Evaluation of stress and displacement of maxillary canine during the single canine retraction in the maxillary first premolar extraction cases- A finite element study.

OBJECTIVES: This finite element study aimed to simulate maxillary canine movement during anterior teeth retraction. MATERIALS AND METHODS: Three methods of maxillary canine movement including miniscrew sliding with high hooks (MSH), miniscrew sliding with low hooks (MSL), and the traditional sliding method (TS) without using miniscrews were simulated using three-dimensional finite element analysis. The initial displacement of the maxillary canine, the maximum principal stress of the periodontal ligament and the Von Mises stress were calculated. RESULTS: The distolingual tipping movements of the canine were shown in three movement modes. MSH showed a small tendency to lingual tipping movement and a extrusion movement while MSL had the largest lingual inclination. TS demonstrated a tendency toward distolingual torsion displacement. Compressive stress values were mainly concentrated in the range - 0.003 to -0.006 MPa. For tensile stress, the distribution of MSH and MSL was concentrated in the range 0.005 to 0.009 MPa, TS was mainly distributed about 0.003 MPa. Von Mises equivalent stress distribution showed no significant difference. CONCLUSIONS: The loss of tooth torque was inevitable, irrespective of which method was used to close the extraction space. However, miniscrew application and higher hooks reduced the loss of torque and avoided lingual rotation. CLINICAL RELEVANCE: This study shows that miniscrew implants with different hooks can better control the movement of the maxillary canines. The non-invasive nature of the finite element analysis and its good simulation of dental stress and instantaneous motion trend have a clinical advantage in the analysis of tooth movement.

A Case Report of Neonatal Lupus Erythematosus with Liver Function Damage and Cytomegalovirus Colonization.

BACKGROUND: Neonatal lupus erythematosus (NLE) is an acquired autoimmune disease. NLE with liver function damage and cytomegalovirus colonization is rarely reported. METHODS: This case describes a newborn male's laboratory testing found sustained liver function damage when he came to see the doctor due to oral candidiasis. The cause was identified through clinical symptoms, laboratory tests, auxiliary examinations, and family history of the patient. RESULTS: The final diagnosis of the child was NLE with liver function damage and cytomegalovirus colonization according to comprehensive analysis and follow-up observation. CONCLUSIONS: NLE and cytomegalovirus colonization can both lead to liver function damage. When the organ function of newborns is abnormal, it is necessary to promptly investigate the cause and determine whether it is NLE.

The development of local ambient air quality standards: A case study of Hainan Province, China.

The ambient air quality standard (AAQS) is a vital policy instrument for protecting the environment and human health. Hainan Province is at the forefront of China's efforts to protect its ecological environment, with an official goal to achieve world-leading air quality by 2035. However, neither the national AAQS nor the World Health Organization guideline offers sufficient guidance for improving air quality in Hainan because Hainan has well met the former while the latter is excessively stringent. Consequently, the establishment of Hainan's local AAQS becomes imperative. Nonetheless, research regarding the development of local AAQS is scarce, especially in comparatively more polluted countries such as China. The relatively high background values and significant interannual fluctuations in air pollutant concentrations in Hainan present challenges in the development of local AAQS. Our research proposes a world-class local AAQS of Hainan Province by reviewing the AAQS in major countries or regions worldwide, analyzing the influence of different statistical forms, and carefully evaluating the attainability of the standard. In the proposed AAQS, the annual mean concentration limit for PM2.5, the annual 95th percentile of daily maximum 8-h mean (MDA8) concentration limit for O3, and the peak season concentration limit for O3 are set at 10, 120, and 85 µg/m3, respectively. Our study indicates that, with effective control policies, Hainan is projected to achieve compliance with the new standard by 2035. The implementation of the local AAQS is estimated to avoid 1,526 (1,253-1,789) and 259 (132-501) premature deaths attributable to long-term exposure to PM2.5 and O3 in Hainan in 2035, respectively.

[Progress in Application of Heparin Coating in Blood Contact Medical Devices].

Blood compatibility is the main restriction of blood-contacting medical devices in clinical application, especially long-term blood-contacting medical devices will stimulate the immune defense mechanism of the host, resulting in thrombosis. Heparin anticoagulant coating links heparin molecules to the surface of medical device product materials, improves the compatibility between the material surface interface and the body, and reduces the host immune defense reactions. This study reviews the structure and biological properties of heparin, the market application status of heparin-coated medical products, the insufficiency and improvement of heparin coating, which can provide a reference for the application research of blood contact medical devices.

Prediction of clinical efficacy of subcutaneous immunotherapy for Artemisia sieversiana pollen allergic rhinitis by serum metabolomics.

