Search tips
Search criteria

Results 1-25 (43)

Clipboard (0)

Select a Filter Below

Year of Publication
1.  Evaluating the Role of PTH in Promotion of Chondrosarcoma Cell Proliferation and Invasion by Inhibiting Primary Cilia Expression 
Chondrosarcoma is characterized by secretion of a cartilage-like matrix, with high proliferation ability and metastatic potential. Previous studies have shown that parathyroid hormone-related protein (PTHrP) has a close relationship with various tumor types. The objectives of this study were to research the function played by PTHrP in human chondrosarcoma, especially targeting cell proliferation and invasion, and to search for the potential interaction between PTHrP and primary cilia in tumorigenesis. Surgical resection tissues and the human chondrosarcoma cell line SW1353 were used in the scientific research. Cells were stimulated with an optimum concentration of recombinant PTH (1-84), and siRNA was used to interfere with internal PTHrP. Cell proliferation and invasion assays were applied, including MTS-8 cell proliferation assay, Western blot, RT-PCR, Transwell invasion assay, and immunohistochemistry and immunofluorescence assays. A high level of PTHrP expression was found in human chondrosarcoma tissues, and recombinant PTH exhibited positive promotion in tumor cell proliferation and invasion. In the meantime, PTHrP could inhibit the assembly of primary cilia and regulate downstream gene expression. These findings indicate that PTHrP can regulate tumor cell proliferation and invasion ability, possibly through suppression of primary cilia assembly. Thus, restricting PTHrP over-expression is a feasible potential therapeutic method for chondrosarcoma.
PMCID: PMC4264140  PMID: 25365173
chondrosarcoma; primary cilia expression; parathyroid hormone-related protein; PTHrP
2.  Feasibility and safety of a novel reverse puncture device (RPD) for laparoscopic esophagogastrostomy/esophagojejunostomy 
Background: We aimed to report the feasibility and safety of the technique after laparoscopy-assisted total gastrectomy (LATG) or laparoscopy-assisted proximal gastrectomy (LAPG): intracorporeal circular stapling esophagogastrostomy/esophagojejunostomy using the reverse puncture device (RPD). Methods: Laparoscopy-assisted esophagogastrostomy/esophagojejunostomy was performed in 14 gastric cancer cases and 4 cases of cardiac stromal tumors using a newly developed RPD to place the anvil. After LATG or LAPG, an approximately 2 cm transverse incision was made at the esophagus anterior wall at 2 cm above the cardia and the RPD was then introduced via the incision. The end of the RPD was sutured out “reversely” at 3 cm above the esophagotomy incision. Double-stapling esophagogastrostomy/esophagojejunostomy with a circular stapler was then performed under laparoscopic assistance. Results: There was no intraoperative complication or conversion to open surgery, the mean operation time was 155 min, the mean anvil placement time was 12 min, and the mean blood loss was 75 mL. Patients resumed oral liquid diet on postoperative day 2, and discharged at day 10. There was no mortality, no anastomotic leakage, anastomotic stenosis, intra-abdominal infections or other complications. No recurrence was found during the 11 to 25 month follow up. Postoperative gastrointestinal iodine solution radiography revealed no anastomosis leakage or stenosis. Conclusions: We have successfully performed LATG or LAPG reconstruction using our technique in 18 patients without any complications. We believe that our procedure is a secure and reliable reconstruction method, and is especially useful in obese patients, in whom conventional manipulations are often difficult.
PMCID: PMC4211752  PMID: 25356102
Esophagogastrostomy; esophagojejunostomy; reverse puncture device
3.  Ferritin light chain interacts with PEN-2 and affects γ-secretase activity 
Neuroscience letters  2013;548:90-94.
Alzheimer’s disease (AD) is primarily caused by overproduction/deposition of β-amyloid (Aβ) in the brain. Dysregulation of iron in the brain also contributes to AD. Although iron affects β-amyloid precursor protein (APP) expression and Aβ deposition, detailed role of iron in AD requires further elucidation. Aβ is produced by sequential proteolytic cleavages of APP by β-secretase and γ-secretase. The γ-secretase complex comprises presenilins (PS1 or PS2), Nicastrin, APH-1, and PEN-2. Herein, we find that PEN-2 can interact with ferritin light chain (FTL), an important component of the iron storage protein ferritin. In addition, we show that overexpression of FTL increases the protein levels of PEN-2 and PS1 amino-terminal fragment (NTF) and promotes γ-secretase activity for more production of Aβ and Notch intracellular domain (NICD). Furthermore, iron treatments increase the levels of FTL, PEN-2 and PS1 NTF and promote γ-secretase-mediated NICD production. Moreover, downregulation of FTL decreases the levels of PEN-2 and PS1 NTF. Together, our results suggest that iron can increase γ-secretase activity through promoting the level of FTL that interacts with and stabilizes PEN-2, providing a new molecular link between iron, PEN-2/γ-secretase and Aβ generation in AD.
