bluuebunny/crossref_metadata_2025 huggingface dataset:
IL‐12 p40 homodimer, the so‐called biologically inactive molecule, induces nitric oxide synthase in microglia via IL‐12Rβ1
Authors: Jana Malabendu , Dasgupta Subhajit , Pal Utpal , Pahan Kalipada
Published: March 2009

Earlier we have demonstrated that IL‐12 p40 homodimer (p402) induces the expression of inducible nitric oxide synthase (iNOS) in microglia. This study was undertaken to investigate underlying mechanisms required for IL‐12 p402‐ and IL‐12 p70‐induced expression of iNOS in microglia. IL‐12 p402 alone induced the activation of both extracellular signal‐regulated kinase (ERK) and p38 mitogen‐activated protein kinase (MAPK). Interestingly, the ERK pathway coupled p402 to iNOS expression via C/EBPβ, but not NF‐κB, whereas the p38 pathway relayed the signal from p402 to iNOS expression via both NF‐κB and C/EBPβ. Furthermore, by using microglia from IL‐12Rβ1 (−/−) and IL‐12Rβ2 (−/−) mice or siRNA against IL‐12Rβ1 and IL‐12Rβ2, we demonstrate that p402 induced the expression of iNOS in microglia via IL‐12Rβ1–(ERK+p38)–(NF‐κB +C/EBPβ) pathway. In contrast, both IL‐12Rβ1 and IL‐12Rβ2 were involved for IL‐12 p70‐induced microglial expression of iNOS. Although IL‐12Rβ1 coupled p70 to NF‐κB and C/EBPβ, IL‐12Rβ2 was responsible for p70‐mediated activation of GAS. This study delineates a new role of IL‐12Rβ1 and IL‐12Rβ2 for the expression of iNOS and production of NO in microglia that may participate in the pathogenesis of neuroinflammatory diseases. © 2009 Wiley‐Liss, Inc.
Sp proteins and Runx2 mediate regulation of matrix gla protein (MGP) expression by parathyroid hormone
Authors: Suttamanatwong Supaporn , Jensen Eric D. , Schilling Jody , Franceschi Renny T. , Carlson Ann E. , Mansky Kim C. , Gopalakrishnan Rajaram
Published: March 2009

As part of its catabolic action in bone, parathyroid hormone (PTH) inhibits extracellular matrix mineralization. We previously showed that PTH dose‐dependently induces matrix gla protein (MGP) expression in osteoblasts and this induction is at least partially responsible for PTH‐mediated inhibition of mineralization. Recently, we identified PKA and ERK/MAPK as the key signaling pathways involved in PTH regulation of MGP expression. The goal of this study was to further characterize the mechanism by which PTH stimulates expression of MGP. Deletion analysis of the murine Mgp gene promoter identified a PTH‐responsive region between −173 bp and−49 bp. Using gel‐mobility shift assays we found that Sp1/Sp3, and Runx2 bind to distinct sites within this region. Mutation of either the Sp or the Runx2 site reduced MGP induction by PTH, while mutation of both sites completely abolished PTH responsiveness. Overexpression of Runx2 or Sp1 activated the Mgp reporter, while Sp3 was a dose‐dependent repressor of Sp1 and PTH‐induced MGP expression. Collectively, these data show that PTH regulates MGP gene transcription in osteoblasts through altered activities of Sp and Runx2 transcription factors. J. Cell. Biochem. 107: 284–292, 2009. © 2009 Wiley‐Liss, Inc.
Suppression of PAI‐1 expression through inhibition of the EGFR‐mediated signaling cascade in rat kidney fibroblast by ascofuranone
Authors: Cho Hyun‐Ji , Kang Jeong‐Han , Kim Teoan , Park Kwang‐Kyun , Kim Cheorl‐Ho , Lee In‐Seon , Min Kwan‐Sik , Magae Junji , Nakajima Hiroo , Bae Young‐Seuk , Chang Young‐Chae
Published: March 2009

Fibrosis in glomerulosclerosis causes progressive loss of renal function. Transforming growth factor (TGF)‐β, one of the major profibrotic cytokines, induces the synthesis of plasminogen activator inhibitor (PAI)‐1, a factor that plays a crucial role in the development of fibrosis. Here, we found that an isoprenoid antibiotic, ascofuranone, suppresses expression of profibrotic factors including matrix proteins and PAI‐1 induced by TGF‐β in renal fibroblasts. Ascofuranone selectively inhibits phosphorylation of epidermal growth factor receptor (EGFR), and downstream kinases such as Raf‐1, MEK‐1/2, and ERK‐1/2. PAI‐1 transcription also is suppressed by treatment with kinase inhibitors for MEK‐1/2 or EGFR, and with small interfering RNA for EGFR. Ascofuranone inhibits cellular metalloproteinase activity, and an inhibitor of metalloproteinases suppresses EGFR phosphorylation and PAI‐1 transcription. These results suggest that ascofuranone suppresses expression of profibrotic factors through the inhibition of an EGFR‐dependent signal transduction pathway activated by metalloproteinases. J. Cell. Biochem. 107: 335–344, 2009. © 2009 Wiley‐Liss, Inc.
Iodothyronine deiodinases and thyroid hormone receptors regulation during flatfish (Solea senegalensis) metamorphosis
Authors: Isorna Esther , Obregon Maria Jesus , Calvo Rosa Maria , Vázquez Rosa , Pendón Carlos , Falcón Jack , Muñoz‐Cueto José Antonio
Published: March 2009

