bluuebunny/crossref_metadata_2025 huggingface dataset:
An electronic device for accelerating bone formation in tissues surrounding a dental implant
Authors: Song Jong K. , Cho Tae H. , Pan Hui , Song Yoon M. , Kim In S. , Lee Tae H. , Hwang Soon J. , Kim Sung J.
Published: March 2009

A dental implant is a unique structure which can be used with a noninvasive method because it is inserted into the bone in part and extended extracorporally. This study presents an electronic device that is temporarily connected with the dental implant, and reports its effect on accelerating bone formation in the surrounding tissues in a canine mandibular model. A small sized and low power consumption biphasic electrical current (BEC) stimulator ASIC was developed and the surrounding tissue was exposed to continuous BEC stimulation for 7 days with the parameters of 20 µA/cm2, 125 µs duration, and 100 pulses/s. After 2 (n = 5) and 5 weeks (n = 5), animals were sacrificed and the specimens were histomorphometrically evaluated. The newly formed bone area (BA) was 1.30 times (3 weeks, P < 0.05) and 1.35 times (5 weeks, P < 0.05) higher in the experimental group compared to the control group, respectively. Bone‐implant contact (BIC) in 3‐week specimens was 1.62 times (P < 0.05) greater in the experimental group, while there was no statistically significant difference in 5‐week specimens. Based on these results showing accelerated bone formation on and around the dental implant, it could be suggested that the latent time for osseointegration in dental implants can be reduced, and the success rate of implants in poor quality bone can be increased by using our device with BEC. Bioelectromagnetics 30:374–384, 2009. © 2009 Wiley‐Liss, Inc.
Separation of product associating E. coli host cell proteins OppA and DppA from recombinant apolipoprotein A‐IMilano in an industrial HIC unit operation
Authors: Hunter Alan K. , Wang Xing , Suda Eric J. , Herberg John T. , Shell Robert E. , Thomas Kristin E. , Dufield Robert L. , Gustafson Mark E. , Mozier Ned M. , Ho Sa. V.
Published: March 2009

We have shown how product associating E. coli host cell proteins (HCPs) OppA and DppA can be substantially separated from apolipoprotein A‐IMilano (apo A‐IM) using Butyl Sepharose hydrophobic interaction chromatography (HIC). This work illustrates the complex problems that frequently arise during development and scale‐up of biopharmaceutical manufacturing processes. Product association of the HCPs is confirmed using co‐immunoprecipitation and Western blotting techniques. Two‐dimensional gel electrophoresis and mass spectrometry techniques are used to confirm the identity of OppA and DppA. In this example, clearance of these difficult to separate HCPs decreased significantly when the process was scaled to a 1.4 m diameter column. Laboratory‐scale experimentation and trouble shooting identified several key parameters that could be further optimized to improve HCP clearance. The key parameters included resin loading, peak cut point on the ascending side, wash volume, and wash salt concentration. By implementing all of the process improvements that were identified, it was possible to obtain adequate HCP clearance so as to meet the final specification. Although it remains speculative, it is believed that viscosity effects may have contributed to the lower HCP clearance observed early in the manufacturing campaign. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
A Tin–Tungsten Mixed Oxide as an Efficient Heterogeneous Catalyst for CC Bond‐Forming Reactions
Authors: Ogasawara Yoshiyuki , Uchida Sayaka , Yamaguchi Kazuya , Mizuno Noritaka
Published: March 2009

Mix and calcinate: The tin–tungsten mixed oxide (Sn–W oxide) prepared by calcination of the Sn–W hydroxide at 800 °C acts as an effective and reusable solid catalyst for CC bond‐forming reactions, such as the cyclization of citronellal, the Diels–Alder reaction, and the cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (see scheme). The observed catalysis was truly heterogeneous, and the recovered catalyst could be reused without loss of its high catalytic performance.

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The tin–tungsten mixed oxide prepared by the calcination of the tin–tungsten hydroxide precursor with a Sn/W molar ratio of 2 at 800 °C (SnW2–800) acts as an effective and reusable solid catalyst for CC bond‐forming reactions, such as the cyclization of citronellal, the Diels–Alder reaction, and the cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (TMSCN). Various kinds of structurally diverse aliphatic, aromatic, and unsaturated, heteroatom‐containing substrates could be converted into the desired products in high to excellent yields. The observed catalyses for these reactions were truly heterogeneous and the recovered catalyst could be reused several times without an appreciable loss of its high catalytic performance. The Brønsted acid sites generated on the aggregated polytungstate species on SnW2–800 likely play an important role in the CC bond‐forming reactions.
Non‐UV‐Induced Radical Reactions at the Surface of TiO2Nanoparticles That May Trigger Toxic Responses
Authors: Fenoglio Ivana , Greco Giovanna , Livraghi Stefano , Fubini Bice
Published: March 2009

Kept in the dark: The non‐photocatalytic generation of free radicals from fine and ultrafine TiO2particles has been studied by means of a spin‐trapping/ESR spectroscopy technique (see figure). The amount and kind of free radicals generated depends on the crystalline structure, but not on the particle dimensions.

