bluuebunny/crossref_metadata_2025 huggingface dataset:
Three‐dimensional 31P magnetic resonance spectroscopic imaging of regional high‐energy phosphate metabolism in injured rat heart
Authors: von Kienlin Markus , Rösch Claudia , Fur Yann Le , Behr Wolfgang , Roder Fridtjof , Haase Axel , Horn Michael , Illin Barbara , Hu Kai , Ertl Georg , Neubauer Stefan
Published: March 2007

The purpose of this study was to measure the spatially varying 31P MR signals in global and regional ischemic injury in the isolated, perfused rat heart. Chronic myocardial infarcts were induced by occluding the left anterior descending coronary artery eight weeks before the MR examination. The effects of acute global low‐flow ischemia were observed by reducing the perfusate flow. Chemical shift imaging (CSI) with three spatial dimensions was used to obtain 31P spectra in 54‐/μl voxels. Multislice 1H imaging with magnetization transfer contrast enhancement provided anatomical information. In normal hearts (n = 8), a homogeneous distribution of high‐energy phosphate metabolites (HEP) was found. In chronic myocardial infarction (n = 6), scar tissue contained negligible amounts of HEP, but their distribution in residual myocardium was uniform. The size of the infarcted area could be measured from the metabolic images; the correlation of infarct sizes determined by histology and 31P MR CSI was excellent (P < 0.006). In global low‐flow ischemia (n = 8), changes of HEP showed substantial regional heterogeneity. Three‐dimensional 31P MR CSI should yield new insights into the regionally distinct metabolic consequences of various forms of myocardial injury.
Magnetization transfer attenuates metabolite signals in tumorous and contralateral animal brain: In vivo observations by proton NMR spectroscopy
Authors: Roell Stefan A. , Dreher Wolfgang , Busch Elmar , Leibfritz Dieter
Published: March 2007

Tumorous and contralateral rat brain was examined by in vivo single voxel proton NMR spectroscopy. Magnetization transfer (MT) experiments cause attenuation of various metabolite signals. Selective saturation of immobile metabolites was achieved by pulsed RF preirradiation. The method is compared with continuous wave MT generation. In contralateral tissue, MT attenuation is detected for both the CH3 and the CH2 protons of (phospho‐)creatine (Cr + PCr) and for a signal at 3.44 ppm ascribed to taurine. Significant attenuation is also observed for a signal at 3.78 ppm that is commonly ascribed to the αCH proton of glutamate and glutamine (Glx); however, no effect is observed for the γCH2 protons of Glx. Within implanted F98 glioma tumors, only the CH3 signal of Cr + PCr shows significant MT attenuation. Although the MT effect detected for lactate in the tumors fails to reach significance, a significant effect is observed for the lactate signal acquired during 3 to 9 min postmortem.
In‐plane motion correction for MR spectroscopic imaging
Authors: Haupt Christine I. , Kiefer Andreas P. , Maudsley Andrew A.
Published: March 2007

A motion‐detection method is described that is specifically suited for MR spectroscopic imaging (MRSI) studies. Information on in‐plane rotation and translation of the subject was obtained using external spatial reference markers that are uniquely identified via their chemical shift. The marker locations were obtained directly from the acquired data at each encoding step, and no additional data acquisition was required. This method was applied to brain 1H MRSI studies that include subcutaneous lipid signals, which otherwise result in enhanced sensitivity to subject motion.
Recovery of the rodent brain after cardiac arrest: A functional mri study
Authors: Schmitz Bernd , Hoehn‐Berlage Mathias , Kerskens Christian M. , Bottiger Bernd W. , Hossmann Konstantin‐Alexander
Published: March 2007

Recovery of the cerebral cortex after 10 min of cardiac arrest was studied in rat using noninvasive MRI techniques. The apparent diffusion coefficient (ADC) of brain water was imaged to document reversal of the metabolic impairment. Per‐fusion‐weighted imaging and blood oxygen level dependent (BOLD) imaging were performed to assess functional recovery. To this purpose, rats were anesthetized with α‐chloralose, and somatosensory cortex was activated by electrical stimulation of the contralateral forepaw. In sham‐operated controls, cortical ADC was 862 ±10 μm2/s, and stimulation of forepaw led to a focal increase of signal intensity in somatosensory cortex by 71 ± 22% in perfusion‐weighted images and by 6 ± 1 % in BOLD images. One hour after successful resuscitation following 10 min of cardiac arrest, ADC did not differ from control but functional activation was completely suppressed. After 3 hours of reperfusion, functional activity began to reappear but the recovery of the BOLD signal progressed faster than that of the perfusion‐weighted signal. The differences in the recovery of ADC, BOLD, and perfusion imaging are related to differences between metabolic and functional recovery on one hand and between blood flow and oxygen extraction on the other. The combination of these MRI methods thus provides detailed qualitative information about the progression of brain recovery after transient circulatory arrest.
Analysis of subcutaneous angiogenesis by gradient echo magnetic resonance imaging
Authors: Abramovitch Rinat , Frenkiel Daphna , Neeman Michal
Published: March 2007

