bluuebunny/crossref_metadata_2025 huggingface dataset:
DNA methylation status is inversely correlated with green tea intake and physical activity in gastric cancer patients
Authors: Yuasa Yasuhito , Nagasaki Hiromi , Akiyama Yoshimitsu , Hashimoto Yutaka , Takizawa Touichirou , Kojima Kazuyuki , Kawano Tatsuyuki , Sugihara Kenichi , Imai Kazue , Nakachi Kei
Published: December 2008

Epigenetic silencing of genes by aberrant DNA methylation is recognized as a crucial component of the mechanism underlying tumorigenesis. However, the relationship between DNA methylation and the past lifestyle in cancer patients remains largely unknown. We examined the methylation statuses of 6 tumor‐related genes, CDX2 (homeobox transcription factor), BMP‐2 (bone morphogenetic protein 2), p16 (INK4A), CACNA2D3 (calcium channel‐related), GATA‐5 (transcription factor) and ER (estrogen receptor), in 106 primary gastric carcinomas by methylation‐specific PCR and compared them with the past lifestyles of the patients. The methylation frequencies of the genes were 23.6, 21.7, 9.4, 32.4, 40.8 and 59.1%, respectively. Significant association was found between a decreased intake of green tea and methylation of CDX2 and BMP‐2. More physical activity was correlated with a lower methylation frequency of CACNA2D3. Of these 6 genes, the methylation statuses of CDX2, BMP‐2 and p16 revealed a significant interrelationship and those of CACNA2D3, GATA‐5 and ER did likewise. Thus, some epidemiological factors, such as green tea intake, could be important as to determination of the methylation statuses of selected genes and may influence the development of cancer, including that of the stomach. © 2008 Wiley‐Liss, Inc.
Modulated release of OP‐1 and enhanced preosteoblast differentiation using a core‐shell nanoparticulate system
Authors: Haidar Ziyad S. , Azari Fereshteh , Hamdy Reggie C. , Tabrizian Maryam
Published: December 2008

A release‐controlled OP‐1 delivery system consisting of a suspension of core‐shell nanoparticles was prepared. The nanoparticles were composed of a core of positively‐charged large unilamellar liposomes and a shell constructed through the L‐b‐L assembly of alternating layers of negatively‐charged sodium alginate and positively‐charged chitosan. Cytotoxicity was assayed with MC3T3‐E1.4 mouse preosteoblast cells and cell viability was determined by colorimetry (CellQuanti‐MTT™ kit). The system was loaded with a range of OP‐1 concentrations and the release profiles were obtained and fitted into the Higuchi model to determine release kinetics. Alkaline phosphatase (ALP) activity of preosteoblasts was evaluated using a micro‐BCA assay. The resulting monodisperse and nontoxic spherical nanoparticles exhibited high physical stability in simulated physiological media as well as an extended shelf‐life allowing for immediate protein loading before future administration. ALP activity increased over time with the OP‐1 loaded delivery system when compared with control, protein alone, and nanoparticles alone (p < 0.05). The system offers copious compartments for protein entrapment including the aqueous core and within the polyelectrolyte layers in the shell and demonstrates a sustained triphasic linear release of OP‐1 over a prolonged period of 45 days, in vitro. This system offers a great advantage for optimum growth factor performance when applied in different anatomical sites of varying defect sizes and vascularity. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
The behavior of mesenchymal stem cells on micropatterned PLLA membranes
Authors: Lee I‐Chi , Lee Yu‐Tsang , Yu Bo‐Yi , Lai Juin‐Yih , Young Tai‐Horng
Published: December 2008

The aim of this study was to evaluate the behaviors of mesenchymal stem cells (MSCs) on Poly(L‐Lactic acid) (PLLA) membranes with different surface topographies. The double‐sided micropatterns, island‐patterned, and sunken‐patterned PLLA membranes with diameters of 60 and 100 μm, were fabricated by the soft lithography method. The cell viability of MSCs on the island‐ and sunken‐patterned PLLA membranes were characterized by scanning electron microscopy (SEM), MTT assay, and flow cytometric analysis. Cell adhesion and proliferation capability were superior for the MSCs seeding on the island‐patterned PLLA membranes than those on the sunken‐patterned PLLA membranes. Especially, we observed the best biocompatibility for MSCs on the island‐patterned surface with diameter of 100 μm. In addition, the improvement of cell attachment and augmenting subsequent cellular response are investigated after the island‐patterned membranes precoating with collagen and fibronectin. Furthermore, the flow cytometric analysis reveals the MSCs can expand and maintain the phenotype on these PLLA membranes without losing its potential for differentiation. Since scale‐up of cell production and optimization of culture conditions are important for stem cell engineering, to control the stem cell proliferation and differentiation is necessary. Therefore, besides topographical properties play a crucial role on the stem cells attachment and proliferative activity, it is suggested that the “relative scale” between cell and pattern also affects the cell adhesion morphologies and cell behaviors. Based on the overall cellular response, this study provides a valuable guidance to prepare appropriate topographic surface for tissue engineering application. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Osteogenic differentiation of human mesenchymal stem cells on poly(ethylene glycol)‐variant biomaterials
Authors: Briggs Tonye , Treiser Matthew D. , Holmes Paul F. , Kohn Joachim , Moghe Prabhas V. , Arinzeh Treena Livingston
Published: December 2008

