bluuebunny/crossref_metadata_2025 huggingface dataset:
Hormone receptor status and survival in a population‐based cohort of patients with breast carcinoma
Authors: Grann Victor R. , Troxel Andrea B. , Zojwalla Naseem J. , Jacobson Judith S. , Hershman Dawn , Neugut Alfred I.
Published: April 2005

BACKGROUND

The objective of this study was to assess hormone receptor status as an independent predictor of survival in a population‐based cohort of women with breast carcinoma who were followed for up to 11 years.

METHODS

Since 1990, the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program has collected data on hormone receptor status among patients with breast carcinoma. In a cohort of 205,736 women with breast carcinoma age ≥ 20 years at diagnosis who were entered into the SEER data base between 1990 and 2000, the authors analyzed the association of hormone receptor status with year of diagnosis, patient age, disease stage, tumor histology, tumor grade, race/ethnicity, and metropolitan/statewide residence areas. Kaplan–Meier survival curves were compared according to hormone receptor status, and Cox proportional‐hazards regression models were used to assess the association of hormone receptor status with breast carcinoma‐specific and all‐cause mortality controlling for age, disease stage, tumor grade, tumor histology, race/ethnicity, and SEER region.

RESULTS

Women who had tumors that were positive for both estrogen and progesterone hormone receptors had significantly better survival than other women with breast carcinoma in the overall cohort, within each stage, and in the younger and older age groups, although the survival advantage was greater among women age ≤ 50 years than among older women. Hormone receptor status was associated with mortality even when patient age, disease stage, tumor grade, tumor histology, race/ethnicity, and metropolitan/statewide residence areas were taken into account.

CONCLUSIONS

Hormone receptor status was identified as an independent predictor of outcome in women with breast carcinoma. Data from clinical trials with long follow‐up may shed light on whether and how the benefit of hormonal and other treatment varies with hormone receptor status. Cancer 2005. © 2005 American Cancer Society.
Descending projections from the auditory cortex to the inferior colliculus in the gerbil, Meriones unguiculatus
Authors: Bajo Victoria M. , Moore David R.
Published: April 2005

Corticofugal projections to the auditory midbrain, the inferior colliculus (IC), influence the way in which specific sets of IC neurons process acoustic signals. We used retrograde tracer (Fluorogold, Fluororuby, microbeads) injections in the IC to study the morphology and location of cortico‐collicular projecting neurons and anterograde tracer (dextran biotin) injections in auditory cortical fields to describe the distribution of terminals in the IC. Nissl staining, cytochrome oxidase activity, and neurofilament SMI32 immunostaining were used to delimit the different auditory areas. We defined a primary or “core” auditory cortex and a secondary “caudal” auditory area containing layer V pyramidal neurons that project to the IC. These projections target the central nucleus of the IC (CNIC) ipsilaterally and the IC cortices bilaterally, with the ipsilateral component predominant. Other secondary auditory areas, dorsal and ventral to the core, do not directly participate in this projection. The ventral secondary cortex targets midbrain periaqueductal gray. The projection from the core cortex originates from two classes of layer V pyramidal cells. Cells presenting a tufted apical dendrite in layer I have dense terminal fields in the IC cortices. Pyramids lacking layer I dendritic tufts target the CNIC in a less dense but tonotopic manner. The caudal cortex projection originates from smaller layer V pyramids and targets the IC cortices with dense terminal fields. Descending auditory inputs from the core and caudal areas converge in the dorsal and external cortices of the IC. Descending connections to the gerbil IC form a segregated system in which multiple descending channels originating from different neuronal subpopulations may modulate specific aspects of ascending auditory information. J. Comp. Neurol. 486:101–116, 2005. © 2005 Wiley‐Liss, Inc.
Morphological and biochemical heterogeneity in facial and vagal nerve innervated taste buds of the channel catfish, Ictalurus punctatus
Authors: Eram Mojgan , Michel William C.
Published: April 2005

In catfish, the facial nerve innervates taste buds distributed over the entire body including the barbels, while the glossopharyngeal and vagal nerves innervate oropharyngeal taste buds. Facial nerve innervated taste buds (FITBs) are thought to be involved in food detection and localization, while glossopharyngeal and vagal nerve innervated taste buds (VITBs) evaluate the palatability of food prior to ingestion. Physiological studies indicate that both oral and extra‐oral taste buds detect sapid substances such as amino acids and nucleotides, but the facial taste system is more sensitive to some of these substances. The anatomical, molecular, and/or physiological mechanisms underlying the functional differences in these two gustatory pathways remain to be identified. In the current investigation we compare the basic morphological features of FITBs and VITBs and the distribution of the following metabolites: γ‐aminobutyric acid (GABA), glutamate, aspartate, alanine, taurine, and glutathione. Vagal innervated taste buds are significantly longer and narrower than FITBs, with fewer taste cells and a smaller nerve plexus. Each of the metabolites examined was heterogeneously distributed in taste cells with notably more GABA positive cells present in the VITBs. Patterns of metabolite colocalization suggest the presence of several taste cell subtypes. The morphological and metabolite differences noted between FITBs and VITBs provide a potential anatomical basis for the previously noted differences in physiological sensitivity. J. Comp. Neurol. 486:132–144, 2005. © 2005 Wiley‐Liss, Inc.
Expression of Xenopus XlSALL4 during limb development and regeneration
Authors: Neff Anton W. , King Michael W. , Harty Mark W. , Nguyen Trent , Calley John , Smith Rosamund C. , Mescher Anthony L.
Published: April 2005

