[Observational study on peripapillary hyper-reflective ovoid mass-like structures in children and adolescents with myopia].

Objective: To investigate the correlation of peripapillary hyper-reflective ovoid mass-like structures (PHOMS) in children and adolescents with myopia and its correlation factors. Methods: It was a cross-sectional study. From September 2021 to January 2022, myopic children and adolescents aged 6-16 years treated in Wuhan Central Hospital and Renmin Hospital of Wuhan University with a myopic spherical equivalent (SE) ≥0.5 D were consecutively included. All patients underwent best corrected visual acuity, refraction, intraocular pressure, slit lamp microscope, axial length, fundus photography and enhanced depth imaging optical coherence tomography (EDI-OCT) examination. EDI-OCT optic disc parameter measurements included diameter, degree of tilt and shift and PHOMS height. The patients were divided into PHOMS group and non-PHOMS group according to the presence or absence of PHOMS. According to the height of PHOMS, the patients were further divided into 3 subgroups: large (>400 µm), medium (200-400 µm) and small (<200 µm). The optic disc characteristics of the PHOMS group and the non-PHOMS group and each subgroup were observed, and the correlation factors of PHOMS were analyzed. Mann-Whitney U test, Kruskal-Wallis test, chi-square test, Logistic regression analysis and Kendall's tau-b correlation coefficient were used. Results: A total of 108 patients (108 eyes) were included, including 46 males (46 eyes) and 62 females (62 eyes). There were 70 eyes (64.8%) in the PHOMS group and 38 eyes (35.2%) in the non-PHOMS group. Small PHOMS can only be detected by EDI-OCT, while medium to large PHOMS showed blurred optic disc boundaries on fundoscopy images. Univariate Logistic regression analysis showed that PHOMS was associated with age (OR=1.36, 95%CI: 1.13-1.65, P=0.001) and myopic SE (OR=4.57, 95%CI: 2.51-8.32, P<0.001), axial length (OR=2.28, 95%CI: 1.37-3.82, P=0.002), optic disc tilt (OR=3.44, 95%CI: 2.09-5.66, P<0.001), optic disc shift (OR=0.95, 95%CI: 0.93-0.98, P<0.001) and optic disc diameter (OR=0.75, 95%CI: 0.58-0.95, P=0.019). Multivariate Logistic regression analysis showed that the higher the myopic SE (OR=3.01, 95%CI: 1.27-7.17, P=0.013) and the greater the tilt of the optic disc (OR=4.06,95%CI:1.99-8.29,P<0.001), the higher the risk of PHOMS. Kendall's tau-b correlation coefficient analysis showed that the height of PHOMS was negatively correlated with optic disc shift (r=-0.31, P<0.001). Conclusions: PHOMS can be found in a subset of myopic children. The fundus manifestations of PHOMS of different heights are slightly different. The large myopic SE and great optic disc tilt are risk factors of PHOMS, and their magnitudes correlate with the border tissue angle.

[HIV/AIDS surveillance in men who have sex with men aged 15-24 based on internet in Fuzhou,2016-2021].

