bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of the encephalitogenic immune response in a model of multiple sclerosis
Authors: de Graaf Katrien L. , Barth Silvia , Herrmann Martin M. , Storch Maria K. , Wiesmüller Karl‐Heinz , Weissert Robert
Published: November 2007

Experimental autoimmune encephalomyelitis (EAE) can be actively induced with the extracellular domain of myelin oligodendrocyte glycoprotein (MOG 1–125). MOG‐EAE closely mimics multiple sclerosis (MS) especially as far as demyelination, lesion formation and axonal pathology are concerned. MOG 91–108 is the encephalitogenic stretch within MOG 1–125 in two EAE‐susceptible MHC congenic LEW rat strains [LEW.1AV1 (RT1av1) and LEW.1N (RT1n)] and DA (RT1av1) rats. In LEW.1AV1 rats, disease could be induced with MOG 96–104 and to a lesser extent with MOG 98–106, whereas in LEW.1N rats, only MOG 98–106 was pathogenic. Both peptides bound well to their restricting MHC class II molecules, i.e., RT1.Dn in the LEW.1N rat and RT1.Ba in the LEW.1AV1 rat. TCR spectratyping of MOG 91–108 immunized LEW.1N, LEW.1AV1 and DA rats revealed that MHC class II determined the TCRBV preference of CNS infiltrating T cells. The data demonstrate that the most critical factor in inducing MS like pathology is presentation of autoantigenic peptides on MHC class II molecules resulting in demyelination and axonal pathology.
Structural Diversity and Modulation of Coordination Architectures with Flexible Dithioether or Disulfoxide Ligands
Authors: Li Jian‐Rong , Bu Xian‐He
Published: November 2007

Metal complexes of flexible dithioether and disulfoxide ligands are briefly reviewed, focusing on the structural investigations based on X‐ray crystallographic analyses. Recent investigations from our laboratory have produced compelling experimental evidence that flexible dithioether and disulfoxide ligands exhibit rich coordination chemistry towards metal ions and have great potential in constructing metal complexes with diverse structures. The design and synthesis of the ligands and their complexes are described. A wide variety of crystal structures of mononuclear, discrete multinuclear complexes and coordination polymers are classified by their assembling fashions, and the coordination modes of the two types of ligands are summarized. Series of structurally related ligands with varied spacer lengths or terminal groups were systematically used to coordinate the same metal ion in similar reaction conditions to afford complexes with different structures, indicating that the spacer lengths and terminal groups of ligands have important effects on the structures of the complexes. Using the same ligand to coordinate with different metal ions gave distinct complexes, showing the influences of the affinity and geometry of metal ions on the structures of the complexes. In addition, varying the anions, the solvent used, and the ratio of reactants in synthesis also led to the formation of complexes with different structures. These results present a feasible way to control the structures of complexes with these or other ditopic flexible ligands by modifying the ligands, selecting metal ions, as well as adjusting reaction conditions, which has been regarded as a long‐time challenge in engineering metal–organic coordination architectures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Response Mechanism of Ion‐Selective Electrodes Based on a Guanidine Ionophore: An Apparently ‘Two‐Thirds Nernstian’ Response Slope
Authors: Koseoglu Secil S. , Lai Chun‐Ze , Ferguson Chad , Bühlmann Philippe
Published: November 2007

While ion‐selective electrodes (ISEs) based on anion ionophores with guanidine groups were reported in the past, their response mechanism was poorly understood. In this study, an ionophore with one guanidine group was prepared as a model compound, and the chloride and sulfate responses of ISE membranes containing this ionophore were investigated. The electrodes exhibit Nernstian responses resulting from a neutral or charged ionophore mode when added cationic or anionic sites are used, respectively. Based on this observation, it might be expected that membranes without added ionic sites exhibit Nernstian responses according to a charged carrier mechanism. However, experimental results show an apparently ‘two–thirds Nernstian’ equilibrium response, which can be explained on the basis of the phase boundary model.
Aberrant splicing of the PTPRD gene mimics microdeletions identified at this locus in neuroblastomas
Authors: Nair Prakash , DePreter Katleen , Vandesompele Jo , Speleman Frank , Stallings Raymond L.
Published: November 2007

Neuroblastoma (NBL), a pediatric tumor arising from precursor cells of the sympathetic nervous system, is characterized by numerous recurrent large‐scale chromosomal imbalances. High resolution oligonucleotide array CGH analysis of NBL has previously identified microdeletions that are confined to the 5′ UTR of the protein tyrosine phosphatase receptor D (PTPRD) gene, implicating this gene in the pathogenesis of these tumors. Here, we demonstrate that the 5′ UTR of this gene, consisting of 11 noncoding exons, is also aberrantly spliced in >50% of NBL primary tumors and cell lines. The loss of exons from the 5′ UTR region through aberrant splicing results in aberrant mRNA isoforms that are similar to those generated through microdeletions. The aberrant splicing or microdeletion of 5′ UTR exons in such a high proportion of tumors indicates that loss of these exons dys‐regulates the mRNA sequence. To further validate the role of PTPRD in NBL, we have examined the expression of this gene in normal fetal adrenal neuroblasts (the cell of origin of NBL) and in tumors from patients with either low stage or high stage disease. This gene is expressed at lower levels in high stage NBL tumors, particularly those with amplification of MYCN, relative to low stage tumors or normal fetal adrenal neuroblasts, consistent with the possibility that loss of the 5′ UTR exons have destabilized the mRNA. © 2007 Wiley‐Liss, Inc.
Comprehensive analysis of loss of heterozygosity events in glioblastoma using the 100K SNP mapping arrays and comparison with copy number abnormalities defined by BAC array comparative genomic hybridization
Authors: Lo Ken C. , Bailey Dione , Burkhardt Tania , Gardina Paul , Turpaz Yaron , Cowell John K.
Published: November 2007

