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Wang E.-T.,General Hospital of Air Force | Zhao M.,University of California at Davis
Chinese Journal of Traumatology - English Edition | Year: 2010

Endogenous electric fields (EFs) have been detected at wounds and damaged tissues. The potential roles of EFs in tissue repair and regeneration have been an intriguing topic for centuries. Recent researches have provided significant insights into how naturally occurring EFs may participate in the control of tissue repair and regeneration. Applied EFs equivalent to the size of fields measured in vivo direct cell migration, cell proliferation and nerve sprouting at wounds. More remarkably, physiological EFs are a guidance cue that directs cell migration which overrides other well accepted directional signals including initial injury stimulation, wound void, contact inhibition release, population pressure and Chemotaxis. EFs activate many intracellular signaling pathways in a directional manner. Modulation of endogenous wound EFs affects epithelial cell migration, cell proliferation, and nerve growth at cornea wounds in vivo. Electric stimulation is being tested clinically for the treatments of bone fracture, wound healing and spinal cord injury. EFs thus may represent a novel type of signaling paradigm in tissue repair and regeneration. Combination of the electric stimulation and other well understood biochemical regulatory mechanisms may offer powerful and effective therapies for tissue repair and regeneration. This review introduces experimental evidence for the existence of endogenous EFs and discusses their roles in tissue repair and regeneration.

Zhao Y.,CAS Institute of Process Engineering | Sun W.,General Hospital of Air Force | Wang Y.,CAS South China Botanical Garden | Saxena P.K.,University of Guelph | Liu C.-Z.,CAS Institute of Process Engineering
Applied Biochemistry and Biotechnology | Year: 2012

A temporary immersion bioreactor system was found to be suitable for mass shoot proliferation of Rhodiola crenulata. The shoot multiplication ratio and hyperhydration rate reached 46.8 and 35.4%, respectively, at a temporary immersion cycle of 3-min immersion every 300 min. Forced ventilation was employed in the temporary immersion bioreactor culture in order to decrease the hyperhydration rate, improve shoot quality and enhance the multiplication ratio. The highest multiplication ratio of 55.7 was obtained under a temporary immersion cycle of 3-min immersion every 180 min with the forced ventilation at an air flow rate of 40 l/h, and the hyperhydration rate was reduced to 26.1%. Forced ventilation also improved the subsequent elongation and rooting rate of these proliferated shoots, and the shoot cultures from the temporary immersion bioreactor formed complete plantlets when subcultured onto a rooting medium containing 5 μmol/l indole-3-acetic acid. © Springer Science+Business Media, LLC 2012.

Liu R.,CAS Institute of Process Engineering | Liu R.,University of Chinese Academy of Sciences | Sun W.,General Hospital of Air Force | Liu C.-Z.,CAS Institute of Process Engineering | Liu C.-Z.,University of Chinese Academy of Sciences
Biotechnology Progress | Year: 2011

A two-dimensional axisymmetric computational fluid dynamics (CFD) model based on a porous media model and a discrete population balance model was established to investigate the hydrodynamics and mass transfer behavior in an airlift bioreactor for hairy root culture. During the hairy root culture of Echinacea purpurea, liquid and gas velocity, gas holdup, mass transfer rate, as well as oxygen concentration distribution in the airlift bioreactor were simulated by this CFD model. Simulative results indicated that liquid flow and turbulence played a dominant role in oxygen mass transfer in the growth domain of the hairy root culture. The dissolved oxygen concentration in the hairy root clump increased from the bottom to the top of the bioreactor cultured with the hairy roots, which was verified by the experimental detection of dissolved oxygen concentration in the hairy root clump. This methodology provided insight understanding on the complex system of hairy root culture and will help to eventually guide the bioreactor design and process intensification of large-scale hairy root culture. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011 © 2011 American Institute of Chemical Engineers (AIChE).

Ladas I.D.,National and Kapodistrian University of Athens | Kotsolis A.I.,National and Kapodistrian University of Athens | Ladas D.S.,General Hospital of Air Force | Niskopoulou M.,National and Kapodistrian University of Athens | And 3 more authors.
Retina | Year: 2010

Purpose: The purpose of this study was to evaluate the efficacy of intravitreal ranibizumab in eyes with macular choroidal neovascularization secondary to angioid streaks. Methods: A prospective interventional case series was conducted on eyes with macular choroidal neovascularization, secondary to angioid streaks, treated by repeated injections of intravitreal ranibizumab (0.5 mg) and completing a follow-up time of 1 year. The outcome measures were best-corrected visual acuity, greatest lesion height as evaluated by optical coherence tomography, and lesion size as assessed by fluorescein angiography. Results: Over a 16-month period, we treated 15 consecutive eyes. The average number of injections was 7.1 ± 0.5. Mean best-corrected visual acuity was improved from 20/100 to 20/50 (P = 0.006). Best-corrected visual acuity either improved or stabilized in 14 eyes (93.3%). At baseline, 3 of the 15 eyes (20%) had a best-corrected visual acuity of ≥ 20/50 compared with 10 eyes (66.7%) at the end of the first year. Fourteen eyes (93.3%) presented reduction in greatest lesion height and stabilization or reduction in lesion size. The mean greatest lesion height was decreased from 377.3 ± 139.7 μm to 270.2 ± 88.6 μm (P < 0.001). Conclusion: Intravitreal ranibizumab is highly effective in improving or stabilizing vision and lesion morphology in patients with macular choroidal neovascularization secondary to angioid streaks. Copyright © by Ophthalmic Communications Society, Inc.

Yin Q.,General Hospital of Air Force
Nan fang yi ke da xue xue bao = Journal of Southern Medical University | Year: 2013

To assess a minipig model of acute myocardial infarction (AMI) established by percutaneous balloon occlusion using delayed-enhanced magnetic resonance imaging (DE-MRI). A minipig model of AMI was established by placement of a 2.0 mm×15.0 mm percutaneous transluminal coronary angioplasty balloon in the middle left anterior descending artery (LAD) through a percutaneous femoral puncture in the right inguinal region. The left anterior descending coronary artery (LAD) was occluded for 90 min, followed by assessment of the infarct size and cardiac function with DE-MRI, and the results were confirmed by pathological examination. DE-MRI showed a mean infarcts size of 10.2∓2.9 cm3 in the minipig models. Compared to the control group, the minipigs with AMI had significantly increased end-diastolic and end-systolic volumes (P<0.05) with a decreased stroke volume, ejection fraction and cardiac output (P<0.001). These DE-MRI values were matched with the microsphere values obtained from short-axis slices in pathological examination. We have established a feasible approach for evaluating minipig models of AMI as a platform for assessing the therapeutic effect of stem cell transplantation for AMI.

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