bluuebunny/crossref_metadata_2025 huggingface dataset:
Can physical activity modulate pancreatic cancer risk? a systematic review and meta‐analysis
Authors: O'Rorke Michael A. , Cantwell Marie M. , Cardwell Chris R. , Mulholland Helen G. , Murray Liam J.
Published: October 2009

Numerous epidemiological studies have examined the association between physical activity and pancreatic cancer; however, findings from individual cohorts have largely not corroborated a protective effect. Among other plausible mechanisms, physical activity may reduce abdominal fat depots inducing metabolic improvements in glucose tolerance and insulin sensitivity, thereby potentially attenuating pancreatic cancer risk. We performed a systematic review to examine associations between physical activity and pancreatic cancer. Six electronic databases were searched from their inception through July 2009, including MEDLINE and EMBASE, seeking observational studies examining any physical activity measure with pancreatic cancer incidence/mortality as an outcome. A random effects model was used to pool individual effect estimates evaluating highest vs. lowest categories of activity. Twenty‐eight studies were included. Pooled estimates indicated a reduction in pancreatic cancer risk with higher levels of total (five prospective studies, RR: 0.72, 95% CI: 0.52–0.99) and occupational activity (four prospective studies, RR: 0.75, 95% CI: 0.59–0.96). Nonsignificant inverse associations were seen between risks and recreational and transport physical activity. When examining exercise intensity, moderate activity appeared more protective (RR: 0.79, 95% CI: 0.52–1.20) than vigorous activity (RR: 0.97, 95% CI: 0.85–1.11), but results were not statistically significant and the former activity variable incorporated marked heterogeneity. Despite indications of an inverse relationship with higher levels of work and total activity, there was little evidence of such associations with recreational and other activity exposures.
Probing the interaction between recombinant human myelin basic protein and caseins using surface plasmon resonance and diffusing wave spectroscopy
Authors: Al‐Ghobashy Medhat A. , Cucheval Aurelie , Williams Martin A. K. , Laible Götz , Harding David R. K.
Published: October 2009

An intrinsically unstructured human myelin basic protein (hMBP) was expressed in the milk of transgenic cows (TGmilk) and found exclusively associated with the casein micellar phase. The interaction between the recombinant protein and milk caseins was investigated using surface plasmon resonance (SPR). An anti‐human myelin basic protein antibody was covalently immobilized to the surface of the sensor chip. Subsequently the interaction between the recombinant protein (captured by this antibody) and caseins was studied in comparison to that noted with its human counterpart. Results showed a calcium‐mediated interaction between the recombinant protein and caseins. The order of magnitude of this interaction was in agreement with the number of phosphorylated residues carried by each type of casein (αs‐ > β‐ > κ‐casein). This selective interaction was not noted between the human protein and milk caseins indicating that the recombinant protein was phosphorylated to a higher extent than the human protein. The obtained results indicated that the co‐expression of the recombinant protein and caseins by the mammary gland along with the recombinant protein's ability to form calcium bridges played a key role in the association of the recombinant human myelin basic protein (rhMBP) with the casein micelles of milk. Despite this association between the recombinant protein and milk caseins, light scattering investigations using diffusing wave spectroscopy (DWS) showed no significant differences between the milks of the transgenic and the non‐transgenic control cows, with respect to both the average micelle size and surface charges. This was attributed to the low expression levels of the recombinant protein in milk. Copyright © 2009 John Wiley & Sons, Ltd.
Cross‐validation of magnetic resonance elastography and ultrasound‐based transient elastography: A preliminary phantom study
Authors: Oudry Jennifer , Chen Jun , Glaser Kevin J. , Miette Véronique , Sandrin Laurent , Ehman Richard L.
Published: October 2009

Purpose:

To cross‐validate two recent noninvasive elastographic techniques, ultrasound‐based transient elastography (UTE) and magnetic resonance elastography (MRE). As potential alternatives to liver biopsy, UTE and MRE are undergoing clinical investigations for liver fibrosis diagnosis and liver disease management around the world. These two techniques use tissue stiffness as a marker for disease state and it is important to do a cross‐validation study of both elastographic techniques to determine the consistency with which the two techniques can measure the mechanical properties of materials.

Materials and Methods:

In this study, 19 well‐characterized phantoms with a range of stiffness values were measured by two clinical devices (a Fibroscan and an MRE system based respectively on the UTE and MRE techniques) successively with the operators double‐blinded.

Results:

Statistical analysis showed that the correlation coefficient was r2 = 0.93 between MRE and UTE, and there was no evidence of a systematic difference between them within the range of stiffnesses examined.

Conclusion:

These two noninvasive methods, MRE and UTE, provide clinicians with important new options for improving patient care regarding liver diseases in terms of the diagnosis, prognosis, and monitoring of fibrosis progression, as well for evaluating the efficacy of treatment. J. Magn. Reson. Imaging 2009;30:1145–1150. © 2009 Wiley‐Liss, Inc.
Optimization of the contrast dose and injection rates in whole‐body MR angiography at 3.0T
Authors: Waugh Shelley A. , Ramkumar P. Guntur , Gandy Stephen J. , Nicholas R. Stephen , Martin Patricia , Belch Jill J.F. , Struthers Allan D. , Houston J. Graeme
Published: October 2009

Purpose:

To optimize the contrast agent dose and delivery rate used in a novel whole‐body magnetic resonance angiography (MRA) protocol using a 3.0T MR scanner.

Materials and Methods:

Six groups of 20 consenting volunteers underwent whole‐body MRA, with each group receiving a different contrast dose and contrast delivery rate. The arterial tree was divided into 16 segments and the image quality at each of the anatomical locations, covering the whole body, was assessed. Qualitative analysis was carried out using a scoring assessment of image quality, and quantitative assessments were performed by measuring contrast‐to‐noise (CNR) and a signal‐to‐noise (SNR) index.

