141 research outputs found
Gravitational potential and X-ray luminosities of early-type galaxies observed with XMM-Newton and Chandra
We study dark matter content in early-type galaxies and investigate whether
X-ray luminosities of early-type galaxies are determined by the surrounding
gravitational potential. We derived gravitational mass profiles of 22
early-type galaxies observed with XMM-Newton and Chandra. Sixteen galaxies show
constant or decreasing radial temperature profiles, and their X-ray
luminosities are consistent with kinematical energy input from stellar mass
loss. The temperature profiles of the other 6 galaxies increase with radius,
and their X-ray luminosities are significantly higher. The integrated
mass-to-light ratio of each galaxy is constant at that of stars within 0.5-1
r_e, and increases with radius, where r_e is the effective radius of a galaxy.
The scatter of the central mass-to-light ratio of galaxies was less in K-band
light. At 3r_e, the integrated mass-to-light ratios of galaxies with flat or
decreasing temperature profiles are twice the value at 0.5r_e, where the
stellar mass dominates, and at 6r_e, these increase to three times the value at
0.5r_e. This feature should reflect common dark and stellar mass distributions
in early-type galaxies: Within 3r_e, the mass of dark matter is similar to the
stellar mass, while within 6r_e, the former is larger than the latter by a
factor of two. By contrast, X-ray luminous galaxies have higher gravitational
mass in the outer regions than X-ray faint galaxies. We describe these X-ray
luminous galaxies as the central objects of large potential structures; the
presence or absence of this potential is the main source of the large scatter
in the X-ray luminosity.Comment: 22 pages, 18 figures, 6 tables, accepted for publication in A&
The central black hole mass of the high-sigma but low-bulge-luminosity lenticular galaxy NGC 1332
The masses of the most massive supermassive black holes (SMBHs) predicted by
the M_BH-sigma and M_BH-luminosity relations appear to be in conflict. Which of
the two relations is the more fundamental one remains an open question. NGC
1332 is an excellent example that represents the regime of conflict. It is a
massive lenticular galaxy which has a bulge with a high velocity dispersion
sigma of ~320 km/s; bulge--disc decomposition suggests that only 44% of the
total light comes from the bulge. The M_BH-sigma and the M_BH-luminosity
predictions for the central black hole mass of NGC 1332 differ by almost an
order of magnitude. We present a stellar dynamical measurement of the SMBH mass
using an axisymmetric orbit superposition method. Our SINFONI integral-field
unit (IFU) observations of NGC 1332 resolve the SMBH's sphere of influence
which has a diameter of ~0.76 arcsec. The sigma inside 0.2 arcsec reaches ~400
km/s. The IFU data allow us to increase the statistical significance of our
results by modelling each of the four quadrants separately. We measure a SMBH
mass of (1.45 \pm 0.20) x 10^9 M_sun with a bulge mass-to-light ratio of 7.08
\pm 0.39 in the R-band. With this mass, the SMBH of NGC 1332 is offset from the
M_BH-luminosity relation by a full order of magnitude but is consistent with
the M_BH-sigma relation.Comment: 15 pages, 12 figures, accepted for publication in MNRA
Complete necrosis of hepatocellular carcinoma after preoperative portal vein embolization: a case report
The outer halos of elliptical galaxies
Recent progress is summarized on the determination of the density
distributions of stars and dark matter, stellar kinematics, and stellar
population properties, in the extended, low surface brightness halo regions of
elliptical galaxies. With integral field absorption spectroscopy and with
planetary nebulae as tracers, velocity dispersion and rotation profiles have
been followed to ~4 and ~5-8 effective radii, respectively, and in M87 to the
outer edge at ~150 kpc. The results are generally consistent with the known
dichotomy of elliptical galaxy types, but some galaxies show more complex
rotation profiles in their halos and there is a higher incidence of
misalignments, indicating triaxiality. Dynamical models have shown a range of
slopes for the total mass profiles, and that the inner dark matter densities in
ellipticals are higher than in spiral galaxies, indicating earlier assembly
redshifts. Analysis of the hot X-ray emitting gas in X-ray bright ellipticals
and comparison with dynamical mass determinations indicates that non-thermal
components to the pressure may be important in the inner ~10 kpc, and that the
properties of these systems are closely related to their group environments.
