bluuebunny/crossref_metadata_2025 huggingface dataset:
Adenocarcinoma arising from a gastric duplication cyst with invasion to the stomach: a case report with literature review
Authors: Kuraoka K , Nakayama H , Kagawa T , Ichikawa T , Yasui W
Published: March 2004

This report describes a rare case of adenocarcinoma arising from a gastric duplication cyst, with invasion to the stomach wall, in a 40 year old Japanese man. A cystic lesion was found between the stomach and the spleen. The cyst had a well circumscribed smooth muscle layer, corresponding to the muscularis propria of the stomach and the mucosa of the alimentary tract. A well differentiated adenocarcinoma was found within the duplication cyst, invading its serosa. Well differentiated adenocarcinoma was independently found in the fundus of the stomach; the tumour of the cyst was connected by fibrous tissue. Microscopically, there was neither adenocarcinoma in situ nor precancerous lesions, such as epithelial dysplasia, suggesting that the carcinoma derived from a gastric duplication cyst that invaded the stomach. Duplication cysts should be included in the differential diagnosis of cystic masses of the gastrointestinal tract, and the possibility of malignancy within these cysts should be considered.
THZ-FREQUENCY SPECTROSCOPIC SENSING OF DNA AND RELATED BIOLOGICAL MATERIALS
Authors: GLOBUS T. , WOOLARD D. , BYKHOVSKAIA M. , GELMONT B. , WERBOS L. , SAMUELS A.
Published: March 2004

The terahertz frequency absorption spectra of DNA molecules reflect low-frequency internal helical vibrations involving rigidly bound subgroups that are connected by the weakest bonds, including the hydrogen bonds of the DNA base pairs, and/or non-bonded interactions. Although numerous difficulties make the direct identification of terahertz phonon modes in biological materials very challenging, recent studies have shown that such measurements are both possible and useful. Spectra of different DNA samples reveal a large number of modes and a reasonable level of sequence-specific uniqueness. This chapter utilizes computational methods for normal mode analysis and theoretical spectroscopy to predict the low-frequency vibrational absorption spectra of short artificial DNA and RNA. Here the experimental technique is described in detail, including the procedure for sample preparation. Careful attention was paid to the possibility of interference or etalon effects in the samples, and phenomena were clearly differentiated from the actual phonon modes. The results from Fourier-transform infrared spectroscopy of DNA macromolecules and related biological materials in the terahertz frequency range are presented. In addition, a strong anisotropy of terahertz characteristics is demonstrated. Detailed tests of the ability of normal mode analysis to reproduce RNA vibrational spectra are also conducted. A direct comparison demonstrates a correlation between calculated and experimentally observed spectra of the RNA polymers, thus confirming that the fundamental physical nature of the observed resonance structure is caused by the internal vibration modes in the macromolecules. Application of artificial neural network analysis for recognition and discrimination between different DNA molecules is discussed.
Fundamentals of Terrestrial Millimeter-Wave and THz Remote Sensing
Authors: Brown E. R.
Published: March 2004

Having long been the realm of molecular chemistry, astronomy, and plasma diagnostics, the upper millimeter-wave band (~100 to 300 GHz) and the THz region above it have recently become the subject of heightened activity in the engineering community because of exciting new technology (e.g., sub-picosecond optoelectronics) and promising new "terrestrial" applications (e.g., counter-terrorism and medical imaging). The most challenging of these applications are arguably those that demand remote sensing at a stand-off of roughly 10 m or more between the target and the sensor system. As in any other spectral region, remote sensing in the THz region brings up the complex issues of sensor modality and architecture, free-space electromagnetic effects and components, transmit and receive electronics, signal processing, and atmospheric propagation. Unlike other spectral regions, there is not much literature that addresses these issues from a conceptual or system-engineering viewpoint. So a key theme of this chapter is to review or derive the essential engineering concepts in a comprehensive fashion, starting with fundamental principles of electromagnetics, quantum mechanics, and signal processing, and building up to tradc-off formulations using system-level metrics such as noise-equivalent power and receiver operating characteristics. A secondary theme is to elucidate aspects of the THz region and its incumbent technology that are unique, whether advantageous or disadvantageous, relative to other spectral regions. The end goal is to provide a useful tutorial for graduate students or practicing engineers considering the upper mm-wave or THz regions for system research or development.
TERAHERTZ EMISSION USING QUANTUM DOTS AND MICROCAVITIES
Authors: SOLOMON GLENN S. , XIE ZHIGANG , AGRAWAL MUKUL
Published: March 2004

Semiconductor solid-state lasers based on conduction-valence band recombination are now commonplace for low-power red emission, and are available commercially at nearly continuous wavelengths throughout the near-UV and near-IR communications bands. Furthermore, new lasers and broadband spontaneous emission sources are available through a wide wavelength range, including 3-8μm based on both conduction-valence band and intersubband transitions, and up to 70μm using cascaded intersubband transitions. Competing processes make the design of these semiconductor lasers extremely difficult when extended to the very long, 300μm wavelength regime corresponding to low terahertz frequencies. We discuss material and device-design considerations for extending semiconductor lasers to this regime. We suggest a new set of device structures based on a semiconductor quantum dot (QD) gain medium, where the lasing occurs through discrete conduction states. In one implementation, two QDs are coupled to make a coupled-asymmetric quantum dot (CAD) laser. In another implementation, an ensemble of non-coupled QDs is selectively placed in a high quality cavity, called a microdisk, which is resonant with an intersublevel QD transition. We demonstrate the initial fabrication of these structures.
TERAHERTZ TRANSPORT IN SEMICONDUCTOR QUANTUM STRUCTURES
Authors: ALLEN S. J. , SCOTT J. S.
Published: March 2004

