bluuebunny/crossref_metadata_2025 huggingface dataset:
DNA demethylation of vascular endothelial growth factor‐C is associated with gene expression and its possible involvement of lymphangiogenesis in gastric cancer
Authors: Matsumura Shunji , Oue Naohide , Mitani Yoshitsugu , Kitadai Yasuhiko , Yasui Wataru
Published: January 2007

Previous studies have indicated that lymphangiogenesis in solid tumors is associated with lymphatic metastasis. Overexpression of Vascular endothelial growth factor (VEGF)‐C plays a major role in lymphangiogenesis in cancers. In the present study, DNA methylation and expression of the VEGF‐C gene was investigated in gastric cancer (GC). Four GC cell lines (MKN‐45, MKN‐74, HSC‐39 and HSC‐43) showed no expression of VEGF‐C, and the VEGF‐C gene was found to be methylated in these cells. In contrast, 7 GC cell lines (MKN‐1, MKN‐7, MKN‐28, TMK‐1, KATO‐III, SH101‐P4 and HSC‐44PE) expressed VEGF‐C, and the VEGF‐C gene was found to be unmethylated in these cell lines. In addition, expression of VEGF‐C mRNA was retrieved by treatment with a demethylating agent, Aza‐2′‐deoxycytidine. In GC tissue samples, bisulfite DNA sequencing analysis revealed that VEGF‐C was not methylated in 9 (29.0%) of 31 GC samples, whereas demethylation was not observed in corresponding non‐neoplastic mucosa samples. Overexpression of VEGF‐C mRNA was observed in 16 (51.6%) of 31 GC samples by quantitative reverse transcription‐polymerase chain reaction. Of the 9 GC cases with VEGF‐C demethylation, 8 (88.9%) overexpressed VEGF‐C. In contrast, of the 22 GC cases without VEGF‐C demethylation, 8 (36.4%) overexpressed VEGF‐C (p = 0.0155). Furthermore, lymphatic vessel density determined by immunostaining of podoplanin in GC tissues was associated with overexpression of VEGF‐C (p < 0.0001). These results suggest that demethylation and activation of the VEGF‐C gene is likely involved in lymphangiogenesis in GC. © 2007 Wiley‐Liss, Inc.
Mammalian target of rapamycin is activated in human gastric cancer and serves as a target for therapy in an experimental model
Authors: Lang Sven A. , Gaumann Andreas , Koehl Gudrun E. , Seidel Ulrike , Bataille Frauke , Klein Dagmar , Ellis Lee M. , Bolder Ulrich , Hofstaedter Ferdinand , Schlitt Hans‐Jürgen , Geissler Edward K. , Stoeltzing Oliver
Published: January 2007

The mammalian target of rapamycin (mTOR) has become an interesting target for cancer therapy through its influence on oncogenic signals, which involve phosphatidylinositol‐3‐kinase and hypoxia‐inducible factor‐1α (HIF‐1α). Since mTOR is an upstream regulator of HIF‐1α, a key mediator of gastric cancer growth and angiogenesis, we investigated mTOR activation in human gastric adenocarcinoma specimens and determined whether rapamycin could inhibit gastric cancer growth in mice. Expression of phospho‐mTOR was assessed by immunohistochemical analyses of human tissues. For in vitro studies, human gastric cancer cell lines were used to determine S6K1, 4E‐BP‐1 and HIF‐1α activation and cancer cell motility upon rapamycin treatment. Effects of rapamycin on tumor growth and angiogenesis in vivo were assessed in both a subcutaneous tumor model and in an experimental model with orthotopically grown tumors. Mice received either rapamycin (0.5 mg/kg/day or 1.5 mg/kg/day) or diluent per intra‐peritoneal injections. In addition, antiangiogenic effects were monitored in vivo using a dorsal‐skin‐fold chamber model. Immunohistochemical analyses showed strong expression of phospho‐mTOR in 60% of intestinal‐ and 64% of diffuse‐type human gastric adenocarcinomas. In vitro, rapamycin‐treatment effectively blocked S6K1, 4E‐BP‐1 and HIF‐1α activation, and significantly impaired tumor cell migration. In vivo, rapamycin‐treatment led to significant inhibition of subcutaneous tumor growth, decreased CD31‐positive vessel area and reduced tumor cell proliferation. Similar significant results were obtained in an orthotopic model of gastric cancer. In the dorsal‐skin‐fold chamber model, rapamycin‐treatment significantly inhibited tumor vascularization in vivo. In conclusion, mTOR is frequently activated in human gastric cancer and represents a promising new molecular target for therapy. © 2007 Wiley‐Liss, Inc.
Silibinin synergizes with mitoxantrone to inhibit cell growth and induce apoptosis in human prostate cancer cells
Authors: Flaig Thomas W. , Su Lih‐Jen , Harrison Gail , Agarwal Rajesh , Glodé Leonard Michael
Published: January 2007

