bluuebunny/crossref_metadata_2025 huggingface dataset:
Pyrrole‐substituted alkyl silanes as new adhesion promoters on oxidic substrates
Authors: Cai Xuediao , Jaehne Evelin , Adler Hans‐Juergen P.
Published: May 2004

ω‐(Pyrrol‐1‐yl alkyl) dimethylchlorosilanes with different chain length were synthesized and characterized with IR, NMR and elemental analysis. The growth of self‐assembled monolayers of ω‐(pyrrol‐1‐yl alkyl) dimethylchlorosilanes on oxide surfaces has been investigated. The order gradually improved with adsorption time and highly ordered SAMs were obtained for nearly 2 days adsorption time. Characterization of the films has been performed with contact angle measurements, ellipsometry, SPR and grazing incident FTIR. The chemical deposition of polypyrrole on the modified surface was investigated. The thickness of polypyrrole layer was influenced by the concentration of monomer, the deposition time, and the ratio of monomer to oxidant.
Reversible switching of protein uptake and release at polyelectrolyte multilayers detected by ATR‐FTIR spectroscopy
Authors: Müller M. , Kessler B. , Adler H.‐J. , Lunkwitz K.
Published: May 2004

The reversible switching of uptake and release of the proteins lysozyme (LYZ, IEP = 11.1) and human serum albumin (HSA, IEP = 4.8) at the surface attached polyelectrolyte multilayer (PEM) consisting of poly(ethylene‐imine) (PEI) and poly(acrylic acid) (PAC) is shown. Protein adsorption could be switched by pH setting due to electrostatic interaction. Adsorption of positively charged LYZ at PEM‐6 took place at pH = 7.3, where the outermost PAC layer was negatively charged. Complete desorption was obtained at pH = 4, where the outermost PAC layer was neutral. Additionally the charge state of the last adsorbed PAC layer in dependence of the pH of the medium could be determined in the ATR‐FTIR difference spectra by the ν(COO−) and ν(C=O) band due to carboxylate and carboxylic acid groups. Adsorption of negatively charged HSA at PEM‐7 was achieved at pH = 7.3, where the outermost PEI layer was positively charged. Part desorption was obtained at pH = 10, where the outermost PEI layer was neutral. PEM of PEI/PAC may be used for the development of bioactive and bionert materials and protein sensors.
Nonstoichiometric interpolyelectrolyte complexes as colloidal dispersions based on NaPAMPS and their interaction with colloidal silica particles
Authors: Schwarz Simona , Dragan Stela
Published: May 2004

Preparation and characterization of some nonstoichiometric interpolyelectrolyte complexes (NIPECs) as stable colloidal dispersions by the interaction between poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate) (NaPAMPS) and three strong polycations bearing quaternary ammonium salt centres in the backbone, poly(diallyldimethylammonium chloride) (PDADMAC) and two polycations containing N,N‐dimethyl‐2‐hydroxypropyleneammonium chloride units (PCA5 and PCA5D1), have been followed in this study as a function of the polycation structure and polyelectrolyte concentration. Complex characteristics were followed by polyelectrolyte titration, turbidity and quasi‐ellastic light scattering. Almost monodisperse NIPECs nanoparticles with a good storage stability were prepared when total concentration of polyelectrolyte was varied in the range 0.85‐6.35 mmol/L, at a ratio between charges (n−/n+) of 0.7. NIPECs as a new kind of flocculants were used to flocculate a stable monodisperse silica suspension. The main advantage of NIPECs as flocculants is the broad flocculation window, which is a very important aspect for industrial applications.
Preparation of PA6/nano titanium dioxide (TiO2) composites and their spinnability
Authors: Zhu Meifang , Xing Qiang , He Houkang , Zhang Yu , Chen Yanmo , Pötschke Petra , Adler Hans‐Jürgen
Published: May 2004

In this work, surface modification technique with coupling agents and anchoring polymerization was adopted to tailor the surface properties of nanoscaled titanium dioxide (TiO2). Ethyl glycol sols with TiO2 were prepared in order to simulate the dispersibility of differently modified TiO2 in a molten polyamide 6 (PA6) matrix. The modified TiO2 were melt compounded with PA6 and composites and fibers were prepared. The average filler diameter of 47 nm (in composites) and 44 nm (in fibers) indicated homogeneous dispersion of TiO2 in the matrix, whereas unmodified TiO2 showed agglomerated structures in the PA6 matrix. The mechanical properties of the composite fibers were improved as compared to pure PA6 fibers and composite fibers with unmodified TiO2.
Surface properties and swelling behaviour of hyperbranched polyester films in aqueous media
Authors: Mikhaylova Y. , Pigorsch E. , Grundke K. , Eichhorn K.‐J. , Voit B.
Published: May 2004

Thin films of hydroxyl (POH) and carboxyl (PCOOH) terminated aromatic hyperbranched polyesters (HBPs) were prepared by spin coating on silicon wafers and subsequently annealed above their glass transition temperature (Tg). The surface properties and the swelling behaviour of these films in aqueous buffer solutions were studied as a function of annealing time using contact angle measurements and ellipsometry. Non‐annealed films were hydrophilic with surface free energies of 51 mJ/m2 for POH and 49 mJ/m2 for PCOOH, respectively. The swelling behaviour of the polymer films in buffer solution with pH 7.4 was described in terms of changes of the thickness and effective refractive index of the swollen layer. Under identical conditions a lower water uptake was found for hydroxyl terminated HBPs (POH) which were annealed more then 2 h. The lower water uptake correlates with the surface properties of the films. The annealed films were less hydrophilic. Their surface free energy was 38 mJ/m2 independent of the annealing. Films of carboxyl terminated HBPs (PCOOH) showed similar surface properties after annealing. However, these films were unstable under the same conditions in aqueous solutions. Stable PCOOH films were obtained by additional covalent binding to the substrate using an epoxy silane as a coupling agent.
A polyelectrolyte bearing metal ion receptors and electrostatic functionality for layer‐by‐layer self‐assembly
Authors: Krass Henning , Papastavrou Georg , Kurth Dirk G.
Published: May 2004

