The Effect of Leonurine on Multiterritory Perforator Flap Survival in Rats.

BACKGROUND: Leonurine (Leo), a natural active compound of Leonurus cardiaca, has been shown to possess various biological activities. However, it is not known whether Leo promotes perforator flap survival. METHODS: In this study, a perforator flap was outlined in the rat dorsum. The rats that survived surgery were divided randomly to control and Leo groups (n = 36 per group). Flap viability, flap perfusion, and level of protein linked with oxidative stress, cell apoptosis, and angiogenesis were evaluated. RESULTS: Relative to control group, the Leo group showed significantly higher the flap survival percentage (70.5% versus 90.2%, P < 0.05) and blood perfusion (197.1 versus 286.3, P < 0.05). Leo also increased 1.8-fold mean vessel density and upregulated 2.1-fold vascular endothelial growth factor protein expression compared with the control group, both of which indicate increased angiogenesis. Moreover, it significantly inhibited apoptosis by lowering caspase-3 activity. Superoxide dismutase expression was remarkably elevated in Leo group compared with the control group (56.0 versus 43.2 U/mg/protein, P < 0.01), but malondialdehyde quantities were significantly lower in the Leo group compared with control group (41.9 versus 57.5 nmol/mg/protein, P < 0.05). CONCLUSIONS: Leo may serve as an effective drug for improving perforator flap survival in rats via antioxidant and antiapoptotic mechanisms and promotion of angiogenesis.

Knockdown of MicroRNA-21 Promotes Neurological Recovery After Acute Spinal Cord Injury.

To assess the therapeutic effects of microRNA-21 (miR-21) knockdown (KD) for acute thoracic spinal cord contusion using a mouse model. Forty C57/BL6 mice were randomly divided into four groups: mice in the sham-operated (Sham) group received surgical procedure without spinal cord contusion; the spinal cord injury (SCI) group mice underwent spinal cord contusion without treatment; mice in the miR-21 KD group underwent spinal cord contusion followed by a single dose subdural injection of miR-21 KD vectors (1 × 107 TU); and the negative control (NC) group mice were given subdural injection of comparable amount of NC vectors (1 × 107 TU) after spinal cord contusion. The Basso Mouse Scale (BMS) was employed to assess hindlimb motor functions. Hematoxylin-eosin and Luxol fast blue staining were performed to evaluate pathologic changes in spinal cord tissues. Peripheral blood serum levels of tumor necrosis factor α (TNFα), transforming growth factor ß (TGF-ß) and interleukin-1ß (IL-1ß) were determined by the enzyme-linked immunosorbent assay, and mRNA expression of Brain derived neurotrophic factor (BDNF) was examined by reverse transcription-polymerase chain reaction (RT-PCR). Western blotting was performed to analyze the AKT signaling pathway. KD of miRNA-21 effectively improved the BMS scores at day 14 post-surgery compared with the SCI group (p < 0.01). The spinal cord tissue in the miR-21 KD group displayed the most overt histologic signs of recovery, with axonal regeneration and the recovery of neuronal morphology at day 14 post-surgery. Significantly alleviation of TGF-ß1, TNF-α and IL-1ß was also found in sera from the miR-21 inhibition group in comparison to others, whereas BDNF gene expression was upregulated following miR-21 KD (p < 0.01). Further, significantly decreased AKT phosphorylation activity was illustrated in the miR-21 KD group (p < 0.001). The data suggest that miR-21 KD significantly reduces the inflammatory response at the damaged spinal cord site and promotes motor functional recovery. The treatment also elevated expression of BDNF, a neurotrophin participating in nerve regeneration.

Macrophage Polarization in IL-10 Treatment of Particle-Induced Inflammation and Osteolysis.