The purpose of these experiments was to assess the synergistic activity of silibinin with chemotherapy agents in clinical use against prostate cancer. Silybin‐phytosome, a commercially available formulation containing silibinin, has recently been studied in a phase I clinical trial. The silibinin doses used in the present study are clinically achievable based on the preliminary phase I data. DU145, PC‐3 and LNCaP prostate cancer cells were seeded in 96‐well plates in triplicate. Twenty‐four hours later, silibinin (10, 20 and 40 μM) and either mitoxantrone or docetaxel were added to the designated wells. Seventy‐two hours post‐treatment, cell viability was determined with a tetrazolium‐based assay. The combination index (CI) for determination of a synergistic effect was calculated, with values of <0.9 indicating synergy and values >1.1 antagonism. Apoptosis was also assessed using a luminescent assay after 72 hr of treatment with media alone, silibinin, mitoxantrone, or silibinin plus mitoxantrone. Silibinin showed a synergistic effect with mitoxantrone, as measured by reduction in cell viability. The CI values ranged from 0.413 to 2.650 for the combination of silibinin and mitoxantrone; in contrast, treatment with docetaxel and silibinin showed little or no synergy, with CI values of 0.898–4.469. In concordance with these findings, the addition of silibinin increased the level of apoptosis compared to mitoxantrone alone, particularly in the PC‐3 cells. The combination of silibinin and mitoxantrone exhibits a pattern of synergy in reducing cell viability with increased apoptosis. These data are important in the planning of future clinical applications of silibinin. © 2007 Wiley‐Liss, Inc.
Simultaneous blockade of VEGFR‐1 and VEGFR‐2 activation is necessary to efficiently inhibit experimental melanoma growth and metastasis formation
Authors: Gille Jens , Heidenreich Regina , Pinter Andreas , Schmitz Judith , Boehme Beatrice , Hicklin Daniel J. , Henschler Reinhard , Breier Georg
Published: January 2007

Metastasis continues to be the major cause of morbidity and mortality in malignant melanoma. In our study, we explored whether inhibition of VEGFR‐1 or VEGFR‐2 signaling conveys distinct suppressive effects on B16 melanoma subcutaneous growth and metastasis formation. The inhibition of VEGFR‐1 or ‐2 alone had no significant influence on both melanoma growth and metastasis formation. In contrast, simultaneous blockade of VEGFR‐1 and ‐2 signaling strongly suppressed progression in both B16 tumor models. There was no expression of VEGFR‐1 or ‐2 detectable on the B16 cells used, excluding the melanoma cells as direct therapeutic targets. Analyzing the contribution of progenitor‐like cells during melanoma metastasis formation, we observed an enhanced proliferation and mobilization of VEGFR‐1+ myeloid and VEGFR‐2+ endothelial cells with progenitor potential by the induction of melanoma lung metastasis, which was not influenced by interference with VEGFR signaling. These results indicate that the antimetastatic effects exerted by combined inhibition of VEGFR‐1 and ‐2 signaling were mediated via targeting cell populations other than progenitors only. Sole inhibition of VEGFR‐1 signaling led to a strong reduction of the CD45‐positive inflammatory infiltrate in the tumor tissue. However, the formation of lung metastasis was not affected, indicating that inhibition of the inflammatory response was not sufficient to efficiently block B16 melanoma metastasis development. Taken together, our data suggest that in the utilized B16 tumor models the blockade of both the inflammatory and the VEGFR‐2‐dependent angiogenic response are necessary to effectively inhibit solid tumor growth and formation of lung metastasis by B16 melanoma cells. © 2007 Wiley‐Liss, Inc.
Theoretical density functional theory studies on interactions of small biologically active molecules with isolated heme group
Authors: Rutkowska‐Zbik Dorota , Witko Malgorzata , Stochel Grazyna
Published: January 2007

We present ab‐initio density functional theory studies on the interactions of small biologically active molecules, namely NO, CO, O2, H2O, and NO with the full‐size heme group. Our results show that the small molecule–iron bond is the strongest in carbonyl and the weakest in nitrite system. Trans influence induced by NO binding to the five‐coordinate heme complex is shown. Nitric oxide in the resulting complex might be described as NO−. The differences among the small ligands of XO type (CO, NO, O2), and their distant chemical behavior from H2O and NO ligands in binding to the Fe(II) ion, are shown. Moreover, the role of the heme ring as a reservoir of electrons in the studied complexes is invoked. The analysis of the parameters defining the iron–histidine bond indicates that this bond is longer and weaker in nitrosyl and carbonyl complexes than in the other systems. Our findings support the proposed mechanism of soluble guanylate cyclase (sGC) activation and suggest that the first step of sGC activation by CO may be the same as during the activation by NO. Obtained results are then compared with the data concerning smaller model of the heme, the porphyrin complexes, available in the literature. © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 825–831, 2007
Long range behavior of high‐rank topological multipole moments
Authors: Rafat Michel , Popelier Paul L. A.
Published: January 2007

The construction of a high‐rank multipolar force field (for peptides) is a complex task, leading to several intermediate questions in need of a clear answer. Here we focus on the convergence of the (electrostatic) multipolar expansion at medium and long range. Using molecular electron densities, quantum chemical topology (QCT) defines the atoms as finite volumes, each endowed with multipole moments. The terms in the multipole expansion are grouped according to powers of the internuclear distance,R−L. Given two atom types at a given distance, we determine which rank (L) is necessary for the electrostatic energy to converge to the exact interaction energy within a certain error. With this information, the rank of the expansion for each interaction can be adapted to the required accuracy and the available computing power. © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 832–838, 2007
Identification of proteins directly from tissue: in situ tryptic digestions coupled with imaging mass spectrometry
Authors: Groseclose M. Reid , Andersson Malin , Hardesty William M. , Caprioli Richard M.
Published: January 2007

