[Effects of bioactive glass on proliferation, differentiation and angiogenesis of human umbilical vein endothelial cells].

OBJECTIVE: To investigate the effects of phytic acid derived bioactive P2O5-SiO2-CaO gel-glasses (PSC) on the proliferation, differentiation and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro. METHODS: HUVECs were cultured in PSC extracts, which were prepared with endothelial cell medium (ECM) at a gradient concentration of 0.01, 0.1, 1 and 2 g/L. Cells cultured in ECM were used as the control. The effect of PSC on HUVECs proliferation was assessed on the 1st, 3rd, 5th, 7th and 10th days with (4, 5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide assay (MTT), and the optimum PSC concentration for HUVECs proliferation was used in the following experiments. The subsequent experiments were divided into two groups. The experimental group used PSC extracts to culture HUVECs (PSC group) and the control group used ECM to culture HUVECs (ECM group). Gene expression of angiogenic factors, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), was detected on the 2nd, 4th and 7th days by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). The morphology and number of tubules formation were observed at the 4th and 10th hours. Image J software was used for counting and quantitative analysis. RESULTS: The results of MTT assay showed that 0.1 g/L PSC group had the most significant effect on promoting HUVECs proliferation. The optical density values of 0.1 g/L PSC group on the 5th and 7th days were significantly higher than those of the other PSC groups and the control group (P < 0.05). The result of real-time RT-PCR showed that 0.1 g/L PSC extract up-regulated the mRNA expression of VEGF and bFGF significantly (P < 0.05). On the 4th day, the gene expressions of VEGF and bFGF in PSC group were 1.59 and 1.45 times higher than those in ECM group respectively, and on the 7th day, the gene levels of VEGF and bFGF in PSC group were 1.98 and 1.37 times higher than those in ECM group respectively. The tubule formation assay showed that the maturity and density of the tubules in 0.1 g/L PSC group was much better than that in the ECM group at the 10th hour. The quantitative analysis by Image J indicated that the tubules number in PSC group (29.63±2.29) was higher than in the ECM group (20.13±2.36), with statistical significance (P < 0.05). CONCLUSION: PSC showed significant promoting effects on HUVECs' proliferation, differentiation and angiogenesis in vitro.

[Effect of bioactive glass pretreatment on the durability of dentin bonding interface].

OBJECTIVE: To study the effect of bioactive glass (BG) on the dentin bond strength and the microleakage of hybrid layer. METHODS: In the study, 30 dentin planes were prepared from the third molars with no caries and equally assigned to the control group, BG group, and sodium trimetaphosphate (STMP)-polyacrylic acid (PAA)-BG group (S-P-BG group), randomly. After etched with 35% phosphoric acid, the dentin planes of BG group were pretreated with 0.5 g/L BG, and the dentin planes of S-P-BG group were pretreated with 5% STMP, 5% PAA and 0.5 g/L BG. No additional pretreatment was done to the dentin planes of control group. Then the dentin planes were bonded using 3M Single Bond 2 adhesive to 3M Z350XT composite resin, and cut into 0.9 mm×0.9 mm column samples, which were stored at 37 ℃ artificial saliva (AS). After 24 hours, 1 month, and 3 months, the microtensile bond strength test was performed. The data were analyzed using one-way ANOVA and LSD method. The morphology of the bond fracture interface was observed with scanning electron microscope. Other 27 teeth were collected and the enamel layer and roots cut off, with the pulp chamber exposed. 0.1% rhodamine B was added to the 3M Single Bond 2 adhesive, and then the adhesive was applied to complete the bonding procedures as above. The teeth were stored in 37 ℃ AS for 24 hours, 1 month, 3 months, and then 0.1% sodium fluorescein solution was placed in the chambers and stained for 1 hour. Confocal laser scanning microscopy was used to observe the interface morphology and microleakage of the hybrid layer. RESULTS: At the end of 24 hours and 1 month, there was no significant difference in the microtensile bond strength among the three groups (P>0.05). After 3 months of soaking, the S-P-BG group [(36.91±7.07) MPa] had significantly higher microtensile bond strength than the control group [(32.73±8.06) MPa] (P=0.026); For the control group and the BG group, the microtensile bond strength significantly decreased at the end of 3 months compared with 24 hours (control group: P=0.017, BG group: P=0.01); The microtensile bond strength of S-P-BG group af the end of 3 months had no significant difference in compared with 24 hours [(37.99±7.98) MPa] (P>0.05). Observation of the fracture surface at the 24 hours showed no obvious mineralization in all the three groups. After 1 and 3 months, mineral formation was observed in BG group and S-P-BG group, and no obvious collagen exposure was observed in S-P-BG group. Confocal laser scanning microscopy revealed no obvious differences in the morphology and quantity of the resin tag in the control group, BG group and S-P-BG group. At the end of 24 hours, leakage was found in all the three groups. The microleakage of the control group increased at the end of 3 months, while the microleakage of the BG and S-P-BG groups decreased. CONCLUSION: BG pretreatment of dentin bonding interface can induce mineralization at the bonding interface and reduce the microleakage of the hybrid layer; pretreating the dentin bonding interface with STMP, PAA and BG may enhance the maintaining of the dentin bonding durability.

