大鼠肝再生过程中增殖细胞核抗原的表达

目的:探讨大鼠肝再生过程中肝细胞增殖细胞核抗原(PCNA)表达的变化. 方法:建立肝切除动物模型,用免疫组织化学法、图像分析仪检测肝细胞PCNA的表达. 结果:PCNA强阳性肝细胞数及其总灰度值在肝大部切除后24 h明显增高,肝细胞阳性表达率在48 h达到峰值,至120 h趋于正常水平.结论:PCNA强阳性肝细胞呈规律性变化,提示残余肝可再生.     

芪仙通络方对脑缺血大鼠内源性神经干细胞再生的影响及机制

目的:探讨芪仙通络方对脑缺血大鼠内源性神经干细胞再生的影响及可能机制。方法:采用线栓法复制大脑中动脉阻塞(middle cerebral artery occlusion,MCAO)局灶性脑缺血模型;将160只大鼠随机分为正常组,假手术组,模型组,吡拉西坦组(吡拉西坦片灌胃),芪仙通络方组(芪仙通络方灌胃);5-溴脱氧尿嘧啶核苷(5-bromo-2-deoxy uridine,Brd U)腹腔注射标记脑内增殖细胞,造模后3,7,14,28 d,分别采用免疫荧光Brd U/神经元核抗原(neuronal nuclei antigen,Neu N),Brd U/胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)双标法检测缺血海马区新生的神经元及星形胶质细胞,并计算其双标阳性细胞率,免疫组化法检测缺血侧脑内脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)的表达。结果:术后7,14,28 d,芪仙通络方组、吡拉西坦组Brd U/Neu N,Brd U/GFAP双标阳性细胞率均高于模型组(P0.01),且各时间点芪仙通络方组Brd U/Neu N阳性细胞均高于吡拉西坦组(P0.05),而仅在术后7 d,芪仙通络方组Brd U/GFAP双标阳性细胞率高于吡拉西坦组(P0.05),随后均呈下降趋势;与模型组比较,术后各时间点芪仙通络方组、吡拉西坦组缺血脑内BDNF表达均升高(P0.01),芪仙通络方组BDNF表达于术后3 d达到高峰,之后水平虽有所下降,但仍高于吡拉西坦组(P0.05)。结论:芪仙通络方可促进脑缺血大鼠内源性神经干细胞再生,以恢复期和后遗症期明显,而早期活化星形胶质细胞及上调BDNF的表达可能是其作用机制之一。     

Periodontal tissue regeneration by recombinant human transforming growth factor-beta 3 in Papio ursinus

Background and Objective: Osteogenic proteins of the transforming growth factor‐β superfamily induce periodontal tissue regeneration in animal models, including primates. To our knowledge, no studies have been performed in periodontal regeneration using the transforming growth factor‐β3 isoform. In the present study, recombinant human transforming growth factor‐β3 was examined for its ability to induce periodontal tissue regeneration in the nonhuman primate, Papio ursinus. Material and Methods: Class II furcation defects were surgically created bilaterally in the maxillary and mandibular molars of four adult baboons. Heterotopic ossicles, for transplantation to selected furcation defects, were induced within the rectus abdominis muscle by recombinant human transforming growth factor‐β3. Forty days later, the periodontal defects were implanted with recombinant human transforming growth factor‐β3 in Matrigel^® as the delivery system, with recombinant human transforming growth factor‐β3 plus minced muscle tissue in Matrigel^®, or with the harvested recombinant human transforming growth factor‐β3‐induced ossicles. Sixty days after periodontal implantation, the animals were killed and the specimens harvested. Histological analysis on undecalcified sections measured the area and volume of new alveolar bone and the coronal extension of newly formed alveolar bone and cementum. Results: Morphometric analyses showed pronounced periodontal regeneration in experimental defects compared with controls. Substantial regeneration was observed in defects implanted with fragments of heterotopically induced ossicles and with recombinant human transforming growth factor‐β3 plus minced muscle tissue. Conclusion: Recombinant human transforming growth factor‐β3 in Matrigel^® significantly enhanced periodontal tissue regeneration in the nonhuman primate, P. ursinus.     

A review of the functional and esthetic requirements for dental implants

BACKGROUND: The esthetic replacement of teeth has become an important standard for implant dentistry. While defining this goal has not been difficult, the ability to restore implants esthetically has been fraught with obstacles and sometimes has not been attainable. The purpose of this review is to summarize essential anatomical and surgical considerations for cosmetic implant dentistry. METHODS: This article provides a summary of the predominant findings from clinical studies and case reports that help develop implant surgical guidelines for better esthetic outcomes. RESULTS: Soft- and hard-tissue requirements for placing an implant in an ideal position are defined. The authors discuss the best treatment approaches as well as the limitations associated with esthetic implant placement. They evaluate the available data specifically for the maxillary anterior sextant, since this anatomical region has higher esthetic demands. CONCLUSIONS: Several parameters and various surgical techniques have been developed to manipulate soft- and hard-tissue contours and to control the esthetic outcome for implant-supported restorations. CLINICAL IMPLICATIONS: It is essential for practitioners to understand the anatomical basis for and limitations of implant dentistry in the esthetic zone.     

