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.
目的探討鉬靶X線導絲定位切除觸診陰性乳腺病灶手術的臨床應用價值。 方法對291例299個觸診陰性乳腺病灶在鉬靶X線指引下經導絲定位并切除活檢，確定病理類型。 結果299個觸診陰性乳腺病灶中乳腺癌病灶42個（14.05%），癌前病變40個（13.38%），良性病變257個（85.95%），其中乳腺癌灶多表現為簇狀或彌漫細點狀鈣化，乳腺癌病灶中原位癌22個（52.38%，22/42），浸潤癌Ⅰ期13個（30.95%，13/42），Ⅱ期4個（9.52%，4/42），Ⅲ期3個（7.15%，3/42）。40例乳腺癌患者（2例為雙側癌）均長期隨訪，最長隨訪時間為10年，復發轉移2例。應用鉬靶X線診斷乳腺癌的靈敏度為92.86%（39/42）；特異度為95.33%（245/257），診斷比值比（DOR）為265.42。 結論鉬靶X線導絲定位病灶切除技術可提高觸診陰性乳腺病灶的早期診斷率，指導手術切除病灶，其組織損傷小，可靠性高，促進了乳腺癌二級預防，適合二級醫院廣泛應用。