Newborn screening for Citrin deficiency and molecular characteristics of SLC25A13 variants in Guangzhou population / 中华实用儿科临床杂志

Objective:To investigate the sensitivity of newborn screening for neonatal intrahepatic cholestasis caused by Citrin deficiency (NICCD) based on tandem mass spectrometry and the carrying rate of known pathogenic variants of SLC25A13 in Guangzhou population. Methods:A total of 124 250 neonates born in Guangzhou from January 1, 2015 to December 31, 2018 were performed newborn screening for NICCD by tandem mass spectrometry technology. SLC25 A13 gene mutation analysis was performed to diagnose patients with suspected NICCD.The carrying rate of known pathogenic variants of the SLC25 A13 gene in the whole exon sequencing results of 2 395 healthy children in Guangzhou was retrospective analyzed. Results:Among the 124 250 screened neonates, 31 cases were screened positive for NICCD and one of them was confirmed.Three false negative patients with NICCD were found in this cohort.NICCD screening sensitivity was 25%(1/4 cases). All of the four patients were homozygous for c. 851_854del of SLC25A13.Among 2 395 controls, 60 cases were detected heterozygous variant of SLC25A13, including 8 kinds of reported pathogenic variants.The carrying rate of pathogenic alleles was 1/40 (60/2 395 cases). The estimated prevalence of citrin deficiency was about 1/6 400.The most common variant was c. 851_854del (56.7%, 34/60 cases), and the second was c. 790G>A (23.3%, 14/60 cases). The controversial variant c. 2T>C was detected in 113 children with heterozygous and 2 cases with homozygous and the carrying rate of c. 2T>C was 1/20(117/2 395 cases). Conclusions:The carrying rate of pathogenic variants of SLC25A13 and the estimated prevalence of Citrin deficiency in Guangzhou population are high.The sensitivity of newborn screening for NICCD by tandem mass spectrometry is limited.Even if the negative results for screening of multiple genetic and metabolic diseases by tandem mass spectrometry, it is recommended to recheck blood for newborns or infants with delayed jaundice to avoid missed diagnosis.

Newborn screening program and blood amino acid profiling in early neonates with citrin deficiency / 中华儿科杂志

Objective@#To investigate the profiles of blood amino acid and acylcarnitine in early neonates with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and the sensitivity of newborn screening, and to explore potential biochemical metabolic markers for newborn screening program.@*Methods@#Amino acid and acylcarnitine profiles in dried blood spots of newborn screening program were analyzed by tandem mass spectrometry (MS/MS). A total of 158 651 neonates born in Guangzhou from January 1, 2015 to June 30, 2019 were enrolled in this newborn screening program, and additionally 55 patients with NICCD confirmed by SLC25A13 gene analysis in Guangzhou Women and Children Medical Center were included in this study. NICCD screen-positive was defined as the cutoff value of citrulline (Cit) ≥ 30 μmol/L. The values of blood sampling time of the true positive group and those of the false negative group were compared by t-test. The levels of amino acid and acylcarnitine among different groups, including true positive group (Cit≥30 μmol/L), false negative group (Cit 21-<30 μmol/L and Cit<21 μmol/L) and the normal control group, were analyzed by F test, respectively.@*Results@#Among 158 651 neonates, 39 neonates were positive for NICCD screening. Three of them were confirmed NICCD and 4 cases were found to be false negatives. The positive predictive value was 7.7% and the sensitivity was about 43.0%. Among 55 patients with NICCD, 18 cases (18/55, 32.7%) were true positives and 37 cases (37/55, 67.3%) were false negatives based on the cutoff value of citrulline in the dried blood spots for newborn screening. The blood sampling time was significantly different between true positive group and false negative group ((4.28±1.6) vs. (2.98±0.74) d, t=4.06, P<0.01). The increased levels of tyrosine((176.0±98.4) μmol/L), methionine ((37.0±26.9) μmol/L) and phenylalanine ((133.0±80.9)μmol/L) in Cit≥30 μmol/L group (n=18) were significantly different as compared with those in the other three groups, respectively (F=117.0, 58.5, 135.0, P<0.01). The levels of arginine ( (10.0±9.2) , (11.0±9.3) , (9.0±17.8) μmol/L), valine ( (119.0±29.8) , (107.6±14.1) , (102±68) μmol/L) and leucine ( (167.0±37.1) , (161.0±37.7) , (163.5±180.6) μmol/L) were not statistically significant among groups of Cit≥30 μmol/L(n=18), Cit21-<30 μmol/L(n=7) and Cit<21μmol/L(n=30,P>0.05), but they were significantly higher than those of the normal control group ((4±3), (78±21), (114.0±31.5) μmol/L, n=1 000), respectively(F=30.1, 23.0, 29.8, P<0.01). Alanine (Ala) ( (150±50) , (156.0±30.2), (168±105), (152±52) μmol/L) levels showed no significant difference (F=0.86, P>0.05) but the ratios of Ala/Cit (1.52±1.44, 6.82±1.56, 12.06±7.71, 19.42±6.27) decreased significantly among the four groups (F=69.0, P<0.05). The acylcarnitine levels showed no statistically significant results among the different groups (P>0.05). With Cit≥30 μmol/L and Ala/Cit<7.5 as cutoff values, the number of screen-positive cases reduced from 39 to 22 cases with no additional false negative case. With Cit≥21 μmol/L and Ala/Cit<7.5 as cutoff values the number of screen-positive cases increased to 117 cases with 1 additional true positive.@*Conclusions@#The profiles of blood amino acid in early neonates with NICCD present the increased levels of multiple amino acids including citrulline, tyrosine, methionine and phenylalanine, and decreased ratio of Ala/Cit. Taking citrulline and ratio of Ala/Cit as screening markers can improve the positive predictive value appropriately. The limited sensitivity of NICCD newborn screening may be related to early blood sampling time.

