bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of microtextured surfaces on the performance of percutaneous devices
Authors: Walboomers X. F. , Jansen J. A. 
Published: June 2005

AbstractAlong the percutaneous part of implantable devices, like (semi‐)permanent catheters, epithelial downgrowth can occur. This process can eventually lead to implant loss. Various treatments for the catheter surface have been proposed, to improve their performance. The purpose of the current study was to investigate the effect of a microgroove pattern on the tube surface, on epithelial downgrowth. Catheterlike implants were made of silicone tubes, with anchoring cuffs made of titanium‐fiber mesh. A thin sheet of silicone with microgrooves was applied on the tubes. Two types of texturing were used, a square groove of 10 μm wide and 1 μm deep; or a V‐shaped groove of 40 μm wide. The grooves were directed either along the long axis of the catheter tube (grooves perpendicular to the skin surface) or circling around the catheter (grooves directed parallel to the skin surface). As controls, catheters with a smooth outer surface were used. Implants were placed in 30 rats, with a follow‐up period of 9 weeks. During this time, animals were inspected biweekly, and catheter exit sites were evaluated using a scoring system. At the end of the 9‐week period the implants and surrounding tissues were processed for histological evaluation. For the clinical evaluation of the exit sites, no statistical differences were found between the study groups. Histologically, epithelial downgrowth was observed for all samples. The histomorphometrical measurements showed that there were no differences in downgrowth between the smooth and parallel‐grooved catheters. However, there was increased epithelial downgrowth along the catheters with grooves perpendicular to the skin. In conclusion, a grooved microtexture can direct epithelial tissue ingrowth, but this study found no beneficial effects of the guidance phenomenon. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Electrochemical studies on zirconium and its biocompatible alloys Ti‐50Zr at.% and Zr‐2.5Nb wt.% in simulated physiologic media
Authors: Oliveira Nilson T.C. , Biaggio Sonia R. , Rocha‐Filho Romeu C. , Bocchi Nerilso 
Published: June 2005

AbstractDifferent electrochemical studies were carried out for Zr and its biocompatible alloys Ti‐50Zr at.% and Zr‐2.5Nb wt.% in solutions simulating physiologic media, Ringer and PBS (phosphate buffered saline) solutions. The results from rest‐potential measurements showed that the three materials are spontaneously passivated in both solutions and that the Ti‐50Zr alloy has the greatest tendency for spontaneous oxide formation. Some corrosion parameters (such as the pitting and repassivation potentials) were obtained via cyclic voltammetry in both solutions, revealing that the Ti‐50Zr has the best corrosion protection while Zr has the worst. On the other hand, the pre‐anodization (up to 8 V vs. SCE) of the alloys in a 0.15 mol/L Na2SO4 solution led to a significant improvement in their protection against pitting corrosion when exposed to the Ringer solution. Elemental analyses by EDX showed that during pitting corrosion, there is no preferential corrosion of any of the alloying elements (Zr, Ti, Nb). © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Au(III), Pd(II), Ni(II), and Hg(II) alter NFκB signaling in THP1 monocytic cells
Authors: Lewis J. B. , Wataha J. C. , McCloud V. , Lockwood P. E. , Messer R. L. W. , Tseng W.‐Y. 
Published: June 2005