Results:

Reducing the contrast dose from 40 mL to 25 mL was found to significantly increase the CNR in several vessels of interest in the arterial tree. There was also a significant increase in the qualitative image quality score (P < 0.001).

Conclusion:

This study demonstrates that reducing the contrast dose at 3.0T can result in an increase in the CNR in the vessels of interest without significantly affecting the SNR. J. Magn. Reson. Imaging 2009;30:1059–1067. © 2009 Wiley‐Liss, Inc.
High‐b‐value diffusion‐weighted MR imaging of hepatocellular lesions: Estimation of grade of malignancy of hepatocellular carcinoma
Authors: Muhi Ali , Ichikawa Tomoaki , Motosugi Utaroh , Sano Katsuhiro , Matsuda Masanori , Kitamura Takatoshi , Nakazawa Tadao , Araki Tsutomu
Published: October 2009

Purpose:

To evaluate the effectiveness of diffusion‐weighted magnetic resonance imaging (DWI) in estimating the grade of malignancy of hepatocellular carcinoma.

Materials and Methods:

Dynamic contrast‐enhanced computed tomography (CE‐CT) and DWI (b value, 1000 s/mm2) were performed on 73 patients. Using DW images, the lesions were classified as “visible” or “invisible.” The apparent diffusion coefficient (ADC) of the lesions was measured. Furthermore, the lesions were classified as hypervascular or iso‐hypovascular using arterial phase CE‐CT images. The image findings for each lesion type were compared.

Results:

The 73 patients had 98 hepatocellular lesions, of which 12 were histologically diagnosed as dysplastic nodules; 39, well‐differentiated HCCs; 33, moderately differentiated HCCs; and 14, poorly differentiated HCCs. The mean ADC values of moderately poorly‐differentiated HCCs were significantly lower than well‐differentiated HCCs and dysplastic nodules (P < 0.01). On DW images, >90% of moderately (30/33) and poorly differentiated HCCs (13/14) were visible, while 51% of well‐differentiated HCCs (20/39) and all dysplastic nodules were invisible. Of 22 iso‐hypovascular lesions, 4 were visible on DW images and were poorly differentiated HCCs, whereas 18 were invisible and were dysplastic nodules (12/18) or well‐differentiated HCCs (6/18).

Conclusion:

A combination of hypovascularity and visibility on DW images can help distinguish poorly differentiated HCCs from low‐grade hepatocellular lesions (dysplastic nodules and well‐differentiated HCCs). J. Magn. Reson. Imaging 2009;30:1005–1011. © 2009 Wiley‐Liss, Inc.
Utility of phase contrast MR imaging for assessment of pulmonary flow and pressure estimation in patients with pulmonary hypertension: Comparison with right heart catheterization and echocardiography
Authors: Nogami Munenobu , Ohno Yoshiharu , Koyama Hisanobu , Kono Atsushi , Takenaka Daisuke , Kataoka Toshiya , Kawai Hiroya , Kawamitsu Hideaki , Onishi Yumiko , Matsumoto Keiko , Matsumoto Sumiaki , Sugimura Kazuro
Published: October 2009

Purpose:

To compare the utility of phase contrast MR imaging (PC‐MRI) for assessment of pulmonary flow and pressure estimation with that of right heart catheterization and echocardiography (cardiac US) in patients with pulmonary arterial hypertension (PAH).

Materials and Methods:

Twenty consecutive patients with suspected PAH underwent PC‐MRI, cardiac US, and right heart catheterization. In each patient, PC‐MRI was acquired by cine 2D‐PC method on a 1.5 Tesla scanner, and stroke volume (SV) and pulmonary arterial systolic pressure (PASP) were assessed by using the modified Bernoulli's equation. To evaluate the agreements of SV and PASP among the three methods, correlations and limits of agreement among the three methods were statistically assessed by using the Bland‐Altman's analyses.

Results:

The correlations and limits of agreement for SV and PASP between PC‐MRI and catheterization (r = 0.96, r2 = 0.94, 1.1 ± 6.9 mL and r = 0.94, r2 = 0.88, −3.2 ± 14.5 mmHg, respectively) were better than between cardiac US and catheterization (r = 0.01, r2 < 0.01, 8.9 ± 42.1 mL and r = 0.86, r2 = 0.72, −5.9 ± 27.7 mmHg, respectively).

Conclusion:

PC‐MRI is more compatible with right heart catheterization than cardiac US in pulmonary flow and pressure estimation. J. Magn. Reson. Imaging 2009;30:973–980. © 2009 Wiley‐Liss, Inc.
Imaging of the walls of saccular cerebral aneurysms with double inversion recovery black‐blood sequence
Authors: Park Ji Kang , Lee Chang Sub , Sim Ki Bum , Huh Ji Soon , Park Jung Cheol
Published: October 2009

