bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of microvessels in canine lymph nodes
Authors: Tonar Zbyněk , Egger Gunter F. , Witter Kirsti , Wolfesberger Birgitt 
Published: July 2008

AbstractQuantification of microvessels in tumors is mostly based on counts of vessel profiles in tumor hot spots. Drawbacks of this method include low reproducibility and large interobserver variance, mainly as a result of individual differences in sampling of image fields for analysis. Our aim was to test an unbiased method for quantifying microvessels in healthy and tumorous lymph nodes of dogs. The endothelium of blood vessels was detected in paraffin sections by a combination of immunohistochemistry (von Willebrand factor) and lectin histochemistry (wheat germ agglutinin) in comparison with detection of basal laminae by laminin immunohistochemistry or silver impregnation. Systematic uniform random sampling of 50 image fields was performed during photo‐documentation. An unbiased counting frame (area 113,600 μm2) was applied to each micrograph. The total area sampled from each node was 5.68 mm2. Vessel profiles were counted according to stereological counting rules. Inter‐ and intraobserver variabilities were tested. The application of systematic uniform random sampling was compared with the counting of vessel profiles in hot spots. The unbiased estimate of the number of vessel profiles per unit area ranged from 100.5 ± 44.0/mm2 to 442.6 ± 102.5/mm2 in contrast to 264 ± 72.2/mm2 to 771.0 ± 108.2/mm2 in hot spots. The advantage of using systematic uniform random sampling is its reproducibility, with reasonable interobserver and low intraobserver variance. This method also allows for the possibility of using archival material, because staining quality is not limiting as it is for image analysis, and artifacts can easily be excluded. However, this method is comparatively time‐consuming. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
The acute temperature tolerance of green sturgeon (Acipenser medirostris) and the effect of environmental salinity
Authors: Sardella Brian A. , Sanmarti Enio , Kültz Dietmar 
Published: July 2008

AbstractWe investigated the effect of environmental salinity on the upper thermal tolerance of green sturgeon (Acipenser medirostris), a threatened species whose natural habitat is vulnerable to temperature and salinity variation as a result of global climate change. Freshwater (FW)‐reared sturgeon were gradually acclimated to salinities representing FW, estuary water (EST), or San Francisco Bay water (BAY) at 18°C, and their critical thermal maximum (CTMax) was measured by increasing temperature 0.3°C/min until branchial ventilation ceased. CTMax was 34.2±0.09°C in EST‐acclimated fish, with FW‐ and BAY‐acclimated fish CTMax at 33.7±0.08 and 33.7±0.1°C, respectively. Despite the higher CTMax in EST‐acclimated fish, FW‐acclimated sturgeon ventilation rate reached a peak that was 2°C higher than EST‐ and BAY‐acclimated groups and had a greater range of temperatures within which they exhibited normal ventilatory function as assessed by Q10 calculation. The osmoregulatory consequences of exposure to near‐lethal temperatures were assessed by measuring plasma osmolality and hematocrit, as well as white muscle, brain, and heart tissue water contents. Hematocrit was increased following CTMax exposure, most likely owing to the elevated metabolic demands of temperature increase, and plasma osmolality was significantly increased in EST‐ and BAY‐acclimated fish, which was likely the result of a greater osmotic gradient across the gill as metabolism increased. To our knowledge, this represents the first evidence for an effect of salinity on the upper thermal tolerance of sturgeon, as well as the first investigation of the osmoregulatory consequences of exposure to near‐lethal temperatures. J. Exp. Zool. 309A:477–483, 2008. © 2008 Wiley‐Liss, Inc.
Urea production capacity in the wood frog (Rana sylvatica) varies with season and experimentally induced hyperuremia
Authors: Schiller Tamar M. , Costanzo Jon P. , Lee Richard E. 
Published: July 2008

