bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibrillar assembly and stability of collagen coating on titanium for improved osteoblast responses
Authors: Kim Hae‐Won , Li Long‐Hao , Lee Eun‐Jung , Lee Su‐Hee , Kim Hyoun‐Ee
Published: August 2005

Collagen, as a major constituent of human connective tissues, has been regarded as one of the most important biomaterials. As a coating moiety on Ti hard‐tissue implants, the collagen has recently attracted a great deal of attention. This article reports the effects of fibrillar assembly and crosslinking of collagen on its chemical stability and the subsequent osteoblastic responses. The fibrillar self‐assembly of collagen was carried out by incubating acid‐dissolved collagen in an ionic‐buffered medium at 37°C. The degree of assembly was varied with the incubation time and monitored by the turbidity change. The differently assembled collagen was coated on the Ti and crosslinked with a carbodiimide derivative. The partially assembled collagen contained fibrils with varying diameters as well as nonfibrillar aggregates. On the other hand, the fully assembled collagen showed the complete formation of fibrils with uniform diameters of ∼100–200 nm with periodic stain patterns within the fibrils, which are typical of native collagen fibers. Through this fibrillar assembly, the collagen coating had significantly improved chemical stability in both the saline and collagenase media. The subsequent crosslinking step also improved the stability of the collagen coating, particularly in the unassembled collagen. The fibrillar assembly and the crosslinking of collagen significantly influenced the osteoblastic cell responses. Without the assembly, the collagen layer on Ti adversely affected the cell attachment and proliferation. However, those cellular responses were improved significantly when the collagen was assembled to fibrils and the assembly degree was increased. After crosslinking the collagen coating, these cellular responses were significantly enhanced in the case of the unassembled collagen but were not altered much in the assembled collagen. Based on these observations, it is suggested that the fibrillar assembly and the crosslinking of collagen require careful considerations in the collagen administration as a coating moiety. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Nanoscale topography modulates corneal epithelial cell migration
Authors: Diehl K. A. , Foley J. D. , Nealey P. F. , Murphy C. J.
Published: August 2005

The purpose of this study was to evaluate the effect of surface topographic features that mimic the corneal epithelial basement membrane on cell migration. We used electron‐beam and X‐ray lithography and reactive ion etching to pattern silicon wafers with pitches (groove width plus ridge width) of nano‐ and microscale dimensions (pitches ranged from 400 to 4000 nm). Additionally, polyurethane patterned surfaces were created by replication molding techniques to allow for real‐time imaging of migrating cells. Individual SV40‐transformed human corneal epithelial cells frequently aligned with respect to the underlying surface patterns and migrated almost exclusively along grooves and ridges of all pitches. Direction of migration of individual cells on smooth surfaces was random. In cell dispersion assays, colonies of cells migrated out from initially circular zones predominantly along grooves and ridges, although there was some migration perpendicular to the ridges. On smooth surfaces, cells migrated radially, equally in all directions, maintaining circular colony shapes. We conclude that substratum features resembling the native basement membrane modulate corneal epithelial cell migration. These findings have relevance to the maintenance of corneal homeostasis and wound healing, as well as to the evolution of strategies in tissue engineering, corneal prosthesis development, and cell culture material fabrication. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Photochemical crosslinking improves the physicochemical properties of collagen scaffolds
Authors: Chan B. P. , So K.‐F.
Published: August 2005

Collagen is a natural biomaterial with excellent biocompatibility. However, unprocessed collagen has low stability and weak mechanical strength, which limits its application in tissue engineering. The current study aimed to improve the physicochemical properties of collagen scaffolds by using photochemical crosslinking. Collagen gel was reconstituted and photochemically crosslinked by using laser irradiation in the presence of a photosensitizer. Scanning electron microscope was used to characterize the surface and cross‐sectional morphology. Stress‐strain relationship and other mechanical properties were determined by uniaxial tensile tests. Thermostability and water‐binding capacities also were analyzed by using differential scanning calorimetry and swelling ratio measurements, respectively. Photochemically crosslinked porous structures showed fine microstructure with interconnected micron‐sized pores, whereas uncrosslinked controls only showed macrosheet‐like structures. The stabilizing effect of photochemical crosslinking also was revealed by retaining the three‐dimensional lamellae‐like structures after thermal analysis in crosslinked membranes but not in the controls. Photochemical crosslinking also significantly reduced the swelling ratio, improved the stress‐strain relationship, peak load, ultimate stress, rupture strain, and tangent modulus of collagen membranes. The current study showed that an innovative photochemical crosslinking process was able to produce collagen scaffolds with fine microstructures; to strengthen, stiffen, and stabilize collagen membranes; and to modify their swelling ratio. This may broaden the use of collagen‐based scaffolds in tissue engineering, particularly for weight‐bearing tissues. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Removal of toluene from air streams using a gas–liquid–solid three‐phase airlift loop bioreactor containing immobilized cells
Authors: Jianping Wen , Yu Chen , Xiaoqiang Jia , Guozhu Mao
Published: August 2005