In this study, we evaluated the wall of saccular cerebral aneurysms (SCAs) using two‐dimensional double inversion recovery black‐blood sequence (BBDI). We examined 14 patients with an unruptured SCA (USCA). The BBDI was peripheral‐pulse gated, and was acquired during the mid‐diastolic period. We evaluated whether the aneurysmal wall could be visualized with BBDI, and the wall thickness in the neck and dome portion of the aneurysm was measured in cases with acceptable imaging quality. BBDI demonstrated the USCA walls in ten patients. In four patients, the USCA walls were poorly delineated from the adjacent brain parenchyma or cerebrospinal fluid. The mean aneurysm size was 8.0 mm. The mean thickness of the aneurysmal wall in the neck portion was 0.60 ± 0.13 mm in 10 cases. The mean thickness at the dome portion was 0.46 ± 0.05 mm in five cases. In this study, BBDI revealed some portion of the USCA wall, despite the limited spatial and contrast resolution for delineation of the entire USCA wall. In our opinion, this technique may be used as an additional imaging tool for the evaluation of the aneurysmal wall. J. Magn. Reson. Imaging 2009;30:1179–1183. © 2009 Wiley‐Liss, Inc.
Diffusion‐weighted imaging of human carotid artery using 2D single‐shot interleaved multislice inner volume diffusion‐weighted echo planar imaging (2D ss‐IMIV‐DWEPI) at 3T: Diffusion measurement in atherosclerotic plaque
Authors: Kim Seong‐Eun , Jeong Eun‐Kee , Shi Xian‐Feng , Morrell Glen , Treiman Gerald S. , Parker Dennis L.
Published: October 2009

Purpose:

To determine if 2D single‐shot interleaved multislice inner volume diffusion‐weighted echo planar imaging (ss‐IMIV‐DWEPI) can be used to obtain quantitative diffusion measurements that can assist in the identification of plaque components in the cervical carotid artery.

Materials and Methods:

The 2D ss‐DWEPI sequence was combined with interleaved multislice inner volume region localization to obtain diffusion weighted images with 1 mm in‐plane resolution and 2 mm slice thickness. Eleven subjects, six of whom have carotid plaque, were studied with this technique. The apparent diffusion coefficient (ADC) images were calculated using DW images with b = 10 s/mm2 and b = 300 s/mm2.

Results:

The mean ADC measurement in normal vessel wall of the 11 subjects was 1.28 ± 0.09 × 10−3 mm2/s. Six of the 11 subjects had carotid plaque and ADC measurements in plaque ranged from 0.29 to 0.87 × 10−3 mm2/s. Of the 11 common carotid artery walls studied (33 images), at least partial visualization of the wall was obtained in all ADC images, more than 50% visualization in 82% (27/33 images), and full visualization in 18% (6/33 images).

Conclusion:

2D ss‐IMIV‐DWEPI can perform diffusion‐weighted carotid magnetic resonance imaging (MRI) in vivo with reasonably high spatial resolution (1 × 1 × 2 mm3). ADC values of the carotid wall and plaque are consistent with similar values obtained from ex vivo endarterectomy specimens. The spread in ADC values obtained from plaque indicate that this technique could form a basis for plaque component identification in conjunction with other MRI/MRA techniques. J. Magn. Reson. Imaging 2009;30:1068–1077. © 2009 Wiley‐Liss, Inc.
Effect of contrast media on single‐shot echo planar imaging: Implications for abdominal diffusion imaging
Authors: Gulani Vikas , Willatt Jonathan M. , Blaimer Martin , Hussain Hero K. , Duerk Jeffrey L. , Griswold Mark A.
Published: October 2009

Purpose:

The goal of this study was to determine the effect of contrast media on the signal behavior of single‐shot echo planar imaging (ssEPI) used for abdominal diffusion imaging.

Materials and Methods:

The signal of an ssEPI spin echo sequence in a water phantom with varying concentrations of gadolinium was modeled with Bloch equations and the predicted behavior validated on a phantom at 1.5T. Six volunteers were given gadolinium contrast and signal intensity (SI) time courses for regions of interest (ROIs) in the liver, pancreas, spleen, renal cortex, and medulla were analyzed. Student's t‐test was used to compare precontrast SI to 0, 1, 4, 5, 10, and 13 minutes following contrast.

Results:

The results show that following contrast ssEPI SI goes through a nadir, recovering differently for each organ. Maximal contrast‐related signal losses relative to precontrast signal are 20%, 20%, 53%, and 67% for the liver, pancreas, renal cortex, and medulla, respectively. The SIs remain statistically below the precontrast values for 5, 4, and 1 minute for the pancreas, liver, and spleen, and for all times measured for the renal cortex and medulla.

Conclusion:

Abdominal diffusion imaging should be performed prior to contrast due to adverse effects on the signal in ssEPI. J. Magn. Reson. Imaging 2009;30:1203–1208. © 2009 Wiley‐Liss, Inc.
Relationship of temporal resolution to diagnostic performance for dynamic contrast enhanced MRI of the breast
Authors: El Khouli Riham H. , Macura Katarzyna J. , Barker Peter B. , Habba Mohamed R. , Jacobs Michael A. , Bluemke David A.
Published: October 2009

Purpose:

To investigate the relationship between temporal resolution of dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) and classification of breast lesions as benign versus malignant.

Materials and Methods:

Patients underwent T1‐weighted DCE MRI with 15 s/acquisition temporal resolution using 1.5 Tesla (n = 48) and 3.0T (n = 33) MRI scanners. Seventy‐nine patients had pathologically proven diagnosis and 2 had 2 years follow‐up showing no change in lesion size. The temporal resolution of DCE MRI was systematically reduced as a postprocessing step from 15 to 30, 45, and 60 s/acquisition by eliminating intermediate time points. Average wash‐in and wash‐out slopes, wash‐out percentage changes, and kinetic curve shape (persistently enhancing, plateau, or wash‐out) were compared for each temporal resolution. Logistic regression and receiver operating characteristic (ROC) curve analysis were used to compare kinetic parameters and diagnostic accuracy.

Results:

Sixty patients (74%) had malignant lesions and 21 patients (26%) had benign lesions. All temporal‐resolution parameters significantly predicted benign versus malignant diagnosis (P < 0.05). However, 45 s/acquisition and higher temporal‐resolution datasets showed higher accuracy than the 60 s/acquisition dataset by ROC curve analysis (0.72 versus 0.69 for average wash‐in slope; 0.85 versus 0.82, for average wash‐out slope; and 0.88 versus 0.80 for kinetic curve shape assessment, for 45 s/acquisition versus 60 s/acquisition temporal‐resolution datasets, respectively (P = 0.027).

