[Effects of ascorbic acid on the expression of p53 and Bcl-2 protein in NIH/3T3 cells exposed to nickel]

Objective: To study the protective effect of Ascorbic acid (AA) on the injury of nickel-exposed mouse embryonic fibroblasts (NIH/3T3) . Methods: A model of damage induced by 50 μg/mL nickel refining dust was established to determine the relative survival rate of cells, superoxide dismutase (SOD) , lactate dehydrogenase (LDH) and glutathione peroxidase. (GSH-Px) activity, hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) content, and p53 (wild-type) , Bcl-2 protein expression. To investigate the protective effect of different doses of ascorbic acid (25, 50, 100 mmol/L) on nickel-refined dust-induced NIH/3T3 cell injury. Results: The study showed that ascorbic acid Ⅲ group can make the NIH/3T3 cell survival rate increased significantly; Apoptosis rate was reduced; The vitality of SOD and GSH-Px increased significantly, and the difference was statistically significant (P<0.05) . At the same time, the level of MDA and H(2)O(2) and the activity of extracellular LDH enzyme were significantly reduced, and the difference was statistically significant (P<0.05) . The results showed that nickel refining dust induced cell damage through up-regulation of p53 protein and down-regulation of Bcl-2 protein expression; ascorbic acid interventions, the expression level of Bcl-2 protein in ascorbic acid II and III groups was higher than that of nickel refining dust group, and the difference was statistically significant (P<0.05); The expression level of p53 protein in each dose group of ascorbic acid was lower than that of nickel refined dust group, and the difference was statistically significant (P<0.05). Conclusion: With the increase of concentration of ascorbic acid, oxidative damage levels, antioxidant enzyme levels, reduce cell apoptosis, reduce expression of p53, increased expression of Bcl-2. It showed that ascorbic acid had protective effect on NIH/3T3 cell injury induced by nickel refining dust.

[Outcomes of severe primary fetal hydrothorax treated by prenatal intervention]

Objective: To investigate the effect of intrauterine intervention on severe primary fetal hydrothorax. Methods: Twelve cases with severe fetal primary hydrothorax who underwent prenatal intervention from January 2014 to December 2017 in Guangdong Women and Children Hospital were retrospectively reviewed. Results: The median gestational age of prenatal diagnosis was 30.8 weeks (24.0-33.0 weeks) . All cases were excluded congenital chromosomal abnormalities by prenatal diagnosis, and had no complications of pregnancy during prenatal diagnosis and had hydrothorax. Three cases (3/12) were right hydrothorax, the other 9 cases (9/12) were bilateral. Thoracoamniotic shunting was performed in 7 cases (7/12) . Thoracentesis was performed in 5 cases (5/12) , and the hydrothorax reappeared soon after operation in 4 cases, shunt placement was performed again. The hydrothorax was dissolved in 2 cases, released in 6 cases.Tube falling off occurred in 1 case,treatment was abandoned in 1 case and intrauterine fetal death happened in 1 case, and 1 case wasn't rechecked by ultrasonic due to premature birth following thoracentesis. In 10 cases who had deliveries, 5 newborns (5/10) were premature, 6 newborns (6/10) underwent assisted mechanical ventilation, 8 newborns (8/10) underwent thoracic close drainage, all of them were discharged when hydrothorax resolved. Conclusions: Antenatal intervention may improve the chance of survival in severe primary fetal hydrothorax. Thoracoamniotic shunting is the first-choice for the primary severe fetal hydrothorax.

[Economic evaluation of treatments under dental general anesthesia and protective stabilization]

