bluuebunny/crossref_metadata_2025 huggingface dataset:
Poly(ethylene terephthalate)/expanded graphite conductive composites: Structure, properties, and transport behavior
Authors: Zhang Ming , Li Da‐Jun , Wu De‐Feng , Yan Chang‐Hao , Lu Ping , Qiu Guan‐Ming
Published: January 2008

Poly(ethylene terephthalate)/expanded graphite conductive composites were prepared by the melt‐blending method. The relationships between the preparation methods, microstructures, and conductivity properties of the composites were studied with scanning electron microscopy and conductivity measurements. The results showed that the composites presented a low percolation threshold and strong anisotropic conductivity. The epoxy resin had a strong intercalation effect on the expanded graphite that led to the easy formation of the conductive network. With classical statistical percolation theory, the conductivity behaviors of the composites were investigated. The results indicated that the nonuniversal critical exponent should be attributed to the anisotropy of conductivity, the tunneling conduction, and the particular structure. In addition, preliminary studies on the crystallization and dynamic mechanical behavior of the composites were performed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Micro and nano fibrils from polypropylene/nylon 6 blends
Authors: Fallahi E. , Barmar M. , Kish M. Haghighat
Published: January 2008

Some previous publications are pointed out to put forward a technique to make fibrils in the range of micro and nano. Blends of polypropylene, nylon 6, and polypropylene grafted with maleic anhydride as compatibilizer were spun into continuous filaments by a laboratory extruder. In a sample containing 70% nylon 6, 25% polypropylene, and 5% polypropylene grafted with maleic anhydride, nylon 6 component that forms the matrix of the blend was dissolved in the solution of formic acid (98%) to leave the other component as micro and/or nanofibrils. The remaining polypropylene fibrils were examined by polarizing microscopy, scanning electron microscopy, FTIR spectroscopy, differential scanning calorimetry, and wide angle X‐ray diffraction. The extracted fibrils were found to be partially crystalline having melting temperature close to the neat polypropylene. The fibrils have diameter less than one micrometer. The diameter of the fibrils decreases by cold drawing. This particular finding suggests a possibility for making mat containing micro and nanofibers from polypropylene. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
The Analysis of Stratified Multiple Responses
Authors: Liu Ivy , Suesse Thomas
Published: January 2008

Surveys often contain qualitative variables for which respondents may select any number of the outcome categories. For instance, for the question “What type of contraception have you used?” with possible responses (oral, condom, lubricated condom, spermicide, and diaphragm), respondents would be instructed to select as many of the outcomes that apply. This situation is known as multiple responses. When the data includes stratification variables, we discuss two approaches: (1) the “GEE” approach which uses logit models directly applying the generalized estimating equations (GEE) method (Liang and Zeger, 1986); and (2) the “GMH” approach which extends the generalized Mantel–Haenszel type estimators (Greenland, 1989) to make inferences across multiple responses. These approaches can also be used for data with dependent observations across strata. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inference of Haplotype Effects in Case‐Control Studies Using Unphased Genotype and Environmental Data
Authors: Chen Xiaowu , Li Zhaohai
Published: January 2008

A retrospective likelihood‐based approach was proposed to test and estimate the effect of haplotype on disease risk using unphased genotype data with adjustment for environmental covariates. The proposed method was also extended to handle the data in which the haplotype and environmental covariates are not independent. Likelihood ratio tests were constructed to test the effects of haplotype and gene‐environment interaction. The model parameters such as haplotype effect size was estimated using an Expectation Conditional‐Maximization (ECM) algorithm developed by Meng and Rubin (1993). Model‐based variance estimates were derived using the observed information matrix. Simulation studies were conducted for three different genetic effect models, including dominant effect, recessive effect, and additive effect. The results showed that the proposed method generated unbiased parameter estimates, proper type I error, and true β coverage probabilities. The model performed well with small or large sample sizes, as well as short or long haplotypes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biostatistical Aspects of Genome‐Wide Association Studies
Authors: Ziegler Andreas , König Inke R. , Thompson John R.
Published: January 2008

To search the entire human genome for association is a novel and promising approach to unravelling the genetic basis of complex genetic diseases. In these genome‐wide association studies (GWAs), several hundreds of thousands of single nucleotide polymorphisms (SNPs) are analyzed at the same time, posing substantial biostatistical and computational challenges. In this paper, we discuss a number of biostatistical aspects of GWAs in detail. We specifically consider quality control issues and show that signal intensity plots are a sine qua condition non in today's GWAs. Approaches to detect and adjust for population stratification are briefly examined. We discuss different strategies aimed at tackling the problem of multiple testing, including adjustment of p ‐values, the false positive report probability and the false discovery rate. Another aspect of GWAs requiring special attention is the search for gene‐gene and gene‐environment interactions. We finally describe multistage approaches to GWAs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cross‐over: A generalizable phenomenon necessary for secondary intraneural ganglion cyst formation
Authors: Spinner Robert J. , Amrami Kimberly K. , Wang Huan , Kliot Michel , Carmichael Stephen W.
Published: January 2008

