bluuebunny/crossref_metadata_2025 huggingface dataset:
Absence of genotoxic effects after exposure of mammalian cells to the recombinant human bone morphogenetic protein 2 (BMP‐2) prepared from E. coli
Authors: Rumpf H. M. , Dopp E. , Rettenmeier A. W. , Chatzinikolaidou M. , Jennissen H. P.
Published: January 2004

Recombinant human bone morphogenetic protein 2 (rhBMP‐2) has been widely employed for the induction of bone growth in animal models and in clinical trials. Since rhBMP‐2 is commercially available only to a very limited extent, we have prepared our own recombinant material for the current testing and for future applications. As yet, no toxicological data on rhBMP‐2 has been reported to the knowledge of the authors. Therefore, it was considered necessary to apply the in vitro‐micronucleus assay to our preparation to monitor a possible genotoxic effect. A total of approximately 24500 nuclei from V79 Chinese hamster cells and more than 40000 nuclei from human amniotic fluid fibroblast‐like (AFFL) cells were screened for the frequency of micronuclei following incubation with 3‐300 nM rhBMP‐2, which covers the concentration range from initial biological activity to the begin of a maximal response in MC3T3‐E1 cells. It can be concluded from the results that our preparations of recombinant human BMP‐2 prepared in E. coli do not cause DNA damage in the concentration range tested.
Central Venous Catheter Associated Infections Pathophysiology, Incidence, Clinical Diagnosis, and Prevention – A Review
Authors: Guggenbichler J. P.
Published: January 2004

The incidence of catheter related bloodstream infections poses a substantial burden on patient’s life’s and well‐being. Estimated 2 – 6 % of patients suffer from catheter associated bloodstream infections (BSI). Reports on mortality of these patients are up to 30 % in addition to a substantial prolongation of hospital days. The estimated cost of therapy of a BSI is approximately 10 000 € per patient.

There is a definitive need for antimicrobially active medical devices for prophylaxis. Endowment of catheters with antibiotics and desinfectants have substantial limitations regarding spectrum of activity, duration of activity and clinical efficacy.

The oligodynamic activity of silver has the greatest potential for prevention of catheter related infections. Various technologies in particular surface coating of these medical devices have been advocated previously with limited success. A new technology with impregnation of the entire catheter matrix with billions of nanoparticles of silver0 which results in a surface of 2000 cm2/g polyurethane (PU) has been developed.

Central venous catheters manufactured according to the technology of the first and second generation have been investigated with good results of antimicrobial activity and biocompatibility. Favorable results in experimental investigations and good clinical results in controlled prospective, randomized, investigator blinded studies of the first generation silver catheter have been obtained. In 660 patients in an overall reduction of BSI of 66 % was observed. Favorable results in a postmarketing surveillance with 3000 patients were seen.

The premarketing surveillance of the second generation silver‐catheter indicated an even greater reduction of catheter related BSI. In 204 patients with a mean duration of catheter placement of 9.2 days only one catheter related BSI was diagnosed. The rate of catheter colonization was <10 %. The catheter was well tolerated.

A further improvement with increased antimicrobial activity was achieved by activation of silver nanoparticles in the third generation catheter: The superior results of in vitro tests and excellent biocompatibility lets us expect an additional improvement of preventive measures.

The duration of antimicrobial activity has been investigated and lasts at least 370 days.

The concept of impregnation of a polymer matrix and silicone can be extended to various other clinical applications e.g. Sheldon, Hickman and urologic catheters. Substantial savings in the cost of patient care through prevention of complications can be expected which is of particular importance with the disease oriented (DRG) remuneration system.
Osteogenic Response of C2C12 Cells on Thermoreversible Polymers
Authors: Uludag H. , Smith E. , McGann L. E. , Yang J.
Published: January 2004

Bone Morphogenetic Proteins (BMPs) in combination with biomaterials are being explored for clinical bone regeneration. The current biomaterials used for BMPs delivery are not specifically designed to support BMP‐induced osteogenesis. Towards this goal, we designed synthetic N‐isopropylacrylamide (NiPAM)‐based thermosensitive polymers and investigated their ability to support osteogenic transformation of pluripotent C2C12 cells. Cell attachment to the polymers was limited as compared to attachment to the plastic surfaces optimized for cell culture. Short‐term (<7 days) studies indicated relatively little cell growth on the polymer surfaces. However, C2C12 cells retained their ability to respond to BMP‐2, as determined by alkaline phosphatase (ALP) induction, when cultured on thermoreversible polymers. Some polymers supported ALP induction that was far superior (∼10‐fold) to cells grown on tissue culture surfaces. We conclude that thermosensitive polymers, although limited in their ability to support cell attachment and growth, did support the pluripotent cells' ability to be transformed under the influence of BMP‐2. The ALP induction was dependent on the compositional details of the polymers, suggesting that in vivo osteoinduction was likely to be influenced by the physicochemical properties of the polymers.
Comparison of Diamond‐Like‐Carbon and Alumina‐Oxide articulating with Polyethylene in Total Hip Arthroplasty
Authors: Taeger G. , Podleska L.E. , Schmidt B. , Ziegler M. , Nast‐Kolb D.
Published: January 2004

To reduce wear in joint bearings of total hip arthroplasty (THA) is the most important issue for improving long term results and implant survival. Due to low wear rates and excellent tribological features in simulator tests Diamond‐Like‐Carbon coating (DLC) of femoral balls is still discussed as an alternative articulation in THA. This clinical prospective study compares survivorship of DLC‐coated femoral heads and of Aluminia‐Oxide‐ (Al2O3) heads articulating with Polyethylene (PE).