Conclusion:

DCE MRI data with at least 45‐s temporal resolution maximized the agreement between the kinetic parameters and correct classification of benign versus malignant diagnosis. J. Magn. Reson. Imaging 2009;30:999–1004. © 2009 Wiley‐Liss, Inc.
Minimization of Nyquist ghosting for echo‐planar imaging at ultra‐high fields based on a “negative readout gradient” strategy
Authors: van der Zwaag Wietske , Marques José P. , Lei Hongxia , Just Nathalie , Kober Tobias , Gruetter Rolf
Published: October 2009

Purpose:

To improve the traditional Nyquist ghost correction approach in echo planar imaging (EPI) at high fields, via schemes based on the reversal of the EPI readout gradient polarity for every other volume throughout a functional magnetic resonance imaging (fMRI) acquisition train.

Materials and Methods:

An EPI sequence in which the readout gradient was inverted every other volume was implemented on two ultrahigh‐field systems. Phantom images and fMRI data were acquired to evaluate ghost intensities and the presence of false‐positive blood oxygenation level‐dependent (BOLD) signal with and without ghost correction. Three different algorithms for ghost correction of alternating readout EPI were compared.

Results:

Irrespective of the chosen processing approach, ghosting was significantly reduced (up to 70% lower intensity) in both rat brain images acquired on a 9.4T animal scanner and human brain images acquired at 7T, resulting in a reduction of sources of false‐positive activation in fMRI data.

Conclusion:

It is concluded that at high B0 fields, substantial gains in Nyquist ghost correction of echo planar time series are possible by alternating the readout gradient every other volume. J. Magn. Reson. Imaging 2009;30:1171–1178. © 2009 Wiley‐Liss, Inc.
Impact of papillary and trabecular muscles on quantitative analyses of cardiac function in hypertrophic cardiomyopathy
Authors: Han Yuchi , Osborn Eric A. , Maron Martin S. , Manning Warren J. , Yeon Susan B.
Published: October 2009

Purpose:

To examine the impact of cardiovascular magnetic resonance (CMR) partitioning methods on volumetric analysis in hypertrophic cardiomyopathy (HCM) patients. The standard CMR method for partitioning ventricular myocardium from ventricular cavity includes the myocardial papillary and trabecular muscles in the cavity volume. This approach may misrepresent ventricular mass and volume in patients with HCM due to large papillary muscles and extensive trabeculations.

Materials and Methods:

Ventricular volume and mass analyses were performed in 30 patients with HCM using the standard method and a detailed method that excluded papillary and trabecular muscles from the left ventricular (LV) volume while including them in LV mass. We also analyzed the degree of mitral regurgitation and compared the results with Doppler echocardiography in a subgroup of 12 patients. Interobserver variability was assessed.

Results:

The detailed method yielded 17% higher indexed LV mass, 20% lower indexed LV diastolic volume, 13% higher LV ejection fraction (EF) (all P < 0.0001). The resultant mitral regurgitant volumes using the detailed method had less discrepancy with Doppler echocardiography results compared with the results from the standard methods. Interobserver variability was similar by both methods.

Conclusion:

For patients with HCM, a detailed analysis in which the ventricular papillary and trabecular muscles are excluded from LV volume is preferred. J. Magn. Reson. Imaging 2009;30:1197–1202. © 2009 Wiley‐Liss, Inc.
7 Tesla MR imaging of the human eye in vivo
Authors: Richdale Kathryn , Wassenaar Peter , Teal Bluestein Katharine , Abduljalil Amir , Christoforidis John A. , Lanz Titus , Knopp Michael V. , Schmalbrock Petra
Published: October 2009

Purpose:

To develop a protocol which optimizes contrast, resolution and scan time for three‐dimensional (3D) imaging of the human eye in vivo using a 7 Tesla (T) scanner and custom radio frequency (RF) coil.

Materials and Methods:

Initial testing was conducted to reduce motion and susceptibility artifacts. Three‐dimensional FFE and IR‐TFE images were obtained with variable flip angles and TI times. T1 measurements were made and numerical simulations were performed to determine the ideal contrast of certain ocular structures. Studies were performed to optimize resolution and signal‐to‐noise ratio (SNR) with scan times from 20 s to 5 min.

Results:

Motion and susceptibility artifacts were reduced through careful subject preparation. T1 values of the ocular structures are in line with previous work at 1.5T. A voxel size of 0.15 × 0.25 × 1.0 mm3 was obtained with a scan time of approximately 35 s for both 3D FFE and IR‐TFE sequences. Multiple images were registered in 3D to produce final SNRs over 40.

Conclusion:

Optimization of pulse sequences and avoidance of susceptibility and motion artifacts led to high quality images with spatial resolution and SNR exceeding prior work. Ocular imaging at 7T with a dedicated coil improves the ability to make measurements of the fine structures of the eye. J. Magn. Reson. Imaging 2009;30:924–932. © 2009 Wiley‐Liss, Inc.
Highly accelerated first‐pass contrast‐enhanced magnetic resonance angiography of the peripheral vasculature: Comparison of gadofosveset trisodium with gadopentetate dimeglumine contrast agents
Authors: Maki Jeffrey H. , Wang Maisie , Wilson Gregory J. , Shutske Matthew G. , Leiner Tim
Published: October 2009

Purpose:

To investigate the blood pool agent gadofosveset trisodium for first‐pass, dynamic peripheral contrast‐enhanced magnetic resonance angiography (pMRA), and compare the results with a conventional gadolinium contrast agent.