A polyelectrolyte (BiPE) containing bipyridine ligands as metal ion receptors and quaternary ammonium groups is described, which can be assembled via electrostatic interactions or metal ion coordination. Electrostatic layer‐by‐layer self‐assembly of BiPE with sodium poly(styrene sulfonate) (PSS) as oppositely charged component results in striated multilayers. The BiPE/PSS multilayers can reversibly bind and release transition metal ions including Fe(II), Ni(II), and Zn(II). Formation of 2‐D arrays of metallo‐units is achieved by μ‐contact stamping transition metal salts onto the BiPE/PSS interface. Also, multilayers of BiPE are readily assembled through metal ion coordination. Due to the reversible nature of metal ion coordination, exposure of the multilayers to EDTA causes instant disassembly of the layer, a property needed to implement stimulus triggered release functions. The importance of metal ion coordination for multilayer formation is demonstrated by force‐distance curves measured with AFM.
Conformational transitions and aggregations of regioregular polyalkylthiophenes
Authors: Kiriy Nataliya , Jähne Evelin , Kiriy Anton , Adler Hans‐Juergen
Published: May 2004

Diverse conformational transitions and aggregations of regioregular poly (3‐alkylthiophene)s (PATs) in different environment have been studied by means of AFM and UV‐vis‐spectroscopy. In methanol, which is a non‐solvent for both alkyl side groups and aromatic backbone at low polymer concentration, PATs chains fold into compact poorly ordered flat structures. At higher polymer concentration PATs molecules undergo 3D aggregation into near spherical particles. In hexane, which is a selective solvent for alkyl side chains, PATs molecules undergo ordered main‐chain collapse followed by 1D aggregation. Concentration‐independent red shift of λmax and good resolved fine vibronic structure in the electronic absorption spectra indicate that planarization occurs on the single‐molecule level.
Mixed conducting polymers on ion‐conducting sensor glasses – charge transfer in the system polymer/glass
Authors: Jahn Heimo , Kaden Heiner , Berthold Monika
Published: May 2004

Mixed ion/electron conducting polymer layers based on polypyrrole have been used as internal reference electrodes in all‐solid‐state pH glass electrodes. The effect of the nature and composition of the polymer used and of the deposition technique applied on the performance of the resulting sensor has been studied. For this purpose, crucial sensor properties, e.g. parameters of the calibration function, response behaviour and complex impedance, have been determined experimentally at room temperature. The results show that several properties studied remained nearly uninfluenced by changes of the polymer composition. The zero potential point of the calibration line was found to be the most sensitive parameter. Principally, almost all mixed conducting polymers used seems to result in a stable charge transfer in the system polymer/glass.
Synthesis and characterization of polypyrrole dispersions prepared with different dopants
Authors: Lu Yan , Pich Andrij , Adler Hans‐Juergen P.
Published: May 2004

Stable polypyrrole dispersions were prepared by chemical oxidative polymerization of pyrrole in an aqueous medium containing different anionic salts ‐ sodium benzoate, potassium hydrogen phthalate and sodium hydrogen succinate. Results of the elemental analysis and FT‐IR spectroscopy confirmed that the anionic salts are incorporated in the conducting polymers and functioned as the dopants. The retardation of pyrrole polymerization was observed when a certain amount of the salt was used as dopant. SEM images of polypyrrole dispersions indicate large spherical particles (150‐180nm). The conductivity of polypyrrole composites has also been investigated.
Versatility of potential biomedical use of functional polysuccinates
Authors: Łukaszczyk Jan , Benecki Piotr , Jaszcz Katarzyna , Śmiga Monika
Published: May 2004

Polysuccinates with pendant allyl groups (PSAGE) were synthesized by melt copolymerization of succinic anhydride with allyl glycidyl ether and eventually other glycidyl ethers. It was found that PSAGE could be crosslinked by radical copolymerization with methyl methacrylate. Oxidized PSAGE considered as multifunctional epoxy resin was cured with use of glutaric anhydride to form solid material susceptible to hydrolytic degradation to water‐soluble non‐toxic products. Comb‐like amphiphilic polysuccinates containing both pendant poly(oxyethylene) chains and epoxy groups have been synthesized as well and checked for their solubility in water. Properties of PSAGE‐type polymers suggests their potential use as biomaterials and polymeric drug carries.

