bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymorphism in nucleotide excision repair gene XPC correlates with bleomycin‐induced chromosomal aberrations
Authors: Laczmanska Izabela , Gil Justyna , Karpinski Pawel , Stembalska Agnieszka , Trusewicz Alicja , Pesz Karolina , Ramsey David , Schlade‐Bartusiak Kamilla , Blin Nikolaus , Sasiadek Maria Malgorzata
Published: August 2007

Chromosomal aberrations (CAs) are important genetic alterations in the development and progression of the majority of human cancers. The frequency with which such alterations occur depends to a large extent on polymorphisms of DNA‐repair genes and in genes coding for xenobiotic metabolizing enzymes, which are involved in the processes of activation and inactivation of xenobiotics. The frequency of bleomycin (BLM)‐induced CAs is an indirect measure of the effectiveness of DNA repair mechanisms, and a predictor of environment‐related risk of cancer. Our study was conducted on the human peripheral blood lymphocytes of 82 healthy volunteers. The aim of the study was to elucidate whether the frequency of BLM‐induced CAs is correlated with polymorphisms of selected genes involved in different mechanisms of DNA repair such as: XRCC1 [base excision repair]; XPA, XPC, XPG, XPD, XPF, ERCC1 [nucleotide excision repair], NBS1, RAD51, XRCC2, XRCC3, RAD51, and BRCA1 [homologous recombination], as well as in genes encoding xenobiotic metabolizing enzymes, such as CYP1A, CYP2E1, NAT2, GSTT1, and EPHX (mEH). Our study indicated that, of the polymorphisms studied, only XPC (exon 15 and intron 11) is associated with BLM‐induced CAs, suggesting a role of the NER pathway in the repair of BLM‐induced chromosomal aberrations. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
On the dynamics of rocking motion of single rigid‐block structures
Authors: Peña F. , Prieto F. , Lourenço P. B. , Campos Costa A. , Lemos J. V.
Published: August 2007

This paper describes the behavior of single rigid‐block structures under dynamic loading. A comprehensive experimental investigation has been carried out to study the rocking response of four blue granite stones with different geometrical characteristics under free vibration, and harmonic and random motions of the base. In total, 275 tests on a shaking table were carried out in order to address the issues of repeatability of the results and stability of the rocking motion response. Two different tools for the numerical simulations of the rocking motion of rigid blocks are considered. The first tool is analytical and overcomes the usual limitations of the traditional piecewise equations of motion through a Lagrangian formalism. The second tool is based on the discrete element method (DEM), especially effective for the numerical modeling of rigid blocks. A new methodology is proposed for finding the parameters of the DEM by using the parameters of the classical theory. An extensive comparison between numerical and experimental data has been carried out to validate and define the limitations of the analytical tools under study. Copyright © 2007 John Wiley & Sons, Ltd.
Apparent damping induced by spurious pitching in shaking‐table testing
Authors: Molina F. J. , Magonette G. , Viaccoz B. , Géradin M.
Published: August 2007

A seismic shaking‐table test performed on a one‐storey steel frame with an 8 ton RC floor slab was reproduced on a similar specimen by means of the pseudo‐dynamic (PsD) method. A satisfactory agreement of the results could only be achieved after recalibration of the theoretical mass in the PsD equation and proper inclusion in the PsD test input of the horizontal and pitching accelerations measured on the table. In the shaking‐table test, the spurious pitching motion produced a significant increase in the apparent damping that could be estimated as a function of the pitching dynamic flexibility of the system. Dynamic and PsD snap‐back tests were also performed to provide an additional check of the reliability of the PsD method. The spurious pitching motion of the shaking table should always be measured during the tests and reported as a mean to increase the reliability and
usefulness of the results. Copyright © 2007 John Wiley & Sons, Ltd.
Modeling the spatial distribution of landslide‐prone colluvium and shallow groundwater on hillslopes of Seattle, WA
Authors: Schulz William H. , Lidke David J. , Godt Jonathan W.
Published: August 2007

Landslides in partially saturated colluvium on Seattle, WA, hillslopes have resulted in property damage and human casualties. We developed statistical models of colluvium and shallow‐groundwater distributions to aid landslide hazard assessments. The models were developed using a geographic information system, digital geologic maps, digital topography, subsurface exploration results, the groundwater flow modeling software VS2DI and regression analyses. Input to the colluvium model includes slope, distance to a hillslope–crest escarpment, and escarpment slope and height. We developed different statistical relations for thickness of colluvium on four landforms. Groundwater model input includes colluvium basal slope and distance from the Fraser aquifer. This distance was used to estimate hydraulic conductivity based on the assumption that addition of finer‐grained material from down‐section would result in lower conductivity. Colluvial groundwater is perched so we estimated its saturated thickness. We used VS2DI to establish relations between saturated thickness and the hydraulic conductivity and basal slope of the colluvium. We developed different statistical relations for three groundwater flow regimes. All model results were validated using observational data that were excluded from calibration. Eighty percent of colluvium thickness predictions were within 25% of observed values and 88% of saturated thickness predictions were within 20% of observed values. The models are based on conditions common to many areas, so our method can provide accurate results for similar regions; relations in our statistical models require calibration for new regions. Our results suggest that Seattle landslides occur in native deposits and colluvium, ultimately in response to surface‐water erosion of hillslope toes. Regional groundwater conditions do not appear to strongly affect the general distribution of Seattle landslides; historical landslides were equally dispersed within and outside of the area potentially affected by regional groundwater conditions. Published in 2007 by John Wiley & Sons, Ltd.
GIS‐based regional landslide susceptibility mapping: a case study in southern California
Authors: He Yiping , Beighley R. Edward
Published: August 2007