AbstractWood frogs (Rana sylvatica) can accumulate substantial amounts of urea during fall and winter. In this study, maximal urea production capacity was examined in R. sylvatica collected at various times of the year and in response to experimental hyperuremia and dehydration. Activity and expression of carbamoyl phosphate synthetase I (CPS I), the hepatic regulatory enzyme of the urea cycle, were used as indicators of urea production capacity. The high levels of CPS I activity in summer frogs were maintained through much of winter, a time when many metabolic processes are downregulated, suggesting that urea production is important during hibernation. In laboratory experiments, hyperuremia in fully hydrated frogs caused CPS I activity to decrease by ∼41%, suggesting that urea functions as a feedback inhibitor. In contrast, CPS I activity was maintained in hyperuremic, dehydrated frogs. The significance of this response is unclear, although perhaps urea functions to counteract inhibitory effects of concentrated salts. Generally, changes in CPS I activity were not reflected by corresponding changes in CPS I quantity, indicating that this enzyme is not primarily regulated through transcription and translation; rather, control may be achieved by posttranslational modifications and/or feedback inhibition. Our findings suggest that maintenance of urea production capacity in hibernating R. sylvatica facilitates accumulation of this osmolyte, which has important roles in the winter biology of this species. J. Exp. Zool. 309A:484–493, 2008. © 2008 Wiley‐Liss, Inc.
RNA interfering connective tissue growth factor prevents rat hepatic stellate cell activation and extracellular matrix production
Authors: Li Guangming , Li Dingguo , Xie Qing , Shi Yi , Jiang Shan , Jin Youxin 
Published: July 2008

AbstractBackgroundConnective tissue growth factor (CTGF) is a possible key determinant of progressive fibrosis. Small interfering RNA (siRNA) is a powerful tool for silencing gene expression post‐transcriptionally. Therefore, the present study aimed to determine whether synthetic siRNA target CTGF down‐regulates the expression of the CTGF gene in primary rat hepatic stellate cells (HSC) and HSC T6, and, furthermore, whether it prevents rat HSC activation and extracelluar matrix (ECM) production.MethodsPrimary HSC were obtained by enzymatic perfusion of rat liver. HSC T6, primary HSC were treated with siRNAs that target CTGF or a control siRNA by addition to the culture medium.ResultsWe obtained one siRNA that could sequence‐specifically reduce target gene expression by over 90% at a concentration of 200 nM in the cell culture medium for a total of three siRNAs targeting CTGF genes. In HSC T6 cells, the effect of CTGF siRNA was dose‐dependent (50–200 nM) and time‐limited to a 24–72‐h period. The siRNA knockdown of CTGF significantly reduced the expression of α‐smooth muscle actin protein, increased the number of cells, upregulated the ratios of G0/G1 stage in rat HSC at 7 days of culture after plating, and attenuated the expression of type I and III collagen mRNA with a supernatant concentration of hyaluronic acid, and type III procollagen in an activated HSC of culture for 24–72 h.ConclusionsCTGF siRNA could effectively and sequence‐specifically down‐regulate the expression of CTGF in rat HSC, resulting in significant inhibition of HSC activation and proliferation as well as ECM production. These findings indicate that synthetic siRNA targeting CTGF could prove to be a useful treatment of liver fibrosis. Copyright © 2008 John Wiley & Sons, Ltd.
Mitigation of radiation‐induced skin injury by AAV2‐mediated MnSOD gene therapy
Authors: Yan Shiqing , Brown Stephen L. , Kolozsvary Andrew , Freytag Svend O. , Lu Mei , Kim Jae Ho 
Published: July 2008

AbstractBackgroundRadiation‐induced, long‐lived free radicals, reactive oxygen species and pro‐inflammatory cytokines have been implicated in the resultant tissue injury after exposure to ionizing radiation.MethodsAn approach designed to reduce the damaging effects of reactive oxidants employs metalloenzymes of superoxide dismutase (SOD), such as MnSOD. Recombinant adeno‐associated virus 2 (AAV2) provides safe and long‐term expression in humans. We tested the effectiveness of AAV2‐MnSOD‐hrGFP, a vector expressing MnSOD and green fluorescent protein (GFP) in preclinical models.ResultsInfection of cultured cells with AAV2‐MnSOD‐hrGFP showed enhanced expression of MnSOD and GFP. Sustained expression of GFP was achieved for at least 1 month in vivo following administration of AAV2‐MnSOD‐hrGFP to subcutaneous tissue of C57BL/6J mice. A single subcutaneous injection of AAV2‐MnSOD‐hrGFP significantly mitigated acute skin injury following single dose of irradiation of either 30 or 35 Gy.ConclusionsThe proof‐of‐concept demonstrated in the present study together with the known safety profile in humans indicate that AAV‐mediated MnSOD expression has potential countermeasure utility against normal tissue injury following radiation therapy or radiological accident. Copyright © 2008 John Wiley & Sons, Ltd.
Adenovirus‐mediated inhibition of SPARC attenuates liver fibrosis in rats
Authors: Camino Alejandra M. , Atorrasagasti Catalina , Maccio Daniela , Prada Federico , Salvatierra Edgardo , Rizzo Miguel , Alaniz Laura , Aquino Jorge B. , Podhajcer Osvaldo. L. , Silva Marcelo , Mazzolini Guillermo 
Published: July 2008

