bluuebunny/crossref_metadata_2025 huggingface dataset:
Management of inoperable hepatocellular carcinoma
Authors: HUO TEH‐IA , LEE SHOU‐DONG
Published: December 2004

Abstract  Hepatocellular carcinoma (HCC) is a common and difficult‐to‐treat malignant tumor. Surgical interventions are feasible in only a small proportion of patients, and non‐surgical therapy has been frequently administered to patients with inoperable HCC. Various modalities of loco‐regional therapy have gained much interest during the past decade. Among them, transarterial chemoembolization (TACE), percutaneous injection of ethanol (PEI) or acetic acid (PAI), radiofrequency ablation (RFA) and microwave coagulation therapy (MCT) are effective treatment options. TACE can target multiple hypervascular tumors but has the potential risk of inducing hepatic or renal failure. PEI is a well‐established method for small (< 3 cm) HCC, and PAI has the advantage over PEI as being more effective with fewer treatment sessions. RFA has excellent tumor ablation ability, and has been extended to treat medium‐ or large‐sized HCC. However, the overall complication rate may be higher than previously assumed. MCT is similar to RFA in its clinical application and adverse effects. Although combination therapy often achieves a higher response rate, the side‐effects may also be additive. Other therapies, such as injection of hot saline or yttrium‐90 microspheres, interstitial laser photocoagulation and cryoablation are seldom used nowadays. Thalidomide may be useful in a minority of HCC patients, whereas radiotherapy, chemotherapy and tamoxifen are generally ineffective. In conclusion, although long‐term survival in patients with inoperable HCC is possible in selected patients, the overall prognosis remains unsatisfactory, especially in those with aggressive tumor behavior. Newer antitumor therapy with better treatment efficacy is urgently needed. Information of the design for a more comprehensive approach using the existing therapeutic options may help refine the treatment strategy.
The liver as an immunological organ
Authors: WEILER‐NORMANN CHRISTINA , REHERMANN BARBARA
Published: December 2004

Abstract  The liver is an immunologically distinct organ that contains its own unique population of cells of the innate and adaptive cellular immune response. The liver is known as a site of inflammatory immune responses as well as a site of tolerance induction. This dual function is important to understand the pathogenesis of infectious liver diseases and to understand induction of tolerance upon exposure to oral and allograft antigens. This review will address the unique role of the liver in the immune system.
Antiviral drug resistance in hepatitis B and C
Authors: LOCARNINI STEPHEN A , SHAW TIM
Published: December 2004

Abstract  Six factors have been directly implicated in the emergence of antiviral drug resistant mutants: the magnitude and rate of virus replication, the viral mutation frequency, the intrinsic mutability of the antiviral target site, the selective pressure exerted by the drug, the overall replication fitness of the mutant and the availability of replication space. Both the hepatitis B virus (HBV) and hepatitis C virus (HCV) have long natural histories of infection over many decades, during which each virus adapts via the processes of natural selection to its infected host. In the context of therapeutic intervention using antiviral drugs, escape mutants are selected from the pre‐existing pool of quasispecies. Particular escape mutants emerge as the dominant virus species, replacing those that have become less fit in the changed environment. In the case of HBV, the emergence of lamivudine‐resistant virus can be associated with worsening liver function and progressive liver disease. In the case of HCV, interferon alpha and ribavirin have complex and indirect actions, making the mechanisms of HCV resistance quite different from those of viral resistance in HBV. Molecular mechanisms of resistance to IFN‐based therapy have indicated that treatment failure appears to be multifactorial, reflecting both host and viral elements. The clinical and public health importance of drug‐resistance for the wider community is clear, and improved treatment strategies are urgently required to prevent their continued selection.
Expression of p73 in normal skin and proliferative skin lesions
Authors: Kamiya Makoto , Takeuchi Yuko , Katho Mari , Yokoo Hideaki , Sasaki Atsushi , Nakazato Yoichi
Published: December 2004

The p73 gene is a member of the p53 gene family and the structure and functions of p73 protein are similar to those of  p53.  However,  these  two  proteins  have  different  roles. In the present study, p73 protein was found immunohistochemically to be distributed in the basal cells of the epidermis, columnar basal cells in the hair follicle and peripheral cells without lipid droplets in the sebaceous and meibomian glands; it was expressed strongly in tumor cells in basal cell carcinomas and in the basal cell‐like cells in seborrheic keratosis, and weakly or negatively in the squamous cell‐like cells in seborrheic keratosis and in the tumor cells in squamous cell carcinomas. No relationship was detected between p73 and p53 protein distribution and between p73 protein expression and the proliferative potential, as shown by the Ki‐67 immunopositive cell ratio. The present study shows that p73 protein is likely to play important roles in skin differentiation rather than proliferation or carcinogenesis of the skin.
Phyllodes tumor of the seminal vesicle: Case report and literature review
Authors: Son Hyun‐Jin , Jeong Yeon‐Jun , Kim Jong‐Hun , Chung Myoung‐Ja
Published: December 2004

