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.
目的探讨钼靶X线导丝定位切除触诊阴性乳腺病灶手术的临床应用价值。 方法对291例299个触诊阴性乳腺病灶在钼靶X线指引下经导丝定位并切除活检，确定病理类型。 结果299个触诊阴性乳腺病灶中乳腺癌病灶42个（14.05%），癌前病变40个（13.38%），良性病变257个（85.95%），其中乳腺癌灶多表现为簇状或弥漫细点状钙化，乳腺癌病灶中原位癌22个（52.38%，22/42），浸润癌Ⅰ期13个（30.95%，13/42），Ⅱ期4个（9.52%，4/42），Ⅲ期3个（7.15%，3/42）。40例乳腺癌患者（2例为双侧癌）均长期随访，最长随访时间为10年，复发转移2例。应用钼靶X线诊断乳腺癌的灵敏度为92.86%（39/42）；特异度为95.33%（245/257），诊断比值比（DOR）为265.42。 结论钼靶X线导丝定位病灶切除技术可提高触诊阴性乳腺病灶的早期诊断率，指导手术切除病灶，其组织损伤小，可靠性高，促进了乳腺癌二级预防，适合二级医院广泛应用。