bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface modification of poly(L‐lactic acid) by entrapment of chitosan and its derivatives to promote osteoblasts‐like compatibility
Authors: Liu Zonghua , Jiao Yanpeng , Zhang Ziyong , Zhou Changren
Published: June 2007

Surface modification of biomaterials has been adopted over the years to improve their biocompatibility. In this study, aiming to promote hydrophilicity and to introduce natural recognition sites onto poly(L‐lactic acid) (PLLA) films, chitosan and its derivatives, carboxymethyl chitosan (CMC) and N‐methylene phosphonic chitosan (NPC), were used to modify the surface of PLLA films by an entrapment method. The surface properties of original and modified PLLA films were measured by using water contact angle measurement and X‐ray photoelectron spectroscopy (XPS). Subsequently, the cytocompatibility of these PLLA films was investigated by testing osteoblasts‐like cytocompatibility, cell attachment, cell proliferation, alkaline phosphatase activity, and cell cycle. Experimental results indicated that the hydrophilicity of the modified films was improved and the surface of the modified PLLA films became enriched with chitosan and its derivatives. Moreover, the surface modification with chitosan and its derivatives significantly promoted osteoblasts‐like compatibility of PLLA films. This surface modification, combining the individual advantages of PLLA with good mechanical property and chitosan as well as its derivatives with good cytocompatibility, is a promising method to prepare desirable biomaterials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Physical adsorption of human thrombomodulin (ART‐123) onto polymeric biomaterials for developing an antithrombogenic blood‐contacting material
Authors: Matsusaki Michiya , Omichi Masaaki , Maruyama Ikuro , Akashi Mitsuru
Published: June 2007

Human thrombomodulin (hTM) is an endothelial cell‐associated protein with potent natural anticoagulant activity by converting thrombin from a procoagulant protease to an anticoagulant. ART‐123 is a recombinant soluble hTM (amino acid residues 1‐498), and we focused on the physical adsorption of ART‐123 onto a polymeric biomaterial surface to develop an antithrombogenic blood‐contacting material with preventing the denaturation of hTM and the remaining chemical reagents. The adsorption of hTM onto polysulfone (PSF) films was analyzed quantitatively by quartz crystal microbalance analysis. The adsorption constant and the maximum adsorption amount, calculated by the assumption of a Langmuir‐type adsorption, showed that hTM adsorbed with a relatively weak interaction onto the PSF film. The hydrophilic protein lysozyme also showed a Langmuir‐type monolayer adsorption, although hydrophobic catalase and fibrinogen showed multilayer adsorption accompanying the denaturation. The physically adsorbed hTM showed high coenzymatic activity for the activation of protein C, as well as anticoagulant activity. Furthermore, the surface wettability of the PSF film was easily controllable by the physical adsorption of hydrophobic and hydrophilic bioactive proteins. The physical adsorption of hTM or bioactive proteins onto polymeric biomaterials will be instrumental for developing an antithrombogenic blood‐contacting biomaterial, and for controlling the surface properties of biomaterials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
In silico modulation of apoptotic Bcl‐2 proteins by mistletoe lectin‐1: Functional consequences of protein modifications
Authors: Khwaja Tasneem A. , Wajahat Tayyaba , Ahmad Ishtiaq , Hoessli Daniel C. , Walker‐Nasir Evelyne , Kaleem Afshan , Qazi Wajahat M. , Shakoori Abdul R. , Din Nasir‐ud‐
Published: June 2007

The mistletoe lectin‐1 (ML‐1) modulates tumor cell apoptosis by triggering signaling cascades through the complex interplay of phosphorylation and O‐linked N‐acetylglucosamine (O‐GlcNAc) modification in pro‐ and anti‐apoptotic proteins. In particular, ML‐1 is predicted to induce dephosphorylation of Bcl‐2‐family proteins and their alternative O‐GlcNAc modification at specific, conserved Ser/Thr residues. The sites for phosphorylation and glycosylation were predicted and analyzed using Netphos 2.0 and YinOYang 1.2. The involvement of modified Ser/Thr, and among them the potential Yin Yang sites that may undergo both types of posttranslational modification, is proposed to mediate apoptosis modulation by ML‐1. J. Cell. Biochem. 103: 479–491, 2008. © 2007 Wiley‐Liss, Inc.
Angiogenic CXC chemokine expression during differentiation of human mesenchymal stem cells towards the osteoblastic lineage
Authors: Bischoff D.S. , Zhu J.H. , Makhijani N.S. , Kumar A. , Yamaguchi D.T.
Published: June 2007

The potential role of ELR+CXC chemokines in early events in bone repair was studied using human mesenchymal stem cells (hMSCs). Inflammation, which occurs in the initial phase of tissue healing in general, is critical to bone repair. Release of cytokines from infiltrating immune cells and injured bone can lead to recruitment of MSCs to the region of repair. CXC chemokines bearing the Glu‐Leu‐Arg (ELR) motif are also released by inflammatory cells and serve as angiogenic factors stimulating chemotaxis and proliferation of endothelial cells. hMSCs, induced to differentiate with osteogenic medium (OGM) containing ascorbate, β‐glycerophosphate (β‐GP), and dexamethasone (DEX), showed an increase in mRNA and protein secretion of the ELR+CXC chemokines CXCL8 and CXCL1. CXCL8 mRNA half‐life studies reveal an increase in mRNA stability upon OGM stimulation. Increased expression and secretion is a result of DEX in OGM and is dose‐dependent. Inhibition of the glucocorticoid receptor with mifepristone only partially inhibits DEX‐stimulated CXCL8 expression indicating both glucocorticoid receptor dependent and independent pathways. Treatment with signal transduction inhibitors demonstrate that this expression is due to activation of the ERK and p38 mitogen‐activated protein kinase (MAPK) pathways and is mediated through the Gαi‐coupled receptors. Angiogenesis assays demonstrate that OGM‐stimulated conditioned media containing secreted CXCL8 and CXCL1 can induce angiogenesis of human microvascular endothelial cells in an in vitro Matrigel assay. J. Cell. Biochem. 103: 812–824, 2008. © 2007 Wiley‐Liss, Inc.
Prenatal sonographic diagnosis of congenital heart disease and intrauterine growth restriction: A case–control study
Authors: Perez‐Delboy Annette , Simpson Lynn L.
Published: June 2007