A 39‐year‐old man presented with urinary retention and lower abdominal discomfort at our hospital, and a computed tomography scan showed a huge cystic mass posterior to the urinary bladder. During surgical exploration, a mass superior to the prostate in the region of the left seminal vesicle was found. Histologically, the tumor was characterized by cystically dilated or slit‐like glands mixed in a densely cellular stroma with pleomorphism and resembled those of phyllodes tumor of the breast or prostate. The glandular epithelium within the tumor showed focal lipofuscin pigment and negative staining for prostate specific antigen (PSA). The stromal cells showed positive immunoreactivity for vimentin and CD34, and focal positive reactions for desmin and α‐smooth muscle actin. Mitosis was present 0 to 1 per 10 high power fields of magnification in the stromal cells. Approximately 20% of the stromal cells were positive for progesterone receptor. The patient is alive with no evidence of disease 12 months after surgery. Mixed epithelial‐stromal tumors of the seminal vesicle are extremely rare. A combination of stromal cellularity, atypia and mitosis might be used for the histological grading, and a prostatic origin might be excluded by the location of the primary lesion itself and by the failure to show PSA.
High‐tech rural clinics and hospitals in Japan: a comparison to the Japanese average
Authors: Matsumoto Masatoshi , Okayama Masanobu , Inoue Kazuo , Kajii Eiji
Published: December 2004

Context:  Japanese medical facilities are noted for being heavily equipped with high‐tech equipment compared to other industrialised countries. Rural facilities are anecdotally said to be better equipped than facilities in other areas due to egalitarian health resource diffusion policies by public sectors whose goal is to secure fair access to modern medical technologies among the entire population.

Objectives:  To show the technology status of rural practice and compare it to the national level.

Design:  Nationwide postal survey.

Setting, Subjects & Interventions:  Questionnaires were sent to the directors of 1362 public hospitals and clinics (of the 1723 municipalities defined as ‘rural’ by four national laws). Information was collected about the technologies they possessed. The data were compared with figures from a national census of all hospitals and clinics.

Results:  A total of 766 facilities responded (an effective response rate of 56%). Rural facilities showed higher possession rates in most comparable technologies than the national level. It is noted that almost all rural hospitals had gastroscopes and colonoscopes and their possession rates of bronchoscopes and dialysis equipment were twice as high as the national level. The discrepancy in possession rates between rural and national was even more remarkable in clinics than in hospitals. Rural clinics owned twice as many abdominal ultrasonographs, and three times as many gastroscopes, colonoscopes, defibrillators and computed tomography scanners as the national level.

Conclusions:  Rural facilities are equipped with more technology than urban ones. Government‐led, tax based, technology diffusion in the entire country seems to have attained its goal.

What is already known on this subject:  As a general tendency in both developing and developed countries, rural medical facilities are technologically less equipped than their urban counterparts.

What does this paper add?:  In Japan, rural medical facilities are technologically better equipped than urban facilities.
Role of reactive oxygen species in gynecologic diseases
Authors: SHARMA RAKESH K. , AGARWAL ASHOK
Published: December 2004

Free radicals derived from molecular oxygen and nitrogen are highly reactive metabolites called reactive oxygen species (ROS). Cells continuously produce free radicals and ROS as part of the metabolic process. They are involved in the various functions of the reproductive system. Antioxidants are enzymes or compounds that scavenge and reduce the presence of free radicals. Normally, a balance exists between concentrations of reactive oxygen species and antioxidant scavenging systems. The disruption of the delicate balance between pro‐ and antioxidants results in oxidative stress. Oxidative stress has been implicated in embryo fragmentation, DNA damage, apoptosis and poor pregnancy outcome. It has also been implicated in a large number of gynecologic diseases, such as endometriosis, pre‐eclampsia and maternal diabetes. The use of antioxidants may be beneficial in combating the harmful effects of oxidative stress in many of these diseases. The present review outlines the importance of these species in the pathology of various gynecologic diseases. (Reprod Med Biol 2004;3: 177 – 199)
Functional roles of cell surface peptidases in reproductive organs
Authors: FUJIWARA HIROSHI
Published: December 2004

A number of biologically active peptides have been proposed to regulate function and differentiation of reproductive organs in an autocrine and/or paracrine fashion. Regulation of the local concentrations of these peptides is one of the important factors influencing their physiological effects on target cells. Membrane‐bound cell surface peptidases can activate or inactivate biologically active peptides before peptide factors access their receptors on the cell surface. Aminopeptidase A (EC 3.4.11.7), placental leucine aminopeptidase (EC 3.4.11.3), aminopeptidase‐N/CD13 (EC 3.4.11.2), dipeptidyl peptidases IV/CD26 (EC.3.4.14.5), carboxypeptidase‐M (EC 3.4.17.12), neutral endopeptidase/CD10 (EC 3.4.24.11) and endothelin converting enzyme‐1 (EC 3.4.23) are differentially expressed on the ovary, endometrium and placenta. The inhibition of enzyme activity affects steroid hormone production by granulosa and thecal cells, decidualization of endometrium and migration of extravillous trophoblasts. These findings suggest that membrane‐bound cell surface peptidases are local regulators for cellular growth and differentiation in reproductive organs by controlling extracellular concentration of peptide factors. (Reprod Med Biol 2004; 3: 165 –176)
PLACING OURSELVES
Authors: Fisher George W.
Published: December 2004