Objective: To analyze HIV/AIDS surveillance data in men who have sex with men (MSM) aged from 15 to 24 years in Fuzhou and understand the HIV infection status in MSM and related factors. Methods: From 2016 to 2021, MSM aged 15-24 years who had oral or anal sex with men in the past 6 months were recruited through internet, and their demographic and behavioral characteristics, HIV antibody positive rate and risk factors were analyzed. Results: From 2016 to 2021, a total of 4 234 MSM aged 15-24 years were surveyed. The proportion of MSM from other provinces increased from 13.00% (85/654) to 23.42% (163/696) (trend χ2=60.23, P<0.001); and the proportion of MSM seeking male partners through internet increased from 93.27% (610/654) to 99.71% (694/696) (trend χ2=65.20, P<0.001); In the last anal sex in the past 6 months, the proportion of MSM using condom decreased from 88.16% (484/549) to 74.11% (415/560) (trend χ2=32.32, P<0.001); and in the past 6 months, the proportion of MSM using condom at each anal sex decreased from 65.76% (361/549) to 55.54% (311/560) (trend χ2 =6.82, P<0.001); The proportion of MSM with HIV antibody testing increased from 5.66% (37/654) to 25.29% (176/696) (trend χ2=98.51, P<0.001). The cumulative HIV antibody positive rate in the MSM was 3.64% (154/4 234), and there was no significant difference in annual HIV antibody positive rate in the MSM (trend χ2=0.50, P=0.453). The HIV antibody positive rate in the MSM with education level of junior high school or below and the MSM living in Fuzhou for 1-2 years showed an upward trend (P<0.05). The results of multivariate logistic regression analysis showed that the risk for HIV infection in the MSM with education level of high school or technical secondary school was 0.54 times higher than that in those with education level of junior high school or below (95%CI: 0.30-0.99), and the risk for HIV infection in the MSM with education level of junior college or below was 0.29 times higher than that in those with education level of junior high school or below (95%CI: 0.17-0.51). The risk for HIV infection in the MSM who lived in Fuzhou for 1-2 years was 0.35 times higher than that in those who lived in Fuzhou for less than 1 year (95%CI: 0.16-0.74), the risk for HIV infection in the MSM who lived in Fuzhou for more than two years was 0.58 times higher than that in those who lived in Fuzhou for less than 1 year (95%CI: 0.37-0.91). The number of MSM using condoms at each anal sex was 0.18 times higher than that in the those never using condoms (95%CI: 0.08-0.42), and the number of the MSM who didn't suffered from sexually transmitted diseases was 0.25 times higher than that in those who suffered from sexually transmitted diseases (95%CI: 0.13-0.50). Conclusions: The MSM aged 15-24 years in Fuzhou have higher risk for HIV infection, and internet based intervention should be strengthened in adolescent MSM without permanent residence and with low education level.

Changes in macular vascular density and retinal thickness in young myopic adults without pathological changes: an OCTA study.

OBJECTIVE: The aim of the study was to quantify the macular vascular density and retinal thickness in the eyes of young myopic people with myopia without pathological changes using optical coherence tomography angiography (OCTA). PATIENTS AND METHODS: In this cross-sectional study, 160 eyes of 80 myopia subjects without pathological changes were classified into three groups: mild myopia (N=40 eyes), moderate myopia (N=66 eyes), and high myopia (N=54 eyes). Macular vascular density (VD), retinal thickness, area of the foveal avascular zone, the flow area of the outer retina and choriocapillaris (CC) were measured using OCTA. The effects of other confounding factors including axial length, the spherical equivalent, and some systemic factors (blood pressure, height, weight, etc.) were also considered. RESULTS: As the severity of myopia increases, the CC flow area decreased (p=0.029). The superficial VD in the temporal, superior, nasal, and inferior regions was significantly lower in high myopia group compared to moderate and low myopia groups (all p<0.001). With increasing myopia, a significant reduction of deep VD was found in the superior region of the macula (p=0.007). In the fovea, there was no difference in the superficial or deep VD across groups (p=0.268 and p=0.413, respectively). Parafoveal retinal thickness was thinnest in the high myopia group and thickest in the mild myopia group (all p<0.05). The fovea was thickest in the high myopia group and thinnest in the mild myopia group (p=0.030). CONCLUSIONS: In young myopic people without pathological changes, superficial VD and retinal thickness decreased with myopia progression, except in the fovea. The CC flow area decreased with increasing myopia.

Effect of Na2O and ZnO on the microstructure and properties of laser cladding derived CaO-SiO2 ceramic coatings on titanium alloys.

