[Preliminary MRI evaluation of anterior repositioning splint in treatment of disc displacement with reduction of temporomandibular joint].

Objective: MRI images were used to study the efficacy of anterior repositioning splint (ARS) in the treatment of different types of disc displacement with reduction (DDWR) in temporomandibular joint. Methods: From September 2020 to December 2021, 26 patients with DDWR were enrolled in the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Zhengzhou University. There were 5 males and 21 females with an average age of (20.8±5.8) years. ARS was used for 3-6 months. The changes of joint clicking, opening type and joint pain before and after treatment were compared. The changes of disc position, disc-condyle angle and condylar bone mass before and after treatment were compared by MRI. Paired t-test was performed on the disc-condyle angle before and after treatment, Fisher's exact test was performed on the change of disk position, and other count data were expressed as rate (%). Results: After ARS treatment, the effective rates of joint clicking,abnormal opening, joint pain and disc displacement were 97%(35/36), 14/18, 7/9 and 95%(36/38). MRI analysis found that there was a significant difference between the disc position before and after treatment (P<0.001), MRI analysis showed that the anterior disc displacement (48%, 25/52) and the anterolateral disc displacement (17%, 9/52) were the most common before treatment. In contrast, the normal superior disc (75%, 39/52) and the anterior disc displacement (17%, 9/52) were the most common after treatment, no significant changes were seen after treatment in the anteromedial disc displacement. The disc-condylar angle was (36.09±19.02) ° before ARS treatment and (3.94±10.12) ° after ARS treatment(t=9.23, P<0.001). After treatment, 46% (12/16) of the patients showed new bone formation, and the height of the condyle recovered. Conclusions: The clinical efficacy of ARS in the treatment of anterior disc displacement and anterolateral displacement of temporomandibular joint is remarkable, which can restore the disc-condylar relationship of most patients with indications.

[The role of heme oxygenase-1 on oxidative stress injury induced by zinc oxide nanoparticles in human umbilical vein endothelial cells line EA.hy926 cells].

Objective: To explore the effect of heme oxygenase-1 (HO-1) on level of reactive oxygen species (ROS) induced by zinc oxide nanoparticles (ZnO-NPs) in Human umbilical vein endothelial cells line EA.hy926. Methods: The EA.hy926 cells in logarithmic growth phase were incubated with 0.0, 2.5, 5.0, 10.0 and 15.0 mg/L ZnO-NPs respectively. The ROS level, reflected by mean fluorescence intensity (MFI), was examined by flow cytometer after 4 hours exposure, the protein expression of HO-1 which was determined by Western Blot after exposed to ZnO-NPs for 24 hours. Cells incubated with 15.0 mg/L were set as the ZnO-NPs group; a blank control group was set at the same time. Cells were pretreated with HO-1 inhibitor zinc protoporphyrin (ZnPPIx) and HO-1 activator cobalt protoporphyrin (CoPPIx), they were classified as ZnPPIx group and CoPPIx group. 15 mg/L ZnO-NPs was chosen to conduct the experiment of HO-1 activation and inhibition. Cells were classified as ZnPPIX+ ZnO-NPs group and CoPPIx+ ZnO-NPs group after pretreated with 10 µmol/L ZnPPIx or CoPPIx for 1 h, added 15 mg/L ZnO-NPs to cell culture medium. In all groups ROS levels were detected after exposed to ZnO-NPs for 4 hours, the protein expression of HO-1 was detected after exposed to ZnO-NPs for 24 hours. Results: With the increased dose of ZnO-NPs, levels of ROS and HO-1 in EA.hy926 cells were clearly elevated (the MFI of 0.0, 2.5, 5.0, 10.0 and 15.0 mg/L ZnO-NPs incubated groups was 22 627.22±718.27, 24 726.47±568.52, 31 141.75±1 312.24, 39 824.82±4 774.74, 50 569.03±1 497.63 respectively, and HO-1 relative expression were 0.16±0.01, 0.19±0.02, 0.16±0.01, 0.23±0.02, 0.92±0.06 respectively). HO-1 expression in ZnPPIx pretreatment group decreased compared with ZnO-NPs group (1.05±0.05 vs. 1.12±0.01, P<0.05), meanwhile ROS level enhanced (62 683.95±2 589.59 vs. 53 654.53±2 229.01, P<0.05). However, CoPPIx pretreatment had higher HO-1 level and lower level of ROS compared with ZnO-NPs group (HO-1: 1.74±0.11 vs. 0.22±0.03, P<0.05; ROS: 32 845.04±993.48 vs. 53 654.53±2 229.01, P<0.05). Conclusions: Exposure to ZnO-NPs significantly induced ROS generation in EA.hy926 cells in a dose-dependent manner. HO-1 regulated ZnO-NPs-induced oxidative stress.

Plant regeneration from long term suspension culture-derived protoplasts of hexaploid wheat (Triticum aestivum L.).

Highly regenerable callus cultures have been obtained from immature embryos of hexaploid wheat cv. Oderzo. Friable fast growing calli were induced at high frequency. Suspensions were initiated from the most friable callus lines: they became established in about two months. Suspensions consisted of cell aggregates of 30 to 1000 um in diameter. Upon plating on MS hormone-free medium, suspensions regenerated green plantlets, and their regenerative capability was maintained for at least 10 months. Protoplasts were isolated from 7-8 day old suspension cultures with a yield of 4-6×10(6) protoplasts/g fresh weight cells. Protoplast culture was either in liquid medium or in a bead-type system with agarose beads. First divisions were detected at day 5. At day 14 visible colonies were detected and the plating efficiency was evaluated between 2 and 8% over the initial number of protoplasts plated. Protoplast-derived calli were cultured in the presence of 1 mg/l IAA and 0.5 mg/l zeatin and were used for reinitiating new suspension cultures. Upon plating onto MS hormone-free medium, with or without the addition of 0.1 mg/l GA3, calliclones were induced to differentiate. Regeneration of complete plantlets, with shoot and roots took about two months. Plantlets were grown in sterile conditions until 12-15 cm height, and were subsequently transplanted in soil.