The appearances of intraneural ganglion cysts are being elucidated. We previously introduced the cross‐over phenomenon to explain how a fibular (peroneal) or tibial intraneural ganglion cyst arising from the superior tibiofibular joint could give rise to multiple cysts: cyst fluid ascending up the primarily affected nerve could reach the level of the sciatic nerve, fill its common epineurial sheath and spread circumferentially (cross over), at which time pressure fluxes could result in further ascent up the sciatic or descent down the same parent nerve or the opposite, previously unaffected fibular or tibial nerves. In this study, we hypothesized that cross‐over could occur in other nerves, potentially leading to the formation of more than one intraneural ganglion cyst in such situations. We analyzed the literature and identified a single case that we could review where proximal extension of an intraneural ganglion cyst involving a nerve at a different site could theoretically undergo cross‐over in another major nerve large enough for available magnetic resonance images to resolve this finding. A case of a suprascapular intraneural ganglion cyst previously reported by our group that arose from the glenohumeral joint and extended to the neck was reanalyzed for the presence or absence of cross‐over. An injection of dye into the outer epineurium of the suprascapular nerve in a fresh cadaveric specimen was performed to test for cross‐over experimentally. Retrospective review of this case of suprascapular intraneural ganglion cyst demonstrated evidence to support previously unrecognized cross‐over at the level of the upper trunk, with predominant ascent up the C5 and the C6 nerve roots and subtle descent down the anterior and posterior divisions of the upper trunk as well as the proximal portion of the suprascapular nerve. This appearance gave rise to multiple interconnected intraneural ganglion cysts arising from a single distant connection to the glenohumeral joint. The injection study also demonstrated the cross‐over phenomenon and produced a similar pattern as the cyst dissection. This article illustrates that cross‐over can occur in another nerve (apart from the prototype fibular nerve). Furthermore, understanding the more complex anatomic nature of the upper trunk cross‐over model provides insight into important mechanistic information regarding the bidirectional propagation patterns and formation of primary and secondary intraneural ganglion cysts not afforded by the previously described sciatic nerve cross‐over model. Clin. Anat. 21:111–118, 2008. © 2008 Wiley‐Liss, Inc.
Emission under Hypoxia: One‐Electron Reduction and Fluorescence Characteristics of an Indolequinone–Coumarin Conjugate
Authors: Tanabe Kazuhito , Hirata Nao , Harada Hiroshi , Hiraoka Masahiro , Nishimoto Sei‐ichi
Published: January 2008

A characteristic feature of the reactivity of indolequinone derivatives, substituents of which can be removed by one‐electron reduction under hypoxic conditions, was applied to the development of a new class of fluorescent probes for disease‐relevant hypoxia. A reducing indolequinone parent molecule conjugated with fluorescent coumarin chromophores could suppress efficiently the fluorescence emission of the coumarin moieties by an intramolecular electron‐transfer quenching mechanism and a conventional internal‐filter effect. Under hypoxic conditions, however, the conjugate, denoted IQ‐Cou, underwent a one‐electron reduction triggered by X irradiation or the action of a reduction enzyme to release a fluorescent coumarin chromophore, whereupon an intense fluorescence emission with a maximum intensity at 420 nm was observed. The one‐electron reduction of IQ‐Cou was suppressed by molecular oxygen under aerobic conditions. IQ‐Cou also showed intense fluorescence in a hypoxia‐selective manner upon incubation with a cell lysate of the human fibrosarcoma cell line HT‐1080. The IQ‐Cou conjugate has several unique properties that are favorable for a fluorescent probe of hypoxia‐specific imaging.
Amphotericin B lipid complex versus liposomal amphotericin B monotherapy for invasive aspergillosis in patients with hematologic malignancy
Authors: Hachem Ray Y. , Boktour Maha R. , Hanna Hend A. , Husni Rola N. , Torres Harrys A. , Afif Claude , Kontoyiannis Dimitrios P. , Raad Issam I.
Published: January 2008

BACKGROUND.

Invasive aspergillosis (IA) is a major cause of morbidity and mortality in patients with hematologic malignancy (HM). There are 2 lipid formulations of amphotericin B (AMB) currently in widespread use: AMB lipid complex (ABLC) and liposomal AMB (L‐AMB). There are limited data comparing the efficacy and safety of these 2 agents in the treatment of IA in patients with cancer.

METHODS.

The authors retrospectively studied 381 consecutive patients with HM who had proven or probable IA (according to European Organization for Research and Treatment of Cancer/Mycosis Study Group of the National Institute of Allergy and Infectious Diseases criteria) between June 1993 and December 2005. Of these patients, 158 received primary antifungal therapy with either L‐AMB (n = 106) or ABLC (n = 52). The number of salvage antifungal regimens given were 51 L‐AMB regimens and 30 ABLC regimens. It should be noted that the population described in this report was not typical of the hematologic cancer population with IA because of the advanced stage and the severity of the underlying diseases.

RESULTS.

Risk factors for IA, such as underlying malignancy, neutropenia, steroid use, admission to an intensive care unit, and the presence of graft‐versus‐host disease, were comparable among the study drug group in the primary or salvage setting. Likewise, comparable distribution of types of Aspergillus species and the presence of disseminated IA were observed. Response to primary or salvage therapy was equally poor in both drug study groups regardless of treatment modality (range, 7.7–15.8% response). In the primary therapy group, ABLC was associated with significantly higher nephrotoxicity than L‐AMB (P < .001).

CONCLUSIONS.

