bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of conditioning of fused‐silica capillaries on their electrophoretic performance
Authors: Gómez Jorge E. , Sandoval Junior E. 
Published: December 2007

AbstractIn CE practice, conditioning of the capillary tube with strong base, acid, or both in sequence, has been recognized as essential to obtain reasonable precision in electroosmotic mobility (EOM), and consequently, in the migration times of analytes. This report focuses on the comparative study of three different approaches for capillary conditioning: etching with HF, etching with NaOH, and leaching with HCl after NaOH treatment. EOM‐based measurements, including the hysteresis effect that characterizes the dependence of EOM with pH, were used to evaluate the conditioned silica surface. Additionally, indirect inspection of the conditioned surface was carried out by examining the electrophoretic profile of the cationic probe Ru(bpy)32+, known to strongly interact with the ionized silica surface while displaying no significant acid–base activity. It was shown that, once conditioned and prior to any CE measurement, extensive rinse of the capillary with the running electrolyte at high flow rate was essential to attain relatively rapid re‐equilibration of the tube with the fluid. Insufficient rinse with the running electrolyte would result in negatively biased EOM measurements and significant drift in migration times. It was also established that relatively high flow rates of 1 M NaOH conditioning solution (4–5 column volumes per minute) was required to attain capillaries with reproducible electrophoretic performance within a reasonable conditioning time (typically, 1 h). In addition to relatively more extensive rehydroxylation of the silica surface, evidenced by the highest EOM values obtained, the sequential use of NaOH‐etching and HCl‐leaching provided better precision than HF‐etching or NaOH‐etching alone.
A multiplex assay to identify 18 European mammal species from mixtures using the mitochondrial cytochrome b gene
Authors: Tobe Shanan S. , Linacre Adrian M. T. 
Published: December 2007

AbstractA novel species‐specific multiplex to identify 18 common European mammalian species (badger, cat, cow, dog, donkey, fox, goat, guinea pig, harvest mouse, hedgehog, horse, house mouse, human, pig, rabbit, rat, red deer and sheep), many of which are often associated with forensic investigations, has been developed. The assay is based on the mitochondrial cytochrome b gene, which is commonly used in species identification and phylogeny studies. Areas of homology and variation were identified and were used to create universal and species‐specific primers. The species‐specific primers were designed such that they will only react with the species for which they were designed. Two primer sets were designed for each species making the test self‐confirmatory. All primer sets produced the expected results. The multiplex was balanced at template concentration of 40 000 copies (approximately 1.36 pg). Validation was accomplished by analysing the same sample ten times to determine run variation and several samples for each species to determine between‐sample variation. Twenty‐eight additional mammalian species were reacted with the multiplex. The multiplex provides, for the first time, a definitive method for identification of species in a forensic context.
Type III neuregulin‐1 promotes oligodendrocyte myelination
Authors: Taveggia Carla , Thaker Pratik , Petrylak Ashley , Caporaso Gregg L. , Toews Arrel , Falls Douglas L. , Einheber Steven , Salzer James L. 
Published: December 2007

AbstractThe axonal signals that regulate oligodendrocyte myelination during development of the central nervous system (CNS) have not been established. In this study, we have examined the regulation of oligodendrocyte myelination by the type III isoform of neuregulin‐1 (NRG1), a neuronal signal essential for Schwann cell differentiation and myelination. In contrast to Schwann cells, primary oligodendrocytes differentiate normally when cocultured with dorsal root ganglia (DRG) neurons deficient in type III NRG1. However, they myelinate type III NRG1‐deficient neurites poorly in comparison to wild type cultures. Type III NRG1 is not sufficient to drive oligodendrocyte myelination as sympathetic neurons are not myelinated even with lentiviral‐mediated expression of NRG1. Mice haploinsufficient for type III NRG1 are hypomyelinated in the brain, as evidenced by reduced amounts of myelin proteins and lipids and thinner myelin sheaths. In contrast, the optic nerve and spinal cord of heterozygotes are myelinated normally. Together, these results implicate type III NRG1 as a significant determinant of the extent of myelination in the brain and demonstrate important regional differences in the control of CNS myelination. They also indicate that oligodendrocyte myelination, but not differentiation, is promoted by axonal NRG1, underscoring important differences in the control of myelination in the CNS and peripheral nervous system (PNS). © 2007 Wiley‐Liss, Inc.
Ultrastructural plasticity in the rat suprachiasmatic nucleus. Possible involvement in clock entrainment
Authors: Becquet Denis , Girardet Clémence , Guillaumond Fabienne , François‐Bellan Anne‐Marie , Bosler Olivier 
Published: December 2007