Landslides threaten lives and property throughout the United States, causing in excess of $2 billion in damages and 25–50 deaths annually. In regions subjected to urban expansion caused by population growth and/or increased storm intensities caused by changing climate patterns, the economic and society costs of landslides will continue to rise. Using a geographic information system (GIS), this paper develops and implements a multivariate statistical approach for mapping landslide susceptibility. The presented susceptibility maps are intended to help in the design of hazard mitigation and land development policies at regional scales. The paper presents (a) a GIS‐based multivariate statistical approach for mapping landslide susceptibility, (b) several dimensionless landslide susceptibility indexes developed to quantify and weight the influence of individual categories for given potential risk factors on landslides and (c) a case study in southern California, which uses 11 111 seismic landslide scars collected from previous efforts and 5389 landslide scars newly digitized from local geologic maps. In the case study, seven potential risk factors were selected to map landslide susceptibility. Ground slope and event precipitation were the most important factors, followed by land cover, surface curvature, proximity to fault, elevation and proximity to coastline. The developed landslide susceptibility maps show that areas classified as having high or very high susceptibilities contained 71% of the digitized landslide scars and 90% of the seismic landslide scars while only occupying 26% of the total study area. These areas mostly have ground slopes higher than 46% and 2‐year, 6‐hour precipitation greater than 51 mm. Only 12% of digitized landslides and less than 1% of recorded seismic landslides were located in areas classified as low or very low susceptibility, while occupying 42% of the total study region. These areas mostly have slopes less than 27% and 2‐year, 6‐hour precipitation less than 41 mm. Copyright © 2007 John Wiley & Sons, Ltd.
Bibliographie der Flechten und lichenicolen Pilze Mecklenburg‐Vorpommerns von 1996 bis 2006
Authors: Schiefelbein U. , Litterski B.
Published: August 2007

In der Bibliographie sind aus dem Zeitraum von 1996 bis 2006 Publikationen mit Angaben zu Flechten und lichenicolen Pilzen des Bundeslandes Mecklenburg‐Vorpommern erfasst. Aufgeführt ist auch die in der Bibliographie von Litterski (1997c) nicht enthaltene Literatur. In den 63 zitierten Literaturstellen werden 646 Arten angegeben. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantification and correction of bias in tagging SNPs caused by insufficient sample size and marker density by means of haplotype‐dropping
Authors: Iles Mark M.
Published: August 2007

Tagging single nucleotide polymorphisms (tSNPs) are commonly used to capture genetic diversity cost‐effectively. It is important that the efficacy of tSNPs is correctly estimated, otherwise coverage may be inadequate and studies underpowered. Using data simulated under a coalescent model, we show that insufficient sample size can lead to overestimation of tSNP efficacy. Quantifying this we find that even when insufficient marker density is adjusted for, estimates of tSNP efficacy are up to 45% higher than the true values. Even with as many as 100 individuals, estimates of tSNP efficacy may be 9% higher than the true value. We describe a novel method for estimating tSNP efficacy accounting for limited sample size. The method is based on exclusion of haplotypes, incorporating a previous adjustment for insufficient marker density. We show that this method outperforms an existing Bootstrap approach. We compare the efficacy of multimarker and pairwise tSNP selection methods on real data. These confirm our findings with simulated data and suggest that pairwise methods are less sensitive to sample size, but more sensitive to marker density. We conclude that a combination of insufficient sample size and overfitting may cause overestimation of tSNP efficacy and underpowering of studies based on tSNPs. Our novel method corrects much of this bias and is superior to a previous method. However, sample sizes larger than previously suggested may be required for accurate estimation of tSNP efficacy. This has obvious ramifications for tSNP selection both in candidate regions and using HapMap or SNP chips for genomewide studies. Genet. Epidemiol. 31, 2007. © 2007 Wiley‐Liss, Inc.
Missing phenotype data imputation in pedigree data analysis
Authors: Fridley Brooke L. , de Andrade Mariza
Published: August 2007

Mapping complex traits or phenotypes with small genetic effects, whose phenotypes may be modulated by temporal trends in families are challenging. Detailed and accurate data must be available on families, whether or not the data were collected over time. Missing data complicate matters in pedigree analysis, especially in the case of a longitudinal pedigree analysis. Because most analytical methods developed for the analysis of longitudinal pedigree data require no missing data, the researcher is left with the option of dropping those cases (individuals) with missing data from the analysis or imputing values for the missing data. We present the use of data augmentation within Bayesian polygenic and longitudinal polygenic models to produce k complete datasets. The data augmentation, or imputation step of the Markov chain Monte Carlo, takes into account the observed familial information and the observed subject information available at other time points. These k complete datasets can then be used to fit single time point or longitudinal pedigree models. By producing a set of k complete datasets and thus k sets of parameter estimates, the total variance associated with an estimate can be partitioned into a within‐imputation and a between‐imputation component. The method is illustrated using the Genetic Analysis Workshop simulated data. Genet. Epidemiol. 2007. © 2007 Wiley‐Liss, Inc.
Preoperative radiotherapy and bevacizumab for angiosarcoma of the head and neck: Two case studies
Authors: Koontz Bridget F. , Miles Edward F. , Rubio Mary Ann D. , Madden John F. , Fisher Samuel R. , Scher Richard L. , Brizel David M.
Published: August 2007

Background.