We have undertaken an extensive high‐resolution analysis of loss of heterozygosity (LOH) in 30 high grade gliomas using the Affymetrix 100K SNP mapping array. Only 70% of LOH events were accompanied by a copy number loss (CNAloss), and of the other 30%, the distal region of 17p preferentially showed copy number neutral (CNN)‐associated LOH. Combined analysis of CNAloss and LOH using MergeLevels analysis software predicts whether the observed losses occurred on a diploid or tetraploid background. In a side‐by‐side comparison between SNP and bacterial artificial chromosome (BAC) arrays, the overall identification of CNAs was similar on both platforms. The resolution provided by the SNP arrays, however, allowed a considerably more accurate definition of breakpoints as well as defining small events within the cancer genomes, which could not be detected on BAC arrays. CNN LOH was only detected by the SNP arrays, as was ploidy prediction. From our analysis, therefore, it is clear that simultaneously defining CNAs and CNN‐LOH using the SNP platform provides a higher resolution and more complete analysis of the genetic events that have occurred within tumor cells. Our extensive analysis of SNP array data has also allowed an objective assessment of threshold LOH scores that can accurately predict LOH. This capability has important implications for interpretation of LOH events since they have consistently been used to localize potential tumor suppressor genes within the cancer genome. © 2007 Wiley‐Liss, Inc.
The association between activity participation and time to discharge in the assisted living setting
Authors: Tighe Sarah K. , Leoutsakos Jeannie‐Marie S. , C. Carlson Michelle , Onyike Chiadi U. , Samus Quincy , Baker Alva , Brandt Jason , Rabins Peter V. , Mayer Lawrence , Rosenblatt Adam , Lyketsos Constantine G.
Published: November 2007

Objectives

Given recent evidence that activity participation may reduce functional decline, the effect of activity on resident ability to remain in assisted living (AL) is of interest. This study examines the relationship between participation in activities and the length of time residents remain in AL.

Methods

The data reported here were gathered in the initial phase of the Maryland Assisted Living Study (MDAL), an epidemiologic study of psychiatric disorders in AL. A stratified, random sample of 198 residents of 22 AL facilities in central Maryland was evaluated using a number of cognitive, behavioral, general health, and functional assessments. The total amount of time each resident spent in group and solitary activity in the prior month was quantified. The dependent variable, time to discharge (TTD), was the number of days between the date of initial assessment by the study team and the date of death in AL, discharge, or administrative censoring.

Results

Greater levels of activity participation at baseline are associated with longer TTD in an univariate Cox proportional hazards model. After adjustment for global cognitive functioning, general medical health, and mobility, greater activity participation remained associated with longer TTD in AL (p = 0.017).

Conclusions

Higher levels of activity are associated with longer retention in the AL setting. This effect appeared to be independent of other potentially confounding factors such as general health, cognitive impairment, and mobility. This finding is consistent with the hypothesis that engagement in activities delays functional decline, but further longitudinal research is needed to understand this finding. Copyright © 2007 John Wiley & Sons, Ltd.
Impact of late‐life self‐reported emotional problems on Disability‐Free Life Expectancy: results from the MRC Cognitive Function and Ageing Study
Authors: Pérès Karine , Jagger Carol , Matthews Fiona E
Published: November 2007

Objectives

Depression in old age is a major public health problem though its relationship to onset of disability and death is not well understood. We aim to quantify the impact of late‐life self‐reported depression and emotional problems on both the length and quality of remaining life.

Methods

Longitudinal analysis of 11,022 individuals from the MRC Cognitive Function and Ageing Study (MRC CFAS), multi‐centre longitudinal study on ageing in individuals age 65 years and older living in England and Wales. Individuals have been followed at intermittent time intervals over 10 years. Subjects reporting at baseline that they had consulted about emotional problems for the first time since the age of 60 years were considered, along with a subgroup where a GP suggested depression. Disability was defined as an IADL or ADL disability that required help at least once a week. Total and Disability‐Free Life Expectancy (TLE and DFLE) were calculated using multi‐state models, separately by gender, and with presence of emotional problems/depression and multimorbidity as covariates.

Results

Emotional problems had a greater impact on DFLE than TLE, reducing DFLE by 1.8 years, but TLE by only 0.5 years at age 65 with the effect increasing with age. The effect was most marked in older people reporting other co‐morbidities where emotional problems in addition resulted in a reduction of 0.9 years in total and 2.6 years disability‐free.

