bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement in variability of the horizontal meridian of the primary visual area following high‐resolution spatial normalization
Authors: Kochunov P. , Hasnain M. , Lancaster J. , Grabowski T. , Fox P. 
Published: January 2003

AbstractWe investigated the decrease in intersubject functional variability in the horizontal meridian (HM) of the primary visual area (V1) before and after individual anatomical variability was significantly reduced using a high‐resolution spatial normalization (HRSN) method. The analyzed dataset consisted of 10 normal, right‐handed volunteers who had undergone both an O‐15 PET study, which localized retinotopic visual area (V1), and a high‐resolution anatomical MRI. Individual occipital lobes were manually segmented from anatomical images and transformed into a common space using an in‐house high‐resolution regional spatial normalization method called OSN. Individual anatomical and functional variability was quantified before and after HRSN processing. The reduction of individual anatomical variability was judged by the reduction in gray matter (GM) mismatch and by the improvement in overlap frequency between individual calcarine sulci. The reduction in intersubject functional variability of HM was determined by measurements of the overlap frequency between individual HM areas and by improvement in intersubject Z‐score maps. The HRSN processing significantly reduced the individual anatomical variability: GM mismatch was reduced by a factor of two and the mean calcarine sulcus overlap frequency was improved from 37 to 68%. The reduction in functional variability was more subtle. However, both HM mean overlap (increased from 18 to 28%) and the average Z‐score (increased from 2.2 to 2.55) were significantly improved. Although, functional registration was significantly improved by matching sulci, there was still residual variability. This is believed to be the variability of individual areas within the calcarine sulcus, and cannot be resolved by sulcal match. Thus, the proposed methodology provides an efficient, unbiased, and automated way to study structure‐functional relationship in human brain. Hum. Brain Mapping 18:123–134, 2003. © 2002 Wiley‐Liss, Inc.
Tubewells and arsenic in Bangladesh: challenging a public health success story
Authors: Caldwell Bruce K. , Caldwell John C. , Mitra S. N. , Smith Wayne 
Published: January 2003

AbstractBangladesh has seen one of the developing world's great public health successes, the conversion of the drinking water source for 94% of the rural population to ‘safe water’, in the form of tubewells, with the aim of reducing morbidity and mortality from water‐borne disease. Now, that success is being endangered by the discovery that 20 million people may be in great danger and another 20 million in lesser danger of being poisoned by arsenic contamination from tubewell water. This article reports findings from the first national probability sample survey of the rural population and a census of tubewells investigating the social, demographic and epidemiological context of the crisis. The survey covered 3780 households containing 20260 people. The tubewell census covered 9174 tubewells. The article presents data on the respondents' history of drinking tubewell water, knowledge of the arsenic problem, identification of arsenicosis, as well as the impact upon them of the national campaign, the testing of tubewells, and their subsequent sources of water. Eighty‐seven per cent of households drank water from ordinary tubewells (at most risk from arsenic poisoning) and 7% from deep tubewells. Among males, 47.5% had heard that something may be wrong with tubewell water, compared with 39.6% of females. A much lower proportion (20.6% males, 11.3% females) had heard that the water contained a poison called arsenic. Only about 1.5% of the entire population had stopped using tubewell water. Of survey respondents, 0.5% of males and 0.4% of females reported symptoms consistent with chronic arsenicosis. Suggestions are made for a more effective programme. Copyright © 2003 John Wiley & Sons, Ltd.
Discovery and design of novel inhibitors of botulinus neurotoxin A: targeted ‘hinge’ peptide libraries
Authors: Hayden J. , Pires J. , Roy S. , Hamilton M. , Moore G. J. 
Published: January 2003

