bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum proteomic profiling of physical activity reveals CD300LG as a novel exerkine with a potential causal link to glucose homeostasis
Authors: Lee-Ødegård Sindre , Hjorth Marit , Olsen Thomas , Moen Gunn-Helen , Daubney Emily , Evans David M , Hevener Andrea , Lusis Aldons Jake , Zhou Mingqi , Seldin Marcus Michael , Allayee Hooman , Viken Jonas Krag , Gulseth Hanne L. , Norheim Frode , Drevon Christian A. , Birkeland Kåre I.
Published: April 2024

Physical activity has been associated with preventing the development of type 2 diabetes and atherosclerotic cardiovascular disease. However, our understanding of the precise molecular mechanisms underlying these effects remains incomplete and good biomarkers to objectively assess physical activity are lacking.We analyzed 3072 serum proteins in 26 men, normal weight or overweight, undergoing 12 weeks of a combined strength and endurance exercise intervention. We estimated insulin sensitivity with hyperinsulinemic euglycemic clamp, maximum oxygen uptake, muscle strength, and used MRI/MRS to evaluate body composition and organ fat depots. Muscle and subcutaneous adipose tissue biopsies were used for mRNA sequencing. Additional association analyses were performed in samples from up to 47,747 individuals in the UK Biobank, as well as using 2-sample Mendelian randomization and mice models.Following 12 weeks of exercise intervention, we observed significant changes in 283 serum proteins. Notably, 66 of these proteins were elevated in overweight men and positively associated with liver fat before the exercise regimen, but were normalized after exercise. Furthermore, for 19.7% and 12.1% of the exercise-responsive proteins, corresponding changes in mRNA expression levels in muscle and fat, respectively, were shown. The protein CD300LG displayed consistent alterations in blood, muscle, and fat. Serum CD300LG exhibited positive associations with insulin sensitivity, and to angiogenesis-related gene expression in both muscle and fat. Furthermore, serum CD300LG was positively associated with physical activity and negatively associated with glucose levels in the UK Biobank. In this sample, the association between serum CD300LG and physical activity was significantly stronger in men than in women. Mendelian randomization analysis suggested potential causal relationships between levels of serum CD300LG and fasting glucose, 2-hour glucose after an oral glucose tolerance test, and HbA1c. Additionally, Cd300lg responded to exercise in a mouse model, and we observed signs of impaired glucose tolerance in male, but not female,
Cd300lg
knockout mice.Our study identified several novel proteins in serum whose levels change in response to prolonged exercise and were significantly associated with body composition, liver fat, and glucose homeostasis. Serum CD300LG increased with physical activity and is a potential causal link to improved glucose levels. CD300LG may be a promising exercise biomarker and a therapeutic target in type 2 diabetes.
The comparative plastisphere microbial community profile at Kung Wiman beach unveils potential plastic-specific degrading microorganisms
Authors: Chaimusik Nutsuda , Sombuttra Natthaphong , Nakaramontri Yeampon , Sompongchaiyakul Penjai , Charoenpong Chawalit , Intra Bungonsiri , Euanorasetr Jirayut
Published: April 2024

Background

Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously reported at Kung Wiman Beach, located in Chanthaburi province along with the Eastern Gulf of Thailand. Our research aimed to study the microbial population of the sand and plastisphere and isolate microorganisms with potential plastic degradation activity.

Methods

Plastic and sand samples were collected from Kung Wiman Beach for microbial isolation on agar plates. The plastic samples were identified by Fourier-transform infrared spectroscopy. Plastic degradation properties were evaluated by observing the halo zone on mineral salts medium (MSM) supplemented with emulsified plastics, including polystyrene (PS), polylactic acid (PLA), polyvinyl chloride (PVC), and bis (2-hydroxyethyl) terephthalate (BHET). Bacteria and fungi were identified by analyzing nucleotide sequence analysis of the 16S rRNA and internal transcribed spacer (ITS) regions, respectively. 16S and ITS microbiomes analysis was conducted on the total DNA extracted from each sample to assess the microbial communities.

Results

Of 16 plastic samples, five were identified as polypropylene (PP), four as polystyrene (PS), four as polyethylene terephthalate (PET), two as high-density polyethylene (HDPE), and one sample remained unidentified. Only 27 bacterial and 38 fungal isolates were found to have the ability to degrade PLA or BHET on MSM agar. However, none showed degradation capabilities for PS or PVC on MSM agar. Notably, Planococcus sp. PP5 showed the highest hydrolysis capacity of 1.64 ± 0.12. The 16S rRNA analysis revealed 13 bacterial genera, with seven showing plastic degradation abilities: Salipiger, Planococcus, Psychrobacter, Shewanella, Jonesia, Bacillus, and Kocuria. This study reports, for the first time of the BHET-degrading properties of the genera Planococcus and Jonesia. Additionally, The ITS analysis identified nine fungal genera, five of which demonstrated plastic degradation abilities: Aspergillus, Penicillium, Peacilomyces, Absidia, and Cochliobolus. Microbial community composition analysis and linear discriminant analysis effect size revealed certain dominant microbial groups in the plastic and sand samples that were absent under culture-dependent conditions. Furthermore, 16S and ITS amplicon microbiome analysis revealed microbial groups were significantly different in the plastic and sand samples collected.

