Guo D.,Heart Health |
Lian J.,Heart Health |
Lian J.,Ningbo Medical Center |
Liu T.,Heart Health |
And 6 more authors.
Heart Rhythm | Year: 2011
Background: Abnormal rate adaptation of ventricular repolarization is arrhythmogenic. There is controversy on the underlying ionic mechanisms for rate-dependent change in repolarization. Objective: The purpose of this study was to examine the role of the late sodium current (I Na-L) in normal rate-dependence of ventricular repolarization and reverse use-dependence of QT-prolonging agents. Methods: The effects of I Na-L blockade, I Na-L enhancement, I Kr blockade, and changes in extracellular potassium concentration ([K +] o) on rate adaptation of the QT interval and action potential duration (APD) were examined in isolated rabbit ventricular wedges and single myocytes. Rate dependence of I Na-L, delayed rectifier potassium current (I K), and L-type calcium current (I Ca) was determined using a whole-cell, voltage clamp technique. Results: At control, APD exhibited rate-dependent changes in the multicellular preparations as well as in the isolated single ventricular myocytes when [K +] o remained constant. The rate dependence of APD was significantly enhanced by reduction of [K +] o from 4 to 1 mM or by I Na-L enhancement but was markedly blunted by the selective sodium channel blocker tetrodotoxin. The I Kr blocker dofetilide (3 nM) amplified the QT to basic cycle length slope (71.2 ± 13.1 ms/s vs 35.1 ± 8.8 ms/s in control, n = 4, P <.05). This reverse use-dependence was abolished by tetrodotoxin at 5 μM (11.4 ± 4.3 ms/s, n = 4, P <.01). There were no significant differences in I Ca or I K over the range of basic cycle lengths from 2,000 to 500 ms. However, I Na-L exhibited a significant rate-dependent reduction. Conclusion: I Na-L is sensitive to rate change due to its slow inactivation and recovery kinetics and plays a central role in the rate dependence of APD/QT and in the reverse use-dependence of select APD/QT-prolonging agents. © 2011 Heart Rhythm Society.
Zhang X.,LiHuiLi Hospital |
Yin B.,Ningbo University |
Zhu F.,Ningbo University |
Huang G.,Ningbo Medical Center |
Li H.,LiHuiLi hospital
Chinese Journal of Cancer Research | Year: 2015
Background: To identify PTEN isoform and explore its potential role in tumor suppression. Methods: Western blotting, over-expression, shRNA mediated knocking-down, and bioinformatic analysis were used to identify PTEN isoform and test its effect on PI3K-Akt signaling pathway. Cell proliferation, apoptosis, and migration assays were used to test PTEN isoform’s biological activities. Results: The PTEN isoform is about 15 kDa bigger than PTEN and its expression is dependent on PTEN status. Immunoprecipitation for PTEN isoform followed by screening with antibodies against ISG15, SUMO1/2/3, Ubiquitin, and Nedd8 showed the identified PTEN isoform is not a general proteinaceous post-translational modification. In addition, overexpression of PTEN cDNA in cells did not generate PTEN isoform whereas knocking-down of PTEN reduced the protein levels of both PTEN and PTEN isoform in a proportional manner. Analysis of PTEN DNA sequence disclosed an alternative translational starting code (CTG) upstream of canonical PTEN coding sequence. Expression of cloned PTEN isoform generated a protein with a size about 15 kDa bigger than PTEN and suppressed PI3K-Akt signaling pathway in cells. Overexpression of PTEN isoform also led to decrease in cell growth and enhanced serum starvation—and UV irradiation—induced apoptosis through activation of Caspase 3. Finally, expression of PTEN isoform inhibited cell migration in scratch assay. Conclusions: PTEN isoform has PTEN-like activity and might be a new tumor suppressor. © Chinese Journal of Cancer Research. All rights reserved.
Lin N.,Ningbo Medical Center |
Xie L.,Zhejiang University |
Zhang P.,Ningbo Medical Center |
Min Y.,Ningbo Medical Center |
And 3 more authors.
Urology | Year: 2013
Objective To evaluate the accuracy of computed tomography urography (CTU) in the detection of caliceal diverticulum (CD) complicated with urolithiasis and the effect of compression and prolongation of acquisition delay. Materials and Methods All data were collected from a previous research between 2002 and 2011 at 3 hospitals. A total of 182 patients with evidence of renal parenchymal cystic lesion with calcific density were evaluated by CTU. Excretory phase imaging was acquired at 10 minutes and 60 minutes for each patient. Eighty-three patients received abdominal compression intervention during 10-minutes delay. Results CDs with stones were finally diagnosed in 41 patients (22.5%). Opacification within an apparent cyst was found in 31 patients (75.6%) when excretory phase images were acquired at 10 minutes and 38 patients (92.7%) at 60 minutes. The sensitivity and accuracy were significantly better with 60-minutes delay than with 10-minutes delay (92.7% vs 75.6%, P =.016 and 97.8% vs 94.0%, P =.016, respectively). The diagnostic results of compression group had significantly higher sensitivity and accuracy than that of the noncompression group (94.4% vs 60.9%, P =.025 and 98.8% vs 90.9%, P =.023, respectively). Conclusion It is important to distinguish CD from other diseases such as complex cyst when diagnosing a renal parenchymal cystic lesion with wall calcification. CTU has high sensitivity and accuracy in the detection of CD. Abdominal compression and longer imaging delay can significantly improve the diagnostic effect of CTU. © 2013 Elsevier Inc. All Rights Reserved.
Zhang J.,Ningbo Medical Center |
Zhou C.,Ningbo Medical Center |
Wang Y.,Ningbo Medical Center |
Chen B.,Ningbo Medical Center
Shanghai kou qiang yi xue = Shanghai journal of stomatology | Year: 2013
PURPOSE: To investigate the role of repairing tissue defects by infrahyoid myocutaneous flap after oral cancer surgery in elder patients.METHODS: From December 2005 to November 2010, we used infrahyoid myocutaneous flaps to reconstruct soft tissue defects in 19 elder patients after radical operation of oral cancer. There were 11 males and 8 females with the age range of 65 to 89 years (average: 72.8) .The lesions included 10 tongue cancers, 2 buccal cancers, 6 mouth floor cancers and 1 gingival cancer.RESULTS: All wound healed uneventfully, and all the 19 infrahyoid myocutaneous flaps survived without total or partial necrosis. The results were satisfactory both in appearance and functions. The patients were followed up for 6 months to 5 years, no tumour relapse and metastasis occurred.CONCLUSIONS: The procedure of preparing the infrahyoid myocutaneous flap is simple and the result is reliable. The flap is useful for reconstruction of soft tissue defects in elder patients.