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Find video protocols related to scientific articles indexed in Pubmed.
In vitro investigation of a tissue-engineered cell-tendon complex mimicking the transitional architecture at the ligament-bone interface.
J Biomater Appl
PUBLISHED: 10-15-2014
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Restoration of the transitional ligament-bone interface is critical for graft-bone integration. We postulated that an allogenic scaffold mimicking the fibrogenic, chondrogenic, and osteogenic transition gradients could physiologically promote ligament-bone incorporation. The aim of this study was to construct and characterize a composite tendon scaffold with a continuous and heterogeneous transition region mimicking a native ligament insertion site. Genetically modified heterogeneous cell populations were seeded within specific regions of decellularized rabbit Achilles tendons to fabricate a stratified scaffold containing three biofunctional regions supporting fibrogenesis, chondrogenesis, and osteogenesis. The observed morphology, architecture, cytocompatibility, and biomechanics of the scaffolds demonstrated their improved bio-physico-chemical properties. The formation of the transitional regions was augmented via enhanced delivery of two transcription factors, sex determining region Y-box 9 and runt-related transcription factor 2, which also triggered early up-regulated expression of cartilage- and bone-relevant markers, according to quantitative PCR and immunoblot analyses. Gradient tissue-specific matrix formation was also confirmed within the predesignated regions via histological staining and immunofluorescence assays. These results suggest that a transitional interface could be replicated on an engineered tendon through stratified tissue integration. The scaffold offers the advantages of a multitissue transition involving controlled cellular interactions and matrix heterogeneity, which can be applied for the regeneration of the ligament-bone interface.
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Size separation of graphene oxide with preparative free-flow electrophoresis.
J Sep Sci
PUBLISHED: 09-11-2014
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Graphene oxide nanosheets often bear a wide size distribution. However, it is critical to have nanosheets with narrow size distribution for their unique size-dependent physiochemical properties, and nanosheets with a narrow size distribution are the cornerstones for application. Therefore, efficient separation methods of graphene nanosheets have been given considerable attention in many scientific areas recently. Free-flow electrophoresis is extensively used in the separation and purification of biological molecules with continuous flow separation. The charged graphene oxide nanosheets to some extent are very close in size to biological molecules and share similarity in motion behavior in an electric field. Thus, in the present work, we present a new and simple means to separate graphene oxide nanosheets into more mono-dispersed size groups by using the free-flow electrophoresis technique. By optimizing the separation conditions, we were able to obtain graphene oxide sheets with narrow size distribution. The separated samples were characterized by atomic force microscopy, and the size measurements were made by using the software "Image Pro Plus". In addition, a brief discussion is also given into the theoretic background of the separation of graphene oxide according to the size by by the technique of preparative free-flow electrophoresis. This article is protected by copyright. All rights reserved.
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MiR-7b directly targets DC-STAMP causing suppression of NFATc1 and c-Fos signaling during osteoclast fusion and differentiation.
Biochim. Biophys. Acta
PUBLISHED: 08-11-2014
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DC-STAMP is a key regulating molecule of osteoclastogenesis and osteoclast precursor (OCP) fusion. Emerging lines of evidence showed that microRNAs play crucial roles in bone metabolism and osteoclast differentiation, but no microRNA has yet been reported to be directly related to OCPs fusion. Through a microarray, we found that the expression of miR-7b in RAW264.7 cells was significantly decreased after induction with M-CSF and RANKL. The overexpression of miR-7b in RAW264.7 cells attenuated the number of TRAP-positive cells number and the formation of multinucleated cells, whereas the inhibition of miR-7b enhanced osteoclastogenesis. Through a dual luciferase reporter assay, we confirmed that miR-7b directly targets DC-STAMP. Other fusogenic molecules, such as CD47, ATP6v0d2, and OC-STAMP, were detected to be down-regulated in accordance with the inhibition of DC-STAMP. Because DC-STAMP also participates in osteoclast differentiation through the ITAM-ITIM network, multiple osteoclast-specific genes in the ITAM-ITIM network were detected to identify how DC-STAMP is involved in this process. The results showed that molecules associated with the ITAM-ITIM network, such as NFATc1 and OSCAR, which are crucial in osteoclastogenesis, were consistently altered due to DC-STAMP inhibition. These findings suggest that miR-7b inhibits osteoclastogenesis and cell-cell fusion by directly targeting DC-STAMP. In addition, the inhibition of DC-STAMP and its downstream signals changed the expression of other fusogenic genes and key regulating genes, such as Nfatc1, c-fos, Akt, Irf8, Mapk1, and Traf6. In conclusion, our findings indicate that miR-7b may be a potential therapeutic target for the treatment of osteoclast-related bone disorders.
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Polyploid giant cancer cells with budding and the expression of cyclin E, S-phase kinase-associated protein 2, stathmin associated with the grading and metastasis in serous ovarian tumor.
BMC Cancer
PUBLISHED: 08-08-2014
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We previously reported that polyploid giant cancer cells (PGCCs) exhibit cancer stem cell properties and express cell cycle-related proteins. HEY PGCCs induced by cobalt chloride generated daughter cells and the daughter cells had a strong migratory and invasive ability. This study is to compare the expression of cyclin E, S-phase kinase-associated protein 2 (SKP2), and stathmin between PGCCs with budding and control HEY cells, and determine the clinicopathological significance of cell cycle-related protein expression in ovarian tumors.
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[Study on the influence of pregnancy-induced hypertension on neonatal birth weight and its interaction with other factors].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 07-11-2014
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To research the influence of pregnancy-induced hypertension (PIH) on neonatal birth weight and its interaction with other factors.
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Enhanced fluorescence quenching in an acridine orange - alizarin red system through matrine and its analytical application.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 06-16-2014
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This study shows that alizarin red (AR) only slightly quenched fluorescence for acridine orange (AO) in an AR/AO mixed solution at pH=5-6. The reduced fluorescent signal was closely and linearly associated with the level of MT added to the system, which is the basis for a new quantitative MT assay method using the fluorescence quenching reaction in the AO-AR system. The results show that under optimal conditions, this method had a 14.9-43.5 mg L(-1) linear detection range with a 1.38 mg L(-1) detection limit and 1.24% precision. In addition, this method was used to determine the MT levels in the commercially available MT-containing pesticides and suppositories, which showed a 96.6-103% recovery. Therefore, this method has multiple advantages, including simple and fast operation, high accuracy and low cost. Moreover, herein, we investigated the underlying mechanism in-depth using an ultraviolet (UV) spectroscopic technique.
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Maternal glucose level and body mass index measured at gestational diabetes mellitus screening and the risk of macrosomia: results from a perinatal cohort study.
BMJ Open
PUBLISHED: 05-22-2014
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To examine the impact of maternal blood glucose (BG) level and body mass index (BMI) measured at gestational diabetes mellitus (GDM) screening on the risk of macrosomia.
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Asymmetric cell division in polyploid giant cancer cells and low eukaryotic cells.
Biomed Res Int
PUBLISHED: 05-09-2014
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Asymmetric cell division is critical for generating cell diversity in low eukaryotic organisms. We previously have reported that polyploid giant cancer cells (PGCCs) induced by cobalt chloride demonstrate the ability to use an evolutionarily conserved process for renewal and fast reproduction, which is normally confined to simpler organisms. The budding yeast, Saccharomyces cerevisiae, which reproduces by asymmetric cell division, has long been a model for asymmetric cell division studies. PGCCs produce daughter cells asymmetrically in a manner similar to yeast, in that both use budding for cell polarization and cytokinesis. Here, we review the results of recent studies and discuss the similarities in the budding process between yeast and PGCCs.
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Sex disparity and perception of obesity/overweight by parents and grandparents.
Paediatr Child Health
PUBLISHED: 05-06-2014
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To explore the factors associated with the sex disparity showing a greater prevalence of obesity/overweight in boys compared with girls in Chinese school children.
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Clinicopathological significance of cancer stem cells marked by CD133 and KAI1/CD82 expression in laryngeal squamous cell carcinoma.
World J Surg Oncol
PUBLISHED: 04-07-2014
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Presently, CD133 is one of the hottest markers to characterize cancer stem cells and KAI1/CD82 is reported as an important marker for the metastasis and prognosis of many cancers. The purpose of our study is to explore the relationship between cancer stem cells (CSCs) marked by CD133 and KAI1/CD82 expression and the clinicopathological characteristics of patients with laryngeal squamous cell carcinoma (LSCC).
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Malignant gastrointestinal neuroectodermal tumor: A case report and review of the literature.
