BACKGROUND:Scaffold materials are the important part of tissue engineering bone, and the ideal biodegradation speed of the scaffold materials can be in accordance with the regeneration speed of bone formation in order to achieve a long-term stability. OBJECTIVE:To summarize the biodegradability of different types of currently available scaffold materials and its relationship with bone formation. METHODS:The PubMed and CNKI database were searched by the first author using the key words of “tissue engineering bone, composite scaffold, scaffold degradation” in English and Chinese for articles addressing biodegradability of scaffold materials and its relationship with bone formation published during January 1996 and December 2013. RESULTS AND CONCLUSION:Many scaffold materials under organic, inorganic and organic-inorganic categories have been available and the current studies focus on inorganic materials and organic-inorganic composite materials.In vivo andin vitro studies indicate the different characteristics and relative merits of these scaffold materials. Organic materials have a relatively slow degradation rate while inorganic materials can completely degrade but have an insufficient mechanical property. For organic-inorganic composite materials, further studies are needed.

Objective:To evaluate the effect of segmental approach in the treatment of Angle class Ⅱ division 1 malocclusion.Methods:7 cases of classⅡ,division 1 maloclusion were treated.Upper first premolar and lower second premolars were extracted in all cases.Lower first molars were mesially moved by means of segmental arch. Cephalometric analysis was used to evaluate the effects of the treatment.Results:Facial profile improvement and lower anterior facial height maintenance were achieved.The occlusion plane angle,mandibular plane angle were well controlled with lower anterior teeth upright on the lower basal bone.All patients represented good mandible response.Conclusion:Segmental technique is a simple and effective approach in correcting class Ⅱ,division 1 maloclusion

Objective:To evaluate the reliability of localization of the impacted teeth by assessing various conventional radiographies. Methods:32 patients with impacted teeth were included. The impacted teeth were localized by conventional roentgenographic techniques including panoramic radiography (PR) and linear tomography (LT).Results:Dentomaxillary orthopantomographic solution (PR,LT and PR combined with LT) clearly presented the position of the impacted teeth. Serial cross-section linear tomography also ensured the shape and axis of the impacted teeth captured on the radiograph. The accuracy of the localization was further verified by the surgical exposure in 5 cases. Conclusion:Orthopantomographic assessing can directly and precisely localize the buccal and lingual position of the impacted teeth.

Objective To analyze the incidence of complications during and after interventional therapy for common con-genital heart disease (CHD) in children. Methods From January 2011 to December 2013, interventional therapy of common congenital heart disease which include ventricular septal defect (VSD), atrial septal defect (ASD), patent ductus arteriosus (PDA) and pulmonary valve stenosis (PS) were performed in 2356 patients. Among them, 159 patients who developed complications during and post to interventional therapy were retrospectively analyzed. Results The overall complication rate was 6.75%(159/2356) (11.40% post VSD occlusion, 7.50% post ASD occlusion, 3.09% post PDA occlusion, 1.63% post percutaneous balloon pulmonary valvuloplasty (PBPV) ).The rate of arrhythmia was 4.41%(102/2356). The severe complication rate was 2.71%(64/2356) (3.62%post VSD occlusion, 2.21%post ASD occlusion, 2.53%post PDA occlusion, 1.63%post PBPV). The intraoperative severe complication rate was 0.51%(12/2356);the early severe complication rate was 1.99%(47/2356);the late severe complication rate was 0.21%(5/2356). Interventional therapy rate was 0.13%(3/2356); cardiovascular surgery rate was 0.64%(15/2356);conservative treatment rate was 1.95%(46/2356). The mortality rate was 0.08%(2/2356). Conclusions The complications and mortality rate of interventional therapy for CHD in children are relatively low, but cannot be ignored. The complication could be reduced by choosing proper indications, following the operational procedures and careful operative follow-up.

