bluuebunny/crossref_metadata_2025 huggingface dataset:
Offspring from intracytoplasmic sperm injection of aged mouse oocytes treated with caffeine or MG132
Authors: Ono Tetsuo , Mizutani Eiji , Li Chong , Yamagata Kazuo , Wakayama Teruhiko
Published: April 2011

Postovulatory mammalian oocytes age significantly in culture. B6D2F1 or ICR strain mouse oocytes were collected 16 h after hCG injection and then cultured for up to 40 h post hCG at 37°C under 5% CO2 in air. After intracytoplasmic sperm injection (ICSI), B6D2F1 and ICR oocytes lost full‐term developmental potential by 30 h and 26 h after hCG administration, respectively. However, using supplementation with 10 mM caffeine or 1‐5 μM of MG132, we could obtain live offspring from oocytes at 34 h (BDF1, 5%–21%) or 28 h (ICR, 5%–18%), whereas none were obtained from untreated aged oocytes. Caffeine maintained normal meiotic spindle morphology, whereas MG132 maintained maturation‐promoting factor activity. These treatments did not affect the potential of fresh oocytes for fertilization and subsequent development. Thus, it should be safe to use these chemicals in routine in vitro fertilization and offspring could be generated by ICSI of aged fertilization failed oocytes. genesis 49:460–471, 2011. © 2011 Wiley‐Liss, Inc.
Inducible recombination in the cardiac conduction system of minK: CreERT2 BAC transgenic mice
Authors: Arnolds David E. , Moskowitz Ivan P.
Published: April 2011

Inducible Cre recombination is a powerful technology that allows for spatial and temporal modulation of gene expression in vivo. Diseases of the cardiac conduction system (CCS) pose a significant clinical burden but are not currently well understood at the molecular level. To enable inducible recombination in the murine CCS, we created a minK:CreERT2 bacterial artificial chromosome (BAC) transgenic mouse line. Cre activity is present after tamoxifen administration in the atrioventricular (AV) node, AV bundle, and bundle branches of adult transgenic mice. We anticipate that by enabling inducible recombination specifically in the AV node, bundle, and bundle branches, minK:CreERT2 BAC transgenic mice will prove useful in advancing our understanding of CCS disease and function. genesis 49:878–884, 2011. © 2011 Wiley‐Periodicals, Inc.
Toward high‐content/high‐throughput imaging and analysis of embryonic morphogenesis
Authors: Truong Thai V. , Supatto Willy
Published: April 2011

In vivo study of embryonic morphogenesis tremendously benefits from recent advances in live microscopy and computational analyses. Quantitative and automated investigation of morphogenetic processes opens the field to high‐content and high‐throughput strategies. Following experimental workflow currently developed in cell biology, we identify the key challenges for applying such strategies in developmental biology. We review the recent progress in embryo preparation and manipulation, live imaging, data registration, image segmentation, feature computation, and data mining dedicated to the study of embryonic morphogenesis. We discuss a selection of pioneering studies that tackled the current methodological bottlenecks and illustrated the investigation of morphogenetic processes in vivo using quantitative and automated imaging and analysis of hundreds or thousands of cells simultaneously, paving the way for high‐content/high‐throughput strategies and systems analysis of embryonic morphogenesis. genesis 49:555–569, 2011. © 2011 Wiley‐Liss, Inc.
Synthesis and Crystal Structures of μ‐Oxido‐ and μ‐Hydroxido‐Bridged Dinuclear Iron(III) Complexes with an N2O Donor Ligand – A Theoretical Study on the Influence of Weak Forces on the Fe–O–Fe Bridging Angle
Authors: Biswas Rituparna , Drew Michael G. B. , Estarellas Carolina , Frontera Antonio , Ghosh Ashutosh
Published: April 2011

The synthesis and crystal structures of three nonheme diiron(III) complexes with a tridentate N,N,O Schiff‐baseligand, 2‐({[2‐(dimethylamino)ethyl]imino}methyl)phenol (HL), are reported. Complexes [Fe2OL2(NCO)2] (1a) and [Fe2OL2(SAL)2]·H2O [SAL =o‐(CHO)C6H4O–] (1b) are unsupported μ‐oxido‐bridged dimers, and [Fe2(OH)L2(HCOO)2(Cl)] (2) is a μ‐hydroxido‐bridged dimer supported by a formato bridging ligand. All complexes have been characterized by X‐ray crystallography and spectroscopic analysis. Complex1bhas been reported previously; however, it has been reinvestigated to confirm the presence of a crucial water molecule in the solid state. Structural analyses show that in1athe iron atoms are pentacoordinate with a bent Fe–O–Fe angle [142.7(2)°], whereas in2the metal centers are hexacoordinate with a normal Fe–OH–Fe bridging angle [137.9(2)°]. The Fe–O–Fe angles in complexes1aand1bdiffer significantly to those usually shown by (μ‐oxido)FeIIIcomplexes. A theoretical study has been performed in order to rationalize this deviation. Moreover, the influence of the water molecule observed in the solid‐state structure of1bon the Fe–O–Fe angle is also analyzed theoretically.
Short‐Circuiting Azobenzene Photoisomerization with Electron‐Donating Substituents and Reactivating the Photochemistry with Chemical Modification
Authors: Bandara H. M. Dhammika , Cawley Shannon , Gascón José A. , Burdette Shawn C.
Published: April 2011