Photon assisted transport, dynamic localization and absolute negative conductance appear in the terahertz photoconductivity in semiconductor quantum structures and are close analogs of quasi-particle transport in microwave irradiated superconducting junctions. By embedding superlattice devices in quasi-optical arrays and integrating them into terahertz cavities, the dynamical conductance of electrically biased superlattices can be measured. Models including the complications of electric field domains can account for the results in a semi quantitative manner. Uniform electrically biased superlattices appear to be potentially important as a terahertz gain medium.
Advanced Theory of Instability in Tunneling Nanostructures
Authors: Woolard D. L. , Cui H. L. , Gelmont B. L. , Buot F. A. , Zhao P.
Published: March 2004

This work is concerned with the quantum structure of resonant tunneling diodes, which exhibits intrinsic instability that can be exploited for the development of high-speed, high-frequency devices. The article examines in detail the physics underlying the non-liner instability, in both a one-band model and a multiple-band model. The theoretical basis of the description of electronic processes in such structures are described in some detail in terms of nonequilibrium Green's functions. Also presented here is a semi-phenomenological model of the resonant tunneling diode based on nonlinear circuit theory. Recent works and progresses in this and related areas are summarized here as well.
Wigner Function Simulations of Quantum Device-Circuit Interactions
Authors: GRUBIN H. L. , BUGGELN R. C.
Published: March 2004

Issues associated with modeling of quantum devices within the framework of the transient Wigner equation are addressed. Of particular importance is the structure of the Wigner function, hysteresis, and device switching time, whose value is determined by the large signal device properties.
POWER-LOW EXPANSION IN k-ESSENCE COSMOLOGY
Authors: CHIMENTO LUIS P. , FEINSTEIN ALEXANDER
Published: March 2004

We study spatially flat isotropic universes driven by k-essence. It is shown that Friedmann and k-field equations may be analytically integrated for arbitrary k-field potentials during evolution with a constant baryotropic index. It follows that there is an infinite number of dynamically different k-theories with equivalent kinematics of the gravitational field. We show that there is a large "window" of stable solutions, and that the dust-like behavior separates stable from unstable expansion. Restricting to the family of power law solutions, it is argued that the linear scalar field model, with constant function F, is isomorphic to a model with divergent speed of sound and this makes them less suitable for cosmological modeling than the nonlinear k-field solutions we find in this paper.
TRANSVECTANT, INTEGRABILITY AND THE BORN–INFELD EQUATION
Authors: GUHA PARTHA
Published: March 2004

We show some interesting relation between the Born–Infeld and Chaplygin gas equation and its connection to transvectant and Euler–Poincaré flows on infinite dimensional group.
LATTICE QCD AT THE END OF 2003
Authors: DEGRAND THOMAS
Published: March 2004

We review recent developments in lattice QCD. We first give an overview of its formalism, and then discuss lattice discretizations of fermions. We then turn to a description of the quenched approximation and why it is disappearing as a vehicle for QCD phenomenology. We describe recent claims for progress in simulations which include dynamical fermions and the interesting theoretical problems they raise. We conclude with brief descriptions of the calculations of matrix elements in heavy flavor systems and for kaons.
AN $\mathcal{N}=1$ TRIALITY BY SPECTRUM MATCHING
Authors: MISRA A.
Published: March 2004

On promoting the type IIA side of the [Formula: see text] heterotic/type IIA dual pairs of Ref. 1 to M-theory on a "barely G2 manifold" of Ref. 2, by spectrum-matching we show a possible triality between heterotic, M and F theories. The manifolds that figure in this triality are a self-mirror Calabi–Yau, a barely G2 manifold and an elliptically fibered Calabi–Yau four-fold with trivially rationally ruled CP1× Enriques surface base, respectively. We raise an apparent puzzle on the F-theory side, namely, the Hodge data of the 4-fold derived cannot be obtained by a naive freely acting orbifold of CY 3(3,243)×T2 as one might have guessed on the basis of arguments related to dualities involving string, M and (definition of) F theories. There are some interesting properties of the antiholomorphic involution used in Ref. 1 for constructing the type IIA orientifold and by us in constructing the "barely G2 manifold," that we also study.
PATH INTEGRAL TREATMENT OF SINGULAR PROBLEMS AND BOUND STATES
Authors: CAMBLONG HORACIO E. , ORDÓÑEZ CARLOS R.
Published: March 2004

A path-integral approach for the computation of quantum-mechanical propagators and energy Green's functions is presented. Its effectiveness is demonstrated through its application to singular interactions, with particular emphasis on the inverse square potential — possibly combined with a delta-function interaction. The emergence of these singular potentials as low-energy nonrelativistic limits of quantum field theory is highlighted. Not surprisingly, the analog of ultraviolet regularization is required for the interpretation of these singular problems.
TRANSFER MATRIX METHOD FOR THE FRÖHLICH ELECTRON–INTERFACE OPTICAL PHONON INTERACTION IN MULTILAYER COAXIAL CYLINDRICAL QUANTUM-WELL WIRES
Authors: ZHANG LI , XIE HONG-JING
Published: March 2004

