bluuebunny/crossref_metadata_2025 huggingface dataset:
MiR‐221 and MiR‐222 alterations in sporadic ovarian carcinoma: Relationship to CDKN1B, CDKNIC and overall survival
Authors: Wurz Kaitlyn , Garcia Rochelle L. , Goff Barbara A. , Mitchell Patrick S. , Lee Jun Haeng , Tewari Muneesh , Swisher Elizabeth M.
Published: March 2010

MicroRNAs are often aberrantly expressed in human neoplasms and are postulated to play a role in neoplastic initiation and progression. miR‐221 and miR‐222 negatively regulate expression of CDKN1B (p27) and CDKN1C (p57), two cell cycle regulators expressed in ovarian surface epithelium and down‐regulated in ovarian carcinomas. We characterized miR‐221 and miR‐222 expression in 49 sporadic high grade ovarian carcinomas and determined whether somatic mutation or epigenetic alterations explained the differences in expression of these miRNAs. We correlated these findings with protein expression of CDKN1B and CDKN1C as assessed by immunohistochemistry. Expression of miR‐221 and miR‐222 were closely correlated with each other (P = 0.0001). Interestingly, a lower ratio of miR‐221 to miR‐222 expression was significantly correlated with worse overall survival (P = 0.01) and remained a significant predictor of overall survival in multivariate analysis using the covariate adequacy of surgical cytoreduction (P = 0.03). Higher miR‐222 and miR‐221 expression were significantly associated with decreased CDKN1C expression (P = 0.009 and 0.01). In contrast, CDKN1B expression was not associated with miR‐221 or miR‐222 expression. Neither somatic mutations nor methylation of the studied region explained the alterations in miR‐221 and miR‐222 expression in most carcinomas. © 2010 Wiley‐Liss, Inc.
Cannabinoid and cannabinoid‐like receptors in microglia, astrocytes, and astrocytomas
Authors: Stella Nephi
Published: March 2010

CB1 and CB2 receptors are activated by a plethora of cannabinoid compounds, be they endogenously‐produced, plant‐derived or synthetic. These receptors are expressed by microglia, astrocytes and astrocytomas, and their activation regulates these cells' differentiation, functions and viability. Recent studies show that glial cells also express cannabinoid‐like receptors, and that their activation regulates different cell functions, but also control cell viability. This review summarizes this evidence, and discusses how selective compounds targeting cannabinoid‐like receptors constitute promising therapeutics to manage neuroinflammation and eradicate malignant astrocytomas. Importantly, the selective targeting of cannabinoid‐like receptors should provide therapeutic relieve without inducing the typical psychotropic effects and possible addictive properties associated with the use of Δ9‐tetrahydrocannabinol, the main psychotropic ingredient produced by the plantCannabis sativa© 2010 Wiley‐Liss, Inc.
The perivascular astroglial sheath provides a complete covering of the brain microvessels: An electron microscopic 3D reconstruction
Authors: Mathiisen Thomas Misje , Lehre Knut Petter , Danbolt Niels Christian , Ottersen Ole Petter
Published: March 2010

The unravelling of the polarized distribution of AQP4 in perivascular astrocytic endfeet has revitalized the interest in the role of astrocytes in controlling water and ion exchange at the brain–blood interface. The importance of the endfeet is based on the premise that they constitute a complete coverage of the vessel wall. Despite a number of studies based on different microscopic techniques this question has yet to be resolved. We have made an electron microscopic 3D reconstruction of perivascular endfeet in CA1 (stratum moleculare) of rat hippocampus. The endfeet interdigitate and overlap, leaving no slits between them. Only in a few sites do processes—tentatively classified as processes of microglia—extend through the perivascular glial sheath to establish direct contact with the endothelial basal lamina. In contrast to the endfoot covering of the endothelial tube, the endfoot covering of the pericyte is incomplete, allowing neuropil elements to touch the basal lamina that enwraps this type of cell. The 3D reconstruction also revealed large bundles of mitochondria in the endfoot processes that came in close apposition to the perivascular endfoot membrane. Our data support the idea that in pathophysiological conditions, the perivascular astrocytic covering may control the exchange of water and solutes between blood and brain and that free diffusion is limited to narrow clefts between overlapping endfeet. © 2010 Wiley‐Liss, Inc.
A new bridge in [2.2]cyclophanes: The addition of Se2Cl2 to pseudogeminally substituted bispropargylic alcohols
Authors: Lucian Birsa M. , Hopf Henning
Published: March 2010

The regio‐ and stereo‐specific addition of monoselenium monochloride to pseudogeminally substituted bispropargylic alcohols has been performed under high dilution conditions. The disproportionation reaction of selenium monochloride to selenium dichloride and triselenium dichloride leads to the corresponding divinylic mono‐ and tri‐selenides. The stereochemistry of the newly generated double bond was assigned as Z by 2D NMR experiments. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:126–130, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20586
Epidermal growth factor receptor targeted therapy of squamous cell carcinoma of the head and neck
Authors: Sharafinski Mark E. , Ferris Robert L. , Ferrone Soldano , Grandis Jennifer R.
Published: March 2010

Background

Cumulative evidence implicates the epidermal growth factor receptor (EGFR) as an important therapeutic target in head and neck squamous cell carcinoma (HNSCC). The basis for the lack of correlation between EGFR expression in the HNSCC tumor and clinical responses to EGFR inhibitors is incompletely understood. Although a variety of mechanisms likely contribute to the effectiveness of EGFR blockade, this review focuses on the biologic implications of known EGFR variations and the role of the immune system in mediating clinical responses to EGFR inhibitors.