The goal of this study was to develop an experimental method for noninvasive analysis of angiogenesis, namely the sprouting of capillaries from existing blood vessels. Angiogenesis was assayed in the subcutaneous vasculature of nude mice in a region of 3 × 3 cm that included in its center a defined angiogenic stimulus. Angiogenic stimuli included agarose beads containing angiogenic growth factors, multicellular tumor spheroids, and dermal incisions. Highly significant correlation (r = 0.905, P = 0.0001) was found between the apparent vessel density determined by gradient echo MRI and the density of blood‐containing vessels determined postmortem. The functionality of the neovasculature was demonstrated in mice breathing alternatingly carbogen or 95% air/5% CO2. Large signal enhancement with carbogen breathing corresponded to regions of high vessel density. The assay reported here can be applied for the study of dermal wound healing, primary vascularization of subcutaneous implants, and for measuring the activity of angiogenic and antiangiogenic agents.
Multislice imaging of quantitative cerebral perfusion with pulsed arterial spin labeling
Authors: Yang Yihong , Frank Joseph A. , Hou Lei , Ye Frank Q. , McLaughlin Alan C. , Duyn Jeff H.
Published: March 2007

A method is presented for multislice measurements of quantitative cerebral perfusion based on magnetic labeling of arterial spins. The method combines a pulsed arterial inversion, known as the FAIR (Flow‐sensitive Alternating Inversion Recovery) experiment, with a fast spiral scan image acquisition. The short duration (22 ms) of the spiral data collection allows simultaneous measurement of up to 10 slices per labeling period, thus dramatically increasing efficiency compared to current single slice acquisition protocols. Investigation of labeling efficiency, suppression of unwanted signals from stationary as well as intraarterial spins, and the FAIR signal change as a function of inversion delay are presented. The assessment of quantitative cerebral blood flow (CBF) with the new technique is demonstrated and shown to require measurement of arterial transit time as well as suppression of intraarterial spin signals. CBF values measured on normal volunteers are consistent with results obtained from H2O15 positron emission tomography (PET) studies and other radioactive tracer approaches. In addition, the new method allows detection of activation‐related perfusion changes in a finger‐tapping experiment, with locations of activation corresponding well to those observed with blood oxygen level dependent (BOLD) fMRI.
Three‐dimensional coronary MR angiography using zonal echo planar imaging
Authors: Yang Guang Z. , Gatehouse Peter D. , Keegan Jennifer , Mohiaddin Raad H. , Firmin David N.
Published: March 2007

Using an adapted two‐dimensional spatially selective RF excitation scheme, a novel yet practical three‐dimensional (3D) zonal echo‐planar imaging technique for MR coronary angiography has been developed. The robustness of the technique compared with the two‐dimensional (2D) segmented fast low angle shot (FLASH) method was evaluated using the right coronary artery images of 16 asymptomatic volunteers with a 0.5‐T mobile scanner. Each 3D acquisition required multiple breath‐holds, and real‐time navigator echoes were used to ensure consistent breath‐holding. Advantages of the technique include an improved signal‐to‐noise ratio, clearer depiction of tortuous coronary vessels due to decreased partial volume effects, and reduced motion blurring by the use of a short echo‐planar readout.
An MR‐based technique for quantifying the deformation of articular cartilage during mechanical loading in an intact cadaver joint
Authors: Herberhold Christoph , Stammberger Tobias , Faber Sonja , Putz Reinhard , Englmeier Karl‐Hans , Reiser Maximilian , Eckstein Felix
Published: March 2007

The objective of this study was to develop an MR‐based technique for quantifying the deformation of articular cartilage during mechanical loading in an intact cadaver joint at high spatial and temporal resolution. A nonmetallic pressure device was constructed for applying loads of >1000 N to a femoro‐patellar articulation within an extremity coil of a clinical 1.5 T MRI scanner. Digital image processing methods were used to determine the location‐ and time‐dependent cartilage deformation in consecutive 2D fat‐suppressed FLASH images. Additionally, three‐dimensional reconstruction of the cartilage was performed from 3D fat‐suppressed FLASH image data. During the first 10 min of static compression, thickness changes between 10 and 30% were observed. Thickness changes greater than 50% and volume changes of 20% were recorded after 3 h. The technique permits analysis of the load and time‐dependent mechanical behavior of articular cartilage in its natural environment.
Volumetric spectroscopic imaging with spiral‐based k‐space trajectories
Authors: Adalsteinsson Elfar , Irarrazabal Pablo , Topp Simon , Meyer Craig , Macovski Albert , Spielman Daniel M.
Published: March 2007

Spiral‐based k‐space trajectories were applied in a spectroscopic imaging sequence with time‐varying readout gradients to collect volumetric chemical shift information. In addition to spectroscopic imaging of low signal‐to‐noise ratio (SNR) brain metabolites, the spiral trajectories were used to rapidly collect reference signals from the high SNR water signal to automatically phase the spectra and to aid the reconstruction of metabolite maps. Spectral‐spatial pulses were used for excitation and water suppression. The pulses were designed to achieve stable phase profiles in the presence of up to 20% variation in the radiofrequency field. A gridding algorithm was used to resample the data onto a rectilinear grid before fast Fourier transforms. This method was demonstrated by in vivo imaging of brain metabolites at 1.5 T with 10 slices of 18 × 18 pixels each. Nominal voxel size was 1.1 cc, spectral bandwidth was 400 Hz, scan time was 18 min for the metabolite scan and 3 min for the reference scan.
Temporal and anatomical variations of brain water apparent diffusion coefficient in perinatal cerebral hypoxic‐ischemic injury: Relationships to cerebral energy metabolism
Authors: Thornton John S. , Ordidge Roger J. , Penrice Juliet , Cady Ernest B. , Amess Philip N. , Punwani Shonit , Clemence M. , Wyatt J. S.
Published: March 2007