This study investigated the therapeutic influence and potential mechanism of IL-10 in ameliorating orthopedic debris particle-induced inflammation and osteolysis. A murine air pouch with bone implantation and polyethylene particles was also used to evaluate the therapeutic effects of IL-10. The data suggested that the particle challenges significantly promoted macrophage activation and osteoclastogenesis, with dramatically increased macrophage infiltration into the pouch membranes and elevated tartrate-resistant acid phosphatase-positive cell deposition. Immunohistochemical stains revealed a significantly higher ratio of induced nitric oxide synthase-expressing cells in the particle-challenged group; treatment with IL-10 resulted in marked switching to CD163(+) cells. Also, IL-10 effectively reduced tartrate-resistant acid phosphatase-positive stained cells in the pouch membranes, and minimized the bone mineral density loss compared with untreated samples. Real-time PCR and Western blot examination indicated that IL-10 treatment significantly diminished the particle-induced IL-1ß expression but promoted expression of CD163, transforming growth factor-ß1, and CCR2. Furthermore, IL-10 significantly inhibited the ultra-high-molecular-weight polyethylene particle-elevated phospho-STAT1 and phospho-NF-κB p65 productions, and promoted phospho-STAT3 expression. Overall, the data indicate the pivotal effects of IL-10 on macrophage polarization. The effects of IL-10 in ameliorating local inflammation and osteolysis may be associated with macrophage polarization through the up-regulation of the Janus activating kinase/STAT3 signaling pathway, and the down-regulation of NF-κB and Janus activating kinase/STAT1 expression.

ß-Aescin shows potent antiproliferative activity in osteosarcoma cells by inducing autophagy, ROS generation and mitochondrial membrane potential loss.

PURPOSE: Osteosarcoma is one of the frequent bone tumor affecting mainly children and is associated with considerable mortality. The limited availability of anticancer drugs and less efficacious treatment options have led to poor survival rates of patients with osteosarcoma. Therefore, there is need to look for more viable treatment options and against this backdrop, natural products may prove handy. Therefore the aim of the present study was to evaluate the anticancer activity of a natural product of plant origin, ß-aescin, against U2OS human osteosarcoma cells. METHODS: U205 human osteosarcoma cell line was used in this study. Antiproliferative activity was determined by MTT assay. Reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were evaluated by flow cytometry. Autophagy was detected by monodansylcadaverine (MDC) staining and immunofluorescence. Protein expression was examined by western blotting. RESULTS: The results indicated that ß-aescin showed significant anticancer activity against U2OS human osteosarcoma cells and exhibited an IC50 of 40 µM. ß-aescin treatment caused significant increase in ROS and decrease in the MMP. The anticancer effect of ß-aescin was found to be due mainly to autophagic cell death as evidenced from MDC staining and immunofluorescence. Moreover, ß-aescin caused significant increase in the expression levels of LC3- II protein in U2OS osteosarcoma cells in a time and dosedependent manner. CONCLUSION: Taken together we propose that ß-aescin may prove a lead molecule in the management of osteosarcoma and deserves further research efforts.

Molecular mechanism underlying the tumor-promoting functions of carcinoma-associated fibroblasts.

Tumor microenvironment is composed of all the untransformed elements in the vicinity of tumor, mainly including a large number of stromal cells and extracellular matrix proteins, which play an active role in most solid tumor initiation and progression. Carcinoma-associated fibroblasts (CAFs), one of the most common stromal cell types in the tumor microenvironment, have been demonstrated to be involved in tumor growth, invasion, and metastasis. Therefore, they are becoming a promising target for anti-cancer therapies. In this review, we firstly summarize the current understandings of CAFs' molecular biology, including the heterogeneous cellular origins and molecular markers, and then, we focus on reviewing their various tumor-promoting phenotypes involved in complex mechanisms, which can be summarized to the CAF-conveyed paracrine signals in tumor cells, cancer stem cells, and metastasis-initiating cancer cells, as well as the CAF-enhanced extrinsic tumor-promoting processes including angiogenesis, extracellular matrix remodeling, and tumor-related inflammation; finally, we describe the available directions of CAF-based target therapy and suggest research areas which need to be further explored so as to deepen the understanding of tumor evolution and provide new therapeutic targets for cancer treatment.

ADAMTS-12: a multifaced metalloproteinase in arthritis and inflammation.

