Cancer Subtype Discovery Using Prognosis-Enhanced Neural Network Classifier in Multigenomic Data.

OBJECTIVE: The main objective in studying large-scale cancer omics is to identify molecular mechanisms of cancer and discover novel biomedical targets. This work not only discovers the cancer subtypes in genome scale data by using clustering and classification but also measures their accuracy. METHODS: Initially, candidate cancer subtypes are recognized by max-flow/min-cut graph clustering. Finally, prognosis-enhanced neural network classifier is proposed for classification. We analyzed the heterogeneity and identified the subtypes of glioblastoma multiforme, an aggressive adult brain tumor, from 215 samples with microRNA expression (12 042 genes). The samples were classified into 4 different classes such as mesenchymal, classical, proneural, and neural subtypes owing to mutations and gene expression. The results are measured using the metrics such as silhouette width, biological stability index, clustering accuracy, precision, recall, and f-measure. RESULTS: Max-flow/min-cut clustering produces higher clustering accuracy of 88.93% for 215 samples. The proposed prognosis-enhanced neural network classifier algorithm produces higher accuracy results of 89.2% for 215 samples efficiently. CONCLUSION: From the experimental results, the proposed prognosis-enhanced neural network classifier is seen as an alternative, which is full of promise for cancer subtype prediction in genome scale data.

Comparison of gadoxetic acid to gadobenate dimeglumine for assessment of biliary anatomy of potential liver donors.

PURPOSE: To compare MRI using gadobenate dimeglumine (Gd-BOPTA) vs. gadoxetic acid disodium (Gd-EOB-DTPA) for the assessment of biliary anatomy of potential liver donors. METHODS: 76 potential liver donors (39 M/37 F, mean 38 years) who underwent 1.5T MRI using Gd-BOPTA (n = 37) or Gd-EOB-DTPA (n = 39) were retrospectively evaluated. T2 cholangiogram (T2 MRC) and delayed hepatobiliary phase (HBP) T1 cholangiogram (T1 MRC) (performed during HBP 20 min after injection of Gd-EOB-DTPA and 1-2 h after Gd-BOPTA injection) were obtained in addition to MR angiogram/venogram. Two independent observers evaluated image quality (IQ) and conspicuity scores (CS) of the biliary system. Biliary anatomy was assessed in 3 reading sessions (T2 MRC, T1 MRC, and combined T2/T1 MRC). Reference standard consisted of consensus reading of two separate observers of all image sets, clinical/surgical information and intraoperative cholangiogram when available. Datasets were compared using the Mann-Whitney U test or Chi-squared test. RESULTS: There was no difference in IQ for T1 MRC using either contrast agent or T2 MRC vs. T1 MRC for both observers (all p values >0.07). There was superior CS for T2 MRC vs. Gd-BOPTA T1 MRC for both observers and T2 MRC vs. Gd-EOB for one observer (p < 0.001). No difference was found for biliary variant detection for T1 MRC (with either contrast agent) vs. T2 MRC. Combined T2/T1 MRC demonstrated improved sensitivity for biliary variant detection using Gd-BOPTA for both observers (p < 0.004) and Gd-EOB-DTPA for one observer (p < 0.001). CONCLUSION: Equivalent image quality was found for T1 MRC obtained with Gd-BOPTA or Gd-EOB-DTPA and T2 MRC. T1 MRC is equivalent to T2 MRC for detection of variant biliary anatomy, and the combination of sequences may have added value.

Non-invasive prediction of portal pressures using CT and MRI in chronic liver disease.

PURPOSE: To assess the diagnostic value of a fast scoring system based on non-invasive cross-sectional imaging to predict portal hypertension (PH) in patients with liver disease. METHODS: In this retrospective study, we included patients who underwent contrast-enhanced CT or MRI within 3 months of hepatic venous pressure gradient (HVPG) measurements. Two independent observers provided an imaging-based scoring system (max of 9): number of variceal sites, volume of ascites, and spleen size. ROC analysis was performed to predict the presence of PH (HVPG ≥ 5 mmHg) and clinically significant PH (HVPG ≥ 10 mmHg). RESULTS: Our cohort consists of 143 patients with mean HVPG of 13.1 ± 2.0 mmHg. Mean PH scores from the two observers were 3.9 ± 2.7 and 3.2 ± 2.5. There was a significant correlation between PH score and HVPG (r = 0.58, p < 0.001 for both observers) with high inter-observer agreement (kappa 0.71). AUCs of 0.78-0.76 and 0.83-0.81 were observed for diagnosing HVPG ≥ 5 mmHg and HVPG ≥ 10 mmHg, respectively, for observers 1 and 2. CONCLUSIONS: We have developed a fast PH imaging-based composite score, which could be used for non-invasive detection of clinically significant PH.

The effect of acute postoperative pain and chronic neuropathic pain on subsequent weight gain in the rat.

OBJECT: Acute postoperative pain has demonstrated effects on appetite and weight gain in human studies. This study was designed to test the hypothesis that chronic neuropathic pain has a more significant effect on weight than acute postsurgical pain. METHODS: One hundred eighteen rats were separated into 3 groups: common sciatic nerve ligation, surgery without ligation, and no surgery. Each group was further divided to undergo testing at 3, 7, and 14 days. On the day of testing, the rats were tested for signs of pressure and heat hyperalgesia and were weighed. RESULTS: The effect on the percentage of change in body weight from the day of surgery to the day of testing was statistically significant for both the condition (F = 15.0, p < 0.0001) and the day of testing (F = 43.3, p < 0.0001). The rats that received no surgery had a change in weight of 2.3% on Day 3, 4.0% on Day 7, and 10.7% on Day 14. In the nonligation surgery group, the change was -3.8% on Day 3, 2.0% on Day 7, and 9.7% on Day 14. In the ligation surgery group, the change was -6.3% on Day 3, -0.7% on Day 7, and 4.9% on Day 14. This group began gaining weight by Day 14 but continued to have less weight gain than the other groups by Day 14. CONCLUSIONS: Neuropathic pain inhibits weight gain more than normal, postsurgical pain. Recognizing the difference and initiating effective treatment for neuropathic pain may have an impact on the patient's nutrition.