Objective To verify the effectiveness of electrical impedance tomography (EIT) with multi-layer electrodes in gastric emptying measurement by simulation experiments using EIT with three-layer electrodes.Methods Firstly,EIT system with three-layer electrodes and gastric emptying measurement simulation equipment was designed and constructed to simulate gastric emptying process and obtain EIT reconstruction images.Secondly,the region where the electrical characteristic of gastric changes was selected as region of interest.Finally,the relative impedance change rate in region of interest for every image obtained from all three layers was consecutively recorded,then the gastric emptying curve was formed and gastric emptying time was calculated.Results There are obvious differences among the sharp of impedance change curves of interested region for three layers,and the gastric emptying time and process of each layer is also different from one another.It is suggested that the passing path and emptying manner of food in gastric emptying process reflected by EIT images varied from layer to layer.Therefore,the necessity and feasibility of using EIT with three-layer electrodes in gastric emptying measurement study is verified.Conclusions EIT with three-layer electrodes can provide more abundant information of gastric motility function associated with gastric emptying pathology and physiology state.It is likely to be a noninvasive,convenient and effective imaging method for the detection and evaluation research on gastric emptying and gastric motility.

Arrhythmias, Cardiac ; etiology ; therapy ; Gap Junctions ; Stem Cell Transplantation ; adverse effects

Objective To detect Tp-e/QT ratio in patients with acute ST-segment elevation myocardial infarction (STEMI) and explore its clinical significance. Methods Healthy individuals and patients with acute STEMI were recruited in this study. Their first QTc,QTd and Tp-e were measured within 24 h after admission to hospital,and Tp-e/QT ratio was calculated so as to analyze the relation between Tp-Te/QT ratio and malignant ventricular arrhythmia. Results Compared with those of the healthy individuals,the intervals of QTd,Tp-e and QTc were significantly lengthened \[(33.66?16.76)ms vs. (55.29?31.12)ms,(89.55?12.61)ms vs. (142.65?39.33)ms,and (426.57?65.03)ms vs. (482.26?48.03)ms,P

Background Cardiomyocytes apoptosis was related to oxidative stress which has been shown to play an important role in ventricular remodeling after myocardial infarction(MI).Probucol is a hypolipidemic and antioxidant agents.Several reports demonstrated its cardioprotective effect after MI.However,the exact effect of probucol on the modification of the apoptosis related gene Bcl-2 and Bax is not clear.Objective To investigate the effects of probucol on mRNA and protein expression of Bcl-2,Bax and oxidative stress in myocardial infarcted rats.Methods Forty-one SD rats that survived 24 h after ligating left anterior descending coronary artery were randomly to receive placebo-saline(5 mL/d,n=20)or probucol(probucol 60 mg/kg?d,n=21).Twelve rats underwent sham operation were served as control(n=12).Six weeks after treatment,hemodynamic pararmeters and left ventricular function were measured with catheterization.Cardiomyocytes apoptosis were determined by TUNEL method.Myocardium mRNA of Bcl-2 and Bax expression levels in the non-infarcted myocardium were as- sessed by RT-PCR.The myocardium protein expression of Bcl-2 and Bax in the non-infarcted myocardium were de- termined by Western blot.Colorimetry was used to determine oxidative metabolism index in myocardium.Results 1)Compared with the sham rats,all MI rats showed marked decrease in Bcl-2 mRNA and protein expression in myo- cardium with increase of Bax mRNA and protein expression and apoptosis index(P

