bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractIn 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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractProprotein 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

AbstractWe 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

AbstractIt 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

AbstractInternal 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

AbstractThis 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

AbstractTwo 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

AbstractAn 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

AbstractA 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

AbstractThis 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

AbstractT2* 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

AbstractSpherical 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

AbstractHigh‐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

AbstractMagnetic 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

AbstractA 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.