A novel method for on‐tissue identification of proteins in spatially discrete regions is described using tryptic digestion followed by matrix‐assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) with MS/MS analysis. IMS is first used to reveal the protein and peptide spatial distribution in a tissue section and then a serial section is robotically spotted with small volumes of trypsin solution to carry out in situ protease digestion. After hydrolysis, 2,5‐Dihydroxybenzoic acid (DHB) matrix solution is applied to the digested spots, with subsequent analysis by IMS to reveal the spatial distribution of the various tryptic fragments. Sequence determination of the tryptic fragments is performed using on‐tissue MALDI MS/MS analysis directly from the individual digest spots. This protocol enables protein identification directly from tissue while preserving the spatial integrity of the tissue sample. The procedure is demonstrated with the identification of several proteins in the coronal sections of a rat brain. Copyright © 2007 John Wiley & Sons, Ltd.
Retropubic versus perineal radical prostatectomy in early prostate cancer: Eight‐year experience
Authors: Martis Gianni , Diana Massimo , Ombres Maurizio , Cardi Antonio , Mastrangeli Roberta , Mastrangeli Bruno
Published: January 2007

Background

Prostate cancer is the most common malignancy in men and the second leading cause of cancer death. A randomized study was performed on patients with localized prostate cancer and treated with radical prostatectomy using the perineal or the retropubic approach comparing oncological outcomes, cancer control, and functional results.

Study Design

Between 1997 and 2004, in a randomized study 200 patients underwent a radical prostatectomy performed by retropubic (100 patients) or perineal (100 patients) approach.

Results

Differences between hospital stay, duration of catheter drainage, intraoperative blood loss, and transfusion requirements were statistically significant in favor of perineal prostatectomy. Differences between positive surgical margins and urinary continence in the two groups were not statistically significant at 6 and 24 months. Differences between erectile function at 24 months were statistically significant in favor of retropubic prostatectomy.

Conclusions

Radical perineal prostatectomy is an excellent alternative approach for radical surgery in the treatment of early prostate cancer. J. Surg. Oncol. 2007; 95: 513–518. © 2007 Wiley‐Liss, Inc.
The case for routine use of adjuvant therapy in pancreatic cancer
Authors: Kennedy Eugene P. , Yeo Charles J.
Published: January 2007

Pancreatic cancer is a devastating disease with a poor prognosis for most patients. Surgical resection remains the cornerstone of treatment, providing the only realistic hope of long‐term survival. Even with optimal surgical management, 5‐year survival averages 15% to 20% for resectable disease. Progress is being made, however. Currently, the benefits of postoperative therapy for resected pancreatic ductal adenocarcinoma appear clear, and recommendations for such therapy appear to us to be well justified. Additional benefit to patients awaits the development of new agents, molecular targeted drugs, and novel approaches such as immunotherapy. J. Surg. Oncol. 2007;95:597–603. © 2007 Wiley‐Liss, Inc.
A simple method to accurately position Port‐A‐Cath without the aid of intraoperative fluoroscopy or other localizing devices
Authors: Horng Huann‐Cheng , Yuan Chiou‐Chung , Chao Kuan‐Chong , Cheng Ming‐Huei , Wang Peng‐Hui
Published: January 2007

Background

To evaluate the efficacy and acceptability of the Port‐A‐Cath (PAC) insertion method with (conventional group as II) and without (modified group as I) the aid of intraoperative fluoroscopy or other localizing devices.

Methods

A total of 158 women with various kinds of gynecological cancers warranting PAC insertion (n = 86 in group I and n = 72 in group II, respectively) were evaluated. Data for analyses included patient age, main disease, dislocation site, surgical time, complications, and catheter outcome.

Results

There was no statistical difference between the two groups in terms of age, main disease, complications, and the experiencing of patent catheters. However, appropriate positioning (100% in group I, and 82% in group II) in the superior vena cava (SVC) showed statistical differences between the two groups (P = 0.001). In addition, the surgical time in group I was statistically shorter than that in group II (P < 0.001).

Conclusions

The modified method for inserting the PAC offered the following benefits: including avoiding X‐ray exposure for both the operator and the patient, defining the appropriate position in the SVC, and less surgical time. J. Surg. Oncol. 2007;95:582–586. © 2007 Wiley‐Liss, Inc.
Health‐care product advertising: The influences of message framing and perceived product characteristics
Authors: Chang Chun‐Tuan
Published: January 2007

Message framing readily lends itself to marketing communication and advertising persuasion strategies. However, past research yields contradictory and inconsistent predictions as to whether positive or negative frames are more persuasive. This study examines the most appropriate message framing to present to consumers in print advertisements for health care products. Two experimental studies are conducted to investigate the moderating effects of product functions: perceived innovativeness and perceived risk on the processing of framed advertising messages. Findings of Study 1 indicate that messages for familiar products should be framed differently depending on perceived product functions (prevention vs. detection), but gain‐framed messages are more persuasive for both new prevention and detection products. Results of Study 2 suggest that a mixed‐framed message (combining gain and loss) could enhance message effectiveness only when subjects have prior experience. Similar to the role of product function, product perceived risk is found to moderate the framing effects on message effectiveness. © 2007 Wiley Periodicals, Inc.
Hysterical chorea: Report of an outbreak and movie documentation by Arthur Van Gehuchten (1861–1914)
Authors: Giménez‐Roldán Santiago , Aubert Geneviève
Published: January 2007