AbstractThe transcription factor NFκB plays a key role in the tissue inflammatory response. Metal ions released into tissues from biomaterials (e.g., Au, Pd, Ni, Hg) are known to alter the binding of NFκB proteins to DNA, thereby modulating the effect of NFκB on gene activation and, ultimately, the tissue response to biomaterials. Little is known about the effect of these metals on key signaling steps prior to NFκB‐DNA binding such as transcription factor activation or nuclear translocation, yet these steps are equally important to modulation of the pathway. Oxidative stress is known to alter NFκB proteins and is suspected to play a role in metal‐induced NFκB signaling modulation. Our aim in the current study was to assess the effects of sublethal levels of Ni, Hg, Pd, and Au ions on NFκB activation and nuclear translocation in the monocyte, which is acknowledged as an important orchestrator of the biological response to materials and the pathogenesis of chronic disease. Sublethal concentrations of Au(III), Ni(II), Hg(II), and Pd(II) were added to cultures of human THP1 monocytic cells for 72 h. In parallel cultures, lipopolysaccharide (LPS) was added for the last 30 min to activate the monocytic cells. Then cellular cytoplasmic and nuclear proteins were isolated, separated by electrophoresis, and probed for IκBα degradation (activation) and NFκB p65 translocation. Protein levels were digitally quantified and statistically compared. The levels of reactive oxygen species (ROS) in the monocytic cells were measured as a possible mechanism of metal‐induced NFκB modulation. Only Au(III) activated IκBα degradation by itself. Au(III) and Pd(II) enhanced LPS‐induced IκBα degradation, but Hg(II) and Ni(II) suppressed it. Au(III), Ni(II), and Pd(II) activated p65 nuclear translocation without LPS, and all but Ni(II) enhanced LPS‐induced translocation. Collectively, the results suggest that these metal ions alter activation and translocation of NFκB, each in a unique way at unique concentrations. Furthermore, even when these metals had no overt effects on signaling by themselves, all altered activation of signaling by LPS, suggesting that the biological effects of these metals on monocytic function may only be manifest upon activation. None of the metal ions elevated levels of ROS at 72 h, indicating that ROS were probably not direct modulators of the NFκB activation or translocation at this late time point. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Synthesis of deramciclane* labeled with tritium in various positions
Authors: Szammer János , Simon‐Trompler Edit , Banka Zoltán , Szúnyog József , Klebovich Imre 
Published: June 2005

Abstract[(1R)‐endo]‐(+)‐3‐bromocamphor was dehalogenated with tritium gas to [3‐3H]camphor and via [3‐3H]phenylborneol converted to [3‐3H]deramciclane isolated as the fumarate salt (specific activity 51.8 GBq/mmol). This three step synthesis from [3‐3H]camphor gave an overall yield of 22%.Benzyloxy‐acetic acid methyl ester was reduced with sodium‐borotritide to 2‐benzyloxy‐ethanol‐[1‐3H], and through a four step procedure was converted to 2‐dimethylaminoethyl‐[2‐3H] chloride. The latter was condensed with the sodium derivative of 2‐phenylborneol giving rise to [2‐dimethylamino‐[2‐3H]ethoxy]deramciclane isolated as the fumarate (specific activity 8.177 GBq/mmol). This six step synthesis from [3H]NaBH4 gave an overall yield of 6%. Copyright © 2005 John Wiley & Sons, Ltd.
Gi/Go protein‐dependent presynaptic mechanisms are involved in clozapine‐induced down‐regulation of tyrosine hydroxylase in PC12 cells
Authors: Tejedor‐Real Purificación , Vogel Roland , Mallet Jacques , Biguet Nicole Faucon 
Published: June 2005

AbstractAlthough the clinical effects of antipsychotics have been extensively studied, the molecular mechanisms underlying their antipsychotic activity are unclear. Chronic clozapine has been reported to reduce significantly the expression of tyrosine hydroxylase (TH) in the mesolimbic system. To characterize the mechanisms of action of clozapine on TH expression, PC12 cells turned out to be a useful model, being by far less complex than the entire brain. Both the quantity of TH protein and the amount of TH mRNA in PC12 cells were found to be decreased during incubation of the cells in the presence of clozapine. This decline was followed by a decrease in the enzymatic activity of TH. The effect of clozapine was blocked by preincubation with N‐ethylmaleimide, a sulphydryl‐alkylating reagent that interferes in Gi/o protein‐mediated second messenger pathways. Clozapine may thus decrease TH expression by interacting with Gi/o protein‐coupled receptors, such as D2 and 5HT1A. Knowledge of the molecular mechanisms underlying the clinical effects of established antipsychotics will promote the development of new and more efficient antipsychotic drugs. © 2005 Wiley‐Liss, Inc.
Micro‐Raman spectroscopic study of pottery fragments from the Lapatsa tomb, Cyprus, ca 2500 BC
Authors: Sendova M. , Zhelyaskov V. , Scalera M. , Ramsey M. 
Published: June 2005

AbstractMicro‐Raman spectroscopy was applied to the mineralogical characterization of Bronze Age Cypriot ceramic fragments from the Lapatsa Tomb collection of the Ringling Museum of Art. Micro‐probing was carried out on the surface and the results were compared with those of micro‐probing from the cross‐section of the two samples studied. Significant statistics were collected from 500 locations on each sample. Various phases were identified: quartz, albite, calcite, ilmenite, anatase, rutile, hematite and maghemite. It was determined that the different red coloration of both pieces is due not only to different hematite concentrations, but also to different grain sizes. The presence of low‐temperature albite and anatase suggests low firing temperatures. The presence of hematite suggests firing in an oxidizing atmosphere. Copyright © 2005 John Wiley & Sons, Ltd.
ΓD‐convergence for a class of quasilinear elliptic equations in thin structures
Authors: Amaziane B. , Goncharenko M. , Pankratov L. 
Published: June 2005