Azobenzene (AB) undergoes (E) → (Z) isomerization upon exposure to light. Whereas the light‐induced structural change can be exploited for numerous applications, a second, light‐orthogonal switch would facilitate the development of new uses for AB derivatives. Electron‐donating groups on the AB ring system change not only the absorption wavelengths, but also the isomerization properties. Experimental observations and computational studies suggest that the inclusion of multiple electron‐donating groups can short‐circuit the concerted inversion isomerization mechanism of AB by providing new conical intersections between excited states. This phenomenon has been exploited in a unique AB derivative where the conversion of a phenol into an ester restores the isomerization activity.
Chiral micellar electrokinetic chromatography‐atmospheric pressure photoionization of benzoin derivatives using mixed molecular micelles
Authors: He Jun , Shamsi Shahab A.
Published: April 2011

In the present work we report, for the first time, the successful on‐line coupling of chiral MEKC (CMEKC) to atmospheric pressure photoionization MS (APPI‐MS). Four structurally similar neutral test solutes (e.g. benzoin (BNZ) derivatives) were successfully ionized by APPI‐MS. The mass spectra in the positive ion mode showed that the protonated molecular ions of BNZs are not the most abundant fragment ions. Simultaneous enantioseparation by CMEKC and on‐line APPI‐MS detection of four photoinitiators, hydrobenzoin, BNZ, benzoin methyl ether, benzoin ethyl ether, were achieved using an optimized molar ratio of mixed molecular micelle of two polymeric chiral surfactants (polysodium N‐undecenoxy carbonyl‐L‐leucinate and polysodium N‐undecenoyl‐L,L‐leucylvalinate). The CMEKC conditions, such as voltage, chiral polymeric surfactant concentration, buffer pH, and BGE concentration, were optimized using a multivariate central composite design (CCD). The sheath liquid composition (involving %v/v methanol, dopant concentration, electrolyte additive concentration, and flow rate) and spray chamber parameters (drying gas flow rate, drying gas temperature, and vaporizer temperature) were also optimized with CCD. Models built based on the CCD results and response surface method were used to analyze the interactions between factors and their effects on the responses. The final overall optimum conditions for CMEKC‐APPI‐MS were also predicted and found in agreement with the experimentally optimized parameters.
Fiber‐free coupling between bulk laser beams and on‐chip polymer‐based multimode waveguides
Authors: Jensen Thomas G. , Nielsen Lars B. , Kutter Jörg P.
Published: April 2011

In this paper, we demonstrate the design of a virtually alignment‐free optical setup for use with microfluidic applications involving a layered glass/SU‐8/PDMS (polydimethylsiloxane) chip. We show how inexpensive external lenses combined with carefully designed on‐chip lenses can be used to couple light from a bulk beam to on‐chip waveguides and back into a bulk beam again. Using this setup, as much as 20% of the light coming from the source can be retrieved after passing through the on‐chip waveguides. The proposed setup is based on a pin‐aided alignment system that makes it possible to change chips in the optical train in only a few seconds with a standard deviation of about 2% in the transmitted power. Furthermore, we demonstrate how these optical setups can be combined with microfluidics to create an on‐chip flow cytometer enabling detection and counting of polystyrene particles down to 1 μm at a rate of 100 Hz.
A high‐throughput microchip‐based glycan screening assay for antibody cell culture samples
Authors: Primack Jeremy , Flynn Gregory C. , Pan Hai
Published: April 2011

A high‐throughput screening assay was developed to quantify major glycan species in the crude mammalian cell culture samples for monoclonal antibodies (mAbs). This method utilizes high‐speed microchip electrophoresis separation following a fast sample preparation procedure. Using a 96‐well ultra‐filtration membrane, interfering species in the cell culture media were efficiently removed as the samples were concentrated. A commercial microchip electrophoresis instrument was used for high‐speed separation, allowing each sample to be analyzed in less than 1 min. This method is well suited for the purpose of high‐throughput antibody glycan profiling during cell culture expression, including clone selection and cell culture process optimization. The relative levels of high mannose (HM), fucosylated and galactosylated glycan species in the Fc domain can be determined for hundreds of crude cell culture samples in a few hours.
Interdigitated comb‐like electrodes for continuous separation of malignant cells from blood using dielectrophoresis
Authors: Alazzam Anas , Stiharu Ion , Bhat Rama , Meguerditchian Ari‐Nareg
Published: April 2011

In this paper, a method for continuous flow separation of circulating malignant cells from blood in a microfluidic device using dielectrophoresis is discussed. Separation of MDA231 breast cancer cells after mixing with normal blood cells was achieved with a level of accuracy that enabled precise counting of the malignant cells, separation and eventually, sub‐culturing. MDA231 cells were separated from the blood to a daughter channel using two pairs of interdigitated activated comb‐like electrode structures. All experiments are performed with conductivity adjusted medium samples. The electrode pairs were positioned divergent and convergent with respect to the flow. The AC signals used in the separation are 20 V peak‐to‐peak with frequencies of 10–50 kHz. The separation is based on balance of magnitude of the dielectrophoretic force and hydrodynamic force. The difference in response between circulating malignant cells and normal cells at a certain band of alternating current frequencies was used for rapid separation of cancer cells from blood. The significance of these experimental results is discussed in this paper, with detailed reporting on the suspension medium, preparation of cells, flow condition and the fabrication process of the microfluidic chip. The present technique could potentially be applied to identify incident cancer at a stage and size that is not yet detectable by standard diagnostic techniques (imaging and biochemical testing). Alternatively, it may also be used to detect cancer recurrences.
Hepatic B7 homolog 1 expression is essential for controlling cold ischemia/reperfusion injury after mouse liver transplantation
Authors: Ueki Shinya , Castellaneta Antonino , Yoshida Osamu , Ozaki Kikumi , Zhang Matthew , Kimura Shoko , Isse Kumiko , Ross Mark , Shao Lifang , Stolz Donna B. , Thomson Angus W. , Demetris Anthony J. , Geller David A. , Murase Noriko
Published: April 2011