Cerebral apparent diffusion coefficients {ADCs) were determined in nine newborn piglets before and for 48 h after transient hypoxia‐ischemia. Phosphorus MRS revealed severely reduced cerebral energy metabolism during the insult and an apparently complete recovery 2 h after resuscitation commenced. At this time, mean ADC over the imaging slice (ADCglobal) was 0.88 (0.04) × 109 m2 · s1 (mean (SD}), which was close to the baseline value of 0.92 (0.4) × 109 m2 · s1. In seven of the animals, a “secondary” failure of energy metabolism then evolved, accompanied by a decline in ADCglobal to 0.64 (0.17) × 109 m2 · s1 at 46 h postresuscitation (P < 0.001 versus baseline). For these seven animals, ADCglobal correlated linearly with the concentration ratio [phosphocreatine (PCr)][inorganic phosphate (Pi)] (0.94 r < 0.99; P > 0.001). A nonlinear relationship was demonstrated between ADCglobal, and the concentration ratio [nucleotide triphosphate (NTP)]/ [Pi + PCr + 3 NTP]. The ADC reduction commenced in the parasagittal cortex before spreading in a characteristic pattern throughout the brain. ADC seems to be closely related to cerebral energy status and shows considerable potential for the assessment of hypoxic‐ischemic injury in the newborn brain.
A simplified method to measure the diffusion tensor from seven MR images
Authors: Basser Peter J. , Pierpaoli Carlo
Published: March 2007

Analytical expressions of the diffusion tensor of water, D, and of scalar invariants derived from it, are given in terms of the intensities of seven diffusion‐weighted images (DWIs). These formulas simplify the post‐processing steps required in diffusion tensor imaging, including estimating D in each voxel (from the set of b‐matrices and their corresponding DWIs), and then computing its eigenvalues, eigenvectors, and scalar invariants. In a study conducted using artifact‐free DWIs with high diffusion weighting (bmax ˜ 900 s/mm2), maps of Trace(D) and the Relative and Lattice Anisotropy indices calculated analytically and by multivariate linear regression showed excellent agreement in brain parenchyma of a healthy living cat. However, the quality of the analytically computed maps degraded markedly as diffusion weighting was reduced. Although diffusion tensor MRI with seven DWIs may be useful for clinical applications where rapid scanning and data processing are required, it does not provide estimates of the uncertainty of the measured imaging parameters, rendering it susceptible to noise and systematic artifacts. Therefore, care should be taken when using this technique in radiological applications.
Cardiac MRI of the normal and hypertrophied mouse heart
Authors: Slawson Susan E. , Roman Brian B. , Williams Donald S. , Koretsky Alan P.
Published: March 2007

With the development of recent transgenic techniques, studies involving mice offer opportunities to increase understanding of cardiac disease. This provides motivation for the current study to perform noninvasive evaluation of the normal and hypertrophied mouse heart with MRI. By acquiring EGG and respiratory signals, the MR image acquisition was gated to both the cardiac and respiratory cycles. Combining a spin‐warp imaging sequence with an RF surface coil resulted in short‐axis images that allowed quantification of in vivo cardiac mass. Excellent agreement between MRI‐determined (y) and postmortem heart weight (x) was obtained: y = 0.991x + 1.43 (r = 0.996). Isoproterenol, at 282 μMmol/kg body weight (BW) and 573 μMmol/kg BW, induced a dose‐dependent increase in the ratio of heart weight to BW of 16.8 ± 1.09% and 24.1 ± 1.71 %, respectively, which was accurately measured by MRI. These results demonstrate the ability of MRI to non‐invasively monitor cardiac anatomy in the mouse.
In vivo measurement of T*2 and field inhomogeneity maps in the human heart at 1.5 T
Authors: Reeder Scott B. , Faranesh Anthony Z. , Boxerman Jerrold L. , McVeigh Elliot R.
Published: March 2007

Cardiac echo‐planar imaging suffers invariably from regions of severe distortion and T*2 decay in the myocardium. The purpose of this work was to perform local measurements of T*2 and field inhomogeneities in the myocardium and to identify the sources of focal signal loss and distortion. Field inhomogeneity maps and T*2 were measured in five normal volunteers in short‐axis slices spanning from base to apex. It was found that T*2 ranged from 26 ms (SD = 7 ms, n = 5) to 41 ms (SD = 11 ms, n = 5) over most of the heart, and peak‐to‐peak field inhomogeneity differences were 71 Hz (SD = 14 Hz, n = 5). In all hearts, regions of severe signal loss were consistently adjacent to the posterior vein of the left ventricle; T*2 in these regions was 12 ms (SD = 2 ms, n = 5), and the difference in resonance frequency with the surrounding myocardium was 70‐100 Hz. These effects may be caused by increased magnetic susceptibility from deoxygenated blood in these veins.
A novel k‐space trajectory measurement technique
Authors: Zhang Yantian , Hetherington Hoby P. , Stokely Ernest M. , Mason Graeme F. , Twieg Donald B.
Published: March 2007

A new k‐space trajectory measurement technique is proposed and demonstrated. This technique measures the k‐space trajectory, in seconds, using only a few readout lines, using phase values of acquired MR signals. As a result of the technique's efficiency, k‐space trajectory measurement using patient data becomes possible. The utility of this techniques is demonstrated in phantom and human studies at 4.1 T.
Lack of effect of oral choline supplement on the concentrations of choline metabolites in human brain
Authors: Tan Jeannie , Bluml Stefan , Hoang Tuan , Dubowitz David , Mevenkamp Gregor , Ross Brian
Published: March 2007

