One-Way Intestinal Perfusion of PVP/VA-Poloxamer 188-Curcuma longa L. Extract Solid Dispersion in Rats In Vivo and Its Effect on HSC-T6 Cell Proliferation.

Turmeric was the dried rhizome of Curcuma longa L., and its extract had important pharmacological effects such as anti-tumor, cholagogic, and antioxidant. However, curcuma extract had poor water solubility and low bioavailability, which had become the main limiting factor for its clinical application. The purpose of this study was to prepare PVP/VA-Poloxamer-188-curcuma extract solid dispersion (PAP-CSD) to improve the solubility and bioavailability of the curcuma extract. The intestinal absorption mechanism of solid dispersion of this extract was studied by one-way intestinal perfusion in rats. PAP-CSD,PVP/VA-curcuma extract solid dispersion (PA-CSD) and Poloxamer-188-curcuma extract solid dispersion (P-CSD) was able to improve the intestinal absorption of the curcuma extract (P < 0.05), and PAP-CSD (combined use of two carriers) was better than that of PA-CSD and P-CSD. CCK8 method was used to investigate the effects of the curcuma extract and PAP-CSD on the proliferation of hepatic stellate cells (HSC)-T6 cells. The inhibitory effect of PAP-CSD on the proliferation of HSC-T6 cells, related to the p38 MAPK pathway, was better than that of the curcuma extract.

[Permeation mechanism of phenolic acid components from traditional Chinese medicine on PES membrane separation process].

To explore the permeation mechanism of micro-molecule medicinal ingredients of water extract of tradition Chinese medicine(TCM) in membrane separation process. With phenolic acid components as the model solute, five phenolic acids with similar molecular weight and structure, namely gallic acid, protocatechuate acid, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid and salicylic acid, were selected in the PES membrane separation experiments. With the relative flux and the transmission rate as indexes, the scanning electron microscopy(SEM) and the electrochemical impedance spectroscopy(EIS) were used to analyze the permeation mechanism of different phenolic acid components. The results showed phenolic acids with similar molecular weight had different permeation behaviors, with decreased relative flux and increased solute permeation with the increase of solute concentration. According to the permeation behavior analyzed by the molecular structure of solute, the transmission rate of phenolic acids increased with the increase of the number of hydroxyl, and the order of substituent positions of phenolic acids based on the permeation rate as follows: para-substituted > meta-substitution > ortho-substitution. Electrochemical impedance spectroscopy reflected the role of charge repulsion in the membrane process; that is to say, the greater the resistance is, the less the solute permeation is. Therefore, the permeation phenomenon of the phenolic acid components in the PES membrane is not only the result of simple sieving mechanisms, but also has the effects of steric hindrance and charge repulsion during the membrane process.

[Efficient discovery and capturing of nNOS-PSD-95 uncouplers from Trifolium pratense].

Magnetic molecularly imprinted polymers(MMIPs) were prepared with ZL006 as template, acrylamide(AA) as the functional monomer, and acetonitrile as pore-forming agent; then Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscopy(SEM) were used to characterize their forms and structures. Simultaneously, the MMIPs prepared previously were used as sorbents for dispersive magnetic solid phase extraction(DSPE) to capture and identify potential nNOS-PSD-95 uncouplers from extracts of Trifolium pratense and the the activities of the screened compounds were evaluated by the neuroprotective effect and co-immunoprecipitation test. The experiment revealed that the successfully synthesized MMIPs showed good dispersiveness, suitable particle size and good adsorption properties. Formononetin, prunetin and biochanin A were separated and enriched from Trifolium pratense by using the MMIPs as artificial antibodies and finally biochanin A was found to have higher cytoprotective action and uncoupling action according to the neuroprotective effect and co-immunoprecipitation test.

[Preparation and release behaviour of mPEG-PLA α-asarone nanoparticles designed for nasal administration].