PMCID: PMC3724929  PMID: 23685131
γ-secretase; Alzheimer’s disease; ferritin light chain; iron; PEN-2
4.  Programmed Death 1 Deficiency Induces the Polarization of Macrophages/Microglia to the M1 Phenotype After Spinal Cord Injury in Mice 
Neurotherapeutics  2014;11(3):636-650.
The inflammatory response following spinal cord injury (SCI) involves the activation of resident microglia and the infiltration of macrophages. Macrophages and microglia can be polarized into the classically activated proinflammatory M1 phenotype or the alternatively activated anti-inflammatory M2 phenotype. Programmed cell death 1 (PD-1) is a critical immune inhibitory receptor involved in innate and adaptive immune responses. However, whether PD-1 is involved in the modulation of macrophage/microglial polarization is unknown. In this study, the mRNA levels of pd1 gradually increased after SCI, and PD-1 protein was found in macrophages/microglia in injured spinal cord sections. PD-1 knockout (KO) mice showed poor locomotor recovery after spinal cord crushing compared with wild-type mice. M1-type macrophages/microglia accumulated in greater numbers in the injured spinal cord of PD-1-KO mice. Under polarized stimulation, induced expression of PD-1 occurred in cultured macrophages and microglia. PD-1 suppressed M1 polarization by reducing the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and promoted M2 polarization by increasing STAT6 phosphorylation. In PD-1-KO mice, the M1 response was enhanced via the activation of STAT1 and nuclear factor-kappa B. Furthermore, PD-1 played various roles in phagocytosis in macrophages and microglia. Therefore, our results suggest that PD-1 signaling plays an important role in the regulation of macrophage/microglial polarization. Thus, deregulated PD-1 signaling may induce the polarization of macrophages/microglia toward the M1 phenotype. Overall, our results provide new insights into the modulatory mechanisms of macrophage/microglial polarization, thereby possibly facilitating the development of new therapies for SCI via the regulation of macrophage/microglial polarization through PD-1 signaling.
Electronic supplementary material
The online version of this article (doi:10.1007/s13311-013-0254-x) contains supplementary material, which is available to authorized users.
PMCID: PMC4121443  PMID: 24853068
Macrophage; Microglia; Polarization; Programmed death 1; Spinal cord injury
5.  BL153 Partially Prevents High-Fat Diet Induced Liver Damage Probably via Inhibition of Lipid Accumulation, Inflammation, and Oxidative Stress 
The present study was to investigate whether a magnolia extract, named BL153, can prevent obesity-induced liver damage and identify the possible protective mechanism. To this end, obese mice were induced by feeding with high fat diet (HFD, 60% kcal as fat) and the age-matched control mice were fed with control diet (10% kcal as fat) for 6 months. Simultaneously these mice were treated with or without BL153 daily at 3 dose levels (2.5, 5, and 10 mg/kg) by gavage. HFD feeding significantly increased the body weight and the liver weight. Administration of BL153 significantly reduced the liver weight but without effects on body weight. As a critical step of the development of NAFLD, hepatic fibrosis was induced in the mice fed with HFD, shown by upregulating the expression of connective tissue growth factor and transforming growth factor beta 1, which were significantly attenuated by BL153 in a dose-dependent manner. Mechanism study revealed that BL153 significantly suppressed HFD induced hepatic lipid accumulation and oxidative stress and slightly prevented liver inflammation. These results suggest that HFD induced fibrosis in the liver can be prevented partially by BL153, probably due to reduction of hepatic lipid accumulation, inflammation and oxidative stress.
PMCID: PMC3997087  PMID: 24803983
6.  Gambogenic Acid Kills Lung Cancer Cells through Aberrant Autophagy 
PLoS ONE  2014;9(1):e83604.
Lung cancer is one of the most common types of cancer and causes 1.38 million deaths annually, as of 2008 worldwide. Identifying natural anti-lung cancer agents has become very important. Gambogenic acid (GNA) is one of the active compounds of Gamboge, a traditional medicine that was used as a drastic purgative, emetic, or vermifuge for treating tapeworm. Recently, increasing evidence has indicated that GNA exerts promising anti-tumor effects; however, the underlying mechanism remains unclear. In the present paper, we found that GNA could induce the formation of vacuoles, which was linked with autophagy in A549 and HeLa cells. Further studies revealed that GNA triggers the initiation of autophagy based on the results of MDC staining, AO staining, accumulation of LC3 II, activation of Beclin 1 and phosphorylation of P70S6K. However, degradation of p62 was disrupted and free GFP could not be released in GNA treated cells, which indicated a block in the autophagy flux. Further studies demonstrated that GNA blocks the fusion between autophagosomes and lysosomes by inhibiting acidification in lysosomes. This dysfunctional autophagy plays a pro-death role in GNA-treated cells by activating p53, Bax and cleaved caspase-3 while decreasing Bcl-2. Beclin 1 knockdown greatly decreased GNA-induced cell death and the effects on p53, Bax, cleaved caspase-3 and Bcl-2. Similar results were obtained using a xenograft model. Our findings show, for the first time, that GNA can cause aberrant autophagy to induce cell death and may suggest the potential application of GNA as a tool or viable drug in anticancer therapies.
