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Wen Cheng

Publications and source records attributed to Wen Cheng.

14 recordsLinked to original sources
PubMed2006

Cavo-atrial tumor resection under total circulatory arrest without a sternotomy.

Surgical management of intracardiac tumors arising in the inferior vena cava often requires total circulatory arrest for safe and adequate resection. Total circulatory arrest has traditionally been accomplished by accessing the great vessels through a sternotomy. Combination of a sternotomy and a large abdominal incision results in excellent exposure but also creates the potential for significant morbidity. We report here the resection of cavoatrial tumors by achieving total circulatory arrest through femoral arterial and venous cannulation without requiring a sternotomy. This minimal-access total circulatory approach has the potential to greatly diminish morbidity when managing tumors of the inferior vena cava.

Adult↗
PubMed2006

The hypothetical protein CT813 is localized in the Chlamydia trachomatis inclusion membrane and is immunogenic in women urogenitally infected with C. trachomatis.

Using antibodies raised with chlamydial fusion proteins, we have localized a protein encoded by hypothetical open reading frame CT813 in the inclusion membrane of Chlamydia trachomatis. The detection of the C. trachomatis inclusion membrane by an anti-CT813 antibody was blocked by the CT813 protein but not unrelated fusion proteins. The CT813 protein was detected as early as 12 h after chlamydial infection and was present in the inclusion membrane during the entire growth cycle. All tested serovars from C. trachomatis but not other chlamydial species expressed the CT813 protein. Exogenously expressed CT813 protein in HeLa cells displayed a cytoskeleton-like structure similar to but not overlapping with host cell intermediate filaments, suggesting that the CT813 protein is able to either polymerize or associate with host cell cytoskeletal structures. Finally, women with C. trachomatis urogenital infection developed high titers of antibodies to the CT813 protein, demonstrating that the CT813 protein is not only expressed but also immunogenic during chlamydial infection in humans. In all, the CT813 protein is an inclusion membrane protein unique to C. trachomatis species and has the potential to interact with host cells and induce host immune responses during natural infection. Thus, the CT813 protein may represent an important candidate for understanding C. trachomatis pathogenesis and developing intervention and prevention strategies for controlling C. trachomatis infection.

Antibodies, Bacterial↗
PubMed2006

[Expression of PPAR-gamma in human hilar bile duct carcinoma cell line QBC939 and the effects of PPAR-Y activated by its ligand on the growth of QBC939].

OBJECTIVE: To explore the expression of Peroxisome Proliferator-activated Receptor-gamma (PPAR-gamma) in QBC939 and the effects of PPAR-gamma activated by its ligand pioglitazone on the growth of human bile duct carcinoma cell line. METHODS: QBC939 cells were cultured and treated with different concentration of pioglitazone; the expression of PPAR-gamma mRNA was detected by RT-PCR; the effects of PPAR-gamma activated by its ligand on cell proliferation were examined by cell count under light microscope; the influences of activated PPAR-gamma on cell cycle were examined by flow cytometry, and the apoptosis of cancer cells induced by PPAR-gamma ligand pioglitazone was detected by flow cytometry and TUNEL methods. RESULTS: PPAR-gamma was expressed in human hilar bile duct carcinoma cell line QBC939. And after PPAR-gamma was activated by its ligand pioglitazone, it significantly inhibited cell proliferation, produced G2/M phase arrest and induced apoptosis of QBC939. CONCLUSIONS: PPAR-gamma, after being activated by its ligand pioglitazone, can inhibit the cell growth of QBC939 remarkably through suppression of cell proliferation, increase in proportion of G2/M phase cells and induction of apoptosis, so PPAR-gamma may be a molecular therapeutical target against the human bile duct carcinoma.

Apoptosis↗
PubMed2005

Experimental evaluation of hotspot identification methods.

Identifying crash "hotspots", "blackspots", "sites with promise", or "high risk" locations is standard practice in departments of transportation throughout the US. The literature is replete with the development and discussion of statistical methods for hotspot identification (HSID). Theoretical derivations and empirical studies have been used to weigh the benefits of various HSID methods; however, a small number of studies have used controlled experiments to systematically assess various methods. Using experimentally derived simulated data--which are argued to be superior to empirical data, three hot spot identification methods observed in practice are evaluated: simple ranking, confidence interval, and Empirical Bayes. Using simulated data, sites with promise are known a priori, in contrast to empirical data where high risk sites are not known for certain. To conduct the evaluation, properties of observed crash data are used to generate simulated crash frequency distributions at hypothetical sites. A variety of factors is manipulated to simulate a host of 'real world' conditions. Various levels of confidence are explored, and false positives (identifying a safe site as high risk) and false negatives (identifying a high risk site as safe) are compared across methods. Finally, the effects of crash history duration in the three HSID approaches are assessed. The results illustrate that the Empirical Bayes technique significantly outperforms ranking and confidence interval techniques (with certain caveats). As found by others, false positives and negatives are inversely related. Three years of crash history appears, in general, to provide an appropriate crash history duration.

