重组人生长激素影响去势大鼠下颌骨骨量变化的研究

目的:观察重组人生长激素(Recombinant human growth hormone,rh-GH)对双侧卵巢切除(去势)(Ovariectomy,OVX)大鼠下颌骨骨量变化的影响.方法:将40只雌性大鼠随机分为4组,以rh-GH及OVX作为两处理因素,各自设有施加和不施加两种水平,不施加组以生理盐水及假去势分别进行对照;于第8周和第12周用骨密度仪测定每只大鼠的下颌骨骨密度(Bone mineral density,BMD).结果:通过方差分析,OVX对大鼠下颌骨骨密度的变化有影响,8周和12周均比对照组显著减低(P＜0.05),rh-GH对下颌骨骨密度也有影响,8周和12周均比对照组显著增高(P＜0.05),然而,两处理因素同时存在,与对照组比较差别无统计学意义(P＞0.05).结论:rh-GH能减缓雌激素低下所引起的下颌骨骨量丢失,对于绝经后的老年患者有减少骨质疏松症状发生,减缓颌骨吸收速度的作用.     

姜黄素对去势骨质疏松大鼠下颌骨和股骨EZH2基因表达的影响

目的 研究姜黄素对去势骨质疏松大鼠下颌骨和股骨EZH2（enhancer of zeste homolog 2,EZH2）表达的影响,探讨其对骨质疏松大鼠的保护作用及机制。方法 将30只6月龄SD雌性大鼠随机分为假手术组（SHAM组）、去势模型组（OVX组）和姜黄素治疗组(OVX+C组)。治疗组将姜黄素溶于羧甲基纤维素钠溶液后,按110 mg/kg·d灌胃给药;假手术组和去势模型组灌胃同等剂量羧甲基纤维素钠溶液,每天1次,连续12周后取材。检测大鼠血清钙、磷、碱性磷酸酶的指标变化,采用Micro-CT对左侧下颌骨和股骨的骨形态计量学参数进行测定。取右侧下颌骨和股骨,采用PT-PCR法检测骨组织EZH2mRNA的表达。采用SPSS22.0软件包对数据进行统计学分析。结果 OVX组骨组织中EZH2mRNA的表达显著高于SHAM组（P<0.05）。与OVX组相比,姜黄素可以改善骨质疏松大鼠的骨微结构,增加骨密度,降低骨质疏松大鼠血清碱性磷酸酶含量,使骨组织EZH2mRNA表达显著下调（P<0.05）。结论 姜黄素能够防治去势大鼠的骨量丢失和改善骨微结构,其机制可能与下调EZH2mRNA的表达水平有关。     

“骨疏康”对去势大鼠下颌骨骨量变化的影响

目的 :观察防治骨质疏松症的药物“骨疏康”如何影响下颌骨的骨量变化。方法 :以去势大鼠 (Ovariectomizedrats,OVX)为绝经后骨质疏松症模型以诱发下颌骨骨丢失 ;对去势大鼠分别以“骨疏康”一代、二代 (2 .5g/kg/day)进行灌胃。结果 :“骨疏康”一代和二代均可抑制去势大鼠下颌骨骨量丢失和骨小梁结构破坏 ,使下颌骨骨密度、骨组织形态计量学指标维持在假去势组 (Sham OVX)水平。结论 :本研究表明防治骨质疏松症药物不仅对全身骨起作用 ,对预防下颌骨骨丢失也有一定的作用。     

辛伐他汀对去势大鼠骨生长代谢的影响

目的:观察辛伐他汀对去势大鼠骨密度和骨生长代谢的作用。方法:40只雌性SD大鼠随机分成4组,正常对照假手术组(Sham)-A,单纯去势组(OVX)-B,去势雌激素治疗组-C;去势辛伐他汀治疗组-D。术后第30天,C组以体质量每100g每天给0.1mg尼尔雌醇灌胃,每周1次,持续12周。D组以辛伐他汀5mg/(kg·d)灌胃,连续服用1周,停2周,再服用1周,间断持续12周。用药12周后,所有大鼠被处死采取胫骨标本,处死前第12和第4天进行四环素双标记。标本行不脱钙骨切片,硝酸银和VonKossa染色,骨形态计量学方法检测各治疗方法对胫骨近心端干骺的作用效果。结果:单纯去势组(OVX)-B与对照假手术组(Sham)-A相比,其胫骨有明显的骨质疏松表现。与OVX相比,雌激素组、辛伐他汀组去势大鼠胫骨骨形态计量学静态参数%Tb.Ar、Tb.N,Tb.Sp有明显差异(P<0.01)。辛伐他汀组的动态骨形成参数%L.Pm、MAR、BFR/BV、%O.Pm及荧光双标间隔均明显高于其他各组(P<0.01),骨吸收参数Oc.N、%E.Pm低于单纯去势组,但高于雌激素组和假手术组(P<0.01),雌激素组骨吸收参数Oc.N、%E.Pm相对单纯去势组显著下降(P<0.01)。结论:辛伐他汀能降低大鼠去势后骨转换,促进骨的生长,并能抑制骨的吸收作用。     

雌激素对骨质疏松熏烟大鼠种植体周围骨的影响

目的:评价雌激素对骨质疏松熏烟大鼠种植体周围骨的影响.方法:40只3月龄雌性SD大鼠随机均分为4组:假手术组(sham)、卵巢去势组(OVX)、卵巢去势+吸烟组(OVX+S)、卵巢去势+吸烟+雌激素组(OVX+S+E),分别进行假手术和卵巢去势术,术后OVX+S和OVX+S+E组持续熏烟24周.去势术后12周,在大鼠右...     

雌激素缺乏对大鼠核因子C（Nfic）与成骨相关基因表达的影响

目的：通过检测分析骨质疏松大鼠股骨组织核因子C(Nuclear Factor I-c,Nfic)与成骨相关基因表达情况,探讨雌激素缺乏状况下两类基因表达的相关性,探寻雌激素相关的骨质疏松发生原理。方法：3月龄未交配雌性SD大鼠20只,随机分为两组： A、假去势手术组(SHAM); B、去势手术组(OVX)。对A组大鼠行假去势手术,B组大鼠行去势手术。去势手术前、去势手术后1、2、3、4、5、6周及处死前称重,观察大鼠体重变化。卵巢切除术后1.5个月,采用双能骨密度测量仪测量大鼠腰椎及股骨远中骨密度,处死后,取双侧后肢股骨进行Q-PCR,检测核因子C(Nfic)、核心结合因子2(Runx2)、碱性磷酸酶(Alp)的mRNA表达情况。结果：去势手术前,两组大鼠体重差异无统计学意义(P>0.05);术后2、4、6周, OVX组大鼠体重较SHAM组显著增加(P<0.05, P<0.01, P<0.01)。术前,两组大鼠腰椎及左股骨骨密度差异无统计学意义(P>0.05);术后1.5个月, OVX组大鼠腰椎及左股骨骨密度较SHAM组显著降低(P<0.01, P<0.05)。去势组大鼠的Nfic、 Runx2、 Alp基因表达量明显低于假去势手术组(P<0.05)。结论：雌激素缺乏大鼠较正常组肥胖,骨密度减低,骨质改变,成骨能力减弱,成脂功能提高; Nfic基因与Runx2、 Alp成骨相关基因表达量呈正相关。     

甲状旁腺激素与雌激素对去势雌性大鼠牙槽骨代谢的影响

目的 观察甲状旁腺激素与雌激素单独和联合应用对去势雌性大鼠牙槽骨代谢的影响。方法选用4月龄雌性Wistar大鼠66只,分成两组,分别为伪手术组（n=18）和去势组（n=48）。8周后各处死8只证实骨质疏松造模成功。剩余的伪手术组（A组,n=10）Wistar大鼠作为对照;将剩余的去势组Wistar大鼠随机分成4组,分别为去势组（B组）、去势加雌激素组（C组）、去势加甲状旁腺激素组（D组）、去势加雌激素和甲状旁腺激素组（E组）,每组10只。A组和B组注射生理盐水（1 mL·kg-1）;C组注射苯甲酸雌二醇（10 μg·kg-1）; D组注射甲状旁腺激素（20 μg·kg-1）;E组注射苯甲酸雌二醇（10 μg·kg-1）和甲状旁腺激素（20 μg·kg-1）。隔日腹腔注射1次,用药8周。治疗后处死大鼠并测定牙槽骨骨密度,观察每组大鼠骨组织形态计量学参数及血清钙、磷、碱性磷酸酶（ALP）水平。结果去势手术8周后,去势组大鼠牙槽骨密度明显低于伪手术组（P<0.05）。用药8周后,C、D、E组骨密度、骨小梁面积百分比（%Tb.Ar）、骨小梁宽度（Tb.Th）和骨小梁数量（Tb.N）较B组均有明显提高,其中E组提高最明显（P<0.05）。各组血清钙磷值无明显改变（P>0.05）,B组ALP值较A组明显升高（P<0.05）。结论间歇性、小剂量注射甲状旁腺激素能增加去势大鼠牙槽骨的骨密度和改善骨结构,与雌激素联合使用对骨质疏松的治疗有协同作用。     

去势法大鼠骨质疏松症模型建立的探讨

目的 探讨去势法建立大鼠骨质疏松症模型的可行性。方法 将30只老年Wistar雌性大鼠随机分成手术组(OVX)和假手术组(SHAM),手术组切除双侧卵巢。两组于术前、术后3个月行股骨X线检查,测定大鼠血清碱性磷酸酶水平;术后3个月处死大鼠,取其右侧股骨拍摄X线片,并制作脱钙切片行苏木精-伊红(HE)染色,行骨组织形态学分析。结果 去势3个月后,X线片显示OVX组股骨骨密度明显低于SHAM组,表现为骨皮质密度降低,透光性增加明显;血清中ALP水平,OVX组术后水平明显高于术前,高于SHAM组;股骨横断面HE染色结果 显示OVX组骨小梁结构疏松或断裂,骨髓腔扩大,骨质流失较多,但骨皮质厚度无明显下降。结论 去势法建立大鼠骨质疏松症模型切实可行,造模3个月。大鼠股骨骨密度下降,骨质丢失增加,骨小梁形成减少,骨质疏松形成。     

雌激素对骨质疏松状态下牙种植体周围骨组织内BMP2含量的影响

目的：研究系统应用17β-雌二醇对骨质疏松大鼠种植体周围骨组织BMP2含量的影响。方法：42只6月龄未交配SD雌性大鼠平均分为3组,每组14只,即A：假去势手术组（SHAM）,B：去势手术非用药组（OVX）,C：去势手术雌激素治疗组（E2）。将后两组大鼠卵巢切除后1.5月对其右股骨远中行牙种植手术,E2组在种植术后一周开始给予17β-雌二醇（30ug/kg）治疗。分别于种植术后1.5月及3月,随机处死各组动物的一半。处死后,取种植部位做脱钙切片,进行免疫组化染色,对种植体周围骨组织的BMP-2含量进行定量分析。结果：种植术后1.5月及3月处死时,各组BMP2含量由高到低的顺序为：E2组、SHAM组、OVX组,统计差异显著。同时,各组BMP2含量均较1.5月处死时显著增高,统计差异显著。结论：1骨质疏松改变可使大鼠种植体-骨界面BMP2含量降低。2 17β-estradiol可使骨质疏松大鼠种植体-骨界面BMP2含量增加。3雌激素长期用药的效果优于短期用药。     

1α(OH)-D_3对去势大鼠下颌骨骨量变化的影响

目的　评价防治骨质疏松症药物 1α(OH) -D3 如何影响下颌骨的骨量变化。方法　以去势大鼠作为绝经后骨质疏松症模型以诱发下颌骨骨丢失。对去势大鼠 (ovariectomizedrats,OVX)分别以 0 .0 4μg/kg/day、0 .5μg/kg/day两种不同浓度进行灌胃。 结果　 1α(OH) -D3 可抑制去势大鼠下颌骨骨丢失和骨小梁结构破坏 ,下颌骨骨密度、骨组织形态计量学指标维持在假去势组 (Sham -OVX)水平。结论　防治骨质疏松症药物不仅对全身骨起作用 ,对预防下颌骨骨丢失也有一定的效果     

