bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of glyceroltriheptanoate in processed animal by‐products by GC‐FID
Authors: Baglio Daniela , Folegatti Liliana
Published: April 2012

The European Regulation concerning animal by‐products (ABPs) established rules on safe use, transportation and disposal of these materials. According to the health risks, the products were sorted in three categories, and the materials belonging to category 1 and 2 (high and intermediate health risk) needed to be permanently marked in order to allow full traceability and avoid their entering in the feed and food chain. The selected marker was glyceroltriheptanoate (GTH) with a minimum permissible level of 250 mg/kg fat fraction. This study presents the implementation and validation of an analytical method for the determination of GTH in processed ABPs using GC‐FID. Two injection systems (split–splitless and programmable temperature vaporization injector) and chromatographic columns were evaluated in order to select the best instrumental conditions. The method was in‐house validated by assessing linearity, precision, trueness, and limit of detection (LOD) and quantification (LOQ). The linearity range was tested from 90 to 2800 mg GTH/kg, the relative SD for repeatability and intermediate precision were, respectively, 1.8 and 2.9%. The mean recovery rate was 99% and the LOD and LOQ were 6.8 and 22.8 mg/kg. In addition, the performance characteristics were compared with those of the reference method developed by the Institute for Reference Materials and Measurements (IRMM) with good agreement. A collection of real samples, obtained from different rendering plants in Italy, were subjected to analysis for the determination of GTH for routine quality controls.

Practical applications: After the European Regulation (EC) 1432/2007 that established a minimum added level of GTH to processed ABPs belonging to category 1 and 2 has been put in force, a reliable and simple analytical method became necessary. The Institute for Reference Materials and Measurements (IRMM) of the European Commission developed and validated a methodology based on a GC‐MS instrumentations, used by the official control laboratories. The aim of this study was the implementation of an analytical method using a GC‐FID, a widespread and easy to use instrumentation. This analytical protocol found its application in the processed quality control laboratories for the routine analysis of the GTH added to ABPs, and in particular for materials belonging to category 1 and 2.
Capillary zone electrophoresis and polymer dynamics
Authors: Phillies George D. J.
Published: April 2012

Capillary electrophoresis with a polymer solution support medium is a well‐established powerful analytical tool. This paper discusses a possible alternative application of capillary electrophoresis, namely a path for studying the dynamics of polymer solutions. The key to the approach is an inversion of perspective. Instead of treating the migrating species as the object of experimental importance and the support medium as being of importance only because it facilitates separations, one treats the polymer solution as being of experimental importance, and the choice of migrating species as being of interest only because different species may probe different aspects of polymer dynamics.
Sampling strategies for capillary isoelectric focusing with electroosmotic zone mobilization assessed by high‐resolution dynamic computer simulation
Authors: Takácsi‐Nagy Anna , Kilár Ferenc , Páger Csilla , Mosher Richard A. , Thormann Wolfgang
Published: April 2012

The impact of initial sample distribution on separation and focusing of analytes in a pH 3–11 gradient formed by 101 biprotic carrier ampholytes under concomitant electroosmotic displacement was studied by dynamic high‐resolution computer simulation. Data obtained with application of the analytes mixed with the carrier ampholytes (as is customarily done), as a short zone within the initial carrier ampholyte zone, sandwiched between zones of carrier ampholytes, or introduced before or after the initial carrier ampholyte zone were compared. With sampling as a short zone within or adjacent to the carrier ampholytes, separation and focusing of analytes is shown to proceed as a cationic, anionic, or mixed process and separation of the analytes is predicted to be much faster than the separation of the carrier components. Thus, after the initial separation, analytes continue to separate and eventually reach their focusing locations. This is different to the double‐peak approach to equilibrium that takes place when analytes and carrier ampholytes are applied as a homogenous mixture. Simulation data reveal that sample application between two zones of carrier ampholytes results in the formation of a pH gradient disturbance as the concentration of the carrier ampholytes within the fluid element initially occupied by the sample will be lower compared to the other parts of the gradient. As a consequence thereof, the properties of this region are sample matrix dependent, the pH gradient is flatter, and the region is likely to represent a conductance gap (hot spot). Simulation data suggest that sample placed at the anodic side or at the anodic end of the initial carrier ampholyte zone are the favorable configurations for capillary isoelectric focusing with electroosmotic zone mobilization.
Integration of on‐column catalysis and EKC analysis: Investigation of enantioselective sulfoxidations
Authors: Fuessl Simone , Trapp Oliver
Published: April 2012

A novel technique is presented to investigate catalytic reactions by coupling a fused‐silica capillary coated with an immobilized catalyst and a bare fused‐silica capillary to achieve separation of the reaction products and to generate an electroosmotic flow, which drives the transport of the reactants and products through the catalytically active capillary. The principle of this technique is illustrated by the enantioselective sulfoxidation of benzylphenylsulfide with hydrogen peroxide to the corresponding sulfoxide in the presence of a vanadium(IV)‐salen catalyst, which is immobilized to nonpolar polysiloxane and permanently bonded to the inner surface of the reaction capillary. The enantiomeric ratio of the reaction product is simultaneously determined by electrokinetic chromatography using 150 mg/mL sulfated β‐cyclodextrin as chiral additive in 10 mM sodium dihydrogenphosphate background electrolyte at pH 8.3. In contrast to conventional enantioselective sulfoxidations of benzylphenylsulfide using the vanadium(IV)‐salen catalyst, which give ees of up to 11%, an ee of up to 23% was achieved by this approach. Furthermore, the presented technique offers many more advantages, such as improved substrate selectivity using the nonpolar polysiloxane phase as a solvent, the feasibility to perform high‐throughput kinetic measurements of substrate libraries, rapid screening and investigation of stereolabile compounds, that is, chiral sulfoxides, and screening of reactions using only minute amounts of reagents.
Improving the reproducibility in capillary electrophoresis by incorporating current drift in mobility and peak area calculations
Authors: Petersen Nickolaj J. , Hansen Steen H.
Published: April 2012