Under dielectric continuum approximation, by adopting the transfer matrix method, interface optical (IO) phonon modes and the Fröhlich electron–IO-phonon interaction Hamiltonian in a multilayer coaxial cylindrical quantum-well wire (QWW) were deduced and investigated. Numerical calculations on a four-layer GaAs / Al x Ga 1-x As QWW have been performed. Results reveal that there are six branches of IO phonon modes. When the wave vector in z-direction kz and the azimuthal quantum number m are small, the dispersion frequencies of IO modes sensitively depend on kz and m. When kz and m are relatively large, with the increasing of kz and m, the frequency for each mode converges the limit frequency value of IO mode in single heterostructure, and the electrostatic potential distribution of each mode tends to be more and more localized at the interfaces, meanwhile, the coupling between the electron–IO-phonon becomes weaker and weaker. The calculation also shows that the phonon modes with higher frequencies have more significant contribution to the electron–phonon interaction. At last, it is found that kz and m have analogous effects on the frequencies and the electrostatic potentials of the IO phonons.
GRAVITATIONAL COLLAPSE OF SPHERICAL STRING FLUIDS
Authors: GHOSH SUSHANT G. , SASTE N. N.
Published: March 2004

We discuss the spherical collapse of a two fluid system: a string fluid and a null fluid described by a generalized Vaidya metric. This led us to explicitly describe the effect of a string fluid on the established picture of a null fluid collapse (Vaidya collapse). It is found that there is a shrinkage of the initial data space for naked singularities of Vaidya collapse upon taking into account a string fluid. The implications of the results in the context of the cosmic censorship conjecture are discussed.
EXPONENTIAL STRETCH–ROTATION FORMULATION OF EINSTEIN'S EQUATIONS
Authors: KHOKHLOV ALEXEI , NOVIKOV IGOR
Published: March 2004

We study an exponential stretch–rotation (ESR) transformation, γij=e∊ikmθmeϕke-∊jknθn, of a three-dimensional metric γij of space-like hypersurfaces embedded in a four-dimensional space–time, where ϕk are logarithms of the eigenvalues of γij, θk are rotation angles, and ∊ijk is a fully anti-symmetric symbol. This tensorial exponential transformation generalizes particular exponential transformations used previously in cases of spatial symmetry. General formulae are derived that relate γij and its differentials to ϕk, θk and their differentials in a compact form. The evolution part of Einstein's equations formulated in terms of ESR variables describes time evolution of the metric at every point of a hyper-surface as a continuous stretch and rotation of a triad associated with the main axes of the metric tensor in a tangential space. An ESR 3+1 formulation of Einstein's equations may have certain advantages for long-term stable integration of these equations.
PERIODICITY IN DAILY VARIATION OF COSMIC RAY INTENSITY AS AN EFFECT OF SOLAR POLOIDAL MAGNETIC FIELD ORIENTATION
Authors: MISHRA REKHA AGARWAL , MISHRA RAJESH K.
Published: March 2004

A detailed analysis of the Deep River neutron monitor (NM) data for four different phases of solar activity cycle and for four groups of days chosen according to their different geomagnetic conditions is being carried out. It is found that the 60 quiet day (QD) in a year serve a better purpose for investigating the short/long term variation in cosmic ray (CR) intensity. Furthermore, data has been harmonically analysed for the period 1964–95 to investigate the effect of solar poloidal magnetic field (SPMF) orientation in daily variation (diurnal/semi-diurnal) of CR on geomagnetically QD. The phase of the diurnal and semi-diurnal anisotropy vectors on QD has shown a significant shift to early hours when the SPMF in the northern hemisphere (NH) is positive during the periods 1971–79 and 1992–95 as compared to that during the periods 1964–70 and 1981–90 when the SPMF in NH is negative, showing a periodic nature of daily variation in CR intensity with SPMF.
THE NORMAL INVERSE GAUSSIAN DISTRIBUTION AND SPOT PRICE MODELLING IN ENERGY MARKETS
Authors: BENTH FRED ESPEN , ŠALTYTĖ-BENTH JŪRATĖ
Published: March 2004

We model spot prices in energy markets with exponential non-Gaussian Ornstein–Uhlenbeck processes. We generalize the classical geometric Brownian motion and Schwartz' mean-reversion model by introducing Lévy processes as the driving noise rather than Brownian motion. Instead of modelling the spot price dynamics as the solution of a stochastic differential equation with jumps, it is advantageous from a statistical point of view to model the price process directly. Imposing the normal inverse Gaussian distribution as the statistical model for the Lévy increments, we obtain a superior fit compared to the Gaussian model when applied to spot price data from the oil and gas markets. We also discuss the problem of pricing forwards and options and outline how to find the market price of risk in an incomplete market.
CAUSAL LINKAGES AMONG SHANGHAI, SHENZHEN, AND HONG KONG STOCK MARKETS
Authors: ZHU HONGQUAN , LU ZUDI , WANG SHOUYANG , SOOFI ABDOL S.
Published: March 2004

In this paper, we test for causal relationship between China's stock markets by using returns and a measure of volatility for the Shanghai Composite index, the Shenzhen Composite Subindex, and the Hong Kong Hang Seng Index. We also show that the stock index series are nonstationary and that cointegrating vectors and error correction models do not exist for the series.

Based on these tests, for the return series, we conclude that Shenzhen Granger caused Shanghai before 1994. For the volatility data, we find that there exists a positive feedback relationship between Shanghai and Shenzhen stock markets, and that Hong Kong volatility Granger causes Shanghai volatility, but not vice versa.
Activation of cAMP-guanine exchange factor confers PKA-independent protection from hepatocyte apoptosis
Authors: Cullen Kimberly A. , McCool John , Anwer M. Sawkat , Webster Cynthia R. L.
Published: March 2004