Conclusions

Although emotional problems were only self‐reported, these results highlight the burden of late‐life depression on the quality of remaining years of life. Copyright © 2007 John Wiley & Sons, Ltd.
The presence of high‐risk chromosome aberrations in chronic lymphocytic leukaemia does not correlate with centrosome aberrations
Authors: Ottaggio Laura , Zunino Annalisa , Maric Irena , Grozio Alessia , Rossi Edoardo , Spriano Mauro , Viaggi Silvia
Published: November 2007

Chromosome aberrations are frequently found in B‐cell chronic lymphocytic leukaemia (B‐CLL), and specific chromosome aberrations identify poor prognostic subgroups. Almost all the aberrations identified in B‐CLL involve loci where genes with a role in the regulation of centrosome duplication have been mapped. Centrosome aberrations have been described as a possible cause of numerical chromosome abnormalities in both solid and haematological tumours. However, little is known about the possible role of centrosome aberrations in B‐CLL. To investigate whether centrosome aberrations do occur in B‐CLL and correlate with cytogenetically defined prognostic subgroups, we examined a set of 64 B‐CLL samples by immunofluorescent staining. B‐CLL cases differed significantly from controls in the mean frequency of cells with centrosome aberrations, while no difference was found between subgroups with or without specific chromosome aberrations. Our results indicated that although centrosome aberrations were a common feature in B‐CLL, they did not represent a reliable prognostic marker. Copyright © 2007 John Wiley & Sons, Ltd.
Hospital costs estimation and prediction as a function of patient and admission characteristics
Authors: Ramiarina Robert , Almeida Renan MVR , Pereira Wagner CA
Published: November 2007

The present work analyzed the association between hospital costs and patient admission characteristics in a general public hospital in the city of Rio de Janeiro, Brazil. The unit costs method was used to estimate inpatient day costs associated to specific hospital clinics. With this aim, three “cost centers” were defined in order to group direct and indirect expenses pertaining to the clinics. After the costs were estimated, a standard linear regression model was developed for correlating cost units and their putative predictors (the patients gender and age, the admission type (urgency/elective), ICU admission (yes/no), blood transfusion (yes/no), the admission outcome (death/no death), the complexity of the medical procedures performed, and a risk‐adjustment index). Data were collected for 3100 patients, January 2001–January 2003. Average inpatient costs across clinics ranged from (US$) 1135 [Orthopedics] to 3101 [Cardiology]. Costs increased according to increases in the risk‐adjustment index in all clinics, and the index was statistically significant in all clinics except Urology, General surgery, and Clinical medicine. The occupation rate was inversely correlated to costs, and age had no association with costs. The (adjusted) per cent of explained variance varied between 36.3% [Clinical medicine] and 55.1% [Thoracic surgery clinic]. The estimates are an important step towards the standardization of hospital costs calculation, especially for countries that lack formal hospital accounting systems. Copyright © 2007 John Wiley & Sons, Ltd.
Extending social health insurance to the informal sector in Kenya. An assessment of factors affecting demand
Authors: Mathauer Inke , Schmidt Jean‐Olivier , Wenyaa Maurice
Published: November 2007

This paper contributes to analysing and understanding the demand for (social) health insurance of informal sector workers in Kenya by assessing their perceptions and knowledge of and concerns regarding health insurance and the Kenyan National Hospital Insurance Fund (NHIF). It serves to explore how informal sector workers could be integrated into the NHIF.

To collect data, focus group discussions were held with organized groups of informal sector workers of different types across the country, backed up by a self‐administered questionnaire completed by heads of NHIF area branch offices.

It was found that the most critical barrier to NHIF enrolment is the lack of knowledge of informal sector workers about the NHIF, its enrolment option and procedures for informal sector workers. Inability to pay is a critical factor for some, but people were, in principle, interested in health insurance, and thus willing to pay for it.

In sum, the mix of demand‐side determinants for enrolling in the NHIF is not as complex as expected. This is good news, as these demand‐side determinants can be addressed with a well‐designed strategy, focusing on awareness raising and information, improvement of insurance design features and setting differentiated and affordable contribution rates. Copyright © 2007 John Wiley & Sons, Ltd.
Low molecular weight hyaluronan shielding of DNA/PEI polyplexes facilitates CD44 receptor mediated uptake in human corneal epithelial cells
Authors: Hornof Margit , de la Fuente Maria , Hallikainen Marjut , Tammi Raija H. , Urtti Arto
Published: November 2007

Aim

It was the aim of this study to prepare purified DNA/PEI polyplexes, which are coated with hyaluronan to facilitate CD44 receptor mediated uptake of the DNA/PEI polyplex and to reduce unspecific interactions of the complex with negatively charged extracellular matrix components on the ocular surface.

Methods

Hyaluronans of different molecular weights (<10 kDa, 10–30 kDa and 30–50 kDa) were isolated after enzymatic degradation of high molecular weight hyaluronan via ultrafiltration by centrifugation. The influence of the different hyaluronans used for coating on the stability and transfection efficiency of the complexes was evaluated in vitro. Transfection and uptake studies were performed in human corneal epithelial (HCE) cells. CD44 receptor expression of this cell model was evaluated by immunohistochemistry.

Results

Coating of purified DNA/PEI polyplexes with low molecular weight hyaluronan (<10 kDa) facilitated receptor‐mediated uptake via the CD44 receptor in HCE cells, increased complex stability in vitro, and effectively shielded the positive surface charges of the polyplex without decreasing its transfection efficiency. Higher molecular weights and larger amounts of hyaluronan in the complexes resulted in lesser improvements in the stability and transfection efficacy of the complexes.

Conclusions

Coating of polyplexes with low molecular weight hyaluronan is a promising strategy for gene delivery to the ocular surface, where CD44 receptor mediated uptake decreased cytotoxicity and reduced non‐specific interactions with the negatively charged extracellular matrix components are considered beneficial for increased transfection efficiency of non‐viral vectors. Copyright © 2007 John Wiley & Sons, Ltd.
Transgene expression of human PON1 Q in mice protected the liver against CCl4‐induced injury
Authors: Zhang Chi , Peng Wei , Jiang Xiaoling , Chen Bo , Zhu Jie , Zang Yuhui , Zhang Junfeng , Zhu Tongyang , Qin Junchuan
Published: November 2007

Background

Oxidative stress, often in association with decreased antioxidant defenses, plays a pathogenetic role in both initiation and progression of liver injuries, leading to almost all clinical and experimental conditions of chronic liver diseases. Human paraoxonase 1 (hPON1) is a liver‐synthesized enzyme possessing antioxidant properties. Here, we investigate the effects of transgene‐expressed hPON1 Q on alleviating lipid peroxidation and preventing liver injury in a mouse model.