Three dimensional electrical impedance tomography (3D-EIT) became an important branch of EIT recently. It is important to research imaging and image quality evaluation methods for single targets of different positions and multi-targets in 3D field. Using finite element subdivision method, 3D-EIT field was dispersed into cube unit in the present study for models with single target located in the center of field, middle of field, and near to the edge, respectively. For models with two targets and four targets near to the field edge, Tikhonov-Noser algorithm was adopted in image reconstruction. Imaging error function ER and structure similarity degree function SSIM were introduced to evaluate the reconstructed images. For the models with signal target, with the movement of the target from the center to the edge of the field, the value of ER increased and SSIM decreased, and reconstruction quality decreased. For the models with multi-targets near to the field edge, ER and SSIM increased and decreased respectively with the increase of target number, mage quality also decreased. Tikhonov-Noser algorithm is an effective 3D-EIT algorithm. ER and SSIM are adaptive for the characteristic of 3D-EIT images, and it can quantitatively evaluate the 3D-EIT imaging effect from the two perspective of imaging error and structure quality.
Algorithms ; Electric Impedance ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; Tomography

Objective Practical electrical impedance tomography (EIT) system with certain measurement resolution (MR) and signal-to-noise ratio (SNR) differs a lot from ideal simulation conditions in EIT methodology research. The aim of this paper was to study the impact of practical system with different MR and SNR on EIT. Methods Based on the ideal simulation boundary voltages of adjacent excitation and adjacent measurement pattern, practical systems whose MR were 0.1 mV and 0.01 mV, SNR ranged from 40-80 dB and no noises were simulated, simulation study for three imaging models A, B and C with different positions in the to-be imaged field under practical system conditions above was carried out using the combined Tikhonov-NOSER regularization algorithm, and error of reconstruction (ER) function and structure similarity (SSIM) function were adopted for quantitative evaluation of image effect. Results There are differences between images obtained under different MR and SNR for different image models. In order to obtain images for three models, SNR of system should be at least 40-50 dB when MR was 0.01 mV. For the goal to obtain high quality images of A, B and C, SNR should be 80, 70 and 60 dB respectively. When MR was 0.1 mV, SNR for obtaining images of A, B, C were 60, 50 and 40 dB. Moreover, the improvement of images with increasing SNR under MR of 0.1 mV was not as obvious as that of MR at 0.01 mV. Conclusions Blind pursuit of single high SNR is of no help to improve system performance and image reconstruction effect except increasing the difficulties in hardware design. The extremity SNR is 50-60 dB for system with MR of 0.01 mV and 60-70 dB for system with MR of 0.1 mV.

Objective: To investigate the effects of connective tissue growth factor (CTGF) on proliferation and migration of human osteosarcoma 143B cells in simulated osteosarcoma microenvironment by coculture technique in vitro, and to explore their underlying mechanisms. Methods: The osteosarcoma 143B cells were infected with recombinant adenovirus AdCTGF, then an indirect co-culture system was established with bone marrow stromal HS-5 cells for 3 days. The proliferation capacity of 143B cells was detected by MTT, and the migration ability of 143B cells was determined by wound-healing test and Transwell assay. The expression levels of CTGF and β-catenin were examined by reverse transcription-PCR (RT-PCR) and Western blotting. The expression levels of phosphorylated Akt (p-Akt) and phosphorylated glycogen synthase kinase 3β (p-GSK3β) were examined by Western blotting. Results: After infection with recombinant adenovirus AdCTGF, CTGF was overexpressed in osteosarcoma 143B cells in co-culture system. In simulated osteosarcoma microenvironment in vitro, CTGF overexpression could significantly promote the proliferation of 143B cells (P < 0.01), and the wound-healing rate and the number of migratory 143B cells also remarkably increased (both P < 0.01). The expression levels of P-catenin, p-Akt and p-GSK3β increased significantly in 143B cells after overexpressing CTGF (all P < 0.05). Conclusion: CTGF can significantly promote the proliferation and migration of human osteosarcoma 143B cells in simulated osteosarcoma microenvironment. PI3K (phosphatidylinositol 3-kinase)/Akt and Wnt/β-catenin pathways may be involved in this process.

