bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic microheterogeneity of human transthyretin detected by IEF
Authors: Altland Klaus , Benson Merrill D. , Costello Catherine E. , Ferlini Alessandra , Hazenberg Bouke P. C. , Hund Ernst , Kristen Arnt V. , Linke Reinhold P. , Merlini Giampaolo , Salvi Fabrizio , Saraiva Maria J. , Singer Reinhard , Skinner Martha , Winter Pia 
Published: May 2007

AbstractMutations of the human transthyretin (TTR) gene have attracted medical interest as a cause of amyloidosis. Recently, we have described in detail an electrophoretic procedure with PAGE followed by IEF in urea gradients for the study of the microheterogeneity of TTR monomers (Altland, K., Winter, P., Sauerborn, M. K., Electrophoresis 1999, 20, 1349–1364). In this paper, we present a study on 49 different mutations of TTR including 33 that result in electrically neutral amino acid substitutions. The aims of the investigation were to test the sensitivity of the procedure to detect TTR variants in patients with TTR amyloidosis and their relatives and to identify some common characteristics that could explain the amyloidogenicity of these variants. We found that all tested amyloidogenic mutations could be detected by our method with the exception of those for which the corresponding variant was absent in plasma samples. Most of the electrically neutral amyloidogenic TTR variants had in common a reduced conformational stability of monomers by the activity of protons and urea. For three variants, e.g. TTR–F64L, TTR–I107V and TTR–V122I, the monomers had a conformational stability close to that of normal monomers but we found experimental and structural arguments for a weakening of the monomer‐monomer contact. All types of amyloidogenic mutations affected the stability of TTR tetramers.
NG2‐positive cells generate A2B5‐positive oligodendrocyte precursor cells
Authors: Baracskay Karen L. , Kidd Grahame J. , Miller Robert H. , Trapp Bruce D. 
Published: May 2007

AbstractCellular specification of the oligodendrocyte lineage occurs through a series of stages identified by expression of distinct biochemical characteristics. The best characterized oligodendrocyte progenitor cell (OPC) in vitro is the bipotential O2‐A progenitor, identified by labeling with monoclonal antibody A2B5, which proliferates predominantly in response to platelet derived growth factor (PDGF). The cellular ancestors of O2‐A progenitor cells are currently unclear. In vivo OPCs can be identified by expression of the cell surface markers NG2 (a sulfated proteoglycan) and platelet derived growth factor receptor αR). Substantial evidence supports the generation of oligodendrocytes from NG2+, PDGFαR+ cells both in vivo and in vitro. The developmental relationship between NG2+ cells and A2B5− positive cells is unknown and it is unclear whether they represent identical, partially overlapping or nonoverlapping populations of cells. Here we show that in cultures of developing brain NG2+ and A2B5+ cells arise from overlapping cell populations. NG2+ cells appear prior to the expression of A2B5+ cells and generate A2B5+ cells. We propose that during development NG2+/A2B5− cells (pre‐OPCs) represent the direct ancestor to A2B5+ O2A progenitor cells (OPCs). © 2007 Wiley‐Liss, Inc.
An opportunity cost approach to sample size calculation in cost‐effectiveness analysis
Authors: Gafni A. , Walter S. D. , Birch S. , Sendi P. 
Published: May 2007

AbstractThe inclusion of economic evaluations as part of clinical trials has led to concerns about the adequacy of trial sample size to support such analysis. The analytical tool of cost‐effectiveness analysis is the incremental cost‐effectiveness ratio (ICER), which is compared with a threshold value (λ) as a method to determine the efficiency of a health‐care intervention. Accordingly, many of the methods suggested to calculating the sample size requirements for the economic component of clinical trials are based on the properties of the ICER. However, use of the ICER and a threshold value as a basis for determining efficiency has been shown to be inconsistent with the economic concept of opportunity cost. As a result, the validity of the ICER‐based approaches to sample size calculations can be challenged. Alternative methods for determining improvements in efficiency have been presented in the literature that does not depend upon ICER values. In this paper, we develop an opportunity cost approach to calculating sample size for economic evaluations alongside clinical trials, and illustrate the approach using a numerical example. We compare the sample size requirement of the opportunity cost method with the ICER threshold method. In general, either method may yield the larger required sample size. However, the opportunity cost approach, although simple to use, has additional data requirements. We believe that the additional data requirements represent a small price to pay for being able to perform an analysis consistent with both concept of opportunity cost and the problem faced by decision makers. Copyright © 2007 John Wiley & Sons, Ltd.
Delayed behavioral and endocrine effects of sarin and stress exposure in mice
Authors: Mach Mojmir , Grubbs Robert D. , Price William A. , Nagaoka Maya , Dubovický Michal , Lucot James B. 
Published: May 2007

