bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biocompatibility and drug release behavior of spontaneously formed phospholipid polymer hydrogels
Authors: Kimura Mizuna , Takai Madoka , Ishihara Kazuhiko 
Published: September 2006

AbstractHydrogels containing 2‐methacryloyloxyethyl phosphorylcholine (MPC) moieties were formed from aqueous solutions with water‐soluble MPC polymers with carboxylic acid and alkyl groups because of hydrogen bonding formation. To investigate the biocompatibility and drug release behavior of the hydrogels, we used random‐ and block‐type carboxylic acid MPC polymers, such as poly [MPC‐co‐methacrylic acid (MA)] (rPMA), poly[MPC‐co‐4‐(2‐methacryloyloxyethyl) trimellitic acid (MET)] (rPMT), poly (MA‐block‐MPC‐block‐MA) (bPMA) and poly(MET‐block‐MPC‐block‐MET) (bPMT), and alkyl MPC polymers, such as poly[MPC‐co‐n‐butyl methacrylate] (PMB) and poly(MPC‐co‐benzyl methacrylate) (PMBz). We investigated the biocompatibility of the spontaneously formed MPC polymer hydrogels by a hemolysis test and an in vivo injection test. The random MPC polymers having carboxylic acid groups expressed more hemolytic activity compared to the block polymers. The results of the in vivo injection test also indicated low biocompatibility of the carboxylic acid polymers especially at high concentration. The alkyl MPC polymers, the PMB and PMBz showed excellent biocompatibility in both hemolysis and in vivo injection test. However, the hydrogels, the rPMA/PMB hydrogel (rABgel) and the rPMT/PMBz hydrogel (rTZgel) lowered the hemolytic activity of elemental polymers, the rPMA and rPMT. Thus, suppression of the ionization of the carboxylic acid groups is necessary for biocompatibility. We also investigated the drug release behavior with attention to the interaction between the polymer and the drugs. The release behavior of a relatively low‐molecular‐weight hydrophilic drug, 5‐fluorouracil, did not depend on the structure of the polymers. The higher‐molecular‐weight drugs, ketoprofen and indomethacin, were released faster from the block polymer hydrogel than the random polymer hydrogel, the rABgel, while the highest‐molecular‐weight drug, doxorubicin, was released faster from the random polymer hydrogel. A probable reason for this is the difference in the molecular structure; that is, the separated hydrophilic and hydrophobic sections in the block polymers constructed pathways where a drug can diffuse. In addition, the rTZgel suppressed the release of a drug with a large number of aromatic rings probably because of the stacking effect. The results of the compression test also suggested the existence of the stacking effect between the rTZgel and the drugs. Based on these results, control of drug release is possible by selecting a reservoir with an appropriate chemical structure to interact with the drug. For example, release of a relatively linear‐structured drug with less aromatic rings can be suppressed in the rABgel rather than in the rTZgel. Thus, it can be concluded that if the ionization is suppressed, these MPC polymer hydrogels can be used as a material for a drug reservoir that can be selected according to the drug. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Purified titanium oxide with novel morphologies upon spark anodization of Ti alloys in mixed H2So4/H3PO4 electrolytes
Authors: Kern P. , Zinger O. 
Published: September 2006

AbstractThe spark anodization behavior of α/β Ti6Al4V and Ti6Al7Nb alloys and of α c.p. Ti in H2SO4, H3PO4, and mixtures of these acids was studied. Chemical depth profiling revealed oxides purified with respect to the substrate alloying elements. This was particularly pronounced on Ti alloys spark anodized in H2SO4/H3PO4 mixtures, the Al content decreasing continuously towards the surface, and V and Nb hardly detectable in the outermost 200 nm. The incorporation of S was significantly reduced in mixed electrolytes, while about 8 at‐% P was present. A novel oxide morphology with “worm‐like” features in the micrometer range, very different from well‐known nano/microporous oxides, was found in mixed electrolytes under suitable conditions. Similar but more porous‐like morphologies were formed on Ti. Simple α/β substrate microstructural considerations cannot explain the morphological and chemical observations. Raman spectroscopy indicated the presence of mixed anatase, rutile, and brookite phase on anodized Ti alloys. Bond strengths of 34 MPa for worm‐like and 40–50 MPa for nano/microporous morphologies as well as excellent abrasion behavior were found. The compatibility of grit‐blasting with the spark anodization process for creating multitopography surfaces was demonstrated. Neither the observed chemical effects, nor the observed particular morphology or the presence of brookite have been reported before. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
In vitro pyrogen test—A new test method for solid medical devices
Authors: Mazzotti Francesca , Beuttler Julia , Zeller Richard , Fink Ulrich , Schindler Stefanie , Wendel Albrecht , Hartung Thomas , von Aulock Sonja 
Published: September 2006

