bluuebunny/crossref_metadata_2025 huggingface dataset:
Confocal laser scanning microscopy using dialkylcarbocyanine dyes for cell tracing in hard and soft biomaterials
Authors: Heinrich Laurence , Freyria Anne‐Marie , Melin Martine , Tourneur Yves , Maksoud Rami , Bernengo Jean‐Claude , Hartmann Daniel Jean
Published: August 2006

The aim of this work was to study, in vitro, cell colonization of two biomaterials currently used for bone and cartilage repair, this step being important to understand the function of engineered tissues. Current methods that use histological approaches are not always suited to tissue‐engineering analysis. We, therefore, set up a protocol to assess cell distribution, utilizing noninvasive confocal microscopy and fluorescent labels with a far red emission wavelength to optimize scaffold transparency and minimize light scattering. Hard (ceramic substitute) and soft (collagen sponge) biomaterials were seeded respectively, on one side of the scaffold, with human fibroblasts and bovine chondrocytes labelled with carbocyanine dyes (DiD and DiR). The mean penetration depth for DiR labelled fibroblasts and chondrocytes in the two scaffolds, around 270 m, was greater than for DiD (136–218 μm) labelled cells. These depths were independent of cell origin but were influenced by the nature of the scaffolds. Collagen sponge is transparent in contrast to ceramic substitutes where measurements could only be made in opened macropores. Besides the limits of the equipment, the limits of the supports were diffusion for collagen sponges and transmission for ceramic substitutes. Confocal microscopy techniques could thus be used to address the question of cell colonization of porous biomaterials in a noninvasive manner. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Human microvascular endothelial synthesis of interleukin‐8 during in vitro ischemia and reperfusion
Authors: Albadawi Hassan , Patton George M. , Bratton Charles F. , Peterson Brian G. , Watkins Michael T.
Published: August 2006

These studies were undertaken to evaluate human microvascular endothelial cell (MEC) synthesis of interleukin‐8 (IL‐8), a potent neutrophil chemoattractant, under in vitro conditions of ischemia and reperfusion. IL‐8 and other related CXC chemokines are believed to mediate tissue injury in a variety of pathologic conditions in humans. MEC grown on microcarrier beads were exposed to 3 or 6 h of in vitro ischemia followed by 2 h of reperfusion. Conditioned medium, MEC protein, and total RNA extracts were assayed for IL‐8 using an ELISA. During ischemia alone, MEC increased intracellular, but not extracellular levels of IL‐8 secretion. In contrast, reperfusion markedly stimulated both intracellular and extracellular IL‐8 secretion. Neither 3 h of ischemia alone or followed by reperfusion altered steady‐state levels of IL‐8 mRNA when compared to pre‐ischemic levels. In contrast, after 6 h of ischemia alone and ischemia followed by reperfusion, IL‐8 mRNA was increased eight‐ and sixfold, respectively, when compared to pre‐ischemic levels. These studies demonstrate an inverse relationship between the rate of IL‐8 protein secretion and the steady‐state levels of IL‐8 mRNA during ischemia and reperfusion. During ischemia and reperfusion both the increase in cell‐associated IL‐8 protein and the release of IL‐8 into the medium is dependent on de novo protein synthesis rather than the intracellular accumulation of IL‐8. These experiments indicate that post‐ischemic modulation of IL‐8 release and synthesis following ischemia reperfusion will require strategies directed towards inhibition of IL‐8 transcription and in depth knowledge of the mechanisms regulating IL‐8 secretion. J. Cell. Biochem. 100: 412–420, 2007. © 2006 Wiley‐Liss, Inc.
Suppression of fibroblast metalloproteinases by ajulemic acid, a nonpsychoactive cannabinoid acid
Authors: Johnson David R. , Stebulis Judith A. , Rossetti Ronald G. , Burstein Sumner H. , Zurier Robert B.
Published: August 2006

Production of matrix metalloproteinases (MMP) in joint tissue of patients with inflammatory arthritis facilitates cartilage degradation and bone erosion, and leads to joint deformities and crippling. Thus, MMPs are important targets for agents designed to treat inflammatory arthritis. Oral administration of ajulemic acid (AjA), a synthetic, nonpsychoactive cannabinoid acid, prevents joint tissue injury in rats with adjuvant arthritis. AjA binds to and activates PPARγ directly. Therefore, we investigated the influence of AjA on MMP production in human fibroblast‐like synovial cells (FLS), and examined the role of PPARγ in the mechanism of action of AjA. FLS, treated or not with a PPARγ antagonist, were treated with AjA then stimulated with TNFα or IL‐1α. Release of MMPs‐1, 3, and 9 was measured by ELISA. The influence of AjA on MMP‐3 release from stimulated PPARγ positive (PPAR+/−) and PPARγ null (PPAR−/−) mouse embryonic fibroblasts (MEF) was also examined. Addition of AjA to FLS suppressed production of MMPs whether or not PPARγ activation was blocked. Secretion of MMP‐3 was also suppressed by AjA in both TNFα‐ and IL‐1α‐stimulated PPARγ+/−and PPARγ−/−MEF. Suppression of MMP secretion from FLS by AjA appears to be PPARγ independent. Prevention by AjA of joint tissue injury and crippling in the rat adjuvant arthritis model may be explained in large part by inhibition of MMPs. These results suggest that AjA may be useful for treatment of patients with rheumatoid arthritis and osteoarthritis. J. Cell. Biochem. 100: 184–190, 2007. © 2006 Wiley‐Liss, Inc.
Iron chelation study in a normal human hepatocyte cell line suggests that tumor necrosis factor receptor‐associated protein 1 (TRAP1) regulates production of reactive oxygen species
Authors: Im Chang‐Nim , Lee Jae‐Seon , Zheng Ying , Seo Jeong‐Sun
Published: August 2006

