Multi-level basis selection of wavelet packet decomposition tree for heart sound classification

Wavelet packet transform decomposes a signal into a set of orthonormal bases (nodes) and provides opportunities to select an appropriate set of these bases for feature extraction. In this paper, multi-level basis selection (MLBS) is proposed to preserve the most informative bases of a wavelet packet decomposition tree through removing less informative bases by applying three exclusion criteria: frequency range, noise frequency, and energy threshold. MLBS achieved an accuracy of 97.56% for classifying normal heart sound, aortic stenosis, mitral regurgitation, and aortic regurgitation. MLBS is a promising basis selection to be suggested for signals with a small range of frequencies.     

hIL-10基因修饰的L02肝细胞的克隆培养和最高表达株的筛选

目的:确认hIL-10基因修饰的L02肝细胞的克隆培养可实现hIL-10在L02肝细胞中的高效表达．方法:通过构建真核质粒表达载体pchIL-10, 并纯化后转染L02肝细胞．通过G418的压力选择获得hIL-10高表达的克隆株,并以ELISA测定其表达水平．结果:经过测序和酶切验证,真核质粒表达载体pchIL-10构建成功．电泳显示一长约540 bp 条带．hIL-10基因转导可在L02肝细胞中实现 hIL-10的高效表达．最高表达株表达量为每小时69．875 ng/106细胞．结论:hIL-10基因修饰的L02肝细胞的克隆培养可实现hIL-10的高效表达,为抗肝纤维化、肝硬化提供有效途径．     

Quantitative proteomics and phosphoproteomics on serial tumor biopsies from a sorafenib-treated HCC patient

Compensatory signaling pathways in tumors confer resistance to targeted therapy, but the pathways and their mechanisms of activation remain largely unknown. We describe a procedure for quantitative proteomics and phosphoproteomics on snap-frozen biopsies of hepatocellular carcinoma (HCC) and matched nontumor liver tissue. We applied this procedure to monitor signaling pathways in serial biopsies taken from an HCC patient before and during treatment with the multikinase inhibitor sorafenib. At diagnosis, the patient had an advanced HCC. At the time of the second biopsy, abdominal imaging revealed progressive disease despite sorafenib treatment. Sorafenib was confirmed to inhibit MAPK signaling in the tumor, as measured by reduced ribosomal protein S6 kinase phosphorylation. Hierarchical clustering and enrichment analysis revealed pathways broadly implicated in tumor progression and resistance, such as epithelial-to-mesenchymal transition and cell adhesion pathways. Thus, we describe a protocol for quantitative analysis of oncogenic pathways in HCC biopsies and obtained first insights into the effect of sorafenib in vivo. This protocol will allow elucidation of mechanisms of resistance and enable precision medicine.Hepatocellular carcinoma (HCC) is a global health concern with an estimated 750,000 new cases per year (1). In more than 80% of cases, HCC arises in a setting of liver cirrhosis mainly of alcoholic or viral origin (2). The prognosis for HCC patients is poor, with less than 30% qualifying for curative treatments such as tumor resection or liver transplantation (2). Median survival time of patients that cannot be treated surgically is less than 1 y. Sorafenib is the only approved targeted therapy for HCC, prolonging median patient survival by ∼3 mo (3). Sorafenib is a multikinase inhibitor of Raf (B and C), vascular endothelial growth factor receptor (VEGFR), and platelet-derived growth factor receptor (PDGFR) (4), which presumably inhibits not only tumor cells but also endothelial cells responsible for tumor vascularization.Resistance to a targeted cancer drug can be intrinsic or adaptive (5). Sorafenib is largely cytostatic (6), suggesting that intrinsic resistance is more common in tumors, although some reports describe tumor shrinkage upon sorafenib treatment (7). Studies involving HCC cell lines or immunohistochemical staining of tumor sections revealed that sorafenib resistance correlates with the up-regulation of several signaling pathways, including the mammalian target of rapamycin (mTOR) pathway as assayed by S6 S235/236 (8) and Akt S473 phosphorylation (9). Other potential resistance mechanisms involve epithelial-to-mesenchymal transition (EMT) and autophagy (10, 11). However, the molecular mechanisms of sorafenib resistance in patients are largely unknown. Understanding the pathways that confer intrinsic or adaptive resistance would allow precision medicine and increase treatment efficacy.Proteomic analysis allows the identification of drug targets for cancer treatment and biomarkers for cancer classification or recurrence. In particular, MS is a powerful tool for resolving the complexity of cancer signaling pathways. With regard to HCC, qualitative proteomics has been performed on resected tumor material (12), laser-capture microdissected material from tissue sections (13, 14), and primary hepatocytes or serum derived from patients (15, 16). These studies (17, 18) identified HCC biomarkers such as glutamine synthetase and heat shock protein 70 (Hsp70) that are currently in use for diagnosis (19, 20). Quantitative proteomics has been performed on HCC resected tissue and serum (21, 22). Recently, proteomics has been performed on tumor biopsies of renal cell carcinoma patients (23). Several studies also have described phosphoproteomic analyses of resected HCC or other cancer material (24–26), in some cases quantifying up to 8,000 phosphorylated sites (hereafter referred to as “phosphosites”) starting with 2 mg of protein (18, 27–30). However, to our knowledge, quantitative proteomics and phosphoproteomics, hereafter collectively referred to as “(phospho)proteomics,” have yet to be performed on tumor biopsies, possibly because biopsy material is nonrenewable and typically provides only a very small amount of protein. Importantly, quantitative (phospho)proteomics on serial biopsies taken before and during treatment has not been described. We note that although a biopsy procedure generates less material than a resection, it has the important advantage of capturing normally dynamic properties of a tumor, such as the phosphorylation status of signaling pathways. Biopsies are immediately snap-frozen upon removal from the patient and, unlike resected tissue, are obtained without causing ischemia or hypoglycemia in the collected tissue. Needle biopsies are taken routinely to diagnose and stage the disease. Another important consideration is a method to perform quantitative (phospho)proteomics, such as super-SILAC (“SILAC” is an acronym for “stable isotope labeling of amino acids in cell culture”), that allows direct comparison of biopsies obtained at different times or from different patients (31).We describe quantitative (phospho)proteomic analyses of needle biopsies of HCC and matched nontumor tissue from a human patient. These analyses provide a global snapshot of signaling pathways in the biopsy material. Analyzing serial biopsies taken from a patient before and during therapy, we measured differences in signaling pathways between tumor and matched nontumor control tissue and the changes in these signaling pathways upon sorafenib treatment. Our findings provide insight into mechanisms of tumor progression and resistance to cancer therapy.     

心房利钠肽与心血管疾病

心房利钠肽属于利钠肽家族,其通过与受体结合激活鸟苷酸环化酶,促进细胞内环鸟苷酸水平升高而发挥生物学功能。心房利钠肽具有利钠、利尿、舒张血管平滑肌、抑制细胞增殖等多种作用,在维持血压,水、钠平衡以及在心血管疾病的病理生理过程中发挥重要作用。     

QRS Amplitude of ECG in Normal Humans: Effects of Orthostatic Challenge on Linear and Nonlinear Measures of Beat-to-Beat Variability

When respiratory signal is not available, it can be derived from the surface electrocardiogram (ECG) with some limitations. This is particularly useful to understand the contribution of respiratory variability in several conditions where there is an increased risk of cardiovascular mortality. ECG-derived respiratory signal is also more valuable in situations of 24-h ECG records, where the continuous respiratory signal is not usually available. We have previously shown that respiratory variability in tidal volume significantly increases during standing posture compared to supine posture. In this study, we obtained respiratory signal derived from the ECG in 17 normal adult controls without a history of heart disease and quantified the time of occurrence of peaks and amplitudes or the QRS complex and performed cross-spectral analysis between R-R (interbeat) interval and the QRS-amplitude time series sampled at 4 Hz. Our findings show that the supine QRS amplitude HF power (0.15–0.5 Hz) correlates significantly with the R-R HF power (r (0.62; n (17; p ((0.004). However, this was negatively correlated in standing posture (r (−0.5; n (17; p (0.04). While there was a significant decrease of R-R HF power upon standing (p(0.01), there was a significant increase in QRS amplitude HF power (p (0.004). These findings indicate that the variability of QRS amplitude behaves differently in standing posture compared to R-R time series and thus the supine QRS amplitudinal changes may reflect more closely, the respiratory variability. These findings are discussed in relation to the increased QRS amplitude variability in conditions such as coronary artery disease and other populations at risk for increased cardiac mortality.     