Recent reports suggest that oral choline supplement may alter the cerebral choline/creatine (Cho/Cr) ratio and might be used to treat neurodegenerative disorders of cholinergic transmission. Using both 1H and 31P MRS, we reexamined the Cho/Cr ratio and quantified cerebral choline and its major constituents: phosphoethanolamine (PE), phosphorylcholine (PC), glycerophosphorylethanolamine (GPE), and glycero‐phosphorylcholine (GPC). In the four brain locations examined, no significant increases in Cho/Cr, [Cho], or in its major constituents were found in response to an oral challenge of 50 mg/kg of choline bitartrate. Oral choline did not significantly affect human cerebral metabolism in the short term.
Three‐dimensional MRI of coronary arteries using an intravascular contrast agent
Authors: Li Debiao , Dolan Robert P. , Walovitch Richard C. , Lauffer Randall B.
Published: March 2007

To assess the effectiveness of an intravascular contrast agent, MS‐325, for enhancing the vascular signal in coronary MR angiograms, six minipigs were studied using a three‐dimensional, gradient‐echo sequence with retrospective respiratory gating. To suppress the myocardial signal, preparatory RF pulses were applied before data acquisition. With the administration of MS‐325, the blood signal‐to‐noise ratio increased by 97‐276%, depending on the region of interest in which the blood signal was measured and the precontrast imaging sequence structures. The blood/myocardium contrast‐to‐noise ratio also significantly increased. High‐resolution images (0.58 × 0.58 × 1 mm3) obtained from postmortem pig hearts demonstrated the potential delineation of coronary arteries with MS‐325. In conclusion, this study supports further evaluation of the utility of MS‐325 in improving coronary MR angiography in humans.
Virtual frequency encoding: Achieving symmetry in k‐space
Authors: Hinks R. Scott , Derbyshire J. Andrew , Leroux Patrick L.
Published: March 2007

Chemical shift artifacts and other off‐resonance spatial shifts in 2DFT MRI arise from the linear time dependence in the k‐space data in the readout direction. Introduction of a view‐dependent time shift of the readout window adds a time dependence to the phase‐encoding direction and results in a virtual frequency‐encoding direction that is a linear combination of the phase‐encode and readout axes. By this method, the readout and phase‐encode directions can be made identical in their sensitivity to off‐resonance effects and can be arbitrarily swapped with no change in chemical shift or inhomogeneity effects, improving previously reported methods that swap these axes for signal averaging or reduction of motion artifacts.
Evaluation of extra‐ and intracellular apparent diffusion in normal and globally ischemic rat brain via 19F NMR
Authors: Duong Timothy Q. , Ackerman Joseph J. H. , Ying Howard S. , Neil Jeffrey J.
Published: March 2007

The biophysical mechanism(s) underlying diffusion‐weighted MRI contrast following brain injury remains to be elucidated. Although it is generally accepted that water apparent diffusion coefficient (ADC) decreases after brain injury, it is unknown whether this is associated with a decrease in intracellular or extracellular water displacement, or both. To address this question, 2‐[19F]luoro‐2‐deoxyglucose‐6‐phosphate (2FDG‐6P) was employed as a compartment‐specific marker in normal and globally ischemic rat brain. Through judicious choice of routes of administration, 2FDG‐6P was confined to the intra‐ or extracellular space. There was no statistical difference between intra‐ and extracellular 2FDG‐6P ADCs in normal or in globally ischemic brain (P > 0.16), suggesting that water ADCs in both compartments are similar. However, ischemia did result in a 40% ADC decrease in both compartments (P < 0.001). Assuming that 2FDGbP reflects water motion, this study shows that water ADC decreases in both spaces after ischemia, with the reduction of intracellular water motion being the primary source of diffusion‐weighted contrast.
An optimal and efficient new gridding algorithm using singular value decomposition
Authors: Rosenfeld Daniel
Published: March 2007

The problem of handling data that falls on a nonequally spaced grid occurs in numerous fields of science, ranging from radio‐astronomy to medical imaging. In MRI, this condition arises when sampling under time‐varying gradients in sequences such as echo‐planar imaging (EPI), spiral scans, or radial scans. The technique currently being used to interpolate the nonuniform samples onto a Cartesian grid is called the gridding algorithm. In this paper, a new method for uniform resampling is presented that is both optimal and efficient. It is first shown that the resampling problem can be formulated as a problem of solving a set of linear equations Ax = b, where x and b are vectors of the uniform and nonuniform samples, respectively, and A is a matrix of the sinc interpolation coefficients. In a procedure called Uniform Re‐Sampling (URS), this set of equations is given an optimal solution using the pseudoinverse matrix which is computed using singular value decomposition (SVD). In large problems, this solution is neither practical nor computationally efficient. Another method is presented, called the Block Uniform Re‐Sampling (BURS) algorithm, which decomposes the problem into solving a small set of linear equations for each uniform grid point. These equations are a subset of the original equations Ax = b and are once again solved using SVD. The final result is both optimal and computationally efficient. The results of the new method are compared with those obtained using the conventional gridding algorithm via simulations.
In vivo proton magnetic resonance spectroscopy of the medial temporal lobes of subjects with combat‐related posttraumatic stress disorder
Authors: Freeman Thomas W. , Cardwell David , Karson Craig N. , Komoroski Richard A.
Published: March 2007

Recent findings using volumetric MRI techniques have revealed that patients with combat‐related and noncombat‐re‐lated posttraumatic stress disorder (PTSD) have reductions in right hippocampal volume. Twenty‐one veterans with PTSD and eight age‐matched control veterans were studied using proton magnetic resonance spectroscopy to test the hypothesis that the N‐acetyl‐L‐aspartic acidkreatine (NAAICr) ratio would be decreased in the right medial temporal lobe structures of patients with PTSD compared to controls. Patients with PTSD displayed significantly lower NAA/Cr ratio for the right medial temporal lobe relative to the left (P ⩽ 0.011). Patients with PTSD also had lower NNCr in right medial temporal lobe (P ⩽ O.013) and lower choline/Cr in left medial temporal lobe (P ⩽ 0.030) compared to control subjects. Because NAA is regarded as an indicator of neuronal density, this finding suggests that the neuronal density of right‐sided medial temporal structures in patients with combat‐related PTSD may be decreased.
A systematic study of the lactate lineshape in PRESS‐localized proton spectroscopy
Authors: Marshall Ian , Wild James
Published: March 2007