Among patients with HM, primary therapy and salvage therapy for IA with either ABLC or L‐AMB as single agent were associated equally with poor outcome. L‐AMB appeared to be less nephrotoxic in the primary therapy setting. Cancer 2008. © 2008 American Cancer Society.
Fibroblast growth factor homologous factor 1 (FHF1) is expressed in a subpopulation of calcitonin gene‐related peptide‐positive nociceptive neurons in the murine dorsal root ganglia
Authors: Hubert Thomas , Bourane Steeve , Ventéo Stéphanie , Mechaly Ilana , Puech Sylvie , Valmier Jean , Carroll Patrick , Fichard‐Carroll Agnès
Published: January 2008

Dorsal root ganglia (DRG) neurons exhibit a wide molecular heterogeneity in relation to the various sensory modalities (mechanoception, thermoception, nociception) that they subserve. Finding markers of subpopulations is an important step in understanding how these neurons convey specific information. We identified fibroblast growth factor homologous factor 1 (FHF1) in a search for markers of subpopulations of DRG neurons. FHFs constitute a family of four factors that share some structural properties with fibroblast growth factors (FGFs) but are functionally distinct. They are expressed in specific subsets of neurons and are involved in the modulation of sodium channel activity. The pattern of expression of FHF1 in the DRG was determined during development, in the adult and after axotomy. We show that in the adult, FHF1 is expressed in two populations, one composed of nociceptors and another in which no neurotrophic factor receptors were detected (panTrk−/c‐Ret−). Interestingly, in the nociceptors, FHF1 expression was restricted to a subset of TrkA+/calcitonin gene‐related peptide (CGRP)‐positive neurons. Neurofilament 200 (NF‐200) and peripherin labeling indicates that 70% of the FHF1‐expressing neurons contribute to A‐fibers and 30% to C‐fibers. FHF1 interacts with the Nav1.9 sodium channel isoform, which is strongly expressed in cRet+/isolectin‐B4 binding neurons, but we show that FHF1 is not expressed in the cRet+/IB4+ subclass and that it does not colocalize with Nav1.9. Our results argue strongly against the possibility that FHF1 has a modulatory effect on this channel in cRet+/IB4+ neurons, but FHF1 could play a role in a distinct subset of TrkA+/CGRP+ nociceptors. J. Comp. Neurol. 507:1588–1601, 2008. © 2008 Wiley‐Liss, Inc.
Brain distribution and evidence for both central and neurohormonal actions of cocaine‐ and amphetamine‐regulated transcript peptide inXenopus laevis
Authors: Roubos Eric W. , Lázár Gyula , Calle Marinella , Barendregt Henk P. , Gaszner Balázs , Kozicz Tamás
Published: January 2008

We tested the hypothesis that, in the amphibianXenopus laevis, cocaine‐ and amphetamine‐regulated transcript peptide (CARTp) not only has widespread actions in the brain but also acts as a local factor in endocrine pituitary cells and/or is neurohemally secreted into the circulation to control peripheral targets. CARTp‐immunoreactive cells occur in the olfactory bulb, nucleus accumbens, amygdala, septum, striatum, nucleus of Bellonci, ventrolateral nucleus, central thalamic nucleus, preoptic nuclei, and suprachiasmatic nucleus, and particularly in the medial pallium, ventromedial nucleus, hypothalamus, Edinger‐Westphal nucleus, optic tectum, raphe nuclei, central gray, nucleus of the solitary tract, and spinal cord. From the hypothalamic magnocellular nucleus, CARTp‐containing axons run to the neurohemal median eminence, and to the neural pituitary lobe to form neurohemal terminals, as shown by immunoelectron microscopy. Starvation increases the number of CARTp‐cells in the optic tectum by 46% but has no effect on such cells in the torus semicircularis. CARTp does not affect in vitro release of α‐melanophore‐stimulating hormone from pituitary melanotrope cells. Our results support the hypothesis that inX. laevis, CARTp not only has multiple and not exclusively feeding‐related actions in the brain but is also secreted as a neurohormone 1) into the portal system to control endocrine targets in the pituitary distal lobe and 2) from neurohemal axon terminals in the neural pituitary lobe to act peripherally. The differences in CARTp distribution betweenX. laevisandRana esculentamay be related to different environmental and physiological conditions such as feeding, sensory information processing, and locomotion. J. Comp. Neurol. 507:1622–1638, 2008. © 2008 Wiley‐Liss, Inc.
The mechanical response of Achilles tendon during different kinds of sports
Authors: Gu Y. D. , Li J. S. , Lake M. J. , Ren X. J. , Zeng Y. J.
Published: January 2008

The present study investigated the mechanical properties of human Achilles tendon (AT) during different forms of human locomotion, by combining biomechanical tests and numerical modelling. A Pedar‐X plantar pressure measurement system and Mega multichannel SEMG system were used to measure the dynamic data of a female athlete during hopping and walking. The human Achilles tendon force (ATF) was determined through inverse muscle force calculation. A 3D finite element (FE) model was developed using subject‐specified CT images to simulate the deformation of AT during hopping and walking. The stress/strain within the AT during different subphases (e.g. heel strike, midstance, forefoot contact, push off and toe off) was successfully predicted. Results showed that the muscle forces in hopping were much higher than in normal gait. The maximum stress in hopping was three times of that in walking. The tendon stress increased with external load over different subphases and the maximum ATF was found to be in the push‐off phase. Copyright © 2008 John Wiley & Sons, Ltd.
Static and Frequency‐Dependent Dipole–Dipole Polarizabilities of All Closed‐Shell Atoms up to Radium: A Four‐Component Relativistic DFT Study
Authors: Bast Radovan , Heßelmann Andreas , Sałek Paweł , Helgaker Trygve , Saue Trond
Published: January 2008