Methods

The hPON1 Q gene was cloned into pcDNA3.0 plasmid and electro‐transferred into mouse skeletal muscle. After CCl4 had been administrated to induce liver injury, mice were monitored for serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malonyldialdehyde (MDA). The extent of CCl4‐induced liver injury was also analyzed through histopathological observations.

Results

After gene delivery, hPON1 mRNA expression was detected in mouse muscle and serum PON1 activity was 1.5 times higher than that of the control counterpart. In the PON1 Q gene transferred mice, protection against CCl4‐induced liver injury was reflected by significantly decreased serum ALT, AST and MDA levels compared to those in control mice (P < 0.01). Histological observations also revealed that hepatocyte necrosis, hemorrhage, vacuolar change and hydropic degeneration were apparent in control mice after CCl4 administration. In contrast, the damage was significantly prevented (P < 0.01) in the hPON1 Q transferred mice.

Conclusions

Intramuscular electro‐transfer of the hPON1 Q gene led to efficient expression of hPON1 in mice. Elevated levels of PON1, by virtue of its potency to alleviate oxidative stress, could protect mice from suffering CCl4‐induced liver damage. Copyright © 2007 John Wiley & Sons, Ltd.
AAV serotype 1 mediates more efficient gene transfer to pig myocardium than AAV serotype 2 and plasmid
Authors: Su H. , Yeghiazarians Y. , Lee A. , Huang Y. , Arakawa‐Hoyt J. , Ye J. , Orcino G. , Grossman W. , Kan Y. W.
Published: November 2007

Adeno‐associated virus (AAV) has many properties of an ideal vector for delivery of therapeutic genes into the myocardium. Previous studies in a mouse model of myocardial infarction showed that AAV serotype 1 (AAV1) is superior to AAV serotypes 2–5 to transfer genes into the myocardium by direct injection. Since vectors may behave differently in humans and because the human and the pig hearts resemble each other closely, we tested whether AAV1 is also superior to AAV2 in transferring genes into the pig myocardium. We also compared gene transduction efficiency between AAV vectors and plasmid. We injected CMVLacZ and CMVVEGF (vectors with the cytomegalovirus (CMV) promoter driving LacZ and VEGF gene expression) unpackaged or packaged in AAV serotypes 1 or 2 capsids into pig myocardium. Hearts were collected 3, 14 and 28 days after the injection. Gene expression was analyzed by real‐time reverse‐transcription polymerase chain reaction (RT‐PCR) and histological staining. Capillaries and smooth muscle α‐actin (SMA)‐positive vessels were quantified. Potential lymphocyte infiltration at the injection sites was analyzed by immunostaining using specific antibodies. As in the mouse, AAV1 mediated better gene transduction than AAV2. Plasmid mediated minimal gene expression only. More capillaries and SMA‐positive vessels were detected at AAV1CMVVEGF‐ and AAV2CMVVEGF‐injected than AAV1CMVLacZ‐injected sites. We did not detect inflammatory cell infiltration at the injection sites. In conclusion, by direct injection, AAV1 is more efficient than AAV2, and plasmid is inefficient in mediating gene transfer into the pig myocardium. AAV‐mediated VEGF gene transfer can also induce neovascular formation in the pig myocardium. Copyright © 2007 John Wiley & Sons, Ltd.
Usefulness of apparent diffusion coefficient map in diagnosing prostate carcinoma: Correlation with stepwise histopathology
Authors: Yoshimitsu Kengo , Kiyoshima Keijiro , Irie Hiroyuki , Tajima Tsuyoshi , Asayama Yoshiki , Hirakawa Masakazu , Ishigami Kousei , Naito Seiji , Honda Hiroshi
Published: November 2007

Purpose

To elucidate the performance of apparent diffusion coefficient (ADC) map in localizing prostate carcinoma (PC) using stepwise histopathology as a reference.

Materials and Methods

Preoperative MR images of 37 patients with PC who had undergone radical prostatectomy were retrospectively evaluated. First, T2‐weighted images (T2WI) alone were interpreted (T2WI reading), and then T2WI along with ADC map were interpreted (T2WI/ADC map reading). Sextant‐based sensitivity and specificity, and the ratio of the detected volume to the whole tumor volume (% tumor volume) were compared between the two interpretations, and results were also correlated to Gleason's scores (GS). ADC values were correlated to histological grades.

Results

Sensitivity was significantly higher in T2WI/ADC map reading than in T2WI reading (71% vs. 51%), but specificity was similar (61% vs. 60%). By adding ADC map to T2WI, % tumor volume detected increased significantly in transitional zone (TZ) lesions, but not in peripheral zone (PZ) lesions. % tumor volume detected with T2WI/ADC map reading showed a positive correlation with GS of the specimens. Less differentiated PC were associated with lower ADC values and higher detectability.

Conclusion

T2WI/ADC map reading was better than T2WI reading in PC detection and localization. This approach may be particularly useful for detecting TZ lesions and biologically aggressive lesions. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Stimulated‐echo acquisition mode (STEAM) MRI for black‐blood delayed hyperenhanced myocardial imaging
Authors: Ibrahim El‐Sayed H. , Weiss Robert G. , Stuber Matthias , Kraitchman VMD Dara L. , Pan Li , Spooner Amy E. , Osman Nael F.
Published: November 2007

Purpose

To develop a breathhold method for black‐blood viability imaging of the heart that may facilitate identifying the endocardial border.