Over a period of two years 101 THA with DLC‐coated heads and PE cups (DLC‐group) and another 101 THA consisting of Al2O3 heads (Al2O3‐group) and PE cups as well were implanted. Both articulations were based on the same type of cementless hip joint prosthesis. All hips were implanted by one surgeon in consecutive series consisting of 51 Al2O3 and 101 DLC‐articulations and further 50 Al2O3. All perioperative and follow‐up data was processed with SPSS®. Survival of THA in both groups was evaluated according to Kaplan‐Meier survivorship analysis with an intervall of 90 months (range:78‐101). Qualitative surface analysis was performed in nineteen retrieved DLC‐heads which were revised for aseptic loosening using field scanning electron microscopy (FE‐SEM, XL 30 SFEG Philips, Eindoven NL).

178 patients (88.2 %) were evaluated for follow‐up. Fourteen patients died meantimes (nine DLC, five Al2O3) with the implant components not revised. Ten patients (five DLC, five Al2O3) were lost to follow‐up. Both groups were comparable regarding patient age, weight and indications for THA with a normal distribution. Survivorship analysis for aseptic loosening 8.5 years following implantation resulted in a significant difference between both groups with a 54 % survival for DLC/PE compared to 88 % for Al2O3/PE bearings (p <0.001). No correlation to variables as age, gender or bodyweight could be detected. Surfaces of nineteen retrieved DLC‐heads showed numerous smallest pits of the diamond‐carbon layers in different quantity. SEM showed delamination of the carbon layer which caused excessive debris of polyethylene and in some cases even of the metallic substrate of the heads.

Despite modern manufacturing technology and excellent experimental results for its tribochemical characteristics and wear, even “new” DLC‐coating of femoral heads is to be considered critically due to very high rates of clinical failure.
The ice‐fishing problem: the fundamental sloshing frequency versus geometry of holes
Authors: Kozlov Vladimir , Kuznetsov Nikolay
Published: January 2004

We study an eignevalue problem with a spectral parameter in a boundary condition. This problem for the Laplace equation is relevant to sloshing frequencies that describe free oscillations of an inviscid, incompressible, heavy fluid in a half‐space covered by a rigid dock with some apertures (an ice sheet with fishing holes). The dependence of the fundamental eigenvalue on holes' geometry is investigated. We give conditions on a plane region guaranteeing that the fundamental eigenvalue corresponding to this region is larger than the fundamental eigenvalue corresponding to a single circular hole. Examples of regions satisfying these conditions and having the same area as the unit disk are given. New results are also obtained for the problem with a single circular hole.

On the other hand, we construct regions for which the fundamental eigenfrequency is larger than the similar frequency for the circular hole of the same area and even as large as one wishes. In the latter examples, the hole regions are either not connected or bounded by a rather complicated curves. Copyright © 2004 John Wiley & Sons, Ltd.
On the absence of eigenvalues of Maxwell and Lamé systems in exterior domains
Authors: Bauer Sebastian
Published: January 2004

The arguments showing non‐existence of eigensolutions to exterior‐boundary value problems associated with systems—such as the Maxwell and Lamé system—rely on showing that such solutions would have to have compact support and therefore—by a unique continuation property—cannot be non‐trivial. Here we will focus on the first part of the argument. For a class of second order elliptic systems it will be shown that L2‐solutions in exterior domains must have compact support. Both the asymptotically isotropic Maxwell system and the Lamé system with asymptotically decaying perturbations can be reduced to this class of elliptic systems. Copyright © 2004 John Wiley & Sons, Ltd.
Asymptotic and spectral properties of operator‐valued functions generated by aircraft wing model
Authors: Balakrishnan A. V. , Shubov Marianna A.
Published: January 2004

The present paper is devoted to the asymptotic and spectral analysis of an aircraft wing model in a subsonic air flow. The model is governed by a system of two coupled integro‐differential equations and a two parameter family of boundary conditions modelling the action of the self‐straining actuators. The differential parts of the above equations form a coupled linear hyperbolic system; the integral parts are of the convolution type. The system of equations of motion is equivalent to a single operator evolution–convolution equation in the energy space. The Laplace transform of the solution of this equation can be represented in terms of the so‐called generalized resolvent operator, which is an operator‐valued function of the spectral parameter. More precisely, the generalized resolvent is a finite‐meromorphic function on the complex plane having a branch‐cut along the negative real semi‐axis. Its poles are precisely the aeroelastic modes and the residues at these poles are the projectors on the generalized eigenspaces. The dynamics generator of the differential part of the system has been systematically studied in a series of works by the second author. This generator is a non‐selfadjoint operator in the energy space with a purely discrete spectrum. In the aforementioned series of papers, it has been shown that the set of aeroelastic modes is asymptotically close to the spectrum of the dynamics generator, that this spectrum consists of two branches, and a precise spectral asymptotics with respect to the eigenvalue number has been derived. The asymptotical approximations for the mode shapes have also been obtained. It has also been proven that the set of the generalized eigenvectors of the dynamics generator forms a Riesz basis in the energy space. In the present paper, we consider the entire integro‐differential system which governs the model. Namely, we investigate the properties of the integral convolution‐type part of the original system. We show, in particular, that the set of poles of the adjoint generalized resolvent is asymptotically close to the discrete spectrum of the operator that is adjoint to the dynamics generator corresponding to the differential part. The results of this paper will be important for the reconstruction of the solution of the original initial boundary‐value problem from its Laplace transform and for the analysis of the flutter phenomenon in the forthcoming work. Copyright © 2004 John Wiley & Sons, Ltd.
Global regularity for the viscous Boussinesq equations
Authors: Li Yanguang
Published: January 2004