Abstract This essay set the stage for the 2003 Star Island conversation on “Ecomorality” by remembering the cosmic, geological, and ecological context in which we live. It reflects on the immense journey that matter and life have traveled from the beginning and reminds us that, throughout that journey, all that was and is emerged from a fertile mix of individual well‐being and reciprocity. But to sense the meaning of the story and to know our place in it takes more than hearing its broad outline. We need to remember the individual actors who have gone before us; to read their stories in particular places, like the rocks and ecosystems of Star Island; and to listen carefully for the meaning to be found in those actors and those places. Those stories, actors, and places invite us to sense the sacredness of our time and place and to reconsecrate our selves and our energies to developing an ethic that honors our common ancestry.
FAITH AND DOUBT IN SCIENCE AND RELIGION
Authors: Raman Varadaraja V.
Published: December 2004

Abstract One of the contexts in which religion and science come into conflict is with regard to faith and doubt. Generally speaking, we associate faith with religion, which is opposed to doubt, and doubt with science, which is opposed to faith. Some critics of science have argued that science is also based on faith; others have shown that there is doubt in the religious context also. In this essay I clarify these positions by defining different types of faith and different types of doubt.
Lucian Leape on Patient Safety in U.S. Hospitals
Authors: Buerhaus Peter I.
Published: December 2004

Purpose:

To describe and discuss the status of patient safety in U.S. hospitals.

Methods:

Personal interview. This report is part of a series of discussions with a leading expert on patient safety.

Findings and Conclusions:

Some improvements have been made in the past 10 years. But changes have not been adequate. Continuing barriers include the punitive environment in hospitals, physicians' denial of the scope of the problem, lack of national leadership, and lack of systems thinking.
Distribution of yttrium and neodymium in magnesium melts between metal and magnesium fluoride containing salt
Authors: Ditze André , Scharf Christiane
Published: December 2004

WE magnesium alloys contain yttrium and neodymium as valuable alloying elements. By remelting these alloys with flux, the distribution of yttrium and neodymium between the alloy and the utilized salt was investigated at 750°C. Three compositions of various salts free of magnesium chloride, with and without barium and containing magnesium fluoride were selected. The presumed reaction is the exchange of the two metals with magnesium fluoride. A simple thermodynamic examination can verify this. Thus in the course of the reaction yttrium and neodymium are distributed differently among the alloy and the salt with yttrium reacting more strongly with magnesium fluoride. Consequently, for the investigated fluxes, there is only a small loss of neodymium to the salt mixtures. Based on the distributions of yttrium and neodymium, the losses at the remelting of the magnesium alloys have been calculated versus the salt amount used.
Control of muscle glucose uptake: test of the rate‐limiting step paradigm in conscious, unrestrained mice
Authors: Fueger Patrick T. , Shearer Jane , Bracy Deanna P. , Posey Kelly A. , Pencek R. Richard , McGuinness Owen P. , Wasserman David H.
Published: December 2004

The aim of this study was to test whether in fact glucose transport is rate‐limiting in control of muscle glucose uptake (MGU) under physiological hyperinsulinaemic conditions in the conscious, unrestrained mouse. C57Bl/6J mice overexpressing GLUT4 (GLUT4Tg), hexokinase II (HKTg), or both (GLUT4Tg+ HKTg), were compared to wild‐type (WT) littermates. Catheters were implanted into a carotid artery and jugular vein for sampling and infusions at 4 month of age. After a 5‐day recovery period, conscious mice underwent one of two protocols (n= 8–14/group) after a 5‐h fast. Saline or insulin (4 mU kg−1 min−1) was infused for 120 min. All mice received a bolus of 2‐deoxy[3H]glucose (2‐3HDG) at 95 min. Glucose was clamped at ∼165 mg dl−1 during insulin infusion and insulin levels reached ∼80 μU ml−1. The rate of disappearance of 2‐3HDG from the blood provided an index of whole body glucose clearance. Gastrocnemius, superficial vastus lateralis and soleus muscles were excised at 120 min to determine 2‐3HDG‐6‐phosphate levels and calculate an index of MGU (Rg). Results show that whole body and tissue‐specific indices of glucose utilization were: (1) augmented by GLUT4 overexpression, but not HKII overexpression, in the basal state; (2) enhanced by HKII overexpression in the presence of physiological hyperinsulinaemia; and (3) largely unaffected by GLUT4 overexpression during insulin clamps whether alone or combined with HKII overexpression. Therefore, while glucose transport is the primary barrier to MGU under basal conditions, glucose phosphorylation becomes a more important barrier during physiological hyperinsulinaemia in all muscles. The control of MGU is distributed rather than confined to a single rate‐limiting step such as glucose transport as glucose transport and phosphorylation can both become barriers to skeletal muscle glucose influx.
Charge immobilization of the voltage sensor in domain IV is independent of sodium current inactivation
Authors: Sheets Michael F. , Hanck Dorothy A.
Published: December 2004

