bluuebunny/crossref_metadata_2025 huggingface dataset:
Basic FGF downregulates TSP50 expression via the ERK/Sp1 pathway
Authors: Wang Miao , Bao Yong‐Li , Wu Yin , Yu Chun‐Lei , Meng Xiang‐Ying , Huang Yan‐Xin , Sun Ying , Zheng Li‐Hua , Li Yu‐Xin
Published: April 2010

Previous studies demonstrated that the expression of testes‐specific protease 50 (TSP50) was increased in breast cancer cells and that overexpression of TSP50 can promote tumorigenesis. Thus, it is important to identify the regulatory mechanisms of TSP50 for tumor therapy. In this study, we elucidated the mechanism underlying TSP50 downregulation by basic fibroblast growth factor (bFGF). We used MDA‐MB‐231 and HEK293T cell lines to address this issue. RT‐PCR and promoter activity assays indicated that bFGF downregulates TSP50 expression via transcriptional activation. We next investigated the signaling pathway that mediated the effect of bFGF on TSP50 transcription, and identified that bFGF induced the phosphorylation of ERK and Sp1. An ERK inhibitor suppressed Sp1 phosphorylation and bFGF‐reduced TSP50 expression at the mRNA level. In addition, the dominant negative (DN) mutants of ERK and Sp1 both suppressed the reduction of TSP50 by bFGF. Deletion and mutation analyses indicated that the Sp1 site, located within the +237/+239 region of the human TSP50 promoter, is the major responsive element for bFGF. Taken together, our results strongly suggest that bFGF mediates TSP50 downregulation by ERK activation, leading to the phosphorylation of Sp1 in this process. J. Cell. Biochem. 111: 75–81, 2010. © 2010 Wiley‐Liss, Inc.
Anti‐atherogenic effect of berberine on LXRα‐ABCA1‐dependent cholesterol efflux in macrophages
Authors: Lee Tzong‐Shyuan , Pan Ching‐Chian , Peng Chien‐Chung , Kou Yu Ru , Chen Chien‐Yu , Ching Li‐Chieh , Tsai Tsung‐Huang , Chen Shu‐Fen , Lyu Ping‐Chiang , Shyue Song‐Kun
Published: April 2010

Berberine, a botanical alkaloid purified from Cortidis rhizoma, has effects in cardiovascular diseases, yet the mechanism is not fully understood. Foam cells play a critical role in the progression of atherosclerosis. This study aimed to investigate the effect of berberine on the formation of foam cells by macrophages and the underlying mechanism. Treatment with berberine markedly suppressed oxidized low‐density lipoprotein (oxLDL)‐mediated lipid accumulation, which was due to an increase in cholesterol efflux. Berberine enhanced the mRNA and protein expression of ATP‐binding membrane cassette transport protein A1 (ABCA1) but did not alter the protein level of ABCG1 or other scavenger receptors. Additionally, functional inhibition of ABCA1 with a pharmacological inhibitor or neutralizing antibody abrogated the effects of berberine on cholesterol efflux and lipid accumulation. Moreover, berberine induced the nuclear translocation and activation of liver X receptor α (LXRα) but not its protein expression. Knockdown of LXRα mRNA expression by small interfering RNA abolished the berberine‐mediated protective effects on ABCA1 protein expression and oxLDL‐induced lipid accumulation in macrophages. These data suggest that berberine abrogates the formation of foam cells by macrophages by enhancing LXRα‐ABCA1‐dependent cholesterol efflux. J. Cell. Biochem. 111: 104–110, 2010. © 2010 Wiley‐Liss, Inc.
Immortalized mouse floxed Bmp2 dental papilla mesenchymal cell lines preserve odontoblastic phenotype and respond to BMP2
Authors: Wu Li‐an , Feng Junsheng , Wang Lynn , Mu Yan‐dong , Baker Andrew , Donly Kevin J , Gluhak‐Heinrich Jelica , Harris Stephen E , MacDougall Mary , Chen Shuo
Published: April 2010

Bone morphogenetic protein 2 (Bmp2) is essential for odontogensis and dentin mineralization. Generation of floxed Bmp2 dental mesenchymal cell lines is a valuable application for studying the effects of Bmp2 on dental mesenchymal cell differentiation and its signaling pathways during dentinogenesis. Limitation of the primary culture of dental mesenchymal cells has led to the development of cell lines that serve as good surrogate models for the study of dental mesenchymal cell differentiation into odontoblasts and mineralization. In this study, we established and characterized immortalized mouse floxed Bmp2 dental papilla mesenchymal cell lines, which were isolated from 1st mouse mandibular molars at postnatal day 1 and immortalized with pSV40 and clonally selected. These transfected cell lines were characterized by RT‐PCR, immunohistochemistry, and analyzed for alkaline phosphatase activity and mineralization nodule formation. One of these immortalized cell lines, iBmp2‐dp, displayed a higher proliferation rate, but retained the genotypic and phenotypic characteristics similar to primary cells as determined by expression of tooth‐specific markers as well as demonstrated the ability to differentiate and form mineralized nodules. In addition, iBmp2‐dp cells were inducible and responded to BMP2 stimulation. Thus, we for the first time described the establishment of an immortalized mouse floxed Bmp2 dental papilla mesenchyma cell line that might be used for studying the mechanisms of dental cell differentiation and dentin mineralization mediated by Bmp2 and other growth factor signaling pathways. J. Cell. Physiol. 225: 132–139, 2010. © 2010 Wiley‐Liss, Inc.
Cancer stem cells: A stride towards cancer cure?
Authors: Sengupta Amitava , Cancelas Jose A.
Published: April 2010