The global regularity for the viscous Boussinesq equations is proved. Copyright © 2004 John Wiley & Sons, Ltd.
Efficient distributions of arms‐control inspection effort
Authors: Avenhaus Rudolf , Kilgour D. Marc
Published: January 2004

A rule that constrains decision‐makers is enforced by an inspector who is supplied with a fixed level of inspection resources—inspection personnel, equipment, or time. How should the inspector distribute its inspection resources over several independent inspectees? What minimum level of resources is required to deter all violations? Optimal enforcement problems occur in many contexts; the motivating application for this study is the role of the International Atomic Energy Agency in support of the Treaty on the Non‐Proliferation of Nuclear Weapons. Using game‐theoretic models, the resource level adequate for deterrence is characterized in a two‐inspectee problem with inspections that are imperfect in the sense that violations can be missed. Detection functions, or probabilities of detecting a violation, are assumed to be increasing in inspection resources, permitting optimal allocations over inspectees to be described both in general and in special cases. When detection functions are convex, inspection effort should be concentrated on one inspectee chosen at random, but when they are concave it should be spread deterministicly over the inspectees. Our analysis provides guidance for the design of arms‐control verification operations, and implies that a priori constraints on the distribution of inspection effort can result in significant inefficiencies. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Fitting Lanchester equations to the battles of Kursk and Ardennes
Authors: Lucas Thomas W. , Turkes Turker
Published: January 2004

Lanchester equations and their extensions are widely used to calculate attrition in models of warfare. This paper examines how Lanchester models fit detailed daily data on the battles of Kursk and Ardennes. The data on Kursk, often called the greatest tank battle in history, was only recently made available. A new approach is used to find the optimal parameter values and gain an understanding of how well various parameter combinations explain the battles. It turns out that a variety of Lanchester models fit the data about as well. This explains why previous studies on Ardennes, using different minimization techniques and data formulations, have found disparate optimal fits. We also find that none of the basic Lanchester laws (i.e., square, linear, and logarithmic) fit the data particularly well or consistently perform better than the others. This means that it does not matter which of these laws you use, for with the right coefficients you will get about the same result. Furthermore, no constant attrition coefficient Lanchester law fits very well. The failure to find a good‐fitting Lanchester model suggests that it may be beneficial to look for new ways to model highly aggregated attrition. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Effects of lethality in naval combat models
Authors: Armstrong Michael J.
Published: January 2004

In the context of both discrete time salvo models and continuous time Lanchester models we examine the effect on naval combat of lethality: that is, the relative balance between the offensive and defensive attributes of the units involved. We define three distinct levels of lethality and describe the distinguishing features of combat for each level. We discuss the implications of these characteristics for naval decision‐makers; in particular, we show that the usefulness of the intuitive concept “more is better” varies greatly depending on the lethality level. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
A note on scheduling parallel machines subject to breakdown and repair
Authors: Leung Joseph Y.‐T. , Pinedo Michael
Published: January 2004

In this paper we consider n jobs and a number of machines in parallel. The machines are identical and subject to breakdown and repair. The number may therefore vary over time and is at time t equal to m(t). Preemptions are allowed. We consider three objectives, namely, the total completion time, ∑ Cj, the makespan Cmax, and the maximum lateness Lmax. We study the conditions on m(t) under which various rules minimize the objective functions under consideration. We analyze cases when the jobs have deadlines to meet and when the jobs are subject to precedence constraints. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Facility location models for immobile servers with stochastic demand
Authors: Wang Qian , Batta Rajan , Rump Christopher M.
Published: January 2004

This paper presents several models for the location of facilities subject to congestion. Motivated by applications to locating servers in communication networks and automatic teller machines in bank systems, these models are developed for situations in which immobile service facilities are congested by stochastic demand originating from nearby customer locations. We consider this problem from three different perspectives, that of (i) the service provider (wishing to limit costs of setup and operating servers), (ii) the customers (wishing to limit costs of accessing and waiting for service), and (iii) both the service provider and the customers combined. In all cases, a minimum level of service quality is ensured by imposing an upper bound on the server utilization rate at a service facility. The latter two perspectives also incorporate queueing delay costs as part of the objective. Some cases are amenable to an optimal solution. For those cases that are more challenging, we either propose heuristic procedures to find good solutions or establish equivalence to other well‐studied facility location problems. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.
Ketolide:Klinische Aspekte: Stellenwert bei Atemwegsinfektionen
Authors: Lorenz Joachim , Steiert Petra
Published: January 2004

Telithromycin, der erste Vertreter der Ketolide, besitzt eine hohe In‐vitro‐Aktivität gegen Erreger ambulant erworbener Atemwegsinfektionen. Das Wirkspektrum umfasst auch atypische und intrazelluläre Erreger sowie Pneumokokken (einschließlich Penicillin‐ und Makrolid‐resistente Stämme) und β‐Laktamasebildende Stämme von Haemophilus influenzae und Moraxella catarrhalis. Die Wirksamkeit von Telithromycin wurde in mehreren randomisierten Doppelblindstudien untersucht. Bei Patienten mit AECB, CAP, akuter Sinusitis und Tonsillitis/Pharyngitis war Telithromycin bei einer täglichen Einmalgabe von 800 mg und kürzerer Therapiedauer sowohl klinisch als auch bakteriologisch mindestens genauso effektiv und genauso gut verträglich wie Standardantibiotika. Telithromycin stellt somit eine wertvolle Bereicherung des Antibiotikaspektrums dar und ist eine viel versprechende Substanz zur Therapie von leichten bis mittelschweren ambulant erworbenen Atemwegsinfektionen.
Unerwünschte Wirkungen und Interaktionen der Ketolide und Oxazolidinone: Verträglichkeit von Antiinfektiva
Authors: Stahlmann Ralf , Sendzik Judith
Published: January 2004

