Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by Y Park
Total Records ( 8 ) for Y Park
  J Yang , Y Park , H Zhang , X Xu , G. A Laine , K. C Dellsperger and C. Zhang
 

We hypothesized that the interaction between tumor necrosis factor- (TNF-)/nuclear factor-B (NF-B) via the activation of IKK-β may amplify one another, resulting in the evolution of vascular disease and insulin resistance associated with diabetes. To test this hypothesis, endothelium-dependent (ACh) and -independent (sodium nitroprusside) vasodilation of isolated, pressurized coronary arterioles from mLeprdb (heterozygote, normal), Leprdb (homozygote, diabetic), and Leprdb mice null for TNF- (dbTNF–/dbTNF–) were examined. Although the dilation of vessels to sodium nitroprusside was not different between Leprdb and mLeprdb mice, the dilation to ACh was reduced in Leprdb mice. The NF-B antagonist MG-132 or the IKK-β inhibitor sodium salicylate (NaSal) partially restored nitric oxide-mediated endothelium-dependent coronary arteriolar dilation in Leprdb mice, but the responses in mLeprdb mice were unaffected. The protein expression of IKK- and IKK-β were higher in Leprdb than in mLeprdb mice; the expression of IKK-β, but not the expression of IKK-, was attenuated by MG-132, the antioxidant apocynin, or the genetic deletion of TNF- in diabetic mice. Leprdb mice showed an increased insulin resistance, but NaSal improved insulin sensitivity. The protein expression of TNF- and NF-B and the protein modification of phosphorylated (p)-IKK-β and p-JNK were greater in Leprdb mice, but NaSal attenuated TNF-, NF-B, p-IKK-β, and p-JNK in Leprdb mice. The ratio of p-insulin receptor substrate (IRS)-1 at Ser307 to IRS-1 was elevated in Leprdb compared with mLeprdb mice; both NaSal and the JNK inhibitor SP-600125 reduced the p-IRS-1-to-IRS-1 ratio in Leprdb mice. MG-132 or the neutralization of TNF- reduced superoxide production in Leprdb mice. In conclusion, our results indicate that the interaction between NF-B and TNF- signaling induces the activation of IKK-β and amplifies oxidative stress, leading to endothelial dysfunction in type 2 diabetes.

  S. H Kim , J Lee , M. J Kim , Y. H Jeon , Y Park , D Choi , W. J Lee and H. K. Lim
 

OBJECTIVE. We compared the diagnostic performance of gadoxetic acid–enhanced MRI with that of triple-phase 16-, 40-, and 64-MDCT in the preoperative detection of hepatocellular carcinoma (HCC).

SUBJECTS AND METHODS. Sixty-two consecutively registered patients (54 men, eight women; age range, 31–67 years) with 83 HCCs underwent triple-phase (arterial, portal venous, equilibrium) CT at 16-, 40-, or 64-MDCT and gadoxetic acid–enhanced 3-T MRI. The diagnosis of HCC was established after surgical resection. Three observers independently and randomly reviewed the MR and CT images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques in the detection of HCC was assessed with alternative free response receiver operating characteristic (ROC) analysis. Sensitivity, positive and negative predictive values, and sensitivity according to tumor size were evaluated.

RESULTS. For each observer, the areas under the ROC curve were 0.971, 0.959, and 0.967 for MRI and 0.947, 0.950, and 0.943 for CT. The differences were not statistically significant between the two techniques for each observer (p > 0.05). The differences in sensitivity and positive and negative predictive values between the two techniques for each observer were not statistically significant (p > 0.05). Among 10 HCCs 1 cm in diameter or smaller, each of the observers detected seven tumors with MRI. With CT, one observer detected five, one observer detected four, and one observer detected three HCCs with no statistically significant difference (p > 0.05).

CONCLUSION. Gadoxetic acid–enhanced MRI and triple-phase MDCT have similar diagnostic performance in the preoperative detection of HCC, but MRI may be better than MDCT in the detection of HCC 1 cm in diameter or smaller.

  T Yu , Y Park , J. M Johnson and D. P. Jones
 

Motivation: Liquid chromatography-mass spectrometry (LC/MS) profiling is a promising approach for the quantification of metabolites from complex biological samples. Significant challenges exist in the analysis of LC/MS data, including noise reduction, feature identification/ quantification, feature alignment and computation efficiency.

Result: Here we present a set of algorithms for the processing of high-resolution LC/MS data. The major technical improvements include the adaptive tolerance level searching rather than hard cutoff or binning, the use of non-parametric methods to fine-tune intensity grouping, the use of run filter to better preserve weak signals and the model-based estimation of peak intensities for absolute quantification. The algorithms are implemented in an R package apLCMS, which can efficiently process large LC/ MS datasets.

  Y. H Jeong , J. Y Hwang , I. S Kim , Y Park , S. J Hwang , S. W Lee , C. H Kwak and S. W. Park
 

Background— Optimal platelet inhibition is an important therapeutic adjunct in patients acute myocardial infarction (AMI) undergoing coronary stenting. Whether adjunctive cilostazol to dual antiplatelet therapy (triple antiplatelet therapy) can inhibit enhanced platelet reactivity in patients with AMI yet has not been determined. The aim of this study was to assess the degree of platelet inhibition by triple antiplatelet therapy in patients with AMI.