Oncol Lett
PUBLISHED: 04-06-2014
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Malignant gastrointestinal neuroectodermal tumor (GNET) is a rare soft tissue sarcoma, previously referred to as clear cell sarcoma-like gastrointestinal tumor (CCSLGT) and also commonly reported in the literature as clear cell sarcoma of the gastrointestinal tract (CCS-GI). The current study reports a case of GNET arising in the stomach of a 17-year-old male, who presented with symptoms of fatigue, anemia and low temperature. Examination with positron emission tomography-computed tomography revealed a soft tissue mass in the gastric antrum. Subsequently, radical distal gastric resection was performed, and the mass measured 6.0×4.0×3.5 cm(3). Histopathological analysis revealed that the tumor cells were arranged in nests and focally formed fascicular, pseudopapillary, pseudoalveolar and rosette-like growth patterns. Osteoclast-like giant cells were also observed. Immunohistochemically, the tumor cells were positive for S-100 protein, vimentin and BCL-2, and negative for HMB45, Melan-A, CD117, CD34 and CD99. Additionally, the osteoclast-like giant cells were positive for CD68. Fluorescence in situ hybridization demonstrated EWSR1 gene rearrangement. After 10 months of follow-up, no evidence of recurrence or metastasis was observed. As GNET is currently classified differently and under various names in the literature, the information provided by this case study and review is predicted to be useful towards the accurate diagnosis, treatment and prognosis of this rare tumor type.
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Number of polyploid giant cancer cells and expression of EZH2 are associated with VM formation and tumor grade in human ovarian tumor.
Biomed Res Int
PUBLISHED: 03-24-2014
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To investigate the associations among the number of polyploid giant cancer cells (PGCCs) and vasculogenic mimicry (VM), EZH2 expression, and serous ovarian tumor grade, a total of 80 paraffin-embedded serous ovarian tumor samples including 21 cases of primary carcinoma and their metastatic tumors, 26 cases of primary carcinoma without metastasis, and 12 cases of serous borderline cystadenoma were analyzed. PGCCs and VM were detected in human serous ovarian tumor. The metastatic foci of ovarian carcinoma had the highest number of PGCCs and VM. The number of PGCCs and VM increased with the grade of ovarian carcinomas. PGCCs generated erythrocytes via budding and together they formed VM. Tumor cells and cancer-associated fibroblasts were positive for EZH2 immunohistochemical staining. The tumor cells and cancer associated fibroblasts in the metastatic foci had the highest staining index of EZH2 staining. Both tumor cells and cancer-associated fibroblasts express EZH2 which then contributes to the malignant grade of serous ovarian tumor.
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Mid-term results after treatment of intertrochanteric femoral fractures with percutaneous compression plate (PCCP).
Injury
PUBLISHED: 03-10-2014
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With the ageing of the population, intertrochanteric femoral fracture is associated with increased morbidity. There is continuing controversy over the best treatment for the injury, and the choice of internal fixation method has been a focus of dispute. The purpose of this study was to evaluate the results of these fractures being treated with the percutaneous compression plate (PCCP) technique.
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Effect of microRNA-145 on IL-1?-induced cartilage degradation in human chondrocytes.
FEBS Lett.
PUBLISHED: 03-03-2014
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MicroRNA-145 has been shown to regulate chondrocyte homeostasis. It seems that miR-145 is implicated in cartilage dysfunction in Osteoarthritis (OA). However, the functional role of miR-145 in interleukin-1 beta (IL-1?)-induced extracellular matrix (ECM) degradation of OA cartilage has never been clarified. Here, we show that miR-145 expression increased in OA chondrocytes and in response to IL-1? stimulation. We confirm that mothers against decapentaplegic homolog 3 (Smad3), a key factor in maintaining chondrocyte homeostasis, is directly regulated by miR-145. Modulation of miR-145 affects the expression of Smad3 causing a change of its downstream target gene expression as well as IL-1?-induced ECM degradation in OA chondrocytes. This indicates that miR-145 contributes to impaired ECM in OA cartilage probably in part via targeting Smad3.
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A composite demineralized bone matrix--self assembling peptide scaffold for enhancing cell and growth factor activity in bone marrow.
Biomaterials
PUBLISHED: 03-03-2014
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The need for suitable bone grafts is high; however, there are limitations to all current graft sources, such as limited availability, the invasive harvest procedure, insufficient osteoinductive properties, poor biocompatibility, ethical problems, and degradation properties. The lack of osteoinductive properties is a common problem. As an allogenic bone graft, demineralized bone matrix (DBM) can overcome issues such as limited sources and comorbidities caused by invasive harvest; however, DBM is not sufficiently osteoinductive. Bone marrow has been known to magnify osteoinductive components for bone reconstruction because it contains osteogenic cells and factors. Mesenchymal stem cells (MSCs) derived from bone marrow are the gold standard for cell seeding in tissue-engineered biomaterials for bone repair, and these cells have demonstrated beneficial effects. However, the associated high cost and the complicated procedures limit the use of tissue-engineered bone constructs. To easily enrich more osteogenic cells and factors to DBM by selective cell retention technology, DBM is modified by a nanoscale self-assembling peptide (SAP) to form a composite DBM/SAP scaffold. By decreasing the pore size and increasing the charge interaction, DBM/SAP scaffolds possess a much higher enriching yield for osteogenic cells and factors compared with DBM alone scaffolds. At the same time, SAP can build a cellular microenvironment for cell adhesion, proliferation, and differentiation that promotes bone reconstruction. As a result, a suitable bone graft fabricated by DBM/SAP scaffolds and bone marrow represents a new strategy and product for bone transplantation in the clinic.
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High level expression, efficient purification, and bioactivity of recombinant human metallothionein 3 (rhMT3) from methylotrophic yeast Pichia pastoris.
Protein Expr. Purif.
PUBLISHED: 02-28-2014
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Metallothionein 3 (MT3) is an important biochemical mediator regulating many physiological and pathophysiological processes including neuron cell protection, privation of reactive oxygen species-induced DNA damage, and protection against light induced retinal damage. In this study, a human gene encoding for MT3 with c-terminal extension of His6-tag was inserted into vector pPICZaA, and overexpressed in Pichia pastoris strain X-33. The rhMT3 was purified by one step Ni(+)-NTA affinity chromatography yielding 270mg/L of over 90% purity. Functional analysis of the purified rhMT3 using inductively coupled plasma mass spectrometry demonstrated that it has biological function, binding with metal ions Cd(2+), Cu(2+) and Zn(2+). In summary, the experimental procedure we have developed facilitates production of large amounts of an active rhMT3 for further research and drug development.
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Designing a wearable navigation system for image-guided cancer resection surgery.
Ann Biomed Eng
PUBLISHED: 02-27-2014
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A wearable surgical navigation system is developed for intraoperative imaging of surgical margin in cancer resection surgery. The system consists of an excitation light source, a monochromatic CCD camera, a host computer, and a wearable headset unit in either of the following two modes: head-mounted display (HMD) and Google glass. In the HMD mode, a CMOS camera is installed on a personal cinema system to capture the surgical scene in real-time and transmit the image to the host computer through a USB port. In the Google glass mode, a wireless connection is established between the glass and the host computer for image acquisition and data transport tasks. A software program is written in Python to call OpenCV functions for image calibration, co-registration, fusion, and display with augmented reality. The imaging performance of the surgical navigation system is characterized in a tumor simulating phantom. Image-guided surgical resection is demonstrated in an ex vivo tissue model. Surgical margins identified by the wearable navigation system are co-incident with those acquired by a standard small animal imaging system, indicating the technical feasibility for intraoperative surgical margin detection. The proposed surgical navigation system combines the sensitivity and specificity of a fluorescence imaging system and the mobility of a wearable goggle. It can be potentially used by a surgeon to identify the residual tumor foci and reduce the risk of recurrent diseases without interfering with the regular resection procedure.
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MicroRNA-125b regulates osteogenic differentiation of mesenchymal stem cells by targeting Cbf? in vitro.
Biochimie
PUBLISHED: 02-10-2014
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Differentiation of mesenchymal stem cells (MSCs) into a specific lineage is firmly and precisely regulated via crucial transcription factors and signaling cascades, but the accurate mechanisms still need to be revealed. MicroRNAs (miRNA) negativity regulates the target mRNA protein synthesis to regulate various kinds of biological processes. In the present study we investigate miRNAs mediated regulatory mechanisms of osteoblastic differentiation in C3H10T1/2 cells and we identified that the level of miR-125b expression was obviously decreased compared with undifferentiated ones during differentiation process. Subsequently, dual-luciferase reporter gene assay data demonstrated that miR-125b targets a putative binding site in the 3'-UTR of Cbf? gene, a key transcription factor for osteogenesis. We observed over and interferential expression of miR-125b down-regulate for Cbf? protein in C3H10T1/2 cells and the over-expression decrease the mRNA levels of three osteoblastic marker genes, alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OPN) by BMP-2-induced, whereas, anti-miR-125b increased the expression of these marker genes and hence up-regulated mRNA levels of Cbf?. It is concluded from the result that miR-125b is a key regulatory factor of osteoblastic differentiation by directly targeting Cbf? and indirectly acting on Runx2 at an early stage osteoblastic differentiation.