Angiosarcoma of the face is a vascular tumor with poor local control and short median survival despite standard treatment. Bevacizumab is a humanized monoclonal antibody to vascular endothelial growth factor (VEGF), which can inhibit tumor growth. It is synergistic with radiotherapy in gastrointestinal malignancies. Given the vascular nature of angiosarcoma and the need for better treatment of this disease, we investigated the concurrent use of bevacizumab with preoperative radiotherapy for head and neck angiosarcoma.

Methods.

Two patients diagnosed with angiosarcoma of the nose were treated preoperatively with bevacizumab (5–10 mg/kg) and concurrent radiotherapy (50 Gy), followed by resection of the tumor bed.

Results.

Both patients had a complete pathologic response with no residual disease. Neither has developed recurrence, with follow‐up of 8.5 months and 2.1 years.

Conclusions.

The neoadjuvant combination of bevacizumab and radiation therapy is promising and should be further studied in the setting of vascular malignancies. © 2007 Wiley Periodicals, Inc. Head Neck 2008
Pediatric mandibular reconstruction using a vascularized fibula flap
Authors: Crosby Melissa A. , Martin Jack W. , Robb Geoffrey L. , Chang David W.
Published: August 2007

Background.

The purpose of this study was to address questions concerning the functional outcome following mandibular reconstruction with vascularized fibula flap in skeletally immature children

Methods.

Eleven patients 14 years old or younger who underwent mandibular reconstruction using a free fibula flap were evaluated.

Results.

The mean follow‐up was 3.4 years. One flap loss occurred and required a second fibula flap. Panorex radiographs showed good bone union and growth in all patients. Functional outcomes were normal according to age in all patients. Two patients had long‐term malocclusion. No patients had to undergo corrective orthognathic surgery. Donor‐site morbidities consisted of great toe flexion contracture (n = 4) and a valgus deformity (n = 1). All patients had a normal gait, and there were no discrepancies in leg length

Conclusion.

A mandible reconstructed using a vascularized fibula flap appears to grow accordingly as the child grows, with minimal disturbance to the growth pattern of the midface. © 2007 Wiley Periodicals, Inc. Head Neck 2008
The role of serpinb9/serine protease inhibitor 6 in preventing granzyme B–dependent hepatotoxicity
Authors: Stout-Delgado Heather W. , Getachew Yonas , Rogers Thomas E. , Miller Bonnie C. , Thiele Dwain L.
Published: August 2007

Virally infected hepatocytes are resistant to cytotoxic lymphocyte killing by perforin-dependent and granzyme-dependent effector mechanisms. The present studies were designed to examine the role of serine protease inhibitor 6 (SPI-6) in limiting granzyme B–dependent cytotoxic effector mechanisms in the liver. SPI-6–specific small interfering RNA (siRNA) administration to C57Bl/6J (B6) mice elicited transient alanine aminotransferase (ALT) elevations that were not observed in either granzyme B–deficient B6 (B6.

gzmb

−/−) or natural killer (NK) cell–depleted B6 mice. When SPI-6 expression was abolished by siRNA administration at the time of infection with a recombinant, replication-deficient adenovirus [E1-deleted adenovirus encoding β-galactosidase (AdCMV-
LacZ

)], earlier and dramatically increased, and earlier ALT elevations were observed in wild-type B6 but not in B6.

gzmb

−/− or NK cell–depleted mice. When a 3-fold higher dose of AdCMV-
LacZ

was administered to B6 mice, the coadministration of SPI-6 siRNA resulted in the early onset of lethal, acute liver failure. Of note, the accelerated clearance of AdCMV-
LacZ

was observed in recipients of SPI-6 siRNA.

Conclusion:

These results indicate that the regulated expression of SPI-6 in hepatocytes during viral infection or following noninfectious causes of liver injury protects hepatocytes against excessively vigorous granzyme B–dependent killing but may also delay immune clearance of virally infected hepatocytes.
Medical images compression for remote diagnosis using modified SPIHT data organization and fidelity enhancement filter
Authors: Chen Yen‐Yu
Published: August 2007

In this work, an 8 × 8 Discrete Cosine Transform (DCT) approach is adopted to perform DCT shrinkage, followed by modified set partitioning in hierarchical trees (SPIHT) data organization and fidelity enhancement filter for reducing the memory required to store a remote diagnosis and rapidly transmit it. The DCT shrinkage has the ability to retain the detailed characteristics of an image. By means of a simple transformation to gather the DCT spectrum data with the same frequency domain, the DCT shrinkage exploits all the characteristics of individual blocks to a global framework. In this scheme, insignificant DCT coefficients that correspond to the same spatial location in the high‐frequency sub‐bands can be used to reduce the redundancy by a combined function proposed in association with the modified SPIHT. Meanwhile, quad‐tree decomposition and a set of morphological filters for reducing the artifacts are presented. This set of filters employs 8 predefined morphological operations, namely 4 structuring elements (SE), each of which includes both dilation and erosion operations. The voting strategy is used to select the most suitable morphological filter for each block. Simulation results show that the image compression reduced the computational complexity to only a half of the wavelet based sub‐band decomposition and improved the quality of the reconstructed medical image in terms of both the peak signal‐to‐noise ratio (PSNR) and the perceptual results close to JPEG2000 and the original SPIHT at the same bit rate. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 49–61, 2007
Binocular imaging of a laser stripe and approximation networks for shape detection
Authors: Muñoz‐Rodríguez J. Apolinar
Published: August 2007