We test the performance of four‐component relativistic density functional theory by calculating the static and frequency‐dependent electric dipole–dipole polarizabilities of all (ground‐state) closed‐shell atoms up to Ra. We consider 12 nonrelativistic functionals, including three asymptotically shape‐corrected functionals, by using two smooth interpolation schemes introduced by the Baerends group: the gradient‐regulated asymptotic connection (GRAC) procedure and the statistical averaging of (model) orbital potentials (SAOP). Basis sets of doubly augmented triple‐zeta quality are used. The results are compared to experimental data or to accurate ab initio results. The reference static electric dipole polarizability of palladium has been obtained by finite‐field calculations using the coupled‐cluster singles, doubles, and perturbative triples method within this work. The best overall performance is obtained using hybrid functionals and their GRAC shape‐corrected versions. The performance of SAOP is among the best for nonhybrid functionals for Group 18 atoms but its precision degrades when considering the full set of atoms. In general, we find that conclusions based on results obtained for the rare‐gas atoms are not necessarily representative of the complete set of atoms. GRAC cannot be used with effective core potentials since the asymptotic correction is switched on in the core region.
Wnt6 expression in epidermis and epithelial tissues during Xenopus organogenesis
Authors: Lavery Danielle L. , Davenport Ian R. , Turnbull Yvonne D. , Wheeler Grant N. , Hoppler Stefan
Published: January 2008

Here, we report the localization within embryonic tissues of xWnt6 protein; together with the temporal and spatial expression of Xenopus laevis Wnt6 mRNA. Wnt6 expression in Xenopus embryos is low until later stages of neurulation, when it is predominantly found in the surface ectoderm. Wnt6 expression increases during early organogenesis in the epidermis overlaying several developing organs, including the eye, heart, and pronephros. At later stages of development, Wnt6 mRNA and protein generally localize in epithelial tissues and specifically within the epithelial tissues of these developing organs. Wnt6 localization correlates closely with sites of both epithelial to mesenchymal transformations and mesenchymal to epithelial transformations. Xenopus Wnt6 sequence and its expression pattern are highly conserved with other vertebrates. Xenopus embryos, therefore, provide an excellent model system for investigating the function of vertebrate Wnt6 in organ development and regulation of tissue architecture. Developmental Dynamics 237:768–779, 2008. © 2008 Wiley‐Liss, Inc.
Membrane dynamics of cleavage furrow closure in Xenopus laevis
Authors: Danilchik Michael V. , Brown Elizabeth E.
Published: January 2008

Epithelial membrane polarity develops early in Xenopus development, with membrane inserted along the earliest cleavage furrows by means of localized exocytosis. The added surface constitutes a new basolateral domain important for early morphogenesis. This basolateral surface becomes isolated from the outside by furrow closure, a zippering of adjacent apical–basolateral margins. Time‐lapse microscopy of membrane‐labeled embryos revealed two distinct kinds of protrusive activity in furrow closure. Early in furrowing, protrusive activity was associated with purse‐string contractility along the apical–basolateral margins. Later in furrow progression, a basolateral protrusive zone developed entirely within the new membrane domain, with long motile filopodia extending in contractile bands from the exposed surfaces. Filopodia interacting with opposing cell surfaces across the cleavage furrow appeared to mediate blastomere–blastomere adhesion, contact spreading and lamellipodial protrusion. Interference with these dynamic activities prevented furrow closure, indicating a basic role for both marginal and basolateral protrusive activities in early embryogenesis. Developmental Dynamics 237:565–579, 2008. © 2008 Wiley‐Liss, Inc.
Structural Effects of Codoping of Nb and Sc in Titanium Dioxide Nanoparticles
Authors: Ahmad Akhlaq , Shah Jawad Ali , Buzby Scott , Shah Syed Ismat
Published: January 2008

Nanoparticles of TiO2codoped with 0.5, 0.75, and 1 atom‐% Nb and Sc each were synthesized by sol–gel technique. After drying, as‐synthesized samples were calcined at temperatures ranging from 250–900 °C. Changes in phase transformation of the doped samples with reference to dopant concentration and calcination temperature have been studied. The samples were analyzed by various analytical tools such as XRD, SEM, TEM, XPS, and EDS. The XRD results indicate that the presence of Nb and Sc substitutional ions in the anatase crystal structure inhibits the phase transition and growth of the nanoparticles with an increase in temperature. The XPS results indicate the incorporation of Nb as Nb2O5and Sc as Sc2O3.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Nanostructure Evolution: From Aggregated to Spherical SiO2 Particles Made in Diffusion Flames
Authors: Camenzind Adrian , Schulz Heiko , Teleki Alexandra , Beaucage Gregory , Narayanan Theyencheri , Pratsinis Sotiris E.
Published: January 2008

The formation of nanostructured silica particles by oxidation of hexamethyldisiloxane (HMDSO) in co‐annular diffusion flames is investigated by in‐situ small‐angle X‐ray scattering (SAXS). This enabled the nonintrusive monitoring of the mass fractal dimension, the aggregate size, and the number of primary particles per aggregate, along with the silica volume fraction, the primary particle diameter, the geometric standard deviation, and the number density along the flame axis. Parallel to this, thermophoretic sampling (TS) of the particles and analysis by transmission electron microscopy (TEM) allowed for direct comparison of particle morphology to that obtained from the above SAXS analysis, which were compared also to the ultra‐small‐angle X‐ray scattering (USAXS) data for product particles collected from the filter. The flame temperature was measured by in‐situ Fourier transform infrared (FTIR) spectroscopy. By increasing the oxygen flow rate, the laminar diffusion flame changed to a turbulent, premixed‐like flame. Non‐aggregated, spherical particles were formed in the former, while aggregates were formed in the latter flame. The relatively long high‐temperature particle residence times in the laminar diffusion flame facilitated sintering of the aggregates formed earlier into compact spherical particles at later stages of the flame.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Design‐based empirical orthogonal function model for environmental monitoring data analysis
Authors: Munoz Breda , Lesser Virginia M. , Ramsey Fred L.
Published: January 2008