Iron is an essential component of many proteins, and has crucial roles in the proper functioning of proteins involved in cellular respiration, proliferation, and differentiation. It has been recently reported that the deferoxamine (DFO), an iron chelator, induces mitochondrial dysfunction, characterized by an attenuation of oxidative phosphorylation, as well as senescence‐like cellular morphology. However, the effects of DFO on mitochondrial heat shock proteins (HSPs) remain poorly understood. In this study, we examined the effect of DFO on tumor necrosis factor receptor‐associated protein 1 (TRAP1), a representative mitochondrial HSP, in a normal human hepatocyte cell line, Chang cells. DFO specifically decreased TRAP1 levels, increasing reactive oxygen species (ROS) and caveolin‐1 (Cav‐1), a marker protein of senescence. To examine whether these effects of DFO are reversed, we established TRAP1‐overexpressing Chang cells. DFO treatment to TRAP1‐overexpressing cells resulted in decreases in levels of ROS, Cav‐1, glutathione peroxidase (GPX), and manganese superoxide dismutase (MnSOD) levels as well as senescence‐associated β‐galactosidase (SA β‐gal) activity. These results suggest that TRAP1 might play a role in protecting mitochondria against damaging stimuli via decrease of ROS generation. J. Cell. Biochem. 100: 474–486, 2007. © 2006 Wiley‐Liss, Inc.
Structural and biochemical advances in mammalian RNAi
Authors: Collins Robert E. , Cheng Xiaodong
Published: August 2006

RNAi is a collection of processes mediated by small RNAs that silence gene expression in a sequence‐specific manner. Studies of processes as divergent as post‐transcriptional gene silencing, transcriptional silencing through RNA‐directed DNA methylation, or heterochromatin formation, and even RNA‐guided DNA elimination have converged on a core pathway. This review will highlight recent structural and mechanistic studies illustrating siRNA and miRNA processing, RISC formation, the execution of RNAi by RISC, and the regulation of these pathways, with a specific focus on vertebrate systems. J. Cell. Biochem. 99: 1251–1266, 2006. © 2006 Wiley‐Liss, Inc.
Induction of salivary polypeptides associated with parotid hypertrophy by gallotannins administered topically into the mouse mouth
Authors: Gho Francesca , Peña‐Neira Alvaro , López‐Solís Remigio O.
Published: August 2006

Isoproterenol‐induced salivary polypeptides (IISP), a group of proline‐rich proteins synthesized by mouse parotids, have been considered as markers for isoproterenol‐induced parotid hypertrophy. Rodents fed diets containing high‐tannin cereals (sorghum), also develop parotid hypertrophy. To test whether tannins are directly involved in provoking sialotrophic growth, we studied the effect of intraperitoneal and topical oral administrations of tannic acid (TA) on the induction of IISP polypeptides in endogamic mice (A/Snell). TA was characterized by HPLC chromatography and spectral analysis and shown to be composed solely of gallotannins, a complex family of glucose and gallic acid esters. IISP polypeptides were monitored in saliva by SDS–polyacrylamide gel electrophoresis during 36 h after ending TA stimulation. Single daily intraperitoneal administrations of TA for 3 consecutive days (0.033 mg/g bw/day), at variance of parallel administrations of isoproterenol (0.042 mg/g bw/day) failed to induce IISP polypeptides. However, repeated topical applications of TA into the mouse mouths (1.21 mg/g bw divided into three equal doses given at 4‐h intervals within a single day) resulted in unequivocal induction of IISP polypeptides. That response was clearly intensified by increasing the stimulation frequency to eight equivalent doses given at 1.5‐h intervals within a single day (corresponding to 3.23 mg/g bw) and even further by repeating this protocol for 3 days. Under these productive schemes of stimulations by TA, electrophoretic fractionation of parotid homogenates showed new polypeptide bands migrating in parallel to salivary IISP. These results suggest that topically administered gallotannins are effective inducers of trophic growth in mouse parotids. J. Cell. Biochem. 100: 487–498, 2007. © 2006 Wiley‐Liss, Inc.
Activation of FAK is necessary for the osteogenic differentiation of human mesenchymal stem cells on laminin‐5
Authors: Salasznyk Roman M. , Klees Robert F. , Boskey Adele , Plopper George E.
Published: August 2006

Human mesenchymal stem cell (hMSC) differentiation into osteoblasts and the signaling events involved are poorly understood. We recently established that contact with specific extracellular matrix (ECM) proteins, in particular laminin‐5, is sufficient to induce an osteogenic phenotype in hMSC through an extracellular signal‐related kinase (ERK)‐dependent pathway. Activation of ERK 1/2 by laminin‐5 induces phosphorylation of the runx2/cbfa‐1 transcription factor that controls osteogenic gene expression. We hypothesized that focal adhesion kinase (FAK) mediated signaling pathways supply a link between cell surface integrin‐ECM binding and activation of ERK 1/2, and that laminin‐5 promotes its osteogenic effects through this pathway. To test this hypothesis, we plated hMSC on a laminin‐5 matrix in the presence or absence of FAK‐specific small inhibitory RNAs (siRNA), and assayed for phosphorylation of runx2/cbfa‐1 as well as expression of established osteogenic differentiation markers (bone sialoprotein, osteocalcin, alkaline phosphatase, calcium deposition, and mineral:matrix ratio). We found that siRNA treatment reduced total endogenous FAK protein by ∼40%, and reduced FAK phosphorylation on Y397 by ∼33% in cells plated on laminin‐5 for 30 min. SiRNA treated cells exhibited a decrease in ERK 1/2 phosphorylation after 1 h, and reduced serine/threonine phosphorylation of Runx2/Cbfa‐1 after 8 days. Finally, FAK inhibition blocked osteogenic differentiation of hMSC, as assessed by lowered expression of osteogenic genes (RT‐PCR), decreased alkaline phosphatase activity, greatly reduced calcium deposition, and a lower mineral:matrix ratio after 28 days in culture. These results establish FAK as an important mediator of laminin‐5‐induced osteogenic differentiation of hMSC. J. Cell. Biochem. 100: 499–514, 2007. © 2006 Wiley‐Liss, Inc.
Phosphatase PTEN is inactivated in bovine aortic endothelial cells exposed to cyclic strain
Authors: Hoshino Yuji , Nishimura Kengo , Sumpio Bauer E.
Published: August 2006