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Treatment of AO/OTA 31-A3 intertrochanteric femoral fractures with a percutaneous compression plate.
Clinics (Sao Paulo)
PUBLISHED: 01-30-2014
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AO/OTA 31-A3 intertrochanteric femoral fractures have completely different fracture line directions and biomechanical characteristics compared with other types of intertrochanteric fractures. The choice of the fixation method has been a focus of dispute among orthopedic trauma surgeons. The purpose of this study was to review the outcomes of these fractures treated with a percutaneous compression plate at our institute.
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Establishment and application of a loop-mediated isothermal amplification (LAMP) system for detection of cry1Ac transgenic sugarcane.
Sci Rep
PUBLISHED: 01-20-2014
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To meet the demand for detection of foreign genes in genetically modified (GM) sugarcane necessary for regulation of gene technology, an efficient method with high specificity and rapidity was developed for the cry1Ac gene, based on loop-mediated isothermal amplification (LAMP). A set of four primers was designed using the sequence of cry1Ac along with optimized reaction conditions: 5.25?mM of Mg(2+), 4:1 ratio of inner primer to outer primer, 2.0?U of Bst DNA polymerase in a reaction volume of 25.0??L. Three post-LAMP detection methods (precipitation, calcein (0.60?mM) with Mn(2+) (0.05?mM) complex and SYBR Green I visualization), were shown to be effective. The sensitivity of the LAMP method was tenfold higher than that of conventional PCR when using templates of the recombinant cry1Ac plasmid or genomic DNA from cry1Ac transgenic sugarcane plants. More importantly, this system allowed detection of the foreign gene on-site when screening GM sugarcane without complex and expensive instruments, using the naked eye. This method can not only provide technological support for detection of cry1Ac, but can also further facilitate the use of this detection technique for other transgenes in GM sugarcane.
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Expression of recombinant human IL-4 in Pichia pastoris and relationship between its glycosylation and biological activity.
Protein Expr. Purif.
PUBLISHED: 01-10-2014
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Secretory human interleukin 4 (hIL4) is an N-glycosylated pleiotropic cytokine. It is unknown if these N-linked glycans are required and essential for hIL4 protein stability, expression, secretion, and activity in vivo, and hIL4 expressed from Pichia pastoris yeast has not been tested to date. In this study, we successfully expressed human hIL4 in P. pastoris, the methylotrophic yeast, with a yield of 15.0mg/L. Using the site-directed mutagenesis technique, we made two mutant hIL4 cDNA clones (N38A and N105L) and subsequently expressed them in P. pastoris to analyze the relevant function of each N-glycosylation site on hIL4. Our results demonstrate that the glycosylation only occurs at position Asn38, but not Asn105. The glycosylated form of hIL4 unexpectedly has lower biological activity and lower stability when compared to its non-glycosylated form. The implications of this are discussed.
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DC-STAMP, the key fusion-mediating molecule in osteoclastogenesis.
J. Cell. Physiol.
PUBLISHED: 01-08-2014
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As a member of the mononuclear phagocyte system, osteoclasts (OC) absorb the bone matrix and participate in bone modeling by keeping a balance with osteoblasts (OB) and stromal cells. Mature OC derive from the fusion of mononuclear osteoclasts (mOC) and the fusion is considered as the indispensable process for the osteoclastogenesis and absorbing activity of OC. DC-STAMP (dendritic cell-specific transmembrane protein) has been validated playing a key role in the fusion of mOC. DC-STAMP is mainly expressed in OC, macrophages and dendritic cells (DC). While DC-STAMP was discovered in DC, more attentions have been paid to DC-STAMP in OC in this decade. This review will mainly focus on the function of DC-STAMP in OC. Studies on DC-STAMP in DC may also provide new sight for the study of DC-STAMP in OC. Since the function of DC-STAMP is still poorly understood and few studies have been implemented for illustration, many issues are still unknown and need to be revealed. We will also discuss these questions in this review.
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The effect of mechanical stimulation on the maturation of TDSCs-poly(L-lactide-co-e-caprolactone)/collagen scaffold constructs for tendon tissue engineering.
Biomaterials
PUBLISHED: 01-08-2014
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Mechanical stimulation plays an important role in the development and remodeling of tendons. Tendon-derived stem cells (TDSCs) are an attractive cell source for tendon injury and tendon tissue engineering. However, these cells have not yet been fully explored for tendon tissue engineering application, and there is also lack of understanding to the effect of mechanical stimulation on the maturation of TDSCs-scaffold construct for tendon tissue engineering. In this study, we assessed the efficacy of TDSCs in a poly(L-lactide-co-?-caprolactone)/collagen (P(LLA-CL)/Col) scaffold under mechanical stimulation for tendon tissue engineering both in vitro and in vivo, and evaluated the utility of the transplanted TDSCs-scaffold construct to promote rabbit patellar tendon defect regeneration. TDSCs displayed good proliferation and positive expressed tendon-related extracellular matrix (ECM) genes and proteins under mechanical stimulation in vitro. After implanting into the nude mice, the fluorescence imaging indicated that TDSCs had long-term survival, and the macroscopic evaluation, histology and immunohistochemistry examinations showed high-quality neo-tendon formation under mechanical stimulation in vivo. Furthermore, the histology, immunohistochemistry, collagen content assay and biomechanical testing data indicated that dynamically cultured TDSCs-scaffold construct could significantly contributed to tendon regeneration in a rabbit patellar tendon window defect model. TDSCs have significant potential to be used as seeded cells in the development of tissue-engineered tendons, which can be successfully fabricated through seeding of TDSCs in a P(LLA-CL)/Col scaffold followed by mechanical stimulation.
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Irisin Promotes Human Umbilical Vein Endothelial Cell Proliferation through the ERK Signaling Pathway and Partly Suppresses High Glucose-Induced Apoptosis.
PLoS ONE
PUBLISHED: 01-01-2014
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Irisin is a newly discovered myokine that links exercise with metabolic homeostasis. It is involved in modest weight loss and improves glucose intolerance. However, the direct effects and mechanisms of irisin on vascular endothelial cells (ECs) are not fully understood. In the current study, we demonstrated that irisin promoted Human Umbilical Vein Endothelial Cell (HUVEC) proliferation. It was further demonstrated that this pro-proliferation effect was mediated by irisin-induced activation of extracellular signal-related kinase (ERK) signaling pathways. Inhibition of ERK signaling with U0126 decreased the pro-proliferation effect of irisin on HUVECs. It was also demonstrated that irisin reduced high glucose-induced apoptosis by up-regulating Bcl-2 expression and down-regulating Bax, Caspase-9 and Caspase-3 expression. In summary, these results suggested that irisin plays a novel role in sustaining endothelial homeostasis by promoting HUVEC proliferation via the ERK signaling pathway and protects the cell from high glucose-induced apoptosis by regulating Bcl-2,Bax and Caspase expression.
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Progress in aptamer-mediated drug delivery vehicles for cancer targeting and its implications in addressing chemotherapeutic challenges.
Theranostics
PUBLISHED: 01-01-2014
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Aptamers are novel oligonucleotides with flexible three-dimensional configurations that recognize and bind to their cognate targets, including tumor surface receptors, in a high-affinity and highly specific manner. Because of their unique intrinsic properties, a variety of aptamer-mediated nanovehicles have been developed to directionally transport anti-cancer drugs to tumor sites to minimize systemic cytotoxicity and to enhance permeation by these tumoricidal agents. Despite advances in the selection and synthesis of aptamers and in the conjugation and self-assembly of nanotechnologies, current chemotherapy and drug delivery systems face great challenges. These challenges are due to the limitations of aptamers and vehicles and because of complicated tumor mechanisms, including heterogeneity, anti-cancer drug resistance, and hypoxia-induced aberrances. In this review, we will summarize current approaches utilizing tumor surface hallmarks and aptamers and their roles and mechanisms in therapeutic nanovehicles targeting tumors. Delivery forms include nanoparticles, nanotubes, nanogels, aptamer-drug conjugates, and novel molecular trains. Moreover, the obstacles posed by the aforementioned issues will be highlighted, and possible solutions will be acknowledged. Furthermore, future perspectives will be presented, including cutting-edge integration with RNA interference nanotechnology and personalized chemotherapy, which will facilitate innovative approaches to aptamer-based therapeutics.
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Epithelial-mesenchymal transition regulated by EphA2 contributes to vasculogenic mimicry formation of head and neck squamous cell carcinoma.