PMCID: PMC3888381  PMID: 24427275
7.  Dynamic Force Sensing Using an Optically Trapped Probing System 
This paper presents the design of an adaptive observer that is implemented to enable real-time dynamic force sensing and parameter estimation in an optically trapped probing system. According to the principle of separation of estimation and control, the design of this observer is independent of that of the feedback controller when operating within the linear range of the optical trap. Dynamic force sensing, probe steering/clamping, and Brownian motion control can, therefore, be developed separately and activated simultaneously. The adaptive observer utilizes the measured motion of the trapped probe and input control effort to recursively estimate the probe–sample interaction force in real time, along with the estimation of the probing system’s trapping bandwidth. This capability is very important to achieving accurate dynamic force sensing in a time-varying process, wherein the trapping dynamics is nonstationary due to local variations of the surrounding medium. The adaptive estimator utilizes the Kalman filter algorithm to compute the time-varying gain in real time and minimize the estimation error for force probing. A series of experiments are conducted to validate the design of and assess the performance of the adaptive observer.
PMCID: PMC3875182  PMID: 24382944
Adaptive estimation; force measurement; Kalman filtering; optical tweezers; state feedback
8.  Attenuation of Hyperlipidemia- and Diabetes-Induced Early-Stage Apoptosis and Late-Stage Renal Dysfunction via Administration of Fibroblast Growth Factor-21 Is Associated with Suppression of Renal Inflammation 
PLoS ONE  2013;8(12):e82275.
Lipotoxicity is a key feature of the pathogenesis of diabetic kidney disease, and is attributed to excessive lipid accumulation (hyperlipidemia). Increasing evidence suggests that fibroblast growth factor (FGF)21 has a crucial role in lipid metabolism under diabetic conditions.
The present study investigated whether FGF21 can prevent hyperlipidemia- or diabetes-induced renal damage, and if so, the possible mechanism.
Mice were injected with free fatty acids (FFAs, 10 mg/10 g body weight) or streptozotocin (150 mg/kg) to establish a lipotoxic model or type 1 diabetic model, respectively. Simultaneously the mice were treated with FGF21 (100 µg/kg) for 10 or 80 days. The kidney weight-to-tibia length ratio and renal function were assessed. Systematic and renal lipid levels were detected by ELISA and Oil Red O staining. Renal apoptosis was examined by TUNEL assay. Inflammation, oxidative stress, and fibrosis were assessed by Western blot.
Acute FFA administration and chronic diabetes were associated with lower kidney-to-tibia length ratio, higher lipid levels, severe renal apoptosis and renal dysfunction. Obvious inflammation, oxidative stress and fibrosis also observed in the kidney of both mice models. Deletion of the fgf21 gene further enhanced the above pathological changes, which were significantly prevented by administration of exogenous FGF21.
These results suggest that FFA administration and diabetes induced renal damage, which was further enhanced in FGF21 knock-out mice. Administration of FGF21 significantly prevented both FFA- and diabetes-induced renal damage partially by decreasing renal lipid accumulation and suppressing inflammation, oxidative stress, and fibrosis.
PMCID: PMC3857822  PMID: 24349242
9.  Progress Towards the Application of Molecular Force Spectroscopy to DNA Sequencing 
Electrophoresis  2012;33(23):10.1002/elps.201200351.
Many recent advances in DNA sequencing have taken advantage of single-molecule techniques using fluorescently-labeled oligonucleotides as the principle mode of detection. However, in spite of the successes of fluorescent-based sequencers, avoidance of labeled nucleotides could substantially reduce the costs of sequencing. This paper discusses the development of an alternative sequencing method in which unlabeled DNA can be manipulated directly on a massively-parallel scale using single-molecule force spectroscopy. We combine a wide-field optical detection technique (evanescent field excitation) with one of two methods of applying force in parallel, magnetic or dielectrophoretic (DEP) tweezers, to attain near single-base sensitivity in the double-stranded character of DNA. This article will discuss the developments of such a single-molecule force spectroscopy technique as a potential technology for genome sequencing.
PMCID: PMC3815542  PMID: 23161379
dielectrophoresis; DEP tweezers; DNA sequencing; highly parallel; label free; force spectroscopy
10.  Thymic Stromal Lymphopoietin Attenuates the Development of Atherosclerosis in ApoE−/− Mice 
Thymic stromal lymphopoietin (TSLP) is a cytokine with multiple effects on the body. For one thing, TSLP induces Th2 immunoreaction and facilitates allergic reaction; for another, it promotes the differentiation of naturally occurring CD4+CD25+Foxp3+ regulatory T cells (nTregs) and maintains immune tolerance. However, the exact role of TSLP in atherosclerosis remains unknown.