Materials and Methods

Three stimulated‐echo acquisition mode (STEAM) images were obtained almost simultaneously during the same acquisition using three different demodulation values. Two of the three images were used to construct a black‐blood image of the heart. The third image was a T1‐weighted viability image that enabled detection of hyperintense infarcted myocardium after contrast agent administration. The three STEAM images were combined into one composite black‐blood viability image of the heart. The composite STEAM images were compared to conventional inversion‐recovery (IR) delayed hyperenhanced (DHE) images in nine human subjects studied on a 3T MRI scanner.

Results

STEAM images showed black‐blood characteristics and a significant improvement in the blood‐infarct signal‐difference to noise ratio (SDNR) when compared to the IR‐DHE images (34 ± 4.1 vs. 10 ± 2.9, mean ± standard deviation (SD), P < 0.002). There was sufficient myocardium‐infarct SDNR in the STEAM images to accurately delineate infarcted regions. The extracted infarcts demonstrated good agreement with the IR‐DHE images.

Conclusion

The STEAM black‐blood property allows for better delineation of the blood‐infarct border, which would enhance the fast and accurate measurement of infarct size. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Effects of doubling and tripling the spatial resolution in standard 3D contrast‐enhanced magnetic resonance angiography of carotid artery disease
Authors: Hnatiuk Brad , Emery Derek J. , Wilman Alan H.
Published: November 2007

Purpose

To determine whether three‐dimensional (3D) contrast‐enhanced MR angiography (CE‐MRA) of carotid artery disease may be more effective when performed at double or triple the spatial resolution of the present common clinical standard at 1.5T.

Materials and Methods

A total of 110 consecutive patients with suspected carotid artery disease were imaged with elliptical centric 3D CE‐MRA. The total acquisition time was increased from the standard clinical protocol of 21 seconds up to 60 seconds in 10‐second steps, with corresponding voxel volume reductions from 0.95 mm3 down to 0.35 mm3. Quantitative and blinded qualitative measurements were then performed to determine the preferred imaging time.

Results

In patients with significant stenosis, the 40‐second acquisition with 0.53‐mm3 voxels produced significantly sharper images of the carotid bifurcation than the 21‐second standard using 0.95‐mm3 voxels, but did not have a significant effect in patients without disease.

Conclusion

In patients with carotid artery stenosis, decreasing the voxel volume to 0.5 mm3 by increasing the scan time from 21 to 40 seconds resulted in sharper depiction of the carotid stenosis. Further decreases in voxel volume, by extending the acquisition time further, did not improve the vessel depiction due to both signal‐to‐noise ratio (SNR) and sharpness losses. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
In vivo glenohumeral analysis using 3D MRI models and a flexible software tool: Feasibility and precision
Authors: Busse Harald , Thomas Michael , Seiwerts Matthias , Moche Michael , Busse Martin W. , von Salis‐Soglio Georg , Kahn Thomas
Published: November 2007

Purpose

To implement a PC‐based morphometric analysis platform and to evaluate the feasibility and precision of MRI measurements of glenohumeral translation.

Materials and Methods

Using a vertically open 0.5T MRI scanner, the shoulders of 10 healthy subjects were scanned in apprehension (AP) and in neutral position (NP), respectively. Surface models of the humeral head (HH) and the glenoid cavity (GC) were created from segmented MR images by three readers. Glenohumeral translation was determined by the projection point of the manually fitted HH center on the GC plane defined by the two main principal axes of the GC model.

Results

Positional precision, given as mean (extreme value at 95% confidence level), was 0.9 (1.8) mm for the HH center and 0.7 (1.6) mm for the GC centroid; angular GC precision was 1.3° (2.3°) for the normal and about 4° (7°) for the anterior and superior coordinate axes. The two‐dimensional (2D) precision of the HH projection point was 1.1 (2.2) mm. A significant HH translation between AP and NP was found.

Conclusion

Despite a limited quality of the underlying model data, our PC‐based analysis platform allows a precise morphometric analysis of the glenohumeral joint. The software is easily extendable and may potentially be used for an objective evaluation of therapeutical measures. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Evaluation of manual and automatic segmentation of the mouse heart from CINE MR images
Authors: Heijman Edwin , Aben Jean‐Paul , Penners Cindy , Niessen Petra , Guillaume René , van Eys Guillaume , Nicolay Klaas , Strijkers Gustav J.
Published: November 2007

Purpose

To compare global functional parameters determined from a stack of cinematographic MR images of mouse heart by a manual segmentation and an automatic segmentation algorithm.

Materials and Methods

The manual and automatic segmentation results of 22 mouse hearts were compared. The automatic segmentation was based on propagation of a minimum cost algorithm in polar space starting from manually drawn contours in one heart phase. Intra‐ and interobserver variability as well as validity of the automatic segmentation was determined. To test the reproducibility of the algorithm the variability was calculated from the intra‐ and interobserver input.

Results

The mean time of segmentation for one dataset was around 10 minutes and ≈2.5 hours for automatic and manual segmentation, respectively. There were no significant differences between the automatic and the manual segmentation except for the end systolic epicardial volume. The automatically derived volumes correlated well with the manually derived volumes (R2 = 0.90); left ventricular mass with and without papillary muscle showed a correlation R2 of 0.74 and 0.76, respectively. The manual intraobserver variability was superior to the interobserver variability and the variability of the automatic segmentation, while the manual interobserver variability was comparable to the variability of the automatic segmentation. The automatic segmentation algorithm reduced the bias of the intra‐ and interobserver variability.