Purpose

To determine the prevalence of intrauterine growth restriction (IUGR) in cases of congenital heart disease (CHD) and to evaluate whether the prenatal diagnosis of isolated CHD was a significant risk factor for IUGR.

Methods

We conducted a retrospective case–control study of prenatally detected CHD with delivery at ≥20 weeks' gestation between January 1, 1998, and December 31, 2001. Four groups were analyzed: (1) all cases with CHD, (2) after exclusion of abnormal karyotype, (3) after exclusion of abnormal karyotype and prenatally diagnosed extracardiac anomaly, and (4) after exclusion of abnormal karyotype and prenatally and postnatally diagnosed extracardiac anomaly. The prevalence of IUGR was determined in each of the 4 study groups and was compared with controls.

Results

There were 13,395 deliveries at ≥20 weeks' gestation. Of the 180 cases of CHD, 22.8% were associated with IUGR compared with 11.6% of controls (p < 0.01). In contrast, there was no statistically significant difference in the prevalence of IUGR in the 140 cases of isolated CHD compared with controls (12.9% versus 10.0%).

Conclusion

The prenatal detection of isolated CHD does not seem to be associated with IUGR. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Sonographic appearance of ruptured ovarian cyst in the neonatal period
Authors: Gallagher Thomas A. , Lim‐Dunham Jennifer E. , Vade Aruna , Smith Sara , Salhadar Alia , Ward Kathleen A.
Published: June 2007

Rupture is a rare complication of ovarian cysts diagnosed during the prenatal period. We present a case that focuses on the postnatal sonographic appearance of rupture of an ovarian cyst after vaginal delivery. Histopathologic correlation is provided. The main sonographic features include complicated ascites and a collapsed cystic structure in the abdomen. Ruptured ovarian cyst should be included in the differential diagnosis of unexplained ascites in a newborn girl. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Routine intraoperative Doppler sonography in the evaluation of complications after living‐related donor liver transplantation
Authors: Choi Jin‐Young , Lee Jae Young , Lee Jeong Min , Kim Se Hyung , Lee Min Woo , Han Joon Koo , Choi Byung Ihn
Published: June 2007

Purpose

To determine whether quantitative and qualitative analysis of intraoperative Doppler sonography data are predictive of vascular complications after living‐related donor liver transplantation.

Methods

Intraoperative sonograms of 81 transplanted livers (right lobe in 61 patients, left lobe in 20 patients) were analyzed for the presence of blood flow, resistance index, systolic acceleration time (SAT), peak systolic velocity, and morphologic characteristics of spectral waveform of the hepatic artery. Peak velocity and spectral waveforms of portal and hepatic veins were also analyzed. Intraoperative sonography results were compared with information obtained with multidetector‐row CT (MDCT) angiography or conventional angiography. The time interval between operation and angiography ranged from 1 to 23 days (mean, 8.5 days).

Results

Hepatic artery stenosis (HAS) was identified in 20 patients via MDCT angiography, conventional angiography, or both. The Doppler parameters found helpful for predicting HAS were tardus‐parvus pattern and delayed SAT. The sensitivity, specificity, and negative predictive value (NPV) were 60.0%, 73.7%, and 84.9%, respectively, for tardus‐parvus pattern and 40.0%, 83.6%, and 80.9%, respectively, for delayed SAT. Peak velocities of the portal and hepatic veins were not reliable indicators of vascular complication. Loss of triphasity of the hepatic vein had a 98.4% NPV for venous obstruction.

Conclusions

Delayed SAT of the hepatic artery and loss of triphasity of the hepatic vein had a >80% for specificity for predicting vascular complications. Tardus‐parvus pattern, delayed SAT of the hepatic artery, and loss of triphasity of the hepatic vein showed an acceptable NPV for identifying vascular complications. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Sonographic diagnosis of inferior mesenteric artery aneurysm and marginal artery of Drummond
Authors: Momin Asif A. , Chaubal Nitin G. , Saifi Shenaz G. A. , Kazi Zubair N.
Published: June 2007

We report the case of a patient in whom sonographic examination revealed an aneurysm of the inferior mesenteric artery with severe proximal stenosis and poststenotic dilatation—the enlargement of the proximal portion of the artery of Drummond. This collateral pathway should be kept in mind when studying bowel ischemia, especially when stenosis is present or when there is occlusion of the superior mesenteric artery. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Pyruvate transport in isolated cardiac mitochondria from two species of amphibian exhibiting dissimilar aerobic scope: Bufo marinus and Rana catesbeiana
Authors: Duerr Jeffrey M. , Tucker Kristina
Published: June 2007