An empirical orthogonal function (EOF) model is proposed as a prediction method for data collected over space and time. EOF models are widely used in a number of disciplines, including Meteorology and Oceanography. The appealing feature of this model is the advantage of not requiring any assumption for the covariance matrix structure. However, there is a need to account for the errors associated with the spatial and temporal features of the data. This is accomplished by incorporating information from the sampling design, used to establish the network, into the model. The theoretical developments and numerical solutions are presented in the first section of the paper. An application of the model to real data and the results of validation analyses are also presented. Copyright © 2008 John Wiley & Sons, Ltd.
Low‐cost implicit schemes for all‐speed flows on unstructured meshes
Authors: Kloczko T. , Corre C. , Beccantini A.
Published: January 2008

Matrix‐free implicit treatments are now commonly used for computing compressible flow problems: a reduced cost per iteration and low‐memory requirements are their most attractive features. This paper explains how it is possible to preserve these features for all‐speed flows, in spite of the use of a low‐Mach preconditioning matrix. The proposed approach exploits a particular property of a widely used low‐Mach preconditioner proposed by Turkel. Its efficiency is demonstrated on some steady and unsteady applications. Copyright © 2008 John Wiley & Sons, Ltd.
The lysosomal-mitochondrial axis in free fatty acid–induced hepatic lipotoxicity
Authors: Li ZhengZheng , Berk Michael , McIntyre Thomas M. , Gores Gregory J. , Feldstein Ariel E.
Published: January 2008

Impaired mitochondrial function is largely thought to be a core abnormality responsible for disease progression in nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanisms resulting in mitochondrial dysfunction in NAFLD remain poorly understood. This study examined the effects of excessive accumulation of free fatty acids (FFAs) in liver cells on mitochondrial function and the role of the lysosomal-mitochondrial axis on lipotoxicity. Primary mouse hepatocytes, HepG2 and McNtcp.24 cells, were treated with varied concentrations of FFAs with different degrees of saturation for up to 24 hours. Mitochondrial function was monitored by real-time imaging, cytochrome c redistribution, and reactive oxygen species (ROS) production. The temporal relationship of lysosomal and mitochondrial permeabilization was established. Activity of the lysosomal protease cathepsin B was suppressed by genetic and pharmacological approaches. Cathepsin B–knockout mice and wild-type animals were place on a high-carbohydrate diet for 16 weeks, and mitochondrial function and liver damage were assessed. Exposure of liver cells to saturated FFAs resulted in mitochondrial depolarization, cytochrome c release, and increased ROS production. Lysosomal permeabilization and cathepsin B redistribution into the cytoplasm occurred several hours prior to mitochondrial dysfunction. Either pharmacological or genetic inhibition of cathepsin B preserved mitochondrial function. Finally, cathepsin B inactivation protected mitochondria, decreased oxidative stress, and attenuated hepatic injury

in vivo.

Conclusion:

These data strongly suggest excessive accumulation of saturated FFAs in liver cells directly induce mitochondrial dysfunction and oxidative stress. Our data further suggest this process is dependent on lysosomal disruption and activation of cathepsin B.
Clearance of hepatitis C virus RNA from the peripheral blood mononuclear cells of blood donors who spontaneously or therapeutically control their plasma viremia
Authors: Bernardin Flavien , Tobler Leslie , Walsh Irina , Williams Joan Dunn , Busch Mike , Delwart Eric
Published: January 2008

We determined whether hepatitis C virus (HCV) RNA could be detected associated with peripheral blood mononuclear cells (PBMC) of seropositive blood donors who had spontaneously or therapeutically cleared their plasma viremia. Blood donor plasma viremia status was first determined with a highly sensitive transcription-mediated amplification (TMA) test performed in duplicate assays. PBMC from 69 aviremic and 56 viremic blood donors were then analyzed for the presence of HCV RNA with TMA adapted to detect viral RNA in PBMC and with a reverse transcription–nested polymerase chain reaction assay. PBMC-associated HCV RNA was detected in none of the 69 aviremic donors, including all 6 subjects with a sustained viral response following antiviral therapy. PBMC-associated HCV RNA was detected in 43 of the 56 viremic donors. The 13 viremic donors with no detectable PBMC-associated HCV RNA all had very low viral loads (6 positive only in 1 of 2 duplicate plasma TMA assays, 6 with viral loads below 100 HCV RNA copies/mL, and 1 with a viremia of 2700 HCV RNA copies/mL). The absence of detectable PBMC HCV RNA detection in all 69 aviremic donors reported here contrasts with prior studies, possibly as a result of the higher sensitivity of the TMA assay used to test for plasma viremia.

Conclusion:

Our results indicate that PBMC are unlikely to serve as a long-lived reservoir of HCV in aviremic subjects.
Activation of the α2β1 integrin‐mediated malignant phenotype on type I collagen in pancreatic cancer cells by shifts in the concentrations of extracellular Mg2+ and Ca2+
Authors: Grzesiak John J. , Bouvet Michael
Published: January 2008