Conclusions

We reported on the microbial communities found on the plastisphere at Kung Wiman Beach and isolated and identified microbes with the capacity to degrade PLA and BHET.
Selective concentration of iron, titanium, and zirconium substrate minerals within Gregory’s diverticulum, an organ unique to derived sand dollars (Echinoidea: Scutelliformes)
Authors: Zachos Louis G. , Ziegler Alexander
Published: April 2024

Gregory’s diverticulum, a digestive tract structure unique to a derived group of sand dollars (Echinoidea: Scutelliformes), is filled with sand grains obtained from the substrate the animals inhabit. The simple methods of shining a bright light through a specimen or testing response to a magnet can reveal the presence of a mineral-filled diverticulum. Heavy minerals with a specific gravity of >2.9 g/cm3 are selectively concentrated inside the organ, usually at concentrations one order of magnitude, or more, greater than found in the substrate. Analyses of diverticulum content for thirteen species from nine genera, using optical mineralogy, powder X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, as well as micro-computed tomography shows the preference for selection of five major heavy minerals: magnetite (Fe3O4), hematite (Fe2O3), ilmenite (FeTiO3), rutile (TiO2), and zircon (ZrSiO4). Minor amounts of heavy or marginally heavy amphibole, pyroxene and garnet mineral grains may also be incorporated. In general, the animals exhibit a preference for mineral grains with a specific gravity of >4.0 g/cm3, although the choice is opportunistic and the actual mix of mineral species depends on the mineral composition of the substrate. The animals also select for grain size, with mineral grains generally in the range of 50 to 150 μm, and do not appear to alter this preference during ontogeny. A comparison of analytical methods demonstrates that X-ray attenuation measured using micro-computed tomography is a reliable non-destructive method for heavy mineral quantification when supported by associated analyses of mineral grains extracted destructively from specimens or from substrate collected together with the specimens. Commonalities in the electro-chemical surface properties of the ingested minerals suggest that such characteristics play an important role in the selection process.
Ретроспектива развития отечественной прикладной фотовольтаики и её технологического обеспечения
Authors: Лебедев Андрей Александрович , Вагапова Наргиза Тухтамышевна , Карабанов Андрей Сергеевич , Черенков Павел Геннадьевич
Published: April 2024

В статье дано описание царивших в отечественной прикладной фотовольтаике с момента её появления и до настоящего времени базовых технологических укладов производства фотоэлектрических преобразователей на основе кремния (в том числе аморфного гидрогенизированного) и материалов AIIIBV, а также солнечных батарей, созданных на их основе для энергообеспечения космических аппаратов. Описание выполнено в хронологическом порядке смены пяти кремниевых технологий. Акцент сделан на изложении конструктивных особенностей приборов и связанных с этим технологических решений, а также сопутствующего производственного оборудования.
Differential sensitivity to the effects of nicotine and bupropion in adolescent and adult male OF1 mice during social interaction tests
Authors: Gómez M.C. , Carrasco M.C. , Redolat R.
Published: March 2008

Few studies have compared the action of both nicotine (NIC) and bupropion (BUP), an antidepressant used to treat NIC dependence, on social and aggressive behavior at different ages. This study aims to determine whether these drugs produce differential effects in adolescent (postnatal day: 36–37) and adult (postnatal day: 65–66) mice that have been housed individually for 2 weeks in order to induce aggressive behavior. Mice received BUP (40, 20, or 10 mg/kg), NIC (1, 0.5, and 0.25 mg/kg as base), or vehicle earlier to a social interaction test. BUP (40 mg/kg) decreased social investigation and increased nonsocial exploration in both adolescent and adult mice. The same effects were also observed in adult mice administered with a lower dose of the same drug (20 mg/kg). In adolescents, NIC (1 mg/kg) decreased social investigation, but this effect did not reach statistical significance in adults. In conclusion, a differential sensitivity to the effects of NIC or BUP emerged in some of the behavioral categories when the two age groups were compared. Aggr. Behav. 34:369–379, 2008. © 2008 Wiley‐Liss, Inc.
Electroactive Nanorods and Nanorings Designed by Supramolecular Association of π‐Conjugated Oligomers
Authors: Dautel Olivier J. , Robitzer Mike , Flores Jean‐Charles , Tondelier Denis , Serein‐Spirau Françoise , Lère‐Porte Jean‐Pierre , Guérin David , Lenfant Stéphane , Tillard Monique , Vuillaume Dominique , Moreau Joël J. E.
Published: March 2008

In investigations into the design and isolation of semiconducting nano‐objects, the synthesis of a new bisureido π‐conjugated organogelator has been achieved. This oligo(phenylenethienylene) derivative was found to be capable of forming one‐dimensional supramolecular assemblies, leading to the gelation of several solvents. Its self‐assembling properties have been studied with different techniques (AFM, EFM, etc.). Nano‐objects have successfully been fabricated from the pristine organogel under appropriate dilution conditions. In particular, nanorods and nanorings composed of the electroactive organogelator have been isolated and characterized. With additional support from an electrochemical study of the organogelator in solution, it has been demonstrated by the EFM technique that such nano‐objects were capable of exhibiting charge transport properties, a requirement in the fabrication of nanoscale optoelectronic devices. It was observed that positive charges can be injected and delocalized all along an individual nano‐object (nanorod and nanoring) over micrometers and, remarkably, that no charge was stored in the center of the nanoring. It was also observed that topographic constructions in the nanostructures prevent transport and delocalization. The same experiments were performed with a negative bias (i.e., electron injection), but no charge delocalization was observed. These results could be correlated with the nature of 1, which is a good electron‐donor, so it can easily be oxidized, but can be reduced only with difficulty.
New Architectures for Dye‐Sensitized Solar Cells
Authors: Martinson Alex B. F. , Hamann Thomas W. , Pellin Michael J. , Hupp Joseph T.
Published: March 2008

