Biomedical subjects

G Wang

Publications and source records attributed to G Wang.

At least 37 records · Page 2Linked to original sources

PubMed2006

Thrombin and PAR-1 stimulate differentiation of bone marrow-derived endothelial progenitor cells.

Endothelial progenitor cells (EPCs) from the bone marrow play an important role in vascular response to injury and ischemia. The mediators involved in the mobilization, recruitment, proliferation and differentiation of EPCs are not fully understood. In this study, the role of coagulation factor thrombin and protease-activated receptor-1 (PAR-1) on bone marrow-derived cell proliferation and differentiation was investigated. Bone marrow cells (BMCs) were isolated from C57/BL6 mice and plated on fibronectin-coated flasks. Cell characteristics, proliferation and the expression of endothelial cell markers were determined using immunohistochemistry, thymidine uptake and fluorescence activated-cell sorting (FACS), respectively. The results show that thrombin stimulated enrichment of bone marrow cells with endothelial morphology, exhibiting acetylated-low-density lipoprotein (LDL) uptake and isolectin staining. Thrombin or PAR-1-activating peptide produced a 2- to 3-fold increase in the total number of cells as well as an increase in vascular endothelial (VE)-cadherin-positive cells. Thrombin treatment of VE-cadherin-negative cells prepared after cell sorting resulted in the generation of 3- to 4-fold higher VE-cadherin-positive cells than the untreated cultures. Increase in VE-cadherin-positive cells was inhibited by hirudin and efegatran. These results provide first evidence for a novel activity of thrombin and PAR-1 on bone marrow progenitor cell proliferation and EPC differentiation, and suggest their potential role in vascular regeneration and recanalization of thrombus.

Animals↗

PubMed2006

Effect of cold blood cardioplegia enriched with potassium-magnesium aspartate during coronary artery bypass grafting.

AIM: The aim of this investigation is to evaluate the effect of enriched with potassium-magnesium aspartate cold-blood cardioplegia on early reperfusion injury and postoperative arrhythmias in patients with ischemic heart disease undergoing coronary artery bypass grafting (CABG), using measurements of cardiac troponin I (CTnI), hemodynamic indexes and clinical parameters. METHODS: Forty patients with three-vessel coronary artery disease (CAD) and stable angina, receiving first-time elective CABG, were randomly divided into 2 groups: patients in control group (C group n=20) received routine institutional cold blood cardioplegia (4 degrees C) concentration of Mg2+4 mmol/L, Ca2+1.2 mmol/L and K+ 24mmol/L during myocardial arrest. Patients in P group (n=20) received modified cold blood cardioplegia enriched with potassium-magnesium aspartate and maintained concentration of Mg2+10 mmol/L, Ca2+1.2 mmol/L and K+20mmol/L in the final blood cardioplegia solution. Clinical outcomes were observed during operation and postoperatively. Serial venous blood samples for CTnI were obtained before induction, after cardiopulmonary bypass (CPB), and postoperative 6, 24, and 72 hours. Hemodynamic indexes were obtained before and after bypass by the radial catheter and Swan-Ganz catheter. RESULTS: In both groups, there were no differences regarding preoperative parameters. There were no cardiac related deaths in either group. The time required to achieve cardioplegic arrest after cardioplegia administration was significantly shorter in P group (47.5+/-16.3 s) than in C group (62.5+/-17.6 s) (P<0.01). The number of patients showing a return to spontaneous rhythm after clamp off was significantly greater in P group (n=20, 100%) than in C group (n=14, 70%) (P<0.01). Eight patients in C group had atrial fibrillation (AF) compared with two patients in P group (P<0.05) in the early of postoperative period. The level of CTnI increased 6 hours and 12 hours postoperatively, and there was a significant difference between groups (P<0.05). P group also shortened the time of postoperative mechanical ventilation (P<0.05) after surgery. CONCLUSIONS: Cold blood cardioplegia enriched with potassium-magnesium aspartate is beneficial on reducing reperfusion injury.

Aged↗

PubMed2005

Calibration of projector lens distortions.