Psychogenic movement disorders remain a frequent and important clinical problem. First described in the Middle Ages, the dancing mania is considered to be one form of mass hysteria characterized by outbreaks of collective movement disorders. Patients may exhibit a wide variety of movement and gait disturbances, including tremulousness, jerks, or convulsions, usually with a sudden onset. Arthur Van Gehuchten (1861–1914), a distinguished Belgian neuroanatomist and neurologist, reported an outbreak of sudden involuntary movements in 13 adolescent girls residing in an orphanage. The description is to be found in his book Les Maladies nerveuses, completed before 1914 and published posthumously in 1920. The chapter is illustrated with sequential photographs of a girl exhibiting a peculiar gait, which is descriptively referred to as “chorée salutatoire” (saluting chorea). The original film with these pictures has been retrieved and is presented here together with a very similar film excerpt also found in Van Gehuchten's film collection. Van Gehuchten's movie documentation of a psychogenic movement disorder—labeled chorea but which should probably be considered as dystonia according to contemporary classification—appears to be unique. This report illustrates the tremendous value of moving pictures in recording and analyzing movement disorders. © 2006 Movement Disorder Society
Structural white matter abnormalities in patients with idiopathic dystonia
Authors: Bonilha Leonardo , de Vries Paulien M. , Vincent Diana J. , Rorden Chris , Morgan Paul S. , Hurd Mark W. , Besenski Nada , Bergmann Kenneth J. , Hinson Vanessa K.
Published: January 2007

We investigated whether structural white matter abnormalities, in the form of disruption of axonal coherence and integrity as measured with diffusion tensor imaging (DTI), constitute an underlying pathological mechanism of idiopathic dystonia (ID), independent of genotype status. We studied seven subjects with ID: all had cervical dystonia as their main symptom (one patient also had spasmodic dysphonia and two patients had concurrent generalized dystonia, both DYT1‐negative). We compared DTI MR images of patients with 10 controls, evaluating differences in mean diffusivity (MD) and fractional anisotropy (FA). ID was associated with increased FA values in the thalamus and adjacent white matter, and in the white matter underlying the middle frontal gyrus. ID was also associated with increase in MD in adjacent white matter to the pallidum and putamen bilaterally, left caudate, and in subcortical hemispheric regions, including the postcentral gyrus. Abnormal FA and MD in patients with ID indicate that abnormal axonal coherence and integrity contribute to the pathophysiology of dystonia. These findings suggest that ID is not only a functional disorder, but also associated with structural brain changes. Impaired connectivity and disrupted flow of information may contribute to the impairment of motor planning and regulation in dystonia. © 2006 Movement Disorder Society
Punding prevalence in Parkinson's disease
Authors: Miyasaki Janis M. , Al Hassan Khalid , Lang Anthony E. , Voon Valerie
Published: January 2007

The purpose of this study was to determine punding prevalence in an ambulatory Parkinson's disease (PD) population. We conducted a patient‐and‐caregiver–completed punding survey in 373 consecutive patients in an academic ambulatory center. Completion rate was 78%. Only four patients were identified as punding. Patients did not retain insight to their behavior. Forty patients with high‐dose levodopa monotherapy or levodopa and dopamine agonist treatment had physician‐administered interview. None had punding. Punding incidence was low in this patient group (1.4%) in contrast with previous reports of 14%. Despite the low incidence, this behavior is disruptive and should be carefully elicited by physicians caring for Parkinson's disease patients. © 2006 Movement Disorder Society
Selective diplopia in Parkinson's disease: A special subtype of visual hallucination?
Authors: Nebe Angelika , Ebersbach Georg
Published: January 2007

Diplopia is sometimes reported by patients with Parkinson's disease (PD) without apparent oculomotor disorders. We assessed clinical features and associated oculomotor and perceptual performance in 14 patients (6 male, 8 female) with PD with a peculiar type of selective diplopia. Duplication of images was confined to single objects or persons, occurred repetitively, and lasted few seconds in all subjects. Frequency of episodes ranged from several episodes per day to three episodes per year. In six of seven subjects undergoing comprehensive ophtalmological examination, subtle ocular disorders (heterophoria, strabism, etc.) were found. Nine of 14 patients were suffering from current or previous visual hallucinations and 3 more patients developed hallucinations within 3 years of diplopia onset. Selective diplopia of isolated single objects and persons in PD is possibly related to hallucinosis and minor ocular disturbances seem to be a triggering factor for this peculiar type of misperception. © 2006 Movement Disorder Society
Normal cardiovascular reflex testing in patients with parkin disease
Authors: Del Sorbo Francesca , Elia Antonio E. , De Joanna Gabriella , Romito Luigi M. , Garavaglia Barbara , Albanese Alberto
Published: January 2007