The multi‐C2H2 zinc‐finger domain containing transcriptional regulators of the spalt (SAL) family plays important developmental regulatory roles. In a competitive subtractive hybridization screen of genes expressed in Xenopus laevis hindlimb regeneration blastemas, we identified a SAL family member that, by phylogenetic analysis, falls in the same clade as human SALL4 and have designated it as XlSALL4. Mutations of human SALL4 have been linked to Okihiro syndrome, which includes preaxial (anterior) limb defects. The expression pattern of XlSALL4 transcripts during normal forelimb and hindlimb development and during hindlimb regeneration at the regeneration‐competent and regeneration‐incompetent stages is temporally and regionally dynamic. We show for the first time that a SAL family member (XlSALL4) is expressed at the right place and time to play a role regulating both digit identity along the anterior/posterior axis and epimorphic limb regeneration. Developmental Dynamics 233:356–367, 2005. © 2005 Wiley‐Liss, Inc.
Sef is synexpressed with FGFs during chick embryogenesis and its expression is differentially regulated by FGFs in the developing limb
Authors: Harduf Haggar , Halperin Einat , Reshef Ram , Ron Dina
Published: April 2005

The signaling pathways leading to growth and patterning of various organs are tightly controlled during the development of any organism. These control mechanisms usually involve the utilization of feedback‐ and pathway‐specific antagonists where the pathway induces the expression of its own antagonist. Sef is a feedback antagonist of fibroblast growth factor (FGF) signaling, which has been identified recently in zebrafish and mammals. Here, we report the isolation of chicken Sef (cSef) and demonstrate the conserved nature of the regulatory relationship with FGF signaling. In chick embryos, Sef is expressed in a pattern that coincides with many known sites of FGF signaling. In the developing limb, cSef is expressed in the mesoderm underlying the apical ectodermal ridge (AER) in the region known as the progress zone. cSef message first appeared after limb budding and AER formation. Expression was intense at stages of rapid limb outgrowth, and gradually decreased to almost undetectable levels when differentiation was clearly apparent. Gain‐ and loss‐of‐function experiments showed that FGFs differentially regulate the expression of cSef in various tissues. Thus, removal of the AER down‐regulated cSef expression, and FGF2 but not FGF4 or FGF8 beads substituted for the AER in maintaining cSef expression. At sites where cSef is not normally expressed, FGF4 and FGF2, but not FGF8 beads, induced cSef expression. Our results demonstrate the complexity of cSef regulation by FGFs and point to FGF2 as a prime candidate in regulating cSef expression during normal limb development. The spatiotemporal pattern of cSef expression during limb development suggests a role for cSef in regulating limb outgrowth but not limb initiation. Developmental Dynamics 233:301–312, 2005. © 2005 Wiley‐Liss, Inc.
Genetic analysis of metamorphic and premetamorphic Xenopus ciliary marginal zone
Authors: Casarosa S. , Leone P. , Cannata S. , Santini F. , Pinchera A. , Barsacchi G. , Andreazzoli M.
Published: April 2005

A major event affecting the eye during amphibian metamorphosis is an asymmetrical growth of the ventrotemporal portion of the retina compared with its dorsonasal counterpart. This event is due to an increased proliferation of the precursors of the ventral ciliary marginal zone (CMZ). Here, we analyze the expression patterns of several key homeobox genes implicated in eye development (Xrx1, Xvax2, Xsix3, Xpax6, Xchx10, Xotx2) to understand whether they are active at the time in which the metamorphic changes of the retina occur. We also analyze their expression patterns in the ventral and dorsal CMZ and compare them with bromodeoxyuridine incorporation in the CMZ. Our results suggest that the metamorphic CMZ maintains the functional subdivisions described during embryonic development. Moreover, we find that genes involved in proliferation and cell type determination of the embryonic retina are actively transcribed in the proliferating CMZ, thus indicating a potential regulatory role for these genes in the metamorphic retina. Developmental Dynamics 233:645–651, 2005. © 2005 Wiley‐Liss, Inc.
Proprotein convertase genes in Xenopus development
Authors: Nelsen Sylvia , Berg Linnea , Wong Crispin , Christian Jan L.
Published: April 2005

Proprotein convertases (PCs) are a family of serine endoproteases that proteolytically activate many precursor proteins within various secretory pathway compartments. Loss‐of‐function studies have demonstrated a critical role for these proteases in embryonic patterning and adult homeostasis, yet little is known about how substrate selectivity is achieved. We have identified Xenopus orthologs of three PCs: furin, PC6, and PC4. In addition to previously described isoforms of PC6 and furin, four novel splice isoforms of PC6, which are predicted to encode constitutively secreted proteases, and a putative transmembrane isoform of PC4 were identified. Furin and PC6 are expressed in dynamic, tissue‐specific patterns throughout embryogenesis, whereas PC4 transcripts are restricted primarily to germ cells and brain in adult frogs. Developmental Dynamics 233:1038–1044, 2005. © 2005 Wiley‐Liss, Inc.
Theoretical analysis and reduction of the quantization noise effects in the SA‐DCT
Authors: Acocella Emilio Carlos , Alcaim Abraham
Published: April 2005

