Kyungpook National University

About: Kyungpook National University is a education organization based out in Daegu, South Korea. It is known for research contribution in the topics: Population & Catalysis. The organization has 20497 authors who have published 42107 publications receiving 834608 citations.

Quantitative evaluation of liver function with MRI Using Gd-EOB-DTPA.

Abstract: Objective Gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a newly developed MR contrast agent. After intravenous injection, Gd-EOB-DTPA is gradually taken up by the hepatocytes and eventually excreted via the biliary pathway without any change to its chemical structure. Because of these characteristics, it can be used as a tracer for quantitative liver function testing. The purpose of this study is to develop a noninvasive method of quantitation of the hepatic function using Gd-EOB-DTPA through the deconvolution analysis. Materials and methods Adult New Zealand white rabbits (n = 10, average body weight = 3.5 kg) were used in the present study. Hepatic injury was induced to by the intragastric administration of carbon tetrachloride (CCl4) three times a week for three weeks. Liver enzyme (aspartate aminotransferase, AST; alanine aminotransferase, ALT) levels and the plasma indocyanine green (ICG) retention rate 15 minutes after an intravenous injection of ICG (ICG R15), was checked before and after the three-week administration of CCl4. At the end of experimental period, an observer "blinded" to the treatment given the rabbits performed the histological examination. MRI studies were performed before and after the three-week administration of CCl4 on a 1.5 T scanner using a human extremity coil. After intravenous bolus injection of Gd-EOB-DTPA (0.3 mL of Gd-EOB-DTPA freshly prepared in 2.7 mL of normal saline) through the ear vein, the 250 axial single level dynamic MR images were obtained using a fast low angle shot (FLASH, T /TE = 11/4.2 msec, flip angle = 15, acquisition time 1 second, slice thickness = 5 mm, matrix = 128x128, field of view = 120 mm) sequence with 1.5 sec time intervals. The time-intensity curves were obtained at the abdominal aorta and the liver parenchyma that was devoid of blood vessels. Deconvolution analysis of the aortic (input function) and hepatic parenchymal (output function) time-intensity curves was performed with a modified Fourier transform technique to calculate the hepatic extraction fraction (HEF). The presence and type of hepatic injury were determined by the histopathologic examination and statistical analysis of the changes of the hepatic enzyme levels, the ICG R15 and Gd-EOBDTPA HEF values between the time before and after CCl4 administration with Wicoxon signed rank test. Correlation between the Gd-EOB-DTPA HEF and the change of the ICG R15 were analyzed with Pearson's correlation coefficient. Results Histopathologic examination showed findings that were compatible with hepatic fibrosis caused by chronic liver injury. The initial blood biochemical studies before the administration of carbon tetrachloride showed that the mean AST and ALT levels were 39.8+/-5.2 IU/L and 59.1+/-11.7 IU/L, respectively. The AST and ALT levels increased to 138.4+/-50.5 IU and 172.0+/-71.6 IU/L, respectively, after the three week administration of CCl4. The ALT and AST levels were significantly increased after the three weeks of CCl4 administration (p = 0.018). The ICG R15 values were 4.47+/-2.08% and 19.43+/-3.98% before and after three-week administration of CCl4, respectively. The ICG R15 values were significantly increased after hepatic injury (p = 0.018). After normalizing the HEF as 100% in each rabbit before CCl4 administration, the deconvoluted curve after CCl4 administration revealed less hepatocyte extraction efficiency with a mean value of 77.7+/-3.6. There was a significant correlation between the HEF and changes of the ICG R15 by the Pearson correlation coefficient assessment (correlation coefficient = -0.965, p = 0.000). Conclusion The Gd-EOB-DTPA HEF could be calculated from deconvolution analysis of aortic and hepatic parenchymal time-intensity curves obtained by dynamic MRI. The Gd-EOB-DTPA HEF was well correlated with changes of the ICG R15, which is the most common parameter used in the quantitative estimation of the hepatic function. The Gd-EOB-DTPA HEF is a direct, noninvasive technique for the quantitative evaluation of liver function. It could be a promising alternative for the determination of noninvasive hepatic function in those patients with liver disease.

Observation of Exclusive Charmonium Production and gamma gamma -> mu(+)mu(-) in p(p)over-bar Collisions at root s=1.96 TeV

Abstract: In CDF we have observed the reactions p + (p) over bar -> p + X + (p) over bar, with X being a centrally produced J/psi, psi(2S), or chi(c0), and gamma gamma -> mu(+)mu(-) in p (p) over bar collisions at root s = 1.96 TeV. The event signature requires two oppositely charged central muons, and either no other particles or one additional photon detected. Exclusive vector meson production is as expected for elastic photoproduction, gamma + p -> J/psi(psi(2S)) + p, observed here for the first time in hadron-hadron collisions. We also observe exclusive chi(c0) -> J/psi + gamma. The cross sections d sigma/dy vertical bar(y=0) for J/psi, psi(2S), and chi(c0) are 3.92 +/- 0: 25(stat) +/- 0.52(syst) nb, 0.53 +/- 0.09(stat) +/- 0.10(syst) nb, and 76 +/- 10(stat) +/- 10(syst) nb, respectively, and the continuum is consistent with QED. We put an upper limit on the cross section for Odderon exchange in exclusive J/psi production.

Cementless calcar-replacement hemiarthroplasty compared with intramedullary fixation of unstable intertrochanteric fractures. A prospective, randomized study.

Abstract: Background: Unstable intertrochanteric fractures in elderly patients are associated with a high rate of complications. The purpose of this investigation was to compare the results of long-stem cementless calcar-replacement hemiarthroplasty with those of treatment with a proximal femoral nail for unstable intertrochanteric fractures in elderly patients. Methods: Fifty-eight elderly patients with an AO/OTA type 31-A2 intertrochanteric fracture of the femur were randomized into two treatment groups and were followed for a minimum of two years. The twenty-nine patients in Group I were treated with a long-stem cementless calcar-replacement prosthesis, and the twenty-nine patients in Group II were treated with a proximal femoral nail. The two treatment groups were comparable with regard to demographic and injury variables. Results: There were no significant differences between the groups in terms of functional outcomes, hospital stay, time to weight-bearing, or general complications. Patients treated with a proximal femoral nail had a shorter operative time, less blood loss, fewer units of blood transfused, a lower mortality rate, and lower hospital costs compared with those treated with the long-stem cementless calcar-replacement prosthesis. Conclusions: In elderly patients with an unstable intertrochanteric femoral fracture, a proximal femoral nail provides superior clinical outcomes but no advantage with regard to functional outcome when compared with a long-stem cementless calcar-replacement arthroplasty. Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Application of Saturates, Aromatics, Resins, and Asphaltenes Crude Oil Fractionation for Detailed Chemical Characterization of Heavy Crude Oils by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Equipped with Atmospheric Pressure Photoionization

Abstract: Heavy crude oil samples, fractionated according to the saturates, aromatics, resins, and asphaltenes (SARA) fractionation method, were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) equipped with atmospheric pressure photoionization (APPI). SARA fractionation separates the crude oil into four main classes based on polarity and solubility. FT-ICR MS analyses of each if these fractions yielded spectra quite different from those of unfractionated crude oil. However, the spectrum acquired from the aromatics fraction was very similar to those of the unfractionated crude oil. The class, carbon number, and double-bond equivalence distributions obtained from each fraction were in agreement with what is expected from each SARA fraction. The data acquired from SARA fractions can be used to generate four peak lists for each crude oil sample. A master peak list, representing crude oil, was created by adding the same amount of a synthetic standard compound to each fraction. The abu...