The authors have previously demonstrated that α2β1 integrin‐mediated pancreatic cancer cell adhesion to Type I collagen is Mg2+‐dependent, inhibited by Ca2+, and that this integrin, purified from cell lysates using Type I‐collagen‐sepharose in Mg2+, can be eluted with Ca2+. In the present study, the authors examined the divalent cation‐dependency of α2β1 integrin‐mediated pancreatic cancer cell adhesion, migration and proliferation on Type I collagen, an extracellular matrix protein shown to be highly up‐regulated, and to promote the malignant phenotype in vitro and in vivo. The results indicate that cells attach to Type I collagen maximally when Mg2+ is greater than 1 mM, and that addition of increasing concentrations of Ca2+ reduces this adhesion. These effects are reversible, in that previous cell attachment in Mg2+ can be reversed by adding Ca2+, and vice versa. They also demonstrate that pancreatic cancer cells migrate and proliferate on Type I collagen in Mg2+ alone, but maximally when Mg2+ is present at concentrations that promote maximal cell adhesion and Ca2+ is present at concentrations less than Mg2+. Cell adhesion and proliferation assays, as well as affinity chromatography on Type I collagen using anti‐integrin function‐blocking monoclonal antibodies indicate that the effects of these divalent cation shifts are mediated specifically by the α2β1 integrin. As pancreatic juice contains over 1,200‐fold more Mg2+ than Ca2+ and solid tumors are characterized by increased magnesium load, these data indicate that such pathophysiological divalent cation shifts could be involved in the activation of the α2β1 integrin‐mediated malignant phenotype on Type I collagen in the pancreatic cancer. © 2008 Wiley‐Liss, Inc.
Treatment with ozone/oxygen‐pneumoperitoneum results in complete remission of rabbit squamous cell carcinomas
Authors: Schulz Siegfried , Häussler Ulrich , Mandic Robert , Heverhagen Johannes T. , Neubauer Andreas , Dünne Anja A. , Werner Jochen A. , Weihe Eberhard , Bette Michael
Published: January 2008

Head and neck squamous cell carcinomas (HNSCC) represent a group of metastasizing tumors with a high mortality rate in man and animals. Since the biomolecule ozone was found to inhibit growth of various carcinoma cells in vitro we here applied the highly aggressive and lethal VX2 carcinoma HNSCC tumor model of the New Zealand White rabbit to test whether ozone exerts antitumorous effects in vivo. Therapeutic insufflation of medical ozone/oxygen (O3/O2) gas mixture into the peritoneum (O3/O2‐pneumoperitoneum) at an advanced stage of tumor disease led to a survival rate of 7/14 rabbits. Six of the seven surviving rabbits presented full tumor regression and the absence of local or distant lung metastases. Insufflation of pure oxygen (O2) resulted in a survival rate of 3/13 animals accompanied by full tumor remission in 2 of the 3 surviving animals. Of the 14 sham‐treated animals only 1 had spontaneous tumor remission and survived. No adverse effects or changes in standard blood parameters were observed after repeated intraperitoneal insufflations of the O3/O2 or O2 gas. Animals with O3/O2‐induced tumor eradication developed tolerance against reimplantation of the VX2 tumor. This could be reversed by immune suppression with a combination of dexamethasone and cyclosporin A suggesting an antitumorous effect of O3/O2‐mediated activation of the body's own immunosurveillance. Although the exact mechanisms of action are still unclear the present data point to O3/O2‐pneumoperitoneum as a promising new strategy in anticancer therapy. © 2008 Wiley‐Liss, Inc.
Elevated risk for squamous cell carcinoma of the conjunctiva among adults with AIDS in the United States
Authors: Guech‐Ongey Mercy , Engels Eric A. , Goedert James J. , Biggar Robert J. , Mbulaiteye Sam M.
Published: January 2008

Squamous cell carcinoma of the conjunctiva (SCCC) has been associated with HIV infection in equatorial Africa, but the evidence for association with HIV in developed countries, where SCCC is rarer, is controversial. We investigated the risk for SCCC and other eye cancers in the updated U.S. HIV/AIDS Cancer Match Registry Study. We calculated standardized incidence ratios (SIRs) to estimate excess risk for SCCC, primary ocular lymphoma, ocular Kaposi sarcoma (KS) and other eye tumors among 491, 048 adults (aged > 15 years or older) with HIV/AIDS diagnosed from 1980 to 2004. We calculated relative proportions (per 105) to gain insight into risk factors. We identified 73 eye cancers (15 SCCC, 35 primary ocular lymphoma, 17 ocular KS and 6 other). Overall SIRs were elevated for SCCC (SIR, 12.2, 95% CI 6.8–20.2), primary ocular lymphoma (21.7, 95% CI 15.1–30.2) and ocular KS (109, 95% CI 63.5–175). Risk for SCCC was elevated regardless of HIV acquisition category, CD4 lymphocyte count and time relative to AIDS‐onset. Relative proportions of SCCC risk were highest with age ≥50 (8/105), Hispanic ethnicity (7/105) and residence in regions with high‐solar ultraviolet radiation (10/105). We show significantly increased incidence of SCCC among persons with HIV/AIDS in the U.S. The associations with age and geography are in accord with etiological role for ultraviolet radiation in SCCC. © 2008 Wiley‐Liss, Inc.
MRI of the thorax during whole‐body MRI: Evaluation of different MR sequences and comparison to thoracic multidetector computed tomography (MDCT)
Authors: Frericks Bernd B. , Meyer Bernhard C. , Martus Peter , Wendt Michael , Wolf Karl‐Jürgen , Wacker Frank
Published: January 2008

Purpose

To evaluate the accuracy of four MR sequences used as part of a whole‐body MRI protocol to detect pulmonary lesions in cancer patients.

Materials and Methods

A total of 31 oncology patients were imaged in a 1.5T MR scanner (Magnetom Avanto; Siemens Medical Solutions, Germany) for whole‐body staging. MR chest imaging included: axial and coronal T2‐weighted (T2w)–short‐tau inversion‐recovery (STIR), axial T2w turbo spin‐echo (TSE), and contrast‐enhanced (CE) three‐dimensional (3D) volumetric interpolated breathhold examination (VIBE). Multidetector computed tomography (MDCT) of the thorax served as the reference standard. The MDCT and MR images were evaluated independently by two radiologists. Comparative analysis was performed per lesion, per lobe, and per patient. Sensitivity, specificity, and predictive values were determined.

