bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterogeneous basis of the type VIB form of Ehlers–Danlos syndrome (EDS VIB) that is unrelated to decreased collagen lysyl hydroxylation
Authors: Walker L.C. , Overstreet M.A. , Willing M.C. , Marini J.C. , Cabral W.A. , Pals G. , Bristow J. , Atsawasuwan P. , Yamauchi M. , Yeowell Heather N. 
Published: November 2004

AbstractSkin fibroblasts from the majority of patients with the clinical diagnosis of Ehlers–Danlos syndrome type VI (EDS VI; kyphoscoliosis type), have significantly decreased lysyl hydroxylase (LH) activity due to mutations in the LH1 gene (classified as EDS VIA: OMIM no. 225400). A rare condition exists in which patients are clinically similar but have normal levels of LH activity (designated EDS VIB: OMIM no. 229200). To define the biochemical defect, we have examined cultured fibroblasts from four EDS VIB patients for changes in the levels of the mRNAs for LH1, LH2, and LH3, collagen cross‐linking patterns, and the extent of lysine hydroxylation of type I collagen α chains. Although normal levels of LH1 mRNA were observed in all four patients, in two patients the levels of LH2 mRNA were decreased by >50%, and a similar decrease was observed in LH3 mRNA in the other two patients. A distinct pattern of collagen cross‐links, indicative of decreased lysyl hydroxylation, could be identified in EDS VIA patients, but there was no clear correlation between collagen cross‐link pattern and changes in the individual LH mRNAs in EDS VIB patients. Linkage to tenascin‐X was excluded in these patients. This study suggests that the basis for this form of EDS VI is genetically heterogeneous, and that alternative pathways in addition to lysine hydroxylation of collagen may be affected. © 2004 Wiley‐Liss, Inc.
Postnatal maturation of human GABAA receptors measured with positron emission tomography
Authors: Chugani Diane C. , Muzik Otto , Juhász Csaba , Janisse James J. , Ager Joel , Chugani Harry T. 
Published: November 2004

AbstractDuring brain development in nonhuman primates, there are large changes in GABAA receptor binding and subunit expression. An understanding of human GABAA receptor ontogeny is highly relevant in elucidating the pathophysiology of neurodevelopmental disorders in which GABAergic mechanisms play a role as well as in understanding differences that occur during development in the pharmacology of drugs acting on this system. We have measured age‐related changes in the brain distribution of the GABAA receptor complex in vivo using positron emission tomography (PET) in epileptic children under evaluation for surgical treatment. PET imaging was performed using the tracer [11C]flumazenil (FMZ), a ligand that binds to α subunits of the GABAA receptor. FMZ binding was quantified using a two‐compartment model yielding values for the volume of distribution (VD) of the tracer in tissue. All brain regions studied showed the highest value for FMZ VD at the youngest age measured (2 years), and the values then decreased exponentially with age. Medial temporal lobe structures, primary visual cortex, and thalamus showed larger differences between values for age 2 years and adults (approximately 50% decrease) than did basal ganglia, cerebellum, and other cortical regions (25–40% decreases). Furthermore, subcortical regions reached adult values earlier (14–17.5 years) than did cortical regions (18–22 years). The ontogeny data of FMZ VD from children may contribute to understanding regional differences in synaptic plasticity as well as improve rational therapeutic use of drugs acting at the GABAA receptor in the pediatric population.
Hemispheric influence on autonomic modulation and baroreflex sensitivity
Authors: Hilz Max J. , Dütsch Matthias , Perrine Ken , Nelson Peter K. , Rauhut Ute , Devinsky Orrin 
Published: November 2004

AbstractSeveral studies suggest hemispheric lateralization of autonomic cardiovascular control. There is controversy regarding which hemisphere dominates sympathetic or parasympathetic activity. Hemispheric influences on baroreflex sensitivity (BRS) have not yet been evaluated. To determine hemispheric autonomic control in epilepsy patients, we assessed cardiovascular and baroreflex modulation before and during hemispheric inactivation. For 15 patients with drug‐refractory epilepsy, we analyzed autonomic heart rate (HR) and blood pressure (BP) modulation and BRS before and during left and right intracarotid amobarbital procedure (IAP). After Blackman‐Tukey spectral analysis, we calculated the low‐frequency (LF: 0.04–0.15 Hz) and high‐frequency (HF: 0.15–0.5 Hz) power of HR and BP as well as BRS as the LF transfer function gain between BP and HR. Right hemispheric inactivation induced a significant decrease of BP and an increase of HF power of HR and BP (p< 0.05). Left inactivation increased HR, BP, and LF power of both signals and decreased BRS by nearly 30% (p< 0.05). The results confirm previous IAP studies showing sympathetic lateralization in the right hemisphere and, moreover, demonstrate parasympathetic predominance and up‐regulation of BRS in the left hemisphere. In epilepsy patients, unilateral electrical activity might derange autonomic balance between both hemispheres and contribute to cardiovascular dysregulation and sudden fatalities.
Diminished adenosine A1 receptor expression on macrophages in brain and blood of patients with multiple sclerosis
Authors: Johnston James B. , Silva Claudia , Gonzalez Guido , Holden Janet , Warren Kennith G. , Metz Luanne M. , Power Christopher 
Published: November 2004