Accidents, Traffic↗
PubMed2005

In the current era, complete revascularization improves survival after coronary artery bypass surgery.

BACKGROUND: Complete revascularization has been the standard for coronary bypass grafting. However, surgical intervention has evolved with increasing use of arterial conduits and off-pump techniques. METHODS: Patients undergoing non-redo bypass surgery from January 1998 through December 2000 were followed up with questionnaires and telephone contact. Incomplete revascularization was defined as absence of bypass grafts placed to a coronary territory supplied by a vessel with 50% or greater stenosis. RESULTS: One thousand thirty-four patients were followed for a mean of 3.3 +/- 1.6 years. Complete revascularization was found in 937 (90.6%) patients, and incomplete revascularization was found in 97 (9.4%) patients. Eight hundred twenty-seven (80.4%) patients underwent on-pump operations, and 207 (19.6%) underwent off-pump operations. Incomplete revascularization was more prevalent in off-pump versus on-pump operations (21.7% vs 6.3%, P < .001). Multivariable Cox regression analysis indicated that in-hospital cerebrovascular accidents (hazard ratio, 5.49; P < .001), chronic obstructive pulmonary disease (hazard ratio, 1.97; P = .019), and incomplete revascularization (hazard ratio, 1.85; P = .040) predicted an increased hazard (risk) of cardiac death. Left internal thoracic artery (hazard ratio, 0.38; P = .047), right internal thoracic artery (hazard ratio, 0.25; P = .019), and radial artery (hazard ratio, 0.36; P < .001) grafting reduced the risk of cardiac death. The 5-year unadjusted survival rate was 52.6% versus 82.4% in patients undergoing incomplete and complete revascularization ( P < .001), with cardiac survival rates of 74.5% versus 93.1%, respectively ( P < .001). However, this difference in cardiac survival was smaller in octogenarians with incomplete versus complete revascularizations (77.4% vs 87.6%, P = .101) and was essentially absent in off-pump versus on-pump operations if complete revascularization was achieved in both cases (93.6% vs 93.1%, P > .200). CONCLUSIONS: Complete revascularization and arterial grafting improve 5-year survival. Off-pump techniques do not affect survival. Complete revascularization should be performed whenever possible.

Aged↗
PubMed2005

[Value of preoperative urodynamics to the prognosis of transurethral prostate resection for benign prostatic hyperplasia].

OBJECTIVE: To establish the value of preoperative urodynamics to the outcome prediction of transurethral prostate resection (TURP) for benign prostatic hyperplasia (BPH). METHODS: One hundred and sixty patients with BPH underwent urodynamic tests. Preoperative IPSS (International Prostate Symptom Score) and QOL (Quality of Life) were compared with those 8 to approximately 11 months after operation. RESULTS: The parameters of urodynamic tests (max. free flow, detrusor pressure at max. flow, Schafer grade, Abrams-Griffiths No, urethral resistance factor, cystometric capacity, effective capacity). IPSS and QOL were improved after operation (P < 0.001). And all the relative coefficients of linear dependence analysis, IPSS, QOL and max. free flow, detrusor pressure at max. flow, Schafer grade, Abrams-Griffiths value, urethral resistance factor, cystometric capacity, and effective capacity conducted postoperatively, were statistically significant. CONCLUSION: Preoperative urodynamics of transurethral prostate resection for benign prostatic hyperplasia may provide indication for operation and predict postoperative improvement of symptoms. Preoperative urodynamics should be considered as a routine examination.

Aged↗
PubMed2005

Screening of flocculant-producing strains by NTG mutagenesis.

Screening of new microorganism being able to produce efficiently flocculants was carried out. A new model for screening efficient flocculant-producing strains was designed and tested. The results showed that this model for screening efficient flocculant-producing strains is very reliable and can greatly shorten the screening period. 13 flocculant-producing strains were isolated from activated sludge by conventional method. A strain, designated as HHE6, produced the bioflocculant with the turbidity removal 98% for kaolin suspension. Six of 13 strains selected as the original strains were treated with NTG as mutagen, and five mutant strains (HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) with high flocculation efficiency was obtained by selection, which exhibited the flocculation rate for kaolin suspension above 90%. Strains HHE6, HHE-P7, and HHE-P24 were classified as Penicillium purpurogenum, HHE-P21 as Penicillium cyclopium, HHE-A26 as Aspergillus versicolor and HHE-A8 as Aspergillus fumigatus, and it is hitherto unreported for biofloccutant-producing strains of Penicillium. The growth of the six strains (HHE6, HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) had similar curves, i.e. firstly increasing rapidly, keeping relatively constant then and finally decreasing gradually with cultivation time. The production of bioflocculants by strains showed the similar pattern to strain growth.