Abstract:

Ischemia/reperfusion (I/R) injury remains a key risk factor significantly affecting morbidity and mortality after liver transplantation (LT). B7 homolog 1 (B7-H1), a recently identified member of the B7 family, is known to play important roles in regulating local immune responses. We hypothesized that B7-H1 plays crucial roles during innate immune responses induced by hepatic I/R injury, and using B7-H1 knockout (KO) liver grafts, we tested this hypothesis in the mouse LT model with 24 hours of cold storage. Cold I/R injury in wild type (WT)-to-WT LT enhanced constitutive B7-H1 expression on dendritic cells and sinusoidal endothelial cells and promptly induced B7-H1 on hepatocytes. When B7-H1 KO liver grafts were transplanted into WT recipients, serum alanine aminotransferase (ALT) and graft necrosis levels were significantly higher than those after WT-to-WT LT. Augmented tissue injury in B7-H1 KO grafts was associated with increased frequencies and absolute numbers of graft CD3+ T cells (particularly CD8+ T cells). B7-H1 KO grafts had significantly fewer annexin V+ CD8+ T cells, and this indicated a failure to delete infiltrating CD8+ T cells. To evaluate the relative contributions of parenchymal cell and bone marrow–derived cell (BMDC) B7-H1 expression, we generated and transplanted into WT recipients chimeric liver grafts lacking B7-H1 on parenchymal cells or BMDCs. A selective B7-H1 deficiency on parenchymal cells or BMDCs resulted in similar levels of ALT and liver injury, and this suggested that parenchymal cell and BMDC B7-H1 expression was involved in liver damage control. Human livers up-regulated B7-H1 expression after LT. Conclusion: The study demonstrates that graft tissue expression of B7-H1 plays a critical role in regulating inflammatory responses during LT-induced hepatic I/R injury, and negative coregulatory signals may have an important function in hepatic innate immune responses. (HEPATOLOGY 2011;)
Clinical utility of hepatitis B surface antigen quantitation in patients with chronic hepatitis B: A review
Authors: Liaw Yun-Fan
Published: April 2011

This clinically relevant review focuses on recent findings concerning hepatitis B surface antigen (HBsAg) quantitation in untreated patients and treated patients with chronic hepatitis B. Recent studies and emerging data have shown that both HBsAg and hepatitis B virus (HBV) DNA levels decline during the natural course of a chronic HBV infection; they are lowest in the inactive phase, which is also characterized by the highest HBsAg/HBV DNA ratio. It has been demonstrated that the combined use of HBsAg and HBV DNA levels might help in the identification of true inactive carriers with high accuracy. Retrospective analyses of HBsAg levels in patients undergoing therapy have suggested a role for HBsAg quantitation in monitoring the response to therapy. In comparison with nucleos(t)ide analogues (NAs), interferon-based therapy results in greater overall declines in serum HBsAg levels. A rapid on-treatment decline in HBsAg levels appears to be predictive of a sustained response. With the aid of HBsAg quantitation, it appears that we can anticipate an individualized approach to tailoring the treatment duration. The proposal of early stopping rules for patients not responding to pegylated interferon (according to a lack of any HBsAg decline) represents a step toward a response-guided approach. The development of stopping rules for patients treated with NAs is desirable for reducing the need for lifelong therapy. However, before stopping rules for antiviral therapy can be applied, we need to learn more about the kinetics of HBsAg declines during the natural history of the infection and as a response to therapy so that we can better define the best timing, the relevant HBsAg cutoff levels, and the best ways to apply these rules in clinical practice. (HEPATOLOGY 2011;)
Mitochondrial calcium regulates rat liver regeneration through the modulation of apoptosis
Authors: Guerra Mateus T. , Fonseca Emerson A. , Melo Flavia M. , Andrade Viviane A. , Aguiar Carla J. , Andrade Lídia M. , Pinheiro Ana Cristina N. , Casteluber Marisa C. F. , Resende Rodrigo R. , Pinto Mauro C. X. , Fernandes Simone O. A. , Cardoso Valbert N. , Souza-Fagundes Elaine M. , Menezes Gustavo B. , de Paula Ana M. , Nathanson Michael H. , de Fátima Leite Maria
Published: April 2011

Abstract:

