bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of veratrine on skeletal muscle mitochondria: Ultrastructural, cytochemical, and morphometrical studies
Authors: Freitas Erika Maria Silva , Fagian Márcia M. , Höfling Maria Alice Da Cruz 
Published: February 2006

AbstractThe alkaloid veratrine is a lipid‐soluble neurotoxin, which target voltage‐gated Na+ channels for their primary action. Recently, we showed that this alkaloid may cause myonecrosis and evidences suggest mitochondria as one of its cell targets. Herein, we investigate the effects caused by variable concentration of veratrine (250 and 550 μg/mL) on mitochondrial oxygen consumption, respiratory chain enzymes activities, and ultrastructure, combining electron microscopy with cytochemical and biochemical approaches. The results showed different sort of ultrastructural changes, both in isolated and intramuscular mitochondria. Veratrine decreased mitochondrial nicotinamide adenine dinucleotide dehydrogenase (NADH‐d), succinic dehydrogenase (SDH), and cytochrome oxidase (COX) activities, significantly and dose‐dependently inhibited the state 3 respiration rate, respiratory control ratio (RCR), and ADP/O on isolated rat skeletal muscle mitochondria, whereas state 4 was unaffected. A tendency of increase in mitochondria diameter was seen with 250 μg/mL veratrine. We conclude that the alkaloid would probably act on mitochondrial membrane phospholipid configuration, which would explain the changes observed. Microsc. Res. Tech. 69:108–118, 2006. © 2006 Wiley‐Liss, Inc.
Waking‐up the sleeping beauty: recovery of the ancestral bird odontogenic program
Authors: Mitsiadis Thimios A. , Caton Javier , Cobourne Martyn 
Published: February 2006

AbstractRecent advances in molecular and developmental genetics have provided tools for understanding evolutionary changes in the nature of the epithelial–mesenchymal interactions regulating the patterned outgrowth of the tooth primordia. Tissue recombination experiments in mice have identified the oral epithelium as providing the instructive information for the initiation of tooth development. Teeth were lost in birds for more than 80 million years ago, but despite their disappearance, a number of gene products and the requisite tissue interactions needed for tooth formation are found in the avian oral region. It is believed that the avian ectomesenchyme has lost the odontogenic capacity, whilst the oral epithelium retains the molecular signaling required to induce odontogenesis. In order to investigate the odontogenic capacity of the neural crest‐derived mesenchyme and its potential activation of the avian oral epithelium, we have realized mouse neural tube transplantations to chick embryos to replace the neural crest cells of chick with those of mouse. Teeth are formed in the mouse/chick chimeras, indicating that timing is critical for the acquisition of the odontogenic potential by the epithelium and, furthermore, suggesting that odontogenesis is initially directed by species‐specific mesenchymal signals interplaying with common epithelial signals. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
Effect of Gd‐DTPA‐BMA on blood and myocardial T1 at 1.5T and 3T in humans
Authors: Sharma Puneet , Socolow Josh , Patel Salil , Pettigrew Roderic I. , Oshinski John N. 
Published: February 2006

AbstractPurposeTo compare T1 values of blood and myocardium at 1.5T and 3T before and after administration of Gd‐DTPA‐BMA in normal volunteers, and to evaluate the distribution of contrast media between myocardium and blood during steady state.Materials and MethodsTen normal subjects were imaged with either 0.1 mmol/kg (N = 5) or 0.2 mmol/kg (N = 5) of Gd‐DTPA‐BMA contrast agent at 1.5T and 3T. T1 measurements of blood and myocardium were performed prior to contrast injection and every five minutes for 35 minutes following contrast injection at both field strengths. Measurements of biodistribution were calculated from the ratio of ΔR1 (ΔR1myo/ΔR1blood).ResultsPrecontrast blood T1 values (mean ± SD, N = 10) did not significantly differ between 1.5T and 3T (1.58 ± .13 sec, and 1.66 ± .06 sec, respectively; P > 0.05), but myocardium T1 values were significantly different (1.07 ± .03 sec and 1.22 ± .07 sec, respectively; P < 0.05). The field‐dependent difference in myocardium T1 postinjection (T1@3T – T1@1.5T) decreased by approximately 72% relative to precontrast T1 values, while the field‐dependent difference of blood T1 decreased only 30% postcontrast. Measurements of ΔR1myo/ΔR1blood were constant for 35 minutes postcontrast, but changed between 1.5T and 3T (0.46 ± .06 vs. 0.54 ± .06, P < 0.10).ConclusionT1 is significantly longer for myocardium (but not blood) at 3T compared to 1.5T. The differences in T1 due to field strength are reduced following contrast administration, which may be attributed to changes in ΔR1myo/ΔR1blood with field strength. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Partial‐volume model for determining white matter and gray matter cerebral blood volume for analysis of gliomas
Authors: Lee Michael C. , Cha Soonmee , Chang Susan M. , Nelson Sarah J. 
Published: February 2006