This study evaluated the osteogenic differentiation of human mesenchymal stem cells (MSCs), on tyrosine‐derived polycarbonates copolymerized with poly(ethylene glycol) (PEG) to determine their potential as a scaffold for bone tissue engineering applications. The addition of PEG in the backbone of polycarbonates has been shown to alter mechanical properties, degradation rates, degree of protein adsorption, and subsequent cell adhesion and motility in mature cell phenotypes. Its effect on MSC behavior is unknown. MSC morphology, motility, proliferation, and osteogenic differentiation were evaluated on polycarbonates containing 0–5% PEG over a 14 day culture. MSCs on polycarbonates containing 0% or 3% PEG content upregulated the expression of osteogenic markers as demonstrated by alkaline phosphatase activity and osteocalcin expression although at different stages in the 14 day culture. Cells on polycarbonates containing no PEG were characterized as having early onset of cell spreading and osteogenic differentiation. Cells on 3% PEG surfaces were delayed in cell spreading and osteogenic differentiation, but had the highest motility as compared with cells on substrates containing no PEG and substrates containing 5% PEG at early time points. Throughout the culture, cells on polycarbonates containing 5% PEG had the lowest levels of osteogenic markers, displayed poor cell‐substrate adhesion, and established cell‐cell aggregates. Thus, designing substrates with minute variations in PEG may serve as a tool to guide MSC adhesion and motility accompanying osteogenic differentiation, and may be beneficial for abundant bone tissue formation in vivo. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Biomimetic control of vascular smooth muscle cell morphology and phenotype for functional tissue‐engineered small‐diameter blood vessels
Authors: Chan‐Park Mary B. , Shen Jin Ye , Cao Ye , Xiong Yun , Liu Yunxiao , Rayatpisheh Shahrzad , Kang Gavin Chun‐Wei , Greisler Howard P.
Published: December 2008

Small‐diameter blood vessel substitutes are urgently needed for patients requiring replacements of their coronary and below‐the‐knee vessels and for better arteriovenous dialysis shunts. Circulatory diseases, especially those arising from atherosclerosis, are the predominant cause of mortality and morbidity in the developed world. Current therapies include the use of autologous vessels or synthetic materials as vessel replacements. The limited availability of healthy vessels for use as bypass grafts and the failure of purely synthetic materials in small‐diameter sites necessitate the development of a biological substitute. Tissue engineering is such an approach and has achieved promising results, but reconstruction of a functional vascular tunica media, with circumferentially oriented contractile smooth muscle cells (SMCs) and extracellular matrix, appropriate mechanical properties, and vasoactivity has yet to be demonstrated. This review focuses on strategies to effect the switch of SMC phenotype from synthetic to contractile, which is regarded as crucial for the engineering of a functional vascular media. The synthetic SMC phenotype is desired initially for cell proliferation and tissue remodeling, but the contractile phenotype is then necessary for sufficient vasoactivity and inhibition of neointima formation. The factors governing the switch to a more contractile phenotype with in vitro culture are reviewed. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Transcriptional up‐regulation of FoxM1 in response to hypoxia is mediated by HIF‐1
Authors: Xia Li‐Min , Huang Wen‐Jie , Wang Bo , Liu Mei , Zhang Qiong , Yan Wei , Zhu Qian , Luo Min , Zhou Zhen‐Zhen , Tian De‐An
Published: December 2008

The proliferation‐specific Forkhead box M1 (FoxM1) transcription factor is overexpressed in cancer cells and acts as an important regulator of cancer cell growth and survival. Here, we show the molecular mechanisms by which hypoxia regulate FoxM1 expression in cancer cells. When cells were subjected to hypoxia (1% O2), the mRNA and protein levels of FoxM1 had a significant increase in cancer cells (HepG2, MCF‐7, and HeLa). Such increase was due to the direct binding of hypoxia‐inducible factor 1 (HIF‐1) to the HIF‐1 binding sites in the FoxM1 promoter. By deletion and mutation assays, we demonstrated that the HIF1‐1 and HIF1‐3/4 binding sites on the FoxM1 promoter were essential for transcriptional activation of FoxM1 by hypoxia. We also demonstrated that HIF‐1α directly bound to the promoter of FoxM1 and the binding was specific, as revealed by HIF‐1 binding/competition assay and chromatin immunoprecipitation assay. Consequently, the up‐regulation of FoxM1 accelerated the growth of hypoxic cancer cells by decreasing nuclear levels of p21 and increasing expression of cyclin B1 and cyclin D1. These findings provide a new insight into how tumor cells overcome hypoxic stress and survive, and also disclose a new regulatory mechanism of FoxM1 expression in tumor cells. J. Cell. Biochem. 106: 247–256, 2009. © 2008 Wiley‐Liss, Inc.
A transgenic red fluorescent protein‐expressing nude mouse for color‐coded imaging of the tumor microenvironment
Authors: Yang Meng , Reynoso Jose , Bouvet Michael , Hoffman Robert M.
Published: December 2008