Objective: To conduct economic evaluation of treatments under dental general anesthesia (DGA) and protective stabilization (PS), in order to compare the cost and the final therapeutic effect of these two treatments. Methods: Retrospectively studied twenty-six 2 to 4 years old patients treated under DGA and twenty-seven treated under PS in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. The general information, treatment information and total treatment cost information of patients were collected. The cost and cost-survival time ratio of the two groups were compared in units of people and tooth respectively. When compared in unit of people, patients were divided into two groups depending on the number of teeth treated, when compared in unit of tooth, teeth were divided into two groups depending on the treatment received, i.e. restoration or root canal treatment. In addition, we recalculated and compared two groups under the assumption that the treatment charges of DGA was consistent with common outpatient charges. Results: The tooth average cost and cost-survival time ratio of each patient in DGA group which were [(1 133.87±87.37) yuan] and [3.51 (1.30, 5.72) yuan/d] respectively were significantly higher than those in PS group which were [(303.81±155.34) yuan] and [1.54 (0.95, 2.13) yuan/d] respectively (P<0.01). The number of teeth and the way of treatments wouldn't change the result. The recalculated result of the cost-survival time ratio of each patient in DGA group [1.63 (0.72, 2.55) yuan/d] and PS group [1.54 (0.95, 2.13) yuan/d] showed no significant difference (P=0.455). Conclusions: Patients treated in Peking University School and Hospital of Stomatology showed a significant higher cost and cost-survival time radio in DGA group than that in PS group. If the treatment charges of DGA group was consistent with common outpatient charges, PS group will no longer have economic advantage.

[Two-year outcomes of pulpotomy in primary molars using mineral trioxide aggregate: a retrospective study]

OBJECTIVE

To evaluate the two-year outcomes of primary molars pulpotomy using mineral trioxided aggregate (MTA) and to find out the potential influence factor, with the help of electronic medical record database.

METHODS

Children who received primary molars pulpotomy in the Department of Pediatric Dentistry in Peking University School and Hospital of Stomatology from May, 2014 to November, 2015 were searched in the Electronic Medical Record Database of Peking University School and Hospital of Stomatology, via the database for scientific research provided by the corporation of Kaientai. The children who were healthy, no more than 8 years old and followed up over 1.5 years were selected as the subjects of this study. At the same time, those children who didn't have complete medical records and X-rays before and after treatment were removed. Basic information, the relevant medical records and radiographic records of those children were collected. All molars were examined clinically and radiographically, and classified into 1 of 5 outcomes: N, H, P0, PX, PY. Molars classified into P0, PX and PY were regarded as failed. Survival analysis was applied. The survival rate and survival time of the deciduous teeth were calculated.Multivariate analysis was performed by using Cox proportional hazard model.

RESULTS

One hundred and fifteen children were finally included,aged from 2.6 to 8.2 years, with the mean age of (4.5±1.1) years. 211 primary molars were included, and the average follow up time was (880±154) days. A good level of agreement between the raters was found for molars with five outcomes(κ=0.913). Intrarater reliability was good for molars with five outcomes (κ=0.916). Forty-nine molars failed by September, 2017. Forty-three molars had abnormal radiographic manifestation. Six molars suffered premature loss. Only fourteen molars had an associated gingival swelling or parulis, or pathologic mobility upon clinical examination. The cumulative survival probability of half a year, one year, one year and a half, two years, two year and a half for the pulpotomy was 100%, 98.5%, 92.9%, 90.5%,73.8% through the Kaplan-Meier method, respectively. Through the analysis of Cox proportional hazard model, the survival probability was significantly higher when the age was younger. When sodium hypochlorite and the saline were used as the irrigation at the same time, the survival probability was not improved for those teeth with more bleeding in the operation compared with that used saline only. The teeth with preformed metal crown (PMC) gained longer median survival time than those restored with resin composite and others, but the difference was not significant, either. What's more, gender, the restoration time of PMC, the restoration of the opposite teeth were not found to be associated with the success of the treatment.

CONCLUSION

The cumulative survival probability of two years after the primary pulpotomy was 90.5%, complying the current instructions in our department. The survival probability of the molars after the treatment was significantly affected by the age.