cAMP has previously been shown to promote cell survival in a variety of cell types, but the downstream signaling pathway(s) of this antiapoptotic effect is unclear. Thus the role of cAMP signaling through PKA and cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs) in cAMP's antiapoptotic action was investigated in the present study. cAMP's protective effect against bile acid-, Fas ligand-, and TNF-α-induced apoptosis in rat hepatocytes was largely unaffected by the selective PKA inhibitor, Rp-8-(4-chlorophenylthio)-cAMP (Rp-cAMP). In contrast, a novel cAMP analog, 8-(4-chlorophenylthio)-2′- O-methyl (CPT-2-Me)-cAMP, which activated cAMP-GEFs in hepatocytes without activating PKA, protected hepatocytes against apoptosis induced by bile acids, Fas ligand, and TNF-α. The role of cAMP-GEF and PKA on activation of Akt, a kinase implicated in cAMP survival signaling, was investigated. Inhibition of PKA with RP-cAMP had no effect on cAMP-mediated Akt phosphorylation, whereas CPT-2-Me-cAMP, which did not activate PKA, induced phosphatidylinositol 3-kinase (PI3-kinase)-dependent activation of Akt. Pretreatment of hepatocytes with the PI3-kinase inhibitor, Ly-294002, prevented CPT-2-Me-cAMP's protective effect against bile acid and Fas ligand, but not TNF-α-mediated apoptosis. Glucagon, CPT-cAMP, and CPT-2-Me-cAMP all activated Rap 1, a downstream effector of cAMP-GEF. These results suggest that a PKA-independent cAMP/cAMP-GEF/Rap pathway exists in hepatocytes and that activation of cAMP-GEFs promotes Akt phosphorylation and hepatocyte survival. Thus a cAMP/cAMP-GEF/Rap/PI3-kinase/Akt signaling pathway may confer protection against bile acid- and Fas-induced apoptosis in hepatocytes.
Two-breath CO2 test detects altered dynamic cerebrovascular autoregulation and CO2 responsiveness with changes in arterial Pco2
Authors: Edwards Michael R. , Devitt Deanna L. , Hughson Richard L.
Published: March 2004

The new two-breath CO2 method was employed to test the hypotheses that small alterations in arterial Pco2 had an impact on the magnitude and dynamic response time of the CO2 effect on cerebrovascular resistance (CVRi) and the dynamic autoregulatory response to fluctuations in arterial pressure. During a 10-min protocol, eight subjects inspired two breaths from a bag with elevated Pco2, four different times, while end-tidal Pco2 was maintained at three levels: hypocapnia (LoCO2, 8 mmHg below resting values), normocapnia, and hypercapnia (HiCO2, 8 mmHg above resting values). Continuous measurements were made of mean blood pressure corrected to the level of the middle cerebral artery (BPMCA), Pco2 (estimated from expired CO2), and mean flow velocity (MFV, of the middle cerebral artery by Doppler ultrasound), with CVRi = BPMCA/MFV. Data were processed by a system identification technique (autoregressive moving average analysis) with gain and dynamic response time of adaptation estimated from the theoretical step responses. Consistent with our hypotheses, the magnitude of the Pco2-CVRi response was reduced from LoCO2 to HiCO2 [from −0.04 (SD 0.02) to −0.01 (SD 0.01) (mmHg·cm−1·s)·mmHg Pco2−1] and the time to reach 95% of the step plateau increased from 12.0 ± 4.9 to 20.5 ± 10.6 s. Dynamic autoregulation was impaired with elevated Pco2, as indicated by a reduction in gain from LoCO2 to HiCO2 [from 0.021 ± 0.012 to 0.007 ± 0.004 (mmHg·cm−1·s)·mmHg BPMCA−1], and time to reach 95% increased from 3.7 ± 2.8 to 20.0 ± 9.6 s. The two-breath technique detected dependence of the cerebrovascular CO2 response on Pco2 and changes in dynamic autoregulation with only small deviations in estimated arterial Pco2.
Regulation of Na+ transport by aldosterone: signaling convergence and cross talk between the PI3-K and MAPK1/2 cascades
Authors: Tong Qiusheng , Booth Rachell E. , Worrell Roger T. , Stockand James D.
Published: March 2004

Cross talk between the phosphatidylinositol 3-kinase (PI3-K) and mitogen-activating protein kinase (MAPK)1/2 signaling cascades in response to aldosterone-induced K-RasA was investigated in renal A6 epithelial cells. In addition, the contribution of these signaling pathways to aldosterone-stimulated Na+ transport was investigated. Aldosterone increased active K-RasA levels in A6 cells resulting in activation of downstream effectors in both the MAPK1/2 and PI3-K cascades with K-RasA directly interacting with the catalytic p110 subunit of PI3-K in a steroid-dependent manner. Aldosterone-stimulated PI3-K signaling impinged on the MAPK1/2 cascade at the level of Akt-mediated phosphorylation of c-Raf at an established negative regulatory site. Aldosterone also increased Sgk levels as well as stimulated phosphorylation of this kinase in a PI3-K- and K-RasA-dependent manner. Blockade of MAPK1/2 signaling had little effect on Na+ transport. Conversely, inhibition of PI3-K markedly suppressed transport. Likewise, suppression of K-RasA induction decreased transport. However, Na+ transport was subsequently stimulated under these conditions with the PLA2 inhibitor aristolochic acid, an established positive modulator of Na+ transport, suggesting that K-RasA signaling through PI3-K does not directly affect epithelial sodium channel (ENaC) levels but the activity of this channel. Consistent with this possibility, activity of ENaC reconstituted in Chinese hamster ovary cells was increased by coexpression of constitutively active PI3-K. The current study demonstrates that aldosterone increases Na+ transport, in part, by stimulating PI3-K signaling and that during aldosterone actions, there is both signaling convergence between the two aldosterone-induced proteins, K-RasA and Sgk, as well as cross talk between the PI3-K and MAPK1/2 cascades with the prior but not latter cascade enhancing ENaC activity.
Genome scan for QTLs underlying bone size variation at 10 refined skeletal sites: genetic heterogeneity and the significance of phenotype refinement
Authors: Huang Qing-Yang , Xu Fu-Hua , Shen Hui , Deng Hong-Yi , Conway Theresa , Liu Yong-Jun , Liu Yao-Zhong , Li Jin-Long , Li Miao-Xin , Davies K. Michael , Recker Robert R. , Deng Hong-Wen
Published: March 2004

