bluuebunny/crossref_metadata_2025 huggingface dataset:
An Efficient Route to 4/5/6 Polycyclic β‐Lactams
Authors: Desroy Nicolas , Robert‐Peillard Fabien , Toueg Julie , Duboc Romain , Hénaut Charlotte , Rager Marie‐Noëlle , Savignac Monique , Genêt Jean‐Pierre
Published: November 2004

The synthesis of 4/5/6 polycyclic β‐lactams by enyne metathesis and Diels−Alder reactions is described. Compared to the synthesis of 4/6/6 and 4/7/6 polycyclic β‐lactams previously reported by our laboratory, formation of the strained 4/5/6 compounds requires alternative reaction conditions. Indeed, the synthesis of the 4/5 bicyclic diene 12 was more difficult than those of the 4/6 (13) and 4/7 (14) dienes. The strain of the 4/5 system could be observed by NMR spectroscopy and molecular modelling. Moreover, the reactivity of 4/5 diene 12 towards Diels−Alder cycloaddition was also different from that of the 4/6 (13) and 4/7 (14) dienes. Cycloadditions with 4/5 diene 12 therefore had to be performed in lithium perchlorate/diethyl ether (LPDE) or in an ionic liquid in order to proceed in good yields with various dienophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
An Unusual Series of Thiomethylated Canthin‐6‐ones from the North American Mushroom Boletus curtisii
Authors: Bröckelmann Martin G. , Dasenbrock Johannes , Steffan Bert , Steglich Wolfgang , Wang Yuekui , Raabe Gerhard , Fleischhauer Jörg
Published: November 2004

A unique set of thiomethylated canthin‐6‐one derivatives was isolated from Boletus curtisii. The bright yellow color of this mushroom is caused by two optically active canthin‐6‐one sulfoxides for which the names curtisin and 9‐deoxycurtisin are proposed. The structures of the new compounds were established by MS and NMR methods and the absolute configuration of the sulfoxides determined by quantum chemical calculations. This is the first occurrence of canthin‐6‐one alkaloids outside of higher plants. The chemotaxonomic implications of these findings are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Blue light differentially alters cellular redox properties
Authors: Lewis Jill B. , Wataha John C. , Messer Regina L. W. , Caughman Gretchen B. , Yamamoto Tetsuya , Hsu Stephen D.
Published: November 2004

Blue light (λ = 380–500 nm) historically has been used to initiate polymerization of biomaterials and recently has been proposed as a therapeutic agent. New evidence suggests that cell‐type–specific responses result from redox changes induced by exposure to blue light. Cultured cells were exposed to defined doses of blue light, equivalent to exposure times of 10 s and 2 min, to achieve energies of 5 J/cm2 and 60 J/cm2, respectively, after which (a) viable cell number, (b) cellular protein profiles, (c) mitochondrial succinate dehydrogenase (SDH) activity, (d) total reactive oxygen species (ROS), and (e) induction of apoptosis were compared to that of nonexposed control cultures. Results showed that blue‐light exposure arrested monocyte cell growth and increased levels of peroxiredoxins. SDH activity of normal epidermal keratinocytes (NHEK) was slightly enhanced by blue light, whereas identical treatment of OSC2 oral tumor cells resulted in significant suppression of SDH activity. Blue‐light exposure generally induced higher levels of total ROS in OSC2 cells than in NHEK. Finally, only OSC2 cells exhibited signs of apoptosis via Annexin V staining following exposure to blue light. These data support the central hypothesis that blue light induces an oxidative stress response in cultured cells resulting in cell‐type–specific survival outcomes. The identification of oxidative stress as a mediator of the effects of blue light is a critical first step in defining its biological risks and therapeutic opportunities. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 223–229, 2005
Antisense downregulation of SARS‐CoV gene expression in Vero E6 cells
Authors: Shi Yi , Luo Haifeng , Jia Jie , Xiong Jie , Yang Dehua , Huang Bing , Jin Youxin
Published: November 2004

Background

Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus (SARS‐CoV). It is an enveloped, single‐stranded, plus‐sense RNA virus with a genome of ∼30 kb. The structural proteins E, M and N of SARS‐CoV play important roles during host cell entry and viral morphogenesis and release. Therefore, we have studied whether expression of these structural proteins can be down‐regulated using an antisense technique.

Methods

Vero E6 cells were transfected with plasmid constructs containing exons of the SARS‐CoV structural protein E, M or N genes or their exons in frame with the reporter protein EGFP. The transfected cell cultures were treated with antisense phosphorothioated oligonucleotides (antisense PS‐ODN, 20mer) or a control oligonucleotide by addition to the culture medium.

