[Biocompatibility of adult human osteoblasts with coral-derived hydroxyapatite in vitro].

Objective: To study the biocompatibility of the osteoblasts from adult human bone marrow with coral-derived hydroxyapatite (CHA) in in vitro culture.

Methods: Bone marrow was obtained from healthy adult subjects and cultured in Dulbecco's modified Eagle's medium (DMEM) containing 10 % fetal bovine serum. The subsequent cell passaging was conducted in conditioned medium containing dexamethasone, beta-sodium glycerophosphate and ascorbic acid, with the osteoblasts in culture then divided into CHA group (in which the cells were cultured with CHA) and osteoblasts group (without CHA).

[Repair of tibial defect with tissue-engineered bone graft and radionuclide bone imaging in goats].

Objective: To observe the effect of tissue-engineered bone grafts in repairing large tibial defect in goats, and assess the value of radionuclide bone imaging in monitoring the therapeutic effect of this approach.

Methods: Tibial defects measuring 2 cm was artificially made in the left tibia of 27 normal goats that were subsequently divided into 3 groups (9 each) to undergo treatment with tissue-engineered bone grafts, artificial bone grafts or without any grafts (as control group) respectively. The tissue-engineered bone grafts contained bone marrow stroma cells (BMSCs) of the goats and coral hydroxyapatite (CHAP), while the artificial bone grafts were from CHAP only.

Dynamic changes of TNF-alpha content in dogs after gunshot wound in the limbs in hot and humid environment.

OBJECTIVE: To investigate the dynamic changes of TNF-alpha content in the plasma and body tissues of dogs after gunshot wound in the limbs in hot and humid environment. METHODS: Eighteen dogs with gunshot wound were divided into 3 groups (6 in each), one observed in normal environment (Ne group) and the other two in hot and humid environment including a heat-acclimatized group (HA group) and a non-acclimatied group (NHA group). The contents of tumor necrosis factor-alpha (TNF-alpha) in the plasma and muscle tissues from the gunshot wound tract were measured at 0, 1, 3, 4, 6, 8, 10, 14, 18, 24 h respectively after the injury.

[Operative treatment of acetebular fractures].

Objective: To discuss the diagnosis and operative technology of acetabular fracture.

Methods: 41 cases of displaced acetabular fractures were enrolled. CT and 3D-CT were performed before operation to understand the classification of fractures and to determine operative regimen.

[Bacterium culture and flora analysis of gunshot wound on limbs of dogs in hot and humid environment].

Objective: To investigate the time of bacterial invasion into the blood and conduct flora analysis of the blood and secretions in the gunshot wound in the limbs of dogs in hot and humid environment.

Methods: Gun-shot wound was induced in 8 dogs who were subsequently assigned at random into hot and humid environment (HHE) group and normal environment (NE) group for observation. At the time points of 0, 4, 6, 8, 12, 24 h after injury, body temperature was measured and bacterial culture and flora analysis performed.

[Expression of human bone morphogenetic protein 7 mRNA after the gene transfection in rabbit bone marrow-derived mesenchymal stem cells].

Objective: To detect the expression of human bone morphogenetic protein 7 (hBMP-7) mRNA in rabbit bone marrow-derived mesenchymal stem cells with hBMP-7 gene transfection mediated by retroviral vector.

Methods: Retroviral vector for hBMP-7 gene was constructed that was transferred into the packaging cell PT67 mediated by liposome. hBMP-7 gene-positive cell clones were selected with G418 (600 ng/ml) and amplified to obtain the retroviral supernatant containing the target genes that were subsequently used to transfect rabbit bone marrow-derived mesenchymal stem cells (MSCs).

[Dynamic changes of SOD and MDA in canine limbs with gunshot wound in hot and humid environment: an experimental study].

Objective: To study the dynamic changes in lipid peroxidation and the activity of antioxidative enzyme in canine limbs with gunshot wound in hot and humid environment.

Methods: Eighteen dogs with gunshot wound were randomly assigned into 3 groups with equal numbers. Dogs observed after injury in normal environment was designated as NE group, those in hot and humid environment as HHE group and those in hot and humid environment with preceding heat acclimatization training as HA group.

[mRNA expression of recombinant human bone morphogenetic protein 7 in skeletal muscle satellite cells with retroviral vector-mediated rhBMP7 gene transfection].

Objective: To detect the expression of recombinant human bone morphogenetic protein7 (rhBMP7) in skeletal muscle satellite cells (SMSCs) with rhBMP7 gene transfection mediated by retroviral vector.