Modern dye‐sensitized solar cell (DSSC) technology was built upon nanoparticle wide bandgap semiconductor photoanodes. While versatile and robust, the sintered nanoparticle architecture exhibits exceedingly slow electron transport that ultimately restricts the diversity of feasible redox mediators. The small collection of suitable mediators limits both our understanding of an intriguing heterogeneous system and the performance of these promising devices. Recently, a number of pseudo‐1D photoanodes that exhibit accelerated charge transport and greater materials flexibility were fabricated. The potential of these alternative photoanode architectures for advancing, both directly and indirectly, the performance of DSSCs is explored.
Efficient Rhodium‐Catalyzed Installation of Unsaturated Ester Functions onto Porphyrins: Site‐Specific Heck‐Type Addition versus Conjugate Addition
Authors: Baba Hiromi , Chen Jinping , Shinokubo Hiroshi , Osuka Atsuhiro
Published: March 2008

A facile introduction of α,β‐ or α,β,γ,δ‐unsaturated ester functions onto porphyrins was achieved through rhodium‐catalyzed addition of β‐borylporphyrins to acrylate or 2,4‐pentadienoate esters. The reaction of meso‐borylporphyrins with acrylates exclusively afforded saturated esters by 1,4‐conjugate addition under the same reaction conditions. Thus, the reaction mode (Heck‐type versus conjugate addition) is highly dependent on the reaction site (β versus meso). This functionalization has a significant impact on the electronic properties of the π system of porphyrins, which induces a substantial redshift and broadening in the absorption spectra by effective conjugation through the β positions. The coplanar structure of the unsaturated ester moieties with respect to the porphyrin core has been unambiguously elucidated by X‐ray crystallographic analysis.
Modifications of gustatory nerve synapses onto nucleus of the solitary tract neurons induced by dietary sodium‐restriction during development
Authors: May Olivia L. , Erisir Alev , Hill David L.
Published: March 2008

The terminal fields of nerves carrying gustatory information to the rat brainstem show a remarkable amount of expansion in the nucleus of the solitary tract (NTS) as a result of early dietary sodium restriction. However, the extent to which these axonal changes represent corresponding changes in synapses is not known. To identify the synaptic characteristics that accompany the terminal field expansion, the greater superficial petrosal (GSP), chorda tympani (CT), and glossopharyngeal (IX) nerves were labeled in rats fed a sodium‐restricted diet during pre‐ and postnatal development. The morphology of these nerve terminals within the NTS region where the terminal fields of all three nerves overlap was evaluated by transmission electron microscopy. Compared to data from control rats, CT axons were the most profoundly affected. The density of CT arbors and synapses quadrupled as a result of the near life‐long dietary manipulation. In contrast, axon and synapse densities of GSP and IX nerves were not modified in sodium‐restricted rats. Furthermore, compared to controls, CT terminals displayed more instances of contacts with postsynaptic dendritic protrusions and IX terminals synapsed more frequently with dendritic shafts. Thus, dietary sodium restriction throughout pre‐ and postnatal development had differential effects on the synaptic organization of the three nerves in the NTS. These anatomical changes may underlie the impact of sensory restriction during development on the functional processing of taste information and taste‐related behaviors. J. Comp. Neurol. 508:529–541, 2008. © 2008 Wiley‐Liss, Inc.
Insight into the Reactions of Trifluorovinylsilanes with Aromatic Aldehydes
Authors: Kirij Nataliia V. , Dontsova Dariya A. , Pavlenko Natalya V. , Yagupolskii Yurii L. , Scherer Harald , Tyrra Wieland , Naumann Dieter
Published: March 2008

The conditions for the selective addition of trialkyl(trifluorovinyl)silanes to the C=O bond of aromatic aldehydes in the presence of cesium fluoride to give the corresponding“silylated” alcohols in high yields was performed. The reactivity of the “silylated” alcohols in the presence of nucleophilic reagents and Brönsted acids was studied. On the basis of isolated compounds and of intermediates detected by NMR spectroscopic methods, several reaction pathways are proposed. Significant differences between the reaction behaviour of triethyl(trifluorovinyl)silane and trimethyl(trifluoromethyl)silane under comparable conditions are pointed out; the differences can be attributed to the highly reactive trifluorovinyl group. The reactions of the “silylated” alcohols proceed with high stereoselectivity to give propenes, acid fluorides and acids of the (E) isomers in better than 98 % purity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrochemical Quartz Crystal Microbalance Studies on the Codeposition of Dextran Sodium Sulfate with the Charge‐Transfer Complexes Generated During Electrooxidation of Benzidine Derivatives
Authors: Jiang Xueqin , Cao Zhijun , Liu Tao , Xie Qingji , Yao Shouzhuo
Published: March 2008