We present a detailed mathematical analysis of two important problems in object‐based video coders that use shape‐adaptive discrete cosine transform (SA‐DCT). One is the annoying mean distortion effect caused by the quantization process and the other is the quantization noise dependence on the object shape (and not only on the quantizer characteristics). A general expression for the cross‐correlation matrix of the image error magnitude is presented, as well as one for the particular case of white quantization noise. In the latter case, four different implementation options are examined. We propose new strategies to minimize (or even eliminate) the two problems considered in our mathematical formulation. The results of our experiments show that the proposed scheme outperforms those obtained with other strategies described in the literature. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 14, 238–245, 2004; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/ima.20030
Increased expression of MDM2, cyclin D1, and p27Kip1 in carcinogen‐induced rat mammary tumors
Authors: Murray Stephen A. , Yang Shi , Demicco Elizabeth , Ying Haoqiang , Sherr David H. , Hafer Laurie J. , Rogers Adrianne E. , Sonenshein Gail E. , Xiao Zhi‐Xiong Jim
Published: April 2005

It is thought that environmental pollutants, such as polycyclic aromatic hydrocarbons (PAH), contribute to human breast tumorigenesis, yet their roles remain incompletely elucidated. The prototypical PAH 7,12‐dimethylbenz(α)anthracene (DMBA) specifically and effectively induces mammary tumor formation in rodent models. In an attempt to explore the molecular mechanisms by which PAH initiates and promotes mammary tumorigenesis, we examined the expression of several cell cycle regulators in rat mammary tumors induced by DMBA. Expression of cyclin D1, murine double minute‐2 (MDM2), and Akt was up‐regulated in tumors in comparison to normal mammary glands, as indicated by RT‐PCR, Western blot analysis, and immunohistochemical staining. Expression of p27Kip1 protein was also elevated in the tumors with increased cytoplasmic localization. However, RB protein remained hyperphosphorylated. To directly test the effects of DMBA, the MCF‐7 human breast cancer cells were treated. DMBA induced MDM2 expression in a dose‐ and time‐dependent fashion in the MCF‐7 cells, and this activation appeared to be p53 dependent. These data suggest that activation of cyclin D1, MDM2, and AKT as well as increased expression and cytoplasmic localization of p27Kip1 may play a role in this model of environmental pollutant‐induced mammary tumorigenesis. © 2005 Wiley‐Liss, Inc.
Psychometric properties of a Swedish translation of the Clinician‐Administered PTSD Scale‐Diagnostic Version
Authors: Paunović Nenad , Öst Lars‐Göran
Published: April 2005

Internal consistency (N = 172) and convergent validity (N = 73) of a Swedish translation of the Clinician‐Administered PTSD Scale‐Diagnostic Version (CAPS‐DX) were evaluated with violence victims with posttraumatic stress disorder (PTSD). The CAPS‐DX evidenced a promising internal consistency, and significant correlations (Pearson product–moment) with the PTSD Symptom Scale Self‐Report version (PSS‐SR) and the Impact of Event Scale‐Revised (IES‐R). Additionally, each subscale of the CAPS‐DX (intrusion, avoidance/numbing, and arousal) was significantly correlated with the corresponding subscales of the PSS‐SR and the IES‐R. Results of the present study are discussed in the context of internal consistencies and convergent validity coefficients of the CAPS with other PTSD symptom measures in previous studies.
Role of peer support and emotional expression on posttraumatic stress disorder in student paramedics
Authors: Lowery Kim , Stokes Mark A.
Published: April 2005

This exploratory study contrasted and tested the predictive value of the reverse buffering hypothesis of social support and the information processing model of posttraumatic stress disorder (PTSD) in an investigation of trauma‐related symptomatology (TRS) in a single sample of 42 student paramedics. Participants completed several anonymous self‐report measures of PTSD symptomatology, peer social support, and attitude toward emotional expression. Regression‐based path analyses did not support either theory of PTSD in this population. A path model of PTSD in student paramedics was subsequently developed, indicating that a direct relationship exists between duty‐related trauma exposure, dysfunctional peer social support, and students' negative attitudes toward emotional expression. This new model accounted for 30% of the variance in student paramedics' TRS.
Motives to drink as mediators between childhood sexual assault and alcohol problems in adult women
Authors: Grayson Carla E. , Nolen‐Hoeksema Susan
Published: April 2005

Two models are proposed to relate maladaptive emotion regulation strategies and alcohol‐related problems for women with a history of childhood sexual assault (CSA). The distress coping model suggests only one motive—drinking to cope with negative emotions—mediates the relationship between CSA and alcohol problems. The emotion regulation model suggests two motives mediate the relationship between CSA and alcohol problems: drinking to cope with negative emotions and drinking to enhance positive emotions. These models were tested in a random community sample of 697 women, ranging from 25 to 75 years old. Both motives partially mediated the relationship between CSA and alcohol problems. Effects were small, but reliable.
Optimized RF excitation for anatomical brain imaging of the occipital lobe using the 3D MDEFT sequence and a surface transmit coil
Authors: Deichmann Ralf
Published: April 2005

