bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of HCV infection and management on health-related quality of life
Authors: Younossi Zobair , Kallman Jillian , Kincaid John
Published: February 2007

Infection with HCV leads to an array of symptoms that compromise health-related quality of life (HRQL). Chronic hepatitis C is treated primarily with pegylated interferon (peg-IFN) and an inosine 5′ monophosphate dehydrogenase inhibitor, ribavirin (RBV), with the goal of achieving a sustained virologic response (SVR). SVR reduces the rate of hepatic fibrosis and other disease-related complications and, in turn, increases HRQL. Although combination therapy with peg-IFN and RBV produces SVRs in more than 50% of treated patients, it is associated with side effects that can reduce short-term HRQL, can lead to dose reductions and discontinuations, and may impair treatment response. Fatigue and depression are common symptoms of chronic HCV infection that may also be caused by IFN-based therapy. Hemolytic anemia and IFN-mediated bone marrow suppression are well-known consequences of IFN/RBV therapy, often resulting in dose reductions or discontinuations, and have the potential to affect SVR rates. Management of these symptoms is vital to successful outcomes and generally relies on therapy that is adjunctive to the primary treatment of the viral infection itself. Several new drugs with the potential to increase SVR rates without compromising HRQL are in development.

Conclusion:

The relationship of chronic HCV infection, treatment, and HRQL is complex. Successful treatment of chronic hepatitis C requires an understanding of the intricacies of this relationship and appropriate management of treatment-related symptoms. (Hepatology 2007;45:806–816.)
Vaccine-induced early control of hepatitis C virus infection in chimpanzees fails to impact on hepatic PD-1 and chronicity
Authors: Rollier Christine S. , Paranhos-Baccala Glaucia , Verschoor Ernst J. , Verstrepen Babs E. , Drexhage Joost A. R. , Fagrouch Zahra , Berland Jean-Luc , Komurian-Pradel Florence , Duverger Blandine , Himoudi Nourredine , Staib Caroline , Meyr Marcus , Whelan Mike , Whelan Joseph A. , Adams Victoria A. , Larrea Esther , Riezu José I. , Lasarte Juan José , Bartosch Birke , Cosset Francois L. , Spaan Willy J. M. , Diepolder Helmut M. , Pape Gerd R. , Sutter Gerd , Inchauspe Genevieve , Heeney Jonathan L.
Published: February 2007

Broad T cell and B cell responses to multiple HCV antigens are observed early in individuals who control or clear HCV infection. The prevailing hypothesis has been that similar immune responses induced by prophylactic immunization would reduce acute virus replication and protect exposed individuals from chronic infection. Here, we demonstrate that immunization of naïve chimpanzees with a multicomponent HCV vaccine induced robust HCV-specific immune responses, and that all vaccinees exposed to heterologous chimpanzee-adapted HCV 1b J4 significantly reduced viral RNA in serum by 84%, and in liver by 99% as compared to controls (

P

= 0.024 and 0.028, respectively). However, despite control of HCV in plasma and liver in the acute period, in the chronic phase, 3 of 4 vaccinated animals developed persistent infection. Analysis of expression levels of proinflammatory cytokines in serial hepatic biopsies failed to reveal an association with vaccine outcome. However, expression of IDO, CTLA-4 (1) and PD-1 levels in liver correlated with clearance or chronicity.

Conclusion:

Despite early control of virus load, a virus-associated tolerogenic-like state can develop in certain individuals independent of vaccination history. (Hepatology 2007;45:602–613.)
A sensitive bead assay for antimitochondrial antibodies: Chipping away at AMA-negative primary biliary cirrhosis
Authors: Oertelt Sabine , Rieger Roman , Selmi Carlo , Invernizzi Pietro , Ansari Aftab A. , Coppel Ross L. , Podda Mauro , Leung Patrick S.C. , Gershwin Eric M.
Published: February 2007

The antimitochondrial response in primary biliary cirrhosis (PBC) is the most highly directed and specific self-reacting antibody in human immunopathology. Originally, antimitochondrial antibodies (AMAs) were detected by indirect immunofluorescence (IIF) and found in approximately 90% of well-documented patients with PBC. The introduction of recombinant autoantigens and the use of immunoblotting have increased the sensitivity and specificity of AMAs, and they are now considered positive in approximately 95% of patients with PBC. Clearly, accurate autoantibody detection represents one of the fundamental requirements for reliable diagnostics in autoimmunity. To address the 5% of AMA-negative patients with PBC, we have generated and validated a bead assay for the detection of AMA. We enrolled 120 patients with PBC, including a non-random group of 30 rigorously proven AMA-negative patients, 50 healthy subjects, and 74 controls with autoimmune diseases (18 with primary sclerosing cholangitis, 16 with autoimmune hepatitis, and 40 with systemic lupus erythematosus). Individual bead assays were done with the three mitochondrial autoantigens, PDC-E2, BCOADC-E2, and OGDC-E2. As expected, 90 of 90 previously known AMA-positive patients remained positive with this assay but, interestingly, 20% of the rigorously defined AMA-negative patient group had antibodies to one or more of the mitochondrial autoantigens. Furthermore, 100% of these newly detected AMA-positive patients were anti-nuclear antibody (ANA) positive.