[Nano-sized bioactive glass enhances osteogenesis of critical bone defect in rabbits].

OBJECTIVE: To compare the osteogenic effects of a nano-sized 58S bioactive glass (nano-58S BG) and a traditional 45S5 bioactive glass(45S5 BG) in penetrating parietal critical bone defects. METHODS: Critical bone defect with 9 mm diameter was created in the parietal bone of New Zealand rabbits. The bone defects were then filled with either nano-58S BG, or 45S5 BG, or nothing but the newly-formed blood clot as the blank control at random. For histological observation, specimens were gained 4 and 8 weeks after the surgery, sectioned and stained by HE. The amount of collagen type I was observed with Picric-Sirius Red staining through polarimetry. To observe the new bone formation with fluorescence under the laser confocal microscope, we injected fluorescent markers 14, 28, and 42 days after the surgery. The markers were tetracycline hydrochloride, alizarin red and calcin individually in chronological order. Image J software was used to quantify the bone regeneration. RESULTS: HE staining showed that BG particulates were integrated with the surrounding tissue without any inflammatory cells infiltration 4 weeks after surgery. New bone regeneration was observed both from the border and in the center of the defects in both BG groups. No bone regeneration in defect center was observed in control group. At the end of 8 weeks, there was more bone regeneration in nano-58S group compared with 45S5 group and control group. The structure of the new bone in BG groups was hollow, which was similar to the natural normal parietal bone. No hollow structure was observed in the new bone of control group. Picric-sirius Red polarimetry showed that more amount of collagen type I was found in nano-58S group than in either 45S5 or control group. The fluorescent observation of the hard tissue slices at the end of 8 weeks showed statistically larger scope and faster new bone formation in nano-58S group with (29.4±4.48) µm thickness from 4-6 weeks and (35.3±3.74) µm from 6-8 weeks compared with 45S5 group [(13.43±3.44) µm and (17.64±4.13) µm] and control group [(5.88±2.92) µm and (6.07±3.02) µm, P<0.01]. CONCLUSION: Compared with the traditional 45S5 bioactive glass, 58S nano-sized bioactive glass showed better osteogenic effect in bone regeneration in parietal bones of rabbits.

[Prevalence and influencing factors on food allergy among children aged 0-5 years in China].

Objective: To describe the prevalence of food allergy among children aged 0-5 years in China and to explore related influencing factors. Methods: Multistage stratified random sampling method was used to collect data from 275 surveillance sites of the China National Nutrition and Health Survey of Chinese children and lactating mothers programs in 31 provinces (autonomous regions and municipalities) of China in 2016-2017. A total of 70 107 participants aged 0-5 years were included in this study. The study collected information of participants' demographic characteristics and food allergies by face-to-face questionnaire. The prevalence of food allergy was analyzed, using the complex data weighting method. The logistic regression models were used to analyze the influencing factors related to food allergy. Results: The overall prevalence of self-reported food allergy among children aged 0-5 years was 4.81%. Prevalence rates in infants aged 0-5 months, and 6-23 months and preschool children aged 2-5 years were 0.81%, 4.68% and 5.26%, respectively. The results of logistic analysis showed that there was a significantly positive correlation between factors including children from 6 months to 5 years old, urban area, southwest area, first-born, mothers with college education or above, and the prevalence of food allergy in children. Shrimp, poultry eggs, crab shellfish, fruit, milk and fish appeared the common allergic foods in children aged 0-5 years, with prevalence rates of self-reported food allergy as 1.55%, 1.25%, 0.99%, 0.97%, 0.87% and 0.86%, respectively. The proportion of single food allergy in children with allergies was 69.85%. Conclusions: Among children aged 0-5 years, the prevalence of self-reported food allergy increases with age, in China. Foods that is prone to allergies include fish, shrimp, crab, shellfish, poultry eggs, milk and fruits, etc. Most allergies were only caused by single food in children, under observation.

