[Decompensation effectiveness and alveolar bone remodeling analysis of mandibular anterior teeth after preoperative orthodontic treatment in high-angle patients with skeletal class â ¡ malocclusion].

OBJECTIVE: To evaluate the decompensation effectiveness and alveolar bone remodeling of mandibular anterior teeth after preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusion using lateral cephalogram and cone-beam computed tomography (CBCT). METHODS: Thirty high-angle patients with skeletal class Ⅱ malocclusion who had received preoperative orthodontic treatment and orthognathic surgery in Peking University School and Hospital of Stomatology between Ja-nuary 2017 and August 2022 and had taken lateral cephalogram and CBCT before and after preoperative orthodontic treatment were selected. Items were measured with lateral cephalogram including: The lower central incisor (L1)-Frankfort plane angle (L1-FH), the L1-mandibular plane angle (L1-MP), the L1-nasion-supramental angle (L1-NB) and the vertical distance from the incisal edge of lower central incisor to NB line (L1-NB distance), etc. The incidence of dehiscence/fenestration and the length of dehiscence at labial side (d-La) and lingual side (d-Li) were measured using CBCT. Pearson correlation analysis was used to evaluate the correlation between the changes of d-Li of L1 and age, duration of preoperative orthodontic treatment and the cephalometric measurements before preoperative orthodontic treatment to screen out risk factors affecting the periodontal risk of preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusions. RESULTS: After preoperative orthodontic treatment, L1-FH, L1-MP, L1-NB and L1-NB distances changed by 11.56°±5.62°, -11.13°±5.53°, -11.57°±5.43° and (-4.99±1.89) mm, respectively, and the differences were all statistically significant (P < 0.05). Among the 180 measured mandibular anterior teeth, 45 cases with labial dehiscence/fenestration before preoperative orthodontic treatment (T0) had no longer labial dehiscence/fenestration after preope-rative orthodontic treatment (T1); 142 cases without lingual dehiscence/fenestration at T0 had lingual dehiscence/fenestration at T1. After preoperative orthodontic treatment, the d-La of lower lateral incisors (L2), lower canines (L3) and lower anterior teeth (L1+L2+L3) decreased by (0.95±2.22) mm, (1.20±3.23) mm and (0.68±2.50) mm, respectively, and the differences were statistically significant (P < 0.05); the d-Li of L1, L2, L3 and L1+L2+L3 increased by (4.43±1.94) mm, (4.53±2.35) mm, (3.19±2.80) mm and (4.05±2.46) mm, respectively, and the differences were statistically significant (P < 0.05). The increase of d-Li of L1 was positively correlated with L1-FH (r=0.373, P=0.042). CONCLUSION: This study showed that high-angle patients with skeletal class Ⅱ ma-locclusion could achieve ideal decompensation effect of mandibular anterior teeth after preoperative orthodontic treatment with bilateral mandibular first premolars extracted, but the lingual periodontal risk of mandibular anterior teeth was increased. This risk could be correlated to L1-FH before preoperative orthodontic treatment, which should be paid more attention in the design of orthodontic-orthognathic surgical treatment.

[Analysis of PM(2.5) main pollutant components and sources in two cities in north and south of China].

Objective: To analyze the pollution characteristics and source of fine particulate matter (PM(2.5)) in Shenzhen and Taiyuan, two cities in the north and south of China. Methods: PM(2.5) samples were collected from the year of 2017 to 2018. The levels of 10 heavy metal elements (Pb, Al, As, etc.) , 10 water soluble ions (F(-), Cl(-), SO(4)(2-), etc.) and 16 polycyclic aromatic hydrocarbons (PAHs) (Nap, Acy, Ace, etc.) in PM(2.5) were detected by inductively coupled plasma mass spectrometry (ICP-MS) , ion Chromatography and high Performance Liquid Chromatography respectively. USA commercial carbon analysis was applied to detect organic carbon (OC) and elemental carbon (EC) . Source of PM(2.5) was analyzed by Factor analysis method. Results: The concentrations of Pb, Mn, As, Ni, F(-), OC and EC in PM(2.5) of Taiyuan city were significantly higher than those of Shenzhen City, and the concentrations of Na(+), Cl(-), and PO(4)(3-) were lower than those of Shenzhen City (P<0.05) . Except naphthalene, the concentrations of PAHs in PM(2.5) of Taiyuan city were higher than those of Shenzhen City (P<0.05) . The main sources of metal elements and water soluble ions in PM(2.5) in Shenzhen included: industry/vehicle exhaust factor (42.64%) , construction/soil factor (34.22%) and ocean factor (17.93%) . PAHs in PM(2.5) in Shenzhen mostly came from fuel oil/vehicle exhaust factor (38.58%) , coal combustion factor (30.78%) and biomass combustion factor (24.38%) . Differently, the main sources of metal elements and water soluble ions in PM(2.5) in Taiyuan included: construction factor (30.26%) , fuel oil and coal combustion factor (24.58%) , secondary particles/soil factor (22.03%) and industry factor (18.89%) . PAHs in PM(2.5) were from fuel oil/vehicle exhaust factor (54.71%) and coal combustion factor (43.54%) in Taiyuan. Conclusion: The sources of PM(2.5) pollution are different between Shenzhen and Taiyuan, the occupational health management must be continuously strengthened, measures should be strengthened contrapuntally on the basis of different pollution sources.

