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BACKGROUND: Our previous findings have shown that poly(lactic acid)/hydroxyapatite (PLA/HA) composite biomaterials prepared by the supercritical carbon dioxide method have good physiochemical properties and biocompatibility. However, the composite materials only have osteoconductivity but no osteoinductivity. OBJECTIVE: To prepare icariin-PLA/HA (IC-PLA/HA) composite biomaterials with good osteoconduction and osteoinduction. METHODS: The supercritical carbon dioxide method was used to prepare IC-PLA/HA composite biomaterials containing 10-4, 10-5, 10-6mmol/g IC, named as IC-PLA/HA(1 000), IC-PLA/HA(100) and IC-PLA/HA(10). PLA/HA composite material served as controls. Biomechanical properties, porosity, sustained release characteristics were detected, and scanning electron microscope observation was performed, in order to screen out the optimal IC content in the composite materials. RESULTS AND CONCLUSION: (1) Compressive strength and elastic modulus of IC-PLA/HA(1 000), IC-PLA/HA(100) and IC-PLA/HA(10) showed no difference from those of PLA/HA. (2) The porosity of all the composite materials was over 75%, and there was still no difference among groups. (3) The IC release from IC-PLA/HA was faster within the first 3 days, and then reduced gradually. However, after 7 days, the IC release plateaued, and the IC release amount from the IC-PLA/HA(100) was close to 10-7mol/L that had been confirmed to be an effective and safe concentration in the previous experiments. (4) Under the scanning electron microscope, HA and PLA were mixed homogeneously and IC was difficult to be identified. The pore size of the IC-PLA/HA(100) ranged from 50 μm to 150 μm. Overall, the IC-PLA/HA composite biomaterials have good mechanical and sustained-release properties.
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Objective To analyze the monitoring results of urinary iodine of students aged 8 - 10 in Zhangjiakou city,problems in monitoring results,and to provide basic information for working out control strategies of iodine deficiency disorders.Methods A township(town,street) in each country of each city(district) in Zhangjiakou was selected according to 5 positions of the east,the west,the south,the north and center,and 1 village elementary school was sampled in each chosen township,twenty students(half male and female) aged 8 - 10 were selected to collect their urine samples in each school.Urinary iodine concentration was determined by arseniccerium method.Results The median of urinary iodine of the 1700 children aged 8 - 10 was 291.5 μg/L,with ＜ 50 μg/L accounted for 0.8％(13/1700),50 ～ 99 μg/L about 4.9％(83/1700),100 - 199 μg/L about 20.5％ (349/1700),200 - 299 μg/L about 29.7％(504/1700),and ≥300 μg/L about 44.9％(764/1700).Conclusions Urinary iodine has reached the elimination standard of iodine deficiency disorders in Zhangjiakou city.But the situation of more than adequate amount of urinary iodine and iodine excess is relatively serious and it is necessary to lower iodine concentration.
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ObjectiveTo master iodized salt monitoring results in Zhangjiakou city Hebei province,search problems in these monitoring results,and provide a basis for the development of control measures to iodine deficiency disorders.MethodsBy 2010,in Zhangjiakou city,nine salt samples were collected to detect the iodine level in each processing,packing and wholesale enterprise according to their orientation of east,west,north,south and center positions.In each county(district) with nine townships(towns,street offices) and more,nine townships (towns,street offices) were selected according to their east,west,south,north and center positions,in each township (town,street office ) selected,four villages (neighborhoods) were selected,eight residents per household in each village (neighborhood) chosen were selected,and an edible salt was collected in each household to test iodine level; in a county(district) with nine or less townships(towns,street offices),five townships(towns,district offices) were selected according to their east,west,south,north and center positions,four villages (neighborhoods) were selected,and 15 residents per household in each village(neighborhood) were selected to test the iodine level in an edible salt samples;after population-weighted calculation,indicators of iodized salt monitoring were calculated.ResultsA batch quality pass rate of processing,packing and wholesale enterprise was 100％(192/192); the rate of weighted non-iodized salt in a household was 0.04％(2/4932),iodized salt coverage rate was 99.96％ (4930/4932),iodized salt passing rate was 99.55％ (4908/4930),and qualified iodized salt coverage rate was 99.51％ (4908/4932).ConclusionsMonitoring indicators of iodized salt in Zhangjiakou city have reached the standand to eliminate iodine deficiency disorders.However,there still have unqualified iodized salt and non-iodized salt,and the monitoring and iodized salt market management should be strengthened.