An RF excitation scheme is presented for anatomical imaging of occipital brain areas at 3T using the 3D modified driven equilibrium Fourier transform (MDEFT) sequence and a transmit‐receive surface coil. Surface coils operated in the transmit mode usually display a high B1 inhomogeneity. This causes variations of the flip angle and impairs fat saturation, resulting in blurring, signal losses, and artifacts due to high scalp intensities. A composite binomial pulse with one spectral component for water selective excitation and one spatial component for B1 inhomogeneity compensation is presented. It is shown experimentally that the pulse prevents image blurring and reduces the scalp signal considerably. The total pulse duration of only 2.4 ms is compatible with the relatively short repetition times (TRs) required for MDEFT imaging. The method is particularly useful for certain applications in neuroimaging that require technical equipment that is too large for standard coils or should not be exposed to RF fields. Magn Reson Med 53:1212–1216, 2005. © 2005 Wiley‐Liss, Inc.
3D volume‐localized pO2 measurement in the human lung with 3He MRI
Authors: Wild Jim M. , Fichele Stan , Woodhouse Neil , Paley Martyn N.J. , Kasuboski Larry , van Beek Edwin J.R.
Published: April 2005

A method for 3D volume‐localized quantification of pO2 in the lungs is presented that uses repetitive frame 3D gradient‐echo imaging of 3He. The method was demonstrated by experiments on 3He phantoms containing known concentrations of O2 and in vivo on a group of three healthy human volunteers. The results were compared with those obtained by equivalent 2D thin‐slice and 2D projection methodologies, and were found to be consistent with published results from the 2D projection methodologies (pO2 = 0.09–0.18 bar). Studies performed on the same subject, on three separate occasions, demonstrated a repeatability of pO2 measurement to within 14% using the 3D technique. Experimental differences between the 2D and 3D methods were substantiated with theoretical and numerical analyses of the signal decay, which took into account the effects of out‐of‐slice diffusion as a source of error in the thin‐slice 2D experiments. It is shown that the 2D thin‐slice technique systematically underestimates pO2 when there is significant gas diffusion (factor of 4 underestimate for D = 0.9 cm2s−1 representative of free 3He in air). Magn Reson Med 53:1055–1064, 2005. © 2005 Wiley‐Liss, Inc.
k‐space correction of eddy‐current‐induced distortions in diffusion‐weighted echo‐planar imaging
Authors: Papadakis Nikos G. , Smponias Theo , Berwick Jason , Mayhew John E.W.
Published: April 2005

This paper describes a method for correcting eddy‐current (EC)‐induced distortions in diffusion‐weighted echo‐planar imaging (DW‐EPI). First, reference measurements of EC fields within the EPI acquisition window are performed for DW gradient pulses applied separately along each physical axis of the gradient set and for a range of gradient amplitudes. EC fields caused by the DW gradients of the DW‐MRI protocol are then calculated using the reference EC measurements. Finally, these calculated fields are used to correct the respective DW‐EPI raw (k‐space) data during image reconstruction. The technique was implemented in a small‐bore MRI scanner with no digital preemphasis. It corrected EC‐induced image distortions in both phantom and in vivo brain diffusion tensor imaging (DTI) data more effectively than commonly used image‐based techniques. The method did not increase imaging time, since the same reference EC measurements were used to correct data acquired from different phantoms, subjects, and DTI protocols. Because of the simplicity of the reference EC measurements, the method can easily be implemented in clinical scanners. Magn Reson Med 53:1103–1111, 2005. © 2005 Wiley‐Liss, Inc.
Limits of detection of SPIO at 3.0 T using T2* relaxometry
Authors: Dahnke H. , Schaeffter T.
Published: April 2005

T2* relaxometry for quantitative MR imaging is strongly hampered by large‐scale field inhomogeneities, which lead to signal losses and an overestimation of the relaxation rate R2*. This is of particular importance for the sensitive detection of iron oxide contrast agent distributions. To derive an accurate measurement of T2*, a main field inhomogeneity correction is applied: the main field inhomogeneity is derived from multislice T2* relaxometry data and used as an initial value for an iterative optimization, by which the relaxation signal is corrected for each voxel. These corrected T2* maps show reduced influence of the local field variation and contain information about the local SPIO concentration. The method was tested on phantoms and the limit of detection of SPIO labeled cells using T2* relaxometry was estimated in volunteers to be 120 × 103 cells/mL (2.4 μg Fe/mL) in the brain and 385 × 103 cells/mL (8 μg Fe/mL) in the liver. Magn Reson Med 53:1202–1206, 2005. © 2005 Wiley‐Liss, Inc.
Optimizing spherical navigator echoes for three‐dimensional rigid‐body motion detection
Authors: Petrie Daniel W. , Costa Andreu F. , Takahashi Atsushi , Yen Yi‐Fen , Drangova Maria
Published: April 2005

Spherical navigator (SNAV) echoes show promise in correcting for three‐dimensional rigid‐body motion. In this paper, several important parameters in the design and performance of the SNAV technique are discussed, including a novel sampling strategy, the optimal k‐space radius and sampling density of the navigator, and the execution of the SNAV trajectory by the scanner hardware. A variable‐sampling density (VSD) helical‐spiral SNAV trajectory, which can acquire data on the entire spherical shell without exceeding the maximum slew rate of the scanner, is presented. To ensure that the VSD SNAV trajectory was properly executed by the scanner hardware, the gradient waveforms were verified using a self‐encoding technique. The ability of the VSD SNAV to measure rotational and translational motion was studied with in vitro experiments at various k‐space radii and sampling densities. The results of this study show that the best accuracy was attained at k‐space radii of 1.4 and 1.6 cm−1, with 2400 to 4000 samples acquired over the sphere. Magn Reson Med 53:1080–1087, 2005. © 2005 Wiley‐Liss, Inc.
Metabolic characterization of distinct neuroanatomical regions in rats by magic angle spinning 1H nuclear magnetic resonance spectroscopy
Authors: Tsang T. M. , Griffin J. L. , Haselden J. , Fish C. , Holmes E.
Published: April 2005

