Effects of novel bioactive glasses on promoting remineralization of artificial dentin caries / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effects of novel bioactive glasses (BG) including PSC with high phosphorus component and FBG with fluorine-doped element on promoting remineralization of artificial dentin caries.@*METHODS@#(1) BGs were used in this study as follows: PSC (10.8%P2O5-54.2%SiO2-35.0%CaO, mol.%) were synthesized using phytic acid as the phosphorus precursor through sol-gel method. FBG (6.1%P2O5-37.0%SiO2-53.9%CaO-3.0%CaF2, mol.%) and 45S5(6.0%P2O5-45.0%SiO2-24.5%CaO-24.5%Na2O, mol.%) were synthesized by traditional melt method. (2) The above BGs were soaked in simulated body fluid (SBF) for 24 hours. Then X-ray diffraction (XRD) was used to analyze the formation of hydroxyapatite (HA) crystals. (3) Prepared 1 mm thick dentin slices were soaked in 17% ethylene diamine tetraacetic acid (EDTA) for 1 week to demineralize the dentin. Then the dentin slices treated by BG were soaked in SBF for 1 week. Field emission scanning electron micro-scopy (FE-SEM) was used to observe the surface morphology of the dentin slices. (4) Four cavities were prepared to 1 mm depth in each 2 mm thick dentin slice, then were treated with lactic acid for 2 weeks to form the artificial dentin caries. Wax, mineral trioxide aggregate (MTA), PSC and FBG were used to fill four cavities as blank control group, MTA group, PSC group and FBG group respectively. Then the spe-cimens were soaked in SBF for 4 weeks. The changes of depth and density of demineralized dentin were analyzed using Micro-CT before filling and after 2 and 4 weeks filling.@*RESULTS@#(1) PSC and FBG promoted mineral formation on the surfaces of the demineralized dentin. And the speed was faster and crystallinity was higher in PSC group than the FBG and 45S5 groups. (2) The increased mineral density of artificial dentin caries in PSC group were (185.98 ± 55.66) mg/cm3 and (213.64 ± 36.01) mg/cm3 2 and 4 weeks after filling respectively, which were significantly higher than the control group [(20.38 ± 7.55) mg/cm3, P=0.006; (36.46 ± 10.79) mg/cm3, P=0.001]. At meanwhile, PSC group was also higher than MTA group [(57.29 ± 10.09) mg/cm3; (111.02 ± 22.06) mg/cm3], and it had statistical difference (P=0.015; P=0.006). The depth of remineralized dentin in PSC group were (40.0 ± 16.9) μm and (54.5 ± 17.8) μm 2 and 4 weeks respectively, which were also statistically different from the control group (P =0.010;P=0.001). There were no statistical differences between the control group and MTA group. The above effects of FBG group were between PSC and MTA.@*CONCLUSION@#PSC has advantages in the speed, quality and depth of mineral deposition in the demineralized layer of artificial dentin caries. It would be expected to be an ideal material to promote the remineralization of dentin caries.

Research progress in vital pulp therapy in mature permanent teeth with carious pulp exposure / 中华口腔医学杂志

Vital pulp therapy(VPT)is an important pathway to preserve and maintain pulp tissue in a healthy state. VPT has been improved recently as the new progress achieved in pathobiology, bioactive materials and clinical research. The present review summarizes the clinical outcomes and prognostic factors of VPT, including direct pulp capping, partial pulpotomy and full pulpotomy in mature permanent teeth with carious pulp exposure, and briefly introduces the new progress in this field.

Effects of bioactive glass on proliferation, differentiation and angiogenesis of human umbilical vein endothelial cells / 北京大学学报(医学版)

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 / 北京大学学报(医学版)

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.