Conclusion:

The development of this assay reflects the potential for automated detection with rapid and reliable assaying and further highlights the diminished number of truly AMA-negative PBC patients. (Hepatology 2007;45:659–665.)
Bone regeneration of porous β‐tricalcium phosphate (Conduit™ TCP) and of biphasic calcium phosphate ceramic (Biosel®) in trabecular defects in sheep
Authors: Bodde Esther W.H. , Wolke Joop G.C. , Kowalski Rick S.Z. , Jansen John A.
Published: February 2007

In this study bone regeneration between porous β‐tricalcium phosphate (Conduit™ TCP) and biphasic calcium phosphate ceramic (Biosel®), with a hydroxyapatite/β‐TCP ratio of 75/25, was compared. The ceramic particles were implanted in sheep trabecular bone for 3, 12, and 26 weeks. Histomorphometrical analysis revealed that Conduit™ degraded significantly during time and only 36% of the material was left at 26 weeks implantation time. Biosel®, in contrast, remained nearly intact. The degradation of Conduit™ was due to dissolution as well as cell‐mediated. Biosel® showed a high cellular intervention, although this material did not degrade. Both materials were osteoconductive. The amount of newly formed bone appeared greater in the Conduit™ group after 26 weeks (46% ± 8% as compared to 37% ± 8% for Biosel®), but this difference was not significant. Bone distribution over the defect was homogeneous in Conduit™, whereas Biosel® showed significantly more bone in the periphery of the defect after 26 weeks in comparison to the center. In conclusion, both ceramics are biocompatible and osteoconductive. Degradation showed a difference in amount and in cellular events, with more degraded Conduit™ TCP with less cellular intervention as compared to Biosel®. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
The release of nickel from orthodontic NiTi wires is increased by dynamic mechanical loading but not constrained by surface nitridation
Authors: Peitsch T. , Klocke A. , Kahl‐Nieke B. , Prymak O. , Epple M.
Published: February 2007

The influence of dynamic mechanical loading and of surface nitridation on the nickel release from superelastic nickel–titanium orthodontic wires was investigated under ultrapure conditions. Commercially available superelastic NiTi arch wires (size 0.018 × 0.025″) without surface modification (Neo Sentalloy) and with nitrogen ion implantation surface treatment (Neo Sentalloy Ionguard) were analyzed. Mechanical loading of wire segments with a force similar to the physiological situation was performed with a frequency of 5 Hz in ultrapure water and saline solution, respectively. The release of nickel was monitored by atomic absorption spectroscopy for up to 36 days. The mechanically loaded wires released significantly more nickel (∼45 ng cm−2 d−1) than did nonloaded wires (<1 ng cm−2 d−1). There was no statistically significant effect of the testing solution (water or NaCl) or of the surface nitridation. The total amount of released nickel was small in all cases, but may nevertheless account for the occasional clinical observations of adverse reactions during application of NiTi‐based orthodontic appliances. The surface nitridation did not constrain the release of nickel from NiTi under continuous mechanical stress. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
In vitro studies of platelet adhesion, activation, and protein adsorption on curcumin‐eluting biodegradable stent materials
Authors: Pan C.J. , Shao Z.Y. , Tang J.J. , Wang J. , Huang N.
Published: February 2007

A major complication of coronary stenting is in‐stent restenosis (ISR) due to thrombus formation. We hypothesized that locally released curcumin from coronary stent surface would inhibit ISR due to thrombus formation because of antithrombosis of curcumin. In the present work, curcumin‐eluting polylactic acid‐co‐glycolic acid (PLGA) films were fabricated and their properties in vitro were investigated. The in vitro platelet adhesion and activation, as well as protein adsorption on curcumin‐loading PLGA films were investigated to evaluate the blood compatibility of curcumin‐eluting films. The structure of curcumin‐eluting PLGA film and control was examined by Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy indicating that the peaks of curcumin did not shift in curcumin‐eluting films. The results of contact angle and surface free energy indicated that loading curcumin in PLGA would make PLGA become more hydrophilic, which contributed to the increase of polar fraction of surface free energy. With the increase of curcumin in films, platelets adhering to the curcumin‐eluting films decreased significantly. The number of activation platelets decreased after incorporating curcumin in PLGA films. Loading curcumin in PLGA film can markedly reduce the fibrinogen adsorption. All results indicated that incorporating curcumin in PLGA film can improve the blood compatibility of PLGA films. It can be used to fabricate drug‐eluting stent to prevent thrombosis formation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Surface modified poly(L‐lactide‐co‐ε‐caprolactone) microspheres as scaffold for tissue engineering
Authors: Garkhal Kalpna , Verma Shalini , Tikoo K. , Kumar Neeraj
Published: February 2007

P‐15 modified poly(L‐lactide‐co‐ε‐caprolactone) (PLCL) microspheres were investigated as scaffolds for tissue engineering applications. PLCL copolymer was synthesized by ring opening polymerization and was composed of a soft matrix of mainly ε‐caprolactone moieties and hard domains containing more of L‐lactide units thus exhibiting a rubber like elasticity responsible for providing mechanical strength to scaffolds. Microspheres were fabricated by solvent evaporation method and surface modified with P‐15, a synthetic analogue of collagen. These were then evaluated for cell adhesion, ECM formation and cell proliferation. Anchorage dependent cell lines LLCPK‐1 and L6 were seeded on PLCL microspheres (unmodified surface activated microspheres) and P‐15‐PLCL microspheres (P‐15 modified microspheres). P‐15 modified microspheres showed significantly higher cell adhesion and viability than unmodified microspheres. Scanning electron microscopy also revealed copious amount of extra‐cellular matrix production by P‐15. Initial results of cell culture experiment on two different cell lines suggested that the growth of LLCPK‐1 in a 3D environment with P‐15 modified microspheres is via spreading and flattening on the surface of scaffold followed by formation of a sheet‐like structure while L6 grew in the form of multilayered structures with formation of interparticulate cellular bridges. The 3D moldable nature, combined with modification of surface chemistry with cell adhesion molecules such as P‐15 to enhance proliferation of epithelial cells and myoblasts, recommends further investigation of P‐15‐PLCL microspheres for production of an ideal scaffold for soft tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Biocompatilibity‐related surface characteristics of oxidized NiTi
Authors: Danilov Anatoli , Tuukkanen Tuomas , Tuukkanen Juha , Jämsä Timo
Published: February 2007