Methods and Results
In vitro, we examined the phenotype of TSLP‐conditioned bone marrow dendritic cells (TSLP‐DCs) of apolipoprotein E–deficient (ApoE−/−) mice and their capacity to induce the differentiation of Tregs. Our results indicated that TSLP‐DCs obtained the characteristics of tolerogenic dendritic cells and increased a generation of CD4+ latency‐associated peptide (LAP)+ Tregs and nTregs when cocultured with naive T cells. In addition, the functional relevance of TSLP and TSLP‐DCs in the development of atherosclerosis was also determined. Interestingly, we found that TSLP was almost absent in cardiovascular tissue of ApoE−/− mice, and TSLP administration increased the levels of antioxidized low‐density lipoprotein IgM and IgG1, but decreased the levels of IgG2a in plasma. Furthermore, mice treated with TSLP and TSLP‐DCs developed significantly fewer (32.6% and 28.2%, respectively) atherosclerotic plaques in the aortic root compared with controls, along with increased numbers of CD4+LAP+ Tregs and nTregs in the spleen and decreased inflammation in the aorta, which could be abrogated by anti‐TGF‐β antibody.
Our results revealed a protective role for TSLP in atherosclerosis that is possibly mediated by reestablishing a tolerogenic immune response, which may represent a novel possibility for treatment or prevention of atherosclerosis.
PMCID: PMC3835250  PMID: 23985377
atherosclerosis; CD4+LAP+ Tregs; TGF‐β; tolerogenic dendritic cells; TSLP
11.  Different TLR4 expression and microglia/macrophage activation induced by hemorrhage in the rat spinal cord after compressive injury 
Hemorrhage is a direct consequence of traumatic injury to the central nervous system and may cause innate immune reactions including cerebral Toll-like receptor (TLR) 4 upregulation which usually leads to poor outcome in the traumatic brain injury. In spinal cord injury (SCI), however, how hemorrhage induces innate immune reaction in spinal parenchyma remains unknown. The present study aimed to see whether blood component and/or other factor(s) induce TLR4 and microglia/macrophages involved innate immune reactions in the rat spinal cord after traumatic injury.
Using the compressive SCI model of the rat, hemorrhage in the spinal cord was identified by hematoxylin-eosin staining. Microglia/macrophage activation, TLR4 expression, and cell apoptosis were investigated by immunohistochemistry. Nuclear factor (NF)-κB p50 level of the two segments of the cord was detected by western blotting assay. With carbon powder injection, blood origination of the hematoma was explored. The blood-spinal cord barrier (BSCB) states of the lesion site and the hematoma were compared with immunohistochemistry and tannic acid-ferric chloride staining.
Histological observation found blood accumulated in the center of compression lesion site (epicenter) and in the hematoma approximately 1.5 cm away from the epicenter. TLR4 expression, microglia//macrophage activation, and subsequent apoptosis in the area of far-away hematoma were late and weak in comparison to that in epicenter. In addition, TLR4 positive microglia/macrophages appeared to be phagocytotic in the far-away hematoma more obviously than that in the epicenter. Injected carbon powder indicated that accumulated blood of the far-away hematoma originated from the bleeding of the lesion epicenter, and the BSCB around the hematoma was not compromised in the early phase. Accordingly, at 3 days post injury, NF-κB p50 was upregulated based on the similar levels of blood component hemoglobin, and cell apoptosis was obvious in the epicenter but not in the far-away hematoma.
These data suggest that besides blood component, BSCB compromise and the extent of tissue injury contribute more to TLR4 and microglia/macrophage responses to the spinal cord hemorrhage. Therefore, the innate immune environment is a necessary consideration for the SCI therapy targeting TLR4 and microglia/macrophages.
PMCID: PMC3847110  PMID: 24015844
Hemorrhage; Toll-like receptor 4; Microglia/macrophage; Spinal cord injury; Blood-spinal cord barrier; Rat
12.  High Density Single-Molecule-Bead Arrays for Parallel Single Molecule Force Spectroscopy 
Analytical Chemistry  2012;84(11):4907-4914.