ADAMTS-12 is a member of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family of proteases, which were known to play important roles in various biological and pathological processes, such as development, angiogenesis, inflammation, cancer, arthritis, and atherosclerosis. In this review, we briefly summarize the structural organization of ADAMTS-12; concentrate on the emerging role of ADAMTS-12 in several pathophysiological conditions, including intervertebral disc degeneration, tumorigenesis and angioinhibitory effects, pediatric stroke, gonad differentiation, trophoblast invasion, and genetic linkage to schizophrenia and asthma, with special focus on its role in arthritis and inflammation; and end with the perspective research of ADAMTS-12 and its potential as a promising diagnostic and therapeutic target in various kinds of diseases and conditions.

An improved highly sensitive method to determine low oxyresveratrol concentrations in rat plasma and its pharmacokinetic application.

Existing methods to determine oxyresveratrol, a trans-polyphenolic stilbene, lack selectivity, require large plasma sample volumes or have time-consuming sample preparation and chromatographic isolation. Here an improved highly sensitive liquid chromatography-tandem mass spectrometry method was developed to determine low oxyresveratrol concentrations in rat plasma. The plasma samples were prepared by liquid-liquid extraction with acetoacetate. The analytes were separated on Venusil hydrophilic interaction chromatography (HILIC) column (2.1 × 50 mm, 5.0 µm) guarded by a HILIC column (4 × 3.0 mm, 5.0 µm). The mobile phase consisted of acetonitrile-water (containing 1 mmol/L ammonium formate) at gradient elution mode with a flow rate of 0.3 mL/min. Resveratrol was used as the internal standard. An electrospray ionization source was applied and operated in the negative multiple reaction monitoring (MRM) mode. Oxyresveratrol and resveratrol were detected on MRM by the transitions from the precursor to the product ion (m/z 243.1 → 175.1 and 227.1 → 143.0). The total running time was 5 min and the retention times of oxyresveratrol and resveratrol were 1.97 and 1.82 min. Chromatograms showed no endogenous interfering peaks with blank samples. The linear calibration curve was obtained over the concentration range of 1-500 ng/mL. The injection volume was 10 µL and the limit of quantification was 1 ng/mL. The extraction recovery varied from 78.2 to 84.3% for low, medium and high quality control samples. At the same time, the intra- and inter-day relative standard deviations were <6.78 and <10.02%, respectively, while the corresponding intra- and inter-day accuracy relative error values fell in the range of 3.75-6.67%. The HPLC-MS/MS method was successfully applied to a pharmacokinetics study, in which the experimental rats received a single dose of oxyresveratrol (10 mg/kg, intragastric administration). The pharmacokinetic results are presented.

Efficacy and safety of linezolid in treating gram-positive bacterial infection in the elderly: a retrospective study.

Linezolid is commonly used for the treatment of drug-resistant Gram-positive bacterial infection. This study aimed to evaluate the efficacy and safety of linezolid in treating Gram-positive bacterial infection in the elderly from January 2010 to December 2012. Total 40 elderly patients (>60 years old) with Gram-positive bacterial infection were treated with linezolid and their demographic and clinical data were collected and analyzed. Among the 40 patients, 31 patients (77.5 %) were cured. Linezolid caused little adverse effects on liver and renal function. The main adverse effect was thrombocytopenia and its incidence was significantly associated with baseline platelet count and the duration of treatment (P < 0.05). Logistic regression analysis showed that the baseline platelet count <200 × 10(6)/mL, but not the age, the sex, the length of hospital stay, baseline levels of hemoglobin, alanine aminotransferase, or creatinine clearance rate was significantly associated with linezolid-induced thrombocytopenia. In conclusion, linezolid is effective to cure Gram-positive bacterial infection in the elderly and causes little adverse effects on liver and renal function. Timely monitoring of baseline platelet count may be helpful to guide the use of linezolid to avoid the occurrence of thrombocytopenia.

Mismatch of AO anatomically shaped distal humeral plate with humeral shaft forward flexion angulation in adult Chinese population.