AbstractIntoxication by the zinc protease botulinus neurotoxin A (BoNT‐A) results from cleavage of a single Q–R bond in the neuronal protein SNAP‐25, which disables the docking mechanism required for neurotransmitter release. In the present study, potential inhibitors of BoNT‐A were assessed from their effects on the BoNT‐A cleavage of a synthetic 17‐mer peptide (SNAP‐25, residues 187–203) spanning the Q–R cleavage site. Compounds that inhibited BoNT‐A included thiols (zinc chelators) such as dithiothreitol, dimercaptopropanesulfonic acid, mercaptosuccinic acid and captopril. In addition, compounds containing multiple acidic functions, such as the SNARE motif V2 (ELDDRADALQ), the tripeptide Glu‐Glu‐Glu and the steroid glycoside glycyrrhizic acid, were effective inhibitors. ‘Hinge’ peptide mini‐libraries (PMLs) having the structure acetyl‐X1‐X2‐linker‐X3‐X4‐NH2 or X1‐X2‐linker‐X3, where X1–X4 were mixtures of selected amino acids and the flexible linker was 4‐aminobutyric acid, also provided effective inhibition. Targeted PMLs containing the acidic amino acids Asp and Glu, the scissile‐bond amino acids Gln and Arg and the zinc chelators His and Cys produced pronounced inhibition of BoNT‐A. Deconvolution of these libraries will provide novel ligands with improved inhibitory potency as leads in the design of peptide mimetics to treat BoNT poisoning. Copyright ? 2003 Crown in the right of Canada. Published by John Wiley and Sons, Ltd.
Influence of paraoxon (POX) and parathion (PAT) on apoptosis: a possible mechanism for toxicity in low‐dose exposure
Authors: Saleh A. M. , Vijayasarathy C. , Fernandez‐Cabezudo M. , Taleb M. , Petroianu G. 
Published: January 2003

AbstractThe acute effects of poisoning with organophosphorus compounds (OPCs) are well known and have been described extensively. Most of the clinical symptoms are due to inhibition of acetylcholinesterase. Although acute OPC poisoning is a well‐established clinical entity, the existence of chronic poisoning due to exposure to low levels of OPC (below the threshold required for cholinergic clinical symptoms) is a hotly debated issue. Recent studies have suggested the involvement of OPCs in apoptotic processes. However, the mechanisms by which they modulate this process are poorly investigated. In the present study we evaluated the toxic effect of different concentrations of paraoxon (POX) and parathion (PAT) in murine EL4 T lymphocytes. We examined cellular responses, including induction of apoptosis, involvement of a caspase cascade, the activity of effector caspase (caspase‐3) and the biochemical and morphological changes that are the hallmarks of classical apoptosis. The results of our study indicate that at doses below IC50 POX is a potent inducer of apoptosis, as opposed to PAT that shows little apoptotic effect. Copyright © 2003 John Wiley & Sons, Ltd.
Toxicity of some bis mannich bases and corresponding piperidinols in the brine shrimp (Artemia salina) Bioassay
Authors: Gul H. Inci , Gul Mustafa , Erciyas Ercin 
Published: January 2003