The assembly of a highly-parallel force spectroscopy tool requires careful placement of single-molecule targets on the substrate and the deliberate manipulation of a multitude of force probes. Since the probe must approach the target biomolecule for covalent attachment, while avoiding irreversible adhesion to the substrate, the use of the polymer microsphere as force probes to create the tethered bead array poses a problem. Therefore, the interactions between the force probe and the surface must be repulsive at very short distances (< 5 nm) and attractive at long distances. To achieve this balance, the chemistry of the substrate, force probe, and solution must be tailored to control the probe-surface interactions. In addition to an appropriately designed chemistry, it is necessary to control the surface density of the target molecule in order to ensure that only one molecule is interrogated by a single force probe. We used gold-thiol chemistry to control both the substrate’s surface chemistry and the spacing of the studied molecules, through a competitive binding of the thiol-terminated DNA and an inert thiol forming a blocking layer. For our single molecule array, we modeled the forces between the probe and the substrate using DLVO theory and measured their magnitude and direction with colloidal probe microscopy. The practicality of each system was tested using a probe binding assay to evaluate the proportion of the beads remaining adhered to the surface after application of force. We have translated the results specific for our system to general guiding principles for preparation of tethered bead arrays and demonstrated the ability of this system to produce a high yield of active force spectroscopy probes in a microwell substrate. This study outlines the characteristics of the chemistry needed to create such a force spectroscopy array.
PMCID: PMC3389265  PMID: 22548234
DLVO theory; single molecule; force spectroscopy; non-specific binding; surface attachment; DNA array
13.  Intervention Effects of Ganoderma Lucidum Spores on Epileptiform Discharge Hippocampal Neurons and Expression of Neurotrophin-4 and N-Cadherin 
PLoS ONE  2013;8(4):e61687.
Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS), a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg2+ free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE). Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i) control, ii) model (incubated with Mg2+ free medium for 3 hours), iii) GLS group I (incubated with Mg2+ free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours) and iv) GLS group II (neurons incubated with Mg2+ free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours). Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression.
PMCID: PMC3634853  PMID: 23637882
14.  Exposure to gastric juice may not cause adenocarcinogenesis of the esophagus 
AIM: To determine the effects of gastric juice on the development of esophageal adenocarcinoma (EAC).
METHODS: A animal model of duodenogastroesophageal reflux was established in Sprague-Dawley rats undergoing esophagoduodenostomy. The development of EAC and forestomach adenocarcinoma was investigated 40 wk after the treatment. Intraluminal pH and bile of the forestomach were measured.
RESULTS: There were no significant differences in pH (t = 0.117, P = 0.925) or bile (χ2 = 0.036, P = 0.85) in the forestomach before and 40 wk after esophagoduodenostomy. There were also no significant differences between the model and controls during esophagoduodenostomy or 40 wk after esophagoduodenostomy. The incidence of intestinal metaplasia (88%) and intestinal metaplasia with dysplasia and adenocarcinoma (28%) in the esophagus in the model was higher than in the controls 40 wk after surgery (χ2 = 43.06, P < 0.001 and χ2 = 9.33, P = 0.002, respectively) and in the forestomach in the model (χ2 = 32.05, P < 0.001 and χ2 = 8.14, P = 0.004, respectively). The incidence rates of inflammation in the esophagus and forestomach were 100% and 96%, respectively (χ2 = 1.02, P = 0.31) in the model, which was higher than in the esophageal control (6.8%) (χ2 = 42.70, P < 0.001).
CONCLUSION: Gastric juice exposure may not cause intestinal metaplasia with dysplasia or adenocarcinoma of the forestomach and may not be related to EAC.
PMCID: PMC3631996  PMID: 23613638
Intestinal metaplasia; Gastric juice; Pathogenesis; Esophageal adenocarcinoma; Gastroesophageal reflux
15.  Complete Genome Sequence of a Monosense Densovirus Infecting the Cotton Bollworm, Helicoverpa armigera 
Journal of Virology  2012;86(19):10909.
Densoviruses (DNVs) infecting arthropods are members of the family Parvoviridae. Here we report the complete genome sequence of a novel DNV with a monosense genome that infects cotton bollworms (Helicoverpa armigera), named HaDNV-1. Alignment and phylogenetic analysis revealed that HaDNV-1 showed high identity with the genus Iteravirus.
PMCID: PMC3457278  PMID: 22966197
16.  Management of drug-resistant spinal tuberculosis with a combination of surgery and individualised chemotherapy: a retrospective analysis of thirty-five patients 
International Orthopaedics  2011;36(2):277-283.
Drug-resistant tuberculosis is a major public-health concern globally and can be difficult to manage clinically. Spinal tuberculosis is the most common manifestation of extrapulmonary tuberculosis. However, there have been few reports on the topic of drug-resistant spinal tuberculosis. The aim of this study was to investigate the clinical characteristics and drug susceptibility patterns and the outcomes of management with a combination of surgery and individualised chemotherapy, for drug-resistant spinal tuberculosis.
We retrospectively analysed 35 patients with drug-resistant tuberculous spondylitis. After surgery, individualised chemotherapy was tailored for each patient according to the drug-resistance profile and previous history of chemotherapy. The patients were followed up clinically and radiologically for an average period of 35.8 months.