Hemodynamic forces, including cyclic strain (CS) and shear stress (SS), have been recognized as important modulators of vascular cell morphology and function. PTEN (also known as MMAC1/TEP1) is a lipid phosphatase that leads to a decrease in intracellular phosphatidylinositol 3,4,5 trisphosphate (PIP3) and therefore can modulate the stimulating effect of phosphatidylinositol 3‐kinase (PI3K). In this study, we focused on the upstream regulators of the PI3K‐Akt pathway by assessing Akt, PTEN, casein kinase 2 (CK2) (a kinase that catalyzes phosphorylation of PTEN), and PI3K activity in endothelial cells (EC) exposed to CS. The activity of phospho‐PTEN (n = 4) and phospho‐CK2 (n = 4) increased in a time‐dependent fashion, reaching maximal activity by 10 min of CS stimulation. The peak of phospho‐Akt activity (n = 4) occurred later, at 60 min. Akt activity was altered by transfection of EC with dominant negative PTEN plasmids. Furthermore, CS increased PIP3 immunoreactivity in a time‐dependent manner, reaching maximal activity after 60 min of CS stimulation, and these effects were affected by transfection of EC with dominant negative PTEN plasmids. Inhibition of PTEN activity had no effect on CS‐mediated cell proliferation but inhibited CS‐mediated suppression of apoptosis. J. Cell. Biochem. 100: 515–526, 2007. © 2006 Wiley‐Liss, Inc.
Effect of coagulation on palm oil mill effluent and subsequent treatment of coagulated sludge by anaerobic digestion
Authors: Krishnan Vijayaraghavan , Ahmad Desa , Endut Era Mayuza
Published: August 2006

A new effluent treatment scheme is proposed for treating palm oil mill effluent based on coagulation and anaerobic digestion of coagulated sludge. The effectiveness of anionic (N9901) and cationic (N9907) polyelectrolytes manufactured by NALCO (Malaysia) was evaluated both as coagulant and coagulant aid. The results showed that the anionic and cationic polyelectrolytes were best suited as a coagulant aid, and the cationic polyelectrolyte showed better performance than the anionic polyelectrolyte. For an influent chemical oxygen demand (COD) concentration of 59 700 mg L−1 at an alum dosage of 1700 mg L−1, the residual COD, suspended solid removal, sludge volume and pH were found to be 39 665 mg L−1, 87%, 260 mL L−1 and 6.3, respectively. For the above influent COD and alum dosage with the addition of 2 mg L−1 of cationic polyelectrolyte as coagulant aid, the results were 30 870 mg L−1, 90%, 240 mL L−1 and 6.2, respectively. The sludge resulting from the coagulation process using alum as coagulant and cationic polyelectrolyte as coagulant aid was tested for its digestibility in an anaerobic digester. The quantity of biogas generated per gram of volatile solids (VS) destroyed at a loading rate of 26.7 ± 0.5 and 35.2 ± 0.4 g VS L−1 d−1 was found to be 0.68 and 0.72 L g−1 VS destroyed. The anaerobic biomass when subjected to varying alum dosage in the coagulated palm oil sludge did not exhibit inhibition as the digester performance was in conformity with the regular treatment process Copyright © 2006 Society of Chemical Industry
Syntheses of [14C]BAY 59‐7939 and its radiolabeled metabolite M‐4
Authors: Pleiss U. , Seidel D. , Grosser R.
Published: August 2006

BAY 59‐7939 is a novel, oral, direct Factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic diseases. Radiolabeled BAY 59‐7939 was required for drug absorption, distribution, metabolism and excretion (ADME studies). The BAY 59‐7939 was labeled with carbon‐14 in the carboxamide group in one step in an overall radiochemical yield of 85% starting from 4‐{4‐[(5S)‐5‐(aminomethyl)‐2‐oxo‐1,3‐oxazolidin‐3‐yl]phenyl}mor‐pholin‐3‐one and 5‐chlorothiophene‐2‐[14C]carboxylic acid. The radiolabeled metabolite M‐4 was prepared in 77% yield starting from [1‐14C]glycine and 5‐chlorothiophene‐5‐carboxylic acid. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of coronary atherosclerotic plaque using multicontrast MRI acquired under simulated in vivo conditions
Authors: Sun Binjian , Giddens Don P. , Long Robert , Taylor W. Robert , Weiss Diana , Joseph Giji , Vega David , Oshinski John N.
Published: August 2006

Purpose

To compare coronary atherosclerotic plaque characterization using multicontrast MRI on: 1) freshly excised vessels under simulated in vivo conditions, and 2) preserved vessels.

Materials and Methods

T1‐weighted (T1W), T2‐weighted (T2W), proton density‐weighted (PDW), and diffusion‐weighted (DW) MR images were acquired on 13 freshly excised human coronary arteries from explanted hearts. Vessels were imaged in an MR‐compatible tissue culture chamber using a 4.7 Tesla small‐bore MR scanner. Eight vessels were then preserved in buffered formalin and rescanned following the same imaging protocol. A three‐dimensional spatially penalized fuzzy C‐means (3D‐SPFCM) technique was applied to classify different plaque constituents. The classification results from vessels under “fresh” and “preserved” conditions were compared with corresponding histological sections.

Results

For most plaque constituents, the plaque characterization results show no significant difference between fresh and preserved scans, and little difference between scans and the histological reference standard. In the case of thrombus, apparent signal changes between fresh and preserved images were identified. Overall, MR scans conducted under preserved conditions provided a 1.8% to 17.5% greater signal‐to‐noise ratio (SNR) than those conducted in the fresh stage.

Conclusion

Preservation of coronary vessels did not alter the contrast between plaque tissues on multicontrast MRI, and did not significantly change the results of plaque constituent characterization. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
A knowledge‐guided active model method of cortical structure segmentation on pediatric MR images
Authors: Shan Zuyao Y. , Parra Carlos , Ji Qing , Jain Jinesh , Reddick Wilburn E.
Published: August 2006

Purpose

To develop an automated method for quantification of cortical structures on pediatric MR images.

Materials and Methods

A knowledge‐guided active model (KAM) approach was proposed with a novel object function similar to the Gibbs free energy function. Triangular mesh models were transformed to images of a given subject by maximizing entropy, and then actively slithered to boundaries of structures by minimizing enthalpy. Volumetric results and image similarities of 10 different cortical structures segmented by KAM were compared with those traced manually. Furthermore, the segmentation performances of KAM and SPM2, (statistical parametric mapping, a MATLAB software package) were compared.

Results

The averaged volumetric agreements between KAM‐ and manually‐defined structures (both 0.95 for structures in healthy children and children with medulloblastoma) were higher than the volumetric agreement for SPM2 (0.90 and 0.80, respectively). The similarity measurements (kappa) between KAM‐ and manually‐defined structures (0.95 and 0.93, respectively) were higher than those for SPM2 (both 0.86).

Conclusion

We have developed a novel automatic algorithm, KAM, for segmentation of cortical structures on MR images of pediatric patients. Our preliminary results indicated that when segmenting cortical structures, KAM was in better agreement with manually‐delineated structures than SPM2. KAM can potentially be used to segment cortical structures for conformal radiation therapy planning and for quantitative evaluation of changes in disease or abnormality. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Contrast‐driven approach to intracranial segmentation using a combination of T2‐ and T1‐weighted 3D MRI data sets
Authors: Helms Gunther , Kallenberg Kai , Dechent Peter
Published: August 2006

Purpose

To develop a strategy for structural brain imaging when using FSL software for segmentation and subsequent volumetry.

Materials and Methods

Three‐dimensional (3D) structural MRI of 1‐mm isotropic resolution was performed on a 3‐Tesla clinical imaging system. Prescribed signal evolution of a multiple spin‐echo (SE) sequence with variable refocusing flip angle for T2 weighting, and a modified driven equilibrium Fourier transform (MDEFT) sequence were used for T1 weighting. Postprocessing included rigid‐body coregistration, brain extraction, and segmentation using the tools of the FSL 3.2 software package.

Results

T2 weighting provided reliable delineation of the subarachnoidal space, while T1 weighting provided better segmentation of gray matter (GM) and white matter (WM). The combination of T1‐weighted (T1‐w) and T2‐w data allowed the identification of a T2‐hypointense class of “nonbrain” (NB) representing larger vessels and structures of connective tissue, as well as partial volume of bone and air‐filled cavities.

Conclusion

Brain extraction on T2‐w data and subsequent segmentation of the combined T1‐ and T2‐w intensity distribution into four classes are recommended. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
In vivo quantification of delayed gadolinium enhancement in the nucleus pulposus of human intervertebral disc
Authors: Niinimäki Jaakko L. , Parviainen Outi , Ruohonen Jyrki , Ojala Risto O. , Kurunlahti Mauno , Karppinen Jaro , Tervonen Osmo , Nieminen Miika T.
Published: August 2006

Purpose

To quantify the delayed contrast agent enhancement in the nucleus pulposus of the intervertebral disc by means by T1 relaxation time measurements, and to correlate the enhancement with visual grading of disc degeneration. Diffusion of nutrients through the endplate is a key factor in tissue viability in the intervertebral disc. It can be simulated in vivo using magnetic resonance imaging (MRI) by measuring delayed gadolinium (Gd) enhancement of the disc.

Materials and Methods

Twenty male volunteers underwent a lumbar spine examination at 1.5T. T2‐weighted sagittal images were used to score disc degeneration. T1 relaxation times were measured before and 90 minutes after intravenous administration of Gd‐DTPA‐BMA by applying a series of sagittal single‐slice inversion‐recovery fast spin‐echo (IR‐FSE) scans.

Results

A total of 93 discs were analyzed. A statistically significant decrease in the T1 relaxation time of the nucleus pulposus was observed as a result of contrast‐agent intake. The percentage change in the T1 relaxation rate for individual discs was up to 126%. A positive trend was observed between the change in the T1 relaxation rate and the grading of disc degeneration.

Conclusion

Quantification of delayed enhancement of the intervertebral disc may provide a new means of studying alterations in degenerative disc disease (DDD) that explain the variation in diffusion into the intervertebral disc. J. Magn. Reson. Imaging 2006;. © 2006 Wiley‐Liss, Inc.
The fast automatic algorithm for correction of MR bias field
Authors: Milchenko Mikhail V. , Pianykh Oleg S. , Tyler John M.
Published: August 2006

Purpose

To develop a method for efficient automatic correction of slow‐varying nonuniformity in MR images.