Despite major refinements in cancer therapy drugs, our progress at increasing the cure rates of most cancers has been hampered by high relapse rates. A possible biological explanation of the high frequency of relapse and resistance to currently available drugs has been provided by the cancer stem cell (CSC) proposition. Basically, the CSC theory hypothesizes the presence of a hierarchically organized, relatively rare population of cells that is responsible for tumor initiation, self‐renewal and maintenance, mutation accumulation and therapy resistance. Since first postulated by John Dick, multiple reports have provided support for this hypothesis by isolating (more or less) rare cell populations, where the ability to initiate tumors in vivo has been demonstrated. Most progress and stronger data supporting this theory are found predominantly in myelogenous leukemias, whose study has benefited from over half‐a‐century progress in our understanding of the normal hierarchical organization of hematopoiesis. This review, however, also analyzes the advancement in the quantitative and functional analysis of solid tumor stem cells and in the analysis of the tumor microenvironment as specialized, nurturing niches for CSCs. Overall, this review intends to briefly summarize most of the evidences that support the CSC theory and the apparent contradictions, if not skepticism from the scientific community, about its validity for all forms of cancer, or alternatively on just a few cancers initiated by a limited number of somatic or germinal mutations. J. Cell. Physiol. 225: 7–14, 2010. © 2010 Wiley‐Liss, Inc.
Production of polyhydroxyalkanoates: the future green materials of choice
Authors: Akaraonye Everest , Keshavarz Tajalli , Roy Ipsita
Published: April 2010

Polyhydroxyalkanoates (PHAs) have recently been the focus of attention as a biodegradable and biocompatible substitute for conventional non degradable plastics. The cost of large‐scale production of these polymers has inhibited its widespread use. Thus, economical, large‐scale production of PHAs is currently being studied intensively. Various bacterial strains, either wild‐type or recombinant have been utilized with a wide spectrum of utilizable carbon sources. New fermentation strategies have been developed for the efficient production of PHAs at high concentration and productivity. With the current advances, PHAs can now be produced to a concentration of 80 g L−1 with productivities greater than 4 g PHA L−1 h−1. These advances will further lower the production cost of PHAs and allow this family of polymers to become a leading biodegradable polymer in the near future. This review describes the properties of PHAs, their uses, the various attempts towards the production of PHAs, focusing on the utilization of cheap substrates and the development of different fermentation strategies for the production of these polymers, an essential step forward towards their widespread use. Copyright © 2010 Society of Chemical Industry
Evaluation of dynamic contrast‐enhanced MRI in detecting renal scarring in a rat injury model
Authors: Wang Bingyin , Sommer Graham , Spielman Daniel , Shortliffe Linda M. Dairiki
Published: April 2010

Purpose:

To create a reliable rat model with small renal cortical scars and evaluate the accuracy and sensitivity of dynamic contrast‐enhanced MRI in detecting the kinds of lesions that are associated with reflux nephropathy.

Materials and Methods:

In 16 rats, three unilateral renal cortical lesions were created using either electrocautery or pure alcohol with the contralateral kidney serving as control. MRI on a 1.5 Tesla GE Signa was performed 10–14 days after surgery. After bolus injection of 0.2 mM/Kg Gd‐DTPA, sequential MRI acquisitions were performed using a 4‐inch quadrature birdcage coil. Renal and scar volumes and pathology were compared after scanning and killing.

Results:

Of the 48 points of injury, 40 (83%) in the 16 rats were detected grossly. Under microscopy, 36 injuries (75%) were detected on mid‐kidney cross‐sections. The average lesion was 4.2 mm3 corresponding to 0.5% of the kidney volume. Using pathological findings as the gold standard, the sensitivity and specificity of scar detection using MRI was 69% and 93%, respectively.

Conclusion:

A rat model was created to demonstrate the sensitivity of dynamic contrast‐enhanced MRI for detecting renal scars. Alcohol and electrocautery created reliable renal scars that were confirmed pathologically. MRI detected these lesions that averaged 4.2 mm3 (0.5% total renal volume) with sensitivity and specificity of 69% and 93%, respectively. J. Magn. Reson. Imaging 2010;31:1132–1136. © 2010 Wiley‐Liss, Inc.
Exposure to high‐field MRI does not affect cognitive function
Authors: Schlamann Marc , Voigt Melanie A. , Maderwald Stefan , Bitz Andreas K. , Kraff Oliver , Ladd Susanne C. , Ladd Mark E. , Forsting Michael , Wilhelm Hans
Published: April 2010

Purpose

To assess potential cognitive deficits under the influence of static magnetic fields at various field strengths some studies already exist. These studies were not focused on attention as the most vulnerable cognitive function. Additionally, mostly no magnetic resonance imaging (MRI) sequences were performed.

Materials and Methods

In all, 25 right‐handed men were enrolled in this study. All subjects underwent one MRI examination of 63 minutes at 1.5 T and one at 7 T within an interval of 10 to 30 days. The order of the examinations was randomized. Subjects were referred to six standardized neuropsychological tests strictly focused on attention immediately before and after each MRI examination. Differences in neuropsychological variables between the timepoints before and after each MRI examination were assessed and P‐values were calculated

Results

Only six subtests revealed significant differences between pre‐ and post‐MRI. In these tests the subjects achieved better results in post‐MRI testing than in pre‐MRI testing (P = 0.013–0.032). The other tests revealed no significant results.