J‐coupled resonances such as lactate exhibit complex behavior in PRESS‐localized spectroscopy. Polarization transfer effects due to nonideal slice profiles can lead to substantial errors in quantification unless recognized. In this work, it is shown how these effects can be predicted in a systematic way given the sequence timing and the RF pulse envelopes. Experimental results are presented to highlight the problems of working at the popular echo time of 2/J.
Monitoring transplanted human mesenchymal stem cells in rat and rabbit bladders using molecular magnetic resonance imaging
Authors: Song Yun Seob , Ku Ja Hyeon
Published: March 2007

Aims

This study investigated whether superparamagnetic iron oxide (SPIO)‐labeled human mesenchymal stem cells (hMSCs) may be monitored non‐invasively by in vivo magnetic resonance (MR) imaging with conventional 1.5‐T system examinations in the bladders of rats and rabbits.

Methods

SPIO were transferred to hMSCs, using GenePORTER. After SPIO‐labeled hMSCs were transplanted into the animal bladders, serial T2‐weighted MR images and histological examinations were performed over a 4‐week period.

Results

hMSCs loaded with SPIO, compared to unlabeled cells, showed similar viability. SPIO‐labeled hMSCs underwent normal chondrogenic, adipogenic, and osteogenic differentiation. For SPIO‐labeled hMSCs concentrations that were greater than 1 × 105, in vitro MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO‐labeled hMSCs in rat and rabbit bladders were decreased and confined locally. After injection of SPIO‐labeled hMSCs into the bladder, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks post‐injection. The presence of iron was confirmed with Prussian blue staining in histological sections.

Conclusions

Our findings suggest that hMSCs in animal bladders can be monitored non‐invasively with conventional MR imaging. Neurourol. Urodynam. 26:584–593, 2007. © 2007 Wiley‐Liss, Inc.
Overactive bladder in diabetes: A peripheral or central mechanism?
Authors: Yamaguchi Chiharu , Sakakibara Ryuji , Uchiyama Tomoyuki , Yamamoto Tatsuya , Ito Takashi , Liu Zhi , Awa Yusuke , Yamamoto Kaori , Nomura Fumio , Yamanishi Tomonori , Hattori Takamichi
Published: March 2007

Aims

To study diabetic cystopathy with reference to overactive bladder (OAB).

Methods

We retrospectively analyzed diabetic cystopathy in our digitized database that comprised 2300 case records, including data from a lower urinary tract symptoms questionnaire, data from a urodynamic study, and data from neurological examinations.

Results

Diabetic cystopathy was seen in 4% of cases (84 cases): 58 males, 26 females; mean age, 60.8 years; duration of diabetes, 143.5 months; HbA1C, 7.7 %. In addition to large post‐void residual and decreased sensation, OAB, detrusor overactivity (DO), and increased bladder sensation were seen in 55%, 42%, and 14%, respectively. The frequency of DO in patients with increased bladder sensation was 58%. DO increased with age, but not with the duration of diabetes. A brain MRI was performed in 32 cases. The frequency of multiple cerebral infarction (MCI) in patients with DO was 76.5%. The remaining 23.5% of patients with DO had no MCI, and the remaining 42% with increased bladder sensation had no DO.

Conclusions

OAB commonly occurs in diabetic cystopathy. Both central and peripheral mechanisms are involved, e.g., MCI due to diabetic cerebral vasculopathy for the DO, and, to a lesser extent, peripheral nerve irritation for the DO and increased bladder sensation. Neurourol. Urodynam. 26:807–813, 2007. © 2007 Wiley‐Liss, Inc.
Test‐retest reliability of an instrumented speculum for measuring vaginal closure force
Authors: Miller J.M. , Ashton‐Miller J.A. , Perruchini D. , DeLancey J.O.L.
Published: March 2007

Aims:

The study aimed to: a) determine reliability of an instrumented speculum designed for measuring intravaginal closure pressure, and b) compare findings with a comparable device reported in the literature. The goal of these new devices is to reduce subjectivity, improve precision, and acknowledge reliability issues in quantifying levator ani closure force acting on the vagina.

Methods:

The instrumented speculum consisted of two parallel aluminum bills, similar in size to a Peterson speculum. Strain gages located near the root of each bill measure the magnitude of force exerted in the distal vagina. A contraction of the “U‐shaped” levator ani muscle closes the levator hiatus with resultant reaction force measured by the speculum in the mid‐sagittal plane. We tested the device in twelve nulliparous women making repeated measures within and across 3 different visit days. All measures were made by the same investigator.

Results:

Same day measures were repeatable within ±3.8 N by the third visit, with lesser repeatability on the 1st and 2nd visit days. Across days, repeatability was improved by Visits 2 and 3 with a coefficient of repeatability between those days of ±5.5 N. Better repeatability was obtained using averaged scores rather than ‘best effort’ ; but average scores can underestimate best effort.