DUOX2 hotspots variants and outcomes of patients with congenital hypothyroidism suspected thyroid dyshormonogenesis / 中华实用儿科临床杂志

Objective To investigate prospectively molecular and clinical characteristics of infants with congenital hypothyroidism (CH) caused by DUOX2 mutations in Guangzhou.Methods A population-based cohort of 83patients with CH were recruited based on newborn screening results among 108 899 newborns who were born in Guangzhou between April 1 and September 30 in 2015.Genetic analysis of DUOX2 hotspots(including 11 exons) by PCR-direct sequencing was performed in 52 patients with suspected thyroid dyshormonogenesis (SDH) according to thyroid ultrasound at diagnosis.All the patients were followed up for 3 years.The data of this cohort study(prevalence of CH,detection rate of DUOX2,clinical features) were compared with those of 96 patients with SDH in 2011-2012.Results (1) The incidence of CH in 2015 was 1 ∶ 1 312,and 73.5％ (61/83 cases) of CH patients were classified as SDH.Compared with those founded in 2011-2012,the incidence of CH was increased (1 ∶ 1 312 vs.1 ∶ 2 779),and the difference was significant (P ＜ 0.001),while the frequency of SDH was not different significantly (73.5 ％ vs.76.6％,P =0.593).(2) There were 27 cases (51.9％) with SDH detected DUOX2 hotspots variants,including 6 cases with biallelic variants,21 cases with monoallelic variants,and 1 possible new pathogenic variant p.S1091F.The p.K530X was the most common mutation accounting for 51.5％ (17/33 cases) detected allelic and involving in 16 cases (30.8％) with SDH.Novel p.S1091F variant was probably damaging variant.Both detected rate and spectrum of DUOX2 variant were not significantly different compared with those in 2011-2012 (all P ＞ 0.05).(3) There were no significant differences in the levels of thyrotropin (bsTSH),serum TSH (sTSH),free thyroxine (FT4) and thyroglobulin in neonates with dry blood spot at diagnosis between children with DUOX2 and without DUOX2 variants cases (all P ＞ 0.05).Among 27 cases,24 (88.9％) patients with DUOX2 mutation were transient CH,and 3 cases were permanent CH.Conclusions The incidence of CH was increased in last few years in Guangzhou.Most of them were SDH,and 51.9％ of SDH cases had DUOX2 hotspots variants.Temporary CH is the main clinical outcome.The p.K530X was the most common mutation in this cohort population.

