bluuebunny/crossref_metadata_2025 huggingface dataset:
Basal ganglia hypoactivity during grip force in drug naïve Parkinson's disease
Authors: Spraker Matthew B. , Prodoehl Janey , Corcos Daniel M. , Comella Cynthia L. , Vaillancourt David E.
Published: March 2010

The basal ganglia (BG) are impaired in Parkinson's disease (PD), but it remains unclear which nuclei are impaired during the performance of motor tasks in early‐stage PD. Therefore, this study was conducted to determine which nuclei function abnormally, and whether cortical structures are also affected by early‐stage PD. The study also determined if cerebellar hyperactivity is found early in the course of PD. Blood oxygenation level dependent activation was compared between 14 early‐stage drug‐naïve PD patients and 14 controls performing two precision grip force tasks using functional magnetic resonance imaging at 3 T. The grip tasks used in this study were chosen because both tasks are known to provide robust activation in BG nuclei, and the two tasks were similar except that the 2‐s task required more switching between contraction and relaxation than the 4‐s task. The 4‐s task revealed that PD patients were hypoactive relative to controls only in putamen and external globus pallidus, and thalamus. In the 2‐s task, PD patients were hypoactive throughout all BG nuclei, thalamus, M1, and supplementary motor area. There were no differences in cerebellar activation between groups during either task. Regions of interest analysis revealed that the hypoactivity observed in PD patients during the 2‐s task became more pronounced over time as patients performed the task. This suggests that a motor task that requires switching can accentuate abnormal activity throughout all BG nuclei of early‐stage, drug‐naive PD, and that the abnormal activity becomes more pronounced with repeated task performance in these patients. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
The race to learn: Spike timing and STDP can coordinate learning and recall in CA3
Authors: Nolan Christopher R. , Wyeth Gordon , Milford Michael , Wiles Janet
Published: March 2010

The CA3 region of the hippocampus has long been proposed as an autoassociative network performing pattern completion on known inputs. The dentate gyrus (DG) region is often proposed as a network performing the complementary function of pattern separation. Neural models of pattern completion and separation generally designate explicit learning phases to encode new information and assume an ideal fixed threshold at which to stop learning new patterns and begin recalling known patterns. Memory systems are significantly more complex in practice, with the degree of memory recall depending on context‐specific goals. Here, we present our spike‐timing separation and completion (STSC) model of the entorhinal cortex (EC), DG, and CA3 network, ascribing to each region a role similar to that in existing models but adding a temporal dimension by using a spiking neural network. Simulation results demonstrate that (a) spike‐timing dependent plasticity in the EC‐CA3 synapses provides a pattern completion ability without recurrent CA3 connections, (b) the race between activation of CA3 cells via EC‐CA3 synapses and activation of the same cells via DG‐CA3 synapses distinguishes novel from known inputs, and (c) modulation of the EC‐CA3 synapses adjusts the learned versus test input similarity required to evoke a direct CA3 response prior to any DG activity, thereby adjusting the pattern completion threshold. These mechanisms suggest that spike timing can arbitrate between learning and recall based on the novelty of each individual input, ensuring control of the learn‐recall decision resides in the same subsystem as the learned memories themselves. The proposed modulatory signal does not override this decision but biases the system toward either learning or recall. The model provides an explanation for empirical observations that a reduction in novelty produces a corresponding reduction in the latency of responses in CA3 and CA1. © 2010 Wiley‐Liss, Inc.
Two New Sesquiterpene Lactones and a Triterpene Glycoside from Cichorium glandulosum
Authors: Wu Hankui , Su Zhen , Xin Xuelei , Aisa Haji Akber
Published: March 2010

Two new sesquiterpene lactones, namely 8‐O‐methylsenecioylaustricin (1) and epi‐8α‐angeloyloxycichoralexin (2), as well as a new triterpene glycoside (taraxasterol‐3‐O‐β‐D‐glucoside, 3), together with the three known sesquiterpene lactones lactucin (4), lactucopicrin (5), and 11β,13‐dihydrolactucin (6), were isolated from the stems of Cichorium glandulosum Boiss. et Huet. The chemical structures were elucidated on the basis of spectroscopic methods.
Four New Triterpenes from Anchusa azurea var. azurea
Authors: Kuruüzüm‐Uz Ayşe , Güvenalp Zuhal , Kazaz Cavit , Salih Bekir , Demirezer L. Ömür
Published: March 2010

Four new triterpene glycosides, named oleanazuroside 1 (1), oleanazuroside 2 (2), ursolazuroside 1 (3), and ursolazuroside 2 (4), together with the seven known compounds 5–11, were isolated from the MeOH extract of the aerial parts of Anchusa azurea Miller var. azurea. Their structures were elucidated by means of spectroscopic evidence (UV, IR, MALDI‐MS, and 1D‐ and 2D‐NMR). The radical‐scavenging activities against 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) of the BuOH extract and of 8 and 10 were very strong (Table 5).
New Steroids and a New Alkaloid from the Gorgonian Isis minorbrachyblasta: Structures, Cytotoxicity, and Antilarval Activity
Authors: Qi Shu‐Hua , Miao Li , Gao Cheng‐Hai , Xu Ying , Zhang Si , Qian Pei‐Yuan
Published: March 2010