Telithromycin und Linezolid sind jeweils die ersten verfügbaren Antiinfektiva aus zwei neuen Arzneimittelgruppen: den Ketoliden und den Oxazolidinonen. Bei Patienten, die mit dem Ketolid Telithromycin behandelt wurden, kam es relativ häufig zur Diarrhö. Telithromycin hemmt unter anderem das Cytochrom Isoenzym CYP3A4, damit besteht ein ausgeprägtes Potenzial für klinisch relevante Wechselwirkungen mit anderen Arzneimitteln. Es besteht die Aufgabe für Ärzte und Apotheker auf die möglichen Interaktionen bei der Verschreibung und Abgabe des Ketolids hinzuweisen. Das Oxazolidinon Linezolid besitzt ein hämatotoxisches Potenzial, das bei mehrwöchiger Therapie zu Anämie, Leukopenie oder Thrombozytopenie führen kann. Wöchentliche Blutbildkontrollen sind notwendig, um Komplikationen rechtzeitig zu erkennen. Linezolid ist ein Hemmstoff der Monoaminoxidase und darf nicht mit anderen MAO‐Hemmern, Serotonin‐Wiederaufnahme‐Hemmern und einigen anderen Arzneimitteln kombiniert werden, da es sonst zum Serotonin‐Syndrom kommen kann. Bei wohlüberlegter Anwendung und unter Berücksichtigung der spezifischen pharmakologisch‐toxikologischen Wirkungen sind die beiden neuen Arzneimittel sichere und sinnvolle Ergänzungen der antibakteriellen Therapeutika.
Outcome of pediatric recurrent and refractory malignant solid tumors following ifosfamide/carboplatin/etoposide (ICE): A phase II study in a pediatric oncology centre in Brazil
Authors: Loss Jiseh Fagundes , Santos Pedro Paulo Albino , Leone Luciane Di , Brunetto Algemir Lunardi
Published: January 2004

Background

Therapeutic trials using ifosfamide,carboplatin, and etoposide (ICE) regimen have suggested many patients with refractory/relapsed solid tumors may be rendered free of disease using this combination. The aim of this study was to assess the feasibility, response and toxicity of this regimen in a Brazilian Pediatric Oncology Centre.

Procedure

ICE, consisting of ifosfamide 3 g/m2/day ×3 plus Mesna, etoposide 160 mg/m2/day ×3, and carboplatin 400 mg/m2/day ×2 was given at 21–28 days intervals. G‐CSF was used for patients with hematological recovery greater than 4 weeks.

Results

Twenty‐one patients younger than 18 years of age treated with this regimen were studied between July 1996 and November 2000. A total of 93 courses of ICE were administered. Leucopenia/neutropenia grades 3/4 were the most frequent severe adverse effects (82%). Grade 3/4 thrombocytopenia occurred in 73% of cycles, and anemia was common (61%). The most common grade 3/4 non‐hematologic toxicities were fever and proved infection occurring in 25% and 14% of the courses, respectively. Two patients developed renal tubular damage. Other less common grade 3/4 non‐hematologic toxicities included nausea and vomiting, hepatotoxicity, and stomatitis. The overall response rate (complete response/partial response) was 53%. The median progression‐free interval was 15.3 months, with a median survival of 24.2 months.

Conclusions

Although ICE was associated with severe myelosuppression it produced objective response in about half of the cases. The most important non‐hematological toxicity was severe renal tubular damage. This regimen should only be used whenever hematological and infectious supportive care is available. © 2003 Wiley‐Liss, Inc.
Gastric stromal tumors in children
Authors: Haider N. , Kader M. , Mc Dermott M. , Devaney D. , Corbally M.T. , Fitzgerald R.J.
Published: January 2004

Gastrointestinal stromal tumors (GIST) in children are rare and their behavior has been regarded as difficult to predict on pathological criteria. We report our experience with two gastric GISTs in children aged 10 and 11 years. Both remain alive and free of disease at 5 years and 2 years respectively. Comparison of the pathological features in the resected specimens with a recently proposed guidelines for predicting outcome in this group of tumors is reported. © 2003 Wiley‐Liss, Inc.
Carboplatin‐epirubicin regimen for the treatment of hepatoblastoma
Authors: Blouin P. , Brugières Laurence , Tabone M.D. , Leverger G. , Rubie H. , Branchereau S. , De Kraker J.
Published: January 2004

Background

In order to lower the long‐term toxicity of chemotherapy for hepatoblastoma patients, a prospective study was designed based on pre‐operative chemotherapy combining carboplatin and epirubicin (CE).

Procedures

Patients under 16 years of age with an epithelial hepatic tumor diagnosed by ultrasound or CT scan and a high serum alpha‐foetoprotein (AFP) level were eligible. Patients were treated with a pre‐operative chemotherapy regimen combining carboplatin 600 mg/m2 and epirubicin 80 mg/m2. Tumor resectability was assessed after four courses given at 3‐week intervals. After surgery, patients were given two more courses of CE. Response was assessed based on a drop in serum AFP and tumor shrinkage.