Thyroid hormone‐induced metamorphosis seems to represent an ancestral feature of chrordates (urochordates, cephalochordates and vertebrates), but also of nonchordate animals. Although thyroid hormones and thyroid hormone receptor profiles during metamorphosis have been analyzed in different vertebrate taxa, including fish, developmental expression and activity of type 2 (dio2, D2) and type 3 (dio3, D3) iodothyronine deiodinases, two key enzymes in anuran metamorphosis, remain unknown in any fish species. The aim of this work was to investigate the development of thyroid hormone system during the metamorphosis of a flatfish species, the Senegalese sole, focusing on the deiodinases developmental profile. We have cloned sole D2 and D3 and analyzed several parameters of thyroid hormones system in pre‐, early‐, middle‐, and late‐metamorphic larvae. Both deiodinases contain in their catalytic centers an UGA triplet encoding for a selenocystein (Sec) residue as expected. Left eye migration and rotation in body position were associated with a significant increase in both thyroid hormones and thyroid hormone receptors at the middle–late metamorphic stages. Although dio2 expression slightly increased during metamorphosis, D2 activity augmentation was much more significant. Sole dio3 expression declined only slightly, whereas the D3 activity clearly decreased at mid‐late metamorphic period. This developmental profile of deiodinases sustained the rise of thyroid hormones levels observed during sole metamorphosis. No clear cut daily rhythms were observed in the parameters analyzed although it seemed that thyroid hormone system was more active during daytime, in particular at late metamorphic stages. These developmental changes point out the importance not only of thyroid hormones and their receptors but also of dio2 and dio3 in mediating flatfish metamorphosis, as it has been described in amphibians. J. Exp. Zool. (Mol. Dev. Evol.) 312B:231–246, 2009. © 2009 Wiley‐Liss, Inc.
Diffusion‐weighted magnetic resonance imaging detection of renal cancer presenting with diffuse peritoneal metastases in a patient with hemodialysis‐associated acquired cystic disease of the kidney
Authors: Kitazume Yoshio , Satoh Shiro , Taura Shinichi , Kimula Yuji
Published: March 2009

A 59‐year‐old man was admitted with a large amount of ascites, cake‐like omental thickening, and dialysis‐associated acquired cystic disease of the kidney (ACDK). It was difficult to detect renal cancer, which was revealed as a primary site of peritoneal metastases by autopsy, with conventional cross‐sectional imaging, such as enhanced computed tomography and T2, T1, and dynamic gadolinium‐enhanced T1‐weighted magnetic resonance imaging, because multiple renal cysts caused marked distortion of the renal parenchyma and the cancer had necrosis. We demonstrated the usefulness of diffusion‐weighted imaging with a high b‐factor to detect renal cancer presenting with peritoneal metastasis in a patient with ACDK. J. Magn. Reson. Imaging 2009;29:953–956. © 2009 Wiley‐Liss, Inc.
Neuroimaging assessment of memory‐related brain structures in a rat model of acute space‐like radiation
Authors: Huang Lei , Smith Anna , Cummings Peter , Kendall Edward J. , Obenaus Andre
Published: March 2009

Purpose

To investigate the acute effects on the central nervous system (CNS) of 56Fe radiation, a component of high‐energy charged particles (HZE) in space radiation, using quantitative magnetic resonance imaging (MRI) noninvasively.

Materials and Methods

Sprague–Dawley rats were exposed to whole‐brain 56Fe (0, 1, 2, and 4 Gy). At 1 week postirradiation, MRI scans were made using T2‐weighted (T2WI), diffusion‐weighted (DWI), and contrast enhanced T1‐(CET1) imaging. T2 relaxation time and apparent diffusion coefficient (ADC) values were obtained from memory‐related brain regions of interest (ROIs). Histopathology was correlated using ex vivo tissues.

Results

No overt abnormalities were visualized using T2WI and DWI at 1 week postradiation. CET1 values did not differ significantly between the irradiated and control animals. Compared to 0 Gy, there were significant prolongations in T2 values and reductions in ADC after irradiation. In the absence of evident neuronal pathology, immunohistochemistry revealed astrocytic activation in 4 Gy animals.

Conclusion

At 1 week after whole‐brain 56Fe exposure, T2 and ADC values can differentiate radiosensitivity in regions critical for hippocampal‐related memory. MRI may provide noninvasive assessment of the initial molecular/cellular disturbances in vivo after HZE irradiation. J. Magn. Reson. Imaging 2009;29:785–792. © 2009 Wiley‐Liss, Inc.
Use of ultrasmall superparamagnetic particles of iron oxide (USPIO)‐enhanced MRI to demonstrate diffuse inflammation in the normal‐appearing white matter (NAWM) of multiple sclerosis (MS) patients: An exploratory study
Authors: Vellinga Machteld M. , Vrenken Hugo , Hulst Hanneke E. , Polman Chris H. , Uitdehaag Bernard M.J. , Pouwels Petra J.W. , Barkhof Frederik , Geurts Jeroen J.G.
Published: March 2009

Purpose

To explore ultrasmall superparamagnetic particles of iron oxide (USPIO) as a marker for diffuse inflammation in multiple sclerosis (MS) normal‐appearing white matter (NAWM), using quantitative MRI. Disease activity in the NAWM of MS patients partly explains why MRI lesion burden correlates only moderately with disability. USPIO have been shown to visualize the cellular component of inflammation in focal MS lesions. In this study, we aimed to explore USPIO as a marker for the more diffuse inflammation in MS NAWM, using quantitative MRI.

