bluuebunny/crossref_metadata_2025 huggingface dataset:
Reoperative surgery for bilateral multinodular goitre in the era of total thyroidectomy
Authors: Vasica G , O'Neill C J , Sidhu S B , Sywak M S , Reeve T S , Delbridge L W
Published: January 2012

Background

Total thyroidectomy, rather than bilateral subtotal thyroidectomy, is now accepted as the preferred management for bilateral benign multinodular goitre (BMNG) in order to reduce the need for reoperative surgery. The aim of this study was to examine whether this approach has had an impact on presentation for bilateral reoperative thyroid surgery.

Methods

This was a retrospective cohort study. The study group comprised patients presenting with recurrent BMNG who underwent bilateral reoperative thyroid surgery following previous bilateral subtotal or partial thyroidectomy. They were compared with patients undergoing unilateral reoperative thyroid surgery following previous lobectomy, and those undergoing primary total thyroidectomy for BMNG.

Results

Between 1 January 1987 and 31 December 2009, 12 354 consecutive thyroid procedures were undertaken. Among those with BMNG, primary total thyroidectomy was undertaken in 3298 patients, unilateral reoperative thyroidectomy in 337 and bilateral reoperative thyroidectomy in 191. Presentations of patients with recurrent BMNG declined gradually over the study period following the change in policy from subtotal to total thyroidectomy; only five patients (representing less than 0·5 per cent of all thyroid surgery) underwent bilateral reoperative surgery for BMNG in the last year of the study. Four of these patients had their initial operation before 1987 and in another unit, whereas the remaining patient initially had surgery overseas.

Conclusion

The introduction of a policy of initial total thyroidectomy for bilateral BMNG has essentially eliminated the need for bilateral reoperative surgery for recurrent goitre.
Characterization of secondary volatile profiles in Nigella sativa seeds from two different origins using accelerated solvent extraction and gas chromatography‐mass spectrometry
Authors: Liu Xue , Abd El‐Aty A. M. , Cho S.‐K. , Yang Angel , Park Jong‐Hyouk , Shim Jae‐Han
Published: January 2012

The extraction and identification of bioactive compounds from herbs is of great interest. In this study, accelerated solvent extraction (ASE) technique was used to analyze the secondary volatile profiles in Nigella sativa seeds obtained from two different origins, Egypt and Bangladesh. The main extraction parameters, including extraction temperature, pressure and static extraction time, were investigated and optimized. Identification and quantification of the major constituents in nonpolar extracts (hexane) were achieved by means of GC‐FID/GC‐MS analysis with external standards. The two seeds showed a similar variety of chemical composition; however, the secondary volatiles profile of Bangladesh seed was higher than that of the Egyptian seed. A total of 25 compounds were identified from the ASE extract under the following optimum extraction conditions: 100°C, 1500 psi and 5 min, for extraction temperature, pressure and static time, respectively. The proposed technique can be used for the characterization of N. sativa varieties or cultivars. Copyright © 2012 John Wiley & Sons, Ltd.
Kinetics of CO2 Absorption by a Blended Aqueous Amine Solution
Authors: Ume C. S. , Ozturk M. C. , Alper E.
Published: January 2012

The reaction rates of CO2 in an aqueous blend of amine solutions of N‐(2‐hydroxethyl)piperazine (N‐HEPZ) and 2‐amino‐2‐hydroxymethyl‐1,3‐propanediol (AHPD) at 298 K were investigated in a concentration range of 0.0025–0.03 kmol m–3 N‐HEPZ with a blend of 1 kmol m–3 AHPD. The reaction was modeled using a termolecular reaction mechanism with a rate of 12 971 m3kmol–1s–1. The results indicate that the blended aqueous solution of N‐HEPZ and AHPD is a potential candidate as an alternative solvent for CO2 absorption, where the sterically hindered AHPD increases the CO2 capacity and the reaction rate is enhanced by the promoter, N‐HEPZ.
Carbon Dioxide Capture from Power Generation – Status of Cost and Performance
Authors: Finkenrath M.
Published: January 2012

Energy scenarios suggest that CO2 capture and storage (CCS) from power plants might contribute significantly to global greenhouse gas emission reduction. Since CCS from power generation is an emerging technology that has not been demonstrated on a commercial scale, related cost and performance information is still uncertain. This paper presents a detailed analysis of the impact of adding CO2 capture and compression process equipment to fossil‐fuelled power plants. For coal‐fired power generation, no single capture technology outperforms available alternative capture processes in terms of cost and performance.
Examination of the influence of different variables on prediction of unit cell parameters in perovskites using counter‐propagation artificial neural networks
Authors: Kuzmanovski Igor , Dimitrovska‐Lazova Sandra , Aleksovska Slobotka
Published: January 2012

In this work, the unit cell parameter (a) of the series of cubic ABX3 perovskites was modeled using counter‐propagation artificial neural networks, and the influence of different input variables was examined by using algorithm for automatic adjustment of the relative importance of the variables. The input variables used in this model were the ionic radii of A, B, and X as well as the oxidation state (z) and the electronegativity (χ) of the anion.