Taking α-asarone as model drug, mono methoxy polyethylene glycol-polylactic acid copolymer (mPEG-PLA) as the drug carrier material to prepare drug-loading nanoparticles by premix membrane emulsification for nasal administration. The prepared nanoparticles were spherical with smooth surface and average particle size of 360 nm. Polydispersity index (PDI) was 0. 030, average drug loading of (11.5 ± 0.045) % (n = 3), and the encapsulation efficiency of (86.34 ± 0.11) % (n = 3). X-ray diffraction and differential scanning calorimetry results showed that, α-asarone existed in mPEG-PLA carrier in amorphous or molecular state, different from simple physical mixture. In the in vitro release test in simulated human nasal cavity, α-asarone apis can be released quickly at close to 94% at 102 h, in line with the first-order kinetics (R² = 0.981 9). mPEG-PLA drug-loading nanoparticles release only 54%, with slow release effect, in line with Riger-Peppas model (R² = 0.967 9, n = 0.630 2), for non-fick diffusion, released by the spread of drugs and skeleton dissolution dual control. This provided the foundation for nasal drug delivery in vivo pharmacokinetic study.

[Studies on preparation by SPG membrane emulsification method and in vitro characterization of tetradrine-tashionone II(A)-PLGA composite microspheres].

Tetradrine-tashionone II(A)-PLGA composite microspheres were prepared by the SPG membrane emulsification method, and the characterization of tetradrine-tashionone II(A) -PLGA composite microspheres were studied in this experiment. The results of IR, DSC and XRD showed that teradrine and tashionone II(A) in composite microspheres were highly dispersed in the PLGA with amorphous form. The results of tetradrine-tashionone II(A) -PLGA composite microspheres in vitro release experiment showed that the cumulative release amounts of tetradrine and tashionone II(A) were 6.44% and 3.60% in 24 h, and the cumulative release amounts of tetradrine and tashionone II(A) were 89.02% and 21.24% in 17 d. The process of drug in vitro release accorded with the model of Riger-Peppas. Tetradrine-tashionone II(A) -PLGA composite microspheres had slow-release effect, and it could significantly reduce the burst release, prolong the therapeutic time, decrease the dosage of drugs and provide a new idea and method to prepare traditional Chinese medicine compound.

[Preparation and characterization of tetrandrine-loaded PLGA nanocomposite particles by premix membrane emulsification coupled with spray-drying method].

For effective inhalable dry-powder drug delivery, tetrandrine-PLGA (polylactic-co-glycolic acid) nanocomposite particles have been developed to overcome the disadvantages of nanoparticles and microparticles. The primary nanoparticles were prepared by using premix membrane emulsification method. To prepare second particles, they were spray dried. The final particles were characterized by scanning electron microscopy (SEM), dry laser particle size analysis, high performance liquid chromatography (HPLC), X-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared analysis (IR) and confocal laser scanning microscope (CLSM). The average size of the primary particles was (337.5 ± 6.2) nm, while that second particles was (3.675 ± 0.16) µm which can be decomposed into primary nanoparticles in water. And the second particles were solid sphere-like with the drug dispersed as armorphous form in them. It is a reference for components delivery to lung in a new form.

[In vitro and in vivo study of fluorescent probe PLGA particles prepared by premix membrane emulsification method].

Relatively uniform-sized nanoparticles made of poly (lactic-co-glycolic acid) (PLGA) were prepared by premix membrane emulsification method. After the drug loading property was completed, the dynamic tissue distribution of nanoparticles was recorded. With the average particle size and span as indexes, membrane pore size, number of passing membrane times, membrane pressure, volume ratio of oil-water phase and the concentration of poly(vinyl alcohol) (PVA) in external water phase were investigated by single factor test, the optimum preparation technology of blank PLGA nanlparticles was as following: pore size of SPG membrane was 1 µm, membrane pressure was 1. 15 MPa, the number of passing membrane time was 3, the mass fraction of PVA of 2%, volume ratio of oil-water phase of 1 : 5. Prepared nanoparticles were round with smooth surface, the mean diameter was 332.6 nm, span was 0.010, the confocal laser scanning microscope (CLSM) concluded that fluorescent substance is uniform composizion in PLGA nanoparticle, and the in vivo imaging technology in mice include that the nanoparticles show good liver and spleen targeting property.