Materials and Methods

The original MR image is represented by a piecewise constant function, and the bias (nonuniformity) field of an MR image is modeled as multiplicative and slow varying, which permits to approximate it with a low‐order polynomial basis in a “log‐domain.” The basis coefficients are determined by comparing partial derivatives of the modeled bias field with the original image.

Results

We tested the resulting algorithm named derivative surface fitting (dsf) on simulated images and phantom and real data. A single iteration was sufficient in most cases to produce a significant improvement to the MR image's visual quality.dsfdoes not require prior knowledge of intensity distribution and was successfully used on brain and chest images. Due to its design,dsfcan be applied to images of any modality that can be approximated as piecewise constant with a multiplicative bias field.

Conclusion

The resulting algorithm appears to be an efficient method for fast correction of slow varying nonuniformity in MR images. J. Magn. Reson. Imaging 2006;. © 2006 Wiley‐Liss, Inc.
Characterizing coronary motion and its effect on MR coronary angiography—Initial experience
Authors: Al‐Kwifi Osama , Stainsby Jeffrey , Foltz Warren D. , Sussman Marshall S. , Huang Yuexi , Wright Graham A.
Published: August 2006

Purpose

To characterize coronary artery motion as a prescan procedure to select the optimum scan setting that will produce high‐resolution images.

Materials and Methods

A 2D real‐time scan was used to image the major coronary arteries during breath‐holding and free‐breathing conditions. With the use of the 2D images, motion displacement of each artery was measured along three axes. Motion data obtained from a computer simulation were used to estimate point‐spread functions (PSFs) associated with different high‐resolution spiral acquisition strategies, including real‐time, cardiac‐gated, and respiratory‐gated acquisitions. The simulation output determined the optimum acquisition and scan parameters that would produce the highest‐spatial‐resolution images of the coronary arteries. The effects of heart rate (HR), extended breath‐holding, and number of slices per heart cycle were also investigated.

Results

Substantial variations in coronary motion occur among individuals, which directly influences the optimum parameters for a high‐resolution scan. Lower HRs and longer breath‐holds yield substantially increased spatial resolution. The maximum number of slices per heart cycle can also be determined to minimize slice‐to‐slice distortion.

Conclusion

The results suggest that to obtain high‐resolution coronary images, one should perform a prescan coronary‐motion characterization for each individual so that the scan parameters can be optimized before data acquisition. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Comprehensive analysis of glycated human serum albumin tryptic peptides by off‐line liquid chromatography followed by MALDI analysis on a time‐of‐flight/curved field reflectron tandem mass spectrometer
Authors: Brancia Francesco L. , Bereszczak Jessica Z. , Lapolla Annunziata , Fedele Domenico , Baccarin Lorenzo , Seraglia Roberta , Traldi Pietro
Published: August 2006

Glycated peptides arising from in vivo digestion of glycated proteins, usually called advanced glycation end (AGE) product peptides, are biologically relevant compounds due to their reactivity towards circulating and tissue proteins. To investigate their structures, in vitro glycation of human serum albumin (HSA) has been performed and followed by enzymatic digestion. Using different MALDI based approaches the digestion products obtained have been compared with those arising from enzymatic digestion of the protein. Results obtained using 2,5‐dihydroxybenzoic acid (DHB) indicate this as the most effective matrix, leading to an increase in the coverage of the glycated protein. Off‐line microbore liquid chromatography prior to MALDI analysis reveals that 63% of the free amino groups amenable to glycation are modified. In addition, the same approach shows the co‐presence of underivatised peptides. This indicates that, regardless of the high glucose concentration employed for HSA incubation, glycation does not go to completion. Tandem mass spectrometric data suggest that the collision induced dissociation of singly charged glycated peptides leads to specific fragmentation pathways related to the condensed glucose molecule. The specific neutral losses derived from the activated glycated peptides can be used as signature for establishing the occurrence of glycation processes. Copyright © 2006 John Wiley & Sons, Ltd.
Fragmentation studies of synthetic 2‐acylamino‐1,4‐naphthoquinones by electrospray ionization mass spectrometry
Authors: Vessecchi Ricardo , Nascimento Paulo G. B. D. , Lopes José N. C. , Lopes Norberto P.
Published: August 2006

We report here the fragmentation mechanism for five 2‐acylamino‐1,4‐naphthoquinone derivatives using electrospray ionization tandem mass spectrometry (ESI‐MS/MS). Analyses were performed on a low‐resolution, triple‐quadrupole mass spectrometer. Fragmentation pathways for protonated molecular derivatives 2‐acylamino‐1,4‐naphthoquinone [M + H]+ are proposed on the basis of theoretical calculations. There is evidence that the nitrogen atom is the protonation site, based on the nucleophilic atomic indices. Copyright © 2006 John Wiley & Sons, Ltd.
Detection of human sapovirus by real‐time reverse transcription‐polymerase chain reaction
Authors: Oka Tomoichiro , Katayama Kazuhiko , Hansman Grant S. , Kageyama Tsutomu , Ogawa Satoko , Wu Fang‐Tzy , White Peter A. , Takeda Naokazu
Published: August 2006