AbstractThe nucleoside adenosine has been shown to control the production of proinflammatory molecules through its actions on cell surface purine receptors. Previously, we have reported that the adenosine A1 receptor (A1AR) regulates tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6) expression and exhibits diminished function in patients with multiple sclerosis (MS; Mayne et al., Ann Neurol 1999;45:633–639). In the present study, A1AR expression in both brain and peripheral blood mononuclear cells (PBMC) from MS and control groups was characterized by fluorescence‐activated cell sorting (FACS), reverse transcriptase‐polymerase chain reaction (RT‐PCR), and immunohistochemical analyses. FACS analyses of PBMC revealed that A1AR expression was chiefly detectable on CD14‐positive cells and was reduced by 53.1% (p < 0.01) in MS patients compared to controls. A1AR mRNA levels were reduced by 43.1% (p < 0.001) in the brains of MS patients compared to patients with other neurological diseases and controls. A1AR protein expression in brain was detected primarily in CD45‐positive glial cells and was markedly diminished in MS patients. The analysis of A1AR transcripts in the brain revealed that the A1AR‐β transcript was diminished (49.2%) in MS patients compared to controls (p < 0.002). These results indicate that the A1AR, expressed principally on cells of monocyte/macrophage lineage in both brain and blood, is selectively diminished in MS patients. Reduction of the A1AR‐β transcript in MS patients suggests that dysregulated splicing may influence A1AR protein levels, potentially leading to increased macrophage activation and central nervous system inflammation.
Subclinical cerebellar impairment in the common types of migraine: A three‐dimensional analysis of reaching movements
Authors: Sándor Peter S. , Mascia Addolorata , Seidel Laurence , De Pasqua Victor , Schoenen Jean 
Published: November 2004

AbstractMutations in the CACNA1A gene can cause familial hemiplegic migraine (FHM) and/or cerebellar ataxia. CACNA1A codes for the α1 subunit of P/Q‐Ca2+ channels and is highly expressed in the cerebellum. Using a pointing paradigm and infrared optoelectronic tracking system, we found subclinical hypermetria and other subtle cerebellar signs in the common forms of migraine. These were more pronounced in migraine with than without aura. Whether this reflects involvement of Ca2+ channel genes in the common types of migraine needs to be investigated by genetic analyses.
Parkinson's disease is not associated with the combined α‐synuclein/apolipoprotein E susceptibility genotype
Authors: Khan Naheed , Graham Elizabeth , Dixon Peter , Morris Christopher , Mander Adrian , Clayton David , Vaughan J. , Quinn Niall , Lees Andrew , Daniel Susan , Wood Nicholas , De Silva Rohan 
Published: November 2004

AbstractA recent study showed significant association of sporadic Parkinson's disease with a polymorphism within the α‐synuclein gene and closely linked DNA markers on chromosome 4q and the APOE ε4 allele. A combined α‐synuclein/APOE‐ε4 genotype increased the relative risk of developing Parkinson's disease 12‐fold. We failed to confirm this association in a much larger sample of histopathologically proven cases of Parkinson's disease and controls.
Potential for creatine and other therapies targeting cellular energy dysfunction in neurological disorders
Authors: Tarnopolsky Mark A. , Beal M. Flint 
Published: November 2004