DUOX2 hotspots variants and outcomes of patients with congenital hypothyroidism suspected thyroid dyshormonogenesis / 中华实用儿科临床杂志

Objective@#To investigate prospectively molecular and clinical characteristics of infants with congenital hypothyroidism (CH) caused by DUOX2 mutations in Guangzhou.@*Methods@#A population-based cohort of 83 patients with CH were recruited based on newborn screening results among 108 899 newborns who were born in Guangzhou between April 1 and September 30 in 2015.Genetic analysis of DUOX2 hotspots(including 11 exons)by PCR-direct sequencing was performed in 52 patients with suspected thyroid dyshormonogenesis (SDH) according to thyroid ultrasound at diagnosis.All the patients were followed up for 3 years.The data of this cohort study(prevalence of CH, detection rate of DUOX2, clinical features) were compared with those of 96 patients with SDH in 2011-2012.@*Results@#(1) The incidence of CH in 2015 was 1∶1 312, and 73.5%(61/83 cases) of CH patients were classified as SDH.Compared with those founded in 2011-2012, the incidence of CH was increased (1∶1 312 vs.1∶2 779), and the difference was significant (P<0.001), while the frequency of SDH was not different significantly (73.5%vs.76.6%, P=0.593). (2)There were 27 cases(51.9%) with SDH detected DUOX2 hotspots variants, including 6 cases with biallelic variants, 21 cases with monoallelic variants, and 1 possible new pathogenic variant p. S1091F.The p. K530X was the most common mutation accounting for 51.5%(17/33 cases) detected allelic and involving in 16 cases (30.8%) with SDH.Novel p. S1091F variant was probably damaging variant.Both detected rate and spectrum of DUOX2 variant were not significantly different compared with those in 2011-2012 (all P>0.05). (3) There were no significant differences in the levels of thyrotropin (bsTSH), serum TSH (sTSH), free thyroxine (FT4) and thyroglobulin in neonates with dry blood spot at diagnosis between children with DUOX2 and without DUOX2 variants cases(all P>0.05). Among 27 cases, 24(88.9%) patients with DUOX2 mutation were transient CH, and 3 cases were permanent CH.@*Conclusions@#The incidence of CH was increased in last few years in Guangzhou.Most of them were SDH, and 51.9% of SDH cases had DUOX2 hotspots variants.Temporary CH is the main clinical outcome.The p. K530X was the most common mutation in this cohort population.

Evaluations of newborn screening program performance and enzymatic diagnosis of glucose-6-phosphate dehydrogenase deficiency in Guangzhou / 中华儿科杂志

Objective@#To reveal the molecular epidemiologic characteristics of glucose-6-phosphate dehydrogenase (G6PD) gene and to evaluate based on the genetic analysis the newborn screening program performance and enzymatic diagnosis of G6PD deficiency in Guangzhou.@*Methods@#G6PD enzyme activities were measured by quantitative fluorescence assay in dry blood spots of 16 319 newborns(8 725 males, 7 594 females) 3-7 days after birth in Guangzhou Newborn Center. They were born in Guangzhou form Oct. 1 to 20, 2016. The cutoff value of G6PD was less than 2.6 U/g Hb in dry blood spots. G6PD deficiency was diagnosed when G6PD<1 700 U/L or G6PD/6PGD<1 in red blood cells. Genetic analysis of G6PD gene was performed on the dry blood spot samples of 823 newborns (including positive 346, negative 477)with various levels of G6PD enzyme activities through fluorescence PCR melting curve analysis(FMCA) to detect 15 kinds of mutations reported to be common among Chinese.G6PD gene Sanger sequency was performed in seven highly suspicious patients with negative results by FMCA.@*Results@#(1) Using the cutoff value of G6PD< 2.6 U/g Hb , a total of 687(4.2%) newborns showed positive screening results, including 560 (6.4%) males and 127(1.7%) females. (2) Among the newborns with positive screening results, 214 males and 122 females were randomly chosen for G6PD gene analysis. The results showed that 197 (92.1%) males were hemizygote and 108(88.6%) females were mutation carriers with one to four alleles. Among the newborns with negative screening results, 41 males with G6PD 2.6-2.8 U/g Hb and 436 females with G6PD 2.6-4.5 U/g Hb were chosen for genetic analysis.Mutations were detected in 5(12.2%)boys, and 226(51.8%) girls were carriers.G6PD gene Sanger sequency of seven highly suspicious patients showed that c.406C>T, c.551C>T, c.835A>T hemizygote were found in 3 male's samples, respectively. (3) The estimated prevalence of harboring mutation was 6.0% in males and 13.5% in females according to rates of mutation in samples with various levels of G6PD enzyme activities. Six common mutations were c.1388G>A、c.1376G>T, c.95A> G, c.871G>A, c.1024C>T, c.392G>T, accounting for 95.5% of detected alleles .(4) based on results of G6PD gene analysis, the newborn scereening of G6PD deficiency with cutoff value G6PD<2.6 U/g Hb yielded a positive predict value(PPV) of 93.5%, a false-positive rate of 0.5%, and a sensitivity of 99.0% for males. A PPV of 88.5%, a false-positive rate of 0.2% . The prevalence of severe type G6PD deficiency in females was about 1.5%. Compared with to genetic analysis, the sensitivity and PPV of G6PD activity assay in red blood cells were 95.5%, 97.2%, respectively.@*Conclusions@#The prevalence of G6PD deficiency in males was 6.0% in Guangzhou. Six mutations c.1388G>A, c.1376G>T, c.95A>G, c.871G>A, c.1024C>T, c.392G>T accounted for 95.5%. The cutoff value of G6PD<2.6 U/g Hb innewborn screening program and the criteria of biochemical diagnosis could accurately identify G6PD deficiency . Combined with biochemical and molecular analysis will improve the accuracy of diagnosis of G6PD deficiency and detect more heterozygous females.