Conclusion:

Reasonable within‐visit repeatability was found. Across‐visit repeatability is consistent with the known difficulty that women have in maximally isolating and activating their levator ani muscles. The results corroborate the repeatability results of Dumoulin et al. [2004] using a similar type of dynamometer. Neurourol. Urodynam. 26:858–863, 2007. © 2007 Wiley‐Liss, Inc.
Metaheuristics for the vehicle routing problem with loading constraints
Authors: Doerner Karl F. , Fuellerer Guenther , Hartl Richard F. , Gronalt Manfred , Iori Manuel
Published: March 2007

We consider a combination of the capacitated vehicle routing problem and a class of additional loading constraints involving a parallel machine scheduling problem. The work is motivated by a real‐world transportation problem occurring to a wood‐products retailer, which delivers its products to a number of customers in a specific region. We solve the problem by means of two different metaheuristics algorithms: a Tabu Search and an Ant Colony Optimization. Extensive computational results are given for both algorithms, on instances derived from the vehicle routing literature and on real‐world instances. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(4), 294–307 2007
Singular linear systems with delay: ℋ︁∞stabilization
Authors: Boukas E. K.
Published: March 2007

This paper deals with the class of continuous‐time singular linear systems with time‐delay in the state vector. The stabilization problem of this class of systems using a state feedback controller is tackled. New delay‐dependent sufficient conditions on ℋ︁∞stabilization are developed. A design algorithm for a memoryless state feedback controller which guarantees that the closed‐loop dynamics will be regular, impulse‐free and stable with γ‐disturbance rejection is proposed. It is shown that the addressed problem can be solved if the corresponding developed linear matrix inequalities (LMIs) with some constraints are feasible. A numerical example is employed to show the usefulness of the proposed results. Copyright © 2007 John Wiley & Sons, Ltd.
Optimal control problems for anti‐periodic quasi‐linear hemivariational inequalities
Authors: Park Jong Yeoul , Park Sun Hye
Published: March 2007

In this paper, we prove the existence of anti‐periodic solutions to a hyperbolic quasi‐linear hemivariational inequalities by using the Faedo–Galerkin method. Then, we investigate optimal control problems governed by the inequalities. Copyright © 2007 John Wiley & Sons, Ltd.
Genetic variation in hepatic glucose‐6‐phosphatase system genes in cases of sudden infant death syndrome
Authors: Forsyth L , Scott HM , Howatson A , Busuttil A , Hume R , Burchell A
Published: March 2007

Genetic deficiencies of the hepatic glucose‐6‐phosphatase system, either of the enzyme (G6PC1) or of the glucose‐6‐phosphate transporter (G6PT1), result in fasting hypoglycaemia. Low hepatic G6PC1 activities were previously reported in a few term sudden infant death syndrome (SIDS) infants and assumed to be due to G6PC1 genetic deficiencies. In preterm infants, failures of postnatal activation of G6PC1 expression suggest disordered development as a novel cause of decreased G6PC1 activity in SIDS. G6PC1 and G6PT1 functional and mutational analysis was investigated in SIDS and non‐SIDS infants. G6PC1 hepatic activity was abnormally low in 98 SIDS (preterm, n = 13; term, n = 85), and non‐SIDS preterm infants (n = 35) compared to term non‐SIDS infants (n = 29) and adults (n = 9). Mean glycogen levels were elevated, except in term non‐SIDS infants. A novel G6PT1 promoter polymorphism, 259C → T was found; the − 259*T allele frequency was greater in term SIDS infants (n = 140) than in term control infants (n = 119) and preterm SIDS infants (n = 30). Heterozygous and homozygous prevalence of 259C → T was 38.6% and 7.1%, respectively, in term SIDS infants. In cell‐based expression systems, the presence of − 259T in the promoter decreased basal luciferase activity by 3.2‐fold compared to − 259C. Glucose‐6‐phosphatase latency in hepatic microsomes was elevated (indicating decreased G6PT1 function) in heterozygous and homozygous − 259T states. Delayed postnatal appearance of hepatic glucose‐6‐phosphatase in infants makes them vulnerable to hypoglycaemic episodes and this may occur in some SIDS infants. However, SIDS may be an association of more complex phenotypes in which several genes interact with multiple environmental factors. A UK‐wide DNA Biobank of samples from all infant deaths, with an accompanying epidemiological database, should be established by pathologists to allow cumulative data to be collected from multiple genetic investigations on the same large cohort of samples, with the aim of selection of the best combination of genetic markers to predict unexpected infant death. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Molecular dynamics simulations to compute diffusion coefficients of gases into polydimethylsiloxane and poly{(1,5‐ naphthalene)‐co‐[1,4‐durene‐2,2′‐bis(3,4‐dicarboxyl phenyl)hexafluoropropane diimide]}
Authors: Jawalkar Sheetal S , Aminabhavi Tejraj M
Published: March 2007

Diffusion coefficients of N2, O2, CO2 and CH4 at 298 K in polydimethylsiloxane (PDMS) and poly{[(1,5‐naphthalene)‐co‐[1,4‐durene‐2,2′‐bis(3,4‐dicarboxyl phenyl)hexafluoropropane diimide]} (6FDA‐1,5‐NDA) polymers have been estimated using molecular dynamics (MD) simulations. Estimated diffusion coefficients in PDMS decrease systematically with increasing size of the penetrant gas molecules following the experimental observations. For 6FDA‐1,5‐NDA polymer, diffusion coefficients decrease in the same order of magnitude, but differ in their sequential order, due to varying side group interactions of the polymer with the gaseous molecules. Cohesive energy density, solubility parameter and free volume of the polymers were determined using MD simulations. Reliability and accuracy of the simulations have been tested typically with the computed values of the diffusion coefficient of O2 in PDMS polymer, which compare well with the literature data. X‐ray scattering profiles of 6FDA‐1,5‐NDA have been generated to understand the interrelationship between the morphology and diffusion coefficients. The radial distribution function was evaluated to find the contribution of atoms that are important in understanding the molecular interactions during gas diffusion in polymers. Copyright © 2007 Society of Chemical Industry
Polyelectrolyte complexes based on chitosan and poly(L‐glutamic acid)
Authors: Yin Jingbo , Dai Zhengzhan , Yan Shifeng , Cao Tian , Ma Jia , Chen Xuesi
Published: March 2007