High‐resolution magic angle spinning (HRMAS) 1H NMR spectroscopy has been applied to the biochemical characterization of specific brain regions in rats in order to establish baseline levels of tissue metabolite profiles with which to compare models of neuropathology or toxic lesion. Cores of tissue (20 mg) from the brain stem, cerebellum, frontal cortex, and hippocampus were obtained from histologically defined coronal slices of brain from 18 male Sprague–Dawley rats. HRMAS 1H NMR spectra were acquired for each of the regions sampled and the degree of intersample variability, as assessed by principal components analysis and discriminant analysis by projection to latent structure was found to be low. Clear region‐specific differences in the biochemical profiles were observed using both comparison of metabolite ratios and/or pattern recognition methods. Relatively low concentrations of GABA in the cerebellum, high concentrations of taurine and N‐acetylaspartate in the cortex, and high levels of choline, glycerophosphocholine, and phosphocholine in the hippocampus predominantly influenced the classification of the different brain regions. Additionally, N‐acetylaspartylglutamate was detected in the brain stem, but was largely absent from the other regions examined. Such analyses provide a baseline reference for further HRMAS NMR spectroscopic studies to monitor disease and pharmacological insults in specific regions of the brain. Magn Reson Med 53:1018–1024, 2005. © 2005 Wiley‐Liss, Inc.
Quantitative shear wave magnetic resonance elastography: Comparison to a dynamic shear material test
Authors: Ringleb Stacie I. , Chen Qingshan , Lake David S. , Manduca Armando , Ehman Richard L. , An Kai‐Nan
Published: April 2005

Magnetic resonance elastography (MRE), a phase contrast MRI technique, images the propagation of applied mechanical waves in tissue, allowing shear stiffness to be quantified in vivo. This MRE technique has been validated with static mechanical compression tests. Dynamic mechanical analysis (DMA) may be a more appropriate comparison to MRE because it directly measures the shear modulus dynamically, while compression tests convert the measured elastic modulus to shear modulus with an assumed Poisson ratio. This study compared the shear stiffness estimated with various MRE inversion algorithms (i.e., manual calculation, local frequency estimate, phase gradient, direct inversion, and matched filter) to the dynamic mechanical test. The shear stiffness of five agarose gels with concentrations ranging from 1.5 to 3.5% were measured using MRE and DMA. The phase gradient inversion algorithm overestimated the shear modulus at higher concentrations (i.e., 3–3.5% agar), while the results from the other techniques correlated well with the dynamic mechanical test. Magn Reson Med 53:1197–1201, 2005. © 2005 Wiley‐Liss, Inc.
Accelerating MRI by skipped phase encoding and edge deghosting (SPEED)
Authors: Xiang Qing‐San
Published: April 2005

A fast imaging method called skipped phase encoding and edge deghosting (SPEED) is introduced. The k‐space is sparsely sampled into three interleaved datasets, each with a skip‐size N and a relative shift in phase encoding (PE). These datasets are separately reconstructed by 2DFT and edge‐enhanced by a differential filter in the PE direction, resulting in edge maps with phase‐shifted aliasing ghosts. The sparseness of edges reduces the chance of ghost overlapping. Typical ghosted‐edge maps can be adequately modeled with only two dominating ghost layers that are resolved from a set of three equations using least‐square error minimization, yielding N ghost maps of different orders that can be registered and averaged into a single deghosted‐edge map for noise and artifact reduction. Finally, the deghosted‐edge map is transformed into a deghosted image by an inverse filter. A few central k‐space lines are collected without PE skip to aid the inverse filtering. SPEED has been demonstrated by in vivo data to reduce scan time considerably without noticeable artifacts. It has various potential applications, such as MR angiography (MRA), where the signal itself is sparse. As an independent method, SPEED can be combined with other fast imaging methods for further acceleration. Magn Reson Med 53:1112–1117, 2005. © 2005 Wiley‐Liss, Inc.
An adjustable adiabatic pulse for selective population inversion
Authors: Mitschang Lorenz
Published: April 2005

A new adiabatic inversion pulse and its design principles are presented. An analytical expression in the pulse length, inversion bandwidth, inversion efficiency, peak RF amplitude, and width of the transition region is derived and validated. Accordingly, the pulse shape can be adapted to achieve a specified inversion performance. Adjusted for broadband application, population can be inverted band selectively, rather independently of spatial RF field inhomogeneities, and with significantly reduced peak RF amplitude in comparison with the well‐known hyperbolic secant adiabatic pulse. Magn Reson Med 53:1217–1222, 2005. © 2005 Wiley‐Liss, Inc.
Quantification of resting myocardial blood flow in a pig model of acute ischemia based on first‐pass MRI
Authors: Schmitt Melanie , Horstick Georg , Petersen Steffen E. , Karg Andrea , Hoffmann Nico , Gumbrich Thorsten , Abegunewardene Nico , Schreiber Wolfgang G.
Published: April 2005