Methods: rhBMP7 gene was reconstructed in retroviral vector and transferred into packaging cells PT67 via liposome reagent, with the positive cell clones selected with G418. In vitro cultured SMSCs were transfected with the virus granules secreted by PT67 cells and followed by G418 selection.

Effect of pretreatment with adenosine, diazoxide or ischemic preconditioning on ischemia- reperfusion injury in the limbs of rats.

Objective: To study the effect of ischemic preconditioning (PC) and pharmacological preconditioning with adenosine or diazoxide on ischemia-reperfusion (IR) injury in the limbs of rats.

Methods: According to different treatment received before ischemic-reperfusion injury, 66 SD rats were divided into 6 groups including a normal control and a ischemia-reperfusion control group, IP10 group in which the rats received 10-min ischemia followed by 10-min interval for reperfusion for 3 times before IR, IP5 group in which the rats were subjected to 5-min ischemia with 5-min reperfusion intervals for 3 times before IR, adenosine (Ade) pretreatment group and diazoxide (Dia) pretreatment group. Except the normal control group, which consisted of 6 rats, each group contained 12 rats, and IR injury was induced by blocking the blood flow in bilateral limbs for 4 h, followed by reperfusion for 2 or 24 h when twitch and spastic contractility of the tibialis anterior muscle and serum creatine phosphokinase (CPK) were measured.

Beta-arrestin2 is critically involved in CXCR4-mediated chemotaxis, and this is mediated by its enhancement of p38 MAPK activation.

Chemotaxis mediated by chemokine receptors such as CXCR4 plays a key role in lymphocyte homing and hematopoiesis as well as in breast cancer metastasis. We have demonstrated previously that beta-arrestin2 functions to attenuate CXCR4-mediated G protein activation and to enhance CXCR4 internalization. Here we show further that the expression of beta-arrestin2 in both HeLa and human embryonic kidney 293 cells significantly enhances the chemotactic efficacy of stromal cell-derived factor 1alpha, the specific agonist of CXCR4, whereas the suppression of beta-arrestin2 endogenous expression by antisense or RNA-mediated interference technology considerably attenuates stromal cell-derived factor 1alpha-induced cell migration.

Effect of X-ray irradiation on limb allograft rejection in adult rats.

Objective: To establish appropriate animal models for observing the effects of X-ray irradiation on limb allograft rejection.

Methods: Wistar rats were used as donators and SD rats as recipients, the latter divided into 2 groups, namely irradiation group and non-irradiation group according to pretransplant treatment with or without X-ray radiation (5 Gy) on the part of the donators. The donor limbs were transplanted into SD rats who had their own limbs cut off, and the sciatic nerve, femoral nerve, and femoral artery and femoral vein were anastomosed in operation.

Changes of serum MDA and SOD levels in ischemia-reperfusion injuries of the limbs in rats preconditioned with heat stress.

Objective: To study the effect of pretreatment with heat stress on ischemia-reperfusion injuries of the limbs in rats.

Methods: Rat models of ischemia-reperfusion injury were established with or without prior heat stress treatment, in which serum malondialdehyde (MDA) level and superoxide dismutase (SOD) activities were measured by means of thiobarbituric acid and nitroblue tetrazolium respectively.

Results: Comparison between ischemia-reperfusion group and the control group revealed significantly elevated MDA levels (P<0.

Molecular Cloning of Human beta-arrestin1 cDNA, Expression and Functional Study.

Complete coding sequences of beta-arrestin1 (1A and 1B) were cloned through application of bioinformatics analysis to the dbEST database. beta-arrestin1A was overexpressed in E.coli with partial expression products as inclusion body.

Expression, Purification and Characterization of Regulatory Subunit of Type I cAMP-dependent Protein Kinase in E.coli.

Regulatory subunit of type I cAMP-dependent protein kinase (RI) possesses two cAMP-binding sites with high affinity for cAMP. In the current study, human RI cDNA fragment coding for residue 93-381 was cloned from neuronal cells. After subcloning into pET30a, the recombinant RI was expressed in E.

Effects of Deleting the Amino-terminal Domain of GRK-2 on Its Function.

To reveal the possible role of the amino-terminal domain of G protein-coupled receptor kinases(GRKs)in receptor phosphorylation and/or modulation of its kinase activity, a truncated mutant of GRK-2 lacking the amino-terminal domain(deltaN-GRK2)was made. deltaN-GRK2 was expressed effectively in E.coli as a GST fusion protein and was purified by affinity chromatography on a GSH-Sepharose column.