BACKGROUND/PURPOSE: Specific immunotherapy is the only effective etiological treatment for allergic rhinitis, but subcutaneous immunotherapy has a slow onset and poor compliance. Predicting the clinical efficacy of subcutaneous immunotherapy in advance can reduce unnecessary medical costs and resource waste. This study aimed to identify metabolites that could predict the efficacy of subcutaneous immunotherapy on seasonal allergic rhinitis by serum metabolomics. METHODS: Patients (n = 43) with Artemisia sieversiana pollen allergic rhinitis were enrolled and treated with subcutaneous immunotherapy for one year. Patients were divided into the ineffective group (n = 10) and effective group (n = 33) according to the therapeutic index. Serum samples were collected before treatment. Metabolomics was determined by liquid chromatography-mass spectrometry combined with gas chromatography-mass spectrometry and analyzed differential compounds and related metabolic pathways. RESULTS: A total of 129 differential metabolites (P < 0.05) were identified and 4 metabolic pathways, namely taurine and hypotaurine metabolism, pentose and glucuronate interconversions, pentose phosphate pathway, and alanine, aspartate, and glutamate metabolism, were involved. CONCLUSION: Some metabolites, such as hypotaurine, taurine, and l-alanine, have the potential to become predictive biomarkers for effective subcutaneous immunotherapy.

[Epidemiological survey of allergic rhinitis in steppe area of Xilingol League, Inner Mongolian of China].

Objective:To investigate the epidemiologic feature of allergic rhinitis （AR） in the grassland area of Xilin Gol League, in Inner Mongolia, including prevalence rate, clinical characteristics and main allergens, so as to provide scientific evidence for the prevention and treatment of AR. Methods:From May to August of 2015, in strict accordance with the requirements of epidemiological investigation, A multi-stage, stratified， random and cluster sampling method was adopted to investigate the population in three areas of Xilingol Grassland in Inner Mongolia （Xilinhot, Erlianhot and Duolun）, with a face to face questionnaire used to investigate the general situation, the main clinical symptoms and related symptoms of AR and the combined. Simultaneously, the skin prick test （SPT） of 10 common grassland allergens was carried out, and the gravity sedimentation method was used to monitor the daily pollen types and quantity in the area.SAS 9.4 software was used for data analysis． Results:A total of 2878 subjects in the cluster sample completed the questionnaire survey and allergen detection. The positive rate of SPT was 41.10% （1179/2787）, the self-reported prevalence rate of AR was 39.96%（1150/2878） and confirmed prevalence rate of AR was 22.72%（654/2878）. The most obvious clinical symptoms of AR were sneezing （91.13%, 1048/1150） and itchy nose （85.65%, 985/1150）. The most obvious clinical symptoms of ocular were itchy （55.13%, 634/1150） and tearing（42.96%，494/1150）. Fatigue and somnolence were prominent among other symptoms associated with AR. Among comorbidities, AR combined with conjunctivitis accounted for 60.52% （696/1150）, AR combined with asthma accounted for 13.57% （156/1150）. The major allergens of AR from high to low were Artemisia pollen, Chenopodium pollen, and Humulus pollen. The peak of AR symptoms mostly occuredin August.， and the peak period of allergic rhinitis symptoms coincided with the peak period of pollen quantity. Conclusion:The prevalence rate of AR in is extremely high due to the high seasonal pollen exposure in steppe area of Xilingol League in Inner Mongolian. Artemisia pollen is the main sensitized allergen.

Study on the Performance of Titanium Materials Based on Nano Silver Particles in Orthodontic Healing.

Nanomaterials are used as a new type of antibacterial agent in clinical medical research projects due to their unique physical and chemical properties. In this study, silane coupling method was used to coat nano-silver particles on titanium sheets to make the smooth titanium surface have antibacterial properties. Scanning electron microscope to observe the surface morphology of silane coupling modified titanium plate, the shape and size of nano-silver particles, and the adhesion on titanium plate; X-ray energy spectroscopy and line scan analysis of each element on the titanium wafer; X-ray photoelectron spectroscopy quantitative analysis of surface elements on the titanium wafer. The experimental group was nano-silver modified titanium sheet, and the control group was smooth titanium sheet. The experimental results show that the titanium material loaded with nano-silver particles has better antibacterial performance in the orthodontic process than ordinary materials. This material is highly safe and can be promoted for use.

Leukotriene A4 Hydrolase Is a Candidate Predictive Biomarker for Successful Allergen Immunotherapy.