Subcellular Ca2+ signals control a variety of responses in the liver. For example, mitochondrial Ca2+ (Ca Symbol) regulates apoptosis, whereas Ca2+ in the nucleus regulates cell proliferation. Because apoptosis and cell growth can be related, we investigated whether Ca Symbol also affects liver regeneration. The Ca2+-buffering protein parvalbumin, which was targeted to the mitochondrial matrix and fused to green fluorescent protein, was expressed in the SKHep1 liver cell line; the vector was called parvalbumin–mitochondrial targeting sequence–green fluorescent protein (PV-MITO-GFP). This construct properly localized to and effectively buffered Ca2+ signals in the mitochondrial matrix. Additionally, the expression of PV-MITO-GFP reduced apoptosis induced by both intrinsic and extrinsic pathways. The reduction in cell death correlated with the increased expression of antiapoptotic genes [B cell lymphoma 2 (bcl-2), myeloid cell leukemia 1, and B cell lymphoma extra large] and with the decreased expression of proapoptotic genes [p53, B cell lymphoma 2–associated X protein (bax), apoptotic peptidase activating factor 1, and caspase-6]. PV-MITO-GFP was also expressed in hepatocytes in vivo with an adenoviral delivery system. Ca Symbol buffering in hepatocytes accelerated liver regeneration after partial hepatectomy, and this effect was associated with the increased expression of bcl-2 and the decreased expression of bax. Conclusion: Together, these results reveal an essential role for Ca Symbol in hepatocyte proliferation and liver regeneration, which may be mediated by the regulation of apoptosis. (HEPATOLOGY 2011;)
Selection of scFv phages specific for chloramphenicol acetyl transferase (CAT), as alternatives for antibodies in CAT detection assays
Authors: Van Dorst Bieke , Mehta Jaytry , Rouah‐Martin Elsa , Backeljau Jelke , De Coen Wim , Eeckhout Dominique , De Jaeger Geert , Blust Ronny , Robbens Johan
Published: April 2011

Reporter gene assays are commonly used in applied toxicology to measure the transcription of genes involved in toxic responses. In these reporter gene assays, transgenic cells are used, which contain a promoter–operator region of a gene of interest fused to a reporter gene. The transcription of the gene of interest can be measured by the detection of the reporter protein. Chloramphenicol acetyl transferase (CAT) is frequently used as a reporter protein in mammalian reporter gene assays. Although CAT can be measured by different detection systems, like enzymatic and immune assays, most of these tests are expensive, time‐consuming and labor‐intensive. The excellent characteristics of phages, like their high affinity and specificity, their fast, cheap and animal‐friendly manufacturing process with low batch‐to‐batch variations and their stability, make them appropriate as alternatives for antibodies in detection assays. Therefore, in this study single‐chain variable fragment (scFv) phages were selected with affinity for CAT. Several scFv phages were selected that showed affinity towards CAT in a screening ELISA. Surface plasmon resonance analyses showed that the tested scFv phages have an affinity for CAT with a dissociation constant (Kd) around 1 µM. The selected scFv phages in this study could be used as capture elements in a highly sensitive sandwich ELISA to detect CAT concentration as low as 0.1 ng ml−1 or 4 pM. This low detection limit demonstrates the potential of the scFv phages as an alternative for capturing antibodies in a highly sensitive detection test to measure CAT concentrations in reporter gene assays. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative analysis of shape and volume changes in activated thrombocytes in real time by single‐shot spatial light modulator‐based differential interference contrast imaging
Authors: Khan Saranjam , Jesacher Alexander , Nussbaumer Walter , Bernet Stefan , Ritsch‐Marte Monika
Published: April 2011

We suggest to use a combination of optical tweezers and single‐image quantitative differential interference contrast (DIC) emulated by a spatial light modulator (SLM) to study physiological shape changes in thrombocytes after activation and demonstrate the effectiveness of this system for the given task. A specially designed phase mask displayed at the SLM enables quantitative phase calculation from only a single recording. The optical tweezers stabilize trapped thrombocytes for long‐time monitoring of changes in the optical thickness profile of thrombocytes during activation by adenosine diphosphate (ADP). (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sea cucumber (Stichopus hermanii) based hydrogel to treat burn wounds in rats
Authors: Zohdi Rozaini Mohd , Zakaria Zuki Abu Bakar , Yusof Norimah , Mustapha Noordin Mohamed , Abdullah Muhammad Nazrul Hakim
Published: April 2011

Malaysian sea cucumber was incorporated into hydrogel formulation by using electron beam irradiation technique and was introduced as novel cross‐linked Gamat Hydrogel dressing. This study investigated whether Gamat Hydrogel enhanced repair of deep partial skin thickness burn wound in rats and its possible mechanism. Wounds were treated with either Gamat Hydrogel, control hydrogel, OpSite® film dressing or left untreated. Skin samples were taken at 7, 14, 21, and 28 days post burn for histological and molecular evaluations. Gamat Hydrogel markedly enhanced wound contraction and improved histological reorganization of the regenerating tissue. Furthermore, the dressing modulated the inflammatory responses, stimulated the activation and proliferation of fibroblasts, and enhanced rapid production of collagen fiber network with a consequently shorter healing time. The level of proinflammatory cytokines; IL‐1α, IL‐1β, and IL‐6, were significantly reduced in Gamat Hydrogel treated wounds compared with other groups as assessed by reverse transcription‐polymerase chain reaction (RT‐PCR). In summary, our results showed that Gamat Hydrogel promoted burn wound repair via a complex mechanism involving stimulation of tissue regeneration and regulation of pro‐inflammatory cytokines. The resultant wound healing effects were attributed to the synergistic effect of the hydrogel matrix and incorporated sea cucumber. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
High‐efficiency cell seeding method by relatively hydrophobic culture strategy
Authors: Hsieh Chin‐Hsiung , Kuo Wei‐Ti , Huang Yi‐Cheng , Huang Yi‐You
Published: April 2011