The electrochemical quartz crystal microbalance (EQCM) technique was used to investigate the electrochemistry of three benzidine derivatives, o‐tolidine (o‐TD), 3,3′,5,5′‐tetramethyl‐benzidine (TMB) and o‐dianisidine (o‐DA), in Britton‐Robinson (B‐R) buffer solutions with and without coexisting dextran sodium sulfate (DSS), respectively. During the anodic potential sweep from 0.1 to 0.7 V vs. SCE in pH 5.0 B‐R buffer solution containing o‐TD, the EQCM frequency was decreased during the first‐step oxidation of o‐TD and then increased to some extent during its second‐step oxidation, implying that a poorly soluble charge‐transfer complex (CTC) was produced here as an oxidation intermediate, and its precipitation and then dissolution at the EQCM Au electrode decreased and then increased the frequency. The depth of the V‐shaped time‐dependent frequency response (−Δf0V) to the redox switching of the CTC/o‐TD couple (0.1–0.37 V vs. SCE) was notably enhanced in the presence of DSS, being due to the formation of a mass‐enhanced CTC‐DSS adduct via electrostatic affinity. Similar phenomena were evident in the TMB system, but the CTC behavior was not observed during o‐DA oxidation in the absence of DSS, namely, the EQCM frequency kept decreasing all the time, due probably to the too high lability of the CTC from o‐DA oxidation, and the coexistence of DSS could well stabilize this CTC and turn on its CTC behavior. The o‐TD system showed the highest sensitivity to DSS and was thus examined in detail. The mechanism for the CTC‐DSS interaction is discussed from EQCM, FT‐IR and UV‐vis data. The CTC‐based EQCM determination of DSS, which is featured by a dynamically renewed surface of the detection electrode, was thus proposed, with a linear range from 0.002 to 1.6 μmol L−1 and a detection limit down to 0.7 nmol L−1 (o‐TD system).
Fabrication and Application of a Novel Modified Electrode Based on Multiwalled Nanotubes/Cerium(III) 12‐Tungstophosphoric Acid Nanocomposite
Authors: Fang Bin , Chen Daolei , Huang Qiang , Wei Yan , Wang Guangfeng
Published: March 2008

A novel multiwalled nanotubes (MWNTs)/Cerium(III) 12‐tungstophosphoric acid (CePW) nanocomposite film glassy carbon electrode was prepared in this paper. Electrochemical behaviors of the CePW/MWNTs modified electrode were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). This modified electrode brought new capabilities for electrochemical devices by combining the advantages of carbon nanotubes, rare‐earth, and heteropoly‐acids. The results demonstrated that the CePW/MWNTs modified electrode exhibited enhanced electrocatalytic behavior and good stability for the detection of guanine and adenine in 0.1 M PBS (pH 7.0). The experimental parameters were optimized and a direct electrochemical method for the simultaneous determination of guanine and adenine was proposed. The detection limit (S/N=3) for guanine and adenine was 2.0×10−8 M and 3.0×10−8 M, respectively. Further, the acid‐denatured calf thymus DNA was also detected and the result was satisfied.
Electrocatalytic Application of an Overoxidized Dopamine Film Prepared on a Gold Electrode Surface to Selective Epinephrine Sensing
Authors: Łuczak Teresa
Published: March 2008

A dopamine polymer film was prepared ex situ on a bare gold template from a 10 mM dopamine solution in phosphate buffer, pH 7 followed by an overoxidation in 500 mM NaOH. The modified electrode was used for quantitative determination of epinephrine. A linear relationship between epinephrine concentration and current response was obtained in the range between 2 μM and 800 μM with the detection limit of 0.3 μM. The results have shown that using the overoxidized dopamine film it is possible to perform electrochemical analysis of epinephrine without interference of ascorbic and uric acids.
Electrochemical Determination of the Antioxidant Capacity: The Ceric Reducing/Antioxidant Capacity (CRAC) Assay
Authors: de Queiroz Ferreira Rafael , Avaca Luis Alberto
Published: March 2008

The CRAC assay is a direct electron transfer test of antioxidant capacity for several organic compounds. The ability of eight different compounds in reducing Ce4+ was studied by chronoamperometric measurements of the remaining Ce3+ species. The following antioxidant classification was observed: tannic acid $\rm{ \gg }$ quercetin>rutin>gallic acid≈catechin>ascorbic acid>BHA>Trolox. These results agree with others already published and a good correlation (R2=0.937) was found with the classical spectrophotometric FRAP assay. The CRAC assay is simple, fast, free from sample pretreatment and applicable to nontransparent samples.
Dual‐Genic Hybridization Sensor Employing Electrochemical Impedance Spectroscopy
Authors: Bonanni Alessandra , Calvo Daniel , del Valle Manuel
Published: March 2008

A dual‐genic impedimetric sensor for DNA hybridization detection is proposed for the first time. Two different single‐stranded DNA probes (P1=d(pA)20 and P2=d(pG)20) were immobilized onto the graphite‐epoxy electrode surface and impedimetric measurements were performed. Hybridization experiments were carried out employing complementary targets (P1c=d(pT)20 or P2c=d(pC)20) alone, or combined (P1c+P2c), as well as noncomplementary DNA sequences. As from the direct observation of impedance spectra it was not possible to resolve the binary gene mixture, the use of artificial neural networks (ANN) was proposed for extracting significant information to get desired results.
Electroanalytical Study of the Antioxidant and Antitumor Agent Curcumin
Authors: Stanić Z. , Voulgaropoulos A. , Girousi S.
Published: March 2008

Curcumin (CU) shows a wide range of pharmacological properties including antioxidant, anti‐inflammatory, and antitumor effects. In order to understand the chemical basis of different activities of curcumin, we have studied the oxidation and reduction of curcumin. Based on cyclic and differential pulse voltammetric methods, using carbon paste and hanging mercury drop electrodes, in the present study we tested different parameters to optimize the conditions for the determination of curcumin and its electrochemical characteristics. Better results were obtained via differential pulse voltammetry using carbon paste electrode. Curcumin yields well‐defined differential pulse voltammetric responses with well‐defined oxidation (in the potential region of 0.3–0.6 V, vs. Ag/AgCl) and reduction (at 0.3 V) peaks using carbon paste electrode.
Evaluation of the genotoxicity of river sediments from industrialized and unaffected areas using a battery of short‐term bioassays
Authors: Aouadene Assia , Di Giorgio Carole , Sarrazin Luc , Moreau Xavier , De Jong Laetitia , Garcia Fabrice , Thiery Alain , Botta Alain , De Méo Michel
Published: March 2008

