[Effect of 2-year resistance exercises on cardiovascular disease risk in prediabetes patients]

Objective: To investigate the effect of a 2-year resistance and aerobic training on reducing the risk of cardiovascular disease in patients with prediabetes. Methods: A total of 248 patients with prediabetes were enrolled from Chinese and Western Medicine Hospital Affiliated to Nanjing University of Chinese Medicine from January to April 2014, and Danyang People's Hospital and The First Affiliated Hospital of Guangxi Medical University from May to December 2014.Based on random number table method, the patients were divided into 3 groups: the resistance training group (RT group, 82 cases), the aerobic training group (AT group, 83 cases) and control group (83 cases). Participants in the RT group and the AT group underwent a total of 24 months of exercise training. Changes in indicators (blood glucose,blood lipid, etc.) at baseline and the end of 12 and 24 months among the groups were compared. Results: After intervention, glycosylated hemoglobin (HbA1c), low density lipoprotein cholesterol (LDL-C), blood pressure and homeostasis model 2 insulin resistance index (HOMA2-IR) in the RT and AT groups tended to decrease, and the steady state model 2 β cell function index (HOMA2-β) tended to increase. At the end of 24 months, HbA1c [5.80 (5.43, 6.20) %, 5.70 (5.50, 6.00)% vs. 6.20 (5.70, 6.60) %, all P ≤ 0.01], LDL-C [3.07 (2.69, 3.58) mmol/L, 2.97 (2.62, 3.95) mmol/L vs. 3.21(2.54, 3.78) mmol/L, all P<0.05] and HOMA2-IR [0.96 (0.82, 1.47), 1.20 (0.99, 1.43) vs. 1.34 (1.09, 1.51), all P<0.05] were significantly decreased in the RT and AT groups than in the control group. In addition, HOMA2-β [84.50 (60.55, 107.33), 93.00 (78.60, 119.75) vs. 53.40 (37.70, 80.40), all P = 0.001] was significantly increased in the AT and RT groups compared with that in the control group. There were no significant differences in triglyceride (TG) and high-density lipoproteincholesterol (HDL-C) levels between the training groups and the control group (all P>0.05). After adjusting for age, sex and blood pressure, the cardiovascular risk of prediabetes was significantly reduced in RT (P =0.017) and AT groups (P =0.018). The Cox regression analyses showed that both the resistance training (HR=0.419, 95%CI =0.415-0.942, P=0.037) and the aerobic training (HR=0.310, 95%CI=0.447-0.866, P=0.026) were protective factors for cardiovascular disease in prediabetic patients after adjustment of age, sex, statins, body mass index and waist-to-hip ratio, which reduced the risks of cardiovascular disease in prediabetic patients by 58.1% and 69.0%, respectively. Conclusions: Two years of aerobic and resistance training interventions have obvious advantages on glycemic and insulin resistance control in prediabetes patients. The resistance training can reduce the risk of cardiovascular disease, and it is, thus, recommended for prediabetic patients without obvious exercise contraindications.

Discontinuous Transitions and Rhythmic States in the D-Dimensional Kuramoto Model Induced by a Positive Feedback with the Global Order Parameter

From fireflies to cardiac cells, synchronization governs important aspects of nature, and the Kuramoto model is the staple for research in this area. We show that generalizing the model to oscillators of dimensions higher than 2 and introducing a positive feedback mechanism between the coupling and the global order parameter leads to a rich and novel scenario: the synchronization transition is explosive at all even dimensions, whilst it is mediated by a time-dependent, rhythmic, state at all odd dimensions. Such a latter circumstance, in particular, differs from all other time-dependent states observed so far in the model. We provide the analytic description of this novel state, which is fully corroborated by numerical calculations. Our results can, therefore, help untangle secrets of observed time-dependent swarming and flocking dynamics that unfold in three dimensions, and where this novel state could thus provide a fresh perspective for as yet not understood formations.