Combined use of adipose derived stem cells and TGF-β3 microspheres promotes articular cartilage regeneration in vivo

We investigated enhancement of articular cartilage regeneration using a combination of human adipose derived stem cells (hADSCs) and TGF-β3 microspheres (MS) in vivo. Poly-lactic-co-glycolic acid (PLGA)MS were prepared using a solid/oil/water emulsion solvent evaporation-extraction method. The morphology of the MS was evaluated by scanning electron microscopy (SEM). The release characteristic of the TGF-β3 MS was evaluated. A New Zealand rabbit model for experimental osteoarthritis (OA) was established using the anterior medial meniscus excision method. Thirty OA rabbits were divided randomly into three groups according to different treatments of the right knee joints on day 7 after surgery: hADSCs/MS group received injection of both hADSCs and TGF-β3 MS; hADSCs group was injected with hADSCs; control group was injected with normal saline. Gross observation, histological staining and RT-PCR for collagen II and aggrecan) were used to assess the severity of OA and for evaluating the effect of combined use of hADSCs and TGF-β3 MS on articular cartilage regeneration in vivo. The MS were spherical with a smooth surface and the average diameter was 28 ± 2.3 µm. The encapsulation efficiency test showed that 73.8 ± 2.9% of TGF-β3 were encapsulated in the MS. The release of TGF- β3 lasted for at least 30 days. At both 6 and 12 weeks after injection, three groups exhibited different degrees of OA. Histological analysis showed that the hADSCs/MS group exhibited less OA than the hADSCs group, and the control group exhibited the most severe OA. Real-time RT-PCR showed that the gene expression of both collagen II and aggrecan were significantly up-regulated in the hADSCs/MS group. At 12 weeks after injection, the hADSCs/MS group also exhibited less OA than the other two groups. Combined use of hADSCs and TGF-β3 MS promoted articular cartilage regeneration in rabbit OA models.

[Ibrutinib inhibits mesenchymal stem cells-mediated drug resistance in diffuse large B-cell lymphoma]

Objective: To explore the mechanism of ibrutinib on drug resistance diffuse large B-cell lymphoma (DLBCL) cells. Methods: DLBCL cell line was cultured with mesenchymal stem cells (MSC) , and DLBCL cells which migrated and adhered to MSC under microscope was counted. The secretion of CXCL12 by MSC were measured by ELISA. The expression of CXCR4 on DLBCL cells were measured by flow cytometry, HBL-1 cells were transfected with a CXCR4-lentivector. An Annexin Ⅴ-binding assay was used to detect the induction of apoptosis. Clonogenic growth of DLBCL cells was evaluated on MethoCult media. Ibrutinib was injected into NOD/SCID mice, tumor growth was assessed via caliper measurements every 3 days. Results: MSC promoted migration and adhesion of DLBCL cells to MSC. Ibrutinib inhibited migration and adhesion of DLBCL cells to MSC in a dose-dependent manner (P<0.05) . CXCL12 secreted by MSC and CXCR4 expressed on DLBCL cells could induce each other, which upgraded the levels of secretion and expression. Ibrutinib could inhibit the secretion of CXCL12 (SUDHL10: 660 pg/ml vs 1 400 pg/ml, P=0.004; HBL-1: 720 pg/ml vs 1 490 pg/ml, P=0.018; DLBCL:850 pg/ml vs 1 450 pg/ml, P=0.004) and expression of CXCR4 (P<0.05) . When co-cultured with MSC, the ratio of HBL-1 cells apoptosis in the group of control, mitoxantrone, ibrutinib, mitoxantrone+ibrutinib were respectively 15.1%, 17.5%, 23.5%, 58.7%. After transfected with a CXCR4-lentivector and overexpressed CXCR4, the ratios of HBL-1 cells apoptosis were 14.2%, 16.1%, 22.5%, 38.3% respectively. The ratio of DLBCL cells apoptosis induced by mitoxantrone was lower when co-cultured with MSC (P<0.05) . But with the addition of ibrutinib, the ratio of apoptosis was increaed and it was similar to cultivation without MSC, which suggested ibrutinib could inhibit drug-resistance induced by MSC. But after transfected with a CXCR4-lentivector, the overexpression of CXCR4 was detected and the ratio of apoptosis was significantly lower when co-cultured with MSC which demonstrated that ibrutinib inhibited drug-resistance by inhibiting the expression of CXCR4. MSC enhanced lymphoma clonogenicity in vitro and lymphoma cell growth in vivo. The number of colonies of control, MSC, Ibrutinib, MSC+Ibrutinib were 113±5, 205±4, 62±9, 123±3 (2.5×10(3)/well, x±s) , respectively. The tumor volume of NOD/SCID mice were respectively 6 500, 17 000, 4 000, 10 000 mm(3). Ibrutinib inhibited lymphoma clonogenicity in vitro and lymphoma cell growth in vitro. Conclusion: Ibrutinib targeted the CXCL12/CXCR4 axis, inhibited the expression of CXCR4 and inhibited MSC-mediated drug resistance. Ibrutinib also inhibited lymphoma clonogenicity in vitro and lymphoma cell growth in vivo. These results provided a scientific rationality for relapsed/refractory DLBCL treatment with ibrutinib.