Conclusion

The improvement in post‐MRI testing is only explicable as a result of learning effects. MRI examinations, even in ultrahigh‐field scanners, do not seem to have any persisting influence on the attention networks of human cognition immediately after exposure. J. Magn. Reson. Imaging 2010;31:1061–1066. © 2010 Wiley‐Liss, Inc.
Three‐dimensional balanced steady state free precession imaging of the prostate: Flip angle dependency of the signal based on a two component T2‐decay model
Authors: Storås Tryggve H. , Gjesdal Kjell‐Inge , Gadmar Øystein B. , Geitung Jonn‐Terje , Kløw Nils‐Einar
Published: April 2010

Purpose:

To investigate the contrast of three‐dimensional balanced steady state free precession (3D bSSFP) in the two component T2 model and to apply the results to optimize 3D bSSFP for prostate imaging at 1.5 Tesla.

Materials and Methods:

In each of seven healthy volunteers, six 3D bSSFP acquisitions were performed with flip angles (α) equally spaced between 10° and 110°. Predictions of signal and contrast were obtained from synthetic bSSFP images calculated from relaxation parameters obtained from a multi‐spin‐echo acquisition. One biexponential and two monoexponential models were applied. Measured and predicted signals were compared by simple linear regression.

Results:

The measured contrast to signal ratio increased continuously with α. Mean R2 for the biexponential model was almost constant for α in the range 50–110°. The biexponential model was a better predictor of the measured signal than the monoexponential model. A monoexponential model restricted to the echoes TE = 50–125 ms performed similar to the biexponential model. The predicted contrast peaked at α between 50° and 90°.

Conclusion:

Prostate imaging with bSSFP benefited from high flip angles. The biexponential model provided good signal prediction while predictions from the monoexponential models are dependent on the range of TE used for T2 determination. J. Magn. Reson. Imaging 2010;31:1124–1131. © 2010 Wiley‐Liss, Inc.
Perforator flap magnetic resonance angiography for reconstructive breast surgery: A review of 25 deep inferior epigastric and gluteal perforator artery flap patients
Authors: Newman Tiffany M. , Vasile Julie , Levine Joshua L. , Greenspun David T. , Allen Robert J. , Chao Minh‐Tam , Winchester Priscilla A. , Prince Martin R.
Published: April 2010

Purpose

To evaluate the accuracy of magnetic resonance angiography (MRA) for preoperative mapping of rectus and gluteal muscle perforating arteries prior to autologous flap breast reconstruction.

Materials and Methods

Preoperative MRA on 25 consecutive patients undergoing perforator artery‐based autologous breast reconstruction was performed at 1.5 T using 3D liver accelerate volume acquisition (LAVA) of abdominal or gluteal regions acquired during injection of 20 mL of gadobenate dimeglumine with bolus timing optimized using MR fluoroscopy or SmartPrep. Perforator artery size and coordinates relative to umbilicus or top of gluteal crease on 3D MRA were compared to findings at surgery. Reconstructed breast volume estimates from MRA were also compared to weights at harvesting.

Results

In all, 132 perforator arteries were found at surgery to be located within 1 cm of the coordinates measured on MRA and were surgically verified to be suitable for flap perfusion. Surgery verified the arterial course and caliber through the rectus and gluteal muscles visualized on MRA in 48 of 49 arteries. Volume rendering of 3D MRA predicted a breast reconstruction volume with a mean difference of 47 g compared to measurements at harvesting.

Conclusion

MRA accurately maps rectus and gluteal muscle perforator arteries for preoperative planning of autologous flaps for breast reconstruction. J. Magn. Reson. Imaging 2010;31:1176–1184. © 2010 Wiley‐Liss, Inc.
Pulmonary kinematics from tagged hyperpolarized helium‐3 MRI
Authors: Tustison Nicholas J. , Awate Suyash P. , Cai Jing , Altes Talissa A. , Miller G. Wilson , de Lange Eduard E. , Mugler John P. , Gee James C.
Published: April 2010

Purpose:

To propose and test the feasibility of a novel method for quantifying 3D regional pulmonary kinematics from hyperpolarized helium‐3 tagged MRI in human subjects using a tailored image processing pipeline and a recently developed nonrigid registration framework.

Materials and Methods:

Following image acquisition, inspiratory and expiratory tagged 3He magnetic resonance (MR) images were preprocessed using various image filtering techniques to enhance the tag surfaces. Segmentation of the three orthogonal sets of tag planes in each lung produced distinct point‐set representations of the tag surfaces. Using these labeled point‐sets, deformation fields and corresponding strain maps were obtained via nonrigid point‐set registration. Kinematic analysis was performed on three volunteers.

Results:

Tag lines in inspiratory and expiratory images were coregistered producing a continuous 3D correspondence mapping. Average displacement and directional strains were calculated in three subjects in the inferior, mid, and superior portions of the right and left lungs. As expected, the predominant direction of displacements with expiration is from inferior to superior.

Conclusion:

Kinematic quantitation of pulmonary motion using tagged 3He MRI is feasible using the applied image preprocessing filtering techniques and nonrigid point‐set registration. Potential benefits from regional pulmonary kinematic quantitation include the facilitation of diagnosis and local assessment of disease progression. J. Magn. Reson. Imaging 2010;31:1236–1241. © 2010 Wiley‐Liss, Inc.
Residual magnetism in an MRI suite after field‐rampdown: What are the issues and experiences?
Authors: Sammet Steffen , Koch Regina Maria , Aguila Francisco , Knopp Michael Vinzenz
Published: April 2010

Purpose

To investigate residual magnetization at different locations in the MRI suite at several time points prior, during and after field‐rampdown with the goal to determine if the MRI suites could be reused in a clinical environment after the field‐rampdown of MR scanners of different field strengths.

Materials and Methods

Residual magnetism was measured with two gaussmeters in the MRI suites of an 8 Tesla (T) and a 0.7T whole body magnet at several time points prior, during and after field‐rampdown.