Materials and Methods:

A total of 16 patients were imaged at 1.5T using a prototype peripheral vascular coil with high SENSE acceleration. Five received gadopentetate dimeglumine (≈0.25 mmol/kg), and 11 received gadofosveset trisodium (five standard‐dose 0.03 mmol/kg, six high‐dose 0.05 mmol/kg). Quantitative contrast‐enhancement and qualitative image quality evaluation was compared between agents and doses.

Results:

High‐quality diagnostic images were uniformly obtained. The contrast ratio did not significantly differ between gadopentetate dimeglumine and high‐dose gadofosveset trisodium, both of which were greater than standard‐dose gadofosveset trisodium. High‐dose gadofosveset trisodium was equivalent to gadopentetate dimeglumine in image quality and subjective vessel‐to‐background ratio, but significantly better for depicting small muscular arteries. Standard‐dose gadofosveset trisodium showed equivalent image quality and small artery depiction with a slight but significant decrease in vessel‐to‐background ratio as compared to gadopentatate dimeglumine. Both gadofosveset trisodium doses trended toward more venous enhancement, but this was not a diagnostic problem.

Conclusion:

First‐pass peripheral CE‐MRA using gadofosveset trisodium is feasible, yielding image quality comparable to double to triple‐dose gadopentetate dimeglumine. Increasing the gadofosveset trisodium dose to 0.05 mmol/kg yields further improvements. J. Magn. Reson. Imaging 2009;30:1085–1092. © 2009 Wiley‐Liss, Inc.
MRI: A charmed past and an exciting future
Authors: Macovski Albert
Published: October 2009

The invention and development of MRI took place under very desirable circumstances. Dr. Lauterbur, a distinguished NMR chemist, conceived of the basic idea. Once this concept was presented to the medical imaging community, a wonderful synergy developed between the two mature disciplines of NMR physical chemistry and medical imaging. This resulted in amazingly rapid progress and acceptance by the clinical community. This adventure is in sharp contrast to the history of x‐ray imaging. This began with the accidental discovery of x‐rays by Roentgen at the end of the 19th century. Unlike NMR, the basic x‐ray mechanism was not understood and was mistakenly thought to not be an electromagnetic wave. MRI is now at an advanced stage where investigators study advanced hardware and software improvements. These studies include improved signal‐to‐noise ratio, resolution, and speed, which generally involve higher B0. The high readout field results in numerous problems. These can be overcome by prepolarizing techniques using a high polarization field and a relatively low readout field. J. Magn. Reson. Imaging 2009;30:919–923. © 2009 Wiley‐Liss, Inc.
Development and application of magnetic resonance elastography of the normal and pathological thyroid gland in vivo
Authors: Bahn Mark M. , Brennan Michael D. , Bahn Rebecca S. , Dean Diana S. , Kugel Jennifer L. , Ehman Richard L.
Published: October 2009

Purpose:

To noninvasively assess the shear stiffness of the thyroid gland in vivo in order to determine whether magnetic resonance elastography (MRE) might hold clinical utility in the diagnosis of thyroid disease.

Materials and Methods:

Quantitative parametric images of thyroid stiffness in normal volunteers and patients were produced and quantitative stiffness values measured. Average gland stiffness was determined by region of interest analysis of the parametric images. This technique was used to assess stiffness of the thyroid in normal individuals (n = 12), patients with Hashimoto's thyroiditis (HT; n = 5), and patients with a solitary benign (n = 8) or malignant (n = 2) thyroid nodule.

Results:

Mean shear modulus of normal thyroid glands was 1.9 ± 0.6 kPa at 100 Hz and 1.3 ± 0.5 kPa at 80 Hz, while that of HT glands was 2.8 ± 0.6 kPa and 1.8 ± 0.6 kPa at 80 Hz, respectively (P = 0.004 at 100 Hz). Elastographic parameters could not differentiate benign from malignant thyroid nodules in these small sample sizes.

Conclusion:

We developed a method for the application of MRE to the study of thyroid gland pathology. The results show that the HT gland can be differentiated from normal thyroid. The clinical utility of this imaging modality in the diagnosis and management of thyroid disease awaits further study. J. Magn. Reson. Imaging 2009;30:1151–1154. © 2009 Wiley‐Liss, Inc.
Increased volume of coverage for abdominal contrast‐enhanced MR angiography with two‐dimensional autocalibrating parallel imaging: Initial experience at 3.0 Tesla
Authors: Lum Darren P. , Busse Reed F. , Francois Christopher J. , Brau Anja C. , Beatty Philip J. , Huff Joshua , Brittain Jean H. , Reeder Scott B.
Published: October 2009

Purpose:

To assess the feasibility and the quality of abdominal three‐dimensional (3D) contrast enhanced MR angiograms acquired at 3.0 Tesla (T) using a new 2D‐accelerated autocalibrating parallel reconstruction method for Cartesian sampling (2D‐ARC).

Materials and Methods:

With institutional review board approval and written informed consent, a prospective trial in 6 normal healthy volunteers and 23 patients referred for evaluation of suspected renovascular disease was performed. The volunteers underwent abdominal MRA with and without 2D‐ARC acceleration. Images were evaluated independently by two blinded vascular radiologists in randomized order. Vessel conspicuity was rated on a five‐point scale. Evaluation for significant differences between the scores for each technique was performed using a Wilcoxon signed‐rank test.

Results:

In the series of six volunteers, no statistical significance was found between the image quality scores for 2D‐ARC accelerated and nonaccelerated exams. A high proportion of the 23 clinical 2D‐ARC exams were graded as diagnostic (vessel conspicuity score ≥2; Reader 1, 96%; Reader 2, 100%) for overall image quality.