Materials and Methods

In this prospective MRI study, 16 MS patients (eight relapsing‐remitting MS [RRMS] and eight primary‐progressive MS [PPMS] cases) and five healthy control (HC) subjects were included. Using a flip‐angle (FA) array, B1‐corrected T1 maps were generated before and 24 hours after USPIO (SHU555C) injection. White‐matter (WM) T1 histogram and region‐of‐interest (ROI) characteristics were compared between both time points using Wilcoxon signed‐rank test.

Results

Both NAWM ROI and histogram analyses showed T1 shortening after USPIO injection in MS patients (P < 0.01), but not in HCs (P = 0.68).

Conclusion

This exploratory study suggests that USPIO‐enhanced MRI may be a new potential marker for subtle inflammatory activity in MS NAWM. Further studies should focus on relating diffuse inflammation to clinical disease activity and treatment efficacy. J. Magn. Reson. Imaging 2009;29:774–779. © 2009 Wiley‐Liss, Inc.
Diffusion tensor and tensor metrics imaging in intracranial epidermoid cysts
Authors: Santhosh Kannath , Thomas Bejoy , Radhakrishnan Vishnupuri V. , Saini Jitender , Kesavadas Chandrasekharan , Gupta Arun Kumar , Kapilamoorthy Tirur Raman , Nair Suresh N.
Published: March 2009

Purpose

To explore the utility of diffusion tensor imaging (DTI) and diffusion tensor metrics (DTM) in characterizing the structural pathology of epidermoid cysts. DTI gives information about the tissue structure; a high fractional anisotropy (FA) indicates a highly structured orientation of the tissue, fibers, or white matter tracts. Based on the tensor rank, a set of three metrics has been described that can be used to measure the directional dependence of diffusion: linear anisotropy (CL), planar anisotropy (CP), and spherical anisotropy (CS). DTM takes into account the shape of diffusion anisotropy and hence may provide better insight into the orientation of structures than FA.

Materials and Methods

DTI was performed in three patients with epidermoid cysts. FA, directionally‐averaged mean diffusivity (Dav), exponential apparent diffusion coefficient (eADC), and DTM, such as CL, CP, and CS, were measured from the tumor core as well as from the normal‐appearing white matter. Histopathological correlation was obtained.

Results

Epidermoid cysts showed high FA with Dav values similar to that of normal white matter. eADC maps did not show any restriction of diffusion. FA values were high, but not as high as that for the white matter. CP values were higher and CL values were lower than those obtained for the white matter in various regions.

Conclusion

High CP values suggest preferential diffusion of water molecules along a two‐dimensional geometry, which could be attributed to the well‐structured orientation of keratin filaments and flakes within the tumor as demonstrated by histopathology. Advanced imaging modalities like DTI with DTM can provide information regarding the microstructural anatomy of the epidermoid cysts. J. Magn. Reson. Imaging 2009;29:967–970. © 2009 Wiley‐Liss, Inc.
Comparison of fMRI data from passive listening and active‐response story processing tasks in children
Authors: Vannest Jennifer J. , Karunanayaka Prasanna R. , Altaye Mekibib , Schmithorst Vincent J. , Plante Elena M. , Eaton Kenneth J. , Rasmussen Jerod M. , Holland Scott K.
Published: March 2009

Purpose

To use functional MRI (fMRI) methods to visualize a network of auditory and language‐processing brain regions associated with processing an aurally‐presented story. We compare a passive listening (PL) story paradigm to an active‐response (AR) version including online performance monitoring and a sparse acquisition technique.

Materials and Methods

Twenty children (ages 11–13 years) completed PL and AR story processing tasks. The PL version presented alternating 30‐second blocks of stories and tones; the AR version presented story segments, comprehension questions, and 5‐second tone sequences, with fMRI acquisitions between stimuli. fMRI data was analyzed using a general linear model approach and paired t‐test identifying significant group activation.

Results

Both tasks showed activation in the primary auditory cortex, superior temporal gyrus bilaterally, and left inferior frontal gyrus (IFG). The AR task demonstrated more extensive activation, including the dorsolateral prefrontal cortex and anterior/posterior cingulate cortex. Comparison of effect size in each paradigm showed a larger effect for the AR paradigm in a left inferior frontal region‐of‐interest (ROI).

Conclusion

Activation patterns for story processing in children are similar in PL and AR tasks. Increases in extent and magnitude of activation in the AR task are likely associated with memory and attention resources engaged across acquisition intervals. J. Magn. Reson. Imaging 2009;29:971–976. © 2009 Wiley‐Liss, Inc.
Multicenter, double‐blind, randomized, intra‐individual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine in MRI of brain tumors at 3 tesla
Authors: Rumboldt Zoran , Rowley Howard A. , Steinberg Fred , Maldjian Joseph A. , Ruscalleda Jordi , Gustafsson Lars , Bastianello Stefano
Published: March 2009

Purpose

To prospectively compare 0.1 mmol/kg doses of gadobenate dimeglumine and gadopentetate dimeglumine for contrast‐enhanced MRI of brain lesions at 3 Tesla (T).

Materials and Methods

Forty‐six randomized patients underwent a first examination with gadobenate dimeglumine (n = 23) or gadopentetate dimeglumine (n = 23) and then, after 2–7 days, a second examination with the other agent. Contrast administration (volume, rate), sequence parameters (T1wSE; T1wGRE), and interval between injection and image acquisition were identical for examinations in each patient. Three blinded neuroradiologists evaluated images qualitatively (lesion delineation, lesion enhancement, global preference) and quantitatively (lesion‐to‐brain ratio [LBR], contrast‐to‐noise ratio [CNR], % lesion enhancement). Differences were assessed using Wilcoxon's signed‐rank test. Reader agreement was determined using kappa (κ) statistics.

