bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of key microhabitats for fish assemblages in tropical Brazilian savanna streams
Authors: Romero Renato M. , Casatti Lilian
Published: October 2012

The habitat use by stream fish can provide an understanding of this important component of species niches, and the changes in the availability of certain structures of instream habitats have a strong influence on the occurrence and abundance of fish species. In this study, we identified the interaction networks between fish and microhabitats in 19 streams of three watersheds from the Brazilian savanna, known as the “Cerrado”. We also investigated whether the connectance between fish species and microhabitats depends on either the species abundance or availability of microhabitats and verified whether the use of stream microhabitats vary among watersheds. The data for the fish were obtained using standardized fish collections and underwater (snorkeling) observations to record the association of fish species with 11 stream microhabitats. We used the incidence data to calculate the connectance of species with different microhabitats, a Spearman correlation analysis to test the dependence of the connectance to the species abundance and microhabitat availability, and an Analysis of Similarity to test whether the use of stream microhabitats by fish can vary among watersheds. In all of the watersheds, the tetras of the family Characidae used the largest number of microhabitats. The most‐used microhabitats by the fish watersheds were the lateral surface, column surface, and unconsolidated substrate, which were differentially used by the fish in each watershed, indicating the variable importance of microhabitats. Despite this observation, the fish occurred more frequently in the lateral microhabitats. When the data for all of the streams were combined, the species connectance was correlated with the species abundance. We also discuss the consequences of the elimination of certain bottom structures in the context of siltation, which is the main issue in the studied region. The results of our study allowed the detection of key microhabitat structures and can be used for the aquatic ecosystems restoration. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biological Quality on the Basis of Macroinvertebrates in Dammed Habitats of Some Estonian Streams, Central – Baltic Europe
Authors: Käiro Kairi , Timm2 Henn , Haldna2 Marina , Virro1 Taavi
Published: October 2012

We assessed the impacts of damming on the biological quality of Estonian streams. A total of 24 dammed sites on 22 streams were sampled. Standard samples were taken during two consecutive springs, 2009 and 2010 in three habitat locations: above dam (reservoir), immediately below dam, and at an undisturbed (reference) site nearby. To estimate biological quality, the national multimetric index (based on five pollution‐sensitive and/or general quality metrics) was used. To estimate direct hydromorphological effects on macroinvertebrates, the locally adapted index, Macroinvertebrates in Estonia: Score of Hydromorphology (MESH) was employed. We found a significant decrease in the biological quality of the above‐dam sites compared to the undisturbed sites (probably due to accumulation of fine sediments and lower flow velocity). Of the five ordinary quality indicators tested, only one (ASPT index) was significantly different between the below‐dam sites and the undisturbed sites. However, the MESH indicated significant stress of macroinvertebrates both at the above‐dam and below‐dam sites, even when flow velocity and bottom type at the below‐dam sites was similar to that at the undisturbed sites. At the same time, hydrochemical parameters were constant among the three habitats. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
INTEGRATION OF RANDOM SAMPLE SELECTION, SUPPORT VECTOR MACHINES AND ENSEMBLES FOR FINANCIAL RISK FORECASTING WITH AN EMPIRICAL ANALYSIS ON THE NECESSITY OF FEATURE SELECTION
Authors: Sun Jie
Published: October 2012

Financial risk forecasting (FRF) is an effective tool to help people forecast whether or not a company will fail in future. Among all techniques of FRF, the support vector machine (SVM) is the most newly developed, and one of the most accurate and effective techniques. This study is devoted to investigating an ensemble model of FRF by integrating bagging with an SVM to generate a data‐driven SVM ensemble. Bagging is used to produce diverse training datasets on which multiple SVM classifiers are trained to make FRF for a target company. Simple voting is employed to produce a final decision from the SVM model committee. The empirical study has two objectives. One is to verify whether the data‐driven SVM ensemble can produce a more dominating performance than the most frequently used techniques in the area of FRF, i.e. multivariate discriminant analysis, logistics regression and a single SVM. The other is to verify whether feature selection is necessary to help the SVM make more precise FRF, although the SVM can handle high‐dimensional data. The results indicate that the data‐driven SVM ensemble significantly improves the predictive ability of SVM‐based FRF. Meanwhile, feature selection can effectively help the SVM achieve better predictive performance, which means that use of feature selection is necessary in SVM‐based FRF. Copyright © 2012 John Wiley & Sons, Ltd.
Attenuation of pain‐related behaviour evoked by carrageenan injection through blockade of neuropeptide Y Y1 and Y2 receptors
Authors: Kostić S. , Puljak L. , Sapunar D.
Published: October 2012

Background

It is well known that neuropeptide Y (NPY) participates in the modulation of chronic pain, but its exact role has not yet been fully explained. In this study, we explored whether targeted delivery of NPY and its antagonists into dorsal root ganglion (DRG) modulates pain‐related behaviour in rats with experimentally induced inflammatory nociception.

Methods

Inflammatory nociception was induced by intraplantar carrageenan injection. Immediately after carrageenan injection, NPY or its antagonists were injected directly into DRG. Behavioural testing was performed on the day preceding the carrageenan injection and four times (5 h after, on the first, fifth and eighth days) following the injection. Immunohistochemical analysis was performed 8 days following the surgery.

Results

Our results showed that NPY, applied directly to DRG, induced cold allodynia in carrageenan inflammatory pain model. NPY in carrageenan‐injected rats did not additionally exacerbate activation of satellite cells in DRG and astrocytes in dorsal horn caused by intraplantar carrageenan injection. However, application of NPY Y1 and Y2 antagonists directly into DRG reversed carrageenan proalgesic effects and reduced gliosis in DRG and dorsal horn.