The present investigation evaluated the capacity of the Salmonella mutagenicity test, the comet assay, and the micronucleus assay to detect and characterize the genotoxic profile of river sediments. Three stations were selected on an urban river (Bouches du Rhône, France) exposed to various sources of industrial and urban pollution (StA, StB, and StC) and one station on its tributary (StD). One station in a nonurban river was included (REF). The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined by HPLC, and the genotoxicity of the sediments was monitored by the Salmonella mutagenicity test (TA98 + S9, YG1041 ± S9), the comet assay, and the micronucleus assay on CHO cells. Chemical analysis showed that the total PAH concentrations ranged from 23 μg kg−1 dw (REF) to 1285 μg kg−1 dw (StD). All the sediments were mutagenic in the Salmonella mutagenicity test. The mutagenicity was probably induced by the presence of nitroarenes (StA, StB, StC, and StD) and aromatic amines (REF) as deduced from the mutagenicity profiles of strains YG1041 ± S9 and TA98 + S9. The comet assay revealed direct DNA lesions in REF, StA, and StB sediments and metabolization‐dependent DNA damage in StC and StD. The micronucleus assay showed an absence of clastogenicity for StA ± S9 and StC‐S9, and a significant clastogenicity ± S9 for the three other stations. The genotoxicity ranking determined by the comet assay + S9 matched the ranking of total and carcinogenic PAH concentrations, and this assay was found to be the most sensitive. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Comparative analysis of genetic toxicity of AZT and ddI antiretrovirals in somatic cells of Drosophila melanogaster
Authors: Guimarães Nilza Nascimento , de Castro Pereira Karla , de Andrade Heloísa Helena Rodrigues , Lehmann Maurício , Silva Cunha Kênya
Published: March 2008

Antiretroviral therapies based on nucleoside reverse transcriptase inhibitors, like zidovudine (3′‐azido‐3′‐deoxythymidine; AZT) and didanosine (2′,3′‐dideoxyinosine; ddI), markedly reduce human immunodeficiency virus loads. The Somatic Mutation And Recombination Test in Drosophila melanogaster (wing SMART), in its standard version, was applied to compare AZT and ddI genetic toxicity expressed as point and chromosomal mutation as well as homologous mitotic recombination. The present findings provide evidence that the mechanistic basis underlying the genetic toxicity of these antiretrovirals is mainly related to mitotic recombination. However, a genotoxic pattern can correspondingly be discerned: AZT is able to induce recombination (∼85%) and mutation (∼15%), and ddI causes only homologous recombination (100%) in the wing SMART assay. Another point to be considered is the fact that ddI is 3.8 times less active to induce mutant clones per mg/ml unit as compared to AZT. The clinical significance of these observations has to be interpreted in the light of data obtained from long‐term toxicity in patients treated with the above mentioned agents. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Confirmation of the chromosome damaging effects of lamivudine in in vitro human peripheral blood lymphocytes
Authors: Bayram Süleyman , Topaktaş Mehmet
Published: March 2008

The aim of this study was to investigate genotoxic effects of lamivudine (an analogue of cytidine) using in vitro sister chromatid exchange (SCE), chromosome aberration (CA), and micronucleus (MN) tests in human peripheral lymphocytes. The cells were treated with 75, 100, 125, and 150 μg/ml concentrations of lamivudine (roughly 30–60 times higher than plasma levels achieved in patients receiving this drug) for two (24‐ and 48‐hr) treatment periods. Lamivudine induced SCEs at the highest concentration (150 μg/ml) in the 24‐hr treatment, and at 125 and 150 μg/ml in the 48‐hr treatment, when compared to the solvent control. During both treatment periods, structural chromosome aberrations were significantly increased at 100, 125, and 150 μg/ml lamivudine concentrations. However, the increases of SCEs (22%) and CAs (50%) were weak. In addition, lamivudine reduced both the proliferation index (PI) and the mitotic index (MI) significantly at all concentrations for the two treatment periods. The MI was reduced by lamivudine in a dose‐dependent manner during both the 24‐ and 48‐hr treatment periods. In contrast, the PI was reduced by lamivudine only during the 48‐hr treatment period. A weak but significant increase in MN formation was observed following lamivudine treatment at 100, 125, and 150 μg/ml for 48 hr, but no significant increase in micronuclei were observed following 24‐hr treatment. In conclusion, lamivudine has a weak genotoxic effect at elevated doses on human peripheral lymphocytes. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Oxidative DNA damage in gastric cancer: CagA status and OGG1 gene polymorphism
Authors: Farinati Fabio , Cardin Romilda , Bortolami Marina , Nitti Donato , Basso Daniela , de Bernard Marina , Cassaro Mauro , Sergio Adriana , Rugge Massimo
Published: March 2008

