bluuebunny/crossref_metadata_2025 huggingface dataset:
Chondrosarcoma of bone: Functional outcome and quality of life
Authors: van der Geest I.C.M. , Servaes P. , Schreuder H.W.B. , Bleijenberg G. , Verhagen C.A.H.H.V.M. , Pruszczynski M. , Lemmens J.A.M. , Veth R.P.H.
Published: October 2002

Background and Objectives

Outcome studies of chondrosarcoma have so far only reported oncological and functional results. Quality‐of‐life assessment becomes more important because more long‐term survival after treatment of malignant diseases occur. The objective of this study is to analyze functional outcome and quality of life.

Methods

Functional evaluation of the patients was carried out according to the MSTS functional scoring system. For assessment of quality of life, questionnaires were used.

Results

Response of the questionnaires sent to 45 disease‐free patients was 84%. The mean functional score of these 38 patients was 74% (20–100%). Best functional results were seen after bone graft reconstruction and curettage and cryosurgery with reconstruction. Quality‐of‐life analysis revealed a mean global health status of 75 (66–84). Furthermore, 24% of the patients experienced severe fatigue. Patients reported more problems with regard to physical functioning and sleep in comparison with healthy controls. No correlation was found between global health status scores and functional scores.

Conclusions

Functional scores depend on the type of treatment with best results after curettage and cryosurgery. Quality‐of‐life analysis reveals problems on several domains, including fatigue, physical functioning and sleep. J. Surg. Oncol. 2002;81:70–74. © 2002 Wiley‐Liss, Inc.
Intraluminal albumin stent assisted laser welding for ureteral anastomosis
Authors: Xie Hua , Shaffer Brian S. , Prahl Scott A. , Gregory Kenton W.
Published: October 2002

Background and Objectives

The success of laser tissue welding or soldering depends on optimal laser settings, solder material, and tissue type and geometry. To develop a practical laser welding technique for ureteral repair, an intraluminal albumin stent was designed to enhance the welding effects on ureteral end to end anastomosis.

Study Design/Materials and Methods

In vitro porcine ureters were anastomosed using an albumin stent alone, the albumin stent plus a solder, and the solder alone. All welding was performed with an 810‐nm diode laser with either a continuous wave (1 W, CW) or two pulse modes (2 W, 3.3 Hz; 1 W, 5 Hz). Laser parameters, tensile strength (TS) and burst pressure (BP) of the ureteral anastomosis, and tissue thermal injury were measured.

Results

In the 2‐W pulse mode, BP in the albumin stent plus solder group (mean 185 mmHg) and the stent only group (mean 133 mmHg) were significantly higher than the solder only group (mean 77 mmHg, P < 0.05). Laser ureteral anastomosis with the stent plus solder group at 1‐W CW and 2‐W pulse laser modes yielded the highest TS (mean 97, 82 g) and BP (mean 183, 185 mmHg). Among the three modes, the 1 W pulse delivered the lowest energy and yielded the lowest TS and BP in ureteral anastomosis. There was no significant difference in the thermal damage to the tissue among the modes and groups.

Conclusions

Using the albumin stent increased the reliability of ureter end‐to‐end laser anastomosis. Further studies will be warranted in vivo and other tubular organs as well. Lasers Surg. Med. 31:225–229, 2002. © 2002 Wiley‐Liss, Inc.
Potential use of diode laser soldering in middle ear reconstruction
Authors: Ditkoff Michael , Blevins Nikolas H. , Perrault Donald , Shapshay Stanley M.
Published: October 2002

Background and Objectives

To assess the potential use of diode laser soldering to improve mechanical stability of middle ear reconstruction. The diode laser with a biological solder may offer benefits over traditional methods. We evaluated the strength of soldered bonds and a means to apply such a technique in the human middle ear.

Study Design/Materials and Methods

The strength of soldered junctions using fascia, cartilage, bone, and hydroxyappatite was evaluated in vitro. A diode laser (810‐nm wavelength) and 50% albumin with 0.1% indocyanine green dye was used. Soldered bonds were compared to those obtained with adhesive alone. A fiberoptic delivery system was evaluated. Ten hydroxyappatite prostheses were soldered to the stapes in human cadaver temporal bones, and the force required to disrupt the bonds were measured.

Results

Statistically significant greater strength was obtained with soldering. Ossicular prostheses can be effectively secured to the stapes in a cadaver model.

Conclusions

Soldering techniques show promise in middle ear reconstruction. Lasers Surg. Med. 31:242–246, 2002. © 2002 Wiley‐Liss, Inc.
Effect of budesonide on the methylation and mRNA expression of the insulin‐like growth factor 2 and c‐myc genes in mouse lung tumors
Authors: Tao Lianhui , Li Yingzhe , Wang Wei , Kramer Paula M. , Gunning William T. , Lubet Ronald A. , Steele Vernon E. , Pereira Michael A.
Published: October 2002