AbstractSome acetophenone‐derived bis Mannich bases were synthesized: bis[β‐benzoylethyl]ethylamine hydrochloride (IIa), bis[β‐(p‐methylbenzoyl)ethyl]ethylamine hydrochloride (IIb), bis[β‐(p‐chlorobenzoyl)ethyl]ethy‐ lamine hydrochloride (IId), bis[(2‐thienylcarbonyl)ethyl]ethylamine hydrochloride (IIe); some corresponding piperidinol derivatives: 3‐benzoyl‐1‐ethyl‐4‐phenyl‐4‐piperidinol hydrochloride (IIIa), 1‐ethyl‐3‐(p‐methyl‐ benzoyl)‐4‐(p‐methylphenyl)‐4‐piperidinol hydrochloride (IIIb), 1‐ethyl‐3‐(p‐methoxybenzoyl)‐4‐(p‐methoxy‐ phenyl)‐4‐piperidinol hydrochloride (IIIc), 1‐ethyl‐3‐(p‐chlorobenzoyl)‐4‐(p‐chlorophenyl)‐4‐piperidinol hydrochloride (IIId), 1‐ethyl‐4‐(2‐thienyl)‐3‐(2‐thienylcarbonyl)‐4‐piperidinol hydrochloride (IIIe); and some representative quaternary piperidinols: 3‐benzoyl‐1‐ethyl‐4‐hydroxy‐1‐methyl‐4‐phenylpiperidinium iodide (IIIf), 1‐ethyl‐4‐hydroxy‐1‐methyl‐3‐(p‐methylbenzoyl)‐4‐(p‐methylphenyl)piperidinium iodide (IIIg). Toxicity was tested by the brine shrimp bioassay as an intermediate test before further in vivo animal experiments. Piperidine derivatives were found to be more potent than bis Mannich bases. Quaternary piperidine derivatives IIIf and IIIg and also non‐quaternary piperidine derivatives IIIb, IIIe, IIIc and IIId were more toxic than 5‐fluorouracil in brine shrimp bioassay. Except for IIe, bis Mannich bases were not effective. Quaternization and conversion of bis Mannich bases to corresponding piperidines improved the toxicity. The lipid solubility of the compounds may not affect the toxicity. From these findings the quaternary piperidine derivatives IIIf and IIIg could be used in further drug development and also for in vivo experiments. Copyright © 2003 John Wiley & Sons, Ltd.
Application of pharmacokinetic/pharmacodynamic and stochastic modelling to 6‐mercaptopurine micronucleus induction in mouse bone marrow erythrocytes
Authors: Klés Virginie , Hyrien Ollivier , Poul Jean‐Michel , Sanders Pascal 
Published: January 2003

AbstractThis study investigates the kinetics of bone marrow micronucleated polychromatic erythrocytes and some mechanistic aspects of micronuclei induction using mathematical models. Female mice were administered a single intraperitoneal injection of the purine antagonist 6‐mercaptopurine at 50 mg kg−1. The time course evolution of the drug concentrations in the plasma and the micronucleated polychromatic erythrocyte kinetic rate in bone marrow were observed. Two mathematical models were developed for this study. The first model was built from a simultaneous pharmacokinetic/pharmacodynamic approach, but was invalidated after comparing its predictions to experimental data. The second model was a stochastic model based on some biological hypotheses involved in micronuclei induction. This model predicted a wavy kinetic rate of micronucleated polychromatic erythrocytes that was confirmed by a second data set obtained from a specifically built experimental design. The biological hypotheses were then discussed. It turned out from this work that mathematical modelling could be used as a tool to explore the cellular mechanisms of toxicity of the compound: for instance, the assumptions that 6‐mercaptopurine induced micronuclei mainly in cells entering the S phase, and not only during the last cell cycle but during one of the earlier cycles preceding the extrusion of the main nucleus, were confirmed. Moreover, the use of the stochastic model would help to schedule more accurately the bone marrow or blood harvesting times in the in vivo rodent micronucleus test. Copyright © 2003 John Wiley & Sons, Ltd.
Study of novel chitosan‐gelatin artificial skin in vitro
Authors: Mao Jinshu , Zhao Liguo , de Yao Kang , Shang Qingxin , Yang Guanghui , Cao Yilin 
Published: January 2003