Discussion on teaching reform of orthodontics with the fusion of aesthetics principle / 中华医学教育探索杂志

Aiming at the new problems in orthodontics teaching and employment,this study aims to explore a more suitable undergraduate teaching mode of Orthodontics,and reform the teaching of Orthodontics for five-year program students in department of stomatology of Xi'an Medical University.During the teaching of Orthodontics,teachers use the aesthetic principles that students have learned to integrate into the orthodontics teaching,and guide students to analyze,understand and master orthodontic knowledge based on the principles of aesthetics.After the course,students give good feedback on the teaching reform,and their scores of basic knowledge and case analysis of Orthodontics theoretical examination have been improved.This teaching reform is very helpful for students to learn,understand and master the knowledge of orthodontics.It helps to improve classroom teaching effect,improve students' interest in learning,and adapt to the needs of discipline and industry development,so it is worth studying and promoting.

Genetic analysis of TPO, DUOX2 and DUOXA2 genes in children with permanent congenital hypothyroidism suspected dyshormonogenesis / 中华儿科杂志

Objective@#To explore the TPO, DUOX2 and DUOXA2 genotypes and phenotypes of children with permanent congenital hypothyroidism(PCH) suspected dyshormonogenesis in Guangzhou, identified and treated at Guangzhou Newborn Screening Center. Six of them were born between 2011 and 2012.@*Method@#Retrospectively analyzed the clinical data of 9 children with PCH suspected dyshormonogenesis. Genetic analysis of TPO, DUOX2 and DUOXA2 genes were performed with Sanger sequencing.@*Result@#Of the 9 patients, four were identified variants in TPO gene including three cases with biallelic variants and one case with monoallelic variant. Novel c. 1784G>C( p. R595T) variant in TPO was predicted to be damaging by SIFT and PolyPhen-2. Four patients harbored monoallelic known variants in DUOX2 gene and the other one harbored heterozygous known mutation c. 738C>G(p.Y246X) in DUOXA2 gene.Two adolescent patients with biallelic variants in TPO gene showed classical PCH phenotypes with thyroid goiter or nodules. The six patients with monoallelic variant in TPO, DUOX2 or DUOXA2 presented variable phenotypes. Among the 433 578 newborns in the 2011-2012 cohort, there were 156 cases of CH. Six of these cases were PCH suspected dyshormonogenesis, among which 1 case was confirmed TPO biallelic variants and 5 cases were monoallelic variants of TPO, DUOX2, or DUOXA2 genes.@*Conclusion@#TPO and DUOX2 variants are the common molecular pathogenesis in children with PCH suspected dyshormonogenesis. Monoallelic variants in TPO, DUOX2 or DUOXA2 are associated with PCH and showed wide variability in their phenotypes. The novel variant p. R595T in TPO is probably a pathologic variant. The prevalence of PCH caused by TPO gene defects is rare in Guangzhou.