Bacteria↗
PubMed2004

A novel sub-population of bone marrow-derived myocardial stem cells: potential autologous cell therapy in myocardial infarction.

BACKGROUND: Several studies have identified beta2-microglobulin-negative (beta2M(-)) cells as a potential stem cell fraction in the bone marrow of rats and humans. We studied the ability of bone marrow-derived beta2M(-) cells to differentiate into cardiomyocytes and reconstitute the myocardium in a model of myocardial infarction. METHODS: beta2M(-) cells were purified from bone marrow of Lewis rats using a magnetic activated cell-sorting technique. beta2M(-) cells, 2.5 x 10(6) cells in 100 microl of phosphate-buffered saline (PBS), were transplanted 7 days after infarction into a transmural myocardial scar induced by cryoinjury in Lewis rats (n = 9). Control Group 1(n = 10) received a 100-microl injection of PBS, and Control Group 2 (n = 15) received no injection. The beta2M(-) cells were labeled before transplantation, using the membrane fluorescent intercalated dye, PKH26. Repopulation was examined at 6 and 8 weeks after transplantation. Differentiation of beta2M(-) cells into cardiac myocytes was determined by the colocalization of troponin and PKH26 to the same cell, utilizing immunohistochemistry, ultraviolet photomicroscopy and fluorescence microscopy on 6-microm serial sections. Area of engraftment within the scar was calculated by planimetry. RESULTS: The treatment group had multiple islands of de novo-formed myocardium within the fibrous matrix of the transmural scar (mean area 35 +/- 4.2% of scar area at 6 and 8 weeks). These cells colocalized cardiac-specific troponin and PKH26. Using these techniques, no myocardial islands were seen in the control groups. Before transplantation, beta2M(-) cells were troponin-negative. CONCLUSIONS: This study demonstrates that beta2M(-) cells represent a novel sub-population of bone marrow-derived stem cells capable of successful and substantial engraftment in areas of transmural myocardial scar, with de novo formation of cardiac myocytes. The functional significance of this observation is being studied.

Animals↗
PubMed2004

[Expression of SOCS-1, 3 induced by Chlamydia trachomatis-infected Hela229].

OBJECTIVE: To explore the relationship between SOCS, immune suppression and chlamydial persistence of Chlamydia trachomatis-infected cells. METHODS: After being infected with Chlamydia trachomatis, RT-PCR was used to examine the expression of SOCS-1, 3 mRNA and Western blotting to examine the expression of SOCS-1,3 protein in Hela229 cells. Immunofluorescence was used to examine the effect of SOCS obstruction on the multiplication of Chlamydia trachomatis. RESULTS: Chlamydia trachomatis-infected Hela229 cells can induce the expression of SOCS-1,3 both on mRNA level and on protein level. The multiplicity of Chlamydia trchomatis can be suppressed after the expression of SOCS-1,3 was obstructed. CONCLUSION: Chlamydia trachomatis-infected Hela229 cells can induce the expression of SOCS-1,3, which is one of the mechanisms that Chlamydia trachomatis can suppress host immune and result in persistence.

Chlamydia Infections↗
PubMed2003

[Residual fraction in the evaluation of bladder outlet obstruction resulting from benign prostatic hyperplasia].

OBJECTIVES: To study residual fraction (RF) in the bladder outlet obstruction (BOO) resulting from benign prostatic hyperplasia (BPH). METHODS: Fifty adult outpatients with BPH were evaluated. With ultrasound and uroflowmetry, prevoid volume (PV) and postvoid residual volume (PRV) and peak flow rate (Qmax) were determined. Linear dependence analysis of RF and Qmax, PRV and Qmax were conducted. RESULTS: The coefficient between RF and Qmax showed extremely negative correlation(r = -0.3859, P < 0.01). Also, PRV and Qmax showed significant negative correlation (r = -0.2831, P < 0.05). CONCLUSIONS: The greater the RF, the more serious the BOO, the poorer potency of bladder. It is recommended that RF be used as a good supplement to PVR in the routine non-invasive evaluation of BOO caused by BPH.