Two new polyoxygenated steroids, (1α,3β,7α,11α,12β)‐gorgost‐5‐ene‐1,3,7,11,12‐pentol 12‐acetate (1) and 11‐O‐acetyl‐22‐epihippuristanol (2), and a new alkaloid, 2,3,5,6,11,11b‐hexahydro‐2‐hydroxy‐1H‐indolizino[8,7‐b]indole‐2‐carboxylic acid (3), together with three known compounds, 22‐epihippuristanol (4), hippuristanol (5), and tryptamine (6), were isolated from the EtOH/CH2Cl2 extracts of the South China Sea gorgonian Isis minorbrachyblasta. The structures of the new compounds were determined by spectroscopic methods. Compound 1 showed weak cytotoxicity against A549, HONE1, and HeLa cancer cell lines and strong antilarval activity towards Bugula neritina larvae with an EC50 value of 5.8 μg/ml. Compound 5 showed moderate cytotoxicity against A549, HONE1, and HeLa cell lines, and the epimer mixture 4/5 (weight ratio 3 : 2) exhibited potent cytotoxicity against A549 and HONE1 cell lines with IC50 values of 4.2 and 4.8 μg/ml, which indicated that epimers 4 and 5 might have a synergistic effect on their cytotoxicity against A549 and HONE1 cell lines.
H5IO6/KI: A New Combination Reagent for Iodination of Aromatic Amines, and Trimethylsilylation of Alcohols and Phenols through in situ Generation of Iodine under Mild Conditions
Authors: Zolfigol Mohammad Ali , Khazaei Ardeshir , Kolvari Eskandar , Koukabi Nadiya , Soltani Hamid , Behjunia Maryam
Published: March 2010

A simple method for the in situ generation of iodine using H5IO6/KI has been developed, and its application in silylation of OH group and iodination of aromatic amines is described.
New Epoxy‐Substituted Nitrogenous Bisabolene‐Type Sesquiterpenes from a Hainan Sponge Axinyssa sp.
Authors: Sun Ji‐Zheng , Chen Kao‐Shan , Liu Hai‐Li , van Soest Rob , Guo Yue‐Wei
Published: March 2010

Two new uncommon epoxy‐substituted nitrogenous bisabolene‐type sesquiterpenes, 3‐formamido‐7,8‐epoxy‐α‐bisabolane (4), 3‐isocyano‐7,8‐epoxy‐α‐bisabolane (5), together with three known related sesquiterpenes, 1–3, were isolated from the Hainan sponge Axinyssa sp. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison of their NMR data with those of structurally related compounds.
Three New Benzophenone Glucosides from the Leaves of Planchonella obovata
Authors: Lee Shoei‐Sheng , Tseng Chang‐Cheng , Chen Chien‐Kuang
Published: March 2010

Chemical investigation of the EtOH extract of the leaves of Planchonella obovata resulted in the isolation of four benzophenone glucosides, 1–4, of which three, 2–4, are new chemical entities together with five known flavonol glycosides. Their structures were elucidated by spectroscopic analysis. Among the isolated compounds, iriflophenone 2‐O‐(2,6‐di‐O‐galloyl)‐β‐D‐glucopyranoside (4) showed some activity (91.4 and 15.0% inhibition at 100 and 10 μg/ml, resp.) against the α‐glucosidase of Bacillus stearothermophilus.
Coagulansins A and B, New Withanolides from Withania coagulansDunal
Authors: Jahan Erum , Perveen Shagufta , Fatima Itrat , Malik Abdul
Published: March 2010

Coagulansins A (1) and B (2), two new withanolides, were isolated from the CHCl3‐soluble fraction of Withania coagulans Dunal, along with two known withanolides, coagulin R and withanolide P. Their structures were assigned by means of 1H‐ and 13C‐NMR spectra, DEPT, and 1H,1H‐COSY, NOESY, HMQC, and HMBC experiments.
A Convenient Approach to C2‐Chiral 1,1,4,4‐Tetrasubstituted Butanetetraols: Direct Alkylation or Arylation of Enantiomerically Pure Diethyl Tartrates
Authors: Shan Zixing , Hu Xiaoyun , Zhou Yan , Peng Xitian , Li Zhen
Published: March 2010

C2‐Chiral 1,1,4,4‐tetraaryl‐ or 1,1,4,4‐tetraalkyl‐substituted butanetetraols have been conveniently synthesized via arylation or alkylation of unprotected diethyl (2R,3R)‐ and (2S,3S)‐tartrates with Grignard reagent. The chiral 1,1,4,4‐tetrasubstituted butanetetraols were characterized by IR, 1H‐ and 13C‐NMR, as well as LC/MS.
Diversity of Sesquiterpenoids from Carpesium cernuum
Authors: Liu Lei‐Lei , Wang Rui , Yang Jun‐Li , Shi Yan‐Ping
Published: March 2010

Two new sesquiterpene lactones, 6β‐hydroxy‐8α‐ethoxyeremophil‐7(11)‐en‐12,8β‐olide (1) and 4β,10β‐dihydroxy‐1αH,5αH,11αH‐guaian‐12,8β‐olide (2), together with 22 known sesquiterpenoids with various structural types, were isolated from Carpesium cernuum (Compositae). Their structures and configurations were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic analysis in combination with MS experiments, and comparison with literature data of related compounds.
Three New Illudalane Sequiterpenoids from Pteris semipinnata
Authors: Zhan Zha‐Jun , Ying You‐Min , Zhang Fu‐Yu , Li Cheng‐Ping , Shan Wei‐Guang
Published: March 2010

The chemical investigation of the aerial parts of Pteris semipinnata resulted in the isolation of three illudalane sesquiterpenoids, namely (2R)‐norpterosin B (1), (2R)‐12‐O‐β‐D‐glucopyranosylnorpterosin B (2), and semipterosin A (3), along with three known compounds. The structures of 1–3 were established by spectroscopic methods, including extensive 2D‐NMR and CD analyses.
The antitumor activity of the fungicide ciclopirox
Authors: Zhou Hongyu , Shen Tao , Luo Yan , Liu Lei , Chen Wenxing , Xu Baoshan , Han Xiuzhen , Pang Jia , Rivera Chantal A. , Huang Shile
Published: March 2010