AbstractSubstantial evidence indicates that bioenergetic dysfunction plays either a primary or secondary role in the pathophysiology of cell death in neurodegenerative and neuromuscular disorders, and even in normal aging. Agents that ameliorate bioenergetic defects may therefore be useful in therapy. Creatine, which increases muscle and brain phosphocreatine concentrations, and may inhibit the activation of the mitochondrial permeability transition, protects against neuronal degeneration in transgenic murine models of amyotrophic lateral sclerosis and Huntington's disease and in chemically mediated neurotoxicity. Initial studies of creatine use in humans appear promising; however, further long‐term, well‐designed trials are needed. Coenzyme Q10, Gingko biloba, nicotinamide, riboflavin, carnitine, lipoic acid, and dichloroacetate are other agents which may have beneficial effects on energy metabolism, but the preclinical and clinical evidence for efficacy in neurological diseases remains limited. These compounds are widely used as dietary supplements; however, they must be subjected to rigorous evaluation through randomized, double‐blinded trials to establish efficacy, cost‐effectiveness and safety in neurological disorders.
The resistance to ischemia of white and gray matter after stroke
Authors: Falcao Antonio L. E. , Reutens David C. , Markus Romesh , Koga Masatoshi , Read Stephen J. , Tochon‐Danguy Henri , Sachinidis John , Howells David W. , Donnan Geoffrey A. 
Published: November 2004

AbstractA contributing factor to the failure of trials of neuroprotectants in acute ischemic stroke may be the differing vulnerability to ischemia of white compared with gray matter. To address this issue, we determined to establish the existence of potentially viable tissue in white matter and its evolution to infarction or salvage in both gray and white matter compartments in patients with ischemic stroke. Twenty‐seven patients (mean age, 73.4 years) at a median of 16.5 hours after symptom onset were studied using the hypoxic marker 18F‐misonidazole with positron emission tomography (PET). Tissue was segmented using an magnetic resonance probabilistic map. Although there was a greater volume of initially “at‐risk tissue” in gray matter (58.3cm3, 29.9–93.0cm3) than white matter (42.0cm3, 15.8–74.0cm3; p < 0.001) at the time of PET imaging, a higher proportion of this was still potentially viable in white matter (41.4%, 4.6–74.5%) than in gray matter (23.6%, 3.2–61.1%; p < 0.05). However, a similar proportion in each compartment spontaneously survived. These data provide evidence for the existence of potentially salvageable tissue in human white matter and is consistent with it having a similar or even greater resistance to ischemia than gray matter. For the latter possibility, alternative therapeutic strategies may be required for its salvage. Ann Neurol 2004;56:695–701
Vertical conjugate eye deviation in postresuscitation coma
Authors: Johkura Ken , Komiyama Atsushi , Kuroiwa Yoshiyuki 
Published: November 2004

AbstractVertical eye deviation in hypoxic coma is considered to be rare. In contrast, we found that in a consecutive series of 50 postresuscitation comatose patients, 28 (56.0%) developed tonic upward or downward eye deviation. We suggest that both the upward and the downward deviations resulted from diffuse cerebrocerebellar damage sparing the brainstem. Upward deviation is an early sign, whereas downward deviation appears later and generally implies a transition to the vegetative state. Ann Neurol 2004
Surface chemistry and mechanical property changes of wood‐flour/high‐density‐polyethylene composites after accelerated weathering
Authors: Stark Nicole M. , Matuana Laurent M. 
Published: November 2004

AbstractAlthough wood–plastic composites have become more accepted and used in recent years and are promoted as low‐maintenance, high‐durability building products, they do experience a color change and a loss in mechanical properties with accelerated weathering. In this study, we attempted to characterize the modulus‐of‐elasticity (MOE) loss of photostabilized high‐density polyethylene (HDPE) and composites of wood flour and high‐density polyethylene (WF/HDPE) with accelerated weathering. We then examined how weathering changed the surface chemistry of the composites and looked at whether or not the surface changes were related to the MOE loss. By examining surface chemistry changes, we hoped to begin to understand what caused the weathering changes. The materials were left unstabilized or were stabilized with either an ultraviolet absorber or pigment. After 1000 and 2000 h of accelerated weathering, the samples were tested for MOE loss. Fourier transform infrared (FTIR) spectroscopy was employed to monitor carbonyl and vinyl group formation at the surface. Changes in the HDPE crystallinity were also determined with FTIR techniques. It was determined that structural changes in the samples (carbonyl group formation, terminal vinyl group formation, and crystallinity changes) could not be reliably used to predict changes in MOE with a simple linear relationship. This indicated that the effects of crosslinking, chain scission, and crystallinity changes due to ultraviolet exposure and interfacial degradation due to moisture exposure were interrelated factors for the weathering of HDPE and WF/HDPE composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2263–2273, 2004
Studies on the blends of polycarbonate and highly branched polystyrene
Authors: Qiang Ren , Aiying Li , Bibiao Jiang , Dongliang Zhang , Jianhai Chen 
Published: November 2004