Inhibitory effect of salidroside on proliferation of HFLS-RA induced by TNF-α and its significance / 吉林大学学报(医学版)

Objective:To study the inhibitory effect of salidroside on the proliferation of fibroblast-like synoviocytes with rheumatoid arthritis in human(HFLS-RA) induced by tomor necrossi factor-α(TNF-α),and to clarify the molecular mechanism of its control effect on rheumatoid arthritis(RA).Methods:The HFLS-RA were cultured in vitro,then treated with TNF-α and different concentrations of salidroside.The cells were divided into normal control group(0 μg·L-1TNF-α),model control group(10.0 μg·L-1TNF-α)and 12.5,25.0,50.0,and 100.0 μmol·L-1 salidroside groups(10.0 μg·L-1TNF-α+salidroside).The proliferation activity was detected by MTT mehthod;the expression levels of β-catenin,matrix metalloproteinase-7(MMP-7),and Cyclin-D1 in supernatant of the cells were detected by ELISA method;the expression level of β-catenin protein in cells was detected by Western blotting method.Results:Compared with normal control group,the proliferation activity of the HFLS-RA in model control group was significantly increased (P0.05),and the proliferation activities of the HFLS-RA in 50.0 and 100.0 μmol·L-1 salidroside groups were significantly decreased (P0.05);the expression levels of β-catenin,MMP-7,and Cyclin-D1 in the supernatant of the cells in 50.0 and 100.0 μmol·L-1 salidroside groups were decreased(P0.05);the expression levels of β-catenin protein in the cells in 50.0 and 100.0 μmol·L-1 salidroside groups were lower than that in model control group(P<0.05).Conclusion:Salidroside could inhibit the proliferation of HFLS-RA,and its control effect might be related to the regulation of Wnt/β-catenin single pathway.

Comparative study on the anti-demineralization effect of pinus massoniana bark extract and grape seed extract on human root dentin in vitro / 实用口腔医学杂志

Objective:To evaluate the effect of pinus massoniana bark extract (PMBE) and grape seed extract (GSE) on dentin demineralization caused by acid.Methods:40 root dentin blocks with half of the surface covered were randondy divided into 4 groups (n =10).All samples were subjected to pH cycling for 8 days,and deionized distilled water(DDW),0.1％NaF,12％ PMBE solution and 12％ GSE solution were used as the experimental solutions in the 4 groups.The dentin mineral density(DMD) of the both sides was determined using micro-computed tomography.The D-value of DMD between nn-demineralized and demineralized side (△DMD)was calculated.The samples were observed with field emission scanning electron microscops (FE-SEM).Results:The △DMD of DDW,NaF,PMBE and GSE groups was 198.64 ±59.97,45.94 ±24.21,90.23 ±28.77 and 105.07 ±29.53 respectively.The △DMD between PMBE and GSE groups had no significant difference (P ＞ 0.05),which were both higher than that of NaF group (P ＜ 0.05) and lower than that of DDW group(P ＜ 0.05).The FE-SEM revealed that the dentin tubules in DDW group were completely open,but in NaF group were essentially closed in PMBE group and GSE group were spindle shaped or narrow crack opening.Conclusion:PMBE and GSE had almost the same effect on improving the acid resistance of dentin.

Effect of Pinus massoniana needle extract on root dentin demineralization in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to evaluate the effects of Pinus massoniana needle extract (PMNE) on inhibiting demineralization of root dentin.</p><p><b>METHODS</b>Root dentin blocks were randomly divided into distilled deionized water (DDW) group, fluoride sodium (NaF) group, and 4%, 8% and 12% PMNE groups according to the experimental solution used in the process of pH cycling in each group. All specimens in each group experienced pH cycling for 8 d. The dentin mineral density (DMD) of the normal dentin and demineralized dentin and their D-value (ΔDMD) were determined using micro computed tomography. The morphology of dentin surface after pH cycling was also observed using a scanning electron microscope.</p><p><b>RESULTS</b>The ΔDMD values in all PMNE groups and the NaF group were considerably lower than the ΔDMD in the DDW group (P<0.05). The ΔDMD values of the 8% and 12% PMNE groups had no difference (P>0.05), both of which were lower than the ΔDMD in the 4% PMNE group and higher than that in the NaF group (P<0.05). The dentin tubules were partly opened in the PMNE groups. The opening degrees of the dentin tubule in PMNE groups were significantly less and smaller than the opening degree in the DDW group and were larger than that in the NaF group.</p><p><b>CONCLUSIONS</b>PMNE can inhibit the deminera-lization of root dentin and can slow down the reduction in DMD. PMNE has the potential to prevent caries, and 8% PMNE can effectively inhibit dentin demineralization.</p>