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Titania is generally considered to be an inert and safe material. Several studies, however, have reported that nanosized TiO2may elicit toxic effects. In some cases the observed adverse effects have been related to free radicals. Although new studies mainly concern irradiated titania, the role and the mechanisms of the generation of free radicals by TiO2in the absence of UV irradiation are not well known. The purpose of the present study is to investigate the free‐radical‐generation mechanisms by nano‐ and micronsized anatase or rutile powders under normal laboratory illumination or in the dark by means of a spin‐trapping/ESR spectroscopy technique. This technique is used to identify the nature and the amount of free radicals released in solution, and in the solid‐state to characterise the paramagnetic centres at the surface of particles that may participate in the reactions. The following radical‐generating mechanisms have been considered: 1) the generation of oxygenated free radicals (HO2., O2.−, HO.) following the reaction of TiO2with oxygen, water or H2O2and 2) the generation of carbon‐centred radicals following the cleavage of the CH bond in a model molecule. Although no free radicals were detected in a simply buffered solution, anatase and rutile generated O2.−and HO., respectively, in the presence of H2O2. Both polymorphs were also active in the cleavage of the CH bond. Although the formation of O2.−appears to be related to exposure to sunlight, the generation of HO.and carbon‐centred free radicals also occurs in the dark. When samples of equal surface area were tested, micron‐ and nanosized anatase was found to react in the same way indicating that a reduction in diameter does not generate new kinds of reactive sites. The data presented herein may have implications in the assessment of the health risk associated with the exposure to TiO2nanoparticles and in the ecotoxicological impact following their possible leakage into the environment.
Methane Activation by Metal‐Free Radical Cations: Experimental Insight into the Reaction Intermediate
Authors: de Petris Giulia , Troiani Anna , Rosi Marzio , Angelini Giancarlo , Ursini Ornella
Published: March 2009

A precise jab to methane: The SO2.+ radical cation (see figure) effectively activates CH4 at room temperature through a [H3C.⋅⋅⋅HOSO+] methyl intermediate isolated in the gas phase by mass spectrometry. Methanol and ionized methyl hydrogen sulfoxylate, CH3OSOH.+, are formed by selective, direct attack of the incipient methyl radical at the O atom of the intermediate. The reaction shows radical and charge effects in the activation of methane by metal‐free radical cations.

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Synthesis of Pyrimidines and Triazines in Ice: Implications for the Prebiotic Chemistry of Nucleobases
Authors: Menor‐Salván César , Ruiz‐Bermejo Dra. Marta , Guzmán Marcelo I. , Osuna‐Esteban Susana , Veintemillas‐Verdaguer Sabino
Published: March 2009

From urea to nucleobases: Freeze–thaw cycles in urea (1) solutions under methane/nitrogen atmospheres lead, with application of an energy source, to the synthesis of pyrimidines (mainly cytosine (2) and uracil (3)), triazines (such as cyanuric acid (4)), and adenine. This synthesis appears to be dependent on the atmosphere and the freezing conditions. At room temperature, hydantoin (5) is obtained. However, a freezing urea/water system subjected to an energy source under an inert atmosphere generates s‐triazines.

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Herein, we report the efficient synthesis of RNA bases and functionalized s‐triazines from 0.1 M urea solutions in water after subjection to freeze–thaw cycles for three weeks. The icy solution was under a reductive, methane‐based atmosphere, which was subjected to spark discharges as an energy source for the first 72 h of the experiment. Analysis of the products indicates the synthesis of the s‐triazines cyanuric acid, ammeline, ammelide, and melamine, the pyrimidines cytosine, uracil, and 2,4‐diaminopyrimidine, and the purine adenine. An experiment performed as a control at room temperature, with the urea solution in the liquid phase and with the same atmosphere and energy source, led to the synthesis of hydantoins and insoluble tholin, but there was no evidence of the synthesis of pyrimidines or triazines. The synthesis of pyrimidines from urea is possible under a methane/nitrogen atmosphere only at low temperature, in the solid phase. The generation of both pyrimidines and triazines in comparable yields from urea, together with a possible role for triazines as alternative nucleobases, opens new perspectives on the prebiotic chemistry of informational polymers.
Density Functional Theory Investigation of the Alkyl–Alkyl Negishi Cross‐Coupling Reaction Catalyzed by N‐Heterocyclic Carbene (NHC)–Pd Complexes
Authors: Chass Gregory A. , O'Brien Christopher J. , Hadei Niloufar , Kantchev Eric Assen B. , Mu Wei‐Hua , Fang De‐Cai , Hopkinson Alan C. , Csizmadia Imre G. , Organ Michael G.
Published: March 2009

Why bigger is better: A “steric wall” created by theN‐(2,6‐diisopropylphenyl) substituent on the bulky NHC ligand IPr (1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene) guides the reactants to and from the Pd center through weak, fleeting (IPr)H–Pd interactions that help the oxidative addition intermediate escape “the anti‐trap”. The alternative “side” approach leads to transmetalation (the rate‐limiting step) for which a novel Pd–Zn interaction was identified.

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A novel mechanism is proposed for the Pd–1,3‐(2,6‐diisopropylphenyl)imidazolyl‐2‐ylidene (1) catalyzed Negishi reaction. DFT computations supported by atoms‐in‐molecules (AIM) analyses of non‐truncated models show that a “steric wall” created by theN‐substituent on the ligand guides reactants to and from the Pd center. Notably, transmetalation and not oxidative addition is found to be rate‐limiting. Additionally, a key Pd–Zn interaction (≈2.4 Å,ρb≈0.0600 au) is identified in the mechanism. This interaction persists beyond reductive elimination and, in combination with the ligand, facilitates reductive elimination by creating a highly sterically crowded environment in the coordination sphere of the Pd center.
A Very Efficient Cerium(IV) Ammonium Nitrate Catalyzed, Four‐Component Synthesis of Tetrahydropyridines and Its Application in the Concise Generation of Functionalized Homoquinolizine Frameworks
Authors: Sridharan Vellaisamy , Maiti Swarupananda , Menéndez J. Carlos
Published: March 2009

Molecular diversity: A cerium(IV) ammonium nitrate (CAN) catalyzed, four‐component reaction from very simple acyclic starting materials afforded densely substituted tetrahydropyridines, which were transformed into homoquinolizines by using a γ‐alkylation–ring‐closing metathesis (RCM) sequence (see scheme).

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The cerium(IV) ammonium nitrate (CAN) catalyzed, four‐component reaction between primary aliphatic amines, β‐ketoesters or β‐ketothioesters, α,β‐unsaturated aldehydes, and alcohols provided a very efficient and atom‐economical access to substituted 6‐alkoxy‐2‐methyl‐1,4,5,6‐tetrahydropyridines. These materials were then transformed into homoquinolizine derivatives in excellent yields by using a two‐step sequence comprised of regioselective γ‐deprotonation–allylation and ring‐closing metathesis reactions. The possibility of displacing the alkoxy group by allylsilane nucleophiles, presumably through a vinylogous acyliminium intermediate species, was also demonstrated.
Structure‐Based Optimization of Benzoic Acids as Inhibitors of Protein Tyrosine Phosphatase 1B and Low Molecular Weight Protein Tyrosine Phosphatase
Authors: Maccari Rosanna , Ottanà Rosaria , Ciurleo Rosella , Paoli Paolo , Manao Giampaolo , Camici Guido , Laggner Christian , Langer Thierry
Published: March 2009

We have optimized previously discovered benzoic acids 1, which are active as inhibitors of PTP1B and LMW‐PTP, two protein tyrosine phosphatases that have emerged as attractive targets for the development of novel therapeutic agents for the treatment of diabetes, obesity, and cancer. Our efforts led to the identification of new and more potent analogues with appreciable selectivity toward human PTP1B and the IF1 isoform of human LMW‐PTP.

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The Ever‐Elusive Tetra‐tert‐butylethene (TTBE, 3,4‐Di‐tert‐butyl‐ 2,2,5,5‐tetramethylhex‐3‐ene): Further Insight on Its Preparation
Authors: Klein Oliver , Hopf Henning , Grunenberg Jörg
Published: March 2009

Diketone 4 was prepared by hydrolysis of hexendiyne 5, the latter being available through McMurry coupling of acetylenic ketone 26. Upon treatment with dimethyltitanium dichloride, 4 cyclizes into fully alkylated furan derivative 30; the still unknown tetra‐tert‐butylethene (1, TTBE, 3,4‐di‐tert‐butyl‐2,2,5,5‐tetramethylhex‐3‐ene) was not produced. The structural properties of 4 and the mechanism of its cyclization into 30 are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Morphological effects of different channel‐forming discharges in a gravel‐bed river
Authors: Surian Nicola , Mao Luca , Giacomin Matteo , Ziliani Luca
Published: March 2009

The study analyses the morphological response of a gravel‐bed river to discharges of different magnitude (from moderate events that occur several times a year to a 12‐year flood) and so defines the range of formative discharges for single morphological units (channels, bars, islands) and a range of magnitude of morphological activity from the threshold discharges for gravel transport and minor bar modification up to flows causing major morphological changes.

The study was conducted on the Tagliamento River, a large gravel‐bed river in north‐eastern Italy, using two different methods, analysis of aerial photographs and field observation of painted gravel particles. The available photographs (five flights from August 1997 to November 2002) and the two commissioned flights (June 2006 and April 2007) do not define periods with a single flood event, but the intervals are short enough (11 to 22 months) to have a limited number of flood events in each case. The fieldwork, which involved cross‐section survey, grain‐size analysis and observation of painted sediments, complemented the aerial surveys by allowing analysis of channel response to single flood events.

Substantial morphological changes (e.g. bank erosion of several tens of metres up to more than 100 m) associated with flood events with a recurrence interval between 1·1 year and 12 years have been documented. Multiple forming discharges were defined based on the activity of different morphological units. Discharges equal to 20–50% of the bankfull discharge are formative for the channels, whereas the bankfull discharge (1·1 year flood in this case of the Tagliamento River) is formative for low bars. Larger floods, but still relatively frequent (with a recurrence interval less than five years), are required for full gravel transport on high bars and significant morphological changes of islands. Copyright © 2009 John Wiley & Sons, Ltd.
Shortcomings of discontinuous‐pressure finite element methods on a class of transient problems
Authors: Jog C. S. , Kumar Rakesh
Published: March 2009

Past studies that have compared LBB stable discontinuous‐ and continuous‐pressure finite element formulations on a variety of problems have concluded that both methods yield solutions of comparable accuracy, and that the choice of interpolation is dictated by which of the two is more efficient. In this work, we show that using discontinuous‐pressure interpolations can yield inaccurate solutions at large times on a class of transient problems, while the continuous‐pressure formulation yields solutions that are in good agreement with the analytical solution. Copyright © 2009 John Wiley & Sons, Ltd.
Tuning of the visual word processing system: Distinct developmental ERP and fMRI effects
Authors: Brem Silvia , Halder Pascal , Bucher Kerstin , Summers Paul , Martin Ernst , Brandeis Daniel
Published: March 2009

Visual tuning for words vs. symbol strings yields complementary increases of fast occipito‐temporal activity (N1 or N170) in the event‐related potential (ERP), and posterior–anterior gradients of increasing word‐specific activity with functional magnetic resonance imaging (fMRI) in the visual word form system (VWFS). However, correlation of these coarse ERP and fMRI tuning responses seems limited to the most anterior part of the VWFS in adult and adolescent readers (Brem et al. [ 2006]: Neuroimage 29:822–837). We thus focused on fMRI tuning gradients of young readers with their more pronounced ERP print tuning, and compared developmental aspects of ERP and fMRI response tuning in the VWFS. Children (10.3 y, n = 19), adolescents (16.2 y, n = 13) and adults (25.2 y, n = 18) were tested with the same implicit reading paradigm using counterbalanced ERP and fMRI imaging. The word‐specific occipito‐temporal N1 specialization, its corresponding source activity, as well as the integrated source activity (0–700 ms) were most prominent in children and showed a marked decrease with age. The posterior–anterior fMRI gradient of word‐specific activity instead which was fully established in children did not develop further, but exhibited a dependence on reading skills independent of age. To conclude, prominent developmental dissociation of the ERP and fMRI tuning patterns emerged despite convergent VWFS localization. The ERP response may selectively reflect fast visual aspects of print specialization, which become less important with age, while the fMRI response seems dominated by integrated task‐ and reading‐related activations in the same regions. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Effect of plasmonic nanostructures and nanofilms on fluorescence resonance energy transfer
Authors: Szmacinski Henryk , Ray Krishanu , Lakowicz Joseph R.
Published: March 2009