A technique for shape detection based on binocular imaging of a laser stripe is presented. In this technique, the object shape is recovered by means of laser stripe projection and binocular imaging. The approach of the binocular imaging in this technique is to avoid stripe occlusions, which appear due to the variation to the object surface. Based on the behavior of the stripe displacement, the object topography is computed by a Bezier approximation network. By means of this network, the measurements of the binocular geometry are avoided. The parameters of the binocular imaging are computed based on the Bezier approximation network. To reconstruct the topography, the object is scanned by a laser stripe. From the scanning, a set of binocular images of the stripe are processed to compute the object dimensions by means of the network. By applying Bezier approximation networks, the performance of the binocular imaging and the accuracy are improved. It is because the errors of the measurement are not added to the computational procedure, which performs the shape reconstruction. This procedure represents a contribution for the stripe projection methods and the binocular imaging. To describe the accuracy a root mean square of error is calculated. This technique is tested with real objects and its experimental results are presented. Also, the time processing is described. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 62–74, 2007
Mechanisms of DNA breaks induction in vivo by 5‐azacytidine: paths of micronucleus induction by azaC
Authors: Morales‐Ramírez P. , Vallarino‐Kelly T. , Cruz‐Vallejo V. L.
Published: August 2007

The aim of the present study was to correlate the time‐response curves of micronucleated polychromatic erythrocyte (MN‐PCE) induction by 5‐azacytidine (azaC) with the possible processes involved in DNA break production; this is based on the results previously published by other authors. The MN‐PCE induction at two different doses of azaC was determined by sampling blood from the tails of mice before the acute treatment and over nine periods of 8 h each afterwards. Both doses caused two peaks of MN‐PCE induction, one at 32 h and another at 48 h, approximately; a shoulder was detected that remained high from 56 h up to the end of the study (72 h). These results suggest that azaC induced DNA breaks and subsequently MN (micronucleus) by three different mechanisms, and in agreement with data in the literature, these could be successively the following: (i) during excision of the large adduct comprising the DNA methyl transferase covalently linked to DNA; (ii) failure of recombination repair or mismatch repair; and (iii) persistent chromosome fragility in G‐C rich sites due to DNA demethylation and chromatin decondensation. Copyright © 2007 John Wiley & Sons, Ltd.
Atrazine‐induced changes in aromatase activity in estrogen sensitive target tissues
Authors: Holloway A. C. , Anger D. A. , Crankshaw D. J. , Wu M. , Foster W. G.
Published: August 2007

Atrazine (ATR) is a pesticide used widely throughout North America. Although not directly estrogenic, ATR treatment has been shown to increase aromatase activity in tumor cell lines. Thus, it is suggested that ATR can increase local tissue estrogen levels in estrogen sensitive target tissues through increased aromatase activity. Therefore the effect of ATR on aromatase activity was measured in human granulosa‐lutein cell cultures, cells that abundantly express aromatase, and endometrial stromal cell (ESC) cultures, cells that do not express aromatase. Aromatase activity was quantified by the tritiated water method and the specificity of the assay was confirmed by co‐incubation with 4‐hydroxyandrostenedione, an irreversible inhibitor of the catalytic activity of aromatase. Aromatase activity in ATR treated (1–10 µm) granulosa‐lutein cells was increased more than 2‐fold compared with control cultures. There were no treatment related changes in cellular protein and thus it is suggested that the ATR‐induced change in aromatase activity was not due to an increase in cell number. ATR‐treatment had no effect on ESC aromatase activity at any concentration tested. Similarly, there was no effect of ATR treatment on human recombinant aromatase activity in our cell‐free test system. Therefore it is concluded that µm concentrations of ATR can increase aromatase activity of human granulosa cells but not ESC and this effect is not elicited at the enzyme level. Copyright © 2007 John Wiley & Sons, Ltd.
Time course of the change and amelioration of nedaplatin‐induced nephrotoxicity in rats
Authors: Uehara Takeki , Tsuchiya Noriko , Masuda Aki , Torii Mikinori , Nakamura Masuhisa , Yamate Jyoji , Maruyama Toshiyuki
Published: August 2007

Nedaplatin (NDP) is a second‐generation antineoplastic platinum complex, with reduced nephrotoxicity. Two experiments were conducted to characterize the time course of changes of its nephrotoxicity and to further evaluate whether hydration is useful for amelioration of nephrotoxicity. In the first experiment, 8‐week‐old male rats treated with 6 or 9 mg kg−1 NDP at a single intravenous dose were killed 2, 4, 7 and 14 days after dosing. In the second experiment, nonhydrated (Nhyd) or hydrated (Hyd) rats, treated with a single intravenous dose of 20 mg kg−1 NDP, were killed 7 days after dosing. Besides renal function and histopathological examinations, the urinary excretion of platinum was measured. Histopathologically, NDP‐induced nephrotoxicity was initially characterized by single cell and/or focal necrosis in the epithelium of distal tubules and collecting ducts as well as proximal tubules. In the later stage, subsequent cystic dilatation and regeneration occurred in these affected tubules, but incomplete tissue repair was still observed in the kidney 14 days after dosing. However, NDP‐induced nephrotoxicity was dramatically reduced by hydration, while it had no clear effects on myelotoxicity. Measurement of urinary platinum excretion revealed that the total amount of platinum excretion was significantly higher in Hyd‐NDP rats than that in Nhyd‐NDP rats. In terms of urinary concentration, Hyd‐NDP rats showed a lower concentration compared with that in Nhyd‐NDP rats. The current results suggest that NDP has the potential risk to cause nephrotoxicity at a human therapeutic dose without hydration and that pre‐ and post‐hydration at dosing can ameliorate this nephrotoxicity. Copyright © 2007 John Wiley & Sons, Ltd.
An introduction of various spectroscopic methods to identify in vivo metal wear in total knee arthroplasty
Authors: Kovacik M. W. , Gradisar I. A. , Tokash J. C. , Stojilovic N. , Ehrman J. D. , Bender E. T. , Ramsier R. D.
Published: August 2007