The traditional way of calculating mobility and peak areas in capillary electrophoresis does not take into account the changes in the buffer viscosity at different thermostatic control and that the analytes may accelerate during the individual runs due to Joule heating effects. We present a method for accounting for these changes based on the monitored changes in current during the separation. The calculation method requires measuring the initial resistance of the buffer filled capillary, performed using a 0.2 min voltage ramping at the start of a separation. The mobility calculation corrected for current drift allowed identification of the tested analytes independent from capillary dimensions, electric field strengths and temperature control. Furthermore, the peak areas become less influenced by the experimental conditions, since the velocities of the analytes passing the detector are corrected for the acceleration during the run. The short voltage ramping could be further used to evaluate the heat transfer of the capillary to the surroundings and to estimate the temperature changes during the separation. The temperature was shown to change the ionization of 2‐phenylethylamine in accordance to a pKa dependency of primary amines reported in literature.
Mortality and Its Predictors in Severe Bulimia Nervosa Patients
Authors: Huas Caroline , Godart Nathalie , Caille Agnès , Pham‐Scottez Alexandra , Foulon Christine , Divac Snezana M. , Lavoisy Guillaume , Guelfi Julien‐Daniel , Falissard Bruno , Rouillon Frédéric
Published: April 2012

Background

The risk of mortality remains unclear for bulimia nervosa (BN) patients, especially the most severe. The aims of this study were to improve knowledge on BN and mortality.

Methods

With initial evaluation at admission, 258 BN (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) consecutive inpatients were included (1988–2004). Vital status was established from the French national register. Standardized Mortality Ratio (SMR) calculation and bivariate Cox analysis were performed for the hypothesised predictors of mortality.

Results

Mean follow‐up duration was 10.5 years. Ten deaths were recorded, and the crude mortality ratio was 3.9%; SMR = 5.52 [CI95 (2.64–10.15)]. The majority of deaths were from suicide [6/10, SMR = 30.9 (5.7–68.7)]. The mean age at time of death was 29.6 years. Predictive factors were previous suicide attempt and low minimum BMI.

Conclusions

Severe BN patients are at higher risk of death (mainly suicide) especially if previous suicide attempt or previous low BMI. More studies are needed to confirm these results. Copyright © 2012 John Wiley & Sons, Ltd and Eating Disorders Association.
The prevalence of cirrhosis and hepatocellular carcinoma in patients with human immunodeficiency virus infection
Authors: Ioannou George N. , Bryson Christopher L. , Weiss Noel S. , Miller Richard , Scott John D. , Boyko Edward J.
Published: April 2012

Cirrhosis is a leading cause of death among patients infected with human immunodeficiency virus (HIV). We sought to determine risk factors for and time trends in the prevalence of cirrhosis, decompensated cirrhosis, and hepatocellular carcinoma (HCC) among patients diagnosed with HIV who received care in the Veterans Affairs (VA) health care system nationally between 1996 and 2009 (n = 24,040 in 2009). Among patients coinfected with HIV and hepatitis C virus (HCV), there was a dramatic increase in the prevalence of cirrhosis (3.5%-13.2%), decompensated cirrhosis (1.9%-5.8%), and HCC (0.07%-1.6%). Little increase was observed among patients without HCV coinfection in the prevalence of cirrhosis (1.7%-2.2%), decompensated cirrhosis (1.1%-1.2%), and HCC (0.03%-0.13%). In 2009, HCV infection was present in the majority of patients with HIV who had cirrhosis (66%), decompensated cirrhosis (62%), and HCC (80%). Independent risk factors for cirrhosis included HCV infection (adjusted odds ratio [AOR], 5.82; 95% confidence interval [CI], 5.0-6.7), hepatitis B virus (HBV) infection (AOR, 2.40; 95% CI, 2.0-2.9), age (AOR, 1.03; 95% CI, 1.02-1.04), Hispanic ethnicity (AOR, 1.76; 95% CI, 1.4-2.2), diabetes (AOR, 1.79; 95% CI, 1.6-2.1), and alcohol abuse (AOR, 1.78; 95% CI, 1.5-2.1), whereas black race (AOR, 0.56; 95% CI, 0.48-0.64) and successful eradication of HCV (AOR, 0.61; 95% CI, 0.4-0.9) were protective. Independent risk factors for HCC included HCV infection (AOR, 10.0; 95% CI, 6.1-16.4), HBV infection (AOR, 2.82; 95% CI, 1.7-4.7), age (AOR, 1.05; 95% CI, 1.03-1.08), and low CD4+ cell count (AOR, 2.36; 95% CI, 1.3-4.2). Among 5999 HIV/HCV-coinfected patients, 994 (18%) had ever received HCV antiviral treatment, of whom 165 (17%) achieved sustained virologic response. Conclusion: The prevalence of cirrhosis and HCC has increased dramatically among HIV-infected patients driven primarily by the HCV epidemic. Potentially modifiable risk factors include HCV infection, HBV infection, diabetes, alcohol abuse, and low CD4+ cell count. (Hepatology 2013)
Neuropeptide PACAP in mouse liver ischemia and reperfusion injury: Immunomodulation by the cAMP-PKA pathway
Authors: Ji Haofeng , Zhang Yu , Shen Xiu-da , Gao Feng , Huang Cynthia Y. , Abad Catalina , Busuttil Ronald W. , Waschek James A. , Kupiec-Weglinski Jerzy W.
Published: April 2012

Hepatic ischemia and reperfusion injury (IRI), an exogenous antigen-independent local inflammation response, occurs in multiple clinical settings, including liver transplantation, hepatic resection, trauma, and shock. The immune system and the nervous system maintain extensive communication and mount a variety of integrated responses to danger signals through intricate chemical messengers. This study examined the function and potential therapeutic potential of neuropeptide pituitary adenylate cyclase-activating polypeptides (PACAP) in a murine model of partial liver “warm” ischemia (90 minutes) followed by reperfusion. Liver IRI readily triggered the expression of intrinsic PACAP and its receptors, whereas the hepatocellular damage was exacerbated in PACAP-deficient mice. Conversely, PACAP27, or PACAP38 peptide monotherapy, which elevates intracellular cyclic adenosine monophosphate/protein kinase A (cAMP-PKA) signaling, protected livers from IRI, as evidenced by diminished serum alanine aminotransferase levels and well-preserved tissue architecture. The liver protection rendered by PACAP peptides was accompanied by diminished neutrophil/macrophage infiltration and activation, reduced hepatocyte necrosis/apoptosis, and selectively augmented hepatic interleukin (IL)-10 expression. Strikingly, PKA inhibition readily restored liver damage in otherwise IR-resistant, PACAP-conditioned mice.

In vitro
, PACAP treatment not only diminished macrophage tumor necrosis factor alpha/IL-6/IL-12 levels in a PKA-dependent manner, but also prevented necrosis and apoptosis in primary mouse hepatocyte cultures.

Conclusion:

Our novel findings document the importance of PACAP-mediated cAMP-PKA signaling in hepatic homeostasis and cytoprotection

in vivo
. Because the enhancement of neural modulation differentially regulates local inflammation and prevents hepatocyte death, these results provide the rationale for novel approaches to manage liver inflammation and IRI in transplant patients. (Hepatology 2013)
Breast cancer mortality in Norway after the introduction of mammography screening
Authors: Olsen Anne Helene , Lynge Elsebeth , Njor Sisse H. , Kumle Merethe , Waaseth Marit , Braaten Tonje , Lund Eiliv
Published: April 2012

An organized mammography screening program was gradually implemented in Norway during the period 1996–2004. Norwegian authorities have initiated an evaluation of the program. Our study focused on breast cancer mortality. Using Poisson regression, we compared the change in breast cancer mortality from before to during screening in four counties starting the program early controlling for change in breast cancer mortality during the same time in counties starting the program late. A follow‐up model included death in all breast cancers diagnosed during the follow‐up period. An evaluation model included only breast cancers diagnosed in ages where screening was offered. The study group had been invited for screening one to three times and followed for on average of 5.9 years. In the follow‐up model, 314 breast cancer deaths were observed in the study group, and 523, 404 and 638, respectively, in the four control groups. The ratio between the changes in breast cancer mortality between early and late starting counties was 0.93 (95% confidence interval [CI] 0.77–1.12). In the evaluation model, this ratio was 0.89 (95% CI: 0.71–1.12). In Norway, where 40% of women used regular mammography prior to the program, the implementation of the organized mammography screening program was associated with a statistically nonsignificant decrease in breast cancer mortality of around 11%.
International trends in the incidence of malignant melanoma 1953–2008—are recent generations at higher or lower risk?
Authors: Erdmann Friederike , Lortet‐Tieulent Joannie , Schüz Joachim , Zeeb Hajo , Greinert Rüdiger , Breitbart Eckhard W. , Bray Freddie
Published: April 2012

The incidence of cutaneous malignant melanoma has steadily increased over the past 50 years in predominately fair‐skinned populations. This increase is reported to have leveled off recently in several Northern and Western European countries, Australia, New Zealand and in North America. We studied the global patterns and time trends in incidence of melanoma by country and sex, with a focus on and age‐ and cohort‐specific variations. We analyzed the incidence data from 39 population‐based cancer registries, examining all‐ages and age‐truncated standardized incidence rates of melanoma, estimating the annual percentage change and incidence rate ratios from age‐period‐cohort models. Incidence rates of melanoma continue to rise in most European countries (primarily Southern and Eastern Europe), whereas in Australia, New Zealand, the U.S., Canada, Israel and Norway, rates have become rather stable in recent years. Indications of a stabilization or decreasing trend were observed mainly in the youngest age group (25–44 years). Rates have been rising steadily in generations born up to the end of the 1940s, followed by a stabilization or decline in rates for more recently born cohorts in Australia, New Zealand, the U.S., Canada and Norway. In addition to the birth cohort effect, there was a suggestion of a period‐related influence on melanoma trends in certain populations. Although our findings provide support that primary and secondary prevention can halt and reverse the observed increasing burden of melanoma, they also indicate that those prevention measures require further endorsement in many countries.
Developing methacrylate‐based copolymers as an artificial Bruch's membrane substitute
Authors: Treharne Andrew J. , Thomson Heather A. J. , Grossel Martin C. , Lotery Andrew J.
Published: April 2012

Age‐related macular degeneration (AMD) is the most common cause of blindness in the developed world. There is currently no treatment for the cellular loss, which is characteristic of AMD. Transplantation of retinal pigment epithelium (RPE) cells represents a potential therapy. Because of AMD‐related pathology in the native support, Bruch's membrane, transplanted RPE cells require a scaffold to reside on. We present here the development of an electrospun fibrous scaffold derived from methyl methacrylate and poly(ethylene glycol) (PEG) methacrylate for novel application as an RPE scaffold. Scaffolds were chemically modified to improve cell adhesion by functionalization not previously reported for this type of copolymer system. A human RPE cell line was used to investigate cell‐scaffold interactions for up to two weeks in vitro. Scanning electron microscopy was used to characterize the fibrous scaffolds and confirm cell attachment. By day 15, cell area was significantly (p < 0.001) enhanced on scaffolds with chemical modification of the PEG chain terminus. In addition, significantly, less‐apoptotic cell death was demonstrable on these modified surfaces. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2358–2364, 2012.
The interplay between physical and chemical properties of protein films affects their bioactivity
Authors: Grover Chloe N. , Farndale Richard W. , Best Serena M. , Cameron Ruth E.
Published: April 2012

Although mechanical properties, roughness, and receptor molecule expression have all been shown to influence the cellular reactivity of collagen‐based biomaterials, their relative contribution, in a given system remains unclear. Here, we study films containing combinations of collagen, gelatin, and soluble and insoluble elastin, crosslinking of which results in altered film stiffness and roughness. Collagen and gelatin have similar amino acid sequences but altered cell‐binding sites. We studied cell response with both C2C12 myoblast cells (which possess RGD‐recognizing integrins αVβ3 and α5β1) and C2C12‐α2+ cells (which, in addition, express the collagen‐binding integrin α2β1) to establish the effect of altering the available binding sites on cell adhesion and spreading on films. Systematically altering the composition, crosslinking and cell type, allows us to deconvolute the effects of physical parameters and available binding sites on the cell reactivity of films in this system. Collagen‐based films were rougher and stiffer and supported lower cell surface coverage than gelatin‐based films. Additionally, C2C12‐α2+ cells showed preferential attachment to collagen‐based films compared with C2C12 cells, but no significant difference was seen using gelatin‐based films. The cell count and surface coverage were found to decrease significantly on all films after crosslinking (Coll XL coverage = 2–6%, Gel XL coverage = 20–32%), but cell area and aspect ratio on collagen films were affected to a greater extent than on gelatin films. The results show that, in this system, the composition, and more significantly, crosslinking, of films affects the cell reactivity to a greater extent than their stiffness or roughness. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2401–2411, 2012.
Oxidative damage of lung and its protective mechanism in mice caused by long‐term exposure to titanium dioxide nanoparticles
Authors: Sun Qingqing , Tan Danlin , Zhou Qiuping , Liu Xiaorun , Cheng Zhe , Liu Gan , Zhu Min , Sang Xuezi , Gui Suxin , Cheng Jie , Hu Renping , Tang Meng , Hong Fashui
Published: April 2012

Exposure to titanium dioxide nanoparticles (TiO2 NPs) elicits an adverse response such as oxidative damage. The molecular targets of TiO2 NPs remain largely unidentified. In the present study, the function and signal pathway of nuclear factor erythroid 2 related factor 2 (Nrf2) in protection against TiO2 NPs‐induced oxidative stress in the mouse lung were investigated. Mice were exposed to 10 mg/kg body weight by an intratracheal administration for 15–90 days. With increasing exposed terms, TiO2 NPs were significantly accumulated and increased the reactive oxygen species (ROS) production in lung, which resulted in severe pulmonary edema, inflammatory response and pneumonocyte apoptosis for 90 days. Furthermore, TiO2 NPs exposure could greatly induce expression of Nrf2, heme oxygenase 1 (HO‐1), and glutamate‐cysteine ligase catalytic subunit (GCLC) from 15‐day to 75‐day exposure, whereas 90‐day exposure caused significant decreases of three factors expression levels in lung. Our findings imply that the induction of Nrf2 expression is an adaptive intracellular response to TiO2 NPs‐induced oxidative stress in the mouse lung, and that Nrf2 is protective against TiO2 NPs‐induced pulmonary damages during certain exposure terms. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2554–2562, 2012.
Dynamics of monocyte count: A good predictor for timing of peripheral blood stem cell collection
Authors: Yang Shen‐Miao , Chen Huan , Chen Yu‐Hong , Zhu Hong‐Hu , Zhao Ting , Liu Kai‐Yan
Published: April 2012

To investigate potential predictive parameters for successful collection of autologous peripheral blood stem cells (PBSC), 60 consecutive first mobilization attempts and 145 leukapheresis procedures for patients with hematologic malignancies (multiple myeloma: n = 20; acute leukemia: n = 27; lymphoma: n = 13) were analyzed. All patients underwent chemotherapy and granulocyte‐colony stimulating factor combined mobilization protocols. PBSC collection began when white blood cell (WBC) count rebounded to >1.0 × 109/L. Poor mobilization (PM) was defined as <2.0 × 106/kg of ideal body weight CD34+ cells were collected from at least three leukapheresis procedures. PM incidence was 15% (9/60). On the first apheresis day, CD34+ cell yield was closely associated with the final yield. Failure to reach the first‐day target of 0.7 × 106 CD34+ cells/kg was perfectly matched with PM. Circulating WBC and monocyte (MO) counts preleukapheresis had a positive correlation with final CD34+ cell yield. For the first‐day apheresis target, receiver operator characteristic (ROC) curve analysis showed that MO count had an area under the curve (AUC) of 0.806 (P = 0.004). An optimal predictive cutoff value for MO count was 1.455 × 109/L with both high sensitivity and specificity of 0.739 and 0.899, respectively. Patients who began leukapheresis with an MO count of ≥1.455 × 109/L accomplished more successful first‐day collections than those of their counterparts (P = 0.021). ROC analysis also showed preapheresis WBC count had a high AUC of 0.768 (P = 0.012). However, we could not find a WBC indicator to initiate leukapheresis. In conclusion, circulating MO count after mobilization is a helpful parameter to determine the optimal time point for starting a PBSC collection. J. Clin. Apheresis 2012. © 2012 Wiley Periodicals, Inc.
Unilateral and bilateral expression of a quantitative trait: asymmetry and symmetry in coronal craniosynostosis
Authors: Heuzé Yann , Martínez‐Abadías Neus , Stella Jennifer M. , Senders Craig W. , Boyadjiev Simeon A. , Lo Lun‐Jou , Richtsmeier Joan T.
Published: April 2012

Bilateral symmetry in vertebrates is imperfect and mild asymmetries are found in normal growth and development. However, abnormal development is often characterized by strong asymmetries. Coronal craniosynostosis, defined here as consisting of premature suture closure and a characteristic skull shape, is a complex trait. The premature fusion of the coronal suture can occur unilaterally associated with skull asymmetry (anterior plagiocephaly) or bilaterally associated with a symmetric but brachycephalic skull. We investigated the relationship between coronal craniosynostosis and skull bilateral symmetry. Three‐dimensional landmark coordinates were recorded on preoperative computed tomography images of children diagnosed with coronal nonsyndromic craniosynostosis (N= 40) and that of unaffected individuals (N= 20) and analyzed by geometric morphometrics. Our results showed that the fusion pattern of the coronal suture is similar across individuals and types of coronal craniosynostosis. Shape analysis showed that skulls of bilateral coronal craniosynostosis (BCS) and unaffected individuals display low degrees of asymmetry, whereas right and left unilateral coronal craniosynostosis (UCS) skulls are asymmetric and mirror images of one another. When premature fusion of the coronal suture (without taking into account cranial dysmorphology) is scored as a qualitative trait, the expected relationship between trait frequency and trait unilateral expression (i.e. negative correlation) is confirmed. Overall, we interpret our results as evidence that the same biological processes operate on the two sides in BCS skulls and on the affected side in UCS skulls, and that coronal craniosynostosis is a quantitative trait exhibiting a phenotypic continuum with BCS displaying more intense shape changes than UCS.J. Exp. Zool. (Mol. Dev. Evol.) 318:109–122, 2012. © 2011 Wiley Periodicals, Inc.
Stiffness changes of tumor HEp2 cells correlates with the inhibition and release of TRAIL‐induced apoptosis pathways
Authors: Targosz‐Korecka Marta , Biedron Rafal , Szczygiel Agnieszka Maria , Brzezinka Grzegorz , Szczerbinski Jacek , Zuk Anna
Published: April 2012

Tumor necrosis factor (TNF)‐related apoptosis inducing ligand (TRAIL) is a promising apoptotic agent that can selectively act on tumor cells. However, some cancer cells are resistant to TRAIL mediated apoptosis. In specific type of cells, sensitization by chemotherapeutic drugs may overcome the resistance to TRAIL induced apoptosis. In this work, atomic force microscopy (AFM) nanoindentation spectroscopy combined with fluorescence methods were used to investigate the biomechanical aspects of the resistance and unblocking of apoptosis in larynx carcinoma HEp2 cells treated with TRAIL. It is shown that there is a direct correlation between the increase in mechanical cell stiffness and the inhibition of apoptosis induced by TRAIL in HEp2 cells. Conversely, unblocking of apoptosis by sensitization of HEp2 cells with a chemotherapeutic drug Actinomycin D is related to the depolymerization of F‐actin and to the decrease in the cell stiffness. Both effects, that is, changes in the mechanical stiffness of the cell and the inhibition of apoptotic pathway, are closely related to the Bcl‐2 activity. Most probably, the depolymerization of F‐actin results from downregulation of Rho protein, which in turn is accompanied by a lower activity of Bcl‐2 and in consequence releases the intrinsic apoptotic channel. The presented results reveal a promising application of nanoindentation spectroscopy with an AFM tip as a novel tool for monitoring the processes of apoptosis inhibition. Copyright © 2012 John Wiley & Sons, Ltd.
Isolation of bioactive components from Flaveria bidentis (L.) Kuntze using high‐speed counter‐current chromatography and time‐controlled collection method
Authors: Wei Yun , Zhang Kai , Yin Li , Du Jilin , Zhang Guoliang
Published: April 2012

Semipreparative high‐speed counter‐current chromatography (HSCCC) by time‐controlled collection method was successfully applied for isolation and purification of α‐terthienyl, 5‐(3‐buten‐1‐ynyl)‐2,2′‐bithienyl, and 5‐(3‐penten‐1‐ynyl)‐2,2′‐bithienyl from Flaveria bidentis (L.) Kuntze for the first time. The two‐phase solvent system composed of n‐hexane and acetonitrile at the volume ratio of 1:1 (v/v) was used for the semipreparative HSCCC. The 5.2 mg α‐terthienyl, 2.2 mg 5‐(3‐buten‐1‐ynyl)‐2,2′‐bithienyl, and 4.3 mg 5‐(3‐penten‐1‐ynyl)‐2,2′‐bithienyl with the purity of 99.9, 90.2, and 92.1% were produced from 265.6 mg crude extract, respectively, and 5‐(3‐penten‐1‐ynyl)‐2,2′‐bithienyl was first isolated from Flaveria bidentis (L.) Kuntze. The structures of the separated compounds were identified by electrospray‐ionization mass spectrometry and proton and carbon nuclear magnetic resonance (1H‐ and 13C‐NMR).
Optimization of matrix solid‐phase dispersion conditions for organic fungicides determination in soil samples
Authors: Carpinteiro Inmaculada , Casado Jorge , Rodríguez Isaac , Ramil María , Cela Rafael
Published: April 2012

A simplified sample preparation method, based on the matrix solid‐phase dispersion technique, is proposed for the sensitive determination of 15 organic fungicides in vineyard soils by gas chromatography–mass spectrometry (GC–MS). Under final working conditions, sieved samples (0.5 g) were blended and dispersed with 2 g of C18 and transferred to a polypropylene syringe containing 1 g of diatomaceous earth. Analytes were recovered using 10 mL of ethyl acetate, this extract was concentrated to 1 mL and fungicides determined by GC–MS, without additional cleanup. The method provided recoveries in the range from 74 to 122% for soils with total carbon contents up to 5.5% and it allowed the use of external standard as quantification technique. Inter‐day precision, given as relative standard deviations, stayed between 3 and 13%, and the limits of quantification were comprised between 0.6 and 15 ng g−1. Several fungicides were found in the top layer of vineyard soils with the highest detection frequency and maximum concentration corresponding to iprovalicarb. Some real samples were also submitted to pressurized liquid extraction. Measured concentrations were in excellent agreement with those obtained by matrix solid‐phase dispersion, which reinforces the accuracy of the latter methodology.
Impact of infrared laser light‐induced ablation at different wavelengths on bovine intervertebral disc ex vivo: Evaluation with magnetic resonance imaging and histology
Authors: Cselik Zsolt , Aradi Mihály , von Jako Ronald A. , Lelovics Zsuzsanna , Juhász Ivett , Egyházi Zsolt , Bogner Péter , Repa Imre , Schwarcz Attila
Published: April 2012

Background and Objective

Percutaneous laser disc decompression is commonly used to lower high pressure in the nucleus pulposus in degenerative disc diseases. The aim of this study was to investigate the impact of diode laser disc decompression at different wavelengths (980‐nm vs. 1,470‐nm, i.e., different water absorption characteristics).

Materials and Methods

To model decompression, a flexible laser quartz fiber inserted into the nucleus pulposus of ex vivo bovine spines using computer‐assisted surgical navigation was utilized to vaporize tissue. The same energy (500 J) was delivered using both 980‐nm and 1,470‐nm wavelength lasers. To determine the different impact of the wavelengths before and after the procedure we evaluated the discs with MRI (T1, T2, diffusion maps) and with histopathology.

Results

There were no visible changes on T1 and T2 maps after 1,470‐nm wavelength laser irradiation; however, the 980‐nm wavelength caused significant changes on T1 (decrease) and T2 (increase) in the vaporization zone at the site of the quartz fiber. Pathological findings showed carbonization and steam‐bubble formation in addition to the T1 and T2 changes. No significant changes were detected in the value of apparent diffusion coefficient (ADC) measurements in intervertebral disc with the 980‐nm wavelength, but significant ADC and T1 signal increase was detected with the 1,470‐nm wavelength when the whole nucleus pulposus was considered.

Conclusion

The 1,470‐nm laser light had an effect in the whole nucleus pulposus and not only at the site of the quartz fiber, whereas with the 980‐nm laser irradiation, significant changes were demonstrated only at the application site. Lasers Surg. Med. 44: 406–412, 2012. © 2012 Wiley Periodicals, Inc.
Low Charge Density Cationic Polymers for Gene Delivery: Exploring the Influence of Structural Elements on in vitro Transfection
Authors: Mindemark Jonas , Tabata Yasuhiko , Bowden Tim
Published: April 2012

A series of end‐functionalized poly(trimethylene carbonate) DNA carriers, characterized by low cationic charge density and pronounced hydrophobicity, is used to study structural effects on in vitro gene delivery. As the DNA‐binding moieties are identical in all polymer structures, the differences observed between the different polymers are directly related to the functionality and length of the polymer backbone. The transfection efficiency and cytotoxicity of the polymer/DNA complexes are thus found to be dependent on a combination of polymer charge density and functionality, highlighting the importance of such structural considerations in the development of materials for efficient gene delivery.

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Feather Fiber‐Based Thermoplastics: Effects of Different Plasticizers on Material Properties
Authors: Ullah Aman , Wu Jianping
Published: April 2012

Poultry feather fiber is transformed into biothermoplastics using a twin screw extruder, and the plasticizing effect of four different plasticizers on the material properties is investigated. Conformational changes, viscoelastic behavior, thermal degradation, and phase transitions are assessed by means of FTIR spectroscopy, DMA, TGA, and DSC, respectively. The mechanical properties of the plasticized resins are assessed by tensile measurements, while optical transmittance is recorded using UV‐Vis spectrophotometry. The water uptake behavior of the fiber keratin and plasticized resins is also investigated.

