Abstract: Objective Using Amplex red fluorometric assay to detect the lysyl oxidase (LOX) enzyme activity in tissue engineered heart valve (TEHV). Methods Porcine aortic valves were decellularized with trypsin+ethylene diaminetetraacetic acid(EDTA), TritonX-100, and RNaseⅠ＋DNaseⅠ, then they were seeded by myo-fibroblasts that harvested from rats. Then they were fed with Dulbecco’s modified Eagle medium (DMEM) which contained high glucose for 27 days, they were fed with phenol red-free and serumfree DMEM for 24 hours, and the medium was harvested and used for LOX enzyme activity assays with the Amplex red fluorometric assay. And reverse transcription-polymerase chain reaction (RT-PCR) technique was used to analyze the expression of LOXmRNA in TEHV. Results All the samples produced measurable amounts of active LOX enzyme. The fluorescence units were 45.60±1.66, and the corresponding concentration of LOX enzyme were 0.123±0.003μg/ml. At the same time, all the samples expressed LOXmRNA. The expression of LOXmRNA was corresponding to the results of the Amplex red fluorometric assay. Conclusion It is feasible to detect the LOX enzyme activity in TEHV with the Amplex red fluorometric assay. And this assay gives a way to reflect that LOX plays an important role in collagen cross-linking of extracellar matrix in TEHV.
ObjectiveTo analyze the effectiveness of in vitro fenestration versus bypass surgery techniques in the treatment of type B aortic dissection involving the left subclavian artery by thoracic endovascular aortic repair (TEVAR).MethodsAmong the 53 patients with type B aortic dissection involving the left subclavian artery admitted to our center from January 2017 to October 2020, 23 underwent in vitro fenestration + TEVAR (a fenestration group with 18 males and 5 females aged 53.6±5.3 years), and 30 patients underwent left common carotid artery-left subclavian artery bypass + TEVAR (a bypass group with 24 males and 6 females aged 51.8±3.8 years). The effectiveness and safety between the two groups were compared.ResultsThe surgical success rate was 100.0% in both groups. And there was no death within postoperative 30 days and during the follow-up. There was no endoleak immediately postoperatively and during 1-year follow-up in the two groups. The operation time and hospitalization expenses in the fenestration group was less or shorter than those in the bypass group (P<0.05). The reduction in blood pressure of the left upper limb in the fenestration group was greater than that in the bypass group (P<0.05). There was no symptom of left upper limb ischemia, dizziness or hoarseness in both groups.ConclusionThe two methods of reconstruction of the left subclavian artery are safe and effective. In vitro fenestration can reduce surgical trauma and costs, and bypass surgery can provide better forward blood flow for the left subclavian artery.