BACKGROUND:Strontium-containing hydroxyapatite bone cement can improve the crystal inity and compatibility of the materials, but the effects on celltoxicity, cellsurface adhesion, proliferation and expression stil need further studies. OBJECTIVE:To observe the in vitro cytobiological properties of gradient strontium-containing hydroxyapatite bone cement.
METHODS:Four groups of strontium-containing hydroxyapatite bone cement samples were prepared at a strontium content of 0%, 1%, 5%and 10%. Six paral el samples selected from each group were subjected to ultraviolet radiation sterilization for 3 hours for standby. Dulbecco’s modified Eagle’s medium containing 10%fetal bovine serum served as extraction neurotransmitter. Strontium-containing hydroxyapatite cement powder was mixed with extract solution at a ratio of 1 g to 10 mL. L-929 fibroblasts and osteoblasts from immature rabbits were selected and identified. Scanning electron microscopy was used to observe the adhesion and proliferation of osteoblasts on the surface of gradient strontium-containing hydroxyapatite cement, and cellviability was detected using alkaline phosphatase activity method.
RESULTS AND CONCLUSION:(1) Cytotoxicity of different amount of strontium-containing hydroxyapatite cement was graded 0 or 1, suggesting the cytotoxicity of each sample was certainly associated with strontium content, reaction time, and extract concentration. (2) Hydroxyapatite bone cement containing a certain amount of strontium can promote osteoblast adhesion, proliferation and expression and improve the dissolution kinetics and biodegradability of materials, becoming more in line with the clinical requirements. But there is stil lack of long-term results.

Embryonic Stem Cells ; Humans ; Myocardial Infarction ; therapy ; Stem Cell Transplantation

The article gives a brief analysis of student characteristics of medical independent college and the aim and purpose of medical education to propose the corresponding measures to improve the students work of independent college.

Objective To investigate the effect of ketamine on the synaptic long-term potentiation(LTP) in the CA1 area of rat hippocampal slices,and to elucidate the mechanisms underlying the effect of ketamine on memory.Methods Hippocampal slices(400 ?m thick) were obtained from the brains of male Sprague-Dawley rats(2 months old) weighing 200-250 g that were decapitated.The slices were incubated in artificial cerebrospinal fluid(ACSF) at room temperature for at least 120 min before use.Forty-nine slices were randomly divided into 7 groups(n=7):control group,ketamine 1,5,10,30,50 and 100 ?mol?L-1 groups.All the slices in each group were perfused with ACSF,ketamine 1,5,10,30,50 or 100 ?mol?L-1,respectively.The slices in each group were performed to record evoked population spikes(PS) using extracellular microelectrode recording technique.Another forty-nine slices were randomly divided into 7 groups(n=7):LTP group,ketamine-LTP 1,5,10,30,50 and 100 ?mol?L-1 groups.All the slices in each group were perfused with ACSF,ketamine 1,5,10,30,50 or 100 ?mol?L-1,respectively.PSs were recorded for at least 30 min before LTP in each group.For LTP induction,high-frequency stimulation(HFS) conditioning pulses(100 Hz?s-1) were applied to the Schaffer collateral-commissural pathway of hippocampus using a bipolar stimulating electrode.The changes in PS amplitude after HFS were analyzed in each group.Results The PS amplitude of the rat hippocampal slices in ketamine 1,5,and 10 ?mol?L-1 groups had no significant difference compared with control group.The PS amplitude in ketamine 30,50 and 100 ?mol?L-1 groups decreased compared with control group(P

AIM: To examine the effect of protamine sulfate, lipopolysaccharide(LPS),tumor necrosis factor(TNF), epidermal growth factor(EGF) and " Bushen Huoxue Xiezhuo" (BHX) decoction on the proliferation of extracorporeal cultured rat glomerular epithelial cells (GEC). METHODS: Their action on the proliferation of rat GEC were investigated using the -TdR incorporation. Meanwhile, the serum of rats treated with BHX decoction was extracted pharmacologically and its effects on the growth of GEC were also studied. RESULTS: LPS, protamine sulfate, TNF-? and EGF could significantly inhibit the -TdR incorporation of GEC in a dose- and time-dependent manner. However, this inhibition could be efficiently reversed by the serum containing BHX decoction. CONCLUSION: GEC is one of the main target cells on which BHX decoction act, and the protection on GEC might be one of the mechanisms underlying the role of BHX decoction in preventing the progression of nephrosis.

