Although much health services research has been conducted using national health insurance claims data in Korea, the validity of this method has not been ascertained. The objective of this study was to validate the use of claims data for health services research by comparing incidence rate of cancers found using insurance claims data against rates of the national cancer registry of Korea. An algorithm to estimate incidence rates using claims data was developed and applied. The claims data from 2005-2008 were acquired and the patients admitted to hospitals due to cancer in 2008 without admission to hospital from 2005-2007 by the same diagnosis code were regarded as incident cases. The acquired results were compared with the values from the National Cancer Registry of Korea. The incidence rate of all cancers found using claims data was 363.1 per 100,000 people, which is very similar to the 361.9 per 100,000 rate of the national cancer registry. Also the age-, gender-and disease-specific rates between the two data sources were similar. Therefore, national health insurance claims data may be a worthwhile resource for health services research if appropriate algorithms are applied, especially considering the cost effectiveness of this method.

Background and ObjectivesApurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/Ref-1) is a multifunctional protein involved in the DNA base excision repair pathway, inflammation, angiogenesis, and survival pathways. We investigated serum APE1/Ref-1 in patients with coronary artery disease (CAD).Subjects and MethodsSerum APE1/Ref-1 was measured with a sandwich enzyme-linked immunosorbent assay from 360 patients who received coronary angiograms. They were divided into two groups; a control (n=57) and a CAD group (n=303), the latter included angina (n=128) and myocardial infarction (MI, n=175).ResultsThe levels of APE1/Ref-1 were higher in the CAD than the control (0.63±0.07 vs. 0.12±0.07 ng/100 µL, respectively; p<0.01). They were also higher in MI than angina (0.81±0.10 vs. 0.38±0.11 ng/100 µL, respectively; p<0.01) and different according to the thrombolysis in myocardial infarction (TIMI) flow (0.88±0.09 for TIMI flow 0, 1, 2 vs. 0.45±0.13 ng/100 µL for TIMI flow 3, p<0.01) in acute coronary syndrome. In correlation analysis, the levels of APE1/Ref-1 were positively correlated with Troponin I (r=0.222; p<0.0001) and N-terminal pro-B type natriuretic peptide (NT-proBNP, r=0.217; p<0.0001) but not high sensitivity to C-reactive protein. Also, they revealed a negative correlation with ejection fraction (EF, r=-0.221; p=0.002). However, there were no significant differences among the three groups, were divided by their levels of APE1/Ref-1, for major adverse cardiovascular events (death, recurrent MI, stroke, revascularization) (8.2 vs. 14.0 vs. 12.5%, p=ns).ConclusionThe levels of serum APE1/Ref-1 are elevated in CAD, and are higher in MI than in angina. They are correlated with Troponin I, NT-proBNP, and EF.

BackgroundTwo-dimensional black phosphorus nanosheets (BPNSs) have recently emerged as a successive novel nanomaterial owing to their uniqueness in optical and electrical properties. Although BPNSs have found a wide range of biomedical applications, their biosafety is still a major concern to be addressed.MethodsIn this study, we have prepared layered BPNSs using liquid exfoliation procedure, and evaluated their physicochemical properties using Fourier Transform-infrared (FTIR) spectroscopy, Raman spectroscopy, atomic force microscopy, and Zetasizer analyses. We have investigated potential cytotoxicity of BPNSs against three different types of fibroblast cells, i.e. mouse embryonic fibroblast (NIH3T3), primary cultured normal human dermal fibroblast (nHDF), and fibrosarcoma (HT1080). Cell counting kit-8 (CCK-8) assay was carried out to assess cellular metabolic activity in cells whereas lactate dehydrogenase (LDH) activity assay was helpful to study plasma membrane integrity.ResultsOur salient research findings showed that BPNSs were polydispersed in solution due to aggregation. Toxic response of BPNSs against fibroblast cells was in the order, HT1080>nHDF>NIH3T3. The nanosheets reduced the number of cancerous cells with significant difference to normal cells.ConclusionsWe suggest that BPNSs can be considered for cancer treatment as they destroy cancerous cells effectively. However, a comprehensive study is required to elucidate other biological effects of BPNSs.

Myocarditis is an inflammatory disease of the myocardium that causes cardiogenic shock and death. However, endomyocardial biopsy that is, the gold standard for a diagnosis is limited. Apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/Ref-1) is a multifunctional protein, which is involved in DNA-based excision repair pathway, and in redox signaling, its changes are observed in various cardiovascular diseases including hypertension and coronary artery disease. We analyzed serum APE1/Ref-1 in experimental murine myocarditis. To induce myocarditis, coxsackievirus B3 was injected intraperitoneally to BALB/c mice. The serum APE1/Ref-1, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and troponin I were measured. The histology and virus titers measurements were performed. The troponin I and inflammation were significantly elevated at day 3, peaked to day 7 and decreased at day 10. The NT-proBNP and virus titers were significantly peaked at day 3, and dropped at day 7 and 10. The serum APE1/Ref-1 was gradually raised and its elevation is still maintained until a later time, namely day 10. Also, its level was positively correlated with myocardial inflammation, reflecting severity of myocardial injury. We suggest that serum APE1/Ref-1 can be used to assess for myocardial injury in viral myocarditis without endomyocardial biopsy.

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