In the present study, we examined the effect of NiTi oxidation on material surface characteristics related to biocompatibility. Correspondence between electron work function (EWF) and adhesive force predicted by electron theory of adsorption as well as the effect of surface mechanical stress on the adhesive force were studied on the nonoxidized and oxidized at 350, 450, and 600°C NiTi alloy for medical application. The adhesive force generated by the material surface towards the drops of α‐minimal essential medium (α‐MEM) was used as a characteristic of NiTi adsorption properties. The study showed that variations in EWF and mechanical stress caused by surface treatment were accompanied by variations in adhesive force. NiTi oxidation at all temperatures used gave rise to decrease in adhesive force and surface stress values in comparison to the nonoxidized state. In contrary, the EWF value revealed increase under the same condition. Variations in surface oxide layer thickness and its phase composition were also followed. The important role of oxide crystallite size in EWF values within the range of crystallite dimensions typical for NiTi surface oxide as an instrument for the fine regulation of NiTi adsorption properties was demonstrated. The comparative oxidation of pure titanium and NiTi showed that the effect of Ni on the EWF value of NiTi surface oxide is negligible. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Comparative in vitro study of the proliferation and growth of human osteoblast‐like cells on various biomaterials
Authors: Itthichaisri C. , Wiedmann‐Al‐Ahmad M. , Huebner U. , Al‐Ahmad A. , Schoen R. , Schmelzeisen R. , Gellrich N.‐C.
Published: February 2007

In vitro studies about the growth behavior of osteoblasts onto biomaterials is a basic knowledge and a screening method for the development and application of scaffolds in vivo. In this in vitro study human osteoblast‐like (HOB) cells were cultured on seven different biomaterials used in dental and craniomaxillofacial surgery, respectively. The tested biomaterials were synthetic biodegradable (MacroPore®, Ethisorb®, PDS®, Beriplast® P) and nonbiodegradable polymers (Palacos®) as well as calcium phosphate cement (BoneSource®) and titanium. The cell proliferation and cell colonization were analyzed by scanning electron microscopy and EZ4U‐test. Statistical analysis were performed. HOB‐like cells cultivated on Ethisorb showed the highest proliferation rate. The proliferation rate was statistically significant compared with Palacos, MacroPore, and BoneSource. Whereas, Beriplast, PDS, and titanium yielded lower proliferation rates. However, there was no statistically significant difference compared with Palacos, MacroPore, and BoneSource. SEM analysis showed no significant difference in individual cell features and cell colonization. But an infiltration and a growth of HOB‐like cells throughout the porous structure of Ethisorb, which is formed by crossing fibers, is a striking different feature (macrotopography). This feature can explain the highest proliferation rate of Ethisorb. The results showed that HOB‐like cells appear to be sensitive to substrate composition and topography. Moreover, the basis for further studies with such biomaterial/osteoblast constructs in vivo are provided. Further focusing points are developing techniques to fabricate three‐dimensional porous biomaterial/cell constructs, studying the tissue reaction and the bone regeneration of such constructs compared with the use of autologous bone. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Surface characterization and platelet adhesion studies for the mixed self‐assembled monolayers with amine and carboxylic acid terminated functionalities
Authors: Chuang Wen‐Hsi , Lin Jui‐Che
Published: February 2007

The mixed self‐assembled monolayers (SAM) prepared from long chain alkanethiols, HS(CH2)11NH2 and HS(CH2)10COOH, on gold are employed as the model surface for investigating the interactions between the biological environment and synthetic surface. A distinctive SAM preparation scheme was utilized in this investigation. The triethylamine was added to the alkanethiol solution during SAM formation and then followed by additional rinsing of SAM with 10% CH3COOH or 1% HCl ethanolic solution. The contact angle values of NH2 + COOH mixed SAMs were between those of the pure SAMs, except that it was prepared with solution mole fraction of amine‐terminated alkanethiol at 0.2. X‐ray photoelectron spectroscopy (XPS) analysis has indicated that these two distinctive SAM preparation procedures had both resulted in a reduction in oxidized sulfur species on pure NH2 terminated SAM. However, the procedure utilizing 1% HCl ethanolic washing solution was more effective in reducing the unbound thiol fraction and to form a pure NH2 SAM with better quality. XPS analysis has also revealed that the surface of NH2 + COOH mixed SAMs was “amine‐rich”. In vitro platelet adhesion assay has shown that the amount of adherent platelets on pure positive charged NH2 terminated SAM is less than that on anionic COOH terminated counterpart in both acidic ethanolic washing schemes. Moreover, the lowest platelet adhesion density was noted on the mixed SAM surfaces with surface amine mole fraction at 0.51 and 0.57. This finding suggests that the surface charge with near neutrality might be of importance in reducing platelet adhesion and activation on artificial biomaterial. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Financial crisis in Malaysia: did FDI flows contribute to vulnerability?
Authors: Doraisami Anita Giselle
Published: February 2007

To date there has been greater awareness that the sudden interruption and reversal of capital flows can cause financial crisis. However for the most part it is thought that the volatility of capital flows applies predominantly to short‐term flows and not longer‐term capital flows such as FDI. The Malaysian experience of financial crisis challenges the conventional wisdom and has profound implications for other developing countries seeking to attract FDI flows as a source of long‐term stable financing. Malaysia succumbed to crisis in spite of the fact that FDI flows accounted for the bulk of financial flows on average. This paper argues that FDI flows in Malaysia contributed to vulnerability to crisis by causing chronic current account deficits and was associated with a slowdown in export growth prior to the crisis. This suggests that when assessing a country's vulnerability to financial crisis, emphasis should not only be placed on the reversibility of flows but also on the macroeconomic impact of these flows. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and evaluation of a water‐soluble polymer to reduce Ac‐225 daughter migration
Authors: Fitzsimmons Jonathan , Atcher Robert
Published: February 2007

