bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of epoxy–montmorillonite nanocomposite
Authors: Chen K. H. , Yang S. M.
Published: October 2002

To synthesize an epoxy–montmorillonite nanocomposite, the intercalation of clay layers with acid onium ions {[H3N(CH2)n−1COOH]+, [H3N(CH2)n−1CH3]+, [H3N(CH2)−NH2]+, and [H3N(CH2)nNH3]2+} by different methods were studied. The intercalated clay was characterized by XRD, ICP, and CHN elemental analysis. An acid onium ion [H3N(CH2)17CH3]+ enlarged the d‐spacing of CWC–, AMS–, and Kunipia–montmorillonite to 21.6, 18.1, and 20.7 Å, respectively. The results of CHN elemental analysis confirmed that onium ions were intercalated between the clay layers. Ion exchange of montmorillonite with onium ions is a better way to intercalate more onium ions. Among those onium ions mentioned above, [H3N(CH2)nNH3]2+ displaced more sodium ions from the clay layers than did the others. An epoxy–montmorillonite nanocomposite was synthesized by heating a mixture of [H3N(CH2)17CH3]+–montmorillonite (CWC) with an epoxy monomer and curing agent. The nanocomposite was characterized by XRD, TEM, DSC, UV, TGA, and Instron testing. TEM photographs showed that the spacing between the clay layers was further enlarged to about 50 Å and no segregation between the clay particle and the polymer was observed. The glass transition temperature of the nanocomposite containing 20 phr of [H3N(CH2)17CH3]+–montmorillonite (CWC) increased from 108.4 to 146.1°C. Especially, the nanocomposite possesses higher water resistance than that of the epoxy resin or of the physical mixture of epoxy and montmorillonite (CWC). According to the transmittance measurement (λ = 550 nm), the nanocomposite shows good light transmittance. Although, we cannot improve the mechanical properties, improvements of other properties can be evidenced for the formation of nanoscale composites. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 414–421, 2002
Effect of degree of saponification on the rheological properties of syndiotactic poly(vinyl alcohol)/ water solution
Authors: Lyoo Won Seok , Seo In Seok , Yeum Jeong Hyun , Yoon Won Sik , Ji Byung Chul , Kim Bong Shik , Lee Sang‐Seob , Kim Byoung Chul
Published: October 2002

To identify the effect of degree of saponification (DS) of syndiotactic poly(vinyl alcohol)s (s‐PVA)s having similar tacticity and molecular weight on the rheological properties of s‐PVA/water solution, four kinds of (s‐PVA)s with assigned (DS)s, from 93.1 to 97.5%, were prepared by copolymerization of vinyl pivalate (VPi) and vinyl acetate (VAc), followed by saponifying the corresponding copoly(VPi/VAc). The DS played a significant role in rheological behavior. Over the frequency range of 10−1 to 102 rad/s s‐PVA with higher DS shows more shear thinning at similar molecular weight and tacticity of polymer, suggesting that PVA molecules are more readily oriented as DS increases. This may provide indirect evidence of the spontaneous in situ orientation of s‐PVA molecules at the late stage of saponification. Yield stress is higher for s‐PVA with higher DS at similar molecular weight and tacticity of s‐PVA. This indicates that more domains with internal order are produced at higher saponification. These facts result from increase in stiffness of s‐PVA molecules with proceeding the saponification reaction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 463–467, 2002
Bone density of the arm and forearm as an age indicator in specimens of stranded striped dolphins (stenella coeruleoalba)
Authors: Guglielmini Carlo , Zotti Alessandro , Bernardini Daniele , Pietra Marco , Podestá Michela , Cozzi Bruno
Published: October 2002

The age of odontocetes living in the wild is determined mainly by analysis of dentine layers in sections of the teeth. We examined a series of specimens from striped dolphins (Stenella coeruleoalba, Meyen, 1833) that had stranded along the Italian coast of the Mediterranean sea. The present study analyzes and describes bone density in the arm and forearm of the stranded specimens, and correlates the data with total body length of the animal and age as determined by the number of dentine layers in sections of the teeth. According to our model, age can be predicted on the basis of bone density and total body length of the stranded animal. This is the first study to use bone density as a biological parameter to understand the wear and tear of life in the sea. The results suggest that bone density is a new tool for recording age in wild odontocetes. Anat Rec 267:225–230, 2002. © 2002 Wiley‐Liss, Inc.
Dosimetry implications of upper tracheobronchial airway anatomy in two mouse varieties
Authors: Oldham Michael J. , Phalen Robert F.
Published: October 2002

Strain‐ and variety‐related differences in responses of mice have been reported for a variety of inhaled particulate and gaseous materials. It is important to understand the potential contributions to such responses of differences in delivered doses to the respiratory tract as well as differences in biochemical processes. Deposition doses of inhaled particles are influenced by several factors, including airway anatomy, ventilation, and particle characteristics. Tracheobronchial airway morphometry for airway generations 1–6 of the BALB/c mouse was generated using replica lung casts prepared in situ. Measurements were performed on two groups: control and ovalbumin‐sensitized male BALB/c mice. These measurements were compared with previously published airway morphometry of male B6C3F1 mice. Sensitization did not significantly change measured airway dimensions in the BALB/c mouse. However, the two mouse varieties had significant differences in airway anatomy. The differences found in airway anatomy between mouse varieties correlated with differences in body length and chest circumference. Particle deposition predictions for both varieties of mice were performed for unit density spherical particles from 0.1 to 10 μm in diameter at two ventilation rates using a published aerosol dosimetry computer code. Particle deposition in the proximal tracheobronchial tree ranged up to 3 times greater for the BALB/c mouse for a 2 μm particle diameter and high ventilation rate. These differences in predicted particle deposition suggest that observed strain and variety differences in response to inhaled particulate matter may be in part due to differences in delivered doses to the respiratory tract. Anat Rec 268:59–65, 2002. © 2002 Wiley‐Liss, Inc.
Nitric oxide synthase in the frog cerebellum: Response of Purkinje neurons to unilateral eighth nerve transection
Authors: Pisu Maria Bonaria , Conforti Elena , Botta Laura , Valli Paolo , Bernocchi Graziella
Published: October 2002

When vestibular damage occurs, nitric oxide synthase (NOS) expression in rat cerebellar flocculus is affected. Since compensation for postural symptoms occurs and Purkinje cells play an important role in movement coordination and motor learning, we analyzed in situ the induction of NOS in the Purkinje cell population of the cerebellum (corpus cerebelli) of frog after unilateral transection of the eighth statoacoustic nerve to gain insight into the role of NO in neural plasticity after injury. Three days after neurectomy, the early effects induced NADPH diaphorase reactivity in most of the Purkinje cells on the ipsilateral side, while on the contralateral side the highest labeling was observed at 15 days. This finding can give information on the dynamics of vestibular compensation, in which NOS involvement was investigated. At 30 days, NADPH diaphorase reactivity was present in a large number of Purkinje cells of the whole cerebellum, while at 60 days a down‐regulation for NADPH diaphorase reactivity was evident. A similar trend was observed for NOS‐immunoreactivity, which was still present at 60 days in a high percentage of Purkinje cells, mainly on the ipsilateral side. On the basis of cell density evaluations, it was proposed that the early induction of NOS after neurectomy was linked to the degeneration of a part of the Purkinje neurons, while the permanence of NOS labeling might be due to a neuroprotective role of NO in the restoration phase of the vestibular compensation process. Anat Rec 268:73–83, 2002. © 2002 Wiley‐Liss, Inc.
Increased life span of human osteoarthritic chondrocytes by exogenous expression of telomerase
Authors: Piera‐Velazquez Sonsoles , Jimenez Sergio A. , Stokes DavidG.
Published: October 2002

Objective

To extend the life span of human osteoarthritic (OA) articular chondrocytes by introduction of the catalytic component of human telomerase while preserving the chondrocyte‐specific phenotype.

Methods

Human articular chondrocytes were isolated from the femoral head and tibial plateau of patients undergoing knee joint replacement for OA. The chondrocytes were cultured as monolayers and infected with a retroviral telomerase expression construct followed by selection with G418 for 10–14 days. Telomeric‐repeat amplification protocol assays and telomere terminal restriction fragment length assays were performed on pools of transduced cells in order to measure telomerase activity and telomere length. Growth kinetics and population doubling capacity were assessed by passaging the cells in monolayer culture. Redifferentiation of the monolayer chondrocyte cultures was induced by transfer to suspension culture on poly‐(2‐hydroxyethyl‐methacrylate) (polyHEMA)–coated dishes. Induction of the chondrocyte‐specific phenotype was monitored by analysis of gene expression utilizing reverse transcription–polymerase chain reaction.

Results

OA chondrocytes isolated from 3 different donors (ages 41, 69, and 75 years) were transduced with a retroviral construct expressing telomerase. After selection, pooled populations of cells from all donors and a clonal cell line from 1 donor expressed telomerase activity and exhibited lengthening of telomeres. Chondrocytes expressing telomerase showed an increase of 5–9 population doublings over 234 days of culture in monolayer. The telomerase‐transduced cells recovered a chondrocyte‐specific gene expression pattern following culture on polyHEMA‐coated dishes.

Conclusion

The exogenous expression of telomerase may represent a way to expand human OA chondrocytes while allowing maintenance of the chondrocyte‐specific phenotype. These cells have the potential to be used for restoration of the articular cartilage defects occurring in this disease.
Assessment of vascular function in systemic sclerosis: Indications of the development of nitrate tolerance as a result of enhanced endothelial nitric oxide production
Authors: Andersen Grethe Neumann , Mincheva‐Nilsson Lucia , Kazzam Elsadig , Nyberg Gunnar , Klintland Natalia , Petersson Ann‐Sofi , Rantapää‐Dahlqvist Solbritt , Waldenström Anders , Caidahl Kenneth
Published: October 2002

Objective

To investigate the relationship between endothelium‐dependent and endothelium‐independent functions and the stiffness of conduit arteries as well as levels of endothelial activation markers in patients with systemic sclerosis (SSc).

Methods

Endothelium‐dependent (i.e., flow‐mediated) and endothelium‐independent (i.e., nitroglycerin‐induced) dilation of the brachial artery was measured as the percentage of change from baseline (FMD% and NTG%, respectively) in 24 SSc patients and 24 age‐ and sex‐matched healthy controls by high‐resolution ultrasound imaging. The maximum increase in systolic pressure per unit of time (dP/dtmax), as a measure of arterial wall stiffness, was assessed in the radial artery by pulse applanation tonometry. Plasma nitrate, the most important metabolite of nitric oxide, and 24‐hour urinary excretion of nitrate were measured by gas chromatography mass spectrometry. Soluble E‐selectin and soluble vascular cell adhesion molecule 1 (sVCAM‐1) were measured by enzyme‐linked immunosorbent assay.

Results

Brachial artery FMD% and NTG% did not differ between SSc patients and controls. Radial artery dP/dtmax was significantly increased in the patients and correlated significantly with elevated levels of plasma nitrate and sVCAM‐1. Twenty‐four‐hour urinary nitrate excretion tended to be elevated. Brachial artery NTG% was significantly inversely correlated with levels of plasma nitrate and soluble endothelial adhesion molecules.

Conclusion

The ability of the brachial arteries to dilate in response to hyperemia and nitroglycerin challenge is preserved in SSc. Stiffness of the radial artery is increased, however. Endothelial activation seems to determine the extent of the brachial artery NTG% and the radial artery dP/dtmax. The data are compatible with the hypothesis that nitrate tolerance is present in the vascular smooth muscle cells of the brachial artery wall in SSc.
The α5β1 integrin provides matrix survival signals for normal and osteoarthritic human articular chondrocytes in vitro
Authors: Pulai Judit I. , Del Carlo Marcello , Loeser Richard F.
Published: October 2002

Objective

Chondrocyte cell death may play an important role in the development of arthritis. The goal of the present study was to evaluate the role of the extracellular matrix (ECM) in promoting chondrocyte survival via signals through the integrin family of ECM receptors.

Methods

Chondrocytes were isolated by sequential enzymatic digestion from normal ankle cartilage of organ donors and from osteoarthritic (OA) knee tissue obtained from patients undergoing total knee replacement. Cell survival in monolayer and in suspension culture was measured using fluorescent labels after treatment with specific integrin‐blocking antibodies and echistatin, a disintegrin peptide. A quantitative enzyme‐linked immunosorbent assay for histone‐associated DNA fragments and morphologic evaluation by electron microscopy were used to evaluate apoptosis.

Results

Freshly isolated chondrocytes died when plated in serum‐free media at low density on poly‐L‐lysine, but showed >95% survival on fibronectin (FN). A monoclonal blocking antibody to the α5‐integrin subunit (FN receptor) significantly inhibited survival on FN, whereas control antibodies had no effect. Likewise, treatment of freshly isolated chondrocytes in serum‐free alginate‐suspension culture with the α5‐blocking antibody resulted in cell death in a dose‐dependent manner, with 20 μg/ml of the antibody reducing normal chondrocyte survival to 20% of that in controls, and OA chondrocyte survival to 23% of that in controls. Antibody inhibition of αv and α1 integrins or treatment with echistatin did not cause cell death. Addition of insulin‐like growth factor 1 (IGF‐1; 100 ng/ ml) was not able to improve survival of α5‐antibody–treated cells. However, treatment with 10% fetal bovine serum improved normal chondrocyte survival to 98% (a 5.1‐fold increase) and OA chondrocyte survival to 64% (a 2.8‐fold increase). Cell death due to α5 inhibition was associated with apoptosis.

Conclusion

These results demonstrate that chondrocyte survival signals are transmitted via the α5β1 FN receptor. Inhibition of matrix survival signals mediated by α5β1 also inhibits the ability of IGF‐1 to promote survival, suggesting that IGF‐1–mediated survival signaling may require a cosignal from α5β1.
Underutilization of gastroprotective measures in patients receiving nonsteroidal antiinflammatory drugs
Authors: Smalley Walter , Stein C. Michael , Arbogast Patrick G. , Eisen Glenn , Ray Wayne A. , Griffin Marie
Published: October 2002

Objective

To determine the frequency of use of recommended gastroprotective strategies in a cohort of patients receiving recurrent treatment with nonsteroidal antiinflammatory drugs (NSAIDs).

Methods

A cross‐sectional study was performed using administrative data from the Tennessee Medicaid (TennCare) program. The study population consisted of 76,765 recurrent recipients of NSAIDs (NSAID users), comprising 24% of the 319,402 persons ages 50 years or older enrolled in the TennCare program from January 1999 through June 2000. Frequency of use of either of 2 recommended gastroprotective strategies, involving either traditional NSAIDs combined with recommended anti‐ulcer cotherapy or use of a selective cyclooxygenase 2–inhibiting drug (coxib), was measured and categorized by risk for ulcer complication.

Results

Among this cohort of recurrent NSAID users, 16% received 1 of the 2 recommended gastroprotective therapies: 10% received traditional NSAIDs along with antiulcer drugs at the recommended doses and 6% received coxibs. Among those patients with ≥2 risk factors for ulcer complications (age 75 years or older, peptic ulcer or gastrointestinal bleeding in the past year, or concurrent use of oral anticoagulants or corticosteroids), 30% received such gastroprotective therapy.

Conclusion

Use of recommended strategies to decrease ulcer complications in vulnerable populations is relatively uncommon.
Systemic lupus erythematosus in three ethnic groups. XI. Sources of discrepancy in perception of disease activity: A comparison of physician and patient visual analog scale scores
Authors: Alarcón Graciela S. , McGwin Gerald , Brooks Kemi , Roseman Jeffrey M. , Fessler Barri J. , Sanchez Martha L. , Bastian Holly M. , Friedman Alan W. , Baethge Bruce A. , Reveille John D. ,   LUMINA STUDY GROUP
Published: October 2002

Objective

To compare patient's and physician's assessment of disease activity in a multiethnic (Hispanic, African American, and Caucasian) cohort of systemic lupus erythematosus (SLE) patients.

Methods

Three hundred patients with SLE from the LUMINA (Lupus in Minority populations: Nature versus nurture) cohort were included. Disease activity was assessed with the Systemic Lupus Activity Measure (SLAM); patients and physicians assessed disease activity using a 10‐cm anchored visual analog scale (VAS). The difference between VAS scores was termed discrepancy (>1 cm was considered a priori clinically relevant). Selected sociodemographic, clinical, behavioral, and psychological variables were examined in relation to discrepancy in univariable and multivariable models adjusting for the physician global VAS score in order to eliminate ceiling and floor effects.

Results

A discrepancy was exhibited by 58% of the patients. Abnormal laboratory findings were negatively associated with discrepancy, and poor self‐perceived functioning and joint involvement were positively associated with discrepancy. Ethnicity did not account for discrepant perception of disease activity.

Conclusion

Patients and physicians rate disease activity in SLE differently. Physicians appear to place more emphasis on laboratory features while patients place more emphasis on function.
Cartilage‐specific constitutive expression of TSG‐6 protein (product of tumor necrosis factor α–stimulated gene 6) provides a chondroprotective, but not antiinflammatory, effect in antigen‐induced arthritis
Authors: Glant Tibor T. , Kamath Rajesh V. , Bárdos Tamás , Gál István , Szántó Sándor , Murad Yanal M. , Sandy John D. , Mort John S. , Roughley Peter J. , Mikecz Katalin
Published: October 2002

Objective

To study the chondroprotective effect of constitutively expressed TSG‐6 protein (tumor necrosis factor α–induced protein 6; Tnfip6) in cartilage, using antigen‐induced arthritis (AIA) in mice.

Methods

Transgenic mice constitutively expressing TSG‐6 protein in cartilage were generated. Cartilage‐specific constitutive expression of TSG‐6 protein was confirmed by in situ hybridization, Western blot analysis, and immunohistochemistry. Control and transgenic mice were immunized with methylated bovine serum albumin (mBSA), and arthritis was induced by the intraarticular injection of mBSA. Mice were monitored up to day 35 after the challenge, and knee joint sections were examined for loss of cartilage proteoglycan (aggrecan) using Safranin O staining and antibodies to neoepitopes generated by various metalloproteinases (MPs). The loss of aggrecan in Safranin O–stained sections was quantified by morphometric methods.

Results

Tsg6/tnfip6 transgenic mice constitutively expressed tsg6/tnfip6 messenger RNA and corresponding TSG‐6 protein in cartilage from embryonic life through adulthood, without any phenotypic abnormalities. These mice were used for AIA studies. Intraarticular injection of mBSA uniformly induced severe inflammation both in control (wild‐type and an irrelevant transgenic line) mice and in tsg6/tnfip6 transgenic mice. In contrast to the mBSA‐injected knee joints of control animals that were heavily damaged from day 5, the cartilage of transgenic mice that constitutively expressed TSG‐6 protein remained intact for at least 1 week, and this was followed by a relatively reduced loss of aggrecan. Concomitant with the loss of aggrecan, MP‐generated neoepitopes accumulated in unprotected joints. By day 35, the proteoglycan content returned to nearly normal levels in tsg6/tnfip6 transgenic mice, whereas it remained low in MP‐damaged knee cartilage of control mice.

Conclusion

TSG‐6 protein is known to form a complex with inter‐α–inhibitor (IαI), a potent serine protease inhibitor, which may be immobilized via the hyaluronan (HA)–binding domain of TSG‐6 protein in the HA‐rich extracellular matrix of cartilage. Thus, the local accumulation of TSG‐6 protein and TSG‐6 protein–bound IαI in tsg6/tnfip6 transgenic mice may inhibit serine proteases and subsequent activation of MPs. It is suggested that this mechanism might protect cartilage from extensive degradation even in the presence of acute inflammation.
HLA–B27 modulates nuclear factor κB activation in human monocytic cells exposed to lipopolysaccharide
Authors: Penttinen Markus A. , Holmberg Carina I. , Sistonen Lea , Granfors Kaisa
Published: October 2002

Objective

To study whether HLA–B27 modifies some key factors controlling inflammatory responses on lipopolysaccharide (LPS) stimulation in human monocytic cells.

Methods

U937 human monocytic cells were stably transfected with either HLA–B27 genomic DNA, HLA–B27 complementary DNA, HLA–A2 genomic DNA, or with the resistant vector pSV2neo (mock) alone. The cells were stimulated with LPS. Electrophoretic mobility shift assay was performed to determine nuclear factor κB (NF‐κB) and heat‐shock factor 1 activities, Western blotting was performed to detect the expressions of inhibitory κBα (IκBα) and heat‐shock proteins (HSPs), and enzyme‐linked immunosorbent assay was performed to measure tumor necrosis factor α (TNFα) secretion.

Results

The expression of HLA–B27 modulated the response to LPS in U937 human monocytic cells. Stimulation with LPS led to faster degradation of IκBα regulatory proteins, accompanied by faster and prolonged activation of NF‐κB in HLA–B27–expressing cells compared with HLA–A2 and mock transfectants. The secretion of TNFα upon LPS stimulation correlated well with the activation of NF‐κB. No activation of the heat‐shock response was observed.

Conclusion

Our data indicate that HLA–B27 has effects on host responses to LPS that are unrelated to antigen presentation. Two crucial events in the development of arthritis, the activation of NF‐κB and the secretion of TNFα, were found to be enhanced in HLA–B27–expressing cells upon LPS stimulation. Because LPS is known to be present in the inflamed joints of patients with reactive arthritis (ReA), the enhanced inflammatory response of HLA–B27–positive cells upon LPS stimulation offers an attractive explanation for the role of HLA–B27 in the development of ReA.
The effects of menu design on information‐seeking performance and user's attitude on the World Wide Web
Authors: Yu Byeong‐Min , Roh Seak‐Zoon
Published: October 2002

As the Web becomes more popular, the interest in effective navigation is increasing. Menu design is becoming a central issue of human computer interface design as the focus of computer applications moves from the computer as a machine to the human as a user. The purpose of this study was to investigate the effect of three different Web menu designs (a simple selection menu, a global and local navigation menu, and a pull‐down menu) on users' information‐seeking performance and attitudes. Three Cyber‐shopping mall Web sites were developed for the experiment. These Web sites had the same content and a constant information structure, but each had a different menu design. The results showed different effect of menu design on both searching performance and browsing performance. More specifically, participants' searching performance was superior in the pull‐down menu condition compared to the global and local navigation menu and the simple selection menu conditions. Browsing task performance was the fastest with the global and local navigation menu. However, there were no significant differences among three menu designs in terms of users' perception on appeal of the Web site and disorientation.
On using genetic algorithms for multimodal relevance optimization in information retrieval
Authors: Boughanem M. , Chrisment C. , Tamine L.
Published: October 2002

This article presents a genetic relevance optimization process performed in an information retrieval system. The process uses genetic techniques for solving multimodal problems (niching) and query reformulation techniques commonly used in information retrieval. The niching technique allows the process to reach different relevance regions of the document space. Query reformulation techniques represent domain knowledge integrated in the genetic operators structure to improve the convergence conditions of the algorithm. Experimental analysis performed using a TREC subcollection validates our approach.
Investigation of the effects of concomitant caffeine administration on the metabolic disposition of pyrazinamide in rats
Authors: Mehmedagic Aida , Verite Philippe , Menager Sabine , Tharasse Christine , Chabenat Christiane , Andre Dominique , Lafont Olivier
Published: October 2002

The utility of pyrazinamide (PZA) in the short‐course antituberculous treatment is well established. All available data support the idea that the PZA metabolite pyrazinoic acid (PA) is the active compound against M. tuberculosis. This situation warranted a deeper investigation of possible interactions with respect to its metabolic disposition. Caffeine, which is widely used as a drug and is a common constituent of most diets, shares with PZA the same metabolic enzyme, xanthine oxidase (XO). This study investigated if, and in what manner, concomitant administration of caffeine affects PZA metabolism. PZA and caffeine, in various doses (PZA=50 or 100 mg kg−1 and caffeine= 0, 50, 100, and 150 mg kg−1), were administered to female Sprague‐Dawley rats. PZA and its three main metabolites were quantified in 24 h urine samples by reversed phase‐HPLC Concomitant administration of 100 mg kg−1 caffeine and 50 mg kg−1 PZA increased from the excretion (p<0.05) of the most water‐soluble and the least toxic PZA metabolite 5‐hydroxypyrazinoic acid (5‐OH‐PA) from 66.18±10.87 to 94.56±8.65 μmol/24 h. This effect was more pronounced when 100 mg kg−1 of PZA was administered increasing excretion of 5‐OH‐PA from 113.28±70 to 173.23±17.82 μmol/24 h. These results show that the metabolic disposition of PZA is affected by concomitant caffeine intake. Copyright © 2002 John Wiley & Sons, Ltd.
Initial perceptions in negotiations: evaluation and response to ‘logrolling’ offers
Authors: Moran Simone , Ritov Ilana
Published: October 2002

In negotiations, where several issues are under consideration and parties have different priorities among these issues, integrative agreements can be reached through ‘logrolling’: concessions on low priority issues in exchange for gains on higher priority issues. The present research focuses on the potential role of initial offers in the development of integrative agreements. We show first, that in a simulated competitive market the specific composition of initial offers influences the final agreements, beyond the effect predicted by their overall value. In order to obtain some insight into the judgmental processes that might play a role, we explore the way in which inexperienced negotiators presented with a hypothetical negotiation context evaluate and respond to logrolling versus distributive initial offers. Three hypotheses were tested: logrolling offers convey an implicit message of cooperation, logrolling offers promote understanding of the mutual interest structure of the task, and, finally, logrolling offers establish within‐issue anchors. Results do not support the first two hypotheses: logrolling offers were not necessarily judged more attractive than distributive ones, and they did not seem to affect the deeply rooted fixed‐pie assumption. However, initial offers did establish within‐issue anchors: counter‐offers were affected by the specific composition of the initial offers beyond the effect of their overall value. This anchoring process resulted in logrolling offers yielding a higher profit for their initiator, as well as higher combined profits for both parties. Copyright © 2002 John Wiley & Sons, Ltd.
Myoblast fusion in Drosophila
Authors: Dworak Heather A. , Sink Helen
Published: October 2002

Somatic muscle formation is an unusual process as it requires the cells involved, the myoblasts, to relinquish their individual state and fuse with one another to form a syncitial muscle fiber. The potential use of myoblast fusion therapies to rebuild damaged muscles has generated continuing interest in elucidating the molecular basis of the fusion process. Yet, until recently, few of the molecular players involved in this process had been identified. Now, however, it has been possible to couple a detailed understanding of the cellular basis of the fusion process with powerful classical and molecular genetic strategies in the Drosophila embryo. We review the cellular studies, and the recent genetic and biochemical analyses that uncovered interacting extracellular molecules present on fusing myoblasts and the intracellular effectors that facilitate fusion. With the conservation of proteins and protein functions across species, it is likely that these findings in Drosophila will benefit understanding of the myoblast fusion process in higher organisms. BioEssays 24:591–601, 2002. © 2002 Wiley Periodicals, Inc.
Potential genetic variance and the domestication of maize
Authors: Gottlieb Tanya M. , Wade Michael J. , Rutherford Suzanne L.
Published: October 2002

Since Darwin, there has been a long and arduous struggle to understand the source and maintenance of natural genetic variation and its relationship to phenotype. The reason that this task is so difficult is that it requires integration of detailed, and as yet incomplete, knowledge from several biological disciplines, including evolutionary, population, and developmental genetics. In this ‘post‐genomic’ era, it is relatively easy to identify differences in the DNA sequence between individuals. However, the task remains to delineate how this abundant genetic diversity actually contributes to phenotypic diversity. This necessitates tackling the problem of hidden genetic variation. Genetic polymorphisms can be conditionally cryptic, but have the potential to contribute to phenotypic variation in particular genetic backgrounds or under specific environmental conditions. A recent paper by Lauter and Doebley highlights the contribution of hidden genetic variation to traits characterizing the morphological evolution of modern maize from its wild grass‐like progenitor teosinte.1 This work is the first to demonstrate hidden variance for selected (agronomically ‘adaptive’) traits in a well‐characterized model for morphological evolution. BioEssays 24:685–689, 2002. © 2002 Wiley Periodicals, Inc.
Structural analysis of peptide helices containing centrally positioned lactic acid residues
Authors: Aravinda S. , Shamala N. , Das Chittaranjan , Balaram P.
Published: October 2002

The effect of insertion of lactic acid (Lac) residues into peptide helices has been probed using specifically designed sequences. The crystal structures of 11‐residue and 14‐residue depsipeptides Boc–Val–Val–Ala–Leu–Val–Lac–Leu–Aib–Val–Ala–Leu–OMe (1) and Boc–Val–Ala–Leu–Aib–Val–Ala–Leu–Val–Lac–Leu–Aib–Val–Ala–Leu–OMe (3), containing centrally positioned Lac residues, have been determined. The structure of an 11‐residue peptide Boc–Val–Ala–Leu–Aib–Val–Ala–Leu–Aib–Val–Ala–Leu–OMe (2), analog of a which is an amide previously determined Lac‐containing depsipeptide, Boc–Val–Ala–Leu–Aib–Val–Lac–Leu–Aib–Val–Ala–Leu–OMe I. L. Karle, C. Das, and P. Balaram, Biopolymers, Vol. 59, (2001) pp. 276–289], is also reported. Peptide 1 adopts a helical fold, which is stabilized by mixture of 4→1 and 5→1 hydrogen bonds. Peptide 2 adopts a completely α‐helical conformation stabilized by eight successive 5→1 hydrogen bonds. Peptide 3 appears to be predominately α‐helical, with seven 5→1 hydrogen bonds and three 4→1 interaction interspersed in the sequence. In the structure of peptide 3 in addition to water molecules in the head‐to‐tail region, hydration at an internal segment of the helix is also observed. A comparison of five related peptide helices, containing a single Lac residue, reveals that the hydroxy acid can be comfortably accommodated at interior positions in the helix, with the closest CO…O distances lying between 2.8 and 3.3 Å. © 2002 Wiley Periodicals, Inc. Biopolymers 64: 255–267, 2002
Integration of reactive membrane extraction with lipase‐hydrolysis dynamic kinetic resolution of naproxen 2,2,2‐trifluoroethyl thioester in isooctane
Authors: Lu Chu‐Hsun , Cheng Yu‐Chi , Tsai Shau‐Wei
Published: October 2002

Lipases immobilized on polypropylene powders have been used as the biocatalyst in the enantioselective hydrolysis of (S)‐naproxen from racemic naproxen thioesters in isooctane, in which trioctylamine was added to perform in situ racemization of the remaining (R)‐thioester substrate. A detailed study of the kinetics for hydrolysis and racemization indicates that increasing the trioctylamine concentration can activate and stabilize the lipase as well as enhance the racemization and non‐stereoselective hydrolysis of the thioester. Effects of the aqueous pH value and trioctylamine concentration on (S)‐naproxen dissociation and partitioning in the aqueous phase as well as the transportation in a hollow fiber membrane were further investigated. Good agreements between the experimental data and theoretical results were obtained when the dynamic kinetic resolution process was integrated with a hollow fiber membrane to reactively extract the desired (S)‐naproxen out of the reaction medium. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 200–210, 2002.
Active site titration as a tool for the evaluation of immobilization procedures of penicillin acylase
Authors: van Langen Luuk M. , Janssen Michiel H. A. , Oosthoek Natasja H. P. , Pereira Sílvia R. M. , Švedas Vytas K. , van Rantwijk Fred , Sheldon Roger A.
Published: October 2002

Native and immobilized preparations of penicillin acylase from Escherichia coli and Alcaligenes faecalis were studied using an active site titration technique. Knowledge of the number of active sites allowed the calculation of the average turnover rate of the enzyme in the various preparations and allowed us to quantify the contribution of irreversible inactivation of the enzyme to the loss of catalytic activity during the immobilization procedure. In most cases a loss of active sites as well as a decrease of catalytic activity per active site (turnover rate) was observed upon immobilization. Immobilization techniques affected the enzymes differently. The effect of increased loading of penicillin acylase on the average turnover rate was determined by active site titration to assess diffusion limitations in the carrier. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 224–228, 2002.
Low‐temperature electron microscopy for the study of polysaccharide ultrastructures in hydrogels. I. Theoretical and technical considerations
Authors: Serp D. , Mueller M. , von Stockar U. , Marison I. W.
Published: October 2002

The high‐pressure freezing (HPF) technique was applied to the cryo‐immobilization of alginate gels and the quality of the freezing analyzed on a TEM by comparison of the segregation pattern of samples of decreasing thickness. Dynamic simulations of heat transfer within an idealized slab of pure water surrounded by two walls of aluminium were performed to illustrate the effect of the heat‐transfer coefficient by convection on the cooling rate of the sample. Heat‐transfer coefficients in liquid nitrogen and liquid propane at ambient pressure were measured using a carefully characterized thermocouple and the values incorporated as parameters in heat‐transfer simulations to compare the efficiency of the plunge‐freezing technique with the high‐pressure freezing technique. Values of the heat‐transfer coefficient in liquid nitrogen and liquid propane, calculated between 273 K and 173 K were 670 and 18420 W/m2/K, respectively. Based on TEM observations and the results of heat‐transfer simulations, the HPF technique was adapted to the cryo‐fixation of 50‐μm‐thick alginate gels. The occurrence of artifacts was rejected because no differences were observed in the pattern of cryo‐fixed and freeze‐substituted samples of various thickness, with and without ethanol as cryo‐protectant. A sample thickness of 50 μm was found to ensure an adequate preservation of structures as small as a few nanometers, as verified by TEM and SEM observations. Finally, DSC measurements on alginate solutions and alginate beads revealed that under the experimental conditions (0–3%), alginate cannot be considered to be an efficient cryo‐protectant. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 243–252, 2002.
Protein‐mediated isolation of plasmid DNA by a zinc finger‐glutathione S‐transferase affinity linker
Authors: Woodgate John , Palfrey David , Nagel David A. , Hine Anna V. , Slater Nigel K. H.
Published: October 2002

The sequence‐specific affinity chromatographic isolation of plasmid DNA from crude lysates of E. coli DH5α fermentations is addressed. A zinc finger‐GST fusion protein that binds a synthetic oligonucleotide cassette containing the appropriate DNA recognition sequence is described. This cassette was inserted into the SmaI site of pUC19 to enable the affinity isolation of the plasmid. It is shown that zinc finger‐GST fusion proteins can bind both their DNA recognition sequence and a glutathione‐derivatized solid support simultaneously. Furthermore, a simple procedure for the isolation of such plasmids from clarified cell lysates is demonstrated. Cell lysates were clarified by cross‐flow Dean vortex microfiltration, and the permeate was incubated with zinc finger‐GST fusion protein. The resulting complex was adsorbed directly onto glutathione‐Sepharose. Analysis of the glutathione‐eluted complex showed that plasmid DNA had been recovered, largely free from contamination by genomic DNA or bacterial cell proteins. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 450–456, 2002.
Anchorage of cyclodextrin glucanotransferase on the outer membrane of Escherichia coli
Authors: Wan Hsiao‐Ming , Chang Ban‐Yang , Lin Sung‐Chyr
Published: October 2002

The gene encoding cyclodextrin glucanotransferase (CGTase) was successfully cloned from B. macerans by PCR. A recombinant plasmid pCS005 with a gene encoding the Lpp‐OmpA‐CGTase trifusion protein was constructed and transformed into E. coli for the surface display of CGTase. Results of immunoblotting analysis and protease accessibility on the fractionated cell membranes confirmed that the Lpp‐OmpA‐CGTase trifusion protein was successfully anchored on the outer membrane of E. coli. However, only 50% of the membrane‐anchored trifusion proteins were displayed on the outer surface of E. coli with the remaining 50% un‐translocated. The low efficiency of surface display is attributed to the large size of CGTase. Only a trace amount of CGTase activity was detected for both the whole cells and the cell debris fractions. Because the results of the protease accessibility study suggested that the trypsin‐resistant conformation of CGTase was preserved in the membrane‐anchored CGTase, we believe that the lack of enzyme activity is mainly due to the inaccessibility of the CGTase active site, near the N‐terminus, for substrate molecules. It can be estimated that the critical size for surface display of protein in E. coli is approximately 70 kDa. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 457–464, 2002.
p27Kip1‐mediated controlled proliferation technology increases constitutive sICAM production in CHO‐DUKX adapted for growth in suspension and serum‐free media
Authors: Meents Heiko , Enenkel Barbara , Werner Rolf G. , Fussenegger Martin
Published: October 2002

We have engineered dihydrofolate reductase‐deficient (dhfr−) Chinese hamster ovary (CHO)‐DUKX B11 cells adapted for growth in serum‐free suspension cultures for unlinked muristerone‐inducible expression of the cyclin‐dependent kinase inhibitor p27Kip1 and constitutive expression of the soluble intercellular adhesion molecule‐1 (sICAM), a potent common cold therapeutic. Conditional overexpression of p27Kip1 resulted in a sustained G1‐specific growth arrest of transgenic CHO‐DUKX associated with up to fivefold‐increased specific sICAM productivity. Herein we exemplify the implementation of controlled proliferation technology in a major biopharmaceutical production cell line that is compatible with key requirements for large‐scale production procedures, including constitutive transgene expression and anchorage‐independent growth in serum‐free media. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 619–627, 2002.
Water and glucose gradients in the substrate measured with NMR imaging during solid‐state fermentation with Aspergillus oryzae
Authors: Nagel Frank‐Jan , Van As Henk , Tramper Johannes , Rinzema Arjen
Published: October 2002

Gradients inside substrate particles cannot be prevented in solid‐state fermentation. These gradients can have a strong effect on the physiology of the microorganisms but have hitherto received little attention in experimental studies. We report gradients in moisture and glucose content during cultivation of Aspergillus oryzae on membrane‐covered wheat‐dough slices that were calculated from 1H‐NMR images. We found that moisture gradients in the solid substrate remain small when evaporation is minimized. This is corroborated by predictions of a diffusion model. In contrast, strong glucose gradients developed. Glucose concentrations just below the fungal mat remained low due to high glucose uptake rates, but deeper in the matrix glucose accumulated to very high levels. Integration of the glucose profile gave an average concentration close to the measured average content. On the basis of published data, we expect that the glucose levels in the matrix cause a strong decrease in water activity. The results demonstrate that NMR can play an important role in quantitative analysis of water and glucose gradients at the particle level during solid‐state fermentation, which is needed to improve our understanding of the response of fungi to this nonconventional fermentation environment. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 653–663, 2002.
Pattern analysis techniques to process fermentation curves: Application to discrimination of enological alcoholic fermentations
Authors: Roger Jean‐Michel , Sablayrolles Jean‐Marie , Steyer Jean‐Philippe , Bellon‐Maurel Véronique
Published: October 2002

In fermentation processes, kinetic curves are generally aimed at control purposes. However, these curves could also contain information about inherent features of the product (such as origin, quality, etc.). This article presents several pattern analysis techniques used to classify fermentation curves. An application to alcoholic fermentation is presented as an illustration: it aims at retrieving the origin of a must from its fermentation curve. The fermentation kinetics of five vineyard musts, harvested over 9 years on the same parcels, were recorded. From these curves two sets of variables were generated: The first (p1) gathers all the kinetic curve points. The second (p2) contains a restrained number of variables, generated by the expert knowledge of the enologist. The set p2 was processed by two very different techniques: a linear one (factorial discriminant analysis) and a nonlinear one (artificial neural networks). The set p1 was processed by a new chemometric technique, the discriminant partial least‐squares regression. For all the sets and the techniques used the selection of variables was studied. The interest in the latter is largely demonstrated both by theoretical and practical discussions. The discrimination results (up to 94% of good predictions) enhance the interest of the on‐line measurements and their use in such pattern analysis tools. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 804–815, 2002.
From moral theory to penal attitudes and back: a theoretically integrated modeling approach
Authors: de Keijser Jan W. , van der Leeden Rien , Jackson Janet L.
Published: October 2002

From a moral standpoint, we would expect the practice of punishment to reflect a solid and commonly shared legitimizing framework. Several moral legal theories explicitly aim to provide such frameworks. Based on the theories of Retributivism, Utilitarianism, and Restorative Justice, this article first sets out to develop a theoretically integrated model of penal attitudes and then explores the extent to which Dutch judges' attitudes to punishment fit the model. Results indicate that penal attitudes can be measured in a meaningful way that is consistent with an integrated approach to moral theory. The general structure of penal attitudes among Dutch judges suggests a streamlined and pragmatic approach to legal punishment that is identifiably founded on the separate concepts central to moral theories of punishment. While Restorative Justice is frequently presented as an alternative paradigm, results show it to be smoothly incorporated within the streamlined approach. Copyright © 2002 John Wiley & Sons, Ltd.
William Hunter's Gravid Uterus: The specimens and plates
Authors: McCulloch N.A. , Russell D. , McDonald S.W.
Published: October 2002

William Hunter's collection of anatomical specimens of the pregnant uterus forms one of the finest displays in the Anatomy Museum at the University of Glasgow. We were interested to know which specimens in the Museum matched the plates in Hunter's The Anatomy of the Human Gravid Uterus Exhibited in Figures (1774). In our investigation we were greatly assisted by Teacher's Catalogue of the Anatomical and Pathological Preparations of Dr William Hunter (1900). Thirteen specimens in the Museum and one from the pathological collection at the Royal Infirmary are represented in Hunter's book. The specimens can be recognized in 25 of its illustrations. A further three specimens may correspond to figures but we could not prove this. With one possible exception, all the specimens matching plates noted in Teacher's catalogue remain in the Museum and one believed missing in Marshall's (1970) revision of the catalogue has been found. Clin. Anat. 15:253–262, 2002. © 2002 Wiley‐Liss, Inc.