Homology difference analysis of invasive mealybug species Phenacoccus solenopsis Tinsley in Southern China with COI gene sequence variability.

The mealybug species Phenacoccus solenopsis (P. solenopsis) has caused much agricultural damage since its recent invasion in China. However, the source of this invasion remains unclear. This study uses molecular methods to clarify the relationships among different population of P. solenopsis from China, USA, Pakistan, India, and Vietnam to determine the geographic origin of the introduction of this species into China. P. solenopsis samples were collected from 25 different locations in three provinces of Southern China. Samples from the USA, Pakistan, and Vietnam were also obtained. Parts of the mitochondrial genes for cytochrome oxidase I (COI) were sequenced for each sample. Homologous DNA sequences of the samples from the USA and India were downloaded from Gen Bank. Two haplotypes were found in China. The first was from most samples from the Guangdong, Guangxi, and Hainan populations in the China and Pakistan groups, and the second from a few samples from the Guangdong, Guangxi, Hainan populations in the China, Pakistan, India, and Vietnam groups. As shown in the maximum likelihood of trees constructed using the COI sequences, these samples belonged to two clades. Phylogenetic analysis suggested that most P. solenopsis mealybugs in Southern China are probably closely related to populations in Pakistan. The variation, relationship, expansion, and probable geographic origin of P. solenopsis mealybugs in Southern China are also discussed.

[A study on alveolar ridge augmentation guided by orthodontic forced eruption in patients with severe periodontitis].

Objective: To evaluate the clinical effect of alveolar bone augmentation in teeth with severe periodontitis using orthodontic forced eruption. Methods: Twelve patients (5 males and 7 females) with severe periodontitis and malocclusion who visited the Department of Orthodontics and Department of Periodontology, Peking University School and Hospital of Stomatology from October 2018 to May 2022 were included in this retrospective study. The age was (38.8±6.6) years (24-49 years). A total of 16 maxillary incisors that could not be retained due to severe periodontitis were included. The orthodontic fixed appliance was used to extrude the teeth. Cone-beam CT (CBCT) images of the patients before and after orthodontic forced eruption were collected. The voxel-based registration was used to superpose the images before and after orthodontic forced eruption. The height, thickness, and apical alveolar bone area were measured on the sagittal plane. The alveolar bone volume before and after orthodontic forced eruption was measured using three-dimensional reconstruction technique, and the influencing factors related to the alveolar volume change were analyzed. Results: The results of this study showed that the eruption distance of the teeth was (2.37±0.82) mm, and the alveolar bone height increased by (1.11±0.79) and (0.98±0.79) mm (t=3.73, P=0.010; t=4.85, P<0.001). The proximal and distal alveolar bone height increased by (1.10±0.78) and (0.86±1.08) mm, respectively (t=5.59, P<0.001; t=3.18, P=0.006). The alveolar bone thickness decreased (0.30±0.31) mm (t=-3.75, P=0.002) and alveolar bone area increased (6.84±5.86) mm2 (t=3.71, P<0.001). The alveolar bone volume increased (53±49) mm3 (t=4.38, P<0.001). The alveolar bone volume was moderately positively correlated with eruption distance, apical and mesial alveolar bone thickness (r=0.55, P=0.028; r=0.63, P=0.008; r=0.67, P=0.005). Conclusions: Orthodontic forced eruption results in a favorable increase of the alveolar bone in the upper incisor that cannot be retained due to severe periodontitis, which provides better periodontal hard tissue conditions for subsequent dental implant.

[Clinical and radiographic effect of simultaneously labial and lingual augmented corticotomy: a prospective case series study].