Oxidative DNA damage is thought to play an important part in the pathogenesis of H. pylori‐induced mucosal damage. 8‐OHdG is a sensitive marker of DNA oxidation and is repaired by a polymorphic glycosylase (OGG1) more effectively than by OGG1‐Cys326. The aims of this study were to ascertain the respective roles of H. pylori, cagA status and OGG1 polymorphism in determining 8‐OHdG levels in benign and premalignant stomach diseases and in gastric cancer (GC). The study involved 50 GC patients (for whom both neoplastic tissue and surrounding mucosa were available), 35 with intestinal metaplasia and atrophy (IMA) and 43 controls. H. pylori and cagA status were determined by histology and polymerase chain reaction for urease and cagA. 8‐OHdG was assayed using HPLC with an electrochemical detector (HPLC‐ED). The OGG1 1245C→G transversion was identified using RFLP analyses. 8‐OHdG levels were significantly higher in GC, with no differences in relation to H. pylori or cagA status. OGG1 polymorphism was documented in 34% of GC (15 Ser/Cys, 2 Cys/Cys). OGG1 1245C→G polymorphism was detected in 54% of IMA patients, but only 16% of controls (p = 0.0004) and coincided with significantly higher 8‐OHdG levels. In the multivariate analysis, 8‐OHdG levels were predicted by histotype and OGG1 status. OGG1 1245C→G polymorphism was common in both GC and IMA, but very rare in controls, and correlated more closely with 8‐OHdG levels than do H. pylori infection or cagA status. © 2008 Wiley‐Liss, Inc.
The role of maternal responsiveness in predicting infant affect during the still face paradigm with infants born very low birth weight
Authors: Erickson Sarah J. , Lowe Jean R.
Published: March 2008

There is limited empirical literature addressing infants' response to a standardized stressor with infants born very low birth weight (VLBW). The purpose of this study was to assess the relative strength of maternal responsiveness in predicting infant affect in response to the Still Face (SF) paradigm in a cross‐sectional cohort of ethnically diverse infants born VLBW and their mothers (N = 50; infants 6–8 months old). Infant affect and maternal responsiveness were coded in 1‐s intervals while dyads participated in the SF. In addition, perinatal medical status, developmental status, and infant temperament were assessed. Findings revealed that positive infant affect during and after the SF stressor were strongly associated with baseline infant positive affect and maternal responsiveness at the reunion episode, respectively. In contrast, when predicting negative infant affect during and after the SF stressor, prior infant negative affect was strongly and uniquely significant. Infant positive affect, negative affect, and maternal responsiveness were not significantly associated with gender, infant perinatal medical history, developmental status, or temperament. Future research is warranted to determine how these findings relate to infants' stress reactions in naturalistic settings and if relationship‐focused interventions may reverse infant negative emotionality, enhance positive emotionality, and thereby improve self‐regulation and longer term social and cognitive developmental outcomes in medically at‐risk infants.
Energy‐based prediction of amino acid‐nucleotide base recognition
Authors: Marabotti Anna , Spyrakis Francesca , Facchiano Angelo , Cozzini Pietro , Alberti Saverio , Kellogg Glen E. , Mozzarelli Andrea
Published: March 2008

Despite decades of investigations, it is not yet clear whether there are rules dictating the specificity of the interaction between amino acids and nucleotide bases. This issue was addressed by determining, in a dataset consisting of 100 high‐resolution protein‐DNA structures, the frequency and energy of interaction between each amino acid and base, and the energetics of water‐mediated interactions. The analysis was carried out using HINT, a non‐Newtonian force field encoding both enthalpic and entropic contributions, and Rank, a geometry‐based tool for evaluating hydrogen bond interactions. A frequency‐ and energy‐based preferential interaction of Arg and Lys with G, Asp and Glu with C, and Asn and Gln with A was found. Not only favorable, but also unfavorable contacts were found to be conserved. Water‐mediated interactions strongly increase the probability of Thr‐A, Lys‐A, and Lys‐C contacts. The frequency, interaction energy, and water enhancement factors associated with each amino acid–base pair were used to predict the base triplet recognized by the helix motif in 45 zinc fingers, which represents an ideal case study for the analysis of one‐to‐one amino acid–base pair contacts. The model correctly predicted 70.4% of 135 amino acid–base pairs, and, by weighting the energetic relevance of each amino acid–base pair to the overall recognition energy, it yielded a prediction rate of 89.7%. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Stereoelectronic properties of spiroquinazolinones in differential PDE7 inhibitory activity
Authors: Daga Pankaj R. , Doerksen Robert J.
Published: March 2008

A detailed computational study on a series of spiroquinazolinones showing phosphodiesterase 7 (PDE7) inhibitory activity was performed to understand the binding mode and the role of stereoelectronic properties in binding. Our docking studies reproduced the essential hydrogen bonding and hydrophobic interactions for inhibitors of this class of enzymes. The N1 proton of the quinazolinone scaffold was involved in H‐bonding to an amide side chain of the conserved glutamine residue in the active site. The central bicyclic ring of the molecules showed hydrophobic and π‐stacking interactions with hydrophobic and aromatic amino acid residues, respectively, present in the PDE7 active site. The docked conformations were optimized with density functional theory (DFT) and DFT electronic properties were calculated. Comparison of molecular electrostatic potential (MEP) plots of inhibitors with the active site of PDE7 suggested that the electronic distribution in the molecules is as important as steric factors for binding of the molecules to the receptor. The hydrogen bonding ability and nucleophilic nature of N1 appeared to be important for governing the interaction with PDE7. For less active inhibitors (pIC50 < 6.5), the MEP maximum at N1 of the spiroquinazolinone ring was high or low based on the electronic properties of the substituents. All the more active molecules (pIC50 > 6.5) had MEP highest at N3, not N1. Efficient binding of these inhibitors may need some rearrangement of side chains of active‐site residues, especially Asn365. This computational modeling study should aid in design of new molecules in this class with improved PDE7 inhibition. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
The PI 3‐kinase and mTOR signaling pathways are important modulators of epithelial tubule formation
Authors: Walid Shereaf , Eisen Randi , Ratcliffe Don R. , Dai Kezhi , Hussain M. Mahmood , Ojakian George K.
Published: March 2008