To improve the bioactivity of titanium alloy (Ti-6Al-4V), CaO-SiO2 coatings on titanium alloys were fabricated using laser cladding method. The effect of Na2O and ZnO on the microstructure and properties of the prepared coatings was discussed. The microstructure of the CaO-SiO2 coatings consists of cellular grains and cellular dendrites. The mutual diffusion of elements occurs between the coating and substrate. The base CaO-SiO2 coating is composed of different phases including CaTiO3, α-Ca2(SiO4), SiO2, TiO2 and CaO. The formation of CaTiO3 in the ceramic layer was analyzed through thermodynamics. Na2O has little influence on the microstructure, average hardness and wear resistance. When ZnO is added to the precursor, the microstructure turns to cell dendrite, and ZnO and Zn2SiO4 appear in the corresponding coating. The addition of ZnO reduces the average hardness and wear resistance of the ceramic layer. The in vitro soaking in SBF shows that the laser cladding coating has the ability to form an apatite layer.

[Study on diagnostic value of extracellular volume imaging by magnetic resonance imaging for liver fibrosis of hepatitis B].

Objective: To investigate the diagnostic value of extracellular volume (ECV) imaging by magnetic resonance imaging for liver fibrosis of hepatitis B. Methods: A retrospective analysis was recruited in patients with chronic hepatitis B, who underwent liver surgery from April to October 2017 for pathological evaluation of liver tissues, and all patients underwent Gd-EOB-DTPA-enhanced T1 mapping to calculate the liver ECV score. The correlation between ECV and staging of hepatic fibrosis and inflammatory activity were compared to clarify the diagnostic value of staging of fibrosis. Results: 66 patients were enrolled in this study. Concerning the staging of liver fibrosis, there were 13, 4, 13, 10, and 26 cases with F0, F1, F2, F3 and F4 stages, respectively. ECV values had high interobserver consistency (correlation coefficient 0.860). The ECV difference between different stages of liver fibrosis was statistically significant (F = 15.02, P < 0.001). There was a significant positive correlation between ECV and fibrosis stage (r = 0.622, P < 0.001), and weak correlation with inflammatory activity (r = 0.332, P = 0.007). Fibrosis staging was an independent factor influencing ECV (P < 0.001). The area under the receiver operator characteristic curve for the diagnosis of liver fibrosis staging F≥1, F≥3 and F4 were 0.760, 0.846 and 0.873, respectively. The diagnostic sensitivity and specificity were 64.15%, 92.31%, 77.78%, 80.00% and 88.46, 72.50%, respectively. Conclusion: MRI-ECV imaging has great value for staging hepatic fibrosis of hepatitis B, and it can provide an effective method for diagnosis, staging, and evaluating the curative effect of fibrosis.

[Lack of progesterone receptor expression predicts poor prognosis in patients with operable ER-positive invasive breast cancer].

OBJECTIVE: To investigate the impact of lack of progesterone receptor (PR) expression on the prognosis of patients with operable ER (estrogen receptor)-positive invasive breast cancer. METHODS: We retrospectively analyzed the clinicopathological features, treatment and survival data of 318 women with ER+ /PR+ and ER+ /PR- invasive breast cancer. RESULTS: Among the 318 patients, there were 219 PR-positive and 99 PR-negative cases. The 5-year overall survival (OS) rate was 92.5%, and the 5-year disease-free survival (DFS) rate was 87.2% in the 318 ER-positive patients. Among them, the 5-year OS rates were significantly different between the PR-positive group (94.6%) and PR-negative group (87.8%, P=0.020), and the 5-year DFS rates were also significantly different from each other (89.8% and 81.6%, respectively, P=0.019). Univariate analysis showed that PR status, tumor size, T stage, axillary lymph node metastasis, and clinical stage were prognostic factors for OS (P<0.05 for all). Multivariate analysis showed that lack of PR expression, T stage ≥2, and positive axillary lymph node metastasis were independent risk factors for poor DFS and OS in ER-positive breast cancer patients (P<0.05 for all). Subgroup analysis showed that lack of PR expression was not significant in predicting poor DFS or OS when patients were in stage Ⅰ or with a small tumor (≤2 cm) (P>0.05 for all), and also showed that premenopausal women with PR-negative disease had poorer DFS and OS than PR-positive patients (P<0.05 for both). CONCLUSIONS: Lack of PR expression is an independent risk factor for poor prognosis in patients with operable ER-positive invasive breast cancer, especially in patients with a large tumor (>2 cm), advanced clinical stage (Stage Ⅱ or Ⅲ) or in premenopausal status.

AMFR gene silencing inhibits the differentiation of porcine preadipocytes.

Our study clarifies the role of the autocrine motility factor receptor (AMFR) gene in porcine preadipocyte differentiation. AMFR-siRNA was transfected into porcine preadipocytes and the preadipocytes were induced to differentiation. Subsequently, qRT-PCR was conducted to examine changes in mRNA expression of a series of genes in porcine preadipocytes, including AMFR, sterol-regulatory element-binding protein-1a (SREBP1a), SREBP2, insulin-induced gene 1 (Insig1), and Insig2. Expression changes in the mRNA of genes regulating adipocyte differentiation were also analyzed using qRT-PCR, including peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and Kruppel-like factor 2 (KLF2). Western blot analysis was conducted to examine the changes in AMFR protein expression in porcine preadipocytes. Additionally, morphological changes in differentiated porcine preadipocytes were examined by oil red O staining, and changes in optical density (OD) values were measured using an ultraviolet spectrophotometer. At 24 h after transfection with AMFR-siRNA, AMFR mRNA expression significantly reduced (P < 0.01), and AMFR protein expression markedly decreased (P < 0.05). The mRNA expression of SREBP1a, SREBP2, Insig1, and C/EBPα was significantly reduced (P < 0.01), whereas the expression of KLF2 mRNA was significantly elevated (P < 0.01). After induction of preadipocyte differentiation, the number of lipid droplets decreased in the AMFR-silenced group, and the OD value markedly reduced (P < 0.05). In addition, the expression of C/EBPα mRNA significantly decreased (P < 0.05), whereas the expression of KLF2 mRNA considerably increased (P < 0.05). Taken together, silencing of the AMFR gene inhibits the differentiation of porcine preadipocytes.

Effects of choice of month of treatment and parity order on bovine superovulation traits.

In this study, the performance of 300 Changbaishan Black cattle treated for superovulation from June to September was evaluated to determine the optimal conditions and herds for bovine embryo production. Data analysis revealed that cattle treated in July and August had higher numbers of available embryos (NAE), M1 embryos (NM1), and total embryos (NTE), as well as a higher percentage of M1 embryos (PM1). The temperature and precipitation observed during July and August were greater than those seen in the other two months; strong correlations were observed between these traits and the choice of month of treatment. In addition, multiparous cattle showed a better performance, higher NTE, NAE, NM1, and PM1 values, higher percentages of available embryos, and a lower percentage of degenerated embryos. The co-efficient correlation analysis showed that the month chosen for the treatment did not affect the superovulation traits of nulliparous cattle; however, the choice of the month affected multiparous cattle. Multiparous and nulliparous cattle exhibited many significant differences when treated in July and in August. In addition, the superovulatory traits of multiparous cattle, and not the nulliparous cattle, were strongly correlated to the choice of month of treatment. The results suggested that superovulation is more effective during a period with appropriate environmental temperature and humidity, and that multiparous cattle are more suitable for morula production.

Association of a hypoxia-inducible factor-3α gene polymorphism with superovulation traits in Changbaishan black cattle.

This study was designed to examine a single nucleotide polymorphism (SNP) in the HIF-3α gene in three hundred Changbaishan black cattle using PCR-restriction fragment length polymorphism to determine whether there is an association between this SNP and superovulation. The cloning and sequencing results indicate that the polymorphism is due to a point mutation at the 278-bp position in the HIF-3α gene, resulting in 3 genotypes (AA, AB, and BB). Association analysis indicated that the polymorphism has a significant effect on the number of unfertilized embryos (NUE) (P < 0.05) in the cattle. Cattle with genotype BB had a higher NUE than those with genotype AA, but the difference in NUE between AB and AA or BB was not significant. The polymorphism also has a highly significant effect on the number of degenerative embryos (NDE) and the number of total embryos (NTE) (P < 0.01). Genotype BB was associated with a higher NDE than AA, but the difference in NDE between AB and AA or BB was not significant. Genotype BB showed a higher NTE than AA or AB, but the difference in NTE between AA and AB was not significant. No significant conclusions could be drawn with respect to susceptibility to other traits. HIF-3α could serve as a useful biomarker for donor selection, superovulation improvement, and assisted fertility.

Liver fibrosis staging using T1 mapping on gadoxetic acid-enhanced MRI compared with DW imaging.

AIM: To evaluate the utility of T1 mapping on gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) for staging liver fibrosis. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board and included 145 patients (mean age: 54 years old; 115 men and 30 women). Necro-inflammatory activity grade (G) and liver fibrosis stage (S) were histopathologically determined. T1 relaxation time and apparent diffusion coefficient (ADC) of the liver were measured and the reduction rate of the T1 relaxation time (Δ%) was calculated. T1 relaxation time measurements were compared with ADC values according to S/G scores. RESULTS: Unenhanced hepatobiliary phase (HBP) and Δ% of T1 relaxation times showed significant correlations with S/G scores (rho: 0.28, 0.51, -0.35 for the S score, 0.26, 0.39, -0.26 for the G score, respectively, p<0.05). ADC values showed significant correlation with the S score (rho: -0.17, p = 0.04) and did not correlate significantly with the G score (rho: -0.07, p = 0.39). The areas under receiver operator characteristics (AUC) curve of unenhanced HBP, Δ% T1 relaxation time, and the ADC value were 0.68, 0.82, 0.71, 0.61 for the identification of S ≥ 3, and 0.63, 0.68, 0.62, 0.52 for the identification of G ≥ 3, respectively. The HBP T1 relaxation time was better than that of ADC for identification of S ≥ 3 (p = 0.0005) and G ≥ 3 (p = 0.014). CONCLUSIONS: The HBP T1 relaxation time measurement on gadoxetic acid-enhanced MRI images might be a potential biomarker in the staging of hepatic fibrosis, and was more accurate than the ADC measurement.

Effect of CeO2 and Y2O3 on microstructure, bioactivity and degradability of laser cladding CaO-SiO2 coating on titanium alloy.

To solve the lack of strength of bulk biomaterials for load-bearing applications and improve the bioactivity of titanium alloy (Ti-6Al-4V), CaO-SiO2 coatings on titanium alloy were fabricated by laser cladding technique. The effect of CeO2 and Y2O3 on microstructure and properties of laser cladding coating was analyzed. The cross-section microstructure of ceramic layer from top to bottom gradually changes from cellular-dendrite structure to compact cellular crystal. The addition of CeO2 or Y2O3 refines the microstructure of the ceramic layer in the upper and middle regions. The refining effect on the grain is related to the kinds of additives and their content. The coating is mainly composed of CaTiO3, CaO, α-Ca2(SiO4), SiO2 and TiO2. Y2O3 inhibits the formation of CaO. After soaking in simulated body fluid (SBF), the calcium phosphate layer is formed on the coating surface, indicating the coating has bioactivity. After soaking in Tris-HCl solution, the samples doped with CeO2 or Y2O3 present a lower weight loss, indicating the addition of CeO2 or Y2O3 improves the degradability of laser cladding sample.

Expression pattern of JMJD1C in oocytes and its impact on early embryonic development.