Please note, in the print publication of D. Theis, T. Schmidt, K.‐F. Arndt, Macromol. Symp. 210 (2004), 465, erroneously the DOI 10.1002/masy.200450651 is repeated. There, the DOI should read: 10.1002/masy.200450652
Preinvasive and invasive cervical cancer: an ex vivo proton magic angle spinning magnetic resonance spectroscopy study
Authors: Mahon Marrita M. , deSouza Nandita M. , Dina Roberto , Soutter W. Patrick , McIndoe G. Angus , Williams Andreanna D. , Cox I. Jane
Published: May 2004

The aim of this study was to obtain 1H MR spectra using magic angle spinning (MAS) techniques from punch biopsies (<20 mg) of preinvasive and invasive cervical disease and to correlate the spectral profiles with sample classification on the basis of histopathology. Tissue samples were obtained at colposcopic examination, during local treatment of cervical intraepithelial neoplasia (CIN) or at hysterectomy. 1H MAS MRS was performed at 25°C while spinning the sample at 4.5 kHz. After measurement, the tissue was immersed in formalin and the pathology determined. Histological examination after 1H MAS MRS defined 27 samples with squamous cell carcinoma (SCC), 12 with CIN and 39 with only normal tissue. The standardized integrals of the lipid, choline and creatine regions of the spectra were significantly higher in SCC than in normal or CIN tissue. There was no obvious difference in the standardized integral of the region 4.15–3.5 ppm. The acyl fatty acid side‐chain length was longer or less unsaturated in SCC than in normal tissue. Normal tissue from patients with SCC showed significantly higher triglycerides than normal tissue from patients with benign uterine disease but significantly lower triglycerides than SCC tissue. 1H MAS MRS of the uterine cervix ex vivo may be used to differentiate non‐invasive from invasive cervical lesions, increase interpretation of in vivo MRS and provide insights into tumor biology. Copyright © 2004 John Wiley & Sons, Ltd.
Voice over IP versus voice over frame relay
Authors: Francis‐Cobley Pauline P. , Coward Adrian D.
Published: May 2004

This paper presents a comparison of the voice‐enabling features of the Internet protocol (IP) and frame relay (FR) networks. The discussion focuses on the issues that affect the quality of service of voice applications and the relative suitability of IP and FR for delivering voice applications. This independent assessment serves to assist network managers in decision‐making regarding suitable packetized voice solutions. Copyright © 2004 John Wiley & Sons, Ltd.
Surgery of cavoatrial tumor thrombus in nephroblastoma: A report of the SIOP/GPOH study
Authors: Szavay Philipp , Luithle Tobias , Semler Oliver , Graf Norbert , Fuchs Joerg
Published: May 2004

Background

Resection of a Wilms tumor extending through the inferior vena cava into the right atrium represents a challenge to the pediatric surgeon. Exact preoperative diagnosis is essential to identify the tumor and its in travascular extension. To achieve a complete excision of the tumor cardiopulmonary bypass and hypothermia may be required. The feasibility of a complete resection is important as it guides subsequent therapy such as chemotherapy and radiation.

Procedure

In order to define these issues, we reviewed the records of 33 of 1,151. Patients enrolled in the SIOP 93‐01/GPOH Study and the SIOP 2001/GPOH Study who had a tumor thrombus into the inferior venacava and into the right atrium.

Results

The median age at diagnosis was 3.73 years. Twenty‐four patients had a tumor thrombus into the inferior vena cava, in nine patients the thrombus reached into the right atrium. All patients were operated on; cardiopulmonary bypass was used in nine patients. There were no deaths intraoperatively. Twenty‐nine children are still alive; four patients died, one patient due to aspiration and failed resuscitation, two patients died from a recurrent tumor, and one child due to an unresectable primary tumor.

Conclusion

Our report suggests that Wilms tumor extending to the inferior vena cava and the right atrium is technical challenging, but with adequate preoperative diagnosis and a multidisciplinary surgical approach including cardiopulmonary bypass and hypothermia, the prognosis is favorable. © 2004 Wiley‐Liss, Inc.
Mondini dysplasia and recurrent bacterial meningitis in a girl with relapsing Langerhans cell histiocytosis
Authors: Kitazawa Katsuhiko , Matsumoto Marika , Senda Masayoshi , Honda Akihito , Morimoto Noriko , Kawashiro Nobuko , Imashuku Shinsaku
Published: May 2004

We report a case of a girl with Langerhans cell histiocytosis (LCH) of multifocal bone disease, who developed recurrent bacterial meningitis and unilateral sensorineural hearing loss during the relapsing course of the disease. Mondini dysplasia, a congenital inner ear anomaly, was suspected by high resolution computed tomographic scan and the dysplasia with cerebrospinal fluid leakage was confirmed by surgery in the ipsilateral ear showing hearing loss. Although rare, congenital inner ear anomalies such as Mondini dysplasia should be kept in mind in pediatric patients with hearing impairment and/or recurrent bacterial meningitis during chemotherapy for various types of neoplasms including LCH. © 2004 Wiley‐Liss, Inc.
CD19 negative precursor B acute lymphoblastic leukemia presenting with hypercalcemia
Authors: Sultan Iyad , Kraveka Jacqueline M. , Lazarchick John
Published: May 2004

A 9‐month‐old infant presented with hypercalcemia and lytic bone lesions. Suspicion for malignancy led to a bone marrow examination, which showed replacement of the marrow by a small round blue cell infiltrate. Flow cytometric analysis of these cells showed an unusual immunophenotype in that these cells were dim CD45, HLA‐DR, and CD10 positive, but CD19, CD20, CD79a, and CD34 negative. Southern blotting showed clonal rearrangement of immunoglobulin heavy chain (IgH) which confirmed a diagnosis of precursor B acute lymphoblastic leukemia (ALL). He received supportive treatment with hydration and pamidronate, but had recurrent episodes of hypercalcemia. Once the correct diagnosis of ALL was established, the patient was treated with an infantile ALL chemotherapeutic regimen and the hypercalcemia resolved. This case highlights the usefulness of immunoglobulin gene rearrangement studies in atypical cases of ALL. © 2004 Wiley‐Liss, Inc.
Ein Pionier der Raumfahrt
Authors: Loos Andreas
Published: April 2004