Biomed Res Int
PUBLISHED: 01-01-2014
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Vasculogenic mimicry (VM) was related to invasion and metastasis of head and neck squamous cell carcinoma (HNSCC) patients. This study was designed to investigate the role of EphA2 in VM formation of HNSCC.
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C-Abl inhibitor imatinib enhances insulin production by ? cells: c-Abl negatively regulates insulin production via interfering with the expression of NKx2.2 and GLUT-2.
PLoS ONE
PUBLISHED: 01-01-2014
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Chronic myelogenous leukemia patients treated with tyrosine kinase inhibitor, Imatinib, were shown to have increased serum levels of C-peptide. Imatinib specifically inhibits the tyrosine kinase, c-Abl. However, the mechanism of how Imatinib treatment can lead to increased insulin level is unclear. Specifically, there is little investigation into whether Imatinib directly affects ? cells to promote insulin production. In this study, we showed that Imatinib significantly induced insulin expression in both glucose-stimulated and resting ? cells. In line with this finding, c-Abl knockdown by siRNA and overexpression of c-Abl markedly enhanced and inhibited insulin expression in ? cells, respectively. Unexpectedly, high concentrations of glucose significantly induced c-Abl expression, suggesting c-Abl may play a role in balancing insulin production during glucose stimulation. Further studies demonstrated that c-Abl inhibition did not affect the major insulin gene transcription factor, pancreatic and duodenal homeobox-1 (PDX-1) expression. Of interest, inhibition of c-Abl enhanced NKx2.2 and overexpression of c-Abl in ? cells markedly down-regulated NKx2.2, which is a positive regulator for insulin gene expression. Additionally, we found that c-Abl inhibition significantly enhanced the expression of glucose transporter GLUT2 on ? cells. Our study demonstrates a previously unrecognized mechanism that controls insulin expression through c-Abl-regulated NKx2.2 and GLUT2. Therapeutic targeting ? cell c-Abl could be employed in the treatment of diabetes or ? cell tumor, insulinoma.
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TCR??(+)CD4(-)CD8(-) T cells suppress the CD8(+) T-cell response to hepatitis B virus peptides, and are associated with viral control in chronic hepatitis B.
PLoS ONE
PUBLISHED: 01-01-2014
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The immune mechanisms underlying failure to achieve hepatitis B e antigen (HBeAg) seroconversion associated with viral control in chronic hepatitis B (CHB) remain unclear. Here we investigated the role of CD4(-)CD8(-) T (double-negative T; DNT) cells including TCR??(+) DNT (?? DNT) and TCR??(+) DNT (?? DNT) cells. Frequencies of circulating DNT cell subsets were measured by flow cytometry in a retrospective cohort of 51 telbivudine-treated HBeAg-positive CHB patients, 25 immune tolerant carriers (IT), 33 inactive carriers (IC), and 37 healthy controls (HC). We found that ?? DNT cell frequencies did not significantly change during treatment, being lower at baseline (P?=?0.019) in patients with HBeAg seroconversion after 52 weeks of antiviral therapy (n?=?20) than in those without (n?=?31), and higher in the total CHB and IT than IC and HC groups (P<0.001). ?? DNT cell frequencies were similar for all groups. In vitro, ?? DNT cells suppressed HBV core peptide-stimulated interferon-? and tumor necrosis factor-? production in TCR??(+)CD8(+) T cells, which may require cell-cell contact, and could be partially reversed by anti-NKG2A. These findings suggest that ?? DNT cells limit CD8(+) T cell response to HBV, and may impede HBeAg seroconversion in CHB.
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[Pre-conception factors for intrauterine growth retardation].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 12-10-2013
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Objective: To analyze the pre-conception factors for intrauterine growth retardation. Methods: A nested case-control study was conducted in a cohort of 1368 women from 14 Child and Maternity Health Care Departments by cluster sampling method in Liuyang City, Hunan Province. Following-up until delivery, we collected their medical records and maternal health care manual materials. All neonates with intrauterine growth retardation were detected in the follow-up (the case group) and another 186 neonates without intrauterine growth retardation, matched with gender and mothers age, were randomly selected from the cohort as controls. ?2 test and multiple conditional logistic regression were used to investigate the determinants of intrauterine growth retardation. Results: Intrauterine growth retardation was associated with BMI (OR=64.775), waist circumference (OR=0.166), abortion (OR=6.997), level of total cholesterol (OR=0.045), folic acid (OR=0.077), and cortisol (OR=9.164). Conclusion: Intrauterine growth retardation is associated with BMI, waist circumference, abortion,level of total cholesterol, folic acid, and cortisol. Effective measures to reduce intrauterine growth retardation in children include strengthening the detection of pre-pregnancy blood biochemical indicators to guide health care during pregnancy, and increasing nutrition during pregnancy according to pre-pregnancy BMI and waist circumference.
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[Micro RNA-451 promoting osteogenesis of mesenchymal stem cells by targeting regulatory calcium binding protein 39].
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
PUBLISHED: 11-28-2013
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To investigate the role of micro RNA-451 (miRNA-451) in promoting the osteogenesis of mesenchymal stem cells (MSCs) by targeting regulatory calcium binding protein 39 (CAB39).
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[Expressions of CD133 and CD44 in gastric adenocarcinoma and their relationship with E-cadherin expression].
Nan Fang Yi Ke Da Xue Xue Bao
PUBLISHED: 11-26-2013
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To explore the expression of CD133 and CD44 in the primary gastric adenocarcinoma (GAC) and their relationship with the expression of E-cadherin.
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Irisin Stimulates Browning of White Adipocytes through Mitogen-Activated Protein Kinase p38 MAP Kinase and ERK MAP Kinase Signaling.
Diabetes
PUBLISHED: 10-22-2013
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The number and activity of brown adipocytes are linked to the ability of mammals to resist body fat accumulation. In some conditions, certain white adipose tissue (WAT) depots are readily convertible to a brown-like statewhich is associated with weight loss. Irisin, a newly identified hormone, is secreted by skeletal muscles into circulation and promotes WAT "browning" with unknown mechanisms. In the current study, we demonstrated in mice that recombinant irisin decreased the bodyweight and improved glucose homeostasis. We further showed that irisin upregulated UCP-1 (a regulator of thermogenic capability of brown fat) expression. This effect was possibly mediated by irisin induced phosphorylation of p38 MAPK and ERK signaling pathway. Inhibition of the p38 MAPK by SB203580 and ERK by U0126 abolished the upregulatory effect of irisin on UCP-1. In addition, irisin also promoted the expression of betatrophin, another newly identified hormone that promotes pancreatic beta cell proliferation and improves glucose tolerance. In summary, our data suggest that irisin can potentially prevent obesity and associated type 2 diabetes by stimulating expression of WAT browning-specific genes via p38 MAPK and ERK pathway.
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[Changes and the implications of CD4(+);CD25(+);CD127(low); regulatory T cells in drug addicts during natural drug withdrawal].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
PUBLISHED: 10-10-2013
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To study the changes of CD4(+);CD25(+);CD127(low); regulatory T cells (Tregs) and transforming growth factor beta 1 (TGF-?1) mRNA in peripheral blood mononuclear cells (PBMCs) in drug addicts during natural drug withdrawal, and explore the effects of addictive drugs on their Tregs.
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[Expressions of CD133 and CD82/KAI1 in bladder urothelial carcinoma and their correlation with vasculogenic mimicry].
Nan Fang Yi Ke Da Xue Xue Bao
PUBLISHED: 09-27-2013
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To explore the expressions of CD133 and CD82/KAI1 in bladder urothelial carcinoma, their association with the clinicopathological factors and their roles in vasculogenic mimicry (VM) in the tumor.
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rFN/Cad-11-modified collagen type II biomimetic interface promotes the adhesion and chondrogenic differentiation of mesenchymal stem cells.
Tissue Eng Part A
PUBLISHED: 08-06-2013
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Properties of the cell-material interface are determining factors in the successful function of cells for cartilage tissue engineering. Currently, cell adhesion is commonly promoted through the use of polypeptides; however, due to their lack of complementary or modulatory domains, polypeptides must be modified to improve their ability to promote adhesion. In this study, we utilized the principle of matrix-based biomimetic modification and a recombinant protein, which spans fragments 7-10 of fibronectin module III (heterophilic motif) and extracellular domains 1-2 of cadherin-11 (rFN/Cad-11) (homophilic motif), to modify the interface of collagen type II (Col II) sponges. We showed that the designed material was able to stimulate cell proliferation and promote better chondrogenic differentiation of rabbit mesenchymal stem cells (MSCs) in vitro than both the FN modified surfaces and the negative control. Further, the Col II/rFN/Cad-11-MSCs composite stimulated cartilage formation in vivo; the chondrogenic effect of Col II alone was much less significant. These results suggested that the rFN/Cad-11-modified collagen type II biomimetic interface has dual biological functions of promoting adhesion and stimulating chondrogenic differentiation. This substance, thus, may serve as an ideal scaffold material for cartilage tissue engineering, enhancing repair of injured cartilage in vivo.