BACKGROUND: LCP extra-articular distal humerus plate (LCPEA) designed by AO has been introduced as an anatomically shaped plate that improves the results of surgical fixation in extra-articular distal humeral shaft fractures. However, no study analyzed whether LCPEA matches humeral shaft forward flexion angulation (FFA). OBJECTIVE: The aims of this study were to evaluate the morphological discrepancies between LCPEA and the humeral shaft FFA in Chinese cadaveric dried adult humeri and to propose a further design of pre-contoured plates to accommodate the FFA. MATERIALS AND METHODS: Forty-four Chinese cadaveric dried adult humeri were used for this study. An eight-hole LCPEA was applied to the posterior aspect of the distal humerus according to the contour. Mismatches between the bone and the plate were recorded. The distance between the inner surface of the plate and the underlying humeral dorsal cortex was measured at the sites of mismatch. The humeral shaft FFA was measured from the intersection angle between tangent lines placed on the dorsal aspect of the 1/3 distal humeral shaft and the dorsal ridge of the 2/3 proximal humeral shaft. The location of the apex of the FFA was determined by measuring the distance from the most distal point of trochlea of humerus to the point of intersection of the FFA tangent lines. The distance was defined as forward flexion distance (FFD). RESULTS: Mismatch was found at the level of proximal 3-6 holes of LCPEA with an average distance of 6.9 ± 3.1 mm (range 2.3-14.0 mm) at the tip of the plate. The FFA was present in all specimens. The average FFA was 8.2° ± 2.2° (range 4°-13°), the average FFD was 99.9 ± 9.6 mm (range 79.2-117.9 mm), and the average ratio of FFD to humerus length was 0.33 ± 0.03 (range 0.27-0.39). CONCLUSIONS: A rather consistent pattern of mismatch was found at the proximal part of LCPEA. An attempt to fit the plate to the bone at this level may cause a gap of the fracture at the opposite cortex. The main reason for the mismatch is the existence of the humeral shaft FFA. LCPEA is usually made a bend of about 8° between the fourth and the fifth dynamic-compression portion of the combination hole in the distal-to-proximal direction.

Upregulated miR-125b mitigates inflammation, astrocyte activation, and dysfunction of spinal cord injury by inactivating the MAPK pathway.

BACKGROUND: Since the abnormal expression of miR-125b in spinal cord injury (SCI) and the regulatory effect of miR-125b on the MAPK pathway have been expounded, we attempt to investigate whether miR-125b exerts a regulatory effect on SCI by modulating the MAPK pathway. METHOD: A SCI rat model was established. The rats were treated with miR-125b antagomir or agomir, and their motor function affected by miR-125b was further detected by Basso-Beattie-Bresnahan (BBB) scoring. The histopathological changes and neuronal loss in the spinal cord were evaluated using hematoxylin-eosin and Nissl staining. Microglia-conditioned medium (MCM) was prepared and further used to treat the astrocytes, the activation of which was evaluated via immunofluorescence staining. The expressions of miR-125b, inflammation-related factors (IL-6, IL-1ß, TNF-α, and IL-10), and MAPK pathway-related proteins (p38, ERK1/2, and JNK1/2 as well as their phosphorylated (p) forms) in the spinal cord, serum, and MCM-treated astrocytes of rats were determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay, and Western blot. RESULT: MiR-125b was lowly expressed in SCI-modeled rats. MiR-125b downregulation aggravated the impaired motor function, the disorder within the tissue, astrocyte activation, and neuron loss in the spinal cord tissues of SCI-modeled rats, while miR-125b upregulation did oppositely. MiR-125b downregulation enhanced the levels of IL-6, IL-1ß, TNF-α, p38, p-p38, p-ERK1/2, and p-JNK1/2, whilst reducing that of IL-10. Contrarily, miR-125b upregulation exerted the opposite effects in SCI-modeled rats and MCM-treated astrocytes. CONCLUSION: Up-regulation of miR-125b mitigates inflammation, astrocyte activation, and dysfunction in SCI by inactivating the MAPK pathway.

Current research in the pathogenesis of aseptic implant loosening associated with particulate wear debris.

