bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre‐Irradiation Grafting of Styrene into Modified Fluoropolymers
Authors: Lappan Uwe , Geißler Uwe , Uhlmann Steffi
Published: August 2007

Summary: The grafting of styrene into commercially available fluoropolymer films by the pre‐irradiation method has been investigated. Poly(tetrafluoroethylene) (PTFE), poly(tetrafluoroethylene‐co‐hexafluoropropylene) (FEP), poly(tetrafluoroethylene‐co‐perfluoropropylvinyl ether) (PFA) and poly(tetrafluorethylene‐co‐ethylene) (ETFE) were chosen as the base polymer material. The influence of the base material, the pre‐irradiation dose, and the storage time between the irradiation and the grafting step on the yield of grafting was examined. The base materials were pre‐treated by irradiation in the molten state under oxygen‐free conditions in order to create branches and cross‐links. The effect of pre‐treatment on the yield of grafting was studied.
Structure – Directing Effect of Renewable Resource Based Amphiphilic Dopants on the Formation of Conducting Polyaniline‐Clay Nanocomposite
Authors: Sudha Janardhanannair D. , Reena Viswan L.
Published: August 2007

Summary: The structure‐directing effect of two amphiphilic dopants on the nucleation and growth mechanism during the formation of micro/ nanostructured polyaniline (PANI) and polyaniline‐clay nanocomposites (PANICNs) is described. PANIs and PANICNs were prepared by in‐situ intercalative emulsion polymerization of aniline using the amphiphilic dopants, 3‐pentadecyl phenyl phosphoric acid (3‐PDPPA) and 3‐pentadecyl phenol–4‐sulphonic acid (3‐PDPSA), derived from cashew nut shell liquid, a renewable resource. These molecules act as intercalating agents, dopants and also as structure‐directing agents. X‐ ray diffraction (XRD) and scanning electron microscopic (SEM) studies revealed the formation of lamellar/fibrillar – network in PANI‐ PDPPA and cylinder/rod morphology in PANI‐PDPSA. Experimental data reveal that fibrillar morphology arises from the heterogeneous nucleation followed by an indefinite growth mechanism. On the other hand rod‐like structures are formed from the self‐assembled rod‐like micelle guided polymerization through homonucleation followed by an anisotropic growth mechanism. Electrical conductivity measurement revealed lower conductivities for PANICNs than that of PANIs.
Conductive UV Curable Adhesives for Printed RFID Antenna Structures
Authors: Kowalik T. , Worch S. , Hartwig A. , Joachimi H.
Published: August 2007

Summary: For the use as RFID antennas conductive adhesives were developed and investigated which are UV curable and could be applied with printing methods like offset printing or flexography. Further investigated aspects of the materials have been the range of the distance between emitter and receiver. The resulting formulations which are based on acrylates filled with silver pigments for the conductivity allow to cure layers with a thickness of up to 50 µm with a maximal volume resistance of 1.6 × 10−5 Ω/cm.
On the Modeling of Polyelectrolyte Gels
Authors: Wallmersperger Thomas , Ballhause Dirk , Kröplin Bernd
Published: August 2007

Summary: Ionic polymer gels are very attractive actuation materials with a great similarity to biological contractile tissues. They consist of a polymer network with bound charged groups and a liquid phase with mobile ions. Absorption and delivery of solvent lead to a considerably large change of volume. This swelling mechanism results from the equilibrium of different forces such as osmotic pressure forces, electrostatic forces and viscoelastic restoring forces and can be triggered by chemical (change of salt concentration or pH in the solution), thermal or electrical stimulation. In the present work, chemically and electrically stimulated electrolyte polymer gels in a solution bath are investigated. To describe the different phenomena occurring in these gels adequately, the modeling can be conducted on different scales. If only the global macroscopic behavior is of interest, the statistical theory which is capable to describe the global swelling ratio, is sufficient. By refining the scale, the mesoscopic coupled multi‐field theory can be applied. Here, the chemical field is described by a convection‐diffusion equation for the different mobile species. The electric field is directly obtained by solving the Poisson equation in the gel and solution domain. The mechanical field is formulated by the momentum equation. By further refining the scale, the whole structure can be investigated on the microscale by the discrete element (DE) method. In this model, the material is represented by distributed particles comprising a certain amount of mass; the particles interact with each other mechanically by a truss or beam network of massless elements. The mechanical behavior, i.e. the dynamics of the system, is followed by solving the Newton's equations of motion while the chemical field, i.e. the ion movement inside the gel and from the gel to the solution, is described by diffusion equations for the different mobile particles. All three formulations can give chemical, (electrical) and mechanical unknowns and all rely on the assumption that the concentration differences between the different regions of the gel and between gel and solution form the osmotic pressure difference, which is a main cause for the mechanical deformation of the polyelectrolyte gel film.
Novel Hydrogels for Rhythmic Pulsatile Drug Delivery
Authors: Mujumdar Siddharthya K. , Bhalla Amardeep S. , Siegel Ronald. A
Published: August 2007