The actinium decay chain has been promoted as an in vivo alpha generator for therapy, but migration of daughters from the primary conjugate has lead to increased toxicity away from the target organ. To reduce daughter migration, polyethylenimine (PEI) was used with a primary chelator and secondary chelators. The primary chelator, DOTA, was used to coordinate 225Actinium and secondary chelators‐acetate and DTPA, were added to the polymer for coordination of daughters formed by decay. The 225Actinium polymer derivatives containing secondary chelators were found to retain radioactive daughters better than the 225Actinium bond to the primary alone. The retention of 213Bismuth and 209Thallium had the following order from highest retained to lowest DOTA‐PEI‐DTPA≈DOTA‐PEI‐CH2OO‐ > DOTA‐PEI. The data suggests this polymer approach could be used to reduce daughter migration and has potential for development of actinium labeled radiopharmaceuticals. Copyright © 2007 John Wiley & Sons, Ltd.
Labeled oxazaphosphorines for applications in MS studies. Synthesis of deuterium labeled cyclophosphamides and ifosfamides
Authors: Springer James B. , Michael Colvin O. , Ludeman Susan M.
Published: February 2007

A variety of deuterated 3‐amino‐1‐propanols were made by the LiAlD4or AlD3reduction of nitrile or ester precursors. The labeled aminopropanols and/or deuterated bis(2‐chloroethyl)amines were used to synthesize [4,4‐2H2]‐, [6,6‐2H2]‐, [α,α.α′,α′‐2H4]‐, and [4,4,β,β,β′,β′‐2H6]‐cyclophosphamide. The labeled aminopropanols were also used to synthesize deuterated 3‐(2′‐benzyloxyethylamino)‐1‐propanols [BnOCH2CH2NH(CH2)3OH] which, along with labeled and unlabeled 2‐chloroethylamines, led to [4,4‐2H2]‐, [6,6‐2H2]‐, [α,α‐2H2]‐, [α′,α′‐2H2]‐, [α,α.α′,α′‐2H4]‐, and [6,6,α,α,α′,α′‐2H6]‐ifosfamide. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and biological evaluation of 131I‐labelled pyronaridine
Authors: Hyun Park Sang , Jeong Gwon Hui , Pradeep Kannampalli
Published: February 2007

131I‐Labelled pyronaridine, an antimalarial drug was synthesized and evaluated for its stability and biodistribution in rabbits. We observed that there was >99% yield of the labelled compound as determined by HPLC and radio‐TLC in our study. Dynamic imaging studies in rabbits showed that 131I‐labelled pyronaridine was not concentrated in the thyroid for up to 30 min as that of Na131I. Biodistribution studies in the blood, liver, heart, spleen, kidney and lung of rats revealed that the maximum percentage of the injected dose (% ID) and the percentage of the injected dose per gram organ weight (% ID/g) of 131I‐labelled pyronaridine was found in the blood and liver when compared to the other organs even after 6 days of the drug administration. Results suggest that 131I‐labelled pyronaridine can be effectively used as an imaging agent to study the metabolism and mode of a response of pyronaridine. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of 3H, 14C and 2H4 labelled SCH 211803
Authors: Hesk D. , Voronin K. , McNamara P. , Royster P. , Koharski D. , Hendershot S. , Saluja S. , Truong V. , Chan T. M.
Published: February 2007

[3H]SCH 211803, at a specific activity of 1.56 Ci/mmol, was prepared by direct exchange with tritiated water and platinum metal. [2H4]SCH 211803 was prepared from [2H]formaldehyde in a seven step synthesis in 10% yield. [14C]SCH 211803 was prepared from N‐benzyl‐4‐hydroxy[2‐14C]piperidine in a four‐step synthesis in 35% radiochemical yield. Additionally a high specific activity batch of [3H]SCH 211803 was prepared by Ru(Ph3P)3Cl2 catalysed exchange with 90 at% tritiated water to a specific activity of 35 Ci/mmol. Copyright © 2007 John Wiley & Sons, Ltd.
Gadobenate dimeglumine–enhanced MRI of intraductal papillary mucinous tumor of the bile ducts
Authors: Park Mi‐Suk , Yu Jeong‐Sik , Lee Dong Ki , Yoon Dong‐Sup , Cha Seung‐Whan , Kim Ki Whang
Published: February 2007

We present the case of a 63‐year‐old male with intraductal papillary mucinous tumor (IPMT) of the bile ducts. We discuss the role of gadobenate dimeglumine (Gd‐BOPTA)–enhanced T1‐weighted MRI in the visualization of mucin flow, localization of the papillary tumor, and confirming the diagnosis of this uncommon disease. J. Magn. Reson. Imaging 2007;25:625–627. © 2007 Wiley‐Liss, Inc.
R2* imaging of transfusional iron burden at 3T and comparison with 1.5T
Authors: Storey Pippa , Thompson Alexis A. , Carqueville Christine L. , Wood John C. , de Freitas R. Andrew , Rigsby Cynthia K.
Published: February 2007

Purpose

To determine normative R2* values in the liver and heart at 3T, and establish the relationship between R2* at 3T and 1.5T over a range of tissue iron concentrations.

Materials and Methods

A total of 20 healthy control subjects and 14 transfusion‐dependent patients were scanned at 1.5T and 3T. At each field strength R2* imaging was performed in the liver and heart.