Results

Among a total of 26 antisense PS‐ODNs targeting E, M and N genes, we obtained six antisense PS‐ODNs which could sequence‐specifically reduce target genes expression by over 90% at the concentration of 50 µM in the cell culture medium tested by RT‐PCR. The antisense effect was further proved by down‐regulating the expression of the fusion proteins containing the structural proteins E, M or N in frame with the reporter protein EGFP. In Vero E6 cells, the antisense effect was dependent on the concentrations of the antisense PS‐ODNs in a range of 0–10 µM or 0–30 µM.

Conclusions

The antisense PS‐ODNs are effective in downregulation of SARS. The findings indicate that antisense knockdown of SARS could be a useful strategy for treatment of SARS, and could also be suitable for studies of the pathological function of SARS genes in a cellular model system. Copyright © 2004 John Wiley & Sons, Ltd.
PEGylated adenovirus vectors containing RGD peptides on the tip of PEG show high transduction efficiency and antibody evasion ability
Authors: Eto Yusuke , Gao Jian‐Qing , Sekiguchi Fumiko , Kurachi Shinnosuke , Katayama Kazufumi , Maeda Mitsuko , Kawasaki Koichi , Mizuguchi Hiroyuki , Hayakawa Takao , Tsutsumi Yasuo , Mayumi Tadanori , Nakagawa Shinsaku
Published: November 2004

Background

PEGylation of adenovirus vectors (Ads) is an attractive strategy in gene therapy. Although many types of PEGylated Ad (PEG‐Ads), which exhibit antibody evasion activity and long plasma half‐life, have been developed, their entry into cells has been prevented by steric hindrance by polyethylene glycol (PEG) chains. Likewise, sufficient gene expression for medical treatment could not be achieved.

Methods

A set of PEG‐Ads, which have different PEG modification rates, was constructed, and gene expression was evaluated using A549 cells. A novel PEGylated Ad (RGD‐PEG‐Ad), which contained RGD (Arg‐Gly‐Asp) peptides on the tip of PEG, was developed. We evaluated gene expression both in Coxsackie‐adenovirus receptor (CAR)‐positive as well as ‐negative cells, and in vivo gene expression was also determined. Furthermore, the antibody evasion ability and the specificity of infection exhibited by this RGD‐PEG‐Ad were also evaluated.

Results

Whereas PEG‐Ads decreased gene expression in CAR‐positive cells, RGD‐PEG‐Ad enhanced gene expression notably, to a level about 200‐fold higher than that of PEG‐Ads. Moreover, gene expression of RGD‐PEG‐Ad was almost equal to that of Ad‐RGD, which contains an RGD‐motif in the fiber and exhibits among the highest gene expression of CAR‐positive and ‐negative cells. Furthermore, although Ad‐RGD gene expression decreased remarkably in the presence of anti‐Ad antiserum, RGD‐PEG‐Ad maintained its activity against antibodies. In vivo experiments also demonstrated that the modification of Ads with RGD‐PEG induced efficient gene expression.

Conclusions

In the present study, we demonstrated that a new strategy, which combined integrin‐targeting the RGD peptide on the tip of PEG and modified the Ad using this material, could enhance gene expression in both CAR‐positive and ‐negative cells. At the same time, this novel PEGylated Ad maintained strong protective activity against antibodies. This strategy could also be easily modified for developing other vectors using other targeting molecules. Copyright © 2004 John Wiley & Sons, Ltd.
Relationship between atmospheric circulation types over Greece and western–central Europe during the period 1958–97
Authors: Anagnostopoulou Christina , Flocas Helena , Maheras Panagiotis , Patrikas Ioannis
Published: November 2004

An attempt is made to examine the relationship of the surface circulation prevailing over Europe with the corresponding surface and 500 hPa over Greece by correlating Lamb weather types for western Europe and Hess and Brezowsky (HB) types for central Europe with those derived from a new classification scheme for the Greek area. It was found that it was difficult to formulate rules controlling the frequency distributions of the circulation types over the Greek area in relation to the circulation over western and central Europe. However, statistically significant correlation was found between certain types with high frequency, which is greater between Lamb and HB types with the surface circulation types over the Greek area, compared with 500 hPa circulation types. For the most correlated pairs, seasonal composites of mean sea‐level pressure and 500 hPa geopotential height anomalies demonstrated that the formation of the circulation types over the Greek area depends on the extent, intensity of the anticyclonic or cyclonic centres, air mass characteristics, and stability profile in the lower troposphere over the regions examined, but especially over the central and eastern Mediterranean. Copyright © 2004 Royal Meteorological Society
The factors governing the summer regime of the eastern Mediterranean
Authors: Ziv Baruch , Saaroni Hadas , Alpert Pinhas
Published: November 2004

The synoptic scale features over the eastern Mediterranean (EM) for July–August are examined using National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis data. The region is subjected to two primary factors: mid–upper level subsidence and lower level cool advection, associated with the Etesian winds.