The use of surrogate end‐point biomarkers could help in the development of chemopreventive agents. To define potential surrogate end‐point biomarkers, the ability of budesonide to decrease mRNA expression of the insulin‐like growth factor‐2 (Igf‐II) and c‐myc genes and to cause the remethylation of the genes was investigated in lung tumors. Lung tumors were induced in female strain A mice by administering i.p. 16 mg/kg vinyl carbamate for 2 consecutive wk or by a single dose of 100 mg/kg benzo[a]pyrene (B[a]P). Thirty‐four weeks later, the mice given vinyl carbamate received budesonide (0.6 or 2.4 mg/kg diet) for 7 d and then were killed. Mice were killed 24 wk after administration of B[a]P. The mRNA expression of the Igf‐II and c‐myc genes was increased in lung tumors relative to normal lung tissue. Budesonide decreased mRNA expression of both genes in tumors. The methylation status of 27 CpG sites in the differentially methylated region 2 in the Igf‐II gene was determined with the bisulfite‐treated DNA‐sequencing procedure. The numbers of methylated CpG sites were 17–21 in normal lung (70.4 ± 2.6%); 0–2, and 1–2 in lung tumors induced by vinyl carbamate and B[a]P (4.9 ± 1.2% and 4.6 ± 1.2%, respectively); and 4–5 or 7–16 in tumors after treatment with 0.6 or 2.4 mg/kg budesonide (16.0 ± 1.2% and 46.2 ± 5.1%, respectively). Thus, lung tumors had strikingly less methylated CpG sites than normal lung tissue, while even limited treatment with budesonide resulted in remethylation of the CpG sites in tumors. With HpaII digestion followed by Southern blot analysis, the internal cytosine of CCGG sites in the c‐myc gene was found to be methylated in normal lung tissue, whereas some of the sites were unmethylated in lung tumors. Treatment for 7 d with budesonide resulted in the remethylation of these sites. In conclusion, mouse lung tumors showed decreased methylation of the Igf‐II and c‐myc genes that was associated with increased expression of these genes. Budesonide treatment caused remethylation and decreased expression of both genes. The results support the possibility of using decreased mRNA expression and remethylation of the Igf‐II and c‐myc genes as biomarkers for the efficacy of budesonide. © 2002 Wiley‐Liss, Inc.
Effect of an attentional strategy on movement‐related potentials recorded from subjects with Huntington's disease
Authors: Johnson Katherine A. , Cunnington Ross , Bradshaw John L. , Chiu Edmond , Iansek Robert
Published: October 2002

Huntington's disease patients perform automatic movements in a bradykinetic manner, somewhat similar to patients with Parkinson's disease. Cortical activity relating to the preparation of movement in Parkinson's disease is significantly improved when a cognitive strategy is used. It is unknown whether patients with Huntington's disease can utilise an attentional strategy, and what effect this strategy would have on the premovement cortical activity. Movement‐related potentials were recorded from 12 Huntington's disease patients and controls performing externally cued finger tapping movement, allowing an examination of cortical activity related to movement performance and bradykinesia in this disease. All subjects were tested in two conditions, which differed only by the presence or absence of the cognitive strategy. The Huntington's disease group, unlike controls, did not produce a rising premovement potential in the absence of the strategy. The Huntington's disease group did produce a rising premovement potential for the strategy condition, but the early slope of the potential was significantly reduced compared with the control group's early slope. These results are similar to those found previously with Parkinson's disease patients. The strategy may have put the task, which previously might have been under deficient automatic control, under attentional control. © 2002 Movement Disorder Society
Long‐term course of restless legs syndrome in dialysis patients after kidney transplantation
Authors: Winkelmann Juliane , Stautner Anette , Samtleben Walter , Trenkwalder Claudia
Published: October 2002

Restless legs syndrome (RLS) is a common cause of sleep disturbance and is frequently experienced by hemodialysis patients. Factors triggering the disease in uremia have not yet been identified. To our knowledge, the course of RLS symptoms after kidney transplantation has not been investigated systematically. We investigated the clinical long‐term course of RLS in hemodialysis patients who underwent kidney transplantation. Patients were given a standardized questionnaire three times: at baseline, and twice after their kidney transplants. The severity of RLS was rated by the patients (0 =no symptoms, 10 = very severe symptoms). The description of the final outcome was based on the last follow‐up visit. Eleven of 64 hemodialysis patients with RLS received a transplant (5 men, 6 women; severity of RLS at baseline, 7.8 ± 0.7 [mean ± SEM]). In all patients, RLS symptoms disappeared within 1 to 21 days after transplantation. At follow‐up visits, 4 patients whose transplanted kidneys still functioned well were still free of RLS symptoms up to the longest follow‐up period of 9 years. In 3 other patients, RLS symptoms gradually reappeared (severity, 1 ± 0). In 3 of 11 patients, the transplant failed and RLS symptoms reoccurred within 10 days to 2 months (severity, 7.3 ± 2.6). RLS symptoms reoccurred in 1 patient with failure of the transplant but disappeared again after a second, successful transplant. Kidney transplantation has a strong and positive influence on RLS symptoms in hemodialysis patients. Hemodialysis patients can expect a substantial improvement of RLS symptoms after a successful kidney transplant. © 2002 Movement Disorder Society.
Note on a versatile Liapunov functional: applicability to an elliptic equation
Authors: Flavin J. N. , Rionero S.
Published: October 2002