Methods

A Medline review of articles published in the last 10 years (1999–present) on EGFR in HNSCC was performed in combination with preliminary data from our laboratories.

Results

Studies published to date suggest no association between the expression of EGFR on HNSCC tumors and clinical responses to EGFR inhibitors. Several mechanisms have been proposed to mediate clinical response to EGFR inhibitors in HNSCC. Cumulative results from our laboratories support the role of several mechanisms, including cellular immune activation and mutated EGFR variants, in contributing to the discrepancy between level of EGFR expression and clinical response to EGFR inhibitors.

Conclusion

The efficacy of EGFR targeted therapies may be mediated, at least in part, by the immune system and the presence of the truncated EGFR variant, EGFRvIII, among other factors. Criteria to identify the subset of patients likely to be responsive to EGFR targeted therapies are needed. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Multiple Effects of Silymarin on the Hepatitis C Virus Lifecycle
Authors: Wagoner Jessica , Negash Amina , Kane Olivia J. , Martinez Laura E. , Nahmias Yaakov , Bourne Nigel , Owen David M. , Grove Joe , Brimacombe Claire , McKeating Jane A. , Pécheur Eve-Isabelle , Graf Tyler N. , Oberlies Nicholas H. , Lohmann Volker , Cao Feng , Tavis John E. , Polyak Stephen J.
Published: March 2010

Silymarin, an extract from milk thistle (

Silybum marianum

), and its purified flavonolignans have been recently shown to inhibit hepatitis C virus (HCV) infection, both

in vitro

and

in vivo

. In the current study, we further characterized silymarin's antiviral actions. Silymarin had antiviral effects against hepatitis C virus cell culture (HCVcc) infection that included inhibition of virus entry, RNA and protein expression, and infectious virus production. Silymarin did not block HCVcc binding to cells but inhibited the entry of several viral pseudoparticles (pp), and fusion of HCVpp with liposomes. Silymarin but not silibinin inhibited genotype 2a NS5B RNA-dependent RNA polymerase (RdRp) activity at concentrations 5 to 10 times higher than required for anti-HCVcc effects. Furthermore, silymarin had inefficient activity on the genotype 1b BK and four 1b RDRPs derived from HCV-infected patients. Moreover, silymarin did not inhibit HCV replication in five independent genotype 1a, 1b, and 2a replicon cell lines that did not produce infectious virus. Silymarin inhibited microsomal triglyceride transfer protein activity, apolipoprotein B secretion, and infectious virion production into culture supernatants. Silymarin also blocked cell-to-cell spread of virus.

Conclusion:

Although inhibition of

in vitro

NS5B polymerase activity is demonstrable, the mechanisms of silymarin's antiviral action appear to include blocking of virus entry and transmission, possibly by targeting the host cell. Hepatology 2010
Do openness to experience and recognizing opportunities have the same genetic source?
Authors: Shane Scott , Nicolaou Nicos , Cherkas Lynn , Spector Tim D.
Published: March 2010

Recognizing opportunities for new businesses is an important part of the entrepreneurial process, one that researchers seek to explain and human resource managers seek to encourage. In this study, we examined whether the same genetic factors that affect openness to experience also influence recognizing opportunities. We applied bivariate genetics techniques to a sample of twins and found that a substantial part of the heritability of recognizing opportunities is mediated through genetic influences on openness to experience. Evidence of genetic effects on opportunity recognition has important implications for how companies might think about selection and training and raises important ethical issues in human resource management. ©2010 Wiley Periodicals, Inc.
Apparent/spurious multifractality of data sampled from fractional Brownian/Lévy motions
Authors: Neuman Shlomo P.
Published: March 2010

Many earth and environmental variables appear to be self‐affine (monofractal) or multifractal with spatial (or temporal) increments having exceedance probability tails that decay as powers of − α where 1 < α ≤ 2. The literature considers self‐affine and multifractal modes of scaling to be fundamentally different, the first arising from additive and the second from multiplicative random fields or processes. We demonstrate theoretically that data having finite support, sampled across a finite domain from one or several realizations of an additive Gaussian field constituting fractional Brownian motion (fBm) characterized by α = 2, give rise to positive square (or absolute) increments which behave as if the field was multifractal when in fact it is monofractal. Sampling such data from additive fractional Lévy motions (fLm) with 1 < α < 2 causes them to exhibit spurious multifractality. Deviations from apparent multifractal behaviour at small and large lags are due to nonzero data support and finite domain size, unrelated to noise or undersampling (the causes cited for such deviations in the literature). Our analysis is based on a formal decomposition of anisotropic fLm (fBm when α = 2) into a continuous hierarchy of statistically independent and homogeneous random fields, or modes, which captures the above behaviour in terms of onlyE+ 3 parameters whereEis Euclidean dimension. Although the decomposition is consistent with a hydrologic rationale proposed by Neuman (2003), its mathematical validity is independent of such a rationale. Our results suggest that it may be worth checking how closely would variables considered in the literature to be multifractal (e.g. experimental and simulated turbulent velocities, some simulated porous flow velocities, landscape elevations, rain intensities, river network area and width functions, river flow series, soil water storage and physical properties) fit the simpler monofractal model considered in this paper (such an effort would require paying close attention to the support and sampling window scales of the data). Parsimony would suggest associating variables found to fit both models equally well with the latter. Copyright © 2010 John Wiley & Sons, Ltd.
Spatial and temporal variations in summer precipitation in Japanese mountain areas
Authors: Shinohara Yoshinori , Kume Tomonori , Komatsu Hikaru , Otsuki Kyoichi
Published: March 2010