The interdiurnal variations of these factors were found to be correlated with each other, with a maximum of r = 0.76, found between the 700 hPa subsidence and the 925 hPa wind speed. The impact of these factors on the temperature regime was examined through their contributions in the temperature tendency equation at 32.5°N, 35°E. A significant correlation was found between them at the 850 hPa level, indicating that they tend to balance each other. This explains the low interdiurnal temperature variations there in summer.

Zonal‐vertical and isentropic cross‐sections indicate the existence of a closed circulation connecting the EM with the Asian monsoon, and a meridional‐vertical cross‐section indicates a signature of the Hadley cell across eastern North Africa. Air back‐trajectories demonstrate that the EM is connected at the lower troposphere with Europe, at the mid‐troposphere with eastern North Africa and at the higher troposphere with the Asian monsoon. Significant correlation was found between the interdiurnal variations in the upward motion over the Asian monsoon and the subsidence over the Levant, with a 1 day lag, implying that the Asian monsoon controls the interdiurnal variations over the Levant.

A detailed analysis shows that the correlation between the two dynamic factors governing the EM results from a linkage existing between each one of them and the Asian monsoon. An intensification of the Asian monsoon enhances both the subsidence over the Levant, via the circulation connecting them, and the Etesian winds, due to the enhanced pressure gradient between the two regions. Copyright © 2004 Royal Meteorological Society
Interference effects of C2‐radicals in nitrogen vibrational CARS thermometry using a frequency‐doubled Nd:YAG laser
Authors: Malarski A. , Beyrau F. , Leipertz A.
Published: November 2004

Generally, in coherent anti‐Stokes Raman spectroscopy a frequency‐doubled Nd:YAG laser emitting at 532 nm along with a broadband dye laser is used for nitrogen vibrational CARS thermometry, resulting in a signal wavelength of 473 nm. Unfortunately, emission and absorption bands of C2 radicals occur in the same spectral region, hence the CARS signal can be disturbed by interferences. C2 radicals are an intermediate species especially in hydrocarbon flames and, moreover, they can be produced by laser‐induced vaporization of soot particles present in the flame. The described interferences can be a severe problem resulting in erroneous temperature data. The influence of the interferences on the determined temperatures was analyzed in this work. For this purpose, an experimental set‐up was chosen that simultaneously generates the vibrational nitrogen signal at 473 and 487 nm, i.e. in a undisturbed spectral region. This was realized by using the dual‐pump CARS technique with an annular phase‐matching geometry (USED CARS). Hence a direct comparison of temperature results from disturbed and undisturbed spectra can be performed. Measurements conducted in one‐dimensional ethylene–air flames established on a McKenna‐type burner are presented. Copyright © 2004 John Wiley & Sons, Ltd.
Chromatographic methods for the separation of biocompatible iron chelators from their synthetic precursors and iron chelates
Authors: Kovaříková Petra , Mokrý Milan , Klimeš Jiří , Vávrová Kateřina
Published: November 2004

Chromatographic methods have been developed for the separation of the three novel biocompatible iron chelators pyridoxal isonicotinoyl hydrazone (PIH), salicylaldehyde isonicotinoyl hydrazone (SIH), and pyridoxal 2‐chlorobenzoyl hydrazone (o‐108) from their synthetic precursors and iron chelates. The chromatographic analyses were achieved using analytical columns packed with 5 μm Nucleosil 120‐5 C18. For the evaluation of all chelators in the presence of the synthetic precursors, EDTA was added to the mobile phase at a concentration of 2 mM. The best separation of PIH and its synthetic precursors was achieved using a mixture of phosphate buffer (0.01 M NaH2PO4, 5 mM 1‐heptanesulfonic acid sodium salt; pH 3.0) and methanol (55 : 45, v/v). For separation of SIH and its synthetic precursors, the mobile phase was composed of 0.01 M phosphate buffer (pH 6.0) and methanol (60 : 40, v/v). o‐108 was analyzed employing a mixture of 0.01 M phosphate buffer (pH 7.0), methanol, and acetonitrile (60 : 20 : 20, v/v/v). These mobile phases were slightly modified to separate each chelator from its iron chelate. Furthermore, a RP‐TLC method has also been developed for fast separation of all compounds. The chromatographic methods described herein could be applied in the evaluation of purity and stability of these drug candidates.
Capillary electrophoretic and micellar electrokinetic separations of asymmetric dimethyl‐L‐arginine and structurally related amino acids: Quantitation in human plasma
Authors: Trapp Gabriele , Sydow Karsten , Dulay Maria T. , Chou Tina , Cooke John P. , Zare Richard N.
Published: November 2004

