bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal stabilization of human albumin by medium‐ and short‐chain n‐alkyl fatty acid anions
Authors: Shrake Andrew , Frazier Douglas , Schwarz Frederick P. 
Published: November 2005

AbstractA comprehensive study of the thermal stabilization of defatted human albumin monomer by n‐alkyl fatty acid anions (FAAs), formate through n‐decanoate, was carried out by differential scanning calorimetry (DSC). The concentration of each ligand affording maximum thermal stabilization was determined; n‐nonanoate provides the greatest stabilization but is only marginally better than n‐octanoate and n‐decanoate. The use of reversible thermodynamics and a two‐state denaturation model for albumin has been validated. Standard free energies of binding, calculated from increases in free energy of denaturation, for n‐butanoate and longer FAAs, are linear with n‐alkyl chain length whereas those for formate, acetate, and n‐propionate deviate from linearity; those for acetate and n‐propionate are even greater than that of n‐butanoate, thereby suggesting, in addition to the common class of sites available to all such ligands, the presence of an additional class of lower affinity binding sites available only to these shortest ligands. Competition experiments involving acetate and n‐octanoate and involving n‐pentanoate and n‐octanoate confirmed the binding of acetate to lower affinity sites unavailable to n‐octanoate and n‐pentanoate. Furthermore, an equation is provided, allowing computation of the transition temperature as a function of the free energy for any reversible process causing a change in thermal stability of a protein undergoing reversible, two‐state denaturation. With this equation, modeling the competition experiments by using the binding parameters determined by DSC provides additional support for the class of lower affinity sites, which play a significant role in thermal stabilization of albumin at higher concentrations of these shortest FAAs. © 2005 Wiley Periodicals, Inc. Biopolymers 81: 235–248, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
One‐ and two‐photon induced fluorescence of Pacific Blue‐labeled human serum albumin deposited on different core size silver colloids
Authors: Lukomska Joanna , Gryczynski Ignacy , Malicka Joanna , Makowiec Slawomir , Lakowicz Joseph R. , Gryczynski Zygmunt 
Published: November 2005

AbstractWe studied one‐ and two‐photon induced fluorescence of Pacific Blue (PB)‐labeled human serum albumin (HSA) in the presence of different size silver colloids. The PB fluorescence emission intensity was observed with small (30–40 nm) and large (about 120 nm) colloids and compared with PB emission in absence of colloids. For the system with a small core size colloids we did not detect any fluorescence enhancement with one‐photon excitation and the enhancement observed with two‐photon excitation was about 2.5‐fold. In contrast, for large silver colloids we observed about a 2‐fold increase in PB fluorescence brightness for one‐photon excitation, and the enhancement with two‐photon excitation excided 13‐folds. Much stronger increases in brightness observed with two‐photon excitation, compared to one‐photon excitation, indicate a dominant role of enhanced local field in fluorescence enhancement on silver colloids in solutions. © 2005 Wiley Periodicals, Inc. Biopolymers 81: 249–255, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Asymmetric enone epoxidation by short solid‐phase bound peptides: Further evidence for catalyst helicity and catalytic activity of individual peptide strands
Authors: Berkessel Albrecht , Koch Burkhard , Toniolo Claudio , Rainaldi Mario , Broxterman Quirinus B. , Kaptein Bernard 
Published: November 2005

AbstractIn the presence of short solid‐phase bound peptide catalysts, the Juliá–Colonna epoxidation of enones (such as chalcone) with hydrogen peroxide can be performed with high enantiomeric excess (≥95% ee). It was proposed earlier (A. Berkessel, N. Gasch, K. Glaubitz, C. Koch, Organic Letters, 2001, Vol. 3, pp. 3839–3842) that this remarkable catalysis is governed by the N‐terminus of individual and helical peptide strands. This mechanistic proposal was scrutinized further. (i) Nonaggregation of the peptide catalysts: five solid‐phase bound statistic mixtures (0/100; 30/70; 50/50; 70/30; 100/0) of D‐Leu and L‐Leu heptamers were generated and assayed as catalysts. A linear dependence of the epoxide ee on the enantiomeric composition of the catalysts resulted. (ii) Catalyst helicity [introduction of the helix‐stabilizing Cα–methyl‐L‐leucine, L‐(αMe)Leu]: solid‐phase bound Leu/(αMe)Leu‐pentamers of composition TentaGel–NH–[(αMe)‐L‐Leu]n–(L‐Leu)m–H (n = 0–4; m = 5–n) were prepared and assayed as catalysts. The introduction of up to two (αMe)‐L‐Leu residues (n = 1, 2) significantly enhanced the catalyst activity relative to the L‐Leu homopentamer (n = 0). Higher (αMe)‐L‐Leu contents (n = 3, 4) led to a decrease in both catalyst activity and enantiopurity of the product epoxide. In summary, both the individual catalytic action of the peptide strands and the helical conformation as the catalytically competent state of the peptide catalysts were further supported. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 90–96, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Preparative synthesis of dTDP‐L‐rhamnose through combined enzymatic pathways
Authors: Kang Young‐Bok , Yang Yung‐Hun , Lee Kwang‐Won , Lee Sun‐Gu , Sohng Jae Kyung , Lee Hei Chan , Liou Kwangkyoung , Kim Byung‐Gee 
Published: November 2005

AbstractdTDP‐L‐rhamnose, an important precursor of O‐antigen, was prepared on a large scale from dTMP by executing an one‐pot reaction in which six enzymes are involved. Two enzymes, dTDP‐4‐keto‐6‐deoxy‐D‐glucose 3,5‐epimerase and dTDP‐4‐keto‐rhamnose reductase, responsible for the conversion of dTDP‐4‐keto‐6‐deoxy‐D‐glucose to dTDP‐L‐rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP‐4‐keto‐6‐deoxy‐D‐glucose involving TMP kinase, acetate kinase, dTDP‐glucose synthase, and dTDP‐glucose 4,6‐dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP‐L‐rhamnose using dTMP and glucose‐1‐phosphate as starting materials. About 82% yield of dTDP‐L‐rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose‐1‐phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP‐L‐rhamnose was obtained in an overall yield of 60% after two‐step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identified by HPLC, ESI‐MS, and NMR, showing about 95% purity. © 2005 Wiley Periodicals, Inc.
New reaction system for hydrocarbon oxidation by chloroperoxidase
Authors: Park Jin‐Byung , Clark Douglas S. 
Published: November 2005

AbstractA novel reaction system was developed to maximize the catalytic efficiency of chloroperoxidase (CPO, from Caldariomyces fumago) toward the oxidation of hydrocarbons. The reaction system consisted of an organic/aqueous emulsion comprising pure substrate and aqueous buffer supplemented with the surfactant dioctyl sulfosuccinate. The emulsion system attenuated not only the destabilizing effects of the substrate and product on the enzyme by emulsifying the compounds, but also oxidant toxicity (oxidative stress) by increasing substrate availability. As a result, CPO exhibited total turnover numbers (TTNs, defined as the amount of product produced over the catalytic lifetime of the enzyme) of ca. 20,000 mol product/mol enzyme for the oxidation of styrene, toluene, and o‐, m‐, p‐xylenes. The TTNs are over 10‐fold higher than those previously reported for the oxidation of benzylic hydrocarbons by CPO. This study represents a significant step toward the development of CPO as a practical catalyst for large‐scale organic syntheses. © 2005 Wiley Periodicals, Inc.
Anorectal motility responses to selective stimulation of the ventral sacral nerve roots in an experimental model
Authors: Andersen I S , Rijkhoff N J M , Vukovic A , Buntzen S , Djurhuus J C , Laurberg S 
Published: November 2005

Abstract

Background
Control of defaecation and continence may be lost in patients with spinal cord injury. Electrical stimulation of sacral nerve roots to promote defaecation simultaneously activates both the rectum and the external anal sphincter (EAS), and may actually obstruct defaecation. The aim of this study was to investigate whether the EAS could be blocked selectively by selective stimulation of the ventral sacral nerve roots, and whether activation of the rectum without activation of the EAS could be obtained by stimulation of the ventral sacral nerve roots.

Methods
Selective electrical stimulation was performed using anodal blocking, a tripolar cuff electrode and monophasic rectangular current pulses applied to the sacral nerve roots in nine Göttingen minipigs.

Results
Simultaneous responses in the rectum and the anal canal were observed in five animals, whereas only anal responses were noted in four. Variations in cross-sectional area and an increase in rectal pressure seemed to facilitate defaecation. Without blocking, the increase in anal canal pressure was 16–45 cmH2O. With blocking, this increase was abolished in seven and reduced to 3–6 cmH2O in two animals.

Conclusion
Selective activation of the rectum is possible using an anodal block of somatic motor fibres. This technique holds promise in further development of electro-defaecation.
Operative mortality after colorectal resection in the Netherlands
Authors: Engel A F , Oomen J L T , Knol D L , Cuesta M A 
Published: November 2005

Abstract

Background
The aim of this study was to quantify factors related to operative mortality after colorectal resection in the Netherlands.

Methods
Multilevel logistic regression modelling was used. Institutional effects were calculated with and without adjustment for specific patient (age, sex, urgency of operation) and hospital (number of procedures, type of hospital) characteristics. All adult Dutch patients who underwent primary colorectal resection between 1994 and 1999 were included, except those who had (sub)total colectomy or local rectal resection.

Results
A total of 67 594 patients underwent colorectal resection. The in-hospital mortality rate was 7·0 per cent (elective 3·9 per cent, acute 14·3 per cent). Acute operation (odds ratio 3·89) and age (odds ratios 2·63, 5·23 and 10·13 for patients aged 50–69, 70–79 and 80 or more years respectively compared with those aged less than 50 years) had the strongest effects, followed by male sex (odds ratio 1·48) and type of hospital. There was no difference in operative mortality rate between low-, medium- and high-volume hospitals.

Conclusion
In the Netherlands, advanced age and acute operation are by far the most important factors related to operative mortality after colorectal resection. Male sex and type of hospital have only a modest effect, and there is no discernible effect of hospital volume.
The evolving role of gene-based treatment in surgery
Authors: Tan P H , Chan C L H , Chan C , George A J T 
Published: November 2005

AbstractBackgroundThe completion of the sequencing of the human genome in 2003 marked the dawn of a new era of human biology and medicine. Although these remarkable scientific advances improve the understanding of human biology, the question remains how this rapidly expanding knowledge of functional genomics affects the role of surgeons. This article reviews the potential therapeutic application of gene therapy for various surgical conditions.MethodsThe core of this review was derived from a Medline database literature search.Results and conclusionThe currently available vectors in the field of gene therapy and their limitations for clinical applications were analysed. The achievements of gene therapy in clinical trials and the future ramifications for surgery were also explored. Whether gene therapy takes a major role in surgical practice will depend greatly on the success of future vector development. Advances in viral vector technology to reduce the inflammatory effect, and improvements in the efficiency of gene delivery using non-viral vector technology, would allow this form of therapy to become more clinically applicable.
Duct-to-mucosa pancreaticogastrostomy is a safe anastomosis following pancreaticoduodenectomy
Authors: Payne R F , Pain J A 
Published: November 2005

Abstract

Background
Pancreatic fistula following pancreaticoduodenectomy is relatively common, and remains a major cause of morbidity and mortality. The aim of this study was to evaluate the results of two-layered duct-to-mucosa pancreaticogastrostomy as a method for restoring pancreaticoenteric continuity.

Methods
Prospectively collected data from 100 consecutive patients who underwent Whipple's pancreaticoduodenectomy for tumour were evaluated. All operations were performed by the same surgeon.

Results
The perioperative 60-day mortality rate was 1·0 per cent. There were no pancreatic fistulas or anastomotic leaks. Sixteen patients had significant complications that delayed discharge from hospital. Twenty-one patients subsequently required empirical pancreatic exocrine supplements.