The developed models have good generalization performances—good agreement between experimental and predicted values for lattice parameter. One of the important outcomes from this work is obtained from the results of the automatic adjustment of the relative importance of input variables. That is to say, this analysis gave us an insight that the most pronounced influence on the successful prediction of the unit cell parameter of the analyzed data set of cubic ABX3 perovskites has the effective ionic radii of B‐cation. In addition to this, it may be concluded that the separation of the compounds in different regions of counter‐propagation artificial neural networks was predominantly influenced by the input variables with regard to the physical parameters of the anion. Copyright © 2012 John Wiley & Sons, Ltd.
Switchable Self‐Assembly of a Bioinspired Alkyl Catechol at a Solid/Liquid Interface: Competitive Interfacial, Noncovalent, and Solvent Interactions
Authors: Saiz‐Poseu Javier , Faraudo Jordi , Figueras Antoni , Alibes Ramon , Busqué Felix , Ruiz‐Molina Daniel
Published: January 2012

The large tendency of catechol rings to adsorb on surfaces has been studied by STM experiments with molecular resolution combined with molecular‐dynamics simulations. The strong adhesion is due to interactions with the surface and solvent effects. Moreover, the thermodynamic control over the differential adsorption of 1 and the nonanoic solvent molecules has been used to induce a new temperature‐induced switchable interconversion. Two different phases that differ in their crystal packing and the presence of solvent molecules coexist upon an increase or decrease in the temperature. These results open new insight into the behavior of catechol molecules on surfaces and 2D molecular suprastructures.
Practical exercises for learning to construct NMR/MRI probe circuits
Authors: Wheeler Dustin D. , Conradi Mark S.
Published: January 2012

Nine sets of laboratory exercises are designed to acquaint the student with many aspects of NMR/MRI probe resonant circuits. These include demonstrations of stray inductance and capacitance, matching a resonant circuit to 50 Ω, inductive coupling, doubly resonant circuits, loading effects of tissue, and radiation from the probe circuit. Many of the exercises are for the bench, but some are performed in an NMR system. The exercises should lead to an understanding of, as well as some intuitive knowledge about, basic NMR/MRI probe circuits. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40: 1–13, 2012.
Synthesis and characterization of 5‐methoxy‐2‐methyl‐N,N‐dialkylated tryptamines
Authors: Brandt Simon D. , Tearavarich Ruchanok , Dempster Nicola , Cozzi Nicholas V. , Daley Paul F.
Published: January 2012

The absence of reference material is a commonly experienced difficulty among medical and forensic professionals tasked with identifying new psychoactive substances that are encountered for the first time. The identification of newly emerging substances lies at the heart of forensic and clinical analysis, and a proactive public health policy calls for a thorough analysis of the properties of new psychoactive substances before they appear in the emergency clinic, where they may be noticed because of adverse reactions or toxicity. For example, a wide range of N,N‐dialkyltryptamines show psychoactive properties in humans and these tryptamines are sometimes encountered as intoxicants. However, most of the existing reference data on new psychoactive tryptamines have been obtained retrospectively, after reports of acute toxicities. To address the need for reference standards for new tryptamines, thirteen 5‐methoxy‐2‐methyl‐N,N‐dialkyltryptamines were prepared. Analytical characterization was based on 1H and 13C nuclear magnetic resonance (NMR), gas chromatography‐electron ionization ion‐trap mass spectrometry (GC‐EI‐IT‐MS) and chemical ionization‐ion‐trap tandem mass spectrometry (CI‐IT‐MS/MS), respectively. Differentiation among isomers was feasible by NMR and MS. In addition to the expected iminium ion base peak, indole‐related key ions were detected under EI‐IT‐MS conditions at m/z 174, 159, 131, 130, and 103. CI‐IT‐MS/MS analysis of the 5‐methoxy‐2‐methyl derivatives revealed the presence of m/z 188 in addition to [M+H]+ and the iminium species. This study served as an extension from previous work on isomeric 5‐ethoxylated counterparts and confirmed the ability to differentiate between the two groups. The data provided here add to the existing body of literature and aim to serve both forensic and clinical communities. Copyright © 2012 John Wiley & Sons, Ltd.
A Systematic Study of Electrochemical and Spectral Properties for the Electronic Interactions in Porphyrin–Triphenylamine Conjugates
Authors: Huang Chih‐Yen , Hsu Chao‐Yen , Yang Luo‐Yi , Lee Chia‐Jung , Yang Te‐Fang , Hsu Chia‐Chan , Ke Chung‐Hsiu , Su Yuhlong Oliver
Published: January 2012

A series of mono‐, di‐, tri‐, and tetra‐triphenylamine (TPA)‐substituted porphyrinatozinc complexes have been synthesized to investigate their spectral and electrochemical properties. The varied shapes of absorption spectra of porphyrin–triphenylamine (Por–TPA) conjugates in comparison with tetramesitylporphyrinatozinc (ZnTMP) indicate that there are strong interactions between porphyrin and TPA moieties. In general, the electron‐donating capability of a substituent on TPA and the number of TPA derivatives that bond with porphyrin would cause Soret band broadening and intensification of the Q(0,0) band. Due to the antenna effect of these conjugates, the fluorescence quantum yields were enhanced when more TPA moieties were linked. Cyclic voltammetry and spectroelectrochemical methods revealed the redox properties of Por–TPA conjugates. Axial ligation of porphyrinatozinc with N‐methylimidazole was useful in differentiating the oxidation site of Por–TPA conjugates. The first one‐electron oxidations of these conjugates are at the porphyrin ring. The charge‐transfer bands present in the near‐IR region in the absorption spectra of Por–TPA radical cations are evidence of an electronic interaction between porphyrin and TPA. The electron‐donating strength of the TPA group and the symmetry of the Por–TPA conjugate affect the intensity of the charge‐transfer band.
Kβ Detected High‐Resolution XANES of FeII and FeIII Models of the 2‐His‐1‐Carboxylate Motif: Analysis of the Carboxylate Binding Mode
Authors: Mijovilovich Ana , Hayashi Hisashi , Kawamura Naomi , Osawa Hitoshi , Bruijnincx Pieter C. A. , Klein Gebbink Robertus J. M. , de Groot Frank M. F. , Weckhuysen Bert M.
Published: January 2012