Ciclopirox olamine (CPX) is a synthetic antifungal agent clinically used to treat mycoses of the skin and nails. Here, we show that CPX inhibited tumor growth in human breast cancer MDA‐MB‐231 xenografts. To unveil the underlying mechanism, we further studied the antitumor activity of CPX in cell culture. The results indicate that CPX inhibited cell proliferation and induced apoptosis in human rhabdomyosarcoma (Rh30), breast carcinoma (MDA‐MB231) and colon adenocarcinoma (HT‐29) cells in a concentration‐dependent manner. By cell cycle analysis, CPX induced accumulation of cells in G1/G0phase of the cell cycle. Concurrently, CPX downregulated cellular protein expression of cyclins (A, B1, D1 and E) and cyclin‐dependent kinases (CDK2 and CDK4) and upregulated expression of the CDK inhibitor p21Cip1, leading to hypophosphorylation of retinoblastoma protein. CPX also downregulated protein expression of Bcl‐xL and survivin and enhanced cleavages of Bcl‐2. Z‐VAD‐FMK, a pan‐caspase inhibitor, partially prevented CPX‐induced cell death, suggesting that CPX‐induced apoptosis of cancer cells is mediated at least in part through caspase‐dependent mechanism. The results indicate that CPX is a potential antitumor agent.
Colorectal cancer risk in relation to antidepressant medication use
Authors: Chubak Jessica , Boudreau Denise M. , Rulyak Stephen J. , Mandelson Margaret T.
Published: March 2010

Laboratory studies suggest that antidepressants affect the risk of some cancers, including colorectal cancer. To investigate whether selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) are associated with colorectal cancer risk, we conducted a case‐control study among enrollees of an integrated healthcare delivery system in Washington State. Cases were first diagnosed with invasive colorectal cancer between 2000 and 2003; controls were randomly selected from Group Health enrollees and matched to cases on age, sex and length of enrollment before diagnosis/reference date. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for colorectal cancer in relation to use of any antidepressant, SSRIs only or TCAs only, among 649 cases and 656 controls. Use of any antidepressant was associated with a reduced risk of colorectal cancer (OR = 0.7, 95% CI = 0.5–0.9). Associations were similar for persons who used SSRIs exclusively (OR = 0.7, 95% CI = 0.4–1.1) and TCAs exclusively (OR = 0.7, 95% CI = 0.5–1.2); however, this reduction in risk appeared limited to persons without a prior cancer at another site. Our data support findings from previous epidemiologic and animal studies that suggest antidepressants may reduce the risk of colorectal cancer. Future studies with larger sample sizes should further examine individual drugs as well as dose, duration and recency of use.
Changes on surface morphology of corn starch blend films
Authors: Araújo Maria Alberta , Cunha António M. , Mota Manuel
Published: March 2010

This study aims at evaluating the influence of enzymatic degradation solution on the surface morphology and thermal properties of a poly(ethylene‐vinyl alcohol) copolymer—corn starch thermoplastic blend (SEVA‐C), as a function of immersion time. To perform this study, three different batches were assessed using SEVA‐C samples of different thicknesses and a fixed weight of 1.6 g, immersed in α‐amylase (50 u/L) up to 90 days at 37°C. TGA, contact angle measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques were used. Three degradation mechanisms are considered in these systems: namely, mass loss due to plasticizer leaching (glycerol), starch enzymatic cleavage, and synthetic polymer fractions degradation. Enzymatic hydrolysis of the starch fraction and subsequent leaching from the internal bulk structure led to an increase in surface porosity, pore size, roughness, and to the development of small pits throughout the surface, as observed by SEM and AFM. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010
Synthesis and characterization of injectable bioadhesive hydrogels for nucleus pulposus replacement and repair of the damaged intervertebral disc
Authors: Vernengo J. , Fussell G. W. , Smith N. G. , Lowman A. M.
Published: March 2010

Bioadhesive polymers are natural or synthetic materials that can be used for soft tissue repair. The aim of this investigation was to develop an injectable, bioadhesive hydrogel with the potential to serve as a synthetic replacement for the nucleus pulposus of the intervertebral disc or as an annulus closure material. Branched copolymers of poly(N‐isopropylacrylamide) (PNIPAAm) and poly(ethylene glycol) (PEG) were blended with poly(ethylene imine) (PEI). This three component injectable system can form a precipitated gel at physiological temperature due to the phase transition of PNIPAAm. The injection of glutaraldehyde into the gel core will adhere the implant to the surrounding tissues.1H NMR results indicated the successful physical incorporation of PEI into the PNIPAAm‐PEG network by blending. In addition, the covalent crosslinking between the amine functionalities on the PEI and the aldehyde functionalities on the glutaraldehyde was verified using FTIR difference spectroscopy. Mechanical characterization of these blends showed a significant increase (p< 0.05) in compressive modulus following glutaraldehyde injection. Thein vitrobioadhesive force studies with porcine skin showed a significant increase (p< 0.05) in the mean maximum force of detachment for PNIPAAm‐PEG/PEI gels when glutaraldehyde was injected into the gel core. The results of this study indicate that the reactivity between amines and aldehyde functionalities can be exploited to impart bioadhesive properties to PNIPAAm‐PEG/PEI copolymers. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Role of protein contaminants in the immunogenicity of alginates
Authors: Ménard Martin , Dusseault Julie , Langlois Geneviève , Baille Wilms E. , K. Tam Susan , Yahia L'Hocine , Zhu X X , Hallé Jean‐Pierre
Published: March 2010