While the industrial community already employs multiple surface analytical techniques to study compositional wearing of various metallic and nonmetallic materials, as yet, these methods have not been widely introduced into the biological community. We report on a novel approach, using the industrial spectroscopic techniques of X‐ray photoelectron spectroscopy, micro‐Raman spectroscopy, and scanning electron microscopy equipped with energy dispersive spectroscopy, to identify the fine wear particulates and other impurities deposited within the knee‐joint following total knee arthroplasty. In this study, synovial fluid was extracted from knee‐joints scheduled for revision of total knee arthroplasty. The small debris flake formed by centrifugation of the fluid was analyzed using the spectroscopic techniques mentioned above. These nondestructive techniques were successful in identifying numerous micron and submicron sized metallic particulates that appear to emanate from both the prosthetic bearing (articulating) surfaces and from backside (nonarticulating) surfaces, even when gross wearing of the prosthetic device was not detectable by direct visual inspection intraoperatively. Most interesting is that the ratio of the in vivo metallic debris is approximately the same ratio as that of the manufactured alloy, indicating prosthetic wearing as opposed to chemical dissolution. More importantly, using these spectroscopic techniques to probe both the surface and below the surface of the synovial deposits, we identify an inhomogeneous distribution of the wear debris. This indicates the need to use multiple techniques in order to adequately identify the elemental composition of the prosthetic wear material. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Biological response of tissues with macrophagic activity to titanium dioxide
Authors: Olmedo Daniel G. , Tasat Deborah R. , Evelson Pablo , Guglielmotti María B. , Cabrini Rómulo L.
Published: August 2007

The titanium dioxide layer is composed mainly of anatase and rutile. This layer is prone to break, releasing particles to the milieu. Therefore, corrosion may cause implant failure and body contamination. We have previously shown that commercial anatase–titanium dioxide (TiO2–anatase) is deposited in organs with macrophagic activity, transported in the blood by phagocytic‐mononuclear cells, and induces an increase in the production of reactive oxygen species (ROS). In this study, we evaluated the effects of rutile–titanium dioxide (TiO2–rutile). Male Wistar rats were injected i.p. with a suspension of TiO2–rutile powder at a dose of 1.60 g/100 g b.w. Six months postinjection, the presence of Ti was assessed in serum, blood cells, liver, spleen, and lung. Titanium was found in phagocytic mononuclear cells, serum, and in the parenchyma of all the organs tested. TiO2–rutile generated a rise in the percentage of reactive cells, which was smaller than that observed when TiO2–anatase was employed in a previous study. Although TiO2–rutile provoked an augmentation of ROS, it failed to induce damage to membrane lipids, possibly due to an adaptive response. The present study reveals that TiO2–rutile is less bioreactive than TiO2–anatase. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
A low‐toxic and efficient gene vector: Carboxymethyl dextran‐graft‐polyethylenimine
Authors: Sun Yun‐Xia , Zhang Xian‐Zheng , Cheng Han , Cheng Si‐Xue , Zhuo Ren‐Xi
Published: August 2007

In this study, the low molecular weight branched polyethylenimine (PEI) (800 Da PEI) was grafted to the biodegradable and biocompatible carboxymethyl dextran (CMD) to obtain CMD‐g‐PEI, and the plasmid DNA was complexed with CMD‐g‐PEI polycation to form the polyion complex. The acid‐base titration profile showed that the CMD‐g‐PEI had endosomal disruption capacity, and the agarose gel electrophoresis suggested that the CMD‐g‐PEI could condense DNA efficiently. The transfection efficiency of CMD‐g‐PEI/DNA complexes was measured by luciferase and green fluorescent protein assay in HEK293 cells. The results revealed that the transfection efficiency of CMD‐g‐PEI at the N/P ratios over 30–70 was higher than or comparable to that of the 25 kDa PEI at optimal ratio (N/P = 10). The cytotoxicity of CMD‐g‐PEI as well as 25 kDa PEI was evaluated in NIH3T3 and HEK293 cells, respectively, and it was also found that the cytotoxicity of CMD‐g‐PEI was much lower than that of 25 kDa PEI. The resulted CMD‐g‐PEI with high transfection efficiency and low cytotoxicity have promising applications when used as gene vector. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Differential regulation of endothelial cell adhesion, spreading, and cytoskeleton on low‐density polyethylene by nanotopography and surface chemistry modification induced by argon plasma treatment
Authors: Tajima S. , Chu J.S.F. , Li S. , Komvopoulos K.
Published: August 2007