AbstractBackgroundThe interaction between fibrogenic cells and extracellular matrix plays a role in liver fibrosis, yet the mechanisms are largely unknown. Secreted protein, acidic and rich in cysteine (SPARC) is a matricellular glycoprotein that is expressed by hepatic stellate cells and is overexpressed in fibrotic livers. We investigated the in vivo role of SPARC in experimentally induced liver fibrosis in rats.MethodsA recombinant adenovirus carrying antisense SPARC was constructed (AdasSPARC). Advanced liver fibrosis was induced in Sprague‐Dawley rats by prolonged intraperitoneal administration of thioacetamide. Animals received injections of AdasSPARC or Adβgal (control adenovirus) via the tail vein and directly into the liver 1 week after the first dose. The pathological changes in liver tissues and indices of fibrosis were assessed at eight weeks. Expression of SPARC, transforming growth factor (TGF)‐β and α‐smooth muscle actin were evaluated by quantitative real‐time polymerase chain reaction, western blotting, enzyme‐linked immunosorbent assay and immunohistochemistry.ResultsHepatic SPARC expression significantly increased during the development of liver fibrosis. AdasSPARC markedly attenuated the development of hepatic fibrosis in rats treated with thiocetamide, as assessed by decreased collagen deposition, lower hepatic content of hydroxyproline and less advanced morphometric stage of fibrosis. AdasSPARC treatment reduced inflammatory activity (Knodell score) and suppressed transdifferentiation of hepatic stellate cell to the myofibroblasts like phenotype in vivo. Furthermore, in vitro inhibition of SPARC on hepatic stellate cells decreases the production of TGF‐β.ConclusionsThis is the first study to demonstrate that knockdown of hepatic SPARC expression ameliorates thioacetamide‐induced liver fibrosis in rats with chronic liver injury. SPARC is a potential target for gene therapy in liver fibrosis. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of peptides bearing nuclear localization signals on therapeutic ultrasound mediated gene delivery
Authors: Duvshani‐Eshet Maayan , Keren Hadas , Oz Shira , Radzishevsky Inna S. , Mor Amram , Machluf Marcelle 
Published: July 2008

AbstractBackgroundOne of the major limitations of nonviral gene delivery methods is nuclear transport of plasmid DNA (pDNA). Peptides bearing nuclear localization signal (NLS) were shown to mediate nuclear import of macromolecules. We have explored the use of cell‐permeable peptides (CPP) bearing NLS sequences to enhance transfection mediated by a nonviral approach: therapeutic ultrasound (TUS).MethodsTwo CPP‐NLS peptides which differ in the location of the NLS relative to the CPP were used: S413‐PV and PV‐S413. The peptides were attached to pDNA using electrostatic interactions. Gel‐electrophoresis and fluorescent assays were performed to evaluate pDNA–peptide interactions and condensation effects. Confocal microscopy was used to evaluate pDNA–peptide interaction inside cells. Transfection studies were conducted with the luciferase gene, using pDNA‐peptides alone, or with the application of TUS.ResultsAttachment of both peptides to pDNA condensed the pDNA, with higher affinity for the S413‐PV peptide. This interaction protected pDNA from endonucleases, but was also reversible. Both peptides mediated pDNA delivery to cell cytoplasm, but less significantly to the nucleus. Thus, both peptides produced transfection in cells, when added after incubation with DNA, with higher transfection‐level for PV‐S413. Application of TUS increased transfection mediated by these peptides, but was not higher compared to transfection using TUS and pDNA alone.ConclusionsThis study suggests that CPP‐NLS peptides may be used for condensing pDNA and bringing it into the cell cytoplasm, but their ability to mediate nuclear import of pDNA is insignificant. Copyright © 2008 John Wiley & Sons, Ltd.
Can macroeconomic policy stimulate private investment in South Africa? New insights from aggregate and manufacturing sector‐level evidence
Authors: Ndikumana Leonce 
Published: July 2008