AbstractWe study the asymptotic behaviour of the solution of a stationary quasilinear elliptic problem posed in a domain Ω(ε)of asymptotically degenerating measure, i.e. meas Ω(ε)→ 0 asε→ 0, whereεis the parameter that characterizes the scale of the microstructure. We obtain the convergence of the solution and the homogenized model of the problem is constructed using the notion of convergence in domains of degenerating measure. Proofs are given using the method of local characteristics of the medium Ω(ε)associated with our problem in a variational form. Copyright © 2005 John Wiley & Sons, Ltd.
Long time behaviour of a flow in infinite pipe conforming to slip boundary conditions
Authors: Mucha Piotr Bogusław , Sadowski Witold 
Published: June 2005

AbstractThe paper analyses long time behaviour of solutions of the Navier–Stokes equations in a two‐dimensional pipe‐like domain. The system is studied with perfect slip boundary conditions with arbitrary inflow conditions at infinity. The main results show the existence of global in time solutions and of an attractor for the dynamical system generated by the model. The paper also establishes an upper bound for the Hausdorff dimension of the attractor. Copyright © 2005 John Wiley & Sons, Ltd.
Trace identities for solutions of the wave equation with initial data supported in a ball
Authors: Finch David , Rakesh  
Published: June 2005

AbstractSuppose u is the solution of the initial value problem

Suppose n ≥ 1 is odd, f and g are supported in a ball B with boundary S, and one of f or g is zero. We derive identities relating the norm of f or g to the norm of the trace of u on S × [0,∞) . These identities are derived using integral geometric and multiplier methods. Copyright © 2005 John Wiley & Sons, Ltd.
Filtered backprojection for thermoacoustic computed tomography in spherical geometry
Authors: Haltmeier M. , Schuster T. , Scherzer O. 
Published: June 2005

AbstractThermoacoustic computed tomography (TCT) is a novel imaging technique for non‐destructive evaluation and medical imaging. It uses electromagnetic energy as input and the induced thermoacoustic pressure field as measurement output. The determination of the unknown energy deposition function is based on the integral geometric problem of reconstructing a function from its integrals over certain spheres. We apply the method of approximate inverse to derive filtered backprojection type reconstruction algorithms in spherical scanning geometry. Numerical results are presented and show the validity of the resulting algorithms. Copyright © 2005 John Wiley & Sons, Ltd.
A study on the orientation structure and mechanical properties of polyacrylonitrile precursors
Authors: Xu Qiang , Xu Lianghua , Cao Weiyu , Wu Sizhu 
Published: June 2005

AbstractThe polyacrylonitrile precursors were made through the two‐stage drawing process. The orientation structure was examined through wide‐angle X‐ray diffraction (WAXD). The orientation factors and the modulus were measured through the sound velocity method. The mechanical properties, such as the Young's modulus, the tensile strength and the breaking elongation ratio were obtained by the single fiber tensile test. The results showed that the Young's modulus and the strength of the precursors increased with draw ratio, which is accordant with the enhancement of the micromolecular orientation degree. Therefore the orientation factors obtained from the experiments were compared with the theoretical curves which were predicted through the Crawford and Kolsky's model. The physical meaning of the parameters m and n were analyzed. A good agreement of the orientation factor between the experimental data and the theoretical curve was achieved. Copyright © 2005 John Wiley & Sons, Ltd.
Factors affecting the efficacy of non‐fumigant nematicides for controlling root‐knot nematodes
Authors: Giannakou Ioannis O , Karpouzas Dimitrios G , Anastasiades Ioannis , Tsiropoulos Nicholas G , Georgiadou Athena 
Published: June 2005