The distortions introduced into high-resolution transmission electron microscope (HRTEM) images by the projector lens system are an important source of systematic error for quantitative displacement and strain determination. Using geometric phase analysis of images of perfect crystals, we measured these errors for two different transmission electron microscopes. Local magnification varies by as much as 5%, and rotation can reach 2 degrees across a typical image. Our experimental results are compared with theory, and optical pincushion and spiral distortion coefficients are determined. A method for calibrating and removing these distortions is presented that enables quantification to 0.1% strain and 0.1 degrees rotation across the whole field of view. This calibration is also critical for the accurate measurement of local lattice parameters from HRTEM images.

Journal Article↗

PubMed2005

Highly pathogenic H5N1 influenza virus infection in migratory birds.

H5N1 avian influenza virus (AIV) has emerged as a pathogenic entity for a variety of species, including humans, in recent years. Here we report an outbreak among migratory birds on Lake Qinghaihu, China, in May and June 2005, in which more than a thousand birds were affected. Pancreatic necrosis and abnormal neurological symptoms were the major clinical features. Sequencing of the complete genomes of four H5N1 AIV strains revealed them to be reassortants related to a peregrine falcon isolate from Hong Kong and to have known highly pathogenic characteristics. Experimental animal infections reproduced typical highly pathogenic AIV infection symptoms and pathology.

Amino Acid Sequence↗

PubMed2005

Antitumor effect of beta-elemene in non-small-cell lung cancer cells is mediated via induction of cell cycle arrest and apoptotic cell death.

Beta-elemene is a novel anticancer drug, which was extracted from the ginger plant. However, the mechanism of action of beta-elemene in non-small-cell lung cancer (NSCLC) remains unknown. Here we show that beta-elemene had differential inhibitory effects on cell growth between NSCLC cell lines and lung fibroblast and bronchial epithelial cell lines. In addition, beta-elemene was found to arrest NSCLC cells at G2-M phase, the arrest being accompanied by decreases in the levels of cyclin B1 and phospho-Cdc2 (Thr-161) and increases in the levels of p27(kip1) and phospho-Cdc2 (Tyr-15). Moreover, beta-elemene reduced the expression of Cdc25C, which dephosphorylates/activates Cdc2, but enhanced the expression of the checkpoint kinase, Chk2, which phosphorylates/ inactivates Cdc25C. These findings suggest that the effect of beta-elemene on G2-M arrest in NSCLC cells is mediated partly by a Chk2-dependent mechanism. We also demonstrate that beta-elemene triggered apoptosis in NSCLC cells. Our results clearly show that beta-elemene induced caspase-3, -7 and -9 activities, decreased Bcl-2 expression, caused cytochrome c release and increased the levels of cleaved caspase-9 and poly(ADP-ribose) polymerase in NSCLC cells. These data indicate that the effect of beta-elemene on lung cancer cell death may be through a mitochondrial release of the cytochrome c-mediated apoptotic pathway.

Apoptosis↗

PubMed2005

Antiproliferative effect of beta-elemene in chemoresistant ovarian carcinoma cells is mediated through arrest of the cell cycle at the G2-M phase.

Elemene is a natural antitumor plant drug. However, the effect of elemene on cell growth in ovarian cancer is unknown. In this study, we show that beta-elemene inhibited the proliferation of cisplatin-resistant human ovarian cancer cells and their parental cells, but had only a marginal effect in human ovary cells, indicating differential inhibitory effects on cell growth between ovarian cancer cells and normal ovary cells. We also demonstrated for the first time that beta-elemene markedly enhanced cisplatin-induced growth inhibition in resistant cells compared to sensitive cells. In addition, cell cycle analysis revealed a synergistic effect of beta-elemene and cisplatin on the induction of cell cycle G2-M arrest in our resistant ovarian carcinoma cells. Furthermore, we showed that treatment of these cells with both drugs downregulated cyclin B1 and Cdc2 expression, but elevated the levels of p53, p21waf1/cip1, p27kip1 and Gadd45. Finally, the combination of beta-elemene and cisplatin was found to increase the phosphorylation of Cdc2 and Cdc25C, which leads to a reduction in Cdc2-cyclin B1 activity. These novel findings suggest that beta-elemene sensitizes chemoresistant ovarian carcinoma cells to cisplatin-induced growth suppression partly through modulating the cell cycle G2 checkpoint and inducing cell cycle G2-M arrest, which lead to blockade of cell cycle progression.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2005

HLA DR B104, 07-restricted epitopes on Keratin 17 for autoreactive T cells in psoriasis.