Toluene, a kind of volatile organic compound (VOC), is widely used as a solvent (paints and coatings, gums, resins, rubber) as well as a reagent (medicines, dyes, perfumes) and is one of the components of gasoline. Over the more recent decades, many studies have led to the development of biological methods to treat toluene. This paper presents the results of a study on the treatment of airborne toluene using a laboratory‐scale gas–liquid–solid three‐phase airlift loop bioreactor containing immobilized cells. Based on the optimum operating conditions such as the temperature of 28–30 °C, pH of 7.0–7.2, and an empty bed residence time (EBRT) of 39.6 s, a continuous bioprocess showed that this immobilized airlift loop bioreactor had a steady‐state performance within 15 days, the outlet concentrations of toluene were lower than the national emission standard in China (GB 16297‐1996), and the chemical oxygen demand and NH4+‐N of the effluent also satisfied the primary discharge standard in China (GB 8978‐1996). In addition, this immobilized airlift loop bioreactor had a good ability to tolerate shock loads, while the maximum elimination capacity of toluene was 168 g m−3 h−1 which was higher than those not only in biofilters and biotrickling filters but also in the airlift bioreactor with free microorganisms. Copyright © 2005 Society of Chemical Industry
Biomass estimation using fluorescence measurements in Pichia pastoris bioprocess
Authors: Surribas Anna , Montesinos José Luis , Valero Francisco F
Published: August 2005

The utilisation of tryptophan fluorescence as an indirect biomass measurement for the yeast Pichia pastoris, an excellent host system for the production of heterologous proteins, is presented. Direct fluorescence measurements for cell densities above 3 g dm−3 presented important interferences due to inner filter effects. To overcome this drawback, a dilution protocol is provided which allows the quenching of the emission signal caused by solid particles to be controlled. The measured tryptophan fluorescence intensities were used to estimate biomass concentration during a P pastoris batch bioprocess growing either on glycerol or methanol. The best measurement model tested was based on the application of a Luedeking–Piret‐based equation to fluorometric measurements. Thus, a linear relationship between the specific fluorescence evolution rate and specific growth rate was applied. The mean absolute relative prediction error (MARE) for biomass concentration was about 6%. Copyright © 2005 Society of Chemical Industry
Direct electrochemistry and electrocatalysis of hemoglobin in lactobionic acid film
Authors: Zhou Hui , Chen Zhong , Yang Rongwu , Shang Libin , Li Genxi
Published: August 2005

Hemoglobin (Hb) embedded in lactobionic acid (LA) film can give a pair of stable, well‐defined, and quasi‐reversible cyclic voltammetric peaks, located at the potential characteristic of the heme Fe(III)/Fe(II) redox couple. The formal potential of the protein in LA film was −209 mV. The apparent heterogeneous electron transfer rate constant and the number of protons concomitant per electron during the electron transfer process have been calculated. Hydrogen peroxide could also be catalytically reduced by the protein in LA film. Copyright © 2005 Society of Chemical Industry
Effect of type of carbon activation on adsorption and its reversibility
Authors: Aktaş Özgür , Çeçen Ferhan
Published: August 2005

In biological treatment processes combined with the use of activated carbon, adsorbability and desorbability receive special attention. In particular, desorbability is of crucial importance for bioregeneration of activated carbon in these systems. This study aims to clarify the effect of the type of activated carbon on the extent of adsorption of phenol and the reversibility of adsorption. For this purpose, four different types of activated carbon: thermally‐activated and chemically‐activated powdered carbons (PAC), and their granular countertypes (GAC) with similar physical characteristics, were used. Adsorption and desorption isotherms showed that thermally‐activated carbons, either in powdered or granular form, were better adsorbers for phenol than chemically‐activated ones. However, apparently higher degrees of hysteresis (higher adsorption irreversibility) were calculated in the case of thermally‐activated carbons. Chemisorption was the dominant adsorption mechanism for thermally‐activated carbons, whereas physisorption was dominant for chemically‐activated ones. Degrees of hysteresis for the PACs were found to be only slightly higher than their GAC countertypes, but desorption was faster from the PACs. The results suggest that, rather than the physical form, the type of carbon activation and the chemical characteristics of the surface play a more important role on the adsorbability of phenol and its reversibility. Copyright © 2005 Society of Chemical Industry
Coupling ultraviolet photolysis and biofiltration for enhanced degradation of aromatic air pollutants
Authors: Mohseni Madjid , Zhao Joy Lan
Published: August 2005

Coupling UV photolysis and biofiltration was evaluated as an effective treatment strategy for the enhanced degradation of hardly biodegradable aromatic volatile organic compounds (VOCs). o‐Xylene, a recalcitrant and poorly water‐soluble VOC, was used as a model compound and treated in two parallel treatment systems with and without UV pretreatment. Contaminated streams with flow rates of 0.186–0.384 m3 h−1 and inlet o‐xylene concentrations of up to 0.22 g m−3 were passed through the treatment system. About 20% (between 10 and 35%) of o‐xylene was converted into water‐soluble intermediates during the UV photolysis stage, which partially oxidized o‐xylene to more water‐soluble and biodegradable byproducts. The untreated contaminant along with the byproducts of UV photolysis was then removed effectively in the biofiltration stage, with improvements of up to 100% compared with the control biofiltration process. The results suggested that combined UV photolysis–biofiltration is promising as an effective technique to eliminate hydrophobic and recalcitrant organic compounds from contaminated air steams. Copyright © 2005 Society of Chemical Industry
Initial experience with balanced turbo field echo in depicting carotid artery stenosis: Comparison with multiple overlapping thin slab acquisition and 3D contrast‐enhanced magnetic resonance angiography
Authors: Gupta Neeraj , Swaminathan Srirama V. , DeMarco J. Kevin
Published: August 2005

Purpose

To compare balanced turbo field echo (bTFE) with multiple overlapping thin slice acquisition (MOTSA) and contrast‐enhanced MR angiography (CE‐MRA) in depicting carotid artery stenosis.