Anti-inflammatory and repaired effects of non-steroidal anti-inflammatory drugs on human dental pulp cells / 北京大学学报(医学版)

OBJECTIVE@#To study the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on anti-inflammation and repair of human dental pulp cells (hDPCs).@*METHODS@#Primary hDPCs from the freshly extracted human third molars were cultured and passaged in vitro, and the following experiments were performed using the 4th-6th generations of hDPCs. HDPCs were cultured in Dulbecco's modified eagle medium (DMEM) containing 1 mg/L lipopolysaccharide (LPS) to obtain LPS irritated hDPCs (LPS-hDPCs), which served as the inflammatory positive group. LPS-hDPCs in the experimental group were cultured in DMEM containing different concentrations (1, 10, and 100 μmol/L) of NSAIDs (aspirin or meloxicam). HDPCs cultured in DMEM were used as the negative control group. The effects of NSAIDs on the proliferation of hDPCs were assessed on the 1st, 3rd, 5th, and 7th day by MTT assay. The effects of NSAIDs on the expression of inflammation related genes interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) of LPS-hDPCs were detected at the 6th hour by real-time PCR. The expression of differentiation related markers dentin matrix protein-1 (DMP-1) and dentin sialophosphoprotein (DSPP) were detected on the 7th day by real-time PCR. The effects of NSAIDs on the mineralization of LPS-hDPCs were assesd on the 14th day by alizarin red staining. Calcium mineralized nodules were semi-quantitatively determined by cetyl pyridine chloride.@*RESULTS@#MTT assay showed that 1-100 μmol/L aspirin or meloxicam significantly promoted the proliferation of hDPC in a concentration dependent manner (P<0.05). Real-time PCR showed that 1-100 μmol/L meloxicam or 100 μmol/L aspirin down-regulated significantly the mRNA expression of TNF-α and IL-6 of LPS-hDPCs (P<0.05), and 100 μmol/L meloxicam down-regulated IL-6 and TNF-α more significantly than 100 μmol/L aspirin of LPS-hDPCs (P<0.05). Real-time PCR showed that 100 μmol/L meloxicam up-regulated the mRNA expression of DMP-1 and DSPP of LPS-hDPCs significantly (P<0.05). Alizarin red staining showed the meloxicam at the concentration of 100 μmol/L significantly promoted the mineralization of LPS-hDPCs (P<0.05).@*CONCLUSION@#In this study, meloxicam promoted the proliferation of hDPCs, inhibited the inflammatory reaction and promoted differentiation and mineralization of hDPCs under LPS irritation. The present results suggest that meloxicam may play a role in anti-inflammation and repair of pulp inflammation.

Physical and chemical properties of pulp capping materials based on bioactive glass / 北京大学学报(医学版)

OBJECTIVE@#To investigate the physical and chemical properties of pulp capping materials based on bioactive glass (BG).@*METHODS@#Novel BG pulp capping materials were composed of powder and fluid. The powder was BG (82.36% SiO2, 15.36% CaO, and 2.28% P2O5) synthesized by using the sol-gel method combined with template technology. Two kinds of fluid were provided: (1) phosphate buffer (PB) solution and (2) phosphate buffer solution with 1% sodium alginate (SA) addition. After mixing the powder and fluid, BG-PB and BG-PB-SA were prepared. Setting time and compressive strength of the BG pulp capping materials were tested by setting time loading system and mechanical testing machine. Statistical analysis was performed using the independent sample t-test, with the significance set at 0.05. pH meters was used to test the pH of the BG pulp capping materials and mineral trioxide aggregate (MTA). The sealing ability of the BG pulp capping materials and MTA was tested by methylene blue dye leakage model. Statistical analysis was performed using one-way ANOVA analysis and LSD multiple comparison, with the significance set at 0.05.@*RESULTS@#(1) Setting time: the initial and final setting time of BG-PB were (7.2±0.3) min and (12.7±0.9) min, respectively. And the initial and final setting time of BG-PB-SA was (7.5±0.3) min and (13.6±1.6) min. There was no significant difference between BG-PB and BG-PB-SA groups (P>0.05). (2) Compressive strength: the compressive strength of BG-PB was (16.5±1.8) MPa at 1 day and (14.1±3.7) MPa at the end of 28 days. However, the compressive strength of BG-PB-SA was (26.6±6.3) MPa on day 1 and (21.6±5.6) MPa on day 28, which was significantly higher than that of BG-PB (P<0.05). (3) pH: the pH of BG pulp capping materials' bulk immersed in simulated body fluid (SBF) went up to 8.06, and the highest pH of MTA was 8.47. Significant difference was observed between the BG pulp capping materials and MTA (P<0.05). (4) Sealing ability: the optical density (D) in positive control group was significantly higher than ln BG-PB, BG-PB-SA and MTA groups (P<0.05). And BG-PB and BG-PB-SA showed the similar favorable sealing ability with MTA, and no significant difference was observed among the three groups (P>0.05).@*CONCLUSION@#The novel BG pulp capping materials showed good physical properties, especially BG's setting time was short; BG pulp capping materials are promising.