Alginate is widely used for cell microencapsulation and transplantation. There is a lack of standardization of alginate purity and composition. In a previous study, we compared different alginate purification methods and concluded that polyphenol and endotoxin contaminants were eliminated efficiently but residual protein contaminants persisted with all of the methods under evaluation. The objective of this study was to test the hypothesis that residual proteins play a role in the immunogenicity of certain alginate preparations. Using preparative size exclusion chromatography (SEC) and a large scale purification protocol that was derived from the findings obtained with SEC, we substantially decreased the protein content of alginate preparations. When implanted into mouse peritoneum, barium alginate beads made of alginates that were purified using SEC or the derived large scale protocol induced significantly less pericapsular cell adhesion than those made with control alginates. In conclusions, these results suggest that removing residual protein contamination may decrease the immunogenicity of certain alginate preparations. The measurement of proteins could be used as a screening method for evaluating alginate preparations. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Gd‐DTPA‐loaded PLGA microbubbles as both ultrasound contrast agent and MRI contrast agent—A feasibility research
Authors: Ao Meng , Wang Zhigang , Ran Haitao , Guo Dajing , Yu Jinhong , Li Ao , Chen Weijuan , Wu Wei , Zheng Yuanyi
Published: March 2010

Objective: To prepare the Gd‐DTPA‐loaded poly (lactic‐co‐glycolic acid) (PLGA) microbubbles for both ultrasound imaging and MRI imaging. Methods: Biodegradable high‐molecular‐weight poly (lactic‐co‐glycolic acid) (PLGA) was used as an encapsulating vehicle to fabricate a contrast agent composed of gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) and fluorocarbon‐filled microbubbles by using double emulsion method. The morphology, size, and Gd loading capacity of PLGA microparticles were assessed. The efficacy of the contrast agent for ultrasound and magnetic resonance (MR) imaging was evaluated by in vivo imaging of hepatic vessels and the liver parenchyma of rabbit following injection of the contrast agent. Additionally, the liver and kidney functions were examined before and at 7, 14, 30 days after injection. Results: Electron microscopy showed Gd loaded PLGA microbubbles were spherical in shape. The mean diameter were 1.47 ± 0.38 μm and the Gd loading was 25 ± 2 μg/mg. Right after the injection of the PLGA microbubbles, the ultrasound echo intensity of hepatic vessels and the liver parenchyma was significantly enhanced. Moreover, enhanced signal intensity of the liver parenchyma on MR images was observed for ∼30 min after injection of the contrast agent. Neither marked changes in the liver and kidney functions nor other severe complications were detected during the follow‐up period. Conclusion: Gd‐DTPA‐loaded PLGA microbubbles could enhance both ultrasound imaging and MRI imaging. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
ZnO nanoparticles enhanced antibacterial activity of ciprofloxacin against Staphylococcus aureus and Escherichia coli
Authors: Banoee Maryam , Seif Sepideh , Nazari Zeinab E. , Jafari‐Fesharaki Parisa , Shahverdi Hamid R. , Moballegh Ali , Moghaddam Kamyar M. , Shahverdi Ahmad R.
Published: March 2010

Nanoparticle metal oxides offer a wide variety of potential applications in medicine due to the unprecedented advances in nanobiotechnology research. In this work, the effect of zinc oxide (ZnO) nanoparticles prepared by mechano–chemical method on the antibacterial activity of different antibiotics was evaluated using disk diffusion method against Staphylococcus aureus and Escherichia coli. The average size of ZnO nanoparticles was between 20 nm and 45 nm. Although ZnO nanoparticles (500 μg/disk) decreased the antibacterial activity of amoxicillin, penicillin G, and nitrofurantoin in S. aureus, the antibacterial activity of ciprofloxacin increased in the presence of ZnO nanoparticles in both test strains. A total of 27% and 22% increase in inhibition zone areas was observed for ciprofloxacin in the presence of ZnO nanoparticles in S. aureus and E. coli, respectively. The enhancing effect of this nanomaterial on the antibacterial activity of ciprofloxacin was further investigated at three different contents (500, 1000, and 2000 μg/disk) against various clinical isolates of S. aureus and E. coli The enhancing effect of ZnO nanoparticles on the antibacterial activity of ciprofloxacin was concentration‐dependent against all test strains. The most enhancing activities were observed in the contents of the 2000 μg/disk. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
A rapid method for creating drug implants: Translating laboratory‐based methods into a scalable manufacturing process
Authors: Wang Cheng‐Kuo , Wang Wan‐Yi , Meyer Robert F. , Liang Yuling , Winey Karen I. , Siegel Steven J.
Published: March 2010

Low compliance with medication is the major cause of poor outcome in schizophrenia treatment. While surgically implantable solvent‐cast pellets were produced to improve outcome by increased compliance with medication, this process is laborious and time‐consuming, inhibiting its broader application (Siegel et al., Eur J Pharm Biopharm 2006;64:287–293). In this study, the previous fabrication process was translated to a continuous and scalable extrusion method. Extrusion processes were modified based on in vitro release studies, drug load consistency examination, and surface morphology analysis using scanning electron microscopy. Afterward, optimized haloperidol implants were implanted into rats for preliminary analysis of biocompatibility. Barrel temperature, screw speed and resulting processing pressure influenced surface morphology and drug release. Data suggest that fewer surface pores shift the mechanism from bulk to surface PLGA degradation and longer lag period. Results demonstrate that extrusion is a viable process for manufacturing antipsychotic implants. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Antibacterial activity of dental composites containing zinc oxide nanoparticles
Authors: Aydin Sevinç Berdan , Hanley Luke
Published: March 2010