A novel, very effective Liapunov functional was used in previous papers to derive decay and asymptotic stability estimates (with respect to time) in a variety of thermal and thermo‐mechanical contexts. The purpose of this note is to show that the versatility of this functional extends to certain non‐linear elliptic boundary value problems in a right cylinder, the axial co‐ordinate in this context replacing the time variable in the previous one. A steady‐state temperature problem is considered with Dirichlet boundary conditions, the condition on the boundary being independent of the axial co‐ordinate. The functional is used to obtain an estimate of the error committed in approximating the temperature field by the two‐dimensional field induced by the boundary condition on the lateral surface. Copyright © 2002 John Wiley & Sons, Ltd.
A survey of essential problems in the design of smart antenna system
Authors: Im Heung‐Jae , Choi Seungwon , Choi Byungcho , Kim Hyeongdong , Choi Jaehoon
Published: October 2002

This Letter addresses some problems arising in smart antenna systems (SAS). The problems considered in this Letter are (1) the criterion of computing the weight vector, (2) the number of quantization bits for the weight vector, (3) the selection of the reference antenna element, and (4) what happens in the angle spread? © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 31–34, 2002; DOI 10.1002/mop.10022
Parasitic element dependent scattering parameter evaluation of GaN MESFET
Authors: Singh Adarsh , Bose Srikanta , Gupta Mridula , Gupta R. S.
Published: October 2002

Analytical expressions for parasitic‐element‐dependent scattering parameters of a non‐self‐aligned GaN MESFET are evaluated and their variation with frequency is shown. Maximum stable gain and maximum transducer power gain of the device are also evaluated and it is found that a GaN MESFET with the dimensions (1.5 × 100 μm) has maximum stable gain of about 13 dB. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 54–57, 2002; DOI 10.1002/mop.10230
Scattering characteristics of FSS on two anisotropic layers for incident co‐polarized plane waves
Authors: Campos A. L. P. S. , d'Assunção A. G. , Neto A. Gomes
Published: October 2002

A full‐wave analysis is presented for the scattering problem from a frequency‐selective surface (FSS) comprised of a periodic array of conducting patch elements on two dielectric layers. The formulation is carried out in the spectral domain, where the convolution form of the integral equation for the induced current is reduced to an algebraic one. This equation is then solved with the use of the immittance approach and the moment method in the spectral domain. A set of entire‐domain basis functions is included in the expansion for the unknown induced current. This analysis is computationally efficient. Numerical and experimental results are presented. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 57–61, 2002; DOI 10.1002/mop.10231
Dielectric cover effect on mutual coupling between cylindrical–rectangular microstrip patch elements with the use of the conformal FDTD method
Authors: Lee Byungje , Byun Joonho , Kang Gi‐Cho , Lee Hark‐Yong , Lee Ho‐Joon , Lee Jong‐Chul , Kim Jong‐Heon , Kim Nam‐Young
Published: October 2002

The mutual coupling between cylindrical–rectangular microstrip patch antennas with a cylindrical superstrate is analyzed with the use of the conformal FDTD (CFDTD) method. The method is also applied to antennas mounted on flat structures for comparison. The effects of superstrate permittivity and thickness on the mutual coupling between cylindrical–rectangular microstrip patch antennas are presented. Curvature effects on the mutual coupling are also shown. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 64–68, 2002
Synthesis method and tapering rule choice for tapered nonlinear transmission lines
Authors: Jrad A. , Ferrari P. , Tao J. W.
Published: October 2002

Tapered NLTLs are very interesting for pulse‐compression applications. They allow metallic losses to be minimized and need fewer diodes than classical NLTLs. But their design is not easy due to the choice of the input Bragg frequency and the tapering rule. This Letter proposes a systematic method where input and output Bragg frequencies are automatically fixed. The importance of the tapering rule is also shown. Linear tapering gives better results than geometric. For the same number of diodes, output fall time is smaller and the NLTL is shorter for the same amplitude. The systematic method is applied with linear tapering to GaAs NLTL designed for pulse compression from 16 to 2 ps and shows a great improvement in the output amplitude (more than 50%). The present results are based on SPICE simulations, including diode and linear transmission line dc metallic losses. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 68–71, 2002
Multisection frequency filter consisting of a series of cylindrical resonators loaded with ring gratings
Authors: Khardikov Vyacheslav V. , Kazanskiy Vadim B.
Published: October 2002

The problem of diffraction of cylindrical TEon‐wave on an axial‐symmetric series of N identical inhomogeneous resonators and sections of uniform waveguide is solved by the methods of theory of circuits and matrix functions. The resonator's internal region contains three magnetodielectric layers and a dense grating of conducting rings. The frequency and interference dependencies of the scattered field amplitudes and their dynamics are determined in the cases of strong and weak coupling between the resonators, single‐mode and multi‐mode bands, and high power density at the peripheric region. A correlation between the frequency dependence of the investigated filter and the pass bands of its infinite analogue's eigenwaves are established. The mechanism of exciting super‐high‐Q resonance oscillations absolutely transparent with loss‐free systems is analyzed. A model of the frequency filter with non‐mechanical control is proposed. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 87–90, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10524
Application of the multipole theory method to the analysis of finlines
Authors: Zheng Qinhong , Song Ming
Published: October 2002