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The expression and regulation of microRNA-125b in cancers.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 06-25-2013
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Cancer is one of the leading causes of death worldwide. There is a definite need for novel approaches to improve the diagnostics and treatment of cancers. The pathological processes leading to carcinoma are associated with the altered expression of a specific gene relevant to malignancy. MicroRNA-125b (miR-125b) is a small non-coding, multipurpose miRNA that plays a key role in several different biological processes. Increasing amounts of evidence indicates that miR-125b may serve as a diagnostic biomarker of certain kinds of cancers. miR-125b may be suitable to be used as a therapeutical target in several human diseases including neoplastic disease. Here, we review the latest progress in the identification and validation of the relationship between cancer-related miR-125b and cancers, and discuss the functions of miR-125b that regulates many processes of diseases, including cell proliferation, differentiation, and apoptosis.
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Investigation on LD end-pumped passively Q-switched c-cut Nd: YVO4 self-Raman laser.
Opt Express
PUBLISHED: 06-06-2013
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The compact LD end-pumped passively Q-switched c-cut Nd:YVO4/Cr4+:YAG self-Raman laser is realized, and its output performance is investigated in detail. The maximum average output power at 1178nm is 800mW with the pulse repetition frequency of 44kHz and pulse width of 2.6ns, and the first Stokes conversion efficiency is 10.1%. The outputs of fundamental and first Stokes laser are found to be linearly polarized along the diagonals of the rectangular cross section of the c-cut Nd:YVO4 crystal, and the polarization mode competition is observed in the outputs of fundamental and first Stokes laser.
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Theoretical and experimental study on passively Q-switched intracavity frequency-doubled solid-state yellow Raman lasers.
Appl Opt
PUBLISHED: 06-06-2013
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Normalized space-dependent rate equations of passively Q-switched intracavity frequency-doubled Raman lasers are deduced for the first time. The normalized rate equations are solved numerically to investigate the influences of the normalized variables on the yellow laser performance. The LD end-pumped passively Q-switched Nd:YAG/SrWO(4)/KTP/Cr:YAG yellow Raman laser is realized, and the maximum yellow laser output power is 350 mW with the incident pump power of 5.9 W with Cr:YAG of 85% initial transmission. The theoretical analysis and optimization are taken out for the experiment, and the theoretical results are in accordance with the experimental ones.
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Bone metastasis from breast cancer involves elevated IL-11 expression and the gp130/STAT3 pathway.
Med. Oncol.
PUBLISHED: 05-25-2013
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To evaluate the relationship between IL-11 and bone metastasis in patients with breast cancer and explore the potential molecular mechanism, total serum samples were collected from 180 breast cancer patients and 20 women without breast cancer. The serum expression level of interleukin (IL)-11, connective tissue growth factor (CTGF), transforming growth factor-?, and Tracp5b was determined by enzyme-linked immunosorbent assay, and mRNA expression of IL-11 in fresh breast cancer tissue was determined by RT-PCR. Immunohistochemical staining was used to detect the expression of IL-11 and CTGF in breast cancer tissue, and Western blot was used to detect the expression of p-38, p-C-JUN, p-STAT3, and p-gp130 in fresh breast cancer tissue. DNA-binding activity of AP-1 was examined by electrophoretic mobility shift assay. Differences were statistically analyzed between the group with breast cancer metastatic to bone (MBC-B) and the group with only primary breast cancer (PBC). Serum level and mRNA expression of IL-11 in the MBC-B group were significantly higher than those in the PBC group. IL-11 immunohistochemical staining showed that the percentage of positively stained cells in the MBC-B group (57.5 %) was significantly higher than that in the PBC group (14.29 %). Western blot analysis showed higher expression of p-p38, p-C-JUN, p-STAT3, and p-gp130 in the MBC-B group than in the PBC group. DNA-binding activity of AP-1 was significantly higher in the MBC-B group than in the PBC group. These data suggest that IL-11 is associated with bone metastasis and may be of value for predicting bone metastasis from breast cancer.
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[A population based study on incidence and determinants of preterm birth in Liuyang Hunan].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 05-07-2013
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To describe the incidence and to discuss the risk factors of premature birth in rural areas of Liuyang.
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Circulating chemokine (C-X-C Motif) receptor 5(+) CD4(+) T cells benefit hepatitis B e antigen seroconversion through IL-21 in patients with chronic hepatitis B virus infection.
Hepatology
PUBLISHED: 04-17-2013
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Given the clinical significance of hepatitis B e antigen (HBeAg) seroconversion in chronic hepatitis B virus (HBV) infection, it is critical to elucidate the mechanisms regulating this process. In the present study, we found that the frequency of circulating chemokine (C-X-C motif) receptor 5 (CXCR5)(+) CD4(+) T cells was higher in patients who had achieved HBeAg seroconversion in both cross-sectional (P?
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Preparation of lactose-free pasteurized milk with a recombinant thermostable ?-glucosidase from Pyrococcus furiosus.
BMC Biotechnol.
PUBLISHED: 04-05-2013
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Lactose intolerance is a common health concern causing gastrointestinal symptoms and avoidance of dairy products by afflicted individuals. Since milk is a primary source of calcium and vitamin D, lactose intolerant individuals often obtain insufficient amounts of these nutrients which may lead to adverse health outcomes. Production of lactose-free milk can provide a solution to this problem, although it requires use of lactase from microbial sources and increases potential for contamination. Use of thermostable lactase enzymes can overcome this issue by functioning under pasteurization conditions.
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ScMT2-1-3, a metallothionein gene of sugarcane, plays an important role in the regulation of heavy metal tolerance/accumulation.
Biomed Res Int
PUBLISHED: 02-10-2013
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Plant metallothioneins (MTs), which are cysteine-rich, low-molecular-weight, and metal-binding proteins, play important roles in detoxification, metal ion homeostasis, and metal transport adjustment. In this study, a novel metallothionein gene, designated as ScMT2-1-3 (GenBank Accession number JQ627644), was identified from sugarcane. ScMT2-1-3 was 700 bp long, including a 240 bp open reading frame (ORF) encoding 79 amino acid residues. A His-tagged ScMT2-1-3 protein was successfully expressed in Escherichia coli system which had increased the host cells tolerance to Cd(2+), Cu(2+), PEG, and NaCl. The expression of ScMT2-1-3 was upregulated under Cu(2+) stress but downregulated under Cd(2+) stress. Real-time qPCR demonstrated that the expression levels of ScMT2-1-3 in bud and root were over 14 times higher than those in stem and leaf, respectively. Thus, both the E. coli assay and sugarcane plantlets assay suggested that ScMT2-1-3 is significantly involved in the copper detoxification and storage in the cell, but its functional mechanism in cadmium detoxification and storage in sugarcane cells needs more testification though its expressed protein could obviously increase the host E. coli cells tolerance to Cd(2+). ScMT2-1-3 constitutes thus a new interesting candidate for elucidating the molecular mechanisms of MTs-implied plant heavy metal tolerance/accumulation and for developing sugarcane phytoremediator varieties.
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Superparamagnetic iron oxide is suitable to label tendon stem cells and track them in vivo with MR imaging.
Ann Biomed Eng
PUBLISHED: 01-26-2013
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Tendon stem cells (TSCs) may be used to effectively repair or regenerate injured tendons. However, the fates of TSCs once implanted in vivo remain unclear. This study was aimed to determine the feasibility of labeling TSCs with super-paramagnetic iron oxide (SPIO) nano-particles to track TSCs in vivo using MRI. Rabbit TSCs were labeled by incubation with 50 ?g/mL SPIO. Labeling efficiency, cell viability, and proliferation were then measured, and the stemness of TSCs was tested by quantitative real time RT-PCR (qRT-PCR) and immunocytochemistry. We found that the labeling efficiency of TSCs reached as high as 98%, and that labeling at 50 ?g/mL SPIO concentrations did not alter cell viability and cell proliferation compared to non-labeled control cells. Moreover, the expression levels of stem cell markers (Nucleostemin, Nanog, and Oct-4) did not change in SPIO-labeled TSCs compared to non-labeled cells. Both labeled and non-labeled cells also exhibited similar differentiation potential. Finally, labeled TSCs could be detected by MRI both in vitro and in vivo. Taken together, the findings of this study show that labeling TSCs with SPIO particles is a feasible approach to track TSCs in vivo by MRI, which offers a non-invasive method to monitor repair of injured tendons.
