OBJECTIVETo study the biomechanical characteristics of Ni-Ti shape-memory alloy-enclosed interlocking intramedular nail Ni-Ti En for clinical application.

METHODSSix transverse fractures were induced in 6 fresh humeral shafts and fixed with Ni-Ti En, plate, interlocking intramedullary nail, and Ender nail, respectively. The specimens then underwent stress analysis for comparison of the bending strength, twisting force, and flexibility.

RESULTSThe bending strength of Ni-Ti En was not significantly different from that of the plate and better than ender's nail; the twisting force of the interlocking intramedullary nail was comparable with the plate, but better than Ender nail.

CONCLUSIONNi-Ti Enpossess good biomechanical property to meet the demand of osteosynthesis, and its less stress protection, freedom of distant nail locking, flexibility and stable fixation may accelerate fracture healing.

Biomechanical Phenomena ; Bone Nails ; Fracture Fixation, Intramedullary ; instrumentation ; methods ; Humans ; Humeral Fractures ; physiopathology ; surgery ; Nickel ; Titanium

A fuzzy Markov random field (FMRF) model is established and a new algorithm based on FMRF for image segmentation proposed in this paper. This algorithm simultaneously deals with the fuzziness and randomness for effective acquisition of the prior knowledge of the images. A conventional Markov random field (CMRF) serves as a bridge between the FMRF, obviously a generalization of the CMRF, and the original images. The FMRF degenerates into the CMRF when no fuzziness is considered. The segmentation results are obtained by fuzzifying the image, updating the membership of prior FMRF based on the maximum posteriori criteria, and defuzzifying the image according to the maximum membership principle. The proposed algorithm can effectively filter the noise and eliminate partial volume effect when processing the degraded image to ensure more accurate image segmentation.
Algorithms ; Fuzzy Logic ; Humans ; Image Enhancement ; methods ; Image Interpretation, Computer-Assisted ; methods ; Markov Chains ; Pattern Recognition, Automated ; methods ; Signal Processing, Computer-Assisted

OBJECTIVETo observe the incidence of double-lumen endobronchial tubes (DLT) malposition caused by body position change or surgical manipulation and its impact on the efficacy of lung separation and ventilation.

METHODSTotally 688 patients undergoing thoracic surgery were enrolled in this study. The patients were intubated with Mallinckrodt DLT following intravenous anesthesia induction. The DLT position was corrected with fiberoptic bronchoscope (FOB), and successful lung separation and satisfactory ventilation were ensured during one-lung ventilation in the supine position. Bronchoscopy was performed immediately and the DLT position was corrected 15 minutes after dependent lung ventilation in the lateral position or in case of ineffective lung separation or SpO(2) declination to below 90%.

RESULTSDLT malposition occurred after lateralization in 112 (16.3%) patients, of whom 12.8% developed hypoxemia and 3.3% encountered air leak. The incidence of left-sided DLT malposition after lateralization was higher than that of right-sided DLT malposition (19.7% vs 12.2%, P<0.01). DLT malposition occurring in 112 patients after lateralization reoccurred in 16 (14.3%) patients during surgery, and the malposition incidence was significantly higher than that of malposition occurring only during surgery (1.2%, P<0.01).

CONCLUSIONMalposition of Mallinckrodt double-lumen tubes for lung separation during thoracic anesthesia occurs in 16.3% patients when shifting to lateral position, may reoccur in 14.3% of the patients despite previous FOB positioning.

Bronchoscopy ; Fiber Optic Technology ; Humans ; Intraoperative Complications ; diagnosis ; etiology ; Intubation, Intratracheal ; adverse effects ; methods ; Respiration, Artificial ; methods ; Thoracic Surgical Procedures ; adverse effects ; methods ; Ventilators, Mechanical

OBJECTIVETo investigate the viability of tissue-engineered heart valve leaflets prepared with cell-polymer constructs in nude mice.

METHODSSheep endothelial cells and smooth muscle cells/fibroblasts were seeded on patches of PHA and implanted subcutaneously in athymic mice (BALB/C). The cell-polymer constructs were harvested 12, 14, 21 and 28 days after implantation.

RESULTSFourteen days after implantation, the cell-polymer constructs exhibited similar color with the autologous tissues, and HE staining showed more numerous cells in the implant. At 28 days following implantation, muscular fibers were formed in the cell-polymer constructs. V-G staining showed positive collagen staining in the implant at 12 days after implantation, while the control implants retrieved 28 days after implantation did not show extensive tissue formation or muscular fiber formation.

CONCLUSIONThe cell-polymer constructs can survive in vivo and has the potential to grow into autologous valve leaflets in the nude mice.

Animals ; Bioprosthesis ; Endothelium, Vascular ; cytology ; Heart Valves ; Implants, Experimental ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Muscle, Smooth, Vascular ; cytology ; Sheep ; Tissue Engineering ; methods

OBJECTIVETo study the feasibility of vector-mediated RNA interference for HER-2-positive breast cancer therapy.

