过量氟诱导成釉细胞钙超载及细胞凋亡的实验研究

目的 研究过量氟对体外培养大鼠成釉细胞内钙超载及细胞凋亡的影响。方法 取大鼠成釉细胞系HAT-7细胞,分别加入不同浓度（0、0.4、0.8、1.6、3.2、6.4 mmol·L^-1）的氟化钠培养液,培养48 h后,采用Cell Counting Kit 8（CCK-8）试剂盒检测各组细胞的活性,流式细胞术分析氟对细胞凋亡的影响,激光扫描共聚焦显微镜、Western blot试验和实时荧光定量聚合酶链反应技术检测过量氟诱导大鼠成釉细胞内Ca²⁺浓度和钙网蛋白表达的变化。结果 氟化钠浓度高于1.6 mmol·L^-1时,可抑制成釉细胞的活性,成釉细胞内Ca²⁺浓度升高,钙网蛋白表达上调,细胞早期凋亡数量增加,并且随着浓度的增加,细胞凋亡的数量也随之增加。结论 过量氟可引起成釉细胞内钙超载,诱导成釉细胞凋亡。     

微小RNA-30a靶向Beclin1抑制舌鳞状细胞癌细胞自噬活性的研究

目的研究微小RNA(mi RNA)-30a转染对舌鳞状细胞癌细胞自噬相关基因Beclin1表达及其自噬活性的影响,探讨舌鳞状细胞癌细胞自噬活性调控的相关机制。方法利用脂质体转染技术,将内源性mi RNA-30a模拟物和抑制物分别转染至舌鳞状细胞癌UM1、UM2和SCC25细胞。实验设mi RNA-30a mimic组、mi RNA-30a inhibitor组和对照组;通过实时荧光定量聚合酶链反应(PCR)检测转染前后Beclin1基因m RNA表达变化,通过Western blot检测Beclin1、LC3的蛋白表达变化。结果在mi RNA-30a mimic组中,Beclin1和自噬标记蛋白LC3-Ⅱ表达量与对照组相比均明显下降(P<0.05);在mi RNA-30a inhibitor组中,Beclin1和LC3-Ⅱ表达量较对照组均明显上升(P<0.05)。结论 mi RNA-30a负调控Beclin1表达,并抑制舌鳞状细胞癌细胞的自噬水平。     

Effect of overdose fluoride on the expression of DSP mRNA in rat incisors

目的 研究过量氟对大鼠切牙发育过程中牙本质涎蛋白( dentin sialoprotein,DSP) mRNA表达的影响.方法 选择6只Wistar大鼠,随机分成两组:对照组常规饲料喂养,自由饮用蒸馏水;实验组常规饲料喂养,自由饮用氟离子浓度为100 mg/L的氟化水,建立大鼠氟斑牙模型.饲养8周处死动物,提取大鼠切牙组织总RNA,逆转录为cDNA,利用实时荧光定量聚合酶链反应技术观察过量氟对大鼠切牙中DSP mRNA表达的影响.结果 实时荧光定量聚合酶链反应结果显示DSP mRNA在实验组表达水平明显高于对照组表达水平(t=2.132,P＜0.01).结论 过量氟可能通过增强DSP mRNA的表达,影响牙本质的发育矿化.     