Conclusion

We conclude that automatic segmentation of the mouse heart provides a fast and valid alternative to manual segmentation of the mouse heart. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Anterior cruciate ligament volume: Analysis of gender differences
Authors: Fayad Laura M. , Rosenthal Elan H. , Morrison William B. , Carrino John A.
Published: November 2007

In this study, gender differences in the anterior cruciate ligament (ACL) were assessed with high resolution MRI. Using a quadrature extremity coil at 1.5T, volumes of the separate bundles of the ACL (anteromedial [AMB] and posterolateral [PLB]) were measured with shaded surface three‐dimensional (3D) reconstruction in 63 knees (33 male, 30 female). Bundle volumes were measured from consecutive fat‐suppressed fast spin‐echo proton‐density coronal MR images and intraobserver reproducibility was recorded. The data were divided into subgroups based on gender, age, height, weight, and body mass index (BMI) for statistical analysis. Results of the study revealed the mean ACL volume to be significantly different for males (1.07 cc) and females (0.77 cc) (P = 0.0025), yet when adjusting for body height differences, these were no longer significantly different. Mean AMB volume was smaller than the PLB volume for females (0.33 cc vs. 0.44 cc; P < 0.0001) and males (0.49 cc vs. 0.58 cc; P < 0.0001). Correlation coefficients were highest for height (r = 0.597) and weight (r = 0.5371) and regression analysis revealed height to be the most significant factor affecting ACL volume. Intraobserver measurements were reproducible (r = 0.90). From this data, we conclude that gender differences in ACL volume are present, but may be accounted for by height differences between males and females. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Improved focal liver lesion detection: Comparison of single‐shot spin‐echo echo‐planar and superparamagnetic iron oxide (SPIO)‐enhanced MRI
Authors: Coenegrachts Kenneth , Orlent Hans , ter Beek Leon , Haspeslagh Marc , Bipat Shandra , Stoker Jaap , Rigauts Hans
Published: November 2007

Purpose

To prospectively compare single‐shot spin‐echo echo‐planar imaging (SSSE‐EPI) using b = 0, 10, 150, and 400 seconds/mm2 with standard MRI techniques after intravenous super paramagnetic iron oxide (SPIO) in the detection and characterization of focal liver lesions with focus on small (<10 mm) focal liver lesions.

Materials and Methods

A total of 25 patients suspected for colorectal liver metastases were included. Number of detected lesions was evaluated. Image quality was compared between SSSE‐EPI sequence and post‐SPIO (fat‐suppressed T1‐weighted [T1w] gradient echo [GE], T2‐weighted [T2w] turbo spin echo [TSE] and T2* GE) sequences using rank order statistic (RIDIT). Lesion characterization was performed for SSSE‐EPI and for all remaining sequences pre‐ and post‐SPIO. Reference standard comprised surgery, biopsy, and/or follow‐up.

Results

Reference standard demonstrated 25 hemangiomas and 70 metastases. Best lesion detection respectively best image quality (P < 0.05) was achieved with SSSE‐EPI (b = 10 seconds/mm2) post‐SPIO T1w GE and T2w turbo spin echo. Lesion characterization using all sequences pre‐ and post‐SPIO performed best for lesion characterization compared with SSSE‐EPI.

Conclusion

This preliminary study shows the potential of SSSE‐EPI as a stand‐alone sequence for the detection of liver hemangiomas and metastases when compared with SPIO‐enhanced imaging. Sequences pre‐ and post‐SPIO are needed for qualitative lesion characterization. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
The use of artificial dermis for surgical defects in the treatment of oral premalignant lesions
Authors: Chen Chun‐Ming , Yang Chia‐Fu , Shen Yee‐Shyong , Huang I‐Yueh , Wu Chih‐Fung
Published: November 2007

Background

This study investigated the application of an artificial dermis as a substitute for split‐thickness skin graft in an oral mucosal defect after excision of a premalignant lesion.

Methods

We examined a total of 125 sites repaired with artificial dermis in 84 patients. Forty‐one of 84 patients had two different defects and 43 had a single defect. Of 84 patients, there were 52 oral leukoplakia and 32 oral submucous fibrosis.

Results

Most patients chewed betel nuts (97.6%). Most of the premalignant lesions were located in the buccal mucosa (94%). The overall success rate was 100% without any or partial graft loss. The minor wound oozing occurred in three grafts (2.4%). No patient had an immunologic reaction or experienced with significant pain.

Conclusions

Therefore, an artificial dermis may be an alterative to a split‐thickness skin graft for patients with oral mucosal defects after removal of premalignant lesions. J. Surg. Oncol. 2008;97:291–293. © 2007 Wiley‐Liss, Inc.
Generation of tailored pulse trains for efficient material processing by a high power MOPA system with birefringence compensation
Authors: Riesbeck T
Published: November 2007