Qualitative and semiquantitative contrast‐enhanced (CE) dynamic perfusion MRI techniques are established as noninvasive diagnostic means of assessing coronary artery disease. However, to date quantification of myocardial blood flow (MBF) has not reached the same acceptance as MBF quantification with nuclear techniques. To validate quantification of MBF at rest using the extracellular contrast agent (CA) Gd‐DTPA, we performed an animal study in a pig model of acute myocardial ischemia. We quantified MBF from MRI data with a mathematical model (MMID4) of the underlying vasculature. These MBF results were subsequently compared with the results from fluorescent microspheres. The study showed a correlation of r = 0.66 between MBF estimates obtained with MRI and those obtained with fluorescent microspheres. The correlation for ischemic and nonischemic myocardium was r = 0.86 and r = 0.47, respectively. In conclusion, quantification of resting MBF using MMID4 is a valid method under conditions of acute myocardial ischemia. Magn Reson Med 53:1223–1227, 2005. © 2005 Wiley‐Liss, Inc.
Hexagonal zero mode TEM coil: A single‐channel coil design for imaging multiple small animals
Authors: Lazovic Jelena , Stojkovic Dragan S. , Collins Christopher M. , Yang Qing X. , Vaughan J. Thomas , Smith Michael B.
Published: April 2005

A novel hexagonal coil design for simultaneous imaging of multiple small animals is presented. The design is based on a coaxial cavity and utilizes the magnetic field formed between two coaxial conductors with hexagonal cross‐sections. An analytical solution describing the B1 field between conductors of the hexagonal coil was found from the Biot‐Savart law. Both experimental results and analytical calculations showed a variation in the B1 field within the imaging region of less than 10%. Numerical calculations predicted ∼35% improvement in B1 field homogeneity with the hexagonal coil design compared to a cylindrical coaxial cavity design. The experimentally‐measured signal‐to‐noise ratio (SNR) of the hexagonal coil loaded with six 50‐mM phantoms was only 4–5% lower than that of a single parallel plate resonator loaded with one phantom. In vivo spin‐echo (SE) images of six 7‐day‐old rat pups acquired simultaneously demonstrated sufficient SNR for microimaging. The construction scheme of the coil, simple methods for tuning and matching, and an anesthesia device and animal holder designed for the coil are described. The hexagonal coil design utilizes a single receiver and allows for simultaneous imaging of six small animals with no significant compromise in SNR. Magn Reson Med 53:1150–1157, 2005. © 2005 Wiley‐Liss, Inc.
Free‐breathing renal magnetic resonance angiography with steady‐state free‐precession and slab‐selective spin inversion combined with radial k‐space sampling and water‐selective excitation
Authors: Katoh Marcus , Spuentrup Elmar , Stuber Matthias , Hoogeveen Romhild , Günther Rolf W. , Buecker Arno
Published: April 2005

The impact of radial k‐space sampling and water‐selective excitation on a novel navigator‐gated cardiac‐triggered slab‐selective inversion prepared 3D steady‐state free‐precession (SSFP) renal MR angiography (MRA) sequence was investigated. Renal MRA was performed on a 1.5‐T MR system using three inversion prepared SSFP approaches: Cartesian (TR/TE: 5.7/2.8 ms, FA: 85°), radial (TR/TE: 5.5/2.7 ms, FA: 85°) SSFP, and radial SSFP combined with water‐selective excitation (TR/TE: 9.9/4.9 ms, FA: 85°). Radial data acquisition lead to significantly reduced motion artifacts (P < 0.05). SNR and CNR were best using Cartesian SSFP (P < 0.05). Vessel sharpness and vessel length were comparable in all sequences. The addition of a water‐selective excitation could not improve image quality. In conclusion, radial k‐space sampling reduces motion artifacts significantly in slab‐selective inversion prepared renal MRA, while SNR and CNR are decreased. The addition of water‐selective excitation could not improve the lower CNR in radial scanning. Magn Reson Med 53:1228–1233, 2005. © 2005 Wiley‐Liss, Inc.
Reliability estimation of grouped functional imaging data using penalized maximum likelihood
Authors: Gullapalli Rao P. , Maitra Ranjan , Roys Steve , Smith Gerald , Alon Gad , Greenspan Joel
Published: April 2005

We analyzed grouped fMRI data and developed a reliability analysis for such data using the method of penalized maximum likelihood (ML). Specifically, this technique was applied to a somatosensory paradigm that used a mechanical probe to provide noxious stimuli to the foot, and a paradigm consisting of four levels of graded peripheral neuromuscular electrical stimulation (NMES). In each case, reliability maps of activation were generated. Receiver operating characteristic (ROC) curves were constructed in the case of the graded NMES paradigm for each level of stimulation, which revealed an increase in the specificity of activation with increasing stimulation levels. In addition, penalized ML was used to determine whether the grouped reliability maps obtained from one stimulus level were significantly different from those obtained at other levels. The results show a significant difference (P< 0.01) in the reliability of activation from one stimulation level to the next. These results are in agreement with those obtained using generalized linear modeling (GLM). While the reliability maps generated are not directly comparable, they are qualitatively similar to those obtained by controlling the expected false discovery rate (FDR). The proposed methodology can be used to objectively compare activation maps between groups, as well as to perform reliability assessments. Furthermore, this method potentially can be used to assess the longitudinal effect of treatment therapies within a group. Magn Reson Med 53:1126–1134, 2005. © 2005 Wiley‐Liss, Inc.
Positive contrast magnetic resonance imaging of cells labeled with magnetic nanoparticles
Authors: Cunningham Charles H. , Arai Takayasu , Yang Phillip C. , McConnell Michael V. , Pauly John M. , Conolly Steven M.
Published: April 2005