Results

Residual magnetism, in the MRI suite after controlled rampdown of an 8T superconducting magnet, was not significantly elevated compared with magnetic fields in the environment. Through 40 days, no significant changes in magnetism could be seen compared with initial measurements directly after rampdown, as both gaussmeters consistently measured. Similar findings were also observed after the quenched shutdown of a 0.7T system but a remanence was observed.

Conclusion

A controlled rampdown of even an ultrahigh field MR system does not lead to retained magnetic contamination, while forced quenched rampdown of a mid‐field system revealed temporary remanence. There is no need to degauss an MRI suite when an appropriate steel composition has been used in the iron shield. J. Magn. Reson. Imaging 2010;31:1272–1276. © 2010 Wiley‐Liss, Inc.
Right coronary artery flow velocity and volume assessment with spiral K‐space sampled breathhold velocity‐encoded MRI at 3 tesla: Accuracy and reproducibility
Authors: Brandts Anne , Roes Stijntje D. , Doornbos Joost , Weiss Robert G. , de Roos Albert , Stuber Matthias , Westenberg Jos J.M.
Published: April 2010

Purpose:

To evaluate accuracy and reproducibility of flow velocity and volume measurements in a phantom and in human coronary arteries using breathhold velocity‐encoded (VE) MRI with spiral k‐space sampling at 3 Tesla.

Materials and Methods:

Flow velocity assessment was performed using VE MRI with spiral k‐space sampling. Accuracy of VE MRI was tested in vitro at five constant flow rates. Reproducibility was investigated in 19 healthy subjects (mean age 25.4 ± 1.2 years, 11 men) by repeated acquisition in the right coronary artery (RCA).

Results:

MRI‐measured flow rates correlated strongly with volumetric collection (Pearson correlation r = 0.99; P < 0.01). Due to limited sample resolution, VE MRI overestimated the flow rate by 47% on average when nonconstricted region‐of‐interest segmentation was used. Using constricted region‐of‐interest segmentation with lumen size equal to ground‐truth luminal size, less than 13% error in flow rate was found. In vivo RCA flow velocity assessment was successful in 82% of the applied studies. High interscan, intra‐ and inter‐observer agreement was found for almost all indices describing coronary flow velocity. Reproducibility for repeated acquisitions varied by less than 16% for peak velocity values and by less than 24% for flow volumes.

Conclusion:

3T breathhold VE MRI with spiral k‐space sampling enables accurate and reproducible assessment of RCA flow velocity. J. Magn. Reson. Imaging 2010;31:1215–1223. © 2010 Wiley‐Liss, Inc.
Reliability of in vivo determination of forearm muscle volume using 3.0 T magnetic resonance imaging
Authors: Smeulders M.J.C. , van den Berg S. , Oudeman J. , Nederveen A.J. , Kreulen M. , Maas M.
Published: April 2010

Purpose:

To apply magnetic resonance imaging (MRI) as a tool for quantifying muscle volume of forearm muscles feasibility and reliability of volume estimation of the flexor carpi ulnaris (FCU) and the extensor carpi ulnaris (ECU).

Materials and Methods:

Forearms of 10 subjects were scanned twice. Muscle volumes were calculated from manual outlines on axial slices, slice thickness, and the number of slices. Observer agreement and repeatability were estimated using intraclass correlation, coefficient of variation, and the smallest detectable difference.

Results:

The average volume of the FCU and ECU was 31.0 mL (SD 11.5 mL) and 16.4 mL (SD 7.7 mL), respectively. Intraclass correlation coefficients of the volumes were all above 0.99 and the coefficient of variation varied between 5.7% and 0.8%. The smallest detectable difference corresponded to ≈7% of muscle volume.

Conclusion:

MRI muscle volume measurement of forearm muscles is feasible, reproducible, and allows for longitudinal studies where expected responsiveness exceeds 7%. J. Magn. Reson. Imaging 2010;31:1252–1255. © 2010 Wiley‐Liss, Inc.
Magnetic resonance imaging of the elbow
Authors: Stevens Kathryn J.
Published: April 2010

Elbow pain is frequently encountered in clinical practice and can result in significant morbidity, particularly in athletes. Magnetic resonance imaging (MRI) is an excellent diagnostic imaging tool for the evaluation of soft tissue and osteochondral pathology around the elbow. Recent advances in magnetic field strength and coil design have lead to improved spatial resolution and superior soft tissue contrast, making it ideal for visualization of complex joint anatomy. This article describes the normal imaging appearances of anatomy around the elbow and reviews commonly occurring ligamentous, myotendinous, neural, and bursal pathology around the elbow. J. Magn. Reson. Imaging 2010;31:1036–1053. © 2010 Wiley‐Liss, Inc.
Comparison of physiological triggering schemes for diffusion‐weighted magnetic resonance imaging in kidneys
Authors: Binser Tobias , Thoeny Harriet C. , Eisenberger Ute , Stemmer Alto , Boesch Chris , Vermathen Peter
Published: April 2010

Purpose:

To determine the potential benefit of combined respiratory‐cardiac triggering for diffusion‐weighted imaging (DWI) of kidneys compared to respiratory triggering alone (RT).

Materials and Methods:

Renal DWI was performed in 17 volunteers comparing RT, combined respiratory‐cardiac triggering (RCT), and combined respiratory‐cardiac triggering with slice position correction (RCTF). Data were analyzed in three ways: A1) Model‐free analysis of the signal stability over repeated measurements; A2) Analysis of the deviation from diffusion‐model fitting comparing the root mean squared error (RMSE), assessing within‐subject variabilities; and A3) Analysis of diffusion indices comparing between‐subject variabilities.