周期性机械应力诱导的自噬抑制caspase通路依赖的成肌细胞凋亡

目的 观察大鼠成肌细胞（L6 myoblast,L6）在周期性机械应力作用下细胞凋亡与自噬的水平变化,探讨机械应力诱导的细胞自噬对凋亡的作用。方法 构建大鼠成肌细胞力学刺激模型,加载参数为细胞拉伸形变率15%,加力周期包括 3 s 拉伸及 3 s 舒张,加力时间为 6、12、24 h,以不加力0 h组为对照组。通过Hoechst染色及AnnexinV-FITC/PI染色观察各组细胞凋亡情况;通过MDC染色及透射电镜（transmission electron microscopy,TEM）评价各组细胞自噬变化;应用 Western 免疫印迹检测各组凋亡相关蛋白caspase-3、caspase-9、Bcl-2、Bax及自噬相关蛋白LC3Ⅱ、LC3Ⅰ、P62表达变化。加入自噬抑制剂3-MA后重复实验,检测各组细胞凋亡情况。采用 SPSS 17.0 软件包对数据进行统计学分析。结果 Hoechst染色及AnnexinV-FITC/PI流式结果表明,大鼠成肌细胞在周期性应力诱导下发生凋亡,24 h 时达到凋亡最大值。Western 免疫印迹结果显示,凋亡相关蛋白表达水平随加力时间延长而逐渐升高, caspase抑制剂z-VAD-fmk有效抑制应力诱导的细胞凋亡。MDC染色及TEM扫描电镜显示,大鼠成肌细胞在周期性应力诱导下发生自噬,24 h细胞自噬达到最大值。Western 免疫印迹结果显示,LC3Ⅱ/LC3Ⅰ随加力时间延长而升高,P62的表达随着加力时间延长而降低。加入自噬抑制剂3-MA后重复试验,发现应力诱导的成肌细胞凋亡被明显抑制。结论 周期性机械应力诱导大鼠成肌细胞发生自噬与caspase通路依赖的细胞凋亡,细胞自噬作为一种代偿机制,保护性地抑制应力诱导的细胞凋亡。     

Temsirolimus诱导的自噬对腺样囊性癌的作用

目的：探讨Temsirolimus对腺样囊性癌ACC-M细胞株自噬水平的影响,以研究该药物诱导的自噬对腺样囊性癌细胞的作用。方法：通过细胞增殖实验研究Temsirolimus对ACC-M细胞增殖的影响;通过Western印迹检测实验组与对照组微管相关蛋白1轻链3（LC3）和Beclin1的表达差异;利用透射电镜观察ACC-M细胞中自噬体的形态及数量,采用SPSS15.0软件包对实验结果进行t检验。结果：Temsirolimus对ACC-M细胞具有明显的生长抑制作用,并呈现出剂量-效应关系;LC3和Beclin1在实验组细胞中表达水平高于对照组（P〈0.05）;透射电镜实验中,实验组细胞胞内自噬体及自噬溶酶体数量明显高于对照组（P〈0.01）。结论：Temsirolimus通过诱导ACC-M细胞自噬,产生了明显的抑制肿瘤细胞生长的作用,提示细胞自噬是Temsirolimus作用于唾液腺腺样囊性癌的重要抗肿瘤机制。     

粪肠球菌脂磷壁酸对巨噬细胞自噬的影响

目的通过研究粪肠球菌脂磷壁酸（LTA）对巨噬细胞自噬功能的影响,为后续进一步深入探讨顽固性根尖周炎的发病机制提供实验依据。 方法体外培养小鼠巨噬细胞系RAW 264.7,细胞计数试剂盒（CCK-8）检测LTA的细胞毒性作用;蛋白免疫印迹法（Western blot）检测LTA作用下巨噬细胞自噬相关蛋白LC3-Ⅱ/LC3-Ⅰ比值、Beclin1的表达水平;实时荧光定量聚合酶链反应（PCR）检测自噬相关基因LC3、Beclin1 mRNA表达水平的变化;构建稳定表达自噬双荧光慢病毒载体HBLV-mRFP-GFP-LC3-PURO的巨噬细胞系,激光共聚焦显微镜观察自噬情况;SPSS 20.0统计软件进行数据分析。 结果CCK-8结果表明,选用20 μg/mL LTA及其以下浓度处理巨噬细胞24 h均未见明显毒性作用（t = 2.102,P = 0.1106）;Western blot结果表明,LTA刺激巨噬细胞后：LC3-Ⅱ/LC3-Ⅰ比值表达量（0.42 ± 0.04）与对照组（0.04 ± 0.02）相比显著提高,差异有统计学意义（F = 14.25,P<0.001）,Beclin1蛋白表达量（0.56 ± 0.11）与对照组（0.28 ± 0.08）相比呈上升趋势（F = 3.459,P = 0.0258）,均存在剂量依赖效应;实时荧光定量PCR结果表明,LTA刺激巨噬细胞后,LC3基因表达水平（5.94 ± 0.85）与对照组（1.03 ± 0.28）相比显著提高（F = 12.93,P<0.001）;Beclin1基因表达水平（2.22 ± 0.21）与对照组（1.02 ± 0.28）相比呈上升趋势（F = 6.036,P<0.001）,存在剂量依赖效应;成功构建稳定表达HBLV-mRFP-GFP-LC3-PURO的巨噬细胞系,激光共聚焦显微镜下观察显示,LTA作用组自噬体形成量（58 ± 6）与对照组（18 ± 8）相比差异有统计学意义（F = 12.36,P = 0.0021）。 结论粪肠球菌LTA可诱导巨噬细胞产生自噬,且存在剂量依赖效应。     