Polyelectrolyte complexes (PECs) were prepared by mixing aqueous solutions of chitosan (CS) and poly(L‐glutamic acid) (PLGA) at various pH. It was found that the stoichiometry of the PECs depends on pH. An investigation of the PECs using Fourier transform infrared spectroscopy proved that the formation of the complexes is due to electrostatic interaction between NH3+ groups of CS and COO− groups of PLGA. The solid PECs were characterized using wide‐angle X‐ray diffraction, which suggested that a strong interaction occurs between the two polymers at pH = 4 or 5 and relatively weak interaction at pH = 3. These results were further confirmed by thermogravimetric analysis data. Transmission electron microscopy showed that the complexes have a spherical shape. The effect of ionic strength on the size of the PECs was also studied using dynamic light scattering. It was found that the size of the PECs is dependent on pH. Copyright © 2007 Society of Chemical Industry
Proteomic characterization of copper stress response in Cannabis sativa roots
Authors: Bona Elisa , Marsano Francesco , Cavaletto Maria , Berta Graziella
Published: March 2007

Cannabis sativa is an annual herb with very high biomass and capability to absorb and accumulate heavy metals in roots and shoots; it is therefore a good candidate for phytoremediation of soils contaminated with metals. Copper is an essential micronutrient for all living organisms, it participates as an important redox component in cellular electron transport chains; but is extremely toxic to plants at high concentrations. The aim of this work was to investigate copper effects on the root proteome of C. sativa, whose genome is still unsequenced. Copper stress induced the suppression of two proteins, the down‐regulation of seven proteins, while five proteins were up‐regulated. The resulting differences in protein expression pattern were indicative of a plant adaptation to chronic stress and were directed to the reestablishment of the cellular and redox homeostasis.
A comprehensive proteome map of the lipid‐requiring nosocomial pathogen Corynebacterium jeikeium K411
Authors: Hansmeier Nicole , Chao Tzu‐Chiao , Daschkey Svenja , Müsken Mathias , Kalinowski Jörn , Pühler Alfred , Tauch Andreas
Published: March 2007

Corynebacterium jeikeium is a lipid‐requiring pathogen that is considered as part of the normal microflora of the human skin and associated with severe nosocomial infections. Systematic reference maps of the cytoplasmic, cell surface‐associated, and extracellular proteome fractions of the clinical isolate C. jeikeium K411 were examined by 2‐DE coupled with MALDI‐TOF MS. A sum total of 555 protein spots were identified by PMF, corresponding to 358 different proteins that were classified into functional categories and integrated into metabolic pathways. The majority of the proteins were linked to housekeeping functions in energy production and translation and to physiological processes in amino acid, carbohydrate, nucleotide, and lipid metabolism. A complete enzymatic machinery necessary to utilize exogenous fatty acids by β‐oxidation was detected in the cytoplasmic proteome fraction. In addition, several predicted virulence factors of C. jeikeium K411 were identified in the cell surface‐associated and extracellular subproteome, including the cell surface proteins SurA and SurB, the surface‐anchored pilus subunits SapA and SapB, the surface‐anchored collagen adhesin CbpA, the cholesterol esterase Che, and the acid phosphatase AcpA.
New polyphenylene‐ and polyphenylenevinylene‐based copolymers containing triarylpyrazoline units in the main chains
Authors: Peng Qiang , Li Mingjun , Tang Xinghua , Lu Shiqiang , Peng Junbiao , Cao Yong
Published: March 2007

Two novel polyphenylene and polyphenylenevinylene copolymers containing triarylpyrazoline units in the main chains were synthesized and characterized. The resulting copolymers were amorphous and showed excellent solubility in common organic solvents, such as dichloromethane, chloroform, 1,2‐dichloroethane, chlorobenzene, toluene, and THF. The polymers possessed good thermal stability with glass transition temperatures of 82 and 96 °C and decomposition onset temperatures of 295 and 309 °C, respectively. They exhibited good photoluminescence properties with high photoluminescence efficiencies. Double‐layered light‐emitting‐diode devices with an indium tin oxide/Poly(3,4‐ethylenedioxythiophene)/polymer/Ba/Al configuration could emit strong green light with external quantum efficiencies of0.53 and 0.92%. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1632–1640, 2007
Novel tobramycin inhalation powder in cystic fibrosis subjects: Pharmacokinetics and safety
Authors: Geller David E. , Konstan Michael W. , Smith Jeffrey , Noonberg Sarah B. , Conrad Carol
Published: March 2007