The objective of this study was to investigate cardiovascular autonomic function in patients with parkin disease. Ten patients with a genetically confirmed diagnosis were compared to 11 healthy controls. Symptoms related to autonomic dysfunction were collected by structured interviews. Cardiovascular autonomic reflex function was evaluated using a standard battery of eight tests. Autonomic tests included the study of sympathetic function through the analysis of blood pressure responses to head‐up tilt, standing, isometric hand grip, cold pressor, mental arithmetic, Valsalva maneuver (Valsalva overshoot), and the study of parasympathetic function through the analysis of heart rate responses to deep breathing, hyperventilation, and Valsalva ratio. Seven out of 10 patients reported symptoms involving different aspects of autonomic function, while 5 out of 11 controls reported symptoms related exclusively to orthostatic dizziness and constipation. Symptoms related to bladder dysfunction were the most frequent autonomic abnormality occurring in six patients, followed by orthostatic dizziness and dry mouth (in four patients each). Constipation occurred in three patients, sialorrhea in two, and erectile dysfunction, dry eye, and warm intolerance in one each. Cardiovascular reflex testing revealed no difference between patients and controls in quantitative assessment of both sympathetic and parasympathetic functions, except for diastolic blood pressure after isometric hand grip that did not increase normally in parkin patients compared to controls (P = 0.007). These data show that cardiovascular dysautonomia is not associated to the parkin phenotype, whereas urinary complaints are more frequently reported by parkin patients than by controls. Urinary dysautonomia warrants further investigation in patients with parkin disease. © 2006 Movement Disorder Society
Data protection in biomaterial banks for Parkinson's disease research: The model of GEPARD (Gene bank Parkinson's Disease Germany)
Authors: Eggert Karla , Wüllner Ullrich , Antony Gisela , Gasser Thomas , Janetzky Bernd , Klein Christine , Schöls Ludger , Oertel Wolfgang
Published: January 2007

Parkinson's disease (PD) is the second most common neurodegenerative disease. Although 10 gene loci have been identified to cause a Parkinsonian syndrome, these loci account only for a minority of PD patients. Large, systematic research programs are required to collect, store, and analyze DNA samples and clinical information to support further discovery of additional genetic components of PD or other movement disorders. Such programs facilitate research into the relationship between genotype and phenotype. The German Competence Network on Parkinson's disease (CNP) initiated the Gene Bank Parkinson's Disease Germany (GEPARD), providing an administrative and scientific infrastructure for the storage of DNA and clinical data that are electronically accessible and protective of patient rights. In this article, we offer guidance on how to establish a framework for a clinical genetic data and DNA bank, and describe GEPARD as a model that may be useful to other local, national, and international research groups developing similar programs. © 2006 Movement Disorder Society
Asymmetrical alien hands in corticobasal degeneration
Authors: FitzGerald David B. , Drago Valeria , Jeong Yong , Chang Yu‐Ling , White Keith D. , Heilman Kenneth M.
Published: January 2007

There are several forms of alien limb, but alien limb in corticobasal degeneration (CBD) is not well understood. We studied a patient with CBD who demonstrated two different types of alien limb. With his right hand he demonstrated a tactile avoidance response with levitation. With his left hand, he demonstrated continuous tactile pursuit of the examiner's hand (“tactile mitgehen”). Mitgehen is often associated with frontal dysfunction, but avoidance response and levitation are often associated with parietal dysfunction. © 2006 Movement Disorder Society
Celiac disease presenting with motor neuropathy: Effect of gluten free‐diet
Authors: Rigamonti Andrea , Magi Stefania , Venturini Elisabetta , Morandi Lucia , Ciano Claudia , Lauria Giuseppe
Published: January 2007

Celiac disease is a rare cause of neuropathy that most commonly presents with symmetric distal sensory disturbances. We describe two patients with celiac disease in whom neuropathy presented unusually with progressive weakness of the limbs. In both patients a gluten‐free diet induced a significant improvement of muscle strength and neurophysiological abnormalities, suggesting a direct pathogenetic role of sensitivity to gluten. Celiac disease should be considered in patients with idiopathic neuropathy even when gastrointestinal symptoms are absent. Muscle Nerve, 2007
Kurtosis correction method for X̄ and R control charts for long‐tailed symmetrical distributions
Authors: Tadikamalla Pandu R. , Popescu Dana G.
Published: January 2007

This paper proposes a kurtosis correction (KC) method for constructing the X̄ and R control charts for symmetrical long‐tailed (leptokurtic) distributions. The control charts are similar to the Shewhart control charts and are very easy to use. The control limits are derived based on the degree of kurtosis estimated from the actual (subgroup) data. It is assumed that the underlying quality characteristic is symmetrically distributed and no other distributional and/or parameter assumptions are made. The control chart constants are tabulated and the performance of these charts is compared with that of the Shewhart control charts. For the case of the logistic distribution, the exact control limits are derived and are compared with the KC method and the Shewhart method. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Dynamic stability of a porous cylindrical shell
Authors: Belica Tomasz , Magnucki Krzysztof
Published: January 2007

This paper is devoted to a closed cylindrical shell made of a porous‐cellular material. The mechanical properties vary continuously on the thickness of a shell. The mechanical model of porosity is as described as presented by Magnucki, Stasiewicz. A shell is simply supported on edges. On the ground of assumed displacement functions the deformation of shell is defined. The displacement field of any cross section and linear geometrical and physical relationships are assumed in cylindrical coordinate system. The components of deformation and stress state were found. Using the Hamilton's principle the system of differential equations of dynamic stability is obtained. The forms of unknown functions are assumed and the system of a differential equations is reduced to a simple ordinary equation of dynamic stability of shell (Mathieu's equation). The derived equation are used for solving a problem of dynamic stability of porous‐cellular shell with intensity of load directed in generators of shell. The critical loads are derived for a family of porous shells. The unstable space of family porous shells is found. The influence a coefficient of porosity on the stability regions in Figures is presented. The results obtained for porous shell are compared to a homogeneous isotropic cylindrical shell. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of crack–propagation in shells
Authors: Hoppe Ulrich , Hackl Klaus
Published: January 2007