[Optimization theory and practical application of membrane science technology based on resource of traditional Chinese medicine residue].

Resource of traditional Chinese medicine residue is an inevitable choice to form new industries characterized of modem, environmental protection and intensive in the Chinese medicine industry. Based on the analysis of source and the main chemical composition of the herb residue, and for the advantages of membrane science and technology used in the pharmaceutical industry, especially membrane separation technology used in improvement technical reserves of traditional extraction and separation process in the pharmaceutical industry, it is proposed that membrane science and technology is one of the most important choices in technological design of traditional Chinese medicine resource industrialization. Traditional Chinese medicine residue is a very complex material system in composition and character, and scientific and effective "separation" process is the key areas of technology to re-use it. Integrated process can improve the productivity of the target product, enhance the purity of the product in the separation process, and solve many tasks which conventional separation is difficult to achieve. As integrated separation technology has the advantages of simplified process and reduced consumption, which are in line with the trend of the modern pharmaceutical industry, the membrane separation technology can provide a broad platform for integrated process, and membrane separation technology with its integrated technology have broad application prospects in achieving resource and industrialization process of traditional Chinese medicine residue. We discuss the principles, methods and applications practice of effective component resources in herb residue using membrane separation and integrated technology, describe the extraction, separation, concentration and purification application of membrane technology in traditional Chinese medicine residue, and systematically discourse suitability and feasibility of membrane technology in the process of traditional Chinese medicine resource industrialization in this paper.

[Experimental study of repairing femoral bone defects with nHA/RHLC/PLA scaffold composite with endothelial cells and osteoblasts in canines].

OBJECTIVE: To explore whether a tissue-engineered construct composed of autogenous endothelial cells, osteoblasts and a new bioresorbable nano-hydroxyapatite/recombinant human-like collagen/polylactic acid (nHA/RHLC/PLA) would enhance bone regeneration and repair femoral head defects in canine models. METHODS: The bone marrow stem cells (BMSCs) were isolated from bone marrow of canine ilium and cultured in Dulbecco's modified eagle medium:nutrient mixture F-12 culture media for 1 week and the second-generation BMSCs were further induced by osteogenic medium (1×10(-8) mol/L dexamethasone, 10 mmol/L B-sodium glycerophosphate and 50 µg/ml vitamin C) and by endothelial cell grow medium (vascular endothelial growth factor and basic fibroblast growth factor) for 14 days in vitro. Thus BMSCs were induced into ECs and OBs. After the second passage, cells were digested and collected.And cell density was adjusted to 1.0×10(6)/ml.The cells and nHA/RHLC/PLA scaffold were co-cultured for 2-4 hours then nHA/RHLC/PLA scaffold composites prepared. Cavity defects of 8 mm in diameter and 10 mm in height were made in femoral heads.The nHA/RHLC/PLA scaffold composited with ECs and osteoblasts (OBs) (group A) and composited with OBs (group B) were inserted into different defects while cell-free nHA/RHLC/PLA scaffold served as controls (group C). New bone formation and defect repair were evaluated at 3 and 6 months by radiographic examination, histology and bone histomorphometry. RESULTS: New bone formation was evident as early as 3 months in groups A, B and C.At 6 months, abundant bone tissue within defects was observed in group A. The control animals with cell-free scaffold showed less bone formation at both timepoints.The scaffold of nHA/RHLC/PLA was degraded and absorbed gradually with the formation of new bone tissues.Histology and bone histomorphometry further revealed significantly increased trabecular bones in group A compared with groups B and C at 6 months postimplantation (P < 0.01). CONCLUSION: More abundant new bone tissue may be found in the bone defect areas implanted with osteoblast-endotheliocyte composite than osteoblasts composite and scaffold materials only.ECs and osteoblasts derived from BMSC are ideal seed cells for repairing femoral head defects.

