bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclometalated IrIII Complexes with Substituted 1,10‐Phenanthrolines: A New Class of Efficient Cationic Organometallic Second‐Order NLO Chromophores
Authors: Valore Adriana , Cariati Elena , Dragonetti Claudia , Righetto Stefania , Roberto Dominique , Ugo Renato , De Angelis Filippo , Fantacci Simona , Sgamellotti Antonio , Macchioni Alceo , Zuccaccia Daniele
Published: March 2010

Cyclometalated cationic IrIII complexes with substituted 1,10‐phenanthrolines (1,10‐phen), such as [Ir(ppy)2(5‐R‐1,10‐phen)]Y (ppy=cyclometalated 2‐phenylpyridine; R=NO2, H, Me, NMe2; Y−=PF6−, C12H25SO3−, I−) and [Ir(ppy)2(4‐R,7‐R‐1,10‐phen)]Y (R=Me, Ph) are characterized by a significant second‐order optical non linearity (measured by the electrical field induced second harmonic generation (EFISH) technique). This nonlinearity is controlled by MLCT processes from the cyclometalated IrIII, acting as a donor push system, to π* orbitals of the phenanthroline, acting as an acceptor pull system. Substitution of cyclometalated 2‐phenylpyridine by the more π delocalized 2‐phenylquinoline (pq) or benzo[h]quinoline (bzq) or by the sulfur‐containing 4,5‐diphenyl‐2‐methyl‐thiazole (dpmf) does not significantly affect the μβ absolute value, which instead is affected by the nature of the R substituents on the phenanthroline, the higher value being associated with the electron‐withdrawing NO2 group. By using a combined experimental (the EFISH technique and 1H and 19F PGSE NMR spectroscopy) and theoretical (DFT, time‐dependent‐DFT (TDDFT), sum over states (SOS) approach) investigation, evidence is obtained that ion pairing, which is controlled by the nature of the counterion and by the concentration, may significantly affect the μβ values of these cationic NLO chromophores. In CH2Cl2, concentration‐dependent high absolute values of μβ are obtained for [Ir(ppy)2(5‐NO2‐1,10‐phen)]Y if Y is a weakly interacting anion, such as PF6−, whereas with a counterion, such as C12H25SO3− or I−, which form tight ion‐pairs, the absolute value of μβ is lower and quite independent of the concentration. This μβ trend is partially due to the perturbation of the counterion on the LUMO π* levels of the phenanthroline. The correlation between the μβ value and dilution shows that the effect of concentration is a factor that must be taken into careful consideration.
PET/CT in cancer research: from preclinical to clinical applications
Authors: Del Vecchio S. , Zannetti A. , Fonti R. , Iommelli F. , Pizzuti L. M. , Lettieri A. , Salvatore M.
Published: March 2010

The identification of genetic and biochemical mechanisms underlying tumor growth and progression along with the unraveling of human genoma provided a plethora of new targets for cancer detection, treatment and monitoring. Simultaneously, the extraordinary development of a number of imaging technologies, including hybrid systems, allowed the visualization of biochemical, molecular and physiological aberrations linked to underlying mutations in a given tumor. In vivo evaluation of complex biological processes such as proliferation, apoptosis, angiogenesis, metastasis, gene expression, receptor–ligand interactions, transport of substrates and metabolism of nutrients in human cancers is feasible using PET/CT and radiolabeled molecular probes. Some of these compounds are in preclinical phases of evaluation whereas others have been already applied in clinical settings. Here we provide prominent examples on how some biological processes and target expression can be visualized by PET/CT in animal tumor models and cancer patients for the noninvasive detection of well‐known markers of tumor aggressiveness, invasiveness and resistance to treatment and for the evaluation of tumor response to therapy. Copyright © 2010 John Wiley & Sons, Ltd.
Does MC1R genotype convey information about melanoma risk beyond risk phenotypes?
Authors: Kanetsky Peter A. , Panossian Saarene , Elder David E. , Guerry DuPont , Ming Michael E. , Schuchter Lynn , Rebbeck Timothy R.
Published: March 2010

BACKGROUND:

A study was carried out to describe associations of MC1R variants and melanoma in a US population and to investigate whether genetic risk is modified by pigmentation characteristics and sun exposure measures.

METHODS:

Melanoma patients (n = 960) and controls (n = 396) self‐reported phenotypic characteristics and sun exposure via structured questionnaire and underwent a skin examination. Logistic regression was used to estimate associations of high‐ and low‐risk MC1R variants and melanoma, overall and within phenotypic and sun exposure strata. A meta‐analysis of results from published studies was undertaken.

RESULTS:

Carriage of 2 low‐risk or any high‐risk MC1R variants was associated with increased risk of melanoma (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.0‐2.8; and OR, 2.2; 95% CI, 1.5‐3.0, respectively). However, risk was stronger in or limited to individuals with protective phenotypes and limited sun exposure, such as those who tanned well after repeated sun exposure (OR, 2.4; 95% CI, 1.6‐3.6), had dark hair (OR, 2.4; 95% CI, 1.5‐3.6), or had dark eyes (OR, 3.2; 95% CI, 1.8‐5.9). We noted this same pattern of increased melanoma risk among persons who did not freckle, tanned after exposure to first strong summer sun, reported little or average recreational or occupational sun exposure, or reported no sun burning events. Meta‐analysis of published literature supported these findings.