Conclusion

These findings indicate an important link between pain‐related behaviour and neuroimmune actions of NPY Y1 and Y2 receptors.
The contribution of satellite glial cells to chemotherapy‐induced neuropathic pain
Authors: Warwick R.A. , Hanani M.
Published: October 2012

Background

Chemotherapy‐induced peripheral neuropathy is a serious side effect in cancer treatment, a major manifestation being neuropathic pain that can be debilitating and can reduce the quality of life of the patient. Oxaliplatin and taxol are common anti‐cancer drugs that induce neuropathic pain by an unknown mechanism. We tested the hypothesis that satellite glial cells in dorsal root ganglia (DRGs) are altered in chemotherapy‐induced peripheral neuropathy models and contribute to neuropathic pain.

Methods

Mice were injected with either oxaliplatin or taxol and examined at 7–30 days. Glial fibrillary acidic protein (glial activation marker) expression was determined by immunohistochemistry. Satellite glial cells in isolated DRG were injected with the fluorescent dye Lucifer yellow and the incidence of dye coupling among these cells that surround different neurons was quantified.

Results

Taxol or oxaliplatin increased glial fibrillary acidic protein expression in satellite glial cells. Gap junction‐mediated coupling between satellite glial cells was increased by up to fivefold after oxaliplatin and by up to twofold after taxol. This is consistent with work on other pain models showing that augmented satellite glial cell coupling contributes to chronic pain. Administration of the gap junction blocker carbenoxolone to chemotherapy‐treated mice produced an analgesic‐like effect.

Conclusions

We propose that increased coupling by gap junctions is part of satellite glial cell activation, and that augmented coupling contributes to the lowering of pain threshold in oxaliplatin‐ and taxol‐treated mice. We further propose that gap junction blockers may have potential in treating chemotherapy‐induced neuropathic pain.
Spinal cord stimulation reduces hypersensitivity through activation of opioid receptors in a frequency‐dependent manner
Authors: Sato K.L. , King E.W. , Johanek L.M. , Sluka K.A.
Published: October 2012

Background

Spinal cord stimulation (SCS) is used for the management of chronic intractable neuropathic pain. While used clinically, it is unclear if SCS produces its effects by activation of opioid receptors. The current study aimed to determine if endogenous opioids mediate the analgesia produced by SCS at different frequencies of stimulation in rats with neuropathic pain [spared nerve injury (SNI) model].

Methods

Mechanical withdrawal thresholds of the paw were tested before and after 6 h of SCS at different frequencies (4 Hz, 60 Hz and sham) given daily for 4 days at 90% motor threshold 2 weeks after SNI. Rats were given naloxone (3–10 mg/kg/h), naltrindole (1 mg/kg/h) or were made tolerant to morphine (375 g pellets daily), and effects of SCS were tested.

Results

A dose of 3 mg/kg/h naloxone prevented the analgesia produced by 4‐Hz, but not 60‐Hz, SCS; 10 mg/kg/h prevented the analgesia produced by 60‐Hz SCS. Naltrindole prevented the analgesia produced by 60‐Hz, but not 4‐Hz, SCS. In morphine‐tolerant rats, 4‐Hz SCS had no effect on withdrawal thresholds, but 60‐Hz SCS remained effective as seen by increased withdrawal thresholds.

Conclusion

These results suggest that both 4‐ and 60‐Hz SCS, in part, work through opioid receptor mechanisms, with 4‐Hz SCS activating μ‐opioid receptors while 60‐Hz SCS activated δ‐opioid receptors.
Intensity of chronic pain modifies postural control in low back patients
Authors: Sipko T. , Kuczyński M.
Published: October 2012

Objective

Some recent studies have provided evidence that alteration in central motor control may have causative impact on the emergence and sustenance of chronic pain. We hypothesized that comparison of postural control between patients with high (HP) and low pain (LP) level would display intergroup differences in favour of the LP group lending support for the postulated relationship between altered cortical function and pain.

Methods

Motivated by this concept, we investigated postural control in 36 subjects with chronic low back pain (CLBP) stratified into two groups according to the reported rest pain intensity on a numerical rating scale: LP group (n = 16) and high pain (HP) group (n = 20). The pressure pain threshold (PPT) of selected muscles was assessed on the involved and uninvolved sides. Body balance was investigated on hard or soft surface using postural performance.

Results

As regards pain measurements, the PPT of muscles was lower in HP than in LP (P < 0.05), without differences between the involved and uninvolved sides. Results indicated that patients in HP group relied more on visual input on hard surface than those in LP group (P < 0.05). Changing the stance condition from hard surface to foam decreased sway entropy in LP (P < 0.001), accounting for higher cognitive investment in balance control, while HP had the same level of sway entropy.

Conclusions

Body balance measurements seemed to confirm the hypothesized role of the altered executive function in the CLBP problems, with a further support from pain assessment that indicated central sensitization. Patients with higher self‐reported pain level displayed deficit in the postural adaptability to environmental challenge and lower level of postural automaticity.
Tributyltin and dibutyltin alter secretion of tumor necrosis factor alpha from human natural killer cells and a mixture of T cells and natural killer cells
Authors: Hurt Kelsi , Hurd‐Brown Tasia , Whalen Margaret
Published: October 2012

Butyltins (BTs) have been in widespread use. Tributyltin (TBT) has been used as a biocide in a variety of applications and is found in human blood samples. Dibutyltin (DBT) has been used as a stabilizer in polyvinyl chloride plastics and as a de‐worming agent in poultry. DBT, like TBT, is found in human blood. Human natural killer (NK) cells are the earliest defense against tumors and viral infections and secrete the cytokine tumor necrosis factor‐alpha (TNF‐α). TNF‐α is an important regulator of adaptive and innate immune responses. TNF‐α promotes inflammation and an association between malignant transformation and inflammation has been established. Previously, we have shown that TBT and DBT were able to interfere with the ability of NK cells to lyse tumor target cells. Here we show that BTs alter cytokine secretion by NK cells as well as a mixture of T and NK lymphocytes (T/NK cells). We examined 24‐, 48‐h and 6‐day exposures to TBT (200–2.5 nM) and DBT (5–0.05 μM) on TNF‐α secretion by highly enriched human NK cells and T/NK cells. The results indicate that TBT (200–2.5 nM) decreased TNF‐α secretion from NK cells. In the T/NK cells, 200 nM TBT decreased secretion whereas 100–5 nM TBT increased secretion of TNF‐α. NK cells or T/NK cells exposed to higher concentrations of DBT showed decreased TNF‐α secretion whereas lower concentrations showed increased secretion. The effects of BTs on TNF‐α secretion are seen at concentrations present in human blood. Copyright © 2012 John Wiley & Sons, Ltd.
Activation of nuclear estrogen receptors induced by low‐power laser irradiation via PI3‐K/Akt signaling cascade
Authors: Huang Lei , Tang Yonghong , Xing Da
Published: October 2012

Low‐power laser irradiation (LPLI) has been shown to exert promotive effects on cell survival and proliferation through activation of various signaling pathways. Estrogen receptors (ERs, ERα, and ERβ) are ligand‐activated transcription factors, which regulate target gene expression, promote cell proliferation, and resist apoptosis. However, it is unclear whether LPLI could induce ligand‐independent activation of ERs. In the present study, we investigated the subcellular pools, nuclear redistribution, and transcriptional activity of ERs under LPLI (1.2 J/cm2, 633 nm) treatment using single‐molecule fluorescence imaging and dual‐luciferase reporter assay. We found that ERs were not only localized to nucleus, but also existed in mitochondria. Moreover, we found that LPLI induced nuclear redistribution and transcriptional activity of ERs in a ligand‐independent manner. Our further investigation showed that PI3‐K/Akt signaling cascade was involved in LPLI‐induced activation of ERs. Wortmannin, a PI3‐K inhibitor, or triciribine (API‐2), a specific Akt inhibitor, potently suppressed the nuclear redistribution and transcriptional activity of ERs induced by LPLI, revealing that PI3‐K/Akt signaling cascade was required for the activation of ERs induced by LPLI. Collectively, we demonstrated the first time that LPLI induced the ligand‐independent nuclear redistribution and transcriptional activity of ERs, which were dependent on the activity of PI3‐K/Akt. Our findings provide direct evidence for the molecular mechanisms of LPLI‐induced transcription factor activation. J. Cell. Physiol. © 2012 Wiley Periodicals, Inc.
A novel adipocytokine visfatin protects against H2O2‐induced myocardial apoptosis: A missing link between obesity and cardiovascular disease
Authors: Xiao Jing , Sun Bing , Li Ming , Wu Ying , Sun Xiao‐Bo
Published: October 2012

Fat accumulation in obese individuals worsens the clinical outcomes of cardiovascular disease (CVD). Paradoxically, increased circulating adipocytokines secreted from visceral fat may confer cardioprotective effects. Visfatin, a novel adipocytokine, has anti‐diabetic, anti‐tumor, and pro‐inflammatory properties. However, its effects on cardiomyocytes and the underlying mechanisms remain unknown. This article demonstrated that visfatin counteracted H2O2‐induced apoptotic damage in H9c2 cardiomyocytes in a time‐dependent manner. Qualitative immunofluorescence approaches demonstrated that visfatin pretreatment attenuated H2O2‐induced DNA fragmentation (TdT‐mediated dUTP‐biotin nick end‐labeling), phosphatidyl serine exposure (Annexin V/PI staining), and mitochondrial membrane potential (ΔΨm) depolarization (JC‐1 staining). Biochemical studies on cardiomyoctes showed improved cell viability and reduced caspase‐3 activation caused by visfatin pretreatment. Visfatin did not inhibit the death receptor‐dependent apoptotic pathways, as characterized by its absence in both Fas and TNFR1 down‐regulation. Instead, visfatin specifically suppressed the mitochondria‐dependent apoptotic pathways, as characterized by changed levels of p53 and its downstream Bcl‐2 family genes. Visfatin also up‐regulated the protein levels of phosphorylated AMPK, and the anti‐apoptotic action of visfatin was attenuated by the AMPK‐specific inhibitor compound C. These results suggested that visfatin plays a critical role in cardioprotection by suppressing myocardial apoptosis via AMPK activation. These findings may be the missing link between obesity and CVD. J. Cell. Physiol. 228: 495–501, 2013. © 2012 Wiley Periodicals, Inc.
α11β1 integrin‐mediated MMP‐13‐dependent collagen lattice contraction by fibroblasts: Evidence for integrin‐coordinated collagen proteolysis
Authors: Barczyk Malgorzata M. , Lu Ning , Popova Svetlana N. , Bolstad Anne Isine , Gullberg Donald
Published: October 2012

