OBJECTIVETo observe mandibular fracture healing after synthesized bioabsorable poly-para-dioxanone (PDS) ligature fixation.

METHODSPara-dioxanone monomer was prepared by chemical reactions of metallic sodium, ethylene glycol and other raw materials. PDS was synthesized by polymerizing the purified para-dioxanone in the presence of catalyst under the conditions of negative pressure and certain temperature. PDS ligature was obtained by processing the polymer into small granules, drying and melt-extruding through a spinnerette. Eighteen adult male New Zealand rabbits were assigned randomly into two groups. After mandibular fracture models were created, reductions of the artificial fractures were accomplished by means of transosseous PDS ligatures on each of 12 rabbits in experimental group. While the other six rabbits without any internal fixation were set as control. Schedules for killing were arranged to give postoperative samples at two-week interval till 12th week.

RESULTSRadiographical and histological examinations demonstrated that all fractures fixed with PDS ligatures healed without any complication. Periosteal and cartilaginous osteogenesis was observed in newly formed external callus. In contrast, bone fragment migration and the consequent nonunion occurred in the control group. PDS ligature degraded and absorbed without interference with osseous union and healing. The tensile strength reduction of PDS ligature was prior to its absorption in vivo.

CONCLUSIONThe synthesized PDS is a colorless, flexible, themoplastic and monofilament fiber, which can be sterilized by ethylene oxide embalmment without serious loss of tensile strength. It seems that the application of this macromolecular material in internal fixation is of great worth for further study.

Absorbable Implants ; Animals ; Biodegradation, Environmental ; Bone Regeneration ; drug effects ; Fracture Fixation, Internal ; instrumentation ; methods ; Fracture Healing ; Male ; Mandibular Fractures ; physiopathology ; surgery ; Materials Testing ; Polydioxanone ; administration & dosage ; chemical synthesis ; Rabbits ; Random Allocation ; Tensile Strength

OBJECTIVETo observe the heterotopic osteogenesis of autogenous marrow stromal cells loading on porous calcium phosphate ceramic scaffolds with rhBMP2 gene transfection in a Sprague-Dawley rat model.

METHODSAutogenous marrow stromal cells were obtained from left femurs and tibias of 20 male adult SD rats under general anesthesia and sterile condition and cultured in alpha-Minimal Essential Medium supplemented with 15% fetal bovine serum. RhBMP2 gene was transfected into stromal cells by means of LipofectAMINE 2000 reagent five days after primary culture. The stably gene expressive cells were selected with G-418 for 14 days and mixed with stromal cells without transfection. The mixture cells were seeded and subcultured for another 10 days in porous calcium phosphate bioceramic that had been subjected to surface-modification via soaking in human plasma fibronectin. The cell-ceramic compound was implanted subcutaneously and intramuscularly in the corresponding rat. Lab animals were sacrificed at two-week intervals till twenty weeks postoperatively and the involved samples were removed.

RESULTSMorphologic and histological study demonstrated that cell-ceramic compound had an ability of heterotopic osteogenesis, which was similar to that of autogenous osteoblasts in previous study.

CONCLUSIONIt seems that autogenous stromal cells with rhBMP2 transfection acts as a bioreactor promoting proliferation and differentiation of stem cells when they are replanted into the corresponding animals.

Animals ; Bone Marrow Cells ; cytology ; physiology ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; biosynthesis ; genetics ; Calcium Phosphates ; pharmacology ; Ceramics ; pharmacology ; Male ; Osteogenesis ; drug effects ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; biosynthesis ; genetics ; Stromal Cells ; cytology ; physiology ; Transfection ; Transforming Growth Factor beta

Objective To investigate the predictive value of plasma homocysteine (Hcy) on contrast-induced nephropathy after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) .Methods Totally 156 patients with AMI receiving PCI in Beijing Electric Power Hospital from January 2014 to December 2015 were enrolled for the study and divided into contrast-induced nephropathy group and non-contrast-induced nephropathy group .Baseline data ,perioperative data and auxilia-ry examination results were compared between two groups .The single factor analysis and multivariate Logistic regression were used to analyze the influencing factors .Results In all 156 patients ,32 cases occurred contrast-induced nephropathy after PCI ,and the in-cidence was 20 .5% .The plasma Hcy level in contrast-induced nephropathy group was (21 .3 ± 8 .7)μmol/L ,significantly higher than (13 .3 ± 6 .1) μmol/L in non-contrast-induced nephropathy group (P< 0 .05) .Multiple Logistic regression analysis results showed that plasma Hcy levels was the independent risk factors of contrast-induced nephropathy (OR=2 .254 ,95% CI:1 .359 -3 .737 ,P=0 .002) .Conclusion About 1/5 of patients with AMI occur contrast-induced nephropathy after PCI ,and preoperative plasma Hcy level can well predict the risk of contrast-induced nephropathy ,which is worthy of clinical application .