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High level expression, efficient purification and bioactivity assay of recombinant human platelet-derived growth factor AA dimer (PDGF-AA) from methylotrophic yeast Pichia pastoris.
Protein Expr. Purif.
PUBLISHED: 01-22-2013
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Platelet-derived growth factors (PDGFs) are important biochemical mediators regulating many physiological and pathophysiological processes, including promotion of the chemotactic recruitment and proliferation of cells involved in wound repair. Previously, homodimers of rhPDGF-AA protein were purified from Escherichia coli. However, eukaryotic proteins often contain posttranslational modifications, such as glycosylation, that are required for biological functions. In this study, an efficient method was established to purify a glycosylated rhPDGF-AA dimer from P. pastoris culture media by one step CM Sepharose ion exchange chromatography yielding about 20mg/L of over 95% highly purified rhPDGF-AA. Mass spectrometry analysis of the purified rhPDGF-AA displayed a molecular weight (MW) of 27,825.513Da, composed of a subunit with MW of 15,042.945Da and a subunit with MW of 12,904.374Da. The size difference is accounted for by differential glycosylation of the monomers. Biological activity of the rhPDGF-AA was confirmed by its ability to induce NIH/3T3 cells proliferation. The experimental procedure we have developed facilitates production of an active glycosylated rhPDGF-AA in large amounts for further research and drug development.
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Tumor stroma and differentiated cancer cells can be originated directly from polyploid giant cancer cells induced by paclitaxel.
Int. J. Cancer
PUBLISHED: 01-17-2013
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Paclitaxel is widely used to treat cancer patients through the blocking of mitosis and result in formation of polyploidy giant cancer cells (PGCCs), which are generally believed to be nondividing cells or in mitotic catastrophe. Here, we showed that PGCCs following the treatment of paclitaxel of MCF-7 breast cancer cell line have capability to generate regular-sized progeny cells through budding. The PGCCs not only grew into well-differentiated cancer cells that formed cancer organotypic structures in vitro but also trans-differentiated into multiple tumor stromal cells including myoepithelial, endothelial and erythroid cells. PGCCs formed glandular and vessel-like cancer organotypic structures that expressed normal stem cell markers. These progeny cells generated from PGCCs showed decreased ability of proliferation, invasion and tumor growth and became more resistant to paclitaxel than parental MCF-7 cells. These results demonstrated that paclitaxel-induced PGCCs have properties of cancer stem cells that can generate both epithelial cancer cells and multilineage of stromal cells. PGCCs are not only the morphogenic determinant to tumor histogenesis and but also contribute to paclitaxel resistance.
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Generation of erythroid cells from fibroblasts and cancer cells in vitro and in vivo.
Cancer Lett.
PUBLISHED: 01-15-2013
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Bone marrow is generally considered the main source of erythroid cells. Here we report that a single hypoxia-mimic chemical, CoCl2, can increase the size of fibroblasts and cancer cells and lead to formation of polyploidy giant cells (PGCs) or polyploidy giant cancer cells (PGCCs), activation of stem cell marker expression, increased growth of normal and cancer spheroid, and lead to differentiation of the fibroblasts and epithelial cells toward erythroid lineage expressing hemoglobins both in vitro and in vivo. Immunohistochemical examination demonstrated that these cells are predominantly made of embryonic hemoglobins, with various levels of fetal and adult hemoglobins. Ectopic expression of c-Myc induced the generation of nucleated erythoid cells expressing variable levels of embryonic and fetal hemoglobins. Generation of these erythroid cells can be also observed via histological examination of other cancer cell lines and human tumor samples. These data suggest that normal and solid cancer cells can directly generate erythroid cells to obtain oxygen in response to hypoxia and may explain the ineffectiveness of conventional anti-angiogenic therapies for cancer, which are directed at endothelium-dependent vessels, and offer new targets for intervention.
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iTRAQ-Based Proteomic Analysis of Polyploid Giant Cancer Cells and Budding Progeny Cells Reveals Several Distinct Pathways for Ovarian Cancer Development.
PLoS ONE
PUBLISHED: 01-01-2013
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Polyploid giant cancer cells (PGCCs) are a morphologically distinct subgroup of human tumor cells with increased nuclear size or multiple nuclei, but they are generally considered unimportant because they are presumed to be nondividing and thus nonviable. We have recently shown that these large cancer cells are not only viable but also can divide asymmetrically and yield progeny cancer cells with cancer stem-like properties via budding division. To further understand the molecular events involved in the regulation of PGCCs and the generation of their progeny cancer cells, we comparatively analyzed the proteomic profiles of PGCCs, PGCCs with budding daughter cells, and regular control cancer cells from the HEY and SKOv3 human ovarian cancer cell lines with and without CoCl2. We used a high-throughput iTRAQ-based proteomic methodology coupled with liquid chromatography-electrospray ionization tandem mass spectroscopy to determine the differentiated regulated proteins. We performed Western blotting and immunohistochemical analyses to validate the differences in the expression patterns of a variety of proteins between PGCCs or budding PGCCs and regular cancer cells identified by iTRAQ approach and also a selected group of proteins from the literature. The differentially regulated proteins included proteins involved in response to hypoxia, stem cell generation, chromatin remodeling, cell-cycle regulation, and invasion and metastasis. In particular, we found that HIF-1alpha and its known target STC1 are upregulated in PGCCs. In addition, we found that a panel of stem cell-regulating factors and epithelial-to-mesenchymal transition regulatory transcription factors were upregulated in budding PGCCs, whereas expression of the histone 1 family of nucleosomal linker proteins was consistently lower in PGCCs than in control cells. Thus, proteomic expression patterns provide valuable insight into the underlying mechanisms of PGCC formation and the relationship between PGCCs and cancer stem cells in patients with ovarian cancers.
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Enhanced production of recombinant secretory proteins in Pichia pastoris by optimizing Kex2 P1 site.
PLoS ONE
PUBLISHED: 01-01-2013
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Pichiapastoris is one of the most widely used expression systems for the production of recombinant secretory proteins. Its universal application is, however, somewhat hampered by its unpredictable yields for different heterologous proteins, which is now believed to be caused in part by their varied efficiencies to traffic through the host secretion machinery. The yeast endoprotease Kex2 removes the signal peptides from pre-proteins and releases the mature form of secreted proteins, thus, plays a pivotal role in the yeast secretory pathways. In this study, we found that the yields of many recombinant proteins were greatly influenced by Kex2 P1 site residues and the optimized P1s amino acid residue could largely determine the final amount of secretory proteins synthesized and secreted. A further improvement of secretory yield was achieved by genomic integration of additional Kex2 copies, which again highlighted the importance of Kex2 cleavage to the production of recombinant secretory proteins in Pichia yeast.
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Pre-B cell leukemia homeobox 1 is associated with lupus susceptibility in mice and humans.
J. Immunol.
PUBLISHED: 12-16-2011
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Sle1a.1 is part of the Sle1 susceptibility locus, which has the strongest association with lupus nephritis in the NZM2410 mouse model. In this study, we show that Sle1a.1 results in the production of activated and autoreactive CD4(+) T cells. Additionally, Sle1a.1 expression reduces the peripheral regulatory T cell pool, as well as induces a defective response of CD4(+) T cells to the retinoic acid expansion of TGF-?-induced regulatory T cells. At the molecular level, Sle1a.1 corresponds to an increased expression of a novel splice isoform of Pbx1, Pbx1-d. Pbx1-d overexpression is sufficient to induce an activated/inflammatory phenotype in Jurkat T cells and to decrease their apoptotic response to retinoic acid. PBX1-d is expressed more frequently in the CD4(+) T cells from lupus patients than from healthy controls, and its presence correlates with an increased central memory T cell population. These findings indicate that Pbx1 is a novel lupus susceptibility gene that regulates T cell activation and tolerance.
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[Expression of CD82/KAI1 and HIF-1? in non-small cell lung cancer and their relationship to vasculogenic mimicry].
Zhongguo Fei Ai Za Zhi
PUBLISHED: 12-14-2011
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Vasculogenic mimicry (VM), found in many high invasive ability tumors, is associated with tumor invasion and metastasis. Many genes exhibit abnormal levels of expression in these tumors. This study aims to find good markers for predicting the invasion and metastasis of non-small cell lung cancer (NSCLC).
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Restored circulating invariant NKT cells are associated with viral control in patients with chronic hepatitis B.