Contrast agents incorporating superparamagnetic iron‐oxide nanoparticles have shown promise as a means to visualize labeled cells using MRI. Labeled cells cause significant signal dephasing due to the magnetic field inhomogeneity induced in water molecules near the cell. With the resulting signal void as the means for detection, the particles behave as a negative contrast agent, which can suffer from partial‐volume effects. In this paper, a new method is described for imaging labeled cells with positive contrast. Spectrally selective RF pulses are used to excite and refocus the off‐resonance water surrounding the labeled cells so that only the fluid and tissue immediately adjacent to the labeled cells are visible in the image. Phantom, in vitro, and in vivo experiments show the feasibility of the new method. A significant linear correlation (r = 0.87, P < 0.005) between the estimated number of cells and the signal was observed. Magn Reson Med 53:999–1005, 2005. © 2005 Wiley‐Liss, Inc.
Sequence design for magnetic resonance spectroscopic imaging of prostate cancer at 3 T
Authors: Cunningham Charles H. , Vigneron Daniel B. , Marjanska Malgorzata , Chen Albert P. , Xu Duan , Hurd Ralph E. , Kurhanewicz John , Garwood Michael , Pauly John M.
Published: April 2005

Magnetic resonance spectroscopic imaging (MRSI) has proven to be a powerful tool for the metabolic characterization of prostate cancer in patients before and following therapy. The metabolites that are of particular interest are citrate and choline because an increased choline‐to‐citrate ratio can be used as a marker for cancer. High‐field systems offer the advantage of improved spectral resolution as well as increased magnetization. Initial attempts at extending MRSI methods to 3 T have been confounded by the J‐modulation of the citrate resonances. A new pulse sequence is presented that controls the J‐modulation of citrate at 3 T such that citrate is upright, with high amplitude, at a practical echo time. The design of short (14 ms) spectral–spatial refocusing pulses and trains of nonselective refocusing pulses are described. Phantom studies and simulations showed that upright citrate with negligible sidebands is observed at an echo time of 85 ms. Studies in a human subject verified that this behavior is reproduced in vivo and demonstrated that the water and lipid suppression of the new pulse sequence are sufficient for application in prostate cancer patients. Magn Reson Med 53:1033–1039, 2005. © 2005 Wiley‐Liss, Inc.
Personality traits, types, and disorders: an examination of the relationship between three self‐report measures
Authors: Furnham Adrian , Crump John
Published: April 2005

As part of an assessment centre 431 candidates completed three self‐report measures: one of personality disorders (Hogan Development Survey, HDS; Hogan & Hogan, 1997), one of personality traits (NEO‐PI, Costa & McCrae, 1992), and one of personality type (MBTI; Briggs & Myers, 1987). Correlational and regressional analysis tested various hypotheses about the overlap between the different dimensions and confirmed previous research using different instruments (Saulsman & Page, 2004). Results revealed highest correlation between the HDS and NEO, showing neuroticism correlating (as predicted) with excitable (borderline) and cautious (avoidant); introversion correlating with avoidant (cautious), schizoid (detached), and (negatively) with colourful (histrionic); openness correlating with schizotypal (imaginative) and conscientiousness with diligent (obsessive–compulsive). Many of the ‘overlaps’ were suggested by Widiger, Trull, Clarkin, Sanderson, and Costa (2002). The overlap and lack of overlap is considered at the psychometric and conceptual level. Copyright © 2005 John Wiley & Sons, Ltd.
Personality and marital satisfaction: a behavioural genetic analysis
Authors: Spotts Erica L. , Lichtenstein Paul , Pedersen Nancy , Neiderhiser Jenae M. , Hansson Kjell , Cederblad Marianne , Reiss David
Published: April 2005

Previous research has found that genetic and nonshared environmental factors influence marital quality (Spotts et al., 2004). The current study explored personality as a source for these genetic and environmental individual differences. A sample of 752 Swedish twin women and their spouses were used. Genetic and environmental influences were found for self‐report measures of marital quality, but only environmental factors contributed to the variance of observational measures of marital quality. Wives' personality characteristics accounted for genetic and nonshared environmental variance in the wives' own marital satisfaction, their husbands' marital satisfaction, and the agreement between the spouses on the quality of their marriage. Genetic influences on the correlation between wives' genetically influenced personality characteristics and their husbands' marital satisfaction indicate a gene–environment correlation. Contrary to expectations, husbands' personality did not explain large portions of wives' marital satisfaction beyond that explained by wives' personality. This study emphasizes the importance of spousal personality to the well‐being of marriages, and results are discussed within the context of three different theories regarding associations between personality and marital quality. Copyright © 2005 John Wiley & Sons, Ltd.
Consequences of liquefied natural gas marine incidents
Authors: Pitblado R. M. , Baik J. , Hughes G. J. , Ferro C. , Shaw S. J.
Published: April 2005