Recovery from fast inactivation in voltage‐dependent Na+ channels is associated with a slow component in the time course of gating charge during repolarization (i.e. charge immobilization), which results from the slow movement of the S4 segments in domains III and IV (S4‐DIII and S4‐DIV). Previous studies have shown that the non‐specific removal of fast inactivation by the proteolytic enzyme pronase eliminated charge immobilization, while the specific removal of fast inactivation (by intracellular MTSET modification of a cysteine substituted for the phenylalanine in the IFM motif, ICMMTSET, in the inactivation particle formed by the linker between domains III and IV) only reduced the amount of charge immobilization by nearly one‐half. To investigate the molecular origin of the remaining slow component of charge immobilization we studied the human cardiac Na+ channel (hH1a) in which the outermost arginine in the S4‐DIV, which contributes ∼20% to total gating charge (Qmax), was mutated to a cysteine (R1C‐DIV). Gating charge could be fully restored in R1C‐DIV by exposure to extracellular MTSEA, a positively charged methanethiosulphonate reagent. The RIC‐DIV mutation was combined with ICMMTSET to remove fast inactivation, and the gating currents of R1C‐DIV‐ICMMTSET were recorded before and after modification with MTSEAo. Prior to MTSEAo, the time course of the gating charge during repolarization (off‐charge) was best described by a single fast time constant. After MTSEA, the off‐charge had both fast and slow components, with the slow component accounting for nearly 35% of Qmax. These results demonstrate that the slow movement of the S4‐DIV during repolarization is not dependent upon the normal binding of the inactivation particle.
Nonlinear Active Cancellation of the Parametric Resonance in a Magnetically Levitated Body
Authors: Yabuno Hiroshi , Kanda Ryo , Lacarbonara Walter , Aoshima Nobuharu
Published: December 2004

An active control strategy for the stabilization of parametric resonance in a magnetically levitated body is proposed. The characteristic feature of the strategy is the exploitation of the nonlinear effect of the inertial force associated with the motion of a pendulum-type vibration absorber driven by an appropriate control torque. As a distinguished feature, the proposed control method does not rely on the effective autoparametric energy transfer between the main system and the absorber. Because the main system is not linearly coupled with the absorber, the drawback inherent in the increase of the system degrees of freedom (i.e., the increase of the linear vibrational mode for the main system due to the attachment of the absorber) is overcome. The effective frequency and amplitude of the pure-tone control input—the torque driving the vibration absorber—are designed so that the nonlinear action of the pendulum on the main system counteracts the effect of the resonant parametric excitation. The effectiveness of the theoretically proposed control method is experimentally validated using an apparatus that comprises a phase-lock loop system.
Minimal Order Nonlinear Observer for Leak Detection
Authors: Verde C.
Published: December 2004

A method for leaks location in a pipeline, using sensors only at the extremes of the line is presented. The detection problem is solved, assuming a nonlinear fluid model of finite dimension with uncertainty in the leak position, and generating the residual with two minimal order nonlinear observers. Flow and pressure data at the beginning and at end of the line are considered as output and input of the system respectively. Since the proposed model satisfies (1) the condition to generate a residual, assuming at the most two leaks, and (2) the strong detectability fault property for each output component, two nonlinear robust filters with respect to a leak are designed to generate the residual. To simplify the residual evaluation and estimate the leak position, a static relationship between each component of the residual and the position error is derived. The main contribution of this paper is to take advantage of the residual equation with uncertainty to isolate a fault. The effectiveness of this approach is shown by a comparison with the practical method reported in [1] using results obtained from simulated and experimental data of a water pilot pipeline of 132 m long, with a diameter of 0.1 m and with a flow rate of 12 l/s.
Nonintrusive Measurement of Contact Forces During Vibration Dominated Impacts
Authors: Singh Satwinder Jit , Chatterjee Anindya
Published: December 2004

Impact force estimation is done indirectly through, e.g., strain measurements away from the contact point, because inserting a force transducer between the contacting objects changes the force. Most prior contact force measurements involved a single contact interval. Here we study transverse impacts of a slender beam and a clamped-free plate; contact occurs more than once within one impact. Strain gauge data, electrical contact detection, and a dynamic model of the beam are used to estimate the contact force. The problem of force estimation from strain gauge data is ill-posed, and Tikhonov regularization fails initially. A reduced-order model is then developed using symmetry, and better initial conditions are estimated using a Kalman filter. Subsequently, Tikhonov regularization gives excellent force estimates, empirically supported by the contact duration measurements. Two other methods that explicitly use the contact duration measurements are also given. The first uses Tikhonov regularization within each contact interval, followed by Kalman filtering during noncontact to get initial conditions for the next contact. The second uses truncated Fourier sine series in each contact interval and is, computationally, the simplest. All three methods provide consistent force estimates. Our work complements recent work by Inoue and coworkers where the impulse response of the colliding object was measured separately using a Hopkinson bar, and electrical contact was not monitored.
Nondestructive Evaluation of Parts With Degenerate Modes Using Pseudorepeated Roots
Authors: Jellison Brandon J. , Kess Harold R. , Adams Douglas E. , Nelson David C.
Published: December 2004