AbstractPurposeTo model the partial voluming of gray matter (GM) and white matter (WM) in perfusion imaging, and to use this model to estimate the cerebral blood volume (CBV) of pure WM and GM, which could then be used to normalize data across patients in preparation for analyzing tumor perfusion.Materials and MethodsDynamic susceptibility contrast (DSC) perfusion imaging was performed on 20 glioma patients. The perfusion data were registered to the T1 image using rigid‐body and non‐rigid algorithms. The rCBV for each voxel was computed by gamma‐variate fitting and then fit as a linear function of the estimated fractional WM content. The estimated CBV of pure WM was used to normalize across patients, and the resulting tumor CBV values were compared with expectations.ResultsRigid registration improved the correlation between the fractional WM content and CBV for all patients, with non‐rigid registration yielding further improvements for all but two patients. The mean GM‐to‐WM CBV ratio was estimated at 2.15 ± 0.33 (mean ± SD). Voxels that exhibited both T1‐Gd contrast enhancement and an abnormal proton spectrum were found to have a CBV 2.53 ± 0.89 times higher than that in the WM.ConclusionA partial‐volume model is demonstrated for estimating pure WM and GM CBV. It is also shown that the relationship between the tumor CBV as estimated with this model is generally consistent with expectations based on spectroscopy and imaging. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Papillary renal carcinoma: Diagnostic approach by chemical shift gradient‐echo and echo‐planar MR imaging
Authors: Yoshimitsu Kengo , Kakihara Daisuke , Irie Hiroyuki , Tajima Tsuyoshi , Nishie Akihiro , Asayama Yoshiki , Hirakawa Masakazu , Nakayama Tomohiro , Naito Seiji , Honda Hiroshi 
Published: February 2006

AbstractPurposeTo elucidate whether MRI can detect fat in interstitial histiocytes and hemosiderin (Hs) deposition (both of which are histological characteristics of papillary renal carcinoma (RCpap)) within RCpap.Materials and MethodsPreoperative MR images of nine surgically confirmed RCpap and 57 clear cell renal carcinoma (RCcc) cases were retrospectively studied. Solid components of the lesions were evaluated. For fat detection, signal reduction on opposed‐phase images of chemical shift MRI (CSI) was used. For Hs detection, signal reduction on echo‐planar images or in‐phase images of CSI was used. The prevalence of fat and Hs detection was compared between RCpap and RCcc.ResultsIn five of nine RCpap (54%), and 38 of 57 RCcc (67%), the presence of fat within the tumor was suggested by CSI (P = 0.71). Hs deposition within tumors was suggested by either EPI or CSI in nine of nine RCpap (100%), and 28 of 57 RCcc (51%) (P = 0.0036). Hs in RCpap was observed without or apart from necrosis or hemorrhage, whereas Hs in RCcc was located predominantly around necrosis.ConclusionDetecting intratumoral Hs by EPI or CSI, particularly that unrelated to necrosis or hemorrhage, may help differentiate RCpap from RCcc. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Elimination of residual blood flow‐related signal in 3D volume‐selective TSE arterial wall imaging using velocity‐sensitive phase reconstruction
Authors: Crowe Lindsey A. , Varghese Anitha , Mohiaddin Raad H. , Yang Guang Zhong , Firmin David N. 
Published: February 2006