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1H and 13C NMR spectral assignments of pyridinium salts linked to a N‐9 or N‐3 adenine moiety
Authors: Rubio‐Ruiz Belén , Conejo‐García Ana , Gallo Miguel A. , Espinosa Antonio , Entrena Antonio
Published: April 2012

1H and 13 C NMR spectral data of 13 new compounds containing a 4‐(dimethylamino)‐ or 4‐(pyrrolidin‐1‐yl)pyridinium moiety linked to the N‐9 or N‐3 nitrogen atom of an adenine moiety were assigned. 1D and 2D NMR experiments (DEPT, HSQC and HMBC) allowed the unequivocal identification of N‐9 and N‐3 isomers. Copyright © 2012 John Wiley & Sons, Ltd.
Premotor potential study in carpal tunnel syndrome
Authors: Kodama Mitsuhiko , Sasao Yu , Tochikura Michi , Kasahara Takashi , Koyama Yuji , Aono Koji , Fujii Chieko , Hanayama Kozo , Takahashi Osamu , Kobayashi Yuka , Masakado Yoshihisa
Published: April 2012

Introduction: Premotor potentials (PMPs) precede compound muscle action potentials evoked from the second lumbrical muscle after median nerve stimulation. Although PMP has been identified as a median sensory nerve action potential, few reports have documented the significance of PMP parameters for diagnosing carpal tunnel syndrome (CTS). Methods: We investigated the relationships between PMP parameters and results of 6 standard median nerve conduction studies in 74 CTS hands. Results: Significant correlations were noted in all comparisons. PMP conduction velocity was strongly correlated with the sensory conduction velocity between wrist and digit 2 (r2 = 0.91). Moreover, PMP parameters were significantly correlated with neurophysiological severity of CTS. Conclusion: Measuring PMP parameters with a second lumbrical–interosseous study may be useful for diagnosing CTS. Muscle Nerve, 2012
Impaired energy‐dependent processes underlie acute lead neuropathy
Authors: Krishnan Arun V. , Park Susanna B. , Huynh William , Lin Cindy S.‐Y. , Henderson Robert D. , Kiernan Matthew C.
Published: April 2012

Introduction:

The mechanisms of lead neuropathy remain unexplained. A 48‐year‐old painter presented after undertaking a 3‐week project of paint removal without the use of a protective mask. Two weeks later, he developed fasciculations, weakness, and muscle wasting. Nerve conduction studies demonstrated a motor neuropathy. A high serum lead level was identified, leading to a diagnosis of acute lead neuropathy.

Methods:

To investigate the pathophysiology, nerve excitability studies were undertaken acutely and in convalescence. Studies were undertaken at baseline and after the induction of limb ischemia.

Results:

Prominent abnormalities of excitability were noted, including a rightward shift of stimulus–response curves, reduction in depolarizing threshold electrotonus, and increased refractoriness. These changes became more severe with limb ischemia, and there was abolition of the superexcitable period and increased refractoriness.

Conclusions:

We identified prominent changes in nerve excitability in lead neuropathy. The results suggest that there is impairment of axonal energy‐dependent processes in lead neuropathy. Muscle Nerve, 2012
A semiorthogonal generalized Arnoldi method and its variations for quadratic eigenvalue problems
Authors: Huang Wei‐Qiang , Li Tiexiang , Li Yung‐Ta , Lin Wen‐Wei
Published: April 2012

In this paper, we are concerned with the computation of a few eigenpairs with smallest eigenvalues in absolute value of quadratic eigenvalue problems. We first develop a semiorthogonal generalized Arnoldi method where the name comes from the application of a pseudo inner product in the construction of a generalized Arnoldi reduction for a generalized eigenvalue problem. The method applies the Rayleigh–Ritz orthogonal projection technique on the quadratic eigenvalue problem. Consequently, it preserves the spectral properties of the original quadratic eigenvalue problem. Furthermore, we propose a refinement scheme to improve the accuracy of the Ritz vectors for the quadratic eigenvalue problem. Given shifts, we also show how to restart the method by implicitly updating the starting vector and constructing better projection subspace. We combine the ideas of the refinement and the restart by selecting shifts upon the information of refined Ritz vectors. Finally, an implicitly restarted refined semiorthogonal generalized Arnoldi method is developed. Numerical examples demonstrate that the implicitly restarted semiorthogonal generalized Arnoldi method with or without refinement has superior convergence behaviors than the implicitly restarted Arnoldi method applied to the linearized quadratic eigenvalue problem. Copyright © 2012 John Wiley & Sons, Ltd.
Delay‐dependent robust H ∞  control for uncertain singular time‐delay system with Markovian jumping parameters
Authors: Lu Hongqian , Zhou Wuneng , Duan Chunmei , Qi Xingguang
Published: April 2012

The problem of robust H ∞  control for a class of uncertain singular time‐delay systems with Markovian jumping parameters is addressed in this paper. The considered Markovian jump singular systems involve constant time delay and norm‐bounded uncertainties. On the basis of LMI approach, a delay‐dependent condition is proposed, which ensures the nominal Markovian jump singular system to be regular, impulse‐free and stochastically stable. From the delay‐dependent condition, a sufficient condition leading to the existence of a state feedback controller that guarantees the robust admissibility and the H ∞  performance is also given. A numerical example is given to demonstrate the applicability of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.
Statin medication in patients treated with antiepileptic drugs in Norway
Authors: Gedde‐Dahl Ane , Devold Helene M. , Molden Espen
Published: April 2012

Purpose

The lipid‐lowering response of statins metabolized by cytochrome P450 3A4 (CYP3A4) has previously been shown to be diminished by concurrent use of enzyme‐inducing antiepileptic drugs (EIAEDs). The aim of this study was to compare statin prescription in patients receiving EIAEDs versus non‐enzyme‐inducing antiepileptic drugs (NEIAEDs), before and after introduction of prescribing restrictions for statins in Norway.

Methods

The Norwegian Prescription Database was used to extract data on patients using antiepileptic drugs and statins during 2004 and 2008. Statin type and dose used were compared between patients treated with at least one EIAED (i.e., carbamazepine, phenobarbital, phenytoin, primidone) and those receiving NEIAEDs only (i.e., all other antiepileptic drugs).