Results

Between July 1988 and August 1995, 27 patients with a hepatoblastoma were included. The initial PRETEXT group according to the SIOPEL classification was: group 2 (5 pts), group 3 (15 pts), group 4 (5 pts), and 2 pts were not assessed. Six patients had lung metastases. Response was partial response (PR) in 20/27 (74%) patients, disease was stable in 3 and 4 had progressive disease (PD). A complete surgical resection was performed in 21 pts. Five‐year overall and disease‐free survival (DFS) were respectively 56% (95%CI: 37–72%) and 63% (95%CI: 44–78%). During the same time period, 7 pts with a hepatocellular carcinoma were treated according to this protocol. Only one achieved a PR. Toxicity was mostly hematologic with ≥grade 3 leukopenia in 23% of the courses, ≥grade 3 thrombocytopenia in 29% of the courses and anemia in 22%.

Conclusion

The CE protocol is feasible and efficient in hepatoblastoma. However, only a randomized study will permit a valid comparison of the efficacy of cisplatin and carboplatin for the treatment of these patients. © 2003 Wiley‐Liss, Inc.
Medulloblastoma in childhood: Impact of radiation technique upon the outcome of treatment
Authors: Chojnacka Marzanna , Skowrońska‐Gardas Anna
Published: January 2004

Background

Medulloblastoma is an infratentorial primitive neuroectodermal tumour, diagnosed in paediatric population. The radiotherapy is an essential method of treatment for these tumours. The impact of technical quality of radiation therapy on survival was recently considered. In this study treatment‐related variables are analysed with a special focus on radiotherapy technical factors.

Procedure

The population of 158 children with a diagnosis of medulloblastoma had been undergoing postoperative radiotherapy at MCMCC in Warsaw in the period 1983–1997. The medical data of these patients were analysed. Simulation films of the whole‐brain irradiation fields were retrospectively reviewed at 112 patients. The distance from the field margin to the cribriform plate and to the floor of the temporal fossa was assessed and correlated with supratentorial relapse.

Results

Five‐year overall survival (OS) and 5‐year disease free survival (DFS) were 46% and 40%, respectively. In multivariate analysis gender (P = 0.008), neurological status before radiotherapy (P = 0.029), M‐stage (P < 0.001) and sequence of craniospinal irradiation (P = 0.019) were significant prognostic factors for OS. For DFS significant factors were M‐stage (P < 0.001) and neurological status (P < 0.001). The cranial fields were not fully correctly covered at 43% patients. The field incorrectness was correlated with isolated supratentorial failure (P = 0.049).

Conclusions

Our results are similar to those published in literature. M0‐stage was the most powerful favourable prognostic factor. Male gender and neurological status before radiation treatment were associated with poor survival. Also protracted radiotherapy and quality of radiation technique may have an impact on the outcome. © 2003 Wiley‐Liss, Inc.
Differentiated thyroid carcinoma in childhood and adolescence—clinical course and role of radioiodine
Authors: Chow Sin‐Ming , Law Stephen C. K. , Mendenhall William M. , Au Siu‐Kie , Yau Stephen , Mang Oscar , Lau Wai‐Hon
Published: January 2004

Background

Differentiated thyroid carcinoma (DTC) in childhood has a good prognosis despite a high incidence of relapse. The use of radioactive iodine (RAI) has not been well established.

Procedure

This is a review of 60 patients less than 21 years of age; mean follow‐up was 14 years.

Results

Patients had a higher relapse rate with papillary thyroid carcinoma (PTC) than with follicular thyroid carcinoma (FTC): 24.5 vs. 9.1%. Compared with 997 patients with age ≥ 21, patients <21 years of age had a higher female to male ratio (7.6 vs. 3.9), higher incidence of nodal metastasis (45 vs. 28%), and lung metastasis (15 vs. 7.8%), and improved 10‐year cause‐specific survival (CSS) (98.3 vs. 89.5%). The 10‐year rates of CSS, local‐regional failure‐free survival (LRFFS), and distant metastasis failure‐free survival (DMFFS) for the young patients were 98.3, 79.3, and 90.7%, respectively. In patients with no distant metastasis at presentation, RAI improved 10‐year LRFFS (71.9 vs. 86.5%; P = 0.04). At last follow‐up, 10 of 12 patients (80%) with local‐regional (LR) relapse and five of nine patients (55.6%) with distant metastasis were rendered disease‐free. No patient has experienced a second malignancy.

Conclusions

Prognosis of DTC in young patients was good. Patients with LR relapse and distant metastasis had a high rate of remission after treatment. RAI treatment can reduce the rate of LR relapse in patients with no distant metastasis and result in complete remission in half of those with distant metastasis. No patient experienced a second malignancy. © 2003 Wiley‐Liss, Inc.
Leukemic cells and the cytokine patchwork
Authors: Kiss Csongor , Benkő Ilona , Kovács Péter
Published: January 2004

Background

In leukemia, the clonal population is characterized by a hierarchical organization. Although the majority of the leukemic population is generated after post‐determinic divisions, a subset of cells retain undifferentiated “blast” morphology. In addition, leukemic cells often have numerical or structural chromosomal abnormalities, aberrant gene expression patterns, and abnormal cell surface marker profiles. Despite these differences when compared to normal bone marrow and blood cells, leukemic cell survival and proliferation, just like that of normal progenitor cells, is influenced by hematopoietic growth factors. A major issue is whether differential regulation of normal and leukemic hematopoietic cells by cytokines can be exploited in antileukemic treatment or, in contrast, whether in vivo cytokine therapy may even be harmful to the patients.

Procedure

Here we review the results of recent experimental and clinical observations that investigated the influence of cytokines on leukemic cell growth and differentiation in vitro and in vivo.