In this paper, the multipole theory (MT) method is presented as a new approach for determining the cutoff frequency and analyzing the propagation characteristics of finlines. The inhomogeneous field domain of finline is treated as a combination of several simple homogeneous regions, and the solution of the governing partial differential equation is represented by a generalized MT formula. An extensive comparison with the exact data of the literature and various configurations of the finlines show the accuracy and flexibility of the MT method. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 100–102, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10528
Research on the dynamic performance of MEMS micromirrors
Authors: Enguang Dai , Matin M. A. , Guan Yan
Published: October 2002

This paper presents a series of dynamic problems in developing and characterizing micromirror. A new application of MEMS micromirror‐based fast tunable VCSEL in wavelength routing switching has been proposed. The micromirror dynamic design aspects such as working modal selection, modal sequence shift, dynamic deformation, and electrical parameter fluctuation have been studied. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 111–113, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10531
Sparse approximate inverse preconditioned CG‐FFT algorithm with block toeplitz matrix for fast analysis of microstrip circuits
Authors: Chen R. S. , Tsang K. F. , Yung Edward K. N.
Published: October 2002

In this paper, the multifrontal method is employed to precondition the conjugate gradient (CG) algorithm with the block Toeplitz matrix based fast Fourier transform (FFT) technique for dense matrix equations from the mixed potential integral equation (MPIE) to enhance the computational efficiency of the CG‐FFT algorithm. Our numerical calculations show that the preconditioned CG‐FFT algorithm with this Sparse Approximate Inverse preconditioner can converge hundreds of times faster than the conventional one for the analysis of microstrip. Some typical microstrip discontinuities are analyzed and the good results demonstrate the validity of the proposed algorithm. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 120–125, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10534
Bandstop characteristics of microstrip slotted patch without periodic elements
Authors: Görür Adnan , Karpuz Ceyhun , Tezekici B. Sami , Görür Hülya
Published: October 2002

A rectangular microstrip slotted patch, which provides the bandgap with different manner of a PBG, is successfully demonstrated with the wideband tuning capability. Both experimental and simulated results confirm that the stopband characteristics can easily be controlled by the slot dimensions, especially by the slot length and the slot position. Moreover, the proposed structure is the simple and compact for MMIC applications. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 125–128, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10535
Surface‐mountable dual side‐feed circularly polarized ceramic chip antenna
Authors: Su Chih‐Ming , Wong Kin‐Lu
Published: October 2002

A novel dual side‐feed circularly polarized ceramic chip antenna suitable for surface mounting on a system circuit board is presented. The antenna mainly comprises a square radiating patch, a square ground plane, and two vertical conformal strips for the dual side‐feed, which are printed on the top, bottom and side surfaces of a ceramic chip. For obtaining circular polarization (CP) radiation for global positioning system (GPS) operation at 1575 MHz, a prototype using a square‐disk ceramic chip of dimensions 4 × 17.5 × 17.5 mm3 and relative permittivity 45 was studied, and the experimental results are presented. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 137–138, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10538
An array of stagger‐tuned printed dipoles as a broadband frequency selective surface
Authors: Sarkar D. , Sarkar P. P. , Das S. , Chowdhury S. K.
Published: October 2002

In this paper, the frequency selective property of an array of rectangular dipole microstrip patches resonant at three different frequencies (within the same frequency band) is investigated. Experimental data indicate a prominent band separation between transmission and reflection bands of the F.S.S. in the normalized transmitted electric field vs. frequency plot. Investigation of the F.S.S. of an array of rectangular dipole microstrip patches resonant at a single frequency shows that the bandwidth of the reflection band is very narrow. In our present investigation resonance at triple frequencies within the same frequency band is used to broaden the bandwidth of the reflection band. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 138–140, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10539
A physical approach to generating time frequency distributions of dynamic CEM targets
Authors: Carr M. , Volakis J. L.
Published: October 2002

Generating accurate, high‐resolution time‐frequency distributions (TFD) is a critical aspect of dynamic radar scattering analysis. Well‐formed TFD's can be used for target identification, target acquisition in high‐noise environments, or extending the range of radar systems. In this paper, we diverge from traditional methods employing complex signal‐processing methods and propose a simple approach for constructing the TFD for computational electromagnetic (CEM) targets based on the physics of the problem. The proposed method allows for an arbitrarily high resolution at any single look angle. Several examples are presented to validate the method. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 186–189, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10552
Slotted ground plane for frequency tunable dielectric resonator antenna
Authors: Huang Chih‐Yu
Published: October 2002

A technique for effectively tuning the resonant frequency of a microstripline feed dielectric resonator (DR) antenna is demonstrated. By embedding a pair of narrow slots in the antenna's ground plane, the resonant frequency of the DR antenna can be varied by adjusting the embedded slot length. Experimental results of the proposed frequency tunable DR antenna are presented and discussed. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 193–195, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10554
Neural network based time domain modelling of 0.18 μm MOSFETs
Authors: Toner B. , Alam M. S. , Fusco V. F. , Armstrong G. A.
Published: October 2002