We develop a finite element method for the simulation of fragmentation of thin shells. The method is valid for completely non–linear problems, but is restricted to through–the–thickness cracks, which are normal to the midsurface. The methodology is based on the extended finite element method (X–FEM). The use of X–FEM allows arbitrary crack path evolution and does not require a priori knowledge of the crack zone or remeshing. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the contact model on the onset of sprag‐slip
Authors: Keitzel Hanna , Hoffmann Norbert
Published: January 2007

In systems with sliding‐friction often strong self‐excited vibrations do occur. One of the possible underlying mechanisms is the so‐called sprag‐slip instability. In the present work the onset of sprag‐slip is investigated by a simple model in which an inclined elastic beam slides over a rigid belt moving with constant velocity. For a Coulomb friction law and a contact model with constant contact stiffness for a certain range of parameters the system loses its static solution corresponding to the steady sliding state. Simultaneously with this loss of existence of the static solution the qualitative properties of the system's flow field in phase space change, resembling a transition from stable to unstable behavior. To investigate the influence of contact models and related parameters on the details of this onset of sprag‐slip also Hertz theory of elastic contact is applied. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The elastic response for microlayered functionally graded media
Authors: Jȩdrysiak J. , Wierzbicki E. , Woźniak Cz.
Published: January 2007

In this note microlayered composites having continuously varying macroscopic properties are considered. Such composites are referred to as the functionally graded laminates (FGL). The aim of this contribution is to derive a new averaged model describing the elastic response of the FGL, using the modified tolerance averaging technique, developed for periodic composites and structures by Woźniak and Wierzbicki (2000). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cavities in a visco‐plastic material: A mesoscopic concept
Authors: Weinberg Kerstin , Böhme Thomas
Published: January 2007

In the present work we investigate the temporal development of arbitrarily distributed voids in a visco‐plastic material under different loading regimes. A mesoscopic continuum model is used in order to take the microstructure of the material into account. In particular, we introduce a mesoscopic space representing an extension of the space‐time domain of the continuum mechanical fields. This extended domain requires a reformulation of the classical balance equations as well as the consideration of additional constitutive quantities. Furthermore a mesoscopic distribution function can be introduced which follows an own balance. Assuming a special model of porous composites, the spherical shell model, all required steps are elaborated in order to describe load‐induced void‐growth in a metal‐like matrix. We conclude with some exemplary results which show astonishing similarities with co‐called LSW‐theories. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Osteosarcoma metastatic to the kidney and iatrogenic hemorrhage
Authors: Marec‐Bérard Perrine , Crassard Nicolas , Schell Matthias , Philip Thierry , Thiesse Philippe , Ranchin Bruno , Frappaz Didier
Published: January 2007

A 16‐year old female presented painful masses in the lumbar region 5 years after the initial diagnosis of a localized osteosarcoma of the tibia. Abdominal X‐ray revealed calcified masses. A bone scan confirmed an increased uptake in the renal areas. An ultrasound‐guided fine needle biopsy confirmed the diagnosis of metastases. The procedure was complicated by subcapsular hemorrhage and gross hematuria. Renal metastases from osteosarcoma are usually asymptomatic and invisible on abdominal X‐rays. The diagnosis is generally established by radionuclide bone scan or abdominal CT‐scan. Our observation suggests that histological documentation of these unusual clinical presentations should be carefully weighed against the risk of the procedure. Pediatr Blood Cancer 2008;50:690–692. © 2007 Wiley‐Liss, Inc.
A stress echocardiography study of cardiac function during progressive exercise in pediatric oncology patients treated with anthracyclines
Authors: De Souza Astrid M. , Potts James E. , Potts Mary T. , De Souza Eustace S. , Rowland Thomas W. , Pritchard Sheila L. , Sandor George G.S.
Published: January 2007

Background

Anthracycline‐treated patients (AP) are at risk for cardiac dysfunction years after treatment. Cardiac function has not been evaluated during exercise in AP. The purpose of this study was to assess exercise tolerance, left ventricular (LV) function, and hemodynamics during progressive exercise.

Procedure

We studied 47 AP (cumulative dose: 36–504 mg/m2) who were in complete remission and 12 healthy controls (CON). AP were further grouped by cumulative dose (LOW ≤ 260 mg/m2; HIGH ≥ 260 mg/m2) and resting echocardiographic function. All subjects performed 3‐min incremental stages on a semi‐recumbent cycle ergometer until volitional fatigue. Using echocardiography and Doppler, LV dimensions, posterior wall thickness (LVPWs), peak aortic velocity (PAoV), shortening fraction (SF), rate‐corrected mean velocity of fiber shortening (MVCFc), wall stress at peak systole (σPS), stroke volume index (SVI), and cardiac index (CI) were determined. Measurements were performed at rest, during each stage of exercise, and in recovery.