Results

Normative R2* values in the liver were estimated from the control group to be 39.2 ± 9.0 second−1 at 1.5T and 69.1 ± 21.9 second−1 at 3T. Normative cardiac values were estimated as 23.4 ± 2.2 second−1 at 1.5T and 30.0 ± 3.7 second−1 at 3T. The combined R2* data from patients and control subjects exhibited a linear relationship between 3T and 1.5T. In the liver, the line of best fit to the 3T vs. 1.5T data had a slope of 2.00 ± 0.06 and an intercept of −11 ± 4 second−1. In the heart, it had a slope of 1.88 ± 0.14 and an intercept of −15 ± 4 second−1.

Conclusion

These preliminary data suggest that the iron‐dependent component of R2* scales linearly with field strength over a wide range of tissue iron concentrations. The incidence of susceptibility artifacts may, however, also increase with field strength. J. Magn. Reson. Imaging 2007;25:540–547. © 2007 Wiley‐Liss, Inc.
Projection‐based estimation and nonuniformity correction of sensitivity profiles in phased‐array surface coils
Authors: Yun SungDae , Kyriakos Walid E. , Chung Jun‐Young , Han Yeji , Yoo Seung‐Schik , Park HyunWook
Published: February 2007

Purpose

To develop a novel approach for calculating the accurate sensitivity profiles of phased‐array coils, resulting in correction of nonuniform intensity in parallel MRI.

Materials and Methods

The proposed intensity‐correction method estimates the accurate sensitivity profile of each channel of the phased‐array coil. The sensitivity profile is estimated by fitting a nonlinear curve to every projection view through the imaged object. The nonlinear curve‐fitting efficiently obtains the low‐frequency sensitivity profile by eliminating the high‐frequency image contents. Filtered back‐projection (FBP) is then used to compute the estimates of the sensitivity profile of each channel. The method was applied to both phantom and brain images acquired from the phased‐array coil.

Results

Intensity‐corrected images from the proposed method had more uniform intensity than those obtained by the commonly used sum‐of‐squares (SOS) approach. With the use of the proposed correction method, the intensity variation was reduced to 6.1% from 13.1% of the SOS. When the proposed approach was applied to the computation of the sensitivity maps during sensitivity encoding (SENSE) reconstruction, it outperformed the SOS approach in terms of the reconstructed image uniformity.

Conclusion

The proposed method is more effective at correcting the intensity nonuniformity of phased‐array surface‐coil images than the conventional SOS method. In addition, the method was shown to be resilient to noise and was successfully applied for image reconstruction in parallel imaging. J. Magn. Reson. Imaging 2007;25:588–597. © 2007 Wiley‐Liss, Inc.
T2‐weighted MRI of rectosigmoid carcinoma: Comparison of respiratory‐triggered fast spin‐echo, breathhold fast‐recovery fast spin‐echo, and breathhold single‐shot fast spin‐echo sequences
Authors: Yamashita Shuhei , Masui Takayuki , Katayama Motoyuki , Sato Kimihiko , Yoshizawa Nobuko , Seo Hidekazu , Sakahara Harumi
Published: February 2007

Purpose

To compare the abilities of T2‐weighted (T2W) imaging using respiratory‐triggered fast spin‐echo (RT‐FSE), breathhold fast‐recovery FSE (BH‐FRFSE), and BH single‐shot FSE (BH‐SSFSE) sequences without an endorectal coil to detect rectosigmoid carcinomas.

Materials and Methods

Forty patients (stage: pT0, 1; pTis‐2, 15; pT3‐4, 24) were included in the study. All examinations were performed on a 1.5T magnet with a phased‐array coil and the patients were studied in the prone position with per‐anal air injection. Qualitative and quantitative evaluations were performed.

Results

Motion artifact was the most prominent with the RT‐FSE sequence, and the least prominent with the BH‐SSFSE sequence. Scores for depiction of the rectal wall layer, tumor recognition, and overall image quality were the highest with the BH‐FRFSE sequence. On the basis of a receiver operating characteristic (ROC) analysis, the detection rate of tumor invasion through the rectal wall was higher with the BH‐FRFSE sequence (Az = 0.9077) than with the RT‐FSE (Az = 0.7762, p < 0.05) or BH‐SSFSE (Az = 0.8602) sequence. Tumor‐to‐fat contrast was highest with the BH‐FRFSE sequence (P < 0.017).

Conclusion

The BH‐FRFSE sequence may be the first choice for rectosigmoid T2W imaging in the prone position with per‐anal air injection for patients who can hold their breath stably. J. Magn. Reson. Imaging 2007;25:511–516. © 2007 Wiley‐Liss, Inc.
Water–fat separation with IDEAL gradient‐echo imaging
Authors: Reeder Scott B. , McKenzie Charles A. , Pineda Angel R. , Yu Huanzhou , Shimakawa Ann , Brau Anja C. , Hargreaves Brian A. , Gold Garry E. , Brittain Jean H.
Published: February 2007

Purpose

To combine gradient‐echo (GRE) imaging with a multipoint water–fat separation method known as “iterative decomposition of water and fat with echo asymmetry and least squares estimation” (IDEAL) for uniform water–fat separation. Robust fat suppression is necessary for many GRE imaging applications; unfortunately, uniform fat suppression is challenging in the presence of B0 inhomogeneities. These challenges are addressed with the IDEAL technique.

Materials and Methods

Echo shifts for three‐point IDEAL were chosen to optimize noise performance of the water–fat estimation, which is dependent on the relative proportion of water and fat within a voxel. Phantom experiments were performed to validate theoretical SNR predictions. Theoretical echo combinations that maximize noise performance are discussed, and examples of clinical applications at 1.5T and 3.0T are shown.

Results

The measured SNR performance validated theoretical predictions and demonstrated improved image quality compared to unoptimized echo combinations. Clinical examples of the liver, breast, heart, knee, and ankle are shown, including the combination of IDEAL with parallel imaging. Excellent water–fat separation was achieved in all cases. The utility of recombining water and fat images into “in‐phase,” “out‐of‐phase,” and “fat signal fraction” images is also discussed.