Objective: To investigate soft-and hard-tissue changes after simultaneously labial and lingual augmented corticotomy in patients with insufficient alveolar bone thickness of lower anterior teeth both in labial and lingual side during orthodontic treatment. Methods: From January 2021 to June 2022, 10 patients [2 males and 8 females, (26.2±3.1) years old] who received orthodontic and orthognathic combined treatment from the Fourth Clinical Division, Peking University School and Hospital of Stomatology were selected. The alveolar bone thickness of lower anterior teeth both in labial and lingual side in these patients was less than 0.5 mm according to cone-beam CT examination before or during treatment, and 60 lower anterior teeth were included. The 10 patients were treated with simultaneously labial and lingual augmented corticotomy. The differences in gingival recession, papilla index and the differences in labial and lingual alveolar bone thickness of lower anterior teeth were compared. Results: Six months after surgery, the alveolar bone thicknesses at the 4 mm under cemento-enamel junction (CEJ), 8 mm under CEJ and at the apical level [labial side: (1.02±0.39), (2.22±0.89) and (4.87±1.35) mm; lingual side: (1.07±0.46), (2.31±1.04) and (3.91±1.29) mm] were significantly higher than that before surgery [labial side: (0.02±0.09), (0.06±0.21) and (2.71±1.33) mm]; lingual side: (0.14±0.29), (0.40±0.52) and (2.13±1.02) mm] (P<0.001), respectively. The increases in alveolar bone thickness of central incisors [apical level on labial side: (2.53±1.20) mm, 8 mm under CEJ on lingual side: (2.27±1.24) mm, apical level on lingual side: (2.66±1.49) mm] and lateral incisors [apical level on labial side: (2.42±1.30) mm, 8 mm under CEJ on lingual side: (2.28±0.92) mm, apical level on lingual side: (1.94±1.15) mm] were significantly higher than that of canines [apical level on labial side: (1.52±1.47) mm, 8 mm under CEJ on lingual side: (1.17±1.09) mm,apical level on lingual side: (0.74±1.37) mm] (P<0.01). There were no significant differences in the degree of gingival recession [labial side before surgery: (0.72±0.88) mm, lingual side before surgery: (0.80±1.09) mm; labial side 6 months after surgery: (0.72±0.81) mm,lingual side 6 months after surgery: (0.89±0.21) mm] and gingival papilla index [before surgery: 1.00(0.75, 2.00); 6 months after surgery: 1.00(1.00, 2.00) ] between pre-operation and 6 months after surgery (P>0.05). No serious complications occurred. Conclusions: The method used in this article for simultaneously labial and lingual augmented corticotomy was safe and feasible. This surgery has positive clinical significance for the stability of the periodontal tissue in orthodontic treatment for patients with alveolar bone thickness less than 0.5 mm of lower anterior teeth both in labial and lingual side.

Meta-analysis confirms that a common G/C variant in the pre-miR-146a gene contributes to cancer susceptibility and that ethnicity, gender and smoking status are risk factors.

Evidence has shown that miR-146a is involved in carcinogenesis, and a common G/C variant (rs2910164) in the pre-miR-146a gene has been associated with various types of cancer. We summarized the data from 22 published case-control studies on the association between rs2910164 and cancer risk and performed subgroup analyses by ethnicity, gender and smoking status. We found a significant association between the pre-miR-146a polymorphism and cancer risk in Caucasian populations (odds ratio (OR) = 0.93, 95% confidence interval (CI) = 0.88-0.99 for G- vs C-allele), while the significance was borderline in Asian populations (OR = 1.11, 95%CI = 1.00-1.23 for G- vs C-allele). A significantly increased risk of cancer was found in males with GG/GC genotypes (OR = 1.23, 95%CI = 1.10- 1.37), and the significance was more pronounced in smokers (OR = 1.82, 95%CI = 1.32-2.51) than in non-smokers (OR = 1.24, 95%CI = 1.01-1.53). We conclude that there is evidence that the pre-miR-146a polymorphism contributes to cancer susceptibilities and that gender and smoking status affect the probability of cancer in individuals with this polymorphism.

Knockdown of long noncoding RNA DLX6-AS1 inhibits migration and invasion of thyroid cancer cells by upregulating UPF1.

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "Knockdown of long noncoding RNA DLX6-AS1 inhibits migration and invasion of thyroid cancer cells by upregulating UPF1, by Z.-B. Zhong, Y.-J. Wu, J.-N. Luo, X.-N. Hu, Z.-N. Yuan, G. Li, Y.-W. Wang, G.-D. Yao, X.-F. Ge, published in Eur Rev Med Pharmacol Sci 2019; 23(24): 10867-10873-DOI: 10.26355/eurrev_201912_19790-PMID: 31858555" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/19790.