Conclusion:

Subjective image quality of 2D‐ARC accelerated MRA was equivalent to the conventional MRA method. However, the 2D‐ARC accelerated sequence provided a 3.5‐fold increase in imaging volume, complete abdominal coverage, and a 30% reduction in voxel volume, all within the same acquisition time. J. Magn. Reson. Imaging 2009;30:1093–1100. © 2009 Wiley‐Liss, Inc.
Analysis of self‐repair mechanisms of Phaseolus vulgaris var. saxa using near‐infrared surface‐enhanced Raman spectroscopy
Authors: Busch Sebastian , Schmitt Katrin , Erhardt Christian , Speck Thomas
Published: October 2009

We used surface‐enhanced Raman spectroscopy (SERS) to investigate ultrastructural changes in cell‐wall composition during the self‐repair of lacerated hypocotyls of Phaseolus vulgaris var. saxa. A detailed study of self‐repair mechanisms requires localized information about cell‐wall structure and morphology in addition to the chemical cell‐wall composition. Characteristic Raman and SER spectra yielded two‐dimensional maps of cross sections of P. vulgaris var. saxa visualizing chemical compositions in the walls of different cell types and during various repair phases. SERS substrate particles were produced by the reduction of gold chloride on the plant tissue surface and characterized with absorption spectroscopy, scanning electron microscopy and energy‐dispersive X‐ray spectroscopy. The SERS results were compared with stained cross sections of the same plant using dark‐field microscopy with focus on lignin and suberin contents in repairing cells. In addition, SERS measurements revealed Au cyanide compounds on the cell surface, indicating the formation of hydrogen cyanide during the self‐repair phase. Copyright © 2009 John Wiley & Sons, Ltd.
Chemoradiation for patients with advanced oral cavity cancer
Authors: Stenson Kerstin M. , Kunnavakkam Rangesh , Cohen Ezra E. W. , Portugal Louis D. , Blair Elizabeth , Haraf Daniel J. , Salama Joseph , Vokes Everett E.
Published: October 2009

Objectives/Hypothesis:

Patients with advanced oral cavity cancer (OCC) typically have not been enrolled in clinical trials utilizing contemporary multimodality strategies. There exist dogmatic expectations of inferior outcome in OCC patients secondary to ineffectiveness of treatment and unacceptable toxicity. The purpose of this study was to analyze survival, swallowing function, and incidence of osteoradionecrosis (ORN) of patients with stage III/IV OCC who have undergone primary concomitant chemoradiotherapy (CRT).

Methods:

All advanced OCC patients who were enrolled in University of Chicago concomitant CRT protocols from 1994 to 2008 were reviewed. One hundred eleven newly diagnosed advanced OCC patients were evaluated. We performed a subset analysis of 27 additional advanced OCC patients who underwent surgery followed by postoperative CRT. Swallowing function was assessed via oropharyngeal motility study, and a Swallowing Performance Status Scale score was assigned. Presence of clinically significant ORN was documented.

Results:

Median follow‐up was 3.25 years. Five‐year overall and progression‐free survival was 66.9% and 65.9%, respectively. There was no difference in overall or progression‐free survival when the surgery‐first group was compared with the primary CRT group (P = .88 and P = .86 respectively). Function, without gastric tube requirement, was excellent, with 92.2% of patients able to maintain weight via oral route. Incidence of ORN was 18.4%, occurring in nine of 49 patients evaluated.

Conclusions:

Our data support the use of primary CRT as a viable treatment option for patients with advanced OCC. Survival is high, and overall function for the majority of patients is satisfactory. Patients with T4 oral tongue cancer may be spared total glossectomy. The incidence of ORN may be considered acceptable, in light of the benefits of enduring life and function. Laryngoscope, 2010
Occurrence limit of stick‐slip: dimensionless analysis for fundamental design of robust‐stable systems
Authors: Nakano Ken , Maegawa Satoru
Published: October 2009

In most practical mechanical systems, sliding surfaces are utilised under the assumption that they operate smoothly. Stick‐slip motion can therefore be a serious nuisance that interferes with achieving high performance in mechanical systems. The present paper describes the nature of stick‐slip based on an analysis of a 1‐DOF sliding system. The dimensionless parameters controlling the stick‐slip are clarified by deriving the dimensionless forms of the governing equations. For a friction model that considers the dependence of the kinetic friction coefficient on the relative velocity, we find three types of sliding systems with regard to stick‐slip: the unstable system, the stable system and the robust‐stable system. A criterion is proposed for the fundamental design of robust‐stable systems; if a sliding system is robust stable, no matter how large a disturbance is, the energy of the disturbance is dissipated perfectly, and steady sliding without any vibration is ensured. Copyright © 2009 John Wiley & Sons, Ltd.
A comparison of methods for the construction of confidence interval for relative risk in stratified matched‐pair designs
Authors: Tang Nian‐Sheng , Li Hui‐Qiong , Tang Man‐Lai
Published: October 2009

A stratified matched‐pair study is often designed for adjusting a confounding effect or effect of different trails/centers/ groups in modern medical studies. The relative risk is one of the most frequently used indices in comparing efficiency of two treatments in clinical trials. In this paper, we propose seven confidence interval estimators for the common relative risk and three simultaneous confidence interval estimators for the relative risks in stratified matched‐pair designs. The performance of the proposed methods is evaluated with respect to their type I error rates, powers, coverage probabilities, and expected widths. Our empirical results show that the percentile bootstrap confidence interval and bootstrap‐resampling‐based Bonferroni simultaneous confidence interval behave satisfactorily for small to large sample sizes in the sense that (i) their empirical coverage probabilities can be well controlled around the pre‐specified nominal confidence level with reasonably shorter confidence widths; and (ii) the empirical type I error rates of their associated test statistics are generally closer to the pre‐specified nominal level with larger powers. They are hence recommended. Two real examples from clinical laboratory studies are used to illustrate the proposed methodologies. Copyright © 2009 John Wiley & Sons, Ltd.
Bayesian methods of analysis for cluster randomized trials with count outcome data
Authors: Clark Allan B. , Bachmann Max O.
Published: October 2009

