Different generations of biomedical materials are analyzed in this paper. The current clinical uses of plates made of metals, polymers or composite materials are evaluated, and nano hydroxyapatite/polylactic acid composites and carbon/carbon composite plates are introduced as emphasis. It is pointed out that the carbon/carbon composites are of great feasibility and advantage as a new generation of biomedical materials, especially in the field of bone plate. Compared to other biomaterials, carbon/carbon composites have a good biocompatibility and mechanical compatibility because they have similar elastic modulus, porosity and density to that of human bones. With the development of the technology in knitting and material preparation, carbon/carbon composite plates have a good application prospect.
The cognitive impairment of type 2 diabetes patients caused by long-term metabolic disorders has been the current focus of attention. In order to find the related electroencephalogram (EEG) characteristics to the mild cognitive impairment (MCI) of diabetes patients, this study analyses the EEG synchronization with the method of multi-channel synchronization analysis--S estimator based on phase synchronization. The results showed that the S estimator values in each frequency band of diabetes patients with MCI were almost lower than that of control group. Especially, the S estimator values decreased significantly in the delta and alpha band, which indicated the EEG synchronization decrease. The MoCA scores and S value had a significant positive correlation in alpha band.
Somatosensory vibration can stimulate somatosensory area of human body, and this stimulation is tranferred to somatosensory nerves, and influences the somatic cortex, which is on post-central gyrus and paracentral lobule posterior of cerebral cortex, so that it alters the functional status of brain. The aim of the present study was to investigate the neural mechanism of brain state induced by somatosensory vibration. Twelve subjects were involved in the 20 Hz vibration stimulation test. Linear and nonlinear methods, such as relative change of relative power (RRP), Lempel-Ziv complexity (LZC) and brain network based on cross mutual information (CMI), were applied to discuss the change of brain under somatosensory vibration stimulation. The experimental results showed the frequency following response (FFR) by RRP of spontaneous electroencephalogram (EEG) in 20 Hz vibration, and no obvious change by LZC. The information transmission among various cortical areas enhanced under 20 Hz vibration stimulation. Therefore, 20 Hz somatosensory vibration may be able to adjust the functional status of brain.
ObjectiveTo explore the effectiveness and safety of the improved approach of intraoperative temporary epicardial pacing lead implantation in complete video-assisted cardiac surgery. Method We included 50 cardiac patients with video-assisted cardiac surgery indications in our hospital from September 2013 to November 2013. According to approach to placing intraoperative temporary epicardial pacing lead, the patients were divided into two groups including an improved group (30 patients with 17 males and 13 females at age of 45.6±15.7 years) and a traditional group (20 patients with 12 males and 8 females at age of 44.2±17.7 years). Time of temporary epicardial pacing lead implantation, potential perioperative complications, and clinical data of intraoperation and postoperation were compared between the two groups. Result All the patients survived during perioperative period. No intraoperative bleeding, no pericardial tamponade, no infection caused by pacing wires, as well as no relevant postoperative complications occurred. Implantation time in the improved group is shorter than that in the traditional group (P<0.001). No patient had been found situations like moderate pericardial effusion, as well as pacing leads shifting during the following-up period. ConclusionThe improved approach has shorten the implantation time, which is simpler and more effective. No patient suffers from postoperative complications during short-term following-up. But the effect in long-term following-up period is still contentious.
ObjectiveTo investigate predictive value of intraoperative graft flow measurements during off-pump coronary artery bypass grafting (OPCAB) for early clinical prognosis. MethodsWe retrospectively analyzed the clinical data of 133 patients with three-vessel disease who underwent OPCAB in the Department of Cardiac Surgery of People's Hospital of Peking University in 2013 year. There were 103 males and 30 females with mean age of 62.84±7.13 years. Pulsatility index (PI) and mean flow were measured using a flow metre before the end of surgery. Then the total graft flow and the average graft flow were calculated. Univariate, bivariate correlation and logistic regression analysis were performed for statistical analysis. ResultsThe blood flow and PI of LIMA-to-LAD graft was respectively 28.69±16.90 ml/min and 2.70±1.39, and the total graft flow and the average graft flow was respectively 79.94±37.20 ml/min and 35.55±16.75 ml/min. The PI of LIMA-to-LAD graft was significantly correlated with serum cardiac troponin I(cTnI)level in 12 hours, with the highest serum cTnI level within 48 hours, with ICU stay and with ventilator time (P<0.01), but the correlation was not strong(coefficient correlation <0.4). Compared with the patients without perioperative myocardial infarction (PMI), the blood flow of LIMA-to-LAD graft, the total graft flow and the average graft flow were lower in the patients with PMI (P<0.01). Logistic regression analysis revealed that the total graft flow was an independent predictor of PMI (P=0.004, RR=0.950, 95%CI 0.918-0.984). ConclusionIntraoperative graft flow measurements during OPCAB can predict shortterm prognosis. The lower total graft flow is a risk factor for PMI.