THU0048 THE FUNCTION CHANGES OF SNPS IN THE P2X7 RECEPTOR BY ALA348TO THR, GLU496TO ALA AND ARG307TO GLN IN THP-1 CELLS WITH HIGH URIC ACID

Background:

Previous studies[1] have shown that ATP acts on the sputum receptor P2X ligand-gated ion channel 7 (P2X7R) as a second signal to induce gouty arthritis.

Objectives:

In this study, the functional changes of three SNP genotypes, Ala348 to Thr, Glu 496 to Ala and Arg307 to Gln, in P2X7R were analyzed with high uric acid.

Methods:

After transfection of HEK-293T cells by lentivirus, observing the uptake ability of HEK-293T cells to ethidium bromide. The effect of three different mutants on the P2X7 receptor was thus observed on the P2X7 channel. In addition, THP-1 cells were also transfected, stable expression of a THP-1 cell line that has been transfected with a wild-type or different mutants and thus established. Then three types were set up separately, and each type was randomized into three groups: MSU(labeled M), MSU+ATP (labeled MA), and unstimulated control group (labeled C).Detection of IL-1β protein expression level in serum by ELISA and NLRP3, ASC and Caspase-1 mRNA levels in transfected THP-1 cells by qRT-PCR.

Results:

1.These three variants have different effects on the uptake function of ATP-induced ethidium+bromide in transfection of HEK-293T cells by lentivirus. Ala348to Thr increased P2X7-dependent ethidium+bromide uptake (145% of wild-type P2X7response, P<0.001). In contrast, Absent or very reduced P2X7function was found in Glu496to Ala and Arg307to Gln subjects, appeared to abolish P2X7-dependent dye uptake (38% and 32% of wild-type P2X7responses, P<0.001,), who were compared with wild-type.

2.Compared the IL-1β levels of the three variants with the wide-type and empty virus in THP-1 cells, the Ala348to Thr mutation significantly up-regulated the serum levels of IL-1β compared with the wide-type and empty virus in group MA with high uric acid (P=0.0007;P=0.013, respectively). Moreover, similar results have also been shown in IL-1β mRNA expressions (P=0.0334; P=0.0307, respectively). The Glu496to Ala and Arg307to Gln mutations down-regulated the serum levels of IL-1β compared with the wide-type in group MA (P=0.0189;P=0.0164, respectively).

3.NLRP3 mRNA was significantly increased in the Ala348to Thr mutation compared with the wide-type and empty virus in group MA (p =0.0003;P=0.0001, respectively). However, NLRP3 mRNA was significantly reduced in the Glu496to Ala and Arg307to Gln mutations compared with the wide-type in group MA (p =0.0294;P=0.0279, respectively).

4.Wild-type was signifcantly higher than empty virus in the ASC gene expression in group MA(P=0.0022). Morever, the Ala348to Thr mutation was higher than empty virus while Arg307to Gln mutation was lower than that in group MA (P=0.0138;P=0.0283, respectively).

5.Unlike NLRP3 gene expression, the data showed that the expression of caspase-1 mRNA in group C, M and MA all with no statistical significance, respectively (P>0.05).

Conclusion:

Our data revealed that Ala348to Thr up-regulate the functional status of P2X7R and Glu496to Ala and Gln460to Arg down-regulate the functional status of P2X7R, which resulted in a significant increase or decrease in IL-1β and NLRP3 expression levels with high uric acid.

References:

[1]Tao JH, Zhang Y, Li XP, et al. P2X7R: a potential key regulator of acute gouty arthritis[J].Semin Arthritis Rheum, 2013,43(3):376–380.

Disclosure of Interests:

None declared

AB0530 CHARACTERISTICS AND MEDIUM-TERM OUTCOMES OF TAKAYASU ARTERITIS–RELATED RENAL ARTERY STENOSIS: ANALYSIS OF A LARGE CHINESE COHORT

Background:

The incidence of renal artery stenosis in Takayasu arteritis (TA) was 20%–60% according to previous reports. The specific characteristics of patients with TA-related renal artery stenosis and the effect of revascularization procedures on prognosis have not been fully investigated.

Objectives:

To investigate the characteristics of patients with TA-related renal artery stenosis and identify the predictors of medium-term adverse outcomes.