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Objective To analyze comprehensively the monitoring data of iodized salt in Zhangjiakou city during 2001 to 2009, and to provide basic information for working out control strategies of the iodine deficiency disorders. Methods According to the iodized salt monitoring requirements in National Iodine Deficiency Disorders Monitoring Program of Ministry of Health, a batch of nine salt samples were taken from each processing (wholesale)company of each county or district of the seventeen counties(districts) of Zhangjiakou once a month. Two townships (towns, street offices) were selected by their location of east, south, west and north in each county(district), and a township in central area each year. Four villages(neighborhoods) were selected in each township(town, street office),and eight household salt samples were collected in each village(neighborhood), and quantitatively determined by direct titration of iodine. Results Iodized salt processing(wholesale) : during 2001 to 2009, a total of 1728 batches was monitored, 1689 batch qualified, batch qualification rate 97.74%;15552 salt samples were tested, 15 357 qualified, iodized salt qualification rate 98.75 %. Household salt levels : 5297 villages (neighborhoods) of 1305 townships(towns, street offices) were monitored, 44 316 salt samples were collected, 43 274 qualified, iodized salt qualification rate 98.04%(43 274/44 141 ), iodized salt coverage rate 99.61%(44 141/44 316), qualified iodized salt consumption rate 97.65%(43 274/44 316). Rate of non-iodized salt was 0.40%(260/44 316), and salt median iodine was 30.02 mg/kg. Conclusions The iodized salt quality indicators are within the state-controlled range in Zhangjiakou city for nine years which remaines at relatively stable levels with a smaller range of annual fluctuations.Detection of non-iodized salt over the years has become the main factors affecting the effectiveness of the prevention and control measures.We should increase monitoring,supervision,and universal health education,and prevent the spread of non-iodized salt.
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Objective To find out the relation between element (non-iodized salt and iodized salt that below standard) and epidemic strength of iodine deficiency disorders and level of iodine, in order to find out the factors affecting the result of using iodized salt in controlling of this disorders. Methods Retrospective analyses was used in the study. Six counties were selected randomly from Zhangjiakou every year from 2000 to 2008, and these counties were randomly divided into non-iodized salt group (the ratio of non-iodized salt > 5%), iodized salt below standard group (the ratio of qualified iodized salt < 95%) and control group (the ratio of using qualified iodized salt > 95%). The indexes from different groups were compared as well as the ratio of large thyroid syndrome in children aged 8-10 years and the level of iodine in urine. Results The number of iodized salt monitored were 12 468 units from 2000 to 2008. We examined 5655 children's thyroid and collected 4404 urine samples. The median was 30.1 mg/kg for the average of iodized salt and 7.30% (232/3180) for ratio of non-iodized salt in noniodized salt group, while 30.9 mg/kg and 93.10%(3776/4056) in iodized salt below standard group, and 32.0 mg/kg and 99.27%(5194/5232) in control group. Compared the median of the three groups[5.31%(78/1468) ,4.84% (92/1902) ,2.06% (47/2285)], we observed significant difference (χ2 = 72.07, P < 0.05), especially the ratio of large thyroid in non-iodized salt group which was apparently higher than that of the control group (χ2 = 8.70, P < 0.017). However there was no significant difference between iodized salt below standard group and non-iodized salt group(χ2 = 6.83, P > 0.017) and control group(χ2 = 5.65, P > 0.017). The median of urinary iodine was 188.20 μg/L in non-iodized salt group, 219.62 μg/L in iodized salt below standard group and 262.39 μg/L in control group, indicated that the index in control group was higher than that of others. Conclusion Both of non-iodized salt and iodized salt below standard have effect on prevalence of child iodine deficiency disorders, especially the non-iodized salt.
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<p><b>OBJECTIVE</b>To identify the mutation spectrum and the distribution of minihaplotypes (STR/VNTR) of phenylalanine hydroxylase (PAH) gene and explore the correlations between genotype and phenotype of patients with phenylketonuria (PKU) in Beijing area of China.</p><p><b>METHOD</b>(1) Fifty cases with PKU were involved in this study. PKU was identified by the Neonatal Screening Center of Beijing. All 13 exons and their flanking intronic sequences of PAH gene of these patients were amplified and then subjected to SSCP analysis and direct sequencing. (2) The distribution of polymorphic locus of short tandem repeat (STR) and variable number tandem repeat (VNTR) was analyzed by PCR and denaturing gel electrophoresis. (3) The correlations between genotype and phenotype were studied by analysis of the matching rate between the expected and observed phenotypes. The predicted phenotype was determined on the basis of the sum of the assigned values of the two mutant alleles.</p><p><b>RESULTS</b>(1) A total of 34 different mutations were detected with the relative frequency of 95% among 50 PKU patients. The prevalent mutations in this study were: R243Q (20%), EX6-96A > G (11%), Y356X (9%), and V399V (7%). The next common mutations were R111X (5%), R413P (5%), R252Q (3%) and A434D (3%). Thirty-four detected mutations were distributed throughout the whole PAH gene, except exon 1, 8 and 13. Exon 7 and 11, with the mutant rate 34% and 19% respectively, seemed to be the hot mutant areas/regions of PAH gene. (2) The minihaplotypes (STR/VNTR) of 34 mutations were identified in this research. The STR and VNTR showed 8 and 3 alleles, respectively. Among them, 244 bp (44%) and 240 bp (34%) were the prevalent STR alleles. Meanwhile, the VNTR3 (83%) was the most common VNTR allele in PKU patients. (3) A better consistency (81.5%) between expected and observed phenotypes was revealed by analysis of correlation between genotype and phenotype. Especially in classic PKU, the consistency rate was up to 87.5%.</p><p><b>CONCLUSION</b>(1) The frequency distribution of common PAH gene mutations in Beijing region was close to that of Tianjin and Yunnan regions, while it was different from that of Southern regions of China, such as Guangzhou, especially Taiwan. The PAH mutation with a highly heterogeneous trait was also demonstrated in this study. (2) STR and VNTR minihaplotype will prove helpful to trace the origins of PAH mutations and to analyze the genetic drift. However, the most minihaplotypes of the STR/VNTR are similar, so it is necessary to associate some other polymorphic loci with the STR/VNTR minihaplotype to analyze the different mutations. (3) The fact that a better consistency existed between phenotypes and genotype with most PKU patients suggested that the study of the genotype of PKU patients would be helpful to the individualized treatment and to genetic counseling for their families.</p>
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Humanos , Recién Nacido , Alelos , China , Epidemiología , Estudios de Asociación Genética , Genotipo , Intrones , Mutación , Fenotipo , Fenilalanina Hidroxilasa , Genética , Fenilcetonurias , Epidemiología , Genética , Polimorfismo GenéticoRESUMEN
<p><b>OBJECTIVE</b>To understand the mutant spectrum of phenylalanine hydroxylase (PAH) gene in Northern Chinese.</p><p><b>METHODS</b>All the exons and flaking introns of PAH gene were detected by PCR-single strand conformation polymorphism (PCR/SSCP) and sequencing in 230 patients with phenylketonuria (PKU).</p><p><b>RESULTS</b>(1) A total of 75 different mutations were detected in 435 out of 460 mutant alleles (94.6%). Among them 3 mutations (S251-R252>SfsX89, Y387D and A389G) have not been reported previously. The mutations, R243Q, EX6-96A>G, R111X, R413P and Y356X, were the prevalent mutations with relative frequencies of 21.7%, 10.2%, 8.3%, 6.5%, and 6.1% respectively, followed by V399V(4.1%), IVS4-1G>A (3.5%), IVS7+2T>A (2.2%) and R241C(2.2%). Most mutations were detected in exons 3, 5, 6, 7, 11 and 12 and flaking introns of PAH gene. (2) Ten polymorphism sites were detected in the study. Four sites, IVS3-22C>T, IVS10+97G>A, Q232Q and V245V, had high relative frequencies of 56.7%, 75.9%, 89.0% and 81.9% respectively. It would suggest that the race diversity exists in PAH cDNA sequence.</p><p><b>CONCLUSION</b>The mutation spectrum of PAH gene in Northern Chinese is similar to other Asian populations but significantly different from European populations.</p>
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Adulto , Niño , Humanos , Alelos , Pueblo Asiatico , Genética , Población Blanca , Genética , Genotipo , Mutación , Fenotipo , Fenilalanina Hidroxilasa , Genética , Fenilcetonurias , Genética , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-SimpleRESUMEN