We report the development of efficient electrophoretic methods for the separation and quantification of L‐arginine and six naturally occurring derivatives that are structurally and functionally related. Capillary electrophoresis (CE) employing a concentrated borate buffer at pH 9.4 achieves the separation of mixtures containing dimethyl‐L‐arginine, N G‐monomethyl‐L‐arginine, L‐arginine, L‐homoarginine, L‐ornithine, and L‐citrulline as 4‐fluoro‐7‐nitrobenzofurazan derivatives. In addition, the separation of the isomeric dimethyl‐L‐arginine derivatives (symmetric and asymmetric) is attained with baseline resolution by micellar electrokinetic chromatography (MEKC) when a high concentration of deoxycholic acid is added as a surfactant to the same running buffer. The influence of buffer type, concentration, and pH on the separation was studied to optimize separation conditions. The limit of quantitation (LOQ) for asymmetric dimethyl‐L‐arginine in aqueous solution was determined to be 20 μM using UV absorption in a CE separation and 0.1 μM using laser induced fluorescence (LIF) detection in an MEKC separation. This newly developed method was successfully applied for the quantitation of asymmetric dimethyl‐L‐arginine and L‐arginine in human plasma samples at levels that might be used as a clinical diagnostic for cardiovascular disease (0.125 μM LOQ).
Significant Role of Bacterial Undecaprenyl Diphosphate (C55‐UPP) for Rubber Synthesis by Hevea Latex Enzymes
Authors: Rattanapittayaporn Atiya , Wititsuwannakul Dhirayos , Wititsuwannakul Rapepun
Published: November 2004

Summary: Washed bottom fraction (BF) membrane‐bound particles of centrifuged fresh Hevea latex were found to be very active in rubber biosynthesis (RB). The washed BF membrane (WBM) showed higher RB activity and is strongly stimulated by anionic surfactants – more by DOC than SDS. WBM enzymes system can synthesize rubber either with allylic isoprenes (higher RB) or without (lower RB). Washed rubber particles (WRP), used generally in RB assays, had very low RB activity compared to the much higher activity observed for WBM. Bacterial undecaprenyl diphoshate (C55‐UPP) was very active allylic initiator for rubber synthesis by WBM. Comparisons of allylic UPP with the shorter ones (C15‐FPP, C20‐GGPP) showed that UPP was the most effective. WBM activity orders were UPP ≫ GGPP > FPP. The DOC activated WBM synthesized less polyprenyl intermediates (butanol extractable) but more final rubber product (toluene/hexane extract), different than FPP and GGPP. WBM enzymes were highly versatile in using diverse different allylics, but UPP was most preferable. WRP was found a little active for UPP with DOC, but still much lower than WBM. Rubber product analysis by RP‐TLC with acetone/hexane solvent system showed that WBM was mostly rubber, but WRP was mainly the intermediates. Quantitative analysis showed that WBM labeled rubber was confined to the origin spot, different than WRP as mainly labeled intermediates. It was thus confirmed that the WBM plays the key role in RB functions, and not WRP as mostly reported. WBM served as the actual rubber synthesis site, and bacterial UPP was very good RB initiator.

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Reinvestigation of the Mechanism of the Free Radical Polymerization Photoinitiation Process by Camphorquinone–Coinitiator Systems: New Results
Authors: Pyszka Ilona , Kucybała Zdzisław , Pączkowski Jerzy
Published: November 2004

Summary: Comparative studies of photoinitiation processes using camphorquinone (CQ) and benzophenone (BP) as light absorbers were performed. The experimental results show that after the transformation of (phenylthio)acetic acid (PTAA) into its tetrabutylammonium salt (PTAA AS), a substantial decrease of the polymerization photoinitiation ability for the CQ–PTAA AS pair in comparison to the CQ–PTAA pair is observed. The mechanism of the photoinitiated polymerization for the tested photoredox pair was clarified based on laser flash photolysis experiments obtained using benzophenone as an electron acceptor and (phenylthio)acetic acid and its tetrabutylammonium salt as electron donors in solution in MeCN. It is documented and deduced that the photoreduction of benzophenone in the presence of (phenylthio)acetic acid and its tetrabutylammonium salt occurs by a photoinduced electron transfer process, while for CQ as initiator, the free radicals are formed by hydrogen atom abstraction by the triplet state of camphorquinone.