AbstractThe organophosphorus agent sarin is a potent inhibitor of acetylcholinesterase. Experiments tested the influence of exposure to low doses of sarin along with psychological stress on delayed behavioral and endocrine changes in mice. Motor activity, acoustic startle response (ASR), pre‐pulse inhibition (PPI) of ASR, activity of cholinesterase in blood and catecholamine levels in adrenals were evaluated after low dose sarin exposure (3 × 0.4 LD50subcutaneously) combined with chronic intermittent stress in C57BL/6J mice. While sarin alone produced depression of motor activity, no interaction of the stress with sarin exposure was observed. Cholinesterase activity was significantly reduced 24 h after exposure to sarin; however, the basal activity was re‐established 3 weeks later. The combination of low dose sarin exposure and stress produced delayed behavioral change manifested as excessive grooming together with endocrine alterations in adrenals 7 weeks after exposure. The size of the adrenals in the combined exposure group was increased and the concentration of catecholamines was significantly decreased. In conclusion, these findings indicate that sarin in low doses is more dangerous when combined with shaker stress inducing delayed behavioral and endocrine changes. Copyright © 2007 John Wiley & Sons, Ltd.
Bone response to three different chemical compositions of fluorcanasite glass‐ceramic
Authors: da Rocha Barros Valdemar Mallet , Liporaci Jorge Luiz J. , Rosa Adalberto L. , Junqueira Marcela Caffarena , de Oliveira Paulo Tambasco , Johnson Anthony , van Noort Richard 
Published: May 2007

AbstractThe aim of this study was to evaluate the bone response to three fluorcanasite glass‐ceramic compositions with different solubilities (K3, K5, and K8) after implantation in a femur rabbit model. Fluorcanasite glass‐ceramic rods were implanted bilaterally in the mid‐shafts rabbit femurs. Implants were harvested at 8 and 12 weeks and prepared for histological and histomorphometric analyses at the light microscope level. Bioglass 45S5 rods were used as a control material. At 8 weeks, all fluorcanasite glass‐ceramics were entirely surrounded by a nonmineralized connective tissue. At 12 weeks, reduced areas of bone tissue were observed in the cortical area in direct contact with the K3 and K5 fluorcanasite glass‐ceramics compared to Bioglass 45S5, whereas no bone tissue was observed in direct contact with the K8 surface. Bone‐to‐implant contact in the cortical area was affected by the material chemical composition and ranked as follows: Bioglass 45S5 > K3 > K5 > K8 (p = 0.001). In the bone marrow, a layer of fibrous connective tissue formed in direct contact with the fluorcanasite glass‐ceramics and Bioglass 45S5, and only rarely exhibited contact osteogenesis. All the fluorcanasite glass‐ceramics appeared to degrade in the biological environment. The solubility ratio did not alter significantly the biological reply of the fluorcanasite glass‐ceramics in vivo. Further modifications of the chemical composition of the fluorcanasite glass‐ceramic are required to increase the stability of the material in vivo. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Characterization, degradation, and mechanical strength of poly(D,L‐lactide‐co‐ϵ‐caprolactone)‐poly(ethylene glycol)‐poly(D,L‐lactide‐co‐ϵ‐caprolactone)
Authors: Bramfeldt Hanna , Sarazin Pierre , Vermette Patrick 
Published: May 2007