Proteins sharing the same “2‐His‐1‐carboxylate” structural motif have little amino acid sequence similarity and are able to perform many different reactions. Many factors have been cited to explain their different specificity and turnover rates, like protein environment, coordinated ligand geometry, electronic structure of the active site, etc. In this paper, we present a combined approach applying high‐resolution XANES spectroscopy and theory simulations to different model complexes that mimic the binding modes of the amino acids to the metal site. Experiments were performed on three compounds showing three metal sites: ferrous hexacoordinate, ferric pentacoordinate and ferrous pentacoordinate. The first two compounds bear an N,N,O‐tridentate 3,3‐bis(1‐alkylimidazol‐2‐yl)propionate ligand that features a monodentate carboxylate group. These complexes mimic the activity of extradiol dioxygenases but also exhibit intradiol cleavage activity. The third compound features a bidentate terphenylcarboxylate ligand and a sterically hindered bidentate N,N‐donor, thus providing a good structural mimic of the ternary enzyme‐tetrahydrobiopterin‐substrate complex in pterin‐dependent phenylalanine hydroxylase, which also contains a bidentate carboxylate. Modeling of high‐resolution XANES on well‐defined model complexes of different geometry can aid in protein structure elucidation. XANES gives the oxidation state and coordination number of the metal in the non‐crystallized protein at natural pH. The accuracy of the results is limited by the core‐hole and experimental broadenings. We found that high‐resolution XANES experiments give increased resolution at the pre‐edges, but limited improvement at the main edge. These high‐resolution pre‐edges can be accurately simulated by using crystal field multiplet theory (CFM). We show that by combining modelling and XANES simulations with FEFF8, detailed structural and chemical information can be obtained. We found that a short O2–metal distance for the carboxylate oxygen atom not bound to the metal causes a higher white line in FeII, which is similar to the results obtained for the pterin‐dependent hydroxylase, tyrosine hydroxylase (TYH). Full‐potential FDMNES simulations for each sample confirm the accuracy of the main results with muffin‐tin approximation (FEFF8).
Efficient Synthesis of Arylated Flavones by Site‐Selective Suzuki–Miyaura Cross‐Coupling Reactions of the Bis(triflate) of 5,7‐ and 7,8‐Dihydroxyflavone
Authors: Eleya Nadi , Malik Imran , Reimann Sebastian , Wittler Kai , Hein Martin , Patonay Tamás , Villinger Alexander , Ludwig Ralf , Langer Peter
Published: January 2012

Suzuki–Miyaura reactions of the bis(triflate) of 5,7‐ and 7,8‐dihydroxyflavone proceed with very good site selectivity in favor of position 7 and allow the synthesis of various arylated flavones. The reaction of 5,7‐dihydroxyflavone with one equivalent of triflic anhydride also proceeds with very good site selectivity in favor of position 7. The subsequent Suzuki–Miyaura reaction of the product allows the synthesis of 7‐aryl‐5‐hydroxyflavones. The regioselectivity is discussed based on DFT calculations.
An Efficient Route to Quinolines and Other Compounds by Iron‐Catalysed Cross‐Dehydrogenative Coupling Reactions of Glycine Derivatives
Authors: Liu Peng , Wang Zhiming , Lin Jue , Hu Xianming
Published: January 2012

A simple method has been developed for functionalizing glycine derivatives by iron‐catalysed cross‐dehydrogenative coupling (CDC) reactions. In particular, N‐arylglycine derivatives reacted with alkynes by oxidative C–H/C–H coupling reactions to provide a series of substituted quinolines starting from commercially inexpensive materials. Moreover, N‐arylglycine esters can be oxidatively coupled to ketones by using FeCl3 in the presence of DDQ.
Microbial trans‐glutaminase enhances the physical and mechanical properties of depigmented wool
Authors: Montazer Majid , Pajootan Elmira , Lessan Fatemeh
Published: January 2012

This study investigates the effects of enzymatic treatment with microbial trans‐glutaminase (m‐TGase) on the physical and mechanical properties of the depigmented wool yarns. Coarse pigmented wool yarns were treated with iron (II) followed by depigmentation with both oxidative and oxidative‐reductive chemicals. The depigmented wool yarns were then treated with m‐TGase to reduce the negative effects of the harsh chemicals. Diverse features of the wool yarns, including: tensile strength, elongation, color, diameter, moisture content, alkali solubility, and weight reduction, were measured before and after bleaching and enzymatic treatments. The treatment with the oxidative and reductive agents led to reduced tensile strength and elongation, and increased lightness, alkali solubility, and moisture content of the yarns. In contrast, the enzymatic treatment by m‐TGases cross‐linked the proteins of wool fibers via reaction between glutamine and lysine isodipeptide remediated the wool yarns. This improved the tensile strength and elongation and decreased the alkali solubility and moisture content. Fourier transform infrared spectroscopy (FTIR) was used to follow the chemical changes in wool fibres during depigmentation and enzymatic treatments.
Development and sensory profile of a probiotic beverage from apple fermented with Lactobacillus casei
Authors: de Souza Neves Ellendersen Luciana , Granato Daniel , Bigetti Guergoletto Karla , Wosiacki Gilvan
Published: January 2012