The modes of vibration of manufactured parts can be good indicators of the overall quality of the manufacturing process. That is, deviations in the modal frequencies or modal vectors of mechanical parts can help to identify outlier or systemic problems in the raw materials or fabrication procedure. A novel method for characterizing nonuniformities in homogeneous symmetric parts using pseudorepeated modal frequencies is discussed in this paper. It is demonstrated that the spacing between pseudorepeated roots in dominantly symmetric manufactured parts is a direct indicator of nonuniformities (i.e., inclusions, voids) in the stiffness or mass distributions. Smaller differences between split-peaks indicate less nonuniformity, and hence, higher quality parts. A simple fourth-order lumped parameter model is used to elaborate on this technique analytically, a representative finite element model is used to further this development, root locus techniques are used to study the sensitivity to nonuniformities, and acceleration response data from impact vibration tests on deep drawn hemispherical shells are used to verify the approach experimentally.
Controller Synthesis Methodology for Multivariable Nonlinear Systems With Application to Aerospace
Authors: Nassirharand Amir , Karimi Hassan
Published: December 2004

In this paper, a new systematic controller synthesis methodology for use with highly nonlinear multivariable and nonautonomous systems with application to a class of multivariable nonlinear aerospace systems is presented. The procedure is applied to a typical liquid propellant engine, and the performance of the resulting new control system is presented. In this research, the nonlinear dynamic model of the engine, which includes both soft and hard nonlinearities, is developed. The systematic controller design procedure is based on describing function models of the engine coupled with a new multivariable exact model matching procedure.
The Duration of Forest Stages in Southern Europe and Interglacial Climate Variability
Authors: Tzedakis P. C. , Roucoux K. H. , de Abreu L. , Shackleton N. J.
Published: December 2004

Foraminiferal oxygen isotope and pollen analyses from a deep-sea sequence off southwest Portugal show that the duration of temperate stages on land over the past 350,000 years varied considerably. The record shows forest contractions during intervals of low ice volume, coeval with declines in atmospheric methane, after which tree populations did not always recover. What emerges is that, although the broad timing of interglacials is consistent with orbital theory, their specific duration may be dictated by millennial variability. This complicates the prediction of the natural duration of interglacials, at least until the origin of this climate variability is understood.
Asynchronous Terrestrial and Marine Signals of Climate Change During Heinrich Events
Authors: Jennerjahn Tim C. , Ittekkot Venugopalan , Arz Helge W. , Behling Hermann , Pätzold Jürgen , Wefer Gerold
Published: December 2004

Tropical regions have been reported to play a key role in climate dynamics. To date, however, there are uncertainties in the timing and the amplitude of the response of tropical ecosystems to millennial-scale climate change. We present evidence of an asynchrony between terrestrial and marine signals of climate change during Heinrich events preserved in marine sediment cores from the Brazilian continental margin. The inferred time lag of about 1000 to 2000 years is much larger than the ecological response to recent climate change and appears to be related to the nature of hydrological changes.
Coherent Atomic Motions in a Nanostructure Studied by Femtosecond X-ray Diffraction
Authors: Bargheer M. , Zhavoronkov N. , Gritsai Y. , Woo J. C. , Kim D. S. , Woerner M. , Elsaesser T.
Published: December 2004

Reversible structural changes of a nanostructure were measured nondestructively with subpicometer spatial and subpicosecond temporal resolution via x-ray diffraction (XRD). The spatially periodic femtosecond excitation of a gallium arsenide/aluminum gallium arsenide superlattice results in coherent lattice motions with a 3.5-picosecond period, which was directly monitored by femtosecond x-ray pulses at a 1-kilohertz repetition rate. Small changes (Δ
R
/
R
= 0.01) of weak Bragg reflexes (
R
= 0.005) were detected. The phase and amplitude of the oscillatory XRD signal around a new equilibrium demonstrate that displacive excitation of the zone-folded acoustic phonons is the dominant mechanism for strong excitation.
DIFFERENCE EQUATION OF THE COLORED JONES POLYNOMIAL FOR TORUS KNOT
Authors: HIKAMI KAZUHIRO
Published: December 2004

We prove that the N-colored Jones polynomial for the torus knot [Formula: see text] satisfies the second order difference equation, which reduces to the first order difference equation for a case of [Formula: see text]. We show that the A-polynomial of the torus knot can be derived from the difference equation. Also constructed is a q-hypergeometric type expression of the colored Jones polynomial for [Formula: see text].
HOMOGENIZATION OF L∞ FUNCTIONALS
Authors: BRIANI ARIELA , PRINARI FRANCESCA , GARRONI ADRIANA
Published: December 2004

We study, via Γ-convergence, the homogenization in L∞ of supremal functionals of the form [Formula: see text]. We prove that the homogenized problem is still supremal and its energy density is given by a cell-problem formula.
PARALLEL COMPUTING METHOD OF VALUING FOR MULTI-ASSET EUROPEAN OPTION
Authors: ZHENG WEIMIN , SHU JIWU , GU YONGGEN , DENG XIAOTIE
Published: December 2004

A critical problem in finance engineering is to value the option and other derivatives securities correctly. The Monte Carlo method (MC) is an important one in the computation for the valuation of multi-asset European option. But its convergence rate is very slow. So various quasi Monte Carlo methods and the relative parallel computing method are becoming an important approach to the valuing of multi-asset European option. In this paper, we use a number-theoretic method, which is a H–W method, to generate identical distributed point set in order to compute the value of the multi-asset European option. It turns out to be very effective, and the time of computing is greatly shortened. Comparing with other methods, the method computes less points and it is especially suitable for high dimension problem.
STABILITY OF PARTITIONS UNDER $\mathcal{WB}$-PREFERENCES AND $\mathcal{BW}$-PREFERENCES
Authors: CECHLÁROVÁ KATARÍNA , HAJDUKOVÁ JANA
Published: December 2004