Methods:

Data for 567 patients registered in a large prospective observational cohort-the East China Takayasu arteritis cohort-up to April 30, 2019, were retrospectively analyzed.

Results:

Renal artery stenosis was confirmed in 172/567 (30.34%) patients, with left renal artery involvement seen in 73/172 (42.44%) patients. Renal insufficiency at presentation (HR = 2.37, 95% CI: 1.76-15.83, p = 0.03), bilateral renal artery involvement (HR = 6.95, 95% CI: 1.18-21.55, p = 0.01), and severe (>75%) stenosis (HR = 4.75, 95% CI 1.08-11.33, p = 0.05) were predictors of adverse outcomes. Revascularization was performed for 46/172 (26.74%) patients. Patients without preoperative treatment had higher rate of restenosis (44.44% vs. 15.79%, p < 0.01) and hypertension deterioration (25.93% vs. 10.53%, p < 0.01) after the procedure. Non-receipt of preoperative treatment (HR = 6.5, 95% CI: 1.77-32.98, p = 0.04) and active disease at revascularization (HR = 4.21, 95% CI 2.01-21.44, p = 0.04) were independent predictors of adverse outcomes after revascularization.

Conclusion:

Patients with uncontrolled or worsening hypertension or/and renal function may benefit from revascularization. Those who have received preoperative treatment may have more favorable revascularization outcomes. Prognosis appears to be poorer for patients with renal insufficiency at presentation, bilateral artery involvement, and severe stenosis.

References:

[1]Watanabe Y, Miyata T, Tanemoto K. Current clinical features of new patients with Takayasu arteritis observed from a cross-country research in Japan: age and sex specificity. Circulation 2015; 132: 1701-9.

[2]Peng M, Jiang XJ, Dong H, et al. Etiology of renal artery stenosis in 2047 patients: a single-center retrospective analysis during a 15-year period in China. J Hum Hypertens 2016; 30: 124-8

Disclosure of Interests:

None declared

Comparative transcriptome profiling reveals candidate genes related to insecticide resistance of Glyphodes pyloalis

Glyphodes pyloalis Walker (Lepidoptera: Pyralididae) is a common pest in sericulture and has developed resistance to different insecticides. However, the mechanisms involved in insecticide resistance of G. pyloalis are poorly understood. Here, we present the first whole-transcriptome analysis of differential expression genes in insecticide-resistant and susceptible G. pyloalis. Clustering and enrichment analysis of DEGs revealed several biological pathways and enriched Gene Ontology terms were related to detoxification or insecticide resistance. Genes involved in insecticide metabolic processes, including cytochrome P450, glutathione S-transferases and carboxylesterase, were identified in the larval midgut of G. pyloalis. Among them, CYP324A19, CYP304F17, CYP6AW1, CYP6AB10, GSTs5, and AChE-like were significantly increased after propoxur treatment, while CYP324A19, CCE001c, and AChE-like were significantly induced by phoxim, suggesting that these genes were involved in insecticide metabolism. Furthermore, the sequence variation analysis identified 21 single nucleotide polymorphisms within CYP9A20, CYP6AB47, and CYP6AW1. Our findings reveal many candidate genes related to insecticide resistance of G. pyloalis. These results provide novel insights into insecticide resistance and facilitate the development of insecticides with greater specificity to G. pyloalis.

Gene duplication and subsequent functional diversification of sucrose hydrolase in Papilio xuthus