AbstractSecond‐stage juveniles (J2) and egg masses of root‐knot nematodes as well as root debris heavily infected by the latter were exposed for different periods of time to six different doses of the nematicides cadusafos and fenamiphos. The efficacy of the nematicides increased significantly with increasing exposure time. Both nematicides were more effective against J2, although they could not provide acceptable control of J2 inside egg masses or heavily galled root debris. The effect of different application strategies on the efficacy and persistence of certain nematicides was also assessed in a field study. Cadusafos, fenamiphos, fosthiazate and oxamyl were applied in field micro‐plots either as a single full dose at the time of crop establishment or as multiple reduced‐rate applications at 14‐day intervals throughout the cropping period, and their efficacy and persistence were determined using bioassays and analytical studies. Fosthiazate was the most efficient nematicide studied, and this was mainly attributed to its long soil persistence. Oxamyl also provided adequate nematode control for the first 48–56 days after its application, regardless of the application method used and its relatively rapid field dissipation. Fenamiphos and cadusafos failed to provide adequate nematode control, although cadusafos was the most persistent of the nematicides tested. The failure of fenamiphos to provide adequate nematode control was mainly attributed to its rapid degradation by soil micro‐organisms, which were stimulated after its repeated low‐rate application at 14‐day intervals. In contrast cadusafos failure was attributed to the inability of the nematicide to reduce nematode populations even at relatively high concentrations in soil. Copyright © 2005 Society of Chemical Industry
Genetic screening, testing and treatment: How far can we go?
Authors: Scriver C. R. 
Published: June 2005

SummaryTreatment comes in three forms: care, control, cure; each will be part of any new development in the management of genetic disease, either Mendelian or complex. Diagnosis recognizes three states of disease: impairment, disability, and handicap when the disease is symptomatic and has manifestations. Genetics in health care has the potential to prevent these manifestations by interventions at the presymptomatic stage. Wherever cause of disease involves genotypic variation that undermines homeostasis, genetic testing and screening could play a predictive role. The area of greatest interest will be the common multifactorial diseases. While some persons worry that geneticists have taken society too fast and far along the road to ruin, it is closer to the truth that we have actually gone rather slowly and not very far along the road to better personal and collective health. With wisdom and caution the new opportunities for genetic testing or screening will become part of health care; and sooner rather than later when better treatments for our inherited infirmities are found.
Somatic gene therapy for phenylketonuria and other hepatic deficiencies
Authors: Eisensmith R. C. , Woo S. L. C. 
Published: June 2005

SummaryGene therapy is the delivery of genetic material to specific cell types of an organism to alter its physiology or function. This technology is being explored as a means of treating diseases caused by deficiencies of hepatic gene products. The two diseases being used as models for hepatic gene therapy are classical phenylketonuria (PKU) and haemophilia B. Vectors derived from adenoviruses can be used to completely correct these diseases in animal models. The phenotypic correction generated in these studies is transient, and cannot be duplicated by vector readministration. The transient nature of transgene expression results from the destruction of the virally‐transduced cells by a cellular immune response directed against the late viral gene products that are also expressed in the target cells. The inability to repeatedly administer virus is caused by a humoral immune response directed against viral proteins present at the time of infusion. If the host immune response is suppressed, transgene expression can persist for 6 months or more. These findings suggest that host immunomodulation in combination with further modification of the adenoviral vector to reduce or eliminate late viral gene expression may permit long‐term expression of potentially therapeutic gene products in mammalian liver.
Metabolic fuel utilization and pyruvate oxidation during the postnatal period
Authors: Medina J. M. , Tabernero A. , Tovar J. A. , Martín‐Barrientos J. 
Published: June 2005

SummaryThe transplacental supply of nutrients is interrupted at birth, which diverts maternal metabolism to lactation. After birth, energy homeostasis is rapidly regained through milk nutrients which supply the newborn with the fatty acids and ketone bodies required for neonatal development. However, immediately after birth and before the onset of suckling there is a time lapse in which the newborn undergoes a unique kind of starvation. During this period glucose is scarce and ketone bodies are not available owing to the delay in ketogenesis. Under these circumstances, the newborn is supplied with another metabolic fuel, lactate, which is utilized as a source of energy and carbon skeletons. Neonatal rat lung, heart, liver and brain utilize lactate for energy production and lipogenesis. Lactate is also utilized by the brain of human babies with type I glycogenosis. Both rat neurons and astrocytes in primary culture actively use lactate as an oxidizable substrate and as a precursor of phospholipids and sterols. Lactate oxidation is enhanced by dichloroacetate, an inhibitor of the pyruvate dehydrogenase kinase in neurons but not in astrocytes, suggesting that the pyruvate dehydrogenase is regulated differently in each type of cell. Despite the low activity of this enzyme in newborn brain, pyruvate decarboxylation is the main fate of glucose in both neurons and astrocytes. The occurrence of a yeast‐like pyruvate decarboxylase activity in neonatal brain may explain these results.
Neurological presentations of mitochondrial diseases
Authors: Zeviani M. , Bertagnolio B. , Uziel G. 
Published: June 2005