Among 35 drug-resistant spinal tuberculosis cases, 13 were retreatment cases. Twelve were multi-drug resistant tuberculosis (MDR-TB), and 23 were non-MDR-TB. The patients with MDR-TB and non-MDR-TB had undergone previous chemotherapy for an average of 14.50 ± 2.00 (0–60) months and 4.56 ± 1.54 (0–74) months, respectively. A total of 32 cases underwent open operations, and the other three had percutaneous drainage and local chemotherapy. Patients received individualised chemotherapy for an average of 23.6 months postoperatively. Local recurrence was observed in six patients. Thirty-three patients had been cured at the final follow-up, and the other two were still receiving chemotherapy.
Drug-resistant tuberculous spondylitis is mainly acquired through previous irregular chemotherapy and the spreading of drug-resistant strains. Management with a combination of surgery and individualised chemotherapy is feasible in the treatment of severe complications and the prevention of acquired drug resistance.
PMCID: PMC3282866  PMID: 22065055
17.  Dielectrophoretic Tweezers as a Platform for Molecular Force Spectroscopy in a Highly Parallel Format 
Lab on a Chip  2011;11(24):4248-4259.
We demonstrated the application of a simple electrode geometry for dielectrophoresis (DEP) on colloidal probes as a form of molecular force spectroscopy in a highly parallel format. The electric field between parallel plates is perturbed with dielectric microstructures, generating uniform DEP forces on colloidal probes in the range of several hundred piconewtons across a macroscopic sample area. We determined the approximate crossover frequency between negative and positive DEP using electrodes without dielectric microstructures—a simplification over standard experimental methods involving quadrupoles or optical trapping. 2D and 3D simulations of the electric field distributions validated the experimental behavior of several of our DEP tweezers geometries and provided insight into potential improvements. We applied the DEP tweezers to the stretching of a short DNA oligomer and detected its extension using total-internal reflection fluorescence microscopy. The combination of a simple cell fabrication, a uniform distribution of high axial forces, and a facile optical detection of our DEP tweezers makes this form of molecular force spectroscopy ideal for highly parallel detection of stretching or unbinding kinetics of biomolecules.
PMCID: PMC3383857  PMID: 22051576
18.  Rapid and accurate detection of RMP- and INH- resistant Mycobacterium tuberculosis in spinal tuberculosis specimens by CapitalBio™ DNA microarray: A prospective validation study 
BMC Infectious Diseases  2012;12:303.
DNA microarrays can detect tuberculosis and its multi-drug resistant form in M. tuberculosis isolates and sputum specimens with high sensitivity and specificity. However, no performance data currently exists for its use in spinal tuberculosis specimens. This study was aimed to assess the performance of the CapitalBio™ DNA microarray in the detection of isoniazid (INH) and rifampicin (RMP) resistance in spinal tuberculosis compared with the BACT/MGIT 960 system.
From March 2009 to December 2011, 153 consecutive patients from Southwest Hospital, Chongqing with clinically and pathologically diagnosed spinal tuberculosis were enrolled into this study. Specimens collected during surgery from the tuberculosis patients were subjected to M. tuberculosis species identification and drug-resistance detection by the CapitalBio™ DNA microarray, and results were compared with those obtained from the absolute concentration drug susceptibility testing.
The CapitalBio™ DNA microarray achieved 93.55% sensitivity for the correct M. tuberculosis species identification of the 93 specimens that tested positive for spinal tuberculosis through culture. In addition, twenty-seven additional patients (45.0%) were detected by the DNA microarray to be positive for M. tuberculosis among sixty spinal tuberculosis patients who were culture negative. Moreover, the DNA microarray had a sensitivity of 88.9% and a specificity of 90.7% for RMP resistance, and the microarray had a sensitivity of 80.0% and a specificity of 91.0% for INH resistance. The mean turn-around time of M. tuberculosis species identification and drug resistance detection using the DNA microarray was 5.8 (range, 4–9) hours.
The CapitalBio™ DNA microarray is a feasible and accurate tool for the species identification of M. tuberculosis and for directly detecting RMP and INH resistance from spinal tuberculosis specimens in fewer than 9 hours.
PMCID: PMC3527135  PMID: 23151186
DNA microarray; Spinal tuberculosis; Drug resistance; Gene mutation
19.  Vascular endothelial growth factor participates in modulating the C6 glioma-induced migration of rat bone marrow-derived mesenchymal stem cells and upregulates their vascular cell adhesion molecule-1 expression 
Bone marrow-derived mesenchymal stem cells (BMSCs) have been shown to be able to migrate towards glioma, but the molecular mechanisms responsible for this migratory behavior still require further elucidation. This study aimed to test the role of vascular endothelial growth factor (VEGF) in the C6 glioma-induced migration of BMSCs, evaluate the effect of VEGF on the migratory capacity and vascular cell adhesion molecule-1 (VCAM-1) expression of BMSCs and explore the role of VCAM-1 in the VEGF-induced migration of BMSCs. The results showed that C6 glioma cells significantly increased the migration of BMSCs in vitro, which was partially blocked by a VEGF neutralizing antibody, and 20 ng/ml recombinant rat VEGF164 incubation enhanced the migration of BMSCs. Moreover, 12 h of 20 ng/ml VEGF164 incubation upregulated the VCAM-1 expression of BMSCs and the blocking of VCAM-1 reduced the VEGF164-induced migration of BMSCs. The data also revealed that LY294002, an inhibitor of phosphoinositide-3-kinase (PI3K), decreased the VEGF-induced migration and VCAM-1 expression of BMSCs. These findings indicate that VEGF participates in mediating the C6 glioma-induced migration of BMSCs by upregulating their VCAM-1 expression, and that PI3K is involved in the signal transduction of VEGF164-induced migration and VCAM-1 expression of BMSCs.