The antagonistic effect of magnesium-selenium against fluorosis on the expressions of amelogenin in dental germ of mice incisor / 中华地方病学杂志

Objective To study the antagonistic effects of magnesium-selenium-fluorine preparation on dental fluorosis of mice and its mechanism,and to provide a foundational basis for prevention and control of dental fluorosis.Methods Eighty male SPF ICR mice,were divided into 8 groups according to body weight by random number table method:control group,magnesium group,selenium group,magnesium-selenium group,fluoride group,magnesium-fluorine group,selenium-fluorine group and magnesium-selenium-fluorine group.The control group,magnesium group,selenium group and magnesium-selenium group drank double steamed water,and the other four groups drank 50 mg/L F-double steamed water.The control group and fluoride group fed conventionally.Magnesium group and magnesium-fluorine group fed conventionally by adding MgSO4·7H2O 162.5 mg/kg.Selenium group andselenium-fluorine group fed conventionally by adding Na2SeO3 ·5H2O 2.0 mg/kg.Magnesium-selenium group and magnesium-selenium-fluorine group fed conventionally by adding MgSO4·7H2O 162.5 mg/kg and Na2SeO3·5H2O 2.0mg/kg.Then incisor specimens were obtained after the mice were put into death after treatment for 42 days.The expression of amelogenin was observed with immunohistochemical staining.And gray value is expressed as a result,the greater the gray value,the less protein expression.Results The results of light microscope showed that ameloblasts in the fluoride group showed disarrangement and even had vacuolar.The change of ameloblasts in the magnesium-selenium-fluorine group had no significant difference with control group.The expressions of amelogenin in enamel matrix of fluoride group (131.03 ± 11.14) was significantly higher than those of others (control group:143.44 ± 2.52,magnesium group:143.73 ± 12.43,selenium group:148.89 ± 2.85,magnesium-selenium group:148.38 ± 7.58,magnesium-fluorine group:145.90 ± 7.00,selenium-fluorine group:148.70 ± 4.90,and magnesiumselenium-fluorine group:151.89 4± 4.59,all P ＜ 0.05).The expression of amelogenin in ameloblast of fluoride group (165.49 ± 5.66) was significantly lower than those of control group,magnesium group,magnesium-fluorine group and selenium group (151.35 ± 2.52,149.27 ± 11.13,146.21 ± 4.84 and 150.39 ± 6.65,all P ＜ 0.05).The expression of amelogenin in ameloblast of selenium-fluorine group (165.46 ± 5.81) was significantly lower than those of magnesium group,magnesium-fluorine group and selenium group (all P ＜ 0.05).The results of factorial analysis showed that magnesium and selenium affected the expression of amelogenin in enamel matrix (F =4.195,15.009,all P ＜ 0.05),the interaction between fluoride and magnesium had an effect on the expression of amelogenin in enamel matrix (F =4.402,P ＜ 0.05).Interaction of fluoride,magnesium and selenium had no effect on the expression of amelogenin in enamel matrix (F =1.561,P ＞ 0.05).The fluoride,magnesium and selenium affected the expression of amelogenin in ameloblast (F =18.463,9.372,4.741,all P ＜ 0.05),the interactions between fluoride and magnesium,magnesium and selenium had effects on the expression of amelogenin in ameloblast (F =10.351,5.919,all P ＜ 0.05).Interaction of fluoride,magnesium and selenium had no effect on the expression of amelogenin in ameloblast (F =1.460,P ＞ 0.05).Conclusions There is an antagonistic effect of magnesium on the expression of enamel protein in fluorosis mice.However,it can not be considered that there is an effect of selenium on the expression of enamel protein in fluorosis mice.