Results:

Combined respiratory‐cardiac triggering yielded lower signal fluctuations and more reliable diffusion parameter estimation than respiratory triggering alone in all three analysis methods: A1) The mean coefficient of variation (CV) for all subjects was 4.2 ± 1.1% and 4.3 ± 0.9% for RCT and RCTF, respectively, which was significantly lower compared to RT (5.3 ± 0.9%, P < 0.005); A2) RT yielded significantly higher RMSEs than RCT and RCTF; A3) The between‐subject variations of diffusion indices tended toward higher values for RT. The results were independent of perfusion contributions to the DWI data. No difference was determined between RCT and RCTF. Total acquisition time was only slightly prolonged for respiratory‐cardiac double‐triggering.

Conclusion:

Respiratory‐cardiac double‐triggering seems advantageous for renal DWI. J. Magn. Reson. Imaging 2010; 31:1144–1150. © 2010 Wiley‐Liss, Inc.
Structural and mechanical parameters of trabecular bone estimated from in vivo high‐resolution magnetic resonance images at 3 tesla field strength
Authors: Wald Michael Jeffrey , Magland Jeremy Franklin , Rajapakse Chamith Sudesh , Wehrli Felix Werner
Published: April 2010

Purpose:

To evaluate the performance of a new 3 Tesla (T) high‐resolution trabecular bone (TB) imaging technique at two resolution regimens in terms of serial reproducibility and sensitivity.

Materials and Methods:

The left distal tibial metaphysis of seven healthy volunteers was imaged at three time‐points using a FLASE (fast large‐angle spin‐echo) pulse sequence at 137 × 137 × 410 μm3 and (160 μm)3 voxel sizes. Image artifacts, motion degradation, and serial image volume misalignments were controlled to maximize reproducibility of image‐derived measures of scale, topology, orientation in terms of structural anisotropy, and finite‐element derived Young's and shear moduli. Coefficients of variation (CV) and intraclass correlation coefficients (ICC) for structural and mechanical parameters were evaluated as measures of reproducibility and reliability. The ability of structural and mechanical parameters to distinguish between subjects was tested by analysis of variance.

Results:

Reproducibility was generally higher in the anisotropic data (CVs 1–5% versus 1–9% for isotropic images). Anisotropic voxel size yielded greater measurement reliability (ICCs 0.75–0.99, mean = 0.92 versus 0.62–0.99, mean = 0.86) and better discrimination of the seven subjects (75% versus 50% of the possible comparisons were significantly different [P < 0.05]) except for measures of structural anisotropy and topology. Isotropic resolution improved detection of structural orientation and permitted visualization of small perforations in longitudinal trabecular plates not detected at anisotropic resolution.

Conclusion:

Improved image acquisition and processing techniques enhance reproducibility of structural and mechanical parameters derived from high‐resolution MRI of metaphyseal bone in the distal tibia. J. Magn. Reson. Imaging 2010;31:1157–1168. © 2010 Wiley‐Liss, Inc.
In vivo MRI of altered proton signal intensity and T2 relaxation in a bleomycin model of pulmonary inflammation and fibrosis
Authors: Jacob Richard E. , Amidan Brett G. , Soelberg Jolen , Minard Kevin R.
Published: April 2010

Purpose:

To investigate the ability of proton (1H) magnetic resonance imaging (MRI) to distinguish between pulmonary inflammation and fibrosis.

Materials and Methods:

Three groups of Sprague‐Dawley rats (n = 5) were instilled intratracheally with bleomycin (2.5 U/kg or 3.5 U/kg) in saline or with saline only. Rats were imaged at 2.0 Tesla using a multi‐slice Carr‐Purcell‐Meilboom‐Gill (CPMG) sequence with 6 ms echo spacing. Signal intensity (S0) and T2 were calculated on a pixel‐by‐pixel basis using images collected before dosing and 1, 2, 4, and 7 weeks after. At each time point, data from dosed animals were compared with controls, and bivariate statistical analysis was used to classify image pixels containing abnormal tissue. At week 7, pulmonary function tests were performed, then all rats were killed, left lungs were formalin fixed and tri‐chrome stained for histological analysis of collagen content, and right lungs were used to measure water and hydroxyproline (collagen) content.

Results:

The product S0×T2 significantly correlated with water and collagen content in the high‐dose group (P = 0.004 and P = 0.03, respectively). However, S0 and T2 of abnormal tissue were correlated for all time points (r = 0.93, P < 0.001), and could not distinguish inflammation from fibrosis.

Conclusion:

MRI can be used to confidently localize pulmonary inflammation and fibrosis, but it lacks specificity. J. Magn. Reson. Imaging 2010;31:1091–1099. © 2010 Wiley‐Liss, Inc.
Pulmonary blast injury in mice: A novel model for studying blast injury in the laboratory using laser‐induced stress waves
Authors: Satoh Yasushi , Sato Shunichi , Saitoh Daizoh , Tokuno Shinichi , Hatano Ben , Shimokawaji Tadasuke , Kobayashi Hideo , Takishima Kunio
Published: April 2010

Background and Objectives

Primary blast injury is produced by shock waves. Blast injuries to lungs are extremely critical threats to survival, but their etiology is largely undefined. The majority of animal models for these injuries use explosive or complex experimental settings, limiting the laboratory study of blast injury. The aim of this study was to establish a small‐animal model for blast injuries, using laser‐induced stress waves (LISWs) with high controllability, high reproducibility, and easy experimental settings.

Study Design/Materials and Methods

LISWs were used to produce isolated pulmonary blast effects in mice. An LISW was generated by the irradiation of an elastic laser target with 532‐nm nanosecond laser pulses of a Q‐switched Nd:YAG laser. Histopathological evaluations of damage to lung tissue were conducted to estimate the relevance between peak pressure and trauma intensity. Blood pressure, heart rate, and percutaneous oxygen saturation were monitored for 60 minutes.