Mesoporous nano-bioactive glass microspheres as a drug delivery system of minocycline / 北京大学学报(医学版)

OBJECTIVE@#To construct mesoporous nano-bioactive glass (MNBG) microspheres load-release minocycline as an antibacterial drug delivery system.@*METHODS@#Sol-gel method was used to synthesze MNBG microspheres as drug carrier. The MNBG consisted of SiO2, CaO, and P2O5. According to the content of silicon, MNBG microspheres were divided into four groups (60S, 70S, 80S and 90S). Scanning electron microscopy (SEM) was used to observe the surface characteristic and particle size of MNBG; Nitrogen adsorption-desorption experiment was performed to calculate the MNBG's specific surface area and the pore sizes; The Fourier transform infrared spectrum (FT-IR) and the thermogravimetric analysis were conducted to calculate the loading efficiencies of minocycline hydrochloride; UV spectrophotometric was used to determine the cumulative release of minocycline from drug-loaded particles in PBS solution within 21 d. Agar diffusion test (ADT) was performed to evaluate the antibacterial properties on Enterococcus faecalis. The inhibition zone was observed and the diameter was measured.@*RESULTS@#The MNBG microspheres had good dispersion, large surface area, and even particle size. The pore sizes ranged from 4.77 nm to 7.33 nm. The loading experiment results showed that the minocycline hydrochloride loading efficiency of MNBG was related to the pore size of the microspheres. Among 60S, 70S, 80S and 90S, 60S MNBG had the highest loading efficiency of 16.33% due to its high calcium content and large pore sizes. A slow minocycline release rate from MNBG particles in PBS solution until d 21 was observed. It was showed that a burst release of 28% of the total drug for the first 24 h. A cumulative release of 35% was found, and the final concentration of minocycline maintained at about 47 mg/L. ADT showed that mino-MNBG had inhibitory effect on the growth of Enterococcus faecalis. 1 g/L minocycline, 1 g/L mino-MNBG, and 0.1 g/L minocycline presented inhibition zone, however, PBS and 1 g/L MNBG didn't. The diameter of the inhibition zone of minocycline groups was significant larger than that of mino-MNBG group (P<0.05), which was also significant larger than those of PBS and MNBG groups (P<0.05). It showed that mino-MNBG drug delivery system had antibacterial properties on Enterococcus faecalis.@*CONCLUSION@#The 60S MNBG that can effectively load and release minocycline may be an ideal drug carrier.

Nano-sized bioactive glass enhances osteogenesis of critical bone defect in rabbits / 北京大学学报(医学版)

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.

Effect of bioactive glasses on angiogenic growth factors of human dental pulp cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of bioactive glasses (BG) including 45S5 and nano-58S on proliferation, angiogenic markers vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) secretion and gene expression of human dental pulp cells (HDPC).</p><p><b>METHODS</b>HDPC of 4th passage were cultured in Dulbecco's modified Eagle's medium (DMEM) which contained 0.1 g/L 45S5 or nano-58S ionic dissolution products. Meanwhile HDPC were cultured in DMEM without BG as control group. Proliferation of the cells was evaluated with methyl thiazolyl tetrazolium (MTT) assay on day 1, 2, 3. Quantitative real-time PCR and quantitative sandwich enzyme immunoassays were used to test VEGF and bFGF gene expression and protein secretion of HDPC on day 1, 2, 3.</p><p><b>RESULTS</b>The relative growth rate (RGR) of 45S5 and nano-58S groups were (134.5 ± 5.0)% and (146.3 ± 19.8)%, which was significantly different from that of control group (P < 0.05). The quantity of VEGF secretion of two experimental groups were (189.29 ± 4.64) and (216.18 ± 14.67) ng/L, respectively, significantly higher than that of the control group [(159.03 ± 11.69) ng/L] (P < 0.05). Furthermore, the nano-58S group secreted much more VEGF than 45S5 group (P < 0.05).bFGF secretion of HDPC was also enhanced by both 45S5 and nano-58S bioactive glasses. The VEGF gene expression of 45S5 and nano-58S on day 1 were (1.70 ± 0.19) and (1.63 ± 0.42), while the bFGF gene expressin on day 3 were (1.49 ± 0.02) and (2.30 ± 0.04), all significantly higher than that of control group (P < 0.05).</p><p><b>CONCLUSIONS</b>Bioactive glasses can enhance the proliferation, VEGF and bFGF secretion and gene expression of human dental pulp cells. Compared with 45S5, nano-58S showed a higher activation.</p>

Evaluation of adaptation of root canal filled with three obturation techniques in vitro / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the adaptation of root canal filled with three obturation techniques in vitro.</p><p><b>METHODS</b>Fifty-seven cleaned and shaped premolars were divided into three groups, each group including 10 single root canal premolars and 9 double root canal premolars, and filled respectively with following techniques: GuttaFlow paste with single master cone (GF group), cold lateral compaction technique with AH plus sealer (LC group), warm vertical compaction technique with AH plus sealer (VC group). The roots were invested and sectioned at 1 mm interval from crown to apex using a microtome saw under water cooling. Both surfaces of the sections were digitally photographed and measured using a stereomicroscope. The number of sections with voids and the area of voids were measured and analyzed.</p><p><b>RESULTS</b>The frequency of sections with voids: VC group (21.4%, 76/355) was significantly lower than GF group (47.7%, 173/363) and LC group (52.6%, 190/361), P < 0.0167. There was no significant difference between GF and LC group (P > 0.0167). The percentage of voids area (AV%): GF group was significantly higher than LC and VC group (P = 0.000, P = 0.008). The median of GF group was 2.67, LC group was 1.55, VC group was 1.01. No significant difference between VC and LC group (P = 0.076). The filling quality of isthmus: 86% (85/99) isthmus were well filled in VC, significantly higher than GF group (55%, 43/78) and LC group (58%, 49/84), P < 0.0167. There was no significant difference between GF and LC group (P > 0.0167).</p><p><b>CONCLUSIONS</b>The adaptation of root canal filled with warm vertical compaction technique was superior to cold lateral compaction technique and GuttaFlow technique.</p>

A clinical study on orthodontic treatment after tooth autotransplantation / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the pulp vitality, the periodontal condition and the success rate of autotransplanted teeth after orthodontic treatment.</p><p><b>METHODS</b>A total of 20 permanent teeth (one of them had been treated by root canal therapy), 17 with completely developed roots and 3 with developing roots, were autotransplanted to the region of missing teeth in 16 admitted patients. Orthodontic treatment was carried out in all cases. Clinical and radiographic evaluation of the transplanted teeth was done.</p><p><b>RESULTS</b>The average time of postoperative orthodontic treatment was 1.9 months. In all, one autotransplanted tooth was lost because of periodontal disease during follow-up. Eight autotransplanted ones had positive electric pulp testing (EPT) response. Fifteen out of 20 autotransplanted teeth were surrounded by newly-formed periodontal space with normal size and lamina dura. The numbers of surviving and successful autotransplanted teeth were 19 and 15, respectively, after an average observation period of 24.5 months.</p><p><b>CONCLUSIONS</b>Orthodontic treatment of autotransplanted teeth was acceptable and the pulp vitality of the teeth might be preserved.</p>

Effects of maternal high protein diet on uncoupling protein and carnitine palmityl transferase 1 in offspring of rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of maternal nutritional manipulation on fetal mRNA abundance of uncoupling protein UCP2, UCP3 and carnitine palmityl transferase 1 (CPT1), and find out an optimal maternal diet and targets for pharmacological prevention and treatment of obesity.</p><p><b>METHODS</b>Wistar pregnant rats were assigned to two groups which received a standard diet (SD) and a high protein diet (HPD) during pregnancy, respectively. After delivery, the male offspring were assigned to control group (CON) and high protein group (HP) according to their maternal diet, which were suckled by dams that received SD during pregnancy. Offspring were fed with SD from weaning (week 3) to week 8. Then CON were allocated to two groups: CON (SD during the whole experiment); HFCON (high fat control). HFCON and HP group rats were fed with high-fat diet (HFD) for 6 wk to induce obesity. At 0, 3, 8 and 14 wk of age, blood and tissue were collected for analyzing blood fat and abundance of UCP2, 3 and CPT1 mRNA.</p><p><b>RESULTS</b>In HP body weight and TG were decreased after weaning (F = 4.589, P = 0.039; F = 27.001, P = 0.000) and HFD (F = 16.076, P = 0.00; F = 71.518, P = 0.000). Obesity rates were significantly decreased in HP after HFD (chi2 = 8.076, P = 0.004). The abundance of UCP3 and CPT1 mRNA was persistently higher in HP than in CON or HFCON, and the abundance of UCP2 mRNA was also persistently higher than in CON or HFCON after weaning. Moreover the abundance of CPT1 mRNA was significantly increased after weaning and HFD compared with that after SD, the abundance of UCP2, UCP3 mRNA was also increased after HFD compared with that after SD.</p><p><b>CONCLUSIONS</b>Increasing protein intake during pregnancy might prevent offspring from HFD-induced obesity in adult, moreover might increase offspring the expression of UCP2, UCP3 and CPT1 mRNA. UCP2, UCP3 and CPT1 might participate in prevention and treatment of obesity by mediating fatty acid oxidation.</p>

The anti-respiratory syncytial virus effect of an active compound (AP3) from a Chinese medicinal herb-Herba patriniae in vitro / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the effect on anti-respiratory syncytial virus of an active compound (AP3) from a Chinese medicinal herb-Herba patriniae in vitro.</p><p><b>METHODS</b>Active component of herba patriniae (AP3) was extracted and its anti-respiratory syncytial virus (RSV) effect was tested. A water soluble substance (AP3) was isolated from a Chinese herb Herba patriniae, by hot water extraction, ethol precipitation and gel permeation column chromatography. The cytotoxicity of AP3 was tested by adding it to HeLa cells directly. Its effect against RSV was estimated by CPEI assay while ribavirin was used as positive control.</p><p><b>RESULTS</b>Chemical test showed that the nature of substance AP3 was polysaccharide. The median cytotoxic concentration (TC(50)) of AP3 was 11.45 mg/ml by morphological observation and the median effective concentration (50% effective concentration, EC(50)) of it against replication of the long strain of RSV in HeLa cells was 0.0986 mg/ml. The Therapeutic index (TI = TC(50)/EC(50)) of AP3 was 116.12, much higher than the TI of herba patriniae (AP1) (TI = 59.26) and ribavirin (TI = 53.45). Moreover, AP3 gave a dose-dependent response in inhibiting RSV. In the assay, the effect of AP3 against RSV growth was also tested. In addition, the effect of AP3 on virus growth, AP3 inhibited replication of RSV in HeLa cells, when added at 0 h, 2 h, 4 h after virus infection, were also tested.</p><p><b>CONCLUSION</b>This study suggested that the AP3 exerted an obvious inhibitory effect to RSV in HeLa cell culture. This study furnished a reliable evidence for development of a new antiviral drug.</p>

Effect of chewing sugar-free gum after sucrose challenge on dental plaque pH in situ / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of chewing sugar-free gum after sucrose challenge on dental plaque pH in situ.</p><p><b>METHODS</b>16 healthy volunteers aged 23 - 32 years were screened as subjects. The pH of 48-hour dental plaque was measured using a Beetrode pH microelectrode when subjects chewed Extra sugar-free gum after sucrose challenge.</p><p><b>RESULTS</b>Dental plaque pH maintained at resting plaque pH when immediately chewed sugar-free gum after sucrose challenge. Chewing sugar-free gum at 5 min after sucrose challenge, dental plaque pH was raised from 5.59 (measured at 5 min after sucrose challenge) to 6.98 (measured at 10 min after sucrose challenge).</p><p><b>CONCLUSIONS</b>Chewing sugar-free gum after sucrose challenge can neutralize organic acid produced by bacteria in dental plaque and rapidly rise plaque pH.</p>