Effect of local application of insulin like growth factor-1 gelatin sponge complex on osseointegration around implant in osteoporosis rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of local application of insulin like growth factor-1 (IGF-1) absorbable gelatin sponge complex in implant fossa on osseointegration around implant in osteoporosis rats.</p><p><b>METHODS</b>Female SD rats, aged 4 months, were randomly individed into ovariectomy group (OVX group) and sham-ovariectomy group (sham-ovx group). The rats in OVX group (n = 15) were ovariectomized, and the rats in Sham-OVX group (n = 10) underwent Sham-ovariectomy. Eight weeks later, 5 rats in each group were randomly selected to confirm the osteoporosis model. The ovariectomized rats were randomly divided into osteoporosis group (OP group) and IGF-1 group after the model was successfully established, 5 rats in each group. Pure titanium implants were implanted in the distal part of right femoral epiphyseal in all groups. Absorbable gelatin sponge particles containing 10 µg IGF-1 were placed in the planting fossa in the IGF-1 group, and absorbable gelatin sponge particles without IGF-1 were used in OP group and sham-OVX group. The rats were sacrificed, and then the distal part of right and left femoral epiphyses were taken out to make undecalcified and decalcified tissue sections respectively after 8 weeks. Combined bone lamella width (CBLW) and implant bone contact rate (IBCR) around implant, trabecular width (TW) and trabecular area percentage (TA) around implant and in the cortical bone of left femoral epiphyses were observed by histomorphometric measurement.</p><p><b>RESULTS</b>The CBLW, IBCR, TW and TA around implant was (55.43 ± 3.50) µm, (81.79 ± 4.45) %, (57.73 ± 4.29) µm and (62.21 ± 7.42) % respectively in sham-OVX group, (60.22 ± 4.70) µm, (83.67 ± 6.63) %, (48.08 ± 3.63) µm and (58.20 ± 8.93) % respectively in IGF-1 group, and (37.11 ± 2.18) µm, (64.60 ± 5.44) %, (41.19 ± 2.93) µm and (42.21 ± 4.34) % respectively in OP group. The CBLW, IBCR and TW around implant had no differences between IGF-1 and sham-OVX group (P > 0.05), which were significantly higher than those in OP group (P < 0.05). The TW and TA of cortical bone in left distal femoral epiphyses was (60.85 ± 6.64) µm, (61.24 ± 6.98) % respectively in sham-OVX group, (38.68 ± 4.74) µm, (43.89 ± 7.76) % respectively IGF-1 group, (40.46 ± 5.38) µm, (44.63 ± 5.39) % respectively in OP group (P < 0.05). The TW and TA of cortical bone in left distal femoral epiphyses had no differences between IGF-1 group and OP group (P > 0.05), which were all significantly lower than those in sham-OVX group (P < 0.05).</p><p><b>CONCLUSIONS</b>The local application of IGF-1 gelatin sponge complex can increase bone tissue around implant and improve osseointegration in osteoporosis.</p>

Isolation,Culture,Identification and Induced Differentiation of Mesenchymal Stem Cells from Human Umbilical Cord / 现代检验医学杂志

Objective To establish the method of isolation,culture and identify biological characterization of mesenchymal stem cells from human umbilical cord (hUCMSCs);and study their multiple differentiation potency.Methods Stem cells from human umbilical cord were cultured by enzyme Wharton jelly method in vitro.The surface markers were identified by flow cytometry.Multi-differentiation capacity was identified by osteogenic and adipogenic differentiation.ALP was detected with Calcium cobalt staining.The mineralized ability in vitro was measured with Alizarin red staining.Theadipocyte differen-tiation ability was measured with oil red-O staining.Results Flow cytometry analysis revealed that CD73 (92.45%),CD90 (95.45%)and CD105 (96.45%)were highly expressed on these cells’surface,while CD34 (1.07%)were negative ex-pressed.Cells were cultured with induced-osteogenic medium after 3 weeks,ALP staining in the cytoplasm of black parti-cles,and a large amount of mineralized nodules within cells was observed after 4 weeks.Cells were cultured with induced-adi-pogenic medium after 2 weeks,the majority of these cells were round,oil red O staining of lipid droplets generated within cells was observed.Conclusion Mesenchymal stem cells from human umbilical cord have the potential of multi-directional differentiation.These cells could be induced to differentiate into adipocytes and osteoblasts,which laid the foundation for clinical stem cell therapy research source of seed cells.