AbstractPurposeTo improve 3D volume‐selective turbo spin–echo (TSE) arterial wall imaging by introducing velocity phase sensitivity to the sequence.Materials and MethodsSlow or recirculating blood may give incomplete nulling in 3D vessel wall imaging, hindering differentiation between arterial wall and lumen. Reconstructed phase images are used to reduce the residual blood signal with postprocessing. A volume‐selective 3D TSE (1) sequence with increased velocity sensitivity perpendicular to the slab was developed. Sensitivity was introduced by modifying the gradient waveforms such that residual signal from slow or recirculating blood is distinguished from the wall by the phase shift introduced. This was tested on a pulsatile flow phantom and the carotid artery wall of six healthy volunteers and 17 patients. Images were acquired on a Siemens Magnetom Sonata 1.5T scanner. A quantitative comparison of the lumen/wall contrast was made using images acquired with and without modification.ResultsVelocity sensitivity produces significantly reduced residual signal by intravoxel dephasing. Phantom “lumen/tissue” contrast improved by 0.10 (P < 0.01), with a similar change in vivo (0.69–0.73, P < 0.01). Postprocessing removal of the blood signal using phase signal provided further improvement.ConclusionIntroducing velocity sensitivity reduces unwanted, potentially misleading residual blood in 3D volume‐selective vessel wall imaging. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Subacute sclerosing panencephalitis: Relationship between clinical stage and diffusion‐weighted imaging findings
Authors: Alkan Alpay , Korkmaz Levent , Sigirci Ahmet , Kutlu Ramazan , Yakinci Cengiz , Erdem Gulnur , Yologlu Saim 
Published: February 2006

AbstractPurposeTo investigate the relationship between clinical stages and apparent diffusion coefficient (ADC) changes in the brain of patients with subacute sclerosing panencephalitis (SSPE).Materials and MethodsA total of 18 patients with stage II (N = 11) and III (N = 7) SSPE and 11 age‐matched controls underwent routine MRI and diffusion‐weighted imaging (DWI). The ADC values were automatically calculated. Seven distinct neuroanatomic structures (frontal, parieto‐occipital, and cerebellar white matter; deep white matter; thalamus; basal ganglia; and brainstem) were selected for analysis in the patient and control groups.ResultsHyperintensities in the periventricular and subcortical white matters on T2‐weighted images and ADC maps were detected in 63.6% of patients with stage II and in all patients with stage III. There were significant differences between stage II and III patients and also between patients and control group in ADC values that obtained from all locations. The highest mean ADC values were calculated in stage III patients. Although MRI and DWI findings were normal in four patients with stage II disease, ADC values were significantly increased when compared with controls.ConclusionThe stage of disorder may be independent of DWI appearance during the early stage (stages I and II), even though the brain is affected. Therefore, DWI and ADC values supplemental to routine MRI should also be utilized for lesion detection and definition to enhance diagnostic accuracy in patients with SSPE. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Improved temporal clustering analysis method for detecting multiple response peaks in fMRI
Authors: Lu Na , Shan Bao‐Ci , Li Ke , Yan Bin , Wang Wei , Li Kun‐Cheng 
Published: February 2006

AbstractPurposeTo develop an improved temporal clustering analysis (TCA) method for detecting multiple active peaks by running the method once.Materials and MethodsTwo cases of simulation data and a set of actual fMRI data from nine subjects were used to compare the traditional TCA method with the new method, termed extremum TCA (ETCA). The first case of simulation data simulated event‐related activation and block activation in one cerebral area, and the second case simulated event‐related activation and block activation in two cerebral areas. An in vivo visual stimulating experiment was performed on a 1.5T MR scanner. All imaging data were processed using both traditional TCA and the new method.ResultsThe results of both the simulated and actual fMRI data show that the new method is more sensitive and exact than traditional TCA in detecting multiple response peaks.ConclusionThe new method is effective in detecting multiple activations even when the timing and location of the brain activation are completely unknown. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Effect of experimental suprascapular nerve block on active glenohumeral translations in vivo
Authors: Werner Clément M. L. , Weishaupt Dominik , Blumenthal Stephan , Curt Armin , Favre Philippe , Gerber Christian 
Published: February 2006