低氧对C2C12细胞分化不同阶段自噬和肌细胞生成素表达的影响

目的:研究低氧对C2C12细胞分化不同阶段自噬相关蛋白Beclin1、微管相关蛋白轻链3(microtubule-associated protein light chain 3,LC3B)和肌细胞生成素(myogenin)表达的影响。方法:C2C12细胞诱导分化1、2、3、4 d,在常氧和低氧状态下观察细胞分化情况。免疫细胞化学染色法检测自噬相关蛋白LC3B和Beclin1的表达。Western blot检测Beclin1、LC3B和myogenin的蛋白表达水平,采用SPSS 22.0软件对数据进行统计学分析。结果:1.与常氧组比较,低氧组分化形成的肌管数量较少,形态细小;2.免疫细胞化学染色结果显示,分化1、2、3、4 d低氧组细胞LC3B和Beclin1荧光强度均低于常氧组;3.Western blot结果显示分化前中期低氧组Beclin1、LC3B和myogenin蛋白表达水平显著低于常氧组(P<0.05)。随着分化时间的增加,低氧状态下LC3B的表达水平进一步降低,而myogenin表达水平回升。结论:低氧抑制C2C12细胞分化;低氧能降低细胞分化前中期Beclin1、LC3B和myogenin蛋白表达水平。     

二氯化钴诱导唾液腺腺样囊性癌ACC-M细胞自噬的实验研究

目的 ：研究二氯化钴(CoCl2)对唾液腺腺样囊性癌ACC-M细胞增殖和自噬的影响。方法 ：应用MTT法对ACC-M细胞进行细胞活力测验,以检测CoCl2对细胞增殖的抑制作用;透射电镜观察自噬体形成;双免疫荧光标记、实时定量PCR（RT-PCR）及Western 蛋白免疫印迹检测自噬相关基因HIF-1α/BNIP3通路相关基因、自噬相关蛋白微管相关蛋白1轻链3（microtubule associated protein 1 light chain 3, LC3）及Beclin 1的表达。采用SPSS15.0软件包对数据进行双尾 t检验。结果 ：CoCl2可降低ACC-M细胞的活性,同时诱导自噬体的形成;透射电镜下,实验组细胞内可见自噬体样的双层膜结构;RT-PCR及Western 蛋白免疫印迹检测显示,CoCl2可使HIF-1α/BNIP3信号通路和自噬相关蛋白的表达显著提高。结论 ：CoCl2可模拟低氧环境,从而诱导ACC-M细胞产生自噬,HIF-1α/BNIP3信号通路在这一过程中扮演着重要角色。     

