Prognostic Value of Combined Programmed Cell Death 1 Ligand and p16 Expression Predicting Responsiveness to Radiotherapy in Patients with Oropharyngeal Squamous Cell Carcinoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES@#This study examined the expressions of p16 and the programmed cell death 1 ligand (PD-L1) in patients with oropharyngeal cancer (OPC) treated with radiotherapy (RT) to identify the correlation between p16 and PD-L1 expression, and to examine the prognostic significance of these markers for OPC patients receiving RT.SUBJECTS AND METHOD: Forty-eight OPC patients diagnosed and treated at a tertiary referral hospital were enrolled in this retrospective analysis. Patients were initially treated with RT or chemoradiotherapy (CRT) with curative intent and completed the planned schedule. Expression of p16 and PD-L1 by primary tumors was evaluated by immunohistochemistry, and results were interpreted separately and dichotomized according to outcome analyses.@*RESULTS@#Of the 48 patients, 25 (52.1%) expressed p16 and 15 (31.3%) expressed PD-L1. Expression of these markers showed a mutual positive correlation (p=0.046). Positive PD-L1 expression was associated with poor complete remission (CR) rates after RT (p=0.040). Positive p16 expression was associated with better recurrence-free survival (RFS) (p=0.004) but not overall survival (OS) (p=0.192). PD-L1 expression showed no independent association with survival (p>0.05); however, PD-L1 expression tended toward poorer RFS, even in p16-positive individuals.@*CONCLUSION@#There was a positive correlation between the expression of p16 and PD-L1 in OPCs. PD-L1 expression was associated with poorer CR rates after RT or CRT. PD-L1 alone did not show an association with RFS or OS, but when combined with p16, it tended toward poorer RFS, even in p16-positive cases.

XDS-I Gateway Development for HIE Connectivity with Legacy PACS at Gil Hospital / 대한의료정보학회지

OBJECTIVES: The ability to support healthcare document sharing is imperative in a health information exchange (HIE). Sharing imaging documents or images, however, can be challenging, especially when they are stored in a picture archiving and communication system (PACS) archive that does not support document sharing via standard HIE protocols. This research proposes a standard-compliant imaging gateway that enables connectivity between a legacy PACS and the entire HIE. METHODS: Investigation of the PACS solutions used at Gil Hospital was conducted. An imaging gateway application was then developed using a Java technology stack. Imaging document sharing capability enabled by the gateway was tested by integrating it into Gil Hospital's order communication system and its HIE infrastructure. RESULTS: The gateway can acquire radiology images from a PACS storage system, provide and register the images to Gil Hospital's HIE for document sharing purposes, and make the images retrievable by a cross-enterprise document sharing document viewer. CONCLUSIONS: Development of an imaging gateway that mediates communication between a PACS and an HIE can be considered a viable option when the PACS does not support the standard protocol for cross-enterprise document sharing for imaging. Furthermore, the availability of common HIE standards expedites the development and integration of the imaging gateway with an HIE.

An Application of the Clustering Threshold Gradient Descent Regularization Method for Selecting Genes in Predicting the Survival Time of Lung Carcinomas

In this paper, we consider the variable selection methods in the Cox model when a large number of gene expression levels are involved with survival time. Deciding which genes are associated with survival time has been a challenging problem because of the large number of genes and relatively small sample size (n << p). Several methods for variable selection have been proposed in the Cox model. Among those, we consider least absolute shrinkage and selection operator (LASSO), threshold gradient descent regularization (TGDR), and two different clustering threshold gradient descent regularization (CTGDR)- the K-means CTGDR and the hierarchical CTGDR - and compare these four methods in an application of lung cancer data. Comparison of the four methods shows that the two CTGDR methods yield more compact gene selection than TGDR, while LASSO selects the smallest number of genes. When these methods are evaluated by the approach of Ma and Huang (2007), none of the methods shows satisfactory performance in separating the two risk groups using the log-rank statistic based on the risk scores calculated from the selected genes. However, when the risk scores are calculated from the genes that are significant in the Cox model, the performance of the log-rank statistics shows that the two risk groups are well separated. Especially, the TGDR method has the largest log-rank statistic, and the K-means CTGDR method and the LASSO method show similar performance, but the hierarchical CTGDR method has the smallest log-rank statistic.