Results

Compared to MDCT that detected 268 pulmonary lesions ranging from 2 to 75 mm in diameter, the MR sensitivities were 91.1%, 92.5%, 90.8%, and 87.3% for the coronal STIR, the axial STIR, the axial T2w‐TSE, and the axial CE 3D‐VIBE, respectively. Undetected pulmonary lesions were either calcified or smaller than 10 mm in the axial diameter. With coronal STIR, six false‐positive findings were detected; with axial STIR, 14 were detected; with axial T2w‐TSE, 10 were detected; and with 3D‐VIBE, seven were detected.

Conclusion

Pulmonary MRI is feasible as part of a whole‐body MRI protocol. In our study, STIR images achieved high accuracy compared to chest MDCT for pulmonary lesions of 3 mm in size or larger. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Abnormal hypermyelination in a neonate with Sturge‐Weber syndrome demonstrated on diffusion‐tensor imaging
Authors: Moritani Toshio , Kim Jinsuh , Sato Yutaka , Bonthius Daniel , Smoker Wendy R.K.
Published: January 2008

In Sturge‐Weber syndrome in neonates, evaluation of the extent of the brain parenchymal involvement is difficult due to the lack of calcification, although it is important for initiation of preventive antiepileptic treatment and prediction of prognosis. We present the first application of diffusion‐tensor imaging with fractional anisotropy and ADC maps in a 7‐day‐old neonate. Abnormal T2 hypointensity in the subcortical white matter corresponded to the areas of increased FA and decreased ADC on diffusion‐tensor imaging, which probably represents abnormal hypermyelination. Diffusion‐tensor imaging enabled to quantify the abnormal hypermyelination, and is useful in early diagnosis of Sturge‐Weber syndrome. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Intracranial contrast‐enhanced magnetic resonance venography with 6.4‐fold sensitivity encoding at 1.5 and 3.0 Tesla
Authors: Hu Houchun H. , Haider Clifton R. , Campeau Norbert G. , Huston John , Riederer Stephen J.
Published: January 2008

Purpose

To prospectively compare vessel conspicuity and diagnostic image quality between three‐dimensional intracranial contrast‐enhanced MR venography acquired at 1.5 Tesla (T) and 3.0T, with 6.4‐fold sensitivity encoding.

Materials and Methods

Ten healthy volunteers were imaged on 1.5T and 3.0T MR scanners using eight‐element head coil arrays. The intracranial venous vasculature was divided into five groups for evaluation based on vessel size and anatomical location. Two radiologists independently assessed vessel conspicuity, level of artifacts, and diagnostic image quality. Informed consent was obtained, and the study was approved by the institutional review board.

Results

With the exception of large cerebral sinuses where 1.5T and 3.0T results were rated as equivalent, 3.0T images demonstrated superior vessel continuity, sharpness, and signal contrast to background tissue than 1.5T for all other intracranial venous vasculature (P < 0.01). No statistical significance in overall image quality was found between 1.5T and 3.0T venograms, and all data sets were deemed sufficient for diagnostic interpretation.

Conclusion

Whole brain contrast‐enhanced venography with 6.4‐fold sensitivity encoding is robust and has the potential to become the method of choice for fast visualization of the intracranial venous vasculature. At 3.0T, demonstration of small cerebral vessels is superior to 1.5T. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Application of optical non-invasive methods in skin physiology
Authors: Lademann J , Patzelt A , Darvin M , Richter H , Antoniou C , Sterry W , Koch S
Published: January 2008

In the present paper the application of optical non-invasive methods in dermatology and cosmetology is discussed. Laser scanning microscopy (LSM) and optical coherent tomography (OCT) are the most promising methods for this application. Using these methods, the analysis of different skin parameters like dryness and oiliness of the skin, the barrier function and the structure of furrows and wrinkles are discussed. Additionally the homogeneity of distribution of topically applied creams, as well as their penetration into the skin were investigated. It is shown that these methods are highly valuable in dermatology for diagnostic and therapy control and for basic research, for instance in the field of structure analysis of hair follicles and sweat glands. The vertical images of the tissue produced by OCT can be easily compared with histological sections. Unfortunately, the resolution of the OCT technique is not high enough to carry out measurements on a cellular level, as is possible by LSM. LSM has the advantage that it can be used for the investigation of penetration and storage processes of topically applied substances, if these substances have fluorescent properties or if they are fluorescent-labelled.
Diode-pumped passively mode-locked YVO4/Nd:YVO4 composite crystal laser with LT-In0.25Ga0.75As saturable absorber
Authors: Li T , Zhuo Z , Zhao S , Wang Y-G
Published: January 2008

A passively mode-locked all-solid-state YVO4/Nd:YVO4 composite crystal laser was realized with a low temperature (LT) In0.25Ga0.75As semiconductor saturable absorber mirror. The saturable absorber was used as nonlinear absorber and output coupler simultaneously. Both the Q-switch and continuous-wave mode locking operation were experimentally realized. At a pump power of 4 W, the Q-switched mode locking changed to continuous wave mode locking. An average output power of 4.1 W with 5 ps pulse width was achieved at the pump power of 12 W, corresponding to an optical-optical conversion efficiency of 34.2%.
Laser treatments on skin enhancing and controlling transdermal delivery of 5‐fluorouracil
Authors: Gómez Clara , Costela Ángel , García‐Moreno Inmaculada , Llanes Felipe , Teijón José M. , Blanco Dolores
Published: January 2008

Background and Objective

Laser ablation of stratum corneum (SC) enhances transdermal delivery of hydrophilic drugs. The influence of the infrared (IR) (λ = 1,064 nm), visible (λ = 532 nm), and ultraviolet (UV) (λ = 355 nm) radiations of a Nd:YAG laser on transdermal delivery of 5‐Fluorouracil (5‐Fu) across skin was studied in vitro.