Results

There were no demographic differences between groups. The three readers preferred gadobenate dimeglumine globally in 22 (53.7%), 21 (51.2%), and 27 (65.9%) patients, respectively, compared with 0, 1, and 0 patients for gadopentetate dimeglumine. Similar significant (P < 0.001) preference was expressed for lesion border delineation and enhancement. Reader agreement was consistently good (κ = 0.48–0.64). Significantly (P < 0.05) higher LBR (+43.5– 61.2%), CNR (+51.3–147.6%), and % lesion enhancement (+45.9–49.5%) was noted with gadobenate dimeglumine.

Conclusion

Brain lesion depiction at 3T is significantly improved with 0.1 mmol/kg gadobenate dimeglumine. J. Magn. Reson. Imaging 2009;29:760–767. © 2009 Wiley‐Liss, Inc.
Self‐tracking of contrast kinetics for automatic triggering of contrast‐enhanced whole‐heart coronary magnetic resonance angiography
Authors: Bhat Himanshu , Lai Peng , Li Debiao
Published: March 2009

Purpose

To develop a method for automatically triggering centric data acquisition during contrast‐enhanced whole‐heart coronary magnetic resonance angiography (MRA).

Materials and Methods

The hypothesis of this work is that the blood signal changes during contrast infusion can be estimated by obtaining a projection of the heart during inversion‐recovery prepared data acquisition. A validation study was performed on seven healthy volunteers to test this hypothesis. The peak blood signal enhancement detected from the projection was then used to automatically trigger the start of central k‐space data acquisition. Simulations were performed to compare the signal‐to‐noise ratio (SNR) of the proposed self‐triggering method with the fixed delay method. Six healthy volunteers were scanned on a 3T MR system using the proposed self‐triggered method to test its effectiveness on coronary artery visualization.

Results

Based on the validation study, the self‐triggering method provides an accurate representation of the contrast enhancement. Based on the simulations, self‐triggering with centric ordering is expected to give a 27% higher SNR than linear ordering with a fixed imaging delay. Self‐triggering was successfully used in all volunteers and showed excellent depiction of the major coronary arteries.

Conclusion

The self‐triggering method can be used to automatically determine the optimal delay time for central k‐space acquisition, for each individual subject, without the need of any extra setup or user interaction. J. Magn. Reson. Imaging 2009;29:809–816. © 2009 Wiley‐Liss, Inc.
Respiratory self‐gating for free‐breathing abdominal phase‐contrast blood flow measurements
Authors: Jin Ning , Lewandowski Robert J. , Omary Reed A. , Larson Andrew C.
Published: March 2009

Purpose

To demonstrate the feasibility of using a free‐breathing (FB) respiratory self‐gated (RSG) approach for abdominal phase‐contrast (PC) blood flow measurements.

Materials and Methods

PC‐magnetic resonance imaging (MRI) flow measurements were performed within the right renal artery, common hepatic artery, and main portal vein during breath‐hold (BH) and FB with both signal averaging and RSG in eight healthy volunteers. The resultant images were qualitatively scored by two independent reviewers blinded to acquisition techniques. Blood flow volume and cross‐sectional vessel size measurements were compared for three techniques.

Results

The overall efficiency for the RSG‐PC sequence was 38.9% ± 4.7%. Images acquired with RSG effectively mitigated respiratory motion artifacts, which were clearly evident within FB signal‐averaged images. RSG produced similar image quality to that of BH techniques (P > 0.146) and resulted in similar vessel size measurements (P = 0.694). Flow results for both FB RSG and signal‐averaged reconstructions correlated well with BH flow measurements (r = 0.97 and 0.92, P < 0.001). However, only the RSG methods demonstrated excellent absolute agreement with BH‐PC flow measurements (P = 0.600), with signal‐averaged methods resulting in significant overestimations.

Conclusion

RSG methods can limit respiratory motion artifacts to reduce flow measurement inaccuracies during free‐breathing PC measurements in the abdomen. J. Magn. Reson. Imaging 2009;29:860–868. © 2009 Wiley‐Liss, Inc.
Quantitative and qualitative comparison of 1.5 and 3.0 tesla MRI in patients with chronic liver diseases
Authors: Ramalho Miguel , Herédia Vasco , Tsurusaki Masakatsu , Altun Ersan , Semelka Richard C.
Published: March 2009

Purpose

To compare the quantitative and qualitative image quality intra‐individually, at 1.5 and 3.0 Tesla (T) in patients with chronic liver diseases.

Materials and Methods

The study group included 24 consecutive patients (17 males, 7 females; mean age ± standard deviation 56.5 ± 11.5) who had chronic liver diseases and underwent abdominal MRI for the liver evaluation at both 1.5 and 3.0T within a 4‐month period. All MRI studies were retrospectively evaluated quantitatively and qualitatively. Quantitative analysis was performed by measuring signal to noise ratio (SNR) on various abdominal organs. Qualitative analysis was performed by two reviewers to assess image quality, artifacts, and imaging findings of chronic liver diseases. Quantitative and qualitative analyses findings were compared between 1.5 and 3.0T using the paired Student t‐test and Wilcoxon signed rank test, respectively.