Results

AP did less work than CON (P < 0.050). CON and LOW had similar resting function, while HIGH had a lower SF and MVCFc (P < 0.050) and a higher σPS (P < 0.001). Resting SVI and CI were also lower in HIGH. At peak exercise, MVCFc and σPS remained different in HIGH, and both AP groups had a lower SF, SVI, and CI (P < 0.001). AP had an abnormal SVI response to exercise. AP showed a smaller initial increase in SVI that was not maintained throughout exercise.

Conclusions

AP have reduced exercise tolerance. There also appears to be a dose‐related effect on myocardial contractility and SVI. These findings may help to guide treatment. Pediatr Blood Cancer 2007;49:56–64. © 2007 Wiley‐Liss, Inc.
Properties and preparation of thermoplastic polyurethane/silica hybrids using a modified sol–gel process
Authors: Lai S.‐M. , Liu S.‐D.
Published: January 2007

Thermoplastic polyurethane elastomer/silica hybrids (TPU/SiO2) were prepared using a modified sol–gel process. This modified approach used tetrahydrofuran (THF) to extract polysilicic acid from aqueous sodium metasilicate solutions. A THF or aqueous solution containing sol particles was mixed with TPU solution to form TPU/silica hybrids. The Fourier transform infrared (FTIR) spectra and dynamical mechanical properties were recorded to depict the interfacial interaction. Storage modulus increased due to the reinforcement of the in situ silica. Tear strength decreased significantly with increasing in situ silica content. Cutting strength decreased slightly due to crack tip confinement. The modified process with extraction showed improved mechanical properties and better optical properties than the conventional sol–gel process without extraction. The fracture surface was revealed through SEM (scanning electron microscopy) to observe the degree of SiO2 dispersion, which in turn confirmed the optical and mechanical property results. POLYM. ENG. SCI., 47:77–86, 2007. © 2007 Society of Plastics Engineers
Microstructure analysis of brominated styrene–butadiene rubber
Authors: Khoee Sepideh , Sorkhi Maedeh
Published: January 2007

The bromine addition to the SBR double bonds in chloroform at 0°C has been investigated by FTIR, 1H NMR and DSC techniques. In this case, bromine molecules react exclusively with the polydiene double bonds and the polystyrene units are unaffected. The bromine reacts preferentially with 1,4‐trans double bonds of the polybutadiene segment of SBR. At low bromination level (below 15%) the bromine reacts mainly with the 1,4‐trans double bonds of SBR, while at higher bromination level (up to 30%) the bromine shows the most reactivity toward the vinylic double bond. Above 30%, the addition reaction occurs on 1,4‐trans double bonds. The microstructure of modified and unmodified styrene–butadiene copolymers were fully characterized by 1H NMR technique. Expanded regions have been utilized to resolve the complex 1H NMR spectrum and establish the compositional and configurational sequences of styrene–butadiene copolymers. POLYM. ENG. SCI., 47:87–94, 2007. © 2007 Society of Plastics Engineers
Mechanical properties and morphologies of polypropylene/single‐filler or hybrid‐filler calcium carbonate composites
Authors: Yang Kun , Yang Qi , Li Guangxian , Zhang Ying , Zhang Peng
Published: January 2007

Three types of polypropylene (PP) with different intrinsic toughness were used to study the mechanical properties and morphologies of the PP composites filled with single‐filler and hybrid‐filler of calcium carbonate particles. The calcium carbonate particles used were with average particle sizes of 25 μm (CC25), and 0.07 μm (CC0.07), respectively. A hybrid‐filler CaCO3 named CC25/CC0.07 was used as a mixture of CC25 and CC0.07 (CC25/CC0.07 weight ratio = 1:1). It was found that the type of PP and the particle size of inorganic filler were the two important factors for the determination of mechanical properties of the composites. And the general mechanical properties of the composites filled with hybrid‐filler CaCO3 were better than those of the composites filled with single‐filler CaCO3, but the synergistic hybridization effect of the hybrid‐filler CaCO3 did not exist. The major toughening mechanism of the PP/CC25 composites was the cavitation of the matrix caused by CC25, and the major toughening mechanism of the PP/CC0.07 composites was the pinning effect introduced by CC0.07. For the PP/CC25/CC0.07 composites, the cavitation of the matrix caused by CC25 and the pinning effect introduced by CC0.07 existed simultaneously. And when the intrinsic toughness of the matrix was large enough, the major factor to toughen PP was the pinning effect introduced by CC0.07, otherwise the major factor to toughen PP was the cavitation of the matrix caused by CC25. POLYM. ENG. SCI., 47:95–102, 2007. © 2007 Society of Plastics Engineers
Preparation and characterization of poly(butylene terephthalate)/poly(ethylene terephthalate) copolymers via solid‐state and melt polymerization
Authors: Jansen M. A. G. , Wu L. H. , Goossens J. G. P. , DE Wit G. , Bailly C. , Koning C. E.
Published: January 2007