Bayesian approaches to inference in cluster randomized trials have been investigated for normally distributed and binary outcome measures. However, relatively little attention has been paid to outcome measures which are counts of events. We discuss an extension of previously published Bayesian hierarchical models to count data, which usually can be assumed to be distributed according to a Poisson distribution. We develop two models, one based on the traditional rate ratio, and one based on the rate difference which may often be more intuitively interpreted for clinical trials, and is needed for economic evaluation of interventions. We examine the relationship between the intracluster correlation coefficient (ICC) and the between‐cluster variance for each of these two models. In practice, this allows one to use the previously published evidence on ICCs to derive an informative prior distribution which can then be used to increase the precision of the posterior distribution of the ICC. We demonstrate our models using a previously published trial assessing the effectiveness of an educational intervention and a prior distribution previously derived. We assess the robustness of the posterior distribution for effectiveness to departures from a normal distribution of the random effects. Copyright © 2009 John Wiley & Sons, Ltd.
Near‐miss function clones in open source software: an empirical study
Authors: Roy C. K. , Cordy J. R.
Published: October 2009

The new hybrid clone detection tool NICAD combines the strengths and overcomes the limitations of both text‐based and AST‐based clone detection techniques and exploits novel applications of a source transformation system to yield highly accurate identification of cloned code in software systems. In this paper, we present an in‐depth study of near‐miss function clones in open source software using NICAD. We examine more than 20 open source C, Java and C# systems, including the entire Linux Kernel, Apache httpd, J2SDK‐Swing and db4o and compare their use of cloned code in several different dimensions, including language, clone size, clone similarity, clone location and clone density both by proportion of cloned functions and lines of cloned code. We manually verify all detected clones and provide a complete catalogue of different clones in an online repository in a variety of formats. These validated results can be used as a cloning reference for these systems and as a benchmark for evaluating other clone detection tools. Copyright © 2009 John Wiley & Sons, Ltd.
Erratum: Pharmacokinetics of nanomaterials: an overview of carbon nanotubes, fullerenes and quantum dots. Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology, 2008; 1: 26–34
Authors: Riviere Jim E.
Published: October 2009

For further resources related to this article, please visit the WIREs website.
A remark on the definition of angular velocity
Authors: Casey J.
Published: October 2009

It is shown how the classical geometrical and modern algebraic conceptions of angular velocity can be unified by making use of a relative rotation tensor that takes the current configuration of a rigid body as a reference configuration.
Preparation of a New Oligomeric Surfactant:N,N,N′,N″,N″‐Pentamethyl Diethyleneamine—N,N″‐Di‐[Tetradecylammonium Bromide] and the Study of its Thermodynamic Properties
Authors: Alehyen Saliha , Bensajjay Fatima , El Achouri Mohammed , Pérez Lourdes , Pinazo Aurora , Infante María Rosa
Published: October 2009

A new oligomeric surfactant:N,N,N′,N″,N″‐ pentamethyl diethyleneamine—N,N″‐di‐[tetradecylammonium bromide] referred to as 14‐2‐N(CH3)‐2‐14 was synthesized, purified and characterized by Elemental Analysis,1H and13C NMR and Electrospray. The micellar properties of this compound were determined by electrical conductivity and surface tension methods. Optical microscopy was also employed to study the behavior of anhydrous surfactant and the binary water/surfactant system as a function of temperature. The critical micellar concentration (cmc), degree of counterion binding and thermodynamic parameters of micellization (standard molar Gibbs energy, enthalpy and entropy of micellization) were determined by electrical conductivity measurements in the temperature range [24–54 °C]. Surface tension measurements also provide information about the dependence of the surface tension at the cmc (γcmc), pC20(negative logarithm of the surfactant's molar concentration C20, required to reduce the surface tension by 20 mN/m, the surface excess (Γmax) at air/solution interface, the minimum area per surfactant molecule at the air/solution interface (Amin), surface pressure at the cmc (Пcmc), critical packing parameter(CPP) and the standard free energies of micellization () and of adsorption ().
Increased sensitivity to heat pain after sad mood induction in female patients with major depression
Authors: Terhaar Janneke , Boettger Michael Karl , Schwier Christiane , Wagner Gerd , Israel Anna‐Karoline , Bär Karl‐Jürgen
Published: October 2009

Patients suffering from major depressive disorder (MDD) have been shown to exhibit increased thresholds towards experimentally induced thermal pain applied to the skin. In contrast, the induction of sad mood can increase pain perception in healthy controls. Here, we aimed to test the hypothesis that heat pain thresholds are further increased after sad mood induction in depressed patients.

Thermal pain thresholds were obtained from 25 female depressed patients and 25 controls before and after sad mood induction applying a modified Velten Mood Induction procedure (MIP). Valence and arousal ratings were obtained using the self‐assessment manikin. The Montgomery Depression Rating Scale and the Beck Depression Inventory (BDI) were obtained at baseline from all participants.