The resin‐based dental composites commonly used in restorations result in more plaque accumulation than other materials. Bacterial biofilm growth contributes to secondary caries and failure of resin‐based dental composites. Methods to inhibit biofilm growth on dental composites have been sought for several decades. It is demonstrated here that zinc oxide nanoparticles (ZnO‐NPs) blended at 10% (w/w) fraction into dental composites display antimicrobial activity and reduce growth of bacterial biofilms by roughly 80% for a single‐species model dental biofilm. Antibacterial effectiveness of ZnO‐NPs was assessed against Streptococcus sobrinus ATCC 27352 grown both planktonically and as biofilms on composites. Direct contact inhibition was observed by scanning electron microscopy and confocal laser scanning microscopy while biofilm formation was quantified by viable counts. An 80% reduction in bacterial counts was observed with 10% ZnO‐NP‐containing composites compared with their unmodified counterpart, indicating a statistically significant suppression of biofilm growth. Although, 20% of the bacterial population survived and could form a biofilm layer again, 10% ZnO‐NP‐containing composites maintained at least some inhibitory activity even after the third generation of biofilm growth. Microscopy demonstrated continuous biofilm formation for unmodified composites after 1‐day growth, but only sparsely distributed biofilms formed on 10% ZnO‐NP‐containing composites. The minimum inhibitory concentration of ZnO‐NPs suspended in S. sobrinus planktonic culture was 50 μg mL−1. ZnO‐NP‐containing composites (10%) qualitatively showed less biofilm after 1‐day‐anaerobic growth of a three‐species initial colonizer biofilm after being compared with unmodified composites, but did not significantly reduce growth after 3 days. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Size and habit of mineral particles in bone and mineralized callus during bone healing in sheep
Authors: Liu Yifei , Manjubala Inderchand , Schell Hanna , Epari Devakara R , Roschger Paul , Duda Georg N , Fratzl Peter
Published: March 2010

Bone healing is known to occur through the successive formation and resorption of various tissues with different structural and mechanical properties. To get a better insight into this sequence of events, we used environmental scanning electron microscopy (ESEM) together with scanning small-angle X-ray scattering (sSAXS) to reveal the size and orientation of bone mineral particles within the regenerating callus tissues at different healing stages (2, 3, 6, and 9 weeks). Sections of 200 µm were cut from embedded blocks of midshaft tibial samples in a sheep osteotomy model with an external fixator. Regions of interest on the medial side of the proximal fragment were chosen to be the periosteal callus, middle callus, intercortical callus, and cortex. Mean thickness (T parameter), degree of alignment (ρ parameter), and predominant orientation (ψ parameter) of mineral particles were deduced from resulting sSAXS patterns with a spatial resolution of 200 µm. 2D maps of T and ρ overlapping with ESEM images revealed that the callus formation occurred in two waves of bone formation, whereby a highly disordered mineralized tissue was deposited first, followed by a bony tissue with more lamellar appearance in the ESEM and where the mineral particles were more aligned, as revealed by sSAXS. As a consequence, degree of alignment and mineral particle size within the callus increased with healing time, whereas at any given moment there were structural gradients, for example, from periosteal toward the middle callus. © 2010 American Society for Bone and Mineral Research.
The tyrosine kinase inhibitor dasatinib dysregulates bone remodeling through inhibition of osteoclasts in vivo
Authors: Vandyke Kate , Dewar Andrea L , Diamond Peter , Fitter Stephen , Schultz Christopher G , Sims Natalie A , Zannettino Andrew CW
Published: March 2010

Dasatinib is a potent tyrosine kinase inhibitor that is used to treat chronic myeloid leukemia in patients resistant or intolerant to imatinib mesylate. While designed to inhibit Abl and Src kinases, dasatinib shows multitarget effects, including inhibition of the macrophage colony-stimulating factor (M-CSF) receptor c-fms. We have shown previously that dasatinib abrogates osteoclast formation and activity in vitro owing, in part, to its specificity for c-fms. In this study we examined whether dasatinib could significantly alter bone volume in a model of physiologic bone turnover. Sprague-Dawley rats were administered dasatinib (5 mg/kg/day) or vehicle by gavage or zoledronic acid (ZOL; 100 µg/kg/6 weeks) subcutaneously. Following 4, 8, and 12 weeks of treatment, serum biochemical, bone morphometric, and histologic analyses were performed. Whole-body bone mineral density and tibial cortical thickness where unchanged in the dasatinib- or ZOL-treated animals relative to controls. However, micro–computed tomographic (µCT) analysis of cancellous bone at the proximal tibias showed that trabecular volume (BV/TV) and thickness (Tb.Th) were increased in dasatinib-treated animals at levels comparable with those of the ZOL-treated group. These changes were associated with a decrease in osteoclast numbers (N.Oc/B.Pm) and surface (Oc.S/BS) and decreased serum levels of the osteoclast marker c-terminal collagen crosslinks (CTX-1). Mineral apposition rate (MAR), bone-formation rate (BFR), and levels of the serum osteoblast markers osteocalcin and N-terminal propeptide of type I procollagen (P1NP) were not altered significantly in the dasatinib-treated animals relative to controls. These studies show that dasatinib increases trabecular bone volume at least in part by inhibiting osteoclast activity, suggesting that dasatinib therapy may result in dysregulated bone remodeling. © 2010 American Society for Bone and Mineral Research
Nestin‐expressing interfollicular blood vessel network contributes to skin transplant survival and wound healing
Authors: Aki Ryoichi , Amoh Yasuyuki , Li Lingna , Katsuoka Kensei , Hoffman Robert M.
Published: March 2010

Using nestin‐driven green fluorescent protein (ND‐GFP) transgenic mice, we previously demonstrated an inter‐hair‐follicle blood vessel network that expresses ND‐GFP and appears to originate from ND‐GFP expressing hair‐follicle stem cells. We report here that angiogenesis of transplanted skin or healing wounds originates from this ND‐GFP‐expressing microvasculature network. ND‐GFP‐expressing blood vessels were visualized growing from the ND‐GFP‐expressing hair‐follicle stem cell area and re‐establishing the dermal microvasculature network after skin transplantation or wound healing. When the ND‐GFP stem cell area from the vibrissa (whisker) from ND‐GFP mice was transplanted to transgenic mice ubiquitously expressing RFP, we observed chimeric ND‐GFP‐RFP blood vessels, suggesting the joining of inter‐follicular blood vessel networks from the transplant and host. These observations suggest that the inter‐hair‐follicle blood‐vessel network contributes to skin transplant survival and wound healing. J. Cell. Biochem. 110: 80–86, 2010. © 2010 Wiley‐Liss, Inc.
The cleidocranial dysplasia‐related R131G mutation in the Runt‐related transcription factor RUNX2 disrupts binding to DNA but not CBF‐β
Authors: Han Min‐Su , Kim Hyo‐Jin , Wee Hee‐Jun , Lim Kyung‐Eun , Park Na‐Rae , Bae Suk‐Chul , van Wijnen Andre J. , Stein Janet L. , Lian Jane B. , Stein Gary S. , Choi Je‐Yong
Published: March 2010