过量氟对大鼠切牙牙本质涎蛋白mRNA表达的影响

目的研究过量氟对大鼠切牙发育过程中牙本质涎蛋白(dentin sialoprotein,DSP)mRNA表达的影响。方法选择6只Wistar大鼠,随机分成两组:对照组常规饲料喂养,自由饮用蒸馏水;实验组常规饲料喂养,自由饮用氟离子浓度为100 mg/L的氟化水,建立大鼠氟斑牙模型。饲养8周处死动物,提取大鼠切牙组织总RNA,逆转录为cDNA,利用实时荧光定量聚合酶链反应技术观察过量氟对大鼠切牙中DSP mRNA表达的影响。结果实时荧光定量聚合酶链反应结果显示DSP mRNA在实验组表达水平明显高于对照组表达水平(t=2.132,P<0.01)。结论过量氟可能通过增强DSP mRNA的表达,影响牙本质的发育矿化。     

周期性张应力作用下Hippo-YAP信号通路调控人牙周膜细胞自噬

目的 探究周期性张应力（CTS）作用下人牙周膜细胞（hPDLCs）自噬激活的分子机制。方法 分离培养正常牙周组织的hPDLCs，利用Forcel四点弯曲细胞加力仪对hPDLCs加载张应力模拟正畸牙移动过程中正畸力诱导的张力侧hPDLCs自噬，利用XMU-MP-1抑制Hippo信号通路探究Hippo-YAP信号通路在张应力激活hPDLCs自噬中的作用。采用实时荧光定量聚合酶链反应（RT-qPCR）检测hPDLCs自噬相关基因（Beclin-1、LC3、p62）的表达；采用蛋白免疫印迹（Western blot）检测hPDLCs自噬相关蛋白（Beclin-1、LC3-Ⅱ/LC3-Ⅰ、p62）及Hippo-YAP通路相关蛋白（active-YAP、p-YAP）的表达；采用免疫荧光染色定位hPDLCs自噬相关蛋白（LC3-Ⅱ、p62）及Hippo-YAP通路相关蛋白（active-YAP）。结果 CTS激活hPDLCs的自噬，自噬相关因子表达随加力时间的延长呈先升高后降低的趋势，30 min自噬开始，3 h达到高峰，随后出现下调（P<0.05）;CTS促进active-YAP蛋白表达增加...     

Variation in periodontal referral in 2 regions in theUK

This study investigated the periodontal referral patterns of general dental practitioners (GDPs) in Northern Ireland (NI) and North West England (NWE). A questionnaire dealing with periodontal referral was sent to all 520 GDPs registered in NI and to 274 GDPs in NWE. A usable return was made by 355 (68%) in NI and 189 (70%) in NWE. The NI dentists made significantly more periodontal referrals (median 5, range 0-80) in the year preceding the survey than those in NWE (median 2, range 0-50), p<0.001. Distance was the only factor significantly related to the referral rate in both regions with those who practised more than 25 miles from a specialist referring significantly fewer patients in both regions. In NI, there was a trend towards increased periodontal referral by GDPs who had attended more postgraduate courses; however, in NWE, this was not the case. The GDPs in NWE were significantly less likely than those in NI to refer patients with medical conditions. It is concluded that there is considerable variation in periodontal referral both within and between the 2 regions studied. It is further concluded that in many cases, non-disease factors, such as the accessibility of the specialist service, have powerful effects on the decisions made by dentists and patients in these regions (NI and NWE) in relation to periodontal referral. Much of the variance in referral in North West England, as in Northern Ireland, remains unexplained.     