BACKGROUND: Psoriasis is a T cell-mediated inflammatory skin disease. Recent evidence suggests that activated CD4+ helper T lymphocytes of the Th1 phenotype play an important role in the pathogenesis of the disease. For psoriatic autoreactive T cells, Keratin 17 is a major target antigen and an epitope containing ALEEAN sequence has been described, but other psoriasis-related epitopes are still unknown. OBJECTIVE: To identify the HLA DR B1*04, *07-restricted T cell epitopes on Keratin 17. METHODS: HLA DRB1*04, *07-restricted T cell epitope regions on Keratin 17 were predicted based on related software and internet servers. Keratin 17 gene was amplified from psoriatic epidermis and the proteins of the predicted epitope regions were expressed, identified and purified. T cells from psoriatic patients reacted in cultivation with peptide-major histocompatibility complex (p-MHC) compound, then the level of cell proliferation and the concentration of interferon-gamma in culture supernatant were detected. After the psoriasis-related epitope regions were narrowed down, the epitopes on them were predicted further. These epitopes were then expressed and validated by T cell response in vitro. RESULTS: Four epitopes--S1 (118-132), S2 (169-183), S4 (323-337) and S4 (348-362) can stimulate the proliferation and interferon-gamma production of psoriatic T cells more effectively than other epitopes (p<0.01) and react weakly with the T cells from healthy volunteers (p>0.05). CONCLUSION: Epitopes S1 (118-132), S2 (169-183), S4 (323-337) and S4 (348-362) are immunodominant DR B1-restricted T cell epitopes for psoriasis. Among them, S1 (118-132) contains the ALEEAN sequence while the others with different amino acid sequence have not been reported before. Further studies based on these peptides would provide a more complete understanding of the immunological basis of psoriasis.

Amino Acid Sequence↗

PubMed2005

Dyschromatosis universalis hereditaria: two cases in a Chinese family.

Two cases of dyschromatosis universalis hereditaria (DUH) from a Chinese family are presented. Case 1 was a 62-year-old woman who had a generalized and progressive hyper- and hypopigmentation of the skin from the age of 8 years. Her brother had also developed a similar skin pigmentary defect from about the same age. Histopathological and ultrastructural examination of lesional skin showed increased melanin content in epidermal keratinocytes but no changes in the appearance or number of melanocytes. Although hereditary defects may influence melanogenesis resulting in a pigmentary anomaly, the pathogenesis of DUH remains unclear.

Female↗

PubMed2005

The expression of prion protein (PrP(C)) in the megakaryocyte lineage.

BACKGROUND: Cellular prion protein (PrP(C)) is a naturally occurring protein in normal individuals which adopts an abnormal conformation, termed scrapie prion protein (PrP(Sc)) that is associated with disease. There is great concern that clinically asymptomatic variant Creutzfeldt-Jacob disease (vCJD) may transmit PrP(Sc) in blood transfusion products. PrP(C) is widely expressed and has been found in human blood. The majority of cellular borne PrP(C) is associated with platelets (84%). Although PrP(C) mRNA has been demonstrated in platelets, the quantity is unknown and may not reflect the total PrP(C) present. OBJECTIVE: To investigate the expression of PrP(C) in the megakaryocyte lineage. METHODS: The expression of PrP(C) was studied in CD34+ cells, cultured megakaryocytes and platelets using electron microscopy, flow cytometry, semi-quantitative RT-PCR and immunofluorescence confocal microscopy. RESULTS AND CONCLUSIONS: The expression of PrP(C) appeared to increase with differentiation and polyploidization in the megakaryocyte lineage. PrP(C) was located within platelet alpha-granules and its source is likely to be from megakaryocyte precursors. If PrP(Sc) has a similar distribution, these results have implications for the selection of blood donors and preparation of cell-depleted blood products.

Antigens, CD34↗

PubMed2005

Myxoma virus M-T5 protects infected cells from the stress of cell cycle arrest through its interaction with host cell cullin-1.