引导组织和骨组织再生术及其生长因子在牙周骨缺损治疗中的应用

引导组织再生术和引导骨再生术广泛用于牙周骨缺损的治疗中,给牙周组织再生开辟了广泛的空间,但二者单独使用却存在一定的局限性。因此,目前的研究多趋向于将骨移植材料和膜材料与多肽生长因子联合应用于牙周骨缺损的修复。下面就引导组织再生膜材料、引导骨再生支架材料和碱性成纤维细胞生长因子的理化性质、生物学功能,以及三者联合应用于牙周骨缺损治疗中的作用作一综述。     

Mechanisms involved in the enhancement of osteoclast formation by enamel matrix derivative

BACKGROUND AND OBJECTIVE: Enamel matrix derivative (EMD) is used clinically to promote periodontal tissue regeneration, and it has been reported that EMD can induce the formation of osteoclasts in mouse marrow cultures. In the present study, we investigated the mechanisms of EMD-induced osteoclast formation using a mouse monocytic cell line, RAW 264.7. MATERIAL AND METHODS: Bioactive fractions were purified from EMD by reverse-phase HPLC using a C18 hydrophobic support, following which RAW 264.7 cells were cultured with EMD or its purified fractions in the presence of receptor activator of nuclear factor-kappaB ligand (RANKL) for 8 d. Following staining with tartrate-resistant acid phosphatase (TRAP), TRAP-positive multinucleated cells were counted. The expression of receptor activator of nuclear factor-kappaB (RANK), as well as phosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase, in RAW 264.7 cells were detected using immunoblotting. To determine whether EMD has an effect on osteoclast function, differentiated RAW 264.7 cells were cultured on Osteologic Multitest slides with RANKL in the presence of EMD. RESULTS: Purified EMD fractions (fraction numbers 21-25; EMD peak 2) were found to enhance the formation and function of RAW 264.7 cells induced by RANKL. Moreover, EMD peak 2 enhanced the levels of phosphorylation of ERK p38 and RANK in RAW 264.7 cells stimulated with RANKL. CONCLUSION: Our results indicate that EMD induces the formation of osteoclasts through interaction with RANKL, while ERK and p38 MAPK may play a critical role in the enhancement of osteoclast formation in RAW 264.7 cells.     

奥硝唑联合牙周组织再生术治疗牙周炎的有效性及安全性评价

目的 探讨奥硝唑联合牙周组织再生术治疗牙周炎的有效性及安全性。方法 选择2018年3月—2019年3月于南京大学医学院附属口腔医院接受治疗的牙周炎患者100例,随机分为再生治疗组、联合治疗组,每组50例,再生治疗组患者进行牙周组织再生治疗,联合治疗组患者使用奥硝唑联合牙周组织再生术进行治疗。对2组患者牙周相关指标牙周探诊深度（periodontal probing depth,PPD）、牙周附着水平（periodontal attachment level,PAL）、牙松动度（tooth mobility degree,MD）进行检测,对2组患者治疗前、后血清丙二醛（malondialdehyde,MDA）、超氧化物歧化酶（superoxide dismutase,SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）、白细胞介素10（interleukin-10,IL-10）、白细胞介素4（interleukin-4,IL-4）、C反应蛋白（c-reactive protein,CRP）水平及免疫球蛋白水平进行检测,对比2组患者治疗效果及并发症发生情况。采用SPSS 21.0软件包对数据进行统计学分析。结果 联合治疗组患者治疗后PPD、PAL及MD水平显著低于再生治疗组（P<0.05）;联合治疗组患者血清MDA水平显著低于再生治疗组,SOD、GSH-Px水平显著高于再生治疗组（P<0.05）;联合治疗组患者血清IgA、IgM、IgG、IgE、IL-10、IL-4、CRP水平显著低于再生治疗组（P<0.05）;联合治疗组患者治疗总有效率显著高于再生治疗组,并发症发生率显著低于再生治疗组（P<0.05）。结论 使用奥硝唑联合牙周组织再生术能显著改善牙周炎患者相关牙周指数水平,减轻患者氧化应激损伤,提升患者免疫功能,抑制炎症反应,治疗效果显著,且安全性较高。     

组织工程用于修复慢性牙周组织缺损的动物实验研究

目的:应用细胞型和/或非细胞型组织工程化牙周组织移植修复慢性牙周缺损的动物实验,探讨其用于牙周再生治疗的可行性。方法:人工构建5只成年杂种狗慢性牙周缺损病变模型,分别随机采用:引导组织再生治疗术+富血小板血浆+B ioOss(GTR+PRP+B ioOss)、引导组织再生治疗术+富血小板血浆+B ioOss+自体牙周膜细胞(GTR+PRP+B ioOss+PDLCs)、引导组织再生治疗术+自体牙周膜细胞(GTR+PDLCs)和GTR治疗,其中GTR组6颗牙,其余3组各为8颗牙。12周后作病理切片,HE染色观察牙周组织再生情况。结果:动物实验发现GTR组的新生牙槽骨、牙骨质和牙周组织高度分别为(0.52±0.21)mm、(0.8±0.13)mm、(1.9±0.10)mm。而另外3组的新生牙槽骨、牙骨质和牙周组织高度分别为GTR+PRP+B ioOss组:(1.36±0.17)mm、(1.92±0.18)mm、(2.62±0.16)mm;GTR+PRP+B ioOss+PDLCs组:(1.42±0.22)mm、(2.07±0.19)mm、(2.68±0.20)mm;GTR+PDLCs组:(1.39±0.19)mm、(1.82±0.16)mm、(2.55±0.12)mm,这3组牙槽骨、牙骨质和牙周组织的修复再生效果均明显优于GTR组(P<0.05),而它们之间的差别无显著性。结论:应用GTR技术结合组织工程可显著促进狗牙周组织缺损的再生。