Results

We could flexibly control the peak pressure of the shock wave by varying the laser energy. Non‐lethal doses of LISWs caused pulmonary contusions with alveolar hemorrhages depending on peak pressure. Pulmonary contusion was observed only in areas that were exposed to LISWs, allowing study of isolated injuries without concomitant ones. These injuries caused decreased blood pressure, heart rate, and percutaneous oxygen saturation, immediately after LISW exposure.

Conclusion

Mice exposed to thoracic LISWs showed pathologic and physiologic changes similar to those seen in other studies in this area, and in clinical practice. Our newly developed model allows fine management of trauma intensity, and concomitant injuries of the exposed animals were limited. This novel mouse model of blast injury using LISWs is suitable for detailed studies of blast lung contusion and other blast injuries in the laboratory. Lasers Surg. Med. 42:313–318, 2010. © 2010 Wiley‐Liss, Inc.
Preliminary investigation on use of high‐resolution optical coherence tomography to monitor injury and repair in the rat sciatic nerve
Authors: Chlebicki Cara A. , Lee Alice D. , Jung Woonggyu , Li Hongrui , Liaw Lih‐Huei , Chen Zhongping , Wong Brian J.
Published: April 2010

Background and Objective

Optical coherence tomography (OCT) has been used in limited settings to study peripheral nerve injury. The purpose of the study is to determine whether high‐resolution OCT can be used to monitor nerve injury and regeneration in the rat sciatic nerve following crush injury, ligation, and transection with microsurgical repair.

Study Design/Materials and Methods

Forty‐five rats were segregated into three groups. The right sciatic nerve was suture ligated (n = 15), cut then microsurgically repaired (n = 15), or crushed (n = 15). The left sciatic nerve served as the control; only surgical exposure and skin closure were performed. Each group was further divided into three subgroups where they were assigned survival durations of 4, 15, or 24 weeks. Following euthanasia, nerves were harvested, fixed in formalin, and imaged at the injury site, as well as proximal and distal ends. The OCT system resolution was approximately 7 µm in tissue with a 1,060 nm central wavelength.

Results

Control (uninjured) nerve tissue showed homogenous signal distribution to a relatively uniform depth; in contrast, damaged nerves showed irregular signal distribution and intensity. Changes in signal distribution were most significant at the injury site and distal regions. Increases in signal irregularity were evident during longer recovery times. Histological analysis determined that OCT imaging was limited to the surrounding perineurium and scar tissue.

Conclusion

OCT has the potential to be a valuable tool for monitoring nerve injury and repair, and the changes that accompany wound healing, providing clinicians with a non‐invasive tool to treat nerve injuries. Lasers Surg. Med. 42:306–312, 2010. © 2010 Wiley‐Liss, Inc.
Clinical study to determine the safety and efficacy of a low‐energy, pulsed light device for home use hair removal
Authors: Elm Courtney M.L. , Wallander Irmina D. , Walgrave Susan E. , Zelickson Brian D.
Published: April 2010

Background and Objectives

The principle of selective photo‐thermolysis has been studied extensively for hair removal applications in a medical setting. A new, portable, hand‐held device featuring two filtered Xenon lamps that utilizes pulsed light in low optical fluencies for hair removal has been developed for consumer use. The purpose of this clinical study was to determine the efficacy and safety of this low‐energy, pulsed‐intense light device intended for home use hair removal.

Study Design/ Materials and Methods

The treatment group consisted of 10 adults with skin types I–IV who possessed unwanted dark hair in the non‐facial region. The subjects received between 4 and 6 treatments on a bi‐weekly basis with the device by a trained member of the clinical staff. The clinical responses were evaluated by performing manual hair counts using magnified vision and photographs which were obtained prior to treatment and at each subsequent visit.

Results

Mean hair reduction was 36% 4 weeks after the final treatment and 10% 12 weeks after the final treatment. This resulted in a mean hair count reduction of 23% over the two follow‐up appointments. There was no definitive correlation between customer satisfaction and hair count reduction. Adverse reactions were limited to transient, localized, post‐treatment erythema. No complications were encountered.

Conclusions

This low‐energy, pulsed‐light device is a quick, safe, and relatively effective at‐home hair reduction treatment option in patients with various skin phototypes. Lasers Surg. Med. 42:287–291, 2010. © 2010 Wiley‐Liss, Inc.
Revising the Cannabis Use Disorders Identification Test (CUDIT) by means of Item Response Theory
Authors: Annaheim Beatrice , Scotto Thomas J. , Gmel Gerhard
Published: April 2010

Cannabis use among adolescents and young adults has become a major public health challenge. Several European countries are currently developing short screening instruments to identify ‘problematic’ forms of cannabis use in general population surveys. One such instrument is the Cannabis Use Disorders Identification Test (CUDIT), a 10‐item questionnaire based on the Alcohol Use Disorders Identification Test. Previous research found that some CUDIT items did not perform well psychometrically. In the interests of improving the psychometric properties of the CUDIT, this study replaces the poorly performing items with new items that specifically address cannabis use.

Analyses are based on a sub‐sample of 558 recent cannabis users from a representative population sample of 5722 individuals (aged 13–32) who were surveyed in the 2007 Swiss Cannabis Monitoring Study. Four new items were added to the original CUDIT. Psychometric properties of all 14 items, as well as the dimensionality of the supplemented CUDIT were then examined using Item Response Theory.