CONCLUSIONS:

These data indicate that MC1R genotypes provide information about melanoma risk in those individuals who would not be identified as high risk based on their phenotypes or exposures alone. Cancer 2010. © 2010 American Cancer Society.
The zebrafish cerebellar upper rhombic lip generates tegmental hindbrain nuclei by long‐distance migration in an evolutionary conserved manner
Authors: Volkmann Katrin , Chen Yi‐Yen , Harris Matthew P. , Wullimann Mario F. , Köster Reinhard W.
Published: March 2010

The upper rhombic lip (URL) of the developing mammalian cerebellum produces different neuronal cell types in a temporal sequence. The first neuronal populations arising from this proliferation zone include the progenitors of the parabrachial, parabigeminal, and laterodorsal‐pedunculopontine tegmental hindbrain nuclei. By means of expression analysis, histology, and retrograde neuronal tracing, we have identified the zebrafish homologues of these nuclei, namely, the secondary gustatory/viscerosensory nucleus, the nucleus isthmi, and the superior reticular nucleus, respectively, in the embryonic and larval brain of a stable transgenic wnt1:Gal4‐VP16‐14 × UAS:GFP zebrafish strain. Combining time‐lapse confocal imaging with individual cell tracing, we characterize the migratory behavior of these neuronal precursor populations in detail by revealing their migration path, velocity, and directionality. In addition, we identify neuronal progenitors of the secondary gustatory/viscerosensory nucleus and nucleus isthmi/superior reticular nucleus as belonging to the polysialic acid (PSA)‐expressing cell population in the cerebellar plate that migrates in a PSA‐dependent manner. Finally, we reveal that circuitries involved in the processing of sensory information (visual, gustatory, general viscerosensory) are already established in the zebrafish larva at day 4 of development. Also the wnt1‐expressing pretectal neuronal precursors (not originating from the URL) sending mossy fiber‐like projections into the cerebellar corpus are established at that time. In sum, our results show that the origin of neurons of some tegmental hindbrain nuclei, namely, nucleus isthmi/superior reticular nucleus and secondary gustatory/viscerosensory nucleus is in the URL, and that the temporal order of cell types produced by the URL and their developmental program are conserved among vertebrate species. J. Comp. Neurol. 518:2794–2817, 2010. © 2010 Wiley‐Liss, Inc.
Histamine‐immunoreactive local neurons in the antennal lobes of the hymenoptera
Authors: Dacks Andrew M. , Reisenman Carolina E. , Paulk Angelique C. , Nighorn Alan J.
Published: March 2010

Neural networks receive input that is transformed before being sent as output to higher centers of processing. These transformations are often mediated by local interneurons (LNs) that influence output based on activity across the network. In primary olfactory centers, the LNs that mediate these lateral interactions are extremely diverse. For instance, the antennal lobes (ALs) of bumblebees possess both γ‐aminobutyric acid (GABA)‐ and histamine‐immunoreactive (HA‐ir) LNs, and both are neurotransmitters associated with fast forms of inhibition. Although the GABAergic network of the AL has been extensively studied, we sought to examine the anatomical features of the HA‐ir LNs in relation to the other cellular elements of the bumblebee AL. As a population, HA‐ir LNs densely innervate the glomerular core and sparsely arborize in the outer glomerular rind, overlapping with the terminals of olfactory receptor neurons. Individual fills of HA‐ir LNs revealed heavy arborization of the outer ring of a single “principal” glomerulus and sparse arborization in the core of other glomeruli. In contrast, projection neurons and GABA‐immunoreactive LNs project throughout the glomerular volume. To provide insight into the selective pressures that resulted in the evolution of HA‐ir LNs, we determined the phylogenetic distribution of HA‐ir LNs in the AL. HA‐ir LNs were present in all but the most basal hymenopteran examined, although there were significant morphological differences between major groups within the Hymenoptera. The ALs of other insect taxa examined lacked HA‐ir LNs, suggesting that this population of LNs arose within the Hymenoptera and underwent extensive morphological modification. J. Comp. Neurol. 518:2917–2933, 2010. © 2010 Wiley‐Liss, Inc.
Tiling among stereotyped dendritic branches in an identified Drosophila motoneuron
Authors: Vonhoff F. , Duch C.
Published: March 2010

Different types of neurons can be distinguished by the specific targeting locations and branching patterns of their dendrites, which form the blueprint for wiring the brain. Unraveling which specific signals control different aspects of dendritic architecture, such as branching and elongation, pruning and cessation of growth, territory formation, tiling, and self‐avoidance requires a quantitative comparison in control and genetically manipulated neurons. The highly conserved shapes of individually identified Drosophila neurons make them well suited for the analysis of dendritic architecture principles. However, to date it remains unclear how tightly dendritic architecture principles of identified central neurons are regulated. This study uses quantitative reconstructions of dendritic architecture of an identified Drosophila flight motoneuron (MN5) with a complex dendritic tree, comprising more than 4,000 dendritic branches and 6 mm total length. MN5 contains a fixed number of 23 dendritic subtrees, which tile into distinct, nonoverlapping volumes of the diffuse motor neuropil. Across‐animal comparison and quantitative analysis suggest that tiling of the different dendritic subtrees of the same neuron is caused by competitive and repulsive interactions among subtrees, perhaps allowing different dendritic compartments to be connected to different circuit elements. We also show that dendritic architecture is similar among different wildtype and GAL4 driver fly lines. Metric and topological dendritic architecture features are sufficiently constant to allow for studies of the underlying control mechanisms by genetic manipulations. Dendritic territory and certain topological measures, such as tree compactness, are most constant, suggesting that these reflect the intrinsic molecular identity of the neuron. J. Comp. Neurol. 518:2169–2185, 2010. © 2010 Wiley‐Liss, Inc.
Coupling of lung tissue tethering force to fluid dynamics in the pulmonary circulation
Authors: Burrowes K. S. , Tawhai M. H.
Published: March 2010

