As the Therapeutic Drug Monitoring Subcommittee (TDMS) of the Korean Association of Quality Assurance for Clinical Laboratories (KAQACL), we organised two trials as an external quality assessment of therapeutic drug monitoring (TDM) and testing for drugs of abuse (DOA) in 2014. In each trial, low and high level control materials for TDM testing, and positive and negative control materials for DOA testing, were requested from institutions. The number of participating laboratories was 107 for the first trial and 106 for the second. The average number of drug items provided was 5.7 per institution. The most commonly tested substances were, in descending order, valproic acid, digoxin, tacrolimus, phenytoin, and vancomycin. The mean inter-laboratory coefficients of variation for low- and high-level TDM control materials were 8.5% and 7.2%, respectively. The most widely used TDM analysers were the Architect i System (Abbott Diagnostics, USA), followed by the Cobas Integra (Roche Diagnostics, Switzerland) and the Cobas c501 analyser (Roche Diagnostics). The number of participating laboratories for DOA testing was 23% higher that than in 2013. In 96.9% of cases, our analysis confirmed the suitability of the tests at participating DOA laboratories in both trials. In the external quality assessment of TDM by the TDMS of KAQACL in 2014, the overall performance of TDM testing was found to be similar to that observed in the previous years, and inter-laboratory precision was higher than that in 2013. Continuous quality improvement of TDM testing by participation in a proficiency-testing program is necessary.
Digoxin ; Drug Monitoring* ; Korea ; Laboratory Proficiency Testing ; Phenytoin ; Quality Improvement ; Street Drugs* ; Tacrolimus ; Valproic Acid ; Vancomycin

PURPOSE: 5-fluorouracil is one of the widely used chemotherapeutic agent whose metabolic product forms tight covalent binding complex with thymidylate synthase (TS) and thereby blocks the DNA synthesis process. Expression of TS has been studied as a mechanism of drug resistance and as a prognostic factor for various cancers. METHODS: The relation between TS expression in surgically resected specimens and clinicopathologic features was examined in 62 patients with gastric cancer. Immuno histochemical demonstration of the protein was achieved using an anti-TS monoclonal antibody. RESULTS: In Lauren's classification, TS expressions of the intestinal type and the diffuse type were 21.93% and 14.96% respectively (P=0.02). And TS expression in a group with lymphatic invasion was higher (26.15%) than that in a group without lymphatic invasion (16.15%)(P=0.0001). There were no significant differences between the TS expressions associated with other clinicopathologic features (P>0.05). CONCLUSION: For the purpose of assessing the applicability of TS expression as a prognostic factor and as a mechanism for drug resistance, assessment of TS expression must be standardized. Although direct correlations between TS expression and other clinicopathologic features were found only in Lauren's classification and lymphatic invasion, further investigations of the relation between TS expression and drug resistance of 5-FU must be continued to provide data for choosing chemotherapuetic agents for use in patients with gastric cancer.
Classification ; DNA ; Drug Resistance ; Fluorouracil ; Humans ; Stomach Neoplasms* ; Thymidylate Synthase*

Adrenal cysts are a rare disease, and its prevalence is reported to be 0.06~0.18%. Its frequency of being recognized is increasing due to the widespread use of ultrasonography and computed tomography (CT) scans. We report here on a case of adrenal cyst that was mistaken as biliary cystadenoma prio-ocation and features. Laparoscopic exploration was performed via the transabdominal approach and this revealed a right adrenal cystic mass in the retroperitoneum beneath the liver (segment IV). We present here a case of adrenal cyst with endothelial lining along with a review of the literature to address the clinical presentation, histology, imaging features and differential diagnosis of this interesting and rare entity.
Cystadenoma* ; Diagnosis, Differential ; Laparoscopy ; Liver ; Prevalence ; Rare Diseases ; Ultrasonography

As an annual function of the Therapeutic Drug Monitoring Subcommittee of Korean Association of External Quality Assessment Service (K-EQAS), we organised two trials for an external quality assessment of therapeutic drug monitoring (TDM) and testing for drugs of abuse (DOA) in 2015. For the TDM assessment, we sent low- and high-level control materials from various clinical institutions, and for the DOA testing, we sent positive and negative control materials. The number of participating laboratories was 105 for the TDM trial and 106 for the DOA test. The average number of drug items provided was 5.6 per institution. The most commonly tested substances, in descending order, were: valproic acid, digoxin, vancomycin, tacrolimus, and carbamazepine. The mean inter-laboratory coefficients of variation for low- and high-level TDM control materials were 7.3% and 7.4%, respectively. The most widely used TDM analysers were the Architect i System (Abbott Diagnostics, USA), followed by the Cobas Integra (Roche Diagnostics, Switzerland) and the Cobas c501 analyser (Roche Diagnostics). The number of participating laboratories for the DOA analysis was 16% higher that than of our 2014 study. In 98.6% of cases, our analysis confirmed the reliabilityviability of the tests at participating DOA laboratories in both trials. In the external quality assessment of TDM by the TDM subcommittee of K-EQAS in 2015, the overall performance of TDM testing was found to be similar to that reported in previous years, and inter-laboratory precision was higher than that of 2014. Continuous improvement in the quality of TDM testing through participation in a proficiency-testing program will remain necessary in the future.
Carbamazepine ; Digoxin ; Drug Monitoring* ; Korea* ; Laboratory Proficiency Testing ; Street Drugs* ; Tacrolimus ; Valproic Acid ; Vancomycin