聚羟基丁酸酯-羟基戊酸酯/溶胶-凝胶生物活性玻璃促进牙周组织再生

BACKGROUND: Our previous studies have shown that the poly(hydroxybutyrate- co-hydroxyvalerate) - sol-gel bioactive glass (PHBV-SGBG) has good biocompatibility and promote bone tissue repair, but its specific role in periodontal tissue regeneration has not been investigated. OBJECTIVE: To investigate the periodontal regenerative effects of a PHBV-SGBG scaffold in beagle dogs. METHODS: Alveolar bone defects (5 mm×5 mm) were surgically created bilaterally at the buccal side of the mandibular third and fourth premolars of four beagle dogs. PHBV-SGBG scaffold was randomly filled in the defects as experimental group and nothing was put into the contralateral as control group. Histological and scanning electron microscopy observations, cone-beam CT evaluation and the Ca/P concentration ratio analysis were processed at 2, 4, 8 and 12 weeks after surgery. RESULTS AND CONCLUSION: After surgery, the height of the regenerated tissue increased with time in both groups, and the regenerated tissue height in the experiment group was higher than that in the control group (P < 0.05). At 12 weeks after surgery, the Ca/P concentration ratio of the experiment group was close to that in the normal tissue (P > 0.05), but higher than that of the control group (P < 0.05); the histological observation showed that the regenerated tissue of the experimental group was close to the normal tissue, and the regenerated tissue of the control group tended to be mature, with a small amount of new blood vessels. Under the scanning electron microscope, no scaffold structure was visible in the experimental group with the presence of bone lacuna at 8 weeks after surgery, while in the control group, there was no bone lacuna and obvious osteoblasts; at 12 weeks after surgery, the structure of the regenerated tissue of experimental group was more regular and close to the normal tissue with no remarkable osteoblasts, and in the control group, the regenerated tissue was disordered, with several cavity. These results show that the PHBV-SGBG scaffold can enhance periodontal bone regeneration effectively.      

重议《难经》注者吕广的年代问题

吕广是《难经》的最早注者,多认为其系三国时吴国人,但相关资料记载尚存矛盾之处。范行准曾提出吕广实为生于齐梁年间的吴地人,并提出《难经》系六朝时著作。综合目前所见的史料,吕广为三国时吴人之说更合理,《难经》应为三国以前著作。文章通过梳理回顾古籍文献,论证吕广的生活年代,为《难经》的研究提供参考。     

替米沙坦抑制U937细胞增殖及诱导凋亡

目的:探讨替米沙坦对U937细胞株的生长抑制及凋亡诱导作用。方法:分别以不同浓度的替米沙坦处理人类急性髓系白血病细胞U937;以CCK-8法检测不同浓度替米沙坦对U937细胞的生长抑制作用;以集落形成实验观察不同浓度替米沙坦对U937细胞集落形成能力的影响;以Annexin V-PI双染法及Hoechst 33342染色法检测不同浓度替米沙坦作用前后U937细胞凋亡程度的变化;以流式细胞术检测U937细胞表面抗原CD11b的阳性表达率,瑞氏染色后倒置显微镜进行细胞形态学观察,了解U937细胞的分化情况;以Western blot法检测不同浓度替米沙坦作用U937细胞后凋亡相关蛋白表达量的改变。结果:CCK-8实验结果证实替米沙坦呈时间和剂量依赖性抑制U937细胞的生长;集落形成实验显示低剂量替米沙坦可以完全抑制U937细胞的集落形成能力;Annexin V-PI双染法及Hoechst 33342法结果证实替米沙坦可以诱导U937细胞凋亡;细胞表面抗原流式检测术及瑞氏染色结果证实替米沙坦可以促进部分U937细胞分化;Western blot实验结果证实替米沙坦作用于U937细胞72 h后,促凋亡相关蛋白cleaved PARP及cleaved caspase-3蛋白的水平明显增高。结论:替米沙坦可以抑制细胞增殖以及诱导U937细胞部分分化,并通过caspase依赖的凋亡途径触发U937细胞凋亡。