• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.255-266
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• 2022

In crustaceans, molting is regulated by interactions between ecdysteroid and juvenile hormone (JH) signaling pathway-related genes. Unlike the ecdysteroid signaling pathway, little information on the role of JH signaling pathway-related genes in molting is available in zooplanktonic crustaceans. In this study, three genes (juvenile hormone acid O-methyltransferase (JHAMT), methoprene-tolerant (Met), and juvenile hormone epoxide hydrolase (JHEH)) which are involved in the synthesis, receptor-binding, and degradation of JH were identified using sequence and phylogenetic analysis in the brackish water flea, Diaphanosoma celebensis. Transcriptional changes in these genes during the molting cycle in D. celebensis were analyzed. Sequence and phylogenetic analysis revealed that these putative proteins may be functionally conserved along with those of insects and other crustaceans. In addition, the expression of the three genes was correlated with the molting cycle of D. celebensis, indicating that these genes may be involved in the synthesis and degradation of JH, resulting in normal molting. This study will provide information for a better understanding of the role of JH signaling pathway-related genes during the molting process in Cladocera.

• Investigative Magnetic Resonance Imaging
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• v.26 no.1
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• pp.10-19
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• 2022

Purpose: To evaluate whether the added value of contrast leakage information from dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) is a better prognostic imaging biomarker than the cerebral blood volume (CBV) value in distinguishing true progression from pseudoprogression in glioblastoma patients. Materials and Methods: Forty-nine glioblastoma patients who had undergone MRI after concurrent chemoradiotherapy with temozolomide were enrolled in this retrospective study. Twenty features were extracted from the normalized relative CBV (nCBV) and extraction fraction (EF) map of the contrast-enhancing region in each patient. After univariable analysis, we used multivariable stepwise logistic regression analysis to identify significant predictors for differentiating between pseudoprogression and true progression. Receiver operating characteristic (ROC) analysis was employed to determine the best cutoff values for the nCBV and EF features. Finally, leave-one-out cross-validation was used to validate the best predictor in differentiating between true progression and pseudoprogression. Results: Multivariable stepwise logistic regression analysis showed that MGMT (O⁶-methylguanine-DNA methyltransferase) and EF max were independent differentiating variables (P = 0.004 and P = 0.02, respectively). ROC analysis yielded the best cutoff value of 95.75 for the EF max value for differentiating the two groups (sensitivity, 61%; specificity, 84.6%; AUC, 0.681 ± 0.08; 95% CI, 0.524-0.837; P = 0.03). In the leave-one-out cross-validation of the EF max value, the cross-validated values for predicting true progression and pseudoprogression accuracies were 69.4% and 71.4%, respectively. Conclusion: We demonstrated that contrast leakage information parameter from DSC MRI showed significance in differentiating true progression from pseudoprogression in glioblastoma patients.

• Korean Journal of Radiology
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• v.21 no.6
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• pp.707-716
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• 2020

Objective: To evaluate pharmacokinetic variables from contrast-enhancing lesions (CELs) and non-enhancing T2 high signal intensity lesions (NE-T2HSILs) on dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging for predicting progression-free survival (PFS) in glioblastoma (GBM) patients. Materials and Methods: Sixty-four GBM patients who had undergone preoperative DCE MR imaging and received standard treatment were retrospectively included. We analyzed the pharmacokinetic variables of the volume transfer constant (Ktrans) and volume fraction of extravascular extracellular space within the CEL and NE-T2HSIL of the entire tumor. Univariate and multivariate Cox regression analyses were performed using preoperative clinical characteristics, pharmacokinetic variables of DCE MR imaging, and postoperative molecular biomarkers to predict PFS. Results: The increased mean Ktrans of the CEL, increased 95th percentile Ktrans of the CELs, and absence of methylated O⁶-methylguanine-DNA methyltransferase promoter were relevant adverse variables for PFS in the univariate analysis (p = 0.041, p = 0.032, and p = 0.083, respectively). The Kaplan-Meier survival curves demonstrated that PFS was significantly shorter in patients with a mean Ktrans of the CEL > 0.068 and 95th percentile Ktrans of the CEL > 0.223 (log-rank p = 0.038 and p = 0.041, respectively). However, only mean Ktrans of the CEL was significantly associated with PFS (p = 0.024; hazard ratio, 553.08; 95% confidence interval, 2.27-134756.74) in the multivariate Cox proportional hazard analysis. None of the pharmacokinetic variables from NE-T2HSILs were significantly related to PFS. Conclusion: Among the pharmacokinetic variables extracted from CELs and NE-T2HSILs on preoperative DCE MR imaging, the mean Ktrans of CELs exhibits potential as a useful imaging predictor of PFS in GBM patients.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.15 no.2
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• pp.178-184
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• 2004

Objectives : This study was conducted to investigate the association of the COMT polymorphism with the TD in Korean sample of families with TD probands. The relationship between risk alleles and specific clinical features (tic severity, comorbidity, drug response) was also explored. Method : Patients were recruited from the Tic Disorder clinic at the Child & Adolescent Psychiatric Division of Seoul National University Hospital and assessed through 2 stage evaluation. Firstly, all the patients and parents received semistructured interview using Korean version of K-SADS-PL. Secondly all the patients received clinical interview and tic severity assessment with Korean version of YGTSS. The subjects in control group were recruited from the health promotion center in out hospital and were evaluated by SCL-90 and SCID-IV. Through these process, total of 42 children and adolescents with TD, their 84 parents and 86 control subjects were finally recruited. Genotyping for The Val158Met polymorphism of the COMT gene was done by standardized method. After collection of genetic data of all the patients, parents and control subjects, case-control comparison and tranmission dysequilibrium test was executed by SPSS version 11. Result : From the case-control comparison, the frequency of L-allele and LL genotype was significantly higher in TD group. However, no differences were found from the TDT. No significant differences were found in in family history of tic, ADHD, OCD, drug response and comorbid conditions among the three different genotypes in patients with TD. Conclusion : Though this study results should be interpreted cautiously due to small sample size and negative finding in TDT test, this study is the first report that there is positive association between the functional polymorphism of COMT gene the TD.