Materials and Methods

In this study 86 patients with cerebrovascular disease, who had been referred for a carotid examination, were imaged. All of the patients underwent MOTSA and one of four bTFE sequences followed by CE‐MRA. Formatted maximum intensity projections (MIPs) and source images were read in a blinded fashion by a radiologist. Inter‐ and intrasequence statistical analyses were performed.

Results

We first compared image quality (IQ) and fat, background, and venous suppression using four distinct bTFE protocols in 118 carotid arteries, and found that bTFE4 performed the best. We then compared IQ, grades of stenosis, and background and venous suppression among bTFE4, MOTSA, and CE‐MRA. bTFE produced significantly better IQ and venous suppression (P < 0.001), and higher SNR and CNR (P < 0.05) when compared to MOTSA.

Conclusion

The bTFE sequence is robust and provides high‐quality images in patients with mild to moderate carotid artery stenosis. Even though there is a tendency to overestimate stenosis with bTFE compared to CE‐MRA, the shorter scan time of bTFE coupled with enhanced SNR and CNR measurements validates it as a clinically useful adjunct to MOTSA, if not a replacement. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
Clinical validation of high‐resolution fast spin‐echo MR colonography after colon distention with air
Authors: Bielen Didier J.L.E. , Bosmans Hilde T.C. , De Wever Liesbeth L.I. , Maes Frederik , Tejpar Sabine , Vanbeckevoort Dirk , Marchal Guy J.F.
Published: August 2005

To evaluate the feasibility of MR colonography (MRC) with air using two‐dimensional (2D) T1‐weighted fast spin‐echo (T1wFSE) in patients scheduled for conventional colonoscopy (CC) after classic bowel preparation, and assess the ability of the technique to detect colonic lesions. The distention was sufficient for diagnosis, and the technique provided adequate delineation of the wall in the majority of segments. Residual fluid obscured the wall in different segments, especially in the ascending and descending colon (supine position) and in the cecum, transverse, and sigmoid colon (prone position). These findings were consistent with CT colonography. MRC visualized three lesions, missed one lesion >10 mm, visualized none of four lesions <5 mm, and yielded one false‐positive lesion (5–10 mm). Missed lesions can be due to inconsistency in the slice positions between consecutive breath‐holds, which is inherent to the multishot technique. Residual fluid may have obscured the smaller lesions. The shortcomings of the technique are limited coverage and signal drop‐off at the borders of the field of view (FOV). Before multishot 2D T1wFSE colonography can become a valid screening method, improved patient preparation and a more practical technique are needed. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
Glomerular filtration rate measured using the Patlak plot technique and contrast‐enhanced dynamic MRI with different amounts of gadolinium‐DTPA
Authors: Hackstein Nils , Kooijman Hendrik , Tomaselli Stefan , Rau Wigbert S.
Published: August 2005

We determined the optimum gadolinium (Gd)‐DTPA dose and time window for calculating the glomerular filtration rate (GFR) using contrast‐enhanced (CE) dynamic MRI and the Patlak plot technique. Twelve adult volunteers with healthy kidneys were included in the study. As a reference method the GFR was measured by iopromide plasma clearance. A three‐dimensional gradient‐echo (GRE) sequence with a flip angle of 50° was used for MRI. Signal was measured using a body surface coil with four elements. Each volunteer was examined on four days using 2 mL, 4 mL, 8 mL, or 16 mL of Gd‐DTPA 0.5 mmol/mL dissolved with sodium chloride (NaCl) 0.9% to a total of 60 mL. The injection rate was 1 mL/second. A Patlak plot was calculated from the kidney and aorta signals. The mean reference GFR was 133 mL/min (min‐max, 116–153 mL/min). The best correlation of GFR calculated from MRI data compared to the reference method was found in a time window 30–90 seconds after aortic signal rise using 16 mL Gd‐DTPA. Pearson's correlation coefficient was r = 0.83, and the standard deviation (SD) from the line of regression was 10.5 mL/minute. We found a significantly lower average GFR(MR) using 16 mL Gd‐DTPA compared to 4 mL and 2 mL in the late time window 60–120 seconds post aortic rise. A dose of 16 mL Gd‐DTPA was optimal for measuring GFR using dynamic MRI and the Patlak plot technique. The slope should be measured in a time window of 30–90 seconds post aortic rise. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
Performance of the computer algorithm COMPLX for the detection of protein complexes in the mass spectra of simulated biological mixtures
Authors: Wong Jason W. H. , Downard Kevin M.
Published: August 2005

The performance of the algorithm COMPLX for detecting protein‐ligand or other macromolecular complexes has been tested for highly complex data sets. These data contain m/z values for ions of proteins of the SWISS‐PROT database within simulated biological mixtures where each component shares a similar molecular weight and/or isoelectric point (pI). As many as 1600 ion signals were entered to challenge the algorithm to identify ion signals associated with a single protein complex that has been ionised and detected within a mass spectrometer. Despite the complexity of such data sets, the algorithm is shown to be able to identify the presence of individual bimolecular complexes. The output data can be re‐evaluated by the user as necessary in light of any additional information that is known concerning the nature of predicted associations, as well as the quality of the data‐set in terms of errors in m/z values as a direct consequence of the mass calibration or resolution achieved. The data presented illustrates that the best results are obtained when output results are ranked according to the largest continuous series of ion pairs detected for a protein or macromolecule and its complex for which the ligand mass is assigned the lowest mass error. Copyright © 2005 John Wiley & Sons, Ltd.
Beyond the center: Intel gives employees more choices through family child care
Authors: Sorensen Adam
Published: August 2005

Flexibility and cost effectiveness became priorities for semiconductor giant Intel when it sought employee child care options in the midst of its worst business downturn. An innovative solution leverages community resources at Intel sites around the country to offer locally managed home‐based programs as an alternative to center‐based child care. In the process, the new program has improved the quality of at‐home child care, created more child care spaces, and given providers access to more clients and resources, to the benefit of the community as a whole. © 2005 Wiley Periodicals, Inc.
Learning a new leadership game plan at Paychex
Authors: Heffernan Dan , Kelly Kimberly
Published: August 2005

The rules for success have changed at perennially successful Paychex. Greater operational and product/service complexity requires a new leadership style to produce the strong performance stakeholders have come to expect. Through a new set of leadership development programs, the Paychex operations organization is rapidly reshaping its leadership culture by setting expectations and building competencies for proactive problem solving, open dialogue, and greater accountability. © 2005 Wiley Periodicals, Inc.
Leadership passages: Being part of an acquisition or merger
Authors: Dotlich David L. , Noel James L. , Walker Norman
Published: August 2005

Having your company absorbed in a merger or acquisition is stressful, even traumatic, for most leaders, who fear the loss of job, staff, status, networks, career paths, and other fruits of a successful career. Despite such misgivings, however, the authors contend that leaders can use this passage to become a better leader—and perhaps find even greater opportunities with the new entity. They describe five ways a leader can grow and thrive, not simply survive, in an acquisition, and they offer practical suggestions for making the process less painful and more productive. © 2005 John Wiley & Sons, Inc.
Developing women leaders: Abbott turns commitment into action and results
Authors: Patterson Delores
Published: August 2005

With women rapidly becoming a larger part of its workforce and its customer base, Abbott got aggressive about increasing the number of women in leadership positions. A sustained five‐year diversity effort on multiple fronts is showing laudable results. Women have made gains at all management levels across the organization—including international and R&D, two areas where long‐standing myths and misconceptions pose additional barriers to diversity. © 2005 Wiley Periodicals, Inc.
Innovation in learning: Agilent technologies thinks outside the box
Authors: Roche Teresa , Wick Cal , Stewart Marie
Published: August 2005

Corporate learning programs are under pressure to show a better return on investment, even as evidence mounts that classroom training may not be enough to ensure transfer of learning to the job. To improve its bottom‐line impact, the Global Learning and Leadership Development group at Agilent Technologies stepped outside the “classroom box” to focus on the learning period after formal instruction ends. It implemented a new follow‐through system and other innovations to encourage on‐the‐job application of course learning and to facilitate coaching and feedback, particularly from participants'managers, who can make the difference in successful learning transfer. © 2005 Wiley Periodicals, Inc.
Enantiomeric separation of mirtazapine and its metabolites by nano‐liquid chromatography with UV‐absorption and mass spectrometric detection
Authors: Fanali Salvatore , Aturki Zeineb , Ka�icka Václav , Raggi Maria Augusta , D'Orazio Giovanni
Published: August 2005

Mirtazapine (MIR) and two of its main metabolites, namely, 8‐hydroxymirtazapine and N‐desmethylmirtazapine, were separated in totheir enantiomers by nanoLC in a laboratory‐made fused‐silica capillary column (75 μm ID) packed with a vancomycin‐modified silica stationary phase. The simultaneous separation of the three couples of the studied enantiomers was achieved in less than 33 min, using an experimentally optimized mobile phase delivered in the isocratic mode. Optimization of the mobile‐phase composition was achieved by testing the influence of the buffer pH and concentration, the water concentration, the organic modifier type and concentration, and on the retention and resolution of the analytes. The optimum mobile‐phase composition contained 500 mM ammonium acetate pH 4.5/water/MeOH/MeCN, 1 : 14 : 40 : 45 v/v/v/v. Using a UV detector at 205 nm, the method was validated studying several experimental parameters such as LOD and LOQ, intraday and interday repeatability, and linearity. Good results were achieved: LOD and LOQ were in the range 5–15 and 10–40 μg/mL, respectively (the highest value was obtained for the DEMIR enantiomers); correlation coefficients, 0.9993–0.9999; the intraday and interday precision was acceptable (RSD < 2%) using an internal standard. The method was tested for the separation of the studied enantiomers in an extracted (solid‐phase) serum sample spiked with standard racemic mixture of MIR and its two metabolites. Finally, the nanoLC system was connected to a mass spectrometer through a nanoelectrospray interface and the MS, MS2, and MS3 spectra were acquired showing the potential of the system used for characterization and identification of the separated analytes.
Development of an analytical method for the determination of antidepressants in water samples by capillary electrophoresis with electrospray ionization mass spectrometric detection
Authors: Himmelsbach Markus , Klampfl Christian W. , Buchberger Wolfgang
Published: August 2005