Methods and Results— Immediately after emergency room arrival, patients with AMI received clopidogrel (600-mg loading dose, followed by 75 mg daily) and aspirin (300-mg loading dose and 200 mg daily throughout the study period). After patients underwent coronary stenting (n=90), they were randomly assigned to 1 of 3 groups before discharge: standard group, clopidogrel of 75 mg daily (n=30); high maintenance dose (MD) group, clopidogrel of 150 mg daily (n=30); and triple group, adjunctive cilostazol of 100 mg twice daily to clopidogrel of 75 mg daily (n=30). Platelet reactivity was assessed at predischarge and 30-day follow-up by conventional aggregometry and the VerifyNow P2Y12 assay. Predischarge platelet reactivities were similar in the 3 groups. At 30-day follow-up, inhibition of maximal aggregation with 20 µM ADP stimuli was 6.0% in the standard group, 19.1% in the high-MD group, and 42.4% in the triple group (P<0.001), whereas inhibition of late aggregation with 20µM ADP stimuli was 10.8%, 38.1%, and 66.4%, respectively (P<0.001). Similar results were demonstrated when 5 µM ADP was used. Furthermore, percent changes of P2Y12 reaction unit were significantly different among regimens (10.6% in the standard group, 30.7% in the high-MD group, and 43.0% in the triple group; P<0.001). With respect to high-postclopidogrel platelet reactivity (prespecified as 20 µM ADP-induced maximal aggregation >50% of light transmission), fewer patients in the triple group (13.3%) met the criteria as compared with those in the standard (76.7%) and high-MD groups (56.7%) at 30-day follow-up (P<0.001). In the triple group, there were more potent and consistent platelet inhibitions by all parameters as compared with the high-MD group except for percent changes of P2Y12 reaction unit (P=0.071).

Conclusions— Among patients with AMI undergoing coronary stenting, triple antiplatelet therapy results in a greater antiplatelet effect at 30 days as compared with a high-MD clopidogrel or standard dual antiplatelet therapy.

  S. J Hwang , Y. H Jeong , I. S Kim , K. S Park , M. K Kang , J. S Koh , J. R Park , Y Park , E. H Koh , C. H Kwak , J. Y Hwang and S. Kim
  Background—

Among patients treated with clopidogrel, carriers of the cytochrome P450 (CYP) 2C19 loss-of-function allele have shown increased platelet reactivity and higher rates of ischemic events. Although adjunctive cilostazol to dual antiplatelet therapy (or "triple antiplatelet therapy") intensifies platelet inhibition, it remains unknown whether triple antiplatelet therapy after percutaneous coronary intervention can achieve adequate platelet inhibition in patients with the CYP2C19 mutant allele.

Methods and Results—

CYP2C19 genotyping for *1, *2, and *3 was performed in 134 high-risk patients undergoing elective percutaneous coronary intervention. After measurement of preprocedural platelet reactivity, patients were randomly assigned to receive either adjunctive cilostazol 100 mg twice daily (triple group; n=69) or high maintenance-dose (MD) clopidogrel of 150 mg daily (high-MD group; n=65). Using light transmittance aggregometry and the VerifyNow P2Y12 assay, platelet reactivity was assessed before the index procedure and at 30-day follow-up. The primary end point was absolute change in maximal platelet aggregation (Aggmax) according to CYP2C19 genotyping. High posttreatment platelet reactivity was defined as 5 µmol/L ADP–induced maximal platelet aggregation >50%. In noncarriers of the CYP2C19*2/*3 mutant allele, Aggmax values after 5 and 20 µmol/L ADP stimuli did not differ significantly between the triple (n=22) versus the high-MD group (n=22) (23.6±21.6% versus 16.6±15.4%, P=0.224 and 26.4±22.2% versus 18.6±14.9%, P=0.174, respectively). Absolute changes in late platelet aggregation and P2Y12 reaction unit were not different between the groups. The rate of high posttreatment platelet reactivity at 30-day follow-up also was comparable between the triple versus the high-MD group (4.5% versus 13.6%, P=0.607). In carriers of at least 1 CYP2C19*2/*3 mutant allele, the triple group (n=47) showed greater values of Aggmax after addition of 5 µmol/L (25.8±16.8% versus 11.1±19.8%, P<0.001) and 20 µmol/L ADP (26.3±16.0% versus 11.5±16.3%, P<0.001) compared with the high-MD group (n=43). Likewise, absolute changes in late platelet aggregation and P2Y12 reaction unit were consistently greater in the triple versus the high-MD group. Fewer patients in the triple group met the criteria of high posttreatment platelet reactivity at 30-day follow-up compared with the high-MD group (6.4% versus 37.2%, P<0.001).

Conclusions—

Among high-risk patients undergoing elective percutaneous coronary intervention, adjunctive cilostazol can achieve consistently intensified platelet inhibition and reduce the risk of high posttreatment platelet reactivity irrespective of CYP2C19 genotyping.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01012193.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility