Application of the ratio of the radiopaque calcified area to the dental follicle (RCA/DF) for dental age assessment on orthopantomograms.

OBJECTIVES: This study aimed at exploring a new tooth development evaluation method for age assessment and investigating the dynamic alteration and potential trend of tooth development by orthopantomograms (OPGs), in order to provide references for tooth development prediction and forensic purpose. MATERIALS AND METHODS: A total of 132 OPGs of children aged 3-8 years were collected. The developmental stages of the permanent mandibular second molar (M2)were evaluated by experienced examiners according to the Nolla method and Mimics software, respectively. Quantitative analysis of the ratio of the radiopaque calcified area to the dental follicle (RCA/DF) in different stages, ages, sexes and quadrants were evaluated and compared via descriptive statistics and Spearman's correlation coefficient analysis. RESULTS: There was a strong, positive correlation between the examiners' evaluation and mimics analysis results. With the age increased, the Nolla stage of M2 observed by OPGs increased, and the RCA/DF showed increased trends both in males and females. There were significant differences of the RCA/DF of the M2 at various ages. The tooth calcification development of female was 9.08% earlier than that of male between 3 and 8 years old. However, teeth of male seemed to develop faster than that of female during this period. There was no significant difference between left and right quadrant either according to the Nolla stage or RCA/DF. CONCLUSIONS: The RCA/DF value obtained from OPGs of the developmental mandibular second permanent molars could be used as a reliable indicator for tooth maturity and age estimation in children aged 3-8 years. CLINICAL RELEVANCE: Age assessment based on radiographs is considered as a reliable and efficient indicator for judging different types of malocclusion, making suitable orthodontic treatment plan, deciding the extraction time of retained deciduous teeth in clinic practice.

Mapping the amelogenin protein expression during porcine molar crown development.

INTRODUCTION: Amelogenin (AMEL) plays critical roles during enamel and dentin matrix deposition and mineralization. Most studies focused on the expression patterns of AMEL through the bud, cap, and bell stages. The spatial-temporal expression of AMEL protein during different mineralization stages, especially from presence of crypts to crown completed stages, remains unknown. Thus, the distribution pattern of AMEL in tooth crown formation from Nolla Stage 1 to 6 was investigated. METHODS: Porcine mandibular molar tooth germs from Nolla Stage 1 to 6 were obtained. The dynamic morphologic changes of tooth germs were examined by X-ray and surgical operating microscope. The AMEL protein expression was evaluated immunohistochemically, then analyzed semi-quantitatively, and further visualized via heat map. RESULTS: Tooth germs continuously increased in size from Nolla Stage 1 to 6. AMEL expression in the newly formed enamel kept negative, but presented intensively positive in the previously formed enamel from Stage 1 to 3. The adjacent enamel-dentin junction (EDJ) was strongly positive during the whole process. In predentin, AMEL was weakly seen at Stage 1 and then dramatically up-regulated from Stage 2 to Stage 3, then down-regulated but was still apparently seen in the whole process. AMEL expression in dentin was decreased during dentin matrix secretion and mineralization. CONCLUSIONS: This study identified the dynamic distribution of AMEL during porcine tooth crown formation. Semi-quantitative analysis and heat map emerged as reliable indicators in demonstrating AMEL distribution pattern.

[Transfection of human beta defensin 2 gene into the lung by aerosol inhalation: experiment with rats].

OBJECTIVE: To investigate the feasibility to transfect human beta defensin 2 (hBD2) gene into the lung so as to enhance the endogenous hBD2 expression to defend infectious diseases. METHODS: Recombinant plasmid containing hBD2 gene, pLXSN-hBD2, was mixed with a new cationic liposome prepared by film at different weight ratios. Sixteen Wistar rats were divided into 2 groups: experimental group (n = 11), undergoing aerosol inhalation of liposome/pLXSN-hBD2 complex, and control group (n = 5), undergoing aerosol inhalation of blank vector pLXSN. The tracheae were taken out from 5 rats of the experiment and control groups each 2 days later, and from 2 rats of the experimental group 6, 15, and 21 days later respectively so as to obtain the epithelial cells of trachea. DNA was extracted from the tracheal epithelial cells and PCR was used to examine the transfection and integration of hBD2. Western blotting was used to detect the protein expression of hBD2. RESULTS: Aerosolization impacted obviously the microcapsule structure of liposome/plasmid complexes, and there was the least structural destruction of complex at a ratio of 10:1 that suited for aerosolization best. After the inhalation the relevant plasmids were all successfully integrated into the epithelial cells in both groups. Protein expression of hBD2 was not detected in the control group and the hBD2 protein expression level 2 days after transfection of the experimental group was 4866.9 +/- 148.2, and then decreased gradually, and reached 3.2 +/- 1.5 twenty-one days after the transfection. CONCLUSION: The recombinant plasmid pLXSN-hBD2 can be transfect into the airway epithelial cells via aerosol inhalation and the expression of hBD2 sustains for a period of time.

Efficacy and safety of biodegradable polymer sirolimus-eluting stents versus durable polymer drug-eluting stents: A meta-analysis of randomized trials.