Cardiac mitochondria were isolated from Bufo marinus and Rana catesbeiana, two species of amphibian whose cardiovascular systems are adapted to either predominantly aerobic or glycolytic modes of locomotion. Mitochondrial oxidative capacity was compared using VO2 max and respiratory control ratios in the presence of a variety of substrates including pyruvate, lactate, oxaloacetate, β‐hydroxybutyrate, and octanoyl‐carnitine. B. marinus cardiac mitochondria exhibited VO2 max values twice that of R. catesbeiana cardiac mitochondria when oxidizing carbohydrate substrates. Pyruvate transport was measured via a radiolabeled‐tracer assay in isolated B. marinus and R. catesbeiana cardiac mitochondria. Time‐course experiments described both α‐cyano‐4‐hydroxycinnamate‐sensitive (MCT‐like) and phenylsuccinate‐sensitive pyruvate uptake mechanisms in both species. Pyruvate uptake by the MCT‐like transporter was enhanced in the presence of a pH gradient, whereas the phenylsuccinate‐sensitive transporter was inhibited. Notably, anuran cardiac mitochondria exhibited activities of lactate dehydrogenase and pyruvate carboxylase. The presence of both transporters on the inner mitochondrial membrane affords the net uptake of monocarboxylates including pyruvate, β‐hydroxybutyrate, and lactate; the latter potentially indicating the presence of a lactate/pyruvate shuttle allowing oxidation of extramitochondrial NADH. Intramitochondrial lactate dehydrogenase and pyruvate carboxylase enables lactate to be oxidized to pyruvate or converted to anaplerotic oxaloacetate. Kinetics of the MCT‐like transporter differed significantly between the two species, suggesting differences in aerobic scope may be in part attributable to differences in mitochondrial carbohydrate utilization. J. Exp. Zool. 307A:425–438, 2007. © 2007 Wiley‐Liss, Inc.
Hairpin DNAzymes: a new tool for efficient cellular gene silencing
Authors: Abdelgany Amr , Wood Matthew , Beeson David
Published: June 2007

Background

RNA‐based gene silencing is potentially a powerful therapeutic strategy. Catalytic 10–23 DNAzymes bind to target RNA by complimentary sequence arms on a Watson‐Crick basis and thus can be targeted to effectively cleave specific mRNA species. However, for in vivo applications it is necessary to stabilise DNAzymes against nucleolytic attack. Chemical modifications can be introduced into the binding arms to increase stability but these may alter catalytic activity and in some cases increase cell toxicity.

Methods

We designed novel 10–23 DNAzyme structures that incorporate stem‐loop hairpins at either end on the DNAzyme binding arms. The catalytic activity of hairpin DNAzymes (hpDNAzyme) were tested in vitro against 32P‐labelled cRNA encoding the muscle acetylcholine receptor (AChR) α‐subunit. Resistance of hpDNAzymes to nucleolytic degradation was tested by incubation of the hpDNAzymes with Bal‐31, DNase1 or HeLa cell extract. Gene silencing by hpDNAzymes was assessed by measuring reduced fluorescence from DsRed2 and EGFP reporters in cell culture systems, and reduced 125I‐alpha‐bungarotoxin binding in cells transfected with cDNA encoding the AChR.

Results

We show that hpDNAzymes show remarkable resistance to nucleolytic degradation, and demonstrate that in cell culture systems the hpDNAzymes are far more effective than standard 10–23 DNAzymes in down‐regulating protein expression from target mRNA species.

Conclusion

hpDNAzymes provide new molecular tools that, without chemical modification, give highly efficient gene silencing in cells, and may have potential therapeutic applications. Copyright © 2007 John Wiley & Sons, Ltd.
Neuron‐specific delivery of nucleic acids mediated by Tet1‐modified poly(ethylenimine)
Authors: Park In‐Kyu , Lasiene Jurate , Chou Shinn‐Huey , Horner Philip J. , Pun Suzie H.
Published: June 2007

Background

The development of minimally invasive, non‐viral gene delivery vehicles for the central nervous system (CNS) is an important technology goal in the advancement of molecular therapies for neurological diseases. One approach is to deliver materials peripherally that are recognized and retrogradely transported by motor neurons toward the CNS. Tet1 is a peptide identified by Boulis and coworkers to possess the binding characteristics of tetanus toxin, which interacts specifically with motor neurons and undergoes fast, retrograde delivery to cell soma. In this work, Tet1‐poly(ethylenimine) (Tet1‐PEI) was synthesized and evaluated as a neurontargeted delivery vehicle.

Methods

Tet1‐PEI and NT‐PEI (neurotensin‐PEI) were synthesized and complexed with plasmid DNA to form polyplexes. Polyplexes were assessed for binding and uptake in differentiated neuron‐like PC‐12 cells by flow cytometry and confocal microscopy. In order to determine gene delivery efficiency, polyplexes were exposed to PC‐12 cells at various stages of differentiation. Targeted binding of polyplexes with primary neurons was studied using dorsal root ganglion cells.

Results

Tet1‐PEI and NT‐PEI polyplexes bound specifically to differentiated PC‐12 cells. The specificity of the interaction was confirmed by delivery to non‐neuronal cells and by competition studies with free ligands. Tet1‐PEI polyplexes preferentially transfected PC‐12 cells undergoing NGF‐induced differentiation. Finally, neuron‐specific binding of Tet1‐PEI polyplexes was confirmed in primary neurons.