Geschichten über seine Person muss man in der Regel mit Vorsicht genießen. Schließlich war der gesuchte Raketenforscher ein begabter Selbstdarsteller, der schon seine ersten größeren Versuche zu öffentlichen Flugschauen machte — und dafür Eintrittsgeld nahm.
Von Kristallen und Zellwänden
Authors: Vilgis Thomas A.
Published: April 2004

Erdbeerzeit! Die leuchtend roten und saftigen Früchte verführen zum heftigsten Naschen, und die zu kurze Saison der Vitaminbomben wirft immer wieder die Frage auf, ob dieser Genuss durch moderne Technik verlängert werden kann. Der Versuch, Erdbeeren als ganze Früchte einzufrieren und diese aus der Kühltruhe in alter Frische hervorzuzaubern ist zwar bestechend, aber zum Scheitern verurteilt.
Phase behaviors of hyperbranched solid polymer electrolyte/salt systems: The structure effect
Authors: Ko Sung Jin , Bae Young Chan , Kong Sung‐Ho , Ryu Si‐Ok
Published: April 2004

We have derived a new molecular thermodynamic model based on the lattice cluster model and melting point depression theory to account for the structural effect on phase behaviors of hyperbranched solid polymer electrolyte/salt systems. The two structural parameters (the generation number and separator length) are introduced to characterize the architecture of the hyperbranched polymer. A thermooptical analysis technique is used to determine the melting points of hyperbranched polymer/ZnI2 systems. Our results show that the eutectic point is presented at a higher weight fraction of the salt as the generation number increases. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2254–2262, 2004
Factors driving the protonation of poly(N‐vinylimidazole) hydrogels
Authors: Molina M. Jesús , Gómez‐Antón M. Rosa , Piérola Inés F.
Published: May 2004

Poly(N‐vinylimidazole) hydrogels immersed in aqueous acid solutions produce an increment in the pH of the bath because of proton uptake by basic imidazole moieties, leading to hydrogel protonation. Both kinetic and equilibrium measurements of the pH of the bath have been performed under a variety of conditions and with different hydrogel samples. The kinetics of the xerogel protonation process (which includes solvent and titrant diffusion, the true protonation reaction or ion–dipole association, and the polymer relaxation to a new conformation) are mostly driven by the size of the hydrogel sample, whereas other magnitudes, such as the initial pH, the effective polymer concentration, and the network structure, governed by the crosslinker ratio and total comonomer concentration in the feeding, have a minor influence. pKa changes with the degree of protonation (α), delimitating two different regions: (1) a broad α range in which pKa decreases with increasing α but less pronouncedly with increasing ionic strength and (2) an α range close to α = 1 in which pKa decreases abruptly, more markedly with sulfate than with chloride counteranions and with larger ionic strengths. In the first region, pKa is determined by repulsive electrostatic interactions and so is larger for titration with H2SO4 than with HCl and increases as the effective polymer concentration and ionic strength increase. Two steps (i.e., two protonation sites) can be observed in the titration curves, the second one corresponding to abrupt changes in the basicity of the second pKa‐versus‐α region. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2294–2307, 2004
Pre‐treatment factors related to cognitive functioning in women newly diagnosed with breast cancer
Authors: Cimprich Bernadine , So Heeyoung , Ronis David L. , Trask Christine
Published: April 2004

Women treated for breast cancer have shown cognitive deficits with reduced capacity to focus and concentrate or to direct attention. This study examined the relationship between cognitive function prior to any treatment for breast cancer and individual factors including age, education, menopausal status, chronic health problems, and distress. Women newly diagnosed with breast cancer (N=184), ages 27–86 years, were assessed with standardized attention tests, self‐reports of effectiveness in cognitive functioning, and measures of distress at about 18 days before surgery. Measured performance on the cognitive tests was not significantly correlated to self‐reports of effectiveness in cognitive functioning. Age, education, presence of a chronic health problem, and menopausal status, but not distress, were associated with performance on the cognitive tests. Only age and education, however, were significant (p<0.001) predictors of overall performance on the cognitive tests, when controlling covariates. In contrast, symptom and mood distress significantly (p<0.001) predicted perceptions of effectiveness in cognitive functioning. Thus, different factors were associated with measured performance versus self‐reports of cognitive functioning. Individual factors that predispose to lowered effectiveness in cognitive functioning prior to treatment in women newly diagnosed with breast cancer are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Endothelin A receptor blockade does not alter PSA secretion in prostate cancer cell lines
Authors: Pecher Stefana , Pflug Beth R. , Brink Alisa K.W. , Nelson Joel B.
Published: May 2004

BACKGROUND

Some men treated with atrasentan (ABT‐627), an endothelin A (ETA) receptor inhibitor, had declines in their serum PSA levels. It is our hypothesis that this decrease is due to anti‐tumoral activity and not a reduction in PSA secretion at the cellular level.

METHODS

Two PSA secreting prostate cancer cell lines (LAPC4 and LNCaP) were treated with atrasentan and an ETB receptor antagonist (A192621) in varying concentrations (10−6–10−10 M) and PSA levels were measured in the culture media.

RESULTS

LNCaP and LAPC4 cells both express ETA receptors. Neither the ETA or ETB antagonist altered PSA secretion, while addition of DHT, a positive control, produced a marked increase in PSA secretion.