A flash lamp pumped, acousto-optical Q-switched Nd:YAG master oscillator power amplifier (MOPA) system with an average output power of almost 150 W and a beam quality of M2 < 2.5 is developed. The system operates with a 100 Hz repetition rate for the flash lamps. In each pumping pulse a pulse train of 5 to 40 Q-switched laser pulses is generated. The pulse length is from 25 to 150 ns. A high beam quality of the amplified beam is realized by an elaborate amplifier design and a careful alignment of the beam diameter to the amplifier rods. Additionally, the thermally induced birefringence of the amplifiers is compensated by a 90° rotator and an optical image-relay system between two identical amplifier rods, so that a linear polarized laser beam could be achieved with depolarization losses below 2%.
Application of optical coherence tomography for imaging of scaffold structure and micro-flows characterization
Authors: Veksler B , Kobzev E , Bonesi M , Meglinski I
Published: November 2007

Tissue engineering, rapidly developing branch of bioscience, is widely adopted for the purposes of the tissue growing using the substrate materials. Three-dimensional porous scaffolds possess a great opportunity for the directional growth of the cells and for the supplying them with nutrients. However, the complex porous structure of the scaffolds create difficulties for the measurements and control of nutrients flow. We applied optical coherence tomography (OCT) for imaging of the scaffold structure. We also investigated the possibility of using Doppler OCT to monitor the flow velocity distribution within the scaffold. The average scaffold's pore diameter has been estimated using electron microscopy. We show that with Doppler OCT it is possible to monitor complex micro-flow and estimate the shear stress (i.e. enhancing factor of cell growing) acting on the cells within the scaffold and to find the optimal input flow rate, consequently.
Manipulating thermal light states by the controlled addition and subtraction of single photons
Authors: Parigi V , Zavatta A , Bellini M
Published: November 2007

We report the generation and the tomographic analysis of novel quantum states of light generated by the controlled addition and subtraction of single photons to and from a classical and fully incoherent thermal light field. Time-domain quantum tomography is used to thoroughly investigate the character of the resulting states. Several different criteria are employed to test and quantify nonclassicality of photon-added thermal states, while the peculiar features concerning the mean photon number of photon-subtracted thermal states are clearly observed.
Resolution of Hepatopulmonary Syndrome After Auxiliary Partial Orthotopic Liver Transplantation in Abernethy Malformation. A Case Report.
Authors: Emre Sukru , Arnon Ronen , Cohen Emil , Morotti Raffaella A. , Vaysman Dmitriy , Shneider Benjamin L.
Published: November 2007

Congenital absence of portal vein and extrahepatic portocaval shunt, also referred to as an Abernethy type 1, is a rare malformation of the mesenteric vasculature. A 9-year-old girl presented with dyspnea on exertion and orthodeoxia. A diagnosis of an Abernethy malformation type 1b and hepatopulmonary syndrome (HPS) was made, and she underwent auxiliary partial orthotopic liver transplantation (APOLT). Symptoms and signs of HPS resolved 2 months after the operation. HPS in Abernethy syndrome is a manifestation of normal portal blood flow bypassing the liver and can be ameliorated by redirecting blood flow to a segment of liver with normal portal anatomy. APOLT is a feasible and successful surgical procedure for patients with Abernethy malformation and HPS. Liver Transpl 13:1662–1668, 2007. © 2007 AASLD.
NMR study of hydroxy protons of di‐ and trimannosides, substructures of Man‐9
Authors: Hakkarainen Birgit , Kenne Lennart , Lahmann Martina , Oscarson Stefan , Sandström Corine
Published: November 2007

The chemical shifts, temperature coefficients and inter‐residual rotating‐frame Overhauser effect (ROE)s for the hydroxy protons of some α‐(1,2)‐, α‐(1,3)‐ and α‐(1,6)‐linked di‐ and trimannosides have been measured for samples in 85% H2O/15% acetone‐d6 solution. These mannosides, Manα(1 → 2)ManαOMe (1) Manα(1 → 3)ManαOMe (2), Manα(1 → 6)ManαOMe (3), Manα(1 → 2)Manα(1 → 2)ManαOMe (4), Manα(1 → 2)Manα(1 → 3)ManαOMe (5), Manα(1 → 2)Manα(1 → 6)ManαOMe (6) and Manα(1 → 3)[Manα1 → 6]ManαOMe (7), are substructures of the N‐glycan Man‐9.

The NMR data show that the hydration of each individual hydroxyl group in the di‐ and trisaccharides is very similar to the hydration of the corresponding hydroxyl in the monomeric methyl α‐D‐mannoside. No hydrogen‐bond interactions were found to stabilize the conformations of the α‐(1,2)‐ and α‐(1,6)‐linkages and the chemical shifts for the hydroxy proton resonances of the α‐(1,6)‐linkage indicated high‐conformational flexibility. For the α‐(1,3)‐linkage, however, the downfield shift for the signal of O(2)H of the 3‐substituted residue together with the ROE between this proton and H5′ on the next residue suggest some weak inter‐residue interactions. Copyright © 2007 John Wiley & Sons, Ltd.
Co‐acquisition of hyperpolarised 13C and 15N NMR spectra
Authors: Day Iain J. , Mitchell John C. , Snowden Martin J. , Davis Adrian L.
Published: November 2007

Recent developments in dynamic nuclear polarisation now allow significant enhancements to be generated in the cryo solid state and transferred to the liquid state for detection at high resolution. We demonstrate that the Ardenkjaer–Larsen method can be extended by taking advantage of the properties of the trityl radicals used. It is possible to hyperpolarise 13C and 15N simultaneously in the solid state, and to maintain these hyperpolarisations through rapid dissolution into the liquid state. We demonstrate the almost simultaneous measurement of hyperpolarised 13C and hyperpolarised 15N NMR spectra. The prospects for further improvement of the method using contemporary technology are also discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Complete assignments of 1H and 13C NMR data for trypanocidal eremantholide C oxide derivatives
Authors: Saúde‐Guimarães Dênia A. , Perry Katia S. P. , Raslan Délio S. , Chiari Egler , Barrero Alejandro F. , Oltra Juan E.
Published: November 2007