AbstractMedical devices manufactured for implantation into humans must be free of any contamination with viable bacteria. However, remnants of dead bacteria and bacterial components alone may induce an inflammatory immune response. Pyrogen tests for such inflammatory contaminations are generally performed either by determining the content of lipopolysaccharide in rinsing solutions of batch samples by limulus amoebocyte lysate assay, by injecting the rinsing solutions into rabbits or by implanting batch samples into rabbits and measuring change of body temperature. In this study, we show that the in vitro pyrogen test (IPT), which measures the release of the inflammatory cytokine IL‐1β in fresh or cryopreserved human whole blood, can be used to assess the pyrogenic contamination of implantable medical devices. This test was used to check neurosurgical implants, namely aneurysm clips, as a proof of principle. Owing to the direct contact of the test material with the blood cells, this test does not require rinsing procedures, which have variable efficacy. The use of human blood ensures the detection of all substances that are pyrogenic for humans and reflects their relative potency. The safety of the products as delivered could be confirmed. The effects of sterilization and depyrogenization procedures on intentional pyrogenic contaminations of samples could be followed. This new application of the already internationally validated method promises to replace further rabbit pyrogen tests. It generates extremely sensitive results with an extended range of detectable pyrogenic contaminants. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Analysis of TIMP‐1 Gene Polymorphisms in Italian Sclerodermic Patients
Authors: Indelicato Manuela , Chiarenza Valentina , Libra Massimo , Malaponte Grazia , Bevelacqua Valentina , Marchini Maurizio , McCubrey James A. , Stivala Franca , Scorza Raffaella , Mazzarino Maria Clorinda 
Published: September 2006

AbstractSystemic sclerosis (SSc) is an autoimmune disease characterized by skin and internal organs fibrosis due to an extracellular matrix (ECM) accumulation of type I collagen. The turnover of the ECM is dependent on the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs). The disruption of this balance is involved in SSc because higher serum TIMP‐1 levels have been demonstrated in SSc patients than in controls. On this basis, we analyzed three polymorphisms: −19A>G, +261C>T, and +372T>C of the TIMP‐1 gene in SSc patients (67 females, eight males) and controls (29 females, nine males). The C allele of the +372T>C single nucleotide polymorphism (SNP) was observed at a higher frequency in male patients than in healthy individuals (P=0.02), while no differences were observed in the female subjects. Our findings suggest that the +372T>C polymorphism of the TIMP‐1 gene is associated with SSc in male individuals. No association with the clinical characteristics of SSc Italian patients and TIMP‐1 gene polymorphisms was observed. Thus, the role of TIMP‐1 gene in predisposition to SSc remains controversial. J. Clin. Lab. Anal. 20:173–176, 2006. © 2006 Wiley‐Liss, Inc.
Zinc (II) ion recovery by biosorption onto powdered waste sludge (PWS): effects of operating conditions
Authors: Kargi Fikret , Cikla Sinem 
Published: September 2006