Cleidocranial dysplasia (CCD) is caused by haploinsufficiency in RUNX2 function. We have previously identified a series of RUNX2 mutations in Korean CCD patients, including a novel R131G missense mutation in the Runt‐homology domain. Here, we examine the functional consequences of the RUNX2R131G mutation, which could potentially affect DNA binding, nuclear localization signal, and/or heterodimerization with core‐binding factor‐β (CBF‐β). Immunofluorescence microscopy and western blot analysis with subcellular fractions show that RUNX2R131G is localized in the nucleus. Immunoprecipitation analysis reveals that heterodimerization with CBF‐β is retained. However, precipitation assays with biotinylated oligonucleotides and reporter gene assays with RUNX2 responsive promoters together reveal that DNA‐binding activity and consequently the transactivation of potential of RUNX2R131G is abrogated. We conclude that loss of DNA binding, but not nuclear localization or CBF‐β heterodimerization, causes RUNX2 haploinsufficiency in patients with the RUNX2R131G mutation. Retention of specific functions including nuclear localization and binding to CBF‐β of the RUNX2R131G mutation may render the mutant protein an effective competitor that interferes with wild‐type function. J. Cell. Biochem. 110: 97–103, 2010. © 2010 Wiley‐Liss, Inc.
Differential antiapoptotic effect of erythropoietin on undifferentiated and retinoic acid‐differentiated SH‐SY5Y cells
Authors: Wenker Shirley D. , Chamorro María E. , Vota Daiana M. , Callero Mariana A. , Vittori Daniela C. , Nesse Alcira B.
Published: March 2010

Erythropoietin (Epo) is known to have a significant role in tissues outside the hematopoietic system. In this work, we investigated the function of Epo in cells of neuronal origin subjected to differentiation. Treatment of SH‐SY5Y cells with all‐trans‐retinoic acid (atRA) generated differentiated neuron‐like cells, observed by increased expression of neuronal markers and morphological changes. Exposure of undifferentiated cells to proapoptotic stimuli such as staurosporine, TNF‐α, or hypoxia, significantly increased programmed cell death, which was prevented by previous treatment with Epo. In contrast, atRA‐differentiated cultures showed cell resistance to apoptosis. No additional effect of Epo was detected in previously differentiated cells. The inhibition of the PI3K/Akt pathway by Ly294002 abrogated the protective effects induced by either Epo or atRA. The effect of atRA was mediated by an increased expression of Bcl‐2 whereas the Epo treatment upregulated not only Bcl‐2 but also Bcl‐xL. This upregulation by Epo was not detected in atRA‐differentiated cells, thus confirming the lack of the protective effect of Epo. As expected, assays with AG490, an inhibitor of Jak2, blocked the Epo action only in undifferentiated cells. This reduced neuroprotective function of Epo on SH‐SY5Y differentiated cells could be explained at least in part by downregulation of the Epo receptor expression, which was observed in atRA‐differentiated cells. This study shows differential cellular protection induced by Epo at two stages of SH‐SY5Y differentiation. The results allow us to suggest that this differential cell behavior can be ascribed to the interaction between atRA and the signaling pathways mediated by Epo. J. Cell. Biochem. 110: 151–161, 2010. © 2010 Wiley‐Liss, Inc.
Subcellular proteome analysis unraveled annexin A2 related to immune liver fibrosis
Authors: Zhang Lijun , Peng Xia , Zhang Zhanqin , Feng Yanling , Jia Xiaofang , Shi Yuxin , Yang Hua , Zhang Zhiyong , Zhang Xiaonan , Liu Liwen , Yin Lin , Yuan Zhenghong
Published: March 2010

It is important to study the mechanism of liver fibrogenesis, and find new non‐invasive biomarkers. In this study, we used subcellular proteomic technology to study the plasma membrane (PM) proteins related to immune liver fibrosis and search for new non‐invasive biomarkers. A rat liver fibrosis model was induced by pig serum injection. The liver fibrogenesis from stage (S) S0‐1, S2, S3‐4, and S4 was detected by Masson staining and HE staining in this rat model after 2, 4, 6, and 8 weeks of treatment. The liver PM was enriched and analyzed using subcellular proteomic technology. The differentially expressed proteins were verified by Western blotting, immunohistochemistry, and ELISA. PM with 149‐fold purification was obtained and 22 differentially expressed proteins were identified. Of which, annexin A2 (ANXA2) was detected to be increased obviously in S4 compared with S0‐1, and verified by Western blotting of rat liver tissue and immunohistochemistry of rat and human liver tissue. The expression of ANXA2 in human plasma with S1‐2 was also found to be up‐regulated for 1.4‐fold than that in S0. Furthermore, ANXA2 was detected to translocate from nuclear membrane and cytosol to PM as HBV stimulation through immunocytochemical analysis in vitro. This study identified 22 differentially expressed proteins related to liver fibrosis, and verified a potential biomarker (ANXA2) for non‐invasive diagnosis of immune liver fibrosis. To our knowledge, it was the first time to dynamically study the proteins related to liver fibrosis and select biomarkers for liver fibrosis diagnosis through PM proteome research. J. Cell. Biochem. 110: 219–228, 2010. © 2010 Wiley‐Liss, Inc.
IL‐6 and high glucose synergistically upregulate MMP‐1 expression by U937 mononuclear phagocytes via ERK1/2 and JNK pathways and c‐Jun
Authors: Li Yanchun , Samuvel Devadoss J. , Sundararaj Kamala P. , Lopes‐Virella Maria F. , Huang Yan
Published: March 2010