A method for the quantitative determination of major antidepressants in aqueous matrices by CE using ESI‐MS is presented. Several aqueous, nonaquoeus, and mixed aqueous/organic solvent BGEs including inorganic and organic acids were investigated with respect to their suitability for the separation of the selected analytes. Finally, due to the necessity to employ MS detection if the developed method should be suitable also for environmental samples, only MS‐compatible electrolytes were taken into account. Based on this fact optimum results were obtained with a system consisting of 1.5 M formic acid and 50 mM ammonium formate in ACN/water (85/15). Linear calibration plots could be obtained for all solutes over a concentration range of almost two orders of magnitude, and the LODs achieved were in the range of 3–6 μg/L for trazodone and 39–43 μg/L for sertraline with the TOF instrument and the single quadrupole instrument in the SIM mode, respectively. This fact allowed the assumption that the presented method can be regarded as suitable for the determination of antidepressants even in the trace amounts commonly present in environmental samples. Spiking of river water and sewage plant effluent extracts with the selected solutes showed that no interferences from the matrix usually found in such samples can be expected. Finally the quantitative determination of the seven antidepressants in environmental samples was used to benchmark the performance of CZE coupled to a single quadrupole MS and a TOF‐MS.
Metabolism of a novel antiangiogenic agent KR‐31831 in rats using liquid chromatography‐electrospray mass spectrometry
Authors: Kim Hui‐Hyun , Paek In Bok , Ji Hye Young , Lee Sunkyung , Yi Kyu Yang , Lee Hye Suk
Published: August 2005

KR‐31831 ((2S,3R,4S)‐4‐(((1H‐imidazol‐2‐yl)methyl)(4‐chlorophenyl)amino)‐6‐amino‐2‐(dimethoxymethyl)‐2‐methyl‐3,4‐dihydro‐2H‐chromen‐3‐ol) is a novel antiangiogenic agent. In vitro and in vivo metabolism of KR‐31831 in rats has been investigated using LC‐MS and LC‐MS/MS analysis. Incubation of rat liver microsomes and hepatocytes with KR‐31831 produced three metabolites (M1–M3). M1, M2, and M3 were identified as N‐((1H‐imidazol‐2‐yl)methyl)‐4‐chlorobenzenamine, (2R,3R,4S)‐4‐(((1H‐imidazol‐2‐yl)methyl)(4‐chlorophenyl) amino)‐6‐amino‐2‐(hydroxymethyl)‐2‐methyl‐3,4‐dihydro‐2H‐chromen‐3‐ol, and N‐((2S,3R,4S)‐4‐(((1H‐imidazol‐2‐yl)methyl)(4‐chlorophenyl)amino)‐2‐(dimethoxymethyl)‐3‐hydroxy‐2‐methyl‐3,4‐dihydro‐2H‐chromen‐6‐yl)acetamide, respectively, by co‐chromatography with the authentic standards and by comparison with product ion spectra of the authentic standards. Those in vitro metabolites were also detected in bile, plasma, or urine samples after an intravenous administration of KR‐31831 to rats. The metabolic routes for KR‐31381 included the metabolism of acetal group to hydroxymethyl group (M2), N‐dealkylation to M1, and N‐acetylation at the 6‐amino group (M3).
Macrophages direct tumour histology and clinical outcome in a colon cancer model
Authors: Oosterling Steven J , van der Bij Gerben J , Meijer Gerrit A , Tuk Cornelis W , van Garderen Evert , van Rooijen Nico , Meijer Sybren , van der Sijp Joost RM , Beelen Robert HJ , van Egmond Marjolein
Published: August 2005

Macrophages generally constitute a major component of the tumour stroma. Although conventionally considered to be cytotoxic effector cells, macrophages have recently been described as promoters of tumour progression. The present study shows that selective depletion of peritoneal or liver macrophages prior to CC531 tumour cell inoculation resulted in highly differentiated tumours in rats. In contrast, tumours from control rats, in which macrophages are abundantly present, showed a desmoplastic stromal reaction with hallmark features of malignancy, such as neovascularization and matrix remodelling, indicating that the presence of macrophages is associated with malignant histopathological differentiation. Remarkably, macrophage‐depleted rats, bearing highly differentiated tumours, had a worse prognosis, as they displayed a higher tumour load and poorer survival. Thus, while macrophages direct tumours towards malignant tumour histology, their role in anti‐tumour defence is important. The selective inhibition of macrophage functions involved in malignant progression without interfering with cytotoxic ability may therefore identify important new targets for cancer therapy. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Acute lymphoblastic leukemia presenting in fulminant hepatic failure
Authors: Litten Jason B. , Rodríguez Maria M. , Maniaci Vincenzo
Published: August 2005

A previously healthy 4‐year‐old boy was admitted because of acute liver failure. He was icteric, lethargic, had elevated ammonia and abnormal liver function tests. Serology was negative for viral hepatitis. There was no history of hepatotoxic drugs. Family history was unremarkable. The child was taken to the operating room for a living‐related hepatic transplant. Frozen section showed massive hepatic leukemic infiltration and hepatocellular necrosis. Bone marrow aspiration confirmed the diagnosis of acute lymphoblastic leukemia (ALL). Transplant was withheld and chemotherapy was attempted. He died the following day due to systemic leukemic infiltration, cerebral edema, and severe anoxic ischemic encephalopathy. Pediatric Blood Cancer 2006;47:842–845. © 2005 Wiley‐Liss, Inc.
Evidence for molecular interactions in drag reduction in turbulent pipe flows
Authors: Berman Neil S.
Published: August 2005

Experiments which test the concentration and molecular weight dependence of turbulent pipe flow drag reduction for random coiling polymers in dilute solutions show correlations with concentration to the one‐half power and molecular weight to the 0.8 power for good solvents. This result is not consistent with a model of extension of single1 molecules, but could be related to the increase in bulk viscosity of interacting molecules after some extension. In this work, measurements for very low amounts of drag reduction for rigid rod molecules arc reported, and the effect of tube diameter on the amount of drag reduction is examined for fiexible rod molecules. No diameter effect is observed for the rigid rods, but an increase in drag reduction with increase in pipe diameter is found for the flexible polyeleetrolytes. In all cases, the volume occupied by spheres which circumscribe the molecules is greater than the actual volume when drag reduction is found. The results indicate that combined effects of individual molecule stretching and molecular interactions are present in drag reduction for random coiling or flexible rod molecules.
Vortex flow of dilute polymer solutions
Authors: Chiou C. S. , Gordon R. J.
Published: August 2005

It has been observed that very d longchain polymers which are effective in turbulent drag reduction inhibit the formation of a vortex or air core as water drains from a tank. This paper considers the fluid mechanical velocity profile measurements have been performed. There appear to be at least two distinct mechanisms for the vortex inhibition—one involving the viscosity enhancement caused by polymer addition, and the other related to the viscoelastic properties of the polymer solutions. This second mechanism is shown to arise due to the generation of high normal stresses as the air core begins to form. The very close correlation between vortex inhibition and turbulent drag reduction suggests that normal stresses may also play an important role in this latter phenomenon.
Conformational changes of macromolecules in transient elongational flow
Authors: Armstrong Robert C. , Gupta Suresh K. , Basaran Osman
Published: August 2005

Calculations are reported which describe the elongation of flexible macromolecules in a pulse‐like elongational How. The polymer molecules are modeled as FENE (finitely extendable nonlinear elastic) dumbbells. The results are in qualitative agreement with experimental results on dilute solutions of polyisobutylene in decalin (10) which form a two parameter family of extension versus position curves. The two parameters‐in the FENE model that are used to fit the data are λH, a time constant and b, which is related to the maximum extension that can be achieved by the molecules. Quantitative comparisons are frustrated by difficulty in estimating the model parameter, b. It is suggested, based on this work, that internal self entanglements in the polymers must be considered in the determination of b.
Drag reduction characteristics of graft copolymers prepared by the gamma irradiation of poly(oxyethylene) in the presence of acrylic acid
Authors: Gryte Carl C. , Koroneos Christopher , Agarwal Anil , Hochberg Arie
Published: August 2005

Graft copolymers were prepared by irradiation of poly(oxyethylene), PEO, aqueous solutions in presence of acrylic acid. Chain transfer to PEO controls the graft length, the measured chain transfer constant of the acrylic acid radicals to PEO being 4.11 × 10−4 at 25°C. The drag reduction characteristics of the graft copolymers were measured in the Reynolds number range 104–105 in a smooth‐walled tube, 0.635 cm inside diameter. The drag reduction falls to near zero as the solution pH is lowered to 3, evidence of the formation of a PEO‐poly(acrylic acid) coacervate.
Effect of ferric ions on drag reduction effectiveness of polyacrylamide
Authors: Hoyt J. W.
Published: August 2005

The drag reduction performance of polyaerylarnide polymers is severely degraded by the presence of ferric ions in solution. This effect has been noticed during the course of earlier experimental work and may have contributed greatly to poor reproducibility of results. The present work provides a more quantitative basis for estimating the effect of ferric ions on the drag reduction performance of polyacrylamide. Tests i a capillary‐tube rheometer and in a one‐in. pipe‐flow facility provide data for estimating the possible degradation effect o several different commercial polyacrylamides. In some case the degradation products deposit on the pipe wall, causing a increased roughness effect.
Effects of drag reducing polymers on initiation of atherosclerosis
Authors: Greene Howard L. , Mostardi Richard F. , Nokes Richard F.
Published: August 2005

Results from two pilot studies using White Carneau pigeons on high cholesterol diets have demonstrated substantial reduction in arterial plaque accumulations when the birds were periodically injected with dilute aqueous solutions of a drag reducing polymer (Separan AP‐30) so as to maintain circulating blood concentrations of approximately 60 ppm. Initiation of arterial plaque formation may be fluid‐mechanically motivated such that regions subjected to fluid turbulence, rapidly developing boundary layers, and alternate separation and reattachment, arc; the most prone lo attack. Viscoelastic fluid response, as seen in drag reducing media, is known to alter such phenomena. Comparative documentation of plaque deposition in experimental as well as control birds shows significant differences in both the aortas and coronary arteries, at optical magnifications from 20 to 15000X.
Scission of non‐interpenetrating macromolecules in transient extensional flows
Authors: Merrill E. W. , Leopairat P.
Published: August 2005

Solutions of the random coiling polymers; polystyrene, poly (methylmethacrylate), and sodium polystyrene sulfonate (NaPSS), all at concentrations well below the critical value for entanglement, were subjected to transient, high, elongational strain rates by passage from a cylinder through an orifice into a gently diverging section, driven by a piston at constant, high velocity over a short stroke. It is shown that a critical orifice flow velocity Vc. exists for each polymer species, above which scission of polymer molecules occurs creating new molecules. By gel permeation chromatography, the number of additional polymer molecules created per initial polymer molecule, the scission index, was determined as Mn,0/Mn – 1 where Mn is the number average molecular weight, and Mn,0 is the initial value thereof. Vc is found to vary as approximately M. Above Vc the scission index was found to be proportional to M, to the difference: orifice velocity V less Vc, and to the number of passes N of the polymer solution through the orifice. Expansion of NaPSS coils by reducing ionic strength of their aqueous solutions, at constant polymer molecular weight, decreases the scission index, The hypothesis is proposed that intramolecular entanglements are responsible for scission. The random coiling macromolecules in the solution cannot respond to the strain rate (imposed in ca, 100 microseconds) so as to avoid having internal sections, caught by loop entanglement, pulled to nearly full extension and thus broken.
Flow‐assisted degradation in dilute polystyrene solutions
Authors: Hunston D. L. , Zakin J. L.
Published: August 2005