This paper aims to explore the biocompatibility of bioengineer active corneal stroma (BACS), as the biological carrier for cornea reconstruction, to provide the basis for future study on clinic application. The cells and immunogenic components of cornea stroma were removed through different extract methods. A complex of functional corneal stroma cells and acellular corneal stroma was used to reconstruct BACS. Their morphological characteristics and ultrastructures were observed with transmission electron microscope. The complex was grafted into interlamellar stromal pockets. Cells were labeled by BrdU to examine the survival and conversion after grafting. The cells could survive and proliferate in acellular corneal stroma. All the nuclei of the corneal stromal cells showed positive labeling with BrdU in the BACS. After 4 weeks, BACS became transparent; after 8 weeks, the bioengineer active cornea stroma was fully reconstructed.
Animals ; Biocompatible Materials ; Corneal Stroma ; cytology ; transplantation ; Materials Testing ; Prostheses and Implants ; Prosthesis Design ; Rabbits ; Swine ; Tissue Engineering ; methods

The subcutaneous adipose tissue from the inguen of four Sprague-Dawley rats was obtained, then digested with one volume of collagenase type I and cultured with BGJb medium. The obtained adipose stromal cells were induced in human endothelial-SFM for 7 d. The cells were observed under inverted microscope every day and identified by transmission electron microscope and immunocytochemical staining with factor VIII antigen. The results showed the induced cells uniformly had characteristic cobblestone morphology of endothelial cells. Factor VIII antigen staining was positive in cytoplasm. Under transmission electron microscope, the cells displayed many finger like microvilli and numerous lysosomes, mitochondria, a few coarse endoplasmic reticulum and Weibel-Palade bodies. The characteristics of the rat adipose tissue-derived endothelial cells were consistent with those of vascular endothelial cells derived from other tissues. It seems that subcutaneous adipose tissue may represent a new alternative source of endogenous vascular endothelial cells.
Adipose Tissue ; cytology ; Animals ; Cell Culture Techniques ; methods ; Cell Differentiation ; Endothelial Cells ; cytology ; Endothelium, Vascular ; cytology ; Male ; Rats ; Rats, Sprague-Dawley ; Stromal Cells ; cytology

p21-activated kinases (PAKs) are key regulators of actin dynamics, cell proliferation and cell survival. Deregulation of PAK activity contributes to the pathogenesis of various human diseases, including cancer and neurological disorders. Using an ELISA-based screening protocol, we identified naphtho(hydro)quinone-based small molecules that allosterically inhibit PAK activity. These molecules interfere with the interactions between the p21-binding domain (PBD) of PAK1 and Rho GTPases by binding to the PBD. Importantly, they inhibit the activity of full-length PAKs and are selective for PAK1 and PAK3 in vitro and in living cells. These compounds may potentially be useful for determining the details of the PAK signaling pathway and may also be used as lead molecules in the development of more selective and potent PAK inhibitors.
Actins ; Cell Proliferation ; Cell Survival ; Humans ; In Vitro Techniques ; Mass Screening ; Nervous System Diseases ; p21-Activated Kinases ; Phosphotransferases* ; rho GTP-Binding Proteins

p21-activated kinases (PAKs) are key regulators of actin dynamics, cell proliferation and cell survival. Deregulation of PAK activity contributes to the pathogenesis of various human diseases, including cancer and neurological disorders. Using an ELISA-based screening protocol, we identified naphtho(hydro)quinone-based small molecules that allosterically inhibit PAK activity. These molecules interfere with the interactions between the p21-binding domain (PBD) of PAK1 and Rho GTPases by binding to the PBD. Importantly, they inhibit the activity of full-length PAKs and are selective for PAK1 and PAK3 in vitro and in living cells. These compounds may potentially be useful for determining the details of the PAK signaling pathway and may also be used as lead molecules in the development of more selective and potent PAK inhibitors.
Actins ; Cell Proliferation ; Cell Survival ; Humans ; In Vitro Techniques ; Mass Screening ; Nervous System Diseases ; p21-Activated Kinases ; Phosphotransferases* ; rho GTP-Binding Proteins