Pil-Jong Kim

Clinicopathological analysis of programmed cell death 1 and programmed cell death ligand 1 expression in the tumour microenvironments of diffuse large B cell lymphomas

To investigate the clinicopathological characteristics of programmed cell death ligand 1 (PD‐L1) and programmed cell death 1 (PD‐1) expression in the tumour microenvironments of diffuse large B cell lymphoma (DLBCL).

Sphingosine-1-phosphate receptor 1 (S1PR1) expression in non-muscle invasive urothelial carcinoma: Association with poor clinical outcome and potential therapeutic target.

AIM Sphingosine-1-phosphate receptor 1 (S1PR1) promotes tumour cell survival, invasion, anti-apoptosis, metastasis and radio/chemo-resistance in various cancers. However, the expression pattern and prognostic implications of S1PR1 in urothelial carcinoma remain unclear and thus were addressed here. METHODS Tissue microarrays composed of 395 initially diagnosed and transurethral resected urothelial carcinomas of the urinary bladder were immunostained for S1PR1 and phosphor-signal transducer and activator of transcription 3 (pSTAT3). S1PR1 expression was analysed according to clinicopathological features, expression of several anti-apoptosis/proliferation-related markers and patients survival. RESULTS S1PR1 positivity was observed in 45.3% of urothelial carcinomas. Among patients with non-muscle invasive urothelial carcinoma (NMIC), S1PR1 positivity was associated with higher grade (P<0.001), higher subepithelial invasive component (P=0.006), lower papillary component (P=0.002), presence of metastasis (P=0.042) and high cancer-specific death (P<0.001). S1PR1 expression was correlated with pSTAT3 (P<0.001), survivin (P=0.008) and Ki-67 (P<0.001) expression. S1PR1 positivity predicted a shorter cancer-specific survival (CSS) in NMICs (P<0.001) and stage T1/high grade (T1HG) tumours (P=0.002). The Cox multivariate model was composed of S1PR1, survivin, lymphovascular invasion and age, and C-index was 0.781. S1PR1 positivity was correlated with shorter CSS in p53-positive T1HG carcinoma (P=0.003) in contrast to p53-negative T1HG carcinoma (P=0.205). In p53-overexpressing NMIC, S1PR1 was the only variable of the survival model and the C-index was 0.719. CONCLUSIONS S1PR1 expression was associated with unfavourable clinicopathological features and the expression of several anti-apoptosis/proliferation-related markers in urothelial carcinoma. S1PR1 serves as an independent predictor of cancer-specific death in NMIC. The model including S1PR1 showed highly accurate prediction for CSS in NMIC patients regardless of the modality of adjuvant therapy.

Disruption of frontal–parietal connectivity during conscious sedation by propofol administration

The sedative state is a transitional state from wakefulness to general anesthesia. However, little is understood regarding the mechanism of conscious sedation, different from general anesthesia while maintaining wakefulness. In this study, we aimed to investigate changes in functional connectivity of the parietal–frontal network, implicated in wakefulness during conscious sedation induced by propofol infusion. The electroencephalography was obtained at the frontal and parietal areas of adult volunteers who maintain wakefulness during low-dose propofol infusion (1.5 mg/kg/h) over 1 h. Spectral Granger causality (GC) (&dgr;, &thgr;, &agr;, &bgr;, and &ggr; frequency bands) and time-domain GC were calculated during each stage of awake (before propofol administration), sedation, and recovery (after discontinuation of propofol). We also calculated the phase-locking index and compared it with GC during each stage. A decrease in GC from the frontal to parietal areas was observed particularly in the low-frequency bands during propofol administration. Contrary to the GC changes in the frontoparietal direction, GC from the parietal to frontal areas was increased in the high-frequency bands during propofol administration and significantly decreased after discontinuation of propofol. In summary, we showed that frontal–parietal neural networks were significantly changed differently by the frequency of the brain rhythm and the directions of connections during sedation by propofol administration. Our result suggests that the alteration of brain interaction may induce sedative state lying between awake and general anesthesia.

Dishevelled segment polarity protein 3 (DVL3): a novel and easily applicable recurrence predictor in localized prostate adenocarcinoma

To identify new biomarkers for biochemical recurrence (BCR) of prostate adenocarcinoma.

Evaluation of electrical impedance ratio measurements in accuracy of electronic apex locators.

Objectives The aim of this paper was evaluating the ratios of electrical impedance measurements reported in previous studies through a correlation analysis in order to explicit it as the contributing factor to the accuracy of electronic apex locator (EAL). Materials and Methods The literature regarding electrical property measurements of EALs was screened using Medline and Embase. All data acquired were plotted to identify correlations between impedance and log-scaled frequency. The accuracy of the impedance ratio method used to detect the apical constriction (APC) in most EALs was evaluated using linear ramp function fitting. Changes of impedance ratios for various frequencies were evaluated for a variety of file positions. Results Among the ten papers selected in the search process, the first-order equations between log-scaled frequency and impedance were in the negative direction. When the model for the ratios was assumed to be a linear ramp function, the ratio values decreased if the file went deeper and the average ratio values of the left and right horizontal zones were significantly different in 8 out of 9 studies. The APC was located within the interval of linear relation between the left and right horizontal zones of the linear ramp model. Conclusions Using the ratio method, the APC was located within a linear interval. Therefore, using the impedance ratio between electrical impedance measurements at different frequencies was a robust method for detection of the APC.

