23 research outputs found
Efficient Mining of Partial Periodic Patterns in Time Series Database
Partial periodicity search, i.e., search for partial periodic patterns in time-series databases, is an interesting data mining problem. Previous studies on periodicity search mainly consider finding full periodic patterns, where every point in time contributes (precisely or approximately) to the periodicity. However, partial periodicity is very common in practice since it is more likely that only some of the time episodes may exhibit periodic patterns
Classification and differential metabolite discovery of liver diseases based on plasma metabolic profiling and support vector machines
Discovery of differential metabolites is the focus of metabonomics study. It has very important applications in pathogenesis and disease classification. The aim of this work is to identify differential metabolites for classifying the patients with hepatocellular carcinoma, cirrhosis and hepatitis based on metabolic profiling data analyzed by gas chromatography-time of flight mass spectrometry. A two-stage feature selection algorithm, F-SVM, combining F-score in analysis of variance and support vector machine (SVM), was applied in discovering discriminative metabolites for three different types of liver diseases. The results show that the accuracy rate of the double cross-validation was 73.68 +/- 2.98%. 22 important differential metabolites selected by F-SVM were identified and related pathophysiological process of liver diseases was set forth. We conclude that F-SVM is quite feasible to be applied in the selection of biologically relevant features in metabonomics
Noralashinol A, a new norlignan from stem barks of <i>Syringa pinnatifolia</i>
<p>One new norlignan, namely noralashinol A (<b>1</b>), one known analogue (<b>2</b>), together with seven known lignans (<b>3</b>–<b>9</b>) were isolated from the stem barks of <i>Syringa pinnatifolia</i>. Their structures were elucidated extensively by spectroscopic methods, including mass spectrometry and 1D and 2D NMR spectroscopies. Compound <b>8</b> significantly inhibited NO production in LPS-induced BV-2 murine microglia cells with its IC<sub>50</sub> value of 20.7 μM, compared to a positive control quercetin with its IC<sub>50</sub> value of 15.3 μM.</p
Integration of lipidomics and transcriptomics unravels aberrant lipid metabolism and defines cholesteryl oleate as potential biomarker of prostate cancer
In-depth delineation of lipid metabolism in prostate cancer (PCa) is significant to open new insights into prostate tumorigenesis and progression, and provide potential biomarkers with greater accuracy for improved diagnosis. Here, we performed lipidomics and transcriptomics in paired prostate cancer tumor (PCT) and adjacent nontumor (ANT) tissues, followed by external validation of biomarker candidates. We identified major dysregulated pathways involving lipogenesis, lipid uptake and phospholipids remodeling, correlated with widespread lipid accumulation and lipid compositional reprogramming in PCa. Specifically, cholesteryl esters (CEs) were most prominently accumulated in PCa, and significantly associated with cancer progression and metastasis. We showed that overexpressed scavenger receptor class B type I (SR-BI) may contribute to CEs accumulation. In discovery set, CEs robustly differentiated PCa from nontumor (area under curve (AUC) of receiver operating characteristics (ROC), 0.90-0.94). In validation set, CEs potently distinguished PCa and non-malignance (AUC, 0.84-0.91), and discriminated PCa and benign prostatic hyperplasia (BPH) (AUC, 0.90-0.96), superior to serum prostate-specific antigen (PSA) (AUC = 0.83). Cholesteryl oleate showed highest AUCs in distinguishing PCa from non-malignance or BPH (AUC = 0.91 and 0.96). Collectively, our results unravel the major lipid metabolic aberrations in PCa and imply the potential role of CEs, particularly, cholesteryl oleate, as molecular biomarker for PCa detection
Analysis of Urinary Metabolic Signatures of Early Hepatocellular Carcinoma Recurrence after Surgical Removal Using Gas Chromatography–Mass Spectrometry
The objective of present study was to offer insights
into the metabolic
responses of hepatocellular carcinoma (HCC) to surgical resection
and the metabolic signatures latent in early HCC recurrence (one year
after operation). Urinary metabolic profiling employing gas chromatography
time-of-flight mass spectrometry (GC-TOF MS) was utilized to investigate
the complex physiopathologic regulations in HCC after operational
intervention. It was revealed that an intricate series of metabolic
regulations including energy metabolism, amino acid metabolism, nucleoside
metabolism, tricarboxylic acid (TCA) cycle, gut floral metabolism,
etc., principally leading to the direction of biomass synthesis, could
be observed after tumor surgical removal. Moreover, metabolic differences
between recurrent and nonrecurrent patients had emerged 7 days after
initial operation. The metabolic signatures of HCC recurrence principally
comprised notable up-regulations of lactate excretion, succinate production,
purine and pyrimidine nucleosides turnover, glycine, serine and threonine
metabolism, aromatic amino acid turnover, cysteine and methionine
metabolism, and glyoxylate metabolism, similar to metabolic behaviors
of HCC burden. Sixteen metabolites were found to be significantly
increased in the recurrent patients compared with those in nonrecurrent
patients and healthy controls. Five metabolites (ethanolamine, lactic
acid, acotinic acid, phenylalanine and ribose) were further defined;
they were favorable to the prediction of early recurrence