The tumor microenvironment (TME) is critical for tumor growth and progression. We have previously developed color‐coded imaging of the TME using a green fluorescent protein (GFP) transgenic nude mouse as a host. However, most donor sources of cell types appropriate for study in the TME are from mice expressing GFP. Therefore, a nude mouse expressing red fluorescent protein (RFP) would be an appropriate host for transplantation of GFP‐expressing stromal cells as well as double‐labeled cancer cells expressing GFP in the nucleus and RFP in the cytoplasm, thereby creating a three‐color imaging model of the TME. The RFP nude mouse was obtained by crossing non‐transgenic nude mice with the transgenic C57/B6 mouse in which the β‐actin promoter drives RFP (DsRed2) expression in essentially all tissues. In crosses between nu/nu RFP male mice and nu/+ RFP female mice, the embryos fluoresced red. Approximately 50% of the offspring of these mice were RFP nude mice. In the RFP nude mouse, the organs all brightly expressed RFP, including the heart, lungs, spleen, pancreas, esophagus, stomach, duodenum, the male and female reproductive systems; brain and spinal cord; and the circulatory system, including the heart, and major arteries and veins. The skinned skeleton highly expressed RFP. The bone marrow and spleen cells were also RFP positive. GFP‐expressing human cancer cell lines, including HCT‐116‐GFP colon cancer and MDA‐MB‐435‐GFP breast cancer were orthotopically transplanted to the transgenic RFP nude mice. These human tumors grew extensively in the transgenic RFP nude mouse. Dual‐color fluorescence imaging enabled visualization of human tumor–host interaction. The RFP nude mouse model should greatly expand our knowledge of the TME. J. Cell. Biochem. 106: 279–284, 2009. © 2008 Wiley‐Liss, Inc.
Transplantation of human embryonic stem cell‐derived endothelial cells for vascular diseases
Authors: Li Zongjin , Han Zhongchao , Wu Joseph C.
Published: December 2008

Using endothelial cells for therapeutic angiogenesis/vasculogenesis of ischemia diseases has led to exploring human embryonic stem cells (hESCs) as a potentially unlimited source for endothelial progenitor cells. With their capacity for self‐renewal and pluripotency, hESCs and their derived endothelial cells (hESC‐ECs) may be more advantageous than other endothelial cells obtained from diseased populations. However, hESC‐ECs' poor differentiation efficiency and poorly characterized in vivo function after transplantation present significant challenges for their future clinical application. This review will focus on the differentiation pathways of hESCs and their therapeutic potential for vascular diseases, as well as the monitoring of transplanted cells' fate via molecular imaging. Finally, cell enhancement strategies to improve the engraftment efficiency of hESC‐ECs will be discussed. J. Cell. Biochem. 106: 194–199, 2009. © 2008 Wiley‐Liss, Inc.
Transcription factor TFII‐I causes transcriptional upregulation of GRP78 synthesis in prostate cancer cells
Authors: Misra U.K. , Wang F. , Pizzo S.V.
Published: December 2008

Receptor‐recognized forms of α2‐macroglobulin (α2M*) bind to cell surface‐associated GRP78 and induce proliferative and survival signaling in prostate cancer cells. As part of the cellular response to α2M*, GRP78 expression is itself upregulated. In response to other stimuli, the transcription factor TFII‐I upregulates GRP78 by binding to its gene promoter. We have, therefore, studied the role of TFII‐I in transcriptional upregulation of GRP78 in 1‐LN human prostate cancer cells stimulated with α2M*. This treatment caused a two‐ to threefold increase in TFII‐I and GRP78 synthesis from [35S]‐labeled precursor amino acids. Synthesis of both TFII‐I and GRP78 were significantly reduced by silencing TFII‐I gene expression or pretreatment of cells with genistein or actinomycin D. Confocal microscopy was employed to demonstrate relocation of TFII‐I to the nucleus. In α2M*‐stimulated cells, moreover, TFII‐I bound to the GRP78 promoter as determined by CHIP assay. We also demonstrate binding of TFII‐I to the c‐fos promoter, consistent with its role in upregulating c‐fos gene expression. In non‐lymphoid cells, phosphorylated c‐Src is an activator of TFII‐I. Ligation of GRP78 on 1‐LN cells with α2M* was followed by tyrosine phosphorylation of c‐Src as well as TFII‐I. We conclude that α2M*‐induced increase in GRP78 synthesis is caused by transcriptional upregulation of TFII‐I which binds to the GRP78 promoter and thus potentiates its cell survival and antipoptotic functions in 1‐LN prostate cancer cells. J. Cell. Biochem. 106: 381–389, 2009. © 2008 Wiley‐Liss, Inc.
Chromatin remodeling in Embryonic stem cells: Regulating the balance between pluripotency and differentiation
Authors: Keenen Bridget , de la Serna Ivana L.
Published: December 2008

Embryonic stem cells have an unlimited potential for self‐renewal yet are pluripotent, capable of differentiating into three different germ layers and ultimately into multiple cell lineages. Key pluripotency specific factors maintain an undifferentiated ES cell phenotype while lineage specific factors work in opposition to promote cell specialization. In addition to these important transcriptional regulators, epigenetic modifiers play a defining role in regulating the balance between pluripotency and differentiation by promoting changes in chromatin structure. J. Cell. Physiol. 219: 1–7, 2009. © 2008 Wiley‐Liss, Inc.
The involvement of Ca2+ and integrins in directional responses of zebrafish keratocytes to electric fields
Authors: Huang Ling , Cormie Peter , Messerli Mark A. , Robinson Kenneth R.
Published: December 2008

