IEEE Trans Biomed Eng
April 2008
The reconstruction of epicardial potentials (EPs) from body surface potentials (BSPs) can be characterized as an ill-posed inverse problem which generally requires a regularized numerical solution. Two kinds of errors/noise: geometric errors and measurement errors exist in the ECG inverse problem and make the solution of such problem more difficulty. In particular, geometric errors will directly affect the calculation of transfer matrix A in the linear system equation AX = B.
View Article and Find Full Text PDFNan Fang Yi Ke Da Xue Xue Bao
November 2007
Objective: To observe the cell binding characteristics of SonoVue microbubbles targeting choriocarcinoma cells and provide evidence for clinical ultrasonic localization of the tumor utilizing the microbubbles.
Methods: The targeted microbubbles were prepared by conjugating anti-HCG antibody with the SonoVue microbubbles and added in choriocarcinoma cells or endometrial stromal cells to compare the cell binding rate of the agents under optical microscope and with flow cytometry.
Results: Flow cytometry demonstrated a binding rate of 77.
Conf Proc IEEE Eng Med Biol Soc
March 2008
Calculating the potentials on the heart's epicardial surface from the body surface potentials constitutes one form of inverse problems in electrocardiography (ECG). Since these problems are ill-posed, one approach is to use zero-order Tikhonov regularization, where the squared norms of both the residual and the solution are minimized, with a relative weight determined by the regularization parameter. In this paper, we used three different methods to choose the regularization parameter in the inverse solutions of ECG.
View Article and Find Full Text PDFObjective: To establish the cells model with high expression CYP1A1 and analyze the expression of the variable genotype.
Methods: Clone the target fragment (CYP1A1-Wt, Asn461, and -Val462) in T-Vectors into pBABE-neo, then transfer into the human embryonic lung fibroblast cells (HLF). The positive cells were selected by G418.
Meningiomas, which originate from arachnoid cells and constitute the largest subgroup of all intracranial tumors, are generally benign, yet have the capacity to progress into a higher histological grade of malignancy associated with an increase in biological aggressivity and/or capacity to recur. To elucidate meningioma pathogenesis and malignancy, we applied a holistic and network approach analyzing cDNA and tissue microarray results. A potential pathway leading to meningioma angiogenesis, apoptosis and proliferation was evidenced as well as a regulatory network of the biomarkers including Ki-67, AR, CD34, P53, c-MYC, etc.
View Article and Find Full Text PDFMetal and semimetal nanotube-nanowire heterojunction arrays have been achieved by sequential electrochemical-deposition inside the nanochannels of anodic aluminium oxide template with a layer of Au thin enough to leave the pores open.
View Article and Find Full Text PDFConf Proc IEEE Eng Med Biol Soc
October 2012
In this paper we present an algorithm as the combination of a low level morphological operation and model based global circular shortest path scheme to explore the segmentation of the right ventricle. Traditional morphological operations were employed to obtain the region of interest, and adjust it to generate a mask. The image cropped by the mask is then partitioned into a few overlapping regions.
View Article and Find Full Text PDFConf Proc IEEE Eng Med Biol Soc
October 2012
To better simulate RF field behavior in the human head for MRI applications, dyadic Green's function (DGF)/method of moment (DGF/MOM) -based solutions of the electromagnetic field (EMFs) inside a head-sized, stratified sphere in different MRI coils are presented. The lossy, multilayered spherical head phantom has similar radial conductivity and permeability profiles as human head and is loaded in MRI surface and RF volume coils. B field pattern, SAR distribution, flip angle, signal intensity (SI), and other MRI image parameters are calculated in this study.
View Article and Find Full Text PDFConf Proc IEEE Eng Med Biol Soc
October 2012
This paper describes an electrical model of the ventricles incorporating real geometry and motion. Cardiac geometry and motion is obtained from segmentations of multiple-slice MRI time sequences. A static heart model developed previously is deformed to match the observed geometry using a novel shape registration algorithm.
View Article and Find Full Text PDFThe liver regenerates by progenitor cells when it is damaged in chronic liver diseases and extensive damage. The progenitor cells, also termed "oval cells" according to their morphological traits, can differentiate into hepatocytes and bile duct cells in vivo. To better understand the transcriptional pattern that accompanies the hepatic differentiation of oval cells, we applied cDNA microarray to analyze the oval cell-derived liver epithelial progenitor cells (LEPCs) during in vitro induced differentiation.
View Article and Find Full Text PDFObjective: Glutathione-S-transferase A1 (GSTA1) is one of the major phase II detoxification enzymes in the cytosol, which genetic polymorphisms distribution is different in different ethnic, national and regional population. Up to now, GSTA1 genetic polymorphisms has been rarely reported in China. The purpose of the study was to investigate the distribution of genetic polymorphisms of human GSTA1 in Hakka population in South China.
View Article and Find Full Text PDFWei Sheng Yan Jiu
September 2006
Objective: To construct Thr461 --> Asn461 and Ile462 --> Val462 mutation vector of P4501A1 gene and to provide scientific base for deeply researching on the function of cytochrome 1A1 gene (CYP1A1) and the mechanism of carcinogenesis.
Methods: According to cDNA sequence of human CYP1A1 gene, universal primers (Pm3/Pm4) and mutant primers (Pt15/Pt16 and Pt17/Pt18) containing restriction enzyme site and mutation site were designed. The first set of primers involving Pm3/Pt16 and Pm3/Pt18 amplified a forward 1.