We examined spatial and temporal variations in precipitation measured during summer season between 1976 and 2007 for 28 stations located in mountain areas across Japan using the amount of precipitation (Pr), the mean depth of precipitation events (η), and the inverse of the mean interval times (λ). We obtained positive correlations between the period mean Pr (Pr) and the period mean η ($\overline{\eta}$) and between Pr and the period mean λ ($\overline{\lambda}$) for the 28 stations. Pr was more strongly related to $\overline{\eta}$ than to $\overline{\lambda}$, indicating the spatial variations in Pr that are primarily related to the variations in $\overline{\eta}$. In addition, Pr was more strongly related to η than to λ for most stations on the basis of data for 1976–2007, indicating that the year‐to‐year variations in Pr are primarily related to η. We also examined temporal trends in Pr, η and λ for 1976–2007 and found no systematic trends for 23 of the 28 stations, suggesting long‐term trends that are not common in mountain areas of Japan. The relationships between Pr and $\overline{\eta}$ and between Pr and η presented in this study enable us to generate a temporal precipitation distribution pattern based on only Pr and Pr data, respectively. Furthermore, probabilistic stochastic hydrological models require precipitation characteristics as input; thus, this study contributes to the determination of hydrological cycles and their possible future changes in Japanese mountain areas and therefore to water resource management. Copyright © 2010 John Wiley & Sons, Ltd.
Stable and unstable internal states of a molecule
Authors: Konarski Jerzy
Published: March 2010

Using a new method for analysis of stability of internal motions in a molecule, it has been shown that coupling between different types of internal motions leads to locally stable rotational states. These sets of states build up a basin of stability where energy is dissiplated by a vibrational channel, not by the rotational one.
Introducing the euro‐sting: Short‐term indicator of euro area growth
Authors: Camacho Maximo , Perez‐Quiros Gabriel
Published: March 2010

We set out a model to compute short‐term forecasts of the euro area GDP growth in real time. To allow for forecast evaluation, we construct a real‐time dataset that changes for each vintage date and includes the exact information that was available at the time of each forecast. With this dataset we show that our simple factor model algorithm, which uses an easy‐to‐replicate methodology, is able to forecast the euro area GDP growth as well as professional forecasters who can combine the best forecasting tools with the possibility of incorporating their own judgement. In this context, we provide examples showing how data revisions and data availability affect point forecasts and forecast uncertainty. Copyright © 2010 John Wiley & Sons, Ltd.
Direct transplantation of uncultured hair‐follicle pluripotent stem (hfPS) cells promotes the recovery of peripheral nerve injury
Authors: Amoh Yasuyuki , Hamada Yuko , Aki Ryoichi , Kawahara Katsumasa , Hoffman Robert M. , Katsuoka Kensei
Published: March 2010

We previously showed that the stem cell marker nestin is expressed in hair follicle stem cells which suggested their pluripotency. We subsequently showed that the nestin‐expressing hair‐follicle pluripotent stem (hfPS) cells can differentiate in culture to neurons, glial cells, keratinocytes, and other cell types and can promote regeneration of peripheral nerve and spinal cord injuries upon injection to the injured nerve or spinal cord. The location of the hfPS cells has been termed the hfPS cell area (hfPSCA). Previously, hfPS cells were cultured for 1–2 months before transplantation to the injured nerve or spinal cord which would not be optimal for clinical application of these cells for nerve or spinal cord repair, since the patient should be treated soon after injury. In the present study, we addressed this issue by directly using the upper part of the hair follicle containing the hfPSCA, without culture, for injection into the severed sciatic nerve in mice. After injection of hfPSCA, the implanted hfPS cells grew and promoted joining of the severed nerve. The transplanted hfPS cells differentiated mostly to glial cells forming myelin sheaths, which promoted axonal growth and functional recovery of the severed nerve. These results suggest that the direct transplantation of the uncultured upper part of the hair follicle containing the hfPSA is an important method to promote the recovery of peripheral nerve injuries and has significant clinical potential. J. Cell. Biochem. 110: 272–277, 2010. © 2010 Wiley‐Liss, Inc.
Targeted disruption of Nemo‐like kinase inhibits tumor cell growth by simultaneous suppression of cyclin D1 and CDK2 in human hepatocellular carcinoma
Authors: Jung Kwang Hwa , Kim Jeong Kyu , Noh Ji Heon , Eun Jung Woo , Bae Hyun Jin , Xie Hong Jian , Ahn Young Min , Park Won Sang , Lee Jung Young , Nam Suk Woo
Published: March 2010