Pain thresholds at baseline did not significantly differ between groups. Pain thresholds and valence of mood significantly decreased both in patients and controls, while arousal showed an inverse time course between groups. Therefore, our hypothesis could not be confirmed. From these data, we propose that the depressed mood as seen in MDD patients influences pain experience differently as compared to the shorter‐lasting mood change after MIP. A differential interaction of both affective states with brain areas of the pain matrix might be assumed. Eventually, the induction of sad mood might mirror the increased number of pain complaints in depressed patients and thus adds to the current concept of adjuvant antidepressant treatment both in depressed patients with pain complaints and in chronic pain patients.
Differential regulation by ATP versus ADP further links CaMKII aggregation to ischemic conditions
Authors: Vest Rebekah S. , O'Leary Heather , Bayer K. Ulrich
Published: October 2009

CaMKII, a major mediator of synaptic plasticity, forms extra‐synaptic clusters under ischemic conditions. This study further supports self‐aggregation of CaMKII holoenzymes as the underlying mechanism. Aggregation in vitro was promoted by mimicking ischemic conditions: low pH (6.8 or less), Ca2+ (and calmodulin), and low ATP and/or high ADP concentration. Mutational analysis showed that high ATP prevented aggregation by a mechanism involving T286 auto‐phosphorylation, and indicated requirement for nucleotide binding but not auto‐phosphorylation also for extra‐synaptic clustering within neurons. These results clarify a previously apparent paradox in the nucleotide and phosphorylation requirement of aggregation, and support a mechanism that involves inter‐holoenzyme T286‐region/T‐site interaction.
A kinome of 2600 in the ciliate Paramecium tetraurelia
Authors: Bemm Felix , Schwarz Roland , Förster Frank , Schultz Jörg
Published: October 2009

Protein kinases play a crucial role in the regulation of cellular processes. Most eukaryotes reserve about 2.5% of their genes for protein kinases. We analysed the genome of the single‐celled ciliate Paramecium tetraurelia and identified 2606 kinases, about 6.6% of its genes, representing the largest kinome to date. A gene tree combined with human kinases revealed a massive expansion of the calcium calmodulin regulated subfamily, underlining the importance of calcium in the physiology of P. tetraurelia. The kinases are embedded in only 40 domain architectures, contrasting 134 in human. This might indicate different mechanisms to achieve target specificity.
Differential regulation of p53 function by protein kinase C isoforms revealed by a yeast cell system
Authors: Coutinho Isabel , Pereira Gil , Leão Mariana , Gonçalves Jorge , Côrte-Real Manuela , Saraiva Lucília
Published: October 2009

The complexity of the mammalian p53 pathway and protein kinase C (PKC) family has hampered the discrimination of the effect of PKC isoforms on p53 activity. Using yeasts co‐expressing the human wild‐type p53 and a mammalian PKC‐α, ‐δ, ‐ε or ‐ζ, we showed a differential regulation of p53 activity and phosphorylation state by PKC isoforms. Whereas PKC‐α reduced the p53‐induced yeast growth inhibition and cell cycle arrest, PKC‐δ and ‐ε enhanced the p53 activity through p53 phosphorylation, and PKC‐ζ had no effect on p53. This work identified positive and negative p53 regulators which represent promising pharmacological targets in anti‐cancer therapy.
Shaping tubular carriers for intracellular membrane transport
Authors: Polishchuk Roman S. , Capestrano Mariagrazia , Polishchuk Elena V.
Published: October 2009

The particular compositions of the intracellular membrane organelles rely on the proteins and lipids received frequently through membrane trafficking. The delivery of these molecules is driven by the membrane‐bound organelles known as transport carriers (TCs). Advanced microscopy approaches have revealed that TC morphology ranges from small vesicles to complex tubular membrane structures. These tubular TCs (TTCs) support effectively both sorting and transport events within the biosynthetic and endocytic pathways, while a coherent picture of the processes that define the formation and further fate of TTCs is still missing. Here, we present an overview of the mechanisms operating during the TTC life cycle, as well as of the emerging role of tubular carriers in different intracellular transport routes.
A locally‐induced increase in intracellular Ca2+ propagates cell‐to‐cell in the presence of plasma membrane Ca2+ ATPase inhibitors in non‐excitable cells
Authors: Nakano Tadashi , Koujin Takako , Suda Tatsuya , Hiraoka Yasushi , Haraguchi Tokuko
Published: October 2009

Intercellular Ca2+ waves are commonly observed in many cell types. In non‐excitable cells, intercellular Ca2+ waves are mediated by gap junctional diffusion of a Ca2+ mobilizing messenger such as IP3. Since Ca2+ is heavily buffered in the cytosolic environment, it has been hypothesized that the contribution of the diffusion of Ca2+ to intercellular Ca2+ waves is limited. Here, we report that in the presence of plasma membrane Ca2+ ATPase inhibitors, locally‐released Ca2+ from the flash‐photolysis of caged‐Ca2+ appeared to induce further Ca2+ release and were propagated from one cell to another, indicating that Ca2+ was self‐amplified to mediate intercellular Ca2+ waves. Our findings support the notion that non‐excitable cells can establish a highly excitable medium to communicate local responses with distant cells.
Essential role of TRPV2 ion channel in the sensitivity of dystrophic muscle to eccentric contractions
Authors: Zanou Nadège , Iwata Yuko , Schakman Olivier , Lebacq Jean , Wakabayashi Shigeo , Gailly Philippe
Published: October 2009

Duchenne myopathy is a lethal disease due to the absence of dystrophin, a cytoskeletal protein. Muscles from dystrophin‐deficient mice (mdx) typically present an exaggerated susceptibility to eccentric work characterized by an important force drop and an increased membrane permeability consecutive to repeated lengthening contractions. The present study shows that mdx muscles are largely protected from eccentric work‐induced damage by overexpressing a dominant negative mutant of TRPV2 ion channel. This observation points out the role of TRPV2 channel in the physiopathology of Duchenne muscular dystrophy.