AbstractA highly branched polystyrene (HBPS) was synthesized via the copolymerization of 4‐(chloromethyl) styrene with styrene using the self‐condensing atom transfer radical polymerization method. The addition of this highly branched polystyrene as a melt modifier for polycarbonate (PC) was attempted. Indeed, the results show that the addition of highly branched polystyrene can decrease the melt viscosity of PC with little change in mechanical properties, although the blends do exhibit lower thermal stability compared with pure PC. Extrapolation shows that all of the blends have an initial weight loss temperature above 450°C with a statistic heat‐resistant index Ts above 225°C. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2425–2430, 2004
Effect of lignin particles as a nucleating agent on crystallization of poly(3‐hydroxybutyrate)
Authors: Weihua Kai , He Yong , Asakawa Naoki , Inoue Yoshio 
Published: November 2004

AbstractThe effect of lignin fine powder, as a new kind of nucleating agent, on the crystallization process of poly(3‐hydroxybutyrate) (PHB) was studied. The kinetics of both isothermal and nonisothermal crystallization processes from the melt for both pure PHB and PHB/lignin blend was studied by means of differential scanning calorimetry. Lignin shortened the crystallization half‐time t1/2 for isothermal crystallization. The activation energy ΔE for PHB/lignin and pure PHB in the isothermal crystallization process was −237.40 and −131.22 kJ/mol, respectively, clearly indicating that the crystallization of the PHB/lignin blend was more favorable than that of pure PHB from a thermodynamic perspective. At the same time, according to polarized optical microscopy, the rate of spherulitic growth from the melt increased with the addition of lignin, which is ascribed to the reduction of surface fold energy σe, that is, σe is 59.2 × 10−3 and 41.6 × 10−3 J m−2 for pure PHB and PHB/lignin, respectively. Polarized optical microscopy also showed that the spherulites found in PHB with lignin were smaller in size and greater in number than those found in pure PHB. The wide‐angle X‐ray diffraction indicated that an addition of lignin caused no change in the crystal structure and degree of crystallinity. These results indicated that lignin is a good nucleating agent for the crystallization of PHB. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2466–2474, 2004
Synthesis and characterization of copolymers of bromoacrylated methyl oleate
Authors: Eren Tarik , Küsefoğlu Selim H. 
Published: November 2004

AbstractIn this study, methyl oleate was bromoacrylated in the presence of N‐bromosuccinimide and acrylic acid in one step. Homopolymers and copolymers of bromoacrylated methyl oleate (BAMO) were synthesized by free radical bulk polymerization and photopolymerization techniques. Azobisisobutyronitrile (AIBN) and 2,2‐dimethoxy‐2‐phenyl‐acetophenone were used as initiators. The new monomer BAMO was characterized by FTIR, GC‐MS, 1H, and 13C‐NMR spectroscopy. Styrene (STY), methylmethacrylate (MMA), and vinyl acetate (VA) were used for copolymerization. The polymers synthesized were characterized by FTIR, 1H‐NMR, 13C‐NMR, and differential scanning calorimetry (DSC). Molecular weight and polydispersities of the copolymers were determined by GPC analysis. Ten different feed ratios of the monomers STY and BAMO were used for the calculation of reactivity ratios. The reactivity ratios were determined by the Fineman–Ross and Kelen–Tudos methods using 1H‐NMR spectroscopic data. The reactivity ratios were found to be rsty = 0.891 (Fineman–Ross method), 0.859 (Kelen–Tudos method); rbamo = 0.671 (Fineman–Ross method), 0.524 (Kelen–Tudos method). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2475–2488, 2004
A Novel Dipeptide‐based HIV Protease Inhibitor Containing Allophenylnorstatine
Authors: Abdel‐Rahman Hamdy M. , El‐Koussi Nawal A. , Alkaramany Gamal S. , Youssef Adel F. , Kiso Yoshiaki 
Published: November 2004