The liquefied natural gas industry in the United States is currently facing challenges in obtaining approvals for new receiving terminals. A factor of concern at public meetings relates to the potential hazards associated with marine transport accidents or terrorist events. The purpose of this study is to develop a range of well‐conceived maximum credible failure cases from accidental or terrorism causes and to predict hazard zones using a well‐validated model. Hazard zones that are presented in this paper tend to fall below many of the values previously quoted. Although additional experimental trials may be warranted, current results are of sufficient confidence to draw valid conclusions. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Feature Article: Thermodynamic properties from ab‐initio calculations: New theoretical developments, and applications to various materials systems
Authors: Fähnle Manfred , Drautz Ralf , Lechermann Frank , Singer Reinhard , Diaz‐Ortiz Alejandro , Dosch Helmut
Published: April 2005

The cover picture from the Feature Article [1] depicts the calculated landscape of lowest formation energies for the ternary compound system Ni–Fe–Al. The figure shows for each composition the difference in the formation energy (in meV/atom) for the respective homogeneous configuration with lowest energy on the bcc and the fcc parent lattice. The phases on the fcc lattice dominate the Ni‐ and Al‐rich regions of the Gibbs triangle.

The first author Manfred Fähnle is Professor at the University of Stuttgart and member of the theory group of the department of Prof. Schütz at the Max‐Planck‐Institut für Metallforschung in Stuttgart. In 1980 he was awarded with the Otto‐Hahn medal of the Max‐Planck Society and in 1985 he received the Academy Award for Physics of the University of Göttingen. His present research interests are the static and dynamic properties of bulk and nanostructured magnetic systems, as well as the ab‐initio statistical mechanics of alloys.
Potential energy surface of the reaction of imidazole with peroxynitrite: Density functional theory study
Authors: Gogonea Valentin
Published: April 2005

This article presents a theoretical investigation of the reaction mechanism of imidazole nitration by peroxynitrite using density functional theory calculations. Understanding this reaction mechanism will help in elucidating the mechanism of guanine nitration by peroxynitrite, which is one of the assumed chemical pathways for damaging DNA in cells. This work focuses on the analysis of the potential energy surface (PES) for this reaction in the gas phase. Calculations were carried out using Hartree–Fock (HF) and density functional theory (DFT) Hamiltonians with double‐zeta basis sets ranging from 6‐31G(d) to 6‐31++G(d,p), and the triple‐zeta basis set 6‐311G(d). The computational results reveal that the reaction of imidazole with peroxynitrite in gas phase produces the following species: (i) hydroxide ion and 2‐nitroimidazole, (ii) hydrogen superoxide ion and 2‐nitrosoimidazole, and (iii) water and 2‐nitroimidazolide. The rate‐determining step is the formation of a short‐lived intermediate in which the imidazole C2 carbon is covalently bonded to peroxynitrite nitrogen. Three short‐lived intermediates were found in the reaction path. These intermediates are involved in a proton‐hopping transport from C2 carbon to the terminal oxygen of the OO moiety of peroxynitrite via the nitroso (ON) oxygen. Both HF and DFT calculations (using the Becke3–Lee–Yang–Parr functional) lead to similar reaction paths for proton transport, but the landscape details of the PES for HF and DFT calculations differ. This investigation shows that the reaction of imidazole with peroxynitrite produces essentially the same types of products (nitro‐ and nitroso‐) as observed experimentally in the reaction of guanine with peroxynitrite, which makes the former reaction a good model to study by computation the essential characteristics of the latter reaction. Nevertheless, the computationally determined activation energy for imidazole nitration by peroxynitrite in the gas phase is 84.1 kcal/mol (calculated at the B3LYP/6‐31++G(d,p) level), too large for an enzymatic reaction. Exploratory calculations on imidazole nitration in solution, and on the reaction of 9‐methylguanine with peroxynitrite in the gas phase and solution, show that solvation increases the activation energy for both imidazole and guanine, and that the modest decrease (15 kcal mol−1) in the activation energy, due to the adjacent six member ring of guanine, is counterbalanced by solvation. These results lead to the speculation that proton tunneling may be at the origin of experimentally observed high reaction rate of guanine nitration by peroxynitrite in solution. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Charge distributions in polyacetylene chains containing a positively charged defect
Authors: Monev Valentin , Spassova Milena , Champagne Benoît
Published: April 2005

We present a comparative study of the AIM, CHELPG, GAPT, MK, Mulliken, NPA, and RESP charge distributions associated with a positively charged soliton on increasingly largetrans‐polyacetylene chains, at HF, MP2, and DFT levels of theory. The charge storage in the soliton‐bearing systems is explored in detail, including charge magnitude, charge separation, charge alternation, and chain length effects. The grouping of the charge distributions at a given level of theory, as well as the sensitivity of a given charge distribution to the inclusion of electron correlation in its computation, are investigated using similarity analysis. Several of the charge definitions have been applied for the first time for charged soliton‐bearing systems, and there are substantial differences between the charge distributions for the charged and neutral systems. Thus, AIM charges are no longer one of the largest charge values, the AIM charges can be in counterphase with other definitions, and the GAPT charges for neutral systems are quite different from the GAPT charges for charged systems, e.g., the magnitudes of the GAPT charges are anomalously large and increase with the size of the charged system. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005