Using MDCK cells as a model system, evidence is presented demonstrating that the signaling pathways mammalian target of rapamycin (mTOR) and phosphoinositide 3‐kinase (PI 3‐kinase) play important roles in the regulation of epithelial tubule formation. Incubation of cells with collagen gel overlays induced early (4–8 h) reorganization of cells (epithelial remodeling) into three‐dimensional multicellular tubular structures over 24 h. An MDCK cell line stably expressing the PH domain of Akt, a PI 3‐kinase downstream effector, coupled to green fluorescent protein (GFP‐Akt‐PH) was used to determine the distribution of phosphatidyl inositol‐3,4,5‐P3 (PIP3), a product of PI 3‐kinase. GFP‐Akt‐PH was associated with lateral membranes in control cells. After incubation with collagen gel overlays, GFP‐Akt‐PH redistributed into the lamellipodia of migrating cells suggesting that PIP3 plays a role in epithelial remodeling. Using the small molecule inhibitor LY‐294002 that inhibits both mTOR and PI 3‐kinase, we demonstrated that kinase activity was required for epithelial remodeling, disruption of cell junctions and subsequent modulation of tubule formation. Since the mTOR signaling pathway is downstream of PI 3‐kinase, the effects of rapamycin, a specific mTOR inhibitor, on tubule formation were assessed. Rapamycin did not affect epithelial remodeling or GFP‐Akt‐PH redistribution but inhibited elongated tubule formation that occurred later (24 h) in morphogenesis. These results were further supported by using RNA interference to down‐regulate mTOR and inhibit tubule formation. Our studies demonstrate that PI 3‐kinase regulates early epithelial remodeling stages while mTOR modulates latter stages of tubule development. J. Cell. Physiol. 216: 469–479, 2008. © 2008 Wiley‐Liss, Inc.
Physiological implications of DLX homeoproteins in enamel formation
Authors: Lézot Frédéric , Thomas Bethan , Greene Scott R. , Hotton Dominique , Yuan Zhi‐An , Castaneda Beatriz , Bolaños Alba , Depew Michael , Sharpe Paul , Gibson Carolyn W. , Berdal Ariane
Published: March 2008

Tooth development is a complex process including successive stages of initiation, morphogenesis, and histogenesis. The role of the Dlx family of homeobox genes during the early stages of tooth development has been widely analyzed, while little data has been reported on their role in dental histogenesis. The expression pattern of Dlx2 has been described in the mouse incisor; an inverse linear relationship exists between the level of Dlx2 expression and enamel thickness, suggesting a role for Dlx2 in regulation of ameloblast differentiation and activity. In vitro data have revealed that DLX homeoproteins are able to regulate the expression of matrix proteins such as osteocalcin. The aim of the present study was to analyze the expression and function of Dlx genes during amelogenesis. Analysis of Dlx2/LacZ transgenic reporter mice, Dlx2 and Dlx1/Dlx2 null mutant mice, identified spatial variations in Dlx2 expression within molar tooth germs and suggests a role for Dlx2 in the organization of preameloblastic cells as a palisade in the labial region of molars. Later, during the secretory and maturation stages of amelogenesis, the expression pattern in molars was found to be similar to that described in incisors. The expression patterns of the other Dlx genes were examined in incisors and compared to Dlx2. Within the ameloblasts Dlx3 and Dlx6 are expressed constantly throughout presecretory, secretory, and maturation stages; during the secretory phase when Dlx2 is transitorily switched off, Dlx1 expression is upregulated. These data suggest a role for DLX homeoproteins in the morphological control of enamel. Sequence analysis of the amelogenin gene promoter revealed five potential responsive elements for DLX proteins that are shown to be functional for DLX2. Regulation of amelogenin in ameloblasts may be one method by which DLX homeoproteins may control enamel formation. To conclude, this study establishes supplementary functions of Dlx family members during tooth development: the participation in establishment of dental epithelial functional organization and the control of enamel morphogenesis via regulation of amelogenin expression. J. Cell. Physiol. 216: 688–697, 2008, © 2008 Wiley‐Liss, Inc.
Sonographic diagnosis of the entrapment of the flexor digitorum profundus tendon complicating a fracture of the index finger
Authors: Pandey Tarun , Al Kandari Salwa Ramadan , Al Shammari Salem Awad
Published: March 2008

Flexor digitorum tendon entrapment is a known complication of proximal phalangeal fractures and is commonly diagnosed clinically. However, it can sometimes be subtle and may not be suspected initially. A case of proximal phalangeal fracture of the index finger complicated by entrapment of the flexor digitorum profundus tendon is presented in which the diagnosis was made based on sonographic findings subsequently confirmed by CT and later surgical findings. This case demonstrates that tendon entrapment complicating phalangeal fractures can be diagnosed using sonography. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
Determination of the expression of fish antifreeze protein (AFP) in 7th generation transgenic mice tissues and serum
Authors: Bagis Haydar , Tas Arzu , Kankavi Orhan
Published: March 2008