ObjectiveTo analyze clinical experience and outcomes of video-assisted thoracoscopic surgery (VATS)for bioprosthetic mitral valve replacement (MVR). MethodsWe retrospectively analyzed 32 patients who underwent VATS bioprosthetic MVR in the Department of Cardiovascular Surgery of Guangdong General Hospital from March to December 2013. There were 14 males and 18 females with a mean age of 55.6±17.3 years (range, 19 to 80 years), mean body weight of 55.7±9.7 kg (range, 37 to 78 kg) and mean body surface area of 1.67±0.16 m2 (range, 1.30 to 1.95 m2). Five patients had atrial fibrillation. There were 20 patients in New York Heart Association (NYHA)functional class Ⅱ, 11 patients in class Ⅲ, and 1 patient in class Ⅳ. There were 16 patients with rheumatic mitral valve disease, 11 patients with degenerative mitral valve disease, 4 patients with infective endocarditis and 1 patient with associated congenital heart disease. ResultsVATS bioprosthetic MVR was successfully performed for all the patients, including 27 patients with Medtronic Hancock Ⅱ Bioprosthesis and 5 patients with Medtronic Mosaic Bioprosthesis. Concomitantly, tricuspid valvuloplasty was performed for 13 patients and atrial septal defect repair was performed for 1 patient. There was no in-hospital death, low cardiac output syndrome or left ventricular rupture. Postoperative echocardiography showed good bioprosthetic function in all the patients without paravalvular leakage. Postoperative cardiac function significantly improved compared with preoperative cardiac function. There were 9 patients in NYHA functional class Ⅰ, 17 patients in class Ⅱ, and 6 patients in class Ⅲ. Left atrial diameter and left ventricular end-diastolic diameter examined postoperatively and 3 months after surgery were significantly smaller than preoperative values. Left ventricular ejection fraction (LVEF)examined postoperatively and 3 months after surgery was significantly lower than preoperative LVEF. ConclusionsVATS bioprosthetic MVR is a minimally invasive, safe and feasible procedure with a low postoperative morbidity. Incision size can be significantly reduced with a special type of bioprosthesis.
Objective To examine the effect and safety of thoracoscopic surgery for left atrium myxoma excision. Method Sixty-nine left atrial myxoma patients underwent excision of left atrial myxoma in our hospital between January 2012 and August 2014 year. The patients were divided into two groups according to the procedure. Thirty patients under-went thoracoscopic surgery, as a thoracoscopic group, with 8 males and 22 females, aged 47.36±13.02 years. Thirty-nine patients received median sternotomy surgery, as a median sternotomy group, with 10 males and 29 females, aged 49.17±13.09 years. The effect and safety between the two groups were compared. Results All patients survived after surgery without death and other serious complications. Compared with the median sternotomy surgery group, longer cardiopul- monary bypass and aortic cross clamp time, shorter ICU stay, ventilator support, and postoperative drainage time, shorter hospital stay time, less postoperative drainage, lower cost, and more higher rate of returning to work in 1 month after surgery were found in the thoracoscopic group with P value less than 0.05. There was no complication of stroke and other neurological complication in the two groups. All patients were followed up for 11 months to 4 years and 7 months, average age of 38.5±12.7 months. There was no recurrence in both groups. Conclusions The thoracoscopic left atrial myxoma excision cardiopulmonary is effective and safe. It can be used as a surgical treatment of left atrial myxoma preferred.