In this paper a new time domain based neural network model of a 0.18 μm RF MOSFET will be demonstrated. The model consists of only three intrinsic non‐linear current sources, each being modelled by a neural network derived from large signal time domain voltage/current waveform measurements at the intrinsic device terminals. This approach negates the traditional method of multi‐bias S‐parameter measurement providing a fast and accurate method of modelling the transistor under large signal conditions. Full verification of the model will be provided against an 80 μm/0.18 μm MOSFET operating at 2.4 GHz. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 203–206, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10558
A procedure to design aperture‐coupled stacked‐microstrip antenna based on experiment
Authors: Zhang Yabin , Li Binhong , Liu Yijun
Published: October 2002

The aperture‐coupled stacked‐microstrip antenna (ACSMA) is an important type of broadband microstrip antenna. A simple and practical procedure for its design is presented in this letter. Utilizing the technique, one ACSMA of L‐band has been designed. The experiments have been carried out and the measurement results verified the applicability of the method. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 244–247, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10569
Full‐wave modelling of offset overlap and gap discontinuity for asymmetric strip conductors in multi‐layered MIC environment
Authors: Shukla Rajiv Kumar , Biswas Animesh
Published: October 2002

A generalised model for characterising the frequency dependent properties of general offset overlap and gap discontinuity of asymmetric strip conductors in multi‐layered MIC environment is presented in this paper. The transverse resonance technique is applied in transformed domain to extract the equivalent PI‐circuit parameters of the discontinuity. The incorporation of options for offset between the strips and asymmetry in strip widths make the present model very general and useful for different structures in multi‐layered substrate environment. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 247–251, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10570
Transfection of embryonal carcinoma cells at high efficiency using liposome‐mediated transfection
Authors: Nowling Tamara , Desler Michelle , Kuszynski Charles , Rizzino Angie
Published: October 2002

Embryonal carcinoma (EC) cells are recognized as an excellent model system for studying the early stages of mammalian development. Many studies performed with EC cells involve transient transfection with promoter/reporter gene constructs and/or mammalian expression vectors. One of the limitations of working with EC cells is their inability to be transfected at high efficiency. In most cases, EC cells are transfected using the calcium phosphate method. The objective of this study was to identify protocols and culture conditions that significantly increase the transfection efficiency of EC cells. F9 EC cells were used for this purpose, because they are the EC cell line studied most commonly. We show that the transfection efficiency of F9 EC cells using the calcium phosphate method is less than 5%; whereas, their transfection efficiency can be improved ∼15‐fold using optimized culture conditions and liposome‐based transfection reagents. Specifically, we demonstrate that more than 50% of F9 EC cells can be transfected using LipofectAMINE 2000. In addition to higher levels of transfection, there is much less plate‐to‐plate variation with liposome‐based reagents as compared to transfection with calcium phosphate. Interestingly, transfection efficiency using these reagents was found to be inversely related to cell density. This contrasts sharply with the recommendation that transfection with LipofectAMINE 2000 or LipofectAMINE in conjunction with the PLUS reagent be performed at high cell densities. Given the improvements in transfection efficiency reported here, it will now be possible to perform studies with F9 EC cells that require transfection at significantly higher levels than that achieved using the calcium phosphate method. Overall, the highest transfection efficiencies were consistently obtained using LipofectAMINE 2000. Mol. Reprod. Dev. 63: 309–317, 2002. © 2002 Wiley‐Liss, Inc.
Developmental changes in inhibitory effects of arsenic and heat shock on growth of pre‐implantation bovine embryos
Authors: Krininger III C.E. , Stephens S.H. , Hansen P.J.
Published: October 2002

Although sensitive to various disrupters, pre‐implantation embryos possess some cellular cytoprotective mechanisms that allow continued survival in the face of a deleterious environment. For stresses such as heat shock, embryonic resistance increases as development proceeds. Present objectives were to determine whether (1) arsenic compromises development of pre‐implantation bovine embryos, (2) developmental changes in embryonic resistance to arsenic mimic those seen for resistance to heat shock, and (3) developmental patterns in induction of apoptosis by arsenic are correlated with similar changes in resistance of embryos to inhibitory effects of arsenic on development. Bovine embryos produced by in vitro fertilization were exposed at the two‐cell stage or at day 5 after insemination (embryos ≥ 16‐cells in number) to either sodium arsenite (0, 1, 5, or 10 μM) or heat shock (exposure to 41°C for 0, 3, 4.5, 6, or 9 hr). Arsenic induced apoptosis and increased group 2 caspase activity for embryos at the ≥ 16‐cell stage, but not for embryos at the two‐cell stage. In contrast to these developmental changes in apoptosis responses, exposure to arsenic reduced cell number 24 hr after exposure for both two‐cell embryos and embryos ≥ 16‐cells. Similarly, the percentage of embryos that developed to the blastocyst stage at day 8 after fertilization was reduced by arsenic exposure at both stages of development. Heat shock, conversely, reduced development to the blastocyst stage when applied at the two‐cell stage, but not when applied to embryos ≥ 16‐cells at day 5 after insemination. In conclusion, arsenic can compromise development of bovine pre‐implantation embryos, the temporal window of sensitivity of embryos to arsenic is wider than for heat shock, and cellular cytoprotective responses that embryos acquire for thermal resistance are not sufficient to cause increased embryonic resistance to arsenic exposure. It is likely that despite common cellular pathologies caused by arsenic and heat shock, arsenic acts to reduce development in part through biochemical pathways not activated by heat shock. Moreover, the embryo does not acquire significant resistance to these perturbations within the time frame in development examined. Mol. Reprod. Dev. 63: 335–340, 2002. © 2002 Wiley‐Liss, Inc.
“Soap‐Bubble” visualization and quantitative analysis of 3D coronary magnetic resonance angiograms
Authors: Etienne Alex , Botnar René M. , van Muiswinkel Arianne M.C. , Boesiger Peter , Manning Warren J. , Stuber Matthias
Published: October 2002