BACKGROUND: A meta-analysis was performed to investigate the safety and efficacy of biodegradable polymer sirolimus-eluting stents (BP-SESs) compared with durable polymer drug-eluting stents (DP-DESs). METHODS: Online databases, including PubMed, EMBASE and the Cochrane Library, were searched for randomized controlled trials that compared BP-SESs and DP-DESs and reported rates of overall and cardiac mortality, myocardial infarction (MI), stent thrombosis (ST), target lesion revascularization (TLR), target vessel revascularization (TVR) and late lumen loss (LLL). RESULTS: A total of 15 studies investigating 14,187 patients were included in the meta-analysis. The BP-SESs significantly reduced the risk of late ST (OR: 0.57; 95% CI: 0.33-0.98; p=0.04), very late ST (OR: 0.53; 95% CI: 0.29-0.97; p=0.04) and in-stent LLL (MD: -0.06, 95% CI: -0.11 to -0.01; p=0.01) compared with the DP-DESs but did not improve mortality (OR: 0.95; 95% CI: 0.81-1.11; p=0.52), cardiac mortality (OR: 0.89; 95% CI: 0.72-1.10; p=0.27), MI (OR: 0.90; 95% CI: 0.76-1.08; p=0.27), TLR (OR: 0.95; 95% CI: 0.81-1.11; p=0.51), TVR (OR: 0.96; 95% CI: 0.81-1.13; p=0.62) or in-segment LLL (MD: -0.03, 95% CI: -0.06-0.01; p=0.10). CONCLUSIONS: In this meta-analysis of randomized controlled trials, the BP-SESs were superior to the DP-DESs in terms of late ST, very late ST and in-stent LLL. Further large randomized controlled trials with long-term follow-up are required to validate the benefits of BP-SESs.

[Effects of tea polyphennols on hepatic lipase activity in rabbits with fatty liver].

OBJECTIVE: To investigate the relationship between hepatic lipase activity and fatty degeneration of hepatocytes and explore the effects of tea polyphennols (TP) on the changes of hepatic lipase (HL) activity in rabbits with fatty liver. METHODS: According to serum cholesterol and triglyceride (TC) levels, 19 rabbits were divided into fatty liver group (FL, n=6) fed with high cholesterol diet, TP group (n=7) fed with high cholesterol diet and 20mug/g/d tea polyphennols everyday orally, control group (n=6) fed with normal diet. After 8 weeks, the levels of serum TC, HL activity, HL activity and malondildehyde (MDA) in hepatic tissue were detected, and the pathomorphology of hepatic tissue were determined in all rabbits. RESULTS: The fatty degeneration of hepatocyts in FL group was more severe than that in TP and control group. The serum TC level in TP group (16.87 6.58) mmol/L was higher than that (1.11 0.82) mmol/L in control group (t=5.786, p<0.05), but lower than that (28.49 5.99) mmol/L in FL group (t=3.968, p<0.05). The serum low density lipoprotein-cholesterol level in Tp group (5.10 4.19) mmol/L also higher than that (0.71 1.14) mmol/L in control group (t=3.763, p<0.05), but lower than that (12.15 1.95) mmol/L in FL group (t=2.478, p<0.05). The number of positive dots presenting HL activity level in 100 square micron, hepatic tissue in TP group (3.24 0.17) was higher than that (1.76 0.10) in FL group (t=-3.153, p<0.05), but lower than that (4.14 0.05) in control group (t=-2.902, p<0.05). The levels of MDA in hepatic tissue in TP group (44.66 26.18) nmol/mg was significantly lower than that (75.58 29.88) nmol/mg in FL group (t=2.261, p<0.05), but no evidently different from that (43.64 16.95) nmol/mg in control group. The plasma HL activity was no difference among the three groups. CONCLUSION: The HL activity in hepatic tissue with fatty degeneration of hepatocytes was lower than that in normal liver. Tea polyphennols can increase HL activity in hepatic tissue and protect hepatocytes from fatty degeneration.

Medium-chain fatty acid nanoliposomes for easy energy supply.

OBJECTIVE: Developing a nanoliposome delivery system for an easy energy supply of medium-chain fatty acids (MCFAs) to improve oral doses and bioavailability. METHODS: Bangham's method and high-pressure microfluidization were used to prepare MCFA liposomes. The easy energy-supply property of MCFA nanoliposomes was estimated by the anti-fatigue experiments of mice including a weight-loaded swimming test and its corresponding parameters (serum urea nitrogen, blood lactic acid, and hepatic glycogen). For comparison, nanoliposomes without MCFAs and MCFAs not entrapped in nanoliposomes were used throughout. RESULTS: Compared with crude MCFA liposomes according to Bangham's method, the MCFA nanoliposomes made by high-pressure microfluidization exhibited great advantages in their characteristics, with a small average diameter (76.2 ± 34.7 nm), narrow size distribution (polydispersity index 0.207), high ζ-potential (-50.51 mV), great entrapment efficiency (70.5%) and drug loading (9.4%), and good stability. The high-dose group and the MCFA group (680 mg/kg) showed a longer weight-loaded swimming time (104 ± 29 min, P = 0.087, and 108 ± 11 min, P = 0.047, respectively) and significantly higher hepatic glycogen (16.40 ± 1.45 mg/g, P < 0.001 and 17.27 ± 2.13 mg/g, P < 0.001, respectively) than the control group (59 ± 11 min and 8.79 ± 2.76 mg/g, respectively). Moreover, serum urea nitrogen (891.5 ± 113.4 mg/L, P = 0.024, and 876.6 ± 70.8 mg/L, P = 0.015, respectively) and blood lactic acid (6.05 ± 1.40 mmol/L, P = 0.001, and 5.95 ± 1.27 mmol/L, P < 0.001, respectively) in the high-dose group and the group with an equivalent MCFA dose were significantly lower than those in the control group (1153.6 ± 102.5 mg/L and 12.53 ± 1.86 mmol/L, respectively). CONCLUSION: Similar to MCFAs, MCFA nanoliposomes prepared by high-pressure microfluidization showed a strong easy energy-supply property, which suggested that MCFA nanoliposomes could be a potential drug candidate for an easy energy supply.