To identify quantitative trait loci (QTLs) underlying variation in bone size, we conducted a whole-genome linkage scan in 53 pedigrees with 630 subjects using 380 microsatellite markers. Lumbar area 1, 2, 3, and 4 at the spine, femoral neck, trochanter, intertrochanter areas at the hip, ultradistal, mid-distal, and one-third distal areas at the wrist were measured by dual-energy X-ray absorptiometry (DXA), and adjusted for age, height, weight, and sex. Two-point and multipoint linkage analyses were performed for skeletal bone size at each site and their composite measurements using the SOLAR package. Two chromosomal regions (1q22 and 10q21) were identified with significant evidence of linkage (LOD > 4.32) to one-third distal area, and three were identified with suggestive evidence of linkage (LOD > 2.93) to bone size in one skeletal site. Our results indicated that the low power of QTLs mapping for composite phenotypic measurements may result from genetic heterogeneity of complex traits.
Determination of a nonlinear source term in a diffusion equationwith final observations
Authors: Li Gongsheng , Ma Yichen , Li Kaitai
Published: March 2004

This paper deals with an inverse problem of determining a
nonlinear source term in a quasilinear diffusion equation with
overposed final observations. Applying integral identity methods,
data compatibilities are deduced by which the inverse source
problem here is proved to be reasonable and solvable.
Furthermore, with the aid of an integral identity that connects
the unknown source terms with the known data, a conditional
stability is established.
T‐neighborhood groups
Authors: Ahsanullah T. M. G. , Al-Thukair Fawzi
Published: March 2004

We generalize min‐neighborhood groups to arbitrary
T‐neighborhood groups, where T is a continuous triangular
norm. In particular, we point out that our results accommodate
the previous theory on min‐neighborhood groups due to T. M. G.
Ahsanullah. We show that every T‐neighborhood group is
T‐uniformizable, therefore, T‐completely regular. We also
present several results of T‐neighborhood groups in conjunction
with TI‐groups due to J. N. Mordeson.
Patient-Controlled Deep Brain Stimulation Can Overcome Analgesic Tolerance
Authors: Romanelli Pantaleo , Romanelli Pantaleo , Heit Gary , Heit Gary
Published: March 2004

We report a technique based on patient-controlled stimulation to restore analgesia after development of tolerance to deep brain stimulation (DBS). A 45-year-old female with neurogenic pain after cerebellar stroke underwent DBS implantation in the right ventralis caudalis (VC) thalamus with excellent stimulus-controlled analgesia for 29 months, followed by development of tolerance and loss of analgesia. Analgesia was restored when a stimulation module that allowed patient-controlled stimulation was implanted.
Quantification of the Major Allergen from Cypress (Cupressus arizonica) Pollen, Cup a 1, by Monoclonal Antibody-Based ELISA
Authors: Arilla M.C. , Ibarrola I. , García R. , de la Hoz B. , Martínez A. , Asturias J.A.
Published: March 2004

Background: Cypress pollen allergy is an important cause of rhinoconjunctivitis and asthma in Mediterranean countries. Cypress allergenic extracts are difficult to produce since they have low protein and high carbohydrate content, thus accurate standardization of them is essential to guarantee their quality. The aim of this study is to develop a sandwich ELISA for the quantification of Cup a 1, the major allergen of cypress (Cupressus arizonica) pollen extract. Methods: Monoclonal antibodies directed to purified Cup a 1 were produced. Two of them (9C7 as capture antibody and 3D2 as the tracer) were selected to develop a quantitative sandwich ELISA. This ELISA was subsequently evaluated and compared with other techniques. Results: The described ELISA is very sensitive with a detection limit of 8.7 ng/ml and a practical working range of 62.5–1,000 ng/ml. The assay is also highly reproducible with intra-assay and interassay coefficients of variation of less than 10%. The purified Cup a 1, used as standard, presents pectate lyase enzymatic activity. The assay also detected Cup a 1-like proteins in pollen from other Cupressaceae. A good correlation was obtained between Cup a 1 content of 12 C. arizonica pollen extracts and their IgE-binding activity. Conclusions: The described Cup a 1 ELISA is sensitive, specific and reproducible and can be used for the quantification of Cup a 1 in C. arizonica and other related pollen extracts. It also provides a reliable indication of the allergenic activity of the whole cypress pollen extract.
Role of Computed Tomography and Magnetic Resonance Imaging for Deep Venous Thrombosis and Pulmonary Embolism
Authors: Kanne Jeffrey P. , Lalani Tasneem A.
Published: March 2004

During the 1990s, computed tomography (CT) and magnetic resonance (MR) imaging underwent extensive technological advancement and expanded clinical use in patients with venous thromboembolic disease, particularly with regard to evaluation of the pulmonary vasculature. In many institutions, helical (spiral) CT pulmonary angiography has become the initial imaging study of choice to evaluate patients with suspected pulmonary embolism, supplanting ventilation/perfusion scintigraphy. In addition, CT venography of the pelvis and lower extremities is often incorporated into the CT angiography protocol to identify or exclude concurrent deep venous thrombosis. MR pulmonary angiography and MR venography are second-line diagnostic tools because of their higher cost, limited availability, and other logistical constraints. As the technology improves and becomes more widely available, MR imaging may play a greater role in the evaluation of patients with venous thromboembolic disease.
Pharmacokinetics of Sumatriptan Nasal Spray in Children
Authors: Christensen Michael L. , Mottern Robin K. , Jabbour J. T. , Fuseau Eliane
Published: March 2004