The myxoma virus (MV) M-T5 gene encodes an ankyrin repeat protein that is important for virus replication in cells from several species. Insight was gained into the molecular mechanisms underlying the role of M-T5 as a host range determinant when the cell cycle regulatory protein cullin-1 (cul-1) was identified as a cellular binding partner of M-T5 and found to colocalize with the protein in both nuclear and cytosolic compartments. Consistent with this interaction, infection with wild-type MV (vMyxlac) or a deletion mutant lacking M-T5 (vMyxT5KO) differentially altered cell cycle progression in a panel of permissive and nonpermissive cells. Cells infected with vMyxlac transitioned rapidly out of the G0/G1 phase and preferentially accumulated at the G2/M checkpoint, whereas infection with vMyxT5KO impeded progression through the cell cycle, resulting in a greater percentage of cells retained at G0/G1. Levels of the cul-1 substrate, p27/Kip-1, were selectively increased in cells infected with vMyxT5KO compared to vMyxlac, concurrent with decreased phosphorylation of p27/Kip-1 at Thr187 and decreased ubiquitination. Compared to cells infected with vMyxlac, cell death was increased in vMyxT5KO-infected cells following treatment with diverse stimuli known to induce cell cycle arrest, including infection itself, serum deprivation, and exposure to proteasome inhibitors or double-stranded RNA. Moreover, infection with vMyxlac, but not vMyxT5KO, was sufficient to overcome the G0/G1 arrest induced by these stimuli. These findings suggest that M-T5 regulates cell cycle progression at the G0/G1 checkpoint, thereby protecting infected cells from diverse innate host antiviral responses normally triggered by G0/G1 cell cycle arrest.

Amino Acid Motifs↗

PubMed2005

Survivin protein expression positively correlated with proliferative activity of cancer cells in bladder cancer.

CONTEXT: Survivin is an inhibitor of apoptosis that is selectively over-expressed in common human cancers, but not in normal tissues, and that correlates with aggressive disease and unfavorable outcomes. AIMS: To identify the role of survivin in bladder carcinogenesis and the correlation between survivin protein expression and the occurrence of spontaneous apoptosis, proliferative activity of cancer cells. SETTINGS AND DESIGN: Retrospective analysis. METHODS AND MATERIAL: Bladder transitional cell cancer (BTCC) tissue samples for 128 patients were investigated, with normal bladder tissues serving as controls. From these tumor samples, 42 (32.8%) were grade I, 59 (46.1%) were grade II, and 27 (21.1%) were grade III; 72 (56.2%) were superficial, 56 (43.8%) were invasive. The survivin protein level was quantified by Western blot analysis. The apoptotic index (AI) using in situ labeling apoptotic DNA fragment kit and the Ki-67 labeling index (Ki-67LI) with an anti-Ki-67 monoclonal antibody were analyzed in these tumors, respectively. STATISTICAL ANALYSIS USED: Differences in the S/beta ratio between tumor grade and stage were evaluated by using unpaired t-test and F-test. The relationships between the S/beta ratios and AIs, Ki-67LIs of tumors were evaluated by Pearson correlation coefficient. RESULTS: High survivin levels were detected by Western blot analysis in tumor tissue extracts. None of the expression of survivin protein was found in normal bladder tissues. Survivin levels were significantly different from different clinical stages and pathological grades of the tumors (P > 0.05, respectively). Spearman rank correlation test revealed a positively correlation between survivin protein level and the proliferative activity (P < 0.001) and failed to find significant correlation between AI and survivin protein level (P > 0.05). CONCLUSIONS: Survivin protein expression played an important role in the malignant progression of BTCC.

Adult↗

PubMed2005

Concentration and detection of SARS coronavirus in sewage from Xiao Tang Shan Hospital and the 309th Hospital of the Chinese People's Liberation Army.

A worldwide outbreak of severe acute respiratory syndrome (SARS) had been reported. Over 8439 SARS cases and 812 SARS-related deaths were reported to the World Health Organization from 32 countries around the world up to 5 July 2003. The mechanism of transmission of SARS-CoV has been limited only to close contacts with patients. Attention was focused on possible transmission by the sewage system because laboratory studies showed that patients excreted coronavirus RNA in their stools in Amoy Gardens in Hong Kong. To explore whether the stool of SARS patients or the sewage containing the stool of patients would transmit SARS-CoV or not, we used a style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing, as well as cell culture, semi-nested RT-PCR and sequencing of genes to detect and identify the viruses from sewage. There was no live SARS-CoV detected in the sewage in these assays. The nucleic acid of SARS-CoV was found in the sewage before disinfection from both hospitals by PCR. After disinfection, SARS-CoV RNA could be detected from some samples from the 309th Hospital of the Chinese People's Liberation Army, but not from Xiao Tang Shan Hospital after disinfection. In this study, we found that the virus can survive for 14 days in sewage at 4 degrees C, 2 days at 20 degrees C, and its RNA can be detected for 8 days though the virus had been inactivated. In conclusion, this study demonstrates that the RNA of SARS-CoV could be detected from the concentrates of sewage of both hospitals receiving SARS patients before disinfection and occasionally after disinfection though there was no live SARS-CoV; thus much attention should be paid to the treatment of stools of patients and the sewage of hospitals receiving SARS patients.