Increased expression of mitogen-activated protein kinase and its upstream regulating signal in human gastric cancer

AIM: To investigate the expression of mitogen-activated protein kinases (MAPKs) and its upstream protein kinase in human gastric cancer and to evaluate the relationship between protein levels and clinicopathological parameters.METHODS: Western blot was used to measure the expression of extracellular signal-regulated kinase (ERK)-1, ERK-2, ERK-3, p38 and mitogen or ERK activated protein kinaseMEK-1 proteins in surgically resected gastric carcinoma, adjacent normal mucosa and metastatic lymph nodes from 42 patients. Immunohistochemistry was employed for their localization.RESULTS: Compared with normal tissues, the protein levels of ERK-1 (integral optical density value 159526±65760 vs 122807±65515, P=0.001), ERK-2 (168471±95051 vs 120469±72874, P<0.001), ERK-3 (118651±71513 vs 70934±68058, P<0.001), P38 (104776±51650 vs 82930±40392, P=0.048) and MEK-1 (116486±45725 vs 101434±49387, P=0.027) were increased in gastric cancer tissues. Overexpression of ERK-3 was correlated to TNM staging [average ratio of integral optic density (IOD)tumor:IODnormal in TNM Ⅰ, Ⅱ, Ⅲ, Ⅳ tumors was 1.43±0.34, 5.08±3.74, 4.99±1.08, 1.44±1.02, n=42, P=0.023] and serosa invasion (4.31±4.34 vs 2.00±2.03, P=0.037). In poorly differentiated cancers (n=33), the protein levels of ERK-1 and ERK-2 in stage Ⅲ and Ⅳ tumors were higher than those in stage Ⅰ and Ⅱ tumors (2.64±3.01 vs 1.01±0.33, P=0.022; 2.05±1.54 vs 1.24±0.40, P=0.030). Gastric cancer tissues with either lymph node involvement (2.49±2.91 vs 1.03±0.36, P=0.023; 1.98±1.49 vs 1.24±0.44, P=0.036) or serosa invasion (2.39±2.82 vs 1.01±0.35, P=0.022; 1.95±1.44 vs 1.14±0.36, P=0.015) expressed higher protein levels of ERK-1 and ERK-2. In Borrmann Ⅱ tumors, expression of ERK-2 and ERK-3 was increased comparedwith Borrmann Ⅲ tumors (2.57±1.86 vs 1.23±0.60, P=0.022; 5.50±5.05 vs 1.83±1.21, P=0.014). Borrmann Ⅳ tumors expressed higher p38 protein levels. No statistically significant difference in expression of MAPKs was found when stratified to tumor size or histological grade (P>0.05). Protein levels of ERK-2, ERK-3 and MEK-1 in metastatic lymph nodes were 2-7 folds higher than those in adjacent normal mucosa. The immunohistochemistry demonstrated that ERK-1, ERK-2, ERK-3, p38 and MEK-1 proteins were mainly localized in cytoplasm. The expression of MEK-1 in gastric cancer cells metastasized to lymph nodes was higher than that of the primary site. CONCLUSION: MAPKs, particularly ERK subclass are overexpressed in the majority of gastric cancers. Overexpression of ERKs is correlated to TNM staging, serosa invasion, and lymph node involvement. The overexpression of p38 most likely plays a prominent role in certain morphological subtypes of gastric cancers. MEK-1 is also overexpressed in gastric cancer, particularly in metastatic lymph nodes. Upregulation of MAPK signal transduction pathways may play an important role in tumorigenesis and metastatic potential of gastric cancer.     

Mechanisms of Transformation by the BCR/ABL Oncogene

The Philadelphia chromosome generates a chimeric oncogene in which the BCR and c-ABL genes are fused. The product of this oncogene, BCR/ABL, has elevated ABL tyrosine kinase activity, relocates to the cytoskeleton, and phosphorylates multiple cellular substrates. BCR/ABL transforms hematopoietic cells and exerts a wide variety of biological effects, including reduction in growth factor dependence, enhanced viability, and altered adhesion of chronic myelocytic leukemia (CML) cells. Elevated tyrosine kinase activity of BCR/ABL is critical for activating downstream signal transduction and for all aspects of transformation. This review will describe mechanisms of transformation by the BCR/ABL oncogene and opportunities for clinical intervention with specific signal transduction inhibitors such as STI-571 in CML.