Periprosthetic osteolysis is the most common long-term complication of a total joint arthroplasty, often resulting in aseptic loosening of the implant, which occurs in up to 34% of younger implant recipients and usually requires surgical revision. Particulate wear debris, continuously generated by articulating motion at the bearing surfaces, has been implicated as one of the primary causes of periprosthetic bone loss and implant loosening. With developing implants and bearing surfaces designs, various types of wear particles with specific chemical nature, dimension and shape are formed, which may initiate different immune or inflammatory responses. Wear debris induces down-regulation or up-regulation of various pro-inflammatory cytokines and chemokines in a range of cell types at the interface between implants and the surrounding bone, such as macrophages, osteoclast precursor cells, osteoblasts, lymphocytes, fibroblasts etc. Concomitantly, these mediators further affect functions of cells through distinct signaling mechanisms in either an autocrine or a paracrine manner. This review summarizes current concepts of how wear debris causes osteolysis, and describes the interaction and effects of wear debris on functions of primary cell types involved in osteolysis.

Inconsistency of Bone Mineral Density Between Femoral Head and Proximal Femur After Femoral Neck Fracture Surgery Indicates Great Possibility of Femoral Head Necrosis.

On clinical observation, it was found that the bone mineral density (BMD) of the femoral head and proximal femur was not consistent in some patients with femoral neck fracture after surgery. The current study was performed to explore whether this phenomenon was associated with femoral head necrosis after surgery for femoral neck fracture. Bone mineral density inconsistency is when the difference of the sum of pixel values on both sides of the fracture line has exceeded 30%. Statistical analysis was performed on the clinical characteristics of 271 patients who had received the operation for femoral neck fracture. Chi-square test, Spearman rank correlation, independent sample t test, Kaplan-Meier method, and log-rank test, as well as univariate Cox regression and multivariate Cox regression, were used to analyze the potential relationship among related factors. It was revealed that the incidence of inconsistency in BMD between the femoral head and proximal femur was significantly increased in patients with femoral head necrosis after surgery for femoral neck fracture, and that the consistency was considerably high between BMD inconsistency and femoral head necrosis. The inconsistent BMD occurred 11.1 months earlier than the necrosis of the femoral head. Cox multivariate regression analysis indicated that the inconsistency in BMD between the femoral head and proximal femur after surgery for femoral neck fracture was an independent prognostic factor affecting femoral head necrosis. The inconsistent changes in BMD between the femoral head and proximal femur after surgery for femoral neck fracture indicate a great possibility of femoral head necrosis. [Orthopedics. 2021;44(2):e223-e228.].

Ginkgolide B improves multiterritory perforator flap survival by inhibiting endoplasmic reticulum stress and oxidative stress.

BACKGROUND: The therapeutics used to promote perforator flap survival function induces vascular regeneration and inhibit apoptosis. The present study aimed to explore the potential mechanism of the angiogenesis effects of Ginkgolide B (GB) in perforator flaps. Methods: A total of 72 rats were divided into three groups and treated with saline, GB, or GB + tunicamycin (TM; ER stress activator) for seven consecutive days, respectively. Apoptosis was assayed by determining the Bax/Bcl-2 ratio and caspase-3 level. Endoplasmic reticulum (ER) stress markers (CHOP, GRP78, and caspase-12) were detected by Western blot analysis. Oxidative stress was assessed by measuring the superoxide dismutase activity (SOD) and malondialdehyde (MDA), heme oxygenase-1(HO-1), and nuclear factor erythroid-2-related factor 2 (Nrf2) mRNA levels in the flaps. The percentage flap survival area and blood flow were assessed on postoperative day (POD) 7. Angiogenesis was visualized by hematoxylin and eosin and CD34 staining on POD 7. Results: GB increased the survival of perforator flaps, the flap survival area of GB, GB + TM, and control groups was 90.83 ± 1.93%, 70.93 ± 4.13%, and 62.97 ± 6.50%. GB decreased the Bax/Bcl-2 ratio and caspase-3 level. ER stress-related proteins were downregulated by GB. GB also decreased the MDA level and increased SOD activity, HO-1 and Nrf2 mRNA levels in the flaps. Further, GB induced regeneration of vascular vessels in comparison with saline or GB + TM. Conclusions: GB increased angiogenesis and alleviated oxidative stress by inhibiting ER stress, which increased the survival of perforator flaps. In contrast, GB + TM alleviated angiogenesis and induced oxidative stress by activating ER stress and decreasing the survival of perforator flaps.