AbstractPowdered waste sludge (PWS) obtained from a paint industry wastewater treatment plant and pretreated with 1% H2O2 was used for biosorption of Zn(II) ions from aqueous solution. The effects of operating conditions, pH, temperature, agitation speed, PWS particle size, Zn ion and PWS concentrations on the extent of Zn ion biosorption were investigated in batch experiments. The optimum pH resulting in maximum Zn ion biosorption was found to be pH = 5, since Zn ions precipitated in the form of Zn(OH)2 at pH levels above 5. The rate and extent of Zn ion biosorption increased with temperature between 25 and 50 °C, although biosorption was not strongly sensitive to temperature variations since the activation energy was low at 4.5 kcal mol−1. Biosorbent particle size had a significant effect on Zn ion biosorption, yielding high percentage Zn removals at small particle sizes (Dp < 100 µm) or large surface areas of PWS. Agitation speed also considerably affected the extent of Zn ion removal, and should be above 150 rpm in order to obtain a high rate. The extent of Zn ion biosorption was also affected by the initial Zn ion and PWS concentrations. At constant biosorbent (PWS) concentration, percentage Zn ion removal decreased, but the biosorbed Zn concentration increased with increasing initial Zn ion concentrations. However, at constant initial Zn concentrations, percentage Zn removal increased, but the biosorbed Zn ion concentration decreased with increasing adsorbent (PWS) concentration. With a maximum Zn ion biosorption capacity of 168 mg g−1 powdered waste sludge was proven to be an effective biosorbent compared to other biosorbents. Copyright © 2006 Society of Chemical Industry
Lentiviral vector integration sites in human NOD/SCID repopulating cells
Authors: Laufs Stephanie , Guenechea Guillermo , Gonzalez‐Murillo Africa , Zsuzsanna Nagy K. , Luz Lozano M. , del Val Coral , Jonnakuty Sunitha , Hotz‐Wagenblatt Agnes , Jens Zeller W. , Bueren Juan A. , Fruehauf Stefan 
Published: September 2006

AbstractBackgroundRecent observations of insertional mutagenesis in preclinical and clinical settings emphasize the relevance of investigating comprehensively the spectrum of integration sites targeted by specific vectors.MethodsWe followed the engraftment of lentivirally transduced human cord blood (CB) progenitor cells after transplantation into NOD/SCID mice using a self‐inactivating HIV‐1‐derived vector expressing the enhanced green fluorescent protein (EGFP).ResultsThe mean of transduction of CD34+ CB cells was 41%, as deduced from the percentage of EGFP+ cells before transplantation. At 3 weeks post‐transplantation, the average of EGFP+ cells in the human cell population was 65 ± 8%, and increased to 75 ± 10% at 12 weeks post‐transplantation. In order to determine the proviral integration sites in human NOD/SCID repopulating cells (SRCs) we used the ligation‐mediated polymerase chain reaction (LM‐PCR) technique. Sixty‐eight percent of the integrations were found to be located in RefSeq genes, most of them in intron regions. Twenty percent of these integrations occurred within a distance of 10 kb from the transcription start site; a percentage that is significantly lower compared to that observed in cells transduced by gammaretroviral vectors. Sixty‐two percent of integrations occurred in genes with a biological function in cell metabolism, and four integrations were located in genes with a role in tumorigenesis.ConclusionsThese investigations indicate that integration of lentiviral vectors in human repopulating cells capable of engrafting NOD/SCID mice preferentially occur in coding regions of the human genome. Nevertheless, the clustering of integrations at the transcriptional start is not as high as that observed for gammaretroviral vectors. Copyright © 2006 John Wiley & Sons, Ltd.
SENSE imaging with a quadrature half‐volume transverse electromagnetic (TEM) coil at 4T
Authors: Avdievich Nikolai I. , Peshkovsky Alexey S. , Kennan Richard P. , Hetherington Hoby P. 
Published: September 2006

AbstractPurposeTo demonstrate the feasibility of high‐field SENSE imaging of large objects, such as the human head, using a semicircular (half‐volume) coil for both transmission and multi‐channel reception.Materials and MethodsAs a proof of concept, we present experimental data obtained using a seven‐element half‐volume (180° of arc) transmit/receive quadrature transverse electromagnetic (TEM) coil. SENSE images of the human brain were acquired with a reduction factor of R = 2, using two degenerate linear modes of the same coil as independent receive channels at 4T. Since the need for additional hardware (i.e., a separate set of receive coils) is eliminated, the design can be substantially simplified.ResultsThe experimental data demonstrate that linear modes of the half‐volume TEM coil have essentially no noise correlation, and their sensitivity profiles satisfy the requirement for small g‐factors. Also, this type of coil provides efficient transmission with a relatively large uniform region and a reception profile that is more uniform than that of the surface coils.ConclusionWe demonstrate the feasibility of SENSE imaging using a half‐volume coil. Half‐volume coils allow reduced total power deposition compared to full‐volume coils, and may replace the latter in body imaging applications in which the target region of interest (ROI) is smaller than the entire torso. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
ENSO and the South China Sea summer monsoon onset
Authors: Zhou Wen , Chan Johnny C. L. 
Published: September 2006