Summary: We are investigating an autonomous glucose‐driven hydrogel/enzyme‐based device prototype for rhythmic, pulsed delivery of gonadotropin releasing hormone (GnRH). The device employs a pH‐sensitive hydrogel membrane in conjunction with the enzyme glucose oxidase. This system delivers GnRH in rhythmic pulses when exposed to a constant level of glucose. These pulses result from autonomous pH oscillations inside the device that are created by an unstable nonlinear feedback between hydrogel permeability to glucose and production of acid by glucose oxidase. Previous versions of this prototype utilized p(N‐isopropylacrylamide‐co‐methylacrylic acid) p(NIPA‐co‐MAA) hydrogels, with 10 mol% MAA incorporated. With this membrane, which undergoes a volume transition (VT) near pH 5, pH oscillations centered around pH 5 are observed. This range is too low to sustain oscillations in physiologically buffered media. To shift the operating pH of oscillations closer to physiologic pH, we have sought ways to increase the pH of the volume transition. In this study we show that increasing the side chain length of the α‐alkylacrylic acid (RAA) comonomer enhances the overall hydrophobicity of the copolymer, and shifts the VT pH closer to physiological pH values. We also demonstrate the ability of such membranes to affect an alkaline shift in the range of oscillations in the prototype oscillator device.
On the Development of the VIPAR Polymer Gel Dosimeter for Three‐Dimensional Dose Measurements
Authors: Kozicki Marek , Maras Piotr , Rybka Krzysztof , Biegański Tadeusz , Kadłubowski Sławomir , Petrokokkinos Loukas
Published: August 2007

Summary: The new polymer gel dosimeter, based on the modification of the VIPAR gel composition, is described for the purpose of radiation dose distribution measurement in radiotherapy. It features increased concentration of the two VIPAR substrates: N‐vinylpyrrolidone (8%) and gelatine (7.5%) (N,N′‐methylenebisacrylamide was maintained at 4%), and the addition of copper sulphate (0.0008%) and ascorbic acid (0.007%) in order to facilitate the preparation through elimination of the need for deoxygenation of the gel. Following the exposure to ionizing radiation, polymerisation and cross‐linking of the new gel monomers occurs retaining the spatial distribution of absorbed dose and causing opacity of the gel. Quantitative parameters of the new gel dose response were studied using magnetic resonance imaging to relate polymerisation induced physicochemical changes of the gel to dose. The dose threshold is found significantly lower than that of the original VIPAR gel. The linear part of measured spin‐spin relaxation rate R2(D) ( = 1/T2(D)) reaches up to 35 Gy. Its slope and an intercept are slightly higher relative to the original VIPAR. The efficiency of the new polymer gel‐magnetic resonance imaging dosimeter was also tested for dose verification of a 3D dose distribution planned by a commercially available treatment planning software (Eclipse External Beam v.6.5) and delivered by a 6 MV medical linear accelerator. The new polymer gel is proposed to be called, VIPARnd (after VIPAR‐normoxic‐double).
Polymersome‐Embedded Nanoparticles
Authors: Sachsenhofer Robert , Binder Wolfgang H. , Farnik Dominique , Zirbs Ronald
Published: August 2007

Summary: Polymersomes are self assembled vesicles composed of fully synthetic amphiphilic diblock copolymers. Many of their properties are similar to lipid vesicles, although with often higher thermal and mechanical stability within their curved membrane. Incorporation of nanosized objects into their hydrophilic interior or hydrophobic membrane represents an important method for functionalization of these biomimetic structures. We report on the embedding of hydrophobic gold nanoparticles (Au‐NPs) into polymersomes. Nanoparticles were prepared and incorporated into polymersomes made by standard film rehydration techniques from commercially available diblock copolymers. Characterization of the resulting structures was achieved by dynamic light scattering (DLS) and by TEM. Results on the preparation method, its influence on the polymersome stability and the application of these new membrane‐mimetics are reported.
Multiwalled Carbon Nanotubes Produced by a Continuous CVD Method and Their Use in Melt Mixed Composites with Polycarbonate
Authors: Potschke Petra , Fischer Dieter , Simon Frank , Haußler Liane , Magrez Arnaud , Forró László
Published: August 2007

Summary: In this study, two samples of multiwalled carbon nanotubes (MWNT) were synthesized by CVD of acetylene over Fe2Co catalysts supported by CaCO3 using different temperatures. The material produced at 660 °C (MWNT600) shows slightly better performance as evidenced by lower mean tube diameter and better conductivity as compared to the sample produced at 700 °C (MWNT700). In addition, it has a higher [O]:[C] ratio. Both materials were incorporated into polycarbonate using melt mixing using a small scale compounder. The results prove that these materials are very suitable for polymer composite applications as they show low electrical percolation concentration and good mechanical enhancement. The percolation threshold is as low as <0.875 wt% for MWNT660 and <1 wt% for MWNT700. MWNT700 showed slightly better dispersability as evidenced from light microscopy, SEM, and TEM. The effects in the stress‐strain curves are similar in both composites, indicating a stress increase with MWNT incorporation.
Therapeutics targeting tumor immune escape: Towards the development of new generation anticancer vaccines
Authors: Mocellin Simone , Nitti Donato
Published: August 2007