Investigating the effects of nitrous oxide sedation on frontal-parietal interactions

Although functional connectivity has received considerable attention in the study of consciousness, few studies have investigated functional connectivity limited to the sedated state where consciousness is maintained but impaired. The aim of the present study was to investigate changes in functional connectivity of the parietal-frontal network resulting from nitrous oxide-induced sedation, and to determine the neural correlates of cognitive impairment during consciousness transition states. Electroencephalography was acquired from healthy adult patients who underwent nitrous oxide inhalation to induce cognitive impairment, and was analyzed using Granger causality (GC). Periods of awake, sedation and recovery for GC between frontal and parietal areas in the delta, theta, alpha, beta, gamma and total frequency bands were obtained. The Friedman test with post-hoc analysis was conducted for GC values of each period for comparison. As a sedated state was induced by nitrous oxide inhalation, power in the low frequency band showed increased activity in frontal regions that was reversed with discontinuation of nitrous oxide. Feedback and feedforward connections analyzed in spectral GC were changed differently in accordance with EEG frequency bands in the sedated state by nitrous oxide administration. Calculated spectral GC of the theta, alpha, and beta frequency regions in the parietal-to-frontal direction was significantly decreased in the sedated state while spectral GC in the reverse direction did not show significant change. Frontal-parietal functional connectivity is significantly affected by nitrous oxide inhalation. Significantly decreased parietal-to-frontal interaction may induce a sedated state.

Analysis of Photoplethysmographic Waveform for Assessment of Pulpal Blood Flow in Children

The purpose of this study was to analyze photoplethysmographic waveforms from pulse oximeter using raw data of red and infrared light and investigate the reference values of parameters (Height, Width50, Maximum slope, Minimum slope, Area) for evaluating pulpal blood flow in maxillary central incisors with normal pulp vitality in children. The study was performed in 30 pediatric patients, aged 7-16 years old, using pulse oximeter (MEKICS Co., Ltd, Korea) combined with a custom-made sensor. The raw data was obtained and recorded by custom-made software and analyzed by LabChart (v.7.3, ADInstruments, Germany) offline. In this study, we analyzed photoplethysmographic waveforms from pulse oximeter applied to maxillary central incisor for assessment of pulpal blood flow and suggested several reference values of young permanent maxillary central incisor with normal pulp. On average, the waveform of red light was higher, stiffer and wider than that of infrared light. Future studies about reference values for other normal teeth and the teeth with impaired pulp vitality are needed.

Abstract 429: Establishment of the classifier for a response to vascular endothelial growth factor (VEGF)-tyrosine kinase inhibitor (TKI) in metastatic renal cell carcinoma

Vascular endothelial growth factor (VEGF)-targeted therapy has been demonstrated to improve the outcome of metastatic renal cell carcinoma (mRCC) patients. However, validated predictors that predict response and prognosis to VEGF-tyrosine kinase inhibitors (VEGF-TKIs) remain to be elucidated. We aimed to define a classifier for VEGF-TKI response in mRCC patients. Among 101 mRCC patients treated with VEGF-TKIs, 73 patients were responder defined as patients showing complete or partial response, or ≥24 weeks stable disease to VEGF-TKI; and 28 patients were nonresponder defined as Citation Format: Heounjeong Go, Mun Jung Kang, Pil-Jong Kim, Ja-Min Park, Jae-Lyun Lee, Ji Young Park, Yong Mee Cho. Establishment of the classifier for a response to vascular endothelial growth factor (VEGF)-tyrosine kinase inhibitor (TKI) in metastatic renal cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 429.

Application of the water subtraction algorithm in determining the degree of conversion of self-etching adhesives.

PURPOSE This study evaluated the effect of residual water included within the FT-IR spectra on the calculation of the degree of conversion (DC) of a self-etching adhesive (SEA). MATERIALS AND METHODS FT-IR spectra of a SEA (Adper Prompt SE, 3M ESPE) were obtained for different amounts of dentin powder, agitation times, and light-curing times. The measured DC (mDC) obtained from the IR spectra was compared to the apparent DC (aDC) from the adjusted IR spectra using the water subtraction algorithm (WSA), by which the water absorption band was subtracted from the obtained IR spectrum. RESULTS When the SEA was mixed with 10 mg of dentin powder, the aDC was significantly higher than the mDC immediately after light curing (paired t-test, p < 0.001). With the increase in the amount of dentin powder, the mDC immediately after curing and the difference between the mDC and the aDC gradually increased. The amount of dentin powder, light-curing time, square of light-curing time, and time until measurement were the variables that significantly affected the aDC (linear mixed model, p < 0.05). However, the agitation time did not affect the aDC or the difference between the mDC and the aDC, except at 20 s. CONCLUSION When the DC of SEA itself is measured with FT-IR, the mDC needs to be adjusted with the water subtraction algorithm. Clinically, SEA needs to be applied under conditions of prolonged contact with the dentin substrate and vigorous and prolonged drying.