Effect of CYP3A4*1G on the fentanyl consumption for intravenous patient-controlled analgesia after total abdominal hysterectomy in Chinese Han population.

WHAT IS KNOWN AND OBJECTIVE: Clinical investigations into postoperative intravenous patient-controlled analgesia (PCA) have indicated interindividual differences in fentanyl consumption. Cytochrome P450 3A4 (CYP3A4) is the main metabolism enzyme of fentanyl, and single nucleotide polymorphisms within the CYP3A4 gene may contribute to the variability of fentanyl analgesic efficacy. The aim of this study was to investigate whether the most common genetic variation in Chinese, CYP3A4*1G, has an impact on the fentanyl consumption for intravenous PCA in Chinese Han women undergone abdominal total hysterectomy. METHODS: A total of 79 female patients (American Society of Anesthesiologist physical status I or II) scheduled to undergo elective abdominal total hysterectomy were enrolled. All patients received combined spinal-epidural anaesthesia with bupivacaine. Intravenous fentanyl PCA was provided postoperatively for satisfactory analgesia. The doses of fentanyl consumption were recorded 2, 4, 24 and 48 h after the initiation of PCA postoperatively. Pain at rest and adverse effects were measured with rating scales. CYP3A4*1G was screened by means of direct sequencing and further confirmed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS AND DISCUSSION: Forty-six patients were GG homozygotes, 27 patients were GA heterozygotes, and six patients were AA homozygotes, respectively. The distribution of the CYP3A4*1G allele was consistent with Hardy-Weinberg equilibrium (P>0·05). At 2 and 4 h, the doses of fentanyl required for patients with GA/AA genotypes were 80·0 (45·0, 112·5) µg and 120·0 (80, 173·8)µg, respectively, and significantly lower than those for GG homozygotes [91·3 (80·0, 125·0) µg and 169·0 (112·5, 226·3) µg, respectively, P<0·05]. There was trend of decreasing fentanyl consumption at 24 and 48h in patients with GA/AA genotypes, relative to GG homozygotes, but the difference was not statistical significant (P>0·05). WHAT IS NEW AND CONCLUSIONS: CYP3A4*1G has an impact on the analgesic effect of fentanyl in Chinese Han subjects. Further validation of our results in a well-powered study would be helpful.

[Clinical efficacy observation of direct pulp capping using iRoot BP Plus therapy in mature permanent teeth with carious pulp exposure].

Objective: To evaluate the clinical efficacy and influence factors of direct pulp capping using a bioactive ceramic in mature permanent teeth with carious pulp exposure, in order to explore the feasibility and indications of vital pulp therapy for such teeth. Methods: From January 2016 to September 2017, 57 patients (57 teeth) with carious pulp exposure in mature permanent teeth were selected from the Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology. All the teeth were preoperatively diagnosed as deep caries with normal pulp or reversible pulpitis. After rubber dam isolation, all the carious dentin was removed and the exposed pulp tissue was observed under microscope. Hemostasis should be achieved within 3 min by using 2.5% sodium hypochlorite cotton pellets with a gently press. A resin composite restoration was performed immediately or 2 weeks later after direct pulp capping by using a bioceramic material (iRoot BP Plus). The patients were re-examined 12 to 50 months after operation (average 30 months) and the outcomes were evaluated by symptoms, clinical examination and X-ray. Kaplan-Meier survival analysis was used to calculate the success rate and influence factors were analyzed by Log-Rank test. Results: Totally 50 patients [age (32±13) years old (13-68 years old), 12 males and 38 females] received the follow-up examination more than one year. The overall success rate was 90% (45/50) and the success rates at 1 year, 2 years, 3 years and more were 98%, 89% and 81%, respectively. Age, gender, symptom, tooth and cavity type, pulpal exposure size and coronal restoration material had no significant correlations with the treatment outcome (P>0.05). Conclusions: Direct pulp capping of mature permanent teeth with carious pulp exposure by using iRoot BP Plus might have high success rate. There's no significant correlations between the major clinical factors and the treatment outcome.