Many cells respond directionally to small DC electrical fields (EFs) by an unknown mechanism, but changes in intracellular Ca2+ are widely assumed to be involved. We have used zebrafish (Danio rerio) keratocytes in an effort to understand the nature of the EF‐cell interaction. We find that the adult zebrafish integument drives substantial currents outward through wounds produced by scale removal, establishing that keratocytes near the wound will experience endogenous EFs. Isolated keratocytes in culture turn toward the cathode in fields as small as 7 mV mm−1, and the response is independent of cell size. Epidermal sheets are similarly sensitive. The frequency of intracellular Ca2+ spikes and basal Ca2+ levels were increased by EFs, but the spikes were not a necessary aspect of migration or EF response. Two‐photon imaging failed to detect a pattern of gradients of Ca2+ across the lamellipodia during normal or EF‐induced turning but did detect a sharp, stable Ca2+ gradient at the junction of the lamellipodium and the cell body. We conclude that gradients of Ca2+ within the lamellipodium are not required for the EF response. Immunostaining revealed an anode to cathode gradient of integrin β1 during EF‐induced turning, and interference with integrin function attenuated the EF response. Neither electrophoretic redistribution of membrane proteins nor asymmetric perturbations of the membrane potential appear to be involved in the EF response, and we propose a new model in which hydrodynamic forces generated by electro‐osmotic water flow mediate EF‐cell interactions via effects on focal adhesions. J. Cell. Physiol. 219: 162–172, 2009. © 2008 Wiley‐Liss, Inc.
Amelogenin in cranio‐facial development: the tooth as a model to study the role of amelogenin during embryogenesis
Authors: Gruenbaum‐Cohen Yael , Tucker Abigail S. , Haze Amir , Shilo Dekel , Taylor Angela L. , Shay Boaz , Sharpe Paul T. , Mitsiadis Thimios A. , Ornoy Asher , Blumenfeld Anat , Deutsch Dan
Published: December 2008

The amelogenins comprise 90% of the developing extracellular enamel matrix proteins and play a major role in the biomineralization and structural organization of enamel. Amelogenins were also detected, in smaller amounts, in postnatal calcifying mesenchymal tissues, and in several nonmineralizing tissues including brain. Low molecular mass amelogenin isoforms were suggested to have signaling activity; to produce ectopically chondrogenic and osteogenic‐like tissue and to affect mouse tooth germ differentiation in vitro. Recently, some amelogenin isoforms were found to bind to the cell surface receptors; LAMP‐1, LAMP‐2 and CD63, and subsequently localize to the perinuclear region of the cell. The recombinant amelogenin protein (rHAM+) alone brought about regeneration of the tooth supporting tissues: cementum, periodontal ligament and alveolar bone, in the dog model, through recruitment of progenitor cells and mesenchymal stem cells.

We show that amelogenin is expressed in various tissues of the developing mouse embryonic cranio‐facial complex such as brain, eye, ganglia, peripheral nerve trunks, cartilage and bone, and is already expressed at E10.5 in the brain and eye, long before the initiation of tooth formation. Amelogenin protein expression was detected in the tooth germ (dental lamina) already at E13.5, much earlier than previously reported (E19). Application of amelogenin (rHAM+) beads together with DiI, on E13.5 and E14.5 embryonic mandibular mesenchyme and on embryonic tooth germ, revealed recruitment of mesenchymal cells. The present results indicate that amelogenin has an important role in many tissues of the cranio‐facial complex during mouse embryonic development and differentiation, and might be a multifunctional protein. J. Exp. Zool. (Mol. Dev. Evol.) 312B:445–457, 2009. © 2008 Wiley‐Liss, Inc.
The role of Tripartism in a global HIV/AIDS workplace initiative
Authors: Rogers Susan J. , Adetoro Abiodun , Burke Patrick , Llado Juan , Lukyanova Natalya
Published: December 2008

A strategic venue to address the global HIV/AIDS pandemic has become the workplace. One program, SMARTWork, implemented by the Academy for Educational Development (AED) in six diverse countries, utilized a tripartite approach fostering partnerships between three sectors—government, business and labour—to advance HIV/AIDS workplace policies and programs at the national, provincial and enterprise levels. The implementation of this approach produced important learnings in the field of HIV/AIDS and the world of work. First, getting an early understanding of the country context and prior tripartite conditions helps identify the facilitators and barriers to tripartite building. Second, inclusion is critical—insisting on a structure where all sector partners have a [place at the table] helps build the credibility of weaker sectors and strengthens tripartism. Third, sector expectations must be clear—tripartite partners need to be transparent with each other about how to plan for and obtain resource commitments to advance their objectives. Most importantly, flexibility is key. While starving for collaboration between the three tripartite partners, individual sectors can have strategic impact, along with bipartite partnerships, in addressing HIV/AIDS in the workplace. Copyright © 2008 John Wiley & Sons, Ltd.
Functional morphology and patterns of blood flow in the heart of Python regius
Authors: Starck J. Matthias
Published: December 2008

Brightness‐modulated ultrasonography, continuous‐wave Doppler, and pulsed‐wave Doppler‐echocardiography were used to analyze the functional morphology of the undisturbed heart of ball pythons. In particular, the action of the muscular ridge and the atrio‐ventricular valves are key features to understand how patterns of blood flow emerge from structures directing blood into the various chambers of the heart. A step‐by‐step image analysis of echocardiographs shows that during ventricular diastole, the atrio‐ventricular valves block the interventricular canals so that blood from the right atrium first fills the cavum venosum, and blood from the left atrium fills the cavum arteriosum. During diastole, blood from the cavum venosum crosses the muscular ridge into the cavum pulmonale. During middle to late systole the muscular ridge closes, thus prohibiting further blood flow into the cavum pulmonale. At the same time, the atrio‐ventricular valves open the interventricular canal and allow blood from the cavum arteriosum to flow into the cavum venosum. In the late phase of ventricular systole, all blood from the cavum pulmonale is pressed into the pulmonary trunk; all blood from the cavum venosum is pressed into both aortas. Quantitative measures of blood flow volume showed that resting snakes bypass the pulmonary circulation and shunt about twice the blood volume into the systemic circulation as into the pulmonary circulation. When digesting, the oxygen demand of snakes increased tremendously. This is associated with shunting more blood into the pulmonary circulation. The results of this study allow the presentation of a detailed functional model of the python heart. They are also the basis for a functional hypothesis of how shunting is achieved. Further, it was shown that shunting is an active regulation process in response to changing demands of the organism (here, oxygen demand). Finally, the results of this study support earlier reports about a dual pressure circulation in Python regius. J. Morphol., 2009. © 2008 Wiley‐Liss, Inc.
Fast 3D 1H MRSI of the corticospinal tract in pediatric brain
Authors: Kim Dong‐Hyun , Gu Meng , Cunningham Charles , Chen Albert , Baumer Fiona , Glenn Orit A. , Vigneron Daniel B. , Spielman Daniel Mark , Barkovich Anthony James
Published: December 2008

Purpose

To develop a 1H magnetic resonance spectroscopic imaging (MRSI) sequence that can be used to image infants/children at 3T and by combining it with diffusion tensor imaging (DTI) tractography, extract relevant metabolic information corresponding to the corticospinal tract (CST).