Dynamic changes in lung volume during breathing and alteration of posture are both known to influence the distribution of perfusion within the lung. Here we couple computational models of pulmonary blood flow and parenchymal tissue mechanics to produce a novel flow model that predicts tissue deformation simultaneously with flow distributions at different lung volumes and postures. The model is used to study the effect of lung volume on flow distribution as a result of normal variation in axial and radial tethering forces. Finite deformation elasticity is used to predict volume changes of the lung tissue and resultant tethering pressures within the tissue. A finite element model of the pulmonary arterial network is embedded within the lung volume and deforms with the tissue. The spatial distribution of steady‐state blood flow is predicted using the Poiseuille resistance (including gravity), conservation of mass, and a vascular pressure–radius relationship. Blood flow gradients with respect to gravitationally dependent height are calculated. Gradients are predicted to be consistently steeper in the supine (compared with prone) model due to increased tissue deformation. Decreased lung volume resulted in increased gravitationally dependent flow gradients, predominantly due to the effect of axial vessel stretch on the length and the radius of the arterial vessels. Copyright © 2010 John Wiley & Sons, Ltd.
In Situ Video‐STM Studies of Adsorbate Dynamics at Electrochemical Interfaces
Authors: Tansel Tunay , Taranovskyy Andriy , Magnussen Olaf M.
Published: March 2010

The dynamic behavior of individual adsorbates at electrochemical interfaces was studied directly by in situ high‐speed scanning tunneling microscopy, using sulfur adsorbed on Cu(100) electrodes in 0.01 M HCl solution as an example. By dosing from diluted Na2S solutions Sad coverages of a few percent can be prepared, with the sulfur adsorbates occupying positions within the c(2×2) lattice of coadsorbed chloride. Sad tracer diffusion occurs via hopping between neighboring c(2×2) lattice sites at considerably higher rates than those of sulfur on Cu(100) under UHV conditions, indicating a pronounced influence of the electrochemical environment on the adsorbate surface dynamics. The diffusion barrier linearly increases by 0.5 eV per V with potential and is strongly affected by neighboring Sad and surface defects. The SadSad interactions extend over ≈7 Å. They are repulsive between nearest‐neighbor and attractive between next‐nearest‐neighbor sites, respectively, and result in significantly reduced diffusion barriers. Sad on the upper terrace side of steps are transiently trapped and exhibit lower diffusion rates, leading to the formation of small metastable p(2×2) domains. Attractive interactions between Sad and domain boundaries in the c(2×2) adlayer result in boundary pinning as well as transient trapping and enhanced diffusion of Sad along the boundary.
Light‐Induced Activation of Bacterial Phytochrome Agp1 Monitored by Static and Time‐Resolved FTIR Spectroscopy
Authors: Piwowarski Patrick , Ritter Eglof , Hofmann Klaus‐Peter , Hildebrandt Peter , von Stetten David , Scheerer Patrick , Michael Norbert , Lamparter Tilman , Bartl Franz
Published: March 2010

Phytochromes, which regulate many biological processes in plants, bacteria, and fungi, can exist in two stable states, Pr and Pfr, that can be interconverted by light, via a number of intermediates such as meta‐Rc. Herein we employ FTIR spectroscopy to study the Pr‐to‐Pfr conversion of the bacteriophytochrome Agp1 from Agrobacterium tumefaciens. Static FTIR Pfr/Pr and meta‐Rc/Pr difference spectra are disentangled in terms of cofactor and protein structural changes. Guided by DFT calculations on cofactor models, the chromophore conformational changes can be grouped into structural adjustments of the cofactor–protein interactions localized in the C–D dipyrrole moiety, that is, the photoisomerisation site, and in the A–B dipyrrole moiety including the protein attachment site. Whereas changes at the C and D rings appear to be largely completed in the meta‐Rc state, the structural changes in the A–B unit occur during the transition from meta‐Rc to Pfr, concomitant with the main protein structural changes, as demonstrated by static and time‐resolved FTIR difference spectroscopy. We employ this technique to monitor, for the first time, the dynamics of the photocycle of phytochrome on the millisecond timescale. By extending the studies to genetically engineered protein variants of Agp1, we further demonstrate that H250 and D197 as well as the PHY domain are essential for formation of the Pfr state. Based on the IR spectroscopic and available crystallographic data we discuss the role of critical amino acid residues for the protein–cofactor interactions during the photoinduced reaction cycle.
Effect of temperature programmes on protein crystallisation
Authors: Wang Xi‐Kai , Yin Da‐Chuan , Zhang Chen‐Yan , Lu Qin‐Qin , Guo Yun‐Zhu , Guo Wei‐Hong
Published: March 2010

Varying the temperature has been proven to be beneficial for improving the screening efficiency of protein crystallisation, and thus a crystallisation screening strategy based on this phenomenon can be developed. Such a temperature varying strategy can be applied in practical crystallisation screening, however, there are no guidelines for determining what temperature programme should be utilised. It is therefore necessary to investigate how the temperature programme affects the crystallisation process, so as to help people design a suitable temperature programme. For this purpose, we investigated the effect of temperature programmes on the protein crystallisation (lysozyme, proteinase K, and concanavalin A) that are characterised by different solubility behaviours with respect to temperature. Judging from the reproducibility studies of protein crystallisation with different temperature programmes, we recommend using linear temperature programmes for a moderate time period (24 to 48 h) and a large temperature range according to the properties of the proteins. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cytological findings of mixed squamous cell and glandular papilloma in the lung
Authors: Kadota Kyuichi , Haba Reiji , Katsuki Naomi , Hayashi Toshitetsu , Miyai Yumi , Bando Kenji , Shibuya Shinsuke , Kushida Yoshio
Published: March 2010

Pulmonary mixed squamous cell and glandular papilloma is an extremely rare neoplasm. This is the first cytological report of such a rare neoplasm. A 59‐year‐old Japanese man was admitted to the hospital complaining of a persistent cough and bloody sputum. A bronchial endoscopic examination revealed an endobronchial polypoid tumor. Upon bronchial brush cytology by Papanicolaou stain, squamous dysplasia showing mild atypia was suspected. The smears showed moderate cellularity with singly scattered cells or loose clusters of cells, consisting of squamous cells and a few columnar cells. Nuclei of the squamous cells showed mild atypia, but there was no nuclear atypia of the columnar cells. Upon intraoperative pathological examination by frozen section, pulmonary mixed squamous cell and glandular papilloma was suspected. Intraoperative imprint cytology by Ultrafast Papanicolaou stain showed a few differences in comparison with bronchial brush cytology, which were thought to be due to differences in obtaining cytological specimens or the steps prior to the staining. The patient underwent a segmentectomy of the left lung. Histopathological diagnosis confirmed a mixed squamous cell and glandular papilloma. The postoperative course has been uneventful for 5 years after surgery. It was thought that cytology was diagnostically inadequate on its own in the present case. However, mixed squamous cell and glandular papilloma must be considered as another type of pulmonary tumor in cytological preparations, especially in a case showing endobronchial papillary growth by bronchoscopy. Diagn. Cytopathol. 2010;38:913–917. © 2010 Wiley‐Liss, Inc.
Cytological diagnosis of actinomycosis and eumycetoma: A report of two cases
Authors: Hemalata Mahantappa , Prasad Sruthi , Venkatesh Kusuma , S. R. Niveditha , Kumar Suja Ajoy
Published: March 2010

Mycetoma and actinomycosis are common in tropical countries and are increasingly diagnosed in other parts of the world due to rapid mobilization of the population. They are usually diagnosed on histopathology. There is very limited data on the role of fine‐needle aspiration cytology (FNAC) in diagnosing these lesions. We report here two cases: one of eumycetoma and the other of an actinomycosis that were reliably diagnosed with FNAC. The cytological features were similar to histopathology features and differentiated eumycetoma and actinomycosis. FNAC is a rapid, simple and inexpensive outpatient procedure that helps in rapid diagnosis. Diagn. Cytopathol. 2010;38:918–920. © 2010 Wiley‐Liss, Inc.
Intrathyroidal oncocytic parathyroid adenoma: A diagnostic pitfall on fine‐needle aspiration
Authors: Paker Irem , Yilmazer Demet , Yandakci Kemal , Arikok Ata Turker , Alper Murat
Published: March 2010

Oncocytic parathyroid adenoma is a rarely seen benign neoplasm of the parathyroid and intrathyroidal location of this lesion is also uncommon. It can be easily misdiagnosed as Hürthle cell thyroid neoplasm on fine‐needle aspiration (FNA). Here, an intrathyroidal oncocytic parathyroid adenoma in a 32‐year‐old male is reported. Ultrasonography showed a nodule 2 cm in largest diameter in the left thyroid lobe. FNA revealed cellular smears containing monotonous oncocytic cells arranged in monolayered sheets, pseudopapillary structures and clusters within a rich vascular network. The case was reported as “suspicious for Hürthle cell thyroid neoplasm” on FNA. Frozen section examination showed intrathyroidal oncocytic parathyroid adenoma with a rim of normal parathyroid tissue. The diagnosis was also confirmed with immunohistochemical stains (TTF‐1, PTH, thyroglobulin) performed on permanent sections. Cytopathologic features of oncocytic parathyroid adenoma and Hürthle cell thyroid neoplasm are similar. It is important to keep oncocytic parathyroid adenoma in mind in the differential diagnosis of Hürthle cell thyroid neoplasm. Prior knowledge of clinical, radiological and laboratory data will avoid wrong cytopathologic diagnosis. Diagn. Cytopathol. 2010;38:833–836. © 2010 Wiley‐Liss, Inc.
SARM inhibits both TRIF‐ and MyD88‐mediated AP‐1 activation
Authors: Peng Jun , Yuan Quan , Lin Bin , Panneerselvam Porkodi , Wang Xiaowei , Luan Xiao Lei , Lim Soon Kok , Leung Bernard P , Ho Bow , Ding Jeak Ling
Published: March 2010

SARM (sterile α‐ and armadillo‐motif‐containing protein), the fifth identified TIR (Toll–interleukin 1 receptor (IL‐1R)) domain‐containing adaptors in humans, downregulates NF‐κB and IRF3 (interferon‐regulatory factor 3)‐mediated TLR3 and TLR4 signaling. SARM was characterized as a negative regulator of the TRIF (TIR‐domain‐containing adaptor protein inducing IFN‐β)‐dependent pathway via its interaction with TRIF. However, the precise mechanism of action of SARM remains unclear. Here, we demonstrate that SARM inhibits MAPK activation in human embryonic kidney 293 cells, and U937 cells. Both the TRIF‐ and MyD88‐mediated, as well as basal MAPK activity, were repressed, indicating that SARM‐mediated inhibition may not be exclusively directed at TRIF or MyD88, but that SARM may also directly inhibit MAPK phosphorylation. The MAPK inhibition effect was verified by RNAi, which increased the basal level of AP‐1. Furthermore, LPS challenge upregulated SARM at both the mRNA and protein levels. Finally, we provide evidence to show that truncated SARM changes its subcellular localization, suggesting the importance of the N‐terminal and sterile alpha motif domains in the autoregulation of SARM activity.
Class switching and consecutive loss of dsDNA‐reactive B1a B cells from the peritoneal cavity during murine lupus development
Authors: Enghard Philipp , Humrich Jens Y. , Chu Vantrung T. , Grussie Erwin , Hiepe Falk , Burmester Gerd‐Rüdiger , Radbruch Andreas , Berek Claudia , Riemekasten Gabriela
Published: March 2010