Conclusions

These studies demonstrate the potential of Tet1‐PEI as a neuron‐targeted material for non‐invasive CNS delivery. Tet1‐PEI binds specifically and is internalized by neuron‐like PC‐12 cells and primary dorsal root ganglion. Future work will include evaluation of siRNA delivery with these vectors. Copyright © 2007 John Wiley & Sons, Ltd.
Isotopic labelling in mass spectrometry as a tool for studying reaction mechanisms of ion dissociations
Authors: Holmes John L. , Jobst Karl J. , Terlouw Johan K.
Published: June 2007

Perhaps the greatest influence that isotopic labelling experiments have had on organic mass spectrometry is that reaction mechanisms originally borrowed from the chemistry of neutral counterparts have proved to be inadequate for explaining the results. It was therefore necessary to devise completely new types of fragmentation mechanisms and unconventional structures for organic gas‐phase cations. In most cases the labelling technique allows one to discover the positions at which the label atoms are found in both the charged and neutral products of an ion's dissociation. These experimental results are often difficult to rationalize by any simple mechanism, but they nearly always indicate how chemical computations should be directed in order for the latter to be able to provide a better mechanistic understanding. This short article describes some significant studies involving D and 18‐O labelling that well support the above assertions, using as examples the behaviour of some quite simple organic molecules. Copyright © 2007 John Wiley & Sons, Ltd.
The effect of cyclooxygenase‐2 overexpression on skin carcinogenesis is context dependent
Authors: Rundhaug Joyce E. , Pavone Amy , Kim Eunjung , Fischer Susan M.
Published: June 2007

The up‐regulation of the inducible form of cyclooxygenase (COX‐2), a central enzyme in the prostaglandin (PG) biosynthetic pathway, occurs in many epithelial tumors and has been associated with tumor cell proliferation and angiogenesis. To better understand the role of COX‐2 in skin tumor development, we generated transgenic mice that overexpress COX‐2 under the control of the keratin 14 promoter. We previously reported (Cancer Res. 62: 2516, 2002) that these mice, referred to as keratin 14 (K14).COX2 mice, were unexpectedly very resistant to 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) tumor promotion. The current studies were undertaken to determine the mechanism of this resistance and determine if it was restricted to TPA promotion. Transgenic and wild‐type mice were subjected to a complete carcinogenesis protocol using 7,12‐dimethylbenz[a]anthracene (DMBA) only, as well as a two‐stage protocol using DMBA plus an unrelated tumor promoter, anthralin. In addition, the responses of transgenic and wild‐type mice to TPA in terms of induction of proliferation and various down‐stream mediators were examined. The TPA resistance phenotype correlated with a reduced ability to induce ornithine decarboxylase, interleukin‐1α, and tumor necrosis factor‐α and a reduced proliferation response. This resistance phenotype appears to be restricted to phorbol ester promotion because K14.COX2 mice developed six times more tumors than wild‐type mice when anthralin was used as the tumor promoter. Additionally, K14.COX2 mice treated only with DMBA developed approximately 3.5 times more tumors than wild‐type mice, suggesting that PGs have intrinsic tumor promoting activity. We conclude that the role of PGs in skin tumorigenesis is context dependent. © 2007 Wiley‐Liss, Inc.
A perspective on murine keratinocyte stem cells as targets of chemically induced skin cancer
Authors: Kangsamaksin Thaned , Park Heui Joon , Trempus Carol S. , Morris Rebecca J.
Published: June 2007

Although ideas on the stem cell origins of cancer date more than one hundred years, critical evidence to support these theories is largely lacking. Our objective here is to outline our historical perspective on keratinocyte stem cells in the cutaneous epithelium and to summarize specific evidence suggesting that epithelial stem cells may contribute to chemically induced skin cancer. We note that, while strong evidence does support this hypothesis, experiments in progress may provide direct visualization of tumors derived from hair follicle stem cells. © 2007 Wiley‐Liss, Inc.
A computational approach for predicting the hydroelasticity of flexible structures based on the pressure Poisson equation
Authors: Liew K. M. , Wang W. Q. , Zhang L. X. , He X. Q.
Published: June 2007

This work is concerned with the modeling of the interaction of fluid flow with flexible solid structures. The flow under consideration is governed by the Navier–Stokes equations for incompressible viscous fluids and modeled with low‐order velocity–pressure finite elements. The motion of the fluid domain is accounted for by the arbitrary Lagrangian–Eulerian formulation. The structure is represented by means of an appropriate standard finite element formulation. The spring smooth analogy is used
to mesh control. The time integrating algorithm is based on the predictor–multi‐corrector algorithm. An important aspect of the present work is the introduction of a new monolithic approach based on the fluid pressure Poisson equation (PPE) to solve the hydroelasticity problem of an incompressible viscous fluid with an elastic body that is vibrating due to flow excitation. The PPE is derived to be consistent with the coupled system equation for the fluid–structure interaction (FSI). Based on this approach, an efficient monolithic method is adopted to simulate hydroelasticity between the flexible structure and the flow. The fluid pressure is implicitly derived to satisfy the incompressibility constraint, and the other unknown variables are explicitly derived. The coefficient matrix of the PPE for the FSI becomes symmetric and positive definite. To demonstrate the performance of the proposed approach, two working examples, a beam immersed in incompressible fluid and a guide vane of a Francis turbine passage, were used. The results show the validity of the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.
Leprosy at the Lazaretto on St Eustatius, Netherlands Antilles
Authors: Gilmore J. K.
Published: June 2007