Conclusion

IDEAL‐SPGR provides robust water–fat separation with optimized SNR performance at both 1.5T and 3.0T with multicoil acquisitions and parallel imaging in multiple regions of the body. J. Magn. Reson. Imaging 2007;25:644–652. © 2007 Wiley‐Liss, Inc.
MRI of the female pelvis at 3T compared to 1.5T: Evaluation on high‐resolution T2‐weighted and HASTE images
Authors: Kataoka Masako , Kido Aki , Koyama Takashi , Isoda Hiroyoshi , Umeoka Shigeaki , Tamai Ken , Nakamoto Yuji , Maetani Yoji , Morisawa Nobuko , Saga Tsuneo , Togashi Kaori
Published: February 2007

Purpose

To evaluate the feasibility of MRI of the female pelvis using high‐resolution T2‐weighted imaging (T2WI) and the half‐Fourier acquisition single‐shot turbo spin‐echo (HASTE) technique at 3 Tesla (T) compared to 1.5T, while focusing on the uterine body and cervical anatomy.

Materials and Methods

A total of 19 healthy women underwent pelvic MR scans on 3T and 1.5T scanners. Axial and sagittal T2W (voxel size of 0.6 × 0.8 × 2 mm) and sagittal HASTE images were obtained. The images were evaluated qualitatively for overall image quality, contrast in the uterine zonal appearance and cervical structure, image inhomogeneity, and artifacts. A quantitative evaluation was performed regarding zonal contrast and image inhomogeneity.

Results

On T2WI, the image contrast in the uterine cervix and vagina were significantly higher at 3T than at 1.5T, although there was no significant difference in the overall image quality or contrast in the uterine zonal appearance. Image inhomogeneity was more prominent at 3T, and motion artifact was more severe at 1.5T.

Conclusion

Our results suggest that MRI of the female pelvis at 3T may potentially provide excellent images of the uterine cervix on high‐resolution T2WI. New techniques to reduce inhomogeneity are thus called for. J. Magn. Reson. Imaging 2007;25:527–534. © 2007 Wiley‐Liss, Inc.
Differentiation of SCA2 from MSA‐C using proton magnetic resonance spectroscopic imaging
Authors: Boesch Sylvia M. , Wolf Christian , Seppi Klaus , Felber Stephan , Wenning Gregor K. , Schocke Michael
Published: February 2007

Purpose

To assess and compare biochemical and volumetric features of the cerebellum in patients with spinocerebellar ataxia type 2 (SCA2) and patients with the cerebellar variant of multiple system atrophy (MSA‐C).

Materials and Methods

Nine genetically assigned SCA2 patients and six MSA‐C patients who met the clinical criteria of MSA‐C underwent a clinical and neuroradiological workup with respect to cerebellar features. The MR protocol consisted of a sagittal T1‐weighted three‐dimensional fast low‐angle shot (3D FLASH) sequence and a transversal T2‐ and spin‐density‐weighted turbo spin‐echo sequence. The proton magnetic resonance spectroscopic imaging (1H‐MRSI) protocol consisted of two chemical shift imaging (CSI) sequences (echo time (TE) = 20 and 135 msec).

Results

Both short‐ and long‐TE MR spectroscopy (MRS) images showed significant decreases in values for N‐acetylaspartate to creatine (NAA/Cr), and choline to creatine (Cho/Cr) ratios in MSA‐C and SCA2 compared to normal controls, though there was no difference between the two patient groups. In contrast, distinct cerebellar lactate (Lac) peaks were detected in seven SCA2 patients, and small peaks were detected in two. However, we did not detect any definite Lac peak in MSA‐C or control subjects.

Conclusion

MRSI revealed Lac pathology in SCA2 but not in MSA‐C. Whether this indicates distinct pathogenetic mechanisms of cerebellar degeneration remains to be established. J. Magn. Reson. Imaging 2007;25:564–569. © 2007 Wiley‐Liss, Inc.
Dose comparison of single‐ vs. double‐dose in contrast‐enhanced magnetic resonance angiography of the carotid arteries: Intraindividual cross‐over blinded trial using Gd‐DTPA
Authors: Jourdan C. , Heverhagen J.T. , Knopp M.V.
Published: February 2007

Purpose

To compare the intraindividual differences of single‐dose (DS) and double‐dose (DD) gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA)‐enhanced magnetic resonance angiography (MRA) in the carotid arterial territory, an open‐label single‐center trial with blinded evaluations by two independent radiologists was undertaken.

Materials and Methods

A total of 11 healthy volunteers were included in the study. Carotid MRAs were carried out in a 1.5 T clinical scanner using a neurovascular phased‐array coil. Images were acquired with three‐dimensional (3D) fast spoiled gradient recalled echo (FSPGR) sequence. Contrast agent was injected with a power injector, keeping the injection time constant for DS and DD.

Results

Both readers found at least 97% of vascular segments evaluable. Median overall image quality and diagnostic confidence were rated excellent and confident to very confident. No statistically significant difference between the dosage groups could be demonstrated. Variability based on a region of interest (ROI) signal intensity (SI) measurement was 7% for the DS and 5% for the DD group. SI, signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR) were significantly higher for the DD group.

Conclusion

Our results demonstrate that while a double dosing of contrast agent does increase SNR, it does not lead to further improvement in visual and perceptual image quality. A single dosage of approximately 0.1 mmol/kg body weight (bw) Gd‐DTPA may be the preferable dosage in the carotid arteries. J. Magn. Reson. Imaging 2007;25:557–563. © 2007 Wiley‐Liss, Inc.
Unifying the analyses of anatomical and diffusion tensor images using volume‐preserved warping
Authors: Xu Dongrong , Hao Xuejun , Bansal Ravi , Plessen Kerstin J. , Geng Weidong , Hugdahl Kenneth , Peterson Bradley S.
Published: February 2007

Purpose

To introduce a framework that automatically identifies regions of anatomical abnormality within anatomical MR images and uses those regions in hypothesis‐driven selection of seed points for fiber tracking with diffusion tensor (DT) imaging (DTI).

