MicroRNAs (miRNAs) are a class of highly conserved small noncoding single stranded RNAs.They participate in the regulation of target genes through the degradation of mRNA and/or inhibition of translation.As the most abundant miRNAs in the central nervous system,miRNA-124 (miR-124) has been widely given attention in recent years.The recent research suggests that miR-124 is closely associated with ischemic cerebral injury,but its specific regulation mechanism remains unclear.This article reviews the roles of miR-124 in ischemic cerebral injury.

BACKGROUND: Metal-on-metal hip surface arthroplasty has improved the abradability for hip joint prosthesis and has the characteristics of normal biological stress transfer.OBJECTIVE: To observe the long-term state of hip-joint function of patients who underwent metal-on-metal hip surface arthroplasty.DESIGN: Follow-up study for cases.SETTING: Department of Orthopaedics, Jiangsu Provincial Corps Hospital of the Chinese People's Armed Police Force; Department of Orthopaedics, Affiliated Hospital of Nantong University.PARTICIPANTS: Eighteen cases (23 hips) who underwent a metal-on-metal hip surface arthroplastyprocedure in the Department of Orthopaedics, Jiangsu Provincial Corps Hospital of the Chinese People's Armed Police Force, and Department of Orthopaedics, Affiliated Hospital of Nantong University between September 2004 and July 2005 were recruited in this study. All cases, aged 28 to 54 years, include 11 males and 7 females. According to the classification of etiology, there were 13 cases of osteonecrosis(16 hips),3 cases of osteoarthritis( 4 hips ),1 case of congenital hip dysplasia (2 hips) and 1 case of posterior trauma arthritis(1 hip ). All cases applied the Conserve Plus resurfacing prosthesis (manufactured by Wright Medical Technology, USA), of which the pattern number of acetabular cup (press-fit depth: 1-2 mm) ranged from 38 mm to 56 mm in the inner diameter and from 44 mm to 62 mm in the outer diameter and that of femoral head cup ranged from 38 mm to 56 mm in the outer diameter. Preoperatively all patients signed the informed consent for the surgery, and the application of this technique also gave the approval of the Ethics Committee of the hospital.METHODS: ①After the epidural and lumbar combination anesthesia was satisfactory, the coxacava was exposed at first and the suitable size acetabular cup coated by hydroxyapatite ceramic was selected to be implanted, to be tightened and to be fixed by press-fit referring to the anatomical position. Subsequently to install the femoral head prosthesis, femoral cup was laid on the ready caput femoris and impacted by the presser to make the metal cup paste close-up with sclerotin when the concocted bone cement was overlaid on the prefabricated caput femoris surface and internal surface of prosthesis. Further, short-term of femoral cup should be kept the conformity with axial ray of the femoral neck. ②Patients were allowed to make the function exercise such as initiative stretch and contract of quadriceps muscle of thigh, passive motion of the knee joint and initiative motion of the knee joint under the non-weight loading on bed. Then they were encouraged to walk with two walking sticks two weeks after operation, progressing to get out of the two walking sticks six weeks postoperatively. All affected extremities were fixated with T-shaped tabula shoes in the abduction position after operation. ③All patients were reviewed with taking the anteroposterior radiographs of pelvis, evaluation of the clinically curative effect on the procedure of metal-on-metal hip surface arthroplasty and biocompatibility between the prosthesis and the host one year and two years after operation. Moreover, Harris score was assessed for all affected hips preoperatively, one year and two years postoperatively.MAIN OUTCOME MEASURES: ①The clinically curative effect on metal on metal hip surface arthroplasty; ②Biocompatibility;③The Harris score for the affected hips; ④The pain status of hip after operation.RESULTS: Eighteen cases were all brought into the outcome analysis at last.①The curative effect on the metal-on-metal hip surface arthroplasty: The femoral component of one case had a varus deformation of 10°six weeks after operation, but such complications as component loosening and femoral neck fractures, etc. Did not occur during the coming follow-up. The locations of rest prosthesis were satisfactory. Substantial radiolucencies were found at the rim of acetabular component (1 and 2 zone) in two hips, respectively one and two years after operation. But there was no evidence of radiolucencies around the short-stem of femoral component.②Biocompatibility: No patients were found to have obvious reactions including renal toxicity, pyretogen and rejection. No radiograph showed signs of loosening, dislocation, heterotopic bone formation, femoral neck narrowing, femoral head necrosis and prosthesis fixation failure, etc.③Harris score for the affected hips: The Harris score of all disease hips was improved from the mean 46 preoperatively to 85 one year after operation to 93 two years postoperatively. Of these,15 hips were excellent(> 90),6 hips good (80-89), and 2 hips fair(70–79).④The pain status of hip after operation: Two patients complained of slight pain, one patient of moderate pain, and no cases of severe pain happened.CONCLUSION: The long-term outcome for hip disease patients who undergo metal-on-metal hip surface arthroplasty is satisfactory.