First results on the outer halo stellar population properties do not yet give a
clear picture. In the halo of one bright galaxy, lower [alpha/Fe] abundances
indicate longer star formation histories pointing towards late accretion of the
halo. This is consistent with independent evidence for on-going accretion, and
suggests a connection to the observed size evolution of elliptical galaxies
with redshift.Comment: 8 pages. Invited review to appear in the proceedings of "Galaxies and
their Masks" eds. Block, D.L., Freeman, K.C. & Puerari, I., 2010, Springer
(New York
Preoperative Y-90 microsphere selective internal radiation treatment for tumor downsizing and future liver remnant recruitment: a novel approach to improving the safety of major hepatic resections
<p>Abstract</p> <p>Background</p> <p>Extended liver resections are being performed more liberally than ever. The extent of resection of liver metastases, however, is restricted by the volume of the future liver remnant (FLR). An intervention that would both accomplish tumor control and induce compensatory hypertrophy, with good patient tolerability, could improve clinical outcomes.</p> <p>Case presentation</p> <p>A 53-year-old woman with a history of cervical cancer presented with a large liver mass. Subsequent biopsy indicated poorly differentiated carcinoma with necrosis suggestive of squamous cell origin. A decision was made to proceed with pre-operative chemotherapy and Y-90 microsphere SIRT with the intent to obtain systemic control over the disease, downsize the hepatic lesion, and improve the FLR. A surgical exploration was performed six months after the first SIRT (three months after the second). There was no extrahepatic disease. The tumor was found to be significantly decreased in size with central and peripheral scarring. The left lobe was satisfactorily hypertrophied. A formal right hepatic lobectomy was performed with macroscopic negative margins.</p> <p>Conclusion</p> <p>Selective internal radiation treatment (SIRT) with yttrium-90 (Y-90) microspheres has emerged as an effective liver-directed therapy with a favorable therapeutic ratio. We present this case report to suggest that the portal vein radiation dose can be substantially increased with the intent of inducing portal/periportal fibrosis. Such a therapeutic manipulation in lobar Y-90 microsphere treatment could accomplish the end points of PVE with avoidance of the concern regarding tumor progression.</p
Portal vein embolization with n-butyl-cyanoacrylate through an ipsilateral approach before major hepatectomy: single center analysis of 50 consecutive patients
Guidelines for the management of biliary tract and ampullary carcinomas: surgical treatment
The only curative treatment in biliary tract cancer is surgical treatment. Therefore, the suitability of curative resection should be investigated in the first place. In the presence of metastasis to the liver, lung, peritoneum, or distant lymph nodes, curative resection is not suitable. No definite consensus has been reached on local extension factors and curability. Measures of hepatic functional reserve in the jaundiced liver include future liver remnant volume and the indocyanine green (ICG) clearance test. Preoperative portal vein embolization may be considered in patients in whom right hepatectomy or more, or hepatectomy with a resection rate exceeding 50%–60% is planned. Postoperative complications and surgery-related mortality may be reduced with the use of portal vein embolization. Although hepatectomy and/or pancreaticoduodenectomy are preferable for the curative resection of bile duct cancer, extrahepatic bile duct resection alone is also considered in patients for whom it is judged that curative resection would be achieved after a strict diagnosis of its local extension. Also, combined caudate lobe resection is recommended for hilar cholangiocarcinoma. Because the prognosis of patients treated with combined portal vein resection is significantly better than that of unresected patients, combined portal vein resection may be carried out. Prognostic factors after resection for bile duct cancer include positive surgical margins, especially in the ductal stump; lymph node metastasis; perineural invasion; and combined vascular resection due to portal vein and/or hepatic artery invasion. For patients with suspected gallbladder cancer, laparoscopic cholecystectomy is not recommended, and open cholecystectomy should be performed as a rule. When gallbladder cancer invading the subserosal layer or deeper has been detected after simple cholecystectomy, additional resection should be considered. Prognostic factors after resection for gallbladder cancer include the depth of mural invasion; lymph node metastasis; extramural extension, especially into the hepatoduodenal ligament; perineural invasion; and the degree of curability. Pancreaticoduodenectomy is indicated for ampullary carcinoma, and limited operation is also indicated for carcinoma in adenoma. The prognostic factors after resection for ampullary carcinoma include lymph node metastasis, pancreatic invasion, and perineural invasion
Background: Tokyo Guidelines for the management of acute cholangitis and cholecystitis
There are no evidence-based-criteria for the diagnosis, severity assessment, of treatment of acute cholecysitis or acute cholangitis. For example, the full complement of symptoms and signs described as Charcot’s triad and as Reynolds’ pentad are infrequent and as such do not really assist the clinician with planning management strategies. In view of these factors, we launched a project to prepare evidence-based guidelines for the management of acute cholangitis and cholecystitis that will be useful in the clinical setting. This research has been funded by the Japanese Ministry of Health, Labour, and Welfare, in cooperation with the Japanese Society for Abdominal Emergency Medicine, the Japan Biliary Association, and the Japanese Society of Hepato-Biliary-Pancreatic Surgery. A working group, consisting of 46 experts in gastroenterology, surgery, internal medicine, emergency medicine, intensive care, and clinical epidemiology, analyzed and examined the literature on patients with cholangitis and cholecystitis in order to produce evidence-based guidelines. During the investigations we found that there was a lack of high-level evidence, for treatments, and the working group formulated the guidelines by obtaining consensus, based on evidence categorized by level, according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence of May 2001 (version 1). This work required more than 20 meetings to obtain a consensus on each item from the working group. Then four forums were held to permit examination of the Guideline details in Japan, both by an external assessment committee and by the working group participants (version 2). As we knew that the diagnosis and management of acute biliary infection may differ from country to country, we appointed a publication committee and held 12 meetings to prepare draft Guidelines in English (version 3). We then had several discussions on these draft guidelines with leading experts in the field throughout the world, via e-mail, leading to version 4. Finally, an International Consensus Meeting took place in Tokyo, on 1–2 April, 2006, to obtain international agreement on diagnostic criteria, severity assessment, and management
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