Bacteriophages↗

PubMed2004

First results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory.

We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2.

Journal Article↗

PubMed2004

Distinct rat neurohypophysial nerve terminal populations identified by size, electrophysiological properties and neuropeptide content.

Voltage-gated ion channels are critical to excitation-secretion coupling in nerve terminals. We have identified two distinct populations of rat neurohypophysial (NHP) terminals distinguished by size, neuropeptide content and electrophysiological properties, including resting membrane potential, action potential (AP) properties, and K+ current and Na+ current characteristics. In large terminals (10-16 microm diameter), resting membrane potential was more negative than in small terminals (5-9.9 microm; -61+/-4 mV vs. -55+/-3 mV; p<0.01), action potential amplitude was larger (69+/-4 mV vs. 53+/-3 mV; p<0.01), peak IK was larger (1460+/-90 pA vs. 1140+/-70 pA; p<0.05) with a more negative V1/2 for activation (-3.1 mV vs. -0.6 mV; p<0.05), and Na+ current density was greater (approximately 470 pA/pF vs. approximately 300 pA/pF; p<0.01) with more negative V1/2 values for activation from -70 or -90 mV holding potentials (-44 mV vs. -24 mV; p<0.01). A positive linear correlation between INa amplitude and terminal size showed an inflection at a diameter of 9.2 microm. Neuropeptide content was generally segregated into a population of small terminals (<10 microm diameter) containing predominantly vasopressin and a population of large terminals (> or =10 microm diameter) containing predominantly oxytocin (OT); a small fraction of terminals in each group contained both peptides. These findings suggest that electrophysiological differences between small vasopressin-containing and large oxytocin-containing neurohypophysial terminals may contribute to their observed differential firing and peptide release patterns.

Action Potentials↗

PubMed2004

ImageParser: a tool for finite element generation from three-dimensional medical images.

BACKGROUND: The finite element method (FEM) is a powerful mathematical tool to simulate and visualize the mechanical deformation of tissues and organs during medical examinations or interventions. It is yet a challenge to build up an FEM mesh directly from a volumetric image partially because the regions (or structures) of interest (ROIs) may be irregular and fuzzy. METHODS: A software package, ImageParser, is developed to generate an FEM mesh from 3-D tomographic medical images. This software uses a semi-automatic method to detect ROIs from the context of image including neighboring tissues and organs, completes segmentation of different tissues, and meshes the organ into elements. RESULTS: The ImageParser is shown to build up an FEM model for simulating the mechanical responses of the breast based on 3-D CT images. The breast is compressed by two plate paddles under an overall displacement as large as 20% of the initial distance between the paddles. The strain and tangential Young's modulus distributions are specified for the biomechanical analysis of breast tissues. CONCLUSION: The ImageParser can successfully exact the geometry of ROIs from a complex medical image and generate the FEM mesh with customer-defined segmentation information.

Computer Graphics↗

PubMed2004

Suppression of large edge-localized modes in high-confinement DIII-D plasmas with a stochastic magnetic boundary.

A stochastic magnetic boundary, produced by an applied edge resonant magnetic perturbation, is used to suppress most large edge-localized modes (ELMs) in high confinement (H-mode) plasmas. The resulting H mode displays rapid, small oscillations with a bursty character modulated by a coherent 130 Hz envelope. The H mode transport barrier and core confinement are unaffected by the stochastic boundary, despite a threefold drop in the toroidal rotation. These results demonstrate that stochastic boundaries are compatible with H modes and may be attractive for ELM control in next-step fusion tokamaks.

Journal Article↗

PubMed2004

Chlorobenzoate-degrading bacteria in similar pristine soils exhibit different community structures and population dynamics in response to anthropogenic 2-, 3-, and 4-chlorobenzoate levels.