Objective To investigate the effects of down-regulation of polo-like kinase-1 (PLK1) gene by RNA interference (RNAi) on the invasion of a human malignant melanoma cell line A375 and their possible mechanisms.Methods Cultured A375 cells were classified into several groups:blank control group receiving no treatment,liposome group transfected with lipofectamine only,and three siRNA groups transfected with three concentrations of a small interference RNA (siRNA) targeting PLK1 respectively.After additional culture,real time quantitative PCR and Western blot analysis were performed to quantify the expressions of PLK1 mRNA and protein in A375 cells respectively,Transwell invasion assay to evaluate the invasive capacity of A375 cells,agarose gel electrophoresis and terminal deoxynucleotidyl-transferase-mediated dUTP-biotin nick end labelling (TUNEL) to detect anoikis in A375 cells.The colony-forming capacity was also evaluated for A375 cells.Statistical analysis was carried out by one-factor analysis of variance.Results There was a significant decrease in PLK1 mRNA and protein expressions as well as in colony-forming units in the siRNA groups compared with the blank control group (all P ＜ 0.05).The invasive capacity of A375 cells was significantly inhibited in the siRNA groups with the number of migrating cells in Transwell assay being 39 ± 5,19 ± 5 and 9 ± 3 in A375 cells transfected with 3.125,6.250 and 12.500 nmol/L siRNAs respectively,compared to 56 ± 5 in the blank control group (all P ＜ 0.05).A characteristic DNA ladder was observed on agarose gel electrophoresis in the siRNA (6.250 nmol/L) group.Compared with the blank control group and liposome group,the three siRNA groups showed increased apoptotic index (3.86％ ± 0.35％ (3.125 nmol/L siRNA),7.35％ ± 0.36％ (6.250 nmol/L siRNA) and 17.56％ ± 0.38％ (12.500 nmol/L siRNA) vs.1.15％ ± 0.25％ (blank control group) and 1.18％ ± 0.22％ (liposome group),all P ＜ 0.05).Conclusions PLK1 siRNA can inhibit the invasion of malignant melanoma cells,likely by inducing anoikis in these cells.

Objective To study the effects of Forkhead box protein M1 (FoxM1) down regulation by small interfering RNA(siRNA) on chemosensitivity and mechanism of human pancreatic cancer cell and its mechanism.Methods Three FoxM1 siRNAs were designed and constructed.All cancer cells were divided into different groups,after transfected with FoxM1 siRNA for different time,the cultured cells were harvested to carry on the next tests.Expression of FoxM1 were determined by red-time PCR and Western blot,and prolifearion and chemosensitivity were evaluated by MTT assay,and the phosphorylation of Akt protein was examined by Western blot.Results FoxM1 siRNA could down-regulate the FoxM1 expression in a dose-and time-dependent manner.The MTF results showed that the inhibit rates was 17.78％,17.56％,35.39％,52.81％,70.98％ indifferentgroups [Con-A + Gemcitabine,Con-B + Gemcitabine,siRNA (3.125nM) + Gemcitabine,siRNA (6.25nM) + Gemcitabine and siRNA(12.5nM) + Gemcitabine,respectively.The phosphorylation of Akt protein was inhibited in a dose-dependent manner.Conclusions FoxM1 siRNA could sensitize human pancreaticr cancer cells chemotherapy sensitivity,it is the one of the important mechanisms through down-regulate Akt phosphorylated levels,but the molecular mechanism need to be explored further.