AbstractA novel absorbable scaffold composed of chitosan and gelatin was fabricated by freezing and lyophilizing methods, resulting in an asymmetric structure. This bilaminar texture is suitable for preparing a bilayer skin substitute. The methods employed to confirm the applicability of this chitosan‐gelatin scaffold as an ideal skin substitute were a water uptake ability test, in vitro fibroblast proliferation, and scaffold tests in which fibroblasts were co‐cultured with keratinocytes. The chitosan‐gelatin scaffolds were more wettable and adsorbed more water than did chitosan alone. In static cell culture the thinner scaffold is better than the thicker one, and because of diffusion limitations in the scaffold, culture time must be within 3 weeks before transplantation to living tissues. Keratinocytes were co‐cultured with fibroblasts in chitosan‐gelatin scaffolds to construct an artificial bilayer skin in vitro. The artificial skin obtained was flexible and had good mechanical properties. Moreover, there was no contraction observed in the in vitro cell culture tests. The data from this study suggest that chitosan‐gelatin scaffolds are suitable for skin tissue engineering goals. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 301–308, 2003
Titanium surface topography alters cell shape and modulates bone morphogenetic protein 2 expression in the J774A.1 macrophage cell line
Authors: Takebe J. , Champagne C. M. , Offenbacher S. , Ishibashi K. , Cooper L. F. 
Published: January 2003

AbstractMacrophage cytokine expression significantly affects wound healing. Macrophage secretion of transforming growth factor beta 1 (TGFβ1) and bone morphogenetic proteins (BMP) may affect osteogenesis at endosseous implant surfaces. The aim of this investigation was to determine the effect of commercially pure titanium (cpTi) substrate topography on adherent macrophage osteogenic and osteoinductive cytokine expression. J774A.1 murine macrophage cell adhesion was examined by scanning electron microscopy, 0–72 h following plating onto polished, machined, and grit‐blasted cpTi surfaces. TGFβ1 and BMP‐2 gene expression by adherent macrophages was determined by the reverse transcription polymerase chain reaction. Macrophage adhesion increased with time on all surfaces and spreading increased with increasing surface roughness (polished < machined < grit‐blasted). BMP‐2 expression was not evident for cells adherent to polished cpTi at 24 h. In contrast, BMP‐2 expression occurred at 24 h in cells adherent to machined and grit‐blasted cpTi. BMP‐2 expression was evident on all surfaces at 72 h and was greatest in grit‐blasted titanium adherent cells. Increasing concentrations of cytochalasin B (0–50 μM) inhibited macrophage spreading and reduced BMP‐2 mRNA expression, suggesting a relationship between cell shape and BMP‐2 expression. This was further characterized using anti‐β1 and anti‐β3 integrin antibodies. The anti‐β1 integrin antibodies inhibited adherent macrophage BMP‐2 mRNA expression. Anti‐β3 integrin antibody treatment only modestly reduced BMP‐2 mRNA expression. Endosseous implant surface topography induced changes in macrophage shape that were associated with changes in BMP‐2 expression in J774A.1 mouse macrophage cell line. This first demonstration of BMP‐2 expression by cpTi adherent macrophages suggests that the macrophage may contribute surface‐specific osteoinductive signals during bone formation at implanted alloplastic surfaces. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 207–216, 2003
An atelocollagen honeycomb‐shaped scaffold with a membrane seal (ACHMS‐scaffold) for the culture of annulus fibrosus cells from an intervertebral disc
Authors: Sato Masato , Asazuma Takashi , Ishihara Masayuki , Kikuchi Toshiyuki , Masuoka Kazunori , Ichimura Shoichi , Kikuchi Makoto , Kurita Akira , Fujikawa Kyosuke 
Published: January 2003