We investigate the effect of silver nanostructures and nanofilms on fluorescence resonance energy transfer (FRET). Thin layers of poly (vinyl alcohol) of 10 or 20 nm with homogenously distributed donor (Cy3) and acceptor (Cy5) molecules were coated on silver islands and continuous silver films. Several geometrical configurations were studied with multiple donor‐acceptor (D‐A) samples with various acceptor concentrations. The acceptor concentrations were adjusted to yield FRET efficiencies from about 10 to 92% on bare glass surfaces. Time‐resolved fluorescence spectroscopy was used to determine the energy transfer efficiency and the relative transfer rate. It was found that the relative transfer rate increased 2‐fold in the presence of continuous silver films and about 25‐fold in presence of silver island films. The largest enhancements in the energy transfer efficiency, up to 90%, were observed for low acceptor concentrations (large donor‐acceptor separations). To a first approximation, observed changes in FRET efficiencies were explained by an increase of the quantum yield of the donor molecules in the presence of silver islands. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Label free optical sensor for Avidin based on single gold nanoparticles functionalized with aptamers
Authors: Hernandez Frank Jeyson , Dondapati Srujan Kumar , Ozalp V. Cengiz , Pinto Alessandro , O'Sullivan Ciara K. , Klar Thomas A. , Katakis Ioannis
Published: March 2009

Optical spectroscopy of a single gold nanoparticle, functionalized with an aptamer, is used to sense the specific binding of avidin. Herewith, the field of single noble metal nanoparticle biosensors is extended to the important field of aptamer based assays. The sensitivity of this initial, but not yet optimized apta‐nano‐sensor is in the range of 20 nM. Due to its nanoscopic size, this single nanoparticle based apta‐sensor may be used in nanoscopic volumes such as in array type assays or even inside cells. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A novel hydrophilic poly(lactide‐co‐glycolide)/lecithin hybrid microspheres sintered scaffold for bone repair
Authors: Shi Xuetao , Wang Yingjun , Ren Li , Lai Chen , Gong Yihong , Wang Dong‐An
Published: March 2009

Novel 3‐D porous scaffolds made of sintered poly(lacide‐co‐glycolide) (PLGA)/lecithin hybrid microspheres (PLGA/Lec‐SMS) were developed and investigated. The addition of lecithin in PLGA bulk successfully managed the desired hydrophilic modification without sacrificing bulk properties. The outcomes were verified with infrared (ATR‐FTIR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), and contact angle analyses. Specifically, this model of scaffold gained significant improvement in mechanical (mainly compressive) strength upon an optimization of lecithin fractions aligning with sintering conditions. Given a perspective of bone tissue engineering use, human fetal osteoblasts were seeded into a series of these PLGA/Lec‐SMS scaffolds upon which key parameters of cytocompatibility and osteoconductivity (including cell viability, alkaline phosphatase activity, calcium secretion, and osteogenic genes expression) were assessed. Osteoblasts seeded on PLGA scaffolds with 5 wt % lecithin demonstrated high cell viability and alkaline phosphatase activity. Moreover, elevated lecithin also enhanced the expression of type I collagen. Taken together, these results suggest PLGA/Lec‐SMS are promising scaffolds for bone repair. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Preparation and evaluation of thiolated chitosan scaffolds for tissue engineering
Authors: Li Zhe , Cen Lian , Zhao Li , Cui Lei , Liu Wei , Cao Yilin
Published: March 2009

Thiolated chitosan (TCS) was proposed as a promising candidate as scaffold material for tissue engineering. However, a continuous exploration of such material as a three‐dimensional (3D) scaffold with controllable design of microstructure as well as mechanical strength was necessitated. The current study was thus carried out to substantiate such potential of TCS. Thioglycolic acid (TGA) was first introduced on the side chain of chitosan (CS) via the amide bond formation between COOH groups of TGA and NH2 groups of CS. Composite TCS/CS scaffolds with different ratios were prepared via freeze‐drying under different temperatures to optimize the structural properties. The microstructure of the scaffolds was observed by scanning electron microscopy (SEM), and tensile strength of scaffolds was measured. Both the TCS/CS proportion and freezing temperature affected the microstructure and mechanical property of scaffolds, which in turn rendered effects on the growth of cultured fibroblasts. Scaffolds obtained from the TCS/CS proportion of 7:3 and a freezing temperature of −20°C had the maximum tensile strength with a pore distribution ranging from a few to several hundred micrometers. The preferential growth of fibroblasts on this scaffold was also demonstrated. Hence, results in this study would offer valuable information on the preparation of suitable TCS scaffolds for tissue engineering. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Docking to heme proteins
Authors: Röhrig Ute F. , Grosdidier Aurélien , Zoete Vincent , Michielin Olivier
Published: March 2009

In silico screening has become a valuable tool in drug design, but some drug targets represent real challenges for docking algorithms. This is especially true for metalloproteins, whose interactions with ligands are difficult to parametrize. Our docking algorithm, EADock, is based on the CHARMM force field, which assures a physically sound scoring function and a good transferability to a wide range of systems, but also exhibits difficulties in case of some metalloproteins. Here, we consider the therapeutically important case of heme proteins featuring an iron core at the active site. Using a standard docking protocol, where the iron–ligand interaction is underestimated, we obtained a success rate of 28% for a test set of 50 heme‐containing complexes with iron‐ligand contact. By introducing Morse‐like metal binding potentials (MMBP), which are fitted to reproduce density functional theory calculations, we are able to increase the success rate to 62%. The remaining failures are mainly due to specific ligand–water interactions in the X‐ray structures. Testing of the MMBP on a second data set of non iron binders (14 cases) demonstrates that they do not introduce a spurious bias towards metal binding, which suggests that they may reliably be used also for cross‐docking studies. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009
Diagnostic assay of chromium (VI) in the ex vivo fluid of the urine of a smoker using a fluorine‐doped handmade sensor
Authors: Ly Suw Young , Kim Min Joon
Published: March 2009