Sapovirus (SaV) is an agent of gastroenteritis for humans and swine, and is divided into five distinct genogroups (GI–GV) based on its capsid gene sequences. Typical methods of SaV detection include electron microscopy (EM), enzyme‐linked immunosorbent assay (ELISA), and reverse transcription‐polymerase chain reaction (RT‐PCR). A novel TaqMan‐based real‐time RT‐PCR assay was developed that is sensitive and has the ability to detect the broad range of genetically diverse human SaV strains. A nucleotide alignment of 10 full‐length SaV genome sequences was subjected to similarity plot analysis, which indicated that the most conserved site was the polymerase‐capsid junction in open reading frame 1 (ORF1). Based on multiple alignments of the 27 available sequences encoding this junction, we designed sets of primers and TaqMan MGB probes that detect human SaV GI, GII, GIV, and GV sequences in a single tube. The reactivity was confirmed with SaV GI, GII, GIV, and GV control plasmids, and the efficiency ranged from 2.5 × 107to 2.5 × 101copies per tube. Analysis using clinical stool specimens revealed that the present system was capable of detecting SaV GI, GII, GIV, and GV sequences, and no cross‐reactivity was observed against other enteric viruses, including norovirus (NoV), rotavirus, astrovirus, and adenovirus. This is the first real‐time RT‐PCR system that could detect all genogroups of human sapoviruses. J. Med. Virol. 78:1347–1353, 2006. © 2006 Wiley‐Liss, Inc.
Rainfall variability in suriname and its relationship with the tropical Pacific ENSO SST anomalies and the Atlantic SST anomalies
Authors: Nurmohamed Riad , Naipal Sieuwnath , Becker Cor
Published: August 2006

Spatial correlations in the annual rainfall anomalies are analyzed using principal component analysis (PCA). Cross correlation analysis and composites are used to measure the influence of sea‐surface temperature anomalies (SSTAs) in the tropical Atlantic (TA) and the tropical Pacific Ocean on the seasonal rainfall in Suriname. It is shown that the spatial and time variability in rainfall is mainly determined by the meridional movement of the inter‐tropical convergence zone (ITCZ). The rainfall anomalies are fairly uniform over the whole country. The strongest correlation in the December–January rainfall (short wet season) at station Cultuurtuin is found to occur with the SSTAs in the Pacific region and is about ckNino1 + 2 = 0.59 at lag 1 month. In the March–May rainfall (beginning of the long wet season), there is a lagged correlation with the SSTAs in the Pacific region (clag3Nino1 + 2 = 0.59). The June–August rainfall (end of the long wet season) shows the highest correlation with SSTAs in the TSA region and is about c = −0.52 for lag 0. In the September–November long dry season there is also a lagged correlation with the TSA SSTAs of about clag3 = 0.66. These different correlations and predictors can be used for seasonal rainfall predictions. Copyright © 2006 Royal Meteorological Society
Episodic Quaternary volcanism in France and Germany
Authors: Nowell David A. G. , Jones M. Chris , Pyle David M.
Published: August 2006

Intra‐plate volcanism in western Europe shows statistically significant episodicity during the Quaternary period. By comparing the known ages for eruptions in France and Germany, which are compiled here, with a composite oxygen isotope record, we have investigated the link between this episodic volcanism and the climate record over the last two million years. We show that increased volcanism between 415–400 ka and 17–5 ka correlates with warming phases at the end of the last Weichselian (Devensian) and earlier Elsterian (Anglian) glacial stages. The three significant caldera explosions in the eastern Eifel, Germany, are all associated with warming phases at the onset of interglacials. The growth and decay of nearby ice sheets suggest that surface changes in continental mass distribution during glacial Milankovich cycles could provide a mechanism for this correlation by means of the distal effects of flexural loading on the lithosphere. Copyright © 2006 John Wiley & Sons, Ltd.
A 100 000‐year record of annual and seasonal rainfall and temperature for northwestern Australia based on a pollen record obtained offshore
Authors: van der Kaars Sander , De Deckker Patrick , Gingele Franz X.
Published: August 2006

Pollen recovered from core tops of deep‐sea cores from offshore northwestern Western Australia were used to build climatic transfer functions applied to sediment samples from major rivers bordering the ocean in the same region and a deep‐sea core offshore Northwest Cape. Results show for the last 100 000 years, with a gap in the record spanning the 64 000 to 46 000 years interval, that from about 100 000 to 82 000 yr BP, climatic conditions represented by rainfall, temperature and number of humid months, were significantly higher than today's values. For the entire record, the coldest period occurred about 43 000 to 39 000 yr BP but it was wetter than today, whereas the Last Glacial Maximum saw a significant reduction in summer rainfall, interpreted as a result of the absence of monsoonal activity in the region. The Holocene can be divided into two distinct phases: one peaking around 6000 cal. yr BP with highest rainfall and summer temperatures; the second one commencing at 5000 cal. yr BP and showing a progressive decrease in summer rainfall in contrast to an increase in winter rainfall, paralleled by a progressive decrease in temperatures. Copyright © 2006 John Wiley & Sons, Ltd.
Methodology for the determination of biological antioxidant capacity in vitro: a review
Authors: MacDonald‐Wicks Lesley K , Wood Lisa G , Garg Manohar L
Published: August 2006

One of the effective means of adding value to agricultural produce is the development of functional foods or dietary supplements enriched with antioxidants. This process involves extraction of antioxidant rich fractions from their sources and then testing for antioxidant activity prior to adding these back to the foods or packing into pills or capsules. Ideally, the antioxidant activity should be tested using both in vitro and in vivo techniques but due to the high cost of conducting animal and human feeding trials, many products undergo only in vitro testing. This review describes popular methods commonly used for testing antioxidant activity in vitro, with particular reference to their reliability, efficiency, accessibility and biological relevance. Copyright © 2006 Society of Chemical Industry
Effects of micronisation on the characteristics and physicochemical properties of insoluble fibres
Authors: Chau Chi‐Fai , Wen Yu‐Ling , Wang Yi‐Ting
Published: August 2006