Cell adhesion efficiency is one of the key factors affecting the results of manufacturing tissue engineering constructs. High efficiency is required for seeding low proliferation cells onto scaffolds. In this study, we designed a strategy to improve the efficiency of cell adhesion using hydrophobic cell culture environment to enhance cells adhering to a scaffold. Cells have lower affinity to the surface of polydimethylsiloxane (PDMS) than tissue culture polystyrene (TCPS) plates. When cells were cultured with gelatin microspheres or chitosan films in a PDMS‐coated plate instead of a normal TCPS plate, there was a significant increase in cell attachment efficiency. Cells cultured in the PDMS‐coated system tended to selectively attach onto the gelatin microspheres or chitosan films, which are relatively more hydrophilic than the PDMS surface. However, minimal cell attachment on gelatin microspheres or chitosan films was observed when gelatin microspheres or chitosan films were placed in normal TCPS plate. Cell counting experiments with gelatin microspheres in the PDMS‐coated system resulted in a cell attachment efficiency of 89.8% after 1 day of cultivation, whereas the cell attachment efficiency was less than 1% in normal TCPS plate. The results demonstrate that the method is easy to use and could be useful for fast cultivation of cell‐scaffold constructs. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Characterizing accelerated capture of deoligomerized TNF within hemoadsorption beads used to treat sepsis
Authors: Kimmel Jeremy D. , Lacko Christopher S. , Delude Russell L. , Federspiel William J.
Published: April 2011

Sepsis is a systemic inflammatory response to infection, characterized by overexpression of cytokines in the circulating blood. Removal of cytokines and other inflammatory mediators from the blood may help attenuate systemic inflammation during sepsis and improve patient outcomes. In this work, we examined the dynamics of TNF capture within porous, polymeric sorbent beads used in a cytokine adsorption device. We sought to quantify how perturbation of TNF oligomeric structure accelerates TNF removal within the device. TNF was incubated with 10% DMSO for 24 h, which promoted complete monomerization of trimeric TNF, and accelerated TNF capture within the sorbent device compared with native TNF; removal halftime = 13.3 ± 1.5 minversus112.8 ± 13.3 min, respectively. Intramolecular crosslinking stabilized the trimeric TNF structure and prevented DMSO monomerization. Results demonstrate that TNF is an unstable oligomeric molecule that can be dissociated into its smaller monomeric constituents to facilitate faster capture by hemoadsorption beads. Strategies to promote localized TNF deoligomerization at the sorbent surface may significantly accelerate TNF capture rates from the circulating blood using hemoadsorption as a treatment for sepsis. This concept could be extended to improve removal of other oligomeric molecules using size exclusion filtration materials for a variety of disease states. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Direct‐write bioprinting three‐dimensional biohybrid systems for future regenerative therapies
Authors: Chang Carlos C. , Boland Eugene D. , Williams Stuart K. , Hoying James B.
Published: April 2011

Regenerative medicine seeks to repair or replace dysfunctional tissues with engineered biological or biohybrid systems. Current clinical regenerative models utilize simple uniform tissue constructs formed with cells cultured onto biocompatible scaffolds. Future regenerative therapies will require the fabrication of complex three‐dimensional constructs containing multiple cell types and extracellular matrices. We believe bioprinting technologies will provide a key role in the design and construction of future engineered tissues for cell‐based and regenerative therapies. This review describes the current state‐of‐the‐art bioprinting technologies, focusing on direct‐write bioprinting. We describe a number of process and device considerations for successful bioprinting of composite biohybrid constructs. In addition, we have provided baseline direct‐write printing parameters for a hydrogel system (Pluronic F127) often used in cardiovascular applications. Direct‐write dispensed lines (gels with viscosities ranging from 30 mPa s to greater than 600 × 106 mPa s) were measured following mechanical and pneumatic printing via three commercially available needle sizes (20 ga, 25 ga, and 30 ga). Example patterns containing microvascular cells and isolated microvessel fragments were also bioprinted into composite 3D structures. Cells and vessel fragments remained viable and maintained in vitro behavior after incorporation into biohybrid structures. Direct‐write bioprinting of biologicals provides a unique method to design and fabricate complex, multicomponent 3D structures for experimental use. We hope our design insights and baseline parameter descriptions of direct‐write bioprinting will provide a useful foundation for colleagues to incorporate this 3D fabrication method into future regenerative therapies. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
The effect of ball milling grinding pathways on the bulk and reactivity properties of calcium phosphate cements
Authors: Lopez‐Heredia M. A. , Bohner M. , Zhou W. , Winnubst A. J. A. , Wolke J. G. C. , Jansen J. A.
Published: April 2011

Calcium phosphate cements (CPCs) are significant alternatives to autologous bone grafting. CPCs can be composed of biphasic or multiphase calcium phosphate (CaP) compounds. A common way to process CPCs is by ball milling. Ball milling can be used for grinding or mechanosynthesis. The aim of this study was to determine the effect of well‐defined ball milling grinding parameters, applied via different milling pathways, on the properties of CPCs. Starting CaP compounds used included α‐tricalcium phosphate, dicalcium phosphate anhydrous and precipitated hydroxyapatite. Scanning electron microscopy showed changes in the powder morphology, which were related to the behavior of the starting CaP materials. Specific surface area (SSA) and particle size (PS) measurements exposed the effect of ball milling on the CaP compounds and CPC powders. X‐ray diffraction revealed no effect of ball milling pathways or milling time on the composition of CPCs or the starting materials, but affected their crystallographic properties. No contamination of the milling media or transformation into an amorphous calcium phosphate compound was found. The milling pathways affected setting and cohesion. Fourier transform infrared spectroscopy (FTIR) revealed differences on the CPC v4‐PO43‐ bands according to the interaction, created between the CaP compounds by the milling pathways. FTIR confirmed that the milling pathways changed the crystallographic properties. This study demonstrates that the pathways used for milling grinding modify the PS, SSA, and crystallographic properties of the powders, without affecting their composition. These modifications affected the bulk and reactivity properties of the CPCs by creating different setting and cohesion behaviors. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Enhanced bonding between YSZ surfaces using a gas‐phase fluorination pretreatment
Authors: Piascik Jeffrey R. , Wolter Scott D. , Stoner Brian R.
Published: April 2011