B1a B cells have been implicated in the pathogenesis of systemic lupus erythematosus; however, their precise contribution to the disease remains unclear. Here we analysed isotype expression, organ accumulation and autoreactivity of B1a cells in the NZB/W F1 murine model for systemic lupus erythematosus using flow cytometry, ELISPOT and adoptive cell transfer. In the course of lupus, the B1a compartment is expanded and B1a cells class switch to IgG. Class‐switched B1a B cells were excluded from the peritoneal cavity but accumulated in the spleen and target organs such as kidneys and thymus. Autoreactive B1a B cells preferentially class switch, which leads to a subsequent loss of autoreactive B1a cells from the peritoneal cavity. We propose a model whereby autoreactive B1a B cells become activated early in the course of lupus and class switch to IgG. These autoreactive B1a B cells accumulate in the spleen and affected organs where they presumably secrete autoantibodies and contribute to the local and systemic pathogenesis.
The CD4+ T‐cell epitope‐binding register is a critical parameter when generating functional HLA‐DR tetramers with promiscuous peptides
Authors: Cecconi Virginia , Moro Monica , Del Mare Sara , Sidney John , Bachi Angela , Longhi Renato , Sette Alessandro , Protti Maria Pia , Dellabona Paolo , Casorati Giulia
Published: March 2010

Detection of CD4+ T cells specific for tumor‐associated antigens is critical to investigate the spontaneous tumor immunosurveillance and to monitor immunotherapy protocols in patients. We investigated the ability of HLA‐DR*1101 multimers to detect CD4+ T cells specific for three highly promiscuous MAGE‐A3 derived peptides: MAGE‐A3191–205 (p39), MAGE‐A3281–295 (p57) and MAGE‐A3286–300 (p58). Tetramers stained specific CD4+ T cells only when loaded with p39, although all peptides activated the specific T cells when presented by plastic‐bound HLA‐DR*1101 monomers. This suggested that tetramer staining ability was determined by the mode rather than the affinity of peptide binding to HLA‐DR*1101. We hypothesized that peptides should bear a single P1 anchor residue to bind all arms of the multimer in a homogeneous register to generate peptide‐HLA‐DR conformers with maximal avidity. Bioinformatics analysis indicated that p39 contained one putative P1 anchor residue, whereas the other two peptides contained multiple ones. Designing p57 and p58 analogues containing a single anchor residue generated HLA‐DR*1101 tetramers that stained specific CD4+ T cells. Producing HLA‐DR*1101 monomers linked with the optimized MAGE‐A3 analogues, but not with the original epitopes, further improved tetramer efficiency. Optimization of CD4+ T‐cell epitope‐binding registers is thus critical to generate functional HLA‐DR tetramers.
Successive Ligand and Metal Oxidation: Redox Reactions Involving Binuclear CuI Complexes of Chelating Guanidine Ligands
Authors: Emeljanenko Dimitri , Peters Anastasia , Wagner Norbert , Beck Johannes , Kaifer Elisabeth , Himmel Hans‐Jörg
Published: March 2010

New binuclear complexes of three‐coordinate CuI have been synthesized with the ligand 1,2,4,5‐tetrakis(tetramethylguanidino)benzene (ttmgb). Subsequent oxidation of the ligand unit was achieved by reaction with Br2 or I2. Reaction with Br2 leads to oxidation of both the ligand and the copper ions and formation of a bicationic dinuclear CuII complex. On the other hand, oxidation with I2 leads only to oxidation of the ligand during the first step. A metastable coordination polymer of ladder‐type structure results, in which the coordination number of the CuI ions increases to four. Electrical measurements show that this polymer is semiconductive with a band gap of around 1 eV. The electronic structure of the polymer was further studied by X‐ray photoelectron spectroscopy (XPS), Raman and Vis/NIR spectroscopy. It decomposes (with oxidation of the copper ions) in an exothermal reaction at temperatures around 230 °C. Oxidation of the copper ions and decomposition of the polymer can also be achieved by reaction of the polymer with phenanthroline.
Preparation and Conformation Analysis of N‐(Ferrocenoyl)dipeptide Esters and Their 1′‐Acetyl Derivatives
Authors: Lapić Jasmina , Djaković Senka , Kodrin Ivan , Mihalić Zlatko , Cetina Mario , Rapić Vladimir
Published: March 2010

Ferrocene‐containing dipeptides X‐Fn‐CO‐AA‐AA‐OMe(3/4, X = H, AA = Gly/Ala; 5/6, X = Ac, AA = Gly/Ala, Fn = ferrocene‐1,1′‐diyl) were prepared in 51–67 % yields from the starting appropriate ferrocenecarboxylic acid and dipeptide ester by the HOBt/EDC protocol. Conformation analysis of these bioconjugates was performed by spectroscopic methods (IR, 1H and 13C NMR, CD) and by X‐ray crystal structure analysis, as well as by molecular modelling (DFT). Crystallographic analysis showed that self‐assembly processes prevailed in compound 5, and almost exclusively hydrogen‐bonded species were also detected in all the compounds studied in the solid state by IR spectroscopy (KBr). Spectroscopic studies of conjugates 3–6 undertaken in solution in nonpolar solvents demonstrated formation of intra‐ and interchain weak to medium hydrogen bonds spanning NHAA2 with 1‐FcCO, 1′‐FcCO and/or NAA1 (Fc = ferrocenyl). The same experiments revealed that NHAA1 is not involved in hydrogen bonds. The interchain hydrogen bond in conjugate 6 caused a (P)‐helical arrangement of the ferrocene moiety exhibiting a positive Cotton effect at 495 nm (246 deg M–1cm–1). All of the experimental findings were corroborated by DFT calculations, which furthermore showed conformation preferences in respect to the natural amino acid side chain of conjugates 3–6.
New 5‐Alkoxypyrimidine Derivatives from β‐Alkoxy β‐Keto Enamides and Ammonium Salts
Authors: Lechel Tilman , Reissig Hans‐Ulrich
Published: March 2010