Let a set of players be given and suppose that players have strict preferences over other players. The preferences are then extended to preferences over sets using the best (worst) player of a set and the worst (best) player as a tie-breaker. For such set-preferences we study the structure and computational questions connected with the existence problem of stable partitions. In the end, we review the known results for stable partitions under various preferences and point out some open questions.
CLASSIFICATIONS OF CREDIT CARDHOLDER BEHAVIOR BY USING FUZZY LINEAR PROGRAMMING
Authors: HE JING , LIU XIANTAO , SHI YONG , XU WEIXUAN , YAN NIAN
Published: December 2004

Behavior analysis of credit cardholders is one of the main research topics in credit card portfolio management. Usually, the cardholder's behavior, especially bankruptcy, is measured by a score of aggregate attributes that describe cardholder's spending history. In real-life practice, statistics and neural networks are the major players to calculate such a score system for prediction. Recently, various multiple linear programming-based classification methods have been promoted for analyzing credit cardholders' behaviors. As a continuation of this research direction, this paper proposes a heuristic classification method by using the fuzzy linear programming (FLP) to discover the bankruptcy patterns of credit cardholders. Instead of identifying a compromise solution for the separation of credit cardholder behaviors, this approach classifies the credit cardholder behaviors by seeking a fuzzy (satisfying) solution obtained from a fuzzy linear program. In this paper, a real-life credit database from a major US bank is used for empirical study which is compared with the results of known multiple linear programming approaches.
RULEMINER: A KNOWLEDGE SYSTEM FOR SUPPORTING HIGH-THROUGHPUT PROTEIN FUNCTION ANNOTATIONS
Authors: YU GONG-XIN
Published: December 2004

In this paper, we present RuleMiner, a knowledge system to facilitate a seamless integration of multi-sequence analysis tools and define profile-based rules for supporting high-throughput protein function annotations. This system consists of three essential components, Protein Function Groups (PFGs), PFG profiles and rules. The PFGs, established from an integrated analysis of current knowledge of protein functions from Swiss-Prot database and protein family-based sequence classifications, cover all possible cellular functions available in the database. The PFG profiles illustrate detailed protein features in the PFGs as in sequence conservations, the occurrences of sequence-based motifs, domains and species distributions. The rules, extracted from the PFG profiles, describe the clear relationships between these PFGs and all possible features. As a result, the RuleMiner is able to provide an enhanced capability for protein function analysis, such as results from the integrated sequence analysis tools for given proteins can be comparatively analyzed due to the clear feature-PFG relationships. Also, much needed guidance is readily available for such analysis. If the rules describe one-to-one (unique) relationships between the protein features and the PFGs, then these features can be utilized as unique functional identifiers and cellular functions of unknown proteins can be reliably determined. Otherwise, additional information has to be provided.
PROGRESSIVE MULTIPLE ALIGNMENT USING SEQUENCE TRIPLET OPTIMIZATIONS AND THREE-RESIDUE EXCHANGE COSTS
Authors: KONAGURTHU ARUN SIDDHARTH , WHISSTOCK JAMES , STUCKEY PETER J.
Published: December 2004

In this paper we demonstrate a practical approach to construct progressive multiple alignments using sequence triplet optimizations rather than a conventional pairwise approach. Using the sequence triplet alignments progressively provides a scope for the synthesis of a three-residue exchange amino acid substitution matrix. We develop such a 20×20×20 matrix for the first time and demonstrate how its use in optimal sequence triplet alignments increases the sensitivity of building multiple alignments. Various comparisons were made between alignments generated using the progressive triplet methods and the conventional progressive pairwise procedure. The assessment of these data reveal that, in general, the triplet based approaches generate more accurate sequence alignments than the traditional pairwise based procedures, especially between more divergent sets of sequences.
IMPROVING GENE NETWORK INFERENCE BY COMPARING EXPRESSION TIME-SERIES ACROSS SPECIES, DEVELOPMENTAL STAGES OR TISSUES
Authors: BOURQUE GUILLAUME , SANKOFF DAVID
Published: December 2004

We present a method for gene network inference and revision based on time-series data. Gene networks are modeled using linear differential equations and a generalized stepwise multiple linear regression procedure is used to recover the interaction coefficients. Our system is designed for the recovery of gene interactions concurrently in many gene regulatory networks related by a tree or a more general graph. We show how this comparative framework can facilitate the recovery of the networks and improve the quality of the solutions inferred.
Generation and functional significance of CXC chemokines for neutrophil-induced liver injury during endotoxemia
Authors: Dorman Robert B. , Gujral Jaspreet S. , Bajt Mary Lynn , Farhood Anwar , Jaeschke Hartmut
Published: December 2004