The present investigation focuses on the surface modification, via gas‐phase fluorination process, of yttria‐ stabilized zirconia (YSZ) to increase its wettability and chemical bonding directly to acrylate‐based resin cements. YSZ plates and cylinders, as‐received and roughened, were pretreated in a fluorine containing plasma and bonded with a commercially available resin cement for simple shear bond adhesion testing. No organo‐silane coupling agent was used to enhance bonding between the two substrates. Shear bond tests revealed that bond strength increased with fluorination time. Furthermore, the pretreated, as received (nonroughened) specimen group displayed relatively high bond strengths suggesting surface reactivity and direct chemical bonding with the resin cement. X‐ray photoelectron spectroscopy analysis revealed the surface conversion layer to be a mixture of phases; zirconium oxyfluoride, zirconium fluoride, and yttrium fluoride. It is hypothesized that these fluoride and oxyfluoride phases have the potential to increase surface hydroxylation, enabling direct covalent bonding between YSZ and resin cement. It is believed that this surface treatment has broad reaching impact when using high‐strength ceramics in a multitude of bioapplications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Ubiquitination and downregulation of ErbB2 and estrogen receptor‐alpha by kinase inhibitor MP‐412 in human breast cancer cells
Authors: Suzuki Tsuyoshi , Fujii Akihiro , Ochi Hiroshi , Nakamura Hideo
Published: April 2011

ErbB2 has been proven to be an important target for breast cancer therapy. MP‐412 is a dual ErbB2 and epidermal growth factor receptor tyrosine kinase inhibitor belonging to an irreversible‐type anilinoquinazoline derivative. We demonstrate herein that along with the kinase inhibition, MP‐412 has the ability to induce ubiquitination, internalization, and degradation of ErbB2 in several human breast cancer cell lines at concentrations relatively higher than those required for kinase inhibition. Another irreversible inhibitor, CI‐1033, showed similar activity, while the reversible compounds were ineffective, suggesting a crucial role of covalent bonding functionality in these effects. In MCF7 cells, MP‐412 depleted not only ErbB2 but also estrogen receptor (ER)‐α, and to some extent, affected Raf‐1, while MP‐412 activated Hsp70 expression. Moreover, we observed that MP‐412 increased immunocomplexing of Hsp70 with ErbB2 and ER‐α, with simultaneous induction of ubiquitination of these client proteins. Furthermore, in combination with proteasome inhibitor, MP‐412 resulted in the noticeable accumulation of ErbB2 and ER‐α in the detergent insoluble fraction of cell lysates. These results suggest that MP‐412 acts as an inhibitor of Hsp90 function, whereas MP‐412 did not bind directly to ATP‐binding site of Hsp90, unlike geldanamycin. We also found that new protein synthesis was involved in the activity of MP‐412 on Hsp90 modulation. Since downregulation of ErbB2 and ER‐α by accelerating the ubiquitin‐proteolysis system will become an attractive approach for breast cancer therapy, we expect MP‐412 to be a lead compound for the drug design and the development of such agents. J. Cell. Biochem. 112: 2279–2286, 2011. © 2011 Wiley‐Liss, Inc.
Combined supplementation of vanadium and fish oil suppresses tumor growth, cell proliferation and induces apoptosis in DMBA‐induced rat mammary carcinogenesis
Authors: Manna Sangita , Das Subhadeep , Chatterjee Mary , Janarthan M. , Chatterjee Malay
Published: April 2011

The anti‐cancer activity of vanadium and fish oil has been shown in a large number of studies. This study was undertaken to analyze the combined effect of vanadium and fish oil on 7,12‐dimethylbenz(α)anthracene (DMBA)‐induced mammary carcinogenesis in female Sprague–Dawley rats. The whole experiment was divided into three parts: (1) DNA strand breaks study, (2) morphological analysis, and (3) histological and immunohistochemical study. Rats were treated with DMBA (0.5 mg/0.2 ml corn oil/100 g body weight) by a tail vein injection. Rats received vanadium (w/v) as ammonium monovanadate at a concentration of 0.5 ppm (4.27 µmol/L) in the drinking water and given ad libitum and/or fish oil (0.5 ml/day/rat) by oral gavage. Histology, morphology, DNA strand breaks, cell proliferation, and apoptosis of the mammary tissue were assessed in this study. Treatment with vanadium or fish oil alone significantly reduced the DNA strand breaks, palpable mammary tumors, tumor multiplicity, and cell proliferation but the maximum protection effect was found in the group that received both vanadium and fish oil and the combination treatment offered an additive effect (P < 0.05). Furthermore, vanadium and fish oil significantly increased the TUNEL‐positive apoptotic cells (P < 0.05) but the increase was maximal with combination treatment and had an additive effect. These results affirm the benefits of administration of vanadium and fish oil in the prevention of rat mammary carcinogenesis which was associated with reduced DNA strand breaks, palpable mammary tumors and cell proliferation and increased TUNEL‐positive apoptotic cells. J. Cell. Biochem. 112: 2327–2339, 2011. © 2011 Wiley‐Liss, Inc.
The role of cognitions in imagery rescripting for posttraumatic nightmares
Authors: Long Mary E. , Davis Joanne L. , Springer Justin R. , Elhai Jon D. , Rhudy Jamie L. , Teng Ellen J. , Frueh B. Christopher
Published: April 2011