A series of highly substituted β‐alkoxy β‐keto enamides were prepared by a multi‐component reaction combining lithiated alkoxyallenes, nitriles and carboxylic acids. Apt conditions were developed for their conversion into 5‐alkoxypyrimidine derivatives. This synthesis is highly flexible with respect to the substitution pattern at C‐2 and C‐4 of the pyrimidine core. The corresponding pyrimidin‐5‐yl nonaflates allowed subsequent transformations at C‐5 by palladium‐catalyzed couplings such as Sonogashira and Suzuki reactions. The Sonogashira coupling of a pyrimidinyl alkyne with a pyridinyl nonaflate and a subsequent cyclization led to an efficient access to pyrimidinyl‐substituted furo[2,3‐c]pyridine derivatives. The C‐6 methyl group which is present in all of the prepared pyrimidines can easily be converted into formyl, carboxylic or alkynyl moieties which allow the synthesis of additional pyrimidine derivatives.
Novel Five‐ to Ten‐Membered Organoselenium Heterocycles from the Selenation of Aromatic Diols
Authors: Hua Guoxiong , Fuller Amy L. , Slawin Alexandra M. Z. , Woollins J. Derek
Published: March 2010

Reaction of Woollins' reagent ― WR, 2,4‐bis(phenyl)‐1,3‐diselenadiphosphetane 2,4‐diselenide [{PhP(Se)(μ‐Se)}2] ― with aromatic diols in refluxing toluene afforded a series of novel five‐ to ten‐membered phosphorus‐selenium heterocycles 1–10 with an O–P(Se)–O or O–P(Se)–Se–P(Se)–O or O–P(Se)–O–P(Se)–O linkage in 12–74 % isolated yields. It was found that the diphosphorus species O–P(Se)–Se–P(Se)–O rings could be readily reduced into the monophosphorus species O–P(Se)–O rings in almost quantitative yields via further reaction with another equivalent of corresponding aromatic diol. All new compounds have been characterized by IR, 1H NMR, 13C NMR, 31P NMR, 77Se NMR, mass spectrometry and elemental analysis or accurate mass measurement. Seven representative X‐ray structures are reported.
Optically Active Trialkynyl(phenyl)methane: Synthesis and Determination of Its Absolute Configuration by Vibrational Circular Dichroism (VCD) and Optical Rotatory Dispersion (ORD)
Authors: Buschhaus Boris , Convertino Vito , Rivera‐Fuentes Pablo , Alonso‐Gómez José Lorenzo , Petrovic Ana G. , Diederich François
Published: March 2010

Both enantiomers of an optically active trialkynyl(phenyl)methane (the key building blocks in the construction of a stable expanded cubane) have been prepared. The strategy involved the resolution of a racemic intermediate by means of HPLC on a chiral stationary phase. The absolute configuration of this intermediate was unambiguously assigned by using vibrational circular dichroism (VCD) and optical rotatory dispersion (ORD), in combination with density functional theory (DFT) calculations.
A Marriage of Convenience: Combining the Power of Isocyanide‐Based Multicomponent Reactions with the Versatility of (Hetero)norbornene Chemistry (Eur. J. Org. Chem. 10/2010)
Authors: Basso Andrea , Banfi Luca , Riva Renata
Published: March 2010

The cover picture shows one of the six paintings of Marriage á‐la‐mode (© National Gallery, London) created by William Hogarth in 1743–1745 and portrays a pointed skewering of upper‐class 18th century society. This moralistic warning shows the disastrous results of an ill‐considered marriage for money. However, the authors of this Microreview demonstrate that the marriage of convenience between the Ugi reaction and the norbornenyl scaffold is not to be blamed. Details are presented in the Microreview by A. Basso et al. on p. 1831 ff.
Continuous dielectrophoretic separation of particles in a spiral microchannel
Authors: Zhu Junjie , Tzeng Tzuen‐Rong J. , Xuan Xiangchun
Published: March 2010

Particle separation is a fundamental operation in the areas of biology and physical chemistry. A variety of force fields have been used to separate particles in microfluidic devices, among which electric field may be the most popular one due to its general applicability and adaptability. So far, however, electrophoresis‐based separations have been limited primarily to batchwise processes. Dielectrophoresis (DEP)‐based separations require in‐channel micro‐electrodes or micro‐insulators to produce electric field gradients. This article introduces a novel particle separation technique in DC electrokinetic flow through a planar double‐spiral microchannel. The continuous separation arises from the cross‐stream dielectrophoretic motion of particles induced by the non‐uniform electric field inherent to curved channels. Specifically, particles are focused by DEP to one sidewall of the first spiral, and then dielectrophoretically deflected toward the other sidewall of the second spiral at a particle‐dependent rate, leading to focused particle streams along different flow paths. This DEP‐based particle separation technique is demonstrated in an asymmetric double‐spiral microchannel by continuously separating a mixture of 5/10 μm particles and 3/5 μm particles.
Pumpless dispensing of a droplet by breaking up a liquid bridge formed by electric induction
Authors: Hong Jin Seok , Lee Beom Seok , Moon Dustin , Lee Jeong–Gun , Kang In Seok
Published: March 2010