We have previously determined that integrin α11β1 is required on mouse periodontal ligament (PDL) fibroblasts to generate the force needed for incisor eruption. As part of the phenotype of α11−/− mice, the incisor PDL (iPDL) is thickened, due to disturbed matrix remodeling. To determine the molecular mechanism behind the disturbed matrix dynamics in the PDL we crossed α11−/− mice with the Immortomouse and isolated immortalized iPDL cells. Microarray analysis of iPDL cells cultured inside a 3D collagen gel demonstrated downregulated expression of a number of genes in α11‐deficient iPDL cells, including matrix metalloproteinase‐13 (MMP‐13) and cathepsin K. α11−/− iPDL cells in vitro displayed disturbed interactions with collagen I during contraction of attached and floating collagen lattices and furthermore displayed reduced MMP‐13 protein expression levels. The MMP‐13 specific inhibitor WAY 170523 and the Cathepsin K Inhibitor II both blocked part of the α11 integrin‐mediated collagen remodeling. In summary, our data demonstrate that in iPDL fibroblasts the mechanical strain generated by α11β1 integrin regulates molecules involved in collagen matrix dynamics. The positive regulation of α11β1‐dependent matrix remodeling, involving MMP‐13 and cathepsin K, might also occur in other types of fibroblasts and be an important regulatory mechanism for coordinated extracellular and intracellular collagen turnover in tissue homeostasis. J. Cell. Physiol. © 2012 Wiley Periodicals, Inc.
Variable velocity encoding in a three‐dimensional, three‐directional phase contrast sequence: Evaluation in phantom and volunteers
Authors: Nilsson Anders , Markenroth Bloch Karin , Carlsson Marcus , Heiberg Einar , Ståhlberg Freddy
Published: October 2012

Purpose:

To evaluate accuracy and noise properties of a novel time‐resolved, three‐dimensional, three‐directional phase contrast sequence with variable velocity encoding (denoted 4D‐vPC) on a 3 Tesla MR system, and to investigate potential benefits and limitations of variable velocity encoding with respect to depicting blood flow patterns.

Materials and Methods:

A 4D PC‐MRI sequence was modified to allow variable velocity encoding (VENC) over the cardiac cycle in all three velocity directions independently. 4D‐PC sequences with constant and variable VENC were compared in a rotating phantom with respect to measured velocities and noise levels. Additionally, comparison of flow patterns in the ascending aorta was performed in six healthy volunteers.

Results:

Phantom measurements showed a linear relationship between velocity noise and velocity encoding. 4D‐vPC MRI presented lower noise levels than 4D‐PC both in phantom and in volunteer measurements, in agreement with theory. Volunteer comparisons revealed more consistent and detailed flow patterns in early diastole for the variable VENC sequences.

Conclusion:

Variable velocity encoding offers reduced noise levels compared with sequences with constant velocity encoding by optimizing the velocity‐to‐noise ratio (VNR) to the hemodynamic properties of the imaged area. Increased VNR ratios could be beneficial for blood flow visualizations of pathology in the cardiac cycle. J. Magn. Reson. Imaging 2012; 36:1450–1459. © 2012 Wiley Periodicals, Inc.
Enhancement of the liver and pancreas in the hepatic arterial dominant phase: Comparison of hepatocyte‐specific MRI contrast agents, gadoxetic acid and gadobenate dimeglumine, on 3 and 1.5 tesla MRI in the same patient
Authors: Kim Hee Jin , Kim Bong Soo , Kim Mi Jeong , Kim Seong Hyun , de Campos Rafael O.P. , Hernandes Mateus , Semelka Richard C.
Published: October 2012

Purpose:

To evaluate the relative enhancement of liver, pancreas, focal nodular hyperplasia (FNH), pancreas‐to‐liver index, and FNH‐to‐liver index in the hepatic arterial dominant phase (HADP) after injection of hepatocyte‐specific MRI contrast agents, gadoxetic acid and gadobenate dimeglumine, on 3 and 1.5 Tesla (T) MRI in the same patient.

Materials and Methods:

The MRI database was retrospectively searched to identify consecutive patients who underwent abdominal MRI at 3T and 1.5T systems, using both 0.025 mmol/kg gadoxetic acid‐enhanced and 0.05 mmol/kg gadobenate dimeglumine‐enhanced MRI at the same magnetic strength field system. 22 patients were identified, 10 were scanned at 3T system and 12 at 1.5T system. The enhancement of liver, pancreas, and FNH was evaluated quantitatively on MR images.

Results:

The relative enhancement of liver in HADP in the gadobenate dimeglumine‐enhanced group in all subjects was significantly higher than that in gadoxetic acid‐enhanced group (P = 0.023). The gadobenate dimeglumine‐enhanced group in HADP had better relative enhancement of pancreas and FNH, pancreas‐to‐liver index, and FNH‐to‐liver index than gadoxetic acid‐enhanced group, but the difference was not statistically significant.

Conclusion:

The 0.05 mmol/kg gadobenate dimeglumine‐enhanced abdominal MRI studies at 3T and 1.5T MR systems are superior in relative enhancement of the liver in HADP to 0.025 mmol/kg gadoxetic acid‐enhanced MRI. This type of assessment may provide comparative effectiveness data. J. Magn. Reson. Imaging 2013;37:903–908. © 2012 Wiley Periodicals, Inc.
Reduced‐cost microwave component modeling using space mapping‐enhanced electromagnetic‐based kriging surrogates
Authors: Koziel Slawomir , Bandler John W. , Cheng Qingsha S.
Published: October 2012