AbstractCircadian rhythms in mammals are synchronized to the light (L)/dark (D) cycle through messages relaying in the master clock, the suprachiasmatic nucleus of the hypothalamus (SCN). Here, we provide evidence that the SCN undergoes rhythmic ultrastructural rearrangements over the 24‐h cycle characterized by day/night changes of the glial, axon terminal, and/or somato‐dendritic coverage of neurons expressing arginine vasopressin (AVP) or vasoactive intestinal peptide (VIP), the two main sources of SCN efferents. At nighttime, we noted an increase in the glial coverage of the dendrites of the VIP neurons (+29%) that was concomitant with a decrease in the mean coverage of the somata (−36%) and dendrites (−43%) of these neurons by axon terminals. Conversely, glial coverage of the dendrites of AVP neurons decreased (−19%) with parallel increase in the extent of somatal (+96%) and dendritic (+52%) membrane appositions involving these neurons. These plastic events were concomitant with daily fluctuations in quantitative expression of glial fibrillary acidic protein (GFAP), which were then used as an index of structural plasticity. The GFAP rhythm appeared to be strictly dependent on light entrainment, indicating that structural reorganization of the SCN may subserve synchronization of the clock to the L/D cycle. Other results presented reinforced this view while showing that circulating glucocorticoid hormones, which are known to modulate photic entrainment, were required to maintain amplitude of the GFAP rhythm to normal values. © 2007 Wiley‐Liss, Inc.
Tissue engineered cartilage from hTGF β2 transduced human adipose derived stem cells seeded in PLGA/alginate compound in vitro and in vivo
Authors: Jin Xiao Bing , Sun Yong Sheng , Zhang Ke , Wang Jing , Shi Tai Ping , Ju Xiao Dong , Lou Si Quan 
Published: December 2007

AbstractChondrogenic potential of human adipose derived stem cells (hASCs) makes them a possible source of seeding cells for cartilage tissue engineering. We aim to examine the chondrogenic differentiation of human transforming growth factor β2 (hTGF β2) transduced hASCs seeded in three‐dimensional scaffold in vitro and in vivo. In this study, hASCs were isolated from human subcutaneous adipose tissue and transduced with a replication deficient adenovirus carrying hTGF β2 (Ad5‐hTGF β2), and then the transduced cells were seeded and cultured in PLGA/alginate compounds. RT‐PCR analysis revealed that Ad5‐hTGF β2 transduced hASCs produced aggrecan and collagen type II after 7‐day induction in vitro and continued throughout the culture period; this was also demonstrated by the positive staining of Alcian blue and immunohistochemistry for collagen type II. For in vivo study, Ad5‐hTGF β2 transduced hASCs seeded in PLGA/alginate compounds were implanted in subcutaneous pockets of nude mice; after 12 weeks, the implants were harvested and examined by haematoxylin and eosin staining, AB‐PAS staining, and immunohistochemical analysis, and the results demonstrated the formation of cartilage tissue. As a control, all these were not observed in the constructs with Ad5‐EGFP transduced hASCs. In conclusion, our study demonstrates that adenovirus‐mediated hTGF β2 gene transfer is able to induce the hASCs into chondrogenic lineage both in vitro and in vivo. Ad5‐hTGF β2 transduced hASCs combined with three‐dimensional PLGA/alginate compound may be a viable method in treating injuries of cartilage. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Subcutaneous transplantation of autologous oral mucosal epithelial cell sheets fabricated on temperature‐responsive culture dishes
Authors: Obokata Haruko , Yamato Masayuki , Yang Joseph , Nishida Kohji , Tsuneda Satoshi , Okano Teruo 
Published: December 2007