Matrix metalloproteinases (MMPs) play a pivotal role in tissue remodeling and destruction in inflammation‐associated diseases such as cardiovascular disease and periodontal disease. Although it is known that interleukin (IL)‐6 is a key proinflamatory cytokine, it remains unclear how IL‐6 regulates MMP expression by mononuclear phagocytes. Furthermore, it remains undetermined how IL‐6 in combination with hyperglycemia affects MMP expression. In the present study, we investigated the regulatory effect of IL‐6 alone or in combination with high glucose on MMP‐1 expression by U937 mononuclear phagocytes. We found that IL‐6 is a powerful stimulator for MMP‐1 expression and high glucose further augmented IL‐6‐stimulated MMP‐1 expression. We also found that high glucose, IL‐6, and lipopolysaccharide act in concert to stimulate MMP‐1 expression. In the studies to elucidate underlying mechanisms, the extracellular signal‐regulated kinase (ERK) and c‐Jun N‐terminal kinase (JNK) pathways were found to be required for stimulation of MMP‐1 by IL‐6 and high glucose. We also observed that IL‐6 and high glucose stimulated the expression of c‐Jun, a key subunit of AP‐1 known to be essential for MMP‐1 transcription. The role of c‐Jun in MMP‐1 expression was confirmed by the finding that suppression of c‐Jun expression by RNA interference significantly inhibited MMP‐1 expression. Finally, we demonstrated that similarly to U937 mononuclear phagocytes, IL‐6 and high glucose also stimulated MMP‐1 secretion from human primary monocytes. In conclusion, this study demonstrated that IL‐6 and high glucose synergistically stimulated MMP‐1 expression in mononuclear phagocytes via ERK and JNK cascades and c‐Jun upregulation. J. Cell. Biochem. 110: 248–259, 2010. © 2010 Wiley‐Liss, Inc.
Effect of IL‐1β, PGE2, and TGF‐β1 on the expression of OPG and RANKL in normal and osteoporotic primary human osteoblasts
Authors: Jurado Susana , Garcia‐Giralt Natalia , Díez‐Pérez Adolfo , Esbrit Pedro , Yoskovitz Guy , Agueda Lídia , Urreizti Roser , Pérez‐Edo Lluís , Saló Guillem , Mellibovsky Leonardo , Balcells Susana , Grinberg Daniel , Nogués Xavier
Published: March 2010

The RANKL/RANK/OPG pathway is essential for bone remodeling regulation. Many hormones and cytokines are involved in regulating gene expression in most of the pathway components. Moreover, any deregulation of this pathway can alter bone metabolism, resulting in loss or gain of bone mass. Whether osteoblasts from osteoporotic and nonosteoporotic patients respond differently to cytokines is unknown. The aim of this study was to compare the effect of interleukin (IL)‐1β, proftaglandin E2 (PGE2), and transforming growth factor‐β1 (TGF‐β1) treatments on OPG and RANKL gene expression in normal (n = 11) and osteoporotic (n = 8) primary osteoblasts. OPG and RANKL mRNA levels of primary human osteoblastic (hOB) cell cultures were assessed by real‐time PCR. In all cultures, OPG mRNA increased significantly in response to IL‐1β treatment and decreased in response to TGF‐β1 whereas PGE2 treatment had no effect. RANKL mRNA levels were significantly increased by all treatments. Differences in OPG and RANKL responses were observed between osteoporotic and nonosteoporotic hOB: in osteoporotic hOB, the OPG response to IL‐1β treatment was up to three times lower (P = 0.009), whereas that of RANKL response to TGF‐β1 was five times higher (P = 0.002) after 8 h of treatment, as compared with those in nonosteoporotic hOBs. In conclusion, osteoporotic hOB cells showed an anomalous response under cytokine stimulation, consistent with an enhanced osteoclastogenesis resulting in high levels of bone resorption. J. Cell. Biochem. 110: 304–310, 2010. © 2010 Wiley‐Liss, Inc.
The graphical representation of protein sequences based on the physicochemical properties and its applications
Authors: He Ping‐An , Zhang Yan‐Ping , Yao Yu‐Hua , Tang Yi‐Fa , Nan Xu‐Ying
Published: March 2010

Based on the chaos game representation, a 2D graphical representation of protein sequences was introduced in which the 20 amino acids are rearranged in a cyclic order according to their physicochemical properties. The Euclidean distances between the corresponding amino acids from the 2‐D graphical representations are computed to find matching (or conserved) fragments of amino acids between the two proteins. Again, the cumulative distance of the 2D‐graphical representations is defined to compare the similarity of protein. And, the examination of the similarity among sequences of the ND5 proteins of nine species shows the utility of our approach. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
The ERK5 and ERK1/2 signaling pathways play opposing regulatory roles during chondrogenesis of adult human bone marrow‐derived multipotent progenitor cells
Authors: Bobick Brent E. , Matsche Alexander I. , Chen Faye H. , Tuan Rocky S.
Published: March 2010