Plasma treatment of polymer surfaces can modify the nanoscale roughness, wettability, and oxygen surface functionalities. However, how these modifications regulate cell behavior is not well understood. The objective of this investigation was to examine adhesion, spreading, and cytoskeleton of vascular endothelial cells seeded on low‐density polyethylene surfaces modified by Ar plasma. In the absence of serum, adhesion and spreading of the cells and actin filament assembly were enhanced by high‐energy Ar plasma‐induced hydrophilicity and formation of CO groups at the surface. Although serum increased cell adhesion and spreading on untreated surfaces for a relatively short period, this behavior was not stable for a long time. In contrast to the untreated polymer surfaces, serum suppressed cell adhesion and spreading on the plasma‐treated surfaces. The preadsorption of albumin from the bovine serum on the polymer surfaces inhibited cell adhesion and spreading. Results demonstrate the differential effects of Ar plasma‐induced surface modifications on endothelial cell behavior and provide insight into complex interactions among polymer surfaces, adsorbed proteins, and cells. The findings of this study have significant implications in surface engineering for vascular repair. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Caspase‐dependent apoptosis induction by targeted expression of DEK in drosophila involves histone acetylation inhibition
Authors: Lee Kyu‐Sun , Kim Dong‐Wook , Kim Ji‐Young , Choo Jong‐Kil , Yu Kweon , Seo Sang‐Beom
Published: August 2007

As a nuclear phosphoprotein, proto‐oncogene protein DEK is capable to changing chromatin structure. DEK was recently identified as an inhibitor of histone acetylation mediated by p300 and PCAF and to facilitate transcriptional repression. To elucidate the biological functions of DEK in vivo, we have constructed transgenic flies that overexpress the human DEK in the developing eye. Transgenic flies developed a severe rough eye phenotype, which is indicative of ectopically induced apoptosis. Genetic and biochemical analyses, including the rescue of the apoptotic phenotype by pan‐caspase inhibitor protein p35 and caspase activity analyses, suggested that DEK induces apoptotic cell death through a caspases‐9 and ‐3 dependent pathway. Using extracts from larval salivary glands, we have determined that the global histone acetylation levels of histone H3 Lys9 and H4 Lys5 were decreased upon DEK overexpression. Using chromatin immunoprecipitation assays, we have demonstrated that overexpression of DEK induced the histone H3 and H4 hypoacetylation of promoter of the antiapoptotic gene bcl‐2. Co‐expression of bcl‐2 also rescued apoptosis and the reduced expression of bcl‐2 gene was analyzed by real‐time PCR. Our results indicate that acidic domain containing protein DEK might have a role in modulating both transcriptional regulation and apoptosis through HAT inhibitory activity. J. Cell. Biochem. 103: 1283–1293, 2008. © 2007 Wiley‐Liss, Inc.
Evaluation of VEGF‐mediated signaling in primary human cells reveals a paracrine action for VEGF in osteoblast‐mediated crosstalk to endothelial cells
Authors: Clarkin Claire E. , Emery Roger J. , Pitsillides Andrew A. , Wheeler‐Jones Caroline P.D.
Published: August 2007

Communication between endothelial and bone cells is crucial for controlling vascular supply during bone growth, remodeling, and repair but the molecular mechanisms coordinating this intercellular crosstalk remain ill‐defined. We have used primary human and rat long bone‐derived osteoblast‐like cells (HOB and LOB) and human umbilical vein endothelial cells (HUVEC) to interrogate the potential autocrine/paracrine role of vascular endothelial cell growth factor (VEGF) in osteoblast:endothelial cell (OB:EC) communication and examined whether prostaglandins (PG), known modulators of both OB and EC behavior, modify VEGF production. We found that the stable metabolite of PGI2, 6‐keto‐PGF1α and PGE2, induced a concentration‐dependent increase in VEGF release by HOBs but not ECs. In ECs, VEGF promoted early ERK1/2 activation, late cyclooxygenase‐2 (COX‐2) protein induction, and release of 6‐keto‐PGF1α. In marked contrast, no significant modulation of these events was observed in HOBs exposed to VEGF, but LOBs clearly exhibited COX‐dependent prostanoid release (10‐fold less than EC) following VEGF treatment. A low level of osteoblast‐like cell responsiveness to exogenous VEGF was supported by VEGFR2/Flk‐1 immunolabelling and by blockade of VEGF‐mediated prostanoid generation by a VEGFR tyrosine kinase inhibitor (TKI). HOB alkaline phosphatase (ALP) activity was increased following long‐term non‐contact co‐culture with ECs and exposure of ECs to VEGF in this system further increased OB‐like cell differentiation and markedly enhanced prostanoid release. Our studies confirm a paracrine EC‐mediated effect of VEGF on OB‐like cell behavior and are the first supporting a model in which prostanoids may facilitate this unidirectional VEGF‐driven OB:EC communication. These findings may offer novel regimes for modulating pathological bone remodeling anomalies through the control of the closely coupled vascular supply. J. Cell. Physiol. 214: 537–544, 2008. © 2007 Wiley‐Liss, Inc.
Design of a birdcage array for lower extremity angiography
Authors: Brown Ryan , Prince Martin R. , Ersoy Hale , Dooley Michael , Ho Bernard Y. , Mareyam Azma , Mohajer Kiyarash , Wang Yi
Published: August 2007

Purpose

To investigate the application of a coil array consisting of multiple birdcages for bolus chase magnetic resonance angiography (MRA) of the lower extremities.

Materials and Methods

The prototype consisted of four birdcage coils; two adjacent birdcages for thigh imaging, and two for calf imaging. Decoupling between adjacent coils was achieved using shared capacitors. Bench measurements and MR images were used to evaluate the decoupling scheme. Image signal‐to‐noise ratios (SNR) were compared between the birdcage array and four commercially available coils. Contrast‐enhanced imaging experiments were performed on 10 volunteers and parallel imaging was simulated. This study was approved by the local institutional review board and written informed consent was obtained from each volunteer.