In order to compare coronary magnetic resonance angiography (MRA) data obtained with different scanning methodologies, adequate visualization and presentation of the coronary MRA data need to be ensured. Furthermore, an objective quantitative comparison between images acquired with different scanning methods is desirable. To address this need, a software tool (“Soap‐Bubble”) that facilitates visualization and quantitative comparison of 3D volume targeted coronary MRA data was developed. In the present implementation, the user interactively specifies a curved subvolume (enclosed in the 3D coronary MRA data set) that closely encompasses the coronary arterial segments. With a 3D Delaunay triangulation and a parallel projection, this enables the simultaneous display of multiple coronary segments in one 2D representation. For objective quantitative analysis, frequently explored quantitative parameters such as signal‐to‐noise ratio (SNR); contrast‐to‐noise ratio (CNR); and vessel length, sharpness, and diameter can be assessed. The present tool supports visualization and objective, quantitative comparisons of coronary MRA data obtained with different scanning methods. The first results obtained in healthy adults and in patients with coronary artery disease are presented. Magn Reson Med 48:658–666, 2002. © 2002 Wiley‐Liss, Inc.
Fast 31P chemical shift imaging using SSFP methods
Authors: Speck O. , Scheffler K. , Hennig J.
Published: October 2002

Steady‐state free precession (SSFP) methods have been very successful due to their high signal and short imaging times. These properties make them good candidates for applications that intrinsically suffer from low signal such as low gamma nuclei imaging. A new chemical shift imaging (CSI) technique based on the SSFP signal formation has been implemented and applied to 31P. The signal properties of the SSFP CSI method have been evaluated and the steady‐state signal of 31P has been measured in human muscles. Due to the T2 and T1 signal dependence of SSFP, the steady‐state signal mainly consists of phosphocreatine (PCr). The technique allows fast CSI acquisitions with high SNR of the PCr signal. The SNR gain for PCr over a FLASH‐based CSI method is approx. 4–5. Fast in vivo CSI of human muscle with subcentimeter resolution and high SNR is demonstrated at 2 T. Magn Reson Med 48:633–639, 2002. © 2002 Wiley‐Liss, Inc.
Somatosensory evoked potentials following stimulation of digital nerves
Authors: Kwast‐Rabben Olga , Libelius Rolf , Heikkilä Hannu
Published: October 2002

Cortical and spinal somatosensory evoked potentials (SEP) were recorded in healthy individuals following stimulation of digits I, III, and V with an intensity below discomfort level. Peak latency of the earliest cortical negativity (N1) was found to be the most consistent and easily measured parameter, whereas a spinal potential (Cv) was not elicited in all subjects. Descriptive statistics, Student's paired t‐test as well as simple and multiple regression, were used for computer analysis of N1 and Cv peak latencies and central conduction time. The results show a strong correlation between the peak latencies of spinal and cortical potentials and height and arm length of the subjects, with a mild but significant correlation with age. Using multiple regression for N1 and Cv latencies significantly improved the standard deviation. The data may provide reference values for neurophysiological evaluation of patients with cervical spine disorders. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 533–538, 2002
Solving generalized transportation problems via pure transportation problems
Authors: Sterbin Gottlieb Elsie
Published: October 2002

This paper investigates certain issues of coefficient sensitivity in generalized network problems when such problems have small gains or losses. In these instances, it might be computationally advantageous to temporarily ignore these gains or losses and solve the resultant “pure” network problem. Subsequently, the optimal solution to the pure problem could be used to derive the optimal solution to the original generalized network problem. In this paper we focus on generalized transportation problems and consider the following question: Given an optimal solution to the pure transportation problem, under what conditions will the optimal solution to the original generalized transportation problem have the same basic variables? We study special cases of the generalized transportation problem in terms of convexity with respect to a basis. For the special case when all gains or losses are identical, we show that convexity holds. We use this result to determine conditions on the magnitude of the gains or losses such that the optimal solutions to both the generalized transportation problem and the associated pure transportation problem have the same basic variables. For more general cases, we establish sufficient conditions for convexity and feasibility. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 666–685, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10034
GPCG–generalized preconditioned CG method and its use with non‐linear and non‐symmetric displacement decomposition preconditioners
Authors: Blaheta Radim
Published: October 2002