Study of anticandidal activity of carvacrol and eugenol in vitro and in vivo

BACKGROUND/AIMS: The mechanism of the anticandidal action of the major phenolic components of oregano and clove essential oils - carvacrol and eugenol - was studied. This activity was also evaluated for the therapeutic efficacy in the treatment of the experimental oral candidiasis induced by Candida albicans in immunosuppressed rats. METHODS: In vitro, the addition of carvacrol at 0.1% or eugenol at 0.2% during the exponential growth of C. albicans was evaluated. The release of substances absorbing at 280 nm by cells treated with these two components was also measured spectrophotometrically. In vivo, oral candidiasis in immunosuppressed rats was established by inoculating 3 x 10(8) cells of C. albicans with a cotton swab on three alternate days. The number of colony counts was evaluated from the oral cavity of rats treated for eight consecutive days with carvacrol, eugenol or nystatin and compared to untreated controls. RESULTS: Carvacrol and eugenol were fungicidal in exponentially growing C. albicans. Interestingly, this fungicidal effect was accompanied by the release of substances absorbing at 280 nm. In an immunosuppressed rat model of oral candidiasis, carvacrol or eugenol treatment significantly (P < 0.05) reduced the number of colony counts sampled from the oral cavity of rats treated for eight consecutive days compared to untreated control rats. Similar results were obtained with nystatin used as a reference treatment. CONCLUSION: The in vitro results indicated that both carvacrol and eugenol exerted an anticandidal effect by a mechanism implicating an important envelope damage. Their in vivo efficacy on experimental oral candidiasis leads us to consider them as possible antifungal agents.     

纳米金颗粒的制备及其生物相容性研究

目的制备纳米金颗粒并初步探讨其生物相容性。方法采用柠檬酸钠还原法合成纳米金颗粒(GNPs),通过透射电子显微镜(TEM)观察其尺寸和形貌,利用光谱仪记录所制得的纳米金溶液的紫外-可见光谱(UV-Vis)。体外实验运用MTT比色分析法研究纳米金颗粒的细胞毒性;体内实验通过HE染色观察注射纳米金颗粒后动物心、肝、脾、肾的组织学变化。结果TEM表征和紫外-可见光谱结果显示成功合成直径均一的球形纳米金颗粒。MTT结果显示一定浓度的纳米金颗粒不影响人咽鳞状细胞癌细胞系Fa Du的增殖,无细胞毒性。HE染色结果显示所有动物心、肝、脾、肾组织无组织学变化和毒副反应。结论成功制备了生物相容性良好的纳米金颗粒,展现出潜在的临床应用前景。     

Chlorhexide and fluoride in prevention of plaque and caries in hamsters.

The effect of combined administration of chlorhexidine and fluoride in the drinking water of hamsters on plaque and caries prevention was studied. Plaque indices of the hamsters receiving chlorhexidine either alone or simultaneously with fluoride were significantly lower than those of the control and fluoride only treated hamsters. The type of plaque indices used in this investigation was area scores. The necessity of quantitatively assessing plaque by several parameters was emphasized. The degrees of caries of the experimental groups were significantly lower than of the control group during the cariogenic diet regime. The anticariogenic effect of chlorhexidine and fluoride at low concentrations each provided simultaneously with a cariogenic diet, was confirmed. The differences in caries rate between the experimental groups were not significant. No additive effect on the cariostatic action of chlorhexidine and fluoride was observed when both reagents were applied simultaneously due probably to the low F concentration in the drinking water. The results did not show a direct quantitative relationship between plaque and caries.     

Intra- and inter-observer variability and accuracy in the determination of linear and angular measurements in computed tomography. An in vitro and in situ study of human mandibles

The observer variability and accuracy of linear and angular computed tomography (CT) software measurements in the transaxial plane were investigated for the temporomandibular joint with the General Electric 8800 CT/N Scanner. A dried and measured human mandible was embedded in plastic and scanned in vitro. Sixteen observers participated in the study. The following measurements were tested: inter- and extra-condylar distances, transverse condylar dimension, condylar angulation, and the plastic base of the specimen. Three frozen cadaveric heads were similarly scanned and measured in situ. Intra- and inter-observer variabilities were lowest for the specimen base and highest for condylar angulation. Neuroradiologists had the lowest variability as a group, and radiology residents and paramedical personnel had the highest, but the differences were small. No significant difference was found between CT and macroscopic measurement of the mandible. In situ measurement by CT of condyles with structural changes in the transaxial plane was, however, subject to substantial error. It was concluded that transaxial linear measurements of the condylar processes free of significant structural changes had an error and an accuracy well within acceptable limits. The error for angular measurements was significantly greater than the error for linear measurements.     