Results

Capacitive decoupling resulted in a reduction in signal leakage. The calf birdcages provided an 84% SNR improvement over a four element array, while the thigh birdcages provided a 53% improvement. Angiographic images illustrated the utility of the coil for peripheral MRA. Parallel imaging was demonstrated with a two‐fold reduction factor.

Conclusion

Birdcage coils were demonstrated to be valuable for lower extremity imaging due to their homogenous sensitivity, good SNR, and cylindrical geometry. Coupling was controlled using shared capacitors that allowed a single birdcage to encompass each leg individually, providing a novel approach to signal reception for peripheral imaging. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Sentinel lymph node biopsy for breast cancer: How many nodes are enough?
Authors: Zakaria Shaheen , Degnim Amy C. , Kleer Celina G. , Diehl Kathleen A. , Cimmino Vincent M. , Chang Alfred E. , Newman Lisa A. , Sabel Michael S.
Published: August 2007

Introduction

Sentinel lymph node (SLN) biopsy using blue dye and radioisotope often results in the removal of multiple SLNs. We sought to determine whether there is a point where the surgeon can terminate the procedure without sacrificing accuracy.

Methods

One thousand one hundred ninety‐seven patients from University of Michigan and the Mayo Clinic undergoing SLN biopsy formed the study population. Surgeons removed all SLNs until counts within the axilla were less than 10% of the highest node ex vivo and recorded the order in which they were removed.

Results

The mean number of SLNs removed per patient was 2.5 (range 1–9). Approximately 42% of patients had three or more lymph nodes removed, while 19% had four or more lymph nodes removed. Eighteen percent of patients (132/725) at University of Michigan and 22% (103/472) at Mayo Clinic had a positive SLN. Ninety‐eight percent (231/235) of patients with lymph node metastases were identified by the 3rd SLN while 100% were identified by the 4th SLN.

Conclusion

Among patients undergoing SLN biopsy for breast cancer, the only positive SLN is rarely identified in the 4th or higher node. Terminating the procedure at the 4th node may lower the cost of the procedure and reduce morbidity. J. Surg. Oncol. 2007;96:554–559. © 2007 Wiley‐Liss, Inc.
High-gain Raman induced multiple Stokes and anti-Stokes generation in monoclinic multiferroic MnWO4single crystals
Authors: Becker P , Bohatý L , Eichler H J , Rhee H , Kaminskii A A
Published: August 2007

Multiple Stokes and anti-Stokes generation in the monoclinic tungstate MnWO4was observed under one-micron picosecond excitation. All the recorded Raman induced laser lines were identified and attributed to the SRS-promoted vibration mode (at ≈ 879 cm-1) of the crystal.
Novel Biodegradable Poly(1,8‐octanediol malate) for Annulus Fibrosus Regeneration
Authors: Wan Yuqing , Feng Gang , Shen Francis H. , Balian Gary , Laurencin Cato T. , Li Xudong
Published: August 2007

A novel elastic scaffold that simulates the deformability of annulus fibrosus (AF) and has good biocompatibility was developed. The scaffold was formed of a malic acid‐based polyester poly(1,8‐octanediol malate) (POM), which was synthesized by direct polycondensation. The tensile strength of POM gradually increased with the extension of the polymerization time, while the degradation rate decreased. Rat AF cells proliferated on the POM films and maintained their phenotype. The 3D scaffold also supported the growth of the AF cells, as confirmed by Safranin‐O and type II collagen staining. POM also demonstrated a good biocompatibility in an in vivo foreign body response assay, an important prerequisite for tissue engineering applications. This study suggests that elastic POM scaffold may be an ideal candidate for AF tissue engineering.

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NLO Behavior of Polymers Containing Y‐Shaped Chromophores
Authors: Carella Antonio , Borbone Fabio , Caruso Ugo , Centore Roberto , Roviello Antonio , Barsella Alberto , Quatela Alessia
Published: August 2007

New polyurethanes containing Y‐shaped chromophores, symmetrical derivatives of 4‐(dicyanomethylene)‐2‐methyl‐6‐[p‐(dimethylamino)styryl]‐4H‐pyran, have been prepared. The polymers show high glass transition temperatures (Tg) and a good thermal stability. SHG measurements on poled polymer films of the synthesized polymers have been carried out and a maximum d33 of 15 pm · V−1 has been found at 1 368 nm fundamental wavelength. Time stability measurements on the most active polymer have shown that after the initial fast relaxation, the d33 value remains constant at 80 °C for 60 d.