Trends in socioeconomic disparities in oral health in Brazil and Sweden

Celeste RK, Nadanovsky P, Fritzell J. Trends in socioeconomic disparities in oral health in Brazil and Sweden. Community Dent Oral Epidemiol 2011; 39: 204–212. © 2010 John Wiley & Sons A/S Abstract – Objectives: To describe the dynamics of trends in socioeconomic disparities in oral health in Brazil and Sweden among adults, to assess whether trends follow expected patterns according to the inverse equity hypothesis. Methods: In Sweden, we obtained nationally representative data for the years 1968, 1974, 1981, 1991 and 2000, and in Brazil, for 16 state capitals in 1986 and in 2002. Trends in the prevalence of ‘edentulism’ and of ‘teeth in good conditions’ were described in two groups aged 35–44 with lower and higher economic standards, respectively. Results: There was an annual decline in disparities in ‘edentulism’ of 0.4 percentage points (pp) (95% CI = 0.2–0.7) in Brazil and 0.7pp (95% CI = 0.5–0.9) in Sweden, as a result of improvements in both income groups. Concerning ‘teeth in good conditions’, in Brazil, there was improvement only in the higher income group and absolute disparities have increased (0.5pp annually), while in Sweden, there was a nonsignificant decrease (0.3pp annually) with improvements in both groups. Since 1991 in Sweden and in 2002 in Brazil, our measures of socioeconomic disparities in ‘edentulism’ were not statistically significant. Trends did not differ by sex or dental visit. Conclusions: Despite improvements in both income groups and a decrease in disparities in ‘edentulism’, the poorer group in Brazil has seen no improvement in ‘teeth in good conditions’ and disparities have increased. It appears that Brazil and Sweden reflect different stages of trend for ‘teeth in good conditions’ and the same stages for ‘edentulism’, represented by the inverse equity hypothesis.     

Trends in endodontic claims in Italy

According to the scant data available in the literature, endodontic claims are common among dental professional liability cases and the second most common type of claim. This study aimed to describe the characteristics of endodontic claims in Italy and the most frequently disputed errors, and the discussion below includes consideration of ethical and medico‐legal aspects thereof. We retrospectively analysed 120 technical reports written on cases of professional malpractice in endodontics in the last 5 years. The complainant patients were males in 22.5% of the cases, while females made up the remaining 77.5%. In the dentist sample, male operators were more often involved in litigation cases (80%) than female operators. The most frequently claimed technical errors were: lack of a complete filling of root canal/s (71.7%), the perforation of tooth structure (12.7%), extrusion of sealing materials beyond the apex of the tooth (9.6%) and the fracture of an endodontic instrument (5.9%). In 1.7% of cases it was found that the expert did not make any errors performing the endodontic therapy. In only very few cases (2.7%) no therapy was considered necessary, while the most common therapeutic solution involved in endodontic misconduct was tooth extraction (53.0%). In many cases the dentist preferred to extract the endodontically undertreated tooth and substitute it prosthetically rather than trying to re‐treat it. The discrepancy between the total number of cases examined and those that eventually go to court leads us to believe that the majority of endodontic malpractice cases are resolved in out‐of‐court settlements.     

Human Herpesviridae in acute necrotizing ulcerative gingivitis in children in Nigeria

Herpesviruses have been implicated in the pathogenesis of human periodontitis. The present study investigated whether herpeasviruses are present in the lesions of acute necrotizing ulcerative gingivitis. Sixty-two Nigerian children, aged 3–14 years, were studied. Twenty-two children had acute necrotizing ulcerative gingivitis and were also malnourished, 20 exhibited no acute necrotizing ulcerative gingivitis but were malnourished, and 20 were free of acute necrotizing ulcerative gingivitis and in a good nutritional state. Polymerase chain reaction methods were used to determine the presence of human cytomegalovirus (HCMV), Epstein-Barr virus type 1 and type 2 (EBV-1, EBV-2), herpes simplex virus (HSV), human herpes virus 6 (HHV-6), human papilloma virus and human immunodeficiency virus type 1 in crevicular fluid specimens collected by paper points. Of the 22 acute necrotizing ulcerative gingivitis patients, 15 (68%) revealed viral infection and 8 (36%) viral coinfection. Thirteen (59%) acute necrotizing ulcerative gingivitis patients demonstrated HCMV, 6 (27%) EBV-1, 5 (23%) HSV and 1 (5%) HHV-6. Only 2 (10%) subjects from each group not affected by acute necrotizing ulcerative gingivitis showed viral presence, and no control subject revealed viral coinfection. These findings suggest that HCMV and possibly other herpesviruses contribute to the onset and/or progression of acute necrotizing ulcerative gingivitis in malnourished Nigerian children.     