The Wnt/β‐catenin signaling pathway regulates various aspects of development and plays important role in human carcinogenesis. Nemo‐like kinase (NLK), which is mediator of Wnt/β‐catenin signaling pathway, phosphorylates T‐cell factor/lymphoid enhancer factor (TCF/LEF) factor and inhibits interaction of β‐catenin/TCF complex. Although, NLK is known to be a tumor suppressor in Wnt/β‐catenin signaling pathway of colon cancer, the other events occurring downstream of NLK pathways in other types of cancer remain unclear. In the present study, we identified that expression of NLK was significantly up‐regulated in the HCCs compared to corresponding normal tissues in five selected tissue samples. Immunohistochemical analysis showed significant over‐expression of NLK in the HCCs. Targeted‐disruption of NLK suppressed cell growth and arrested cell cycle transition. Suppression of NLK elicited anti‐mitogenic properties of the Hep3B cells by simultaneous inhibition of cyclinD1 and CDK2. The results of this study suggest that NLK is aberrantly regulated in HCC, which might contribute to the mitogenic potential of tumor cells during the initiation and progression of hepatocellular carcinoma; this process appears to involve the induction of CDK2 and cyclin D1 and might provide a novel target for therapeutic intervention in patients with liver cancer. J. Cell. Biochem. 110: 687–696, 2010. © 2010 Wiley‐Liss, Inc.
Photovoltaic solar electrochemical oxidation (PSEO) for treatment of lignosulfonate wastewater
Authors: Dominguez‐Ramos Antonio , Aldaco Ruben , Irabien Angel
Published: March 2010

BACKGROUND: Under the current global energy scenario, the need for self‐sustainable processes is encouraged. The photovoltaic solar powered electrochemical oxidation (PSEO) process has been developed to remove the organic matter from a lignosulfonate wastewater.

RESULTS: An electrochemical reactor using boron‐doped diamond electrodes, in a batch configuration, is directly supplied with current from a set of photovoltaic solar modules. Experimental results show that the process can oxidize about 90% of the total organic carbon (TOC) of the organic matter in the wastewater under the described operating conditions.

CONCLUSION: The technical suitability of the PSEO process has been demonstrated. A model to relate solar irradiance and electrical current was applied and used in a kinetic expression which depends on solar irradiance to describe the removal of TOC. Copyright © 2010 Society of Chemical Industry
Bacterial biosynthesis of alginates
Authors: Hay Iain D. , Ur Rehman Zahid , Ghafoor Aamir , Rehm Bernd H. A.
Published: March 2010

Alginates are polysaccharides with many industrial and medical uses, from food additives to encapsulation agents in the emerging transplantation technologies. Alginate is composed of variable proportions of β‐D‐mannuronic acid and α‐L‐guluronic acid linked by 1–4 glycosidic bonds. Traditionally, commercial alginate has been produced by farmed brown seaweeds, but this alginate suffers from heterogeneity in composition and quality partly due to environmental variation. Two bacterial genera, Pseudomonas and Azotobacter, are also capable of producing alginate as an exopolysaccharide. These bacterial alginate producers can provide the means to produce alginates with defined monomer composition and possibly through genetic and protein engineering may allow for the production of ‘tailor made’ bacterial alginates. The paper discusses the mechanisms behind alginate production in bacteria and how they may be used in the commercial production of alginates. Copyright © 2010 Society of Chemical Industry
Testicular microlithiasis: Analysis of prevalence and associated testicular cancer in Taiwanese men
Authors: Chen Jian‐Ling , Chou Yi‐Hong , Tiu Chui‐Mei , Chiou Hong‐Jen , Wang Hsin‐Kai , Chiou See‐Ying , Liang I‐Ping , Lee Chien‐Ho , Chang Cheng‐Yen
Published: March 2010

Purpose.

To determine the incidence of testicular microlithiasis (TM) in Taiwanese males who were referred for scrotal sonography (US) and to evaluate the association between TM and cancer, with state‐of‐the‐art equipment.

Methods.

This retrospective study included 513 males who underwent scrotal US in a period of 7 months. The US images and charts of each patient were reviewed to determine the presence of TM and note relevant clinical information.

Results.

The data for all 513 patients were analyzed. Their age was 0–91 years (mean, 54.3 years). The overall incidence of TM was 14.4% (74/513); 6.2% (32/513) had classic TM, and 8.2% had limited TM. The incidence of testicular cancer in this population was 1.6% (8/513). Six of eight (75%) patients who had testicular cancer at presentation had classic TM or limited TM. There was a significant difference (P < 0.01) between the rate of malignancy in subjects with TM (6/74) and that in subjects without TM (2/439).

Conclusion.

The incidence of TM in Taiwanese people may be higher than previously reported, which may be due to the difference in methodology and increased awareness of the US findings. Although there was a significant difference in the rate of malignancy in males with TM compared with those without TM, the question remains whether TM independently increases the risk of testicular malignancy. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound, 2010
Sonographic diagnosis of unifocal langerhans cell histiocytosis of the skull
Authors: Holley Allison
Published: March 2010

The sonographic (US) findings of unifocal Langerhans cell histiocytosis of the occiput are described. The patient was a 3 year‐old girl who presented with a painful soft tissue mass on the scalp. US demonstrated a large soft tissue mass with destruction of the underlying bone. The mass extended through the bony defect and consisted of a solid intracranial component and a predominantly cystic extracranial component. US is not usually associated with the diagnosis of Langerhans cell histiocytosis but in this case it provided valuable information that led to the primary differential diagnosis of Langerhans cell histiocytosis, which was confirmed by bone biopsy at surgery. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:440–442, 2010
Evolution of paired fins and the lateral somitic frontier
Authors: Johanson Zerina
Published: March 2010