Materials and Methods

Pinna skin of the inner side of rabbit ear, was used for the skin permeation. The light source for laser treatment was a Q‐switched Nd:YAG laser (Lotis TII SL‐2132). Ablation thresholds were estimated by using a photoacoustic technique. In addition, permeation study, and morphological and structural skin examination by histology and differential scanning calorimetry (DSC) were carried out.

Results

A significant increase in the permeation of 5‐Fu across skin pre‐treatment with the three different wavelengths studied was obtained. Since irradiation at 1,064 nm allows deep penetration of the radiation, collagen fibers were affected [7.7 J/cm2 (15 Hz)]. Visible radiation of Nd:YAG laser showed the wider range of fluences (3–8.4 J/cm2 at 15 Hz) to enhance skin delivery of 5‐Fu, without risk of skin lesion. UV radiation required minor energy contribution to produce the same effects within a narrower range of fluences [0.3 J/cm2 (5 Hz)–1.5 J/cm2 (15 Hz)] so the process is less controlled and this radiation shows greater impact on the lipidic structure than visible and IR radiations.

Conclusions

Use of the visible radiation of a Nd:YAG laser is a good method for improving the efficacy of topical chemotherapy of 5‐Fu. Lesers Surg. Med. 40:6–12, 2008. © 2008 Wiley‐Liss, Inc.
Investigation of selective retina treatment (SRT) by means of 8 ns laser pulses in a rabbit model
Authors: Framme Carsten , Schuele Georg , Kobuch Karin , Flucke Barbara , Birngruber Reginald , Brinkmann Ralf
Published: January 2008

Background

It has been shown that selective retina treatment (SRT) using a train of 1.7 microseconds laser pulses allows selective damage of the retinal pigment epithelium (RPE) while sparing the adjacent photoreceptors and thus avoiding laser scotoma. It was the purpose of this work to investigate SRT laser effects with Q‐switched pulses of only 8 nanoseconds in duration by evaluating the angiographic and ophthalmoscopic damage thresholds and the damage range by histology in a rabbit model.

Materials and Methods

A flash lamp pumped frequency doubled (532 nm) Nd:YAG laser with 8 nanoseconds pulse duration was used. In total 210 laser lesions, each calculated to be 102 µm in diameter on retina, were applied through a slit lamp onto the fundus of six eyes of Chinchilla Bastard rabbits. The rabbits were irradiated with increasing energies with single pulses and a train of 10 laser pulses at 10 Hz. After treatment fundus photography and angiography were performed to determine the damage thresholds (ED50‐probability of RPE cell damage and neurosensory retinal damage) as well as the safety range between both thresholds (ratio of angiographic ED86 vs. ophthalmoscopic ED14). Selected histology was taken for single and repetitive pulse lesions after treatment.

Results

Angiographic and ophthalmoscopic ED50‐thresholds decreased with increasing number of pulses. For single pulse application ophthalmoscopic and angiographic ED50 were determined to 365 and 144 mJ/cm2, respectively. Regarding 10 pulses 266 and 72 mJ/cm2 were found. No retinal hemorrhages or disruptions were observed for both sets of parameters. The therapeutic window between angiographic and ophthalmoscopic threshold revealed a factor of 3.1 for single pulses and 2.3 for repetitive pulse irradiation. The safety range respectively had a factor of 0.8 (single pulses) and 1.7 (10 pulses). Histologic examination of laser lesions with single and repetitive pulses at radiant exposures within the therapeutic window—292 and 213 mJ/cm2 respectively—revealed damaged RPE, intact Bruch's membrane and choriocapillaries. Photoreceptors were partly spared but also damaged to various extents.

Conclusions

Short laser pulses of 8 nanoseconds pulse duration can damage the RPE without retinal hemorrhage or disruption. Selective damage of the RPE without affecting the photoreceptors can only rarely be achieved due to the small safety range. Thus, so far microsecond laser pulses for SRT seems favorable compared to nanosecond pulses in order to prevent unintentional photoreceptor damage. Lesers Surg. Med. 40:20–27, 2008. © 2008 Wiley‐Liss, Inc.
Severe upper limb injuries with or without neurovascular compromise in children and adolescents—Analysis of 32 cases
Authors: Ignatiadis Ioannis A. , Yiannakopoulos Christos K. , Mavrogenis Andreas F. , Nomikos George N. , Spyridonos Sarantis G. , Gerostathopoulos Nikolaos E. , Soucacos Panayotis N.
Published: January 2008

The healing and regeneration capacity of the injured tissues in childhood, adolescence, and adult life differs significantly. As a result, the prognosis of compound injuries of the upper limb in different age groups varies; therefore, the decision making and management of these cases should be age‐specific. This article presents a series of 32 patients aged 1.5–14 years, with compound injuries of the upper limb that have been treated in our hospital during the period of the last 6 years. Ten of the above cases involved major vascular lesions that required revascularization or replantation. The injuries were classified according to the SATT (Severity, Anatomy, Topography, Type) classification system. This study shows that the outcome of compound upper limb injuries is age‐related, while the SATT classification system is a valuable tool in the decision making process. Further research should be undertaken to determine age group‐specific indications for the management of compound upper limb injuries, based on the SATT classification system. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.