CONCLUSIONS

Blockade of the ETA receptor does not affect the secretion of PSA in prostate cancer cell lines. © 2004 Wiley‐Liss, Inc.
Electron momentum density of hexagonal cadmium studied by Compton scattering
Authors: Reniewicz H. , Andrejczuk A. , Brancewicz M. , Żukowski E. , Dobrzyński L. , Kaprzyk S.
Published: May 2004

The directional electron momentum density distributions (Compton profiles) of single‐crystal cadmium have been measured in transmission and reflection experimental geometries using high‐energy (662 keV) gamma radiation from a 137Cs isotope source. Profiles along the [100] and [110] directions in reciprocal space were measured in both geometries, whereas only the transmission geometry was used for the measurements along the [001] direction. The experimental data have been compared with corresponding theoretical KKR semi‐relativistic calculations. The directional difference profiles, both experimental and theoretical, show, similarly to other hexagonal systems, very small anisotropy of the electron momentum density in hexagonal cadmium, about 0.3%, i.e. less than half of that presented in the literature for cubic systems. Minor discrepancies between KKR calculations and experiment probably occur due to the necessity to introduce an anisotropic electron–electron correlation correction. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric properties and absorption spectra of trimethylammonium trichlorcobaltate dihydrate single crystals
Authors: Kapustianik V. , Batiuk A. , Dacko S.
Published: May 2004

The dielectric and spectral properties of [NH(CH3)3]CoCl3 × 2H2O (abbreviately TrMA–CoCl3) crystals were investigated in the temperature region of 293–345 K. The anomalous behaviour of the investigated parameters at T1 = 327 K was related to early unknown phase transition. The considerable change of the absorption spectra at T1 is explained by the distorsion and the corresponding change of symmetry of the polyhedron around Co2+ ion. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Erratum: “On uniform (1 ≤ Ii ≤ 3) n‐fold {|IouterM(i1 … in) >} dual tensorial sets, spin irreps from SU(3 ≤ m) × Sn ⊃…⊃ Sn weight sets: A direct role for N(λ ⊢ n)‐partitional catalogs of Sn combinatorics in spin physics,”International Journal of Quantum ChemistryVolume 87, Number 4, 2002, pages 171–180
Authors: Temme F. P.
Published: May 2004

The original article to which this Erratum refers was published in International Journal of Quantum Chemistry (2002) 87(4) 171–180
A new algorithm to evaluate bielectronic integrals with 1s Slater‐type orbitals obtained by the integral transforms
Authors: Pérez J. E. , Cesco J. C. , Taurian O. E. , Ortiz F. S. , Rosso A. E. , Denner C. C. , Giubergia G. O.
Published: May 2004

This article presents a variation of the integral transform method to evaluate multicenter bielectronic integrals (12|34), with 1s Slater‐type orbitals. It is proved that it is possible to define, out of the expression of (12|34) given by the integral transform method, a function F(q) that has the property of having a unique Q, such that F(Q) = (12|34). Therefore, F(q) may be used to calculate (12|34). It is shown that the evaluation of F(Q) turns out to be simpler than the three‐dimensional integral involved in the calculation of (12|34), and an algorithm is presented to calculate Q. The results show that relative errors on the order of 10−3 or lower are obtained very efficiently. In addition, it is shown that the proposed algorithm is very stable. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Incidence and characteristics of umbilical artery intermittent absent and/or reversed end‐diastolic flow in complicated and uncomplicated monochorionic twin pregnancies
Authors: Gratacós E. , Lewi L. , Carreras E. , Becker J. , Higueras T. , Deprest J. , Cabero L.
Published: May 2004

Objective

To evaluate the incidence and clinical relevance of intermittent absent and/or reversed diastolic flow on umbilical artery Doppler in different groups of monochorionic twin pregnancies.

Methods

This was a prospective study involving three groups of monochorionic pregnancies: Group 1: controls followed fortnightly from the first trimester (n = 80); Group 2: cases with selective intrauterine growth restriction (n = 40); and Group 3: cases with severe twin–twin transfusion syndrome (n = 50). The presence and persistence over time of intermittent absent and/or reversed end‐diastolic flow on umbilical artery Doppler was recorded. Placentas were examined and placental sharing and the presence of large arterioarterial anastomoses (AAA) was assessed. Perinatal outcome was recorded in all cases.

Results

Intermittent absent and/or reversed diastolic flow was present in 5% (4/80) of cases in Group 1, 45% (18/40) in Group 2 and 2% (1/50) in Group 3 (P < 0.0001, Group 2 vs. 1 and 3). Placental examination was performed in 76.4% (130/170) of cases and sharing was 58% for Group 1, 81% for Group 2 and 73% for Group 3 (P < 0.0001, Groups 2 and 3 vs. 1). Large AAA were identified in all examined cases with intermittent flow (18/18) and in 3.6% (4/112) of those without. The in‐utero mortality rate was 0% in Group 1 and in Group 2 fetuses without intermittent flow. However, it was 19.4% in Group 2 cases with intermittent diastolic flow.

Conclusions

Intermittent absent and/or reversed end‐diastolic flow may be considered to be a characteristic sign of monochorionic pregnancy, and seems to result from the existence of large AAA. Its incidence is significantly increased in the context of selective intrauterine growth restriction, indicating a high risk for poor pregnancy outcome in these cases. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal heart rate and umbilical artery flow velocity variability in intrauterine growth restriction: a matched controlled study
Authors: Vinkesteijn A. S. M. , Struijk P. C. , Ursem N. T. C. , Hop W. C. J. , Wladimiroff J. W.
Published: May 2004

Objectives

To study heart rate and umbilical artery blood flow velocity variability in growth‐restricted fetuses and investigate the influence of the autonomic nervous system on these parameters.