Recent research on the evolutionary origins of the paired fins (pectoral and pelvic, evolving into the four tetrapod limbs) has focused on genetic, developmental, and fossil evidence. However, a combined synthesis of this evidence has largely been lacking. In living animals, identification of dorsal and ventrolateral zones of fin‐producing competence, the distinction between primaxial and abaxial regions separated by the lateral somitic frontier, and the recognition that fin developmental mechanisms could have been co‐opted from unpaired to paired fins can be used to evaluate vertebrate fin evolution, including fossil forms. These fossil taxa dominate early vertebrate history and possess an unusually wide variety of fin or fin‐like structures; establishing homologies with the paired fins of jawed vertebrates has been challenging, in part owing to the absence of supporting girdles in most jawless vertebrates. An evolutionary scenario is proposed where these fin‐like structures develop from somites, in the same manner as dorsal, unpaired fins. Girdles and the paired fins of osteostracans and jawed vertebrates develop from lateral plate mesoderm when the lateral somitic frontier and the abaxial region of the body evolve. J. Exp. Zool. (Mol. Dev. Evol.) 314B:347–352, 2010. © 2010 Wiley‐Liss, Inc.
Comparative sperm ultrastructure in Nemertea
Authors: von Döhren J. , Beckers P. , Vogeler R. , Bartolomaeus T.
Published: March 2010

Although the monophyly of Nemertea is strongly supported by unique morphological characters and results of molecular phylogenetic studies, their ingroup relationships are largely unresolved. To contribute solving this problem we studied sperm ultrastructure of 12 nemertean species that belong to different subtaxa representing the commonly recognized major monophyletic groups. The study yielded a set of 26 characters with an unexpected variation among species of the same genus (Tubulanus and Procephalothrix species), whereas other species varied in metric values or only one character state (Ramphogordius). In some species, the sperm nucleus has grooves (Zygonemertes virescens, Amphiporus imparispinosus) that may be twisted and give a spiral shape to the sperm head (Paranemertes peregrina, Emplectonema gracile). To make the characters from sperm ultrastructure accessible for further phylogenetic analyses, they were coded in a character matrix. Published data for eight species turned out to be sufficiently detailed to be included. Comparative evaluation of available information on the sperm ultrastructure suggests that subtaxa of Heteronemertea and Hoplonemertea are supported as monophyletic by sperm morphology. However, the data do not provide information on the existing contradictions regarding the internal relationships of “Palaeonemertea.” Nevertheless, our study provides evidence that sperm ultrastructure yields numerous potentially informative characters that will be included in upcoming phylogenetic analyses. J. Morphol. 2010. © 2010 Wiley‐Liss, Inc.
Imaging biomarkers in multiple sclerosis
Authors: Filippi M. , Agosta F.
Published: March 2010

Recent years have witnessed impressive advances in the use of magnetic resonance imaging (MRI) for the assessment of patients with multiple sclerosis (MS). Complementary to the clinical evaluation, conventional MRI provides crucial pieces of information for the diagnosis of MS. However, the correlation between the burden of lesions observed on conventional MRI scans and the clinical manifestations of the disease remains weak. The discrepancy between clinical and conventional MRI findings in MS is explained, at least partially, by the limited ability of conventional MRI to characterize and quantify the heterogeneous features of MS pathology. Other quantitative MR‐based techniques, however, have the potential to overcome such a limitation of conventional MRI. Indeed, magnetization transfer MRI, diffusion tensor MRI, proton MR spectroscopy, and functional MRI are contributing to elucidate the mechanisms that underlie injury, repair, and functional adaptation in patients with MS. Such techniques are likely to benefit from the use of high‐field MR systems and thus allow in the near future providing additional insight into all these aspects of the disease. This review summarizes how MRI is dramatically changing our understanding of the factors associated with the accumulation of irreversible disability in MS and highlights the reasons why they should be used more extensively in studies of disease evolution and clinical trials. J. Magn. Reson. Imaging 2010;31:770–788. ©2010 Wiley‐Liss, Inc.
Human brain MR spectroscopy thermometry using metabolite aqueous‐solution calibrations
Authors: Covaciu Lucian , Rubertsson Sten , Ortiz‐Nieto Francisco , Ahlström Håkan , Weis Jan
Published: March 2010

Purpose:

To estimate absolute brain temperature using proton MR spectroscopy (1H‐MRS) and mean brain–body temperature difference of healthy human volunteers.

Materials and Methods:

Chemical shift difference between temperature‐dependent water spectral line position and temperature‐stable metabolite spectral reference was used for the estimations of absolute brain temperature. Temperature calibrations constants were obtained from the spectra of the N‐acetyl aspartate (NAA line at ∼2.0 ppm), glycero‐phosphocholine (GPC line at ∼3.2 ppm), and creatine (Cr line at ∼3.0 ppm) aqueous solutions with pH values within physiologically pertinent ranges. Single‐voxel PRESS sequence (TR/TE 2000/80 ms) was used for this purpose. Brain temperature was determined by averaging the temperatures computed from water‐Cho, water‐Cr, and water‐NAA chemical shift differences.

Results:

The mean brain temperature of 18 healthy volunteers was 38.1 ± 0.4°C and mean brain–body (rectal) temperature difference was 1.3 ± 0.4°C.

Conclusion:

Improved accuracy of the temperature constants and averaging the temperatures computed from water‐Cho, water‐Cr, and water‐NAA chemical shift differences increased the reliability of the brain temperature estimations. J. Magn. Reson. Imaging 2010;31:807–814. ©2010 Wiley‐Liss, Inc.
Automated segmentation of the aorta from phase contrast MR images: Validation against expert tracing in healthy volunteers and in patients with a dilated aorta
Authors: Herment Alain , Kachenoura Nadjia , Lefort Muriel , Bensalah Mourad , Dogui Anas , Frouin Frédérique , Mousseaux Elie , De Cesare Alain
Published: March 2010

Purpose:

To assess if segmentation of the aorta can be accurately achieved using the modulus image of phase contrast (PC) magnetic resonance (MR) acquisitions.