Conclusion
Two-layered duct-to-mucosa pancreaticogastrostomy for restoration of pancreaticoenteric continuity after pancreaticoduodenectomy is associated with a low incidence of complications.
Collateral warranties: time to break the habit
Authors: Cockram Richard 
Published: November 2005

AbstractUnder English law, one can in general, only sue on a contract if one is a party to it. In simple cases, this is not a problem. However, not all cases are simple. Take, for example, a development project. Key contractual documents are the building contract/subcontracts and also the appointments under which the various consultants are engaged. They contain core obligations, where only the developer and/or the main contractor are the benefiting parties. However, other key players, such as a funder, a purchaser or an occupational tenant, will only participate in the development if they too can enforce those promises. Using collateral warranties is the traditional method for achieving this. In this paper, it will be explained how The Contract (Rights of Third Parties) Act 1999 has created an opportunity to abandon the use of contractors' and consultants' warranties by giving non‐parties to a contract the right to enforce its provisions in cases where the contract expressly provides or clearly intends that they should be able to do so. Copyright © 2005 John Wiley & Sons, Ltd.
High incidence of the os peroneum in a cadaver sample in Johannesburg, South Africa: Possible clinical implications?
Authors: Oyedele Olusegun , Maseko Constance , Mkasi Nkateko , Mashanyana Matshidiso 
Published: November 2005

AbstractThis study set out to investigate the incidence of the os peroneum in a cadaver sample from Johannesburg, South Africa and to note how bio‐demographic parameters affect such incidence. The os peroneum (OP) is a sesamoid bone frequently found in the tendon of the fibularis longus muscle (FLM), as it passes on the plantar aspect of the cuboid bone. While this bone is often an incidental dissection room or radiological finding, OP fractures, with or without associated rupture of the fibularis (peroneus) longus tendons have been reported. Some investigators have also suggested that the presence of the OP may render the tendon of the FLM susceptible to avulsion injuries. The reported incidences of the OP range between 8 and 26%. These data have emanated by and large from radiographic rather than dissection studies, and the influences of biological indices such as age, sex, population group of origin, and side of the body on these incidences remain largely unknown. Forty cadavers (average age = 75 years) were dissected. Os peronei were present in 36 of these cadavers (90.0%), with 96% of them occurring bilaterally. This bilateral incidence was statistically significant (P = 0.007), but there was no significant difference in age (P = 0.38), sex (P = 0.97), or population group (P = 0.17). We hope that the unusually high incidence of the OP reported here will stimulate further research into possible predisposing factors as well as into the speculated associations between sesamoid occurrence, osteoarthritis, and tendon injuries. Clin. Anat. 19:605–610, 2006. © 2005 Wiley‐Liss, Inc.
Discovery of Complex Mixtures of Novel Long‐Chain Quorum Sensing Signals in Free‐Living and Host‐Associated Marine Alphaproteobacteria
Authors: Wagner‐Döbler Irene , Thiel Verena , Eberl Leo , Allgaier Martin , Bodor Agnes , Meyer Sandra , Ebner Sabrina , Hennig Andreas , Pukall Rüdiger , Schulz Stefan 
Published: November 2005

AbstractMore than 100 bacterial isolates from various marine habitats were screened for AHL production by using gfp reporter constructs based on the lasR system of Pseudomonas aeruginosa and the luxR system of Vibrio fischeri. Of the 67 Alphaproteobacteria tested, most of which belonged into the so‐called Roseobacter clade, 39 induced fluorescence in either one or both sensor strains up to 103‐fold compared to controls. Acylated homoserine lactones were identified by GC‐MS analysis and shown to have chain lengths of C8, C10, C13–C16, and C18. One or two double bonds were often present, while a keto or hydroxyl group occurred only rarely in the side chain. Most strains produced several different AHLs. C18‐en‐HSL and C18‐dien‐HSL were produced by Dinoroseobacter shibae, an aerobic anoxygenic phototrophic bacterium isolated from dinoflagellates, and are among the longest AHLs found to date. Z7‐C14‐en‐HSL, which has previously been detected in Rhodobacter sphaeroides, was produced by Roseovarius tolerans and Jannaschia helgolandensis. This signal molecule was synthesised and shown to induce a similar response to the culture supernatant in the respective sensor strain. The widespread occurrence of quorum‐sensing compounds in marine Alphaproteobacteria, both free‐living strains and those associated to eukaryotic algae, points to a great importance of this signalling mechanism for the adaptation of the organisms to their widely different ecological niches.
Solution NMR Studies of an Intrinsically Unstructured Protein within a Dilute, 75 kDa Eukaryotic Protein Assembly; Probing the Practical Limits for Efficiently Assigning Polypeptide Backbone Resonances
Authors: Wang Yuefeng , Filippov Igor , Richter Christian , Luo Rensheng , Kriwacki Richard W. 
Published: November 2005