Results

The statistically significant increase in SNRs in various abdominal tissues ranged from 1.3‐ to 3.5‐fold at 3.0T compared to 1.5T. Three‐dimensional gradient echo (3D‐GE) sequences demonstrated significantly higher image quality at 3.0T (P < 0.01), whereas precontrast spoiled gradient echo (SGE) sequences demonstrated significantly higher image quality at 1.5T (P < 0.01). T2‐weighted sequences did not show any significant difference in image quality between 1.5 and 3.0T (P > 0.05).

Conclusion

The SNRs of various abdominal tissues demonstrated significant increases at 3.0T. The image quality of 3D‐GE sequences was higher at 3.0T, whereas the image quality of precontrast SGE sequences was higher at 1.5T. J. Magn. Reson. Imaging 2009;29:869–879. © 2009 Wiley‐Liss, Inc.
Feasibility of quantifying the mechanical properties of lung parenchyma in a small‐animal model using 1H magnetic resonance elastography (MRE)
Authors: McGee Kiaran P. , Hubmayr Rolf D. , Levin David , Ehman Richard L.
Published: March 2009

Purpose

To evaluate the feasibility of spatially resolving the shear modulus of lung parenchyma using conventional 1H magnetic resonance elastography (MRE) imaging techniques in a small animal model.

Materials and Methods

A 10‐cm diameter transmit‐receive radiofrequency coil was modified to include a specimen stage, an MRE pneumatic drum driver, and needle system. MRE was performed on 10 female Sprague–Dawley rats using a 1H spin‐echo based MRE imaging sequence with a field of view of 7 cm and slice thickness of 5 mm. Air‐filled lungs were imaged at transpulmonary inflation pressures of 5, 10, and 15 cm H2O while fluid‐filled lungs were imaged after infusion of 4 mL of normal saline.

Results

The average shear modulus of air‐filled lungs was 0.840 ± 0.0524 kPa, 1.07 ± 0.114 kPa and 1.30 ± 0.118 kPa at 5, 10, and 15 cm H2O, respectively. Analysis of variance indicated that these population means were statistically significantly different from one another (F‐value = 26.279, P = 0.00004). The shear modulus of the fluid‐filled lungs was 1.65 ± 0.360 kPa.

Conclusion

It is feasible to perform lung MRE in small animals using conventional MR imaging technologies. J. Magn. Reson. Imaging 2009;29:838–845. © 2009 Wiley‐Liss, Inc.
High‐resolution fMRI with higher‐order generalized series imaging and parallel imaging techniques (HGS‐parallel)
Authors: Yun SungDae , Oh Sung Suk , Han Yeji , Park HyunWook
Published: March 2009

Purpose

To develop a novel approach for high‐resolution functional MRI (fMRI) using the conventional gradient‐echo sequence.

Materials and Methods

Echo‐planar imaging (EPI) techniques have generally been used for fMRI studies due to their fast imaging time. However, it is difficult for studying brain function at the submillimeter level using this sequence. In addition, EPI techniques have some drawbacks, such as Nyquist ghosts and geometric distortions in the reconstructed images, and subsequently require additional postprocessing to reduce these artifacts. One way of solving these problems is to acquire fMRI data by means of a conventional gradient‐echo imaging sequence instead of EPI. To provide a fast imaging time, the proposed method combines higher‐order generalized series (HGS) imaging with a parallel imaging technique which is called the HGS‐parallel technique.

Results

The proposed HGS‐parallel technique achieves a 12.8‐fold acceleration in imaging time without the cost of spatial resolution. The proposed method was verified through the application of fMRI studies on normal subjects.

Conclusion

This study suggests that the proposed method can be used for high‐resolution fMRI studies without the geometric distortion and the Nyquist ghost artifacts compared to EPI. J. Magn. Reson. Imaging 2009;29:924–936. © 2009 Wiley‐Liss, Inc.
Multifocal intravascular papillary endothelial hyperplasia in the retroperitoneum and spine: A case report and review of the literature
Authors: Petry Max , Brown Michele A. , Hesselink John R. , Imbesi Steven G.
Published: March 2009

The authors present a unique case of intravascular papillary endothelial hyperplasia (IPEH) localized in the renal hilum, retroperitoneum, and spine in a patient with Wegener granulomatosis. IPEH rarely occurs in the abdomen or spine with few cases reported in the literature. No case has been reported of IPEH involving both the retroperitoneum and spine. In our case, MR imaging revealed enhancing masses in the right renal hilum and retroperitoneum as well as multiple focal enhancing lesions throughout the spine with lower thoracic ventral thecal sac compression. The diagnosis was established by resection of the renal hilum mass, and interval follow‐up is deemed necessary for the remaining lesions because the long‐term evolution of IPEH with conservative treatment alone is not well established. J. Magn. Reson. Imaging 2009;29:957–961. © 2009 Wiley‐Liss, Inc.
Correlation of iron in the hippocampus with MMSE in patients with Alzheimer's disease
Authors: Ding Bei , Chen Ke‐Min , Ling Hua‐Wei , Sun Fei , Li Xia , Wan Tao , Chai Wei‐Min , Zhang Huan , Zhan Ying , Guan Yong‐Jing
Published: March 2009

Purpose

To investigate the brain iron deposits in patients with Alzheimer's disease (AD) and healthy age‐matched controls using phase imaging.

Materials and Methods

Twenty‐six AD patients and 24 healthy controls were recruited. A three‐dimensional high‐resolution, gradient‐echo sequence was used to acquire phase data in the coronal plane. A high‐pass filter was used to remove the phase variation caused by field inhomogeneity. The regions evaluated included the bilateral putamen, globus pallidus, and the head and body of the hippocampus.