Despite growing support for the use of imagery rescripting to treat posttraumatic nightmares (PTNMs), its underlying mechanisms have not been examined. This secondary data analysis piloted the proposal that modification of posttraumatic cognitions is a mechanism of change when using a manualized PTNM imagery rescripting intervention. Significant linear reductions in posttraumatic cognitions were observed from baseline through 6‐month follow‐up evaluations. Change in total negative cognitions was significantly correlated with change in posttraumatic stress disorder symptoms. Initial amount of change in subscale scores also predicted the amount of distal change observed at the 6‐month follow‐up. These findings provide preliminary evidence that trauma‐related cognitions may improve over time as a result of imagery rescripting. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1–9, 2011.
Integrating post‐transcriptional regulation into the embryonic stem cell gene regulatory network
Authors: Cassar Paul A. , Stanford William L.
Published: April 2011

Stem cell behavior is orchestrated as a multilayered, concert of gene regulatory mechanisms collectively referred to as the gene regulatory network (GRN). Via cooperative mechanisms, transcriptional, epigenetic, and post‐transcriptional regulators activate and repress gene expression to finely regulate stem cell self‐renewal and commitment. Due to their tractability, embryonic stem cells (ESCs) serve as the model stem cell to dissect the complexities of the GRN, and discern its relation to stem cell fate. By way of high‐throughput genomic analysis, targets of individual gene regulators have been established in ESCs. The compilation of these discrete networks has revealed convergent, multi‐dimensional gene regulatory mechanisms involving transcription factors, epigenetic modifiers, non‐coding RNA (ncRNA), and RNA‐binding proteins. Here we highlight the seminal genomic studies that have shaped our understanding of the ESC GRN and describe alternate post‐transcriptional gene regulatory mechanisms that require in depth analyses to draft networks that fully model ESC behavior. J. Cell. Physiol. 227: 439–449, 2012. © 2011 Wiley Periodicals, Inc.
MicroRNA‐181b and microRNA‐9 mediate arsenic‐induced angiogenesis via NRP1
Authors: Cui Yi , Han Zhongji , Hu Yi , Song Ge , Hao Chanjuan , Xia Hongfei , Ma Xu
Published: April 2011

Environmental exposure to inorganic arsenic compounds has been reported to have serious health effects on humans. Recent studies reported that arsenic targets endothelial cells lining blood vessels, and endothelial cell activation or dysfunction, may underlie the pathogenesis of arsenic‐induced diseases and developmental toxicity. It has been reported that microRNAs (miRNAs) may act as an angiogenic switch by regulating related genes. The present study was designed to test the hypothesis that arsenite‐regulated miRNAs play pivotal roles in arsenic‐induced toxicity. Fertilized eggs were injected via the yolk sac with 100 nM sodium arsenite at Hamburger–Hamilton (HH) stages 6, 9, and 12, and harvested at HH stage 18. To identify the individual miRNAs and mRNAs that may regulate the genetic network, the expression profiles of chick embryos were analyzed by microarray analysis. Microarray analyses revealed that the expression of a set of miRNAs changed after arsenite administration, especially miRNA‐9, 181b, 124, 10b, and 125b, which exhibited a massive decrease in expression. Integrative analyses of the microarray data revealed that several miRNAs, including miR‐9 and miR‐181b, might target several key genes involved in arsenic‐induced developmental toxicity. A luciferase reporter assay confirmed neuropilin‐1 (Nrp1) as a target of mir‐9 and mir‐181b. Data from the transwell migration assay and the tube‐formation assay indicated that miR‐9 and mir‐181b inhibited the arsenic‐induced EA.hy926 cell migration and tube formation by targeting NRP1. Our study demonstrates that the environmental toxin, sodium arsenite, induced angiogenesis by altering the expression of miRNAs and their cognate mRNA targets. J. Cell. Physiol. © 2011 Wiley Periodicals, Inc.
Homeodomain transcription factors regulate BMP‐2‐induced osteoactivin transcription in osteoblasts
Authors: Singh Maneet , Del Carpio‐Cano Fabiola E. , Monroy M. Alexandra , Popoff Steven N. , Safadi Fayez F.
Published: April 2011

Osteoactivin (OA) is required for the differentiation of osteoblast cells. OA expression is stimulated by bone morphogenetic protein‐2 (BMP‐2). BMP‐2 recruits homeodomain transcription factors Dlx3, Dlx5, and Msx2 to selectively activate or repress transcription of osteogenic genes and hence tightly regulate their transcription during osteoblast differentiation. Considering the key roles of Dlx3, Dlx5, and Msx2 in osteoblast differentiation, here we hypothesize that homeodomain proteins regulate BMP‐2‐induced OA transcription during osteoblast differentiation. Four classical homeodomain binding sites were identified in the proximal 0.96 kb region of rat OA promoter. Deletions and mutagenesis studies of the OA promoter region indicated that all four homeodomain binding sites are crucial for BMP‐2‐induced OA promoter activity. Simultaneous disruption of homeodomain binding sites at −852 and −843 of the transcription start site of OA gene significantly decreased the BMP‐2‐induced OA transcription and inhibited binding of Dlx3, Dlx5, and Msx2 proteins to the OA promoter. Dlx3 and Dlx5 proteins were found to activate the OA transcription, whereas, Msx2 suppressed BMP‐2‐induced OA transcription. Using chromatin immunoprecipitation assays, we demonstrated that the OA promoter is predominantly occupied by Dlx3 and Dlx5 during the proliferation and matrix maturation stages of osteoblast differentiation, respectively. During the matrix mineralization stage, BMP‐2 robustly enhanced the recruitment of Dlx5 and to a lesser extent of Dlx3 and Msx2 to the OA promoter region. Collectively, our results show that the BMP‐2‐induced OA transcription is differentially regulated by Dlx3, Dlx5, and Msx2 during osteoblast differentiation. J. Cell. Physiol. 227: 390–399, 2012. © 2011 Wiley Periodicals, Inc.
Hypoxia enhances cancer cell invasion through relocalization of the proprotein convertase furin from the trans‐golgi network to the cell surface
Authors: Arsenault Dominique , Lucien Fabrice , Dubois Claire M.
Published: April 2011