Results

The number of included patients co‐medicated with statins and AEDs was 4855 in 2004 and 9880 in 2008. Among these patients, 2827 and 3160, respectively, were treated with EIAEDs. The CYP3A4 statins (i.e., simvastatin, atorvastatin and lovastatin) accounted for 85% of all statins in 2004, increasing to 93% in 2008. There was no significant difference in the likelihood of being prescribed a CYP3A4 statin versus a non‐CYP3A4 statin among patients receiving EIAEDs and NEIAEDs. The average daily dose of individual CYP3A4 statins was not different between the AED groups.

Conclusions

The present study shows that the interaction risk between CYP3A4‐metabolized statins and EIAEDs is largely overlooked in Norwegian clinical practice. To avoid therapeutic failure of statin treatment in patients using AEDs, implementation of strategies for systematic management of drug interactions is warranted. Copyright © 2012 John Wiley & Sons, Ltd.
Crystal structure of tandem ACT domain‐containing protein ACTP from Galdieria sulphuraria
Authors: Bitto Eduard , Kim Do Jin , Bingman Craig A. , Kim Hyun‐Jung , Han Byung Woo , Phillips George N.
Published: April 2012

The ACT domain is a structurally conserved small molecule binding domain which is mostly involved in amino acid and purine metabolism. Here, we report the crystal structure of a tandem ACT domain‐containing protein (ACTP) from Galdieria sulphuraria. The two ACTP monomers in the asymmetric unit form a dimer with a non‐crystallographic twofold axis in a domain‐swapped manner, showing a horseshoe‐like structure with a central crevice. This structure contributes to expand our knowledge on the structural diversity of ACT domain‐containing proteins. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Exploring structure–activity data using the landscape paradigm
Authors: Guha Rajarshi
Published: April 2012

In this article, we present an overview of the origin and applications of the activity landscape view of structure–activity relationship (SAR) data as conceived by Shanmugasundaram and Maggiora. Within this landscape, different regions exemplify different aspects of SAR trends—ranging from smoothly varying trends to discontinuous trends (also termed activity cliffs). We discuss the various definitions of landscapes and cliffs that have been proposed as well as different approaches to the numerical quantification of a landscape. We then highlight some of the landscape visualization approaches that have been developed, followed by a review of the various applications of activity landscapes and cliffs to topics in medicinal chemistry and SAR analysis. © 2012 John Wiley & Sons, Ltd.

This article is categorized under:

Computer and Information Science > Chemoinformatics
Return on Quality Improvements in Search Engine Marketing
Authors: Abou Nabout Nadia , Skiera Bernd
Published: April 2012

In search engine marketing, such as on Google, advertisements’ ranking and prices paid per click result from generalized, second-price, sealed bid auctions that weight the submitted bids for each keyword by the quality of an advertisement. Conventional wisdom suggests that advertisers can only benefit from improving their advertisement's quality. With an empirical study, this article shows that quality improvements have complex effects whose returns are actually unclear: 5% of all quality improvements to an advertisement lead to higher prices (measured by price per click) per keyword, 100% to a higher number of clicks, 53% to higher costs for search engine marketing, and 37% to lower profits. Quality improvements lead to higher weighted bids, which only lower prices if they do not improve the ranking of the advertisement. Otherwise, better ranks likely lead to higher prices. A decomposition method can disentangle these effects and explain their effects on search engine marketing costs and profits. Finally, the results indicate that advertisers benefit if they lower their bids after improvements to advertising quality.
Unconscious creativity: When can unconscious thought outperform conscious thought?
Authors: Yang Haiyang , Chattopadhyay Amitava , Zhang Kuangjie , Dahl Darren W.
Published: April 2012

Recent research suggests that unconscious thought is superior to conscious thought in many cognitive domains. In this article, we show that the duration of unconscious thought has an inverted‐U shaped relationship with creativity performance. Unconscious thought is, thus, unlikely to provide creative advantage over conscious thought when deliberation duration is either short or long. However, when deliberation duration is of a moderate length, the creative output of unconscious thought surpasses that of conscious thought. Furthermore, the superiority of unconscious thought pertains only to the novelty dimension of creativity, but not the appropriateness dimension. These findings not only shed light on the powers and limits of unconscious thought but also illuminate the importance of calibration in utilizing unconscious thought to boost creativity.
Tracheostomy and laryngectomy survey: do front-line emergency staff appreciate the difference?
Authors: Darr A , Dhanji K , Doshi J
Published: April 2012

Background:

In an emergency scenario, it is vital to appreciate the difference between a laryngectomy and a tracheostomy so that oxygen can be administered in an appropriate manner. This survey aimed to ascertain the level of emergency healthcare personnel's knowledge with regards to distinguishing between a tracheostomy and a laryngectomy patient, and the emergency management of such patients.

Methods:

Forty-four accident and emergency staff (28 doctors, nine nurses and seven paramedics) within one Foundation Trust were invited to complete a questionnaire to ascertain (1) their confidence at differentiating between a laryngectomy and tracheostomy stoma; (2) knowledge of the appropriate site for oxygen delivery if needed; and (3) overall level of training on this subject.

Results:

There were significant gaps in knowledge, particularly with regards to fundamental differences between a tracheostomy and a laryngectomy; less than 5 per cent were able to describe the anatomical difference. Only 41 per cent correctly identified the route of oxygen administration in laryngectomy patients.

Conclusion:

In this cohort of emergency staff, the fundamental difference between a laryngectomy and a tracheostomy was poorly understood. This lack of awareness of front-line emergency staff needs to be addressed in order to maximise patient safety.