The paper investigates a generalization of the preconditioned conjugate gradient method, which uses explicit orthogonalization of the search directions. This generalized preconditioned conjugate gradient (GPCG) method is suitable for solving the symmetric positive definite systems with preconditioners, which can be non‐symmetric or non‐linear. Such preconditioners can arise from computing of the pseudoresiduals by some additive or multiplicative space decomposition method with inexact solution of the auxiliary subproblems by inner iterations. The non‐linear and non‐symmetric preconditioners based on displacement decomposition for solving elasticity problems are described as an example of such preconditioners. Copyright © 2002 John Wiley & Sons, Ltd.
Relationship between morphology structure and composition of polycaprolactone/Poly(ethylene oxide)/Polylactide copolymeric microspheres
Authors: Li Guangming , Cai Qing , Bei Jianzhong , Wang Shenguo
Published: October 2002

A novel tri‐component copolymer, polycaprolactone/poly(ethylene oxide)/polylactide (PCEL) was synthesized. The effect of the chemical composition on physical properties was investigated by using NMR, differential scanning calorimetry (DSC) and X‐ray diffraction. Both the soft segment poly(ethylene oxide) (PEO) and polycaprolactone (PCL) could enhance the mobility of polymer chains and decrease the crystallizability of the copolymers. The polymeric microspheres, which are of interest for drug delivery systems, were prepared using an emulsification‐solvent evaporation technique. By scanning electron microscopy (SEM) and atomic force microscopy (AFM), the surface morphology of the microspheres was studied. It was found that the presence of PEO segment could improve the hydrophilicity of the copolymers and the morphology of the polymeric microspheres could be altered by adjusting the chemical composition. The accumulation of PEO segments on the outer surface of the polymeric microspheres was proven by X‐ray photoelectron spectroscopy (XPS). It had also been proven that the PCL segment could facilitate the movement of PEO segment to the outer surface. Copyright © 2002 John Wiley & Sons, Ltd.
Preparation and characterization of conducting poly(acryloyl chloride)‐g‐ polypyrrole copolymer
Authors: Park Yun Heum , Kim Kwang Won , Jo Won Ho
Published: October 2002

The electroactive copolymer of poly(acryloyl chloride) (PAC) and polypyrrole (PPy) can be synthesized by electrochemical polymerization using a polymer precursor which contains a pyrrole moiety in its side chain. Poly(acryloyl pyrrole) (PAP) was synthesized chemically with acryloyl chloride and potassium pyrrole salt and characterized using FT‐IR and 1H‐NMR spectroscopy. PAP dissolved in dimethyl formamide (DMF), was spin‐coated on a platinum electrode and polymerized electrochemically in the electrolytic mixture solution consisting of acetonitrile, 0.1 M pyrrole, and 0.1 M lithium perchlorate. Constant potential electrolysis showed that pyrrole groups in the precursor were oxidized to form PPy, that is, they acted as grafting centers at which the PPy grew. Scanning electron microscopy (SEM) results and conductivity measurements supported the formation of the graft copolymer. The morphological feature of PAC‐g‐PPy copolymer films showed homogeneous structure, but that of PAC/PPy composite films showed irregular structure. The maximum conductivity of the final products was about 1 S/cm. Copyright © 2002 John Wiley & Sons, Ltd.
The spectrum of review articles published by The Journal of Pathology
Authors: Herrington Simon
Published: October 2002

The Journal of Pathology publishes a variety of types of ‘review’ material. This editorial describes the range of such material and identifies specific categories of contribution, namely editorial, commentary, perspective, and review. The editorial committee would welcome suggestions for topics and authors from the Journal's readership. Copyright © 2002 John Wiley & Sons, Ltd.
Birth defect classification by organ system: a novel approach to heighten teratogenic signalling in a pregnancy registry
Authors: Scheuerle Angela , Tilson Hugh
Published: October 2002

The Antiretroviral Pregnancy Registry (APR) is an ongoing international prospective exposure‐registration cohort study that monitors outcomes of pregnancies exposed to marketed antiretroviral medications. The population of women exposed to antiretrovirals remains relatively small, which limits the power of the registry. In order to maximize identification of a teratogenic signal, a special birth defect classification system was devised. Birth defects were organized based upon organ system and embryology, using the Metropolitan Atlanta Congenital Defects Program as a model. Grouping defects that share embryology and pathogenesis increases the likelihood that a teratogenic effect will be apparent. The result is a three‐tiered system: organ system, preferred defect term, and reported defect term. This system is text based, which eliminates the need to memorize codes and allows use by anyone familiar with medical terminology. Once established, the new APR Organ System Classification retains enough flexibility that categories may be collapsed or expanded as experience grows. Standardized nomenclature also minimizes variation introduced by collecting defect reports from many different sources. Copyright © 2002 John Wiley & Sons, Ltd.
Pharmacovigilance of over‐the‐counter products based in community pharmacy: methodological issues from pilot work conducted in Hampshire and Grampian, UK
Authors: Layton D. , Sinclair H. K. , Bond C. M. , Hannaford P. C. , Shakir S. A. W.
Published: October 2002

Purpose

The incidence of serious adverse events from non‐prescription medicines remains to be established. The aim of this initial pilot work, using an observational cohort design, was to determine the feasibility of conducting a pharmacovigilance study of a non‐prescription medicine, based in community pharmacies.