Sucrose is the main product of photosynthesis in plants, providing a rich carbon and energy source for the physiological growth and development of insects. In a previous study, we identified a novel sucrose hydrolase (SUH) in the larval midgut of moths. Intriguingly, there are two copies of Suh, namely Suh1 and Suh2, in several species of butterflies. However, the biochemical characteristics of SUHs in butterflies remain unclear. In this study, we found that this duplication and subsequent diversification produced two Suh genes in Papilio xuthus. These two PxSuh genes were significantly divergent in terms of their expression pattern and enzyme properties. PxSuh messenger RNA expression was highest during the larval stage, reduced in the prepupal and pupal stages and, for PxSuh1, slightly increased again in the adult. The observed levels of PxSuh2 were overall below those of PxSuh1 amongst the development stages examined. Compared with PxSUH2, which has maintained the original gene function of maltose hydrolysis, PxSUH1 exhibits substrate specificity for sucrose with an optimum enzyme activity occurring at an alkaline pH. The data show that PxSuh1 is evolutionarily adapted for effective functioning in an alkaline digestive system. Furthermore, we find that functional diversification of Suh facilitates P. xuthus to digestive carbohydrate of host plants. Thus, our findings offer new insights into the ecological and evolutionary adaptation of digestive enzymes in butterflies.

Downregulation of miR-1294 associates with prognosis and tumor progression in epithelial ovarian cancer

OBJECTIVE

Increasing evidence has revealed that microRNAs (miRNAs) act as key players in the regulation of tumor growth and metastasis in epithelial ovarian cancer (EOC). However, the clinical role and functional effects of miR-1294 in EOC remain unknown.

PATIENTS AND METHODS

We examined the expression of miR-1294 in 69 cases of EOC tissues and cell lines by quantitative Real-time polymerase chain reaction (qRT-PCR). The associations of miR-1294 expression with clinicopathologic features and overall survival of EOC patients were analyzed. Biological functional effects of miR-1294 expression on cell growth were analyzed using Cell Counting Kit-8 (CCK8) assays and flow cytometry assays in vitro.

RESULTS

In the present study, we identified that miR-1294 expression was lower in 76 specimens of EOC compared to adjacent normal tissues. Lower miR-1294 expression was related to FIGO stage, lymph node metastasis and shorter overall survival rate in EOC patients. Multivariate Cox analysis demonstrated that miR-1294 expression was an independent prognostic indicator of EOC patients. Gain function assays showed that miR-1294 overexpression inhibited cell proliferation and cell cycle progression in EOC.

CONCLUSIONS

Our results indicated that miR-1294 acted as a prognostic biomarker and potential target of EOC treatment.

MiR-29c suppresses cell invasion and migration by directly targeting CDK6 in gastric carcinoma

OBJECTIVE

Gastric carcinoma (GC) is one common malignant tumor with high morbidity and mortality rates all over the world. Recently, numerous studies have showed that the microRNAs (miRNAs) dysregulation was implicated in GC carcinogenesis. This research aimed to explore the potential associations between miR-29c and cyclin-dependent kinase 6 (CDK6) in GC.

PATIENTS AND METHODS

GC tissues and corresponding normal tissues were collected from 54 GC patients who underwent surgery at the Second Hospital of Anhui Medical University between 2015 and 2017. We measured the expressions of CDK6 and miR-29c in GC tissues using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). We next investigated the functions of miR-29c in GC cells by performing transwell assays. To further determine the correlation between miR-29c and CDK6 in GC cell invasion and migration, the rescue experiments were performed by co-transfecting miR-29c inhibitor and CDK6 siRNA into AGS cells.

RESULTS

MiR-29c expressions were significantly declined in GC tissues and cells. Additionally, functional assays showed that the miR-29c over-expression suppressed the invasion and migration capacities of GC cells. According to TargetScan and dual-luciferase reporter assays, CDK6 was identified as a new miR-29c target. Moreover, the knockout of CDK6 had similar effects as the miR-29c over-expression in GC cells. The current research indicated that miR-29c over-expression could inhibit tumor behaviors in GC partially via down-regulating CDK6.

CONCLUSIONS

We revealed that miR-29c down-regulated in GC tissues and cells. MiR-29c over-expression effectively suppressed the GC cell invasion and migration. Moreover, CDK6 was identified as a direct functional target of miR-29c in GC. The current study provides new insights for the GC treatment and suggests that miR-29c/CDK6 axis is a therapeutic candidate target for GC patients.