The flow‐assisted degradation behavior of polystyrene was studied as a function of solvent, polymer concentration, molecular weight, and molecular weight distribution. To obtain data at concentrations as low as 100 parts per million by weight, turbulent drag reduction measurements were used to augment the usual analytical techniques of viscosity and gel permeation chromatography. Turbulent flow measurements were found to be a valuable technique for evaluating the effects of degradation: the drag reduction onset point provides information about the largest molecules in the sample while the flow rate dependence is related to the shape of the top part of the molecular weight distribution. For the polymers and flow conditions studied, the degradation causes a shift in the distribution to lower molecular weights with little change in the shape. This suggests a complex mechanism where the probability of bond scission is not random but varies along the polymer backbone.
Two‐dimensional liquid chromatography/tandem mass spectrometry analysis of Gradiflow™ fractionated native human plasma
Authors: Wasinger Valerie C. , Locke Vicki L. , Raftery Mark J. , Larance Mark , Rothemund Deborah , Liew Audrey , Bate Irene , Guilhaus Michael
Published: August 2005

One of the major challenges facing protein analysis is the dynamic range of protein expression within massively complex samples (Corthals, G. L. et al.., Electrophoresis 2000, 21, 1104–1115). In plasma this difference is as great as ten orders of magnitude, and this is currently beyond the range of detection achievable by any of the analytical techniques. Plasma has the additional challenge of having a few highly abundant proteins, such as albumin, which mask the detection of lower abundance and biologically significant proteins. The use of the Gradiflow BF400 as a fractionation tool to deplete highly abundant albumin from human plasma is reported here. A sequential three‐step protocol was performed on five plasma samples as part of the International Plasma Proteome Project organised by the HUPO; four containing different anticoagulants: EDTA, citrate, heparin and a control sample (NIBSC); and a serum sample. Plasma from an alternate source also underwent fractionation and served as an in‐house control. Time modulation between 1 and 7 h was observed for the depletion of albumin from these samples. Following albumin depletion, each fraction was trypsin‐digested and the peptides were fractionated further using a 2‐D LC‐MS/MS. Differences in the total number of proteins identified for each sample were also noted.
Overview of the HUPO Plasma Proteome Project: Results from the pilot phase with 35 collaborating laboratories and multiple analytical groups, generating a core dataset of 3020 proteins and a publicly‐available database
Authors: Omenn Gilbert S. , States David J. , Adamski Marcin , Blackwell Thomas W. , Menon Rajasree , Hermjakob Henning , Apweiler Rolf , Haab Brian B. , Simpson Richard J. , Eddes James S. , Kapp Eugene A. , Moritz Robert L. , Chan Daniel W. , Rai Alex J. , Admon Arie , Aebersold Ruedi , Eng Jimmy , Hancock William S. , Hefta Stanley A. , Meyer Helmut , Paik Young‐Ki , Yoo Jong‐Shin , Ping Peipei , Pounds Joel , Adkins Joshua , Qian Xiaohong , Wang Rong , Wasinger Valerie , Wu Chi Yue , Zhao Xiaohang , Zeng Rong , Archakov Alexander , Tsugita Akira , Beer Ilan , Pandey Akhilesh , Pisano Michael , Andrews Philip , Tammen Harald , Speicher David W. , Hanash Samir M.
Published: August 2005

HUPO initiated the Plasma Proteome Project (PPP) in 2002. Its pilot phase has (1) evaluated advantages and limitations of many depletion, fractionation, and MS technology platforms; (2) compared PPP reference specimens of human serum and EDTA, heparin, and citrate‐anti‐coagulated plasma; and (3) created a publicly‐available knowledge base (www.bioinformatics.med.umich.edu/hupo/ppp; www.ebi.ac.uk/pride). Thirty‐five participating laboratories in 13 countries submitted datasets. Working groups addressed (a) specimen stability and protein concentrations; (b) protein identifications from 18 MS/MS datasets; (c) independent analyses from raw MS‐MS spectra; (d) search engine performance, subproteome analyses, and biological insights; (e) antibody arrays; and (f) direct MS/SELDI analyses. MS‐MS datasets had 15 710 different International Protein Index (IPI) protein IDs; our integration algorithm applied to multiple matches of peptide sequences yielded 9504 IPI proteins identified with one or more peptides and 3020 proteins identified with two or more peptides (the Core Dataset). These proteins have been characterized with Gene Ontology, InterPro, Novartis Atlas, OMIM, and immunoassay‐based concentration determinations. The database permits examination of many other subsets, such as 1274 proteins identified with three or more peptides. Reverse protein to DNA matching identified proteins for 118 previously unidentified ORFs.

We recommend use of plasma instead of serum, with EDTA (or citrate) for anticoagulation. To improve resolution, sensitivity and reproducibility of peptide identifications and protein matches, we recommend combinations of depletion, fractionation, and MS/MS technologies, with explicit criteria for evaluation of spectra, use of search algorithms, and integration of homologous protein matches.

