Rapamycin attenuates Tc1 and Tc17 cell responses in cigarette smoke-induced emphysema in mice

Inflammation Research - Chronic exposure to cigarette smoke promotes airway inflammation and emphysema accompanied by enhanced CD8+ interferon (IFN)-γ+ T(Tc1) and CD8+ interleukin (IL)-17+...     

HAB/DBP 复合物修复骨缺损的实验研究

目的：研究羟基磷灰石人工骨（HAB）/异体脱矿骨粉（DBP）复合物修复骨缺损的效果，以期获得一种既具有传导性又具有骨诱导性的复合材料。方法：将HAB/DBP复合物、HAB、异体脱矿骨(DMB)植入兔桡骨中段骨缺损处，设置空白对照，在2、4、8、12周分别取材，观察新骨形成及骨缺损修复情况。结果：HAB/DBP组、DMB组2周时可见骨断端附近有大量软骨细胞聚集，并有少量基质形成。4周时，大量软骨细胞及少量骨小架。8周时，见大量骨小梁和层板状骨形成。12周见层板成熟骨组织和哈佛系统形成。其成骨能力及新骨生成量明显高于HAB组及空白组。结论：HAB/DBP复合物为一种既具有骨传导性又具有骨诱导性的骨缺损修复材料，具有与DMB同样的诱导骨生成的能力，可能成为一种具有临床应用前景的骨缺损及修复材料。     

Actinomyces spp. in supragingival plaque of ethnic Chinese preschool children with and without active dental caries

Very limited molecular epidemiological data are available on the role of Actinomyces spp. in the pathogenesis of caries in the primary dentition. Therefore, we investigated their distribution in supragingival plaque of ethnic Chinese preschool children from Singapore and Hong Kong, either with or without active caries. Plaque samples were taken from intact interproximal enamel areas using dental floss. Bacterial genomic DNA of each sample was extracted and variable regions of 16S ribosomal DNA amplified and labelled with digoxigenin. Oligonucleotide probes specific for Actinomyces bovis, Actinomyces gerencseriae, Actinomyces israelii, Actinomyces meyeri, Actinomyces odontolyticus, catalase-negative Actinomyces naeslundii (genospecies 1 and 2) and catalase-positive Actinomyces naeslundii genospecies 2 (previously Actinomyces viscosus serotype II) were used to detect these species using Southern hybridization with a Minislot and Miniblotter system. A. odontolyticus, A. gerencseriae and A. meyeri were detected with similar frequency in both Singapore and Hong Kong samples or in those with and without active caries. However, the prevalence of A. naeslundii was significantly different in the two locales (p<0.05). A. odontolyticus (88.7%), A. gerencseriae (56.6%) and A. naeslundii (50.9%) were detected in a majority of the samples and the positive hybridization signals of A. gerencseriae in the caries-active group were stronger than from the caries-free group. A. bovis and A. israelii were undetectable in any of the samples. These data imply that A. odontolyticus, A. naeslundii and A. gerencseriae may play an important role in supragingival plaque formation on primary teeth in ethnic Chinese, with others such as A. meyeri contributing.     

局部应用二磷酸盐对鼠正畸牙移动影响的研究

目的 探讨局部注射Zoledronate溶液对鼠正畸牙齿移动距离与牙周组织形态的影响。方法 选用42只雄性Wistar大鼠，牵引其上颌第一磨牙近中移动。实验中分别将Zoledronate溶液及生理盐水注射入实验组（左侧）及对照组大鼠（双侧）上颌第一磨牙腭侧的粘骨膜下。注射于实验前3d开始，共进行9次，每3d一次。分别在加力0、3、7、14、21d后记录上颌第一磨牙移动距离，组织HE染色后，观察牙周组织形态学的改变。结果 ①实验组大鼠牙齿移动距离明显低于对照组。②实验组大鼠压力侧破骨细胞数在实验全过程中均低于对照组，而根分叉区破牙骨质细胞数除加力14d外，2组差异无显著性。③实验过程中Zoledronate溶液对破骨细胞和破牙骨质细胞以外的细胞作用不明显。结论 Zoledronate能有效地抑制支抗牙移动，减少压力侧牙槽骨表面破骨细胞数。     

Molecular evaluation of residual endodontic microorganisms after instrumentation, irrigation and medication with either calcium hydroxide or Septomixine

BACKGROUND AND OBJECTIVE: The correct choice of antimicrobial agents as inter-appointment medicaments is as important as the instrumentation and irrigation to remove pathogens from infected root canals. Calcium hydroxide [Ca(OH)2] and framycetin sulfate (Septomixine) are common endodontic medicaments. Therefore, we evaluated the efficacy of either calcium hydroxide or Septomixine in eliminating residual intra-canal bacteria, particularly Actinomyces spp., during inter-appointment interval in endodontic therapy using molecular methods. METHODS: A total of 31 single-rooted teeth with primary root canal infections were studied immediately after opening the canals and subsequently after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 25) or Septomixine (n = 6). Whole bacterial genomic DNA was isolated directly from samples and PCR with universal primers performed to detect total intra-canal bacteria. The variable regions of 16S rDNA of bacteria were amplified and labeled with digoxigenin for further hybridization to detect Actinomyces spp. A total of seven oligonucleotide probes specific for A. bovis, A. gerencseriae, A. israelii, A. meyeri, catalase-negative A. naeslundii (genospecies 1 and 2), catalase-positive A. naeslundii genospecies 2 and A. odontolyticus were used to detect Actinomyces spp. in 22 of 31 medicated root canals [Ca(OH)2: n = 17; Septomixine: n = 5]. RESULTS: The PCR results showed that 25 of 31 examined canals were positively detected with residual microorganisms after instrumentation, irrigation with sterile saline and 1-week medication with either Ca(OH)2 (n = 20) or Septomixine (n = 5). Thus, only six canals [Ca(OH)2: n = 5, Septomixine: n = 1] were aseptic after treatment. Hybridization results showed higher detection frequency of both A. odontolyticus and A. gerencseriae after treatment. Significant correlation was found between exposed pulp before treatment and positive detection of Actinomyces spp., particularly A. odontolyticus on the second visit (P < 0.05). CONCLUSION: The conventional, 1-week medication of either Ca(OH)2 or Septomixine in endodontic therapy may not effectively inhibit residual bacterial growth in all root canals during inter-appointment intervals. Further investigations using, for instance quantitative real-time PCR analyses, are required to substantiate the present findings.     

硼酸铝（9Al2O3.2B2O3）晶须的制备和性质

目的：制备硼酸铝晶须及测其物理化学特征。方法：原料在电炉中加热至１１５０℃，４ｈ，获得的晶须采用化学方法确定其组成，物理化学方法检测其表征。结果：获得了晶须的化学组成、Ｘ射线粉末衍射图、ＦＴ－ＩＲ光谱和Ｒａｍａｎ光谱图。结论：制备的晶须为四硼酸十八铝。