A new diagnostic index for sarcopenia and its association with short-term postoperative complications in patients undergoing surgery for colorectal cancer

AIM

Sarcopenia is a robust prognostic indicator of outcomes after surgery for colorectal cancer (CRC). However, there are no serum markers routinely available for estimating skeletal muscle mass (SMM). The present study aimed to describe a new sarcopenia index (SI), serum creatinine (Scr) × cystatin C-based glomerular filtration rate, and investigate its association with short-term complications after curative resection of CRC.

METHOD

Consecutive patients who underwent curative resection of CRC from December 2011 to January 2017 were retrospectively identified. Skeletal muscle cross-sectional area was analysed on L3 computed tomographic images. Receiver operating characteristic curve analysis showed that the cutoff points of SI for sarcopenia were below 56.1 in men and below 43.7 in women. Patients were classified into low and high SI groups in accordance with these cutoff values. The association between SI and body composition and the impact of preoperative SI on postoperative outcomes were analysed.

RESULTS

Among 417 patients, SI showed a stronger correlation with skeletal muscle area (SMA) (r = 0.537, P < 0.001) than with the Scr/cystatin C ratio (r = 0.469, P < 0.001) and Scr (r = 0.447, P < 0.001). The low SI group had a lower SMA, lower preoperative haemoglobin, a higher prevalence of sarcopenia and experienced more postoperative complications compared with the high SI group (all P < 0.001). Multivariate logistic regression analysis showed that the independent risk factors for overall complications were low preoperative haemoglobin, low SI, sarcopenia and American Society of Anesthesiologists grade ≥ 3.

CONCLUSION

This new SI is a simple and useful surrogate marker for estimating SMM, and is associated with outcomes after CRC surgery.

The role of long non-coding RNA GAS5 in cancers

Long non-coding RNAs (lncRNAs) have shown potential as a biomarker in the diagnosis and prognosis in multiple cancers. LncRNAs are dysregulated in various cancers, playing either oncogenic or tumor suppressive roles. Emerging evidences have proved that the growth arrest-specific 5 (GAS5) lncRNA can function as a tumor suppressor in several cancers. LncRNA GAS5 is downregulated in many types of cancer, regulating cellular processes such as cell proliferation, apoptosis and invasion. The low level of GAS5 expression often elevates capacity of proliferation and predicts poorer prognosis in some cancers. This review aims to summarize the recent published literature on the biogenesis, regulation mechanism and function of GAS5 in different types of cancers and explore its potential for cancer diagnosis, prognosis and treatment.

NGF increases FGF2 expression and promotes endothelial cell migration and tube formation through PI3K/Akt and ERK/MAPK pathways in human chondrocytes

OBJECTIVE

Vascular invasion is observed at the osteochondral junction in osteoarthritis (OA). Nerve growth factor (NGF) as an angiogenic factor is expressed in OA. This study is to investigate the effects of NGF on angiogenesis in vitro in human chondrocytes.

DESIGN

Articular cartilages of knee joints were harvested from healthy and OA patients. Expressions of NGF and tropomyosin-related kinase A (TrkA) were detected by western blot, Safranin-O and fast green staining and immunohistochemistry in cartilage. Expression of fibroblast growth factor 2 (FGF2) was detected by western blot in cultured chondrocytes. Chondrocytes were transfected by lentiviral vectors to knock down TrkA. Migration and tube formation of human microvascular endothelial cell (HMVEC) were assessed by using transwell co-culture with chondrocyte after treatment of NGF.

RESULTS

We confirmed expressions of NGF and TrkA were significantly up-regulated in OA. NGF induced expression of FGF2 in a time- and dose-dependent manner. Angiogenic activities of endothelial cells were greatly enhanced after co-cultured with NGF pre-treated chondrocytes, while knock-down of TrkA significantly abolished the above effects. We further found that NGF-induced expression of FGF2 promoted angiogenic activities of endothelial cells through PI3K/Akt and ERK/MAPK signaling pathways.

CONCLUSIONS

NGF promotes expression of FGF2 in vitro via PI3K/Akt and ERK/MAPK signaling pathways in human chondrocytes and it increases angiogenesis, which is mediated by TrkA. NGF could be responsible for vascular up-growth from subchondral bone in OA.