Leprosaria established in the Americas during the Colonial period bear many similarities with those found in medieval Europe. They are comparable in terms of isolation, the objectification of leprosy sufferers and their association with religious charities. The Lazaretto on St Eustatius was operated from 1866 to 1923. The site was investigated to recover palaeopathological evidence of leprosy at a leprosarium in the Americas. Five burials were excavated; three individuals showed evidence of bone modifications consistent with those caused by leprosy, including aspects of ‘rhinomaxillary syndrome’ and the bilaterally symmetrical post‐cranial changes that have been described in leprosy examples from medieval Europe. An exceptional find was the presence of potentially leprous bone changes to the hyoid, thyroid and 3rd–6th cervical vertebrae. Copyright © 2007 John Wiley & Sons, Ltd.
Tissue microarray‐based screening for chromosomal breakpoints affecting the T‐cell receptor gene loci in mature T‐cell lymphomas
Authors: Leich E , Haralambieva E , Zettl A , Chott A , Rüdiger T , Höller S , Müller‐Hermelink H‐K , Ott G , Rosenwald A
Published: June 2007

The pathogenesis of mature T‐cell non‐Hodgkin lymphomas (T‐NHLs) is poorly understood. Analogous to B‐cell lymphomas, in which the immunoglobulin (IgH) receptor loci are frequently targeted by chromosomal translocations, the T‐cell receptor (TCR) gene loci are affected by translocations in a subset of precursor T‐cell malignancies. In a large‐scale analysis of 245 paraffin‐embedded mature T‐NHLs, arranged in a tissue microarray format and using improved FISH assays for the detection of breakpoints in the TCRα/δ, TCRβ, and TCRγ loci, we provide evidence that mature T‐NHLs other than T‐cell prolymphocytic leukaemia (T‐PLL) also occasionally show a chromosomal rearrangement that involves the TCRα/δ locus. In particular, one peripheral T‐cell lymphoma (not otherwise specified, NOS) with the morphological variant of Lennert lymphoma displayed a chromosomal translocation t(14;19) involving the TCRα/δ and the BCL3 loci. A second case, an angio‐immunoblastic T‐cell lymphoma (AILT), carried an inv(14)(q11q32) affecting the TCRα/δ and IgH loci. FISH signal constellations as well as concomitant comparative genomic hybridization (CGH) data were also suggestive of the occurrence of an isochromosome 7, previously described to be pathognomonic for hepatosplenic T‐cell lymphomas, in rare cases of enteropathy‐type T‐cell lymphoma. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Altered claudin expression is a feature of chronic plaque psoriasis
Authors: Watson REB , Poddar R , Walker JM , McGuill I , Hoare LM , Griffiths CEM , O'Neill CA
Published: June 2007

Epithelial tight junctions play a central role in cell–cell adhesion and are necessary for the selective paracellular movement of ions. Claudins are key components of tight junctions and their expression is altered in gut epithelia in a variety of inflammatory enteropathies, including ulcerative colitis and Crohn's disease. Psoriasis is a chronic inflammatory skin disease affecting approximately 2% of the western population, with significantly increased occurrence in individuals with Crohn's disease. Initial studies investigated the expression of claudins in skin of healthy volunteers and patients with chronic plaque psoriasis. We report here that claudins‐1 and ‐3 are the major protein species present in the epidermis of healthy skin; they are expressed on the surface of epidermal keratinocytes, consistent with their localization to tight junctions. In plaques of psoriasis, claudin‐1 was not identifiable in the epidermis, although typical staining patterns were observed in clinically normal, uninvolved skin of patients with psoriasis. Claudin‐3 was present in the epidermal granular cell layer in normal skin, but was only identified within the cytosol of epidermal keratinocytes in both involved and uninvolved skin of psoriasis patients. We examined further whether exposure of keratinocytes in vitro to pro‐inflammatory cytokines mimicked the observed changes in claudin expression seen in chronic plaque psoriasis; lipopolysaccharide, interferon‐γ and tumour necrosis factor‐α had no effect on claudin protein expression or distribution. Addition of interleukin‐1β, however, resulted in down‐regulation of claudins‐1 and ‐3. Tumour necrosis factor‐α and interleukin‐1β were further used in an in vivo model of skin inflammation; interleukin‐1β alone modulated claudin protein expression in this system. These data demonstrate that epidermal claudin expression is altered in chronic plaque psoriasis and that expression is in part modulated by interleukin‐1β. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Alagille syndrome and nephroblastoma: Unusual coincidence of two rare disorders
Authors: Bourdeaut Franck , Guiochon‐Mantel Anne , Fabre Monique , Martelli Hélène , Patte Catherine , Porta Gilda , Bernard Olivier , Delattre Olivier , Jacquemin Emmanuel
Published: June 2007

Alagille syndrome is a rare developmental disorder combining bile duct paucity, congenital cardiopathy, facial dysmorphy, vertebrae defects, and ocular abnormalities, and frequent renal abnormalities. It does not usually predispose to malignancies. Nephroblastoma has been observed in many developmental disorders, but never in Alagille syndrome. We report two original cases of nephroblastoma associated to Alagille syndrome. We identified a new V136G JAG1 missense mutation in one patient and a constitutional deletion of 20p12 in the other. In one nephroblastoma an additional somatic 1p36 deletion was present. The link between Alagille syndrome, JAG1 alterations and nephroblastoma is discussed. Pediatr Blood Cancer 2008;50:908–911. © 2007 Wiley‐Liss, Inc.
A molecular classification of congenital neutropenia syndromes
Authors: Boxer Laurence A. , Newburger Peter E.
Published: June 2007

Current knowledge on the molecular pathogenesis of severe congenital neutropenia indicates that the clinical diagnosis includes a heterogeneous group of disorders following different patterns of inheritance. Similarly, multifaceted syndromes associated with neutropenia can be classified molecularly, which in turn allows for a better understanding of the basis of the neutropenia. Many of the neutropenia disorders can be treated with G‐CSF (filgrastim) to increase the neutrophil count, thereby reducing infection morbidity and mortality. In some instances hematopoietic stem cell transplantation remains the only curative treatment currently available. This review describes and classifies, on a molecular basis, both primary congenital neutropenia and multifaceted syndromes associated with neutropenia. Pediatr Blood Cancer 2007;49:609–614. © 2007 Wiley‐Liss, Inc.
Long‐term complications and quality of life in children with intraspinal tumors
Authors: Poretti Andrea , Zehnder Daniel , Boltshauser Eugen , Grotzer Michael A.
Published: June 2007

Background

Spinal cord compression by pediatric intraspinal tumors may result in persisting neurological deficits. The impact such late effects have on social and psychological adjustment and quality of life has not been documented previously.