AbstractThe oral mucosa is an attractive cell source for autologous transplantation in human patients who require regenerative therapies of various epithelia. However, the time‐course of cellular changes in transplanted oral mucosal epithelia at ectopic sites remains poorly understood. By applying a rat model, we analyzed phenotypic changes in oral mucosal epithelial cell sheets after harvest from temperature‐responsive culture dishes and subsequent autologous subcutaneous transplantation. We used monoclonal antibodies to identify epithelial‐specific cytokeratins 4, 10, 13, and 14, the stem/progenitor cell marker p63, and proliferating cell nuclear antigen, within the regenerated tissues. Transplanted oral mucosal epithelial cell sheets proliferated during the first week after grafting in conjunction with host inflammation, but then began to degenerate afterward with complete disappearance after 3 weeks. Our findings suggest that host subcutaneous tissues support proliferation and differentiation of the oral mucosal epithelial cell sheets, but are unable to promote maintenance of stem and progenitor cells and therefore cannot produce long‐term survivability. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Stimulation of osteogenic activity in mesenchymal stem cells by FK506
Authors: Dai Wenda , Dong Jian , Fang Taolin , Uemura Toshimasa 
Published: December 2007

AbstractThe aim of this study was to investigate the osteogenic induction by tacrolimus hydrate (FK506) of rat bone marrow‐derived mesenchymal stem cells (MSCs). MSCs were cultured in α‐MEM containing either (1) L‐ascorbic acid‐2‐phosphate (AsAP) and β‐glycerophosphate (β‐GP) as a control; (2) AsAP and β‐GP plus FK506; (3) AsAP and β‐GP plus Dex; or (4) AsAP and β‐GP plus FK506 and Dex. The concentration of FK506 was varied from 5 to 5000 nM to investigate the dose–effect relationship. Sixteen days later, cells were harvested for analysis. Examination of morphology, alkaline phosphatase (APase) activity, calcium deposition, bone nodule formation, osteocalcin mRNA expression, and mineralized extracellular matrix formation showed that the osteogenic differentiation of MSCs was greatly promoted, bone nodule formation was enhanced, APase activity and the expression of osteocalcin mRNA were increased. FK506 was much more effective when combined with Dex. The best results were achieved with α‐MEM containing 0.25 mM AsAP, 10 mM β‐GP, 10 nM Dex, and 50 nM FK506. Formation of bone in vivo was also studied by transplanting MSCs‐loaded ceramic cubes subcutaneously into the back of rats. Satisfactory results were achieved at 4 and 8 weeks. FK506 should be considered for use as an osteogenic agent. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Antibacterial properties and corrosion resistance of Cu and Ag/Cu porous materials
Authors: Jing Hemin , Yu Zhiming , Li Li 
Published: December 2007

AbstractThe porous materials of Cu and Ag/Cu were successfully prepared by the electrodeposition on a precursor of conventional polyamide foam. The microstructure of the porous materials was observed by scanning electron microscope. Their porosity and specific surface area were measured. The inhibition effect of Cu porous materials against E. coli was also investigated. The broad‐spectrum of antibiosis of the Cu and Ag/Cu porous materials were characterized. The corrosion resistance of Cu, Ag/Cu coatings was also compared. The shape and size of pores are uniform in three directions for the porous materials. Their porosity may reach above 95% and specific surface area is beyond 12.8 m2/m3. The antibacterial test results show that the Cu porous materials not only exhibited high antibacterial effect and good broad‐spectrum antibacterial properties, but also excellent persistent antibacterial effects; the antibacterial effects, and broad‐spectrum of antibiosis were greatly improved through the deposition of a thin Ag coating on the surface of Cu porous material. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Effects of substitution degree of photoreactive groups on the properties of UV‐fabricated chitosan scaffold
Authors: Ling Kai , Zheng Fei , Li Junli , Tang Rupei , Huang Jin , Xu Yongmei , Zheng Hua , Chen Jinghua 
Published: December 2007