Objective To observe the expression changes of 12 ischemia-related microRNAs (miRNA) in cerebral ischemia-reperfusion injury after deep hypothermic low flow (DHLF) in mice.Methods A total of 80 3-w eek-old healthy and clean grade C57BL/6 male mice w ere randomly divided into either a DHLF model group or a sham operation group. Each group w as redivided into 4 subgroups according to the time points of 2, 6, 12, and 24 h (10 in each group). The bilateral carotid arteries of the DHLF model group w ere clipped and a DHLF model w as established, w hile the carotid arteries of the sham operation group w ere not clipped. The mice w ere sacrified at each time point and the brain tissue w as removed. The total RNA w as extracted. Quantitative reverse transcriptase polymerase chain reaction w as used to detect miRNA expression. Results Compared w ith the sham operation group, the expression levels of 9 miRNAs w ere upregulated, 2 w ere dow n-regulated, and 1 did not have any significant change in the DHLF model group. Conclusions The expression levels of 11 miRNAs changed significantly after DHLF. It might have a regulatory role in cerebral ischemia-reperfusion injury after DHLF.

Objective To investigate the effects of miR-10a expression on migration and invasion of human pancreatic cancer cells AsPC-1.Methods Small interfering RNA targeting at miR-10a (miR-10a-siRNA) was constructed,then it was transfected into pancreatic cancer AsPC-1 cells,and nonsense siRNA (Nc-siRNA) group and blank control group was established.Real time PCR assay was used to detect the expression of miR-10a in the 3 groups,and wound healing assay and Transwell assay were used to determine the migration and invasion abilities of cancer cells.The amount of matrix metalloproteinase-13 (MMP-13) in supernatant of cancer cell culture of each group was examined by ELISA assay.Results The miR-10a levels in control group,NC-siRNA group and miR-10a-siRNA group were 1.05 ±0.08,1.03 ±0.06,0.02 ±0.01 ; and the number of transmembrane cell were (150 ± 2.6),(145 ± 2.2),(62 ± 1.8),the levels of MMP-13 in the supernatant were (108.5 ± 2.8),(107.8 ± 2.5),(35.8 ± 1.5) pg/ml.The values were significantly lower in miR-10a-siRNA group than those in control group and NC-siRNA group (P ＜ 0.01).The distance of cultured clone in miR-10a treated cancer cells (736± 18 μm) was significantly longer than those in the controls (385 ±5 μm) and NC-siRNA group (395± 13 μm,P＜0.01).Conclusions Down-regulation of miR-10a by siRNA may inhibit migration and invasion of pancreatic cancer AsPC-1 cells,and the downregulated expression of MMP-13 may be one of the important mechanisms.

We report a complete genomic sequence of rare isolates (minor genotype) of the SARS-CoV from SARS patients in Guangdong, China, where the first few cases emerged. The most striking discovery from the isolate is an extra 29-nucleotide sequence located at the nucleotide positions between 27,863 and 27,864 (referred to the complete sequence of BJ01) within an overlapped region composed of BGI-PUP5 (BGI-postulated uncharacterized protein 5) and BGI-PUP6 upstream of the N (nucleocapsid) protein. The discovery of this minor genotype, GD-Ins29, suggests a significant genetic event and differentiates it from the previously reported genotype, the dominant form among all sequenced SARS-CoV isolates. A 17-nt segment of this extra sequence is identical to a segment of the same size in two human mRNA sequences that may interfere with viral replication and transcription in the cytosol of the infected cells. It provides a new avenue for the exploration of the virus-host interaction in viral evolution, host pathogenesis, and vaccine development.
Base Sequence ; China ; Cluster Analysis ; Gene Components ; Genetic Variation ; Genome, Viral ; Genotype ; Molecular Sequence Data ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; genetics ; Sequence Analysis, DNA ; Severe Acute Respiratory Syndrome ; genetics