PMCID: PMC3494128  PMID: 23226762
mesenchymal stem cells; vascular endothelial growth factor; migration; glioma; vascular cell adhesion molecule-1
20.  Interplay between the Westerlies and Asian monsoon recorded in Lake Qinghai sediments since 32 ka 
Scientific Reports  2012;2:619.
Two atmospheric circulation systems, the mid-latitude Westerlies and the Asian summer monsoon (ASM), play key roles in northern-hemisphere climatic changes. However, the variability of the Westerlies in Asia and their relationship to the ASM remain unclear. Here, we present the longest and highest-resolution drill core from Lake Qinghai on the northeastern Tibetan Plateau (TP), which uniquely records the variability of both the Westerlies and the ASM since 32 ka, reflecting the interplay of these two systems. These records document the anti-phase relationship of the Westerlies and the ASM for both glacial-interglacial and glacial millennial timescales. During the last glaciation, the influence of the Westerlies dominated; prominent dust-rich intervals, correlated with Heinrich events, reflect intensified Westerlies linked to northern high-latitude climate. During the Holocene, the dominant ASM circulation, punctuated by weak events, indicates linkages of the ASM to orbital forcing, North Atlantic abrupt events, and perhaps solar activity changes.
PMCID: PMC3431539  PMID: 22943005
21.  BVT.2733, a Selective 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitor, Attenuates Obesity and Inflammation in Diet-Induced Obese Mice 
PLoS ONE  2012;7(7):e40056.
Inhibition of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is being pursued as a new therapeutic approach for the treatment of obesity and metabolic syndrome. Therefore, there is an urgent need to determine the effect of 11β-HSD1 inhibitor, which suppresses glucocorticoid action, on adipose tissue inflammation. The purpose of the present study was to examine the effect of BVT.2733, a selective 11β-HSD1 inhibitor, on expression of pro-inflammatory mediators and macrophage infiltration in adipose tissue in C57BL/6J mice.
Methodology/Principal Findings
C57BL/6J mice were fed with a normal chow diet (NC) or high fat diet (HFD). HFD treated mice were then administrated with BVT.2733 (HFD+BVT) or vehicle (HFD) for four weeks. Mice receiving BVT.2733 treatment exhibited decreased body weight and enhanced glucose tolerance and insulin sensitivity compared to control mice. BVT.2733 also down-regulated the expression of inflammation-related genes including monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α) and the number of infiltrated macrophages within the adipose tissue in vivo. Pharmacological inhibition of 11β-HSD1 and RNA interference against 11β-HSD1 reduced the mRNA levels of MCP-1 and interleukin-6 (IL-6) in cultured J774A.1 macrophages and 3T3-L1 preadipocyte in vitro.
These results suggest that BVT.2733 treatment could not only decrease body weight and improve metabolic homeostasis, but also suppress the inflammation of adipose tissue in diet-induced obese mice. 11β-HSD1 may be a very promising therapeutic target for obesity and associated disease.
PMCID: PMC3388048  PMID: 22768329
22.  Early Blockade of TLRs MyD88-Dependent Pathway May Reduce Secondary Spinal Cord Injury in the Rats 
To determine the role of toll-like receptors (TLRs) myeloid differentiation factor 88 (MyD88) dependent pathway in the spinal cord secondary injury, compression injury was made at T8 segment of the spinal cord in adult male Sprague-Dawley rats. Shown by RT-PCR, TLR4 mRNA in the spinal cord was quickly elevated after compression injury. Intramedullary injection of MyD88 inhibitory peptide (MIP) resulted in significant improvement in locomotor function recovery at various time points after surgery. Meanwhile, injury area, p38 phosphorylation, and proinflammation cytokines in the injured spinal cord were significantly reduced in MIP-treated animals, compared with control peptide (CP) group. These data suggest that TLRs MyD88-dependent pathway may play an important role in the development of secondary spinal cord injury, and inhibition of this pathway at early time after primary injury could effectively protect cells from inflammation and apoptosis and therefore improve the functional recovery.