Aged↗
PubMed2002

Simultaneous biatrial computerized mapping during permanent atrial fibrillation in patients with organic heart disease.

INTRODUCTION: Activation patterns during permanent atrial fibrillation (AF) in patients with organic heart diseases are unclear. METHODS AND RESULTS: We studied six patients with permanent AF and organic heart diseases undergoing surgery. The duration of AF averaged 4.9+/-7.6 years. Computerized epicardial mappings of the right atrial (RA) free wall and the left atrial (LA) posterior wall were simultaneously performed with 224 bipolar electrodes at 3-mm spatial resolution. In the RA, large wavefronts and conduction blocks were frequently observed. The lines of block correlated with the crista terminalis and large pectinate muscles. In contrast, the LA had rapid repetitive activities originated from corners of the electrode plaque, near the four pulmonary veins (PVs). On average, 2.8+/-1.2 sites of rapid repetitive activities were identified per patient. They activated continuously, intermittently, or alternately during AF. The mean activation cycle length in the RA (196+/-22 msec) was significantly longer than that in the LA (179+/-26 msec; P = 0.004). The maximum dominant frequency in the LA was higher than that in the RA (6.41+/-1.18 Hz vs 5.66+/-0.55 Hz; P = 0.049). The maximum dominant frequency was consistently located in areas with rapid repetitive activations near the PVs. CONCLUSION: During human permanent AF associated with organic heart diseases, the activation cycle length was shorter in the LA posterior wall than in the RA free wall. Rapid repetitive activities are consistently observed in the LA posterior wall, at or near the PVs.

Aged↗
PubMed2002

Off-pump coronary surgery: effect on early mortality and stroke.

BACKGROUND: Avoiding cardiopulmonary bypass in coronary artery bypass grafting is thought to reduce early mortality and morbidity. METHODS: We used our prospective database to compare all patients having off-pump coronary surgery (n = 389) with those having on-pump coronary surgery (n = 2412) between March 15, 1995, and November 1, 2000. Patients were grouped by age (years) in decades (>90, 80-89, 70-79, 60-69, <60 years). The Northern New England risk model was applied. Thirty-two independent variables were entered into a stepwise logistic regression analysis with the end points being surgical mortality and postoperative stroke. RESULTS: Patients undergoing off-pump operations were older (70.9 +/- 12 vs 68.1 +/- 11 years; P <.001), and their Northern New England predicted risk was higher (11.9% +/- 13% vs 9.2% +/- 10%; P <.001). However, patients having on-pump bypass had significantly more bypass grafts constructed (3.3 +/- 0.8 vs 1.9 +/- 0.8; P <.001) and triple-vessel coronary artery disease (58% vs 28%; P <.001). There were no significant differences in postoperative mortality, stroke rate, complications, and length of stay between the groups. Logistic regression analysis did not show that cardiopulmonary bypass was a risk factor for either surgical mortality (odds ratio, 1.08; P =.83) or stroke (odds ratio, 1.59; P =.27). CONCLUSION: Off-pump coronary bypass did not reduce early mortality and morbidity. Early and late results should be compared in a prospective randomized study.

Adult↗
PubMedDate not supplied

Biventricular support in patients with profound cardiogenic shock: a single center experience.

Options for managing heart failure patients with cardiogenic shock refractory to inotropic and intra-aortic balloon pump (IABP) therapy are limited. Ventricular assist devices (VADs) can bridge these patients to heart transplantation. However, controversy exists over whether extracorporeal membrane oxygenation (ECMO) before VAD placement is beneficial. We report our use of biventricular assist devices (BiVADs) as a direct bridge to transplant. Since July 1999, 19 Thoratec BiVADs were implanted for heart failure unresponsive to medical therapy. Patient ages ranged from 20 to 67 years. Causes of heart failure included idiopathic 32%, ischemic 26%, postcardiotomy 21%, and other 21%. All patients were in cardiogenic shock, and three were receiving cardiopulmonary resuscitation (CPR) before implant. Preimplant conditions included IABP 89%, mechanical ventilation 68%, three or more inotropes 84%, hyperbilirubinemia 59%, acute renal failure 63%, and hemodialysis 16%. Fifty-nine percent of patients bridged successfully to transplantation, with 90% posttransplant survival. Duration of BiVAD support ranged from 0 to 91 days, with two patients currently on support awaiting transplantation. Complications included bleeding requiring reoperation 26%, stroke 11%, infection (any positive culture) 68%, and cannula site infection 5%. The Thoratec BiVAD can successfully be used as a direct bridge to transplantation in heart failure patients with cardiogenic shock.

Adult↗