SummaryWe present here a report on a 5‐year experience in clinical investigation, diagnostic management and molecular genetic studies of neuromitochondrial disorders, defined on the basis of morphological, biochemical and genetic findings. Leigh disease is the most frequent clinical presentation in infancy and childhood, but symptoms at onset are poorly informative. In paediatric cases, lactic acidosis and neuroradiological abnormalities are frequent, and can be of help for the diagnostic orientation. In the adult population, muscle weakness, ophthalmoplegia with ragged‐red fibres, retinitis pigmentosa, progressive myoclonal ataxia, and early‐onset stroke‐like episodes, are frequently combined in complex syndromes that are often familial (maternally inherited) and/or associated with well‐established mutations in mitochondrial DNA (mtDNA). However, the presence of overlap syndromes and features common to many neuromitochondrial diseases can complicate the clinical evaluation and the diagnostic approach. The pathogenicity of a given mtDNA mutation can frequently be ascertained by correlating the degree of heteroplasmy with the clinical or biochemical phenotypes. Moreover, transmitochondrial cybrids can be used to test the effects of either mitochondrial or nuclear gene abnormalities in a fully controlled, user‐friendly and highly informative system.
The treatment of congenital lactic acidoses
Authors: Morris A. A. M. , Leonard J. V. 
Published: June 2005

SummaryCongenital lactic acidoses form a heterogeneous group of disorders: this paper considers primarily defects of the pyruvate dehydrogenase complex and the respiratory chain. Attempts to treat these disorders are hampered by uncertainty concerning the pathophysiology and by the central role of the enzymes in cellular metabolism. Few strategies are of proven efficacy, though many have been tried, including dietary manipulation, enhancement of residual enzyme activity, artificial electron acceptors and free‐radical scavengers. Evaluation of treatment is complicated by the rarity, heterogeneity and unpredictable course of the diseases. Double‐blind placebo‐controlled trials are needed.
Hyperphenylalaninaemia due to impaired dihydrobiopterin biosynthesis: Leukocyte function and effect of tetrahydrobiopterin therapy
Authors: Fukuda K. , Tanaka T. , Hyodo S. , Kobayashi Y. , Usui T. 
Published: June 2005

AbstractWe have described the clinical and biochemical status of two patients with tetrahydrobiopterin (BH4) deficiency due to impaired dihydrobiopterin biosynthesis. BH4 administration appeared to improve the mental and psychological status more than did neurotransmitter replacement therapy alone. This enhancement of activities of daily life was seen with a dose of BH4 as low as 1.25 mg kg−1 day−1. Granulocyte adherence capacity was below normal and recovered after BH4 therapy in both patients. B‐cell differentiation capacity was altered either before or after therapy.
Diagnosis of classical Morquio's disease:N‐acetylgalactosamine 6‐sulphate sulphatase activity in cultured fibroblasts, leukocytes, amniotic cells and chorionic villi
Authors: Yuen M. , Fensom A. H. 
Published: June 2005

AbstractThe tritiated disulphated trisaccharide 6‐sulpho‐N‐acetylgalactosamine‐glucuronic acid‐6‐sulpho‐N‐acetyl[1‐3H]galactosaminitol was prepared from chondroitin 6‐sulphate for use as a substrate forN‐acetylgalactosamine 6‐sulphate sulphatase. The reaction product was separated on ECTEOLA cellulose rather than Dowex 1×2. The mean activities of normal fibroblasts, leukocytes and amniotic cells were 8.43, 2.59 and 3.14 nmol h−1 mg protein−1, respectively. Fibroblasts from five patients with classical Morquio's disease (mucopolysaccharidosis IVA; MPSIVA) and one patient with neonatal multiple sulphatase deficiency displayed activities of less than 5% of control mean. Activity in amniotic cells from a pregnancy where the fetus was affected with MPS IVA was 6% of control mean. Activity was also found to be present in normal specimens of chorionic villi (mean value 1.21 nmol h−1 mg protein−1), demonstrating the feasibility of first trimester prenatal diagnosis of MPS IVA by assay of activity in this tissue.