The objective of this study was the development and optimization of a probiotic apple beverage as well as the establishment of a sensory profile by using chemical, microbiological, and quantitative descriptive analysis (sensory profiling). For this purpose, both Lactobacillus casei and L. acidophilus were tested in two different media ‐ Fuji and Gala apple juices ‐ at different pH values. The optimal conditions to develop the apple probiotic beverage were obtained by response surface methodology. They were found to be 10 h of fermentation at 37oC in Gala apple juice. Sensorially, the clarified Gala apple juice was characterized by a caramel color, apple aroma, and an acidic apple taste. The fresh fermented probiotic apple beverage was characterized by a thick texture and sweet taste. The probiotic apple beverage stored for 28 days at 7oC presented a thick texture and acidic taste. Finally, when the fermented probiotic beverage was tested by potential consumers, it presented an acceptance index of 96%.
Velocities of a spatial–temporal stochastic field with embedded dynamics
Authors: Podgórski Krzysztof , Wegener Jörg
Published: January 2012

The paper investigates further an approach to modeling dynamically changing Gaussian spatiotemporal fields. In that approach, the dynamics are introduced by embedding deterministic velocities into a stochastic spatiotemporal Gaussian model. In this way, a dynamically inactive stochastic field with given spatial and temporal covariance structure gains dynamics that in general follow a deterministic pattern. Here, we make an important connection between the resulting stochastic field and underlying deterministic dynamics by demonstrating that in the case of isotropic spatial dependencies, the observed random velocities are centered at the velocities of the underlying physical flow. Additionally, we discuss strategies for simulation of such fields and give foundation for fitting and prediction procedures that are based on the obtained results. In an effort to illustrate attractiveness of the approach for modeling environmental phenomena, we consider a parameterized specification of spatiotemporal correlation structure and embed to it the dynamics driven by the shallow water equations. Through simulations, we show how the spatiotemporal behavior of the resulting nonstationary Gaussian field is altered by the embedded dynamics. Copyright © 2012 John Wiley & Sons, Ltd.
In situ remediation of contaminated sediments using carbonaceous materials
Authors: Rakowska M.I. , Kupryianchyk D. , Harmsen J. , Grotenhuis T. , Koelmans A.A.
Published: January 2012

Carbonaceous materials (CM), such as activated carbons or biochars, have been shown to significantly reduce porewater concentrations and risks by binding hydrophobic organic compounds (HOCs) present in aquatic sediments. In the present study, the authors review the current state-of-the-art use of CM as an extensive method for sediment remediation, covering both technical and ecological angles. The review addresses how factors such as CM type, particle size and dosage, sediment characteristics, and properties of contaminants affect the effectiveness of CM amendment to immobilize HOCs in aquatic sediments. The authors also review the extent to which CM may reduce bioaccumulation and toxicity of HOCs and whether CM itself has negative effects on benthic species and communities. The review is based on literature and datasets from laboratory as well as field trials with CM amendments. The presence of phases such as natural black carbon, oil, or organic matter in the sediment reduces the effectiveness of CM amendments. Carbonaceous material additions appear to improve the habitat quality for benthic organisms by reducing bioavailable HOC concentrations and toxicity in sediment. The negative effects of CM itself on benthic species, if any, have been shown to be mild. The beneficial effects of reducing toxicity at low CM concentrations most probably outweigh the mild negative effects observed at higher CM concentrations. Environ. Toxicol. Chem. 2012;31:693–704. © 2012 SETAC
Numerical control of two‐dimensional shock waves in dual solution domain by instant temperature disturbances
Authors: Alekseev A.K. , Navon I.M.
Published: January 2012

The search for the temperature disturbance causing transition between regular and Mach reflections in the dual solution domain is addressed in an optimization statement. The gradient of the discrepancy between the current and target flow fields was calculated using adjoint equations. The control was determined by gradient‐based optimization. The flow field simulation is verified via a posteriori error estimates using the solution of an additional adjoint problem. Copyright © 2012 John Wiley & Sons, Ltd.
Relationship between glial potassium regulation and axon excitability: A role for glial Kir4.1 channels
Authors: Bay Virginia , Butt Arthur M.
Published: January 2012

Uptake of K+ released by axons during action potential propagation is a major function of astrocytes. Here, we demonstrate the importance of glial inward rectifying potassium channels (Kir) in regulating extracellular K+ ([K+]o) and axonal electrical activity in CNS white matter of the mouse optic nerve. Increasing optic nerve stimulation frequency from 1 Hz to 10–35 Hz for 120 s resulted in a rise in [K+]o and consequent decay in the compound action potential (CAP), a measure of reduced axonal activity. On cessation of high frequency stimulation, rapid K+ clearance resulted in a poststimulus [K+]o undershoot, followed by a slow recovery of [K+]o and the CAP, which were more protracted with increasing stimulation frequency. Blockade of Kir (100 μM BaCl2) slowed poststimulus recovery of [K+]o and the CAP at all stimulation frequencies, indicating a primary function of glial Kir was redistributing K+ to the extracellular space to offset active removal by Na+‐K+ pumps. At higher levels of axonal activity, Kir blockade also increased [K+]o accumulation, exacerbating the decline in the CAP and impeding its subsequent recovery. In the Kir4.1−/− mouse, astrocytes displayed a marked reduction of inward currents and were severely depolarized, resulting in retarded [K+]o regulation and reduced CAP. The results demonstrate the importance of glial Kir in K+ spatial buffering and sustaining axonal activity in the optic nerve. Glial Kir have increasing importance in K+ clearance at higher levels of axonal activity, helping to maintain the physiological [K+]o ceiling and ensure the fidelity of signaling between the retina and brain. © 2012 Wiley Periodicals, Inc.
Bilateral reorganization of posterior temporal cortices in post‐lingual deafness and its relation to cochlear implant outcome
Authors: Lazard Diane S. , Lee Hyo‐Jeong , Truy Eric , Giraud Anne‐Lise
Published: January 2012