Aerosolized antibiotics are associated with a high treatment burden that can result in non‐adherence to chronic therapy. We evaluated the pharmacokinetics (PK) and safety of tobramycin inhalation powder (TIP), a novel dry‐powder formulation designed to deliver a high payload of tobramycin topically to the lungs for management of chronic Pseudomonas aeruginosa infections. This was a multi‐center, open‐label, sequential‐cohort, single‐dose, dose‐escalation study using the standard 300 mg dose of tobramycin solution for inhalation (TSI) as an active control. Subjects were randomized to TIP or TSI in a 3:1 ratio in each of five cohorts. Measurements included serum and sputum tobramycin concentrations, administration time, serum chemistries, acute change in lung function, and adverse events (AEs). Out of 90 randomized subjects, 86 had data for safety analysis; and 84 had data for PK analysis. Serum tobramycin PK profiles were similar for TIP and TSI. Four capsules of 28 mg TIP (total tobramycin dose 112 mg) produced comparable systemic exposure to 300 mg TSI, in less than one‐third the administration time. The most common AEs associated with TIP were cough (20%) and dysgeusia (17%). TIP allows for faster and more efficient pulmonary delivery of tobramycin than TSI and has a safety profile that supports continued clinical investigation. The increased rate of local respiratory tract irritation noted with TIP is not unexpected with a high‐payload powder formulation. The development of dry powder inhaled antibiotics may represent an important advance in the treatment of chronic lung infections. Pediatr Pulmonol. 2007; 42:307–313. © 2007 Wiley‐Liss, Inc.
Acute life threatening event (ALTE) in an infant with human coronavirus HCoV‐229E infection
Authors: Simon Arne , Völz Sebastian , Höfling Katja , Kehl Alexandra , Tillman Ramona , Müller Andreas , Kupfer Bernd , Eis‐Hübinger Anna‐Maria , Lentze Michael J. , Bode Udo , Schildgen Oliver
Published: March 2007

In this short report we discuss the temporal association between an acute life threatening event (ALTE) and a RT‐PCR confirmed coronavirus HCoV‐229E infection in a 4 months old otherwise healthy infant. More detailed microbiological investigations of affected children even without apparent signs of a respiratory tract infection may help to clarify the etiology in some patients and extend our understanding of the pathogenesis. PCR‐based techniques should be utilized to increase the sensitivity of detection for old and new respiratory viral pathogens in comparable cases. Pediatr Pulmonol. 2007; 42:393–396. © 2007 Wiley‐Liss, Inc.
The discovery of biomarkers for type 2 diabetic nephropathy by serum proteome analysis
Authors: Cho Eun‐Hee , Kim Mi‐Ryung , Kim Hyun‐Jung , Lee Do‐Yeon , Kim Pan‐Kyeom , Choi Kyung Mook , Ryu Ohk‐Hyun , Kim Chan‐Wha
Published: March 2007

Diabetic nephropathy (DN) is a serious kidney complication of diabetes, and constitutes the leading cause of end‐stage renal disease. The earliest clinical evidence of DN is microalbuminuria, a term which refers to the appearance of small but abnormal amounts of albumin in the urine. However, screening methods for DN, such as biomarker assays, are yet to be developed for type 2 DN. In the present study, in an attempt to identify the biomarkers for initial diagnoses of type 2 DN, the protein profiles of human sera collected from 30 microalbuminuric type 2 diabetic patients were compared with those collected from 30 normoalbuminuric type 2 diabetic patients, via 2‐DE. As a result, a total of 18 spots were determined to have different protein levels in the microalbuminuric patients. Twelve spots had lower protein levels of approximately 50%, and the other six had higher levels of approximately 100–300% as compared to the spots of normoalbuminuric patients. These spots were identified with ESI‐Q‐TOF (ESI‐quadrupole‐TOF) MS. Among the identified proteins, vitamin D‐binding protein (DBP) and pigment epithelium‐derived factor (PEDF) were verified by Western blotting. The results of this study indicate that the DBP may be employed as diagnostic and monitoring biomarkers of type 2 DN, contingent on further study into the matter.
Anticancer effects of aloe‐emodin on HepG2 cells: Cellular and proteomic studies
Authors: Lu Guo Dong , Shen Han‐Ming , Ong Choon Nam , Chung Maxey C. M.
Published: March 2007

Aloe‐emodin (AE) is one of the main bioactive anthraquinones of Rheum palmatum, a widely used herbal medicine. Several recent studies suggested that AE possesses potent anticancer properties, although the mechanisms are yet to be fully elucidated. The present study aimed to identify the molecular targets of AE in a human hepatocellular carcinoma cell line, HepG2. We first found that AE was more cytotoxic and effective in inducing apoptosis and cell cycle arrest than its analog emodin (EM). Proteomic study using 2‐D DIGE revealed that AE affected multiple proteins associated with oxidative stress, cell cycle arrest, antimetastasis, and hepatitis C virus replication. For example, peroxiredoxins (PRDX) and DJ‐1, both of which are redox‐sensitive proteins, were among those markedly up‐regulated, suggesting the presence of oxidative stress in AE‐treated cells. Further biochemical studies demonstrated that AE enhanced the intracellular level of reactive oxygen species and oxidation of PRDX‐2, ‐4, and DJ‐1. In addition, AE inhibited DNA synthesis via up‐regulation of the CDK4 inhibitor p16 and inhibition of Rb phosphorylation. Furthermore, AE was able to decrease cell migration via up‐regulation of the metastasis inhibitor, nm23. Taken together, AE induced anticancer effects in HepG2 cells via multiple pathways by affecting different protein targets.
Highlights of the first BSPR London Regional Meeting and Fifth Imperial Proteomics Day
Authors: Nagy Judit M.
Published: March 2007

Now that the genomics revolution is tailing off proteomics promises an even more radical transformation of biological and medical research. Ultimately, the clues to the mysteries of biological processes will lye within the proteins present at a given time. Proteomics, the characterization of complex protein mixtures, builds on a wide range of expertise from protein chemistry to mass spectrometry and bioinformatics. Each step from sample preparation, high resolution protein separation to protein identification is underpinned by the latest technological developments in protein separation and mass spectrometry and supported by powerful computational image and data analysis algorithms which requires large scale data management and storage facilities. The success of proteomics depends on further developments in technology which need a wide range of scientific expertise. This meeting, the first BSPR London Regional Meeting, brought together scientists from a broad background who share a common interest in novel solutions for the characterization of complex protein mixtures.