AbstractStatic superior shoulder instability is associated with long‐standing rotator cuff tears. Factors or mechanisms which can prevent superior migration of the humeral head, and therefore allow preservation or restoration of shoulder function despite nonanatomical cuff repair, are poorly understood. The question has therefore arisen, whether centering of the humeral head was the result of active shoulder muscle function. It was the goal of this experimental investigation to (1) determine the pattern of glenohumeral translations during active shoulder abduction measured by open‐magnetic resonance imaging (MRI) techniques, and to (2) determine the influence of experimental paralysis of the infra‐ and supraspinatus muscles on these translations. In contrast to prior experimental investigations, the humeral head remained always centered in the glenoid fossa during active abduction. No superior migration of the humeral head could be provoked with experimental paralysis of the supra‐ and/or infraspinatus muscles. The hypothesis that static or dynamic superior humeral head displacement is prevented by active‐supra‐ and/or infraspinatus muscle function must therefore be rejected, for the shoulder with a structurally intact muscle–tendon–bone unit. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:491–500, 2006
Nonweight‐bearing anterior knee laxity is related to anterior tibial translation during transition from nonweight bearing to weight bearing
Authors: Shultz Sandra J. , Shimokochi Yohei , Nguyen Anh‐Dung , Ambegaonkar Jatin P. , Schmitz Randy J. , Beynnon Bruce D. , Perrin David H. 
Published: February 2006

AbstractWe examined the relationship between anterior knee laxity (AKL), evaluated while the knee was nonweight bearing, and anterior translation of the tibia relative to the femur (ATT), evaluated when the knee transitioned from nonweight‐bearing to weight‐bearing conditions in response to an applied compressive load at the foot. Twenty subjects with normal knees (10 M, 10 F; 25.2 ± 4.1 years, 169.8 ± 11.5 cm, 71.6 ± 16.9 kg) underwent measurements of AKL and ATT of the right knee on 2 days. AKL was measured at 133N with the KT‐2000™. ATT was measured with the Vermont Knee Laxity Device and electromagnetic position sensors attached to the patella and the anteromedial aspect of the proximal tibia. Three trials for each measure were averaged and analyzed. Measurement consistency was high for both AKL (ICC = 0.97; SEM = 0.44 mm) and ATT (ICC = 0.88; SEM = 0.84 mm). Linear regression revealed that AKL predicted 35.5% of the variance in ATT (p = 0.006), with a prediction equation of YATT = 3.20 + 0.543(XAKL). Our findings suggest that increased AKL is associated with increased ATT as the knee transitions from nonweight‐bearing to weight‐bearing conditions. The potential for increased knee joint laxity to disrupt normal knee biomechanics during activities such as landing from a jump, or the foot strike phase of gait deserves further study. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:516–523, 2006
Cells seeded on MBG scaffold survive impaction grafting technique: Potential application of cell‐seeded biomaterials for revision arthroplasty
Authors: Mushipe Moses T. , Chen Xi , Jennings David , Li Gang 
Published: February 2006

AbstractThe objective of this study was to investigate the potential application of cell‐seeded biomaterials for revision arthroplasty and the reconstruction of major joints using the impaction grafting technique. Using morselized cancellous bone graft as a porous scaffold, MG63 cells were seeded on the scaffold and impacted into an acetabulum cup model using a mechanical device constructed from data obtained during impaction grafting by an orthopedic surgeon. Immediately after impaction, cells were trypsinized from the scaffold and processed for cell survival rates using the double‐stranded DNA PicoGreen® assay. Significant reductions in viable cells were observed between the fifth impact and both the first and second impacts ( p < 0.01 and p < 0.05, respectively). Cell survival rate was 21.5% after five impacts. The biological performance of cell‐seeded biomaterials may be enhanced by these surviving cells. Compared to allograft bone that is not osteogenic, a cell‐seeded biomaterial might also be a suitable substitute for allograft bone for major joint reconstruction at revision arthroplasty. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:501–507, 2006
The role of M. popliteus in unpredictable and in self‐initiated balance provocations
Authors: Stensdotter Ann‐Katrin , Holmgren Christer , Dalén Tore , Häger‐Ross Charlotte 
Published: February 2006