Results

The majority of studies indicate that hematopoietic growth factors are involved in the regulation of proliferation and terminal differentiation of leukemic blast cells. Genetic aberrations involving cytokines or their receptors may contribute to leukemogenesis. Abundant interactions, cross‐lineage stimulation, and aberrant response patterns seem to transform the complex cytokine network regulation of normal hematopoiesis into an even more interlaced “patchwork” that controls leukemic hematopoiesis.

Conclusions

Since hematopoietic growth factors are present in high serum concentrations in patients with acute leukemia and myelodysplastic syndromes, consequences of possible interactions should be kept in mind even when well‐defined human recombinant factors in single application are to be involved in antileukemic protocols. © 2003 Wiley‐Liss, Inc.
Malignant infantile osteopetrosis & primary pulmonary hypertension: A new combination?
Authors: Kasow Kimberly A. , Bonfim Carmem , Asch Julie , Margolis David A. , Jenkins Jesse , Tamburro Robert F. , Handgretinger Rupert , Horwitz Edwin M.
Published: January 2004

Malignant infantile osteopetrosis (MIOP), a rare genetic disorder of the osteoclast, is fatal without hematopoietic stem cell transplantation. Primary pulmonary hypertension (PPH), a rare progressive disorder of the pulmonary circulation, is predominately fatal in the absence of successful therapy. A clinical association between these two disorders has not been recognized and a pathophysiologic link between osteoclast function and pulmonary vascular pressure as a rationale for such an association is not readily apparent. Here, we report five infants with MIOP, without cardiac abnormalities, who were found to have PPH after undergoing stem cell transplantation. We suggest that PPH may be linked to a specific variant of MIOP and recognizing the potential for pulmonary hypertension in children with MIOP may lead to a more rapid diagnosis and life‐saving intervention. © 2003 Wiley‐Liss, Inc.
Increased risk for aplastic anemia and myelodysplastic syndrome in individuals lacking glutathione S‐transferase genes
Authors: Sutton Joanne F. , Stacey Michael , Kearns William G. , Rieg Thomas S. , Young Neal S. , Liu Johnson M.
Published: January 2004

Background

Aplastic anemia (AA) and myelodysplastic syndrome (MDS) are marrow failure states that may be associated with chromosomal instability. An absence of the glutathione S‐transferase (GST) enzyme may genetically predispose individuals to AA or MDS.

Procedure and Results

To test this hypothesis, we determined the GSTM1 and GSTT1 genotypes in a total of 196 patients using multiplex PCR. The GSTT1 null genotype was found to be overrepresented in Caucasian, Asian, and Hispanic patients with either AA or MDS. We confirmed a difference in the expected frequency of the GSTM1 null genotype in Caucasian MDS patients. The double null GSTM1/GSTT1 genotype was also overrepresented in Caucasian AA and MDS patients. In our population, 26% of AA patients and 40% of MDS patients had a chromosomal abnormality identified by karyotype or FISH analyses for chromosomes 7 and 8. Patients with AA and the GSTT1 null genotype had an increased frequency of chromosomal abnormalities (P = 0.003).

Conclusion

There seems to be an increased risk for AA and MDS in individuals lacking GSTT1 or both GSTM1/GSTT1. Published 2003 Wiley‐Liss, Inc.
Effects of physical therapy intervention for children with acute lymphoblastic leukemia
Authors: Marchese Victoria G. , Chiarello Lisa A. , Lange Beverly J.
Published: January 2004

Background

The purpose of this study was to examine the effects of physical therapy intervention in children with acute lymphoblastic leukemia (ALL).

Procedure

Twenty‐eight children aged 4–15 years were randomly assigned to an intervention or control group. The intervention group received five sessions of physical therapy and was instructed to perform an individualized home exercise program consisting of ankle dorsiflexion stretching, lower extremity strengthening, and aerobic exercise.

Results

After 4 months children who received physical therapy intervention had significantly improved ankle dorsiflexion active range of motion and knee extension strength (P < 0.01). Differences were not found between the two groups for any of the other dependent variables.

Conclusions

Physical therapy intervention for children with ALL receiving maintenance chemotherapy improved two body functions important for normal gait. Physical therapy programs initiated earlier in treatment and with greater emphasis on endurance activities may also improve stamina and quality of life (QOL). © 2003 Wiley‐Liss, Inc.
Solarzellen aus Folien‐Silizium: Neue Materialien der Photovoltaik
Authors: Hahn Giso
Published: January 2004

Die Photovoltaik wird auf absehbare Zeit vor allem kristallines Silizium als Baumaterial nutzen, mit Tendenz zu billigeren, multikristallinen Wafern. Allerdings werden heutige Wafer aus großen Silizium‐Blöcken gesägt, was viel Material „verpulvert”︁. Das treibt den Anteil des Wafers an den Gesamtkosten des Solarmoduls auf 50% hoch. Folien‐Silizium nutzt dagegen durch eine andere Herstellungstechnik das Material viel besser aus und senkt so die Waferkosten erheblich. Im Wirkungsgrad können Solarzellen aus Folien‐Silizium schon fast mit herkömmlichen Zellen konkurrieren. Ein weiterer Vorteil von Folien‐Silizium: Es kann relativ problemlos in die Produktionslinien heutiger Solarzellen aus kristallinem Silizium eingegliedert werden. Allerdings sind die attraktivsten Herstellungsverfahren noch nicht „serienreif”︁.
Wie die Sonne ins Kraftwerk kommt: Solarthermische Kraftwerke
Authors: Pitz‐Paal Robert
Published: January 2004