Despite the evidence that immune effectors can play a significant role in controlling tumor growth under natural conditions or in response to therapeutic manipulation, it is clear that malignant cells evade immune surveillance in most cases. Considering that anticancer vaccination has reached a plateau of results and currently no vaccination regimen is indicated as a standard anticancer therapy, the dissection of the molecular events underlying tumor immune escape is the necessary condition to make anticancer vaccines a therapeutic weapon effective enough to be implemented in the routine clinical setting. Recent years have witnessed significant advances in our understanding of the molecular mechanisms underlying tumor immune escape. These mechanistic insights are fostering the development of rationally designed therapeutics aimed at reverting the immunosuppressive circuits that undermine an effective antitumor immune response. In this review, the best characterized mechanisms that allow cancer cells to evade immune surveillance are overviewed and the most debated controversies constellating this complex field are highlighted. In addition, the latest therapeutic strategies devised to overcome tumor immune escape are described, with special regard to those entering clinical phase investigation. © 2007 Wiley Periodicals, Inc. Med Res Rev, 28, No. 3, 413–444, 2008
On the Navier–Stokes equations with free convection in three‐dimensional unbounded triangular channels
Authors: Constales D. , Kraußhar R. S.
Published: August 2007

The quaternionic calculus is a powerful tool for treating the Navier–Stokes equations very elegantly and in a compact form, through the evaluation of two types of integral operators: the Teodorescu operator and the quaternionic Bergman projector. While the integral kernel of the Teodorescu transform is universal for all domains, the kernel function of the Bergman projector, called the Bergman kernel, depends on the geometry of the domain. In this paper, we use special variants of quaternionic‐holomorphic multiperiodic functions in order to obtain explicit formulas for unbounded three‐dimensional parallel plate channels, rectangular block domains and regular triangular channels. Copyright © 2007 John Wiley & Sons, Ltd.
The involvement of oxidative stress in ochratoxin A and fumonisin B1 toxicity in rats
Authors: Domijan Ana‐Marija , Peraica Maja , Vrdoljak Ana Lucić , Radić Božica , Žlender Vilim , Fuchs Radovan
Published: August 2007

The aim of this study was to find out whether very low doses of nephrotoxic and hepatotoxic mycotoxins ochratoxin A (OTA) and fumonisin B1 (FB1) induce oxidative stress in rat kidney and liver and whether their effect is synergistic. Rats were treated orally with OTA (5 ng/kg b.w. and 50 μg/kg b.w.) and FB1 (200 ng/kg b.w. and 50 μg/kg b.w.), or their combinations. Malondialdehyde (MDA) and protein carbonyls (PCs) concentration in kidney was affected with lower dose of OTA than in liver (p < 0.05). FB1 did not affect MDA and PCs concentrations in the liver, while in the kidney both FB1 doses increased MDA concentration (p < 0.05). The combination of the lower doses of OTA + FB1 increased the MDA and PCs concentration both in the liver and the kidney, compared to controls and animals treated with respective doses of mycotoxins (p < 0.05). The combinations of mycotoxins reduced the catalase activity only in the kidney when compared to controls (p < 0.05). In contrast to the increased kidney concentrations of MDA and PCs even with very low doses of OTA and FB1, the activity of catalase and SOD does not change. Combinations of OTA + FB1 affected almost all parameters, which indicates their potential to produce oxidative damage.
Gd(III)‐EPTPAC16, a new self‐assembling potential liver MRI contrast agent:in vitrocharacterization andin vivoanimal imaging studies
Authors: Torres Suzana , Prata Maria I. M. , Santos Ana C. , André João P. , Martins José A. , Helm Lothar , Tóth Éva , García‐Martín Maria L. , Rodrigues Tiago B. , López‐Larrubia Pilar , Cerdán Sebastián , Geraldes Carlos F. G. C.
Published: August 2007

The recently reported amphiphilic chelate, [Gd(EPTPAC16)(H2O)]2−, forms supramolecular aggregates in aqueous solution by self‐assembly of the monomers with a relaxometrically determined critical micellar concentration (CMC) of 0.34 mM. The effect of sonication on the aggregate size was characterized by dynamic light scattering and relaxometry, indicating the presence of premicellar aggregates and an overall decrease in aggregate size and polydispersity upon sonication, slightly below the CMC. {[153Sm](EPTPAC16)(H2O)}2−radiotracer was evaluatedin vivofromγscintigraphy and biodistribution in Wistar rats. It was found to depend strongly on the sample concentration, below or above the CMC, and its sonication, in a way that correlates with the effect of the same factors on the size of the aggregates formed in solution. Below CMC, the very large aggregates of the [153Sm]3+‐labeled chelate were persistently and mainly taken up by the lungs, and also by the macrophage‐rich liver and spleen. Sonication of this solution led to loss of the lung uptake. Above CMC, the metal chelate was mainly taken up by the liver, with very little uptake by the spleen and lungs.In vivo, dynamic contrast‐enhanced (DCE)‐MRI evaluation of the micellar [Gd(EPTPAC16)(H2O)]2−compound in Wistar rats showed a persistent hepatic positive‐contrast effect inT1‐weighted images, qualitatively similar to the clinically established GdIII‐based hepatobiliary‐selective agents. No enhancement effect was observed in the lungs because of the scarcity of mobile protons in this organ, despite the scintigraphic evidence of significant lung retention of the [153Sm]3+‐labeled chelate at concentrations below the CMC. Copyright © 2007 John Wiley & Sons, Ltd.
Glass bead grafting with poly(carboxylic acid) polymers and maleic anhydride copolymers
Authors: Zengin H. , Siddiqui J. A. , Ottenbrite R. M.
Published: August 2007