Results

Significantly lower phase values in both the basal ganglion and hippocampus were revealed in the AD group compared to the normal controls (P < 0.05). The phase value in the right side of the head of the hippocampus had a moderate positive correlation with the MMSE score (r= 0.603, P = 0.000) and a negative correlation with the duration of the disease (r = −0.677, P = 0.013). Using −0.0972 radians as an optimal cutoff value, the sensitivity and specificity for differentiation between AD and normal controls reached 95.8 and 80.8%, respectively.

Conclusion

Phase imaging proved to be a useful method for the differentiation between normal controls and AD patients. An investigation of the excessive accumulation of iron in the hippocampus may help us better understand the pathologic process and neuropsychological dysfunction of AD disease. J. Magn. Reson. Imaging 2009;29:793–798. © 2009 Wiley‐Liss, Inc.
Sequencing of peptide‐derived Amadori products by the electron capture dissociation method
Authors: Stefanowicz Piotr , Kijewska Monika , Szewczuk Zbigniew
Published: March 2009

The electron capture dissociation (ECD) of peptide‐derived Amadori products has been successfully applied for their sequencing. In contrast to the collision induced dissociation (CID), based on the vibrational excitation of peptides, the ECD method does not produce ions formed by fragmentation of the hexose moiety, that facilitates interpretation of the obtained spectra. The fragmentation spectrum is dominated by cn and z·n ions, providing the sufficient information for sequencing of peptides and establishing the location of glycated Lys residues in the peptide chain. The ECD experiments were conducted on a series of synthetic peptides and unseparated digests of glycated ubiquitin. Copyright © 2009 John Wiley & Sons, Ltd.
The unbalanced high‐tech life: are employers liable?
Authors: Kakabadse Nada K. , Porter Gayle , Vance David
Published: March 2009

Technology has created new capabilities, as well as new demands, for many of today's employees. For those who work in technology‐enhanced environments, the pace and round‐the‐clock activity creates a source of stimulation that may become addictive.

While the potential for this type of behavioral addiction is recognized by both researchers and the popular press, few companies are seriously considering the associated risks, one of which could be legal action against the organization.

By combining research on addiction, technology use, workplace demands, and legal precedent, this article considers issues likely to require decision by the courts, as well as background on the evolution of related legal questions for insight to possible outcomes.

Copyright © 2009 John Wiley & Sons, Ltd.
Strategy evolution in Central and Eastern European pharmaceutical firms 1992–2005
Authors: Langley Amanda , Fallon Grahame , Kakabadse Nada K.
Published: March 2009

Since the early 1990s the CEE markets have undergone a major transition. This has led to changes in ownership for many indigenous firms as they moved from state to private control.

This paper contributes to a gap in existing knowledge by developing understanding of how the realized strategic actions of these firms evolved. In order to contribute to this gap, evolution theory is applied to address the research question: ‘How did the strategic actions of indigenous pharmaceutical firms evolve as the CEE region developed from a planned to a market economy?’

This is achieved through longitudinal mapping of the strategic actions realized by firms, comparison of patterns in temporal strategy development, together with identification of factors that appear to have influenced this strategic change process. Using a qualitative research design the paper explores and compares how the realized strategic actions of LEK, Richter, and Pliva evolved from 1992–2005.

The findings highlight a range of factors that had the potential to impact upon the strategic process for these firms. The research also shows that although there were some similarities in the strategic actions realized by the firms, in overall terms each firm packaged its realized strategic actions in a unique way.

Copyright © 2009 John Wiley & Sons, Ltd.
Managing privatizations in the telecommunications sector
Authors: Karamanis Kostas
Published: March 2009

Until the 1980s the structure of the telecommunications sector was monopolistic. In almost all developed countries the sector was dominated by a government‐owned organization managing the telecommunication network and exclusively providing telecommunication services. However, the rapid growth of telecommunications in the last two decades has led to the need for structural changes.

These changes include, among others, the progressive liberalization of the sector, the establishment of a regulatory framework, and the privatization of government‐owned telecommunication organizations (PTOs).

The aim of this study is to provide a comprehensive review of the existing relevant literature and to estimate the effect of privatization on the corporate governance of telecommunication organizations.

Copyright © 2009 John Wiley & Sons, Ltd.
Macromol. Rapid Commun. 7/2009
Authors: Wu Chuanliu , Xu Qing‐Hua
Published: March 2009

Front Cover: The cover picture shows the schematic illustration of the PFP‐HP electrostatic assembly and the chemical structures of PFP and HP. This assembly displays significant enhancement of both one‐ and two‐photon excitation emission of HP via FRET from PFP. Further details can be found in the article by C. Wu and Q.‐H. Xu* on page 504.
Prediction of physical properties of Al2TiO5‐based ceramics containing micro and nano size oxide additives by using artificial neural network. Vorhersage der physikalischen Eigenschaften von Al2TiO5‐basierenden Keramiken mit Mikro‐ und Nanoadditiven mittels künstlicher neuronaler Netze
Authors: Shokuhfar A. , Samani M. N. , Naserifar N. , Heidary P. , Naderi G.
Published: March 2009