Post‐lingual deafness induces a decline in the ability to process phonological sounds or evoke phonological representations. This decline is paralleled with abnormally high neural activity in the right posterior superior temporal gyrus/supramarginal gyrus (PSTG/SMG). As this neural plasticity negatively relates to cochlear implantation (CI) success, it appears important to understand its determinants. We addressed the neuro‐functional mechanisms underlying this maladaptive phenomenon using behavioral and functional magnetic resonance imaging (fMRI) data acquired in 10 normal‐hearing subjects and 10 post‐lingual deaf candidates for CI. We compared two memory tasks where subjects had to evoke phonological (speech) and environmental sound representations from visually presented items. We observed dissociations in the dynamics of right versus left PSTG/SMG neural responses as a function of duration of deafness. Responses in the left PSTG/SMG to phonological processing and responses in the right PSTG/SMG to environmental sound imagery both declined. However, abnormally high neural activity was observed in response to phonological visual items in the right PSTG/SMG, i.e., contralateral to the zone where phonological activity decreased. In contrast, no such responses (overactivation) were observed in the left PSTG/SMG in response to environmental sounds. This asymmetry in functional adaptation to deafness suggests that maladaptive reorganization of the right PSTG/SMG region is not due to balanced hemispheric interaction, but to a specific take‐over of the right PSTG/SMG region by phonological processing, presumably because speech remains behaviorally more relevant to communication than the processing of environmental sounds. These results demonstrate that cognitive long‐term alteration of auditory processing shapes functional cerebral reorganization. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Visual cognition in disorders of consciousness: From V1 to top‐down attention
Authors: Monti Martin M. , Pickard John D. , Owen Adrian M.
Published: January 2012

What is it like to be at the lower boundaries of consciousness? Disorders of consciousness such as coma, the vegetative state, and the minimally conscious state are among the most mysterious and least understood conditions of the human brain. Particularly complicated is the assessment of residual cognitive functioning and awareness for diagnostic, rehabilitative, legal, and ethical purposes. In this article, we present a novel functional magnetic resonance imaging exploration of visual cognition in a patient with a severe disorder of consciousness. This battery of tests, first developed in healthy volunteers, assesses increasingly complex transformations of visual information along a known caudal to rostral gradient from occipital to temporal cortex. In the first five levels, the battery assesses (passive) processing of light, color, motion, coherent shapes, and object categories (i.e., faces, houses). At the final level, the battery assesses the ability to voluntarily deploy visual attention in order to focus on one of two competing stimuli. In the patient, this approach revealed appropriate brain activations, undistinguishable from those seen in healthy and aware volunteers. In addition, the ability of the patient to focus one of two competing stimuli, and switch between them on command, also suggests that he retained the ability to access, to some degree, his own visual representations. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Cannabinoid receptor 2 agonist ameliorates mesenteric angiogenesis and portosystemic collaterals in cirrhotic rats
Authors: Huang Hui-Chun , Wang Sun-Sang , Hsin I-Fang , Chang Ching-Chih , Lee Fa-Yauh , Lin Han-Chieh , Chuang Chiao-Lin , Lee Jing-Yi , Hsieh Hsian-Guey , Lee Shou-Dong
Published: January 2012

Angiogenesis in liver cirrhosis leads to splanchnic hyperemia, increased portal inflow, and portosystemic collaterals formation, which may induce lethal complications, such as gastroesophageal variceal hemorrhage and hepatic encephalopathy. Cannabinoids (CBs) inhibit angiogenesis, but the relevant influences in cirrhosis are unknown. In this study, Spraque-Dawley rats received common bile duct ligation (BDL) to induce cirrhosis. BDL rats received vehicle, arachidonyl-2-chloroethylamide (cannabinoid receptor type 1 [CB1] agonist), JWH-015 (cannabinoid receptor type 2 [CB2] agonist), and AM630 (CB2 antagonist) from days 35 to 42 days after BDL. On the 43rd day, hemodynamics, presence of CB receptors, severity of portosystemic shunting, mesenteric vascular density, vascular endothelial growth factor (VEGF), VEGFR-1, VEGFR-2, phospho-VEGFR-2, cyclooxygenase (COX)-1, COX-2, and endothelial nitric oxide synthase (eNOS) expressions as well as plasma VEGF levels were evaluated. Results showed that CB1 and CB2 receptors were present in left adrenal veins of sham rats, splenorenal shunts (the most prominent intra-abdominal shunts) of BDL rats, and mesentery of sham and BDL rats. CB2 receptor was up-regulated in splenorenal shunts of BDL rats. Both acute and chronic JWH-015 treatment reduced portal pressure and superior mesenteric arterial blood flow. Compared with vehicle, JWH-015 significantly alleviated portosystemic shunting and mesenteric vascular density in BDL rats, but not in sham rats. The concomitant use of JWH-015 and AM630 abolished JWH-015 effects. JWH-133, another CB2 agonist, mimicked the JWH-015 effects. JWH-015 decreased mesenteric COX-1, COX-2 messenger RNA expressions, and COX-1, COX-2, eNOS protein expressions. Furthermore, JWH-015 decreased intrahepatic angiogenesis and fibrosis. Conclusions: CB2 agonist alleviates portal hypertension (PH), severity of portosystemic collaterals and mesenteric angiogenesis, intrahepatic angiogenesis, and fibrosis in cirrhotic rats. The mechanism is, at least partly, through COX and NOS down-regulation. CBs may be targeted in the control of PH and portosystemic collaterals. (HEPATOLOGY 2012;56:248–258)
Predictors of pretransplant dropout and posttransplant recurrence in patients with perihilar cholangiocarcinoma
Authors: Murad Sarwa Darwish , Kim Ray W. , Therneau Terry , Gores Gregory J. , Rosen Charles B. , Martenson James A. , Alberts Steven R. , Heimbach Julie K.
Published: January 2012

We have previously reported excellent outcomes with liver transplantation for selected patients with early-stage perihilar cholangiocarcinoma (CCA) following neoadjuvant chemoradiotherapy. Our aim was to identify predictors of dropout before transplantation and predictors of cancer recurrence after transplantation. We reviewed all patients with unresectable perihilar CCA treated with neoadjuvant chemoradiation in anticipation for transplantation between 1993 and 2010. Predictors were identified by univariate and multivariate Cox regression analysis of clinical variables. In total, 199 patients were enrolled, of whom 62 dropped out and 131 underwent transplantation at our institution, with six undergoing transplantation elsewhere. Predictors of dropout were carbohydrate antigen 19–9 (CA 19–9) ≥ 500 U/mL (hazard ratio [HR] 2.3;

P

= 0.04), mass ≥ 3 cm (HR 2.1;

P

= 0.05), malignant brushing or biopsy (HR 3.6;

P

= 0.001), and Model for End-Stage Liver Disease (MELD) score ≥ 20 (HR 3.5;

P

= 0.02). Posttransplant, recurrence-free 5-year survival was 68%. Predictors of recurrence were elevated CA 19–9 (HR 1.8;

P

= 0.01), portal vein encasement (HR 3.3;

P

= 0.007), and residual tumor on explant (HR 9.8;

P

< 0.001). Primary sclerosing cholangitis (PSC), age, history of cholecystectomy, and waiting time were not independent predictors.

Conclusion
: Outcome following neoadjuvant chemoradiation and liver transplantation for perihilar CCA is excellent. Risk of dropout is related to patient and tumor characteristics and this can be used to guide patient counseling before enrollment. Recurrence risk is mostly associated with presence of residual cancer on explant. Patients with PSC do not have an independent survival advantage over

de novo

patients, but present with more favorable tumor characteristics.
Mesenchymal stem cells in the colorectal tumor microenvironment: Recent progress and implications
Authors: Hogan Niamh M. , Dwyer Roisin M. , Joyce Myles R. , Kerin Michael J.
Published: January 2012

Mesenchymal stem cells (MSCs) are nonhematopoietic multipotent adult stem cells. They have been shown to have a natural tropism for many tumors types, including colorectal, and are capable of escaping host immune surveillance. MSCs are known to engraft at tumors and integrate into their architecture, potentially as carcinoma‐associated fibroblasts. In contrast with other malignancies, our understanding of the interactions between colorectal cancer cells and MSCs remains limited. Considering the established importance of inflammation in the colorectal cancer primary tumor microenvironment and the role of stromal cells in this process, there is a potential wealth of information to be gleaned from further investigation of interactions between these cell populations. Epithelial–mesenchymal transition is central to colorectal cancer progression and MSCs have also been implicated in this process. This review explores the current knowledge (both in vitro and in vivo) of interactions between colorectal cancer cells and MSCs. It highlights potential effects of cell source, number and ratio on outcome of in vivo studies and explores strategies to more accurately explore their role in the primary tumor microenvironment. As our understanding of the underlying molecular processes in colorectal cancer develops, elucidation of these interactions will be central to development of novel therapeutic strategies for this prevalent disease.
Dichlorodiphenyltrichloroethane and risk of hepatocellular carcinoma
Authors: Persson E. Christina , Graubard Barry I. , Evans Alison A. , London W. Thomas , Weber Jean‐Philippe , LeBlanc Alain , Chen Gang , Lin Wenyao , McGlynn Katherine A.
Published: January 2012

Dichlorodiphenyltrichloroethane (p,p′‐DDT), an organochlorine pesticide known to have deleterious health effects in humans, has been linked to hepatocellular carcinoma (HCC) in rodents. A recent study has reported that p,p′‐DDT and its most persistent metabolite, dichlorodiphenyldichloroethylene (p,p′‐DDE), may also be associated with HCC in humans. To examine whether there is an association between p,p′‐DDT and/or p,p′‐DDE in a population at high‐risk of developing HCC, a nested case–control study was conducted within the 83,794 person Haimen City Cohort in China. Sera and questionnaire data were collected from all participants between 1992 and 1993. This study included 473 persons who developed HCC and 492 who did not, frequency matched on sex, age and area of residence. p,p′‐DDT and p,p′‐DDE levels were determined by mass spectrometry. Hepatitis B viral infection status (based on hepatitis B virus surface antigen; HBsAg) was also determined. p,p′‐DDT and/or p,p′‐DDE serum levels were significantly associated with sex, area of residence, occupation, alcohol consumption and cigarette smoking. Adjusting for age, sex, area of residence, HBsAg, family history of HCC, history of acute hepatitis, smoking, alcohol, occupation (farmer vs. other) and levels of p,p′‐DDT or p,p′‐DDE, odds ratios (OR) and 95% confidence intervals (CI) were calculated via unconditional logistic regression. Overall, the highest quintile of p,p′‐DDT was associated with an increased risk of HCC, OR = 2.96 95% CI; 1.19–7.40. There were no statistically significant associations with p,p′‐DDE. Overall, these results suggest that recent exposure to p,p′‐DDT may increase risk of HCC.
Effect of dental tissue conditioners and matrix metalloproteinase inhibitors on type I collagen microstructure analyzed by Fourier transform infrared spectroscopy
Authors: Botta Sergio B. , Ana Patricia A. , Santos Moises O. , Zezell Denise M. , Matos Adriana B.
Published: January 2012

This study aimed to evaluate the chemical interaction of collagen with some substances usually applied in dental treatments to increase the durability of adhesive restorations to dentin. Initially, the similarity between human dentin collagen and type I collagen obtained from commercial bovine membranes of Achilles deep tendon was compared by the Attenuated Total Reflectance technique of Fourier Transform Infrared (ATR‐FTIR) spectroscopy. Finally, the effects of application of 35% phosphoric acid, 0.1M ethylenediaminetetraacetic acid (EDTA), 2% chlorhexidine, and 6.5% proanthocyanidin solution on microstructure of collagen and in the integrity of its triple helix were also evaluated by ATR‐FTIR. It was observed that the commercial type I collagen can be used as an efficient substitute for demineralized human dentin in studies that use spectroscopy analysis. The 35% phosphoric acid significantly altered the organic content of amides, proline and hydroxyproline of type I collagen. The surface treatment with 0.1M EDTA, 2% chlorhexidine, or 6.5% proanthocyanidin did not promote deleterious structural changes to the collagen triple helix. The application of 6.5% proanthocyanidin on collagen promoted hydrogen bond formation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Comparison of V‐Loc™ 180 wound closure device and Quill™ PDO knotless tissue‐closure device for intradermal closure in a porcine in vivo model: Evaluation of biomechanical wound strength
Authors: Gingras Kristen , Zaruby Jeffrey , Maul Don
Published: January 2012

Objective:

The objective of this study was to compare the biomechanical strength of two barbed suture devices: V‐Loc™ 180 Wound Closure Device and Quill™ PDO Knotless Tissue‐Closure Device following primary cosmetic skin closures in a porcine dermal model.

Method:

This prospective randomized, controlled in vivo trial compared size 3/0 V‐Loc™ 180 device to size 2/0 Quill™ PDO device. Both products were tested for dermal closure in adult porcine models and evaluated at five timepoints. At postoperative days 0, 3, 7, 14, and 28 sutured tissue regions were excised post mortem and tested for intradermal wound holding strength.

Results:

Wounds closed with V‐Loc™ 180 device were stronger than Quill™ PDO device at days 0, 3, 7, and 14 with these differences being significant (p < 0.05) at days 3 and 7. At day 3, the average maximum load of V‐Loc™ 180 was 13.53 kgf and Quill™ PDO was 10.38 kgf (p = 0.002). At day 7, the average maximum load of V‐Loc™ 180 was 10.4 kgf and Quill™ PDO was 7.56 kgf (p = 0.001). Throughout the duration of the study, there was no suture extrusion or tissue distortion and all wounds healed with no major complications.

Conclusions:

In this study, V‐Loc™ 180 device was significantly stronger than Quill™ PDO device during the critical phases of wound healing in skin. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Removal of ethyl acetate, n‐hexane and toluene from waste air in a membrane bioreactor under continuous and intermittent feeding conditions
Authors: Álvarez‐Hornos F. Javier , Volckaert Diëgo , Heynderickx Philippe M. , Van Langenhove Herman
Published: January 2012

BACKGROUND: European Union environmental policy has focused on abatement of volatile organic compounds (VOCs) from industrial emissions, and new European VOC emission limits have been established. This study analyzes the performance of a composite membrane bioreactor treating air stream contaminated with ethyl acetate, n‐hexane and toluene under continuous and intermittent feeding conditions.

RESULTS: The system was operated under continuous feeding conditions: removal efficiencies (REs) higher than 99% were obtained for inlet loads up to 200 g m−3 h−1 and empty bed residence times (EBRTs) as short as 15 s for ethyl acetate. A maximum elimination capacity of 75 g m−3 h−1 (RE ∼66%) at an EBRT of 60 s was obtained for toluene. The system was unable to degrade n‐hexane when a 1:1:1 ethyl acetate:n‐hexane:toluene was supplied. Intermittent feeding with pollutants supplied for 16 h day−1, 5 days week−1, did not significantly affect the system performance. CO2 production recovered within 1‐2 h and 12 h after night and a weekend closures, respectively.