Human Peripheral Nerve-Derived Pluripotent Cells Can Be Stimulated by In Vitro Bone Morphogenetic Protein-2.

We have recently identified a population of cells within the peripheral nerves of adult rodent animals (mice and rats) that can respond to Bone Morphogenetic Protein-2 (BMP-2) exposure or physical injury to rapidly proliferate. More importantly, these cells exhibited embryonic differentiation potentials that could be induced into osteoblastic and endothelial cells in vitro. The current study examined human nerve specimens to compare and characterize the cells after BMP-2 stimulation. Fresh pieces of human nerve tissue were minced and treated with either BMP-2 (750 ng/mL) or a PBS vehicle for 12 h at 37 °C, before being digested in 0.2% collagenase and 0.05% trypsin-EDTA. Isolated cells were cultured in a restrictive stem cell medium. Significantly more cells were obtained from the nerve pieces with the BMP-2 treatment in comparison with the PBS vehicle controls. Cell colonies started to form at Day 3. Expressions of the four transcription factors, namely, Klf4, c-Myc, Sox2, and Oct4, were confirmed at both the transcriptional and translational levels. The cells can be maintained in the stem cell culture medium for at least 6 weeks without changing their morphology. When the cells were transferred to a fibroblast growth medium, dispersed spindle-shaped motile cells were noted and became fibroblast activated protein-α (FAP) positive with immunocytochemistry staining. The data suggest that human peripheral nerve tissue also contains a population of cells that can respond to BMP-2 and express Klf4, Sox2, cMyc, and Oct4-the four transcription factors driving cell pluripotency. These cells are able to differentiate into FAP-positive fibroblasts. In summary, in human peripheral nerves also reside a population of quiescent cells with pluripotency potential that may be the same cells as rodent nerve-derived adult stem (NEDAPS) cells. It is proposed that these cells are possibly at the core of a previously unknown natural mechanism for healing an injury.

Differential roles of PDGFR-alpha and PDGFR-beta in angiogenesis and vessel stability.

Preclinical and clinical evaluations of individual proangiogenic/arteriogenic factors for the treatment of ischemic myocardium and skeletal muscle have produced unfulfilled promises. The establishment of functional and stable arterial vascular networks may require combinations of different angiogenic and arteriogenic factors. Using in vivo angiogenesis and ischemic hind-limb animal models, we have compared the angiogenic and therapeutic activities of fibroblast growth factor 2 (FGF-2) in combinations with PDGF-AA and PDGF-AB, two members of the platelet-derived growth factor (PDGF) family, with distinct receptor binding patterns. We show that both PDGF-AA/FGF-2 and PDGF-AB/FGF-2 in combinations synergistically induce angiogenesis in the mouse cornea. FGF-2 up-regulates PDGFR-alpha and -beta expression levels in the newly formed blood vessels. Interestingly, PDGF-AB/FGF-2, but not PDGF-AA/FGF-2, is able to stabilize the newly formed vasculature by recruiting pericytes, and an anti-PDGFR-beta neutralizing antibody significantly blocks PDGF-AB/FGF-2-induced vessel stability. These findings demonstrate that PDGFR-beta receptor is essential for vascular stability. Similarly, PDGF-AB/FGF-2 significantly induces stable collateral growth in the rat ischemic hind limb. The high number of collaterals induced by PDGF-AB/FGF-2 leads to dramatic improvement of the paw's skin perfusion. Immunohistochemical analysis of the treated skeletal muscles confirms that a combination of PDGF-AB and FGF-2 significantly induces arteriogenesis in the ischemic tissue. A combination of PDGF-AB and FGF-2 would be optimal proangiogenic agents for the treatment of ischemic diseases.