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Estimates of the first Neumann eigenvalue and the log‐Sobolev constant on non‐convex manifolds
Authors: Wang Feng‐Yu
Published: August 2007

In this paper a number of explicit lower bounds are presented for the first Neumann eigenvalue on non‐convex manifolds. The main idea to derive these estimates is to make a conformal change of the metric such that the manifold is convex under the new metric, which enables one to apply known results obtained in the convex case. This method also works for more general functional inequalities. In particular, some explicit lower bounds are presented for the log‐Sobolev constant on non‐convex manifolds. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The first Dirichlet eigenvalue of a compact manifold and the Yang conjecture
Authors: Ling Jun
Published: August 2007

We give a new estimate on the lower bound of the first Dirichlet eigenvalue of a compact Riemannian manifold with negative lower bound of Ricci curvature and provide a solution for a conjecture of H. C. Yang. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On nodal sextic fivefold
Authors: Cheltsov Ivan
Published: August 2007

We prove birational superrigidity and nonrationality of every sextic fivefold with ordinary double points. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Possibilities and extension of XRD material response analysis in failure research for the advanced evaluation of the damage level of Hertzian loaded components
Authors: Gegner J. , Nierlich W. , Brückner M.
Published: August 2007

Due to clearly distinguishable damage symptoms, it is differentiated between the surface and sub‐surface failure mode of rolling bearings. Material states red out by X‐ray diffraction (XRD) residual stress measurements point to a variety of loading conditions especially at raceway surfaces that are associated with several competing failure mechanisms. The corresponding lifetime reduction can range from the lower fatigue strength region to material ratcheting in extreme cases. Relevant position of the microstructural changes and nature of the failure mechanisms are characterized. The time alteration of the XRD material parameters measured at or near the surface and at the depth of the maximum equivalent stress correlates, in a different manner, with the statistical parameter of the 10 % bearing life. Both failure modes are illustrated by concrete examples. Contaminated lubricant and boundary lubrication, which represent practically important surface‐induced failures, are discussed in more detail. Gray staining, i.e. shallow pitting, often occurs without distinct indication of global material aging by means of XRD characteristics. Here, scanning electron microscopy observations and electron microprobe analyses point to corrosion fatigue as acting surface failure mechanism. The interaction between material and lubricant under complex loading regimes particularly of mixed friction and corrosion opens further failure research areas in the field of tribology.
Über die Beanspruchung oberflächennaher Werkstoffbereiche von Zahnflanken bei Voll‐ und Mangelschmierung
Authors: Schlicht H. , Broszeit E.
Published: August 2007

Bei Zahnradpaarungen, die längere Zeit beansprucht sind, entstehen an den Flanken häufig Risse. Deren Verteilung und deren Ausrichtung zur Flankenoberfläche lassen sich aus der Kinematik des Abrollens erklären. Die Risse bilden zur Oberfläche einen Winkel zwischen 20 ° und 40 ° und sind den auftretenden Tangentialspannungen entgegengesetzt. Nur im negativen Schlupfbereich wachsen die Risse weiter zu Sekundärrissen; vorwiegend dort kommt es zu Ausbrüchen.

Die übliche Berechnung der Werkstoffbeanspruchung oberflächennaher Bereiche aus der Hertz`schen Pressungsverteilung für die Normalspannungen kombiniert mit dem Coulomb`schen Reibungsgesetz für die Tangentialspannungen liefert keinen Hinweis auf einen bevorzugt gefährdeten Flankenbereich mit negativem Schlupf. Die unterschiedlichen Schadensphänomene lassen sich jedoch aus der EHD‐Strömungshypothese erklären. Diese Hypothese macht deutlich, dass die Schmierstoffströmung zusätzliche Beanspruchungen verursacht, die die Lebensdauer beeinflussen und den nach Hertz ermittelten Wert verkürzen.
Botulinum toxin treatment of lateral axial dystonia in parkinsonism
Authors: Bonanni Laura , Thomas Astrid , Varanese Sara , Scorrano Vincenzo , Onofrj Marco
Published: August 2007

Lateral axial dystonia (LAD) has been described in patients with Parkinson's disease (PD), but treatment might be more controversial than treatment of LAD in other neurological conditions. Our study was designed as a blinded cross‐over with botulinum toxin (BTX) and placebo in order to investigate the efficacy of BTX in PD LAD. Nine patients with LAD who failed to experience benefit from oral medications were randomly assigned to 2 groups, 4 patients received BTX and 5 placebo as a first treatment, and were switched‐over to BTX or placebo in the following treatment session, performed 3 months after the first session. Each patient was evaluated at baseline, 2 and 4 weeks after injection and after 3 months follow‐up with the Trunk Dystonia Disability Scale (TDDS), a Visual Analogue Scale (VAS) and a goniometric measurement of the lateral displacement. Patients were videotaped at each visit. None of the patients of the placebo group experienced benefit from treatment. BTX treatment was effective in 6 patients. One patient reported subjective benefit, with improvement of VAS score and mild improvement of TDDS score, but with no improvement of flexion degree. Two patients did not report any benefit. Four patients opted to continue to receive BTX treatment for 2 years after the cross‐over study. Our study shows that BTX could be considered a possible treatment for LAD in parkinsonism. © 2007 Movement Disorder Society
High‐resolution time‐resolved contrast‐enhanced MR abdominal and pulmonary angiography using a spiral‐TRICKS sequence
Authors: Du Jiang , Bydder Mark
Published: August 2007

Both high spatial resolution and high temporal resolution are desirable for contrast‐enhanced magnetic resonance angiography (CE‐MRA) in order to depict the arterial vasculature. In this work a fast MR pulse sequence (spiral time‐resolved imaging with contrast kinetics (Spiral‐TRICKS)) with spiral readout in‐plane and Cartesian slice encoding was developed whereby the slices are partitioned into multiple regions and acquired in the order used with the TRICKS sequence. The combination of highly efficient spiral sampling with TRICKS acquisition significantly reduced imaging time requirements. A unit second temporal reconstructed frame rate could be achieved for three‐dimensional (3D) CE‐MRA without undersampling of the spiral trajectories. Image quality was improved through spiral trajectory measurement and field‐map correction. Phantom and volunteer studies were performed to demonstrate the feasibility of this technique. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.