Objective To observe and analyze the medium and long term follow-up data of arrhythmias after transcatheter closure of children with ventricular septal defect (VSD). Methods Retrospectively analyzed the clinical data of 1071 children with VSD, who successfully underwent transcatheter device closure, at l, 3, 6, 12 months and ev-ery year post procedure from March 2002 to December 2010. Results Of all 1071 children, 272 cases (25.4%) were ob-served of having arrhythmias within 1 month after intervention, mainly including atrioventricular block (AVB), branch block, junctional tachycardia, atrial and ventricular tachycardia, frequent contractions, etc. Among them, 22 cases (2.1%) had above II degree AVB, complete left bundle branch block (CLBBB) and other causes of serious arrhythmias. After treatment, all cases got better and no permanent pacemaker was necessary. After 1 to 107 months (2.8±1.7 years) fol-low-up, 161 cases (18.2%) were observed of having persistent abnormal ECG mainly caused by AVB and branch block, including 10 cases (1.1%) with serious arrhythmias. In 4 cases with late-onset AVB, 3 cases had already appeared AVB in early postoperative, 1 case had recurrence CLBBB, left ventricle enlarge, and died of heart failure during follow up. Four cases were implanted permanent pacemaker. Conclusion During follow-up, serious arrhythmias after VSD closure, such as AVB or CLBBB, have high risk of recurring. Conduction block arrhythmias may reappear or worsen, while arrhythmias like tachycardia and premature heart rhythm mostly return to normal.

[ ABSTRACT] AIM:To investigate the characteristics of the intestinal microbial flora in the pregnant women with congenital heart disease fetus ( PW group) and normal pregnant women ( NW group) .METHODS: Stool samples were collected from 15 NW and 17 PW cases.The bacterial genomic DNA was extracted.The 16S rDNA was amplified by PCR, and the second generation of Illumina sequencing was conducted.RESULTS: We obtained 2 696 276 ( NW group) and 2 445 530 ( PW group) optimized sequences.The coverage was greater than 97%.We obtained 77 243 operational taxono-mic units ( OTUs) in NW group and 75 600 OTUs in PW group after a 97%similarity merge.In NW group, the Chao 1 in-dex and the Shannon index were greater than those in PW group.The diversity analysis of microbial population indicated that they were mainly composed of Firmicutes, Proteobacteria and Actinobacteria.In family, the Bifidobacteriaceae and Cori-obacteriaceae were significantly different through analysis of variance.CONCLUSION: The Bifidobacteriaceae and Cori-obacteriaceae may play an important role in the occurrence of congenital heart disease.

This study is designed to theoretically evaluate the treatment effects of MEAW with tip back bends on the mandible dentition when used as a finishing archwire without elastic and with long class III elastics respectively, and to compare them with those of stainless-steel wire and shape-memory wire. The finite element analysis (FEA) method was adopted and the findings were as follows: (1) In the case of no elastics, the MEAW rotates the second premolar, the first molar and the second molar distally while rotating other teeth mesially, and depresses anterior teeth. However, the stainless-steel wire and the shape-memory wire rotate molars distally while rotating other teeth mesially. Furthermore, they extrude anterior teeth and depress posterior teeth. (2) The MEAW with tip back bends and long class III elastics inclines and rotates posterior teeth more distally than the MEAW with only tip back bends does. In the case of tip back bends and long class III elastics loaded together, the shape-memory wire inclines teeth in greater strength as compared with the stainless-steel wire. (3) The stress level of tooth root is the lowest with MEAW, the highest with stainless-steel wire, and is middle with the shape-memory wire. From these results, it is suggested that: (1) The MEAW therapy technique is effective for leveling the curve of Spee and regulating tooth respectively. (2) The MEAW therapy technique can transfer therapy force efficiently. (3) The MEAW is considered to be suitable for treating openbite malocclusion to make the posterior teeth upright because it effectively rotates teeth distally through the force of posterior bends and long class III elastics. (4) The loaded force on the teeth is more soft and permanent in the MEAW than in the stainless-steel wire and the shape-memory wire.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; Malocclusion ; therapy ; Orthodontic Appliance Design ; Orthodontic Brackets ; Orthodontic Wires ; Orthodontics, Corrective ; methods ; Tooth Movement Techniques ; instrumentation

Objective To investigate the prevalence of GJB2 ,SLC26A4 and mitochondrial DNA 12S rRNA m .1555A>G(mtDNA 1555A>G) mutations in Hui ethic group patients with nonsyndromic hearing loss (NSHL) from Northwest China .Methods A total of 420 peripheral blood samples were collected from unrelated Hui ethic group probands with NSHL in Northwest China .Amplified the target gene by polymerase chain reaction (PCR) af-ter extracting genomic DNA from whole blood .The mtDNA 1555A>G mutation was detected by PCR -Alw26I di-gestion ,then direct sequencing was used to the positive samples of mtDNA 1555A> G ,the coding region of GJB2 gene ,exon 8 and 19 of SLC26A4 gene .Results There were 11(2 .62% ) cases caused by mtDNA 1555A>G homo-zygous mutation in 420 patients with NSHL .There were 41(9 .76% ) cases including homozygote and compound het-erozygote ,caused by GJB2 gene mutation ,which was the most frequent deafness -related gene .The allel frequency of c .235delC accounted for 6 .90% ,as well as the most frequent(51 .33% ) mutational pattern in GJB2 gene .There were 20 patients(4 .76% ) were found carring two allel mutations in SLC26A4 gene .The allel frequency of c .919 -2A>G was 5 .0% ,accounting for a total of 68 .85% in all base alterations of SLC26A4 gene ,which was the major mutant form of SLC26A4 gene .Conclusion GJB2 gene is the most common deafness -gene in Hui ethnic group pa-tients with NSHL from Northwest China ,while c .235delC is the main mutant form ,and c .919-2A>G is the hot-spot mutation of SLC26A4 gene .Through this study we can provide the molecular epidemiology basis for Hui ethnic group patients with NSHL from Northwest China in genetic diagnosis ,genetic counseling and therapy by associated testing of three frequent hearing loss genes .