Background: Allergic rhinitis is a common disorder that affects 10% to 40% of the population worldwide. Allergen immunotherapy (AIT) represents the only therapy that has the potential to resolve clinical symptoms of allergic rhinitis. However, up to 30% of patients do not respond to AIT. Biomarkers predicting the clinical efficacy of AIT as early as possible would significantly improve the patient selection and reduce unnecessary societal costs. Methods: Artemisia pollen allergic patients who received at least 1-year AIT were enrolled. Clinical responses before and after 1-year AIT were evaluated to determine AIT responders. Artemisia specific IgE and IgG4 levels were measured by using ImmunoCAP and enzyme-linked immunosorbent assay (ELISA) separately. Stepwise regression analysis was performed to identify which rhinitis-relevant parameters explained the most variability in AIT results. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics was applied to identify the potential candidate biomarkers in the sera of responders and non-responders collected before and after 1-year therapy. The diagnostic performance of the potential biomarkers was then assessed using enzyme-linked immunosorbent assay (ELISA) in 30 responders and 15 non-responders. Results: Artemisia specific IgE and IgG4 levels were elevated only in the responders. Regression analysis of allergic rhinitis-relevant parameters provided a robust model that included two most significant variables (sneeze and nasal congestion). Thirteen candidate biomarkers were identified for predicting AIT outcomes. Based on their association with allergy and protein fold change (more than 1.1 or less than 0.9), four proteins were identified to be potential biomarkers for predicting effective AIT. However, further ELISA revealed that only leukotriene A4 hydrolase (LTA4H) was consistent with the proteomics data. The LTA4H level in responders increased significantly (P < 0.001) after 1-year therapy, while that of non-responders remained unchanged. Assessment of LTA4H generated area under curve (AUC) value of 0.844 (95% confidence interval: 0.727 to 0.962; P < 0.05) in distinguishing responders from the non-responders, suggesting that serum LTA4H might be a potential biomarker for predicting the efficiency of AIT. Conclusion: Serum LTA4H may be a potential biomarker for early prediction of an effective AIT.

Clinical Efficacy Evaluation of 1-Year Subcutaneous Immunotherapy for Artemisia sieversiana Pollen Allergic Rhinitis by Serum Metabolomics.

Subcutaneous immunotherapy is the only treatment that improves the natural progression of allergic rhinitis and maintains long-term outcomes after discontinuation of the drug. Metabolomics is increasingly applied in the study of allergic diseases, including allergic rhinitis. However, little is known about the discovery of metabolites that can evaluate clinical efficacy and possible mechanisms of Artemisia sieversiana pollen subcutaneous immunotherapy. Thirty-three patients with Artemisia sieversiana pollen allergic rhinitis significantly improved after 1-year subcutaneous immunotherapy treatment, while ten patients were ineffective. Pre- and post-treatment serum samples from these patients were analyzed by metabolomics based on the combined detection of liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. As a result, L-Tyrosine can be a potential biomarker because of its opposite trend in effective patients and ineffective patients. And mechanism of immunotherapy may be closely related to NO and nitric oxide synthase. The discovery of potential biomarkers and metabolic pathways has contributed to the in-depth study of mechanisms of subcutaneous immunotherapy treatment of Artemisia sieversiana pollen allergic rhinitis.

Silencing MEKK3 attenuates cardiomyocyte injury caused by hypoxia/reoxygenation via the sonic hedgehog pathway.

MEKK3 is a member of MAP3K, which plays a pivotal role in cardiac diseases. In this study, we aimed to investigate the effects and potential mechanisms of MEKK3 on hypoxia/reoxygenation (H/R) injury of cardiomyocytes. After exposing H9C2 cells to H/R insult, real-time polymerase chain reaction and western blot analysis showed that MEKK3 was highly expressed. Cell viability, cell apoptosis, caspase 3/7 activity, and cleaved-caspase 3 expression were tested using a CCK-8 assay, Cell Death Detection PLUS ELISA, Caspase-Glo 3/7 Assay Kit and western blot analysis, respectively. Mitochondrial membrane potential, cytochrome C expression, adenosine triphosphate (ATP), and reactive oxygen species also were measured using JC-1 staining, western blot analysis, an ATP Assay Kit, and DCFH 2 -DA staining, respectively. The messenger RNA (mRNA) levels and secretions of TNF-α, IL-6, and IL-1ß were evaluated. The results revealed that MEKK3 silencing promoted cell survival and attenuated lactate dehydrogenase leakage, cell apoptosis, caspase 3/7 activity, and the protein level of cleaved-caspase 3. Moreover, knockdown of MEKK3 blocked mitochondrial impairment by inhibiting the loss of mitochondrial membrane potential and cytochrome C expression as well as promoting ATP synthesis. MEKK3 deficiency led to a decrease in reactive oxygen species and malondialdehyde (MDA) generation and an increase in superoxide dismutase (SOD) activity. Deletion of MEKK3 led to reduced inflammatory cytokines in mRNA level and secretion. MEKK3 suppression activated the sonic hedgehog (Shh) signaling pathway in H9C2 cells. After blocking the Shh signaling pathway with a specific inhibitor, cyclopamine, the cardioprotective functions of MEKK3 downregulation were partly abolished. In conclusion, downregulation of MEKK3 prevented apoptosis and inflammation in H9C2 cells via the Shh signaling pathway.