Identification of potential pathogenic genes associated with osteoporosis

OBJECTIVES

Osteoporosis is a chronic disease. The aim of this study was to identify key genes in osteoporosis.

METHODS

Microarray data sets GSE56815 and GSE56814, comprising 67 osteoporosis blood samples and 62 control blood samples, were obtained from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified in osteoporosis using Limma package (3.2.1) and Meta-MA packages. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to identify biological functions. Furthermore, the transcriptional regulatory network was established between the top 20 DEGs and transcriptional factors using the UCSC ENCODE Genome Browser. Receiver operating characteristic (ROC) analysis was applied to investigate the diagnostic value of several DEGs.

RESULTS

A total of 1320 DEGs were obtained, of which 855 were up-regulated and 465 were down-regulated. These differentially expressed genes were enriched in Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways, mainly associated with gene expression and osteoclast differentiation. In the transcriptional regulatory network, there were 6038 interactions pairs involving 88 transcriptional factors. In addition, the quantitative reverse transcriptase-polymerase chain reaction result validated the expression of several genes (VPS35, FCGR2A, TBCA, HIRA, TYROBP, and JUND). Finally, ROC analyses showed that VPS35, HIRA, PHF20 and NFKB2 had a significant diagnostic value for osteoporosis.

CONCLUSION

Genes such as VPS35, FCGR2A, TBCA, HIRA, TYROBP, JUND, PHF20, NFKB2, RPL35A and BICD2 may be considered to be potential pathogenic genes of osteoporosis and may be useful for further study of the mechanisms underlying osteoporosis.Cite this article: B. Xia, Y. Li, J. Zhou, B. Tian, L. Feng. Identification of potential pathogenic genes associated with osteoporosis. Bone Joint Res 2017;6:640-648. DOI: 10.1302/2046-3758.612.BJR-2017-0102.R1.

[Postoperative complications following dental rehabilitation under general anesthesia in children]

Objective: To assess the postoperative complications in systemically healthy children treated for dental caries under general anesthesia (GA) after discharge and analysis of the correlative factors. Methods: This prospective observational study included 124 children aged 2-8 years old who received extensive dental treatment under GA. General conditions and treatment information were obtained from questionnaires filled by the dentist and the anesthesiologist. Postoperative data were collected from a questionnaire filled by the parents in one week. Pain was assessed by using the dental discomfort questionnaire-8 (DDQ-8) pain assessment scale. Results: The mean anesthesia time for GA procedures was 102.6 min and the mean number of treated teeth was 13.5. Approximately 66.9% (83/124) of the children had one or more postoperative complaints on the first day after the treatments. The most common complaints reported were cough, hoarseness, and dental pain followed by throat discomfort, problems in eating, swelling, weakness, sleepiness, vomiting, fever and nausea. By the seventh day after the treatment, the main complications remained were dental pain and cough, while most of other symptoms disappeared. Preoperative DDQ-8 score and the number of extracted teeth were the factors that showed a significant association with postoperative dental pain on the first day. Conclusions: Dental pain and pharynx discomfort were most frequently noted postoperative symptoms. Postoperative dental discomfort on the first day might be predicted by dental pain before GA and tooth extraction under GA.