AbstractHydroxypropyl chitosan (HPCS), a water‐soluble chitosan derivate, was modified by introducing photoreactive azide groups (4‐azidobenzoic acid, Az‐) to the amino groups of HPCS, resulting in a photocrosslinkable Az‐HPCS. Novel porous chitosan scaffolds thus were fabricated by ultraviolet (UV) light irradiation of Az‐HPCS aqueous solutions. Fourier transform infrared spectroscopy, scanning electron microscopy, measurement of pore size and porosity, mechanical test, swelling test, in vitro biodegradation determination were used to analyze the effects of degree of substitution (DS) of Az‐groups on the properties of the scaffolds. When DS of Az‐groups increased from 2.8% to 5.6%, we found that (i) the pore size of Az‐HPCS scaffolds increased by about twofold and the porosity increased slightly, probably due to more N2 released from the crosslinking reaction with the increase of DS; (ii) both the tensile stress and strain increased by about threefold, relating to the increase of joint points, pore size, and porosity at a relative high DS; (iii) the swelling ratio and degradation rate decreased with the increase of Az‐DS, because of the forming of a more compact network structure. Preliminary data of cell culture on Az‐HPCS scaffold suggested its potential applicability for tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Liver tissue responses to gelatin and gelatin/chitosan gels
Authors: Wang Xiaohong , Yu Xin , Yan Yongnian , Zhang Renji 
Published: December 2007

AbstractGelatin and gelatin/chitosan gels, crosslinked using glutaraldehyde, were previously developed as substrates for three‐dimensional cell‐assembly techniques. In this study, the biocompatibility and biodegradation of gelatin and gelatin/chitosan gels were evaluated following implantation in rat livers for periods up to 16 weeks. The two gels were characterized by different inflammatory responses and degradation rates. The gelatin/chitosan gel is more efficient in inducing fibrin formation and vascularization at the implant‐host interface. The degrees of inflammatory reaction for the gelatin/chitosan gel were significantly stronger than the gelatin gel. Advanced biodegradation of the gelatin gels was observed. These data indicate that the gelatin gel has better liver tissue biocompatibility and a faster biodegraded rate than the gelatin/chitosan gel. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Shell–core imprinted polyacrylamide crosslinked chitosan for albumin removal from plasma
Authors: Okutucu Burcu , Zihnioglu Figen , Telefoncu Azmi 
Published: December 2007

AbstractMolecularly imprinted polymeric beads were prepared using albumin as the imprinted molecule, acrylamide as the functional monomer, and epichlorhydrin crosslinked chitosan beads as the supporting matrix. The recognition and binding of the imprinted beads was also tested with human plasma for the targeted removal of HSA. Plasma is a rich source of biochemical products that can act as biomarkers of disease or physiological status of a patient. The application of current proteomic technologies in the search for potential diagnostic/prognostic indicators in the plasma of patients is limited by highly abundant albumin that constitute >60% of the total plasma proteins. Removal of abundant proteins will help in the discovery and detection of less abundant proteins that may prove to be informative. The adsorption capacities of the imprinted polymeric beads for pure human serum albumin and plasma albumin were estimated as 92% and 80%, respectively. The easy preparation protocol of derivatised beads and good protein recognition properties make them attractive for biotechnologic approaches. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Synthesis and characterization of collagen‐chitosan‐hydroxyapatite artificial bone matrix
Authors: Wang Yan , Zhang Lihai , Hu Min , Liu Hongchen , Wen Weisheng , Xiao Hongxi , Niu Yu 
Published: December 2007

AbstractIn this study, a new artificial bone matrix was constructed with collagen and Ca5(PO4)3OH (hydroxyapatite/HA) which are the main components of natural bone. To improve the property of the artificial bone matrix, chitosan (CS), a kind of positive charged polysaccharide, was crosslinked into the scaffolds. Solid–liquid phase separation method was used to shape 3D porous structure benefited for cells growing into. The artificial bone matrix was investigated by transmission electron microscopy, scanning electron microscopy, and electron spectroscopy for chemical analysis, etc. for structures and characteristics. And its ability of bone repair was investigated by orthotope bone defect reparation in vivo. The results showed that the artificial bone matrix was a porousscaffold with three‐dimension interconnected fiber microstructure. HA particles were dispersed evenly among collagen fiber and CS was modified on the surface of collagen fiber. It was indicated that this artificial bone matrix could be used as a bone substitute with outstanding properties. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Fibronectin and pellet suspension culture promote differentiation of human mesenchymal stem cells into insulin producing cells
Authors: Chang Ching‐Fang , Hsu Ke‐Hsun , Chiou Shih‐Hwa , Ho Larry Low‐Tone , Fu Yu‐Show , Hung Shih‐Chieh 
Published: December 2007