AbstractThe aim of this study was to investigate the possibility of using the atelocollagen honeycomb‐shaped scaffold with a membrane seal (ACHMS‐scaffold) for the culture of annulus fibrosus (AF) cells in tissue engineering procedures of intervertebral disc repair. AF cells from the intervertebral discs of Japanese white rabbits were cultured for up to 3 weeks in the ACHMS‐scaffold to allow a high density, three‐dimensional culture. Although the DNA content in the scaffold increased at a lower rate than in the monolayer culture, scanning electron microscopy data showed that the scaffold was filled with the grown AF cells and produced extracellular matrix on day 21. The amount of type II collagen and its mRNA expression by the scaffold cultured cells were determined using Western blotting and Northern blotting analyses, respectively, and remained at a higher level than in the monolayer cultured cells. Furthermore, glycosaminoglycan (GAG) accumulation in the scaffold culture was at a higher level than in the monolayer culture. Western blot analysis for extracted proteoglycans from the scaffold culture also exhibited a much higher proteoglycan accumulation than the monolayer culture. These results indicate that the AF cells are able to grow and remain phenotypically stable in the scaffold. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 249–256, 2003
In vitro and in vivo degradation of biomimetic octacalcium phosphate and carbonate apatite coatings on titanium implants
Authors: Barrère F. , van der Valk C. M. , Dalmeijer R. A. J. , van Blitterswijk C. A. , de Groot K. , Layrolle P. 
Published: January 2003

AbstractCalcium phosphate (Ca‐P) coatings have been applied onto titanium alloys prosthesis to combine the srength of metals with the bioactivity of Ca‐P. It has been clearly shown in many publications that Ca‐P coating accelerates bone formation around the implant. However, longevity of the Ca‐P coating for an optimal bone apposition onto the prosthesis remains controversial. Biomimetic bone‐like carbonate apatite (BCA) and Octacalcium Phosphate (OCP) coatings were deposited on Ti6Al4V samples to evaluate their in vitro and in vivo dissolution properties. The coated plates were soaked in α‐MEM for 1, 2, and 4 weeks, and they were analyzed by Back Scattering Electron Microscopy (BSEM) and by Fourier Transform Infra Red spectroscopy (FTIR). Identical coated plates were implanted subcutaneously in Wistar rats for similar periods. BSEM, FTIR, and histomorphometry were performed on the explants. In vitro and in vivo, a carbonate apatite (CA) formed onto OCP and BCA coatings via a dissolution‐precipitation process. In vitro, both coatings dissolved overtime, whereas in vivo BCA calcified and OCP partially dissolved after 1 week. Thereafter, OCP remained stable. This different in vivo behavior can be attributed to (1) different organic compounds that might prevent or enhance Ca‐P dissolution, (2) a greater reactivity of OCP due to its large open structure, or (3) different thermodynamic stability between OCP and BCA phases. These structural and compositional differences promote either the progressive loss or calcification of the Ca‐P coating and might lead to different osseointegration of coated implants. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 378–387, 2003
Biochemical characterization of atherosclerotic plaque constituents using FTIR spectroscopy and histology
Authors: Li C. , Ebenstein D. , Xu C. , Chapman J. , Saloner D. , Rapp J. , Pruitt L. 
Published: January 2003

AbstractThe behavior of vulnerable atherosclerotic plaques is believed to be closely related to plaque composition. There is a need for an effective in vivo technique for examining plaque constituent properties. In this study, Fourier transform infrared spectroscopy using attenuated total reflectance (FTIR‐ATR) was used to assess and analyze the biochemical properties of human atherosclerotic plaques. FTIR spectra clearly revealed prominent spectral features corresponding to plaque constituents of interest: the 2930 cm−1 and 2850 cm−1 peaks (indicating the presence of lipids), the 1730 cm−1 peak (lipid esters), the 1550 cm−1 and 1650 cm−1 peaks (fibrous tissues), and the 1100–1000 cm−1 broad phosphate peak (calcification). Spectral data examined on a qualitative basis correlated well with both gross tissue anatomy and histologic features. Gross spatial mappings of tissue sections of both lipidic and calcified plaques were performed. Spectra from various regions of the plaques demonstrated the evolution of lipid peaks, fibrous tissue peaks, and the phosphate calcification band within the plaques. Histologic analysis corroborated the spectral findings in this study. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 197–206, 2003
Human serum albumin incorporating synthetic heme: Red blood cell substitute without hypertension by nitric oxide scavenging
Authors: Tsuchida Eishun , Komatsu Teruyuki , Matsukawa Yasuko , Nakagawa Akito , Sakai Hiromi , Kobayashi Koichi , Suematsu Makoto 
Published: January 2003