Tumor hypoxia is strongly associated with malignant progression such as increased cell invasion and metastasis. Although the invasion‐related genes affected by hypoxia have been well described, the contribution of post‐transcriptional mechanisms such as protein trafficking and proprotein processing associated with the hypoxic response remains poorly understood. The proprotein convertase furin, the major processing enzyme of the secretory pathway, resides in the trans‐Golgi network and most studies support a model where endogenous substrates are processed by furin within this compartment. Here, we report that hypoxia triggered an unexpected relocalization of furin from the trans‐Golgi network to endosomomal compartments and the cell surface in cancer cells. Exposing these cells back to normoxic conditions reversed furin redistribution, suggesting that the tumor microenvironment modulates furin trafficking in a highly regulated manner. Assessment of the mechanisms involved revealed that both Rab4GTPase‐dependent recycling and interaction of furin with the cytoskeletal anchoring protein, filamin‐A, are essential for the cell surface relocalization of furin. Interference with the association of furin with filamin‐A, prevented cell surface relocalization of furin and abolished the ability of cancer cells to migrate in response to hypoxia. Our observations support the notion that hypoxia promotes the formation of a peripheral processing compartment where furin translocates for enhanced processing of proproteins involved in tumorigenesis. J. Cell. Physiol. 227: 789–800, 2012. © 2011 Wiley Periodicals, Inc.
Nestin expression is lost in ventricular fibroblasts during postnatal development of the rat heart and re‐expressed in scar myofibroblasts
Authors: Béguin Pauline C. , Gosselin Hugues , Mamarbachi Maya , Calderone Angelino
Published: April 2011

Studies have reported that the intermediate filament protein nestin was expressed in various non‐stem/progenitor cells during development, downregulated during postnatal growth and re‐expressed following injury. The present study tested the hypothesis that an analogous paradigm was prevalent for ventricular fibroblasts. In the neonatal rat heart, nestin protein levels were significantly higher than the adult heart and the isolation of cardiac cells revealed a selective expression in ventricular fibroblasts. In adult ventricular fibroblasts, nestin protein expression was markedly lower compared to neonatal ventricular fibroblasts. Following ischemic damage to the rat heart, nestin staining was detected in a subpopulation of scar myofibroblasts (37%) and the percentage of immunoreactive cells was greater than adult ventricular fibroblasts (7%) but significantly lower than neonatal ventricular fibroblasts (86%). Moreover, dissimilar rates of 3H‐thymidine uptake were observed among the fibroblast populations and may be related in part to the disparate percentage of nestin(+) cells. To assess the role of nestin in DNA synthesis, neonatal ventricular fibroblasts were infected with a lentivirus containing a shRNAmir directed against the intermediate filament protein. The partial depletion of nestin expression in neonatal ventricular fibroblasts significantly reduced basal DNA synthesis, in the absence of an apoptotic response. Thus, postnatal development of the rat heart was associated with a selective loss of nestin expression in ventricular fibroblasts and subsequent induction in a subpopulation of myofibroblasts following ischemic injury. The re‐expression of nestin in scar myofibroblasts may represent an adaptive response to enhance their proliferative rate and accelerate the healing process. J. Cell. Physiol. 227: 813–820, 2012. © 2011 Wiley Periodicals, Inc.
Involvement of TACE/ADAM17 and ADAM10 in etoposide‐induced apoptosis of germ cells in rat spermatogenesis
Authors: Lizama Carlos , Rojas‐benitez Diego , Antonelli Marcelo , Ludwig Andreas , Moreno Ricardo D.
Published: April 2011

Germ cell apoptosis is important to regulate sperm production in the mammalian testis, but the molecular mechanisms underlying apoptosis are still poorly understood. We have recently shown that in vitro, etoposide induces upregulation of TACE/ADAM17 and ADAM10, two membrane‐bound extracellular metalloproteases. Here we show that in vivo these enzymes are involved in etoposide‐, but not in heat shock‐, induced apoptosis in rat spermatogenesis. Germ cell apoptosis induced by DNA damage was associated with an increase in protein levels and cell surface localization of TACE/ADAM17 and ADAM10. On the contrary, apoptosis of germ cells induced by heat stress, another cell death stimulus, did not change levels or localization of these proteins. Pharmacological in vivo inhibition of TACE/ADAM17 and ADAM10 prevents etoposide‐induced germ cell apoptosis. Finally, Gleevec (STI571) a pharmacological inhibitor of p73, a master gene controlling apoptosis induced by etoposide, prevented the increase of TACE/ADAM17 levels. Our results strongly suggest that TACE/ADAM17 participates in in vivo apoptosis of male germ cells induced by DNA damage. J. Cell. Physiol. 227: 829–838, 2012. © 2011 Wiley Periodicals, Inc.