Dispensing uniform pico‐to‐nanoliter droplets has become one of essential components in various application fields from high‐throughput bio‐analysis to printing. In this study, a new method is suggested and demonstrated for dispensing a droplet on the top plate with an inverted geometry by using electric field. The process of dispensing droplets consists of two stages: (i) formation of liquid bridge by moving up the charged fluid mass using the electrostatic force between the charges on the fluid mass and the induced charges on the substrate and (ii) its break‐up by the motion of the top plate. Different from conventional electrohydrodynamic methods, electric induction enables the droplets to be dispensed on various surfaces including non‐conducting substrate. The use of capillarity with an inverted geometry removes the need of external pumps or elaborates control for constant flow feed. The droplet diameter has been characterized as a function of the nozzle‐to‐plate distance and the plate moving velocity. The robustness of the present method is shown in terms of nozzle length and applied voltage. Finally, its practical applicability is confirmed by rendering a 19 by 24 array of highly uniform droplets with only 1.8% size variation without use of any active feedback control.
Supercritical fluid extraction of lipids from the heterotrophic microalga Crypthecodinium cohnii
Authors: Couto Ricardo Miguel , Simões Pedro Calado , Reis Alberto , Da Silva Teresa Lopes , Martins Vítor Hugo , Sánchez‐Vicente Yolanda
Published: March 2010

Microalgae biomass can be a feasible source of ω‐3 fatty acids due to its stable and reliable composition. In the present study, the Crypthecodinium cohnii growth and docosahexaenoic acid (DHA, 22:6ω3) production in a 100 L glucose‐fed batch fermentation was evaluated. The lipid compounds were extracted by supercritical carbon dioxide (SC‐CO2) from C. cohnii CCMP 316 biomas, was and their fatty acid composition was analysed. Supercritical fluid extraction runs were performed at temperatures of 313 and 323 K and pressures of 20.0, 25.0 and 30.0 MPa. The optimum extraction conditions were found to be 30.0 MPa and 323 K. Under those conditions, almost 50% of the total oil contained in the raw material was extracted after 3 h and the DHA composition attained 72% w/w of total fatty acids. The high DHA percentage of total fatty acids obtained by SC‐CO2 suggested that this extraction method may be suitable for the production of C. cohnii value added products directed towards pharmaceutical purposes. Furthermore, the fatty acid composition of the remaining lipid fraction from the residual biomass with lower content in polyunsaturated fatty acids could be adequate for further uses as feedstock for biodiesel, contributing to the economy of the overall process suggesting an integrated biorefinery approach.
Enzymatic synthesis of short‐chain esters in n‐hexane and supercritical carbon dioxide: Effect of the acid chain length
Authors: Diaz Maria Dolores Romero , Gómez Jose M. , Díaz‐Suelto Beatriz , García‐Sanz Alicia
Published: March 2010

Enzymatic synthesis is the preferred way to produce so‐called “natural products.” Hydrolases have been used for short‐chain ester synthesis. These esters present a pleasant flavor and they have a lot of applications in different industries. Novozym 435 from Candida antarctica (EC 3.1.1.3, triacylglycerol lipase) was used for hexyl ester synthesis in n‐hexane and supercritical carbon dioxide (SCCO2). Direct esterification provided higher yields than transesterification for the synthesis of esters. Several carboxylic acids of different chain lengths were tested for the esterification reactions: acetic, propionic, butyric, caproic and caprylic acids. The reactions were carried out at 40°C and the amount of enzyme used was 13.8 g/mol alcohol. Substrates were added at equimolar concentrations, with sufficient stirring to avoid external diffusion control. Different substrate concentrations up to 1.5 M were used. The working pressure was 14 MPa in the case of SCCO2 and atmospheric pressure in the case of organic solvent. The results in both solvents show that the reaction rate increases with the chain length of the acid, but the final yields were similar. However, some of the reactions prove to be faster in SCCO2, except for hexyl acetate and propionate synthesis, in which acetic and propionic acid presented a lower solubility in SCCO2 due to its high polarity. Moreover, an acetic acid concentration of 1.5 M brought about a strong inhibition of the enzyme activity.
A predictive model for pressure fluctuations on sloping channels using support vector machine
Authors: Guven Aytac
Published: March 2010

In this study, support vector machine (SVM) is proposed as a new predictive model for pressure fluctuations beneath free jump occurring on sloping channels. The proposed model reproduces the pressure fluctuation intensity C′p in terms of normalized flow and channel section characteristics. The model variables were derived from dimensional analysis. The proposed model is calibrated and validated by using a wide range of experimental data. The SVM predicted C′p with a correlation of coefficient (CC) of 0.989 and a root mean square error (RMSE) of 0.004. Also, linear and nonlinear regression analyses are applied on the same experimental data set, and the SVM model is compared to the equations obtained from these regression analyses. CC, RMSE and average absolute deviation (Di) are used in the evaluation of performance of each model. The SVM model predicted the measured pressure fluctuations better than conventional regression equations. The results of this study reveal that the proposed SVM model can be effectively used in predicting the pressure fluctuation beneath free jump. Copyright © 2010 John Wiley & Sons, Ltd.
Phenanthrene decreases neutrophil function by disrupting intracellular redox balance
Authors: Buttignol M. H. P. , Barros M. P. , Macedo R. C. , Marin D. P. , Otton R.
Published: March 2010