PLoS ONE
PUBLISHED: 09-20-2011
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Invariant NKT (iNKT) cells are involved in the pathogenesis of various infectious diseases. However, their role in hepatitis B virus (HBV) infection is not fully understood, especially in human species. In this study, 35 chronic hepatitis B (CHB) patients, 25 inactive carriers (IC) and 36 healthy controls (HC) were enrolled and the proportions of circulating iNKT cells in fresh isolated peripheral blood mononuclear cells (PBMC) were detected by flow cytometry. A longitudinal analysis was also conducted in 19 CHB patients who received antiviral therapy with telbivudine. Thereafter, the immune functions of iNKT cells were evaluated by cytokine secretion and a two-chamber technique. The median frequency of circulating iNKT cells in CHB patients (0.13%) was lower than that in HC (0.24%, P?=?0.01) and IC (0.19%, P?=?0.02), and increased significantly during antiviral therapy with telbivudine (P?=?0.0176). The expressions of CC chemokine receptor 5 (CCR5) and CCR6 were dramatically higher on iNKT cells (82.83%±9.87%, 67.67%±16.83% respectively) than on conventional T cells (30.5%±5.65%, 14.02%±5.92%, both P<0.001) in CHB patients. Furthermore, iNKT cells could migrate toward the CC chemokine ligand 5. Patients with a high ratio (?1.0) of CD4-/CD4+ iNKT cells at baseline had a higher rate (58.33%) of HBeAg seroconversion than those with a low ratio (<1.0, 0%, P?=?0.0174). In conclusion, there is a low frequency of peripheral iNKT cells in CHB patients, which increases to normal levels with viral control. The ratio of CD4-/CD4+ iNKT cells at baseline may be a useful predictor for HBeAg seroconversion in CHB patients on telbivudine therapy.
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Hepatitis B virus genotype B with G1896A and A1762T/G1764A mutations is associated with hepatitis B related acute-on-chronic liver failure.
J. Med. Virol.
PUBLISHED: 07-09-2011
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The existence of statistical associations between hepatitis B-related acute-on-chronic liver failure and both hepatitis B virus (HBV) genotype and mutations in the basal core promoter (BCP) and precore (PC) regions needs to be confirmed. A total of 322 patients with a chronic HBV infection, including 77 with hepatitis B-related acute-on-chronic liver failure, 109 with hepatocellular carcinoma (HCC) and 136 with chronic hepatitis B (CHB) were enrolled. The HBV genotype and the presence of mutations in the BCP/PC regions were determined by direct sequencing, and the frequencies were compared in the three patient groups. Overall, 198/322 (61.5%) were infected with genotype B and 124/322 (38.5%) with genotype C. Genotype B was significantly more frequent in patients with acute-on-chronic liver failure than CHB (92.2% vs. 60.3%, P?
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Defective response of CD4(+) T cells to retinoic acid and TGF? in systemic lupus erythematosus.
Arthritis Res. Ther.
PUBLISHED: 06-27-2011
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CD25(+) FOXP3(+) CD4(+) regulatory T cells (Tregs) are induced by transforming growth factor ? (TGF?) and further expanded by retinoic acid (RA). We have previously shown that this process was defective in T cells from lupus-prone mice expressing the novel isoform of the Pbx1 gene, Pbx1-d. This study tested the hypothesis that CD4(+) T cells from systemic lupus erythematosus (SLE) patients exhibited similar defects in Treg induction in response to TGF? and RA, and that PBX1-d expression is associated with this defect.
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MicroRNA-145 regulates chondrogenic differentiation of mesenchymal stem cells by targeting Sox9.
PLoS ONE
PUBLISHED: 06-08-2011
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Chondrogenic differentiation of mesenchymal stem cells (MSCs) is accurately regulated by essential transcription factors and signaling cascades. However, the precise mechanisms involved in this process still remain to be defined. MicroRNAs (miRNAs) regulate various biological processes by binding target mRNA to attenuate protein synthesis. To investigate the mechanisms for miRNAs-mediated regulation of chondrogenic differentiation, we identified that miR-145 was decreased during transforming growth factor beta 3 (TGF-?3)-induced chondrogenic differentiation of murine MSCs. Subsequently, dual-luciferase reporter gene assay data demonstrated that miR-145 targets a putative binding site in the 3-UTR of SRY-related high mobility group-Box gene 9 (Sox9) gene, the key transcription factor for chondrogenesis. In addition, over-expression of miR-145 decreased expression of Sox9 only at protein levels and miR-145 inhibition significantly elevated Sox9 protein levels. Furthermore, over-expression of miR-145 decreased mRNA levels for three chondrogenic marker genes, type II collagen (Col2a1), aggrecan (Agc1), cartilage oligomeric matrix protein (COMP), type IX collagen (Col9a2) and type XI collagen (Col11a1) in C3H10T1/2 cells induced by TGF-?3, whereas anti-miR-145 inhibitor increased the expression of these chondrogenic marker genes. Thus, our studies demonstrated that miR-145 is a key negative regulator of chondrogenic differentiation by directly targeting Sox9 at early stage of chondrogenic differentiation.
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Combined treatment with exogenous estradiol and progesterone increases the incidence of breast cancer in TA2 mice without ovaries.
Cancer Lett.
PUBLISHED: 05-19-2011
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TA2 mice have a high incidence of spontaneous breast cancer without chemical stimulus. There are two proposed explanations for this phenomenon: one is gravidity and the frequency of pregnancies, and the other is related to the presence of the mouse mammary tumor virus (MMTV). MMTV is hormonally regulated and indirectly promotes tumor formation by leading to the activation of Wnt oncogenes through insertional mutagenesis. In order to clarify the relationship between estrogen, progesterone, MMTV, Wnt oncogenes and breast cancer, ovaries from virgin female TA2 mice were removed and the mice were treated with exogenous estradiol and progesterone in different patterns. This study found that the combination of exogenous estradiol and progesterone induced breast cancer formation in TA2 mice without ovaries. MMTV-LTR mRNA exhibited the highest expression in tumor tissue from the combination treatment group (CT). Mammary tissue from mice in the CT group had the highest Wnt1, Wnt5a, Wnt5b and Wnt10b mRNA expression levels. These results indicate that estradiol and progesterone act in a synergistic manner to upregulate MMTV, which subsequently induces breast cancer in TA2 mice. Various members of the Wnt gene family may play specific roles in different stages of carcinogenesis in TA2 mice.
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Association between posttraumatic stress disorder and preflood behavioral characteristics among children aged 7-15 years in Hunan, China.
Med Princ Pract
PUBLISHED: 05-11-2011
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To explore the relationship between posttraumatic stress disorder (PTSD) and preflood behavioral characteristics among children aged 7-15 years in Hunan, China.
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Overexpression of the ? subunit of human chorionic gonadotropin promotes the transformation of human ovarian epithelial cells and ovarian tumorigenesis.
Am. J. Pathol.
PUBLISHED: 04-26-2011
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Ovarian carcinoma is the most lethal gynecologic malignancy, however underlying molecular events remain elusive. Expression of human chorionic gonadotropin ? subunit (?-hCG) is clinically significant for both trophoblastic and nontrophoblastic cancers; however, whether ?-hCG facilitates ovarian epithelial cell tumorigenic potential remains uncharacterized. Immortalized nontumorigenic ovarian epithelial T29 and T80 cells stably overexpressing ?-hCG were examined for alterations in cell cycle and apoptotic status by flow cytometry, expression of proteins regulating cell cycle and apoptosis by Western blot, proliferation status by MTT assay, anchorage-independent colony formation, and mouse tumor formation. Immunoreactivity for ?-hCG was evaluated using mouse xenografts and on human normal ovarian, fallopian tube, endometrium, and ovarian carcinoma tissues. T29 and T80 cells overexpressing ?-hCG demonstrated significantly increased proliferation, anchorage-independent colony formation, prosurvival Bcl-X(L) protein expression, G2-checkpoint progression, elevated cyclins E/D1 and Cdk 2/4/6, and decreased apoptosis. Collectively, these transformational alterations in phenotype facilitated increased xenograft tumorigenesis (P < 0.05). Furthermore, ?-hCG immunoreactivity was elevated in malignant ovarian tumors, compared with normal epithelial expression in ovaries, fallopian tube, and endometrium (P < 0.001). Our data indicate that elevated ?-hCG transforms ovarian surface epithelial cells, facilitating proliferation, cell cycle progression, and attenuated apoptosis to promote tumorigenesis. Our results further decipher the functional role and molecular mechanism of ?-hCG in ovarian carcinoma. ?-hCG may contribute to ovarian cancer etiology, which introduces a new therapeutic intervention target for ovarian cancer.
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Presence of valine at position 27 of the hepatitis B virus core gene is associated with severe liver inflammation in Chinese patients.