Materials and Methods:

PC image sequences containing both the ascending and descending aorta of 52 subjects were acquired using three different MR scanners. An automated segmentation technique, based on a 2D+t deformable surface that takes into account the features of PC aortic images, such as flow‐related effects, was developed. The study was designed to: 1) assess the variability of our approach and its robustness to the type of MR scanner, and 2) determine its sensitivity to aortic dilation and its accuracy against an expert manual tracing.

Results:

Interobserver variability in the lumen area was 0.59 ± 0.92% for the automated approach versus 10.09 ± 8.29% for manual segmentation. The mean Dice overlap measure was 0.945 ± 0.014. The method was robust to the aortic size and highly correlated (r = 0.99) with the manual tracing in terms of aortic area and diameter.

Conclusion:

A fast and robust automated segmentation of the aortic lumen was developed and successfully tested on images provided by various MR scanners and acquired on healthy volunteers as well as on patients with a dilated aorta. J. Magn. Reson. Imaging 2010;31:881–888. ©2010 Wiley‐Liss, Inc.
Induced magnetic force in human heads exposed to 4 T MRI
Authors: Wang Ruiliang , Wang Gene‐Jack , Goldstein Rita Z. , Caparelli Elisabeth C. , Volkow Nora D. , Fowler Joanna S. , Tomasi Dardo
Published: March 2010

Purpose:

To map the distribution of the magnetic force induced in the human head during magnetic resonance imaging (MRI) at 4 T for a large group of healthy volunteers.

Materials and Methods:

The magnetic field distribution in the head of 100 men and 18 women was mapped using phase mapping techniques. Statistical parametric mapping methods using a family‐wise error (FWE) corrected threshold P < 0.05 and region‐of‐interest analyses were used to assess the significance of the results.

Results:

Eyeballs, orbitofrontal and temporal cortices, subcallosal gyrus, anterior cingulate, midbrain, and brainstem (pons) are the brain regions most susceptible to magnetic force. The strength of the magnetic force density in the head was lower than 11.5 ± 5.3 N/m3 (right eyeball). The strength of the magnetic force density induced in occipital cortex varied linearly with the x‐rotation (pitch) angle.

Conclusion:

We found that the induced magnetic force is highly significant in the eyeballs, orbitofrontal and temporal cortices, subcallosal gyrus, anterior cingulate as well as midbrain and brainstem (pons), regardless of subjects' age or gender. The maximum induced magnetic force was 6 × 105 times weaker than the gravitational force; thus, biological effects of the magnetic force during imaging are not expected to be significant. J. Magn. Reson. Imaging 2010;31:815–820. ©2010 Wiley‐Liss, Inc.
Hypoxia‐like effect of Cobalt Chromium alloy micro particles on fibroblasts in vitro
Authors: Madathil Bernadette K. , Lin Qingsong , Hew Choy‐Leong , Mohanty Mira
Published: March 2010

Periprosthetic osteolysis leading to asceptic loosening remains the primary cause of failure of joint replacement. Although many inflammatory cell types have been implicated, the exact pathomechanisms of asceptic loosening have not been delineated. In the present study we have adopted a proteomic approach to elucidate the initial signals that are expressed to particulate material, using an in vitro cell culture system. Human lung fibroblasts MRC‐5 were cultured with Cobalt Chromium (CoCr ASTM F‐75, 1–7 µm) particles. Cells were harvested after 72 h incubation and total cellular proteins extracted for downstream analysis via 2D Gel Electrophoresis and tandem mass spectrometry using MALDI‐TOF‐TOF‐MS. Thirteen protein spots showed greater than twofold increase, following 72 h incubation of fibroblast with CoCr particles. Four of these proteins were identified by tandem mass spectrometry. These were Annexin II, Pyruvate kinase, Triose phosphate isomerase, and N‐myc downstream regulated gene 1 protein. Cobalt is a hypoxia mimicking agent and N‐myc downstream regulated gene 1 protein, Triose phosphate isomerase, Pyruvate kinase, and Annexin II are important hypoxia regulated gene products that are found to be over expressed in cellular oxidative stress response. Our data indicates that exposure of fibroblast to CoCr alloy induces the transition of these cells into a hypoxia like state and oxidative stress even in normoxic culture conditions. The study reflects the possibility of the presence of a hypoxic environment in the periprosthetic tissue surrounding metallic implants. Published by Wiley Periodicals, Inc. J Orthop Res 28:1360–1367, 2010
Extractionless non‐hydrolysis surface‐enhanced Raman spectroscopic detection of historical mordant dyes on textile fibers
Authors: Jurasekova Z. , del Puerto E. , Bruno G. , García‐Ramos J. V. , Sanchez‐Cortes S. , Domingo C.
Published: March 2010