Materials and Methods

A fast 3D MRSI sequence was developed for pediatric neuroimaging at 3T using spiral k‐space readout and dual band RF pulses (32 × 32 × 8 cm field of view [FOV], 1 cc iso‐resolution, TR/TE = 1500/130, 6:24 minute scan). Using DTI tractography to identify the motor tracts, spectra were extracted from the CSTs and quantified. Initial data from infants/children with suspected motor delay (n = 5) and age‐matched controls (n = 3) were collected and N‐acetylaspartate (NAA) ratios were quantified.

Results

The average signal‐to‐noise ratio of the NAA peak from the studies was ≈22. Metabolite profiles were successfully acquired from the CST by using DTI tractography. Decreased NAA ratios in those with motor delay compared to controls of ≈10% at the CST were observed.

Conclusion

A fast and robust 3D MRSI technique targeted for pediatric neuroimaging has been developed. By combining with DTI tractography, metabolic information from the CSTs can be retrieved and estimated. By combining DTI and 3D MRSI, spectral information from various tracts can be obtained and processed. J. Magn. Reson. Imaging 2009;29:1–6. © 2008 Wiley‐Liss, Inc.
Absolute blood contrast concentration and blood signal saturation on myocardial perfusion MRI: Estimation from CT data
Authors: Ishida Masaki , Sakuma Hajime , Murashima Shuichi , Nishida Junko , Senga Masayo , Kobayasi Shigeki , Takeda Kan , Kato Noriyuki
Published: December 2008

Purpose

To determine the optimal contrast injection rate and absolute blood gadolinium concentration for optimal first‐pass imaging.

Materials and Methods

The concentration of contrast medium in left ventricle (LV) was estimated from dynamic computed tomography (CT) by administering iodinated contrast medium of volume (0.2 mL/kg) equivalent to 0.1 mmol/kg of gadolinium injection in 50 subjects. A blood sample study was performed to determine the relationship between blood signal and gadolinium concentration on perfusion MRI.

Results

The mean peak gadolinium concentration in LV increased as the injection rate increased from 1 mL/sec (3.7 ± 1.2 mM), to 4 mL/sec (6.9 ± 2.7 mM) (P < 0.01). However, no significant improvement was found with an increase in the injection rate from 4 mL/sec to 5 mL/sec (6.8 ± 1.5 mM, P = 0.86). In a blood sample study the linear relationship between blood signal and gadolinium concentration was maintained in the range of ≤0.67 mM (r = 0.992), which corresponds to a peak blood concentration following a 0.01 mmol/kg gadolinium injection.

Conclusion

The optimal contrast injection rate for myocardial perfusion magnetic resonance imaging (MRI) appears to be 4 mL/sec. Saturation of arterial input signal is inevitable if the dose of gadolinium contrast medium exceeds 0.01 mmol/kg. These findings are essential for accurate quantification of myocardial blood flow from perfusion MRI. J. Magn. Reson. Imaging 2009;29:205–210. © 2008 Wiley‐Liss, Inc.
Stimulation threshold comparison of time‐varying magnetic pulses with different waveforms
Authors: Irnich Werner , Hebrank Franz X.
Published: December 2008

Purpose

To clarify whether sinusoidal pulses possess lower thresholds than rectangular ones at perception threshold, a statement often made that contradicts the theory of stimulation.

Materials and Methods

The results of a nerve stimulation study with 65 volunteers and with trapezoidal and sinusoidal gradient pulses were used to apply the combination of the electric field, induced in the tissue of the human body, with the “Fundamental Law of Electrostimulation.” This law claims that the waveshape of a pulse is not essential as long as the amplitude of the pulse does not decrease below rheobase (rheobase condition).

Results

If the rheobase condition is applied to sinusoidal waveforms and the pulse duration and amplitude is corrected accordingly, both trapezoidal and sinusoidal gradient pulses have identical threshold amplitudes as a function of pulse duration.

Conclusion

The “Fundamental Law of Electrostimulation,” including the “rheobase condition,” proved to be a good basis for describing magnetic field stimulation (magnetostimulation) and that application of it to magnetostimulation is suitable as the basis for describing magnetic field stimulation with various waveforms. For nonrectangular pulses, pulse durations and pulse amplitudes must be corrected according to the “rheobase condition.” The exponential Blair Equation is less suited to be applied in magnetostimulation. J. Magn. Reson. Imaging 2009;29:229–236. © 2008 Wiley‐Liss, Inc.
Calibrated magnetic resonance hydrometry to quantify pancreatic juice: A preliminary study
Authors: Jin En‐hao , Ichikawa Tomoaki , Erturk Sukru Mehmet , Motosugi Utaroh , Hirano Masaya , Araki Tsutomu
Published: December 2008

Purpose

To investigate the effectiveness of the calibrated MR hydrometry (CMRH) method for accurately measuring pancreatic secretion.

