Objective To explore the effects of human urine-derived stem cells (hUSCs) and hUSCs combined with chondroitinase ABC (chABC) on the expressions of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in the spinal cord injury (SCI) of rats, and to investigate the underlying mechanism. Methods hUSCs were cultured from human urine, and their phenotypes were detected by flow cytometry. The SCI model of rats were made via Allen method. Sixty Sprague Dawley rats were divided into 5 groups (n=12): the sham operation group (group A), SCI group (group B), SCI+hUSCs group (group C), SCI+chABC group (group D), and SCI+hUSCs+chABC group (group E). Basso, Beattie, Bresnahan (BBB) score was used to measure the lower extremity motor function of rats in each group at 10, 20, and 30 days after operation. Real-time fluorescent quantitative PCR was used to detect the relative mRNA expressions of NGF and BDNF at 30 days. Meanwhile, the protein expression of NGF and BDNF were confirmed by immunohistochemistry staining. The relative protein expressions of Bax and Bcl-2 were detected by Western blot. Results The hUSCs were identified to have multipotential differentiation potential. At 10, 20, and 30 days, BBB score was significantly lower in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05). Real-time fluorescent quantitative PCR and immunohistochemistry staining demonstrated that the expressions of NGF and BDNF were significantly lower in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05); but there was no significant difference between groups C and D (P>0.05). Western blot results indicated that the protein expression of Bax was significantly higher in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05). Meanwhile, the protein expression of Bcl-2 was significantly lower in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05). Conclusion hUSCs can protect SCI and this positive effect can be enhanced by chABC; this neuro-protective effect may depend on promoting the expressions of NGF and BDNF, and suppressing the neuronal apoptosis.
Arrhythmia is a kind of common cardiac electrical activity abnormalities. Heartbeats classification based on electrocardiogram (ECG) is of great significance for clinical diagnosis of arrhythmia. This paper proposes a feature extraction method based on manifold learning, neighborhood preserving embedding (NPE) algorithm, to achieve the automatic classification of arrhythmia heartbeats. With classification system, we obtained low dimensional manifold structure features of high dimensional ECG signals by NPE algorithm, then we inputted the feature vectors into support vector machine (SVM) classifier for heartbeats diagnosis. Based on MIT-BIH arrhythmia database, we clustered 14 classes of arrhythmia heartbeats in the experiment, which yielded a high overall classification accuracy of 98.51%. Experimental result showed that the proposed method was an effective classification method for arrhythmia heartbeats.
Objective To evaluate the safety and ascendancy of small caliber stapler application for anterior resection in ultra-low rectal cancer with anal sphincter preservation. Methods A retrospective analysis of the data of 60 cases of ultra-low rectal cancer treated by anterior resection with anal sphincter preservation by double stapling technique according to TME principle between June 2006 and June 2009 were undertaken. The 60 patients were divided into two groups, each group included 30 cases. One group adopted 33 mm stapler and another group adopted 29 mm stapler, and then the profiles of medi-operation, post-operation, and prognosis were assessed. Results Time of simple anastomose in operation was (9.0±3.3) min in 33 mm stapler group and (6.0±2.6) min in 29 mm stapler group, and there was significant difference between them (P=0.022 5). There were 6 cases needed to be restored because of lesion during operation or dys-anastomosis in 33 mm stapler group, while 2 cases in 29 mm stapler group, there was significant difference between them (P=0.030 1). No significant differences were observed between the two groups in terms of the time for operation, leakage, bleeding, stenosis, anastomotic recurrence, and fecal incontinence after operation or length of stay. Conclusion The application of 29 mm stapler not only can shorten time for anastomose and step down the degree of difficulty, but also dosen’t increase stenostomia and other complications.