Cell reprogramming mediated by histone methylation and demethylation is crucial for the activation of the embryonic genome in early embryonic development. In this study, we employed quantitative real-time polymerase chain reaction (qRT-PCR) to detect mRNA levels and expression patterns of all known histone demethylases in early germinal vesicle stage and in vitro-matured metaphase II (MII) oocytes (which are commonly used as donor cells for nuclear transfer). On screening, the Jumonji domain containing 1C (JMJD1C) gene had the highest level of expression and hence was used for subsequent experiments. We also found that JMJD1C was primarily expressed in the nucleus and showed relatively high levels of expression at the 2-cell, 4-cell, 8-cell, 16-cell, morula, and blastocyst stages of embryos developed from MII oocytes fertilized in vitro. Further, we knocked down the JMJD1C gene in MII oocytes using siRNA and monitored the cleavage of zygotes and development of early embryos after in vitro fertilization. The results showed that the zygote cleavage and blastocyst rates of the transfection group were reduced by 57.1 ± 0.07 and 50 ± 0.01% respectively, which were significantly lower than those of the negative control group (P < 0.05). These data suggest that JMJD1C plays a key role in the normal development of early bovine embryos. Our results also provide a theoretical basis for the investigation of the role and molecular mechanism of histone demethylation in the early development of bovine embryos.

Is aspirin use associated with age-related macular degeneration? A meta-analysis.

WHAT IS KNOWN AND OBJECTIVES: Aspirin is one of the most widely used medications in the world. The evidence on its effect on the risk of age-related macular degeneration (AMD) appears inconsistent across different types of studies. The aim of this meta-analysis was to evaluate the association between aspirin use and the risk of AMD. METHODS: Relevant studies were searched using databases including PubMed, EMBASE, Cochrane Library and MEDLINE up to March 2014. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated by random-effects or fixed-effect models. The heterogeneity was assessed by the inconsistency index (I(2) ). The publication bias was evaluated by Begg's funnel plot and Egger's weighted regression. Sensitivity analysis was also performed in different ways. RESULTS: Ten eligible studies including 180 834 individuals based on the inclusion criteria were analysed in this meta-analysis. The pooled RR for the aspirin use on the risk of AMD was 1·137 (95% CI, 1·003-1·289; I(2) , 68·4%). The pooled RR for the aspirin use on the risk of early and late AMD was 1·19 (95% CI, 0·92-1·53; I(2) , 82·6%) and 1·22 (95% CI, 0·87-1·72; I(2) , 55·7%), respectively. In different types of late AMD, the pooled RR was 1·95 (95% CI, 1·40-2·72; I(2) , 27%) for neovascularization and 0·84 (95% CI, 0·62-1·15; I(2) , 0%) for geographic atrophy. The pooled RR in studies with standardized AMD classification was 1·307 (95% CI, 1·006-1·698; I(2) , 79·2%). WHAT IS NEW AND CONCLUSION: This meta-analysis updates similar reviews that included studies with various types of biases. A rigorous analysis shows a weak but statistically significant association between aspirin use and the risk of AMD; a result which is different to that previously reported.

Effect of ZrO(2) additions on the crystallization, mechanical and biological properties of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics.

A series of ZrO(2) doped MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics were obtained by sintering method. The crystallization behavior, phase composition, morphology and structure of glass-ceramics were characterized. The bending strength, elastic modulus, fracture toughness, micro-hardness and thermal expansion coefficient (TEC) of glass-ceramics were investigated. The in vitro bioactivity and cytotoxicity tests were used to evaluate the bioactivity and biocompatibility of glass-ceramics. The sedimentation mechanism and growth process of apatites on sample surface were discussed. The results showed that the mainly crystalline phases of glass-ceramics were Ca(5)(PO4)3F (fluorapatite) and ß-CaSiO(3). (ß-wollastonite). m-ZrO(2) (monoclinic zirconia) declined the crystallization temperatures of glasses. t-ZrO(2) (tetragonal zirconia) increased the crystallization temperature of Ca(5)(PO4)(3)F and declined the crystallization temperature of ß-CaSiO(3). t-ZrO(2) greatly increased the fracture toughness, bending strength and micro-hardness of glass-ceramics. The nanometer apatites were induced on the surface of glass-ceramic after soaking 28 days in SBF (simulated body fluid), indicating the glass-ceramic has good bioactivity. The in vitro cytotoxicity test demonstrated the glass-ceramic has no toxicity to cell.

Influence of fluoride additions on biological and mechanical properties of Na2O-CaO-SiO2-P2O5 glass-ceramics.

Two series of Na2O-CaO-SiO2-P2O5 glass-ceramics doped with NH4HF2 (G-NH4HF2) or CaF2 (G-CaF2) have been prepared by sol-gel method. The glass-ceramic phase composition and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The mechanical properties and thermal expansion coefficient were measured by a microhardness tester, an electronic tensile machine and a thermal expansion coefficient tester. The structure difference between these two glass-ceramics was investigated by Fourier transform infrared spectroscopy (FTIR), and the in vitro bioactivity of the glass-ceramics was determined by in vitro simulated body fluid (SBF) immersion test. The hemolysis test, in vitro cytotoxicity test, systemic toxicity test and the implanted experiment in animals were used to evaluate the biocompatibility of the glass-ceramics. The mechanical properties of sample G-NH4HF2 are lower than that of sample G-CaF2, and the bioactivity of sample G-NH4HF2 is better than that of sample G-CaF2. The thermal expansion coefficients of these two glass-ceramics are all closer to that of Ti6Al4V. After 7 days of SBF immersion, apatites were induced on glass-ceramic surface, indicating that the glass-ceramics have bioactivity. The hemolysis test, in vitro cytotoxicity test and systemic toxicity test demonstrate that the glass-ceramics do not cause hemolysis reaction, and have no toxicity to cell and living animal. The implanted experiment in animals shows that bone tissue can form a good osseointegration with the implant after implantation for two months, indicating that the glass-ceramics are safe to serve as implants.

Improvement of corrosion and biological properties of microarc oxidized coatings on Mg-Zn-Zr alloy by optimizing negative power density parameters.

Corrosion and biological properties of microarc oxidized calcium phosphate (CaP) coatings on Mg-Zn-Zr alloy were improved by optimizing negative power density parameters. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were employed to characterize the coating morphology and phase composition. The in vitro cytotoxicity and systemic toxicity tests were carried out to evaluate the coating biocompatibility. The degradability and bioactivity of the coatings were determined by in vitro simulated body fluid (SBF) immersion test. The coating microstructure, thickness and growth rate can be influenced by negative power density through changing direction of ions movements, rate of ions exchanges and affecting formation of plasma. The CaP coatings reduced the substrate degradation rate. Calcium phosphates, such as hydroxyapatite (Ca10(PO4)6(OH)2, HA) and calcium pyrophosphate (Ca2P2O7, CPP), etc., were induced after 30 days SBF immersion, indicating that the coatings have bioactivity. The CaP coatings have no toxicity to cell and living mice, indicating that the coatings are safe to serve as implants.

Effect of various additives on microstructure, mechanical properties, and in vitro bioactivity of sodium oxide-calcium oxide-silica-phosphorus pentoxide glass-ceramics.

The partial substitution of MgO, TiO2, or CaF2 for CaO in the Na2O-CaO-SiO2-P2O5 (45S5) system was conducted by the sol-gel method and a comparative study on structural, mechanical properties, and bioactivity of the glasses was reported. Based on thermogravimetric and differential thermal analysis, the gels were sintered with a suitable heat treatment procedure. The glass-ceramic properties were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and so on, and the bioactivity of the glass-ceramic was evaluated by in vitro assays in simulated body fluid (SBF). Results indicate that with the partial substitution of MgO, TiO2, CaF2 for CaO in glass composition, the mechanical properties of the glass-ceramics have been significantly improved. Furthermore, CaF2 promotes glass crystallization and the crystallization does not inhibit the glass-ceramic bioactivity. All samples possess bioactivity; however, the bioactivity of these glass-ceramics is quite different. Compared with 45S5, the introduction of MgO decreases the ability of apatite induction. The addition of TiO2 does not significantly improve the bioactivity, and the replacement of CaO by CaF2 shows a higher bioactivity.