In this study, the presence of antifreeze protein (AFP) gene expression through successive generations in transgenic mice carrying the chimeric gene construct of the coding sequence for the AFP protein from ocean pout was investigated. AFP transgenic hemizygote mice were used for AFP gene expression. AFP genome expressions in transgenic mice were analyzed by Western blotting, and tissue location of AFP protein was shown by immunohistochemical and immunofluorescence techniques. Seventh transgenic mice from the established founders demonstrated the expression of AFP in organs such as the skin, oviduct, lung, kidney and liver tissues and serum except for the heart. Our results demonstrate successful expression of AFP gene products in several tissues and serum of transgenic mice, the association of in vivo expressed AFP protein, for the first time. These results indicate that the coding sequence for the AFP protein gene (ocean pout type III AFP gene) could be integrated and stably transcribed and expressed in the 7th generation of transgenic mice. In conclusion transgenic mouse lines would be a good model for the cryostudy of AFP and for the determination of AFP roles in several organs and tissues. J. Exp. Zool. 309A:255–261, 2008. © 2008 Wiley‐Liss, Inc.
The antioxidant effect of a diet rich in Maillard reaction products is attenuated after consumption by healthy male adolescents. In vitro and in vivo comparative study
Authors: Seiquer Isabel , Ruiz‐Roca Beatriz , Mesías Marta , Muñoz‐Hoyos Antonio , Galdó Gabriel , Ochoa Julio J , Navarro María Pilar
Published: March 2008

BACKGROUND: Maillard reaction products (MRPs) are widely consumed as a part of the human diet. A 2 week randomised two‐period crossover trial to determine whether MRP intake affects the antioxidant defence system in male adolescents (11–14 years, n = 18) was carried out using two diets rich and poor in MRPs (brown diet, BD, and white diet, WD, respectively). Fasting blood samples were collected after the dietary intervention periods to measure oxidative status. The in vitro antioxidant activity of the diets was also assessed.

RESULTS: The BD had stronger in vitro antioxidant activity to scavenge free radicals and greater ability to reduce lipid peroxidation. However, in the in vivo assay, markers of oxidative damage (serum thiobarbituric acid‐reactive substances and erythrocyte hydroperoxides) and antioxidant defence parameters (serum antioxidants and enzymatic activities of catalase, superoxide dismutase and glutathione peroxidase) were unchanged after the dietary treatments. Only treatment of biological samples with external oxidants revealed higher values of the antioxidant capacity after consumption of the MRP‐rich diet.

CONCLUSION: In spite of the higher antioxidant activity of the BD shown in vitro, consumption of diets rich in MRPs does not seem to modify oxidative status in healthy male adolescents. However, a protective effect against induced oxidation was shown. Copyright © 2008 Society of Chemical Industry
Voltammetric analysis of DL‐α‐tocopherol with a paste electrode
Authors: Ly Suw Young
Published: March 2008

BACKGROUND: A voltammetric study of vitamin E (DL‐α‐tocopherol) detection using square wave stripping and cyclic voltammetry is discussed in this paper. The working sensor was made by mixing carbon nanotube powder with DNA (double‐stranded calf thymus DNA) and mineral oil. In this electrode, the anodic peak was obtained for − 0.6 V in a 0.1 mol L−1 phosphate electrolyte solution.

RESULTS: Under optimized stripping conditions, analytical linear working ranges of 0.5–4.0 µg L−1 and 40.0–160.0 µg L−1 were obtained. The RSD precision was pegged at 0.105% with seven points using an 80 µg L−1 spike. The detection limit (S/N) was found to be 0.056 µg L−1 (1.30 × 10−10 mol L−1).

CONCLUSION: The developed method was found to be applicable to quality control analysis in the food, pharmaceutical and other manufacturing sectors. Copyright © 2008 Society of Chemical Industry
Analytical scale supercritical fluid fractionation and identification of single polar lipids from deoiled soybean lecithin
Authors: Yip Shiu‐Hang Henry , Ashraf‐Khorassani Mehdi , Taylor Larry T.
Published: March 2008

The phosphatidylcholine (PC)‐enriched fraction from soybean lecithin is of interest due to its critical role in both the pharmaceutical and industrial field. In this work, enhancement of the purity of the PC fraction along with other individual polar lipid fractions was achieved from crude soybean lecithin by using supercritical fluid extraction (SFE) with methanol‐modified SC‐CO2. Neutral lipids were first removed from the crude sample using pure CO2. Then, the effect of CO2 pressure, temperature, and modifier percentage on phospholipid (PL) fractionation from deoiled lecithin was compared with and without silica gel mixed with the lecithin. Pure fractions of phosphatidylethanolamine (PE) and PC were obtained by varying the modifier concentration of the extraction fluid at 460 atm and 40°C with silica gel added to the deoiled lecithin. Without silica gel, coextraction of PE and PC was observed. A total of six components were isolated and tentatively identified in the extract of deoiled crude soybean lecithin.
Modeling of supercritical fluid extraction of phenanthrene from clayey soil
Authors: Elektorowicz Maria , El‐Sadi Haifa , Ayadat Tahar
Published: March 2008

The supercritical fluid (SFC) extraction efficiency of phenanthrene from clayey soils was modeled. The model accounts for effective diffusion of the phenanthrene in the solid pores, axial dispersion in the fluid phase, and external mass transfer to the fluid phase from the particle surface. This model, involving partial differential equations, was solved using the finite difference. The model showed the relationship between diffusivity, mass transfer coefficient, and properties of porous media (clay texture). The porous media analysis was performed with a microscope and by an image analysis. The proposed model compared well with the experimental data available in the literature.