Generation and functional significance of CXC chemokines for neutrophil-induced liver injury during endotoxemia. Am J Physiol Gastrointest Liver Physiol 288: G880–G886, 2005. First published December 2, 2004;.—The hypothesis that the neutrophil chemoattractant CXC chemokines KC and macrophage inflammatory protein-2 (MIP-2) are involved in neutrophil transmigration and liver injury was tested in C3Heb/FeJ mice treated with galactosamine (Gal, 700 mg/kg), endotoxin (ET, 100 μg/kg), or Gal + ET (Gal/ET). Hepatic KC and MIP-2 mRNA levels and plasma CXC chemokine concentrations were dramatically increased 1.5 h after Gal/ET or ET alone and gradually declined up to 7 h. Murine recombinant cytokines (TNF-α, IL-1α, and IL-1β), but not Gal/ET, induced CXC chemokine formation in the ET-resistant C3H/HeJ strain. To assess the functional importance of KC and MIP-2, C3Heb/FeJ mice were treated with Gal/ET and control IgG or a combination of anti-KC and anti-MIP-2 antibodies. Anti-CXC chemokine antibodies did not attenuate hepatocellular apoptosis, sinusoidal neutrophil sequestration and extravasation, or liver injury at 7 h. Furthermore, there was no difference in liver injury between BALB/cJ wild-type and CXC receptor-2 gene knockout (CXCR2−/−) mice treated with Gal/ET. The higher neutrophil count in livers of CXCR2−/−than in wild-type mice after Gal/ET was caused by the elevated number of neutrophils located in sinusoids of untreated CXCR2−/−animals. The pancaspase inhibitor Z-Val-Ala-Asp-fluoromethylketone eliminated Gal/ET-induced apoptosis and neutrophil extravasation and injury but not CXC chemokine formation. Thus Gal/ET induced massive, cytokine-dependent CXC chemokine formation in the liver. However, neutrophil extravasation and injury occurred in response to apoptotic cell injury at 6–7 h and was independent of CXC chemokine formation.
Increased expression and altered subcellular distribution of PKC-δ in chronically hypoxic rat myocardium: involvement in cardioprotection
Authors: Neckář Jan , Marková Irena , Novák František , Nováková Olga , Szárszoi Ondrej , Ošt'ádal Bohuslav , Kolář František
Published: December 2004

We examined the role of protein kinase C (PKC) in the cardioprotective mechanism induced by long-term adaptation to chronic intermittent hypoxia. Adult male Wistar rats were exposed to hypobaric hypoxia of 7,000 m for 8 h/day, 5 days/wk; the total number of exposures was 24–32. A control group was kept under normoxic conditions. Western blot analysis of PKC isoforms-δ and -ε was performed in the cytosol and three particulate fractions of left ventricular myocardium. Infarct size was determined in open-chest animals subjected to 20-min coronary artery occlusion and 3-h reperfusion. The PKC inhibitors chelerythrine (1 or 5 mg/kg) or rottlerin (selective for PKC-δ isoform; 0.3 mg/kg) were administered intravenously as a single bolus 15 min before ischemia. Chronic hypoxia had no effect on the expression and distribution of PKC-ε. The relative amount of PKC-δ increased in the cytosol and nuclear-cytoskeletal, mitochondrial, and microsomal fractions of chronically hypoxic myocardium by 100%, 212%, 237%, and 146%, respectively, compared with corresponding normoxic values. Chronic hypoxia decreased the size of myocardial infarction (normalized to the area at risk) by about one-third on the average ( P < 0.05). Both doses of chelerythrine tended to reduce infarction in controls, and only the high dose completely abolished the improvement of ischemic tolerance in hypoxic hearts ( P < 0.05). Rottlerin attenuated the infarct size-limiting effect of chronic hypoxia ( P < 0.05), and it had no effect in controls. These results suggest that chronic intermittent hypoxia-induced cardioprotection in rats is partially mediated by PKC-δ; the contribution of other isoforms remains to be determined.
Fluid shear stress induces differentiation of Flk-1-positive embryonic stem cells into vascular endothelial cells in vitro
Authors: Yamamoto Kimiko , Sokabe Takaaki , Watabe Tetsuro , Miyazono Kohei , Yamashita Jun K. , Obi Syotaro , Ohura Norihiko , Matsushita Akiko , Kamiya Akira , Ando Joji
Published: December 2004

Pluripotent embryonic stem (ES) cells are capable of differentiating into all cell lineages, but the molecular mechanisms that regulate ES cell differentiation have not been sufficiently explored. In this study, we report that shear stress, a mechanical force generated by fluid flow, can induce ES cell differentiation. When Flk-1-positive (Flk-1+) mouse ES cells were subjected to shear stress, their cell density increased markedly, and a larger percentage of the cells were in the S and G2-M phases of the cell cycle than Flk-1+ES cells cultured under static conditions. Shear stress significantly increased the expression of the vascular endothelial cell-specific markers Flk-1, Flt-1, vascular endothelial cadherin, and PECAM-1 at both the protein level and the mRNA level, but it had no effect on expression of the mural cell marker smooth muscle α-actin, blood cell marker CD3, or the epithelial cell marker keratin. These findings indicate that shear stress selectively promotes the differentiation of Flk-1+ES cells into the endothelial cell lineage. The shear stressed Flk-1+ES cells formed tubelike structures in collagen gel and developed an extensive tubular network significantly faster than the static controls. Shear stress induced tyrosine phosphorylation of Flk-1 in Flk-1+ES cells that was blocked by a Flk-1 kinase inhibitor, SU1498, but not by a neutralizing antibody against VEGF. SU1498 also abolished the shear stress-induced proliferation and differentiation of Flk-1+ES cells, indicating that a ligand-independent activation of Flk-1 plays an important role in the shear stress-mediated proliferation and differentiation by Flk-1+ES cells.
Evaluation of Three Molecular Biology-Based Assays for the Detection of GB Virus C/Hepatitis G Virus in Clinical Specimens
Authors: Bortolin Maria Teresa , Zanussi Stefania , Tedeschi Rosamaria , Pratesi Chiara , D’Andrea Monica , Bidoli Ettore , di Gennaro Giampiero , de Paoli Paolo
Published: December 2004

Objective: The present study was performed to evaluate the reliability of three reverse transcription-polymerase chain reaction (RT-PCR) assays, one commercial and two ‘homebrew’, for GB virus C (GBV-C)/hepatitis G virus (HGV) RNA detection in clinical specimens. We, therefore, investigated the virus prevalence with the method that gave us the best performances. Methods: The commercial assay amplified sequences from the viral 5′-untranslated region (5′UTR) and non-structural 3 (NS3) region. The non-commercial assays 1 and 2 were based on different primers for the 5′UTR consensus sequence. Results: The percentage of overall concordance by the three methods was 91.7%, raising to 93.0% when only the two non-commercial methods were compared. Assay 1 showed low sensitivity (57.1% vs. the commercial assay, 58.8% vs. assay 2), with 100% specificity. The commercial assay gave 18 of 54 (33.3%) ‘false-negative’ results, concordantly negative by the other assays. The prevalence of GBV-C/HGV RNA among the HIV+ patients was 27.0 and 32.6% in HIV/HCV co-infected patients. Conclusion: These data suggest that assay 2 has higher reliability as compared to the other two methods and may be used for an accurate GBV-C/HGV RNA detection in clinical and epidemiological studies.
Benefit of Lamivudine Therapy and Factors Associated with Clinical Outcome in Spontaneous Severe Acute Exacerbation of Chronic Hepatitis B Virus Infection
Authors: Tsubota Akihito , Arase Yasuji , Suzuki Yoshiyuki , Suzuki Fumitaka , Hosaka Tetsuya , Akuta Norio , Someya Takashi , Kobayashi Masahiro , Saitoh Satoshi , Ikeda Kenji , Kumada Hiromitsu
Published: December 2004

Objective: During the course of chronic hepatitis B virus (HBV) infection, severe acute exacerbations of the infection often occur spontaneously and follow a fulminating progression to fatal hepatic failure. The aim of this study was to clarify potential factors, including benefit of lamivudine therapy, which could influence clinical course of the serious disease in an area of intermediate HBV endemicity. Methods and Results: Using a database of 3,163 chronically HBV-infected patients, 418 (13.2%) developed acute exacerbation of hepatitis B. Of the 418 patients, 52 (12.4%) spontaneously developed severe acute exacerbation and were included in this study. Of the 52 patients, 23 were treated with lamivudine. In multivariate analyses, fulminating progression to hepatic failure (odds ratio, 15.45; 95% confidence interval, 3.71–64.41; p = 0.0002) was a significantly independent predictor of patient survival. Three variables were independently associated with fulminating development of hepatic failure: presence of cirrhosis (29.06, 1.74–85.56, 0.019, respectively), higher baseline bilirubin level (14.89, 1.31–52.91, 0.029, respectively), and genotype B (22.14, 1.59–29.68, 0.021, respectively). Treatment lacking lamivudine was a significant factor that contributed to shorter survival time, development of hepatic failure, and progression to cirrhosis in univariate analyses (p = 0.014, 0.012 and 0.0030, respectively). Conclusion: In an area of intermediate HBV endemicity, certain proportion of chronic hepatitis B patients could spontaneously develop the serious disease. Factors influencing clinical course of the disease should be identified to improve prognosis and establish more rational and effective therapeutic strategies. Lamivudine therapy could potentially benefit the serious disease, although larger series of patients and longer follow-up periods are needed.
Modifications in SENV DNA Detection and/or SENV Subtype Determination over a Prospective Follow-Up in a Cohort of HIV-Positive Patients: Is This a Moving Target?
Authors: Quiros-Roldan Eugenia , Torti Carlo , Pirovano Silvia , Moretti Francesca , Casari Salvatore , Carosi Giampiero , Soriano Vicente , Imberti Luisa
Published: December 2004

SEN virus (SENV) is a new family of single-stranded DNA viruses with eight different strains, A–H. The modifications in SENV DNA detection and subtype distribution were studied over a long-term follow-up (48 ± 32.5 months) in 52 HIV-infected patients. 46% of the patients in the first sample and 34.6% in the second sample were found to have detectable SENV viremia. While the most prevalent variant in the first sample was found to be genotype A (83.3%), the second sample revealed a broader subtype diversification. Several epidemiological and clinical variables were tested in univariate model for clearance of detectable SENV viremia, but none of them reached statistical significance. In conclusion, a high degree of instability of both SENV DNA detection and subtype distribution in a cohort of HIV-infected patients was suggested, which may have important implications for further studies on both SENV epidemiology and its clinical impact.