298 research outputs found
Residual mitral regurgitation after repair for posterior leaflet prolapse- Importance of preoperative anterior leaflet tethering
Background
Carpentier's techniques for degenerative posterior mitral leaflet prolapse have been established with excellent long‐term results reported. However, residual mitral regurgitation (
MR
) occasionally occurs even after a straightforward repair, though the involved mechanisms are not fully understood. We sought to identify specific preoperative echocardiographic findings associated with residual
MR
after a posterior mitral leaflet repair.
Methods and Results
We retrospectively studied 117 consecutive patients who underwent a primary mitral valve repair for isolated posterior mitral leaflet prolapse including a preoperative 3‐dimensional transesophageal echocardiography examination. Twelve had residual
MR
after the initial repair, of whom 7 required a corrective second pump run, 4 underwent conversion to mitral valve replacement, and 1 developed moderate
MR
within 1 month. Their preoperative parameters were compared with those of 105 patients who had an uneventful mitral valve repair. There were no hospital deaths. Multivariate analysis identified preoperative anterior mitral leaflet tethering angle as a significant predictor for residual
MR
(odds ratio, 6.82; 95% confidence interval, 1.8–33.8;
P
=0.0049). Receiver operator characteristics curve analysis revealed a cut‐off value of 24.3° (area under the curve, 0.77), indicating that anterior mitral leaflet angle predicts residual
MR
. In multivariate regression analysis, smaller anteroposterior mitral annular diameter (
P
<0.001) and lower left ventricular ejection fraction (
P
=0.002) were significantly associated with higher anterior mitral leaflet angle, whereas left ventricular and left atrial dimension had no significant correlation.
Conclusions
Anterior mitral leaflet tethering in cases of posterior mitral leaflet prolapse has an adverse impact on early results following mitral valve repair. The findings of preoperative 3‐dimensional transesophageal echocardiography are important for consideration of a careful surgical strategy.
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Suzaku Observation of HCG 62: Temperature, Abundance, and Extended Hard X-ray Emission Profiles
We present results of 120 ks observation of a compact group of galaxies
HCG~62 () with Suzaku XIS and HXD-PIN\@. The XIS spectra for four
annular regions were fitted with two temperature {\it vapec} model with
variable abundance, combined with the foreground Galactic component. The
Galactic component was constrained to have a common surface brightness among
the four annuli, and two temperature {\it apec} model was preferred to single
temperature model. We confirmed the multi-temperature nature of the intra-group
medium reported with Chandra and XMM-Newton, with a doughnut-like high
temperature ring at radii 3.3--6.5 in a hardness image. We found Mg, Si, S,
and Fe abundances to be fairly robust. We examined the possible
``high-abundance arc'' at southwest from the center, however Suzaku
data did not confirm it. We suspect that it is a misidentification of an excess
hot component in this region as the Fe line. Careful background study showed no
positive detection of the extended hard X-rays previously reported with ASCA,
in 5--12 keV with XIS and 12--40 keV with HXD-PIN, although our upper limit did
not exclude the ASCA result. There is an indication that the X-ray intensity in
region is % higher than the nominal CXB level (5--12 keV),
and Chandra and Suzaku data suggest that most of this excess could be due to
concentration of hard X-ray sources with an average photon index of
. Cumulative mass of O, Fe and Mg in the group gas and the
metal mass-to-light ratio were derived and compared with those in other groups.
Possible role of AGN or galaxy mergers in this group is also discussed.Comment: 29 pages with 9 figures, accepted for publication in PASJ Vol 60,
second Suzaku special issu
An open-label, phase 1 study evaluating safety, tolerability, and pharmacokinetics of linifanib (ABT-869) in Japanese patients with solid tumors
PURPOSE: This phase 1 study assessed the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of linifanib in Japanese patients with advanced solid tumors. METHODS: Patients were assigned to one of four sequential cohorts (0.05, 0.10, 0.20, or 0.25 mg/kg) of oral, once-daily linifanib on a 21-day cycle. Adverse events (AEs) were assessed per common terminology criteria for adverse events v3.0; tumor responses were assessed by response evaluation criteria in solid tumors. RESULTS: Eighteen patients were enrolled. Eleven (61%) received ≥3 prior therapies. Dose-limiting toxicities were Grade 3 ALT increase (0.10 mg/kg linifanib) and Grade 1 T-wave inversion (0.25 mg/kg linifanib) requiring dose interruption for >7 days and discontinuation on day 29. The most common linifanib-related AE was hypertension. Other significant treatment-related AEs included proteinuria, fatigue, and palmar-plantar erythrodysaesthesia. Linifanib pharmacokinetics were dose-proportional across 0.10–0.25 mg/kg. Two patients (11.1%) had confirmed partial responses, 12 had a best response of stable disease (11 had stable disease for ≥12 weeks), and four patients were not evaluable due to incomplete data. Four patients (lung cancer, breast cancer, thymic cancer, sarcoma) have continued linifanib for ≥48 weeks (range, 48–96+ weeks). CONCLUSION: Linifanib was well tolerated with promising preliminary clinical activity in Japanese patients. Later-phase global studies examining linifanib efficacy will include Japanese patients