Methods

Doppler velocity waveforms were collected from long‐lasting umbilical artery recordings in 15 fetuses with growth restriction and 15 normal age‐matched controls at 23–35 weeks of gestation. Absolute heart rate and umbilical artery blood flow velocity as well as the coefficient of variation were determined. Using power spectral analysis the low‐ and high‐frequency bands of heart rate variability and blood flow velocity variability were calculated. The low‐to‐high (LH) ratio of heart rate variability and blood flow velocity variability were examined as a measure of sympathovagal balance.

Results

In growth‐restricted fetuses umbilical artery velocities were significantly reduced. Heart rate variability was significantly reduced in the presence of growth restriction, but no significant difference was demonstrated for blood flow velocity variability. The LH ratio for heart rate variability was significantly decreased in growth restriction, but no difference in LH ratio was demonstrated for blood flow velocity variability.

Conclusion

Flow velocity variability in growth restriction seems not to be predominantly influenced by the autonomic nervous system, whereas the decreased heart rate variability seems to be influenced by altered sympathetic–parasympathetic balance. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Lost intrauterine devices during pregnancy: maternal and fetal outcome after ultrasound‐guided extraction. An analysis of 82 cases
Authors: Schiesser M. , Lapaire O. , Tercanli S. , Holzgreve W.
Published: May 2004

Objectives

It is generally agreed that intrauterine devices (IUDs) with visible strings in pregnancy should be removed because of the increased risk of miscarriage, septic complications and premature delivery. The precise management of pregnancies in association with so‐called ‘lost IUDs’, and especially the technique of their removal, has remained controversial. We present our experience of the management of intrauterine pregnancies with a lost IUD.

Methods

Ultrasound‐guided extraction of a lost IUD was performed in 82 intrauterine pregnancies. The subsequent outcome of the pregnancies is described.

Results

There were no intra‐ or post‐procedure maternal complications. Although the miscarriage rate in the first 3 weeks after the procedure was higher than that in normal pregnancy, the complication rate approached that of normal pregnancy as the pregnancies progressed. The total miscarriage rate of 22% was comparable to that following extraction of IUDs with visible filaments. The rate of live births was 77.0%. Delivery before 37 weeks occurred in 13.5% of cases.

Conclusions

Ultrasound‐guided extraction is a minimally invasive and inexpensive procedure that is associated with few postoperative complications. It has a high success rate and is associated with a moderate miscarriage rate and no maternal complications. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound diagnosis of severe thrombotic placental damage in the second trimester: an observational study
Authors: Alkazaleh F. , Viero S. , Simchen M. , Walker M. , Smith G. , Laskin C. , Windrim R. , Kingdom J.
Published: May 2004

Objectives

To screen women with uteroplacental insufficiency between 18 and 26 weeks' gestation for sonographic evidence of destructive placental lesions, to observe the effect of low molecular‐weight heparin (LMWH) in these cases, and to compare the outcome with similar but untreated controls.

Methods

We screened 180 women at high risk for placental damage using 16‐week maternal serum screening (alpha‐fetoprotein and human chorionic gonadotropin), placental shape and texture, and uterine artery Doppler waveforms at the 18–20‐week level II examination. Serial gray‐scale examinations of placental texture were performed at 22, 24 and 26 weeks. LMWH was offered to women with ultrasound evidence of destructive placental lesions in the absence of intrauterine growth restriction and/or pre‐eclampsia.

Results

We prospectively identified six women (3.3%) with abnormal maternal serum screening and uterine artery Doppler in whom abnormal placental texture (echogenic cystic lesions) suggestive of destructive lesions in the placental parenchyma was found either at the 18–20‐week ultrasound examination (n = 4), or by 26 weeks of gestation (n = 2). All six received LMWH and had live births (gestational age at delivery, 33–37 weeks; birth weight, 1000–3200 g). A further 14 women were referred with similar multiparameter evidence of placental damage at or after 26 weeks, outside the screening study. All had significant fetal growth restriction and were therefore not offered heparin. In 9/14 cases there was a perinatal death. Ischemic and/or thrombotic placental pathology was confirmed in each case, but no maternal thrombophilia disorders were identified in the 20 women.

Conclusions

Integrated biochemical and ultrasound testing of placental function at 16–20 weeks of gestation, followed by serial placental gray‐scale ultrasound, may be an effective method of identifying a subset of pregnancies at high risk of adverse pregnancy outcome due to destructive lesions in the placental parenchyma. This strategy of identifying thrombo‐occlusive placental lesions before the development of pregnancy complications may prove useful in the design of trials to study the effectiveness of LMWH in the prevention of clinical complications resulting from thrombo‐occlusive placental disease. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Reduced antioxidant capacity in second‐trimester pregnancies with pathological uterine perfusion
Authors: Stepan H. , Heihoff‐Klose A. , Faber R.
Published: May 2004

Objectives

To examine whether pathological perfusion in the second trimester is characterized by an altered plasma antioxidant capacity and to investigate whether the total antioxidant capacity in maternal plasma is related to the clinical outcome of these high‐risk pregnancies.