A voltammetric diagnosis of a chromium (VI) ion was investigated using a fluorine‐doped graphite pencil electrode. Square wave (SW) stripping working conditions were attained at a high range of 0.051–0.45 mg L−1 and a microrange of 0.05–0.4 µg L−1 in a 0.1 M NH4H2PO4 electrolyte solution, at a relative standard deviation of 1.68% (RSD, n=15), using 10.0 µg L−1 Cr(VI). A fast experimental time was used only for the 120 sec SW accumulation time. An analytical detection‐limit (DL) of 0.008 µg L−1 was attained. DL appeared to be more sensitive than common voltammetric and spectrophotometric assays. The developed sensor was applied to tap water and the urine of a smoker. It was found that the methods can be applicable for in vivo fluid or medicinal diagnosis. J. Clin. Lab. Anal. 23:82–87, 2009. © 2009 Wiley‐Liss, Inc.
Evaluation of metalloproteinases 2 and 9 and their inhibitors in physiologic and pre‐eclamptic pregnancy
Authors: Montagnana Martina , Lippi Giuseppe , Albiero Alessandro , Scevarolli Silvia , Salvagno Gian Luca , Franchi Massimo , Guidi Gian Cesare
Published: March 2009

Matrix metalloproteinases (MMPs) are a family of zinc and calcium‐dependent endopeptidases involved in remodeling and physiological homeostasis of extracellular matrix (ECM). The metalloproteinases activity is predominantly modulated by specific tissue inhibitors of matrix metalloproteinases (TIMPs). The balance between MMPs and TIMPs is likely to play an important role in remodeling uterine arteries in pregnancy, and it may represent means by which vasodilatation is maintained in later pregnancy. Moreover, increased levels of MMPs and in particular MMP‐2 play a role in the vascular alterations induced by hypertension. The aim of this study was the evaluation of MMP‐2 and ‐9, along with their inhibitors TIMP‐1 and ‐2, in pre‐eclamptic women compared with normotensive pregnancy and non‐pregnant women. Fourteen pre‐eclamptic women were compared with 37 normotensive women in different gestational age and 21 non‐pregnant women. Multiplexed sandwich enzyme‐linked immunosorbent assay was used to measure MMPs and TIMPs simultaneously. MMP‐2 levels were significantly higher in pre‐eclamptic women vs. both non‐pregnant and physiologic pregnant women. MMP‐9 concentrations were significantly higher in physiologic pregnant vs. non‐pregnant women. The serum levels of TIMP‐1 were significantly higher in pre‐eclamptic vs. both non‐pregnant and physiologic pregnant women. TIMP‐2 values were higher in physiologic pregnant women and pre‐eclamptic women vs. non‐pregnant women. A positive correlation between MMP‐9 values and gestational age was observed in normal pregnant women. Results of the present investigation confirm that MMP‐2 and TIMP‐1 values are significantly higher in preeclampsia. We confirm that the modification of the fine balance between MMPs and their inhibitors plays a greater role in the structural and functional vascular changes of women with complicated pregnancies. J. Clin. Lab. Anal. 23:88–92, 2009. © 2009 Wiley‐Liss, Inc.
Lipid peroxidation and antioxidant enzyme activities in infertile men: correlation with semen parameter
Authors: Ben Abdallah Fatma , Dammak Ines , Attia Hamadi , Hentati Basma , Ammar‐Keskes Leila
Published: March 2009

The aim of this study was to investigate the oxidative stress status and antioxidant enzyme activities in infertile men's semen and to determine their relationship with spermatozoa characteristics. Four groups of infertile men, normozoospermic (n=9), azoospermic (n=13), oligoasthenozoospermic (n=38), and asthenozoospermic (n=42), were tested for malonaldialdehyde (MDA) concentration and catalase (CAT) and superoxide dismutase (SOD) activities in semen using spectrophotometric methods. We found that MDA levels in semen and SOD activity in seminal plasma (SP) were significantly higher in oligoasthenozoospermic and asthenozoospermic groups compared with normozoospermic group. In contrast, the mean values of CAT activity were not significantly different in all groups. We found positive correlations between semen MDA concentration and SOD activity (P<0.01). MDA levels in sperm pellet and in SP were also positively correlated with mobility grade b (P<0.01), acrosome anomalies (P<0.01), and residual cytoplasmic droplets (P<0.05). In contrast, SOD activity in SP was negatively correlated with sperm concentration and normal morphology (P<0.05). Similarly, CAT activity in SP was negatively correlated with sperm and leukocyte concentrations (P<0.05). In conclusion, our results suggest that the evaluation of oxidative status and antioxidant defenses may be taken as an important tool for diagnosis and treatment of male infertility. J. Clin. Lab. Anal. 23:99–104, 2009. © 2009 Wiley‐Liss, Inc.
Detection of C1236T, G2677T/A, and C3435T polymorphism ofMDR1by amplification refractory mutation system PCR
Authors: Chen Bing , Fang Jie , Zhang Weixia , Jin Zhao , Yu Zichen , Cai Weimin
Published: March 2009