[Expression and prognostic significance of microenvironment related prognostic factors in patients with classical Hodgkin's lymphoma]

Objective: To observe the expression of three microenvironment related prognostic factors, i. e. programmed death 1 (PD-1), forkhead box protein 3(FOXP3) and colony-stimulating factor 1 receptor(CSF-1R) protein in classical Hodgkin's lymphoma (CHL) patients, and to explore the correlation between the protein expression and the prognosis of the patients. Methods: A total of 45 cases of CHL patients, who had been admitted to the Tianjin Medical University Cancer Institute and Hospital and Chinese PLA General Hospital from February 2005 to August 2010 were analyzed, including clinical features, prognostic factors, and treatment regimens. CHL patients' specimens were collected and the expression of PD-1, FOXP3, and CSF-1R proteins analyzed by immunohistochemical staining. Epstein-Barr virus encoded mRNA (EBER) was detected by in situ hybridization analysis. The relationship between the protein expression of PD-1, FOXP3 and CSF-1R and the patients' outcome was analyzed with clinical and follow-up data. Survival analysis was performed by Kaplan-Meier method, the Cox proportional hazard model was used to perform multivariate analysis. Results: In this cohort of 45 CHL patients, PD-1 positive was found in 7 cases (15.6%), FOXP3 high expression in 23 cases (51.1%), CSF-1R positive in 18 cases (40.0%). In the univariate analysis, the expression of FOXP3 and CSF-1R, International Prognostic Index (IPI) score, Ann Arbor stage and EBER were related with the patients' 5-year overall survival (OS); IPI score, the expression of FOXP3 and EBER were related with the patients' 5-year progress-free survival (PFS). Multivariate analysis indicated that CSF-1R protein expression was the independent prognostic factor affecting the patients' 5-year OS(HR: 8.918, P=0.020), and FOXP3 protein expression was the independent prognostic factor affecting the patients' 5-year PFS (HR: 0.122, P<0.001). And EBV was an independent prognostic factor of PFS and OS in the CHL patients. Conclusion: Microenvironment related prognostic factors FOXP3, CSF-1R and EBV may be independent prognostic factors of CHL and this study may provide novel strategies for targeted therapy of CHL.

Compromised BRCA1-PALB2 interaction is associated with breast cancer risk

The major breast cancer suppressor proteins BRCA1 and BRCA2 play essential roles in homologous recombination (HR)-mediated DNA repair, which is thought to be critical for tumor suppression. The two BRCA proteins are linked by a third tumor suppressor, PALB2, in the HR pathway. While truncating mutations in these genes are generally pathogenic, interpretations of missense variants remains a challenge. To date, patient-derived missense variants that disrupt PALB2 binding have been identified in BRCA1 and BRCA2; however, there has not been sufficient evidence to prove their pathogenicity in humans, and no variants in PALB2 that disrupt either its BRCA1 or BRCA2 binding have been reported. Here, we report on the identification of a novel PALB2 variant, c.104T>C [p.L35P], that segregated in a family with a strong history of breast cancer. Functional analyses showed that L35P abrogates the PALB2-BRCA1 interaction and completely disables its abilities to promote HR and confer resistance to platinum salts and PARP inhibitors. Whole-exome sequencing of a breast cancer from a c.104T>C carrier revealed a second, somatic, truncating mutation affecting PALB2, and the tumor displays hallmark genomic features of tumors with BRCA mutations and HR defects, cementing the pathogenicity of L35P. Parallel analyses of other germline variants in the PALB2 N-terminal BRCA1-binding domain identified multiple variants that affect HR function to varying degrees, suggesting their possible contribution to cancer development. Our findings establish L35P as the first pathogenic missense mutation in PALB2 and directly demonstrate the requirement of the PALB2-BRCA1 interaction for breast cancer suppression.