CONCLUSIONS: The membrane bioreactor has been shown to be effective for controlling air emissions and this study illustrated the capacity of the system to handle intermittent feeding conditions that are common in industrial practices. Copyright © 2012 Society of Chemical Industry
Enzyme–magnetic nanoparticle hybrids: new effective catalysts for the production of high value chemicals
Authors: Yiu Humphrey H. P. , Keane Mark A.
Published: January 2012

Magnetic nanoparticles (5–100 nm in diameter) offer the science community a new dimension in many key areas of research, notably nano‐medicine. However, use as catalyst support material (including enzyme immobilization) has largely been overlooked despite the benefits of a facile catalyst separation post‐reaction with reuse through the application of an external magnetic field. This is largely due to the high cost associated with magnetic nanoparticle synthesis in addition to enzyme operating costs. This can, however, be compensated for by effective catalyst recycling in the production of high value chemicals, particularly chiral drugs and their intermediates, circumventing laborious multi‐stage separation and purification procedures in conventional synthesis. Indeed, enzymes (such as lipase) on magnetic carriers have shown prolonged activity in organic solvents, even after recycling, when compared with free enzymes. Further developments can be directed at multi‐functional magnetic nanoparticles with the creation of a reactant‐specific micro‐environment to facilitate multi‐stepped reactions. The potential of enzyme‐magnetic nanoparticle hybrids is discussed and applications in the synthesis of fine chemicals, including precursors for drugs, are identified. Copyright © 2012 Society of Chemical Industry
Thalamic volume measurement in normal fetuses using three‐dimensional sonography
Authors: Sotiriadis Alexandros , Dimitrakopoulos Ioannis , Eleftheriades Makarios , Agorastos Theodoros , Makrydimas George
Published: January 2012

Purpose.

Brain thalami are important for a wide range of sensorimotor and neuropsychiatric functions. This study was carried out to calculate normative values for thalami volume during fetal life.

Methods.

Fetal thalami volumes were measured using 3D ultrasound in 122 normal, singleton fetuses at 20+0–34+6 weeks' gestation. Virtual Organ Computer‐aided AnaLysis (VOCAL) was used to obtain a sequence of six sections of each thalamus, starting from the transthalamic view of the brain at an axial plane. Thalamic contour was drawn manually. Volume contrast imaging was used to enhance image quality when needed. The volume of the thalamus distal to the transducer was also measured by a second operator in 30 randomly selected cases, blind to the measurements of the first, to calculate interobserver agreement.

Results.

Thalamic volume increased with gestational age, following a quadratic equation (R2 = 0.83). There was no significant difference in volume between the right and left thalamus. The mean volume of each thalamus increased from 0.45 ml at 20+0 weeks, to 1.39 ml at 28+0 weeks, to 2.17 ml at 34+0 weeks. The 95% limits of interobserver agreement for thalamic volume were −14.3% to +17.2%.

Conclusions.

The increase in thalamic volume with gestation can be described adequately by a quadratic equation. The moderate interobserver repeatability is attributed to the similar echogenicity between the thalamus and its surrounding structures. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012
Mechanisms underlying molecularly imprinted polymer molecular memory and the role of crosslinker: resolving debate on the nature of template recognition in phenylalanine anilide imprinted polymers
Authors: Olsson Gustaf D. , Karlsson Björn C. G. , Shoravi Siamak , Wiklander Jesper G. , Nicholls Ian A.
Published: January 2012

A series of molecular dynamics simulations of prepolymerization mixtures for phenylalanine anilide imprinted co‐(ethylene glycol dimethacrylate‐methacrylic acid) molecularly imprinted polymers have been employed to investigate the mechanistic basis for template selective recognition in these systems. This has provided new insights on the mechanisms underlying template recognition, in particular the significant role played by the crosslinking agent. Importantly, the study supports the occurrence of template self‐association events that allows us to resolve debate between the two previously proposed models used to explain this system's underlying recognition mechanisms. Moreover, the complexity of the molecular level events underlying template complexation is highlighted by this study, a factor that should be considered in rational molecularly imprinted polymer design, especially with respect to recognition site heterogeneity. Copyright © 2012 John Wiley & Sons, Ltd.
Atomic force microscopy–based molecular studies on the recognition of immunogenic chlorinated ovalbumin by macrophage receptors
Authors: Zapotoczny Szczepan , Biedroń Rafał , Marcinkiewicz Janusz , Nowakowska Maria
Published: January 2012

This report presents simple and reliable approach developed to study the specific recognition events between chlorinated ovalbumin (OVA) and macrophages using atomic force microscopy (AFM). Thanks to the elimination of nonspecific adhesion, the interactions of the native and chlorinated OVA with a membrane of macrophages could be quantified using exclusively the so‐called adhesion frequency (AF). The proposed system not only enabled the application of AFM‐based force measurements for such poorly defined ligand–receptor pairs but also significantly improved both the acquisition and the processing of the data. The proteins were immobilized on the gold‐coated AFM tips from the aqueous solutions containing charged thiol adsorbates. Such surface dilution of the proteins ensured the presence of single or just a few macromolecules at the tip‐surface contact. The formation of negatively charged monolayer on the tip dramatically limited its nonspecific interactions with the macrophage surface. In such systems, AF was used as a measure of the recognition events even if the interaction forces varied significantly for sets of measurements. The system with the native OVA, a weak immunogen, showed only negligible AF compared with 85% measured for the immunogenic chlorinated OVA. The AF values varied with the tip‐macrophage contact time and loading velocity. Blocking of the receptors by the chlorinated OVA was also confirmed. The developed approach can be also used to study other ligand–receptor interactions in poorly defined biological systems with intrinsically broad distribution of the rupture forces, thus opening new fields for AFM‐based recognition on molecular level. Copyright © 2012 John Wiley & Sons, Ltd.