Objective To construct the targeting vector for conditional gene knockout of sex hormone?binding globulin(Shbg)in mice. Methods Based on Red/ET,two LoxP were inserted into both sides of extron 4 and extron 7 for conditional gene knockout of murine Shbg. Firstly,the Shbg gene and its upstream,downstream genes obtained from BAC DNA by PCR were cloned into plasmid pBR322?MK,which was named pBR322?MK?AB. The retrieve plasmid(pBR322?Shbg?Re)was obtained by homologous recombination between the plasmid and BAC.Then a great quantity of Neo fragments obtained from PL452 and PL451 were inserted into the targeting vector after another round of Red/ET and then the final targeting vec?tor(pBR322?MK?SHBG?cko)was achieved. Results The correct structures of the targeting vectors such as pBR322?MK?AB,pBR322?Shbg?Re, SHBG?Ln and pBR322?MK?Shbg?cko were confirmed by restriction enzyme digestion and sequencing analysis. Conclusion The targeting vector for conditional knockout of murine SHBG was successfully constructed. The construction of targeting vector paved the way for conditional knockout mouse strain generated by targeted mutation of Shbg.

Purpose To explore the pathological feature of urinary exfoliated cell examination and influence factors by retrospectively comparing the coincidence of diagnosis between urinary exfoliated cell examination and histopathologic results of cystoscopic biopsy. Methods 735 patients underwent both urinary exfoliated cell examination and histopathologic biopsy of cystoscope evaluation from No-vember 2010 to July 2014 in Peking University Shougang Hospital were enrolled in this study. The urinary exfoliated cells were treated with Pap staining, while the histopathologic biopsy were dealt with HE staining. All cases were divided into three groups according to the diagnosis of urinary exfoliated cell examination:negative group ( no cancer or atypical cell detected) , suspicious group ( atypical cell detected) and positive group ( cancer cell detected) . These above diagnoses were confirmed with the histopathologic biopsy. ROC curve analysis, Cochran-Armitage trend test and logistic regression analysis were performed to evaluate the sensitivity and the specificity of urinary exfoliated cell examination as well as the relationship between diagnoses with age and sex. Results The age range of 735 patients (551 male and 184 female) was 28 ~91 years and the median age was 69 years. There were 187 patients in the positive group, including 184 malignant and 3 false-positive cases. The suspicious group, including 186 cases, consisted of 67 malignant, 119 benign reactive changes. Of all 362 cases in the negative group, malignant tumor was detected in 90 cases. For histologic diagnosis, the AUC of ROC(95%CI)was 0. 800 (0. 767~0. 834), displaying significant difference as compared to the histological pathological diagnostic results(P<0. 001). As the cyto-histologic diagnostic level elevated from negative, suspicious to positive, the results of Co-chran-Armitage trend test showed significant differences(Z=15. 83, P<0. 001). If standardized with the histopathologic biopsy re-sults, the AUC (area under curve) of urinary exfoliated cell examination was 0. 800 (0. 767~0. 834) in ROC curve analysis was sig-nificantly larger (P<0. 001). Furthermore, we also found in Logistic regression that the incidence of cancer was 1. 04 (1. 03~1. 05) times higher if aged one year older ( P<0. 001 ) , while there was no significant relationship between the incidence and the sex ( P=0. 655). Conclusions The coincidence rate of urinary exfoliated cell examination increases with the malignant degree. A positive cor-relation is detected between age and the incidence of malignant tumor. Detailed clinical material can markedly improve the sensitivity and accuracy of cyto-histologic diagnosis.

The microbial populations and community structure characterization technologies of the enhanced biological phosphate removal system were reviewed comprehensively in this paper, and their future research directions were outlined.

Burnout, Professional ; Humans

Cellular Microenvironment ; Humans ; Myocardial Infarction ; metabolism ; rho-Associated Kinases ; metabolism ; rhoA GTP-Binding Protein ; metabolism