Solarthermische Kraftwerke sammeln wie riesige Brenngläser die Sonnenstrahlung und treiben damit eine Wärmekraftmaschine an. Drei Konstruktionsprinzipien haben sich heute durchgesetzt. Bereits im kommerziellen Einsatz sind Systeme mit schwenkbaren, verspiegelten Parabolrinnen, die das Sonnenlicht auf ein zentrales Absorberrohr konzentrieren. Durch dieses fließt ein Wärmetransportmedium. Beim Zentral‐Receiver‐System fokussiert ein Feld verstellbarer Spiegel das Sonnenlicht auf die Spitze eines Turms. Dort sitzt ein Receiver, den ein Wärmetransportmedium durchströmt. Für kleine, dezentrale Anlagen eignen sich Dish‐Stirling‐Systeme. Das sind schwenkbare, paraboloide Spiegelschüsseln mit einem Stirling‐Motor im Brennpunkt. Zentral‐Receiver‐ und Dish‐Stirling‐Systeme sind noch im Entwicklungsstadium.
Kochen mit Zentimeterwellen: Die Physik der Haushaltsmikrowelle
Authors: Möllmann Klaus‐Peter , Vollmer Michael
Published: January 2004

Die Physik der Haushaltsmikrowelle ist erstaunlich reichhaltig: Sie umfasst die Erzeugung von Mikrowellen in Magnetrons, Wellenleiter und Resonatoren für elektromagnetische Felder, die dielektrische Relaxation bei der Orientierungspolarisation von Wasser, und die Eindringtiefe elektromagnetischer Wellen in Materie. Eine Abschätzung der Bedingungen für Multiphotonenionisation und Dissoziation zeigt, dass Haushaltsmikrowellen Speisen chemisch nicht verändern können.
Begeisterung für opalgrünes Meerwasser
Authors: Loos Andreas
Published: January 2004

Seine beiden Vornamen führen leicht zu Knoten in untrainierten europäischen Zungen. Deshalb kürzte sie der Physiker in der Regel zu zwei Buchstaben ab. Das war sehr freundlich. Und sehr vorteilhaft für ihn selbst: Es erleichterte ihm, in aller Munde zu sein.
Reger Elektronenverkehr in Vitamin C
Authors: Vilgis Thomas
Published: January 2004

In dieser nasskalten Jahreszeit wird der Ruf nach wärmender und vitaminreicher Kost laut, den die traditionelle Küche aber schnell verstummen lässt — und es uns erlaubt, genauer über physikalisch‐chemische Prozesse nachzudenken: im Sauerkraut.
Ringelreihen der Nanopartikel
Authors: Drach Volker
Published: January 2004

Nanopartikel zeichnen sich durch Ihre außergewöhnlichen, quantenmechanisch geprägten optischen und elektronischen Eigenschaften aus. Mit Cadmiumsulfid‐Nanopartikeln gelang es jüngst einer japanisch‐britischen Forschergruppe ringförmige Strukturen auf Silizium‐Substrat mittels eines selbst‐organisierenden Prozesses herzustellen [1]. Die Photolumineszenz dieser Nanoringe könnte sie in Zukunft zu einem Grundbaustein für optoelektronische Anwendungen werden lassen.
The discovery of polymer‐clay hybrids
Authors: Kawasumi Masaya
Published: January 2004

The first successful example of a polymer‐clay hybrid was nylon‐clay hybrid (NCH), which is a nano‐meter‐sized composite of nylon‐6 and 1‐nm‐thick exfoliated aluminosilicate layers of the clay mineral. NCH was found and developed at Toyota Central Research and Development Laboratories over 17 years ago. The NCH containing a few weight percentages of clay exhibits superior properties such as high modulus, high strength, and good gas‐barrier properties. The key for the discovery of NCH was the polymerization of a nylon monomer in the interlayer space of the clay. This highlight presents the development of NCH from its discovery to its commercialization. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 819–824, 2004
Living anionic polymerization of lauryl methacrylate and synthesis of block copolymers with methyl methacrylate
Authors: Raghunadh V. , Baskaran D. , Sivaram S.
Published: January 2004

Anionic polymerization of lauryl methacrylate (LMA) with 1,1‐diphenylhexyl lithium in tetrahydrofuran (THF) at −40 °C resulted in a multimodal and broad molecular weight distribution (MWD) with poor initiator efficiency. In the presence of additives such as dilithium salt of triethylene glycol (G3Li2), LiCl, and LiClO4, the polymerization resulted in polymers with a narrow MWD (≤ 1.10). Diblock copolymers of methyl methacrylate (MMA) and LMA were synthesized by anionic polymerization using DPHLi as initiator in THF at −40 °C with the sequential addition of monomers. The molecular weight distribution of the polymers was narrow and without homopolymer contamination when LMA was added to living PMMA chain ends. Diblock copolymers with broad/bimodal MWD were obtained with a reverse‐sequence monomer addition. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 875–882, 2004
Sulfonated naphthalene dianhydride based polyimide copolymers for proton‐exchange‐membrane fuel cells. I. Monomer and copolymer synthesis
Authors: Einsla Brian R. , Hong Young‐Taik , Seung Kim Yu , Wang Feng , Gunduz Nazan , McGrath James E.
Published: January 2004