We present a versatile technique for constructing fast microwave component models at a low computational cost. Our modeling procedure consists of two stages: (i) kriging interpolation of coarsely discretized electromagnetic simulation data of the device under consideration and (ii) enhancing the kriging model by using space mapping and a limited amount of high‐fidelity electromagnetic simulation data. The use of coarse discretization data allows for low‐cost model generation, whereas space mapping is a convenient way of ensuring its accuracy. Our approach can be applied to almost any type of microwave device; it can also work with other types of nonsmooth or costly low‐fidelity models. The operation and performance of our methodology is demonstrated using a variety of microwave components, including a microstrip filter, a planar ultrawideband antenna, and a microstrip‐to‐coplanar waveguide transition. Copyright © 2012 John Wiley & Sons, Ltd.
The effect direction plot: visual display of non‐standardised effects across multiple outcome domains
Authors: Thomson Hilary J , Thomas Sian
Published: October 2012

Visual display of reported impacts is a valuable aid to both reviewers and readers of systematic reviews. Forest plots are routinely prepared to report standardised effect sizes, but where standardised effect sizes are not available for all included studies a forest plot may misrepresent the available evidence. Tabulated data summaries to accompany the narrative synthesis can be lengthy and inaccessible. Moreover, the link between the data and the synthesis conclusions may be opaque.

This paper details the preparation of visual summaries of effect direction for multiple outcomes across 29 quantitative studies of the health impacts of housing improvement. A one page summary of reported health outcomes was prepared to accompany a 10 000‐word narrative synthesis. The one page summary included details of study design, internal validity, sample size, time of follow‐up, as well as changes in intermediate outcomes, for example, housing condition. This approach to visually summarising complex data can aid the reviewer in cross‐study analysis and improve accessibility and transparency of the narrative synthesis where standardised effect sizes are not available. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of aminoglycoside residues in kidney and honey samples by hydrophilic interaction chromatography‐tandem mass spectrometry
Authors: Kumar Praveen , Rúbies Antoni , Companyó Ramon , Centrich Francesc
Published: October 2012

Two methods based on liquid chromatography–tandem mass spectrometry were developed for the determination of ten aminoglycosides (streptomycin, dihydrostreptomycin, spectinomycin, apramycin, paromomycin, kanamycin A, gentamycin C1, gentamycin C2/C2a, gentamycin C1a, and neomycin B) in kidney samples from food‐producing animals and in honey samples. The methods involved extraction with an aqueous solution (for the kidney samples) or sample dissolution in water (for the honey samples), solid‐phase extraction with a weak cation exchange cartridge and injection of the eluate into a liquid chromatography–tandem mass spectrometry system. A zwitterionic hydrophilic interaction chromatography column was used for separation of aminoglycosides and a triple quadrupole mass analyzer was used for detection. The methods were validated according to Decision 2002/657/EC. The limits of quantitation ranged from 2 to 125 μg/kg in honey and 25 to 264 μg/kg in the kidney samples. Interday precision (RSD%) ranged from 6 to 26% in honey and 2 to 21% in kidney. Trueness, expressed as the percentage of error, ranged from 7 to 20% in honey and 1 to 11% in kidney.
Determination of chlorobenzenes in pure, tap, and sea water by static headspace gas chromatography‐electron capture detection
Authors: Hu Hongmei , Sun Xiumei , Zhong Zhi , Chen Xuechang , Zhang Xiaoning , Guo Yuanming
Published: October 2012

A simple, efficient, solvent‐free, and commercial readily available approach for determination of 11 chlorobenzenes (CBs) in water samples using the static headspace (HS) sampling and gas chromatography‐electron capture detector has been described. The proposed static HS sampling method was initially optimized and the optimum experimental conditions found were 10 mL water sample containing 20% (w/v) sodium chloride placed in a 20 mL vial and stirred at 70°C for 30 min. The linearity of the method ranged from 0.16 to 8.0 μg/L for dichlorobenzene isomers, 0.0176∼0.88 μg/L for trichlorobenzene isomers, 0.004∼0.2 μg/L for tetrachlorobenzene isomers, and from 0.001 to 0.05 μg/L for pentachlorobenzene and hexachlorobenzene, with correlation coefficients ranging between 0.9992 and 0.9999. The limits of detection were in the low μg/L level, ranging between 0.0002 and 0.04 μg/L. The relative recoveries of spiked CBs with external calibration or standard addition method at different concentration levels in pure, tap, and sea water samples were 83∼116%, 89∼108%, and 93∼112%, respectively, and with relative standard deviations of 1.9∼6.3%, 1.6∼5.4%, and 2.5∼5.7% (n = 5), respectively. It is concluded that this method can be successfully applied for the determination of CBs in pure, tap, and sea water samples.
Effect of Crystallization Kinetics on Microstructure and Charge Transport of Polythiophenes
Authors: Vakhshouri Kiarash , Gomez Enrique D.
Published: October 2012

We have examined the effects of crystallization kinetics of poly(3‐hexylthiophene) and poly[2,5‐bis(3‐hexadecylthiophen‐2‐yl)thieno(3,2‐b)thiophene] on microstructure and charge transport. Rapid crystallization increases the density of tie molecules in polythiophenes. As a consequence, ordered regions are better connected resulting in higher charge carrier mobilities. Our results suggest that controlling the crystallization kinetics might be an important factor for maximizing the charge mobility in semicrystalline polythiophene thin films.
Smart Poly(N‐isopropylacrylamide) Containing Iridium(III) Complexes as Water‐Soluble Phosphorescent Probe for Sensing and Bioimaging of Homocysteine and Cysteine
Authors: Liu Shujuan , Qiao Weili , Cao Guoyi , Chen Yang , Ma Yun , Huang Yanqin , Liu Xiangmei , Xu Wenjuan , Zhao Qiang , Huang Wei
Published: October 2012