Glass beads were etched with acids and bases to increase the surface porosity and the number of silanol groups that could be used for grafting materials to the surfaces. The pretreated glass beads were functionalized using 3‐aminopropyltriethoxysilane (APS) coupling agent and then further chemically modified by reacting the carboxyl groups of carboxylic acid polymers with the amino groups of the pregrafted APS. Several carboxylic acid polymers and poly(maleic anhydride) copolymers, such as poly(acrylic acid) (PAA), poly(methacrylic acid) (PMA), poly(styrene‐alt‐maleic anhydride) (PSMA), and poly(ethylene‐alt‐maleic anhydride) (PEMA) were grafted onto the bead surface. The chemical modifications were investigated and characterized by FT‐IR spectroscopy, particle size analysis, and tensiometry for contact angle and porosity changes. The amount of APS and the different polymer grafted on the surface was determined from thermal gravimetric analysis and elemental analysis data. Spectroscopic studies and elemental analysis data showed that carboxylic acid polymers and maleic anhydride copolymers were chemically attached to the glass bead surface. The improved surface properties of surface modified glass beads were determined by measuring water and hexane penetration rates and contact angle. Contact angles increased and porosity decreased as the molecular weights of the polymer increased. The contact angles increased with the hydrophobicity of the attached polymer. The surface morphology was examined by scanning electron microscopy (SEM) and showed an increase in roughness for etched glass beads. Copyright © 2007 John Wiley & Sons, Ltd.
Cerebrospinal fluid biomarkers in clinically isolated syndromes and multiple sclerosis
Authors: Fiorini Michele , Zanusso Gianluigi , Benedetti Maria Donata , Righetti Pier Giorgio , Monaco Salvatore
Published: August 2007

A panel of three cerebrospinal fluid (CSF) markers for clinically isolated syndromes (CIS) and multiple sclerosis (MS), based on SDS‐PAGE, 2‐D maps, and immunoblot results, is here proposed. No individual marker has any specificity, though, since they appear in a number of other neurological diseases. However the set of three, with the respective modulation sign (up‐regulated or maintained at constant level), appears to be unique for MS. These proteins are: tau protein (levels remaining constant and undistinguishable from controls, contrary to up‐ and downregulation in other neurological disorders); 14‐3‐3 protein (strong upregulation of distinct isoforms) and cystatin C (changing in accordance to disease stage and progression). As an additional evidence, one can rely in the pattern of isoforms of 14‐3‐3, as obtained by 2‐D maps and Western blot analysis: this pattern further distinguishes the variation of this protein from other neurological syndromes, notably sporadic Creutzfeldt–Jakob disease (sCJD), motor neuron diseases and other dementias. In contrast, a similar qualitative and quantitative upregulation of 14‐3‐3 is observed in Guillain‐Barré syndrome (GBS), a demyelinating condition affecting the peripheral nervous system. To the best of our knowledge, this is the first time in which such a panel of biomarkers is reported in MS.
Protein microarray platforms for clinical proteomics
Authors: Pollard Harvey B. , Srivastava Meera , Eidelman Ofer , Jozwik Catherine , Rothwell Stephen W. , Mueller Gregory P. , Jacobowitz David M. , Darling Thomas , Guggino William B. , Wright Jerry , Zeitlin Pamela L. , Paweletz Cloud P.
Published: August 2007

Proteomics for clinical applications is presently in a state of transition. It has become clear that the classical approaches based on 2‐DE and/or MS need to be complemented by different kinds of technologies. The well‐known problems include sample complexity, sensitivity, quantitation, reproducibility, and analysis time. We suggest that the new technologies for clinical proteomics can be supported by antibody‐centric protein microarray platforms. These platforms presently include antibody microarrays and lysate, or reverse capture/reverse phase protein microarrays. Other forms of these arrays are in less mature developmental stages, including ORF and self assembling protein microarrays. Bioinformatic support for interpreting these arrays is becoming more available as the whole field of systems biology begins to mature. The present set of applications for these platforms is profoundly focused on certain common cancers, immunology, and cystic fibrosis. However, we predict that many more disease entities will become studied as knowledge of the power and availability of these platforms becomes more widely established. We anticipate that these platforms will eventually evolve to accommodate label‐free detection technologies, human genome‐scale numbers of analytes, and increases in analytic and bioinformatic speeds.
Characterization of the self‐reactive decomposition of tert‐butyl hydroperoxide in three different diluents
Authors: Wang Y.‐W. , Duh Y.‐S. , Shu C.‐M.
Published: August 2007

Self‐reactive decompositions associated with the exothermic behavior of tert‐butyl hydroperoxide (TBHP) solutions with three diluents of H2O, tert‐butanol, and nonane were investigated. We used two calorimeters, Differential Scanning Calorimeter and Vent Sizing Package 2, to characterize the inherent thermal hazards of TBHP solutions. By thermal analysis, various heats of decomposition of TBHP in water, in nonane, and in tert‐butanol solutions were determined to be 1622.4, 1438.8, and 753.2 J/g of TBHP, respectively. Adiabatic runaway data, such as exothermic onset temperature, maximum self‐heat rate, maximum pressure rate, adiabatic time to maximum rate, and noncondensable pressure, were obtained using a VSP2. © 2007 American Institute of Chemical Engineers Process Saf Prog 2007
Gelatinization and Pasting Properties of Waxy and Non‐waxy Rice Starches
Authors: Park In‐Myoung , Ibáñez Ana Maria , Zhong Fang , Shoemaker Charles F.
Published: August 2007