METHODSA plasmid vector capable of mediating HER-2 RNA interference was constructed, and HER-2-positive breast cancer cell line SKBR-3 was transfected with this constructed vector. The expression of HER-2 mRNA and protein was analyzed by RT-PCR and Western blotting, and the growth and apoptosis of SKBR-3 cells was analyzed after transfection.

RESULTSThe expressions of HER-2 mRNA and HER-2 protein was downregulated in response to vector-mediated HER-2 RNA interference, which also resulted in tumor cell growth inhibition and increased number apoptotic cells.

CONCLUSIONHER-2 is a good target for RNA interference and RNA interference targeting HER-2 can lead to HER-2 breast cancer cell apoptosis and growth inhibition.

Apoptosis ; Blotting, Western ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Female ; Genetic Vectors ; Humans ; RNA Interference ; RNA, Messenger ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; Receptor, ErbB-2 ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection

OBJECTIVETo ascertain whether mouse c-Kit(+)Lin- bone marrow cells have the potential of hepatic stem cells.

METHODSc-Kit(+)lin- bone marrow cells were isolated and purified by magnetic-activated cell sorting (MACS) from BALB/C male donor mice, and immediately transplanted into age-matched BALB/C syngeneic female mice with 35-Gy total liver irradiation. The recipients were sacrificed 1 month after the transplantation for pathological observation of the liver morphology. The presence of Y-chromosome was examined in the liver cells of the recipient by in situ hybridization (ISH), and alpha-fetoprotein (AFP) and albumin in the cells were detected by immunohistochemistry.

RESULTSThe hepatocytes positive for Sry gene on Y-chromosome were identified 1 month after transplantation, and immunohistochemistry for AFP and albumin confirmed that the donor mice-derived cells were hepatocytes.

CONCLUSIONc-Kit(+)lin- bone marrow cells have the potential of hepatic stem cells, which can reside and differentiate into hepatocytes in the liver after transplantation. c-Kit(+)lin- bone marrow cells can be used as the source cells of cell transplantation for liver disease.

Animals ; Bone Marrow Transplantation ; methods ; Cell Differentiation ; Female ; Hepatocytes ; cytology ; metabolism ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred BALB C ; Multipotent Stem Cells ; metabolism ; transplantation ; Proto-Oncogene Proteins c-kit ; metabolism ; Random Allocation ; Whole-Body Irradiation ; alpha-Fetoproteins ; metabolism

OBJECTIVETo investigate the periodic quantity variation of proliferating neuronal progenitors after global brain ischemia and provide evidence for choosing the time-window of drug therapy to promote neuronal regeneration after ischemia.

METHODSAdult male Wistar rats were subjected to 15-min global brain ischemia (four-vessel occlusion model) and randomized subsequently into 8 groups (n=3). The rats were given intraperitoneal injections of BrdU (75 mg/kg) for 4 times daily (at a 2-hour interval) since day 7 till day 11 after ischemia, and on day 29, the rats were perfused transcardially for fixation. Another 3 normal rats were given BrdU in the same manner and killed the next day. Coronal sections of the brain tissue (30 microm) were prepared for immunocytochemical detection of BrdU-labeled cells and immunofluorescent detection of BrdU/NeuN double-labeled cells. The density of BrdU-positive cells and BrdU/NeuN double-labeled cells in the hippocampal dentate gyrus (DG) and CA1 region were counted and the density of proliferating cells at different days after ischemia were compared using one-way ANOVA.

RESULTSThe proliferation of the neuronal progenitors increased after global brain ischemia. The number of BrdU-positive cells in the DG and CA1 region decreased gradually in 7-10 days after ischemia, and reached the normal level during 11-14 days. The differentiation of the progenitors did not vary after ischemia.

CONCLUSIONIncreased proliferation of the neuroprogenitors occurs mainly within the initial 10 days after global ischemia in rats.

Animals ; Brain Ischemia ; pathology ; physiopathology ; Cell Differentiation ; Cell Proliferation ; Male ; Nerve Regeneration ; Neurons ; pathology ; Random Allocation ; Rats ; Rats, Wistar ; Stem Cells ; pathology ; Time Factors

OBJECTIVETo observe the effect of autologous bone marrow stem cell (BMSC) transplantation via the renal artery on renal function recovery following renal ischemic-reperfusion (I/R) injury in rabbits.

METHODSBMSCs were collected and isolated from rabbits. Twenty-eight rabbits were subjected to renal pedicle clamping for 105 min and randomized subsequently into transplantation group and control group. BMSCs or saline were injected into the kidney via the renal artery, respectively. Before and 1, 3, 5, 7, 14, 21, and 28 days after I/R injury the venous blood was collected to measure the serum levels of SCr and BUN, and the renal tissue was sampled for pathological observation.