AbstractA series of three biocompatible P(CL‐co‐LA)‐PEG‐P(CL‐co‐LA) copolymers were synthesized using ring‐opening polymerization and characterized by 1H‐NMR, gel permeation chromatography, DSC, dynamic‐mechanical analysis, and X‐ray diffraction. The number of monomer units was kept constant, while the D,L‐LA fraction was varied so as to constitute 0, 30, or 70% of the end segments. The molecular weights were sufficiently high to eventually permit 3D scaffold preparation. A degradation study was carried out over 26 weeks, and the effect of monomer composition on the rate of degradation as well as on changes in mechanical strength was investigated. Pure polycaprolactone (PCL)‐poly(ethylene glycol) (PEG)‐PCL copolymer, P(100/0), was a crystalline material displaying no measurable mass loss, a 30% reduction in mean molecular weight (Mn), and only very slight changes in tensile strength. The random incorporation of 30 and 70% D,L‐LA into the end sections of the polymer chain, produced more and more amorphous materials, exhibiting increasingly high rates of degradation, mass loss, and loss of tensile strength. Compared with random P(CL‐co‐LA), the presence of the PEG block was found both to improve hydrophilicity and thus the rate of degradation and to infer a stabilizing quality, thereby pacing the decrease in tensile strength during degradation. The tested copolymers range from materials exhibiting low mechanical strength and high rate of degradation to slow‐degrading materials with high mechanical strength suitable, e.g., for three‐dimensional scaffolding. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Effects of BMP‐2 and pulsed electromagnetic field (PEMF) on rat primary osteoblastic cell proliferation and gene expression
Authors: Selvamurugan Nagarajan , Kwok Sukyee , Vasilov Anatoliy , Jefcoat Stephen C. , Partridge Nicola C. 
Published: May 2007

AbstractBone morphogenetic proteins (BMPs) strongly promote osteoblast differentiation. Pulsed electromagnetic fields (PEMFs) promote fracture healing in non‐union fractures. In this study, we hypothesized that a combined BMP‐2 and PEMF stimulation would augment bone formation to a greater degree than treatment with either single stimulus. BMP‐2 maximally increased the proliferative activity of rat primary osteoblastic cells at 25 ng/ml concentration. Real‐time reverse transcription‐polymerase chain reaction (RT‐PCR) showed that BMP‐2 stimulated mRNA levels of alkaline phosphatase (ALP), α1 (I) procollagen, and osteocalcin (OC) in the differentiation phase and only OC mRNA expression in the mineralization phase after 24‐h treatment. Both BMP‐2 and PEMF (Spinal‐Stim) increased cell proliferation, which was additive when both agents were combined. PEMF alone or together with BMP‐2 increased only ALP mRNA expression and only during the differentiation phase 24 h after one 4‐h treatment. This effect was additive when both agents were combined. Continuous daily 4‐h treatment with PEMF alone or together with BMP‐2 increased expression of all three osteoblast marker genes during the differentiation phase and increased the mineralized matrix. This effect was additive when both agents were combined, suggesting that the two interventions may be working on different cellular pathways. Thus, a combined effect of BMP‐2 and PEMF in vitro could be considered as groundwork for in vivo bone development that may support skeletal therapy. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1213–1220, 2007
A robust method for automated background subtraction of tissue fluorescence
Authors: Cao Alex , Pandya Abhilash K. , Serhatkulu Gulay K. , Weber Rachel E. , Dai Houbei , Thakur Jagdish S. , Naik Vaman M. , Naik Ratna , Auner Gregory W. , Rabah Raja , Freeman D. Carl 
Published: May 2007

AbstractThis paper introduces a new robust method for the removal of background tissue fluorescence from Raman spectra. Raman spectra consist of noise, fluorescence and Raman scattering. In order to extract the Raman scattering, both noise and background fluorescence must be removed, ideally without human intervention and preserving the original data. We describe the rationale behind our robust background subtraction method, determine the parameters of the method and validate it using a Raman phantom against other methods currently used. We also statistically compare the methods using the residual mean square (RMS) with a fluorescence‐to‐signal (F/S) ratio ranging from 0.1 to 1000. The method, ‘adaptive minmax’, chooses the subtraction method based on the F/S ratio. It uses multiple fits of different orders to maximize each polynomial fit. The results show that the adaptive minmax method was significantly better than any single polynomial fit across all F/S ratios. This method can be implemented as part of a modular automated real‐time diagnostic in vivo Raman system. Copyright © 2007 John Wiley & Sons, Ltd.
The effect of instant green tea on the foaming and rheological properties of egg albumen proteins
Authors: Wu Weiguo , Clifford Mike , Howell Nazlin K 
Published: May 2007

AbstractThe effects of three varieties of instant green tea (from China, Japan and Kenya) on the foaming and thermal properties of 1% (w/v) egg albumen and the gelation properties of 5 and 15% (w/v) egg albumen were investigated. All varieties produced similar effects on the foaming and gelation properties of egg albumen, but to different extents depending on the tea constituents. Mixtures of 1% (w/v) egg albumen and 0.25–0.4% (w/v) instant green teas in distilled water showed the greatest foam expansion (800–1140%) and foam stability (97–100%) at 10 min after whipping compared with 1% (w/v) egg albumen alone (226% for foam expansion and 34% for foam stability). Addition of instant green teas at levels above 0.5% (w/v) decreased foam expansion and stability. Small‐deformation rheology of mixtures of 5% (w/v) egg albumen and 1 or 2% (w/v) instant green teas showed an initial increase in elastic modulus (G′) and viscous modulus (G″) followed by a small, broad peak, indicating that the binding of tea constituents (polyphenols) with proteins may be reversible between 20 and 54 °C; this peak was not seen for 5% (w/v) egg albumen on its own. Large‐deformation rheological tests also indicated increased strength of mixed egg albumen/green tea gels with increasing levels of instant green teas. Differential scanning calorimetry thermograms showed that for the same instant green tea a higher concentration decreased the onset and peak (Tm) temperatures and enthalpy change values of all egg albumen protein peaks. Copyright © 2007 Society of Chemical Industry
Rheological characterisation of polysaccharides extracted from brown seaweeds
Authors: Rioux Laurie‐Eve , Turgeon Sylvie L , Beaulieu Martin 
Published: May 2007

AbstractHydrocolloids from seaweeds have interesting functional properties, such as thickening or gelling ability. Structural characteristics of polysaccharides extracted from Québec seaweeds have not yet been established. Thus, the determination of the relationship between their structure and rheological behaviour is limited. Alginate and fucoidan were extracted using selective solvents from three species: Saccharina longicruris, Ascophyllum nodosum and Fucus vesiculosus. Structural analysis (total sugars, uronic acids, sulfates and molecular weight) and rheological characterisation were performed at different polysaccharide concentrations with and without the addition of NaCl. The results showed important variation between species. Fucoidan and alginate exhibited Newtonian behaviour. Fucoidan extracted from F. vesiculosus had the highest viscosity level, which might be explained by the degree of branching of the molecules. For alginate, the one extracted from S. longicruris showed a higher apparent viscosity. This result can partially be explained by the block proportion of alginate. The gelation profile of alginate was also determined for each species. The final storage modulus, G′, was variable for each species. Differences between species were observed for both polysaccharides as a result of structural variation. Copyright © 2007 Society of Chemical Industry
Evaluation of some essential oils as botanical fungitoxicants for the protection of stored food commodities from fungal infestation
Authors: Kumar Rajesh , Dubey Nawal K , Tiwari Om P , Tripathi Yamini B , Sinha Kauskal K 
Published: May 2007

AbstractEssential oils from different parts of 18 plants belonging to 11 families were extracted and tested against two toxigenic strains of Aspergillus flavus Link through the poisoned food technique. The oil of Mentha arvensis was found to be effective against both strains of A. flavus and completely stopped the radial mycelial growth of A. flavus at 0.10 mg mL−1. It was found to be superior over the synthetic fungicides tested and showed a broad fungitoxic spectrum against A. niger, A. fumigatus, Botryodiplodia theobromae, Cladosporium cladosporioides, Fusarium oxysporum, Helminthosporium oryzae, Macrophomina phaseolina and Sclerotium rolfsii at 0.10 mg mL−1. The oil completely inhibited the aflatoxin B1 production by the toxigenic strain of A. flavus at 0.05 mg mL−1. Moreover, the Mentha oil also exhibited potent antioxidant activity in 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulphuric acid (ABTS) bioassay. Keeping in mind the side effects of synthetic pesticides and the global interest in botanical pesticides for plant protection due to their biodegradable nature, M. arvensis oil may be used as a botanical fungitoxicant against fungal attack to stored food commodities. The antiaflatoxigenic and antioxidant nature of the oil suggest the possibility of its exploitation for enhancing the shelf life of stored food commodities. Copyright © 2007 Society of Chemical Industry
A global database of domestic and international tourist numbers at national and subnational level
Authors: Bigano Andrea , Hamilton Jacqueline M. , Lau Maren , Tol Richard S.J. , Zhou Yuan 
Published: May 2007

AbstractWe present a new, global database on tourist destinations. The database differs from other databases in that it includes both domestic and international tourists; and it contains, for the most important destinations, data at national level as well as at lower administrative levels. Missing observations are interpolated using statistical models. The data are freely accessible on the internet. Copyright © 2007 John Wiley & Sons, Ltd.
Mathematical model that predicts the force–intensity and force–frequency relationships after spinal cord injuries
Authors: Ding Jun , Chou Li‐Wei , Kesar Trisha M. , Lee Samuel C.K. , Johnston Therese E. , Wexler Anthony S. , Binder‐Macleod Stuart A. 
Published: May 2007

AbstractWe have previously developed and tested a muscle model that predicts the effect of stimulation frequency on muscle force responses. The aim of this study was to enhance our isometric mathematical model to predict muscle forces in response to stimulation trains with a wide range of frequencies and intensities for the quadriceps femoris muscles of individuals with spinal cord injuries. Isometric forces were obtained experimentally from 10 individuals with spinal cord injuries (time after injury, 1.5–8 years) and then compared to forces predicted by the model. Our model predicted accurately the force–time integrals (FTI) and peak forces (PF) for stimulation trains of a wide range of frequencies (12.5–80 HZ) and intensities (150–600‐μs pulse duration), and two different stimulation patterns (constant‐frequency trains and doublet‐frequency trains). The accurate predictions of our model indicate that our model, which now incorporates the effects of stimulation frequency, intensity, and pattern on muscle forces, can be used to design optimal customized stimulation strategies for spinal cord–injured patients. Muscle Nerve, 2007
Pathogenic mitochondrial DNA mutations in protein‐coding genes
Authors: Wong Lee‐Jun C. 
Published: May 2007

AbstractMore than 200 disease‐related mitochondrial DNA (mtDNA) point mutations have been reported in the Mitomap (http://www.mitomap.org) database. These mutations can be divided into two groups: mutations affecting mitochondrial protein synthesis, including mutations in tRNA and rRNA genes; and mutations in protein‐encoding genes (mRNAs). This review focuses on mutations in mitochondrial genes that encode proteins. These mutations are involved in a broad spectrum of human diseases, including a variety of multisystem disorders as well as more tissue‐specific diseases such as isolated myopathy and Leber hereditary optic neuropathy (LHON). Because the mitochondrial genome contains a large number of apparently neutral polymorphisms that have little pathogenic significance, along with secondary homoplasmic mutations that do not have primary disease‐causing effect, the pathogenic role of all newly discovered mutations must be rigorously established. A scoring system has been applied to evaluate the pathogenicity of the mutations in mtDNA protein‐encoding genes and to review the predominant clinical features and the molecular characteristics of mutations in each mtDNA‐encoded respiratory chain complex. Muscle Nerve, 2007
Iron load and redox stress in skeletal muscle of aged rats
Authors: Altun Mikael , Edström Erik , Spooner Eric , Flores‐Moralez Amilcar , Bergman Esbjörn , Tollet‐Egnell Petra , Norstedt Gunnar , Kessler Benedikt M. , Ulfhake Brun 
Published: May 2007

AbstractLoss of skeletal muscle mass (sarcopenia) is a major contributor to disability in old age. We used two‐dimensional gel electrophoresis and mass spectrometry to screen for changes in proteins, and cDNA profiling to assess transcriptional regulations in the gastrocnemius muscle of adult (4 months) and aged (30 months) male Sprague‐Dawley rats. Thirty‐five proteins were differentially expressed in aged muscle. Proteins and mRNA transcripts involved in redox homeostasis and iron load were increased, representing novel components that were previously not associated with sarcopenia. Tissue iron levels were elevated in senescence, paralleling an increase in transferrin. Proteins involved in redox homeostasis showed a complex pattern of changes with increased SOD1 and decreased SOD2. These results suggest that an elevated iron load is a significant component of sarcopenia with the potential to be exploited clinically, and that mitochondria of aged striated muscle may be more vulnerable to radicals produced in cell respiration. Muscle Nerve, 2007