Method

Community pharmacists from Grampian, Scotland, and Hampshire, England, recruited user‐purchasers of ibuprofen. Exposure data were collected from a series of self‐completed questionnaires. Outcome data were any new symptoms, use of concomitant medication and subsequent health‐care utilization.

Results

A total of 1021 eligible customers were recruited, 6.4% (466/7320) and 48.2% (555/1152) by the Hampshire and Grampian networks respectively. The cohorts differed with regard to age, smoking and socio‐economic status, reason for purchase and recommendation, and duration of use. The two cohorts reported different use of concomitant medication (46.0 and 65.5%), asthma (7.2 and 10.5%), stomach/peptic ulcer (3.5 and 2.1%), a higher prevalence of gastrointestinal symptoms post‐compared to pre‐purchase (12.9 vs. 7.2%, p=0.0006 and 8.8 vs. 5.8%, p=0.034), ingestion of doses in excess of the licensed non‐prescription dose by 5.1 and 3.9%, and discontinuation of treatment because the medicine upset them by 4.5 and 3.1%, respectively. Most participants did not seek medical advice for their symptoms.

Conclusion

Greater vigilance is required for adverse events that may be attributable to non‐prescription product use. Development of pharmacovigilance models using community pharmacies is one means of systematically collecting information regarding drug safety. Further work is needed to identify a method which maximizes patient recruitment whilst maintaining acceptable follow‐up rates. Copyright © 2002 John Wiley & Sons, Ltd.
Substituent effects in reductions of heteroaromatic cations
Authors: Heyes David , Menon Ramesh S. , Watt C. Ian. F. , Wiseman Jake , Kubinski Przemyslaw
Published: October 2002

A set of 11 each of 2,4,6‐triphenylpyrylium, ‐thiopyrylium and ‐N‐methylpyridinium tetrafluoroborates carrying a range of substituents in the phenyl rings were prepared. First and second wave reduction potentials were determined. For the thiopyrylium series there are linear correlations between scaled potentials (E°/0.05915) and summed Hammett constants for substituents in the pendant phenyl groups (σ = 2.29 and 3.38 for first and second waves respectively). For the pyrylium series, a good linear relationship (σ = 2.79) is obtained for all substituent patterns for the first wave reduction potentials, but for the second wave there are separate correlations for salts carrying substituents in the 4‐phenyl and for those carrying substituents in 2‐ and 6‐phenyls. For the pyridinium series, the first wave potentials show separate correlations for salts carrying substituents in the 4‐phenyl and for those carrying substituents in 2‐and 6‐phenyls, but a single linear relationship for the second wave potentials. These are related to particular structural features in the cations, radicals and anions in each series. Rates and products were determined for reductions of the pyrylium and thiopyrylium cations by sodium cyanoborohydride and of all cations by sodium borohydride in acetonitrile solution. Reactions are first order in reducing agent and cation. Primary kinetic isotope effects were determined for borohydride reduction of the least reactive of each of the series of cations. Plots of logarithms of second‐order rate constants against summed Hammett constants for substituents in the pendant phenyl groups are linear for all combinations of reagent and cation with 0.91 < σ < 1.50 across all substituent patterns. For parent pyrylium and thiopyryliums, kBH4/kCNBH3 = 8.4 × 104 and 1.5 × 104, respectively, and for reductions by borohydride the reactivities of the pyrylium, thiopyrylium and pyridinium, series decrease in the order 1.4 × 105:8.8 × 103:1. Constant selectivities are not observed. Comparison of the correlations for electrochemical reduction and for hydride addition leads to the conclusion that charge neutralization in the hydride addition transition states runs ahead of bonding changes at the originating B—H bond. Copyright © 2002 John Wiley & Sons, Ltd.
Classifications of families of homologous organic compounds based on energy by means of ab initio ­HF, MP2 and DFT optimizations
Authors: Neugebauer Alexander , Häfelinger Günter
Published: October 2002

A method is suggested for combining the quantum chemical principle of isolated molecules and the systematics of homologous families for different functional groups in traditional organic chemistry. The classification of organic compounds is performed by statistical treatments of fundamental quantum mechanical quantities such as total and partial energies. We used the total energies (computed by DFT BLYP and B3LYP, HF and MP2 methods, which are size‐extensive, applying the 6–31 G** and some other basis sets) of isolated molecules obtained by gradient optimizations to classify homologous series of organic compounds by linear least‐squares regressions versus the total number of electrons. Two numerical parameters, slope (h) and intercept (s), are obtained characterizing each family of homologous compounds. Families of for example 17 different functional groups of the same CH2‐homologous unit are grouped on parallel lines with the same slope h, differing only in their s parameters. Isomeric compounds differ in their s values if they belong to the same homologous unit. Compounds of other homologous units (conjugated alkenes, cumulenes and benzenoides) are found with different slopes h on regression lines. Energy partitioning leads also to linear regressions of different statistical accuracy for the components which add fully to the observed h and s parameters. The h and s parameters allow the prediction of unknown total energies of homologous compounds from total energies of a subset of smaller compounds which belong to the same homologous family. Likewise, atomization energies can be predicted using the derived h and s parameters. Copyright © 2002 John Wiley & Sons, Ltd.