Comparative proteomes change and possible role in different pathways of microRNA-21a-5p in a mouse model of spinal cord injury.

Our previous study found that microRNA-21a-5p (miR-21a-5p) knockdown could improve the recovery of motor function after spinal cord injury in a mouse model, but the precise molecular mechanism remains poorly understood. In this study, a modified Allen's weight drop was used to establish a mouse model of spinal cord injury. A proteomics approach was used to understand the role of differential protein expression with miR-21a-5p knockdown, using a mouse model of spinal cord injury without gene knockout as a negative control group. We found that after introducing miR-21a-5p knockdown, proteins that played an essential role in the regulation of inflammatory processes, cell protection against oxidative stress, cell redox homeostasis, and cell maintenance were upregulated compared with the negative control group. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis identified enriched pathways in both groups, such as the oxidative phosphorylation pathway, which is relevant to Parkinson's disease, Huntington's disease, Alzheimer's disease, and cardiac muscle contraction. We also found that miR-21a-5p could be a potential biomarker for amyotrophic lateral sclerosis, as miR-21a-5p becomes deregulated in this pathway. These results indicate successful detection of some important proteins that play potential roles in spinal cord injury. Elucidating the relationship between these proteins and the recovery of spinal cord injury will provide a reference for future research of spinal cord injury biomarkers. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Shandong University of China on March 5, 2014.

Circulating blood monocytes traffic to and participate in the periprosthetic tissue inflammation.

OBJECTIVE: To examine the trafficking of human circulating blood monocytes and their influence on the inflammation of periprosthetic tissues using a novel mouse-human chimera model. METHODS: Periprosthetic tissue and bone chips from patients with aseptic prosthetic loosening were implanted into the muscles of immune-deficient SCID mice depleted of host macrophages by periodic intraperitoneal injection of anti-asialo GM1 rabbit sera (ASGM1). Autologous patient peripheral blood monocytes (PBMCs) were labeled with PKH2 fluorescent dye and injected intraperitoneally into the implanted animals. Mice were sacrificed 14 days after PBMC transfusion for molecular and histological analyses. RESULTS: Patient periprosthetic tissues were well tolerated in SCID mice and preserved a high level of viability. Cell trafficking studies revealed the accumulation of fluorescent PBMC within the xenografts, with total cell counts in the xenografts significantly increased following the systemic PBMC infusion. PBMC infusion also promoted the expression of IL-1, IL-6, TNFalpha, and RANK within the periprosthetic tissue. CONCLUSION: Systemic PBMC migrated to the implanted periprosthetic tissues and contributed to the local inflammation. The data provide evidence that circulating blood monocytes may play a role in pathologic process during aseptic loosening of total joint replacement.

Quantitative anatomic basis of antegrade lag screw placement in posterior column of acetabulum.

BACKGROUND: Lag screw fixation has been recommended for treatment of acetabular and pelvic fracture for several years. The aim of the present study was to determine the projection of the axis of the posterior column on the inner table of the iliac wing in the supra-acetabular region. METHODS: Thirty adult dried bony hemipelves specimens and other five intact adult dried pelvic specimens were included in this study. The projection point of the axis of the posterior column of the acetabulum was determined on the inner table of the iliac wing of the hemipelves specimens. The perpendicular distance from the optimal entry point to the linea terminalis of pelvis was measured and recorded as the lateral distance. The same measurement along the linea terminalis from the optimal entry point to the junction between the anterior border of iliosacral articulation and the linea terminalis of pelvis was made and recorded as the posterior distance. The depth of the anchor path and the corresponding average retroversion angulation and extraversion angulation were also measured. According to the results acquired from this study, a series of 6.5 mm lag screws were inserted into the posterior column of each side of the other five intact specimens, respectively, to evaluate the position of the screws. The data were expressed as mean +/- SD and analyzed by using the descriptive methods with SPSS 10.0. RESULTS: The average length of lag screw was 104.8 +/- 4.2 mm. The average lateral distance was 16.8 +/- 2.1 mm. The average posterior distance was 23.5 +/- 3.4 mm. The corresponding average retroversion angulation and extraversion angulation were 57 degrees 36' +/- 4 degrees 28' and 119 degrees 18' +/- 2 degrees 32', respectively. The insertion of the single 6.5 mm lag screw of adequate length was possible in the posterior column along its anchor path and no accidental extraosseous or intraarticular screw placement had occurred. CONCLUSIONS: The present study describes a safe anchor path of antegrade lag screw fixation in the posterior column. Insertion of the lag screws of adequate length is possible in the posterior column along its functional axis.