Brugada syndrome (BS) is a genetic disease identified by an abnormal electrocardiogram (ECG) (mainly abnormal ECGs associated with right bundle branch block and ST-elevation in right precordial leads). BS can lead to increased risk of sudden cardiac death. Experimental studies on human ventricular myocardium with BS have been limited due to difficulties in obtaining data.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
August 2006
This study was aimed to investigate the effect of some culture system composed of various cytokine combinations (TPO, SCF, FL, IL-1, IL-3, IL-6) on ex vivo expansion of megakaryocytic progenitors induced from CD34+ cells of peripheral blood and to seek a optimal cytokine combination and culture time. Mononuclear cells were isolated from mobilized peripheral blood (MPB) by density gradient centrifugation over Ficoll. CD34+ cells were purified by using an immunomagnetic bead separation system.
View Article and Find Full Text PDFNatural killer cells are components of the innate immune system that play an important role in eliminating viruses and malignant cells. Using simian immunodeficiency virus (SIV) infection of macaques as a model, flow cytometry revealed a gradual loss of CD16+ NK cell numbers that was associated with disease progression. Of note, the apparent loss of NK cells was detected in whole-blood samples but not in isolated peripheral blood mononuclear cells (PBMC), suggesting that an inhibitor(s) of the antibody used to detect CD16, the low-affinity immunoglobulin G (IgG) receptor, was present in blood but was removed during PBMC isolation.
View Article and Find Full Text PDFThis paper describes an electrical model of cardiac ventricles incorporating real geometry and motion. The heart anatomy and its motion through the cardiac cycle are obtained from segmentations of multiple-slice MRI time sequences; the special conduction system is constructed using an automated mapping procedure from an existing static heart model. The heart model is mounted in an anatomically realistic voxel model of the human body.
View Article and Find Full Text PDFBackground And Purpose: To investigate the American Joint Commission on Cancer (AJCC) sixth edition staging system of nasopharyngeal carcinoma (NPC) by Magnetic Resonance Imaging (MRI).
Patients And Methods: One hundred and fifty-nine non-disseminated biopsy-proven NPC patients were studied with MRI before treatment. Retrieval of MRI information enabled us to restage all patients accurately according to the sixth edition of the AJCC staging system.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi
February 2006
Objective: To investigate the biological effects of overexpression of the human DNA polymerase (pol-beta) on cellular response to DNA damage.
Methods: The cell strain HLFbeta from the stable overexpression of the human pol-beta was contaminated with methyl methanesulfonate (MMS) for investigating the effects of the pol-beta on the cellular responses to DNA damage on the aspects such as the DNA damage, the cell cycle and the induced mutation rate.
Results: The cell HLFbeta from the stable overexpression of the human pol-beta was obtained through the screening.
X-linked hypohidrotic ectodermal dysplasia (HED) is a rare disease characterized by the hypoplasia or absence of eccrine glands, dry skin, scant hair, and dental abnormalities. Here, we report a Mongolian family with congenital absence of teeth inherited in an X-linked fashion. The affected members of the family did not show other HED characteristics, except hypodontia.
View Article and Find Full Text PDFObjective: To study the effects of cadmium chloride on anterior pituitary and the relation between p38 MAPK & ERK1/2 pathway and apoptosis induced by cadmium chloride.
Methods: In vivo studies, SD male rats were administered with CdCl2 at the doses of 0, 1.0, 2.
An effective approach has been demonstrated for the synthesis of novel composite architectures, SiO2 nanowires (NWs) growing on hexagonally arranged circular patterns surrounded by TiO2 films on Si substrate. First, a solution-dipping template strategy is used to create TiO2 films with hexagonally arranged pores on Au-coated Si substrate, resulting in hexagonally arranged circular patterns of catalysts surrounded by TiO2 films. Then the patterned catalysts guide the growth of SiO2 NWs with the original TiO2 films preserved, realizing the composite structures.
View Article and Find Full Text PDFCamptothecin (CPT) is a potent inhibitor of DNA topoisomerase I with a wide spectrum of anti-tumor activity. Relatively little information is available regarding the relation of known topoisomerase-mediated DNA damage with other intracellular pathways. To gain an insight into the intracellular molecular mechanisms of Topoisomerase I inhibitor camptothecin-mediated DNA damage leading to cell death, we used a high-density cDNA microarray to assess sensitive early gene expression profiles in SGC7901 (gastric cancer), Hela (cervical adenocarcinoma), K562 (chronic myelogenous leukemia) and HL60 (promyelocytic leukemia) tumor cells stimulated with camptothecin for 1 h at the concentrations of GI50 (50 % growth inhibition after 24 h of treatment).
View Article and Find Full Text PDFBiological techniques such as Array-Comparative genomic hybridization (CGH), fluorescent in situ hybridization (FISH) and affymetrix single nucleotide pleomorphism (SNP) array have been used to detect cytogenetic aberrations. However, on genomic scale, these techniques are labor intensive and time consuming. Comparative genomic microarray analysis (CGMA) has been used to identify cytogenetic changes in hepatocellular carcinoma (HCC) using gene expression microarray data.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
September 2005
An inverse methodology for the design of biologically loaded radio-frequency (RF) coils for magnetic resonance imaging applications is described. Free space time-harmonic electromagnetic Green's functions and de-emphasized B1 target fields are used to calculate the current density on the coil cylinder. In theory, with the B1 field de-emphasized in the middle of the RF transverse plane, the calculated current distribution can generate an internal magnetic field that can reduce the central overemphasis effect caused by field/tissue interactions at high frequencies.
View Article and Find Full Text PDFObjective: To investigate the clinicopathologic characteristics and differential diagnosis of myopericytoma.
Methods: Six cases of myopericytomas were analyzed by light microscopy and immunohistochemistry (LSAB detection method).
Results: Tumors from 3 females and 3 males were found on the extremities and chest wall.