Gelatinization and pasting properties of diverse rice types grown in two locations were examined by differential scanning calorimetry (DSC) and rotational rheometry, respectively. The data were compared to previously reported molecular starch properties for these samples: specifically, amylose content, starch molecular weight (Mw), and amylopectin side‐chain‐length distributions. Significant correlations were observed between amylose content, starch Mw, and the weight degree of polymerization of the long side chains of amylopectin F1(DPw) and many of the gelatinization and pasting properties measured. Higher amylose content corresponded with increased gelatinization onset (To) and peak temperatures (Tp), pasting onset and peak temperatures, and decreased peak and trough viscosity. Starch Mw correlated negatively with To, Tp, pasting onset, and peak temperature and positively with peak, trough, final, and breakdown viscosity. Amylopectin with DPw 59‐78 of F1(DPw) correlated with increased To, Tp, pasting onset and peak temperature, and decreased peak, trough, final and breakdown viscosity. Pasting properties were also somewhat related to DPw 21 of shorter side chains of amylopectin (F2(DPw)). Significant correlations between F2(DPw) and peak, final, and breakdown viscosity were observed (r = −0.447*, −0.391*, −0.388*, peak, final, and breakdown viscosity, respectively).
Viscosity, Swelling and Starch Leaching During the Early Stages of Pasting of Normal and Waxy Rice Starch Suspensions Containing Different Milk Protein Ingredients
Authors: Noisuwan Angkana , Hemar Yacine , Bronlund John E. , Wilkinson Brian , Williams Martin A. K.
Published: August 2007

The effects of three milk protein ingredients, sodium caseinate (NaCAS), whey protein isolate (WPI) and skim milk powder (SMP), on the swelling and leaching behaviour of normal and waxy rice starch solutions, during the early stages of pasting, were investigated. It was found that the swelling onset temperature for both starches was increased by NaCAS and SMP but was not affected by WPI. Furthermore, onset temperature determined by the swelling measurements was lower than the onset temperature determined from viscosity measurements. However, the calculated viscometric onset temperature, using the Maron‐Pierce equation and the results of the swelling measurements, was found to be in very good agreement with the measured viscometric onset temperature. This study also showed that the quantity of leached polysaccharides during the early stages of starch pasting was very small, indicating that significant leaching of polysaccharides during pasting primarily occurs after the break‐up of the sheared starch granules.
Ultrasound Effects on the Structure and Chemical Reactivity of Cornstarch Granules
Authors: Huang Qiang , Li Lin , Fu Xiong
Published: August 2007

The changes of structure and chemical reactivity of ultrasound‐treated cornstarch (UTCS) granules are presented and discussed. It was found by polarized light and scanning electron microscopy (SEM) that the crystalline structure of UTCS granules did not change, but the amorphous area was slightly destroyed. Pores or channels were detected in the UTCS granules. X‐ray diffraction revealed that UTCS had the A‐type crystalline pattern of native cornstarch, which were not markedly changed. The gelatinization temperature and enthalpy of gelatinization (ΔH) of UTCS first increased and then slightly dropped with increasing degree of hydrolysis (DH). An increase in the DH of UTCS from 0 to 3.1 % resulted in an insignificant change in the degree of substitution (DS) and reaction efficiency (RE). Further increases in the degree of hydrolysis up to 15.7 % resulted in an obvious increase in the DS and RE, but increase in the DH to even higher values drastically decreased DS and RE. Compared with hydroxypropylated cornstarch, the pasting temperature of hydroxypropylated UTCS increased, but UTCS exhibited a lower maximum viscosity. The breakdown of hydroxypropylated starch paste was reduced after ultrasonic treatment before hydroxypropylation. The setback value increased after ultrasonic pretreatment when the degree of hydrolysis was < 7.8 % but decreased at DH > 7.8 %.
Prospective evaluation of the risk of pre‐eclampsia using logistic regression analysis
Authors: Simonazzi G. , Vicenzi C. , Rizzo M. A. , Farina A. , Gabrielli S. , Arcelli D. , Pilu G. , Sekizawa A. , Rizzo N.
Published: August 2007

Objectives

To calculate the risk of developing pre‐eclampsia (PET) in a consecutive series of low‐risk women at 18–24 weeks' gestation, using recently published logistic regression models.

Methods

This was a prospective study, with complete follow‐up, in a consecutive series of unselected low‐risk singleton pregnancies. Uterine artery pulsatility index as well as a combination of maternal factors were recorded at 18–24 weeks' gestation. The distribution of the estimated risks for the 16 PET patients was compared with that obtained for 136 women who had a normal pregnancy, as assessed by routine testing. A receiver–operating characteristics (ROC) curve was plotted to evaluate the detection rate at fixed false‐positive rates (FPRs) of 5%, 10% and 20% and the corresponding odds cut‐offs.