Effect of Normalization on Detection of Differentially-Expressed Genes with Moderate Effects

The current existing literature offers little guidance on how to decide which method to use to analyze one-channel microarray measurements when dealing with large, grouped samples. Most previous methods have focused on two-channel data;therefore they can not be easily applied to one-channel microarray data. Thus, a more reliable method is required to determine an appropriate combination of individual basic processing steps for a given dataset in order to improve the validity of onechannel expression data analysis. We address key issues in evaluating the effectiveness of basic statistical processing steps of microarray data that can affect the final outcome of gene expression analysis without focusingon the intrinsic data underlying biological interpretation.

Cytoprotective Effect of 15-deoxy-Delta(12,14) Prostaglandin J2 (15d-PGJ2) against H2O2 Induced Death of Neuronally-differentiated PC12 Cells

BACKGROUND: Neurodegenerative diseases are associated with oxidative stress. Antioxidants including 15-deoxy- Delta (12,14) prostaglandin J2 (15d-PGJ2) have been tried as potential therapeutic regimens of the experimental model of neurodegenerative disease. In this study, we investigated the neuroprotective role of 15d-PGJ2 on cytochrome c mediated apoptotic signals in oxidative stress injured neuronally-differentiated PC12 cells (nPC12 cells) by exposing them to H2O2. METHODS: Following 100 micor M H2O2 exposure, the viability of nPC12 cells (pretreated with 15d-PGJ2 vs. not pretreated) was evaluated by using MTT assay. Immunoreactivity (IR) of cytochrome c, caspase-3, and poly (ADP-ribose) polymerase (PARP) was examined by using a Western blot. RESULTS: In this study, 15d-PGJ2 pretreated nPC12 cells showed an increase in cell viability until the concentrations of 15d-PGJ2 reached up to 4 micor M, but there was no increment of cell viability in higher concentrations. The inhibition of cytochrome c release, activation of caspase-3, and cleavage of PARP were demonstrated by the pretreatment of 15d-PGJ2 up to 4 micor M. However, these were not observed in the pretreatment with 8 micor M 15d-PGJ2. CONCLUSIONS: These data show that 15d-PGJ2 affects the apoptotic pathway through downstream signals including cytochrome c and caspase-3 pathway. Therefore, these results suggest that 15d-PGJ2 could be a new potential therapeutic candidate for the oxidative stress-injury model of neurodegenerative diseases.

A Clinical Study of Gallbladder Polyps

PURPOSE: Gallbladder cancer had poor prognosis because it is usually detected at a late stage. Some GB polyps are diagnosed as cancerous on the postoperative pathology. Because of the significance of the early detection of the cancer, the relationship between GB polyp and cancer is important. METHODS: From January 1994 to May, 2004, 94 cases of GB polypoid lesions were identified and diagnosed after cholecystectomy was performed at the Korea University Medical Center Anam hospital. The pateints' age, gender, the symptoms and signs, the diagnostic tools, the operative methods and the histopathologic findings were investigated. RESULTS: For the 94 patients, the mean age was 50.3+/-13.1 years and there were 42 males (44.7%). 92 patients were evaluated by abdominal ultrasonography, and it had a sensitivity of 72.8%. On the histopathologic results, there were 76 cases of benign polyps and 18 cases of malignant polyps. The diameter of the malignant polyps was 17.3+/-8.5 mm and the diameter of the benign polyps was 6.4+/-3.0 mm, so the malignant polyps were larger than the benign polyps. The mean age of the malignant polyp group was 62.6+/-14.2 years and the mean age of the benign polyp group was 47.1+/-11.1. The patients of the malignant polyp group were older than the patients of the benign polyp group. 19 GB polyps were greater than 10 mm in diameter and among them, there were 15 cases of malignant polyps (78.94%). CONCLUSION: The size of the polyps and the patient's age could be risk factors for malignant polyps, and the malignant potential was high for the polyps that exceeded 10 mm and for a patient age that exceeded 60 years. Surgical treatment is recommended for these patients.