The authors studied the pharmacokinetics of sumatriptan nasal spray after a single dose in children migraineurs outside of migraine attack. Seventeen subjects (9 females) ages 6 to 11 years were given one dose of sumatriptan nasal spray based on age and weight; children 6 to 8 years of age weighing ≤ 25 kg received 5 mg (n = 3), children ages 6 to 8 years weighing >25 kg and children ages 9 to 11 years of age weighing ≤ 40 kg received 10 mg (n = 10), and children ages 9 to 11 years weighing > 40 kg received 20 mg (n = 4). Plasma sumatriptan concentrations were determined in serial blood samples obtained over 8 hours. Pharmacokinetic analysis included both noncompartmental and population modeling methods. The pharmacokinetic parameter estimates (geometric mean [95% confidence interval]) following 5, 10, and 20 mg sumatriptan were, respectively, as follows: maximum concentration = 8.1 ng/mL (3.6–18.4), 10.8 ng/mL (7.7–15.4), and 12.3 ng/mL (7.6–19.9); half‐life = 1.4 hours (1.2–1.8), 1.7 hours (1.4–2.0), and 1.7 hours (1.3–2.3); and AUC = 27.8 ng•h/ mL (9.7–79.8), 42.4 ng•h/mL (30.6–58.8), and 49.2 ng•h/mL (32.9–73.7). The median time to maximum concentration for all groups was 2 hours. Population pharmacokinetic modeling included pooled data from this study and from an adolescent study (n = 16). Clearance (CL/F) was 197 L/h for a 30‐kg child with between‐subject variability of 28%, and the volume of distribution was 751 L, normalized for an 11‐year‐old child with variability of 43%. The covariate analysis showed that volume increases with age and clearance increases with body size. The absorption was complex, often displaying double‐peak plasma concentrations, with a rapid absorption phase and a delayed and rate‐limited absorption phase. The dosing scheme based on age and weight resulted in maximal concentrations (Cmax) and systemic exposure (AUC) that were comparable to those observed in adolescents and adults treated with 20 mg. The age‐ and weight‐adjusted dosing scheme appears to an appropriate initial dosing regimen for children with migraine headache. Appropriate safety and efficacy trials will need to be completed in children prior to recommending its use in children.
Serum Metabolite/Caffeine Ratios as a Test for Liver Function
Authors: Jodynis‐Liebert Jadwiga , Flieger Jan , Matuszewska Arleta , Juszczyk Jacek
Published: March 2004

The aim of this study was to test the usefulness of the metabolite/caffeine ratio for the evaluation of hepatic dysfunction. Subjects with liver cirrhosis and chronic hepatitis, as well as healthy volunteers, were given the oral dose of 300 mg caffeine. Blood samples were collected after 4, 8, and 12 hours. Concentrations of caffeine (CA) and its three metabolites—paraxanthine (PX), theobromine (TB), and theophylline (TP)—were determined by high‐performance liquid chromatography. Pharmacokinetic parameters of caffeine and PX/CA, TB/CA, and TP/CA ratios were calculated. Elimination of caffeine was decreased in cirrhotics in comparison with healthy volunteers, as proved by the values of clearance (0.035 vs. 0.094 L/h/kg), elimination coefficient (0.061 vs. 0.153 h−1), and half‐life (11.4 vs. 4.3 h). Serum metabolite/caffeine ratios were significantly reduced in cirrhotic patients: PX/CA by more than 80%, TB/CA by 50% to 70%, and TP/CA by 40% to 70%. The reduction of the ratios in chronic hepatitis patients was lower and did not occur at all time points. A high correlation was found between caffeine clearance and metabolite/caffeine ratios. Metabolite/ caffeine ratios calculated in a single blood sample collected 8 or 12 hours after caffeine administration could provide a practical assessment of hepatic function in cirrhotic patients. The value of the test for the chronic hepatitis patients is limited.
Activating FLT3 mutations in CD117/KIT+ T-cell acute lymphoblastic leukemias
Authors: Paietta Elisabeth , Ferrando Adolfo A. , Neuberg Donna , Bennett John M. , Racevskis Janis , Lazarus Hillard , Dewald Gordon , Rowe Jacob M. , Wiernik Peter H. , Tallman Martin S. , Look A. Thomas
Published: March 2004

Activating FLT3 mutations are the most common genetic aberrations in acute myeloid leukemia (AML), resulting in the constitutive activation of this receptor tyrosine kinase (RTK), but such mutations are rarely found in acute lymphoblastic leukemia (ALL). Here we describe a unique subset of de novo adult T-cell ALL (T-ALL) cases that coexpress CD117/KIT and cytoplasmic CD3 (CD117/KIT+ ALL). Activating mutations in the FLT3 RTK gene were found in each of 3 CD117/KIT+ cases that were analyzed, but not in 52 other adult T-ALL samples from the same series that lacked CD117/KIT expression. Our results indicate the need for clinical trials to test the efficacy of drugs that inhibit the FLT3 RTK in this subset of patients with T-ALL. (Blood. 2004;104:558-560)
Efficacy and Safety of Oral Fludarabine Phosphate in Previously Untreated Patients With Chronic Lymphocytic Leukemia
Authors: Rossi J.-F. , Van Hoof A. , De Boeck K. , Johnson S.A. , Bron D. , Foussard C. , Lister T.A. , Berthou C. , Kramer M.H.H. , Littlewood T.J. , Marcus R.E. , Deconinck E. , Montillo M. , Guibon O. , Tollerfield S.M.
Published: March 2004

Purpose

A prospective, multicenter, open-label, phase II clinical trial to assess oral fludarabine phosphate treatment in terms of safety, efficacy, and quality of life. Reference to a historical group of patients treated with the intravenous (IV) formulation allowed the two formulations to be compared.