PMCID: PMC3364571  PMID: 22675384
23.  Multiple-Locus Variable-Number Tandem-Repeat Analysis of Pathogenic Yersinia enterocolitica in China 
PLoS ONE  2012;7(5):e37309.
The predominant bioserotypes of pathogenic Yersinia enterocolitica in China are 2/O: 9 and 3/O: 3; no pathogenic O: 8 strains have been found to date. Multiple-Locus Variable-Number Tandem-Repeat Analysis (MLVA) based on seven loci was able to distinguish 104 genotypes among 218 pathogenic Y. enterocolitica isolates in China and from abroad, showing a high resolution. The major pathogenic serogroups in China, O: 3 and O: 9, were divided into two clusters based on MLVA genotyping. The different distribution of Y. enterocolitica MLVA genotypes maybe due to the recent dissemination of specific clones of 2/O: 9 and 3/O: 3 strains in China. MLVA was a helpful tool for bacterial pathogen surveillance and investigation of pathogenic Y. enterocolitica outbreaks.
PMCID: PMC3352880  PMID: 22615971
24.  Pilot Scale Production of Highly Efficacious and Stable Enterovirus 71 Vaccine Candidates 
PLoS ONE  2012;7(4):e34834.
Enterovirus 71 (EV71) has caused several epidemics of hand, foot and mouth diseases (HFMD) in Asia and now is being recognized as an important neurotropic virus. Effective medications and prophylactic vaccine against EV71 infection are urgently needed. Based on the success of inactivated poliovirus vaccine, a prototype chemically inactivated EV71 vaccine candidate has been developed and currently in human phase 1 clinical trial.
Principal Finding
In this report, we present the development of a serum-free cell-based EV71 vaccine. The optimization at each step of the manufacturing process was investigated, characterized and quantified. In the up-stream process development, different commercially available cell culture media either containing serum or serum-free was screened for cell growth and virus yield using the roller-bottle technology. VP-SFM serum-free medium was selected based on the Vero cell growth profile and EV71 virus production. After the up-stream processes (virus harvest, diafiltration and concentration), a combination of gel-filtration liquid chromatography and/or sucrose-gradient ultracentrifugation down-stream purification processes were investigated at a pilot scale of 40 liters each. Although the combination of chromatography and sucrose-gradient ultracentrifugation produced extremely pure EV71 infectious virus particles, the overall yield of vaccine was 7–10% as determined by a VP2-based quantitative ELISA. Using chromatography as the downstream purification, the virus yield was 30–43%. To retain the integrity of virus neutralization epitopes and the stability of the vaccine product, the best virus inactivation was found to be 0.025% formalin-treatment at 37°C for 3 to 6 days. Furthermore, the formalin-inactivated virion vaccine candidate was found to be stable for >18 months at 4°C and a microgram of viral proteins formulated with alum adjuvant could induce strong virus-neutralizing antibody responses in mice, rats, rabbits, and non-human primates.
These results provide valuable information supporting the current cell-based serum-free EV71 vaccine candidate going into human Phase I clinical trials.
PMCID: PMC3328501  PMID: 22529942
25.  NMDA Receptor Blockade at Rest Triggers Rapid Behavioural Antidepressant Responses 
Nature  2011;475(7354):91-95.
Clinical studies consistently demonstrate that a single sub-psychomimetic dose of ketamine, an ionotropic glutamatergic n-methyl-d-aspartate receptor (NMDAR) antagonist, produces fast-acting antidepressant responses in patients suffering from major depressive disorder (MDD), although the underlying mechanism is unclear1-3. Depressed patients report alleviation of MDD symptoms within two hours of a single low-dose intravenous infusion of ketamine with effects lasting up to two weeks1-3, unlike traditional antidepressants (i.e. serotonin reuptake inhibitors), which take weeks to reach efficacy. This delay is a major drawback to current MDD therapies, leaving a need for faster acting antidepressants particularly for suicide-risk patients3. Ketamine's ability to produce rapidly acting, long-lasting antidepressant responses in depressed patients provides a unique opportunity to investigate underlying cellular mechanisms. We show that ketamine and other NMDAR antagonists produce fast-acting behavioural antidepressant-like effects in mouse models that depend on rapid synthesis of brain-derived neurotrophic factor (BDNF). We find that ketamine-mediated NMDAR blockade at rest deactivates eukaryotic elongation factor 2 (eEF2) kinase (also called CaMKIII) resulting in reduced eEF2 phosphorylation and desuppression of BDNF translation. Furthermore, we find inhibitors of eEF2 kinase induce fast-acting behavioural antidepressant-like effects. Our findings suggest that protein synthesis regulation by spontaneous neurotransmission may serve as a viable therapeutic target for fast-acting antidepressant development.
PMCID: PMC3172695  PMID: 21677641
antidepressant; BDNF; protein translation; animal model; ketamine

Results 1-25 (43)