Prognosis in different subtypes of metaplastic breast cancer: a population-based analysis

BACKGROUND

Metaplastic breast cancer (MpBC) is a rare histological subtype of breast cancer recognized as a unique pathologic entity in 2000. However, the pathogenesis, optimal therapy, and prognosis of MpBC and the potential effect of systemic treatments on different subtypes of MpBC are not well defined.

METHODS

A retrospective population-based study was performed to identify breast cancer patients with MpBC and other triple-negative breast cancers (TNBC) between 2010 and 2014 using the surveillance, Epidemiology, and End Results (SEER) database. Chi-square test was used to analyze characteristics between subgroups. Kaplan-Meier analysis and Multivariate Cox regressions were used to evaluate overall survival (OS) of MpBC, TNBC, and MpBC subgroups. Competing risk analysis and multivariate regression model of competing risk were used to assess breast cancer-specific survival (BCSS) of MpBC and TNBC RESULTS: We identified a study cohort of 22,433 patients (1112 MpBC and 21,321 TNBC). MpBC correlated with older population, larger tumor size and less lymph node involvement, and TNBC phenotype. Patients with MpBC especially with triple-negative subtype (TN-MpBC) had worse survival than the overall TNBC population. However, the prognosis of MpBC without triple-negative subtype (non-TN MpBC) was not different from that of TNBC. In Kaplan-Meier analysis, chemotherapy was not associated with significant difference in OS of TN-MpBC. In non-TN MpBC group, the 3-year OS was 79.8% for patients receiving chemotherapy and 70.5% in patients without chemotherapy, and chemotherapy was associated (P = 0.033) with improved OS. Within the MpBC patients, radiotherapy was significantly (HR 1.544; 95% CI 1.148-2.078; P = 0.004) associated with improved OS and (HR 1.474; 95% CI 1.067-2.040; P = 0.019) BCSS.

CONCLUSIONS

Patients with TN-MpBC had worse prognosis than TNBC and chemotherapy was not associated with improved survival. In contrast, non-TN MpBC may derive survival benefit from chemotherapy and radiotherapy.

Effects of lipopolysaccharide dosing on bacterial community composition and fermentation in a dual-flow continuous culture system

The objectives of this study were to evaluate the effects of lipopolysaccharide (LPS) dosing on bacterial fermentation and bacterial community composition (BCC), to set up a subacute ruminal acidosis (SARA) nutritional model in vitro, and to determine the best sampling time for LPS dosing in a dual-flow continuous culture system. Diets were randomly assigned to 6 fermentors in a replicated 3 × 3 Latin square with three 11-d experimental periods that consisted of 7 d for diet adaptation and 4 d for sample collection. Treatments were control diet (CON), wheat and barley diet (WBD) to induce SARA, and control diet + LPS (LPSD). Fermenters were fed 72 g of dry matter/d. The forage:concentrate ratio of CON was 65:35. The WBD diet was achieved by replacing 40% of dry matter of the CON diet with 50% ground wheat and 50% ground barley. The LPS concentration in LPSD was 200,000 endotoxin units, which was similar to that observed in cows with SARA. The SARA inducing and LPS dosing started at d 8. The BCC was determined by sequencing the V4 region of the 16S rRNA gene using the Illumina MiSeq platform (Illumina Inc., San Diego, CA). The LPSD and CON maintained pH above 6 for the entire experimental period, and the WBD kept pH between 5.2 and 5.6 for 4 h/d, successfully inducing SARA. Digestibility of neutral detergent fiber and crude protein in LPSD were not different from WBD but tended to be lower than CON. Lipopolysaccharide dosing had no effect on pool of VFA concentrations and profiles but decreased bacterial N; the pattern changes of VFA and LPS in LPSD started to increase and be similar to WBD 6 h after LPS dosing. Pool of LPS concentration was around 11-fold higher in WBD and 4-fold higher in LPSD than CON. In the solid fraction, the BCC of LPSD was different from WBD and tended to be different from CON. In the liquid fraction, the BCC was different among treatments. The LPS dosing increased the relative abundance of Succinimonas, Anaeroplasma, Succinivibrio, Succiniclasticum, and Ruminobacter, which are main gram-negative bacteria related to starch digestion. Our results suggest that LPS dosing does not affect pH alone. However, LPS could drive the development of SARA by affecting bacteria and bacterial fermentation. For future studies, samples are suggested to be taken 6 h after LPS dosing in a dual-flow continuous culture system.