Patients and Methods

Patients with previously untreated B-cell chronic lymphocytic leukemia received 10-mg tablets of fludarabine phosphate to a dose of 40 mg/m2/d for 5 days, repeated every 4 weeks, for a total of six to eight cycles. Efficacy was assessed using International Workshop on Chronic Lymphocytic Leukemia and National Cancer Institute criteria for response. Safety monitoring included WHO toxicity grading for adverse events. Quality of life was also assessed.

Results

Eighty-one patients received treatment. According to International Workshop on Chronic Lymphocytic Leukemia criteria, the overall response rate was 71.6% (complete remission, 37.0%; partial remission, 34.6%). The response rate using National Cancer Institute criteria was 80.2% (complete remission, 12.3%; partial remission, 67.9%). Median time to progression was 841 days (range, 28 to 1,146 days). The most frequently reported grade 3/4 toxicity was myelosuppression. WHO grade 3/4 hematological toxicities included granulocytopenia (32.1%), anemia (9.9%), and thrombocytopenia (4.9%). Gastrointestinal toxicity was more common with the oral formulation than with IV fludarabine phosphate, but was generally mild to moderate and did not require treatment. Statistically significant improvements in mean emotional and insomnia quality-of-life scores were seen after treatment.

Conclusion

This study demonstrates that oral fludarabine phosphate is clinically effective and generally well tolerated by patients with previously untreated B-cell chronic lymphocytic leukemia. Oral fludarabine phosphate has a similar clinical efficacy and safety profile to the IV formulation. Oral fludarabine phosphate does not adversely affect quality of life and may improve emotional and insomnia scores.
Using Patients As Their Own Controls for Cost Evaluation of Phase I Clinical Trials
Authors: Sherman Eric J. , Rubin David M. , Venkatraman Ennapadam , Schwartz Gary K. , Miller Vincent A. , Radzyner Mark H. , Ruchlin Hirsch S. , Spriggs David , Pfister David G.
Published: March 2004

Purpose

Little is known about the cost of phase I trials in cancer patients compared with that of standard treatments, yet the former is often assumed to be greater than the latter. Our objective was to utilize a new approach, using patients as their own controls, to compare in a pilot study the costs of care for patients on phase I trials with those incurred for standard treatment.

Patients and Methods

We retrospectively assessed the direct medical costs (DMCs) of 59 patients participating in one of two phase I trials (TRIAL) in solid tumors conducted at Memorial Hospital (MH): (1) perillyl alcohol, and (2) flavopiridol with paclitaxel. Paired-control DMCs were those accrued by the same patient while receiving standard chemotherapy regimens just before (PRE; n = 41) or after (POST; n = 29) the trial at MH, averaged per day.

Results

For the 41 PRE patients, the median and mean DMCs per day for the clinical trial versus standard treatment were (US $) $123 v $133 and $219 v $267, respectively. For the 29 POST patients, the median and mean DMCs for the clinical trial versus standard treatment were $157 v $152 and $226 v $226, respectively. Using a linear mixed model, there was no significant difference between TRIAL and standard treatment DMCs (P = .54).

Conclusion

Using patients as their own controls represents a new, efficient method for evaluating the cost of phase I trials, and it warrants further study. The results of our pilot study do not suggest that phase I trials always cost payers more than standard treatment.
Outcome of Patients With Residual Germ Cell or Non-Germ Cell Malignancy After Resection of Primary Mediastinal Nonseminomatous Germ Cell Cancer
Authors: Schneider Bryan P. , Kesler Kenneth A. , Brooks Jo Ann , Yiannoutsos Constantin , Einhorn Lawrence H.
Published: March 2004

Purpose

To identify prognostic variables and outcomes in patients with primary mediastinal nonseminomatous germ cell tumor (PMNSGCT) with postchemotherapy resection of persistent cancer.

Patients and Methods

Forty-seven consecutive patients with residual cancer after resection of PMNSGCT were retrospectively reviewed. Univariate comparisons were performed.

Results

At diagnosis, 43 patients had elevated serum tumor markers (STMs), and 20 had extramediastinal disease. At resection, 21 patients had elevated STMs. After resection, 26 patients had germ cell tumors (GCT), 12 had malignant transformation of teratoma with elements of non-GCT, and nine had both GCT and non-GCT. Sixteen of 47 patients continuously have no evidence of disease (NED). This includes eight of 26 patients with GCT histology and two of 12 patients with non-GCT histology. Of 27 patients with mediastinal-only disease at presentation, 14 have continuously NED. Of 20 patients with extramediastinal disease at presentation, two have continuously NED. Seven of 21 patients with elevated STMs at time of resection have continuously NED. Sixteen patients received adjuvant chemotherapy, and seven have continuously NED. Overall, 16 of 47 patients have continuously NED, an additional four patients have NED with further therapy (currently NED), two patients are alive with disease, 23 patients died of disease, and two patients died postoperatively.

Conclusion

The presence of elevated STMs at resection does not appear to alter outcome if residual disease is completely resected. In this poor-risk patient population, surgical resection of persistent cancer, even in the presence of elevated STMs, can still achieve long-term survival.
Phase II Study of R115777, a Farnesyl Transferase Inhibitor, in Myelodysplastic Syndrome
Authors: Kurzrock Razelle , Albitar Maher , Cortes Jorge E. , Estey Elihu H. , Faderl Stefan H. , Garcia-Manero Guillermo , Thomas Deborah A. , Giles Francis J. , Ryback Mary Ellen , Thibault Alain , De Porre P. , Kantarjian Hagop M.
Published: March 2004

Purpose

To perform a phase II study of the farnesyltransferase inhibitor R115777 (Zarnestra; Johnson and Johnson Pharmaceutical Research and Development, Raritan, NJ) in patients with myelodysplastic syndrome (MDS), using doses recommended in a phase I study in relapsed/refractory leukemia.