The aim of the present work was to evaluate whether the treatment of human neutrophils with phenanthrene (PHN) can alter the phagocytic and microbicidal capacity of these cells by causing a disruption in redox balance. Peripheral neutrophils from healthy subjects were treated for up to 24 h with increasing concentrations of phenanthrene. Phagocytic/microbicidal activities, antioxidant enzymes, oxidative lesions (thiobarbituric acid‐reactive substances and protein thiol and carbonyl groups) and redox signaling compounds (intracellular Ca2+, superoxide, hydrogen peroxide and nitric oxide) were monitored on neutrophils exposed to 10 µg PHN ml−1. Cell viability decreased abruptly at PHN concentrations above 10 µg ml−1 (LC50 = 20.86 ± 0.51 µg ml−1 and p‐sigmoidal slope = 19.88 ± 10.11). Phagocytic and microbicidal capacities were decreased by 60 and 82%, respectively. Substantial increases in total‐/Mn‐SOD, catalase, glutathione peroxidase and glutathione reductase activities (by 61, 15, 87, 245 and 70%, respectively) matched the oxidative injury obtained in TBARS (2.5‐fold higher) and protein thiol (54% lower). Diminished productions of superoxide by 18% and hydrogen peroxide by 29% were observed in association to exacerbated calcium (27%) and nitric oxide (63%) levels. The data indicate that phenanthrene might be associated with substantial reduction in human neutrophil functions due to severe intracellular redox imbalances. Copyright © 2010 John Wiley & Sons, Ltd.
The use of fluid boluses to safely perform extracorporeal photopheresis (ECP) in low‐weight children: A novel procedure
Authors: Schneiderman Jennifer , A. Jacobsohn David , Collins Jennifer , Thormann Kimberly , Kletzel Morris
Published: March 2010

Apheresis procedures in small children are technically challenging and require special planning with attention to extracorporeal volume. Discontinuous procedures such as extracorporeal photopheresis (ECP) require additional consideration. Alternative methods to perform ECP have been utilized in small children that require manipulation of mononuclear cells outside the standard closed‐loop system. We present a safe and feasible alternative to the procedure for children who weigh less than 40 Kg, while maintaining a closed loop, sterile system utilizing the UVAR XTS device. A retrospective chart review was performed analyzing the use of fluid boluses (normal saline in those between 20 and 40 Kg, 5% albumin in those under 20 Kg) before ECP. Eleven patients underwent 334 ECP procedures for acute and chronic graft‐versus‐host disease (n = 9), and for prevention of graft‐versus‐host disease (n = 2). Volumes of fluid boluses were calculated based on the expected extracorporeal volume during the first draw cycle. Treatments consisted of at least three draw cycles using the 125 mL bowl. The median weight was 28.5 Kg (range 19 to 39); nine of 11 required red cell transfusions to maintain adequate hematocrit. Complications attributed to ECP included tachycardia, dizziness, nausea, and hypotension; these occurred either in combination or isolation in 31% of the procedures and resolved following additional fluid boluses. Only three (0.8%) required early photoactivation due to these complications. The median time to completion of treatment was 2 h and 58 min (range 1:30 to 5:03). ECP is well tolerated in low‐weight pediatric patients if hematocrit and hydration are carefully maintained. J. Clin. Apheresis, 2010. © 2010 Wiley‐Liss, Inc.
Oxidative damage to DNA and lipids: correlation with protein glycation in patients with type 1 diabetes
Authors: Goodarzi Mohammad Taghi , Navidi Ali Akbar , Rezaei Mohsen , Babahmadi‐Rezaei Hossein
Published: March 2010

Diabetic hyperglycemia is associated with increased production of reactive oxygen species (ROS). ROS reacts with DNA resulting in various products, such as 8‐hydroxydeoxyguanosine (8‐OHdG), that excrete in urine owing to DNA repair processes. Urinary 8‐OHdG has been proposed as an indicator of oxidative damage to DNA. This study aimed to evaluate relationship between oxidative damage to DNA and protein glycation in patients with Type 1 diabetes. We measured urinary 8‐OHdG level in diabetic patients and healthy subjects and discussed its relationship to glycated hemoglobin (HbA1c) and glycated serum protein (GSP) levels. Furthermore plasma malondialdehyde (MDA) level monitored as an important indicator of lipid peroxidation in diabetes. We studied 32 patients with Type 1 diabetes mellitus and compared the measured factors with those of 48 age‐matched nondiabetic controls. GSP and MDA were measured bycolorimetric assay. Urinary 8‐OHdG measurement was carried out using ELISA. In this study urinary 8‐OHdG, HbA1c, plasma MDA, and GSP levels were progressively higher in diabetics than in control subjects (P<0.05). Furthermore we found significant correlation between urinary 8‐OHdG and HbA1c (P<0.05) in diabetic group. Correlation between fasting blood sugar and GSP were significant. We also found significant correlation between fasting blood sugar and MDA. This case–control study in young diabetic patients showed increased blood glucose and related metabolic disorders result in oxidative stress and oxidative damage to DNA and lipids. Furthermore oxidative damage to DNA is associated to glycemic control level, whereas lipid peroxidation level was not significantly correlated with glycemic control level. J. Clin. Lab. Anal. 24:72–76, 2010. © 2010 Wiley‐Liss, Inc.
fbl gene as a species‐specific target for Staphylococcus lugdunensis identification
Authors: Chatzigeorgiou Kalliopi‐Stavroula , Siafakas Nikolaos , Petinaki Efthymia , Zerva Loukia
Published: March 2010

Staphylococcus lugdunensis is an unusually virulent coagulase‐negative species, associated with severe infections. The present report describes the development of a single‐step, species‐specific PCR protocol for S. lugdunensis identification. fbl gene, encoding a fibrinogen‐binding adhesin, was exploited and assessed as a suitable nucleic acid target. The gene was detected in all 17 S. lugdunensis isolates examined, while no amplification product was obtained from 98 isolates representing 11 staphylococcal and 17 nonstaphylococcal species. Forty‐seven percent of the S. lugdunensis strains produced a positive slide coagulase reaction, which is consistent with varying levels of Fbl protein expression within the species. J. Clin. Lab. Anal. 24:119–122, 2010. © 2010 Wiley‐Liss, Inc.