[Factors affecting stability after fixed orthodontic treatment]

Objective: To analyze factors affecting stability after fixed orthodontic treatment. Methods: Five hundred and forty-four patients who had finished fixed orthodontic treatment more than two years in First Department of Orthodontics, China Medical University from January, 2000 to December, 2017 were investigated and the rate of regular revisit was counted. The data of 288 patients were successfully collected by calling or sending text messages and the rate of standard use of retainers as prescribed (patients wore retainers for 24 months or longer) was counted. According to the variation of peer assessment rating (PAR) index at the start of retention and the time the data collected, the patients were divided into relapse group (variation of PAR index >5) and non-relapse group (variation of PAR index ≤5). Difference significance analysis and multiple-factor logistic regression analysis were used. Sixty patients wearing retainers well were collected and the curative effects of Hawley retainer and vacuum formed retainer (VFR) were compared, which included overbite, overjet, maxillary irregularity index, mandibular irregularity index, width betwenn canine and width between first molar. Results: The rate of regular revisit was 41.0% (223/544). Two hundred and one of 288 patients (69.8%) who were visited successfully had regular revisit, and 60.4%(174/288) of the patients wore retainers well; 30.2% (87/288) of the patients who were visited successfully didn't have regular revisit, and 10.4% (30/288) of the patients wore retainers well. Difference significance analysis showed that there was highly significant difference between relapse group and non-relapse group in the type of retainer and duration of retention (P<0.01). One hundred and forty of 224 patients (62.5%) in non-relapse group and 37.5% (24/64) of the patients in relapse group used VFR, and the duration of retention in non-relapse group was significantly longer than that in relapse group (P<0.01). Multiple-factor Logistic regression analysis showed that wearing Hawley retainers (OR=3.067, P<0.05) was the risk factor influencing relapse. The duration of retention (OR=0.832, P<0.01) was the protective factor influencing relapse. Independent-sample t test indicated that the variations of maxillary [(0.82±0.36) mm] and mandibular [(1.05±0.22) mm] irregularity index in Hawley retainer group were larger than maxillary [(0.64±0.29) mm] and mandibular [(0.72±0.35) mm)] irregularity index in VFR group, respectively. The differences between the two groups were significant (P<0.05). Conclusions: Duration of retention was implicated in stability after orthodontic treatment. VFR had better effect in the aspects of irregularity index than Hawley retainer.

Titanium dioxide nanoparticles induce in vitro autophagy

Aim:

Concerns about the possible toxicity to environment and human health of titanium dioxide nanoparticles (TiO2 NPs) are increasing. The aim of this study was to investigate the relationship between toxicology and autophage in vitro.

Methods:

RAW 264.7 cells were exposed to five concentrations (50, 100, 200, 300, and 400 μg/mL) and two particle size of TiO2 NPs (30 and 100 nm) for 24 h.

Results:

The results showed that TiO2 NPs decreased cell viability, phagocytic rate, and phagocytic index in a concentration-dependent manner, thereby inducing autophagy. TiO2 NPs-induced autophagy was indicated by monodansyl cadaverine staining and transmission electron microscopy. TiO2 NPs-induced messenger RNA expression of autophagy-related proteins LC3 and Beclin-1 was also significantly increased compared with those of the unexposed control cells. LC3 and Beclin-1 protein expression levels were markedly increased with the increase of TiO2 NPs concentrations.

Conclusion:

These results suggest the possibility that TiO2 NPs-induced toxicology probably plays a key role in autophagy in RAW 264.7 cells, and further exhaustive research on the harmful effects of these NPs in relevant organisms is needed for their safe application.