Patients and Methods

Patients with MDS were treated with R115777 at doses of 600 mg orally (PO) bid in cycles of 4 weeks of therapy followed by a 2-week rest period. Dose reduction rules for toxicity were applied.

Results

Twenty-seven of the 28 patients treated were assessable. Three patients responded (complete remission, n = 2; partial remission, n = 1). Responders included two patients with refractory anemia with excess blasts and one patient with refractory anemia with excess blasts in transformation. Two of the responders had a diploid karyotype and one had multiple cytogenetic abnormalities including monosomy 5 and 7. The starting dose of 600 mg PO bid resulted in side effects (myelosuppression, fatigue, neurotoxicity, rash, or leg pain) necessitating dose reduction (n = 4) or discontinuation of therapy (n = 7) in 11 (41%) of 27 patients during the induction period (12 weeks). Lower doses of 300 mg PO bid were well tolerated. All responses occurred in patients who had been reduced to this dose level during the initial two cycles.

Conclusion

This study suggests that R115777 has modest activity in MDS patients, but that, in this patient population, 4 weeks of daily doses of 600 mg PO bid is not tolerated. Further exploration of the optimal dose/schedule and correlation with biologic end points are warranted.
Predictors of Viridans Streptococcal Shock Syndrome in Bacteremic Children With Cancer and Stem-Cell Transplant Recipients
Authors: Gassas Adam , Grant Ronald , Richardson Susan , Dupuis L. Lee , Doyle John , Allen Upton , Abla Oussama , Sung Lillian
Published: March 2004

Purpose

To describe episodes of viridans streptococcal bacteremia (VSB) in a cohort of children with cancer and stem-cell transplant (SCT) recipients and to determine predictors of viridans streptococcal shock syndrome (VSSS) in this group of children.

Patients and Methods

For this retrospective review, we included episodes of VSB isolated between March 1997 and September 2002, in children (≤ 18 years) with a diagnosis of cancer or SCT patients. The primary outcome was VSSS, defined as hypotension requiring intravascular volume expansion or inotropic support and/or respiratory insufficiency necessitating assisted ventilation.

Results

Eighty-eight episodes of VSB occurred in 79 children. The mean age of the children was 6.7 years (range, 0.6 to 18.0 years). The most common underlying diagnosis was acute myelogenous leukemia (AML) in 31 (35%) of 88 episodes, and 38 (43%) of 88 had undergone SCT. VSSS occurred in 16 (18%) of 88 episodes, and two children died from VSSS. Two variables were predictive of VSSS, namely peak temperature at presentation (odds ratio [OR], 6.3; 95% CI, 2.1 to 19.0; P = .001) and inpatient status (OR, 5.9; 95% CI, 1.3 to 28.0; P = .02). Diagnosis of AML (OR, 1.1; 95% CI, 0.4 to 3.5; P = .8), receipt of SCT (OR, 1.9; 95% CI, 0.6 to 5.7; P = .2), high-dose cytarabine (OR, 0.6; 95% CI, 0.1 to 3.2; P = .6), and mucositis (OR, 0.8; 95% CI, 0.3 to 2.6; P = .7) were not predictive of VSSS.

Conclusion

VSSS occurred in 18% of episodes of VSB in children with cancer or SCT recipients. Peak temperature before antibiotic therapy and inpatient status were predictive of VSSS.
The Attraction Effect and Political Choice in Two Elections
Authors: Sue O'Curry Yigang Pan , Pitts Robert
Published: March 2004

Findings that challenge several normative assumptions of consumer choice have been documented in the literature on the attraction effect. There has been ample previous empirical evidence supporting the attraction effect. However, there is some concern that findings were generated only in hypothetical choice experiments. The choice of political candidates in elections presents a more complex and “real world” choice setting in which to reexamine the attraction effect. In this article, we report two studies that provide evidence of the attraction effect in the choice of political candidates in the 1994 Illinois State primary election and the 1992 U.S. Presidential election.
Typologies of Compulsive Buying Behavior: A Constrained Clusterwise Regression Approach
Authors: DeSarbo Wayne S. , Edwards Elizabeth A.
Published: March 2004

We present a theoretical framework that posits compulsive buying behavior as a function of various psychological processes and personality traits. We analyze data from actual consumers using a new constrained maximum likelihood clusterwise regression procedure to examine the nature of consumer heterogeneity in compulsive buying behavior. This empirical analysis distinguishes between 2 clusters, or groups, of compulsive buyers in terms of differential drivers of their compulsive buying. A posterior regression analysis reveals additional differences in background characteristics for each cluster. A discussion of future research issues and other applications is provided.
It Seems Like Only Yesterday: The Nature and Consequences of Telescoping Errors in Marketing Research
Authors: Morwitz Vicki G
Published: March 2004

When asked to place the time of a past event, people have a systematic tendency to recall that recent events occurred farther back in time (backward telescoping) and distant events occurred more recently (forward telescoping) than is actually the case. In this article, I provide a conceptual analysis and an empirical examination of the extent of telescoping errors in marketing research and the implications of these errors. The results show that (a) on average, consumers underestimate the time since purchasing a durable good; (b) the magnitude of forward telescoping errors increases and the propensity to make backward telescoping errors decreases with the time since purchase; (c) telescoping errors affect future purchase intentions; and (d) telescoping biases vary across different demographic segments. A propositional inventory linking telescoping errors to product, respondent, and situational factors is presented for future research.