Changes in caries prevalence in Japan

In Japan, the mean DMFT at 12 years of age increased from 2.8 in 1957 to 5.9 in 1975. From the 1981 survey (DMFT=5.43), conversely, the mean DMFT decreased and reached 3.64 in 1993. The increase in caries prevalence can, without doubt, be explained by an increment of sugar consumption, since the intake of sugar increased after World War II and exceeded 18.25 kg/year (50 g/day) in 1965 and reached a maximum value (29.3 kg/year) in 1973 in Japan. On the other hand, the reason why the DMFT has decreased since 1981 is not clear. In many industrialized countries, a caries reduction has been achieved with acceptable fluoride exposure, although sugar consumption was still at a high level. However, fluoride usage was still limited during the last 2 decades in Japan. There is no community where fluoridated drinking water has been supplied since 1972. Fluoride tablet use was also discontinued for children in the 1970s. Fluoride mouthrinsing programs were available for only 19r of school children in 1992. Moreover, the market share of fluoridated dentifrices stayed at 10% until 1986 and became 30% only in 1988. An excellent correlation (r=0.91; P 0.01) is observed between the DMFT in 12-year-olds and per capita sugar consumption per year between 1957 and 1987 in Japan.     

Fluorosis in relation to fluoride levels in water in central Nigeria

Abstract– Objectives : This study was conducted to examine the prevalence of dental fluorosis in relation to fluoride levels in water among children aged 12–15 years in the states of Plateau and Bauchi, Nigeria. Methods : Children ( N =203) were examined using WHO criteria. The children were from two schools and permanent residents of the communities in which the schools are located (Tilden Fulani and Kanadap). Intra-examiner reliability for determining fluorosis scores was 80%. Results : Fluoride levels in the water ranged from 0.0–0.4 mg/L. Prevalence of dental fluorosis in the sample was 51%. Forty-one percent had very mild fluorosis, 7% had mild fluorosis and 3% had moderate to severe fluorosis. The lowest DMFT was observed in the school where the fluoride level of the water ranged between 0.0 and 0.4 mg/L, and in the group with very mild fluorosis. Conclusion : Fluoride levels in water for central Nigeria were appropriate for oral health. In the areas where the children were permanent residents, factors other than the fluoride levels of the water contributed to the severity of dental fluorosis.     

Advances in local anesthesia in dentistry

Local pain management is the most critical aspect of patient care in dentistry. The improvements in agents and techniques for local anesthesia are probably the most significant advances that have occurred in dental science. This article provides an update on the most recently introduced local anesthetic agents along with new technologies used to deliver local anesthetics. Safety devices are also discussed, along with an innovative method for reducing the annoying numbness of the lip and tongue following local anesthesia.     

Patient Recall in Advanced Education in Prosthodontics Programs in the United States

Purpose: This study surveyed program directors of Advanced Education Programs in Prosthodontics (AEPP) in the United States to determine the extent, type, incidence, and perceived effectiveness of implemented recall systems. Material and Methods: Surveys were sent to AEPP directors across the United States to assess their program's recall protocol. This survey first identified whether an active recall program existed. For programs with recall systems, rigor in promoting ongoing oral health was surveyed by focusing on recall frequency, patient tracking protocol, involved personnel, interaction with other university departments, provided clinical procedures, and therapy completion protocol. Whether the directors perceived that their recall system was successful was also investigated. Results: Thirty‐three of 46 programs responded, giving a response rate of 72%. Of these 33 programs, only 21 (64%) had an active recall system, although 30 (91%) believed recall to be important. Twelve (57%) directors with recall programs considered their system to be effective. Conclusions: Prosthodontic program directors felt their program's recall effectiveness could be improved. Due to the numerous potential benefits of an active recall system, AEPPs should consider implementing or enhancing their recall programs. Further studies are indicated to determine specific criteria that describe an effective recall system for prosthodontic programs within the context of patient health promotion, program curriculum, and financial ramifications.