Effect of casein phosphopeptide-amorphous calcium phosphate on the stability of resin-dentin bonds against pH cycling / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the stability of resin-dentin bonds against pH cycling.</p><p><b>METHODS</b>Resin-bonded dentin specimens were prepared following manufacturers' instructions, and randomly divided into 3 groups. Among them, 2 groups experienced pH cycling, in which specimens applied CPP-ACP or distilled and deionized water (DDW) on the bonding interface, respectively. Microtensile bond strength (muTBS) testing, failure mode analysis, micromorphological and nanoleakage evaluation of bonding interface and elemental analysis within hybrid layer were performed after 15 days pH cycling. The other group was tested immediately after specimens' preparation without pH cycling.</p><p><b>RESULTS</b>No significant differences were found in muTBS between no pH cycling and pH cycling/CPP-ACP group. Their muTBS were both significantly higher than that of pH cycling/DDW group (P < 0.05). Mixed fractures were the most prevalent failure mode. The quality of hybrid layer in pH cycling/CPP-ACP group was better than that of pH cycling/DDW group, and the nanoleakage was also less severe. Comparing with pH cycling/DDW group, the atomic percentages of Ca in the other two groups were both significantly higher, while those of Ag were statistically lower (P < 0.05).</p><p><b>CONCLUSION</b>Local application of CPP-ACP can promote the stability of resin-dentin bonding interface against pH cycling and prolong bonding degeneration.</p>

Survey on mental health and social support of students majored in stomatology in internship / 中华医学教育探索杂志

Objective To study the mental health conditions of students majored in stomatology and dental technology in internships,and to provide evidences and guidelines for education before and during exercitation.Methods Totally 90 students majored in stomatology and 60 students majored in dental technology in internships were surveyed by the questionnaires of symptom checklist (SCL90)and perceived social support scale (PSSS).Results were analyzed by SPSS 14.0.Measurement data was analyzed using t test comparison between groups,showed as mean ± standard deviation ((x) ± s).Positive screening rate and rate between male and female were analyzed by Mann-Whitney U inspection.The inspection level is α =0.05.Results Scores of somatization,paranoia and anxiety factors among students majored in stomatology were (1.49 ± 0.56),(1.52 ± 0.43),(1.73 ± 0.58),all significantly higher than those of the national norm of youth.Positive rate of mental diseases among students majored in dental technology was 77.59％ and their scores of somatization,constraint,anxiety,psychotic factors were (1.69 ±0.55),(2.07 ±0.5),(1.68 ±0.51) and (1.54 ±0.39),all significantly higher than those of students majored in stomatology.There was no difference in the scores of rest factors between the two groups.Scores of PSSS among students majored in dental technology were significantly lower than those of students majored stomatology.Conclusions Students of different majors all suffer from psychological problems with different degrees.Therefore,education,management and social support before and during exercitation should be emphasized in the prevention of psychological diseases.

Discussion on better conjunction between postgraduate and undergraduate education of or-thodontics in China / 中华医学教育探索杂志

The paper analyzed on the status quo of postgraduate and undergraduate education of orthodontics in China and seek solutions for improving conjunction between these two different stages by presenting measures in seven respects including grading undergraduate education curricu-lum,launching students seminar,developing students' scientific research activities,adjusting evalua-tion system,emphazing on bilingual teaching,distinguishing types of postgraduates and seting up the communication channel so as to find a proper way for orthodontic education in China.

The effect of estrogen and recombine human growth hormone on residual ridge reduction in osteoporotic rats / 西安交通大学学报(医学版)

Objective To study the effect of estrogen,recombine human growth hormone and their combinations on residual ridge reduction in osteoporotic rats.Methods Animal models were established by ovariectomy and exodontia on left partial maxillary,then were devided into osteoporosis group and treatment groups;treatment groups were given estrogen and recombine human growth hormone medicial alone and their recombinations.After treatment for 4 and 8 weeks with drugs,the effects of estrogen and recombine human growth hormone on the serum tartrate-resistant acid phosphatase level and bone histomorphometry changes in maxillary were observed in each group. Results ① The serum tartrate-resistant acid phosphatase level was obvionsly lower in ERT group and Er-HGH group than in OP group(P

The Relationship Between Doctors and Patients In the Treatment of DA / 中国医学伦理学

Dental anxiety (DA) is the psychology obstacle of the dental patients in the dental treatment. Recently, dental anxiety becomes prevalent in the world and it greatly impacts physical health and the quality of life. The text discussed the relationship between doctors and patients in the treatment of DA