Comparison of the Easyshade Compact and Advance in vitro and in vivo

Objective

The objective of this study was to evaluate the repeatability, inter-examiner and inter-device reliability, and accuracy of the new VITA Easyshade Advance (ES-A) spectrophotometer in comparison with the Easyshade Compact (ES-C).

Methods

For the in vitro study, six porcelain disks of random shade mixtures were fabricated from VITA ceramic powders. To analyze the repeatability of the ES-C and ES-A, readings were obtained by one examiner for one porcelain disk and one shade tab (VITA 3D-Master). Measurements were repeated by two examiners to evaluate inter-examiner reliability. To assess accuracy, porcelain disks and shade tabs were measured with the ES-C and ES-A and by means of a spectroradiometer (SR). ?E values between the shade tabs and disks were calculated. Differences between devices were evaluated by use of univariate analysis. Reliability and accuracy of both devices were also tested in a clinical setting. The intra-class correlation coefficient (ICC) was calculated for all assessments of reliability.

Results

Good agreement was observed for replicate measurements (ICC?>?0.9), for inter-examiner reliability of the ES-A and ES-C (ICC?>?0.9), and for inter-device agreement (ICC?>?0.9). Univariate analysis revealed that ?E values for the spectrophotometers were consistent (p?=?0.783); spectroradiometrically measured ?E was comparable, but the mean value was smaller than that for the spectrophotometers (p?=?0.004). Clinical inter-device agreement was acceptable to high (ICC?>?0.777). The accuracy of the ES-A was higher than that of the ES-C (p?=?0.001).

Conclusion

Within the limitations of the experiment, the spectrophotometers tested enabled reliable and accurate measurement. In the clinical setting, however, the ES-A seems more accurate.

Clinical relevance

ES-C and ES-A can be valuable tools for the determination of tooth colors. Because of their good reliability, they should especially be used for the assessment of tooth color changes over time.     

Prevalence of hypodontia and hyperdontia in paedodontic and orthodontic patients in Budapest

Various publications have reported the prevalence of accessory teeth to be between 1 and 3%. In contrast, hypodontia has a much higher prevalence. In the current work, the authors studied OP radiographs on 2,219 patients aged 6 to 18 years who presented at the Department of Paedodontics and Orthodontics at Semmelweis University in Budapest (patients with systemic disease were excluded). The examined radiographs revealed a prevalence of accessory teeth of 1.53%. The sequence of prevalence was as follows: mesiodens > second incisor > first incisor. 77.5% of the accessory teeth were located in the upper jaw, with 97.5% of those being present in the incisor region. Hypodontia was detected in 326 patients (14.69%); missing wisdom germs were not considered. The sequence of prevalence of missing germ was as follows: upper second incisor > lower second premolar > upper second premolar > lower first incisor. Hypodontia in the molar region was observed in 15 cases (0.68%). The prevalence of oligodontia was 1.04%.     

Expression of matrix metalloproteinases 2 and 9 in odontogenic myxoma in vivo and in vitro

Odontogenic myxoma is a benign neoplasm, which presents local invasiveness and tendency for recurrence. Matrix metalloproteinases (MMPs) 2 and 9 are involved in tumor invasion. Thus, the aim of this study was to analyze the expression and activity of these MMPs in odontogenic myxoma in vivo and in vitro. Three cases of odontogenic myxoma and cultured cells derived from this tumor (Mix1 cell line) were used. The detection and activity of two MMPs (2 and 9) were performed by immunohistochemistry in formalin-fixed, paraffin-embedded sections of odontogenic myxoma and immunofluorescence of the cultured cells and, by gelatin zymographic analysis of Mix1 conditioned media, respectively. MMPs 2 and 9 were detected in vivo and in vitro. The zymographic assay detected latent MMP-2 as well as latent and active MMP-9. Based on our findings, we suggest that MMPs may be involved in local invasiveness of the odontogenic myxoma. MMP-9 is not only secreted by odontogenic myxoma but also has enzyme activity with no further stimulation. Other MMPs were not analyzed; however, our results suggest that the invasive behaviour of odontogenic myxoma could be related at least to MMP-9.