Materials and Methods

All studies were performed on a 1.5‐T MR system using a fat‐suppressed, single‐shot half‐Fourier fast spin‐echo sequence with a standard body coil. A certain volume (20 mL) of saline solution was employed as an extrabody calibrator. The validity of the CMRH method was tested both in vitro and in vivo, and actual and calculated volumes were compared.

Results

The in vitro study yielded a high correlation (r = 0.99; P < 0.0001) between the actual volume of saline solution in the imaging field and the calculated volume. In the in vivo study, for all volunteers, there was a very strong and significant positive correlation between the measured signal intensities or calculated volumes and actual volumes (correlation coefficient range: 0.94–0.99; P < 0.0001).

Conclusion

This preliminary study shows that CMRH is an effective tool to measure the amount of pancreatic fluid secretion. J. Magn. Reson. Imaging 2009;29:217–220. © 2008 Wiley‐Liss, Inc.
Visualization of the lenticulostriate artery with flow‐sensitive black‐blood acquisition in comparison with time‐of‐flight MR angiography
Authors: Gotoh Kimio , Okada Tomohisa , Miki Yukio , Ikedo Masato , Ninomiya Ayako , Kamae Toshikazu , Togashi Kaori
Published: December 2008

Purpose

To evaluate the capability of flow‐sensitive black blood (FSBB) acquisition to visualize the lenticulostriate artery (LSA) in comparison with time‐of‐flight (TOF) angiography.

Materials and Methods

Twenty‐one healthy subjects (13 males and 8 females, 19–44 years old) were enrolled in this study after obtaining written informed consent. Magnetic resonance imaging (MRI) examinations were performed with FSBB and TOF to visualize the LSA using a 1.5T MRI unit. In FSBB acquisition a motion probing gradient of b = 4 sec/mm2 was applied to dephase blood flow. Images were reconstructed into coronal sections and were evaluated in terms of number, length, and image quality at origins and distal areas of visualized LSA branches with a four‐point scale.

Results

In all, 145 LSA branches were visualized with FSBB and 66 branches with TOF. There was no LSA visualized only with TOF. In all evaluated terms, FSBB was significantly better than TOF.

Conclusion

We could better visualize the LSA with FSBB than with TOF, both quantitatively and qualitatively. FSBB is a promising method, although it remains to be evaluated in clinical cases. J. Magn. Reson. Imaging 2009;29:65–69. © 2008 Wiley‐Liss, Inc.
Clinical evaluation of automated scan prescription of knee MR images
Authors: Lecouvet Frederic E. , Claus Jérôme , Schmitz Patrick , Denolin Vincent , Bos Clemens , Vande Berg Bruno C.
Published: December 2008

Purpose

To compare an automated scan planning method to manual scan positioning in routine knee magnetic resonance imaging (MRI) studies.

Materials and Methods

The automated scan planning method uses anatomical landmarks in a 3D survey of the knee. The method is trained by example plannings, consisting of manual slice positioning by an experienced technologist in 15 MRI studies. Automated knee MR examinations obtained in three geometries in 50 consecutive patients were compared to those obtained in 50 consecutive control patients, where imaging planes were planned manually. Anatomical coverage and slice angulation were scored for each geometry on a 4‐grade scale by an experienced radiologist blinded to the way of planning; groups were compared using a Mann–Whitney U‐test.

Results

In 150 automated sequences the technologist adapted slice positioning in four cases (addition of slices to adapt to the size of the knee), representing the only automated sequences that received a poor rating. Thirteen sequences with manual planning received a poor rating. No difference in quality was found (P > 0.05) between automated and manual plannings for coronal coverage, sagittal coverage and angulation, and transverse angulation. Rating of automated planning was higher for transverse coverage, but lower than manual planning for coronal angulation.

Conclusion

Automated sequence prescription for knee MRI is feasible in clinical practice, with similar quality as manual positioning. J. Magn. Reson. Imaging 2009;29:141–145. © 2008 Wiley‐Liss, Inc.
Caudate nuclei volume, diffusion tensor metrics, and T2 relaxation in healthy adults and relapsing‐remitting multiple sclerosis patients: Implications for understanding gray matter degeneration
Authors: Hasan Khader M. , Halphen Christopher , Kamali Arash , Nelson Flavia M. , Wolinsky Jerry S. , Narayana Ponnada A.
Published: December 2008

Purpose

To investigate the utility of caudate nuclei (CN) macro‐ and microstructural metrics as markers of gray matter degeneration in healthy adults and relapsing‐remitting multiple sclerosis (RRMS) patients.

Materials and Methods

The normal age‐ and pathology‐related changes in caudate nuclei volume (CNV), the corresponding diffusion tensor metrics, and the T2 relaxation times were measured in a cohort of 32 healthy adults (12 men/20 women; age range 21–59 years) and 32 age‐matched RRMS patients (8 men/34 women; age range 21–57 years).

Results

Smaller values in both the absolute CNV and the caudate volume ratio relative to the total intracranial volume (CNVp) were observed in the RRMS group relative to healthy controls. The fractional anisotropy (FA), based on the diffusion tensor imaging (DTI) of the CN increased with age in healthy adults (r = 0.52; P = 0.003) but not in patients (r = 0.28; P = 0.12). The caudate FA value was approximately 9% larger in RRMS patients relative to controls (P = 0.001). The mean diffusivity of the CN was greater in the RRMS group compared to controls (P = 0.02). The caudate T2 relaxation times were smaller in the RRMS group relative to the control group (3% reduction, P = 0.05). T2 relaxation times did not exhibit age‐related changes (P > 0.35) in either cohort. Strong and significant correlations between CNVp and whole‐brain lesion load (r = −0.48; P = 0.005) and whole‐brain CSF fraction (r = −0.46; P = 0.01) were also noted.