Effects of phosphates on microstructure and bioactivity of micro-arc oxidized calcium phosphate coatings on Mg-Zn-Zr magnesium alloy.

Calcium phosphate (CaP) coatings were prepared on Mg-Zn-Zr magnesium alloy by micro-arc oxidation (MAO) in electrolyte containing calcium acetate monohydrate (CH3COO)2Ca·H2O) and different phosphates (i.e. disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O), sodium phosphate (Na3PO4·H2O) and sodium hexametaphosphate((NaPO3)6)). Scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray diffractometer (XRD) were employed to characterize the microstructure, elemental distribution and phase composition of the CaP coatings. Simulated body fluid (SBF) immersion test was used to evaluate the coating bioactivity and degradability. Systemic toxicity test was used to evaluate the coating biocompatibility. Fluoride ion selective electrode (ISE) was used to measure F(-) ions concentration during 30 days SBF immersion. The CaP coatings effectively reduced the corrosion rate and the surfaces of CaP coatings were covered by a new layer formed of numerous needle-like and scale-like apatites. The formation of these calcium phosphate apatites indicates that the coatings have excellent bioactivity. The coatings formed in (NaPO3)6-containging electrolyte exhibit thicker thickness, higher adhesive strength, slower degradation rate, better apatite-inducing ability and biocompatibility.

Microstructure and biological properties of micro-arc oxidation coatings on ZK60 magnesium alloy.

Ceramic coatings were prepared on ZK60 magnesium alloy in electrolyte with different concentration ratio of calcium and phosphorus (Ca/P) by micro-arc oxidation (MAO) technique at constant voltage. The microstructure, phase composition, elemental distribution, corrosion resistance, and adhesion of the coatings were investigated by scanning electron microscope (SEM), X-ray diffractometer (XRD), energy-dispersive X-ray spectrometry (EDS), electrochemical workstation, and scratch spectrometer, respectively. The coating biocompatibility was evaluated by in vitro cytotoxicity tests and systemic toxicity tests, and the bioactivity and degradability were evaluated by simulation body fluid (SBF) immersion tests. SEM shows that pores with different shapes distribute all over the coating surface. The adhesion and thickness of the coatings increases with increasing Ca/P ratio of electrolyte. The in vitro cytotoxicity tests and systemic toxicity texts demonstrate that the coatings have no toxicity to cell and living animal, which show that the coatings have excellent biocompatibility. XRD analysis shows that bioactive calciumphosphate (CaP) phases such as hydroxyapatite (HA, Ca(10)(PO(4))(6)(OH)(2)) and calcium pyrophosphate (CPP, Ca(2)P(2)O(7)) are induced in the immersed coatings, indicating that the MAO coatings have excellent bioactivity.

MicroRNAs regulate B-cell receptor signaling-induced apoptosis.

Apoptosis induced by B-cell receptor (BCR) signaling is critical for antigen-driven selection, a process critical to tolerance and immunity. Here, we examined the roles of microRNAs (miRNAs) in BCR signaling-induced apoptosis using the widely applied WEHI-231 model. Comparison of miRNA levels in BCR-stimulated and -unstimulated cells revealed that 39 miRNAs were differentially expressed upon stimulation of the BCR. Importantly, stimulation in the presence of anti-CD40 antibodies, which rescues cells from BCR-induced apoptosis, prevented most changes in miRNA expression. Ectopic expression of mir-150 and mir-181a1b1, miRNAs that were upregulated upon BCR stimulation, resulted in inhibition of cell growth. Finally, we showed that ectopic expression of mir-150, mir-181a1b1 and mir-17∼92 sensitized cells to anti-IgM stimulation-induced growth inhibition. Together, these results demonstrate that miRNAs are involved in BCR signaling, suggesting that they may have important roles in the regulation of B cell-mediated tolerance and immunity.