Homocysteine (Hcy) and cysteine (Cys) are two important kinds of amino acids in human bodies. Herein, we synthesized an iridium(III) complex‐functionalized poly(N‐isopropylacrylamide) and its hydrogel, which could be used as the excellent phosphorescent bioprobe for sensing Hcy and Cys. Their detection can be realized in aqueous system through the variations in absorption and photoluminescence spectra. Furthermore, living cell imaging experiments demonstrate that the phosphorescent bioprobe is membrane permeable and can monitor the changes of Hcy and Cys within living cells. In addition, the probe is also thermoresponsive, and its photoluminescence intensified with increasing temperature. These results suggests that this bioprobe has promising application in biomedical fields.
Dysregulation of FURIN by prostaglandin‐endoperoxide synthase 2 in lung epithelial NCI‐H292 cells
Authors: Brant Kelly A. , Leikauf George D.
Published: October 2012

Because proprotein convertases (PCSKs) activate growth factors and matrix metalloproteinase, these enzymes have been implicated in non‐small cell lung cancer tumor progression and aggressiveness. Previous studies indicate that one PCSK member, FURIN is overexpressed in NSCLC, but little is known regarding the mechanisms driving PCSKs expression during malignant change. We sought to determine whether prostaglandin‐endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase) (PTGS2) (aka COX2), whose expression is also frequently increased in NSCLC, differentially regulates PCSK expression and activity between normal (NHBE) and NSCLC epithelial cells (NCI‐H292, NCI‐H441, A549). NSCLC cells exhibit significantly greater cell‐associated and secreted PCSK activity as compared with NHBE. The heightened activity is consistent with increased FURIN, PCSK4, and PCSK6 protein in the NCSLC cells. Inhibition of PTGS2 activity using NS‐398 and siRNA decreased FURIN mRNA, protein, activity along with cell proliferation in NCI‐H292 cells but not NHBE cells. NSCLC also expressed elevated levels of the transcription factor E2F1. When NCI‐H292 cells were transfected with E2F1 siRNA, both PTGS2 expression and PCSK activity were attenuated, arguing a pivotal role for E2F1 in the differential regulation of PCSKs by PTGS2. Our results highlight a novel role for PTGS2 in NSCLC and may provide a mechanism, whereby PTGS2 inhibitors suppress lung cancer cell growth. © 2012 Wiley Periodicals, Inc.
Tumor‐associated mutations in O6‐methylguanine DNA‐methyltransferase (MGMT) reduce DNA repair functionality
Authors: Lamb Kristy L. , Liu Yanfeng , Ishiguro Kimiko , Kwon Youngho , Paquet Nicolas , Sartorelli Alan C. , Sung Patrick , Rockwell Sara , Sweasy Joann B.
Published: October 2012

MGMT is the primary vehicle for cellular removal of alkyl lesions from the O‐6 position of guanine and the O‐4 position of thymine. While key to the maintenance of genomic integrity, MGMT also removes damage induced by alkylating chemotherapies, inhibiting the efficacy of cancer treatment. Germline variants of human MGMT are well‐characterized, but somatic variants found in tumors were, prior to this work, uncharacterized. We found that MGMT G132R, from a human esophageal tumor, and MGMT G156C, from a human colorectal cancer cell line, are unable to rescue methyltransferase‐deficient Escherichia coli as well as wild type (WT) human MGMT after treatment with a methylating agent. Using pre‐steady state kinetics, we biochemically characterized these variants as having a reduced rate constant. G132R binds DNA containing an O6‐methylguanine lesion half as tightly as WT MGMT, while G156C has a 40‐fold decrease in binding affinity for the same damaged DNA versus WT. Mammalian cells expressing either G132R or G156C are more sensitive to methylating agents than mammalian cells expressing WT MGMT. G132R is slightly resistant to O6‐benzylguanine, an inhibitor of MGMT in clinical trials, while G156C is almost completely resistant to this inhibitor. The impared functionality of expressed variants G132R and G156C suggests that the presence of somatic variants of MGMT in a tumor could impact chemotherapeutic outcomes. © 2012 Wiley Periodicals, Inc.
Genetic alterations of RDINK4/ARF enhancer in human cancer cells
Authors: Li Junan , Knobloch Thomas J. , Poi Ming J. , Zhang Zhaoxia , Davis Andrew T. , Muscarella Peter , Weghorst Christopher M.
Published: October 2012

Recent identification of an enhancer element, RDINK4/ARF (RD), in the prominent INK4/ARF locus provides a novel mechanism to simultaneously regulate the transcription of p15INK4B (p15), p14ARF, and p16INK4A (p16) tumor suppressor genes. While genetic inactivation of p15, p14ARF, and p16 in human tumors has been extensively studied, little is known about genetic alterations of RD and its impact on p15, p14ARF, and p16 in human cancer. The purpose of this study was to investigate the potential existence of genetic alterations of RD in human cancer cells. DNAs extracted from 17 different cancer cell lines and 31 primary pheochromocytoma tumors were analyzed for deletion and mutation of RD using real‐time PCR and direct DNA sequencing. We found that RD was deleted in human cancer cell lines and pheochromocytoma tumors at frequencies of 41.2% (7/17) and 13.0% (4/31), respectively. While some of these RD deletion events occurred along with deletions of the entire INK4/ARF locus, other RD deletion events were independent of genetic alterations in p15, p14ARF, and p16. Furthermore, the status of RD was poorly associated with the expression of p15, p14ARF, and p16 in tested cancer cell lines and tumors. This study demonstrates for the first time that deletion of the RD enhancer is a prevalent event in human cancer cells. Its implication in carcinogenesis remains to be further explored. © 2012 Wiley Periodicals, Inc.
G‐A variant in miR‐200c binding site of EFNA1 alters susceptibility to gastric cancer
Authors: Li Yingfei , Nie Yuqiang , Cao Jie , Tu Sanfang , Lin Yong , Du Yanlei , Li Yuyuan
Published: October 2012

MicroRNAs (miRNAs) post‐transcriptionally modulate gene expression by binding to complementary sites at 3′‐untranslated regions (3′UTRs) of their target messenger RNAs (mRNAs). Genetic variations in miRNA binding sites may alter individual susceptibilities to many cancers. However, whether miRNA binding site single nucleotide polymorphisms (SNPs) interfere with gastric cancer (GC) susceptibility has not been reported. In this case–control study including 525 GC patients and 501 controls, we selected three miRNA binding site SNPs located in 3′UTRs of genes involved in GC to investigated their associations with GC susceptibility. We identified that rs12904 in ephrin‐A1 (EFNA1) gene was significantly associated with risk of GC, with the OR for carrying AG or GG genotype being 0.65 (P = 0.002, OR 0.65; 95% CI, 0.50–0.85) compared with AA genotype. Specifically, we found that rs12904 is in strong linkage disequilibrium (LD) with rs4072037, a susceptibility variant reported by previous genome‐wide association study (GWAS). No significant associations were observed for the other two SNPs (rs699517 in TYMS and rs1042542 in BIRC5). Furthermore, luciferase assays indicated EFNA1 as the target of hsa‐miR‐200c and rs12904 G > A change resulted in altered regulation of luciferase expression. In addition, rs12904 AA genotype was associated with increased expression of EFNA1 mRNA compared with AG or GG genotype in the cancer tissues from 48 patients. Taken together, these findings indicate that the miR‐200c binding site SNP (rs12904 G > A) in the 3′UTR of EFNA1 can modulate EFNA1 expression and is associated with GC susceptibility. Larger replication studies are needed to confirm our findings. © 2012 Wiley Periodicals, Inc.
Inhibition of the focal adhesion kinase and vascular endothelial growth factor receptor‐3 interaction leads to decreased survival in human neuroblastoma cell lines
Authors: Beierle Elizabeth A. , Ma Xiaojie , Stewart Jerry E. , Megison Michael , Cance William G. , Kurenova Elena V.
Published: October 2012

Neuroblastoma continues to be a devastating childhood solid tumor and is responsible for over 15% of all childhood cancer‐related deaths. Focal adhesion kinase (FAK) and vascular endothelial growth factor receptor‐3 (VEGFR‐3) are protein tyrosine kinases that are overexpressed in a number of human cancers, including neuroblastoma. These two kinases can directly interact and provide survival signals to cancer cells. In this study, we utilized siRNA to VEGFR‐3 to demonstrate the biologic importance of this kinase in neuroblastoma cell survival. We also used confocal microscopy and immunoprecipitation to show that FAK and VEGFR‐3 bind in neuroblastoma. Finally, employing a 12‐amino‐acid peptide (AV3) specific to VEGFR‐3, we showed that the colocalization between FAK and VEGFR‐3 could be disrupted, and that disruption resulted in decreased neuroblastoma cell survival. These studies provide insight to the FAK–VEGFR‐3 interaction in neuroblastoma and demonstrate its importance in this tumor type. Focusing upon the FAK–VEGFR‐3 interaction may provide a novel therapeutic target for the development of new strategies for treatment of neuroblastoma. © 2012 Wiley Periodicals, Inc.
Differential expression of CD133 based on microsatellite instability status in human colorectal cancer
Authors: Park Jae Jun , Kwon Ji‐hee , Oh Sun‐Hee , Choi Junjeong , Moon Chang Mo , Ahn Joong Bae , Hong Sung Pil , Cheon Jae Hee , Kim Tae Il , Kim Hoguen , Kim Won Ho
Published: October 2012

The association between the types of genomic instability and cancer stem cell (CSC) has not been elucidated. We aimed to investigate the expressions of CSC markers with respect to microsatellite instability (MSI) status in human colorectal cancer (CRC). Immunostainings for CD133, CD44, and CD166, and K‐ras mutation analysis were performed on 50 MSI‐high (MSI‐H), and 50 microsatellite stable (MSS) CRC tissues. In 11 MSS and MSI‐H CRC cell lines, CD133 expression and DNA methylation statuses of the CD133 promoter were determined. The proportion of CD133 positive cells and the ability of colosphere formation were compared between HCT116 cells and HCT116 + Chr3 cells (hMLH1‐restored HCT116 cells). Immunohistochemistry for CSC markers revealed that high CD133 expression was more frequent in MSS cancers than in MSI‐H (P < 0.001, 74.0% vs. 28.0%, respectively), and related with short disease‐free survival. Neither CD44 nor CD166 expression differed significantly with respect to MSI status. K‐ras mutation showed no association with expressions of CD133, CD44, or CD166. CD133 expression was relatively high in the MSS cell lines compared to those in MSI‐H, and showed a reverse correlation with DNA methylation of the CD133 promoter. hMLH1‐restored HCT116 cells increased proportions of CD133 positive cells and colosphere forming ability, compared to those in HCT116 cells. In conclusion, high levels of CD133 expression were observed more frequently in MSS CRC than in MSI‐H, suggesting that differential expression of colon CSC markers may be linked to tumor characteristics dependent on MSI status. © 2012 Wiley Periodicals, Inc.
Vitamin D reduces the inflammatory response and restores glucose uptake in adipocytes
Authors: Marcotorchino Julie , Gouranton Erwan , Romier Beatrice , Tourniaire Franck , Astier Julien , Malezet Christiane , Amiot Marie‐Josèphe , Landrier Jean‐François
Published: October 2012

Scope

Obesity is strongly associated with low‐grade inflammation, notably due to an overproduction of proinflammatory markers by adipose tissue and adipocytes as well as a vitamin D deficiency. Whether these problems are interrelated has not been clearly established.

Methods and results

In the present report, decreases in the levels of inflammatory markers such as IL‐6, MCP‐1, and IL‐1β (mRNA and protein level) in human adipocytes and in 3T3‐L1 adipocytes were observed after 1,25‐dihydroxyvitamin D3 (1,25‐(OH)2D3) treatment. Such treatment also decreased the expression of the TNF‐α‐mediated proinflammatory marker in 3T3‐L1 and human adipocytes. A similar effect was observed in adipocyte‐macrophage co‐culture systems in which 1,25‐(OH)2D3 decreased proinflammatory marker expression under basal and TNF‐α‐stimulated conditions. The involvement of VDR and NF‐κB was confirmed in these regulations. Incubation with 1,25‐(OH)2D3 also resulted in the dephosphorylation of p38, which is linked to the transcriptional induction of several Dusp family members. Functional consequences of the 1,25‐(OH)2D3 treatment on glucose uptake and AKT phosphorylation were observed.

Conclusion

The improvement of both proinflammatory status and glucose uptake in adipocytes under 1,25‐(OH)2D3 effect suggests that low‐grade inflammation could be linked to vitamin D deficiency. This observation offers new perspectives in the context of obesity and associated physiopathological disorders.
Delayed bacterial colonization of the gut alters the host immune response to oral sensitization against cow's milk proteins
Authors: Morin Stéphanie , Fischer Romy , Przybylski‐Nicaise Laetitia , Bernard Hervé , Corthier Gérard , Rabot Sylvie , Wal Jean‐Michel , Hazebrouck Stéphane
Published: October 2012

Scope

Cow's milk allergy is the most prevalent food allergy in infants whose immune system development is critically stimulated during postnatal gut colonization by commensal bacteria. Allergenic potential of cow's milk β‐lactoglobulin (BLG) and caseins (CAS) was investigated in germ‐free (GF) BALB/c mice and in GF mice conventionalized (CVd) at 6 weeks of age.

Methods and results

Oral sensitization to cow's milk in the presence of cholera toxin led to higher BLG‐specific IgE, IgG1, and IgG2a responses in GF mice than in conventional (CV) mice. No significant difference was observed for CAS‐specific IgE responses although IgG1 responses to αS1‐ and κ‐caseins were higher in GF mice than in CV mice. CVd mice, orally inoculated with fecal preparations from CV mice, also displayed biased antibody responses compared to CV mice. Secretion of Th2 cytokines by BLG‐ and CAS‐reactivated splenocytes of CVd mice was similar to that of GF mice whereas cytokine production by reactivated cells from mesenteric lymph nodes of CVd mice was equivalent to that of CV mice.

Conclusion

Oral sensitization to BLG and CAS was differentially affected by the absence of gut microbiota and delayed bacterial colonization altered persistently the host immune response to oral sensitization against food antigens.
Neurocranial Trauma in the Late Archaic Human Remains from Xujiayao, Northern China
Authors: Wu X. J. , Trinkaus E.
Published: October 2012

The early Late Pleistocene late archaic human remains from Xujiayao, northern China, reveal several abnormalities of the neurocranial vault. The Xujiayao site is located on the northwestern boundary of the Nihewan Basin, and on the basis of various indicators, it dates to the early Late Pleistocene. Among the 15 human neurocranial elements found at Xujiayao in the 1970s, three elements show minor traumatic lesions of the external table: the largely complete Xujiayao 5a immature parietal bone, the Xujiayao 8 small piece of anterior right parietal bone and the Xujiayao 12 partial occipital bone. The lesions are all superior to the temporal or nuchal lines and hence were subcutaneous, covered only by the pericranium, the galea aponeurotica and the overlying skin. The external tables are variably concave with irregular bone within the bony depressions, and the diploë show varying degrees of involvement. The Xujiayao abnormalities join a series of minor neurocranial healed lesions among Pleistocene humans, as well as more pronounced healed neurocranial and facial trauma. Copyright © 2012 John Wiley & Sons, Ltd.
Molecular Recognition in Glycolaldehyde, the Simplest Sugar: Two Isolated Hydrogen Bonds Win Over One Cooperative Pair
Authors: Altnöder Jonas , Lee Juhyon J. , Otto Katharina E. , Suhm Martin A.
Published: October 2012

Carbohydrates are used in nature as molecular recognition tools. Understanding their conformational behavior upon aggregation helps in rationalizing the way in which cells and bacteria use sugars to communicate. Here, the simplest α‐hydroxy carbonyl compound, glycolaldehyde, was used as a model system. It was shown to form compact polar C2‐symmetric dimers with intermolecular OH⋅⋅⋅OC bonds, while sacrificing the corresponding intramolecular hydrogen bonds. Supersonic jet infrared (IR) and Raman spectra combined with high‐level quantum chemical calculations provide a consistent picture for the preference over more typical hydrogen bond insertion and addition patterns. Experimental evidence for at least one metastable dimer is presented. A rotational spectroscopy investigation of these dimers is encouraged, also in view of astrophysical searches. The binding motif competition of aldehydic sugars might play a role in chirality recognition phenomena of more complex derivatives in the gas phase.