Conclusion

These preliminary findings indicate that caudate DTI‐derived metrics can serve as potential quantitative radiological markers of MS pathology. J. Magn. Reson. Imaging 2009;29:70–77. © 2008 Wiley‐Liss, Inc.
A funerary rite study of the Phoenician–Punic necropolis of Mount Sirai (Sardinia, Italy)
Authors: Piga G. , Guirguis M. , Bartoloni P. , Malgosa A. , Enzo S.
Published: December 2008

A recent excavation in the Phoenician–Punic necropolis of Mount Sirai, located in the southwestern part of Sardinia, Italy, has brought to light a number of tombs contextually attributed to a period from the early 6th to early 5th century BC, which is simultaneous with the beginning of the Carthago influence in Sardinia. Among the interred burials recently brought to light, the skeletal remains, sometimes of two superposed bodies, are found in a primary position and with fine anatomic connection. Some of the bones were visually stained, suggesting they were possibly subjected to fire treatment. In order to ascertain more objectively whether the bodies were subjected to burning, the bones from all the tombs were investigated by powder X‐ray diffraction (XRD) and Fourier Transform infra‐red (FT‐IR) spectroscopy techniques. After excluding the role of important diagenetic effects, from line broadening/sharpening analysis of hydroxylapatite in the bones according to the Rietveld method, it was evaluated that the bodies were probably subjected to a temperature regime from 300 to 700°C. These data were supplemented and confirmed by an analysis of the splitting factor (SF) of apatite phosphate peaks in the infra‐red spectrum of the bones. Our results indicate the existence of a rite intermediate between incineration and inhumation. This sort of ‘semi‐combustion’, perhaps limited to the period of the early 5th century BC, appears to be peculiar just to this site. Copyright © 2008 John Wiley & Sons, Ltd.
Spectral response and energy output of concentrator multijunction solar cells
Authors: Kinsey Geoffrey S. , Edmondson Kenneth M.
Published: December 2008

The spectral response of concentrator multijunction solar cells has been measured over a temperature range of 25–75°C. These data are combined with reference spectra representing the AM1·5 standard as well as annual spectral irradiance at representative geographical locations. The results suggest that higher performance in the field may be obtained if multijunction cells are designed for an effective air mass higher than AM1·5. Copyright © 2008 John Wiley & Sons, Ltd.
Copolyfluorenes containing phenothiazine or thiophene derivatives: Synthesis, characterization, and application in white‐light‐emitting diodes
Authors: Hsieh Bar‐Yuan , Chen Yun
Published: December 2008

Four copolyfluorenes chemically doped with 0.1 and 1 mol % 3,7‐bis[2‐thiophene‐2‐yl)‐2‐cyanovinyl]phenothiazine (PFPhT) or 2,5‐bis[2‐(thiophene‐2‐yl)‐2‐cyanovinyl]thiophene chromophores (PFThT) were synthesized using the Suzuki coupling reaction and applied in white‐light‐emitting devices. They were characterized by GPC, elemental analysis, DSC, TGA, optical spectra, and cyclic voltammetry. They exhibited good thermal stability (Td > 420 °C) and moderate glass transition temperatures (>95 °C). The PhT‐Br and ThT‐Br showed PL peaks at 586 and 522 nm (with a shoulder at 550 nm). In film state, PL spectra of the copolymers comprised emissions from the fluorene segments and the chromophores due to incomplete energy transfer. Both monomers exhibited low LUMO levels around −3.50 to −3.59 eV, whereas the PhT‐Br owned the higher HOMO level (−5.16 eV) due to its electron‐donating phenothiazine core. Light‐emitting diodes with a structure of ITO/PEDOT:PSS/copolymer/Ca(50 nm)/Al(100 nm) showed broad emission depending on the chromophore contents. The maximum brightness and maximum current efficiency of PFPhT2 (PFThT1) device were 8690 cd/m2 and 1.43 cd/A (7060 cd/m2 and 0.98 cd/A), respectively. White‐light emission was realized by further blending PFPhT2 with poly(9,9‐dihexylfluorene) (w/w = 10/1), with the maximum brightness and maximum current efficiency being 10,600 cd/m2 and 1.85 cd/A. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 833–844, 2009
The influence of porosity on the Phillips Cr/silica catalyst 2. Polyethylene elasticity
Authors: McDaniel M. P. , Collins K. S.
Published: December 2008

The Phillips Cr/silica catalyst produces low levels of long chain branching (LCB) in polyethylene, which have a powerful influence on industrial molding behavior. Although many catalyst and reactor variables determine the degree of LCB, perhaps the most significant of these is the morphology of the silica support. In this study many different types of silicas were converted into Cr/silica catalysts, which were tested in ethylene polymerization, and the resultant polymer elasticity was then determined. In some experiments, the surface area of the catalyst seemed to correlate quite well with polymer elasticity. In other tests, however, no connection with surface area was evident but the pore volume was quite influential. Together, all these studies suggest that it is the degree of structural reinforcement of the silica matrix, rather than any one physical measurement of porosity, that influences elasticity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 845–865, 2009
Encapsulation of silica nanoparticles by miniemulsion polymerization
Authors: Costoyas Álvaro , Ramos Jose , Forcada Jacqueline
Published: December 2008