[Comparison of long-term dental treatment effects of children treated under general anesthesia and passive restraint]

Objective: To compare the long-term dental treatment effects, oral health habits and oral-health-related qualities of life of children treated under general anesthesia (GA) and passive restraint (PR), respectively. Methods: Twenty seven 2 to 4-year-old children treated under GA and thirty four children treated under PR were recruited in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. Up to 2 years after the treatment, a follow up assessment was conducted. The data of general information, dental plaque level and the unplanned treatments were recorded and analyzed. The questionnaire of oral health habits and early childhood oral health impact scale (ECOHIS) for each child was also completed and analyzed. The survival rate and median survival time of the deciduous teeth were calculated. Multivariate analysis was performed by using Cox proportional hazard model. Results: Twenty-five children under GA and 32 under PR were finally included, with a total of 1 098 deciduous teeth. The postoperative dental plaque indicesin both GA and PR groups had significantly improved than that of before the treatments (P=0.019, P<0.001). The oral health habits had also improved, and the improvement in PR group was more obvious than that in GA group. Totally 128 teeth (27.0%) appeared unplanned treatments in GA group and 232 teeth (37.2%) in PR group during the follow-ups. The new caries and recurrent caries in PR group were significantly more than that in GA group (P<0.001, P=0.012). No significant differences were found between the two groups in restoration failure, secondary caries and endodontic diseases (P=0.129, P=0.822, P=0.642). However, the time of occurrence of endodontic disease and secondary caries in GA group were significantly longer than that in PR group (P<0.01, P<0.001). The median survival time of teeth in GA group was 1 018 days comparing to 944 days in PR group. The difference was statistically significant (P<0.05). The survival rate was associated with such factors as decayed-missing-filled tooth (dmft), anterior or posterior teeth, feeding frequency, brushing habits and behavior management techniques. Conclusions: The long-term dental treatment effects of children treated under GA was significantly better than that of PR group. Continuous reinforcement of proper dietary and oral hygiene habits might help in maintaining the long-term treatment effect.

[Effects of breast-feeding duration, bottle-feeding duration and oral habits on the occlusal characteristics of primary dentition]

OBJECTIVE

To assess the effects of breast-feeding duration, bottle-feeding duration and oral habits on the occlusal characteristics of primary dentition in 3-6-year-old children in Beijing.

METHODS

This cross sectional study was conducted via an examination of the occlusal characteristics of 734 children combined with a questionnaire completed by their parents/guardians. The examination was performed by a single, previously calibrated examiner and the following variables were evaluated: presence or absence of deep overbite, open bite, anterior cross bite, posterior cross bite, deep overjet, terminal plane relationship of the second primary molar, primary canine relationship, crowding and spacing. Univariate analysis and multiple Logistic regressions were applied to analyze the associations.

RESULTS

It was found that a short duration of breast-feeding (never or ≤6 months) was directly associated with posterior cross bite (OR=3.13, 95%CI=1.11-8.82, P=0.031) and no maxillary space (OR=1.63, 95%CI=1.23-2.98, P=0.038). In children breast-fed for ≤6 months, the probability of developing pacifier-sucking habits was 4 times that for those breast-fed for >6 months (OR=4.21, 95%CI=1.85-9.60, P=0.000 2). The children who were bottle-fed for over 18 months had a 1.45-fold higher risk of nonmesial step occlusion and a 1.43-fold higher risk of class II canine relationship compared with those who were bottle-fed for 6-18 months. Non-nutritive sucking habits were also found to affect occlusion: a prolonged digit-sucking habit increased the probability of an anterior open bite, while a pacifier-sucking habit was associated with excessive overjet and absence of lower arch developmental space. Tongue-thrust habit was associated with anterior open bite (OR=4.21, 95%CI=1.85-9.60, P=0.000 2) and posterior cross bite (OR=7.24, 95%CI=1.30-40.13, P=0.024). Lower lip sucking habit was associated with deep overjet and had a negative association with class III canine relationship. Unilateral chewing was associated with spacing in mandibular (OR=1.57, 95%CI=1.03-2.41, P=0.037). Mouth breathing was associated with chronic rhinitis and adenoidal hypertrophy and had an association with spacing in maxillary. The chi-square test did not indicate a statistically significant association between upper lip sucking habit and any occlusal characteristics.

CONCLUSION

Breast-feeding duration was shown to be associated with the prevalence of posterior crossbite, or no maxillary space in the deciduous dentition and development of a pacifier-sucking habit. Children who had a longer duration of bottle-feeding were more likely to develop class II canine relationship. Children who had an oral habit were more likely to develop abnormal occlusal characteristics.