AbstractThis paper investigates the relationship between the onset date of the South China Sea summer monsoon (SCSSM) and the El Niño/Southern Oscillation (ENSO). The monsoon onset date (MOD) is defined on the basis of the switch of the 850‐hPa zonal winds over the South China Sea (SCS) from easterly to westerly for two consecutive pentads. The ENSO signal is represented by the ocean heat content (OHC), which is proportional to the depth of the 20 °C isotherm.It is found that, in years associated with a warm (cold) ENSO event or the year after, the monsoon tends to have a late (an early) onset and the intensity of the SCSSM also tends to be weaker (stronger). During a 2‐year period prior to the onset, anomalies of OHC have an obvious eastward propagation. The 850‐hPa flow east of the Philippines, specifically the strength of the subtropical high, is also found to be critical in determining the MOD. The link between these two results appears to be the propagation of cold (warm) subsurface water into the western North Pacific (WNP), which strengthens (weakens) the subtropical high, and hence a late (an early) SCSSM onset. Copyright © 2006 Royal Meteorological Society.
Hanging on the coat tails of the obesity epidemic: will metabolic syndrome be the next public health crisis and does nutrition have a role in its prevention?
Authors: Buttriss Judith L 
Published: September 2006

AbstractWorldwide rates of obesity are on the increase and following in their tracks are increases in the metabolic syndrome (a cluster of characteristic features associated with an increased risk of cardiovascular disease and type 2 diabetes). Along with these trends, healthcare costs are expected to escalate and part of the solution to coping with this situation is to direct the public health focus towards prevention. The situation is complicated by the fact that people are living longer and longer (and people gradually tend to put on weight as they get older). Cognisant of the major challenges ahead, funding agencies are supporting a variety of multidisciplinary projects, some of which are showcased here (Ob‐Age and Lipgene), that are seeking to understand, on the one hand, the influence our genetic make‐up has on the way our bodies handle particular nutrients and how these relationships relate to disease risk, and at the other end of the spectrum how the food chain can be manipulated to improve the nutritional value of the food we consume. Crucial to developing targeted dietary messages is a sound understanding of the nutritional value of foods. Weaknesses in current databases are being addressed by a pan‐European Project, EuroFIR. Looking to the future, it is to be hoped that new research underway in the UK and around the world, some of which is referred to here, will inform policy that will enable us to really get to grips with the current trends in obesity and related conditions such as the metabolic syndrome and type 2 diabetes, which are currently threatening the improvements in life expectancy seen consistently around the world over the past 150 years. Copyright © 2006 Society of Chemical Industry
High‐capacity purification of hen egg‐white proteins by ion‐exchange electrochromatography with an oscillatory transverse electric field
Authors: Yuan Wei , Zhao Guo‐Feng , Dong Xiao‐Yan , Sun Yan 
Published: September 2006

AbstractThe ion‐exchange electrochromatography with an oscillatory electric field perpendicular to the mobile‐phase flow driven by pressure (pIEEC) was used to separate hen egg‐white (HEW) proteins. The results were compared with those of normal ion‐exchange chromatography (IEC). The column was designed as three‐compartment rectangular column of 2‐mL with dimensions (length×width×depth) of 40×10×5 mm3 and the electric field was applied across the direction of column width. Q Sepharose FF was packed into the central compartment as the chromatographic bed. It was confirmed that the dynamic binding capacity (DBC) of different proteins (ovotransferrin and ovalbumin) in the HEW solution increased 2.3 times when an oscillatory electric current of 30 mA at 1/20 Hz was applied in the transverse column direction. Then, the HEW proteins were separated by the pIEEC at loading amounts 2.3‐fold higher than those by the IEC. When the feedstock of about one‐third of the DBC was applied to the columns (i. e., 7 mL for the pIEEC and 3 mL for the IEC), similar separation efficiencies of the two chromatographic modes were achieved. Both the recovery yield and purity reached 73% to over 90%. The results indicate that the pIEEC is promising for high‐capacity purification of proteins.
Development of dyskinesias in a 5‐year trial of ropinirole and L‐dopa
Authors: Rascol Olivier , Brooks David J. , Korczyn Amos D. , De Deyn Peter P. , Clarke Carl E. , Lang Anthony E. , Abdalla Mona 
Published: September 2006