Hybrid silica/polystyrene nanoparticles were synthesized by miniemulsion polymerization. With the objective to prepare core‐shell hybrid nanoparticles having narrow particle size distributions (PSDs) as well as a high degree of silica encapsulation, the effect of adding surface modifiers, the size of silica nanoparticles, the ratio styrene/silica, the surfactant concentration, and the presence of ethanol in the reaction mixture were studied. A synergistic effect was observed using oleic acid (OA) together with 3‐(trimethoxysilyl)propyl methacrylate (TPM) in the compatibilization step between the organic phase (monomer) and inorganic nanoparticles (silica). Mono and multinuclear eccentric core‐shell hybrid nanoparticles were obtained. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 935–948, 2009
Crystal structure of poly(octamethylene terephthalate) determined by X‐ray fiber diffraction and molecular modeling
Authors: Jeong Young Gyu , Lee Sang Cheol , Shin Kyusoon
Published: December 2008

Poly(octamethylene terephthalate) (POT), a semicrystalline aromatic polyester, is synthesized by melt‐condensation reaction, and its thermal property and crystal structure are investigated by using differential scanning calorimetry, X‐ray diffraction, and molecular modeling methods, respectively. It is revealed that the synthesized POT sample has comparably low melting temperature of 131 °C and forms one crystalline phase. Based on two‐dimensional X‐ray fiber diagram and molecular modeling analyses, the crystal structure of POT is identified to be triclinic with dimensions of a = 4.560 Å, b = 5.597 Å, c = 18.703 Å, α = 104.87°, β = 119.45°, and γ = 100.32°, in which one chemical repeating unit of POT with all‐trans conformation of octamethylene group is packed according to the space group of $$P\overline 1$$. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 276–283, 2009
Transport and time dependent small angle X‐ray morphology in metal cation and polymer modified perfluorocarbon ionomers
Authors: Sauer Bryan B. , Londono J. David , McLean Robert S. , Howard Edward G. , McKinney Ronald , Kampert William G. , Kahn Rachel M. , Lloyd Ralph B.
Published: December 2008

Transport and absorption in metal cation exchanged and polyvinylpyrrolidone (PVP) modified Nafion® films were studied by various techniques. To understand the microscopic basis for permeation, time resolved small angle X‐ray scattering (SAXS) was used to characterize the ionic domain morphology while films were exposed to vapors of water, dimethyl methylphosphonate (DMMP), or triethyl phosphate. Macroscopic weight uptake studies of DMMP vapor into PVP‐Nafion® were also used to help explain the SAXS absorption studies and DMMP permeation properties. The SAXS results were correlated with macroscopic permeation rates of DMMP, Soman, and water through several different membranes. To provide additional basis for the SAXS derived morphologies, tapping‐mode AFM was also used to image the 3–5 nm diameter ionic domains. A goal for protective suit applications is to find films with a balance of high moisture permeation rate for comfort, and low DMMP permeation. The best balance of properties in this context was found with PVP‐ and zirconyl‐modified films. In another extreme, the permeation rates of both water and DMMP through cesium‐modified Nafion® were low. SAXS studies were used to explain this where the ionic domains of cesium‐modified Nafion® did not “expand” when exposed to DMMP or water vapor. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 284–298, 2009
Modeling mechanical aging shift factors in glassy polymers during nonisothermal physical aging. I. Experiments and KAHR‐ate model prediction
Authors: Guo Yunlong , Wang Ni , Bradshaw Roger D. , Brinson L. Catherine
Published: December 2008

This article presents experimental results and model predictions of the mechanical response of polymers during nonisothermal physical aging. The nonisothermal temperature history leads to a complex evolution in the aging behavior of the material. To characterize this response, sequential creep tests of polyether‐ether‐ketone (PEEK) and polyphenylene sulfide (PPS) films are performed at various aging times using a dynamic mechanical analyzer. The resulting strain histories are analyzed to determine discrete aging shift factors (ate) for each of the creep tests. The nonisothermal aging response is then predicted using the KAHR‐ate model, which combines the KAHR model of volume recovery with a suitable linear relationship between aging shift factors and specific volume. The KAHR‐ate model can be utilized to both predict aging response or to determine necessary model parameters from a set of aging shift factor data. For the PEEK and PPS materials considered in the current study, predictions of mechanical response are demonstrated to be in good agreement with the experimental results for several thermal histories. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 340–352, 2009
Promoting evidence‐based psychosocial care for cancer patients
Authors: Jacobsen Paul B.
Published: December 2008

With numerous studies demonstrating that psychosocial care reduces distress and improves quality of life, practitioners have an obligation to treat cancer patients in a manner consistent with this evidence. Although the rationale is straightforward, major challenges exist in achieving the goal of translating research into clinical practice. One challenge has been the nature of the evidence, with many studies of psychosocial interventions characterized by poor methodological quality, absence of eligibility criteria specifying heightened distress, and minimal consideration of dissemination potential. A second challenge has been to make practitioners aware of relevant evidence. Targeted efforts at dissemination, such as the issuance of clinical practice guidelines and evidence‐based recommendations and the distribution of intervention materials via the Internet, appear to be more effective than passive efforts in providing practitioners with useful information. Perhaps the most challenging aspect has been to persuade practitioners to change how they practice. One approach currently under development would allow practitioners and health‐care organizations to perform self‐evaluations of the quality of their psychosocial care based on review of medical records. Feedback showing quality of care to be less than optimal is likely to motivate change, especially if the quality indicators assessed are considered to be important and reliable and point to specific actions that can be taken. The use of evidence to promote changes in clinical practice represents one of the major ways in which the field of psycho‐oncology can fully realize its potential to positively affect the lives of people with cancer. Copyright © 2008 John Wiley & Sons, Ltd.