C1236T, G2677T/A, and C3435T polymorphism of the multidrug resistance (MDR1) gene have substantial impact on expression or activity of P‐glycoprotein (P‐gp). We developed new methods based on amplification refractory mutation system (ARMS) to detect these polymorphisms. Tetra‐primers amplification in a single tube was established to detect C1236T and C3435T polymorphism. For G2677T/A polymorphism, a two‐step allele‐specific amplification method was used.MDR1genotypes of 177 Chinese subjects were determined by the methods we established. The methods we established were verified with gene sequencing. Gene frequencies of 1236C and 1236T were 37.8 and 62.2%, respectively; gene frequencies of 2677G, 2677T and 2677A were 44.1, 38.4 and 17.5%, respectively; the gene frequencies of 3435C and 3435T were 65.0 and 35.0%, respectively. The results were similar with other studies on Oriental subjects. The methods we established are simple, accurate, and economical, and can provide reliable approaches for determiningMDR1polymorphism. J. Clin. Lab. Anal. 23:110–116, 2009. © 2009 Wiley‐Liss, Inc.
Associations of IgG N‐linked oligosaccharide chains and proteases in sera of prostate cancer patients with and without α2‐macroglobulin deficiency
Authors: Kanoh Yuhsaku , Egawa Shin , Baba Shiro , Akahoshi Tohru
Published: March 2009

We previously reported on a number of cases of metastatic prostate cancer (PCa) in which serum α2‐macroglobulin (α2M) levels were markedly decreased to less than 20 mg/dl (α2M deficiency). All PCa patients with α2M deficiency had multiple bone metastases. Proteases in ten PCa patients with and without α2M deficiency were studied and compared against ten healthy controls in order to elucidate the relationships between changes in sugar chain structure and neoplasia. We assessed the relationship between ratios of Fr4 to Fr1 and Fr2 (Fr4/Fr1+Fr2 ratios) of oligosaccharide chains, and ratios of free prostate‐specific antigen (PSA) to total PSA (F/T ratios), and serum levels of matrix‐metalloproteinase‐2 (MMP‐2) in PCa progression. Measurement of serum α2M concentration was performed by laser nephelometry. Serum PSA and MMP‐2 levels were determined by enzyme immunoassay and free PSA by radioimmunoassay. N‐linked oligosaccharides of human serum immunoglobulin G were analyzed using fluorophore‐associated carbohydrate electrophoresis. In those PCa patients with α2M deficiency: (a) serum α2M and F/T ratios were lower (P<0.05) and (b) Fr4/Fr1+Fr2 ratios and serum MMP‐2 levels were higher when compared with those PCa patients without α2M deficiency. There was a significant correlation between Fr4/Fr1+Fr2 ratios and F/T ratios or serum MMP‐2 levels in PCa with α2M deficiency (P<0.05). Therefore, these markers may serve as an auxiliary serum tumor marker for monitoring of the bone metastases or progression of disease in PCa. J. Clin. Lab. Anal. 23:125–131, 2009. © 2009 Wiley‐Liss, Inc.
Serum prolidase activity and oxidative status in patients with bronchial asthma
Authors: Cakmak Alpay , Zeyrek Dost , Atas Ali , Celik Hakim , Aksoy Nurten , Erel Ozcan
Published: March 2009

Asthma is a disease where there is an accumulation of collagen in the reticular basal membrane of the airway leading to chronic inflammation. The enzyme prolidase plays an important role in the breakdown of collagen and the breakdown of intracellular protein especially in the final stage when peptides and dipeptides contain a high level of proline. To evaluate the relationship between prolidase activity and oxidative status in asthma patients. Comparison was made between 42 patients diagnosed with bronchial asthma and 32 healthy children of similar age and gender. Serum prolidase activity was measured spectrophotometrically. Oxidative status was determined using total antioxidant capacity (TAC) and total oxidant status (TOS) measurement. The prolidase activity of the asthma patient group was statistically significant compared with the control group (P≤0.001). TAC and TOS levels in the asthma patient group were higher than the control group (P≤0.001, P≤0.002, respectively). No correlation was found between the prolidase and oxidative levels of the two groups. A positive correlation was determined between the prolidase activity and TAC in the asthma patient group (P≤0.001, r=0.501). The prolidase enzyme activity, which plays a role in the collagen turnover, was low in the asthma patients; therefore, their collagen metabolism had undergone a change and this indicates that there may be an effect on the accumulation of collagen in the reticular basal membrane. Moreover, the high level of TOS indicates that these patients were exposed to severe oxidative stress with an increased TAC response. J. Clin. Lab. Anal. 23:132–138, 2009. © 2009 Wiley‐Liss, Inc.
Detection of Paracoccidioides brasiliensis gp43 Gene in Sputa by Loop‐Mediated Isothermal Amplification Method
Authors: Tatibana B. T. , Sano A. , Uno J. , Kamei K. , Igarashi T. , Mikami Y. , Miyaji M. , Nishimura K. , Itano E. N.
Published: March 2009

The fungus Paracoccidioides brasiliensis is the pathogen of paracoccidioidomycosis (PCM), a systemic mycosis prevalent in Latin America. The loop‐mediated isothermal amplification method (LAMP) was used in this study to detect the presence of P. brasiliensis in sputa samples from patients with chronic PCM, suspected PCM, and a negative control. The target P. brasiliensis gp43 gene was amplified in less than 4 hr in 11 of 18 sputa samples tested. The LAMPmethod had the advantage of speed and simplicity compared with the classic diagnostic methods such as the histopathological test or biological material culture and did not require sophisticated technical apparatus. It would be an important aid in cases where immediate treatment would mean patient survival, especially in immune‐suppressed patients. J. Clin. Lab. Anal. 23:139–143 2009. © 2009 Wiley‐Liss, Inc.
Role of RAF/MEK/ERK pathway, p‐STAT‐3 and Mcl‐1 in sorafenib activity in human pancreatic cancer cell lines
Authors: Ulivi Paola , Arienti Chiara , Amadori Dino , Fabbri Francesco , Carloni Silvia , Tesei Anna , Vannini Ivan , Silvestrini Rosella , Zoli Wainer
Published: March 2009