Monodisperse polyethylene glycol diacrylate hydrogel microsphere formation by oxygen-controlled photopolymerization in a microfluidic device

PEG-based hydrogels have become widely used as drug delivery and tissue scaffolding materials. Common among PEG hydrogel-forming polymers are photopolymerizable acrylates such as polyethylene glycol diacrylate (PEGDA). Microfluidics and microfabrication technologies have recently enabled the miniaturization of PEGDA structures, thus enabling many possible applications for nano- and micro- structured hydrogels. The presence of oxygen, however, dramatically inhibits the photopolymerization of PEGDA, which in turn frustrates hydrogel formation in environments of persistently high oxygen concentration. Using PEGDA that has been emulsified in fluorocarbon oil via microfluidic flow focusing within polydimethylsiloxane (PDMS) devices, we show that polymerization is completely inhibited below critical droplet diameters. By developing an integrated model incorporating reaction kinetics and oxygen diffusion, we demonstrate that the critical droplet diameter is largely determined by the oxygen transport rate, which is dictated by the oxygen saturation concentration of the continuous oil phase. To overcome this fundamental limitation, we present a nitrogen micro-jacketed microfluidic device to reduce oxygen within the droplet, enabling the continuous on-chip photopolymerization of microscale PEGDA particles.

[Children's intelligence quotient following general anesthesia for dental care: a clinical observation by Chinese Wechsler young children scale of intelligence]

OBJECTIVE

It has been demonstrated that anesthetics exposure may lead to neurocognitive impairment in developing brain of animal models. However, for the limitation that the animal models cannot fully mimic the dose and duration in clinical settings especially for dental general anesthesia, the clinical significance of anesthetics exposure on developing central nervous system remains undetermined. Therefore, we conducted the current study in order to observe the fluctuation of intelligence quotient (IQ) after the administration of dental general anesthesia comparing to that before surgery. We conducted the current study in order to observe the fluctuation of intelligence quotient (IQ) after the administration of dental general anesthesia compared with that before surgery.

METHODS

Thirty two patients, ASA I, who were exposed to dental general anesthesia in Department of Pediatric Dentistry Peking University School and Hospital of Stomatology, aged 4 to 6.5 years, were enrolled in this prospective study. Patients with severe learning difficulties or communication disorders were excluded. Written and informed consent was obtained from each patients' family which was fully explained of the purpose and method of study. Their intelligence quotients were evaluated with the Chinese Wechsler young children scale of intelligence (Urban version) before and 2 weeks after dental anesthesia. They were treated by experienced pediatric dentists and the sevoflurane, propofol and nitrous oxide were used for general anesthesia by anesthetist. Articaine hydrochloride and epinephrine tartrate injections were used for their pulp treatment or extraction. The examiners and scorers for IQ had technical training in the test administration. All the patients were tested by the same examiner and with standardized guide language. Each subtest was scored according to the tool review. Verbal IQ and performance IQ consisted of relevant 5 subtests and full scale IQ. Statistical analyses were performed by SPSS 18.0. All the scores of subtests and 3 types of IQ were expressed as mean±standard deviation. Paired two-tailed t test was applied and P<0.05 was accepted as statistically significant.

RESULTS

The results of intelligent assessment from 28 subjects were collected. The anesthetic time was (163.4±32.6) min and the number of treated teeth was 12.1±2.3, mean age (4.60±0.41) years; age range=4.04 to 5.44 years. Among the patients, there were 13 girls and 15 boys. There was no significant difference in gender distribution. The postoperative full IQ (128.46±10.85) was higher than that before surgery (124.64±11.46, P= 0.017). We found that the elevation of performance IQ, to a large extent, contributed to this change in full IQ (P= 0.007). Correspondingly, there was no statistical difference in the verbal IQ, which was 119.68±11.74 to 120.21±15.61 (P=0.854).

CONCLUSION

Dental general anesthesia has no negative effect on the intelligence of preschool children, who were treated under general anesthesia by sevoflurane, propofol and nitrous oxide for 2 to 4 hours. The full IQ and performance IQ were slightly enhanced after treatment which can be explained by the memory effect.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.