Knockdown of long noncoding RNA DLX6-AS1 inhibits migration and invasion of thyroid cancer cells by upregulating UPF1.

OBJECTIVE: Recently, long non- coding RNAs (lncRNAs) have attracted much attention for their roles in tumor progression. The aim of this study was to investigate the exact role of lncRNA DLX6 antisense RNA 1 (DLX6-AS1) in the development of thyroid cancer (TC), and to explore the underlying mechanism. PATIENTS AND METHODS: DLX6-AS1 expression in both TC cells and tissue samples was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Moreover, transwell assay and wound healing assay were conducted. QRT-PCR and Western blot assay were used to explore the underlying mechanism. Furthermore, the function of DLX6-AS1 was identified in vivo. RESULTS: DLX6-AS1 expression level in TC tissues was significantly higher than that of the corresponding normal tissues. Moreover, TC cell migration and invasion were markedly inhibited after DLX6-AS1 was knocked down in vitro. The mRNA and protein expressions of UPF1 were both remarkably up-regulated after knockdown of DLX6-AS1. Meanwhile, the expression level of UPF1 was negatively correlated with the expression of DLX6-AS1 in TC tissues. Furthermore, knockdown of DLX6-AS1 significantly inhibited tumor metastasis in vivo. CONCLUSIONS: Knockdown of DLX6-AS1 could inhibit TC cell migration and invasion via upregulating UPF1, which might be a potential therapeutic target in TC.

Conformation change of bovine serum albumin induced by bioactive titanium metals and its effects on cell behaviors.

The conformation change of bovine serum albumin (BSA) induced by bioactive titanium surfaces, including acid-alkali-treated titanium (AA-Ti) and alkali-heat-treated titanium (AH-Ti), was studied, and its effects on the activity of MC3T3-E1 cell were evaluated. Pure titanium metal (P-Ti) was used as control. The AA-Ti could adsorb more BSA on its surface than AH-Ti and P-Ti. The α-helix part of the protein adsorbed on P-Ti has weakly decreased compared with native BSA, and it dramatically decreased on AA-Ti and AH-Ti. The ß-sheet segment of proteins adsorbed on P-Ti and AH-Ti had obviously increased. Much more tryptophan residues were exposed after the protein conformation changed when it interacted with AH-Ti, and some tryptophan residues were enveloped after it interacted with AA-Ti and P-Ti. AA-Ti has more tryptophan residues enveloped than P-Ti. All titanium surfaces induced tyrosine residues exposed, especially for the P-Ti. The higher ratio of COO(-)/NH3(+) for the proteins on P-Ti and AA-Ti indicated an orientation of proteins on P-Ti and AA-Ti, which makes more COO(-) exposed. The lower ratio of COO(-)/NH3(+) on AH-Ti indicates that more NH3(+) is exposed on its surface. The cell proliferation ability on different treated titanium surfaces coated with BSA followed by the order: P-Ti > AA-Ti > AH-Ti, which indicated that the protein conformation change on different bioactive titanium surfaces has great effect on the cell activity. Our results showed that the different biological response of bioactive titanium metals might depend on the protein conformation change induced by the surface structure.

The chemical properties of silica particle surface in relation to silica-cell interactions.

Although silicosis has been studied extensively, the mechanism is still not fully understood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are thought to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.

Relevance of N-nitrosamines to oesophageal cancer in China.

Oesophageal cancer occurs at a very high frequency in certain areas of China, especially in Linxian county, Henan province. Previous studies suggested that N-nitroso compounds play a causative role. In order to study further the exposure of Linxian inhabitants, the intake of N-nitrosamines in the diet was determined. The total daily intake of volatile nitrosamines and of N-nitroso-N-methylbenzylamine (NMBzA) was higher in Linxian than in two other counties. NMBzA can induce cancer in animal and human oesophageal epithelium. Human fetal oesophageal epithelia were cultured with NMBzA for 4 h, and eight monkeys were treated with NMBzA. High-molecular-weight DNA extracted from explants and from the oesophageal epithelia of monkeys induced malignant transformation of NIH 3T3 cells. Alu and monkey-specific repeat sequences were present in transformed cells, and H-ras was found in the transforming DNA. Human fetal oesophageal epithelium cultured with NMBzA was transplanted into the mesentery of BALB/c nude mice. Tumours were found after eight months; and the Alu sequence was present in DNA extracted from tumours induced by NMBzA, showing that the tumours were of human origin. The results provide direct evidence that NMBzA is carcinogenic in human oesophageal epithelium and that N-nitrosamines are one of the causative factors of oesophageal cancer in Linxian county.