The effects of micronisation on the characteristics and physicochemical properties of (a) an insoluble fibre‐rich fraction (IFRF) prepared from orange peel and (b) cellulose were studied and compared. The results showed that micronisation techniques such as ball milling, jet milling and high‐pressure micronisation could effectively (P < 0.05) reduce particle sizes to microscale, decrease the bulk density and improve the physicochemical properties (water‐holding capacity, swelling capacity, oil‐holding capacity, cation exchange capacity and glucose adsorption capacity) of IFRF and cellulose to different extents (up to 25‐fold). After micronisation the inhibitory effects of these insoluble fibres towards α‐amylase and pancreatic lipase were significantly increased (up to 5.8‐ and 7.8‐fold respectively) and a redistribution of some fibre components from insoluble to soluble fractions was observed. It was concluded that these micronisation treatments, especially high‐pressure micronisation, could effectively improve the functionalities of IFRF and cellulose, which might then be used as potential fibre‐rich ingredients in functional food applications. Copyright © 2006 Society of Chemical Industry
Radiosurgery versus carbon dioxide laser for dermatochalasis correction in Asians
Authors: Yu Carol S. , Chan Henry H.L. , Tse Raymond K.K.
Published: August 2006

Background and Objectives

Carbon dioxide (CO2) laser and radiosurgery are techniques commonly employed in oculoplastic surgery. However, there is no literature comparing their results in blepharoplasty.

Study Design/Materials and Methods

Twenty Chinese patients with dermatochalasis underwent radiosurgery in one upper eyelid and CO2 laser in the contralateral eyelid. Intraoperative time, hemorrhage, and pain control were assessed. Subjects were evaluated at postoperative 1 hour, 1 week, 1 month, and 3 months for hemorrhage and wound healing by a masked assessor.

Results

All patients reported minimal pain with either technique. A significantly shorter operative time was achieved with CO2 laser, with better intraoperative hemostasis. There was no significant difference in postoperative hemorrhage and wound swelling between radiosurgery and CO2 laser. No significant intraoperative complications were noted.

Conclusions

Both radiosurgery and CO2 laser are equally safe and effective for upper lid blepharoplasty. CO2 laser achieves shorter operative time with superior intraoperative hemostasis. Lasers Surg. Med. 39:176–179, 2007. © 2007 Wiley‐Liss, Inc.
Photoacoustic imaging of valves in superficial veins
Authors: Kolkman Roy G.M. , Bosschaart Nienke , Kok Ben , van Leeuwen Ton G. , Steenbergen Wiendelt
Published: August 2006

Background and Objectives

In intravenous access to veins there is a risk of puncturing venous valves or blocking of the catheter by the valves. Therefore, we have investigated whether and how photoacoustic imaging (PAI), which visualizes the lumen of blood vessels, can be used to detect these valves.

Study Design/Materials and Methods

Venous valves in superficial veins on the dorsal side of the hand of human volunteers were located by palpation and visual inspection. Next, this location was imaged using PAI.

Results

In 16 of 21 human volunteers venous valves that were found by palpation could be observed by PAI as local discontinuities in the imaged vessel. From these images, four characteristic features by which venous valves can be recognized in photoacoustic images were identified.

Conclusions

PAI has the potential to be applied in the detection of venous valves. Lasers Surg. Med. 38:740–744, 2006. © 2006 Wiley‐Liss, Inc.
Safe and effective carbon dioxide laser skin resurfacing of the neck
Authors: Kilmer Suzanne L. , Chotzen Vera A. , Silva Susan K. , McClaren Marla L.
Published: August 2006

CO2 laser skin resurfacing remains the gold standard for treatment of photoaged facial skin. It can be used onto the neck to further blend in the treated area with non‐treated, adjacent photodamaged skin as well as improve the superficial textural quality of the neck skin. This article provides an overview of laser skin resurfacing of the neck, including pre‐operative evaluation, patient education and selection, laser settings and technique used, post‐operative care, and identification and treatment of possible complications. Lasers Surg. Med. 38:653–657, 2006. © 2006 Wiley‐Liss, Inc.
Thermal, Optical and Electrochemical Properties of Side‐Chain Azopyridine Polymers Complexed with Metalloporphyrins
Authors: Dahmane Smail , Lasia Andrzej , Zhao Yue
Published: August 2006

Summary: New multifunctional supramolecular polymers were obtained by complexing a side‐chain azopyridine polymer with ZnTPP and CoTPP via axial coordination between the pyridyl group and the transition metals of the metalloporphyrins. Thermal, optical and electrochemical properties of the complexes in the solid state at various molar ratios of metal/pyridine were characterized by means of DSC, TGA, UV‐vis spectroscopy and CV. On one hand, the results show that linking ZnTPP or CoTPP to the azopyridine polymer results in significant changes of its properties, such as an increase in the glass transition temperature and the thermal stability of the polymer, and a decrease in the trans‐cis photoisomerization of azopyridine moieties. On the other hand, both ZnTPP and CoTPP complexed with the polymer exhibit changes in their redox behaviors.

Complexation via axial coordination between PAzPy and ZnTPP or CoTPP.

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Complexation via axial coordination between PAzPy and ZnTPP or CoTPP.
Preparation of Block Copolymers with a Single Tg Based on Segments of Poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) and Polycarbonate of Bisphenol A
Authors: Penco Maurizio , Sartore Luciana , Della Sciucca Stefania , Di Landro Luca , Mendichi Raniero , Samperi Filippo
Published: August 2006

Summary: The synthesis and the properties of block copolymers based on PPO and PC segments are reported. Copolymers that have a multi‐block structure are synthesized by a polycondensation reaction that employs oligomeric PPO and PC diol terminated with phosgene or bischloroformate of bisphenol A. In the reaction scheme two steps are involved: first, the reaction of one of the oligomeric diols (PPO or PC) with the bischloroformate or phosgene; second, the oligomeric bischloroformate is reacted with the other diol. The molecular characteristics of the prepared samples are studied by SEC, 1H and 13C NMR, and FT‐IR spectroscopy. The thermal and rheological properties and the thermal stability have also been investigated by means of DSC, rotational rheometry, and TGA, respectively. Polymers that have a single glass transition temperature are obtained if low‐molecular‐weight segments are used. From a rheological point of view, these materials show a remarkably lower melt viscosity compared with a PPO homopolymer that has a comparable average molecular weight.