[Pollution prevention and control of aqueous extract of astragali radix processed with ZrO2 inorganic ceramic membrane micro-filtration].

OBJECTIVE: To study the measures for preventing and controlling the pollution of aqueous extract of Astragali Radix proceeded with inorganic ceramic membrane micro-filtration, in order to find effective measures for preventing and controlling the membrane pollution. METHOD: The resistance distribution, polymer removal and changes in physical and chemical parameters of the zirconium oxide film of different pore diameters were determined to analyze the state or location of pollutants as well as the regularity of formation. Meanwhile, recoil and ultrasonic physical measures were adopted to strengthen the membrane process, in order to explore the methods for preventing and controlling the membrane pollution. RESULT: When 0.2 microm of ZrO2 micro-filtrated aqueous extract of Astragali Radix, the rate of pollution was as high as 44.9%. The hole blocking resistance and the concentration polarization resistance were the main filtration resistances, while the surface deposit resistance decreased with the increase in the membrane's hold diameter; after micro-filtration, the liquid turbidity significantly reduced, with slight changes in both pH and viscosity. The 0.2 microm ZrO2 micro-filtration membrane performed better than the 0.05 microm pore size membrane in terms of conductivity. The 0. 2 microm and 0.05 microm pore diameter membranes showed better performance in the removal of pectin. The ultrasonic measure to strengthen membranes is more suitable to this system, with a flux rate up by 41.7%. CONCLUSION: The membrane optimization process adopts appropriate measures for preventing and controlling the membrane pollution, in order to reduce the membrane pollution, recover membrane performance and increase filtration efficiency.

Preclinical characteristics of the hepatitis C virus NS3/4A protease inhibitor ITMN-191 (R7227).

Future treatments for chronic hepatitis C virus (HCV) infection are likely to include agents that target viral components directly. Here, the preclinical characteristics of ITMN-191, a peptidomimetic inhibitor of the NS3/4A protease of HCV, are described. ITMN-191 inhibited a reference genotype 1 NS3/4A protein in a time-dependent fashion, a hallmark of an inhibitor with a two-step binding mechanism and a low dissociation rate. Under preequilibrium conditions, 290 pM ITMN-191 half-maximally inhibited the reference NS3/4A protease, but a 35,000-fold-higher concentration did not appreciably inhibit a panel of 79 proteases, ion channels, transporters, and cell surface receptors. Subnanomolar biochemical potency was maintained against NS3/4A derived from HCV genotypes 4, 5, and 6, while single-digit nanomolar potency was observed against NS3/4A from genotypes 2b and 3a. Dilution of a preformed enzyme inhibitor complex indicated ITMN-191 remained bound to and inhibited NS3/4A for more than 5 h after its initial association. In cell-based potency assays, half-maximal reduction of genotype 1b HCV replicon RNA was afforded by 1.8 nM; 45 nM eliminated the HCV replicon from cells. Peginterferon alfa-2a displayed a significant degree of antiviral synergy with ITMN-191 and reduced the concentration of ITMN-191 required for HCV replicon elimination. A 30-mg/kg of body weight oral dose administered to rats or monkeys yielded liver concentrations 12 h after dosing that exceeded the ITMN-191 concentration required to eliminate replicon RNA from cells. These preclinical characteristics compare favorably to those of other inhibitors of NS3/4A in clinical development and therefore support the clinical investigation of ITMN-191 for the treatment of chronic hepatitis C.

The effect of polyethylene glycol recombinant human growth hormone on growth and glucose metabolism in hypophysectomized rats.