J. Med. Virol.
PUBLISHED: 04-19-2011
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Although it is widely believed that cytotoxic T lymphocytes (CTL) are responsible for severe flares of chronic hepatitis B that lead to liver failure, the published evidence to support this hypothesis is weak. The frequency of the I27V mutation in the HBV core gene, which produces a core 18-27 peptide capable of binding HLA-A*02, was compared in Chinese patients with severe liver inflammation (n?=?77, including 39 with acute-on-chronic liver failure), moderate liver inflammation (n?=?44) and inactive disease (n?=?45). The frequency with which V27 reverted to the wild-type I27 was compared in severe liver inflammation patients who were either HLA-A*02 positive (n?=?5) or negative (n?=?5). The frequency of patients with a V27 positive HBV was higher in severe than in moderate liver inflammation (23.4% vs. 6.8%, P?=?0.02) or inactive disease (23.4% vs. 4.7%, P?=?0.006). After a minimum of 3 months follow-up, the frequency of reversion of V27 to the wild-type I27 was higher in HLA-A*02 positive than negative patients (5/5 vs. 1/5, P?=?0.05). In summary, this is the first data showing an association between a specific amino acid mutation (I27V) and severe liver inflammation in patients with chronic hepatitis B. This mutation would produce a peptide that is known to bind HLA-A*02 and stimulate CTL. The high frequency of reversion to wild-type I27 in HLA-A*02 positive subjects suggests that CTL recognizing this peptide exist, and is consistent with the possibility that they contribute to the pathophysiology of severe liver inflammation in chronic hepatitis B.
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Semiclassical approach to plasmon-electron coupling and Landau damping of surface plasmons.
J Chem Phys
PUBLISHED: 04-12-2011
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A semiclassical model is developed to describe plasmon-electron coupling and electronic damping of surface plasmons. It is compared with the ab initio linear response calculations for metallic thin films in the jellium approximation and for a realistic crystalline Mg(0001) surface. The semiclassical model is able to reproduce the quantum oscillations of plasmon linewidth, which was obtained in the previous ab initio calculations. In addition, state-resolved analysis reveals the origin of these oscillations, which result from superposition of the short-period oscillations of individual electron-hole pair transitions. The semiclassical model is further applied to a crystalline Mg(0001) surface, where linewidth dispersion of the surface plasmon is calculated and shows good agreement with earlier ab initio calculation and experiment. Our results suggest that this semiclassical approach is quite promising for the quantitative description of plasmon-electron coupling and associated processes such as surface-enhanced Raman scattering, light emission, and fluorescence.
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High level expression of active recombinant human interleukin-3 in Pichia pastoris.
Protein Expr. Purif.
PUBLISHED: 03-10-2011
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Interleukin-3 (IL-3) is a hematopoietic growth factor involved in the survival, proliferation and differentiation of multipotent hematopoietic cells. A DNA fragment containing the mature human IL-3 sequence was cloned into pPICZ?A, generating a fusion protein with the alpha factor signal sequence in the N-terminus and 6×His as well as c-Myc tags in the C-terminus. The resulting plasmid was integrated into the genome of Pichia pastoris strain X-33. Recombinant yeast transformants with high-level rhIL-3 production were identified, secreting as much as 26mg/L rhIL-3 after 4days of induction by methanol in flask. The rhIL-3 was purified by Ni(+)-NTA affinity chromatography, followed by DEAE anion exchange, yielding over 95% highly purified rhIL-3 preparation at about 21mg/L. Mass spectrometry and MALDI-TOF-TOF analysis of the purified rIL-3 showed molecular weights of 18995.694Da and 22317.469Da, due to different degrees of N-linked glycosylation. The biological activity of the rhIL-3 proteins was confirmed by its ability to support ba/f3 cells proliferation and activate the ERK signaling pathways. The results demonstrate that the experimental procedure we have developed can produce a large amount of active recombinant human IL-3 from P. pastoris.
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Quantum mechanical study of the coupling of plasmon excitations to atomic-scale electron transport.
J Chem Phys
PUBLISHED: 02-24-2011
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The coupling of optical excitation and electron transport through a sodium atom in a plasmonic dimer junction is investigated using time-dependent density functional theory. The optical absorption and dynamic conductance is determined as a function of gap size. Surface plasmons are found to couple to atomic-scale transport through several different channels including dipolar, multipolar, and charge transfer plasmon modes. These findings provide insight into subnanoscale couplings of plasmons and atoms, a subject of general interest in plasmonics and molecular electronics.
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Cellular immune responses in patients with hepatitis B surface antigen seroclearance induced by antiviral therapy.
Virol. J.
PUBLISHED: 02-14-2011
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The mechanisms by which chronic hepatitis B is completely resolved through antiviral therapy are unknown, and the contribution of acquired T cell immunity to hepatitis B surface antigen (HBsAg) seroclearance has not been investigated. Therefore, we measured the T-cell responses to core and envelope antigens in patients with HBsAg seroclearance.
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The microRNA expression profiles of mouse mesenchymal stem cell during chondrogenic differentiation.
BMB Rep
PUBLISHED: 01-27-2011
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MicroRNAs are potential key regulators in mesenchymal stem cells chondrogenic differentiation. However, there were few reports about the accurate effects of miRNAs on chondrogenic differentiation. To investigate the mechanisms of miRNAs-mediated regulation during the process, we performed miRNAs microarray in MSCs at four different stages of TGF-?3-induced chondrogenic differentiation. We observed that eight miRNAs were significantly up-regulated and five miRNAs were downregulated. Interestingly, we found two miRNAs clusters, miR-143/145 and miR-132/212, kept on down-regulation in the process. Using bioinformatics approaches, we analyzed the target genes of these differentially expressed miRNAs and found a series of them correlated with the process of chondrogenesis. Furthermore, the qPCR results showed that the up-regulated (or down-regulated) expression of miRNAs were inversely associated with the expression of predicted target genes. Our results first revealed the expression profiles of miRNAs in chondrogenic differentiation of MSCs and provided a new insight on complicated regulation mechanisms of chondrogenesis.
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Large-scale production, purification and bioactivity assay of recombinant human interleukin-6 in the methylotrophic yeast Pichia pastoris.
FEMS Yeast Res.
PUBLISHED: 12-22-2010
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A DNA fragment containing the mature human interleukin (IL)-6 sequence was cloned into pPICZ?A, generating a fusion protein with the alpha factor from bakers yeast and integrated into the genome of Pichia pastoris strain X-33. Recombinant yeast transformants with high-level rhIL-6 production were identified, secreting as much as 280 mg L(-1) rhIL-6 after 4 days of induction by methanol. The rhIL-6 was purified by PEG-8000 precipitation, followed by DEAE anion exchange and Sephadex G-75 gel filtration, yielding over 95% pure rhIL-6 at about 170 mg L(-1) . Mass spectrometry analysis showed that the rhIL-6 has a molecular weight of 20,908.85 Da, which is close to the mass calculated from the sequence of the protein. Functional analysis of the purified rhIL-6 using the lymphocyte proliferation assay by an MTT [3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl-tetrazoliumbromide] method demonstrated a specific activity that is at least fivefold higher than the commercial rhIL-6 produced in Escherichia coli. In summary, the experimental procedure we have reported here allows us to obtain a large amount of rhIL-6 from P. pastoris suitable for subsequent biophysical studies.
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[Morphological variations of Paris polyphylla var. yunnansensis in different population].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-27-2010
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To study the morphological variations of Paris polyphylla var. yunnansensis in different population for genetic diversity and breeding.
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Laterally tunable plasmon resonance in confined biatomic-layer ag nanodisks.
Nano Lett.
PUBLISHED: 07-10-2010
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We report on the fabrication and investigation of the plasmon excitations in laterally confined quasi-two-dimensional (2D) Ag nanodisks on a Si(111) substrate. Different from the Mie resonance in Ag clusters and the propagating plasmon waves in 2D systems, these ultrathin nanodisks exhibit a low-energy plasmon resonance whose frequency is continuously tunable by the disk diameter. Quantum-mechanical simulations revealed the origin and the effects of screening and charge transfer on the plasmon excitation. The character and size-dependence are promising for engineering plasmonic and optical properties in supported 2D systems.
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The effect of high gravidity on the carcinogenesis of mammary gland in TA2 mice.
Am. J. Reprod. Immunol.
PUBLISHED: 02-08-2010
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Spontaneous breast cancer in Tientsin Albinao 2 (TA2) mice, like human pregnancy-associated breast cancer (PABC), often occurs in pregnancy and puerperium, especially in mice with high gravidity. We hypothesized that the dysfunction of cellular immunity caused by the increase of 17beta-estradiol (E2) and progesterone (P) might be one of the reasons for carcinogenesis of mammary gland.
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Prevalence and risk factors for childhood obesity in Changsha and Shenzhen in China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 02-05-2010
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To determine the prevalence and the risk factors for childhood obesity in Changsha and Shenzhen, China.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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