A study was conducted to determine the diversity of 2-, 3-, and 4-chlorobenzoate (CB) degraders in two pristine soils with similar physical and chemical characteristics. Surface soils were collected from forested sites and amended with 500 microg of 2-, 3-, or 4-CB g(-1) soil. The CB levels and degrader numbers were monitored throughout the study. Degraders were isolated, grouped by DNA fingerprints, identified via 16S rDNA sequences, and screened for plasmids. The CB genes in selected degraders were isolated and/or sequenced. In the Madera soil, 2-CB and 4-CB degraded within 11 and 42 d, respectively, but 3-CB did not degrade. In contrast, 3-CB and 4-CB degraded in the Oversite soil within 14 and 28 d, respectively, while 2-CB did not degrade. Approximately 10(7) CFU g(-1) of degraders were detected in the Madera soil with 2-CB, and the Oversite soil with 3- and 4-CB. No degraders were detected in the Madera soil with 4-CB even though the 4-CB degraded. Nearly all of the 2-CB degraders isolated from the Madera soil were identified as a Burkholderia sp. containing chromosomally encoded degradative genes. In contrast, several different 3- and 4-CB degraders were isolated from the Oversite soil, and their populations changed as CB degradation progressed. Most of these 3-CB degraders were identified as Burkholderia spp. while the majority of 4-CB degraders were identified as Bradyrhizobium spp. Several of the 3-CB degraders contained the degradative genes on large plasmids, and there was variation between the plasmids in different isolates. When a fresh sample of Madera soil was amended with 50, 100, or 200 microg 3-CB g(-1), 3-CB degradation occurred, suggesting that 500 microg 3-CB g(-1) was toxic to the degraders. Also, different 3-CB degraders were isolated from the Madera soil at each of the three lower levels of 3-CB. No 2-CB degradation was detected in the Oversite soil even at lower 2-CB levels. These results indicate that the development of 2-, 3-, and 4-CB degrader populations is site-specific and that 2-, 3-, and 4-CB are degraded by different bacterial populations in pristine soils. These results also imply that the microbial ecology of two soils that develop under similar biotic and abiotic environments can be quite different.

Arizona↗

PubMed2004

Biomechanical evaluation of contemporary posterior spinal internal fixation configurations in an unstable burst-fracture calf spine model: special references of hook configurations and pedicle screws.

STUDY DESIGN: This study attempts to determine the most biomechanically rigid posterior spinal instrumentation configuration in a burst-fracture calf spine model. OBJECTIVES: To compare the biomechanical stability of contemporary posterior spinal instrumentation in various hook and screw configurations in an unstable calf spine model. SUMMARY OF BACKGROUND DATA: Burst-fractures are relatively common injuries seen in the setting of spinal trauma. The use of posterior-only configurations in the treatment of this deformity has become a much more popular approach because of the relative ease of applying the instrumentation. METHODS: Fresh frozen in vitro study using 10 calf spines involving the T11-S1 vertebral segments. Pure moment forces including flexion, extension, axial rotation, and lateral bending were applied to the top of the spinal column at T11. Testing was first performed on all intact specimens. A corpectomy was then performed at L2. Testing was then repeated on each of the ten specimens after internal fixation with different posterior spinal configurations using ISOLA instrumentation (DePuy AcroMed Inc., Raynham, MA). RESULTS: With regards to flexion-extension and lateral bending, all configurations except for distraction hook-rod construct provided stability greater than the intact spine. The distraction hook-rod configuration failed to control extension (P > 0.05) above the intact specimen. All pedicle screw constructs were more rigid than the hook-rod constructs in axial rotation at the level of injury (P < 0.001). CONCLUSIONS: The motion segment at the corpectomy site is adequately stabilized by contemporary spinal internal fixation configurations tested except for the distraction-hook stabilization. Axial rotation is generally poorly controlled by posterior-only internal fixation. Pedicle screw instrumentation was the most rigid compared with other forms of stabilization in stabilizing a burst-corpectomy defect. Based on this study, pedicle screw configurations are preferred over hook-rod strategies in the posterior stabilization of a burst-corpectomy anterior defect. Among hook-rod configurations, the distraction hook-rod strategy provided the least stability.

Animals↗