OBJECTIVE: To study the effect of polyethylene glycol recombinant human growth hormone on growth and glucose metabolism in hypophysectomized rats, and compare the effect of treatment between recombinant human growth hormone (rhGH) and polyethylene glycol rhGH (PEG-rhGH). METHODS: Hypophysectomy was performed in juvenile rats to build the animal model of GH deficiency. The hypophysectomized animals were randomly assigned into three groups and treated with saline (negative control, n=20), rhGH (n=20) and PEG-rhGH (n=20). A sham operation was performed to set up the normal control (n=20). Body weight, body length and tail length were recorded every 2days for a 14-day treatment and bone growth was measured at the end of therapy. Glucose infusion rate (GIR) determined by euglycemic hyperinsulinemic clamp was used to evaluate insulin sensitivity after GH treatment. We also examined plasma glucose and serum insulin levels RESULTS: Compared with the negative control, the body weight, body length, tail length and bone growth increased significantly in hypophesectomized rats treated by GH (P<0.01). Although the weight gain in the first 10days was higher in the PEG-rhGH group than in the rhGH group (P<0.05), the growth promoting effect was similar between rhGH and PEG-rhGH (P>0.05). Neither rhGH nor PEG-rhGH impaired glucose tolerance of rats after hypophesectomy. Compared with negative controls, according to decreased serum insulin, reduced insulin expression in pancreatic cells and increased GIR in the clamp, both rhGH and PEG-rhGH groups had improved insulin sensitivity within 14 days (P<0.01). However, with prolonged treatment, the GIR in the rhGH-treated rats decreased significantly (P<0.05); while PEG-rhGH did not interfere with GIR, even after a doubled dose (P>0.05). CONCLUSIONS: PEG-rhGH had the same linear growth promoting efficacy as unmodified rhGH. The short-term GH replacement could improve insulin sensitivity in hypophysectomized rats, especially after PEGylation.

Alprostadil liposome microsphere preparation stabilizes vascular plaques and inhibits intra-plaque inflammation.

BACKGROUND: Vulnerable plaques play an important role in the onset of sudden cardiac events and strokes. How to stabilize vulnerable plaques is still a challenge to medical science. Alprostadil is a biologically active substance with strong activity on vessel. Our study assessed the stabilizing effects of an alprostadil liposome microsphere preparation (ALMP) on vulnerable plaques in the brachiocephalic artery of apolipoprotein E (Apo E) knockout mice. METHODS: Seventy-two male Apo E-knockout mice were fed a high-fat diet beginning at eight weeks of age. At week 17, they were divided randomly into groups for treatment with a high dose (3.6 µg×kg(-1)×d(-1)) or low dose (1.8 µg×kg(-1)×d(-1)) of an ALMP, or 0.2 ml/d normal saline (control group). The drug was administered using a micro-capsule pump. Twenty weeks after drug administration, pathological changes in the vulnerable plaques within the brachiocephalic artery were assessed, and levels of anti-mouse monocyte/macrophage monoclonal antibody (MOMA-2) and superoxide anions in the plaques were detected using immunofluorescence. The soluble intercellular adhesion molecule-1 (ICAM-1) expression was measured by ELISA, and the expression of matrix metalloproteinase-9 (MMP-9) and CD40 mRNA was measured using RT-PCR. Thrombospindin-1 (TSP-1) expression was detected using Western blotting. RESULTS: Compared with the control group, ALMP treatment significantly reduced the plaque area in the brachiocephalic artery (P < 0.01), significantly lowered the contents of the lipid core (P < 0.01), significantly reduced the number of ruptured fibrous caps (P < 0.05), and increased the thickness of the fibrous cap and significantly reduced the incidence of intra-plaque hemorrhage (P < 0.05). ALMP treatment significantly reduced the expression of MOMA-2, superoxide anion, MMP-9, ICAM-1 and CD40 in the plaques (P < 0.01), decreased plasma ICAM-1 expression (P < 0.01), and increased the expression of TSP-1. CONCLUSIONS: Treatment with ALMP can stabilize vulnerable plaques by inhibiting inflammation.