Method

To study the long‐term outcome of pediatric patients with intraspinal tumors, we followed 28 consecutive patients under 16 years of age who were treated in a single institution from 1975 to 2005. In 20 of 26 survivors (median follow‐up time 8.4 years, range 0.8–31.3 years) who agreed to participate, neurological, orthopedic, and cognitive complications and their impact on behavioral and psychological adjustment, and health‐related quality of life (HRQoL) were comprehensively assessed qualitatively and quantitatively. Primary therapy for spinal cord decompression was surgery in ten patients, chemotherapy in nine, and radiotherapy in one.

Results

Tumor control was good (10‐year overall survival rate of 96%; 10‐year progression‐free survival rate of 84%). Persistent neurological complications occurred in 10 (50%) patients (paraparesis, n = 7; monoparesis, n = 3; neurogenic bladder dysfunction, n = 4; neurogenic bowel dysfunction, n = 2). Two of the ten patients with paresis depended on wheelchair. Seven (35%) patients developed scoliosis and six of these required spondylodesis. Survivors reported no major impairments in daily activities and rated their HRQoL only slightly lower than healthy controls. The only statistically significant difference was in emotional functioning.

Discussion

Most patients with intraspinal tumors have a good chance of cure. Apart from few patients, especially those with severe neurological complications, self‐rated HRQoL is comparable to that of healthy controls. Pediatr Blood Cancer 2008;50:844–848. © 2007 Wiley‐Liss, Inc.
Degradative chain transfer in vinyl acetate polymerizations using toluene as solvent
Authors: Lonsdale Daria E. , Johnston‐Hall Geoffrey , Fawcett Amanda , Bell Craig A. , Urbani Carl N. , Whittaker Michael R. , Monteiro Michael J.
Published: June 2007

In this work, we propose that retardation in vinyl acetate polymerization rate in the presence of toluene is due to degradative chain transfer. The transfer constant to toluene (Ctrs) determined using the Mayo method is equal to 3.8 × 10−3, which is remarkably similar to the value calculated from the rate data, assuming degradative chain transfer (2.7 × 10−3). Simulations, including chain‐length‐dependent termination, were carried out to compare our degradative chain transfer model with experimental results. The conversion–time profiles showed excellent agreement between experiment and simulation. Good agreement was found for the Mn data as a function of conversion. The experimental and simulation data strongly support the postulate that degradative chain transfer is the dominant kinetic mechanism. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3620–3625, 2007
Synthesis and properties of novel regioirregular polyimides from easily synthesized asymmetrical dichlorophthalimide monomers
Authors: Li Wenmu , Chen Guang , Zhang Suobo , Wang He , Yan Donghang
Published: June 2007

New asymmetrical aromatic dichlorophthalimide monomers containing pendant groups (trifluoromethyl or methyl) were conveniently prepared from inexpensive and commercially available compounds. With these monomers, a new class of soluble polyimides with a regioirregular structure within the polymer backbone was obtained by the Ni(0)‐catalyzed polymerization method. The structures of the polymers were confirmed by various spectroscopic techniques. The polyimides displayed better solubility and higher thermal stability than the corresponding regular polyimides. In addition, fluorinated polyimides in this study had low dielectric constants ranging from 2.52 to 2.78, low moisture absorptions of less than 0.59%, and low thermal expansion coefficients between 10.6 and 19.7 ppm/°C. The oxygen permeability coefficients and permeability selectivity of oxygen to nitrogen of the films were in the ranges of 2.99–4.20 barrer and 5.55–7.50, respectively. We have demonstrated that the synthetic pathway for polyimides provides a successful approach to increasing the solubility and processability of polyimides without sacrificing their thermal stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3550–3561, 2007
Synthesis of ethylene‐1‐hexene copolymers from ethylene stock by tandem action of bis(2‐dodecylsulfanyl‐ethyl) amine‐CrCl3 and Et(Ind)2ZrCl2
Authors: Zhang Junwei , Li Bo‐Geng , Fan Hong , Zhu Shiping
Published: June 2007

In this work, ethylene‐1‐hexene copolymers were synthesized with a tandem catalysis system that consisted of a new trimerization catalyst bis(2‐dodecylsulfanyl‐ethyl) amine‐CrCl3/MAO (1/MAO) and copolymerization catalyst Et(Ind)2ZrCl2/MAO (2/MAO) at atmosphere pressure. Catalyst 1 trimerized ethylene with high activity and excellent selectivity in the presence of a relatively low amount of MAO. Catalyst 2 incorporated the 1‐hexene content and produced ethylene‐1‐hexene copolymer from an ethylene‐only stock in the same reactor. Adjusting the Cr/Zr ratio and reaction temperature yielded various branching densities and thus melting temperatures. However, broad DSC curves were observed when low temperatures and/or high Cr/Zr ratios were employed due to an accumulation of 1‐hexene component and composition drifting during the copolymerization. It was found that a short pretrimerization period resulted in more homogeneous materials that gave unimodal DSC curves. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3562–3569, 2007
One‐pot preparation of 3‐miktoarm star terpolymers via click [3 + 2] reaction
Authors: Altintas Ozcan , Yankul Burcu , Hizal Gurkan , Tunca Umit
Published: June 2007