To increase the Tg in combination with a retained crystallization rate, bis(2‐hydroxyethyl)terephthalate (BHET) was incorporated into poly(butylene terephthalate) (PBT) via solid‐state copolymerization (SSP). The incorporated BHET fraction depends on the miscibility of BHET in the amorphous phase of PBT prior to SSP. DSC measurements showed that BHET is only partially miscible. During SSP, the miscible BHET fraction reacts via transesterification reactions with the mobile amorphous PBT segments. The immiscible BHET fraction reacts by self‐condensation, resulting in the formation of poly(ethylene terephthalate) (PET) homopolymer. 1H‐NMR sequence distribution analysis showed that self‐condensation of BHET proceeded faster than the transesterification with PBT. SAXS measurements showed an increase in the long period with increasing fraction BHET present in the mixtures used for SSP followed by a decrease due to the formation of small PET crystals. DSC confirmed the presence of separate PET crystals. Furthermore, the incorporation of BHET via SSP resulted in PBT‐PET copolymers with an increased Tg compared to PBT. However, these copolymers showed a poorer crystallization behavior. The modified copolymer chain segments are apparently fully miscible with the unmodified PBT chains in the molten state. Consequently, the crystal growth process is retarded resulting in a decreased crystallization rate and crystallinity. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 882–899, 2007.
Synthesis and characterization of highly hindered and thermally stable poly(1,4‐spirobifluorenylenevinylene) derivative
Authors: Kim Yun‐Hi , Park Jong‐Won , Shin Dong‐Cheol , You Hong , Kwon Soon‐Ki
Published: January 2007

A new poly(1,4‐spirobifluorenylenevinylene) having advantage PPV and spirobifluorene as new emissive family was synthesized. Compared with PPV derivatives that usually have a tolane bisbenzyl defect, the polymer has the defect free structure because of the steric hindrance of the asymmetric bulky spirobifluorenyl group. Compared with spirobifluorene derivatives that usually have a low solubility, the polymer has the good solubility in common organic solvents. The polymer was amorphous and showed high PL quantum efficiency and high thermal stability with high Tg. The PL emission peaks were shown at 480–490 nm in solution and film, respectively, which may represent the bluest emission peak reported for fully conjugated PPV derivatives. The study of thermal annealing of PL spectrum showed excimer formation inhibited. The thermal and optoelectronic properties of the polymer imply that it is a promising material for the PLED application. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 900–907, 2007.
Peer‐support in coping with medical uncertainty: discussion of oophorectomy and hormone replacement therapy on a web‐based message board
Authors: Kenen Regina H. , Shapiro Pamela J. , Friedman Susan , Coyne James C.
Published: January 2007

The Facing Our Risk of Cancer Empowered (FORCE) website is devoted to women at risk for hereditary breast and ovarian cancers (HBOC). To understand the unique health concerns and emotional support needs of these women, we examined threads on the FORCE archived message boards with relevance to the broader HBOC community. We report on a thread discussing the controversial decision to use hormone replacement therapy (HRT) following prophylactic oophorectomy (PO). We used a qualitative research inductive process involving close reading, coding and identification of recurrent patterns, relationships and processes in the data. Twenty‐nine women posted 177 messages over 7 months. Two main groups of women posted: (1) Women who were BRCA+, had completed PO, and were debating or adjusting their HRT options in terms of optimizing both quality and quantity of life. (2) Women who were BRCA+, were contemplating PO, but wanted to better understand the potential physical and psychological consequences of surgical menopause before deciding. Frustrated by physicians' lack of knowledge and contradictory media articles about the long‐term consequences of HRT in BRCA+ women, they sought resources, emotional support and specific experiential knowledge from each other and generated a unique sense of community and a high level of trust. Copyright © 2007 John Wiley & Sons, Ltd.
Factors associated with middle and secondary students' perceived science competence
Authors: Beghetto Ronald A.
Published: January 2007

The aim of the present study was to gain a better understanding of students' perceived science competence by examining potentially related beliefs and perceptions in a diverse sample of middle and secondary students (N = 1289). Results of hierarchical regression analysis showed that students' perceived science competence was related to: (a) students' age, gender, and ethnicity; (b) students' mastery and performance–approach goals; (c) students' self‐perceptions of their ability to generate creative ideas (i.e., creative self‐efficacy); and (d) students' perceptions of teacher support and press (i.e., challenging academic demands). Of all these factors, creative self‐efficacy was found to have the strongest positive relationship with students' perceived science competence. Implications for subsequent research are discussed. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 800–814, 2007
Juvenile Polyp in Thai Children—Clinical and Colonoscopic Presentation
Authors: Ukarapol Nuthapong , Singhavejakul Jesda , Lertprasertsuk Nirush , Wongsawasdi Lumduan
Published: January 2007

Background

The aim of this prospective study was to describe the clinical characteristics of colorectal polyp in Thai children.

Methods

From December 2002 to February 2005, children under 15 years of age presenting with rectal bleeding were prospectively enrolled. Demographic, clinical, and laboratory information was recorded. Location, number, characteristics, and histopathology of the polyps were noted.

Results

There were 32 patients with a mean age of 6.5 years. The most common presenting symptom was hematochezia, followed by prolapsing rectal mass and diarrhea. In 20 patients there was a single polyp, 6 had 2–4 polyps, and 6 were diagnosed with polyposis coli. Most of the polyps were located exclusively at the rectum and sigmoid colon. In only 7 cases were the polyps proximal to the rectosigmoid region. This included 6 patients who had polyps beyond the splenic flexure. All were juvenile polyps without evidence of adenomatous changes. Compared to those with isolated polyps, the patients with polyposis coli had a statistically significant incidence of right‐sided polyps (P <0.001) and a history of prolapse of the rectal mass (P = 0.006).

Conclusions

Because of the high prevalence of right‐sided polyps and the concern about malignant transformation, colonoscopy should be considered as the initial evaluation in children with rectal bleeding.