Feasibility study of high-temperature thermoseed inductive hyperthermia in melanoma treatment.

Current treatment modalities for melanoma do not offer satisfactory efficacy. We have developed a new, minimally invasive hyperthermia technology based on radio-frequency hyperthermia. Herein, we investigated the feasibility of using a nickel-copper thermoseed for inductive hyperthermia at a relatively high temperature (46-55 ˚C). In vitro, the thermoseed showed good thermal effects and effective killing of B16/F10 melanoma cells. Temperatures of 53.1 ± 0.5 ˚C were achieved for a single thermoseed and 56.5 ± 0.5 ˚C for two in parallel (spacing 5 mm). No B16/F10 melanoma cells survived with heating time longer than 20 min in the parallel thermoseed group. Magnetic fields or thermoseeds alone did not affect the survival rate of B16/F10 cells (P>0.05). In vivo, B16/F10 melanoma cells were subcutaneously injected into the right axilla of C57BL/6 mice. After the tumors grew to ~11-13 mm, two thermoseeds (spacing 5 mm) were implanted into the tumors and the mice were subjected to an alternating magnetic field (100-250 kHz, 15 kA/m) to induce hyperthermia. The temperature at the center of the tumor reached 46 ˚C at 5 min and plateaued at 50 ˚C. Thermoseed treatment produced large necrotic areas, inhibited tumor growth in 60% (6 of 10) of animals and prolonged survival time (P<0.05). Thus, with further optimization and testing, high-temperature thermoseed inductive hyperthermia may have therapeutic potential for melanoma.

[Diffraction enhanced imaging of condylar cartilage of osteoarthritic rats].

OBJECTIVE: To observe the images of early lesions of condylar cartilage of osteoarthritic rats in synchrotron radiation diffraction enhanced imaging (DEI). METHODS: The animal model of temporomandibular joint osteoarthrosis was established in rat following the method of partial resection of the joint disc. The changes of osteoarthritic condylar cartilage in different pathological stages were observed by DEI and compared with those in situ histopathological sections. RESULTS: With DEI, straight and orbicular lines were detected in condylar cartilage 45 to 60 days after discs resection. The lines were confirmed by histopathology to be collagen degradation and tiny fissure formation inside the cartilage. CONCLUSIONS: DEI is capable of imaging the early stages of pathological changes of excised condylar cartilage such as collagen degradation and tiny fissure formation, and this technique is of potential value to clinical application.

[An epidemiological investigation of deciduous dental caries among 5375 preschool children aged between 3 to 6 years in Shenyang City].

PURPOSE: To investigate the status of dental caries of deciduous teeth among preschool children in Shenyang city. METHODS: According to the criteria recommended by the World Health Organization and The Second National Oral Health Investigation, the deciduous caries of 5375 preschool children aged from 3 to 6 years were clinically examined. The mean dmft and the prevalence of dental caries for each age group were calculated. The results were analyzed using SPSS11.0 software package for t test (to compare the difference between the two sample groups), one way ANOVA (to compare the differences among three and more sample groups) and chi2 test (to compare the rate of each group). RESULTS: The prevalence of dental caries was 71.29%. The mean dmft score was 3.88. The prevalence of dental caries and mean dmft increased gradually as the children were growing up (P < 0.05).Dental caries of the upper teeth was significantly more common than that of the lower teeth (P < 0.01). Most caries were minor in degree of severity, and mostly lie in the occlusal and proximal surface. The filling rate was 10.82%.As the age increase, the filling rate increased, too. CONCLUSION: Deciduous dental caries of preschool children was an important problem in Shenyang city, and the filling rate was very low. Necessary methods for early prevention of dental caries must be taken into consideration. Supported by Scientific Research Fund for College and University from Liaoning Provincial Education Bureau (Grant No. 20201316).

[Study of caries polarization in 2-5 year-old children of Shenyang, China].

OBJECTIVE: To investigate dental caries polarization in 2-5 year-old children. METHODS: 3 799 random samples of 2-5 year-old children from attending kindergarten in Shenyang were selected. Means of dmft index and SiC index for each age group were calculated by WHO Collaborating Center. The subjects of each age group were further divided into subgroups of different level of dmft: the dmft of subgroup I was 0, the dmft of subgroup II was 1, the dmft of subgroup III was 2, the dmft of sub-group IV was equal to or more than 3. The obtained data were analyzed statistically with SPSS 10.0. RESULTS: 4.5% of 2-year-old children were carriers of 60.0% of the total dmft in that age group, 13.2% of 3-year-old children were carriers of 69.4% of the total dmft in that age group, 34.4% of 4-year-old children were carriers of 86.6% of the total dmft in that age group, and 47.8% of 5-year-old children were carriers of 89.8% of the total dmft of that age group. CONCLUSION: This study supports the assertion that a small percentage of persons with high dental caries rate and a large percentage of caries-free persons of early childhood caries.

[Development and study of three-dimensional CT scanning system for dental cast measurement and analysis].

OBJECTIVE: To develop a computer assisted CT scanning system for 3D dental cast measurement and to study its reliability. METHODS: 20 dental stone casts were scanned by helical CT and captured a series digital sliced radiographs of them. The program which was developed by Visual C 6.0 language and run under the Windows surroundings rebuilt the 3D graphics and measured the coordinate of the dental cast. These dental casts were scanned and measured to test the reliability of the system, contrasting with manual measurement. RESULTS: There was no significant difference between 3D CT scanning and manual measurement (P > 0.05). CONCLUSION: The system is a valuable computer assisted system for clinical diagnosis and treatment of malocclusion.

[Fluoride concentration in saliva after use of fluoride varnish].

OBJECTIVE: The purpose of this vivo study was to compare fluoride concentration in saliva of patients treated with fluoride varnish and fluoride solution. METHODS: 20 5-year-old children were selected and divided into fluoride varnish and fluoride solution groups. The samples of unstimulated whole saliva were collected at base-line before and after 0.25h,0.5h,1h,2h,6h,12h,24h treatment with fluoride varnish and fluoride solution. Saliva fluoride concentrations were measured using an ion-specific electrode. RESULTS: After 0.25h,0.5h,1h,2h,6h treatment with fluoride varnish, the values of salivary fluoride concentration were higher than baseline,the values of fluoride varnish group were higher than those in fluoride solution group after 0.5h to 6h. CONCLUSION: Compared with fluoride solution, fluoride varnish maintained a longer time of high salivary fluoride concentration.

[An epidemiological survey on fusion of deciduous teeth of 4286 kindergarten children in Shenyang city].

OBJECTIVE: To clarify the occurrence and distribution of the fusion of deciduous teeth in Shenyang. METHODS: By using cross-sectional study, 4286 children were examined, who aged from 2 to 6 years in 37 kindergartens. RESULTS: Of 4286 children investigated, fusion of the deciduous teeth were detected in 65 children (1.52 percent) without sex predilection. The fused teeth typically occurred unilaterally (68.75 percent), and mainly located in the anterior region, more frequently in the mandibular (91.25 percent) than that in the maxillary arch. 12 cases were bilaterally symmetrical (18.46 percent). Two rare cases were found with fused teeth, one occurred in central incisor, lateral incisor and canine, the other occurred between two molars with two incisors fused in the same side. Fused teeth in two cases had caries. CONCLUSION: The occurrence of the fused teeth may cause some complications. Pediatric dentists should pay attention to the fused teeth occurred in preschool children.