AbstractDipeptide analogues incorporating allophenylnorstatine [Apns; (2S, 3S)‐3amino‐2‐hydroxy‐4‐phenylbutyric acid] as a transition state mimic at the scissile bond were designed and synthesized in the hope of obtaining a novel KNI series of HIV protease inhibitors. The precursors, N‐P2′‐3‐(2S, 3S)‐3‐(tert‐butyloxy‐carbonyl)amino‐2‐hydroxy‐4‐phenylbutanoyl)‐5, 5‐dimethylthiazolidine‐4‐carboxamide (N‐Boc‐Apns‐Dmt‐P2′) 4a–p were prepared by deprotection of the synthones N‐P2′‐(tert‐butyloxycarbonyl)‐5, 5‐dimethylthiazolidine‐4‐carboxamide (Boc‐Dmt‐P2′) 2a–p, then coupling with (2S, 3S)3‐(tert‐butyloxycarbonyl)amino‐2‐hydroxy‐4‐phenylbutanoic acid (N‐Boc‐Apns‐OH) 3. The deprotected intermediates 4 were coupled with the activated carboxyl groups of the P2 ligands to afford the target dipeptides. In this work, we fixed at the P2 site either a 2, 6‐dimethylphenoxyacetyl or a 3‐hydroxy‐2‐methylbenzoyl group. Substitutes at the P2′ site were varied to afford the members of the series 7 and 8. Improved activity of most of the members of series 8 relative to their analogues of series 7 can be partially attributed to the differences in the structures of the P2 moieties. Positional isomerism in the P2′ moieties significantly affected the activity and polarity of the target.
From hypocaust to hyperbola: ground‐penetrating radar surveys over mainly Roman remains in the UK
Authors: Linford Neil 
Published: November 2004

AbstractGround‐penetrating radar (GPR) survey can provide a wealth of information when applied to the investigation of buried remains. The strength of the GPR technique lies both in its suitability to a wide range of site conditions and the complementary nature of the data in comparison with other geophysical techniques. However, GPR is not infallible, relying on the careful selection of suitable sites and the application of appropriate data processing and visualization routines to maximize the potential of the acquired data. This paper demonstrates the use of GPR over a variety of mainly Roman remains surveyed recently by English Heritage, within the UK, ranging in scale from an in situ mosaic pavement threatened by water damage at Bignor Roman villa, West Sussex to an entire, suspected amphitheatre at Richborough Castle, Kent. The influence of site conditions, such as soil conductivity and topography, is also considered and a novel application of principal components analysis is presented to enhance the identification of significant anomalies from data where rapid signal attenuation has occurred. This latter technique considers the correlation of GPR response between adjacent amplitude time‐slices in an attempt to isolate the response due to significant buried wall footings from the more cluttered signal of the surrounding clay‐rich soil. Where appropriate, URL links are provided to computer animations of the GPR data that may often serve to accentuate subtle variations through the stratigraphy of the site. Copyright © 2004 John Wiley & Sons, Ltd.
Ground‐penetrating radar facies as an aid to sequence stratigraphic analysis: application to the archaeology of Clonmacnoise Castle, Ireland
Authors: Ruffell Alastair , Geraghty Louise , Brown Colin , Barton Kevin 
Published: November 2004

AbstractThis paper describes the advantages of interpreting ground‐penetrating radar (GPR) facies in a sequence stratigraphic context. These data have been collected adjacent to the River Shannon at Clonmacnoise Castle in central Ireland and demonstrate that stratigraphy is not necessarily made up of horizontal isochronous surfaces; some reflective surfaces are more important than others in interpretation and that two‐dimensional sections must be interpreted with caution. Radar facies analysis and thus sequence stratigraphy can be used to both interpret the sedimentary record in terms of palaeoenvironments as well as identify important (key) surfaces. Bright, continuous surfaces are often found at horizons of palaeoenvironmental change and have distinctive reflector shapes and terminations (or stratal patterns) above and below. Such stratal patterns define and reflect linked fluvial and human environments that have developed and been preserved through the creation of accommodation space. Key surfaces have been identified when sedimentation was altered, thus reflecting a natural or anthropogenic palaeoenvironmental change. In anthropogenically modified or created successions, such as those seen at Clonmacnoise, key surfaces have produced changes in dielectric constants in the sediments that are seen as radar reflections. Natural activity includes lateral migration of point‐bars and fluvial onlap. Anthropogenic activity has created accommodation space (the moat), a major sequence boundary and subdwelling surface disruption of reflectors. A pre‐moat fault can be observed on GPR data that is along strike of a surface scarp to the southwest of Clonmacnoise Castle. The results demonstrate the enhanced interpretive and predictive use of radar facies in sequence stratigraphy. Copyright © 2004 John Wiley & Sons, Ltd.