AbstractThis study explores the determinants of investment using both aggregated industry‐level data and disaggretated data on 27 sub‐sectors of the manufacturing sector for the period 1970–2001. According to the results in this study, the government has potentially powerful means at its disposal to stimulate private investment. In particular, a domestic demand stimulus and public investment expansion will produce large gains in private investment. While the direct effects of lowering the interest rate appear to be quantitatively small, indirect effects operating notably through domestic demand and cheaper credit are likely to be large. The evidence in this study also indicates that it is important to minimise exchange rate instability to encourage investment. Copyright © 2008 John Wiley & Sons, Ltd.
A new chemical method of synthesis of modified nucleoside [32P]phosphates
Authors: Yanvarev D. V. , Shirokova E. A. , Kukhanova M. K. , Skoblov Yu. S. 
Published: July 2008

AbstractA simple method of chemical phosphorylation for modified nucleosides with [32P]orthophosphoric acid in the presence of BrCN is described. The yields of 5′‐[32P]nucleoside monophosphates achieved are 50–65% at nominal specific radioactivities of ca. 1000 Ci/mmol. The mechanism of phosphorylation in the presence of heterocyclic amines is studied. Copyright © 2008 John Wiley & Sons, Ltd.
Sensitivity of redox reactions of dyes to variations of conditions created in mass spectrometric experiments
Authors: Kosevich Marina V. , Chagovets Vitalij V. , Shmigol Irina V. , Snegir Sergej V. , Boryak Oleg A. , Orlov Vadim V. , Shelkovsky Vadim S. , Pokrovskiy Valerij A. , Gomory Agnes 
Published: July 2008

AbstractRedox behaviour of four imidazophenazine dye derivatives under mass spectrometric conditions of matrix‐assisted laser desorption/ionization (MALDI), laser desorption/ionization (LDI) from metal and graphite surface, electrospray, low temperature secondary ion mass spectrometry (LT SIMS) and fast atom bombardment (FAB) was studied and distinctions in the reduction‐dependent spectral patterns were analyzed from the point of view of different quantities of protons and electrons available for reduction in different techniques. The reduction products [M + 2H]+•, [M + 3H]+ and M−•, [M + H]− were observed in the positive and negative ion modes, respectively, which permitted to suggest independent occurrence of reduction and protonation/deprotonation processes. LDI from graphite substrate was the only technique that allowed us to obtain abundant negative ions of all dye derivatives. The yield of field ionization (FI) or field desorption (FD) mechanism to ion formation under LDI from rough graphite surface has been addressed. The sensitivity of reduction of the dyes to variation of reduction‐initiating agents confirms high redox activity of the dyes essential for their functioning in natural and artificial systems. Copyright © 2008 John Wiley & Sons, Ltd.
Targeted identification of phosphorylated peptides by off‐line HPLC–MALDI‐MS/MS using LC retention time prediction
Authors: Chen Vincent C. , Chou Chi‐Chi , Hsieh Hsin‐Yu , Perreault Hélène , Khoo Kay‐Hooi 
Published: July 2008

AbstractProtein phosphorylation is a type of posttranslational modification which plays an important role in cell regulation and signal transduction. Because of its biological relevance, a considerable amount of interest has been paid to the development of efficient techniques for phosphopeptide analysis. Although advances in MS control have enabled the high‐throughput discovery of proteins from limited amounts of sample, automated selection of MS/MS precursor ions based on intensity alone can significantly hamper the detection of low‐abundance phosphopeptides. On the basis of the observation that the introduction of a phosphate moiety does not dramatically change peptide retention time in reverse‐phase chromatography, phosphopeptide specific MS/MS fragmentation attempts based on LC retention time and m/z were evaluated using a standard protein mixture, then using in vitro phosphorylated myelin basic protein. Results indicated that the majority (98%) of phosphopeptides identified eluted within a ± 4‐min window of the predicted LC elution time. While studies presented here are primarily proof of concept in nature, data suggest that the use of LC retention time prediction could be a valuable constraint for the identification of phosphopeptides within a set of off‐line LC deposited sample spots. It is expected that the development of these methods will not only permit the targeted identification of protein phosphorylation sites but also allow the in‐depth analysis of the dynamic events linked to the posttranslational modification. Copyright © 2008 John Wiley & Sons, Ltd.
The McLafferty rearrangement in the Glu residue in a cyclic lipopeptide determined by Q‐TOF MS/MS
Authors: Yang Shi‐Zhong , Liu Xiang‐Yang , Mu Bo‐Zhong 
Published: July 2008