Methods

This was a prospective cohort study that included 25 pregnancies with normal and 25 pregnancies with pathological uterine perfusion. Doppler ultrasound measurement of uterine perfusion was performed between 18 and 23 weeks of gestation. Total antioxidant capacity in maternal plasma was measured using a specific photometric assay.

Results

Plasma antioxidant capacity of pregnant women with pathological uterine perfusion (227.3 ± 4.0 µmol/L) was significantly lower compared with the group with normal uterine perfusion (275.2 ± 10.5 µmol/L; P < 0.05). There was a significant negative correlation between antioxidant capacity and mean pulsatility index of the uterine arteries (r = −0.363; P < 0.05). Patients with pathological perfusion and a normal course of pregnancy did not show significantly changed values compared with those patients with later pre‐eclampsia or intrauterine growth restriction (235.0 ± 4.9 µmol/L vs. 218.6 ± 6.7 µmol/L).

Conclusions

Second‐trimester pregnancies with pathological uterine perfusion are characterized by a decreased antioxidant capacity in maternal plasma. This reduction is related to the impaired uteroplacental blood flow, but does not reflect the changes characteristic of the oxidative status for diseases like pre‐eclampsia since the reduction of the plasma antioxidant capacity is not related to the clinical outcome of these high‐risk pregnancies. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
First‐trimester diagnosis of sacrococcygeal teratoma: the role of three‐dimensional ultrasound
Authors: Roman A. S. , Monteagudo A. , Timor‐Tritsch I. , Rebarber A.
Published: May 2004

A fetus was suspected of having a sacrococcygeal teratoma (SCT) on routine nuchal translucency evaluation by sonography at 12+3 weeks. The patient was referred for three‐dimensional (3D) sonography to further delineate the extent of the mass. In this case, real‐time scanning of the mass in 3D mode assisted the diagnosis of the mass and patient counseling. We present what we believe to be the first case of SCT imaged in the first trimester using 3D ultrasound. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound prenatal diagnosis of a lateral facial cleft (Tessier number 7)
Authors: Presti F. , Celentano C. , Marcazzò L. , Dolcetta G. , Prefumo F.
Published: May 2004

Lateral facial clefting may occur as an isolated phenomenon or in association with other disorders. It may originate from a failed penetration of ectomesenchyme between the developing maxillary and mandibular prominences, but disruptive factors may also occur in a proportion of cases. The frequency of this abnormality is estimated as 1 in 50 000–175 000 live births. We describe a case of isolated symmetrical lateral facial cleft (number 7 according to the Tessier classification) diagnosed prenatally on ultrasound examination at 26 weeks of gestation. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Conservative Surgery for Treatment of Hydatid Cysts in Children
Authors: Türkyılmaz Zafer , Sönmez Kaan , Karabulut Ramazan , Demirogulları Billur , Göl Hakkı , Basaklar A. Can , Kale Nuri
Published: May 2004

Human echinococcosis is endemic in Turkey and many other areas of the world. Fifteen years of surgical assessment related to involved structures, operative procedures, complications, and the recurrence rate is analyzed in pediatric patients with pulmonary and abdominal hydatid cysts. Between 1986 and 2001, the records of 42 pediatric patients (15 girls, 27 boys; ages 2–15 years) with pulmonary and abdominal hydatid cysts operated on in our clinic were analyzed retrospectively. The features of the disease, involved structures, operative procedures, complications, and recurrences were noted. A total of 26 patients presented with solitary cysts in the lung (9) and liver (17). Another 11 had multiple cysts in both lung and liver, and 5 had disseminated abdominal disease. Conservative surgical procedures were used for all lung and liver cysts: cystotomy (7) or cystotomy plus capitonnage (13) for lung cysts; partial pericystectomy with capitonnage (25), omentoplasty (28), tube drainage in the presence of bile leakage (5), or a combination of these procedures for liver cysts. Cyst excision was used for omental and peritoneal localizations when feasible. Radical procedures were never used (wedge or major liver and lung resections). Operative mortality was zero, and the morbidity rate was 14%. Three patients with disseminated disease (7%) showed recurrence. We suggest that no partial organ resections are necessary for hydatid disease, and highly successful results can be achieved using conservative surgical approaches, such as cystotomy plus capitonnage for lung cysts and partial pericystectomy with capitonnage, omentoplasty, or both for liver cysts.
Long‐term Follow‐up of Patients with Elevated PTH Levels following Successful Exploration for Primary Hyperparathyroidism
Authors: Nordenström E. , Westerdahl Johan , Bergenfelz A.
Published: May 2004

Several studies have documented elevated parathyroid hormone (PTH) levels after seemingly successful exploration for primary hyperparathyroidism (pHPT). It is not known if this is a transient phenomenon after pHPT surgery or if it predisposes to recurrent disease. A series of 99 consecutive patients with pHPT who had solitary parathyroid adenomas were followed for 5 years. Serum levels of PTH and biochemical variables reflecting PTH activity were measured before operation, at 8 weeks postoperatively, and then yearly for 5 years. All patients were normocalcemic after exploration. At 8 weeks after operation 28% of the patients had elevated serum PTH levels; at 5 years this figure decreased to 16%. During the 5‐year follow‐up one group of patients normalized their PTH levels, another group’s PTH levels fluctuated, and still another group had consistently normal PTH levels. Patients with fluctuating PTH levels had increased levels of serum calcium and phosphate. Some of these patients (15%) showed signs of impaired renal function. Two patients with consistently elevated PTH levels showed signs of mild renal dysfunction, and one of them developed recurrent HPT. Elevated PTH levels after successful parathyroid surgery is not a transient phenomenon. An increased risk for recurrent disease is postulated for some of the patients who do not normalize their PTH levels postoperatively, and long‐term surveillance of these patients is suggested.
Pheochromocytoma Surgery: Epidemiologic Peculiarities in Children
Authors: Beltsevich Dmitry G. , Kuznetsov Nikolay S. , Kazaryan Airazat M. , Lysenko Maryana A.
Published: May 2004