Sorafenib is a multikinase inhibitor that has shown promising therapeutic results in different tumor histotypes, both as a single agent or in combination with other treatments. We analyzed the in vitro activity of sorafenib in pancreatic cancer, one of the most lethal and chemo‐radio‐resistant tumors, using four human pancreatic cancer cell lines (t3m4, Capan 1, Capan 2, and MiaPaca 2), characterized by different K‐ras gene status and RAF/MEK/ERK profile. Sorafenib exerted a strong anti‐proliferative effect independently of RAS/RAF/MEK/ERK and induced various degrees of apoptosis in the cell lines. The mechanisms involved were explored in detail in t3m4 and Capan 1, in which sorafenib induced the highest and lowest levels of apoptosis, respectively. In t3m4, the RAF/AKT/STAT‐3 rather than the RAF/MEK/ERK pathway was involved, whereas in Capan 1 cells there was a strong decrease in pMEK and pERK which was not accompanied by an important reduction in RAF, AKT, and STAT‐3 proteins or in their phosphorylation. Moreover, U0126‐induced MEK inhibition did not induce apoptosis in any cell line, reinforcing the hypothesis of a MEK/ERK‐independent mechanism of sorafenib activity. Mcl‐1 appears to play a crucial role in sorafenib‐induced apoptosis. In fact, both protein and mRNA were downregulated in t3m4 and upregulated in Capan 1, in which siRNA‐induced silencing resulted in the same level of apoptosis as observed in t3m4. Our results show that sorafenib exerts anti‐proliferative and pro‐apoptotic activity in pancreatic cancer cells. Used singly or in combination with other drugs, it could therefore represent valid treatment for pancreatic cancer. J. Cell. Physiol. 220: 214–221, 2009. © 2009 Wiley‐Liss, Inc.
Defective co‐activator recruitment in osteoclasts from microphthalmia‐oak ridge mutant mice
Authors: Sharma Sudarshana M. , Sif Said , Ostrowski Michael C. , Sankar Uma
Published: March 2009

The three basic DNA‐binding domain mutations of the microphthalmia‐associated transcription factor (Mitf), Mitfmi/mi, Mitfor/or, and Mitfwh/wh affect osteoclast differentiation with variable penetrance while completely impairing melanocyte development. Mitfor/or mice exhibit osteopetrosis that improves with age and their osteoclasts form functional multinuclear osteoclasts, raising the question as to why the Mitfor/or mutation results in osteopetrosis. Here we show that Mitfor/or osteoclasts express normal levels of acid phosphatase 5 (Acp5) mRNA and significantly lower levels of Cathepsin K (Ctsk) mRNA during receptor activator of nuclear factor kappa B (NFκB) ligand (RANKL)‐mediated differentiation. Studies using chromatin immunoprecipitation (ChIP) analysis indicate that low levels of Mitfor/or protein are recruited to the Ctsk promoter. However, enrichment of Mitf‐transcriptional co‐activators PU.1 and Brahma‐related gene 1 (Brg1) are severely impaired at the Ctsk promoter of Mitfor/or osteoclast precursors, indicating that defective recruitment of co‐activators by the mutant Mitfor/or results in impaired Ctsk expression in osteoclasts. Cathepsin K may thus represent a unique class of Mitf‐regulated osteoclast‐specific genes that are important for osteoclast function. J. Cell. Physiol. 220: 230–237, 2009. © 2009 Wiley‐Liss, Inc.
The antioxidant and anticorrosive properties of crude glycerol fraction from biodiesel production
Authors: Jerzykiewicz Maria , Cwielag Irmina , Jerzykiewicz Wojciech
Published: March 2009

BACKGROUND: Raw glycerol fractions as the waste material from biodiesel production were investigated for its antioxidant and anticorrosive properties. For comparison raw glycerol fractions and biodiesel fuels together with different oil feedstocks (as an input material for the transesterification process) were measured by means of electron paramagnetic resonance (EPR) spectroscopy. Additionally glycerol fractions were subjected to corrosivity testing (Herbert method).

RESULTS: 1,2,3‐Propanetriol‐containing fractions exhibited high free radical scavenging properties, in comparison with biodiesel and oil material. Additionally, the Herbert test proved the anticorrosive ability of the crude glycerol fractions investigated. Radical scavenging (antioxidant) properties obtained from EPR spectroscopy paralleled the anticorrosive investigations, with samples having the highest quenching abilities giving the best results in the Herbert tests.

CONCLUSION: The anticorrosive activity of glycerol fractions examined in this paper generates a new application in lubricant manufacturing. The results show new ways of utilising raw glycerol fraction without very costly and time‐consuming purification. Copyright © 2009 Society of Chemical Industry
In vitro and in vivo evaluation of small interference RNA‐mediated gynaecophoral canal protein silencing in Schistosoma japonicum
Authors: Cheng Guofeng , Fu Zhiqiang , Lin Jiaojiao , Shi Yi , Zhou Yuancong , Jin Youxin , Cai Youmin
Published: March 2009

Background

Schistosomiasis causes liver and intestinal damage and can be very debilitating. The pairing of a male worm with a female worm residing in the gynaecophoral canal of male plays a critical role in the development of female parasite. Because the male specific gynaecophoral canal protein of Schistosoma japonicum (SjGCP) is found in significant quantities in the adult female worm after pairing, it could play an important role in parasite pairing.

Methods

In the present study, three small interfering (si)RNA duplexes targeting the SjGCP gene were designed, synthesized and the silencing effects were evaluated in vitro as well as in mice infected with S. japonicum in vivo.