The preparation of 3‐miktoarm star terpolymers using nitroxide mediated radical polymerization (NMP), ring opening polymerization (ROP), and click reaction [3 + 2] are carried out by applying two types of one‐pot technique. In the first one‐pot technique, NMP of styrene (St), ROP of ε‐caprolactone (ε‐CL), and [3 + 2] click reaction (between azide end‐functionalized poly(ethylene glycol) (PEG‐N3)/or azide end‐functionalized poly(methyl methacrylate) (PMMA‐N3) and alkyne) are carried out in the presence of 2‐(hydroxymethyl)‐2‐methyl‐3‐oxo‐3‐(2‐phenyl‐2‐(2,2,6,6‐tetramethylpiperidin‐1‐yloxy)ethoxy) propyl pent‐4‐ynoate, 2, as an initiator for 48 h at 125 °C (one‐pot/one‐step). As a second technique, NMP of St and ROP of ε‐CL were conducted using 2 as an initiator for 20 h at 125 °C, and subsequently PEG‐N3 or azide end‐functionalized poly(tert‐butyl acrylate (PtBA‐N3) was added to the polymerization mixture, followed by a click reaction [3 + 2] for 24 h at room temperature (one‐pot/two‐step). The 3‐miktoarm star terpolymers, PEG‐poly(ε‐caprolactone)(PCL)‐PS, PtBA‐PCL‐PS and PMMA‐PCL‐PS, were recovered by a simple precipitation in methanol without further purification. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3588–3598, 2007
Photopolymerization reactions initiated by a visible light photoinitiating system: Cyanine dye/borate salt/1,3,5‐triazine
Authors: Kabatc Janina , Zasada Magdalena , Pączkowski Jerzy
Published: June 2007

New three‐component photoinitiating systems consisting of a cyanine dye, borate salt, and a 1,3,5‐triazine derivative were investigated by measuring their photoinitiation activities and through fluorescence quenching experiments. Polymerization kinetic studies based on the microcalorimetric method revealed a significant increase in polymerization rate when the concentration of n‐butyltriphenylborate salt or the 1,3,5‐triazine derivative were increased. The photo‐induced electron transfer process between electron donor and electron acceptor was studied by means of fluorescence quenching and SrEt change of the fluorescence intensity. The experiments performed documented that an increase of the n‐butyltriphenylborate salt concentration dramatically increases the rate of dye fluorescence quenching, whereas the increasing of the 1,3,5‐triazine derivative concentration slows down the consumption of the dye. We conclude that the primary photochemical reaction involves an electron transfer from the n‐butyltriphenylborate anion to the excited singlet state of the dye, followed by the reaction of the 1,3,5‐triazine derivative with the resulting dye radical to regenerate the original dye. This reaction simultaneously produces a triazinyl radical anion derived from the 1,3,5‐triazine, which undergoes the carbon‐halogen bond cleavage yielding radicals active in initiation of a free radical polymerization chain. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3626–3636, 2007
Synthesis and reactivity of allyl nickel(II) N‐heterocyclic carbene enolate complexes
Authors: Benson Stefan , Payne Bridgett , Waymouth Robert M.
Published: June 2007

Two new N‐heterocyclic carbene enolate nickel(II) allyl complexes have been prepared and their activity towards ethylene polymerization was investigated. It was found that in the presence of diethyl zinc, the carbene enolate complex bearing a nitro substituent produces highly linear polyethylene of modest molecular weight and high polydispersity. The influence of the reaction parameters on catalytic activity and the characteristics of the resulting polymer were investigated through systematic variation of the time, temperature, and diethyl zinc concentration. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45:3637–3647, 2007
Resolving Concentrated Particle Size Mixtures Using Dynamic Light Scattering
Authors: Kaszuba Michael , Connah Malcolm T. , McNeil‐Watson Fraser K. , Nobbmann Ulf
Published: June 2007

Dynamic light scattering (DLS) is a technique used for measuring the size of molecules and particles undergoing Brownian motion by observing time‐dependent fluctuations in the intensity of scattered light. The measurement of samples using conventional DLS instrumentation is limited to low concentrations due to the onset of a phenomenon called multiple scattering. The problems of multiple scattering have been addressed in a light scattering instrument incorporating non‐ invasive backscatter optics (NIBS). This novel optic arrangement maximizes the detection of scattered light while maintaining signal quality and allows for measurements of turbid samples. This paper discusses the ability of backscatter detection to accurately determine particle sizes at 1 %w/v sample concentrations and demonstrates the correct resolution of different size populations using a series of latex standard mixtures with known volume ratios. The concentration of 1 %w/v is much higher than can be measured on conventional dynamic light scattering instruments.
The Influence of Particle Size Distribution on the Performance of Ceramic Particulate Suspensions
Authors: Rasteiro Maria da Graça , Jorge Albano
Published: June 2007

