bluuebunny/crossref_metadata_2025 huggingface dataset:
Phylogenetic‐affiliation, antimicrobial potential and PKS gene sequence analysis of moderately halophilic Streptomyces sp. inhabiting an Indian saltpan
Authors: Arul Jose P. , Satheeja Santhi V. , Jebakumar Solomon R. D.
Published: March 2011

A Gram‐positive, moderately halophilic Streptomyces strain, designated JAJ06, was isolated from saltpan soil collected at Tuticorin, India, and subjected to a polyphasic characterization with an insight into their biotechnological importance. Growth characteristics and antimicrobial com‐pound producing capabilities of Streptomyces sp. JAJ06 were observed on various International Streptomyces Project (ISP) media and production media. Optimum growth was observed on modified ISP 4 medium supplemented with 4% NaCl (w/v) at 29 °C incubated for 7 days. Maximum antibacterial compound production with good mycelial growth was observed on starch‐yeast extract‐peptone medium prepared with seawater (90%, v/v). The 16S rRNA gene based phylogenetic affiliation was determined by using various bioinformatics tools and the strain was identified as Streptomyces sp. JAJ06 with 99% sequence similarity to Streptomyces radiopugnansT. An antimicrobial assay of antimicrobial compound derived from Streptomyces sp. JAJ06 against a set of bacteria and a yeast strain revealed antimicrobial activity with significant minimal inhibitory concentrations. The potential antimicrobial compound produced by Streptomyces sp. JAJ06 was found to be polyketide in nature. Cloning and sequence analysis of 613‐bp fragment of ketosynthase gene from the type‐II polyketide operon revealed that Streptomyces sp. JAJ06 has the KSα gene with 91% sequence similarity to the type II polyketide synthase gene of Streptomyces peucetius. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Starvation survival of Candida albicans in various water microcosms
Authors: Chaieb Kamel , Kouidhi Bochra , Zmantar Tarek , Mahdouani Kacem , Bakhrouf Amina
Published: March 2011

Candida is a major Human pathogen causing a variety of infections and can survive for extended period of time in aquatic environment including marine and fresh water. In this study we compared a colorimetric XTT assay to colony forming units (CFU) count to evaluate the survival potential of Candida albicans incubated in water microcosms. Our results showed that cells maintain cultivability within a long period followed by a decline in cultivability and a drop of plate counts to less than 20 cell ml–1 after 150 days in tap water, 190 days in rain water and 200 days in seawater. In addition we noted that 10% of cells viability was reached after 150 days in seawater, 180 days in rain water and 210 days in tap water. Molecular method confirms the persistence of C. albicans cells in water during long time starvation period. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of a hydrophobin of the ascomycete Paecilomyces farinosus
Authors: Lunkenbein Stefan , Takenberg Meike , Nimtz Manfred , Berger Ralf G.
Published: March 2011

The entomopathogenic ascomycete Paecilomyces farinosus (alternative name Isaria farinosa) synthesized a hydrophobin, irrespective of being grown in submerged or surface culture. The protein was extracted using trifluoroacetic acid and purified using preparative HPLC and SDS‐PAGE. Partial sequences were obtained using ESI‐MS/MS. The peptides were used as a start to apply a ‘template switching oligo' protocol to elucidate the complete open reading frame of P. farinosus hydrophobin 1 (pfah1). The deduced protein sequence comprised 107 amino acids (10.7 kDa) including a 16 amino acid long hydrophobic signal peptide, showed a calculated pI of 4.56, and was interrupted by one intron. Phylogenetic analyses revealed relationships to hydrophobins of the ascomycetes Magnaporthe grisea and Metarhizium anisopliae. Based on solubility, hydropathy pattern and phylogeny PfaH1 was assigned to the class Ia hydrophobins. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Caenorhabditis elegans as a model for studying Cronobacter sakazakii ATCC BAA‐894 pathogenesis
Authors: Sivamaruthi Bhagavathi Sundaram , Ganguli Abhijit , Kumar Mukesh , Bhaviya Sheker , Pandian Shunmugiah Karutha , Balamurugan Krishnaswamy
Published: March 2011

Cronobacter sakazakii is occasionally associated with food‐borne illness seen in neonates and infants with weakened immune system. It can cause meningitis, local necrotizing enterocolitis and systemic bacteremia leading to infant mortality rates upto 33–80%. With the aim of investigating whether C. sakazakii is also a pathogen of the model organism C. elegans, we have performed killing assays and monitored the mortality of host fed with pathogen. C. elegans fed with C. sakazakii die over the course of several days, as a consequence of an accumulation of bacteria in the host intestine. Further, the rate of C. sakazakii mediated infection in C. elegans depends on the accumulation of the bacterial load inside the host. C. sakazakii killed C. elegans with an LT50 (time for half to die) of 134 ± 2.8 h in liquid assay conditions, whereas the mortality of C. elegans infected with C. sakazakii was less pronounced during solid assays. We found that 24 h of C. sakazakii infection is enough to cause gametogenesis defects and increased cell damage in intestinal tract of host. To monitor the immune regulations during C. sakazakii infection in C. elegans at molecular level, total RNA was isolated and few candidate genes (lys‐7, clec‐60 and clec‐87) were kinetically analyzed by using the semi‐quantitative RT‐PCR. The level of expression of lys‐7, clec‐60 and clec‐87 mRNAs isolated from C. elegans infected with C. sakazakii was significantly higher when compared to C. elegans exposed to E. coli OP50 control. This is the first report in which physiological changes and an induction of host immunity mediated antimicrobial genes by C. sakazakii are shown in C. elegans. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of OXA‐type carbapenemases and integrons among carbapenem‐resistant Acinetobactor baumannii in a Teaching Hospital in China
Authors: Hu Qiaojuan , Hu Zhidong , Li Jing , Tian Bin , Xu Hairu , Li Jin
Published: March 2011

The increasing trend of carbapenem‐resistance (CR) and multi‐drug resistance (MDR) in A. baumannii worldwide has limited the therapeutic effectiveness of antibiotic therapy. The study was conducted to determine the prevalence of carbapenemases and integrons among the isolates of imipenem‐resistant A. baumannii (IRAB). A total of 71 non‐repetitive imipenem‐ resistant A. baumannii isolates were collected and tested for susceptibility to 17 antimicrobials. The modified Hodge test and EDTA‐disc synergy test were performed for the screening of carbapenemases and metallo‐β ‐lactamases (MBLs) production, respectively. Isolates were then subjected to multiplex‐PCR targeting genes encoding for OXA‐type carbapenemase, MBLs and integrases. Random amplified polymorphic DNA (RAPD) genotyping was performed to assess genetic relatedness. All isolates exhibited multi‐drug resistant phenotype. Colistin was the most active antimicrobial agent tested. Seventy‐one isolates (100%) demonstrated positive in the modified Hodge test. Thirty‐nine isolates showed positive in the EDTA‐disc synergy test, however, no MBL genes were detected. All strains possessed a blaOXA‐51‐like gene. The co‐exis‐tence of blaOXA‐51‐like/blaOXA‐23‐like/intI1, blaOXA‐51‐like/blaOXA‐23‐like, blaOXA‐51‐like/blaOXA‐24‐like was detected in 91.6% (n = 65), 5.6% (n = 4), 2.8% (n = 2), respectively. Analysis of the genetic con‐text of blaOXA‐23 showed the presence of ISAba1 upstream of blaOXA‐23. No ISAba1 was detected upstream of blaOXA‐51. Two different gene cassettes were found in these strains, and a high prevalence of aacA4, aadA1 and catB8 genes was observed. RAPD of 71 isolates showed 7 genotypes. The strains were mainly recovered from patients in intensive care unit, neurosurgery and department of respiratory disease. These ﬁndings show that multi‐drug resistance in A. baumannii is a common problem. This study also shows a high distribution of blaOXA‐23‐like and intI1 genes in imipenem‐resistant A. baumannii isolates. The clonal spread played an important role in the increase of OXA‐23 producing IRABs in the hospital environment. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Composition and authentication of virgin olive oil from French PDO regions by chemometric treatment of Raman spectra
Authors: Korifi R. , Le Dréau Y. , Molinet J. , Artaud J. , Dupuy N.
Published: March 2011

The search for the origin and the authentication of virgin olive oils (VOOs) is a problem of topical interest. VOOs with the protected designation of origin (PDO) label can be subject to fraudulent practices owing to high price commanded by these oils. This work evaluates the capability of confocal Raman spectroscopy combined with chemometric treatments for determining the fatty acid and triacylglycerol (TAG) compositions of VOOs and for authenticating the PDO labels of six French VOOs. Fatty acid and TAG compositions were determined by chemometric analysis of the Raman spectra using the partial least square (PLS) algorithms. Predictions have provided good results on the high percentage compounds, but for the fatty acids at very low percentages the predicted results were very poor. The PLS‐discriminant analysis model on Raman spectra was able to correctly classify 92.3% of French PDOs and 100% of PDO samples made with only one principal cultivar. However, it was noticeable that the first regression coefficient (which explains the greatest amount of variation of the data) obtained for each PDO could be compared one by one with the first regression coefficient obtained for the quantitative analysis of fatty acids and TAGs. The first regression coefficients obtained for PDOs differed widely from each other. Their study allowed interpreting the PDOs according to their chemical composition. This work confirms that fatty acid and TAG percentages may be used to authenticate French VOOs into PDOs. Copyright © 2011 John Wiley & Sons, Ltd.
Impact of matrix properties on the survival of freeze‐dried bacteria
Authors: Wessman Per , Mahlin Denny , Akhtar Sultan , Rubino Stefano , Leifer Klaus , Kessler Vadim , Håkansson Sebastian
Published: March 2011

BACKGROUND: Disaccharides are, in general, the first choice as formulation compounds when freeze‐drying microorganisms. Although polysaccharides and other biopolymers are considered too large to stabilise and interact with cell components in the same beneficial way as disaccharides, polymers have been reported to support cell survival. In the present study we compare the efficiency of sucrose and the polymers Ficoll, hydroxyethylcellulose, hydroxypropylmethylcellulose and polyvinylalcohol to support the survival of three bacterial strains during freeze drying. The initial osmotic conditions were adjusted to be similar for all formulations. Formulation characterisation was used to interpret the impact that different compound properties had on cell survival.

RESULTS: Despite differences in molecular size, both sucrose and the sucrose‐based polymer Ficoll supported cell survival after freeze drying equally well. All formulations became amorphous upon dehydration. Scanning electron microscopy and X‐ray diffraction data showed that the discerned differences in structure of the dry formulations had little impact on the survival rates. The capability of the polymers to support cell survival correlated with the surface activity of the polymers in a similar way for all investigated bacterial strains.

CONCLUSION: Polymer‐based formulations can support cell survival as effectively as disaccharides if formulation properties of importance for maintaining cell viability are identified and controlled. Copyright © 2011 Society of Chemical Industry
Mechanical α‐relaxations and stickiness of milk solids/maltodextrin systems around glass transition
Authors: Silalai Nattiga , Roos Yrjö H
Published: March 2011

BACKGROUND: Stickiness correlates with changes in mechanical α‐relaxation properties and often results from glass transition and plasticisation of amorphous food components. In this study, milk solids with maltodextrins with different dextrose equivalents (DE9 and DE17) were analysed for glass transition (Tg), α‐relaxation (Tα) and sticky point (SPT) temperatures using differential scanning calorimetry, dynamic mechanical analysis and a sticky point test respectively.

RESULTS: At the same maltodextrin contents, Tg and Tα were lower for milk solids with the higher‐DE maltodextrin. Increasing maltodextrin contents gave Tg, Tα and SPT at higher temperatures, and the magnitudes of α‐relaxations with high maltodextrin (DE9 and DE17) contents were less pronounced.

CONCLUSION: Stickiness was governed by glass transition and affected by skim milk/maltodextrin composition. Stickiness was reduced with increasing maltodextrin content as a result of maltodextrin miscibility with skim milk solids, particularly lactose, which changed the relaxation behaviour above the glass transition. The mixes of milk solids with low‐DE maltodextrin may show improved dehydration characteristics and powder stability resulting from increased Tg, Tα and SPT. Copyright © 2011 Society of Chemical Industry
Semi‐quantitative expression of tissue inhibitor of matrix metalloproteinase‐2 in cancer of uterine cervix
Authors: Wu Yao‐Chung , Wang Po‐Hui , Tsai Amy , Yang Shun‐Fa , Chen Shiuan‐Chih
Published: March 2011

Background and Objective

Because matrix metalloproteinase‐2 (MMP‐2) is associated with tumor progression and tissue inhibitor of MMP‐2 (TIMP‐2) selectively inhibits MMP‐2, we investigate the implication of TIMP‐2 in carcinogenesis of uterine cervix.

Methods

Twenty‐six cervical cancer tissues and their normal counterparts were collected to evaluate semi‐quantitative mRNA expression of TIMP‐2. Eighty‐two cervical cancer, 26 high‐grade and 26 low‐grade dysplasia, and 26 normal tissues were collected to construct tissue microarrays for immunohistochemical study. We evaluated TIMP‐2 immunoreactivity using H scores in cervical carcinogenesis. Semi‐quantitative expression of MMP‐2 was also detected for comparison.

Results

Cervical cancer tissues exhibited statistically lower semi‐quantitative TIMP‐2 (P = 0.028) or higher MMP‐2 (P = 0.036) mRNA expression than their normal counterparts. None of cervical cancer tissues exerted elevated TIMP‐2 and reduced MMP‐2 mRNA expression simultaneously. Cancer tissues have significantly lower TIMP‐2 or higher MMP‐2 H scores than high‐grade and low‐grade dysplasia or normal tissues of uterine cervix.

Conclusions

Low expression of TIMP‐2 or high expression of MMP‐2 is semi‐quantitatively demonstrated in cancer of uterine cervix. TIMP‐2 is implicated in cervical carcinogenesis. J. Surg. Oncol. 2011;104:210–215. © 2011 Wiley‐Liss, Inc.
Brief cognitive–behavioral intervention for maternal depression and trauma in the neonatal intensive care unit: A pilot study
Authors: Bernard Rebecca S. , Williams Sharon E. , Storfer‐Isser Amy , Rhine William , Horwitz Sarah McCue , Koopman Cheryl , Shaw Richard J.
Published: March 2011

Parents of hospitalized premature infants are at risk for developing psychological symptoms. This randomized controlled pilot study examined the effectiveness of a brief cognitive–behavioral intervention in reducing traumatic and depressive symptoms in mothers 1 month after their infant's discharge from the hospital. Fifty‐six mothers were randomly assigned to the intervention or control group. Results showed that mothers experienced high levels of symptoms initially and at follow‐up. At follow‐up, there was a trend for mothers in the intervention group to report lower levels of depression (p = .06; Cohen's f = .318), but levels of traumatic symptoms were similar for both groups. Brief psychological interventions may reduce depressive symptoms in this population. Estimates of the effect sizes can be used to inform future intervention studies.
What is the role of the receptor for advanced glycation end products–ligand axis in liver injury?
Authors: Basta Giuseppina , Navarra Teresa , De Simone Paolo , Del Turco Serena , Gastaldelli Amalia , Filipponi Franco
Published: March 2011

Multiligand receptor for advanced glycation end products (RAGE) is expressed in a wide variety of tissues, including the liver. Interactions with its ligands lead to cellular activation and thus prolonged inflammation and apoptosis. RAGE also exists in a soluble, truncated isoform called soluble RAGE, which has the same ligand-binding specificity as membrane-RAGE; acting as decoy, it can contribute to the removal/neutralization of circulating ligands and the resultant reduction of signaling pathway activation. Experimental and clinical studies have highlighted the idea that the RAGE-ligand axis is involved in the development of liver fibrosis, inflammation, and regeneration after a massive injury and in the setting of liver transplantation. The involvement of the RAGE-ligand axis in vascular disease, diabetes, cancer, and neurodegeneration is well established, but it still needs to be clarified in the setting of liver diseases. We present a review of the recent literature on this receptor in surgical and clinical settings involving the liver, and we highlight the open issues and possible directions of future research. Liver Transpl 17:633-640, 2011. © 2011 AASLD.
Mixed hepatocellular cholangiocarcinoma and intrahepatic cholangiocarcinoma in patients undergoing transplantation for hepatocellular carcinoma
Authors: Sapisochin Gonzalo , Fidelman Nicholas , Roberts John P. , Yao Francis Y.
Published: March 2011

Mixed hepatocellular cholangiocarcinoma (HCC-CC) and intrahepatic cholangiocarcinoma (I-CC) are increasingly being reported in patients with cirrhosis. The aims of this study were (1) to evaluate the incidence, imaging features, and posttransplant outcomes for patients who underwent transplantation for hepatocellular carcinoma (HCC) and were found to have HCC-CC or I-CC in the explant and (2) to compare the outcomes of these patients with those of controls with HCC who were matched (1:3) by the tumor size and the number of nodules in the explant. In the explant specimens of 10 of 302 patients (3.3%) who underwent liver transplantation (LT) for HCC, mixed HCC-CC or I-CC was identified. There were 4 additional incidental cases of HCC-CC. After a median follow-up period of 32 months, 8 of the 14 patients (57%) suffered from tumor recurrence, and the median disease-free survival time was 8 months. The cumulative risk of tumor recurrence was 40% and 70% at 1 and 5 years, respectively, for these 14 patients. When the 4 incidental cases were excluded, the study group with HCC-CC or I-CC (n = 10) had a significantly lower incidence of well-differentiated tumors (11.1% versus 43.3%, P < 0.02) and a higher rate of recurrence (60% versus 16.7%, P = 0.008) in comparison with the control group of patients with HCC (n = 30). The 1- and 5-year cumulative risks of tumor recurrence were 42% and 65%, respectively, in the study group and 10% and 17%, respectively, in the control group (P < 0.002). The actuarial 1- and 5-year patient survival rates without recurrence were also significantly lower in the study group (79% and 32% in the study group and 90% and 62% in the control group, P < 0.03). Dynamic contrast-enhanced computed tomography or magnetic resonance imaging showed progressive contrast enhancement throughout the arterial and portal venous phases without washout in 8 of the 10 patients. In conclusion, HCC-CC and I-CC are associated with a poor prognosis and a high rate of tumor recurrence after LT, and both tumors exhibit radiographic features that are distinct from those observed with HCC. Liver Transpl 17:934–942, 2011. © 2011 AASLD.
Nanostructured surface pre‐treatment based on self‐assembled molecules for corrosion protection of Alclad 7475‐T761 aluminum alloy
Authors: de Souza S. , Yoshikawa D. S. , Izaltino W. A. S. , Assis S. L. , Costa I.
Published: March 2011

Coatings based on self‐assembled molecules (SAMs) for corrosion protection of aircraft aluminum alloys have been studied to evaluate their potentialities as replacements to yellow chromate conversion coatings (CCC), due to the toxicity of these leading to environmental problems. In this work, the influence of alkane diphosphonates self‐assembling molecules on the corrosion resistance of the AA7475‐T761 cladded with AA7072 was investigated by electrochemical impedance spectroscopy and cathodic and anodic polarization curves, in naturally aerated 0.5 mol/L Na2SO4 aqueous solution, with pH adjusted to 4. Corrosion accelerated experiments (salt spray tests) were also carried out to examine the resistance of the SAM treated samples against corrosion. The results suggested that the development of boehmite (aluminum oxide) layer with incorporation of SAM was beneficial to the corrosion resistance of the tested aluminum alloy. Samples surface treated with SAM or aluminum oxide/SAM (without and with subsequent polyester layer) showed better corrosion resistance results than samples with CCC, indicating that this last type of coating containing hexavalent chromium could be replaced by the environmentally friendly pre‐treatment corresponding to boehmite growth followed by incorporation of SAM.
Stability of the passive state of Zr–Nb crystalline alloys
Authors: Rosalbino F. , Macciò D. , Saccone A. , Angelini E. , Delfino S.
Published: March 2011

Stability of the passive state was assessed for pure Zr and four Zr–Nb alloys (2.5, 5.0, 10.0, 25.0 at.% Nb) after 24 h exposure to naturally aerated 3.5% NaCl solution (pH = 6). Open circuit potential values indicated that all the Zr–Nb alloys studied and the pure Zr undergo spontaneous passivation due to spontaneously formed oxide film passivating the metallic surface. It also indicated that the addition of increasing Nb contents to pure Zr seems to improve the protection characteristics of its spontaneous oxides. Potentiodynamic polarization curves showed an increase of the breakdown potential and the extent of the passive range following an increased niobium amount in the alloy. This leads to the conclusion that a progressive increase of niobium content positively affects the localized corrosion behaviour of the Zr–Nb alloys by enhancing the electrochemical stability of the passive film. Electrochemical impedance spectroscopy (EIS) studies showed high impedance values for all the samples, and its increase on increased niobium content in the alloy indicated an improvement in the corrosion resistance of the spontaneous oxide film. The fit obtained suggests a single passive film present on the metal surface, with resistance improving with the increase of niobium amount in the alloy. All these electrochemical results show the beneficial effect of increasing niobium contents on the passive state stability of the Zr–Nb alloys.
Influence of heat treatments at 475 and 400 °C on the pitting corrosion resistance and sensitization of UNS S32750 and UNS S32760 superduplex stainless steels
Authors: Tavares S. S. M. , Loureiro A. , Pardal J. M. , Montenegro T. R. , da Costa V. C.
Published: March 2011

Some precipitation reactions of superduplex stainless steels (SDSS) can improve hardness, yield, and ultimate strength, but with substantial decrease of corrosion resistance. One of these reactions is the spinodal decomposition of ferrite into Cr‐rich fine precipitates (α′) and Cr‐depleted matrix during low temperature aging. In this work, the effect of the α′ precipitation on the pitting corrosion resistance was investigated. The results showed that short duration heat treatments at 475 °C do not decrease the pitting corrosion resistance, but increase the hardness of UNS S32750 and S32760 SDSS. The limits of heat treatment duration for both steels were determined.
Corrosion resistance of environment‐friendly sealing layer for Zn‐coated sintered NdFeB magnet
Authors: Liu F. , Li Q. , Yang X. K. , Dai Y. , Luo F. , Wang S. Y. , Zhang H. X.
Published: March 2011

In this paper, a protective sealed Zn coating (SZC) was prepared on sintered NdFeB magnet by the combination of electrodeposition and sol–gel method. The unsealed Zn coating (UZC) was also studied for a comparison. The surface morphology of UZC and the cross‐section morphology of SZC were investigated using scanning election microscope (SEM). The microstructure of Zn coating and structure of sealing layer were studied by X‐ray diffraction (XRD) and Fourier transform infrared (FT‐IR) spectrum, respectively. The corrosion characteristics of SZC and UZC in neutral 3.5 wt% NaCl solution were evaluated using electrochemical measurements including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization test, indicating that the anticorrosive properties of SZC coated specimens increased 20 times compared with that of UZC coated specimens. In order to further investigate the anticorrosive properties of SZC, a long‐term immersion test was carried out in neutral 3.5 wt% NaCl solution using EIS. The results of long‐term corrosion test showed that the SZC could provide long‐term protection in neutral 3.5 wt% NaCl solution for NdFeB magnet.
Corrosion behaviour of a new Ti‐6Al‐2Nb‐1Ta alloy in various solutions
Authors: Pirvu C. , Demetrescu I. , Drob P. , Vasilescu E. , Ivanescu S. , Mindroiu M. , Vasilescu C. , Drob S. I.
Published: March 2011

A new Ti‐6Al‐2Nb‐1Ta alloy was obtained for to satisfy the mechanical and anticorrosion requirements in neutral corrosive environment. The corrosion behaviour of this new Ti‐6Al‐2Nb‐1Ta alloy in 0.1 M Na2SO4, 3% NaCl solutions and synthetic sea water was studied in this paper, using potentiodynamic and linear polarisation method, electrochemical impedance spectroscopy (EIS) and monitoring of the open circuit potentials. The structure of the alloy represents an α + β uniform structure with un‐oriented grains. From the potentiodynamic polarisation curves it resulted that the studied alloy is self‐passivated in all three solutions having a very good and very easy tendency to passivation. The most favourable values of the electrochemical parameters were registered in 0.1 M Na2SO4 solution due to its reduced corrosivity. EIS measurements proved the improvement of the passive layer resistance with the immersion time. An electric equivalent circuit with two time constants was fitted. The values of the polarisation resistances showed very good protective capacities which improved in time. The open circuit potentials have the general tendency to ennoble in time, suggesting the thickening of the passive films and the increase of their protective capacities.
Improving Polymer Nanofiber Quality Using a Modified Co‐axial Electrospinning Process
Authors: Yu Deng‐Guang , Branford‐White Christopher , Bligh S. W. Annie , White Kenneth , Chatterton Nicholas P. , Zhu Li‐Min
Published: March 2011

Based on a modified coaxial electrospinning process and suitable selection of solvent mixtures as sheath fluid, a new strategy is presented for systematically improving polymer nanofiber quality. A concentric spinneret with an indented inner capillary is designed for the modified coaxial electrospinning. With a solution of 12% w/v PVP K60 in ethanol as the core electrospinning fluid, six solvents are used as sheath fluids to investigate the impact of solvent properties on the resultant PVP nanofiber quality. The PVP nanofiber quality is closely related to solvent physical‐chemical properties. High quality PVP nanofibers of average diameter 130 ±10 nm with homogeneous structures and smooth surfaces are created using a solvent mixture of acetone, ethanol and DMAc in the ratio of 3:1:1(v/v/v).

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Determination of minimal clinically important change in early and advanced Parkinson's disease
Authors: Hauser Robert A. , Auinger Peggy ,   on behalf of the Parkinson Study Group
Published: March 2011

Two common primary efficacy outcome measures in Parkinson's disease (PD) are change in Unified Parkinson's Disease Rating Scale (UPDRS) scores in early PD and change in “off” time in patients with motor fluctuations. Defining the minimal clinically important change (MCIC) in these outcome measures is important to interpret the clinical relevance of changes observed in clinical trials and other situations. We analyzed data from 2 multicenter, placebo‐controlled, randomized clinical trials of rasagiline; TEMPO studied 404 early PD subjects, and PRESTO studied 472 levodopa‐treated subjects with motor fluctuations. An anchor‐based approach using clinical global impression of improvement (CGI‐I) was used to determine MCIC for UPDRS scores and daily “off” time. MCIC was defined as mean change in actively treated subjects rated minimally improved on CGI‐I. Receiver operating characteristic (ROC) curves defined optimal cutoffs discriminating between changed and unchanged subjects. MCIC for improvement in total UPDRS score (parts I–III) in early PD was determined to be −3.5 points based on mean scores and −3.0 points based on ROC curves. In addition, we found an MCIC for reduction in “off” time of 1.0 hours as defined by mean reduction in “off” time in active treated subjects self‐rated as minimally improved on CGI‐I minus mean reduction in “off” time in placebo‐treated subjects self‐rated as unchanged (1.9–0.9 hours). We hypothesize that many methodological factors can influence determination of the MCIC, and a range of values is likely to emerge from multiple studies. © 2011 Movement Disorder Society
Genotoxicity of dietary, environmental and therapeutic topoisomerase II poisons is uniformly correlated to prolongation of enzyme DNA residence
Authors: Kalfalah Faiza M. , Mielke Christian , Christensen Morten O. , Baechler Simone , Marko Doris , Boege Fritz
Published: March 2011

Scope: DNA damage by genistein and etoposide is determined by the half‐life of topoisomerase II–DNA linkage induced [Bandele O. J. and Osheroff N., Biochemistry 2008, 47, 11900]. Here, we test whether this applies generally to dietary flavonoids and therapeutic compounds enhancing topoisomerase II–DNA cleavage (Topo II poisons).

Methods and results: We compared the impact of Topo II poisons on DNA residence kinetics of biofluorescent human topoisomerases IIα and IIβ (delineating duration of the DNA‐linked enzyme state) with histone 2AX phosphorylation (delineating DNA damage response). Prolongation of topoisomerase II–DNA residence was correlated to DNA damage response, whereas topoisomerase II–DNA linkage was not. Catalytic inhibitors stabilizing topoisomerase II on unbroken DNA also exhibited such a correlation, albeit at a lower level of DNA damage response. Therapeutic Topo II poisons had stronger and more durable effects on enzyme II DNA residence and elicited stronger DNA damage responses than natural or dietary ones.

Conclusions: Topoisomerase II‐mediated DNA damage appears related to the prolongation of enzyme DNA residence more than to enzyme–DNA cleavage. Due to this reason, genistein and other tested natural and dietary Topo II poisons have a much lower genotoxic potential than therapeutic ones under the conditions of equal topoisomerase II–DNA linkage.
Signal‐to‐noise optimization for sodium MRI of the human knee at 4.7 Tesla using steady state
Authors: Watts Alexander , Stobbe Robert W. , Beaulieu Christian
Published: March 2011

Sodium magnetic resonance imaging of knee cartilage is a possible diagnostic method for osteoarthritis, but low signal‐to‐noise ratio yields low spatial resolution images and long scan times. For a given scan time, a steady‐state approach with reduced repetition time and increased averaging may improve signal‐to‐noise ratio and hence attainable resolution. However, repetition time reduction results in increased power deposition, which must be offset with increased radiofrequency pulse length and/or reduced flip angle to maintain an acceptable specific absorption rate. Simulations varying flip angle, repetition time, and radiofrequency pulse length were performed for constant power deposition corresponding to ∼6 W/kg over the human knee at 4.7T. For 10% agar, simulation closely matched experiment. For healthy human knee cartilage, a 37% increase in signal‐to‐noise ratio was predicted for steady‐state over “fully relaxed” parameters while a 29% ± 4% increase was determined experimentally (n = 10). Partial volume of cartilage with synovial fluid, inaccurate relaxation parameters used in simulation, and/or quadrupolar splitting may be responsible for this disagreement. Excellent quality sodium images of the human knee were produced in 9 mins at 4.7T using the signal‐to‐noise ratio enhancing steady‐state technique. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Changes in intracellular water diffusion and energetic metabolism in response to ischemia in perfused C6 rat glioma cells
Authors: Harkins Kevin D. , Galons Jean‐Philippe , Divijak Joseph L. , Trouard Theodore P.
Published: March 2011

This work reports results of experiments in hollow‐fiber bioreactor C6 glioma cell cultures where the apparent diffusion coefficient (ADC) of intracellular water (iADC) was measured at diffusion times between 0.83 and 40 ms. The experiments were carried out before and after the onset of permanent ischemia. The changes in iADC following ischemia were dependent on the diffusion time employed in the experiment. An ischemia‐induced decrease in the iADC was measured at short diffusion times, while at long diffusion times the iADC increased. Decreases in the iADC measured at short diffusion times are interpreted to be a result of a decrease in the intrinsic diffusivity of intracellular water due to energy failure. Increases in iADC measured at long diffusion times, are interpreted to result from cell swelling. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
On the undersampling strategies to accelerate time‐resolved 3D imaging using k‐t‐GRAPPA
Authors: Jung Bernd , Stalder Aurélien F. , Bauer Simon , Markl Michael
Published: March 2011

The purpose of this study was to explore how to optimally undersample and reconstruct time‐resolved 3D data using a k‐t‐space‐based GRAPPA technique. The performance of different reconstruction strategies was evaluated using data sets with different ratios of phase (Ny) and partition (Nz) encoding lines (Ny × Nz = 64–128 × 40–64) acquired in a moving phantom. Image reconstruction was performed for different kernel configurations and different reduction factors (R = 5, 6, 8, and 10) and was evaluated using regional error quantification and SNR analysis. To analyze the temporal fidelity of the different kernel configurations in vivo, time‐resolved 3D phase contrast data were acquired in the thoracic aorta of two healthy volunteers. Results demonstrated that kernel configurations with a small kernel extension yielded superior results especially for more asymmetric data matrices as typically used in clinical applications. The application of k‐t‐GRAPPA to in vivo data demonstrated the feasibility of undersampling of time‐resolved 3D phase contrast data set with a nominal reduction factors of up to Rnet = 8, while maintaining the temporal fidelity of the measured velocity field. Extended GRAPPA‐based parallel imaging with optimized multidimensional reconstruction kernels has the potential to substantially accelerate data acquisitions in time‐resolved 3D MRI. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Highly efficient whole‐heart imaging using radial phase encoding‐phase ordering with automatic window selection
Authors: Kolbitsch Christoph , Prieto Claudia , Smink Jouke , Schaeffter Tobias
Published: March 2011

Three dimensional (3D) whole‐heart magnetic resonance imaging (MRI) has become an important imaging modality to assess cardiovascular diseases. The main challenges for 3D whole‐heart MRI are long acquisition times, required to achieve high spatial resolution, and image artefacts due to physiological motion. Here we propose to overcome these problems by the combination of an interleaved Radial Phase Encoding trajectory and the Phase Ordering with Automatic Window Selection method. This Radial Phase Encoding‐Phase Ordering with Automatic Window Selection approach yields fast 3D whole‐heart imaging with a high isotropic resolution and high navigator efficiency even for extremely irregular breathing. Numerical simulations were performed and Radial Phase Encoding‐Phase Ordering with Automatic Window Selection was implemented on a clinical scanner. A comparison between the proposed method and a respiratory gated 3D Cartesian approach was carried out. Radial Phase Encoding‐Phase Ordering with Automatic Window Selection leads to a better depiction of coronary arteries and an increase in navigator efficiency. In addition to a high resolution image, this method also provides dynamic respiratory information without an increase in scan time. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Clinically constrained optimization of flexTPI acquisition parameters for the tissue sodium concentration bioscale
Authors: Atkinson Ian C. , Lu Aiming , Thulborn Keith R.
Published: March 2011

The rapid transverse relaxation of the sodium magnetic resonance signal during spatial encoding causes a loss of image resolution, an effect known as T2‐blurring. Conventional wisdom suggests that spatial resolution is maximized by keeping the readout duration as short as possible to minimize T2‐blurring. Flexible twisted projection imaging performed with an ultrashort echo time, relative to T2, and a long repetition time, relative to T1, has been shown to be effective for quantitative sodium magnetic resonance imaging. A minimized readout duration requires a very large number of projections and, consequentially, results in an impractically long total acquisition time to meet these conditions. When the total acquisition time is limited to a clinically practical duration (e.g., 10 min), the optimal parameters for maximal spatial resolution of a flexible twisted projection imaging acquisition do not correspond to the shortest possible readout. Simulation and experimental results for resolution optimized acquisition parameters of quantitative sodium flexible twisted projection imaging of parenchyma and cerebrospinal fluid are presented for the human brain at 9.4 and 3.0T. The effect of signal loss during data collection on sodium quantification bias and image signal‐to‐noise ratio are discussed. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Real‐time functional MRI using pseudo‐continuous arterial spin labeling
Authors: Hernandez‐Garcia Luis , Jahanian Hesamoddin , Greenwald Mark K. , Zubieta Jon‐Kar , Peltier Scott J.
Published: March 2011

The first implementation of real‐time acquisition and analysis of arterial spin labeling‐based functional magnetic resonance imaging time series is presented in this article. The implementation uses a pseudo‐continuous labeling scheme followed by a spiral k‐space acquisition trajectory. Real‐time reconstruction of the images, preprocessing, and regression analysis of the functional magnetic resonance imaging data were implemented on a laptop computer interfaced with the MRI scanner. The method allows the user to track the current raw data, subtraction images, and the cumulative t‐statistic map overlaid on a cumulative subtraction image. The user is also able to track the time course of individual time courses and interactively selects a region of interest as a nuisance covariate. The pulse sequence allows the user to adjust acquisition and labeling parameters while observing their effect on the image within two successive pulse repetition times. This method is demonstrated by two functional imaging experiments: a simultaneous finger‐tapping and visual stimulation paradigm, and a bimanual finger‐tapping task. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Longitudinal evaluation of intramyocellular lipids (IMCLs) in tibialis anterior muscle of ob/ob and ob/+ control mice using a cryogenic surface coil at 9.4 T
Authors: Ye Qiong , Danzer Carsten Friedrich , Fuchs Alexander , Krek Wilhelm , Mueggler Thomas , Baltes Christof , Rudin Markus
Published: March 2011

Insulin resistance is a central feature of type II diabetes and is associated with alterations in skeletal muscle lipid metabolism, which manifest themselves, in part, in increased intramyocellular lipid (IMCL) accumulation. The objective of this study was to assess noninvasively the levels of IMCL longitudinally in the tibialis anterior muscle of Lepob/Lepob (ob/ob) mice, a genetic model of obesity and mild diabetes, and Lepob/+ (ob/ + ) heterozygous control animals, using 1H MRS at 9.4 T. The use of a cryogenic surface coil transceiver leads to significant increases in sensitivity. Method implementation included the assessment of the reproducibility and spatial heterogeneity of the IMCL signal and the determination of T2 relaxation times, as IMCL levels were expressed relative to the total creatine signal, and therefore the signal ratios had to be corrected for differences in T2 relaxation. IMCL levels were found to be significantly higher in ob/ob mice relative to ob/+ heterozygous control mice that do not develop disease. An increase in IMCL levels was observed for ob/ob mice until weeks 16/17; after this time point, IMCL levels decreased again, reaching final levels that were slightly higher than the initial values. These noninvasively detected alterations in skeletal muscle lipid metabolism in ob/ob mice were accompanied by a transient increase in plasma insulin concentrations. This study indicates that IMCL may be reliably assessed in mouse tibialis anterior muscle using a cryogenic surface coil, implying that 1H MRS at 9.4 T represents a useful technology for the noninvasive measurement of changes in lipid metabolism in the skeletal muscle that accompany obesity. Copyright © 2011 John Wiley & Sons, Ltd.
Successful bone marrow transplantation in a pediatric patient with chronic myeloid leukemia from a HLA‐identical sibling selected by preimplantation HLA testing
Authors: Goussetis Evgenios , Constantoulakis Pantelis , Kitra Vasiliki , Peristeri Ioulia , Mastrominas Minas , Baka Margarita , Papadimitropoulos Miltiadis , Karamolegos Christos , Paisiou Anna , Vasilatou‐Kosmidis Helen , Graphakos Stelios
Published: March 2011