Recently, artificial neural networks (ANN) are being used as an interdisciplinary tool in many applications. There are various training algorithms used in neural network applications. The aim of this study is to investigate the effect of various training algorithms on the learning performance of the neural networks in the prediction and modeling of the effect of micron and nano size oxide material additives on reaction sintering and physical properties of Al2TiO5‐based ceramics. Aluminum‐titanate (tialite) based ceramics have found widespread applications due to their good thermal shock resistance and low thermal expansion. Eutectoid decomposition in the initial oxides and low mechanical strength limit the well‐known properties of aluminum‐titanate. In the present work, first, good stabilizing behavior was achieved by addition of micron size talc and appropriate properties were obtained by adding nano boehmite and colloidal silica that result in mullite phase formation. Then, the effect of the weight percentages of these different additives and also the temperature on the bulk density was predicted with four different training algorithms using a back‐propagation neural network. The training sets for the neural network were selected from experimental results. After training ANN, a regression analysis was used to check the system accuracy for each training algorithm. In conclusion, Levenberg–Marquardt (LM) learning algorithm gave the best prediction for the bulk density behavior of Al2TiO5 based ceramics. The response surfaces between the response variables, i.e. weight percent of additives and temperature of the tialite and the processing parameter are presented. The trained artificial neural network can be used for optimizing the sintering process of Al2TiO5‐based ceramics.
Sequence context‐specific mutagenesis and base excision repair
Authors: Donigan Katherine A. , Sweasy Joann B.
Published: March 2009

Base excision repair (BER) is critical for the maintenance of genome stability because it repairs at least 20,000 endogenously generated DNA lesions/cell/d. Several enzymes within the BER pathway exhibit sequence context dependency during the excision and DNA synthesis steps of repair. New evidence is emerging that germ line and tumor‐associated variants of enzymes in this repair pathway exhibit sequence context dependence that is different from their ancestral counterparts. We review what is known about the ancestral and variant BER proteins within various sequence contexts. We suggest that altering the sequence context preferences of BER proteins could give rise to rare cellular variants that might have a selective advantage in response to environmental exposure or to the tumor microenvironment. © 2009 Wiley‐Liss, Inc.
Every microsatellite is different: Intrinsic DNA features dictate mutagenesis of common microsatellites present in the human genome
Authors: Eckert Kristin A. , Hile Suzanne E.
Published: March 2009

Microsatellite sequences are ubiquitous in the human genome and are important regulators of genome function. Here, we examine the mutational mechanisms governing the stability of highly abundant mono‐, di‐, and tetranucleotide microsatellites. Microsatellite mutation rate estimates from pedigree analyses and experimental models range from a low of ∼10−6 to a high of ∼10−2 mutations per locus per generation. The vast majority of observed mutational variation can be attributed to features intrinsic to the allele itself, including motif size, length, and sequence composition. A greater than linear relationship between motif length and mutagenesis has been observed in several model systems. Motif sequence differences contribute up to 10‐fold to the variation observed in human cell mutation rates. The major mechanism of microsatellite mutagenesis is strand slippage during DNA synthesis. DNA polymerases produce errors within microsatellites at a frequency that is 10‐ to 100‐fold higher than the frequency of frameshifts in coding sequences. Motif sequence significantly affects both polymerase error rate and specificity, resulting in strand biases within complementary microsatellites. Importantly, polymerase errors within microsatellites include base substitutions, deletions, and complex mutations, all of which produced interrupted alleles from pure microsatellites. Postreplication mismatch repair efficiency is affected by microsatellite motif size and sequence, also contributing to the observed variation in microsatellite mutagenesis. Inhibition of DNA synthesis within common microsatellites is highly sequence‐dependent, and is positively correlated with the production of errors. DNA secondary structure within common microsatellites can account for some DNA polymerase pause sites, and may be an important factor influencing mutational specificity. © 2009 Wiley‐Liss, Inc.
Sciatic nerve injection palsy in the child: Early microsurgical treatment and long‐term results
Authors: Senes Filippo M. , Campus Riccardo , Becchetti Flavio , Catena Nunzio
Published: March 2009

Sciatic nerve injury caused by intramuscular injection in the gluteal region in the child seems as a sensory‐motor palsy of the lower limb of variable degree. In preterm children or in children with severe perinatal distress, requiring intensive care, a drop foot is often missed or misdiagnosed as a malformative clubfoot or late diagnosed. Intramuscular drug injection (mainly antibiotics) during early infancy is another cause of injury. There are very few literature reports on postinjection trauma and on therapeutic indications in the child. The Authors report their experience in early microsurgical exploration of the sciatic nerve. From 1990 to 2004, we observed at different times from diagnosis 17 children with sciatic nerve palsy following intramuscular injection. Nine of them underwent nerve exploration surgery in the gluteal region (neurolysis in seven and nerve grafting in two). Conservative treatment was successful in only three cases showing early signs of recovery (at about 3 months of life). Complete recovery was observed only in five early treated cases, while late treated cases had only mild improvement after surgery. During surgery, anatomical variations predisposing to nerve injury were observed. The authors havingobserved better results and faster recovery in the early treated patients, stress the importance of a rapid therapeutic decision to avoid or limit foot deformities, sensory defects and lower limb length discrepancy due to paralysis during growth. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.
Early stage diabetic Charcot Foot syndrome may respond to nerve decompression
Authors: Nickerson D. Scott , Alzheimer Daniel , Dellon A. Lee
Published: March 2009

Diabetic Charcot Foot syndrome has been postulated to require a triggering event to initiate its puzzling inflammatory process, characterized by bony resorption, pathologic fractures, soft tissue ligamentous failure, and destruction of foot architecture. Two cases are presented where multiple lower extremity nerve decompression was performed early in the Charcot process. Resolution of clinical signs and radiographic abnormalities rapidly followed. The observation that these events were temporally concurrent suggests that nerve entrapment might reasonably be investigated as one of the postulated triggering events for the Charcot Foot in diabetes. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.
Assessment of the patency of microvascular anastomoses using microscope‐integrated near‐infrared angiography: A preliminary study
Authors: Holm Charlotte , Mayr Martina , Höfter Eugen , Dornseifer Ulf , Ninkovic Milomir
Published: March 2009

Background:

Technical problems at the site of the anastomosis compromise an underappreciated proportion of microsurgical free tissue transfers. Intraoperative identification of technical errors may be able to prevent reexploration surgery and early flap failure. We report the first human study on a new microscope‐integrated fluorescence angiography technique, which allows for intraoperative imaging of the anastomotic site.