Materials and Methods

Regions of interest (ROIs) are first extracted from MR images using an automated algorithm for volume‐preserved warping (VPW) that identifies localized volumetric differences across groups. ROIs then serve as seed points for fiber tracking in coregistered DT images. Another algorithm automatically clusters and compares morphologies of detected fiber bundles. We tested our framework using datasets from a group of patients with Tourette's syndrome (TS) and normal controls.

Results

Our framework automatically identified regions of localized volumetric differences across groups and then used those regions as seed points for fiber tracking. In our applied example, a comparison of fiber tracts in the two diagnostic groups showed that most fiber tracts failed to correspond across groups, suggesting that anatomical connectivity was severely disrupted in fiber bundles leading from regions of known anatomical abnormality.

Conclusion

Our framework automatically detects volumetric abnormalities in anatomical MRIs to aid in generating a priori hypotheses concerning anatomical connectivity that then can be tested using DTI. Additionally, automation enhances the reliability of ROIs, fiber tracking, and fiber clustering. J. Magn. Reson. Imaging 2007;25:612–624. © 2007 Wiley‐Liss, Inc.
Precision, signal‐to‐noise ratio, and dose optimization of magnitude and phase arterial input functions in dynamic susceptibility contrast MRI
Authors: Kotys Melanie S. , Akbudak Erbil , Markham Joanne , Conturo Thomas E.
Published: February 2007

Purpose

To determine optimal conditions for precise measurement of arterial input function (AIFs) in dynamic susceptibility contrast (DSC) perfusion MRI.

Materials and Methods

Magnitude‐based (ΔR2*) and phase‐based (Δϕ) AIFs were numerically simulated for several doses and baseline MRI noise levels [SNR(I0)]. Random noise (1000 realizations) was added to real/imaginary MRI signals (derived from an internal carotid AIF), and AIF signal, noise, and signal‐to‐noise ratio (SNR) were determined. The optimal dose was defined as the dose that maximizes mean AIF SNR over the first‐pass (SNRmean), rather than SNR at the AIF peak (SNRpeak) because, compared to SNRpeak, doses predicted by SNRmean reduced the AIF‐induced variability in cerebral blood flow (CBF) by 24% to 40%.

Results

The AIF SNR is most influenced by choice of AIF signal, then optimal dosing, each with little penalty. Compared to ΔR2*, Δϕ signal has 4 to 80 times the SNR over all doses and time points, and ∼10‐fold SNRmean at respective optimal doses. Optimal doses induce 85% to 90% signal drop for the ΔR2* method, and 70% to 75% for Δϕ, with two‐fold dose errors causing ∼1.7‐fold loss in SNRmean. Increases in SNR(I0) proportionally increase AIF SNR, but at a cost.

Conclusion

AIF SNR is affected most by signal type, then dosing, and lastly, SNR(I0). J. Magn. Reson. Imaging 2007;25:598–611. © 2007 Wiley‐Liss, Inc.
Whole‐body 3D water/fat resolved continuously moving table imaging
Authors: Börnert Peter , Keupp Jochen , Eggers Holger , Aldefeld Bernd
Published: February 2007

Purpose

To study the feasibility of three‐dimensional (3D) whole‐body, head‐to‐toe, water/fat resolved MRI, using continuously moving table imaging technology.

Materials and Methods

Experiments were performed on nine healthy volunteers, acquiring 3D whole‐body head‐to‐toe data under continuous motion of the patient table. Two different approaches for water/fat separation have been studied. Results of a three‐point chemical shift encoding and a spectral presaturation technique were compared with respect to image quality and performance. Furthermore, fast, low‐resolution, whole‐body water/fat imaging was performed in two minutes total scan time to derive patient‐specific parameters such as the total water/fat ratio, the intraperitoneal/extraperitoneal fat ratio, and the body mass index (BMI).

Results

Good water/fat separation with decent image quality was obtained in all cases. The three‐point chemical shift encoding approach was found to be more efficient with respect to signal‐to‐noise ratio (SNR) and acquisition time.

Conclusion

Whole‐body water/fat sensitive MRI using continuous table motion is feasible and could be of interest for clinical practice. Some improvements of the method are desirable. J. Magn. Reson. Imaging 2007;25:660–665. © 2007 Wiley‐Liss, Inc.
Structures and fragmentations of Cobalt(II)–cysteine complexes in the gas phase
Authors: Buchmann William , Spezia Riccardo , Tournois Guewen , Cartailler Thierry , Tortajada Jeanine
Published: February 2007

The electronebulization of a cobalt(II)/cysteine(Cys) mixture in water/methanol (50/50) produced mainly cobalt‐cationized species. Three main groups of the Co‐cationized species can be distinguished in the ESI‐MS spectrum: (1) the cobalt complexes including the cysteine amino acid only (they can be singly charged, for example, [Co(Cys)n− H]+ with n = 1–3 or doubly charged such as [Co + (Cys)2]2+); (2) the cobalt complexes with methanol: [Co(CH3OH)n− H]+ with n = 1–3, [Co(CH3OH)4]2+; and (3) the complexes with the two different types of ligands: [Co(Cys)(CH3OH) − H]+. Only the singly charged complexes were observed. Collision‐induced dissociation (CID) products of the [Co(Cys)2]2+, [Co(Cys)2 − H]+ and [Co(Cys) − H]+ complexes were studied as a function of the collision energy, and mechanisms for the dissociation reactions are proposed. These were supported by the results of deuterium labelling experiments and by density functional theory calculations. Since [Co(Cys) − H]+ was one of the main product ions obtained upon the CID of [Co(Cys)2]2+ and of [Co(Cys)2 − H]+ under low‐energy conditions, the fragmentation pathways of [Co(Cys) − H]+ and the resulting product ion structures were studied in detail. The resulting product ion structures confirmed the high affinity of cobalt(II) for the sulfur atom of cysteine. Copyright © 2007 John Wiley & Sons, Ltd.
The reduced scalar potential in regions with permeable materials: Reasons for loss of accuracy and cancellation
Authors: Balac S. , Caloz G.
Published: February 2007