Results

Just 1/16 (6.2%) women with PET developed the disease before the 34th week of gestation. Using the ‘All PET’ logistic regression model, for 16 PET cases the overall median odds was 1 : 1454, higher compared with that of 1 : 41635 estimated for controls. Using the ‘PET ≥ 34 weeks’ model, the median odds of the 15 women who developed PET late was 1 : 3405, compared with 1 : 40785 for controls. In the case of PET before 34 weeks, the risk was 1 : 426373 vs. 1 : 4159823126 estimated for controls (‘PET < 34 weeks’ model). Detection rates for the All PET model were 18%, 50% and 62% at a FPR of 5%, 10% and 20%, respectively. For the PET ≥ 34 weeks model these detection rates were 6%, 46% and 60%, respectively.

Conclusion

Even though the individual odds estimation is too low to represent the real risk of PET, the recently published logistic regression models detected more than 60% of PET at a FPR of 20% for both All PET and PET ≥ 34 weeks models. Using these models in clinical practice does not seem to give any significant improvement over Doppler alone in the prediction of PET, but the use of a PET‐specific odds instead of an actual Doppler value alone seems to be useful for clinical management. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Computerized fetal heart rate analysis, Doppler ultrasound and biophysical profile score in the prediction of acid–base status of growth‐restricted fetuses
Authors: Turan S. , Turan O. M. , Berg C. , Moyano D. , Bhide A. , Bower S. , Thilaganathan B. , Gembruch U. , Nicolaides K. , Harman C. , Baschat A. A.
Published: August 2007

Objective

To investigate the performance of non‐stress test (NST), computerized fetal heart rate analysis (cCTG), biophysical profile scoring (BPS) and arterial and venous Doppler ultrasound investigation in the prediction of acid–base status in fetal growth restriction.

Methods

Growth‐restricted fetuses, defined by abdominal circumference < 5th percentile and umbilical artery (UA) pulsatility index > 95th percentile, were tested by NST, cCTG, BPS, and UA, middle cerebral artery (MCA), ductus venosus (DV) and umbilical vein (UV) Doppler investigation. The short‐term variation (STV) of the fetal heart rate was calculated using the Oxford Sonicaid 8002 cCTG system. Relationships between antenatal test results and cord artery pH < 7.20 were investigated, using correlation, parametric and non‐parametric tests.

Results

Fifty‐six of 58 patients (96.6%) received complete assessment of all variables. All were delivered by pre‐labor Cesarean section at a median gestational age of 30 + 6 weeks. The UA pulsatility index (PI) was negatively correlated with the cCTG STV (Pearson correlation − 0.29, P < 0.05). The DV PI was negatively correlated with the pH (Pearson correlation − 0.30, P < 0.02). The cCTG mean minute variation and pH were not significantly correlated (Pearson correlation 0.13, P = 0.34). UV pulsations identified the highest proportion of neonates with a low birth pH (9/17, 53%), the highest number of false positives among patients with an abnormal BPS, abnormal DV Doppler and a STV < 3.5 ms, and also stratified false negatives among patients with an equivocal or normal BPS. Abnormal DV Doppler correctly identified false positives among patients with an abnormal BPS. cCTG reduced the rate of an equivocal BPS from 16% to 7.1% when substituted for the traditional NST. Elevated DV Doppler index and umbilical venous pulsations predicted a low pH with 73% sensitivity and 90% specificity (P = 0.008).

Conclusion

In fetal growth restriction with placental insufficiency, venous Doppler investigation provides the best prediction of acid–base status. The cCTG performs best when combined with venous Doppler or as a substitute for the traditional NST in the BPS. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound assessment of endometrial morphology and vascularity to predict endometrial malignancy in women with postmenopausal bleeding and sonographic endometrial thickness ≥ 4.5 mm
Authors: Opolskiene G. , Sladkevicius P. , Valentin L.
Published: August 2007

Objectives

To determine which endometrial morphology characteristics as assessed by gray‐scale ultrasound and which endometrial vessel characteristics as assessed by power Doppler ultrasound are useful for discriminating between benign and malignant endometrium in women with postmenopausal bleeding (PMB) and sonographic endometrial thickness ≥ 4.5 mm and to develop logistic regression models to calculate the individual risk of endometrial malignancy in women with PMB, endometrial thickness ≥ 4.5 mm, good visibility of the endometrium and detectable Doppler signals in the endometrium.

Methods

Of 223 consecutive patients with PMB and sonographic endometrial thickness ≥ 4.5 mm, 120 fulfilled our inclusion criteria. They underwent transvaginal gray‐scale and power Doppler ultrasound examination, which was videotaped for later analysis by two examiners with more than 15 years' experience in gynecological ultrasonography. They independently assessed endometrial morphology and vascularity using predetermined criteria. Their agreed‐upon description was compared with the histological diagnosis. Univariate and multivariate logistic regression analyses were used. The best diagnostic test was defined as the one with the largest area under the receiver–operating characteristics curve (AUC).

Results

Thirty (25%) endometria were malignant. Inter‐observer agreement for the description of endometrial morphology and vascularity was moderate to good (Kappa 0.49–0.78). The best ultrasound variables to predict malignancy were heterogeneous endometrial echogenicity (AUC 0.83), endometrial thickness (AUC 0.80), and irregular branching of endometrial blood vessels (AUC 0.77). A logistic regression model including endometrial thickness and heterogeneous endometrial echogenicity had an AUC of 0.91. Its mathematically best risk cut‐off yielded a positive likelihood ratio of 4.4, and a negative likelihood ratio of 0.1. Adding Doppler information to the model improved diagnostic performance marginally (AUC 0.92).