During the preparation of ceramic glaze suspensions it is necessary to guarantee that the suspension possesses the required properties, with several parameters having to be rigorously controlled, e.g., particle size and solids concentration, composition of the suspension and ionic charge of the liquid. This study focuses attention on the influence of particle size distribution on three important properties of glaze suspensions: rheological behavior, opacity and reflectance characteristics and tendency to dissolve. In this paper, results are presented for two glaze formulations prepared with two different commercial frits of distinct composition. The glazes were prepared in a laboratory ball mill and the grinding time was adjusted for each formulation, in order to obtain suspensions with different particle size (at least three different grinding times). The rheological behavior is strongly dependent on the particle size and also on changes in the interactions between the particles, caused by modifications in the cationic content of the suspending medium, as a result of frit dissolution, which is also influenced by the size of the particles.
Bioaerosol Analysis by Single Particle Mass Spectrometry
Authors: Kleefsman Ineke , Stowers Michael A. , Verheijen Peter J. T. , Wuijckhuijse Arjan L. van , Kientz Charles E. , Marijnissen Jan C. M.
Published: June 2007

The performance and improvements of an aerosol mass spectrometer for the real time analysis of bioaerosol particles is described. The instrument can preselect the biological aerosol particles from non‐biological particles, by recording the emitted fluorescence when the particles are irradiated with 266 nm laser light. The fluorescing particles are further investigated by mass spectrometry. With the current performance of the mass spectrometer the produced mass spectra have high resolution and cover a mass range up to 85 kDalton. The capability of the aerosol mass spectrometer to produce good quality spectra of bacteria particles is shown with a mass spectrum of Erwinia herbicola. For the application of the aerosol mass spectrometer the possible interference of (background) soot particles onto the preselection is investigated and a minor interference is determined.
Dry Grinding of Mefenamic Acid Particles for Enhancement of its Water Dissolution Rate
Authors: Iwasaki Tomohiro , Takahara Maiko , Sonoda Ryoichi , Watano Satoru
Published: June 2007

This paper details an investigation into the enhancement of the water dissolution rate of mefenamic acid (MA) by means of a dry grinding treatment. The physico‐chemical properties of the ground MA particles were analyzed by measurements of specific surface area, powder X‐ray diffraction patterns, differential scanning calorimetry thermograms and infrared spectra, and the effects of the change in the physico‐chemical properties (especially, crystalline structure) on the dissolution rate were studied. The polymorphic transition from Form I (original) to II and the change of the molecular structure of MA did not occur in the grinding treatments. However, the specific surface area of the MA particles increased, and the crystallinity decreased (i.e., the amorphization level increased) as the grinding progressed. Hydrogen bonds formed between the carboxyl groups of the opposed asymmetric MA molecules were broken gradually after the grinding limit was attained in the grinding system, resulting in an effective improvement of the initial dissolution rate.
Dynamics on the Group Manifold and Path Integral
Authors: Marinov M. S. , Terentyev M. V.
Published: July 2007

Classical and quantal dynamics on the compact simple Lie group and on a sphere of arbitrary dimensionality are considered. The accuracy of the semiclassical approximation for Green's functions is discussed. Various path integral representations of Green's functions are presented. The special features of these representations due to the compactness and curvature are analysed. Basic results of the theory of Lie algebras and Lie groups used in the main text are presented in the Appendix.
Lattice Textures in Cholesteric Liquid Crystals
Authors: Kleinert H. , Maki K.
Published: July 2007

Based on the Landau‐De Gennes expansion of the free energy in powers of a symmetric traceless order parameter we discuss the energetics of various phases as a function of temperature and cholestericity.
Gatekeeping procedures with clinical trial applications
Authors: Dmitrienko Alex , Tamhane Ajit C.
Published: June 2007

The objective of this paper is to give an overview of a relatively new area of multiplicity research that deals with the analysis of hierarchically ordered multiple objectives. Testing procedures for this problem are known as gatekeeping procedures and have found a variety of applications in clinical trials. This paper reviews main classes of these procedures, including serial and parallel gatekeeping procedures, and tree gatekeeping procedures that account for logical restrictions among multiple objectives. We focus on procedures based on marginal p‐values; extensions to procedures that exploit the joint distribution of the p‐values are also noted. Clinical trial examples are used to illustrate the procedures and their important properties. Copyright © 2007 John Wiley & Sons, Ltd.
Sample size estimation for non‐inferiority trials of time‐to‐event data
Authors: Crisp Adam , Curtis Paula
Published: June 2007

We consider the problem of sample size calculation for non‐inferiority based on the hazard ratio in time‐to‐event trials where overall study duration is fixed and subject enrolment is staggered with variable follow‐up. An adaptation of previously developed formulae for the superiority framework is presented that specifically allows for effect reversal under the non‐inferiority setting, and its consequent effect on variance. Empirical performance is assessed through a small simulation study, and an example based on an ongoing trial is presented. The formulae are straightforward to program and may prove a useful tool in planning trials of this type. Copyright © 2007 John Wiley & Sons, Ltd.
Simulation, a tool for designing‐in reliability
Authors: Brombacher Aarnout , Van Geest Erik , Arendsen Robert , Van Steenwijk Anne , Herrmann Otto
Published: July 2007

This paper describes a new method for the analysis and optimization of reliability as an integrated part of the design process of electronic circuits. It bases itself on the analysis of the susceptibility of failure mechanisms in components as a function of the combinations of external stress factors (stressor‐sets). The paper describes the backgrounds of stressor‐susceptibility analysis, the need for this analysis and the way this method is used for high‐level design and optimization of electronic circuits.
The impact of electronic components on the reliability of cars
Authors: Kumpfmüller Hans‐Georg
Published: July 2007

Electronic control units in automotive applications must meet most demanding quality and reliability requirements. Tomorrow's quality and reliability targets for complete electronic system units are at the same level as those for today's complex components in these units.

The analysis of the present situation reveals the essential deficiencies. The required improvements must be based on early partnership of the component supplier and the system manufacturer at the design phase of components and systems, on matured and controlled processes at component and system manufacturing and on correct application of both components and systems.