AbstractThe administration of extracellular, hemoglobin‐based oxygen carriers often elicits an acute increase in blood pressure by vasoconstriction. This side effect is now recognized to be due to the depletion of nitric oxide (endothelial‐derived relaxing factor) by the extravasuated hemoglobins. We have recently found that the administration of a recombinant human serum albumin (rHSA)‐based oxygen carrier involving synthetic tetraphenyporphinatoiron(II) derivative (FeP) (rHSA‐FeP) does not induce such hypertensive action, because of its low permeability through the vascular endothelium. The heart rate responses after the rHSA‐FeP injection were also negligibly small. Visualization of the intestinal microcirculatory changes clearly revealed the widths of the venule and arteriole to be fairly constant. The entirely synthetic rHSA‐FeP becomes a promising material as a new type of red blood cell substitute. © 2002 Wiley Periodicals Inc. J Biomed Mater Res 64A: 257–261, 2003
Comparison of chemical treatments on the chain dynamics and thermal stability of bovine pericardium collagen
Authors: Samouillan V. , Dandurand J. , Lacabanne C. , Thoma R. J. , Adams A. , Moore M. 
Published: January 2003

AbstractA new approach for the replacement of heart valves consists of obtaining an acellular matrix from animal aortic valves that performs mechanically, is nonantigenic, and is free from calcification and fibroblast proliferation. Novel biochemical treatments must be developed for this purpose. In this work, we focus on the characterization of collagen in acellular bovine cardiovascular tissues, fresh or glutaraldehyde treated, and stored in different solutions [phosphate‐buffered saline (PBS), ethanol, octanol, and glutaraldehyde], to determine whether the resulting fibrous material is structurally preserved. The preservation of the triple helical structure of collagen is checked by differential scanning calorimetry (DSC), which is a well suited technique to analyze thermal transitions in proteins, such as denaturation. To get insight into the molecular dynamics of collagen in the nanometric range, we used thermally stimulated currents, a dielectric technique running at low frequency, that measure the dipolar reorientations in proteins submitted to a static electrical field. The combined use of these two techniques allowed us to evaluate the physical structure and conformation of collagen after the different chemical treatments. We have found that the glutaraldehyde treatment followed by octanol storage preserves the triple helical conformation of the polypeptidic chains of collagen, contrary to the ethanol and PBS storage that induce drastic changes in the thermal and dielectric behavior of the protein. Moreover, this particular chemical treatment stabilizes the collagen structure (shift toward high temperature of the collagen denaturation and stiffening of the chains by a cross‐linking action) when compared to the control sample, and so could provide interesting fibrous material for the conception of bioprosthetic heart valve. © 2002 Wiley Periodicals, Inc., J Biomed Mater Res 64A: 330–338, 2003
Aggregation behaviors and their pH sensitivity of cholesterol‐conjugated proteinoids composed of glutamic acid and aspartic acid matrix
Authors: Bae Soo Kyoung , Kim Jong‐Duk 
Published: January 2003

AbstractCholesterol‐conjugated proteinoids and their aggregation behaviors were investigated with model proteinoid systems. Model proteinoids of molecular weights in the range of 4000 to 6000 were synthesized by anhydrous thermal condensation forming a matrix with glutamic acid and aspartic acid and of naturally occurring amino acids. Nuclear magnetic resonance and Fourier transform infrared spectra suggested that cholesterol was conjugated to carboxyl group–forming pendants. Native water‐soluble proteinoids can form microspheres in acidified or heated conditions, but the cholesterol‐conjugated proteinoids were found to form aggregates in water, regardless of the temperature or pH of the solutions. The hydrophobic pendant moieties come to a compact association in core, whereas the hydrophilic chains provide a shield layer. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 282–290, 2003