Conclusions

In selected high‐risk women with PMB and an endometrial thickness of ≥ 4.5 mm, calculation of the individual risk of endometrial malignancy using regression models including gray‐scale and Doppler characteristics can be used to tailor management. These models would need to be tested prospectively before introduction into clinical practice. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Sonographic visualization of the middle phalanx of the fetal fifth digit between 13 and 17 weeks of gestation
Authors: Zalel Y. , Achiron R. , Kivilevitch Z.
Published: August 2007

Objective

To assess in utero visualization of the middle phalanx of the fifth digit (MPFD) between 13 and 17 weeks of gestation.

Methods

This was a prospective cross‐sectional study in which women attending for fetal sonographic examination between 13 + 0 and 17 + 6 weeks of gestation were evaluated for the presence of the middle phalanx of the fifth digit (MPFD). A total of 682 fetuses with normal findings on first‐trimester anatomical examination were recruited. Using transvaginal multifrequency 4–8 and 5–9 MHz probes, the fifth finger was examined in both axial and lateral views until optimal visualization of the MPFD was achieved.

Results

The MPFD was visualized in 14.3% (2/14) of cases at 13 weeks, 70.3% (154/219) at 14 weeks, 82.2% (240/292) at 15 weeks, 97.4% (111/114) at 16 weeks and 100% (43/43) at 17 weeks of gestation.

Conclusions

Ultrasound visualization of the MPFD gradually increases during the 13‐ to 17‐week period. This emphasizes the limited role of non‐ossification of the MPFD as a sonographic marker of Down syndrome before 17 weeks of gestation. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Tandem mass spectrometric determination of succinylacetone in dried blood spots enables presymptomatic detection in a case of hepatorenal tyrosinaemia
Authors: Weigel J. F. W. , Janzen N. , Pfäffle R. W. , Thiery J. , Kiess W. , Ceglarek U.
Published: August 2007

Tyrosinaemia type I, or fumarylacetoacetase deficiency, causes hepatorenal damage by accumulation of fumarylacetoacetate. Patients are generally in good condition at birth, but are at risk of developing serious metabolic crises with liver failure and hepatic coma. An early start of treatment with NTBC and a tyrosine‐balanced diet can prevent harm to the patients. The application of tandem mass spectrometry to newborn screening allows for easy determination of tyrosine to detect the presence of hypertyrosinaemia in the neonate, but most patients with tyrosinaemia type I do not present with high tyrosine levels at the time of newborn screening. We report on a 7‐week‐old girl presenting with acute hepatopathy and severe coagulopathy due to tyrosinaemia type I. The metabolic screening, which was performed by tandem mass spectrometry at the age of 48 h, had revealed normal values for tyrosine and methionine that were well within ranges observed in the general population and equally normal ratios of methionine/tyrosine and tyrosine/serine. In this patient even lowering the cut‐off levels for tyrosine and methionine would not have provided better sensitivity. Residual blood spots from the newborn screening filter paper were retrospectively analysed using a specific mass‐spectrometric method for the detection of succinylacetone and revealed a 5‐fold elevated succinylacetone concentration. This indicates that identification of all newborns with hepatorenal tyrosinaemia is only possible by determination of succinylacetone as part of the newborn screening process.
Newborn screening: A national public health programme in Brazil
Authors: Marini de Carvalho T. , Pimentel dos Santos H. , dos Santos I. C. G. P. , Vargas P. R. , Pedrosa J.
Published: August 2007

The newborn screening programme started in Brazil (1976) through isolated initiatives, without governmental directions and/or policies. According to Health Ministry (2000) data the coverage was 55% and unevenly distributed. Only 17 out of 27 Brazilian states had more than 30% coverage. Public budgets covered only diagnostic examinations. There were no official data about assistance, patient follow‐up or detected disorders. The creation of the National Programme (2001) has provided new perspective for newborn screening (NBS) in the public health system. It has provided important official data and established management and care units for each state: Reference Services in Newborn Screening. The programme screened about 13 million newborns from October 2001 to December 2005. The coverage increased to 80.2% (2005) and 74% of the states presented coverage of over 70%. Within 34 accredited Reference Services in 27 Brazilian states, all provide screening for PKU and CH. Ten of them provide screening for haemoglobinopathies as well, and three of them provide also for CF. The Reference Services altogether count on at least 170 health professionals, such as paediatricians, endocrinologists, nutritionists, psychologists and social workers. They are qualified to assist positive cases, within the policies established by the National Programme. There has been significant increase in NBS coverage and follow‐up assuredness, including detected cases before the National Programme (10 935 positive cases) mostly in those regions where the programme did not exist. There has been significant evolution in the Newborn Screening as a Public Health Program in Brazil due to the government's commitment (federal and each component state).
Structures for clinical follow‐up: Newborn screening
Authors: Howell R. Rodney , Engelson Gilian
Published: August 2007