AbstractA 5‐year trial of ropinirole and levodopa in early Parkinson's disease showed that ropinirole is associated with reduced incidence of dyskinesias. This post hoc analysis investigated whether the dyskinesia‐sparing benefit of ropinirole is lost when levodopa is added to the regimen and evaluated other risk factors for developing dyskinesias. Patients receiving levodopa had a significantly higher risk of dyskinesias than those taking ropinirole monotherapy (hazard ratio [HR], 6.67; 95% confidence interval [CI], 3.23–14.29; P < 0.001). When patients randomized to ropinirole were treated with supplementary levodopa, the development of dyskinesias was not significantly different from that in those receiving levodopa from the start (HR, 0.80; 95% CI, 0.48–1.33; P = 0.39). However, the onset of dyskinesias was delayed by around 3 years compared with levodopa monotherapy. Adjusted analyses taking into account baseline and on‐treatment factors that influenced use of supplementary levodopa or the development of dyskinesias produced similar results. In conclusion, the risk of developing dyskinesias during maintained initial ropinirole monotherapy is very low. Only once levodopa is added does the risk substantially change. Early use of ropinirole postpones the onset of dyskinesias, but these benefits decline when levodopa therapy is started, with no evidence of a subsequent rapid “catch‐up” or a persisting preventive effect. © 2006 Movement Disorder Society
Clinical phenotype of subjects with Parkinson's disease and orthostatic hypotension: Autonomic symptom and demographic comparison
Authors: Allcock Liesl M. , Kenny Rose Anne , Burn David J. 
Published: September 2006

AbstractThe objective of this study was to characterize the phenotypic associations of orthostatic hypotension (OH) in Parkinson's disease (PD). One hundred fifty‐nine subjects with PD underwent assessment including autonomic symptom severity scoring, disease‐specific rating scales, and measurement of postural blood pressure response. Symptoms of autonomic impairment weakly correlated with disease duration and severity. A posture and gait instability (PIGD) motor phenotype was associated with greater severity of autonomic symptoms. Eighty subjects (50.3%) had OH. These subjects were older, more likely to be male, and taking larger doses of dopaminergic medications than those without OH. There was no difference in disease severity or duration between those with and those without OH. Symptomatic dizziness did not distinguish between groups, although subjects with OH had more symptoms of generalized autonomic impairment than those without. Progressive autonomic involvement may be linked to disease progression in PD, particularly in patients with a PIGD phenotype, but dichotomization into groups with and without OH is a relatively insensitive method for demonstrating this. Longitudinal studies of changes in autonomic reflex abnormalities, autonomic symptom profiles, and motor severity might clarify these associations. © 2006 Movement Disorder Society
Positive radial solutions of p‐Laplacian equation with sign changing nonlinear sources
Authors: Jin Chunhua , Yin Jingxue , Wang Zejia 
Published: September 2006

AbstractThis paper is concerned with the p‐Laplacian equation with singular sources which is allowed to change sign in a ball. The singularity may occur at the zero points of solutions and on the boundary. Using the upper and lower solutions method, we establish the existence of positive radial solutions for the problem considered. Copyright © 2006 John Wiley & Sons, Ltd.
Just how much data need to be collected for reliable bootstrap DT‐MRI?
Authors: O'Gorman Ruth L. , Jones Derek K. 
Published: September 2006

AbstractDiffusion tensor MRI (DT‐MRI) can provide estimates of fiber orientation derived from the orientational dependence of the diffusivity of water molecules, enabling the reconstruction of white matter fiber pathways using tractography methods. However, noise arising from various sources can introduce uncertainty into the estimates of the elements of the diffusion tensor, resulting in errors in fiber orientation estimates such that tractography reconstructions of fiber pathways potentially can be imprecise and inaccurate. Recently, attempts have been made to characterize the uncertainty in DT‐MRI‐derived parameters using the bootstrap method; however, several questions remain open regarding the number of repeat measurements and bootstraps required to accurately and precisely reconstruct the probability distributions of the DT‐MRI parameters. This study investigates the accuracy and precision of the bootstrap method for characterizing distributions of DT‐MRI parameters. A number of experimental bootstrap designs and sampling schemes containing different numbers of isotropically distributed gradient vectors are considered, using an idealized system where the true variability in each parameter is known. This study demonstrates that for most DT‐MRI experiments, robust results will be obtained if the minimum number of bootstraps is approximately 500, and that at least five repeat samples of each diffusion‐weighted intensity should be used for bootstrapping. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.