Results indicate the unidimensionality of CUDIT and an improvement in its psychometric performance when three original items (usual hours being stoned; injuries; guilt) are replaced by new ones (motives for using cannabis; missing out leisure time activities; difficulties at work/school). However, improvements were limited to cannabis users with a high problem score. For epidemiological purposes, any further revision of CUDIT should therefore include a greater number of ‘easier’ items. Copyright © 2010 John Wiley & Sons, Ltd.
T1ρ MRI quantification of arthroscopically confirmed cartilage degeneration
Authors: Witschey Walter R. T. , Borthakur Arijitt , Fenty Matt , Kneeland Bruce J. , Lonner Jess H. , McArdle Erin L. , Sochor Matt , Reddy Ravinder
Published: April 2010

Nine asymptomatic subjects and six patients underwent T1ρ MRI to determine whether Outerbridge grade 1 or 2 cartilage degeneration observed during arthroscopy could be detected noninvasively. MRI was performed 2‐3 months postarthroscopy, using sagittal T1‐weighted and axial and coronal T1ρ MRI, from which spatial T1ρ relaxation maps were calculated from segmented T1‐weighted images. Median T1ρ relaxation times of patients with arthroscopically documented cartilage degeneration and asymptomatic subjects were significantly different (P < 0.001), and median T1ρ exceeded asymptomatic articular cartilage median T1ρ by 2.5 to 9.2 ms. In eight observations of mild cartilage degeneration at arthroscopy (Outerbridge grades 1 and 2), mean compartment T1ρ was elevated in five, but in all observations, large foci of increased T1ρ were observed. It was determined that T1ρ could detect some, but not all, Outerbridge grade 1 and 2 cartilage degeneration but that a larger patient population is needed to determine the sensitivity to these changes. Magn Reson Med 63:1376–1382, 2010. © 2010 Wiley‐Liss, Inc.
Separate MRI quantification of dispersed (ferritin‐like) and aggregated (hemosiderin‐like) storage iron
Authors: Jensen Jens H. , Tang Haiying , Tosti Christina L. , Swaminathan Srirama V. , Nunez Alvaro , Hultman Kristi , Szulc Kamila U. , Wu Ed X. , Kim Daniel , Sheth Sujit , Brown Truman R. , Brittenham Gary M.
Published: April 2010

A new MRI method is proposed for separately quantifying the two principal forms of tissue storage (nonheme) iron: ferritin iron, a dispersed, soluble fraction that can be rapidly mobilized, and hemosiderin iron, an aggregated, insoluble fraction that serves as a long‐term reserve. The method utilizes multiple spin echo sequences, exploiting the fact that aggregated iron can induce nonmonoexponential signal decay for multiple spin echo sequences. The method is validated in vitro for agarose phantoms, simulating dispersed iron with manganese chloride, and aggregated iron with iron oxide microspheres. To demonstrate feasibility for human studies, preliminary in vivo data from two healthy controls and six patients with transfusional iron overload are presented. For both phantoms and human subjects, conventional R2 and R2* relaxation rates are also measured in order to contrast the proposed method with established MRI iron quantification techniques. Quantification of dispersed (ferritin‐like) iron may provide a new means of monitoring the risk of iron‐induced toxicity in patients with iron overload and, together with quantification of aggregated (hemosiderin‐like) iron, improve the accuracy of estimates for total storage iron. Magn Reson Med 63:1201–1209, 2010. © 2010 Wiley‐Liss, Inc.
Single‐breath‐hold multiple‐slice DENSE MRI
Authors: Sigfridsson Andreas , Haraldsson Henrik , Ebbers Tino , Knutsson Hans , Sakuma Hajime
Published: April 2010

A method to acquire multiple displacement encoded slices within a single breath hold is presented. Efficiency is improved over conventional DENSE without compromising image quality by readout of multiple slices in the same cardiac cycle, thus utilizing the position‐encoded stimulated echo available in the whole heart. The method was evaluated by comparing strain values obtained using the proposed method to strain values obtained by conventional separate breath‐hold single‐slice DENSE acquisitions. Good agreement (Lagrangian E2 strain bias = 0.000, 95% limits of agreement ± 0.04, root‐mean‐square‐difference 0.02 [9.4% of mean end‐systolic E2]) was found between the methods, indicating that the proposed method can replace a multiple breath‐hold acquisition. Eliminating the need for multiple breath holds reduces the risk of changes in breath‐hold positions or heart rate, results in higher patient comfort, and facilitates inclusion of DENSE in a clinical routine protocol. Magn Reson Med 63:1411–1414, 2010. © 2010 Wiley‐Liss, Inc.
Respiratory and cardiac self‐gated free‐breathing cardiac CINE imaging with multiecho 3D hybrid radial SSFP acquisition
Authors: Liu Jing , Spincemaille Pascal , Codella Noel C. F. , Nguyen Thanh D. , Prince Martin R. , Wang Yi
Published: April 2010

A respiratory and cardiac self‐gated free‐breathing three‐dimensional cine steady‐state free precession imaging method using multiecho hybrid radial sampling is presented. Cartesian mapping of the k‐space center along the slice encoding direction provides intensity‐weighted position information, from which both respiratory and cardiac motions are derived. With in plan radial sampling acquired at every pulse repetition time, no extra scan time is required for sampling the k‐space center. Temporal filtering based on density compensation is used for radial reconstruction to achieve high signal‐to‐noise ratio and contrast‐to‐noise ratio. High correlation between the self‐gating signals and external gating signals is demonstrated. This respiratory and cardiac self‐gated, free‐breathing, three‐dimensional, radial cardiac cine imaging technique provides image quality comparable to that acquired with the multiple breath‐hold two‐dimensional Cartesian steady‐state free precession technique in short‐axis, four‐chamber, and two‐chamber orientations. Functional measurements from the three‐dimensional cardiac short axis cine images are found to be comparable to those obtained using the standard two‐dimensional technique. Magn Reson Med 63:1230–1237, 2010. © 2010 Wiley‐Liss, Inc.
Model predictive filtering for improved temporal resolution in MRI temperature imaging
Authors: Todd Nick , Payne Allison , Parker Dennis L.
Published: April 2010