Impact of the omicron phase on a highly advanced medical facility in Japan
BackgroundEight waves of the coronavirus disease 2019 (COVID-19) epidemic have been observed in Japan. This retrospective study was conducted to clarify the clinical characteristics of pediatric COVID-19 patients.MethodsWe studied 121 patients admitted to the Jichi Children's Medical Center Tochigi between April 2020 and March 2023. Incidence of pediatric COVID-19 in Tochigi Prefecture was used to examine hospitalization and severe illness rates.ResultsThe mean age of the patients was 3 years and 8 months. One hundred and eleven patients (91.7%) were hospitalized after January 2022 (after the 6th wave), when the Omicron strain became endemic in Japan. Convulsions occurred in 30 patients (24.8%), all of whom were admitted after the 6th wave. Twenty-three of the 30 patients had no underlying disease. Eleven patients (9.1%) were diagnosed with acute encephalopathy. One patient died due to hemorrhagic shock and encephalopathy syndrome and two had sequelae after the 6th wave. The patient who died due to encephalopathy had hypercytokinemia. In the Tochigi Prefecture, the number of pediatric COVID-19 patients increased after the 6th wave, but the hospitalization rate declined. The rate of severe illness did not change before the end of 5th and after the 6th wave.ConclusionAlthough the rate of severe illness in patients with pediatric COVID-19 did not increase after the 6th wave, some patients had complicated critical illnesses. Systemic inflammatory reaction was considered to have been associated with the severe encephalopathy
The LHCf experiment at LHC
The LHCf experiment will be installed in 2007 on the LHC collider in the forward direction at ±140m from the ATLAS interaction point. The purpose of LHCf is to precisely measure the pion production cross section near zero degrees through the measurement of the photons produced in neutral pion decay. This measurement is crucial for the simulation of the showers induced in the atmosphere by very high energy cosmic rays; the 14 TeV energy available in the center of mass frame corresponds in fact to an equivalent energy of 1017 eV in the laboratory system. The paper focus on the proposed experiment and on the physics results that we expect from it
X-Ray Study of Temperature and Abundance Profiles of the Cluster of Galaxies Abell 1060 with Suzaku
We carried out observations of the central and 20' east offset regions of the
cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral
analysis has revealed temperature and abundance profiles of Abell 1060 out to
27' ~ 380; /h_70 kpc, which corresponded to ~ 0.25; r_180. Temperature decrease
of the intra cluster medium from 3.4 keV at the center to 2.2 keV in the
outskirt region are clearly observed. Abundances of Si, S and Fe also decrease
by more than 50% from the center to the outer, while Mg shows fairly constant
abundance distribution at ~ 0.7 solar within r < 17'. O shows lower abundance
of ~ 0.3 solar in the central region (r~ 6'), and indicates a similar feature
with Mg, however it is sensitive to the estimated contribution of the Galactic
components of kT_1 ~ 0.15 keV and kT_2 ~ 0.7 keV in the outer annuli (r ~ 13').
Systematic effects due to the point spread function tails, contamination on the
XIS filters, instrumental background, cosmic and/or Galactic X-ray background,
and the assumed solar abundance tables are carefully examined. Results on
temperature and abundances of Si, S, and Fe are consistent with those derived
by XMM-Newton at r < 13'. Formation and metal enrichment process of the cluster
are discussed based on the present results.Comment: 20 pages, 19 figures, accepted for publication in PAS
High energy electron observation by Polar Patrol Balloon flight in Antarctica
We accomplished a balloon observation of the high-energy cosmic-ray electrons in 10-1000GeV to reveal the origin and the acceleration mechanism. The observation was carried out for 13 days at an average altitude of 35km by the Polar Patrol Balloon (PPB) around Antarctica in January 2004. The detector is an imaging calorimeter composed of scintillating-fiber belts and plastic scintillation counters sandwiched between lead plates. The geometrical factor is about 600cm^2sr, and the total thickness of lead absorber is 9 radiation lengths. The performance of the detector has been confirmed by a test flight at the Sanriku Balloon Center and by an accelerator beam test using the CERN-SPS (Super Proton Synchrotron at CERN). The new telemetry system using the Iridium satellite, the power system supplied by solar panels and the automatic flight level control operated successfully during the flight. We collected 5.7×10^3 events over 100GeV, and selected the electron candidates by a preliminary data analysis of the shower images. We report here an outline of both detector and observation, and the first result of the electron energy spectrum over 100GeV obtained by an electronic counter
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