<p><b>OBJECTIVE</b>To develop a novel porous poly lactic-acid(PLA)/bone matrix gelatin (BMG) bioactive composite biomaterial with supercritical carbon dioxide (SC-CO2) extraction and determine the optimal proportion of the ingredients by evaluating the physical and chemical characteristics and cellular compatibility of the composites.</p><p><b>METHODS</b>The PLA/BMG composite biomaterials with various PLA/BMG proportions were prepared with SC-CO2 technique and evaluated by macroscopic observation, porosity and mechanical assessment, and scanning electron micrograph (SEM). The optimal proportion of PLA/BMG was determined in conjunction with the results of cellular compatibility evaluation.</p><p><b>RESULTS</b>BMG proportion in BLA/BMG composite biomaterials prepared with SC-CO2 technique was positively associated with the cellular compatibility and porosity, and inversely with the mechanics of the prepared composite. The results showed BMG content of 30% in PLA/BMG composite was optimal.</p><p><b>CONCLUSION</b>The composite with PLA and BMG proportion of 7:3 possesses good physical and chemical characteristics and cellular compatibility, suggesting its potential as the bone implant biomaterial and bone-tissue engineering scaffold.</p>
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Animales , Humanos , Ratas , Materiales Biocompatibles , Química , Matriz Ósea , Química , Sustitutos de Huesos , Química , Gelatina , Química , Ácido Láctico , Química , Poliésteres , Polímeros , Química , Porosidad , Ingeniería de Tejidos , Métodos , Andamios del TejidoRESUMEN
<p><b>OBJECTIVE</b>To evaluate the clinical outcomes of allogeneic bone grafting for bone defect resulting from benign neoplasm resection and discuss the clinical application and bone defect repair mechanisms of allogeneic bone.</p><p><b>METHODS</b>A retrospective review was conducted of 135 patients with benign neoplasm resection who received bone defect filling with the allogeneic bone graft.</p><p><b>RESULTS</b>In the 104 patients with complete clinical follow-up data, 96 achieved bone union, 7 experienced relapses to require surgical intervention and 1 had severe infection to lead to failure of the operation. The mean time for bone union was 9.7 months, and during the follow-up, no viral disease in relation to the graft was found after surgery.</p><p><b>CONCLUSION</b>Bone defect filling with allogeneic bone graft can be simple and safe in comparison with that with autograft or other biomaterials, and the bone healing time, infection rate and local tumor recurrence can be comparable with the autograft.</p>
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Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Óseas , Patología , Cirugía General , Trasplante Óseo , Métodos , Estudios de Seguimiento , Estudios Retrospectivos , Trasplante HomólogoRESUMEN
Objective To design a good scoring function for predicting the tertiary structures of proteins. Methods A scoring function,which was composed of simple sum of pairwise distance-dependent potentials of C?-C?,N-N,C′-C′ and backbone dihedral angle-dependent potentials,was proposed in this paper. Results The performance of the scoring function was verified with experiment to be improved. Conclusion The proposed scoring function is effective and valid in predicting the tertiary structures of proteins.
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With the development of tissue engineering,the bone tissue engineering is developing rapidly. Engineering hone typically uses an artificial extracellular matrix (scaffold),osteoblasts or progenitors,and os- teoinductive factors which promote cell attachment,differentiation,and mineralized bone formation.Highly porous scaffolds play a critical role in cell seeding,proliferation,and new 3D-tissue formation.A variety of biodegradable polymer materials and scaffolding fabrication techniques for engineering bone have been developed over the past decade.This article reviews the scaffold design and fabrication methods tor engineering bone to analyze their ad- vantages and limitations.Various architectural parameters of scaffolds important for bone tissue engineering (e.g. porosity,pore size,interconnectivity) are discussed.
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<p><b>OBJECTIVE</b>To study the molecular basis of the phenylalanine hydroxylase (PAH) gene mutation in Chinese patients with phenylketonuria (PKU).</p><p><b>METHODS</b>Using PCR/SSCP and DNA sequencing, we studied the mutations in exons 3, 5, 7, 10, 11, 12 of PAH gene. Totally 120 unrelated children with PKU and their parents from the northern region of China were included in the analysis.</p><p><b>RESULT</b>Ten novel mutations were first time identified in Chinese PKU population as I65T, S70del, G239D, R241fsdelG, L255S, P281L, G346R, L367fsinsC, R400S and Ivsllnt2t-->c. The mutations G239D, R241fsdelG, R400S and Ivsllnt2t-->c have not been yet described in International PAH. In the present study we firstly identified the deletion, insertion and frameshift mutations of PAH gene in China PKU population. So far the mutant type of PAH gene in Chinese included: missense, nonsense, splice, silence, deletion, insertion and frameshift. Novel mutations mainly existed in exon 7: four in exon 7, two in exon 3, two in exon 11, one in exon 10 and one in intron 11. Each proportion of the ten novel mutations was very low (0.42%-1.3%).</p><p><b>CONCLUSION</b>This study demonstrated the high heterogeneity of the PAH gene and the variety of the mutant type of Chinese PKU population and confirmed the exon 7 was the hot spot of PAH gene mutation.</p>