ObjectiveTo investigate the early diagnostic value of transforming growth factor-β1(TGF-β1) on acute rejection after liver transplantation in rhesus by detecting the expression of TGF-β1 in the liver tissue. MethodsLiver transplantation models in rhesus were constructed by the improved vascular dual cuff, supporting tube of biliary tract, and artery anastomosis method.The successful models were randomly divided into experimental group (no immunosuppressant treatment in perioperative period) and control group (treated by immunosuppressant in perioperative period).Then the blood samples and liver tissues were collected at 6, 12, 24, and 72 hours after surgery.Allograft rejections of liver tissue after liver transplantation were monitored by liver function test, hematoxylin-eosin staining and Banff score.Finally, the expression level of TGF-β1 was detected by Western blot analysis or immunohistochemistry technique. Results①The acute rejection happened in all the rhesus at 12 h, 24 h and 72 h after liver transplantation, especially at 72 h after liver transplantation in the experimental group, the Banff grade levels of acute rejection in the liver tissue was more severe than that in the control group (P < 0.05).②The levels of ALT, AST, and TBIL after liver transplantation was gradually increased, which were similar at 6 h and 12 h after transplantation between the two groups, but which at 24 h and 72 h after transplantation in the experimental group were significantly higher than those in the control group (P < 0.05).③The results of TGF-β1 protein expression using immunohistochemical detection:The percentage of positive area of TGF-β1 of liver tissue at 12 h in the experimental group was significantly higher than that in the control group (P < 0.05).With the extension of time, it was gradually increased and significantly higher than that in the control group at 24 h or 72 h (P < 0.05).④The semi-quantitative results of TGF-β1 protein expression using Western blot detection:The TGF-β1 protein expressions began to increase at 6 h after liver transplantation in the experimental group and the control group, and the magnitude of increase was more obvious in the experimental group.The TGF-β1 protein expressions at different time (6 h, 12 h, 24 h, and 72 h) in the experimental group were significantly higher than those in the control group (P value was 0.003, 0.001, 0.001, and 0.001, respectively). ConclusionsThe elevated level of TGF-β1 of liver tissue after liver transplantation might suggest the enhanced cellular immune function, it might have certain significance for early diagnosis of acute rejection after liver transplantation.
ObjectiveTo compare the outcomes of mechanical prosthetic versus bioprosthetic replacement of tricuspid valve. Methods We retrospectively analyzed the clinical data of 344 patients underwent tricuspid valve replacement (TVR) in Guangdong General Hospital between January 2000 and December 2010. There were 227 female and 117 male patients with their age of 8-74 (42.0±13.3) years. We allocated the patients into two groups: 168 patients (48.8%) at age of 37.0±11.6 years underwent mechanical tricuspid valve replacement (the MTVR group) and 176 (51.2%) patients at age of 46.0±13.4 years underwent biological tricuspid valve replacement (the BTVR group). Follow-up data were obtained via patients' visiting the outpatient clinic, telephone or mail contacts. ResultsThe mean follow-up time was 5.7 years (ranged from 2 months to 12.6 years). In the BTVR group, 149 patients survived to discharge from hospital, and 144 patients were followed-up successfully, giving a 96.6% follow-up rate. Early mortality (within 30 days post-operation) occurred in 29 patients (16.5%), and 14 patients (7.9%) died after 30 days post-operation. Eighteen bioprosthetic valve degeneration was found during follow-up, and infective endocarditis in 3 patients. In the MTVR group, 152 patients survived to discharge from hospital, 142 patients (93.4%) were followed-up. Early mortality in 13 patients (7.7%), and 14 patients (8.3%) died after 30 days post-operation. Nineteen patients suffered from mechanical prosthesis obstruction, no infective endocarditis patients was found in the MTVR group. There was no statistical difference between the BTVR group and the MTVR group in mortality rate (24.4% versus 16.1%, P=0.054) and in reoperation rate (4.2% versus 9.9%, P=0.051), respectively．There were statistical differences in long-term survival rates between the BTVR group and the MTVR group with 1 year survival rate(78% vs. 89%), 5 years survival rate(74% vs. 86%), and 10 years survival rate (66% versus 78%) with P value at 0.003. ConclusionsThis study suggests that the type of implanted prosthesis in tricuspid replacement does not affect long-term outcomes or the reoperation rate. The survival rate is higher in the MTVR group than that in the BTVR group, which may contribute to younger age in the MTVR group. There is a tendency in higher infective endocarditis incidence in the BTVR group than that in the MTVR group.
ObjectiveTo evaluate value of percutaneous interventional treatment for portal vein thrombosis combined with occlusion following liver transplantation. Method The data of 3 patients with portal vein thrombosis combined with occlusion following liver transplantation underwent interventional treatment were analyzed retrospectively. Resultsthe mural thrombi were detected preoperatively in the portal venous trunk for the 3 patients, all of which were classified as Yerdel's grade 1 and were underwent porto-portal anastomosis without thrombectomy during liver transplantation. Portal vein thrombosis combined with occlusion occured after 8 months postoperatively. The percutaneous transhepatic balloon venoplasty and self-expanding metallic stents placement was performed in 3 patients. The interventional treatment was successfully achieved in all the patients. The follow-up period ranged from 28 to 38 months, no complications occurred following interventional treatment, the graft function and survival of patients were good. ConclusionPercutaneous interventional treatment is an efficacious and safe method to treat portal vein thrombosis combined with occlusion.