Manifestations of pheochromocytoma have some specific features in children. The aim of this study was to explore epidemiologic differences of the disease course in children and adults, the principal causes of pheochromocytoma recurrence, and the optimal extent of an operative intervention in a group of patients with initial manifestation of their tumor during childhood. A total of 520 patients with pheochromocytoma underwent surgery from 1957 to 2001. The mean age of the patients was 39.3 ± 9.2 years; 50 patients (9.6%) were 16 years or under (children’s group). There were 213 males (41%) in the general group and 32 males (62%) in the children’s group. Bilateral adrenal lesions were present in 68 patients (13.1%), including 16 of the 50 children (32%). The tumors were extraadrenal in 36 patients (6.9%), including 9 of the 50 children (18%). The combination of pheochromocytoma and a hereditary syndrome was present in 36 cases (6.9%). Follow‐up was obtained in 260 patients, including 46 children. Length of follow‐up varied from 4 to 25 years (average 8.4 ± 1.9 years). The pheochromocytoma recurred in 49 patients (18.8% of surveyed patients), with a true recurrence (a tumor in the region of the primary operation or metastases) in 16 patients (6.15%). A true pheochromocytoma recurrence was noted in 6 of the 50 children (12.0%). Organ‐sparing tactics for multicentric adrenal lesions was a principal cause of the true recurrence. Therefore we believe it is necessary to perform a radical operation, which includes adrenalectomy and removal of the tumor, in patients with a high risk of recurrence.
Liver Transplantation Techniques with Preservation of the Natural Venovenous Bypass: Effect on Surgical Resection of Renal Cell Carcinoma Invading the Inferior Vena Cava
Authors: Delis Spiros , Dervenis Christos , Lytras Dimitrios , Avgerinos Costas , Soloway Mark , Ciancio Gaetano
Published: May 2004

Although renal tumors invading the inferior vena cava (IVC) are unusual, they represent a challenge to the surgical team because their accessibility is difficult. Liver transplantation techniques have been developed that preserve the venous collaterals, enhance the exposure, increase the safety of the resection, and avoid cardiopulmonary bypass. We describe our technique for dealing with renal tumors that have invaded the IVC, a combined experience of two centers, and the safety of the procedure and subsequent low morbidity. Between May 1997 and February 2003, a total of 45 patients (mean age 60.7 years) underwent surgical resection of a renal tumor extending into the IVC by techniques developed from liver transplantation, with the intention to avoid sternotomy and cardiopulmonary bypass. In 42 patients (93.3%) surgical resection of the tumor and thrombus was successful using the transabdominal approach while preserving the venous collaterals; 3 patients with a level IV tumor thrombus required cardiopulmonary bypass. The mean operating time was 342 minutes, and the mean estimated blood loss was 1442 cc. Postoperative ileus in one patient required laparoscopic lysis of the adhesions, and 2 patients (4.4%) died owing to multiple system organ failure and massive pulmonary embolism. The median follow‐up was 36 months, during which time 6 patients developed metastatic disease and 37 were disease‐free. We concluded that liver transplantation techniques enhance the surgical management of complicated urologic tumors. Patients with tumor thrombus extending to the IVC can be treated while avoiding thoracotomy and cardiopulmonary bypass.
Pancreaticoduodenectomy with En Bloc Portal Vein Resection for Pancreatic Carcinoma with Suspected Portal Vein Involvement
Authors: Poon Ronnie T. , Fan Sheung Tat , Lo Chung Mau , Liu Chi Leung , Lam Chi Ming , Yuen Wai Key , Yeung Chun , Wong John
Published: May 2004

Pancreaticoduodenectomy combined with portal vein resection is increasingly accepted as a viable treatment option for pancreatic carcinoma with suspected involvement of the portal vein.However, its clinical benefit remains controversial. This study evaluated the outcomes of pancreaticoduodenectomy with portal vein resection for pancreatic carcinoma in a group of Chinese patients operated on by a specialized team in a center with a low case volume of pancreatic cancer. The perioperative and long‐term outcomes of 12 patients with portal vein resection for suspected involvement of the portal vein and 38 patients who underwent pancreaticoduodenectomy without portal vein resection during the same period were compared. In the former group, eight patients underwent segmental resection, and four patients underwent wedge resection of the portal vein. There were no significant differences in operative blood loss (median 0.8 vs. 0.8 liter, p = 0.313), hospital mortality (0% vs. 2.6%, p = 1.000), or operative morbidity (41.7% vs. 42.1%, p = 0.979) between the two groups. Patients who required portal vein resection had higher frequencies of microscopic lymphatic permeation (58.3% vs. 18.4%, p = 0.023) and vascular invasion (50.0% vs. 15.8%, p = 0.025). Long‐term survival was comparable between patients with portal vein resection and those without it (median 19.5 vs. 20.7 months, p = 0.769). These findings suggest that pancreaticoduodenectomy combined with portal vein resection can be performed safely by a specialized team in a center with a low case volume of pancreatic carcinoma and that it may offer survival benefit in patients with suspected portal vein involvement.