OBJECTIVE To investigate the bacterial distribution and drug resistance in patients in intensive care unit(ICU) and provide theoretical bases for rational usage of antibiotics.METHODS The distribution and drug resistance of 372 strains isolated from patients in ICU collected from Jul 2007 to Jun 2008 were investigated and studied retrospectively.RESULTS Among them,the Gram-negative bacilli covered 59.14 %,the Gram-positive cocci 28.49%,and the fungi covered 12.37%.Pseudomonas aeruginosa,Klebsiella,Stenotrophomonas maltophilia and Ancinetobacter were the main Gram-negative bacilli.Staphylococcus aureus,coagulation-negative Staphylococcus and Enterococcus were the main Gram-positive cocci.The resistance rate of P.aeruginosa,S.maltophilia and Acinetobacter to imipenem was over 10%,and the S.maltophilia was 96.7%,the resistance rate of three main Gram-positive cocci to vancomycin and teicoplanin was zero,and the isolated bacteria showed serious multidrug-resistance.CONCLUSIONS Periodic monitoring should be done to learn the drug resistance and bacterial distribution in ICU in order to rationally use antibiotics to avoid the generation of new drug resistant strains and control the infection of patients in ICU.

OBJECTIVE To investigate the change of antibiotics resistance of the Pseudomonas aeruginosa isolated from patients′s sputum in our hospital from Jan 2006 to Dec 2008,and offer basis for prevention of clinical infection and the reasonable use of drugs.METHODS The culture,identification and sensitivity to antibiotics of P.aeruginosa from the clinical sputum specimens were analyzed using USA VITEK-32 system.RESULTS Totally 196 strains of P.aeruginosa were isolated and characterized during the three years.The rates of resistance to cefoperazone/sulbactam were 18.37%,piperacillin/tazobactam 16.84%,netilmicin 17.35%,trimethoprim/sulfamesoxazole 100.00%,ampicillin 99.49%,cefazolin 99.49%,cefotetan 88.78%,and to ceftriaxone were 79.08%.The resistance rate to cephalosporins showed rising tendency.But the resistance rate to ?-lactam antibiotics showed deereasing tendency.CONCLUSIONS P.aeruginosa has single and multi-resistance to antibiotics seriously,but sensitive to ?-lactam antibiotics and aminoglycosides.Using antibiotics reasonably based on bacteria identification and sensitivity test is the best way to reduce the resistance of the pathogens.

OBJECTIVETo investigate the expression of HPA and HIF-1alpha in human esophageal squamous cell carcinoma and their relationship with cancer development, invasion and metastasis.

METHODSThe expression of HPA mRNA and HIF-1alpha protein in 23 mucosa specimens of incisal margin, 26 para-tumorous dysplastic tissues and 70 esophageal squamous cell carcinoma specimens were detected by in situ hybridization assay and immunohistochemical staining, respectively.

RESULTSThe positive expression of HPA mRNA and HIF-1alpha protein were significantly increased as the epithelial cells progressed into carcinoma (P < 0.05). The expression of HPA mRNA and HIF-1alpha protein in the esophageal squamous cell carcinoma were significantly correlated with the invasion depth, lymph node metastasis and clinical staging (P < 0.05), while it was not correlated with the differentiation of tumors (P > 0.05). There was a close correlation between the expression of HPA mRNA and HIF-1alpha protein in the carcinoma tissues (P < 0.01).

CONCLUSIONThe high expression of HPA mRNA and HIF-1alpha protein is correlated with carcinogenesis, progression, invasion and metastasis of esophageal squamous cell carcinoma. There may be a positive cooperation between two of them in the carcinogenesis and development of esophageal carcinoma. The determination of HPA mRNA and HIF-1 alpha will be useful in predicting tumor biological behavior.

Adult ; Aged ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Esophageal Neoplasms ; metabolism ; pathology ; Esophagus ; metabolism ; pathology ; Female ; Gene Expression Regulation, Neoplastic ; Glucuronidase ; genetics ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Immunohistochemistry ; In Situ Hybridization ; Lymphatic Metastasis ; Male ; Middle Aged ; Mucous Membrane ; metabolism ; Neoplasm Invasiveness ; Neoplasm Staging ; RNA, Messenger ; metabolism