[Development of biodegradable polymer scaffolds for bone tissue engineering].

Objective: To investigate the selection and manufacture of ideal extracellular matrix materials in bone tissue engineering.

Methods: The recent literatures about biodegradable polymers served as culture scaffolds of osteoblasts were widely reviewed, the advantages and disadvantages of biodegradable synthetic polymers and natural polymers were analysed.

Results: The ideal extracellular matrix material in bone tissue engineering should be made up of inorganic materials, synthetic polymers and natural polymers, which possesses morphological structure of three-dimensional foam with self-mediated drug slow delivery system of bone growth factors.

A strain of Bacillus sphaericus causes slower development of resistance in Culex quinquefasciatus.

Two field-collected Culex quinquefasciatus colonies were subjected to selection pressure by three strains of Bacillus sphaericus, C3-41, 2362, and IAB59, under laboratory conditions. After 13 and 18 generations of exposure to high concentrations of C3-41 and IAB59, a field-collected low-level-resistant colony developed >144,000- and 46.3-fold resistance to strains C3-41 and IAB59, respectively.

[Biocompatibility studies on bioactive glass ceramics and polylactic acid combined with cultured bone marrow stromal cells in vitro].

Objective: To study the biocompatibility on bioactive glass ceramics (BGC) and polylactic acid (PLA) combined with cultured bone marrow stromal cells (BMSCs) in bone tissue engineering.

Methods: BMSCs were cultured combined with BGC and PLA in vitro, and the morphological characters, cell proliferation, protein content, and alkaline phosphatase activity were detected.

Results: BMSCs could be attached to and extended on both BGC and PLA, and normally grown, proliferated, had active function.

Extremely low vertical-emittance beam in the accelerator test facility at KEK.

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance.

[Peripheral nerve regeneration under immunosuppression].

Objective: To discuss peripheral nerve regeneration under immunosuppression.

Methods: Current research trends about relationship between peripheral nerve injury and immunoreaction, the experimental result of nerve regeneration after using various immunosuppressors, and the clinical findings after human allogenous hand transplantation were extensively reviewed.

Results: Peripheral nerve regeneration was accelerated under immunosuppression.

Free flap transfer bridged by antegrade and retrograde posterior tibial vessel flaps temporally borrowed from the healthy leg.

OBJECTIVE: To study the methods and techniques of free flap transfer bridged by posterior tibial vascular flap in treating large soft tissue defects in low limbs without usable recipient blood vessels. METHODS: Based on morphological observation and measurement of arterial pressure and blood flow, an antegrade and a retrograde vascular bridge flaps were designed using the healthy posterior tibial vessels to serve as vascular pedicles to carry two free flaps for transplantation. RESULTS: Eight cases of patient with one or two large soft tissue defects in the leg region were treated by the method.

Hippocampal long-term potentiation is reduced by chronic opiate treatment and can be restored by re-exposure to opiates.

Chronic exposure to opiates eventually leads to drug addiction, which is believed to involve maladaptive changes in brain function, but the underlying neuronal mechanisms remain primarily unknown. Given the known effects of opiates such as morphine and heroin on hippocampal function, we investigated the potential effect of chronic opiate treatment on long-term potentiation (LTP) at CA1 synapses in rat hippocampus, a leading experimental model for studying synaptic plasticity. Our results revealed that chronic exposure of rats to morphine or heroin, which induced severe drug tolerance and dependence, markedly reduced the capacity of hippocampal CA1 LTP during the period of drug withdrawal (from approximately 190% in control to approximately 120%).

A new approach to tissue repair: gene therapy.

The process of tissue repair involves a complex tissue response to injury in which growth factors, playing a major role in this process, trigger, control and terminate soakage of inflammatory cells, cells proliferation, secretion of matrix and scars formation by autocrine, paracrine or both. Thus, growth factors can be used to alter the microenvironment of the wounded tissues and to promote their repair. But, there are notable disadvantages in using purified recombination growth factors, 1) the source is so limited that their prices are expensive; 2) the ir half-lives are short and easy to be destroyed by wound proteases; 3) there is no perfect carrier; 4) high initial doses are required but easy to bring toxicity; 5) it is difficult to apply growth factors in deep wounded tissues again and again, their function cannot be played enough accordingly; 6) most of growth factors are the products of recombination.