Objective:To evaluate the strategy and safety of the radiofrequency ablation (RFA) on ventricular arrhythmias (VAs) originating from the pulmonary sinus cusp (PSC) in pediatric patients.Methods:Retrospective study.Fifteen patients with VAs originating from the PSC who were intervened by RFA in the Department of Pediatric Cardiology, Guangdong Provincial People′s Hospital between March 2014 to July 2020 were enrolled.All the patients met the indication criteria for RFA in pediatric patients.The electrocardiogram, ablation method of ablation were analyzed.Different curved catheters were selected for RFA according to the age and weight of the patients.The catheter was then inserted in a " U" or inverted " P" shape to the PSC.The long-term effect of ablation were reviewed.Results:The mean age and body weight of 15 patients with VAs originating from the PSC were (11.6±2.6) (6-15) years and (39.9±12.2) (19-65) kg, respectively.The electrocardiogram recorded during VAs originating from the PSC showed left bundle branch block and inferior axis with monomorphic R pattern, as well as a QS-wave in aVR and aVL.The electrocardiogram characteristics varied in patients with VAs originating from the PSC.The ideal excitation point was not found in the right ventricular outflow tract or the ablation was unsuccessful in all patients, and the earliest target was mapped and RFA was successful.Among the 15 patients, the successful ablation site was in the lower regions of the PSC, involving the right cusp in 11 patients(73.3%), the anterior cusp in 3 patients(20.0%), and the left cusp in 1 patient(6.7%). The earliest potential recorded at the PSC ablation site preceded the QRS complex onset by (27.3±6.0) ms.During the follow-up period for (2.7±2.0) years, no recurrence of VAs or complications were recorded.Conclusions:Under the premise of gentle catheterization procedure and appropriate radiofrequency energy, ablation was effective, safe and with low recurrence rate to eradicate VAs originating from the PSC in children.

OBJECTIVETo evaluate the efficacy and experience in right ventricular pacing-percutaneous balloon aortic valvuloplasty (RVP-PBAV) for congenital aortic stenosis (AS).

METHODA total of sixteen children with AS accepted the treatment with RRVP-PBAV. The patients were at ages 6 months to 15 years, their median age was 5.4 years. Their body weight was between 8.5 and 59.0 kg, average (22.3 ± 16.5) kg. The gradient pressure across the aortic valve was measured for all the patients and aortic regurgitation was observed. The follow-up time ranged from 1 month to 5.5 years.

RESULTAll patients underwent RVP-PBAV successfully. The ratios of balloon/valve were 0.86 to 1.12. The gradient pressure varied from preoperative Δp = (96 ± 32) mmHg (1 mmHg = 0.133 kPa) to the immediate postoperative ΔP = (41 ± 26) mmHg, (P < 0.05). One case had postoperative restenosis, and 3 cases were complicated with bicuspid aortic valve deformity.

CONCLUSIONThe treatment with RVP-PBAV for congenital aortic stenosis is safe and reliable. Rapid ventricular pacing is a safe procedure to stabilize the balloon during balloon aortic valvuloplasty and may decrease the incidence of aortic insufficiency.

Adolescent ; Aorta ; Aortic Valve ; abnormalities ; Aortic Valve Insufficiency ; Aortic Valve Stenosis ; therapy ; Balloon Valvuloplasty ; methods ; Body Weight ; Cardiac Surgical Procedures ; Child ; Child, Preschool ; Follow-Up Studies ; Heart Defects, Congenital ; Heart Valve Diseases ; Heart Ventricles ; Humans ; Infant ; Postoperative Period ; Treatment Outcome ; Vascular Malformations