Alizarin and carminic acid have been detected in reference wool and linen fibers dyed with madder and cochineal, respectively, through surface‐enhanced Raman scattering (SERS) measurements carried out directlyon the fiber, without previous hydrolysis of the mordant‐dye complex. For such purpose, Ag nanoparticles were produced and immobilizedin situvia the laser photoreduction of a silver nitrate aqueous solution in contact with the fiber. Control SERS spectra of pure dyes (alizarin, purpurin and carminic acid, as well as of mixtures of the first two) on similar Ag nanoparticles were also obtained. The method has been applied to one archeological Coptic textile (6th–8th A.D.) of Egyptian origin, where alizarin has been clearly identified. Other mordant dyes of the flavonoids family (luteolin, apigenin and flavonols) have also been identified by the same SERS method in wool fibers dyed with natural plants, mainly used in Central and South America (Dyer's greenweed, old fustic, onion and chilca) following pre‐Columbian dying recipes. Copyright © 2010 John Wiley & Sons, Ltd.
The role of protective self‐cognitions in the relationship between childhood trauma and later resource loss
Authors: Walter Kristen H. , Horsey Katie J. , Palmieri Patrick A. , Hobfoll Stevan E.
Published: March 2010

The authors examined a prospective model investigating posttraumatic stress disorder (PTSD) symptoms and protective self‐cognitions (self‐esteem and self‐efficacy) with later resource loss among 402 inner‐city women who experienced childhood abuse. They predicted that women with PTSD may fail to develop or sustain protective self‐cognitions that could protect against future stress. Results from the hypothesized model suggest that child abuse was associated with greater PTSD symptoms and later resource loss. PTSD symptoms were also related to protective self‐cognitions, which, in turn, were associated with less resource loss. The authors also examined an alternative model exploring the relationship between resource loss and later PTSD symptoms. Findings allude to the relationship of risk and resiliency variables among women with childhood trauma histories.
Injectable tissue‐engineered bone repair of a rat calvarial defect
Authors: Stephan Scott J. , Tholpady Sunil S. , Gross Brian , Petrie‐Aronin Caren E. , Botchway Edward A. , Nair Lakshmi S. , Ogle Roy C. , Park Stephen S.
Published: March 2010

Objectives/Hypothesis:

Advances in bone repair have focused on the minimally‐invasive delivery of tissue‐engineered bone (TEB). A promising injectable biopolymer of chitosan and inorganic phosphates was seeded with mesenchymal stem cells (MSCs) and a bone growth factor (BMP‐2), and evaluated in a rat calvarial critical size defect (CSD). Green fluorescent protein (GFP)‐labeled MSCs are used to evaluate patterns of cell viability and proliferation.

Study Design:

Prospective, controlled trial in an animal model.

Methods:

In 30 male rats, 8‐mm calvarial CSDs were created, and divided into five groups of six animals each. In the experimental groups, the defects were injected with either chitosan gel, gel loaded with MSCs (0.3 × 106 cells/defect), gel loaded with BMP‐2 (2 μg/defect), or gel loaded with both MSC and BMP‐2. In the control group, the defect was left untreated. At 4 weeks, in vivo microcomputed tomography (micro‐CT) analysis was performed. At 8 weeks, calvarial specimens were examined by micro‐CT, histology, and immunohistochemistry.

Results:

New areas of bone growth were seen in the defects of all treated animals. Micro‐CT analysis revealed a significant (P < .001) time‐dependent increase in the regeneration of bone volume and bone area in defects treated with gel/MSC/BMP‐2 as compared to all other groups. Histological analysis confirmed this difference. GFP–labeled TEB was detected within the areas of new bone, indicating cell viability and contribution to new bone growth by the injected MSC.

Conclusions:

This study demonstrates that an injectable form of TEB using a chitosan gel, MSC, and BMP‐2 can enhance bone formation in a rat calvarial CSD. Laryngoscope, 2010
Chemical Modification of Hydrophobic Block in Poly(Ethylene Oxide) Poly(Caprolactone) Based Nanocarriers: Effect on the Solubilization and Hemolytic Activity of Amphotericin B
Authors: Falamarzian Arash , Lavasanifar Afsaneh
Published: March 2010

The aim of this study was to develop methoxy poly(ethylene oxide)‐b‐poly(ε‐caprolactone) (MePEO‐b‐PCL) containing stearyl (St) substituents on PCL, and assess the efficacy of nanocarriers formed from this structure in comparison to unmodified MePEO‐b‐PCL and those with carboxyl substitutes on PCL on the solubilization and delivery of Amphotericin B (AmB). Prepared block copolymers were characterized for their molecular weight by 1H NMR and gel permeation chromatography. The self‐assembly of synthesized MePEO‐b‐PStCL to spherical particles of nanometer size range was shown by dynamic light scattering as well as electron and atomic force microscopy. Encapsulated AmB showed a reduction in its hemolytic activity against rat red blood cells in comparison to the commercial formulation of AmB, Fungizone.

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Solid‐State NMR Characterization of the Multiphase Structure of Polypropylene In‐reactor Alloy
Authors: Zhu Haijin , Graf Robert , Hou Guangjin , Zhao Ying , Wang Dujin , Spiess Hans W.
Published: March 2010

A variety of solid‐state NMR techniques were used to characterize the chain dynamics, miscibility and the micro‐phase structure of a polypropylene (PP) in‐reactor alloy system. The alloy was physically separated into three fractions, and the molecular dynamics and relaxation behavior of the pure fractions was then compared with the components in the alloy to achieve comprehensive understanding of the phase structure of the PP in‐reactor alloy. The miscibility among different components of the alloy was studied by the rotational frame spin‐lattice relaxation time. Proton spin‐diffusion methods were used to quantify the domain thicknesses of different regions in the alloy. The results show that the alloy is composed of three phases, namely, a homo‐polyethylene (HPE) matrix, a homo‐polypropylene (HPP) dispersed phase, and a linear low‐density polyethylene (LLDPE) interphase. The thickness of the LLDPE interphase is estimated to be 7.7 nm at room temperature, and changes dramatically with temperature. Finally, based on all the solid‐state NMR results, a model for the micro‐phase‐structure of the PP in‐reactor alloy is proposed, and a correlation between the micro‐phase structure and the excellent mechanical property is established.