VEGF blockade decelerates the growth of a murine experimental osteosarcoma.

Retrovirus-mediated sFlt-1 gene modification was performed to examine the influence of VEGF in controlling the growth of an experimental osteosarcoma in mice. Human osteosarcoma G-292 cells were in vitro infected with retroviral vectors encoding soluble Flt-1 or LacZ gene before transplanted into proximal tibiae of immune deficient SCID mice to establish experimental orthotopic osteosarcoma. Daily observation and biweekly microCT were performed to monitor tumor development and progression till sacrifice at 8 weeks after tumor cell inoculation for histological and molecular analyses. Successful transgene expression was confirmed in the culture media of sFlt-1 transduced G-292 cells using ELISA, and with positive X-gal staining of the LacZ transduced cells. Noteworthy tumors were grown in all mice on the tibiae receiving G-292 cell inoculation, with clear detection on microCT images starting 2 weeks after inoculation. Over the time period, tumors derived from sFlt-1 transduced G-292 cells were distinctively smaller in size when compared to the ones from wide-type G-292 and G-292-LacZ cells. Histology showed typical osteosarcoma characteristics including severe cellular pleomorphism, bone erosions, and neo-vascularization. Real-time polymerase chain reaction indicated significantly higher sFlt-1 expression in sFlt-1 transduced groups than the wild-type G-292 or LacZ-treated groups. Strong expression of oncogenes c-myc and c-fos were also obvious, along with the expression of VEGF in the primary tumor tissue. Overall, data suggest that retrovirus-mediated sFLT-1 gene modification decelerates the osteosarcoma tumor growth in this murine model.

Destructive pathological changes in the rat spinal cord due to chronic mechanical compression. Laboratory investigation.

OBJECT: Chronic mechanical compression of the spinal cord, which is commonly caused by degeneration of the spine, impairs motor and sensory functions insidiously and progressively. Yet the exact mechanisms of chronic spinal cord compression (SCC) remain to be elucidated. To study the pathophysiology of this condition, the authors developed a simple animal experimental model that reproduced the clinical course of mechanical compression of the spinal cord. METHODS: A custom-designed compression device was implanted on the exposed spinal cord of female Wistar rats between the T-7 and T-9 vertebrae. A root canal screw attached to a plastic plate was tightened 1 complete turn (1 pitch) every 7 days for 6 weeks. The placement of the compression device and the degree of compression were validated every week using radiography. Furthermore, a motor sensory deficit index was also calculated every week. After 3, 6, 9, or 12 weeks, the compressed T7-9 spinal cords were harvested and examined histologically. RESULTS: Lateral projection of the thoracic spine showed a progressively increasing rate of mean spinal cord narrowing in the compression group. Motor and sensory deficiencies were observed from Week 3 onward; paralysis was observed in 2 rats at Week 12. Motor deficiency appeared earlier than sensory deficiency. Obvious pathological changes were observed starting at Week 6. The number of neurons in the gray matter of rats with chronic compression of the spinal cord decreased progressively in the 6- and 9-week compression groups. In the white matter, myelin destruction and loss of axons and glia were noted. The number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)-positive neurons increased in the ventral-to-dorsal direction. The number of TUNEL-positive cells increased from Week 6 onward and peaked at Week 9. CONCLUSIONS: This practical model accurately reproduces characteristic features of clinical chronic SCC, including progressive motor and sensory disturbances after a latency and insidious neuronal loss.