RESULTSOne and 3 days after I/R injury, serum Cr and BUN levels increased significantly to the highest level in both groups. On the 7th day serum Cr and BUN levels in the transplantation group were lower than those in control group and remained so till the end of the experiment. On the 28th day, the levels of serum Cr (90.1+/-11.1 micromol/L) and BUN (8.0+/-1.5 mmol/L) in the transplantation group were significantly lower than those in the control group (135.6+/-32.5 micromol/L and 10.9+/-2.5 mmol/L, respectively, P<0.05). Pathological observation of the renal tissue revealed renal tubular epithelial cell degeneration, necrosis and abscission.

CONCLUSIONBMSC transplantation can accelerate renal function repair after acute tubular necrosis resulting from I/R injury, and decrease serum Cr and BUN levels in early stage following the injury.

Acute Kidney Injury ; blood ; etiology ; surgery ; Animals ; Blood Urea Nitrogen ; Bone Marrow Cells ; cytology ; Creatine ; blood ; Female ; Hematopoietic Stem Cell Transplantation ; Kidney ; blood supply ; Male ; Rabbits ; Random Allocation ; Renal Artery ; physiopathology ; Reperfusion Injury ; complications ; physiopathology ; Transplantation, Autologous

OBJECTIVETo investigate the effect of advanced oxidation protein products (AOPP) on nitric oxide (NO) production in mouse peritoneal macrophages (MPMs).

METHODSMPMs were incubated in the absence or presence of lipopolysaccharide (LPS) with AOPP-modified bovine serum albumin (BSA) prepared by exposure of BSA to hypoclorous acid or pre-treated with AOPP-BSA and subsequent stimulation with LPS. NO production in the supernatants of the culture media was determined spectrophotometrically using Griess method. The cell viability was measured by MTT assay.

RESULTSBSA induced significant NO production in MPMs. AOPP modification of BSA significantly inhibited NO production, and AOPP-BSA exhibited time- and dose-dependent inhibition of NO production induced by LPS in MPMs incubated together with LPS or pre-treated before LPS stimulation.

CONCLUSIONAOPP-BSA is capable of inhibiting inducible NO production in MPMs.

Animals ; Cell Survival ; drug effects ; Cells, Cultured ; Culture Media ; chemistry ; pharmacology ; Dose-Response Relationship, Drug ; Glycation End Products, Advanced ; chemistry ; Lipopolysaccharides ; chemistry ; pharmacology ; Macrophages, Peritoneal ; cytology ; drug effects ; metabolism ; Mice ; Nitric Oxide ; biosynthesis ; Oxidation-Reduction ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Serum Albumin, Bovine ; chemistry ; pharmacology ; Time Factors

OBJECTIVETo construct a p38 MAPK protein delivery system based on TAT protein and study its functions in eukaryotic cells.

METHODSRecombinant vectors pHis-TAT-p38 and pHis-TAT-p38(AF) were constructed, and two recombinant proteins, His-TAT-p38 and His-TAT-p38(AF), were expressed and purified in E. coli. The two fusion proteins were then incubated with ECV304 cells, respectively. The phosphorylation of ATF2 was detected to assay the effect of His-TAT-p38 on endogeneious p38 activity after the cells were stimulated by sorbitol.

RESULTSThe results of restriction enzyme digestion and DNA sequencing showed that the two recombinant vectors were correctly constructed. The recombinant proteins of His-TAT-p38 and His-TAT-p38(AF) were isolated and purified by SDS-PAGE, and Western blotting suggested that His-TAT-p38 and its mutant with dual phosphorylation sites could enter the cells efficiently in a time- and concentration-dependent manner. His-TAT-p38 was found capable of increasing the activity of endogenous p38 in ECV304 cells, but His-TAT-p38(AF) inhibited the phosphorylation of ATF2 so as to block the transduction of p38 signal pathway when the cells were stimulated with sorbitol.

CONCLUSIONp38 MAPK protein delivery system based on TAT protein has been constructed successfully. It is confirmed that TAT can transfer the proteins into the cells in a time- and dose-depended manner. TAT-p38 and its dominant negative form possess high biological activity after transduction into ECV304 cells by TAT protein delivery system, and the former can increase the activity of endogenous ATF2, but the latter inhibits the transduction of endogeneious p38 signal pathway in ECV304 cells with high osmotic stress.

Blotting, Western ; Cell Line ; Cell Membrane ; metabolism ; Eukaryotic Cells ; cytology ; metabolism ; Gene Products, tat ; genetics ; metabolism ; Humans ; Peptides ; genetics ; metabolism ; Phosphorylation ; Protein Transport ; Recombinant Fusion Proteins ; genetics ; metabolism ; Transfection ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism