bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of starch‐graft‐polyacrylonitrile hydrolyzate and its characterization
Authors: Sugahara Yasusato , Ohta Takahisa
Published: August 2002

The graft copolymerization of three vinyl monomer species, acrylonitrile (AN), acrylamide (AAm), and acrylic acid (AA), onto starch was carried out with ceric salt (Ce salt) as an initiator. With 3 mmol/L Ce salt, the monomer activity onto starch decreased in the following order: AN > AAm > AA. Grafting efficiency with AN as the grafting monomer was greater than 90%, but with AA and AAm, it was less than 50%. Starch‐graft‐polyacrylonitrile was hydrolyzed to introduce amide and carboxyl groups into starch. The hydrolyzates were analyzed with infrared spectroscopy. The hydrolysis reaction was accelerated with increasing alkali concentration, reaction temperature, and time. The water absorbancy of the hydrolyzate increased with an increasing carboxyl molar fraction in the polymer, and it dissolved in water above a 0.6 molar fraction. The absorbancy of water was 2 times higher than that of a NaCl aqueous solution. The copper‐ion‐exchange capacity of the sample was greater in graft copolymers with higher carboxyl group contents. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1437–1443, 2001
Surface chemical modification of natural cellulose fibers
Authors: Baiardo Massimo , Frisoni Giovanna , Scandola Mariastella , Licciardello Antonino
Published: August 2002

Simple esterification and etherification reactions were applied to steam‐exploded Flax (Linum usitatissimum) with the aim of changing the surface properties through modification of fiber surface chemistry. Native and chemically modified cellulose fibers were characterized in terms of thermal stability, surface chemistry, morphology, and crystal structure. Independent of the substituent nature, chemically modified fibers exhibited a thermal stability comparable to that of native cellulose. Introduction of the desired chemical groups at the fiber surface was demonstrated by TOF‐SIMS analysis, whereas FTIR showed that the substitution reaction involved only a small fraction of the cellulose hydroxyls. No change of the native crystalline structure of cellulose fibers was caused by chemical modification, except in the case where ether substitution was carried out in water‐isopropanol medium. Cellulose fibers with unchanged structure and morphology and carrying at the surface the desired chemical groups were obtained for reinforcing applications in polymer composites. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 38–45, 2002
Correlation of blend and pure component viscosities
Authors: Couchman P. R.
Published: August 2002

An equation for the viscosity of single‐phase blends is derived by considering the fractions of the various kinds of bonds. For binary blends a quadratic term in viscosity is associated with unlike interactions in the melt. Both negative and positive deviations from the logarithmic rule of mixtures are possible. These deviations need not be connected to specific interactions. An extremum can occur and conditions for this are examined. In principle either an absolute maximum or an absolute minimum can occur. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 455–456, 2002
Finishing of textile materials
Authors: Bajaj Pushpa
Published: August 2002

With increasing awareness of environmental concerns, various chemical finishes for processing of textiles have been discussed. In this paper major changes which have occured to satisfy the consumer's demand in terms of comfort, easy care, health, and hygiene are reviewed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 631–659, 2002
Lymphocytes in the bronchoalveolar space reenter the lung tissue by means of the alveolar epithelium, migrate to regional lymph nodes, and subsequently rejoin the systemic immune system
Authors: Lehmann Christine , Wilkening Anja , Leiber Daniela , Markus Astrid , Krug Norbert , Pabst Reinhard , Tschernig Thomas
Published: August 2002

Lymphocytes in the bronchoalveolar space are routinely obtained and examined in lung diseases such as asthma or sarcoidosis. In a pig model, labeled lymphocytes were found in regional lymph nodes after intrabronchial instillation, indicating that reentry of lymphocytes from the bronchoalveaolar space into the body is possible. In the present study, the route and kinetics of the reentry of bronchoalveolar lymphocytes were investigated in a congenic rat model using immunohistochemistry on cryostat and semithin sections and confocal laser scanning microscopy. As early as 15 min after intratracheal instillation lymphocytes were found to leave the bronchoalveolar space by transmigration through alveolar but not bronchial epithelium and were observed in interstitial alveolar tissue. At 6 hr after intratracheal instillation, T and B lymphocytes appeared in the draining lymph nodes of the lung with an increase after 24 and 48 hr. The kinetic pattern clearly differed in nondraining lymph nodes and other organs. After 6 hr, only single cells were found in nondraining lymph nodes, spleen, and blood with a slight increase after 24 hr, and only occasionally were single cells seen in the liver, thymus, or Peyer's patches 24 and 48 hr after instillation. In conclusion, T and B lymphocytes can leave the alveolar space by reentry into the lung tissue through alveolar epithelium. They reach regional lymph nodes by means of lymphatic vessels and are then distributed all over the body to rejoin the systemic immune system. Coming into contact with environmental antigens, these lymphocytes could perform an important function in the lung immune system and might be a target for inhalative therapy. Anat Rec 264:229–236, 2001. © 2001 Wiley‐Liss, Inc.
Effect of culture medium on the in vitro secretion activity of prothoracic glands from Pseudaletia separata
Authors: Komiya Kazuyo , Agui Noriaki , Mitsuhashi Jun
Published: August 2002

The prothoracic glands (PGs) taken from the last instar of the common armyworm, Pseudaletia separata, were cultured in various media for the purpose of finding a suitable medium for relatively long‐term culture of PGs. Among the tested culture media, MGM‐450 medium without serum was the best to maintain PG cells viable for relatively long periods, and to continue to secrete ecdysteroids. Secretion of ecdysteroid by the PG in vitro became marked when the PG was taken from last instar larvae older than 2 days after the last molt. PGs cultured in any of the media secreted ecdysteroid only within the first 2 h after placing them in culture, however, in the MGM‐450 medium, the PGs secreted ecdysteroid even after 5 days of culture. Arch. Insect Biochem. Physiol. 38:147–154, 1998. © 1998 Wiley‐Liss, Inc.
Nitric oxide–mediated chondrocyte cell death requires the generation of additional reactive oxygen species
Authors: Del Carlo Marcello , Loeser Richard F.
Published: August 2002

Objective

Chondrocyte cell death, possibly related to increased production of endogenous nitric oxide (NO), has been observed during the pathogenesis of osteoarthritis and rheumatoid arthritis. The purpose of this study was to investigate the potential role of NO in causing chondrocyte cell death and to determine the contribution of other reactive oxygen species (ROS).

Methods

Cell death and cytotoxicity were evaluated in human articular chondrocytes in response to various NO donor compounds with and without agents that stimulate or inhibit the production of additional ROS using both the alginate bead and the monolayer culture systems. Cell death was quantified by a total cell count with fluorescent labels, and cytotoxicity was measured as a function of cellular NADH‐ and NADPH‐dependent dehydrogenase activity. To determine if the redox status of the chondrocyte could influence the observed effect of NO, cells were preincubated for 24 hours in L‐cystine– and glutathione (GSH)–depleted media to reduce intracellular GSH levels, a major defense mechanism against oxidative stress. Apoptosis was analyzed with the quantification of histone‐associated DNA fragments.

Results

Treatment of chondrocytes with peroxynitrite (ONOO−), 3‐morpholinosydnonimine (SIN‐1), and sodium nitroprusside (SNP) resulted in apoptotic cell death at concentrations of 0.5 mM, 1.0 mM, and 0.5 mM, respectively. In contrast, treatment of chondrocytes with diazeniumdiolates (or the “NOC” compounds, NOC‐5 and NOC‐12) at concentrations as high as 2.0 mM did not cause cell death. Furthermore, NOC‐5 and NOC‐12, at all concentrations tested (0.125–2.0 mM), could prevent cell death caused by oxidative stress. Selective ROS scavengers protected against cell death caused by either SIN‐1 or ONOO−; however, no protection could be afforded against the cytotoxicity of SNP with any of the ROS scavengers tested.

Conclusion

These results show that NO by itself is not cytotoxic to cultured chondrocytes and can even be protective under certain conditions of oxidative stress. Chondrocyte cell death from NO occurs under conditions where other ROS are also generated.
Cognitive styles and hypermedia navigation: Development of a learning model
Authors: Chen Sherry Y. , Macredie Robert D.
Published: August 2002

There has been an increased growth in the use of hypermedia to deliver learning and teaching material. However, much remains to be learned about how different learners perceive such systems. Therefore, it is essential to build robust learning models to illustrate how hypermedia features are experienced by different learners. Research into individual differences suggests cognitive styles have a significant effect on student learning in hypermedia systems. In particular, Witkin's Field Dependence has been extensively examined in previous studies. This article reviews the published findings from empirical studies of hypermedia learning. Specifically, the review classifies the research into five themes: nonlinear learning, learner control, navigation in hyperspace, matching and mismatching, and learning effectiveness. A learning model, developed from an analysis of findings of the previous studies, is presented. Finally, implications for the design of hypermedia learning systems are discussed.
Digital reference: Reference librarians' experiences and attitudes
Authors: Janes Joseph
Published: August 2002

This article reports the results of a survey of reference librarians in public and academic libraries of various sizes in the United States, asking them about their experiences with and attitudes towards the use of digital and networked technologies and resources in reference work. A total of 648 responded. In general, respondents were positive and optimistic in their outlook, but not unreservedly so. Among the strongest findings was a correlation between recent experience at doing digital reference and positive attitudes towards it, a clear set of opinions about what such services would be best and worst at, and differing perspectives and patterns of responses between academic and public librarians. In addition, questions asking about characteristics of librarians, their current and planned reference services, and some of their professional choices in doing reference work are reported.
Bayesian data mining, with application to benchmarking and credit scoring
Authors: Giudici Paolo
Published: August 2002

The purpose of this article is to show that Bayesian methods, coupled with Markov chain Monte Carlo computational techniques, can be successfully employed in the analysis of highly dimensional complex datasets, such as those occurring in data mining applications. Our methodology employs conditional independence graphs to localize model specification and inferences, thus allowing a considerable gain in flexibility of modelling and efficiency of the computations. Copyright © 2001 John Wiley & Sons, Ltd.
Managing uncertainty in call centres using Poisson mixtures
Authors: Jongbloed Geurt , Koole Ger
Published: August 2002

We model a call centre as a queueing model with Poisson arrivals having an unknown varying arrival rate. We show how to compute prediction intervals for the arrival rate, and use the Erlang formula for the waiting time to compute the consequences for the occupancy level of the call centre. We compare it to the current practice of using a point estimate of the arrival rate (assumed constant) as forecast. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of a limited sampling method used to determine the bioequivalence of highly variable drugs with long half‐lives
Authors: Jackson Andre J.
Published: August 2002

The usefulness of a limited sampling method (LSM) to determine the bioequivalence of highly variable drugs with long half‐lives was investigated. The LSM uses multiple linear regression of observed drug plasma concentrations versus area under the curve (AUC) or Cmax (peak plasma concentration) to obtain a best set of coefficients, concentration times and intercept based upon the regression coefficient, R2, to predict the selected pharmacokinetic parameter (i.e. AUC or Cmax). The LSM, used successfully in clinical settings, has also been suggested for data analysis of in vivo bioequivalence studies. Because the method has not yet been thoroughly tested under many conditions likely to be encountered in bioequivalence studies, a further investigation of the method's applicability to bioequivalence determination was undertaken. In the present study, training and test data sets incorporating various levels of intrasubject variability in clearance (CL) with different ratios for fraction absorbed (Fa) of test and reference drug formulations were used to further evaluate the applicability of the limited sampling method (LSM) to the evaluation of bioequivalence for drugs with long half‐lives of elimination. Both simulated (a one‐compartment pharmacokinetic (PK) model with first‐order elimination) and experimental data were used in the study. The results indicated that the determination of bioequivalence using the LSM was significantly influenced by the ratio of Fa(test)/Fa(reference) and by the level of intrasubject error (variability) in CL. Therefore, use of the LSM to determine bioequivalence of drugs with long half‐lives and highly variable in CL seems suitable only for formulations that have point estimates of Fa(test)/Fa(reference) within the range of 0.9–1.10. Because the Fa ratio range would have to be verified through use of observed data obtained from a pilot study, the practical utility of the LSM in the determination of bioequivalence would be severely limited. Copyright © 2001 John Wiley & Sons, Ltd.
Biomedical applications of capillary electrophoresis with laser‐induced fluorescence detection
Authors: Páez Ximena , Hernández Luis
Published: August 2002

Capillary electrophoresis (CE) is a high‐efficiency analytical technique that has had a great impact as a tool in biomedical research, clinical and forensic practice in the last ten years. Only in one of the applications, the DNA analysis, it has had an explosive exponential growth in the last few years. This impact is expressed in an enormous amount of CE articles and many reviews. The CE advantages with respect to other analytical techniques: the required very small sample volume, rapid analysis, great resolution power and low costs, have made this technique ideal for the analysis of a numerous endogenous and exogenous substances present in biological fluids. The different modes of CE have been coupled to different detection techniques such as UV‐absorbance, electrochemical, mass spectrometry and laser‐induced fluorescence detection (LIFD) to detect different nature and molecular size separated analytes. This review focuses mostly on the applications of CE–LIFD, to measure drugs and endogenous neuroactive substances such as amino acids and monoamines, especially in microdialysis samples from experimental animals and humans. CE–LIFD trends are discussed: automated faster analysis with capillary array systems, resolution power improvement, higher detection sensitivity, and CE systems miniaturization for extremely small sample volume, in order to make CE easier and affordable to the lab bench or the clinical bed. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis and screening of combinatorial libraries using mass spectrometry
Authors: Shin Young Geun , van Breemen Richard B.
Published: August 2002

Mass spectrometry is a highly selective and high throughput analytical technique that is ideally suited for the identification and purity determination of large numbers of compounds prepared using combinatorial chemistry or for the dereplication of natural products. Compounds may be characterized based on molecular weight, elemental composition and structural features based on fragmentation patterns. When coupled to a separation technique such as high‐performance liquid chromatography (HPLC) or capillary electrophoresis, mass spectrometric applications may be expanded to include analysis of complex mixtures. However, the slower speed of the separation step reduces the throughput of the analysis. This review concerns the application of mass spectrometry to the characterization of combinatorial libraries and the screening of library and natural product mixtures. Strategies to enhance the throughput of LC–MS are discussed including fast HPLC and parallel LC–MS. Also, mass spectrometry‐based screening methods are described including frontal affinity chromatography–mass spectrometry, gel permeation chromatography LC–MS, direct electrospray mass spectrometry of receptor–ligand complexes, affinity chromatography–mass spectrometry, and pulsed ultrafiltration mass spectrometry. Copyright © 2001 John Wiley & Sons, Ltd.
NF‐κB DNA‐binding activity after high peak power pulsed microwave (8.2 GHz) exposure of normal human monocytes
Authors: Natarajan Mohan , Vijayalaxmi  , Szilagyi Maria , Roldan Francis N. , Meltz Martin L.
Published: August 2002

The hypothesis investigated is that exposure of a mammalian cell to high peak power pulsed RF, at the frequency of 8.2 GHz, can result in the activation of an important eukaryotic transcriptional regulator, nuclear factor kappa B (NF‐κB). This DNA‐binding protein controls genes involved in long term cellular regulation. The selection of 8.2 GHz was based on the availability of a high peak power pulsed RF transmitter. In these studies, triplicate cultures of human monocytes (Mono Mac‐6) were exposed to the pulsed wave radiation. The peak to average power ratio was 455:1 (2.2 μs pulse width and pulse repetition rate of 1000 pulses/s). The average power density at the position of exposure was 50 W/m2, and the mean SAR at the bottom of the culture flask was 10.8 ± 7.1 W/kg. The FDTD analysis indicated that 10% of the cells had an SAR of 22–29 W/kg. The cells were exposed continuously for 90 min at 37 °C, reincubated at this temperature, and harvested 4 h postexposure. The nuclear extracts were analyzed by electrophoretic mobility shift assay. The results showed a profound increase (3.6‐fold) in the DNA binding activity of NF‐κB in monocytes at 4 h after the pulsed RF exposure compared to sham irradiated controls. Competition experiments with cold NF‐κB‐ specific oligonucleotides confirmed the specificity of the DNA binding activity. These results provide evidence that high peak power pulsed radiofrequency radiation can perturb the cell and initiate cell signaling pathways. However, at this point, we are not prepared to advocate that the cause is a nonthermal mechanism. Because of the broad distribution of SAR's in the flask, experiments need to be performed to determine if the changes observed are associated with cells exposed to high or low SARs. Bioelectromagnetics 23:271–277, 2002. © 2002 Wiley‐Liss, Inc.
No effects of pulsed radio frequency electromagnetic fields on melatonin, cortisol, and selected markers of the immune system in man
Authors: Radon K. , Parera D. , Rose D.‐M. , Jung D. , Vollrath L.
Published: August 2002

There is growing public concern that radio frequency electromagnetic fields may have adverse biological effects. In the present study eight healthy male students were tested to see whether or not radio frequency electromagnetic fields as used in modern digital wireless telecommunication (GSM standard) have noticeable effects on salivary melatonin, cortisol, neopterin, and immunoglobulin A (sIgA) levels during and several hours after exposure. In a specifically designed, shielded experimental chamber, the circularly polarized electromagnetic field applied was transmitted by an antenna positioned 10 cm behind the head of upright sitting test persons. The carrier frequency of 900 MHz was pulsed with 217 Hz (average power flux density 1 W/m2). In double blind trials, each test person underwent a total of 20 randomly allotted 4 hour periods of exposure and sham exposure, equally distributed at day and night. The results obtained show that the salivary concentrations of melatonin, cortisol, neopterin and sIgA did not differ significantly between exposure and sham exposure. Bioelectromagnetics 22:280–287, 2001. © 2001 Wiley‐Liss, Inc.
AMP‐activated protein kinase: the energy charge hypothesis revisited
Authors: Hardie D. Grahame , Hawley Simon A.
Published: August 2002

The AMP‐activated protein kinase cascade is a sensor of cellular energy charge, and its existence provides strong support for the energy charge hypothesis first proposed by Daniel Atkinson in the 1960s. The system is activated in an ultrasensitive manner by cellular stresses that deplete ATP (and consequently elevate AMP), either by inhibiting ATP production (e.g., hypoxia), or by accelerating ATP consumption (e.g., exercise in muscle). Once activated, it switches on catabolic pathways, both acutely by phosphorylation of metabolic enzymes and chronically by effects on gene expression, and switches off many ATP‐consuming processes. Recent work suggests that activation of AMPK is responsible for many of the effects of physical exercise, both the rapid metabolic effects and the adaptations that occur during training. Dominant mutations in regulatory subunit isoforms (γ2 and γ3) of AMPK, which appear to increase the basal activity in the absence of AMP, lead to hypertrophy of cardiac and skeletal muscle respectively. BioEssays 23:1112–1119, 2001. © 2001 John Wiley & Sons, Inc.
Control of developmental timing by small temporal RNAs: a paradigm for RNA‐mediated regulation of gene expression
Authors: Banerjee Diya , Slack Frank
Published: August 2002

Heterochronic genes control the timing of developmental programs. In C. elegans, two key genes in the heterochronic pathway, lin‐4 and let‐7, encode small temporally expressed RNAs (stRNAs) that are not translated into protein. These stRNAs exert negative post‐transcriptional regulation by binding to complementary sequences in the 3′ untranslated regions of their target genes. stRNAs are transcribed as longer precursor RNAs that are processed by the RNase Dicer/DCR‐1 and members of the RDE‐1/AGO1 family of proteins, which are better known for their roles in RNA interference (RNAi). However, stRNA function appears unrelated to RNAi. Both sequence and temporal regulation of let‐7 stRNA is conserved in other animal species suggesting that this is an evolutionarily ancient gene. Indeed, C. elegans, Drosophila and humans encode at least 86 other RNAs with similar structural features to lin‐4 and let‐7. We postulate that other small non‐coding RNAs may function as stRNAs to control temporal identity during development in C. elegans and other organisms. BioEssays 24:119–129, 2002. © 2002 Wiley Periodicals, Inc.
How do features of sensory representations develop?
Authors: Kaas Jon H. , Catania Kenneth C.
Published: August 2002

Sensory representations in the brainstem and cortex have a number of features that support the idea that neural activity patterns are important in their development. Many of these features vary across species in ways that could result from perturbances in the balance of the effects of activity patterns and position‐dependent gene expression. (1) Most notably, disruptions or septa in sensory maps often reflect actual discontinuities in the receptor sheet, and the discontinuities may be reflected in a series of interconnected maps. Species with different disruption patterns in sensory sheets have different matching disruption patterns in the sensory maps and variant individuals and strains of the same species have matching variations in the receptor disruption patterns and their sensory maps. (2) In addition, mutations that misdirect some of the retinal afferents from one side of the brain to the other create new sensory maps that preserve continuities in the altered pattern of input, while creating new structural discontinuities. (3) Furthermore, functionally different classes of afferents that are mixed in the receptor sheet often segregate to activate separate populations of target cells. (4) Finally, early developing portions of receptor sheets may gain more than their share of territory in sensory maps. These and other variable features of sensory maps are most readily accommodated by theories that involve roles for instruction by evoked and spontaneous neural activity patterns. BioEssays 24:334–343, 2002. ©2002 Wiley Periodicals, Inc.
Mid‐IR microspectroscopic imaging of breast tumor tissue sections
Authors: Fabian H. , Lasch P. , Boese M. , Haensch W.
Published: August 2002

IR microspectroscopic imaging is a relatively new approach for the examination of tissue sections. In contrast to standard light microscopy based procedures, the IR approach requires neither sample staining nor fixation. The IR spectra of breast tumor tissue sections are obtained via a microscope equipped with a focal plane array detector. This enabled the simultaneous collection of individual mid‐IR spectra from thousands of different sample positions with a spatial resolution near the diffraction limit. The analysis of the IR data reveals a high sensitivity of the IR approach toward changes in tissue biochemistry and variations in breast tissue architecture. Moreover, the data demonstrate the need for collecting spectra with high spatial resolution at the level of individual cells. This minimizes problems associated with tissue microheterogeneity and is an essential prerequisite for future studies aimed at developing IR microspectroscopic imaging as a complement to present diagnostic tools for breast cancer. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 354–357, 2002
Spatially resolved IR microspectroscopy of single cells
Authors: Lasch Peter , Pacifico Anthony , Diem Max
Published: August 2002

Fourier transform IR (FTIR) microspectroscopy at a spatial resolution of 18 μm was used to study skin fibroblasts and giant sarcoma cells. Both cell lines were derived from the same patient; they were metabolically active and in the exponentially growing phase. The IR spectra were acquired for the nuclei and cytosol of untreated cells, cells washed with ethanol, and cells treated with RNase or DNase. A comparison of the spectra of the two cell lines yielded only insignificant spectral differences, indicating that IR spectroscopy monitors the overall cell activity rather than specific signs of cancer. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 335–338, 2002
Thiosulphate improves yield of hydrogen production from glucose by the immobilized formate hydrogenlyase system of Escherichia coli
Authors: Nandi R. , Dey S. , Sengupta S.
Published: August 2002

Escherichia coli cells with formate hydrogenlyase activity that were immobilized in agar beads produced hydrogen from glucose at the approximate yield of 0.6 mole of hydrogen per mole. Succinate or thiosulphate added to glucose increased hydrogen production two‐fold. Thiosulphate did not increase the rate of hydrogen production but reduced the consumption of glucose for the same amount of hydrogen produced compared to control. Oxaloacetate and traces of pyruvate instead of succinate accumulated at the end when thiosulphate was present. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 492–494, 2001.
Microbial synthesis of p‐hydroxybenzoic acid from glucose
Authors: Barker Jessica L. , Frost J. W.
Published: August 2002

A series of recombinant Escherichia coli strains have been constructed and evaluated for their ability to synthesize p‐hydroxybenzoic acid from glucose under fed‐batch fermentor conditions. The maximum concentration of p‐hydroxybenzoic acid synthesized was 12 g/L and corresponded to a yield of 13% (mol/mol). Synthesis of p‐hydroxybenzoic acid began with direction of increased carbon flow into the common pathway of aromatic amino acid biosynthesis. This was accomplished in all constructs with overexpression of a feedback‐insensitive isozyme of 3‐deoxy‐D‐arabino‐heptulosonic acid 7‐phosphate synthase. Expression levels of enzymes in the common pathway of aromatic amino acid biosynthesis were also increased in all constructs to deliver increased carbon flow from the beginning to the end of the common pathway. A previously unreported inhibition of 3‐dehydroquinate synthase by L‐tyrosine was discovered to be a significant impediment to the flow of carbon through the common pathway. Chorismic acid, the last metabolite of the common pathway, was converted into p‐hydroxybenzoic acid by ubiC‐encoded chorismate lyase. Constructs differed in the strategy used for overexpression of chorismate lyase and also differed as to whether mutations were present in the host E. coli to inactivate other chorismate‐utilizing enzymes. Use of overexpressed chorismate lyase to increase the rate of chorismic acid aromatization was mitigated by attendant decreases in the specific activity of DAHP synthase and feedback inhibition caused by p‐hydroxybenzoic acid. The toxicity of p‐hydroxybenzoic acid towards E. coli metabolism and growth was also evaluated. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 76: 376–390, 2001.
Numerical simulation of convective and diffusive transport effects on a high‐pressure‐induced inactivation process
Authors: Hartmann Chr. , Delgado A.
Published: August 2002

High‐pressure‐induced conversions, such as the inactivation of enzymes or of microorganisms, are dependent on the applied pressure and the temperature of the process. The former can be considered to be a spatially homogeneous quantity, while the latter, being a transport quantity, varies over space and time. Here we question whether the uniformity of a high‐pressure conversion can be disturbed by convective and conductive heat and mass transport conditions. Enzyme inactivation is taken as a model process for a high‐pressure conversion. To cover a broad range of parameters and to consider scale‐up effects, the investigation is based on mathematical modeling and numerical simulation for different sizes of the pressure chamber and different solvent viscosities. Apart from viscosity, the physical properties of the enzyme solutions are assumed to be identical in all cases. Therefore, matrix effects other than that of viscosity are excluded. Moreover, the authors postulate that viscosity solely acts on the continuum mechanical scale of momentum exchange but not on the molecular scale on the inactivation kinetics. It has been found that nonuniform thermal conditions can strongly influence the result of a high‐pressure process. A variation of the activity retention between 28% and 48% can be observed after 20 minutes for a 0.8‐L high‐pressure chamber and a matrix fluid with a viscosity comparable to that of edible oils. The same process carried out in a 6.3‐L device leads to an activity retention that varies between 16% and 40%. From the analysis of the time scales for the inactivation and for hydrodynamic and thermal compensation, it can be deduced that a nonuniform activity retention has to be expected if the inactivation time scale is larger than the hydrodynamic time scale and smaller than the thermal compensation time scale. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 94–104, 2002
Improving biomaterial properties of collagen films by chemical modification
Authors: Tiller Joerg C. , Bonner Gary , Pan Li‐Chun , Klibanov Alexander M.
Published: August 2002

Films of bovine collagen were chemically modified with the goal of improving their biomaterial properties. The modified films were investigated with respect to their affinity to fibroblast and endothelial cells, as well as their antibacterial properties tested by adhesion of Staphylococcus aureus. Modifications that only change the net charge of collagen, such as acetylation, succinylation, and treatment with glutaraldehyde (all increase the negative charge), and amination with ethylenediamine (EDA), N,N‐dimethyl‐EDA (DMEDA), or butylamine (all increase the positive charge), did not dramatically alter the mammalian cell attachment to the film. In contrast, derivatization of collagen using methoxypoly(ethylene glycol) (PEG) diminished the attachment of fibroblasts by 98 ± 1% and of endothelial cells by more than 99% compared to unmodified collagen. Moreover, the rate of growth of fibroblasts dropped by 97 ± 1% and that of endothelial cells by 88 ± 3% as a result of PEGylation of collagen. Adhesion of S. aureus cells also plummeted by 93 ± 2% as a result of this PEGylation. With these antifouling properties, PEG‐collagen may be a promising coating material for coronary stents. Sub‐ sequent derivatization of PEG‐collagen with EDA or DMEDA abolished its mammalian cell‐repelling ability, whereas bacterial cell repulsion was partially retained: for example, DMEDA‐modified PEG‐collagen exhibits up to a 5‐fold lower bacterial adhesion than collagen. It is worth noting that a material that allows mammalian cell attachment but reduces bacterial adhesion could be useful as an implant or coating. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 246–252, 2001.
Identification of novel polyphenol oxidase inhibitors by enzymatic one‐pot synthesis and deconvolution of combinatorial libraries
Authors: de la Gôutte Jérome Tricand , Khan Jeffrey A. , Vulfson Evgeny N.
Published: August 2002

The feasibility of enzymatic synthesis of combinatorial libraries using multifunctional starting materials [i.e., 2,4‐dihydroxy‐N‐(2‐hydroxyethyl)benzamide, 1; 4‐hydroxyphenethyl alcohol, 2; 3,5‐dihydroxybenzyl alcohol, 3; and 4‐hydroxybenzyl alcohol, 4] with six vinyl esters, in a one‐pot reaction, was investigated. Candida antarctica lipase was employed as a biocatalyst. The resulting 24‐compound library contained all the expected species with no significant bias toward particular combinations of substrates. As expected, the library contained a substance(s) that showed significant inhibition of polyphenol oxidase, which was used as a model target. The deconvolution was accomplished via resynthesis of ten partial libraries, which were prepared with either an equimolar mixture of the four alcohols and a single vinyl ester, or a single alcohol and equimolar mixture of the activated esters. Analysis of the inhibition pattern observed with these partial libraries suggested that 4‐hydroxybenzyl benzoate (4e) should be the most potent inhibitor. This conclusion was confirmed by the preparation and comparison of all 24 components of the initial library. Finally, it was shown that 4e was a competitive inhibitor of polyphenol oxidase, with a Ki of 40 μM. This value compared favorably with a Ki of 400 μM, which was determined for parent phenol 4. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 93–99, 2001.
CEO compensation: does it pay to be green?
Authors: Stanwick Peter A. , Stanwick Sarah D.
Published: August 2002

The relationship between chief executive officer (CEO) compensation and various organizational variables (i.e., size, length of tenure of the CEO, board composition and firm performance) has been explored in academic research. However, the relationship between CEO compensation and the firm's reputation based on the firm's commitment to the community and the environment has been relatively unexamined in the academic research. This study's purpose is to empirically examine this relationship using the Fortune Reputation Index as revised by Brown and Perry (1995).

Using a sample of 186 firms in 1990 and 188 firms in 1991, the relationships between CEO compensation and organization size, financial performance and environmental reputation are examined. The results of the study demonstrate that there is a strong relationship between CEO compensation and firm environmental reputation, firm size and firm financial performance. Copyright © 2001 John Wiley & Sons, Ltd. and ERP Environment
Randomized comparison of vasoseal and angioseal closure devices in patients undergoing coronary angiography and angioplasty
Authors: Shammas Nicolas W. , Rajendran Vijay R. , Alldredge Stephen G. , Witcik William J. , Robken Jon A. , Lewis J. Randolph , McKinney Dawn , Hansen Christena A. , Kabel M. Elizabeth , Harris Melodee , Jerin Michael J. , Bontu Prakash R. , Dippel Eric J. , Labroo Ajay
Published: August 2002

AngioSeal (AS) and VasoSeal (VS) are collagen‐based arterial closure devices utilized to achieve earlier hemostasis and ambulation in diagnostic and interventional percutaneous procedures. To our knowledge, there has been no randomized studies comparing these two devices as approved for use in the United States. One hundred fifty‐seven patients were randomized to receive either the 8 Fr AS (n = 79) or VS (n = 78) closure device. Data on 95 patients who had coronary angiography (49 AS, 46 VS) and 55 patients who underwent angioplasty (28 AS, 27 VS) were completed. Heparin was not administered during the coronary angiogram procedure. The activated clotting time was kept at approximately 300 sec during angioplasty. Patients on coumadin or GP IIb/IIIa platelet inhibitors were not included in this study. The time unit interval to achieve hemostasis in this study was based on the time the AS tension spring was left over the common femoral artery following collagen deployment as per the manufacturer's instructions (20 min). Time to hemostasis, time to ambulation, and major and minor complications were prospectively recorded. Two‐tailed t‐test and chi‐square analysis were performed on continuous and dichotomous variables, respectively. For the angiogram‐only subgroup, time (min) to hemostasis (20.51 ± 4.36 vs. 18.59 ± 11.77; P = 0.30) and ambulation (145.71 ± 124 vs. 109.89 ± 60.37; P = 0.075) were not statistically different for the AS and VS, respectively. Similarly, for the angioplasty subgroup, time (min) to hemostasis (24.23 ± 12.70 vs. 19.57 ± 2.27; P = 0.077) and ambulation (607.32 ± 344.22 vs. 486.48 ± 200.37; P = 0.12) were not statistically different for both AS and VS, respectively. Furthermore, there were no statistical differences in deployment failure, major, minor, or total complication rates between the two devices. In the absence of GP IIb/IIIa inhibitors, VS and the 8 Fr AS devices have statistically similar time to hemostasis and ambulation as well as device failures and complication rates following coronary angiography and angioplasty. Cathet Cardiovasc Intervent 2002;55:421–425. © 2002 Wiley‐Liss, Inc.
Transient occlusion of an angioguard protection system by massive embolization during angioplasty of a degenerated aortocoronary saphenous vein graft
Authors: Kindel Martin , Spiller Paul
Published: August 2002

Distal embolization is the most important complication of balloon dilatation of degenerated saphenous vein grafts. We describe a case of massive embolization associated with transient occlusion in which larger distal embolization and myocardial infarction were avoided despite transient but complete occlusion of a filter protection system (Angioguard). Cathet Cardiovasc Intervent 2002;55:501–504. © 2002 Wiley‐Liss, Inc.
Acute renal artery thrombosis treated by percutaneous rheolytic thrombectomy
Authors: Greenberg Jeffrey M. , Steiner Mark A. , Marshall J. Jeffrey
Published: August 2002

Renal artery thrombosis or embolus is a rare condition that may lead to hypertension and renal failure. Treatment options in the past have had limited success. We present a case which demonstrates the use of percutaneous rheolytic therapy with the Angiojet atherectomy catheter to treat this condition in the acute setting. Cathet Cardiovasc Intervent 2002;56:66–68. © 2002 Wiley‐Liss, Inc.
Local delivery of paclitaxel using the double‐balloon perfusion catheter before stenting in the porcine coronary artery
Authors: Oberhoff Martin , Herdeg Christian , Al Ghobainy Rasool , Cetin Süha , Küttner Axel , Horch Barbara , Baumbach Andreas , Karsch Karl R.
Published: August 2002

Paclitaxel is a new cancer chemotherapeutic agent that has been approved for clinical use in patients with a variety of different cancers. Paclitaxel inhibits cell proliferation by an action on microtubules. The aim of this study was to evaluate the safety and efficacy of locally delivered paclitaxel after coronary stent implantation. A novel double‐balloon perfusion catheter was used to deliver the drug locally in the pig coronary artery. Twenty‐seven domestic pigs underwent stent implantation of the left anterior descending artery. In the treatment group (n = 11), paclitaxel (10 ml;10 μmol/l) was delivered using the double‐balloon perfusion catheter prior to stent implantation. The control group received stent implantation only (n = 16). The animals were sacrificed 4 weeks later. Vessels were perfusion‐fixed and morphometric analysis was performed using conventional techniques. In addition, the extent of injury was determined at each stent‐strut area. Correlation of local injury and neointimal thickness was evaluated by linear regression. Neointimal thickness (paclitaxel 1.0 ± 0.4 vs. control 0.7 ± 0.3 mm), neointimal area (paclitaxel 4.1 ± 2.2 vs. control 2.4 ± 1.1 mm2), and the lumen area (paclitaxel 2.1 ± 1.9 vs. control 2.5 ± 0.9 mm2) did not show significant differences between both groups. Medial area (3.3 ± 2.3 vs. 1.6 ± 0.4 mm2) was larger in the vessels treated with paclitaxel (P < 0.05). Linear regression failed to show any difference in the response to injury between the two groups. Local delivery of paclitaxel with the double‐balloon‐perfusion catheter did not reduce neointima formation following stent implantation in native pig coronary arteries. Cathet Cardiovasc Intervent 2001;53:562–568. © 2001 Wiley‐Liss, Inc.
Angiographic prevalence and clinical predictors of left subclavian stenosis in patients undergoing diagnostic cardiac catheterization
Authors: English JoAnna L. , Carell Edgar S. , Guidera Steven A. , Tripp Henry F.
Published: August 2002

The angiographic prevalence, clinical predictors, and sensitivity and specificity of a bilateral arm blood pressure differential for predicting proximal left subclavian artery stenosis were established in 492 patients undergoing cardiac catheterization. Seventeen subjects (3.5%) in the overall population and nine subjects (5.3%) with potential surgical coronary disease had proximal left subclavian stenosis. Precatheterization evidence of peripheral vascular disease (PVD) was the only predictor of subclavian stenosis in the overall population (P < 0.001; OR = 7.9; 95% CI = 2.6–24.3) and in patients with potential surgical coronary disease (P = 0.04; OR = 5.4; 95% CI = 1.1–27.2). Both a bilateral blood pressure differential of > 10 mm Hg and of ≥20 mm Hg had a good specificity but a poor sensitivity for predicting left subclavian stenosis. Thus, left subclavian angiography should be performed in patients with surgical coronary disease with either an arm blood pressure differential of > 10 mm Hg or with other precatheterization evidence of PVD. Cathet Cardiovasc Intervent 2001;54:8–11. © 2001 Wiley‐Liss, Inc.
iSPOT: a web tool for the analysis and recognition of protein domain specificity
Authors: Brannetti Barbara , Zanzoni Andreas , Montecchi‐Palazzi Luisa , Cesareni Gianni , Helmer‐Citterich Manuela
Published: August 2002

Methods that aim at predicting interaction partners are very likely to play an important role in the interpretation of genomic information. iSPOT (iSpecificity Prediction Of Target) is a web tool (accessible at http://cbm.bio.uniroma2.it/iSPOT) developed for the prediction of protein‐protein interaction mediated by families of peptide recognition modules. iSPOT accesses a database of position specific residue‐residue interaction frequencies for members of the SH3 and PDZ protein domain families. The software utilises this database to provide a score for any potential domain peptide interaction.

 iSPOT: 1. evaluates the likelihood of the interaction between any of the peptides contained in an input protein and a list of domains of the two different families; 2. searches in the SWISS‐PROT database for potential partners of a query domain; and 3. has access to a repository of all the domain/target peptide interaction data. Copyright © 2001 John Wiley & Sons, Ltd.
The interaction between endopolygalacturonase from Fusarium moniliforme and PGIP from Phaseolus vulgaris studied by surface plasmon resonance and mass spectrometry.
Authors: Mattei Benedetta , Cervone Felice , Roepstorff Peter
Published: August 2002

A combination of surface plasmon resonance (SPR) and matrix‐assisted laser‐desorption‐ionization‐time‐of‐flight
mass spectrometry (MALDI‐TOF‐MS) was used to study the interaction between endopolygalacturonase
(PG) from Fusarium moniliforme and a polygalacturonase‐inhibiting
protein (PGIP) from Phaseolus vulgaris. PG hydrolyses the homogalacturonan
of the plant cell wall and is considered an important pathogenicity factor
of many fungi. PGIP is a specific inhibitor of fungal PGs and is thought to
be involved in plant defence against phytopathogenic fungi. SPR was used either
to study the effect of the PG glycosylation on the formation of the complex
with PGIP, and as a sensitive affinity capture of an interacting peptide from
a mixture of PG fragments obtained by limited proteolysis. Mass spectrometry
allowed to characterise the interacting peptide eluted from the sensor surface.
Copyright © 2001 John Wiley & Sons, Ltd.
REGIA, an EU project on functional genomics of transcription factors from Arabidopsis thaliana
Authors: Paz‐Ares Javier ,   The REGIA Consortium
Published: August 2002

Transcription factors (TFs) are regulatory proteins that have played a
pivotal role in the evolution of eukaryotes and that also have great biotechnological
potential. REGIA (REgulatory Gene Initiative
in Arabidopsis) is an EU‐funded project involving 29 European laboratories
with the objective of determining the function of virtually all transcription
factors from the model plant, Arabidopsis thaliana. REGIA involves:
1. the definition of TF gene expression patterns in Arabidopsis;
2. the identification of mutations at TF loci; 3. the ectopic expression
of TFs (or derivatives) in Arabidopsis and in crop plants; 4. phenotypic
analysis of the mutants and mis‐expression lines, including both RNA and metabolic
profiling; 5. the systematic analysis of interactions between TFs; and 6.
the generation of a bioinformatics infrastructure to access and integrate
all this information. We expect that this programme will establish the full
biotechnological potential of plant TFs, and provide insights into hierarchies,
redundancies, and interdependencies, and their evolution. The project involves
the preparation of both a TF gene array for expression analysis and
a normalised full length open reading frame (ORF) library of TFs in a yeast
two hybrid vector; the applications of these resources should extend beyond
the scope of this programme. Copyright © 2002 John Wiley & Sons,
Ltd.
MaizeDB – a functional genomics perspective
Authors: Polacco Mary , Coe Ed , Fang Zhiwei , Hancock Denis , Sanchez‐Villeda Hector , Schroeder Steve
Published: August 2002

MaizeDB (http://www.agron.missouri.edu/)
has existed since the early 90's as a genome‐specific database that is
grounded in genetic maps, their documentation and annotation. The database
management system is robust and has continuously been Sybase. In this brief
review we provide an introduction to the database as a functional genomics
tool and new accesses to the data: 1) probe tables by bin location 2) BLAST
access to map data 3) cMap, a comparative map graphical tool. Copyright © 2002 John Wiley & Sons, Ltd.