Practical three‐dimensional magnetic field problems usually involve regions containing current sources as well as regions with magnetic materials. For computational purposes, the use of the reduced scalar potential (RSP) as unknown has the advantage to transform a problem for a vector field throughout the space into a problem for a scalar function, thus reducing the number of degrees of freedom in the discretization. However, in regions with high magnetic permeability the use of the RSP alone usually results in severe loss in accuracy and it is recommended to use both the RSP and the total scalar potential. Using an asymptotic expansion, we investigate theoretically the underlying reasons for this lack of accuracy in permeable regions when using the RSP as a unique potential. Moreover, this investigation leads to an efficient numerical method to compute the magnetic field in regions with high magnetic permeability. Copyright © 2007 John Wiley & Sons, Ltd.
Winter snow depth variability over northern Eurasia in relation to recent atmospheric circulation changes
Authors: Popova V.
Published: February 2007

Mean snow depth time‐series for February (1936–2001) over northern Eurasia (incl. Norway, Finland and the former USSR), interpolated into 5 × 5° grid points, are studied using empirical orthogonal function (EOF) analysis. First, five statistically significant rotated PCs are correlated to Northern Hemisphere (NH) teleconnection patterns at the 700 hPa height: North Atlantic Oscillation (NAO), Polar‐Eurasia (Pol), Pacific‐North American (PNA), West Pacific (WP), and Scandinavia (Scand). The impact of the NH circulation modes on snow depth variations is evaluated using the multiple stepwise backward regression (MSBR).

Analyses of the snow depth PCs indicate that within the northern Eurasia territory, there are several regions with snow accumulation, respondent to certain circulation modes. PC1 describes low‐frequency snow depth variation to the north from 55 to 60°N between the White Sea and the Lena river basin, and is positively correlated with NAO and negatively—with Scand. MSBR shows that in 1951–1974 the leading role in snow depth variability belongs to Scand. After 1975, Scand has passed over the leading role to NAO. Scand and NAO are also responsible for the surface air temperature changes over the northern Eurasia. Snow depth PC1 and wintertime temperature are closely related to each other. PC2 describes quasi‐decadal snow depth variability over eastern Europe and is negatively correlated with NAO. For the Baltic and White Sea coasts, Fennoscandia, and the center of the East European plain, decrease of snow accumulation, related to a positive NAO phase, seems to be caused by mild winters. For the southwestern and central regions of eastern Europe, negative snow depth anomalies could also be caused by decrease of precipitation associated with the eastward shift of cyclone tracks related to the positive NAO phase. Two regions, where snow depth variations are described by PC1 and PC2, respectively, reveal the border between the opposite recent tendencies of snow accumulation. Copyright © 2007 Royal Meteorological Society
Antioxidant capacity of Spanish honeys and its correlation with polyphenol content and other physicochemical properties
Authors: Vela Lucía , de Lorenzo Cristina , Pérez Rosa Ana
Published: February 2007

Thirty‐six Spanish honeys of different floral origins (nectars and honeydews) were assessed to estimate their radical‐scavenging capacity against the stable free radical DPPH (1,1‐diphenyl‐2‐picrylhydrazyl), their ability to inhibit enzymatic browning in apple homogenate and their clarifying effect on apple juice. These capacities were evaluated spectrophotometrically. Physicochemical parameters such as pH, acidity, net absorbance, electrical conductivity and total polyphenol content of the samples were also evaluated. It was observed that all these parameters presented a strong correlation with radical‐scavenging capacity, whereas antibrowning capacity had a low correlation with conductivity and no correlation with honey pH. When data of nectar and honeydew honeys were evaluated separately, net absorbance and honey acidity seemed to be good parameters to evaluate the antioxidant activity of nectar honeys; however, in honeydew honeys there were only relationships between radical‐scavenging activity and honey conductivity and between browning inhibition of homogenates and total acidity. In general, honeydew honeys showed higher antioxidant capacities than nectar honeys. Copyright © 2007 Society of Chemical Industry
Use of ozone in a lettuce‐washing process: an industrial trial
Authors: Hassenberg Karin , Idler Christine , Molloy Eleanor , Geyer Martin , Plöchl Matthias , Barnes Jeremy
Published: February 2007

Bacteria such as Escherichia coli and Salmonella spp. may cause serious problems for the quality maintenance of pre‐packaged lettuces. The aim of this study was to evaluate the bactericidal effect of ozonated water in the washing of iceberg lettuce. For this purpose an ozone generator was integrated into a commercial lettuce‐washing facility. Lettuce samples were removed from this process and analysed for mesophilic total viable count (TVC), E. coli, Salmonella spp., vitamin C and sugar content. The analyses were carried out either directly after washing or at the end of best‐before date (BBD), in which lettuces were stored at 4 °C for 6 days. Water samples were analysed for total organic carbon (TOC) content and pH. Through the addition of ozone to the wash water the quality of lettuce during storage time was unaffected while there was only a limited observed decrease in populations of microorganisms. Copyright © 2007 Society of Chemical Industry