Rheometric curves of PPO‐b‐PC (3) compared with a commercial PPO.

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Rheometric curves of PPO‐b‐PC (3) compared with a commercial PPO.
Synthesis and Characterization of Defined Branched Poly(propylene)s with Different Microstructures by Copolymerization of Propylene and Linear Ethylene Oligomers (Cn = 26–28) with Metallocenes/MAO Catalysts
Authors: Rulhoff Sascha , Kaminsky Walter
Published: August 2006

Summary: Copolymers of propylene and hexacosene (Cn = 26–28) were synthesized in the presence of three different metallocene catalysts activated by methylaluminoxane. The poly(propylene) copolymers were prepared with iso‐, syndio‐, and atactic backbone microstructures by using different symmetric metallocenes such as rac‐{Me2Si[2‐Me‐4‐(1‐Naph)Ind]2}ZrCl2 (1), [Ph2C(Cp)(Flu)]ZrCl2 (2), and [(H3C)2Si(9‐Flu)2]ZrCl2 (3) and up to 46.6 mol‐% comonomer content in the feed. The influence of the incorporated linear, ethylene‐based side chains into the poly(propylene) backbone were investigated by DSC, GPC, and 13C NMR. Generally, a decreasing content of comonomer in the feed enhances the activity of metallocene based catalysts. The determination of the branched microstructure by 13C NMR of the copolymers allows a smart identification of the amount of inserted hexacosene because of the separated backbone and side chain signals. Moreover, the relationship between the population of the side chains and the melting behavior of resulting copolymers were discussed. The melting point of the syndiotactic and isotactic poly(propylene) backbone decreases with increasing hexacosene content. When the inserted comonomer content exceeds 2 mol‐%, a second melting point of the crystallized ethylene based side chains can be observed which increases with an increasing amount of hexacosene.

Thermal behavior of isospecific hexacosene/propylene copolymers in dependence on the incorporation of hexacosene.

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Thermal behavior of isospecific hexacosene/propylene copolymers in dependence on the incorporation of hexacosene.
Study of the Crystallinity of Polyesters Derived from the Glycolysis of PET
Authors: Colomines Gaël , Lee Arie Van Der , Robin Jean‐Jacques , Boutevin Bernard
Published: August 2006

Summary:The crystallinity of a glycolysate obtained by glycolysis of PET with diethylene glycol (DEG) was qualitatively studied by optical microscopy using a polarizer and quantitatively by X‐ray diffraction. Moreover, the rheological behavior of this glycolysate was also studied in relation with its crystallinity. New glycolysates obtained using oligoesters of different chemical structures as reagents were studied under the same conditions and they show the total absence of crystallinity. According to the structure of the diol or of the oligoester used, the glycolysate crystallinity can be induced or not.

DSC analyses of different glycolysates.

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DSC analyses of different glycolysates.
Synthesis of Multinuclear Pyridylimine Based Palladium(II) Complexes with a Functionalized Star Polystyrene Core and Evaluation of Their Catalytic Activity Towards Ethylene Oligomerization
Authors: Abraham Sinoj , Ha Chang‐Sik , Kim Il
Published: August 2006

Summary: The synthesis of a novel series of multi‐nuclear macroligated pyridylimine based palladium(II) complexes conjugated to a synthetic star polymer core has been well‐described. Star shaped polystyrene with a finite number of arms were prepared by atom transfer radical polymerization (ATRP) and the chain ends were chemically modified in order to introduce the desired end functionality. Utilizing this polymer as organic supports for pyridylimine‐based ligands, palladium(II) complexes were synthesized. On activating with methylaluminoxane (MAO), this complex showed substantially high activity towards ethylene oligomerization, producing C4 and C6 compositions as major products. The plausible mechanistic insight concerning the process of ethylene oligomerization is also broached.

An example of trinuclear pyridylimine based palladium(II) complex having a functionalized star polystyrene core.

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An example of trinuclear pyridylimine based palladium(II) complex having a functionalized star polystyrene core.
Synthesis of Porous Polyurea with Room‐Temperature Ionic Liquids via Interfacial Polymerization
Authors: Zhu Lining , Huang Chien‐Yueh , Patel Yamini H. , Wu Jing , Malhotra Sanjay V.
Published: August 2006

Summary: Polyurea with exotic porous structures has been synthesized by the interfacial polymerization between hexane and a series of 1‐alkyl‐3‐methylimidazolium room‐temperature ionic liquids (ILs). Scanning electron microscopy micrographs of the polyurea show a macroporous morphology of aggregated polymer particles with sizes around 200 nm and pore sizes between 100 to 500 nm. The geometry of the polymer particles and the pore size vary with the ILs employed. X‐Ray diffraction shows ionic‐liquid‐induced suppression of 3D crystalline order in the polyurea products. The microstructures of the polymer together with the FT‐IR results suggest that the observed exotic polymer morphology originates from interactions between the ionic liquid and the polymer.

SEM micrograph of the interconnected macroporous structure of the polyurea formed in [C2mim][BF4] ionic liquid. The scale bar is 100 nm.

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SEM micrograph of the interconnected macroporous structure of the polyurea formed in [C2mim][BF4] ionic liquid. The scale bar is 100 nm.