AbstractMultipotential mesenchymal stem cells (MSCs) isolated from bone marrow can differentiate into multiple mesenchymal tissues and exhibit a neuronal phenotype under appropriate induction conditions. Methods promoting neural differentiation have been adapted to derive insulin producing cells (IPCs) from embryonic stem cells, but it remains unclear whether neuronal cell‐based differentiation method will be able to derive IPCs from MSCs. Using a four‐stage differentiation protocol which contains neuronal differentiation factor and IPC‐conversion reagent‐nicotinamide, the potential of human MSCs to differentiate into IPCs was evaluated by means of reverse transcription–polymerase chain reaction, immunostaining, and functional analysis. MSCs in monolayer spontaneously expressed genes for islet transcription factors, Nkx6.1 and Ngn3, but did not express insulin after treatment in this protocol. Pellet suspension culture and the addition of fibronectin enhanced pancreatic differentiation with increase in insulin and Glut2 gene expression. Switching of cells to high‐glucose culture further increased immunostaining for proinsulin and insulin. IPCs secreted insulin in response to elevated glucose concentration, which was regulated by reagents that increase cyclic AMP production or modify calcium influx. Our data suggest that MSCs in the monolayer do not undergo IPC differentiation and pellet suspension culture with fibronectin promotes IPCs derived from MSCs. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Successful management of a Jehovah's Witness with thrombotic thrombocytopenic purpura unwilling to be treated with therapeutic plasma exchange
Authors: Dabak Vrushali , Kuriakose Philip , Raman Sundara 
Published: December 2007

AbstractThrombotic thrombocytopenic purpura (TTP) is a life‐threatening disease treated successfully with plasma exchange. Jehovah's Witnesses whose religious beliefs preclude them from accepting plasma exchange may require alternative forms of therapy. We report a case of one such patient who presented with TTP, whom we successfully managed with vincristine and responded favorably without the need for plasma exchange. J. Clin. Apheresis, 2007. © 2007 Wiley‐Liss, Inc.
Distinct osteoblastic differentiation potential of murine fetal liver and bone marrow stroma‐derived mesenchymal stem cells
Authors: Fromigué Olivia , Hamidouche Zahia , Chateauvieux Sébastien , Charbord Pierre , Marie Pierre J. 
Published: December 2007

AbstractBone marrow‐derived mesenchymal stem cells (MSC) are able to differentiate into osteoblasts under appropriate induction. Although MSC‐derived osteoblasts are part of the hematopoietic niche, the nature of the stromal component in fetal liver remains elusive. Here, we determined the in vitro osteoblastic differentiation potential of murine clonal fetal liver‐derived cells (AFT024, BFC012, 2012) in comparison with bone marrow‐derived cell lines (BMC9, BMC10). Bone morphogenetic protein‐2 (BMP2) increased alkaline phosphatase (ALP) activity, an early osteoblastic marker, in AFT024 and 2012 cells, whereas dexamethasone had little or no effect. BMP2, but not dexamethasone, increased ALP activity in BMC9 cells, and both inducers increased ALP activity in BMC10 cells. BMP2 increased ALP mRNA in AFT024, 2012 and BMC9 cells. By contrast, ALP was not detected in BMC10 and BFC012 cells. BMP2 and dexamethasone increased osteopontin and osteocalcin mRNA expression in 2012 cells. Furthermore, bone marrow‐derived cells showed extensive matrix mineralization, whereas fetal liver‐derived cell lines showed no or very limited matrix mineralization capacity. These results indicate that the osteoblast differentiation potential differs in bone marrow and fetal liver‐derived cell lines, which may be due to a distinct developmental program or different microenvironment in the two hematopoietic sites. J. Cell. Biochem. 104: 620–628, 2008. © 2007 Wiley‐Liss, Inc.