Adult human bone marrow‐derived multipotent progenitor cells (MPCs) are able to differentiate into a variety of specialized cell types, including chondrocytes, and are considered a promising candidate cell source for use in cartilage tissue engineering. In this study, we examined the regulation of MPC chondrogenesis by mitogen‐activated protein kinases in an attempt to better understand how to generate hyaline cartilage in the laboratory that more closely resembles native tissue. Specifically, we employed the high‐density pellet culture model system to assess the roles of ERK5 and ERK1/2 pathway signaling in MPC chondrogenesis. Western blotting revealed that high levels of ERK5 phosphorylation correlate with low levels of MPC chondrogenesis and that as TGF‐β3‐enhanced MPC chondrogenesis proceeds, phospho‐ERK5 levels steadily decline. Conversely, levels of phospho‐ERK1/2 paralleled the progression of MPC chondrogenesis. siRNA‐mediated knockdown of ERK5 pathway components MEK5 and ERK5 resulted in increased MPC pellet mRNA transcript levels of the cartilage‐characteristic marker genes SOX9, COL2A1, AGC, L‐SOX5, and SOX6, as well as enhanced accumulation of SOX9 protein, collagen type II protein, and Alcian blue‐stainable proteoglycan. In contrast, knockdown of ERK1/2 pathway members MEK1 and ERK1 decreased expression of all chondrogenic markers tested. Finally, overexpression of MEK5 and ERK5 also depressed MPC chondrogenesis, as indicated by diminished activity of a co‐transfected collagen II promoter‐luciferase reporter construct. In conclusion, our results suggest a novel role for the ERK5 pathway as an important negative regulator of adult human MPC chondrogenesis and illustrate that the ERK5 and ERK1/2 kinase cascades play opposing roles regulating MPC cartilage formation. J. Cell. Physiol. 224:178–186, 2010 © 2010 Wiley‐Liss, Inc.
GP96 C‐terminal improves Her2/neu DNA vaccine
Authors: Pakravan Nafiseh , Soleimanjahi Hoorieh , Mohammad Hassan Zuhair
Published: March 2010

Background

DNA vaccines ensure protective immunity against tumors in a variety of experimental models. The favorite target tumor‐associated antigens have been those that are frequently expressed by human tumors, such as Her2. However, the efficacy of active vaccination is limited because Her2 is a self‐tolerated antigen. Many strategies have been applied to increase the efficacy of DNA vaccination, such as fusion or co‐administration of Her2 with cytokine and co‐stimulatory molecules. GP96 is involved in innate and adaptive immune responses and evokes potent activation and maturation of dendritic cells along with increased secretion of pro‐inflammatory cytokines. On the basis of previous studies, we expected the C‐terminal of GP96 to act as a package and as a suitable substitute for both cytokine and co‐stimulatory genes.

Methods

In the present study, the C‐terminal of GP96 fused or co‐administered with Her2/neu‐containing constructs was used and the resultant immune response was evaluated and compared.

Results

The data obtained showed that the construct containing the C‐terminal of GP96 fused with Her2/neu, but not the co‐administration of the two separated constructs, decreased CD4+CD25+foxp3+ regulatory T cells at the tumor site, enhanced cytotoxic T lymphocyte activity and increased interferon‐γ secretion.

Conclusions

The C‐terminal of GP96 has potent adjuvant activity in eliciting a significant immune response when fused with Her2/neu. It may be used as molecular adjuvant along with other tumor or bacterial/viral antigens. Copyright © 2010 John Wiley & Sons, Ltd.
Exploring the impact of climate and land use changes on streamflow trends in a monsoon catchment
Authors: Adnan Nor Aizam , Atkinson Peter M.
Published: March 2010

Flooding appears to be increasing in Kelantan, Malaysia, in terms of frequency as well as magnitude. This is likely to be due to changes in precipitation, but may also be contributed to by land use change. The Mann–Kendall non‐parametric method was used to test for trends in streamflow and precipitation at the 90% significance level. Several significant trends in streamflow were found for the upstream (River Galas) and downstream (River Kelantan) sub‐catchments for all variables (annual, seasonal and monthly time‐series). In particular, streamflow increased in all seasons in the upstream sub‐catchment, but increased in the wet season and decreased in the dry season downstream. Several trends were also observed for precipitation. Precipitation trends were increasing in the wet season and decreasing in the dry season for both upstream and downstream sub‐catchments. Analysis of land use change revealed that most changes occurred through conversion of forest to agricultural land (i.e. rubber and oil palm), predominantly in the upstream sub‐catchment. The analysis suggests a clear association between streamflow change and precipitation change, but also reveals that land use change may be an important contributing factor, particularly in the upstream sub‐catchment. Copyright © 2010 Royal Meteorological Society
Effect of nicotine and tobacco administration method on the mechanical properties of healing bone following closed fracture
Authors: Hastrup Sidsel Gaarn , Chen Xinqian , Bechtold Joan E. , Kyle Richard F. , Rahbek Ole , Keyler Daniel E. , Skoett Martin , Soeballe Kjeld
Published: March 2010

We previously showed different effects of tobacco and nicotine on fracture healing, but due to pump reservoir limits, maximum exposure period was 4 weeks. To allow flexibility in pre‐ and post‐fracture exposure periods, the objective of this study was to compare a new oral administration route for nicotine to the established pump method. Four groups were studied: (1) pump saline, (2) pump saline + oral tobacco, (3) pump saline/nicotine + oral tobacco, and (4) pump saline + oral nicotine/tobacco. Sprague–Dawley rats (n = 84) received a transverse femoral fracture stabilized with an intramedullary pin 1 week after initiating dosing. After 3 weeks, no difference was found in torsional strength or stiffness between oral nicotine/tobacco or pump nicotine + tobacco, while energy absorption with oral nicotine/tobacco was greater than pump nicotine + tobacco (p < 0.05). Compared to saline control, strength for oral nicotine/tobacco was higher than control (p < 0.05), and stiffnesses for pump nicotine + tobacco and oral nicotine/tobacco were higher than control (p < 0.05). No differences in energy were found for either nicotine–tobacco group compared to saline control. Mean serum cotinine (stable nicotine metabolite) was different between pump and oral nicotine at 1 and 4 weeks, but all groups were in the range of 1–2 pack/day smokers. In summary, relevant serum cotinine levels can be reached in rats with oral nicotine, and, in the presence of tobacco, nicotine can influence mechanical aspects of fracture healing, dependent on administration method. Caution should be exercised when comparing results of fracture healing studies using different methods of nicotine administration. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1235–1239, 2010