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High Temperature Semibatch Free Radical Copolymerization of Styrene and Butyl Acrylate
Authors: Wang Wei , Hutchinson Robin A.
Published: March 2010

Summary: High temperature semibatch free radical solution copolymerizations of n‐butyl acrylate (BA) and styrene (ST) were carried out over a range of copolymer composition. The significant increase in experimental polymer weight‐average molecular weight with time, as well as the shift in the entire polymer molecular weight distribution, is explained by assuming fast β‐scission of BA midchain radicals with an adjacent styrene unit, followed by subsequent addition of the resultant macromonomer to growing radicals. A mechanistic model including backbiting and β‐scission, macronomer incorporation, long‐chain branching, and propagation and termination penultimate effects was constructed in Predici; the model provides a good representation of the experimental data using rate coefficients taken from literature.
In Line Spectroscopic Investigation of Fluorinated Copolymer Synthesis in Supercritical Carbon Dioxide
Authors: Möller Eléonore , Schreiber Ulrike , Beuermann Sabine
Published: March 2010

Summary: In‐line Fourier Transform – near infrared (FT‐NIR) spectroscopy is a very elegant method to follow conversion as well as phase behaviour throughout a reaction. It was applied to two examples of homogeneous phase syntheses of fluorinated copolymers in supercritical carbon dioxide (scCO2). The conventional free radical copolymerization of vinylidene fluoride (VDF) and hexafluoropropene (HFP) on the one hand side, and the Activators Generated by Electron Transfer (AGET) Atom Transfer Radical Polymerization (ATRP) of F‐decene (1H‐1H, 2H perfluoro‐1‐decene) and tBA (tert‐butyl acrylate) on the other hand side were studied. Poly(VDF‐co‐HFP) were synthesized at 75 and 100 °C at pressures above 800 bar to remain in solution, even at high VDF contents. The reactivity ratios, r, were determined from a small number of experiments using the entire conversion vs. time data from in‐line FT‐NIR measurements. The estimated values are rVDF = 4.3 and rHFP = 0.1. In the case of poly(F‐decene‐co‐tBA), a fluorinated macroligand was introduced for AGET ATRP. Molecular weights between 10000 and 40000 g/mol and polydispersities between 1.1 and 2.1 were obtained while remaining in homogeneous phase. Reactivity ratios were determined as rF‐decene = 0.02 and rtBA = 9.1.
Industrial Production of Fluoroelastomer Nanocomposites by Microemulsion Polymerization followed by Co‐Coagulation
Authors: Apostolo M. , Chernysheva L. , Fantoni M. , Verneau B.
Published: March 2010

Summary: In this paper synthesis and properties of fluoroelastomer nano‐composites are discussed. The production technology is based on two steps: first, high solid content nano‐latex of a semi‐crystalline perfluoropolymer is produced by means of a special microemulsion polymerization; then, co‐coagulation of this latex with a fluoroelastomer latex leads to the formation of the nano‐composite. When properly designed, fluoroelastomer nano‐composites develop properties that are better than those of each individual polymer of the blend. This paper is particularly focused on the remarkable values of reinforcement and permeability that can be achieved with these nano‐composites. A simple model is developed to better understand the origin of such properties. The model provides a possible explanation of the observed increase in nano‐composite properties when the size of the dispersed phase is below 100 nm, that is in the nano‐scale region. Finally, selected examples of industrial application of these nano‐composites are briefly discussed.
Biopolymer Synthesis Catalyzed by Tailored Lipases
Authors: Sandoval Georgina , Rivera Ivanna , Barrera‐Rivera Karla A. , Martínez‐Richa Antonio
Published: March 2010

Summary: Enzyme‐catalyzed synthesis of biopolymers is a growing area of green chemistry because the exquisite selectivity and control of the polymer structure allowed by the enzymatic synthesis. In addition, the metal traces of chemical catalysts are avoided, being this feature particularly useful in biomedical applications. Lipases are remarkable catalysts and they are efficient in the synthesis of several kinds of biopolymers. However, one of the limitations of the industrial application of lipase‐catalyzed polymerizations is the cost of commercial immobilized lipases. To overcome this drawback, in this work we present some cheap and simple strategies to produce and obtain immobilized lipases, as well as some examples of biopolymer synthesis using these tailored lipases.
DC Electrical Study of Modified PMMA, PVC and their Blend
Authors: Soman Vijay V. , Kelkar Deepali S.
Published: March 2010

Summary: Thin films of high molecular weight PMMA, PVC and their blend were prepared with solution cast method. Further they were modified by adding Camphor Sulphonic Acid (CSA) to them. DSC studies indicate single glass transition temperature (Tg) for unmodified as well as modified blends indicating the miscibility of polymers. FTIR studies show the interaction between CSA‐PVC, CSA‐PMMA, CSA‐(PVC+PMMA) blend. The D.C. electrical study was carried out at various temperatures from room temperature (307 K) to 373 K. After modification the variation of DC conductivity (σ) is found to decrease in PVC and the PVC‐PMMA blend whereas it is found to increase in PMMA with rise in temperature.