A novel method for reconstructing MRI temperature maps from undersampled data is presented. The method, model predictive filtering, combines temperature predictions from a preidentified thermal model with undersampled k‐space data to create temperature maps in near real time. The model predictive filtering algorithm was implemented in three ways: using retrospectively undersampled k‐space data from a fully sampled two‐dimensional gradient echo (GRE) sequence (reduction factors R = 2.7 to R = 7.1), using actually undersampled data from a two‐dimensional GRE sequence (R = 4.8), and using actually undersampled data from a three‐dimensional GRE sequence (R = 12.1). Thirty‐nine high‐intensity focused ultrasound heating experiments were performed under MRI monitoring to test the model predictive filtering technique against the current gold standard for MR temperature mapping, the proton resonance frequency shift method. For both of the two‐dimensional implementations, the average error over the five hottest voxels from the hottest time frame remained between ±0.8°C and the temperature root mean square error over a 24 × 7 × 3 × 25‐voxel region of interest remained below 0.35°C. The largest errors for the three‐dimensional implementation were slightly worse: −1.4°C for the mean error of the five hottest voxels and 0.61°C for the temperature root mean square error. Magn Reson Med 63:1269–1279, 2010. © 2010 Wiley‐Liss, Inc.
Increased anatomical detail by in vitro MR microscopy with a modified Golgi impregnation method
Authors: Zhang Xiaowei , Bearer Elaine L. , Perles‐Barbacaru Adriana T. , Jacobs Russell E.
Published: April 2010

Golgi impregnation is unique in its ability to display the dendritic trees and axons of large numbers of individual neurons by histology. Here we apply magnetic resonance microscopy to visualize the neuroanatomy of animal models by combining histologic fixation chemistry with paramagnetic contrast agents. Although there is some differential uptake of the standard small‐molecular‐weight contrast agents by different tissue types, detailed discrimination of tissue architecture in MR images does not approach that of standard histology. Our modified Golgi impregnation method significantly increases anatomic detail in magnetic resonance microscopy images. Fixed mouse brains were treated with a solution containing a paramagnetic contrast agent (gadoteridol) and potassium dichromate. Results demonstrate a specific contrast enhancement likely due to diamagnetic hexavalent chromium undergoing tissue specific reduction to paramagnetic trivalent chromium. This new method dramatically improves neuroanatomical contrast compared to conventional fixation, displaying detail approximating that of histologic specimens at low (4×) magnification. Magn Reson Med 63:1391–1397, 2010. © 2010 Wiley‐Liss, Inc.
In vivo detection of PARACEST agents with relaxation correction
Authors: Jones Craig K. , Li Alex X. , Suchý Mojmír , Hudson Robert H. E. , Menon Ravi S. , Bartha Robert
Published: April 2010

Several pulse sequences have been used to detect paramagnetic chemical exchange saturation transfer (PARACEST) contrast agents in animals to quantify the uptake over time following a bolus injection. The observed signal change is a combination of relaxation effects and PARACEST contrast. The purpose of the current study was to isolate the PARACEST effect from the changes in bulk water relaxation induced by the PARACEST agent in vivo for the fast low‐angle shot pulse sequence. A fast low‐angle shot–based pulse sequence was used to acquire continuous images on a 9.4‐T MRI of phantoms and the kidneys of mice following PARACEST agent (Tm3+‐DOTAM‐Gly‐Lys) injection. A WALTZ‐16 pulse was applied before every second image to generate on‐resonance paramagnetic chemical exchange effects. Signal intensity changes of up to 50% were observed in the mouse kidney in the control images (without a WALTZ‐16 preparation pulse) due to altered bulk water relaxation induced by the PARACEST agent. Despite these changes, a clear on‐resonance paramagnetic chemical exchange effect of 4‐7% was also observed. A four‐pool exchange model was used to describe image signal intensity. This study demonstrates that in vivo on‐resonance paramagnetic chemical exchange effect contrast can be isolated from tissue relaxation time constant changes induced by a PARACEST agent that dominate the signal change. Magn Reson Med 63:1184–1192, 2010. © 2010 Wiley‐Liss, Inc.
Estimation of global aortic pulse wave velocity by flow‐sensitive 4D MRI
Authors: Markl Michael , Wallis Wolf , Brendecke Stefanie , Simon Jan , Frydrychowicz Alex , Harloff Andreas
Published: April 2010

The aim of this study was to determine the value of flow‐sensitive four‐dimensional MRI for the assessment of pulse wave velocity as a measure of vessel compliance in the thoracic aorta. Findings in 12 young healthy volunteers were compared with those in 25 stroke patients with aortic atherosclerosis and an age‐matched normal control group (n = 9). Results from pulse wave velocity calculations incorporated velocity data from the entire aorta and were compared to those of standard methods based on flow waveforms at only two specific anatomic landmarks. Global aortic pulse wave velocity was higher in patients with atherosclerosis (7.03 ± 0.24 m/sec) compared to age‐matched controls (6.40 ± 0.32 m/sec). Both were significantly (P < 0.001) increased compared to younger volunteers (4.39 ± 0.32 m/sec). Global aortic pulse wave velocity in young volunteers was in good agreement with previously reported MRI studies and catheter measurements. Estimation of measurement inaccuracies and error propagation analysis demonstrated only minor uncertainties in measured flow waveforms and moderate relative errors below 16% for aortic compliance in all 46 subjects. These results demonstrate the feasibility of pulse wave velocity calculation based on four‐dimensional MRI data by exploiting its full volumetric coverage, which may also be an advantage over standard two‐dimensional techniques in the often‐distorted route of the aorta in patients with atherosclerosis. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.