AbstractThe purpose of this study was to determine whether m. popliteus (POP) activity would contribute to the control of knee joint position in unpredictable and in self‐initiated provocations of standing balance. Ten healthy women (age 25.2 ± 4.5 years, means and SD) without known knee pathology were tested for postural reactions (1) to unpredictable support surface translations in anterior and posterior directions, and (2) in self‐initiated balance provocations in a reaction time (RT) forward reach‐and‐grip task. Electromyographic activity was recorded from POP and other leg muscles plus the deltoid muscle. Three‐dimensional kinematics were captured for the knee joint and the body centre of mass was calculated. POP was active first of all the muscles recorded, regardless of translation direction, and knee joint movements elicited were either knee extension or external rotation of the tibia. In the RT task, the POP was active after initiation of reaching movement, and there was little consistency in the kinematic response. POP activity was not direction specific in response to support surface translation, but appeared triggered from reactive knee joint movement. The response to the support‐surface translation suggests that POP served to control knee joint position rather than posture. In the RT task, we could not deduce whether POP activity was attributed to knee joint control or to postural control. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:524–530, 2006
Characteristics of the rat supraspinatus tendon during tendon‐to‐bone healing after acute injury
Authors: Galatz Leesa M. , Sandell Linda J. , Rothermich Stefan Y. , Das Rosalina , Mastny Ava , Havlioglu Necat , Silva Matthew J. , Thomopoulos Stavros 
Published: February 2006

AbstractRotator cuff repair is known to have a high failure rate. Little is known about the natural healing process of the rotator cuff repair site, hence little can be done to improve the tendon's ability to heal. The purpose of this study was to investigate the collagen formation at the early repair site and to localize TGFβ‐1 and 3 during early healing and compare their levels to cell proliferation and histological changes. Bilateral supraspinatus tendons were transected and repaired in 60 rats. Specimens were harvested and evaluated at 0, 1, 3, 7, 10, 28, and 56 days. Histological sections were evaluated for cell morphology. Immunohistochemistry and in situ hybridization was performed to localize protein and mRNA for collagen types I and III and TGFβ‐1 and 3. Proliferating cell nuclear antigen (PCNA) assay was performed to measure cell proliferation, and cells were counted to determine cell density. Biomechanical properties were evaluated. Repair tissue demonstrated an initial inflammatory response with multinucleated cells present at 1 and 3 days, and lymphocytes and plasma cells presents at 7 and 10 days. Capillary proliferation began at 3 days and peaked at 10 days. Ultimate force increased significantly over the time period studied. Collagen I protein and mRNA significantly increased at 10 days, and reached a plateau by 28 and 56 days. Collagen III showed a similar trend, with an early increase, and remained high until 56 days. TGFβ‐1 was localized to the forming scar tissue and showed a distinct peak at 10 days. TGFβ‐3 was not seen at the healing insertion site. Cell proliferation and density followed the same trend as TGFβ‐1. A wound healing response does occur at the healing rotator cuff insertion site, however, the characteristics of the tendon after healing differ significantly from the uninjured tendon insertion site at the longest time‐point studied. A distinctive collagen remodeling process occurred with an initial increase in the formation of collagen types I and III followed by a decrease toward baseline levels seen at time 0. Growth factor TGFβ‐1 was localized to repair tissue and coincided with a peak in cell proliferation and cellularity. Repair sites remained unorganized histologically and biomechanically inferior in comparison to previously described uninjured insertion sites.. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:541–550, 2006
Determination and removal of impurities in 2‐D LC‐MS of peptides
Authors: Mihailova Albena , Lundanes Elsa , Greibrokk Tyge 
Published: February 2006

AbstractProblems occurring during operation of a 2‐D LC‐MS system for separation and identification of neuropeptides, such as contamination of the used salts and column bleed, are described. When using polysulfoethyl aspartamide, which is widely used as a strong cation exchange stationary phase in the first dimension, interfering peaks were observed in the second‐dimension reversed‐phase chromatograms. The observed peaks, found to be caused by column bleeding, had abundance above the threshold value and influenced the quality of the analyses. The origin of the peaks was verified and appropriate measures are proposed. Additionally, peaks caused by polyethylene glycols (PEGs), covering approximately 5 min of feasible chromatographic time in every fraction, were observed. The commercial ammonium formate salts used to prepare the first‐dimension mobile phase were found to contain PEG impurities, and in subsequent work the salt solutions were prepared from formic acid and ammonia to avoid any additional contaminations.