AbstractThe intraresidue rearrangement and loss of the side chain of the Glu residue was found through MS/MS analysis of both original and methanol‐esterified lipopeptides. Both Glu and Asp residues in the cyclic lipopeptide were esterified. The MS/MS results showed that the loss of fragment 72 or 86 was induced by McLafferty‐type rearrangement from the Glu or esterified Glu. The mechanism of loss of the Glu residue can be used to determine or to corroborate the existence of the Glu and to help understand the fragment formation in MS/MS. The cleavage mechanism and m/z intensities imply that the sodium ion was easier attached and the cleavage would easily occur at specific sites. Copyright © 2008 John Wiley & Sons, Ltd.
Differences between collisionally activated and electron‐transfer dissociations found for CH2X2(X = Cl, Br, and I) by using alkali‐metal targets
Authors: Sasaki Tomohiro , Matsubara Hiroshi , Hayakawa Shigeo 
Published: July 2008

AbstractHigh‐energy collisionally activated dissociation (HE‐CAD) and high‐energy electron‐ transfer dissociation (HE‐ETD) on collisions with alkali‐metal targets (Cs, K, and Na) were investigated for CH2X2+ (X = Cl, Br, and I) ions by tandem mass spectrometry (MS/MS). In the HE‐CAD spectra observed, peaks associated with CH2X+ ions formed by a loss of a halogen atom are always predominant regardless of precursor ions and target metals. The observation of the predominant CH2X+ ions is explained by the lowest energy levels of the fragments of CH2X+ + X among the possible fragment energy levels and internal‐energy distribution in HE‐CAD. In the charge‐inversion spectra, relative peak intensities of the negative ions formed by HE‐ETD strongly depend on the precursor ions and the target metals. While the CHCl2− ion was predominant in the spectra of CH2Cl2+ regardless of target species, the most intense peaks in those of CH2Br2+ and CH2I2+ were ascribed to either Br− or CH2Br− and either I− or I2−, respectively, depending on the target metals. The dependence of the relative intensities of the fragment ions by HE‐ETD on the precursor ions and target species are discussed on the basis of the energy levels of the neutral fragments and the narrow internal‐energy distribution resulting from the near‐resonant neutralization. It was demonstrated that HE‐ETD using the alkali‐metal targets provided rich information on the dissociation of the neutral species. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of satellite footprint patterns from time‐modulated planar arrays with very low dynamic range ratios
Authors: Chen Yikai , Yang Shiwen , Nie Zaiping 
Published: July 2008

AbstractAn efficient pattern synthesis approach has been developed for the synthesis of satellite footprint patterns using time‐modulated planar arrays. The approach can be used to effectively control both the ripples in the coverage zone and the sidelobe levels, due to the adoption of time‐modulated antenna arrays. The optimized time sequences and element excitations are obtained by the method based on a combination of a differential evolution strategy (DES) and a modified 2D Woodward–Lawson method. Normally, planar array synthesis is rather time consuming, partly due to the inherently large number of optimization variables and partly due to the fact that the calculation of fitness function is also time consuming. A fast computation approach based on the 2D fast Fourier transform (FFT) is thus applied in the DES for the planar array pattern computation. Several representative examples are presented to show the flexibility and effectiveness of the proposed approach. Copyright © 2008 John Wiley & Sons, Ltd.
HSPB2/MKBP, a novel and unique member of the small heat‐shock protein family
Authors: Hu Zhiping , Yang Binbin , Lu Wei , Zhou Weijun , Zeng Liuwang , Li Ting , Wang Xiang 
Published: July 2008

AbstractAlthough proteins belonging to the sHSP superfamily are diverse in sequence and size, most share characteristic features, including 1) a small molecular mass of 12–43 kDa, 2) a conserved α‐crystallin domain of 80–100 residues, 3) formation of large oligomers, 4) a dynamic quaternary structure, and 5) induction by stress conditions and chaperone activity in suppressing protein aggregation. HSPB2/MKBP (myotonic dystrophy kinase‐bind‐protein) retains the structural motif of the α‐crystallin family of HSPs but shows a unique nature compared with canonical family members, characterized by gene allocation, specific binding partners in skeletal muscle, and unique stress responsiveness. MKBP may be involved in the pathogenesis of myotonic dystrophy and contribute to the neuropathology in both Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis, Dutch type. © 2008 Wiley‐Liss, Inc.