A novel sulfonated diamine, 3,3′‐disulfonic acid‐bis[4‐(3‐aminophenoxy)phenyl]sulfone (SA‐DADPS), was prepared from m‐aminophenol and disodium‐3,3′‐disulfonate‐4,4′‐dichlorodiphenylsulfone. The conditions necessary to synthesize and purify SA‐DADPS in high yields were investigated in some detail. This disulfonated aromatic diamine, containing ether and sulfone linkages, was used to prepare N‐methyl‐2‐pyrrolidinone‐soluble, six‐membered ring polyimide copolymers containing pendent sulfonic acid groups by a catalyzed one‐step high‐temperature polycondensation in m‐cresol. These materials showed much improved hydrolytic stability with respect to phthalimides. High‐molecular‐weight film‐forming statistical copolymers with controlled degrees of disulfonation were prepared through variations in the stoichiometric ratio of disulfonated diamine (SA‐DADPS) in its soluble triethylamine salt form to several unsulfonated diamines. Three unsulfonated diamines, bis[4‐(3‐aminophenoxy)phenyl] sulfone, 4,4′‐oxydianiline, and 1,3‐phenylenediamine, were used to prepare the copolymers. The characterization of the copolymers by 1H NMR, Fourier transform infrared, ion‐exchange capacity, and thermogravimetric analysis demonstrated that SA‐DADPS was quantitatively incorporated into the copolymers. Solution‐cast films of the sulfonated copolymers were prepared and afforded tough, ductile membranes with high glass‐transition temperatures. Methods were developed to acidify the triethylammonium salt membranes into their disulfonic acid form, this being necessary for proton conduction in a fuel cell. The synthesis and characterization of these materials are described in this article. Future articles will describe the performance of these copolymers as proton‐exchange membranes in hydrogen/air and direct methanol fuel cells. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 862–874, 2004
Fully crosslinked poly(styrene‐co‐divinylbenzene) microspheres by precipitation polymerization and their superior thermal properties
Authors: Shim Sang Eun , Yang Sunhye , Choi Hyang Hee , Choe Soonja
Published: January 2004

Fully crosslinked, stable poly(styrene‐co‐divinylbenzene) microspheres, which are composed of various concentrations of divilylbenzene from 5 to 75 mol % based on styrene monomer, were prepared without a significant particle coagulation by the precipitation polymerization. The number‐average particle diameter ranged from 3.5 to 2.8 μm and decreased with an increasing concentration of divinylbenzene in monomer. In addition, the coefficient of variation of the microspheres was slightly reduced with the increasing concentration of divinylbenzene. The circularity and the measured specific surface area indicated that lesser particles are coagulated because of the improved stability of individual particles at a high divinylbenzene concentration and that the resulting particles have a smooth surface without micropores. The glass‐transition temperature was not observed for all microspheres formed from the range of divinylbenzene concentrations. In addition, the onset of the thermal‐degradation temperature was increased from 339.8 to 376.9 °C upon higher contents of divinylbenzene. On the basis of the DSC and thermogravimetric data, the polymer microspheres prepared by the precipitation polymerization possessed a fully crosslinked structure and highly enhanced thermal stability. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 835–845, 2004
Synthesis and characterization of a novel, fluoride‐releasing dimethacrylate monomer and its dental composite
Authors: Xu Xiaoming , Ling Long , Ding Xingzhe , Burgess John O.
Published: January 2004

A novel, fluoride‐releasing dimethacrylate monomer containing zirconium fluoride chelate for use in dental composites was synthesized by an efficient four‐step procedure starting from 4,4‐bis‐(4‐hydroxyphenyl)‐pentanoic acid and was characterized by electrospray mass spectrometry, Fourier transform infrared (FTIR), and 1H and 13C NMR spectroscopies. The synthesized monomer was photopolymerized with camphorquinone and 1‐phenyl‐1,2‐propane‐dione as initiators and N,N‐dimethylaminoethyl methacrylate as an accelerator. The photopolymerization process was investigated by FTIR spectroscopy. The experimental composite containing 13.7 wt % of the synthesized monomer was tested for fluoride release, fluoride recharge, compressive strength, and flexure strength, each in comparison to three commercial flowable dental composites. The results showed that the experimental composite had significantly higher fluoride release and fluoride recharge capabilities than the commercial flowable composites. The flexure strength was comparable to the commercial materials. The water sorption and solubility met the requirements of the International Organization for Standardization 4049 and the American National Standards Institute/American Dental Association Specification Number 27. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 985–998, 2004
Photoluminescent and electrochemical properties of novel copoly(aryl ether)s with isolated fluorophores
Authors: Chen Shinn‐Horng , Hwang Shiao‐Wen , Chen Yun
Published: January 2004

Two, novel copoly(aryl ether)s (P1 and P2) consisting of alternate, isolated electron‐ and hole‐transporting fluorophores were synthesized and characterized. Furthermore, we investigated the optical, photoluminescent (PL), and electrochemical properties of copoly(aryl ether)s P1–P5. The PL spectra of these polymers in film states showed maximum peaks around 420–498 nm. However, compared with the PL spectra of corresponding model compounds M1–M5, the emissions of P1 and P2 were compositions of the two isolated fluorophores, and that of P3 was dominated by the fluorophores with a longer emissive wavelength via the energy transfer. The formation of an interchain interaction in P4 and P5 was also observed. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of these copolymers were measured by cyclic voltammetry. Both the electron and hole affinities could be enhanced simultaneously because of the introduction of isolated hole‐transporting naphthalene (or fluorene) and electron‐transporting bis‐1,3,4‐oxadiazole segments. The single‐layer devices (Al/polymer/indium tin oxide) of P1, P2, and P4 revealed blue or blue‐green electroluminescence, but that of P3 emitted yellow light because of the excimer emission. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 883–893, 2004