Results

In vitro studies using semi‐quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) and real‐time RT‐PCR revealed the reduction of SjGCP at the transcript level. Similarly, western blotting and immunofluorescence studies showed its reduction at the protein level after treatment of parasites with siRNAs. At a concentration of 200 nM, two siRNAs totally abolished the parasite pairing. To evaluate such a pairing inhibitory effect in vivo, mice infected with S. japonicum were treated with siRNA and both parasite pairing and burden were evaluated. In vivo tests confirmed the in vitro silencing effect of SjGCP siRNA and revealed that the systemic delivery of siRNA significantly inhibited early parasite pairing and the associated burden.

Conclusions

Our preliminary results demonstrated that the SjGCP plays an important role in pairing and subsequent development in S. japonicum, and its silencing might have potential as a therapeutic approach for controlling schistosomiasis. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of heterocyclic compounds using carbon disulfide and their products
Authors: Tominaga Yoshinori
Published: March 2009

This review described developments in the synthesis of heterocyclic compounds using carbon disulfide and their products.
A novel synthesis of 3‐Amino‐1,2‐benzisoxazoles — an entry into the isoxazolo[3,4,5‐ef][1,4]benzoxazepine ring system
Authors: Shutske Gregory M. , Kapples Kevin J.
Published: March 2009

A novel synthesis of 3‐amino‐1,2‐benzisoxazole (3) from 2‐[(isopropylideneamino)oxy]benzonitrile (2) is described. This methodology was used to synthesize 3‐amino‐4‐hydroxy‐1,2‐benzisoxazole (10), which served as an intermediate for a number of isoxazolo[3,4,5‐ef][1,4]benzoxazepines.
The willgerodt‐kindler reactions. 6. Isomerization of the carbonyl group in alkanones and cycloalkanones
Authors: Carmack Marvin , Behforouz Mohammad , Berchtold Glenn A. , Berkowitz Samuel M. , Wiesler Donald , Barone Ralph
Published: March 2009

The most unusual feature of the Willgerodt‐Kindler Reactions is the facile isomerization of the carbonyl function along a chain of unbranched methylene groups, or around a cycloaliphatic ring containing several connected methylene groups. We have demonstrated that the first step in the Kindler process is the formation of enamines by reaction of the carbonyl function with secondary aliphatic amines, followed by reaction of the enamine with certain sulfur‐amine catalysts to form reactive heterocyclic sulfur intermediates that facilitate the elimination‐readdition of the amines reversibly along the chain. It was shown that compounds of the type R2N‐S‐S‐NR2 are effective catalysts but not compounds of the type R2N‐S‐NR2. Some cyclohexanone derivatives undergo aromatization, with anomalous results in certain cases.
Potential antidepressants. Synthesis of 6,11‐dihydrodibenzo[b,e]thiepin‐11‐yl 4‐(dimethylamino‐methyl)phenyl ketone and of some related compounds
Authors: Šindelář Karel , Holubek JiřÍ , Svátek Emil , Matoušová Oluše , Metyšová Jiřina , Protiva Miroslav
Published: March 2009

Reactions of dibenzo[b,e]thiepin‐11(6H)‐one (4) with 2‐, 3‐ and 4‐(dimethylaminomethyl)phenylmagnesium bromide afforded the tertiary alcohols 5a,b,c. The aldehydes 7 and 8 gave similarly the secondary alcohols 9a,b,c and 10c. Numerous attempts to prepare the corresponding ketones, especially by oxidation of 9a,b,c and 10c were unsuccessful. Only the oxidation of 9c with tetrabutylammonium chromate in chloroform afforded the desired ketone 16. Its formation was accompanied by an important side reaction consisting in a cleavage of the “retro‐ene‐reaction” type leading to compound 11 and the aldehyde 13c which reacted with the chloroform present to give the alcohol 17. Compounds 5a,b,c, 9a,b,c and 16 were tested as potential antidepressants but with the exception of some effects in the test of potentiation of yohimbine toxicity in mice, they proved inactive in this line.
Reissert Compound Studies. LXI. Preparation and Reactions of Quinazoline Di‐Reissert Compounds
Authors: Hahn Jung‐Tai , Popp Frank D.
Published: March 2009

Various di‐Reissert compounds and analogs were prepared from quinazoline by use of trimethylsilyl cyanide together with a catalytic amount of anhydrous aluminum chloride. Reactions of these quinazoline di‐Reissert compounds are reported.
A simple regioselective synthesis of ethyl 1,5‐diarylpyrazole‐3‐carboxylates
Authors: Murray William V. , Wachter Michael P.
Published: March 2009

Improved procedures for the regioselective preparation of ethyl 1,5‐diarylpyrazole‐3‐carboxylates are described. The new procedures utilize readily prepared lithium aroylpyruvate intermediates which, when combined with arylphenylhydrazine hydrochlorides form 1,5‐diarylpyrazole‐3‐carboxylates regioselectively in good to excellent yield.
Benzimidazole condensed ring systems. 5. Studies on the Synthesis of Pyrimido[1,6‐α]benzimidazole‐1,3(2H,5H)‐diones
Authors: Badawey El‐Sayed A. M. , Rida Samia M. , Soliman Farid S. G. , Kappe Thomas
Published: March 2009

The reaction of ethyl 1H‐benzimidazole‐2‐acetate (1) with methyl or ethyl isocyantes 2a,b resulted in excellent yields of the respective 2‐methyl‐ or 2‐ethylpyrimido[1,6‐a]benzimidazole‐1,3(2H,5H)‐diones 3a,b, while the reaction of 1 with phenyl isocyanate (2c) gave, unexpectedly, ethyl 2‐(1‐phenylcarbamoyl‐1H,3H‐benzimidazol‐2‐ylidene)‐2‐phenylcarbamoylacetate (4). Alkylation of 3 with trimethyl or triethyl phosphates 5a,b led to the 5‐methyl or 5‐ethyl derivatives 6a‐d. Chlorination of 6 with sulfuryl chloride afforded the 4‐chloro derivatives 7a‐d.