylactide Latex Particle

Polylactide (PLA) latex particle covered with polypeptide chains were prepared by means of solvent exchange method from PLA and PLA-block-polypeptide block copolymer solutions. PLA segment of the block copolymer and PLA homopolymer formed a core of the particle, and the polypeptide segment of the block copolymer, which is designed as tightly fixed biodegradable emulsifier, formed corona around the particle surface. This picture was supported by the fact that zeta-potential of PLA latex particle covered with polypeptide segment was different from that of bare PLA particle because of the presence of the ionizable group in the polypeptide chains. To clarify the effect of the ionizable group on conformation of the polypeptide chain, the relation between the polypeptide chain length and the area occupied by the single block chain was evaluated. The result that the occupied area per a polypeptide chain was linearly increased with the increase in the polypeptide chain length indicates that the polypeptide chains trail on the particle surface and did not take helical structures

Orbital- and spin-phase variability in the X-ray emission from the accreting pulsar Cen X-3

We analyzed 39 ks NuSTAR observation data of the high mass X-ray binary Cen X-3 in order to investigate the orbital- and spin-phase spectral variability. The observation covers the orbital phase of $\Phi=0.199$-$0.414$ of the source, where $\Phi=0$ corresponds to the mid-eclipse. The orbital-phase-resolved spectroscopy revealed that low energy photons are more dominant for the spectral fluctuation, and a large part of the variability can be explained in terms of absorption by clumps of stellar wind. The spin-phase-resolved spectroscopy together with energy-resolved pulse profiles, on the other hand, presented large flux variations in high energy bands, which suggests that the origin of the variability is the different efficiency of Comptonization inside the accretion column. The energy band which includes Fe emission lines or cyclotron resonance scattering feature (CRSF) shows distinct variability compared to the nearby bands. The Fe lines show low variability along the spin phase, which indicates that the emission regions are apart from the neutron star. The central energy and strength of the CRSF are both positively correlated with the spin-phase-resolved flux, which suggests that the emitted photons face stronger magnetic fields and deeper absorption when they come from high-flux regions. We also examined the independence of the orbital- and spin-phase variability. They showed no correlation with each other and were highly independent, which implies the accretion stream is stable during the observation.Comment: 20 pages, 12 figures, accepted for publication in Ap

Application of X-Ray Clumpy Torus Model (XCLUMPY) to 10 Obscured Active Galactic Nuclei Observed with Suzaku and NuSTAR

We apply XCLUMPY, an X-ray spectral model from a clumpy torus in an active galactic nucleus (AGN), to the broadband X-ray spectra of 10 obscured AGNs observed with both Suzaku and NuSTAR. The infrared spectra of these AGNs were analyzed with the CLUMPY code. Since XCLUMPY adopts the same clump distribution as that in the CLUMPY, we can directly compare the torus parameters obtained from the X-ray spectra and those from the infrared ones. The torus angular widths determined from the infrared spectra ($\sigma_{\mathrm{IR}}$) are systematically larger than those from the X-ray data ($\sigma_{\mathrm{X}}$); the difference ($\sigma_{\mathrm{IR}}-\sigma_{\mathrm{X}}$) correlates with the inclination angle determined from the X-ray spectrum. These results can be explained by the contribution from dusty polar outflows to the observed infrared flux, which becomes more significant at higher inclinations (more edge-on views). The ratio of the hydrogen column density and V-band extinction in the line of sight absorber shows large scatter ($\simeq$1 dex) around the Galactic value, suggesting that a significant fraction of AGNs have dust-rich circumnuclear environments.Comment: 17 pages, 3 figures, accepted for publication in Ap