We report successful bone marrow transplantation in an 11‐year‐old male with chronic myeloid leukemia from his HLA‐identical sibling selected by preimplantation HLA testing. Because collection of cord blood failed, the transplantation was performed when the donor reached the age of 19 months, and sufficient bone marrow could be harvested safely. The patient was BCR/ABL negative at the time of transplantation after complete molecular response to imatinib. Currently, 16 months post‐transplantation he is well and in complete molecular remission. This report describes preimplantation HLA‐genotyping to deliver a matched sibling donor for successful transplantation of a malignant disorder. Pediatr Blood Cancer 2011; 57: 345–347. © 2011 Wiley‐Liss, Inc.
Piperacillin/tazobactam versus cefozopran for the empirical treatment of pediatric cancer patients with febrile neutropenia
Authors: Ichikawa Mizuho , Suzuki Daisuke , Ohshima Junjiro , Cho Yuko , Kaneda Makoto , Iguchi Akihiro , Ariga Tadashi
Published: March 2011

Background

The aim of this study was to evaluate the efficacy and safety of piperacillin/tazobactam (PIP/TAZO) and cefozopran (CZOP) monotherapy in pediatric cancer patients with febrile neutropenia (FN).

Procedure

A total of 119 febrile episodes in 49 neutropenic pediatric cancer patients (20 females and 29 males) with a median age of 6.8 years (range, 0.3–18.4 years) received randomized treatment either with PIP/TAZO 125 mg/kg every 8 hr or CZOP 25 mg/kg every 6 hr. Clinical response was determined at completion of therapy. Durations of fever and neutropenia, the need for modification of the therapy, and mortality rates were compared between the two groups.

Results

The frequency of success without modification of treatment was not significantly different between PIP/TAZO (59.6%) and CZOP (53.2%). Durations of fever and antibiotic therapy did not differ between the treatment groups, and no major side effects were observed in either group.

Conclusions

PIP/TAZO and CZOP monotherapy were both effective and safe for the initial empirical treatment of pediatric cancer patients with FN. Pediatr Blood Cancer 2011; 57: 1159–1162. © 2011 Wiley Periodicals, Inc.
Metabolomics Study on Quality Control and Discrimination of Three Curcuma Species based on Gas Chromatograph–Mass Spectrometry
Authors: Xiang Zheng , Wang Xian‐qin , Cai Xiao‐jun , Zeng Su
Published: March 2011

Introduction

Metabonomic analysis is an important molecular phenotyping method for characterising plant ecotypic variations; hence, it may become a powerful tool for quality control and discrimination of traditional Chinese medicine (TCM).

Objective

To discriminate and assess the quality of Curcuma phaeocaulis, C. kwangsiensis and C. wenyujin from different ecotypes. The identification of the compositions of essential oils from the three Curcuma species was included in this study.

Methodology

Metabolomics analysis was carried out on all samples by gas chromatography–mass spectrometry (GC‐MS) coupled with multivariate statistical analysis. Characterisation of phytochemicals in essential oils was performed by automated matching to the MS library and comparison of their mass spectra (NIST05 database).

Results

Principal component analysis (PCA) effectively distinguished the samples from different species and ecotypes. Partial least squares discrimination analysis (PLS‐DA) was successfully employed in classifying the GC‐MS data of authentic, commercial and introduction cultivation samples. Furthermore, the components contributing significantly to the discrimination, namely curzerenone, germacrone, curdione and epicurzerenone, were screened by PCA and PLS‐DA loading plots and further can be used as chemical markers for discrimination and quality control among different groups of samples. Copyright © 2011 John Wiley & Sons, Ltd.
Simultaneous Determination of Eleven Major Flavonoids in the Pollen of Typha angustifolia by HPLC‐PDA‐MS
Authors: Tao Weiwei , Yang Nianyun , Duan Jin‐ao , Wu Dekang , Guo JianMing , Tang Yuping , Qian Dawei , Zhu Zhenhua
Published: March 2011

Introduction

The pollen of Typha angustifolia L. has been used for the treatment of dysmenorrhea, stranguria and metrorrhagia. Flavonoids are major active compounds in this pollen and their quantification is important for its quality control.

Objective

To establish an HPLC‐PDA‐MS method for simultaneous determination of the 11 majority flavonoids in the pollen of T. angustifolia.

Methodology

The optimal condition of separation was achieved on a reversed‐phase C18 column with gradient elution of acetonitrile and 0.05% formic acid (v/v) at a flow‐rate of 0.8 mL/min; the column temperature was set at 35 °C.

Results

All calibration curves showed good linear regression (r2 > 0.9992). The method provided good accuracy, precision, recovery and sensitivity for the quantification of the 11 compounds analysed.

Conclusion

The HPLC method established is appropriate for the quality assurance of the pollen of T. angustifolia. Copyright © 2011 John Wiley & Sons, Ltd.