AbstractThis paper describes an efficient NMR strategy for assigning the backbone resonances of an intrinsically unstructured protein (IUP), p21‐KID, bound to its biological target, Cdk2/cyclin A. In order to overcome the challenges associated with the high molecular weight (75 kDa) and low solubility of the ternary complex (0.2 mM), we used perdeuteration, TROSY, and high‐sensitivity cryogenic NMR probes at high magnetic‐field strengths (i.e. 16.4, 18.8 and 21.1 Tesla). p21‐KID was also prepared by using specific amino acid isotope labels. Most importantly, we studied binary, subcomplexes that allowed resonance assignments to be made in stages. We show that subdomains of p21‐KID folded within binary complexes into the same conformations as observed in the ternary, Cdk2/cyclin A complex. This is a general feature of IUPs, which often adopt highly extended conformations when bound to other proteins. This strategy is suitable for studies of IUPs within considerably larger biomolecular assemblies as long as the IUP can be uniformly and selectively isotope labeled.
Predicting Protein Retention Time in Hydrophobic Interaction Chromatography
Authors: Lienqueo M. E. , Mahn A. 
Published: November 2005

AbstractA review of hydrophobic interaction chromatography (HIC) of proteins and theories for predicting protein retention time in HIC is given in this paper. A brief description of HIC, hydrophobic interactions and amino acid and protein hydrophobicity is presented and different approaches and models for explaining the retention mechanism of proteins and predicting protein retention time in HIC are described. By using these models it is possible to test different operating conditions for the purification of a target protein and to select the best conditions.
Design Considerations for the Batch Capture of Proteins from Raw Whole Milk by Ion Exchange Chromatography
Authors: Fee C. J. , Chand A. 
Published: November 2005

AbstractThe on‐farm extraction of proteins directly from raw whole milk is a promising approach for the production of minor, high‐value proteins from conventional milk and for the production of recombinant proteins from the milk of transgenic animals. The main advantage of the stirred tank process is that protein extraction is rapid and is achieved in a single step without the need for a pre‐treatment. It also includes the minimization of microbial growth and the potential for batch traceability between individual animals and final product lots.
Protein Engineering Strategies for Selective Protein Purification
Authors: Hedhammar M. , Gräslund T. , Hober S. 
Published: November 2005

AbstractWhen producing and purifying recombinant proteins it is of importance to minimize the number of unit operations during the purification procedure. This is accomplished by increasing the selectivity in each step. Due to the high selectivity of affinity chromatography it has a widespread use in protein purification. However, most target proteins lack a suitable affinity ligand usable for capture on a solid matrix. A way to circumvent this obstacle is to genetically fuse the gene encoding the target protein with a gene encoding a purification tag. When the chimeric protein is expressed, the tag allows for specific capture of the fusion protein. In industrial‐scale production, extension of the target protein often is unwanted since it might interfere with the function of the target protein. Hence, a purification scheme developed for the native protein is desired. In this review, different fusion strategies used for protein purification are discussed. Also, the development of ligands for selective affinity purification of native target proteins is surveyed.
Chromatographic Approaches in the Purification of Plasmid DNA for Therapy and Vaccination
Authors: Ferreira G. N. M. 
Published: November 2005

AbstractThe need for large scale plasmid DNA purification processes has increased in the last few years due to the rapid evolution of gene therapy and DNA vaccines. Chromatographic purification of plasmid DNA has specific problems which are mostly related to the structural nature of plasmid DNA, the resemblance of plasmid DNA to some impurities, and the lack of capacity and selectivity of the traditional bead adsorbents. In this paper, plasmid DNA purification using chromatographic processes is reviewed. Initially the most relevant structural and chemical properties of supercoiled plasmid DNA and related impurities are described, and the purification objectives are specified. The most significant properties are highlighted and their possible exploitation for plasmid DNA adsorption is described. After a brief description of currently used chromatographic purification strategies, novel approaches centered on the use and development of new stationary phases with higher capacity utilization are described.