Methods:

Fifty consecutive patients undergoing reconstructive microsurgical procedures were enrolled in the study. Intraoperative near infrared indocyanine green videoangiography (ICGA) was performed on all microsurgical anastomoses, after they had been assessed by the operating surgeon by conventional clinical patency tests. Anastomoses deemed to be occluded by the ICG‐angiography were intraoperatively revised, and the result of revision was compared with angiographic findings.

Results:

In 11/50 (22%) of patients, where the surgeon had classified the anastomoses as patent, microangiography identified a total luminal occlusion (six) and/or significant alterations in blood flow (five), potentially predisposing toward postoperative flap failure. Intraoperative revision confirmed angiographic findings in 100% of cases, and was always associated with flap survival. The decision not to revise despite anastomotic occlusion by the intraoperative angiogram was always followed by flap loss or early reexploration. A delayed return of venous blood from the flap predisposed toward postoperative flap failure.

Conclusions:

Hand‐sewn anastomoses are subject to technical errors, and conventional patency tests have a low sensitivity for revealing anastomotic failure. Microscope integrated microangiography is an excellent method for identifying significant anastomotic problems, which would have otherwise gone unnoticed. The potential impact on early flap failure and reexploration surgery is considerable. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.
Shaping waveguide transmission and reflection characteristics using conducting fabrics
Authors: Meachen J. , Duffy A. , Williams J. , Oxley C. H.
Published: March 2009

Conductive fabrics are finding many applications and improved techniques for assessment required. This article presents a measurement technique using waveguide high‐Q cavities and a finite element model. Reflection and absorption properties of fabrics have been characterized to 10 GHz, and good agreement obtained between experimental and modeled results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1416–1419, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24341
Performance evaluation of 2 × 2 MIMO handset antenna arrays for mobile WiMAX applications
Authors: Choi Jung‐Hwan , Shin Yong‐Sun , Park Seong‐Ook
Published: March 2009

This article presents the performance analysis of the multiple‐input–multiple‐output antenna systems for mobile WiMAX handset applications. To investigate the effect of changing antenna arrangements on the antenna performance, we propose four kinds of two antenna structures considering the practical ground size of a mobile handset. To estimate the proposed structures, mutual coupling and envelope correlations were considered. Also the channel capacity and correlation were measured in the reverberation chamber. The relations between all parameters were analyzed based on the measured results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1558–1561, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24344
Low‐sidelobe pattern synthesis of spherical array using the hybrid genetic algorithm
Authors: Li Wentao , Liu Shufang , Shi Xiaowei , Hei Yongqiang
Published: March 2009

Aiming at increasing the radiation bandwidth and reducing the antenna size, this article designs the stacked patch antenna and forms the spherical antenna array by virtue of fractal geometry. To minimize the sidelobe level and improve the convergence speed, a hybrid genetic algorithm integrating the main features of genetic algorithm (GA) and particle swarm optimization (PSO) called HGAPSO is adopted. Furthermore, a modified Bernstein polynomial is exploited to reduce the number of optimization variables as well as to obtain a smooth unimodal amplitude distribution. Compared with the uniformly excited conformal antenna array, the maximum relative sidelobe can be reduced by more than 10 dB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1487–1491, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24348
Simulation and scale model measurement of a 600‐GHz membrane‐based twin slot antenna
Authors: Miao W. , Delorme Y. , Dauplay F. , Beaudin G. , Shi S. C.
Published: March 2009

In this article, the input impedance (i.e., feed point impedance) of a 600‐GHz membrane‐based twin slot antenna for superconducting hot‐electron‐bolometer (HEB) mixers is investigated through numerical simulation and scale model measurement. The twin‐slot antenna, with an RF choker filter included, was designed with the aid of Microwave Studio CST. A 200‐times scale model of the designed twin slot antenna was fabricated to validate the simulated results. For the scale model measurement, de‐embedding measurement technique was adopted to extract the input impedance of the twin slot antenna. The measured results are found in good agreement with the simulation. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1452–1455, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24350
A simple switched beamforming network for four‐beam Butler matrix
Authors: Kim Jae Hee , Park Wee Sang
Published: March 2009

A simple switched beamforming network with one 90° hybrid, two switches, and delay lines is designed. By controlling the switches, the antenna can produce four beams with the phase differences between adjacent radiating elements being ±135° and ±45°. The proposed feed network is simple, provides a tapered amplitude distribution, and has the same phase characteristics as the four‐beam Butler matrix feed network. The measured S11 of the proposed antenna is less than −10 dB at the operating frequency of 11.2 GHz. When switch 1 is in the “on” position and switch 2 is in the “off” position, or when both switches are in the “on” position, the measured radiation pattern shows that the scan angles are −12° and +35°. The proposed array antenna has the advantage of low cost, small volume, and easy fabrication. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1413–1416, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24352