Effects of calcitonin on orthodontic tooth movement and associated root resorption in rats.

OBJECTIVES: Our main aim was to evaluate the effects of calcitonin (CT) on orthodontic tooth movement (OTM) and orthodontic root resorption in a rat model. MATERIAL AND METHODS: Eighty male Wistar rats were randomly divided into five groups. Rats in the negative control group were not given any appliances or injections. All the remaining rats were used to establish a model of OTM. The positive control group were then injected with normal saline, while rats in the three experimental groups were injected with 0.2 IU, 1 IU or 5 IU/kg/day CT. Nickel-titanium closed-coil springs were used to deliver an initial 50 g mesial force to the left maxillary first molar for 14 days in rats in the positive control group and the experimental groups. Each group was randomly subdivided into two groups, one for analysis of tooth movement, tissue changes and tartrate-resistant acid phosphatase (TRAP)-positive cells in alveolar bone, the other to examine root resorption by scanning electron microscopy. RESULTS: The OTM distance, the number of force-induced osteoclasts and root resorption areas were significantly decreased in CT-injected rats in a dose-dependent manner. CONCLUSIONS: Administration of CT reduces the root resorption area and may therefore be effective as a novel adjunctive orthodontic approach to diminish undesired tooth movement via enhancing anchorage or preventing relapse after OTM.

The 100 top-cited articles in orthodontics from 1975 to 2011.

OBJECTIVE: To identify the 100 top-cited articles published in orthodontics journals and to analyze their characteristics to investigate the achievement and development of orthodontics research in past decades. METHODS AND MATERIALS: The Institute for Scientific Information Web of Knowledge Database and the 2011 Journal Citation Report Science Editions were used to retrieve the 100 top-cited articles published in orthodontics journals since 1975. Some basic information was collected by the Analyze Tool on the Web of Science, including citation time, publication title, journal name, publication year, and country and institution of origin. A further study was then performed to determine authorship, article type, field of study, study design, and level of evidence. RESULTS: The 100 target articles were retrieved from three journals: American Journal of Orthodontics and Dentofacial Orthopedics (n  =  74), The Angle Orthodontist (n = 15), and European Journal of Orthodontics (n  =  11). Since 1975, the articles cited 89 to 545 times mainly originated from the United States, and the overwhelming majority of articles were clinical. The most common study design was case series; 40 articles were classified as level IV and 12 as level V evidence. CONCLUSIONS: The 100 top-cited articles in orthodontics are generally old articles, rarely possessing high-level evidence.

[The contrastive study on lip profile of malocclusion of Class I, II and II in Harbin].

OBJECTIVE: To get reference for the diagnosis design and the clinical diagnosis, the difference is compared among lip profile on malocclusion of Class I, II and III from patients in Harbin, and the relationship is established between the linear cephalometric measurements and the regional cephalometric measurements. METHODS: 120 female patients, 18-25 years old, were selected. According to the value of / ANB which was measured on the pre-treatment cephalographs, they were divided into three groups--Class I, II and III. Each group had 40 patients. Each patient had the same type of skeletal pattern and occlusion pattern, and then 21 lip soft tissues were measured. Finally, the results of measurements were statistically analyzed with ANOVA and were compared between members in each group via SPSS 13.0 software. RESULTS: The differences among patients with lip profile on malocclusion had statistic significances (P < 0.05). In order of Class II, I and III, the UL-E, ULP, ULP-LLP, Sn-Ns-B' and S4 were progressively decreased and the B'-LL-FH, S-Ns-B' and S1 were increased. In order of Class II, III and I, the LL-B'-Pos and Z-angle were raised and LL-E was reduced. The length of the upper lip and the lower lip had no statistic significance (P > 0.05). CONCLUSION: There is difference among the Class I, II and III. The lip covering area is inclined to decrease the changes of the upper lip and increase the changes of the lower lip progressively with the variation of skeletal patterns in order of Class II, I, and III. Moreover, the condition of lip tissues can be accurately presented by the regional cephalometric measurements.