Coevolution of Supermassive Black Holes and Circumnuclear Disks

We propose a new evolutionary model of a supermassive black hole (SMBH) and a circumnuclear disk (CND), taking into account the mass-supply from a host galaxy and the physical states of CND. In the model, two distinct accretion modes depending on gravitational stability of the CND play a key role on accreting gas to a SMBH. (i) If the CMD is gravitationally unstable, energy feedback from supernovae (SNe) supports a geometrically thick, turbulent gas disk. The accretion in this mode is dominated by turbulent viscosity, and it is significantly larger than that in the mode (ii), i.e., the CMD is supported by gas pressure. Once the gas supply from the host is stopped, the high accretion phase ($\sim 0.01- 0.1 M_{\odot} {\rm yr}^{-1}$) changes to the low one (mode (ii), $\sim 10^{-4} M_{\odot} {\rm yr}^{-1}$), but there is a delay with $\sim 10^{8}$ yr. Through this evolution, the gas-rich CND turns into the gas poor stellar disk. We found that not all the gas supplied from the host galaxy accrete onto the SMBH even in the high accretion phase (mode (i)), because the part of gas is used to form stars. As a result, the final SMBH mass ($M_{\rm BH,final}$) is not proportional to the total gas mass supplied from the host galaxy ($M_{\rm sup}$); $M_{\rm BH,final}/M_{\rm sup}$ decreases with $M_{\rm sup}$.This would indicate that it is difficult to form a SMBH with $\sim 10^{9} M_{\odot}$ observed at high-$z$ QSOs. The evolution of the SMBH and CND would be related to the evolutionary tracks of different type of AGNs.Comment: 11 pages, 11 figures, accepted for publication in Ap

The Fate of Young Radio Galaxies: Decelerations Inside Host Galaxies?

We examine the evolution of variously-sized radio galaxies [i.e., compact symmetric objects (CSOs), medium-size symmetric objects (MSOs), Fanaroff-Riley type II radio galaxies (FRIIs)], by comparing the relation between the hot spot size and the projected linear size with a coevolution model of hot spots and a cocoon. We take account of the deceleration effect by the cocoon head growth. We find that the advance speed of hot spots and lobes inevitably show the deceleration phase (CSO-MSO phase) and the acceleration phase (MSO-FRII phase). This is ascribed to the change of the power-law index of ambient density profile in the MSO phase ($\sim$1 kpc). It is also found that the cocoon shape becomes nearly spherical or disrupted for MSOs, while an elongated morphology is predicted for CSOs and FRIIs. This seems to be consistent with the higher fraction of distorted morphology of MSOs than that of CSOs and FRI. Finally, we predict that only CSOs whose initial advance speed is higher than about 0.1c can evolve into FRIIs, comparing the hot spot speed with the sound speed of the ambient medium.Comment: 12 pages, 8 figures, 4 tables, accepted for publication in ApJ; Table 1 and Table 2 are available at http://yso.mtk.nao.ac.jp/~kawakatu/Kawakatu08.pd

血管新生が進行性腎細胞癌の遠隔成績に及ぼす影響

著者らの施設において腎細胞癌の診断で腎摘除を行った148例中32例を対象に, 進行性腎細胞癌における血管新生因子, および治療に奏功した症例と進行した症例の相違について検討した.その結果, 1年, 5年そして10年生存率は各々82.4%, 30%, 30%であった.奏功症例(group A)は計4例で肺転移は3例に認められ, 2例に著効そして1例が有効であった.骨転移1例は有効であった.13例には奏功所見は認められなかった(group B).Thymidine Phosphorylaseはgroup Aがgroup Bより陽性率が高く, また多変量解析の結果, positive mean vascular areaが進行腎細胞癌における遠隔成績に影響をおよぼす独立した因子であることが示されたWe studied the relationship between angiogenic factors and clinical responses in advanced renal cell carcinomas (RCCs) and evaluated the angiogenic factors to clarify the potential impact of these factors on the cancer-specific survival. From January 1990 to December 2000, 148 patients underwent a nephrectomy for RCCs at our institution. Of the 32 patients who had distant metastasis, 17 met the histopathologic analysis requirements for an immuno-histochemical investigation. Fifteen of them were administered interferon-gamma and the remaining two patients were added to interferon-alpha and eight of seventeen patients also underwent radiation therapy. Both thymidine phosphorylase (TP) and Factor VIII immunostaining were performed. The overall survival rates at 1, 5 and 10 years were 82.4%, 30% and 30%, respectively. Three of these patients were diagnosed with lung metastasis and a complete response was seen in two, while a partial response was observed in one. In addition another patient who was diagnosed with bone metastasis also showed a partial response (group A). The remaining 13 patients showed progressive disease (group B). Group A had a higher TP-positive ratio (TP-PR) than that of group B. A multivariate analysis of the clinicopathologic data showed that a positive mean vascular area (PMVA) could be an independent factor regarding the potential impact of these factors on a long survival in advanced RCCS. PMVA was thus found to be an independent factor regarding the prognosis with advanced RCCs

インターフェロンγの腎細胞癌術後再発予防の長期成績 : 末梢血リンパ球は術後再発の指標となりえるか

This study examined the outcome of postoperative recurrence therapy on renal cell carcinoma (RCC) prevention involving treatment with single doses of interferon-gamma (IFN-gamma). From 1990-2000, 37 patients with no distant metastasis at the time they underwent a nephrectomy were enrolled in this investigation. Subcutaneous IFN-gamma was administered once a week. Total and differential white blood cells were counted before the pre-administration of IFN-gamma and then monthly thereafter for all patients. Blood lymphocyte subsets were analyzed phenotypically by direct immunofluorescence. Disease-free survival rates (DFSR) at 5 and 10 years were 81.7% and 75.9%, respectively. To clarify the effects of preoperative peripheral blood lymphocyte (PBL) and NK activity on DFSR, we categorized the patients into two groups according to the median number of PBL before the administration of IFN-gamma. Except for CD11b, PBL level had no effect on DFSR. Multiple logistic regression analysis showed that CD11b levels greater than 16.5% were associated with 25.35 odds ratio increase in the risk of postoperative recurrence. A multivariate analysis found that CD11b may be an independent factor for postoperative recurrence. In terms of preventing postoperative recurrence, our results showed that an elevated CD11b level may indicate patients who can benefit from further combination therapy.[目的]腎細胞癌術後再発に対するインターフェロンγの単剤投与の有用性について検討した.[対象と方法]1990～2000年までの間に原発巣摘除時に転移病巣のない腎細胞癌37例を対象とした.インターフェロンγを毎週連続で皮下投与して末梢血のリンパ球の分画について, 投与前, 投与後各1ヵ月ごとにflow cytometryを用いて検討した.[結果]37例中7例に再発が認められ, 非再発率は5年が81.7%, 10年が75.9%であった.術後再発に関わる影響を調べるため末梢血リンパ球とNK活性について投与前の中央値でおのおの2群に分けた.CD11bとNK活性を除いて術後再発に関連は認められなかった.多変量解析の結果, 投与前CD11bが16.5%以上だと16.5%未満の症例に比較して25.35倍術後再発が高く, 逆に投与前NK活性が13%以上の症例は0.25倍術後再発が減少する.[結語]多変量解析の結果術後に補助療法としてインターフェロンγ投与した症例では, CD11bとNK活性が術後再発に関わる独立した因子であることが判明した.また腎細胞癌の術後再発予防という観点からCD11bが高く, NK活性が低い症例には, さらなるcombination therapyが必要と考えられる(著者抄録