The chemical transformations of eremantholide C (1), a trypanocidal sesquiterpene lactone isolated from Lychnophora trichocarpha Spreng., gave five new oxide derivatives: 3′‐hydroxyeremantholide C (2), 1′‐formyleremantholide C (3), 1′‐carboxyeremantholide C (4), 1′‐carbomethoxyeremantholide C (5) and sodium 1′‐carboxylate of eremantholide C (6). The 1H and 13C NMR data of all these derivatives were assigned based on 1D and 2D techniques. The derivatives were evaluated against Y and CL strains of Trypanosoma cruzi. All of them were inactive against the Y strain. Compounds 2 and 5 displayed 100% activity on the CL strain while compounds 4 and 6 were partially active on the CL strain. Copyright © 2007 John Wiley & Sons, Ltd.
Chemometric analysis of disubstituent effects on the 13C chemical shifts of the carboxyl carbons (δCO) of benzoic acids. A comparative study of the substituent effects on the strength of benzoic acids in apolar aprotic media
Authors: Sen Gupta Susanta K. , Shrivastava Ruchi
Published: November 2007

The results of measurements of substituent induced chemical shifts of carboxyl carbons (δCO) of dichloro‐ and difluorobenzoic acids, including the monosubstituted ones with substituents at meta‐ and/or ortho‐ positions, in chloroform‐d and strengths of these acids (log K) in chlorobenzene show an anomalous reverse trend between δCO and log K, while the electron density at carboxyl carbons should influence similarly both δCO and log K. A detailed chemometric analysis of comparison of disubstituent effects between δCO and log K on the basis of Fujita–Nishioka's multiparameter approach and assumption of additivity of substituent effects shows a dominance of the localized π‐polarization mechanism relative to simple electrostatic effects upon δCO. Further, steric factors play a significant role in determining δCO whereas with respect to log K they were insignificant. The overall anomaly has been rationalized keeping in mind that, while log K is a gross measure of energy differences between the ionized and unionized forms of the acids, δCO is a very sensitive probe for determining changes in electron density at the carboxyl carbon of the unionized acid. Copyright © 2007 John Wiley & Sons, Ltd.
J(F,H), J(C,H) and J(H,H) couplings involving the individual methyl group protons in 1,2,3,4‐tetrachloro‐5,6,7,8‐tetrafluoro‐9‐methyltriptycene. Evidence of blue‐shifting hydrogen bond
Authors: Czerski I. , Kamieńska‐Trela K. , Koźmiński W. , Ratajczyk T. , Szymański S. , Wójcik J.
Published: November 2007

1,2,3,4‐tetrachloro‐5,6,7,8‐tetrafluoro‐9‐methyltriptycene was studied in NMR spectra at low temperatures where the methyl group dynamics is frozen. Values of 5J(19F,1H), 1J(13C,1H), and 2J(1H,1H) for the individual methyl protons were measured. They are in a fair agreement with the corresponding theoretical values calculated at a density functional theory (DFT) level. The 5J(19F,1H) couplings involve the peri‐F nucleus and occur via the ‘through space’ mechanism. Both the natural bond orbital analysis (at a HF level) and the observed pattern of 1J(13C,1H) coupling values corroborate occurrence in this molecule of intramolecular, blue‐shifting hydrogen bonds engaging the methyl hydrogens. The ‘through space’ 5J(19F,1H) couplings may indicate the routes of electron density transfers that escape detection by the natural bond analysis. A consideration of these effects can enrich the chemical intuition involving this specific sort of H‐bonds. Copyright © 2007 John Wiley & Sons, Ltd.
14N NQR study of nicotinamide and related compounds
Authors: Seliger J. , Žagar V.
Published: November 2007

14N nuclear quadrupole resonance (NQR) frequencies have been measured in picolinamide, nicotinamide, isonicotinamide, 2,6‐pyridine dicarboxamide, and acetamide by double resonance. The 14N NQR spectra in picolinamide, nicotinamide, isonicotinamide, and 2,6‐pyridine dicarboxamide show the presence of two distinct nitrogen positions: the ring position with the quadrupole coupling constant about 4,5 MHz and the amide position with the quadrupole coupling constant about 2.6 MHz. The NQR data are related to the structure of the investigated compounds and to the NH···O hydrogen bonds. Copyright © 2007 John Wiley & Sons, Ltd.
Varying kernel‐extent gridding reconstruction for undersampled variable‐density spirals
Authors: Çukur Tolga , Santos Juan M. , Nishimura Dwight G. , Pauly John M.
Published: November 2007

Nonuniform, non‐Cartesian k‐space trajectories enable fast scanning with reduced motion and flow artifacts. In such cases, the data are usually convolved with a kernel and resampled onto a Cartesian grid before reconstruction. For trajectories such as undersampled variable‐density spirals, the mainlobe width of the kernel for undersampled high spatial frequencies has to be larger to limit the amount of aliasing energy. Continuously varying the kernel extent is time consuming. By dividing k‐space into several annuli and using appropriate mainlobe widths for each, the aliasing energy and noise can be reduced at the expense of lower resolution towards the edge of the field of view (FOV). Resolution can instead be preserved at the center of the FOV, which is expected to be free of artifacts, without any artifact reduction. The image reconstructed from each annulus can be deapodized separately. The method can be applied to most k‐space trajectories used in MRI. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.