Clinical follow‐up of children identified by newborn screening is critical in ensuring that the short‐term and long‐term needs of the newborn infant are managed. Within the United States, one of the biggest challenges in the newborn screening programme is clinical follow‐up, and there still remains wide variation in practice patterns among states on how infants are followed up. In addition, there is lack of consistency in the treatment and diagnostic protocols used by health care providers. There is growing interest in the establishment of a systematic process for follow‐up and for the development of a nationwide infrastructure that will ensure that all children will be provided consistent and effective treatment in a timely manner. Within this framework of optimal diagnosis and therapy, there must also be opportunities to study the natural history of these conditions, to monitor short‐ and long‐term health outcomes, to assist with policy decision‐making, to validate the effectiveness of screening, to define the clinical spectrum of the diseases, and to provide opportunities for the advancement of novel therapeutic interventions and screening/diagnostic technologies. It will only be through the development of a structured clinical follow‐up system that we will be able to make certain these newborn infants are provided the most appropriate treatment for their disease variants and allow researchers to make more rapid advances in improving the clinical management of these conditions.
Direct comparison of enzyme measurements from dried blood and leukocytes from male and female Fabry disease patients
Authors: Lukacs Z. , Hartung R. , Beck M. , Keil A. , Mengel E.
Published: August 2007

Anderson–Fabry disease is an X‐linked disorder that is caused by deficiency of the lysosomal enzyme α‐galactosidase A. Symptoms include chronic progressive painful small‐fibre neuropathy, cornea verticillata, renal failure and heart disease. Interestingly, female heterozygous patients may also show severe symptoms. After clinical suspicion, usually the determination of α‐galactosidase activity in leukocytes is requested first. Alternatively, an enzymatic assay using dried blood specimens has been described. Dried blood samples require less material and are substantially more stable (several months at room temperature) than whole‐blood specimens. To validate the new method and to asses its usefulness for diagnosis of female patients, enzyme activities of α‐galactosidase, β‐galactosidase and β‐glucuronidase from 78 known Fabry patients were compared (29 males, 47 females) between both materials. In summary, the determination of α‐galactosidase activity using dried blood and leukocytes as well as the ratio of α‐galactosidase to β‐glucuronidase in dried blood can improve the diagnostic specificity in cases of female patients who are difficult to identify when only leukocyte enzyme activities are considered.
A Hierarchical Framework for Modeling Speed and Accuracy on Test Items
Authors: van der Linden Wim J.
Published: August 2007

Current modeling of response times on test items has been strongly influenced by the paradigm of experimental reaction-time research in psychology. For instance, some of the models have a parameter structure that was chosen to represent a speed-accuracy tradeoff, while others equate speed directly with response time. Also, several response-time models seem to be unclear as to the level of parametrization they represent. A hierarchical framework for modeling speed and accuracy on test items is presented as an alternative to these models. The framework allows a “plug-and-play approach” with alternative choices of models for the response and response-time distributions as well as the distributions of their parameters. Bayesian treatment of the framework with Markov chain Monte Carlo (MCMC) computation facilitates the approach. Use of the framework is illustrated for the choice of a normal-ogive response model, a lognormal model for the response times, and multivariate normal models for their parameters with Gibbs sampling from the joint posterior distribution.
Continuity, comorbidity and longitudinal associations between depression and antisocial behaviour in middle adolescence: A 2‐year prospective follow‐up study
Authors: Ritakallio Minna , Koivisto Anna‐Maija , von der Pahlen Bettina , Pelkonen Mirjami , Marttunen Mauri , Kaltiala‐Heino Riittakerttu
Published: August 2007

The study investigated continuity, comorbidity and longitudinal associations between depression Beck depression inventory (RBDI) and antisocial behaviour Youth self‐report (YSR) in middle adolescence. Data were used from a community sample of 2070 adolescents who participated in a 2‐year prospective follow‐up study. The results indicate that both depression and antisocial behaviour had considerable continuity, and concurrent comorbidity between these disorders was strong. In contrast to several previous studies, antisocial behaviour did not predict subsequent depression, but conversely, depression predicted subsequent antisocial behaviour among girls. Among boys history of depression seemed to protect from subsequent antisocial behaviour. Gender differences in longitudinal associations are discussed.
Squamous cell carcinoma antigen 1 is an inhibitor of parasite‐derived cysteine proteases
Authors: Kanaji Sachiko , Tanaka Yoko , Sakata Yasuhisa , Takeshita Kohei , Arima Kazuhiko , Ohta Shoichiro , Hansell Elizabeth J. , Caffrey Conor , Mottram Jeremy C. , Lowther Jonathan , Donnelly Sheila , Stack Colin , Kadowaki Tomoko , Yamamoto Kenji , McKerrow James H. , Dalton John P. , Coombs Graham H. , Izuhara Kenji
Published: August 2007

The physiological significance of the squamous cell carcinoma antigens 1 (SCCA1) and SCCA2, members of the ovalbumin serpin family, remains unresolved. In this study, we examined whether SCCA1 or SCCA2 inhibits protozoa‐ or helminth‐derived cysteine proteases. SCCA1, but not SCCA2, potently inhibited the cysteine protease activities of CPB2.8 from Leishmania mexicana, cruzain from Trypanosoma cruzi, rhodesain from Trypanosoma brucei rhodesience, and cathepsin L2 from Fasciola hepatica. The inhibitory activities of SCCA1 were due to its resistance to cleavage by the cysteine proteases. The findings indicate that induction of cysteine protease inhibitors might be a novel defense mechanism against parasite development.