This Special Issue of PROTEOMICS presents papers integral to the collaborative analysis plus many reports of supplementary work on various aspects of the PPP workplan. These PPP results on complexity, dynamic range, incomplete sampling, false‐positive matches, and integration of diverse datasets for plasma and serum proteins lay a foundation for development and validation of circulating protein biomarkers in health and disease.
Exploring the Human Plasma Proteome
Authors: Omenn Gilbert S.
Published: August 2005

No abstracts.
Book Review: Proteomics Protocols Handbook. Edited by John M. Walker
Authors: Thiellement Hervé
Published: August 2005

No abstracts.
Computational study of stereoelectronic effects in fluorinated alkylamines
Authors: Urban Joseph J.
Published: August 2005

A systematic evaluation of the stereoelectronic effects in a series of fluorinated amine compounds has been carried out. A variety of computational methods have been employed, including molecular mechanics, semi‐empirical, density functional and ab initio methods. An analysis of the natural bond orbital populations has been carried out and the effect of solvent was considered via the polarized continuum model (PCM). The results indicate a preference for conformations that result in an anti‐periplanar arrangement between the nitrogen lone pair and the CX bond (XF or CF3). There are variations in geometry and natural bond orbital population, with conformation that are consistent with a stereoelectronic effect whereby electron density from the nitrogen lone pair is delocalized into the CX σ* orbital. Similar results are obtained for trifluoromethyl methylamines, although the magnitude of the stereoelectronic effect is attenuated resulting in greater expected conformational diversity for these compounds. The PCM results suggest that these preferences should persist in solution. Comparison among the computational methods used reveals that there is good agreement among the ab initio and density functional methods (at the HF/6‐31 + G(d), MP2/6‐31 + G(d), MP2/6‐311 + G(2d,p) and B3LYP/6‐31 + G(d) levels) and these methods agree well with the available experimental data for ethylmethylamine. Published in 2005 by John Wiley & Sons, Ltd.
A novel, convenient, quinoline‐based merocyanine dye: probing solvation in pure and mixed solvents and in the interfacial region of an anionic micelle
Authors: Martins Clarissa T. , Lima Michelle S. , El Seoud Omar A.
Published: August 2005

A novel solvatochromic probe—2,6‐dibromo‐4‐[(E)‐2‐(1‐butylquinolinium‐4‐yl)ethenyl] phenolate, BuQMBr2—has been synthesized and its properties examined. The quinoline‐based probe is soluble in more organic solvents than the parent merocyanine dye, 4‐[2‐(1‐methylpyridinium‐4‐yl)ethenyl] phenolate, and its pKa is lower by 3.7 units. Its solvatochromic data in binary mixtures of cyclohexane–n‐butanol showed that the deviation from ideal behavior is due to a combination of non‐specific and specific solvent–probe interactions. Its thermo‐solvatochromism has been studied in mixtures of water with methanol, ethanol, 1‐propanol, 2‐propanol and 2‐methyl‐2‐propanol, respectively. The data obtained were analyzed according to a recently introduced model that explicitly considers the presence of 1:1 alcohol–water hydrogen‐bonded species, ROH–W, in bulk solution, and its exchange equilibria with water and alcohol in the probe solvation microsphere. The composition of the latter is given in terms of the appropriate set of solvent fractionation factors. These indicate that the probe is more solvated by alcohol than by water. Additionally, solvation by ROH–W is favored over solvation by either W or ROH. Solvation by alcohols is more affected by probe–ROH hydrophobic interactions than by hydrogen bonding of ROH to the probe phenolate oxygen. Temperature increase results in a gradual desolvation of the probe, due to a decrease in the hydrogen bonding of all components of the binary solvent mixture. The probe has been employed to calculate the effective concentration of interfacial water of sodium dodecyl sulfate micelles, which is 38.9 mol l−1. Copyright © 2005 John Wiley & Sons, Ltd.
Structure and solvatochromism of heteroaromatic aminoketones containing thiophene moieties
Authors: El‐Sayed Mohamed , Walfort Bernhard , Lang Heinrich , Poppitz Wolfgang , Spange Stefan
Published: August 2005

A series of N‐substituted phenyl‐2‐thienyl ketones including 2‐(4‐fluorobenzoyl)thiophene (FLBT, 1a), 2‐(4‐piperidinobenzoyl)thiophene (PIBT, 1b), 2‐(4‐morpholinobenzoyl)thiophene (MOBT, 1c), 2‐(4‐thiomorpholinobenzoyl)thiophene (THBT, 1d), 2‐(4‐phenylpiperazinobenzoyl)thiophene (PHBT, 1e), 2‐(4‐pyrrolidinobenzoyl)‐thiophene (PYBT, 1f), 2‐(4‐hydroxyethylpiperazinobenzoyl)thiophene (HYBT, 1g), 1,4‐bis(4‐benzoyl‐2‐thienyl)piperazine (BBTP, 2) and 1,6‐bis(4‐benzoyl‐2‐thienyl)‐N,N′‐dimethylhexamethylenediamine (BBDA, 3) have been investigated regarding solvatochromism and solid‐state structure. Solvatochromic properties have been analyzed using the Kamlet–Taft linear solvation energy relationship. The influence of the dipolarity/polarizability (π*) and hydrogen‐bond acidity (α) of the solvent, respectively, on the portions of the bathochromic UV–Vis band shift as a function of substituent is discussed. The solid‐state structures of 1b (C16H17NOS), 1c (C15H15NO2S) and 1f (C15H15NOS) have been determined by single‐crystal x‐ray structure analysis. Crystallochromic effects are discussed comparatively with regard to the linear solvation energy relationships and the results of the solid‐state structures. Copyright © 2005 John Wiley & Sons, Ltd.