Schematic of the transients formed after an electron‐transfer process for benzophenone–PTAA and benzophenone–PTAA AS pairs.

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Schematic of the transients formed after an electron‐transfer process for benzophenone–PTAA and benzophenone–PTAA AS pairs.
Endothelin receptor expression in human lungs of newborns with congenital diaphragmatic hernia
Authors: de Lagausie Pascal , de Buys‐Roessingh Anthony , Ferkdadji Latifa , Saada Julien , Aisenfisz Sophie , Martinez‐Vinson Christine , Fund Xavier , Cayuela Jean Michel , Peuchmaur Michel , Mercier Jean Christophe , Berrebi Dominique
Published: November 2004

Congenital diaphragmatic hernia (CDH) is a major cause of refractory respiratory failure in the neonatal period and is characterized by persistent pulmonary hypertension of the newborn (PPHN) and pulmonary hypoplasia. Endothelin‐1 (ET‐1) dysregulation may play a significant role in the pathophysiology of PPHN and ET‐1 acts through binding to type A (ETA) and type B (ETB) receptors. Therefore, ETA and ETB receptor protein expression was studied using immunohistochemistry in 10 lung specimens obtained from newborns with CDH, and 4 normal lung specimens, in order to explore whether dysregulation of ETA and ETB expression contributes to PPHN. ETA and ETB mRNAs were then quantified using real‐time RT‐PCR in laser‐microdissected pulmonary resistive arteries. In the lungs of newborns with CDH, immunohistochemistry of both ETA and ETB receptors demonstrated over‐expression in the thickened media of pulmonary arteries. Using laser microdissection and real‐time RT‐PCR, higher levels of ETA and ETB mRNA were found in CDH pulmonary arteries than in controls: this increase was more pronounced for ETA mRNA. This study provides the first demonstration of ET‐1 receptor dysregulation in association with structural alteration of pulmonary arteries in newborns with CDH and PPHN. This dysregulation preferentially affects the ETA receptor. These results suggest that dysregulation of ET‐1 receptors may contribute to PPHN associated with CDH. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Bone marrow cells engraft within the epidermis and proliferate in vivo with no evidence of cell fusion
Authors: Brittan Mairi , Braun Kristin M , Reynolds Louise E , Conti Francesco J , Reynolds Andrew R , Poulsom Richard , Alison Malcolm R , Wright Nicholas A , Hodivala‐Dilke Kairbaan M
Published: November 2004

In adults, bone marrow‐derived cells (BMDC) can contribute to the structure of various non‐haematopoietic tissues, including skin. However, the physiological importance of these cells is unclear. This study establishes that bone marrow‐derived epidermal cells are proliferative and, moreover, demonstrates for the first time that BMDC can localize to a known stem cell niche: the CD34‐positive bulge region of mouse hair follicles. In addition, engraftment of bone marrow cells into the epidermis is significantly increased in wounded skin, bone marrow‐derived keratinocytes can form colonies in the regenerating epidermis in vivo, and the colony‐forming capacity of these cells can be recapitulated in vitro. In some tissues this apparent plasticity is attributed to differentiation, and in others to cell fusion. Evidence is also provided that bone marrow cells form epidermal keratinocytes without undergoing cell fusion. These data suggest a functional role for bone marrow cells in epidermal regeneration, entering known epidermal stem cell niches without heterokaryon formation. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Over‐expression of TGF‐β1 in Smad4‐deficient human oral carcinoma cells causes tumour regression in vivo by mechanisms that sensitize cells to apoptosis
Authors: Thavaraj Selvam , Paterson Ian C , Hague Angela , Prime Stephen S
Published: November 2004

We have shown previously that transforming growth factor‐β (TGF‐β) is a potent tumour suppressor in Smad4‐deficient human malignant oral keratinocytes but the mechanism by which this occurs is unknown. In the present study, we show that over‐expression of TGF‐β1 causes regression of tumours derived from Smad4‐deficient oral keratinocytes transplanted orthotopically to athymic mice. Further, tumour regression is associated with the induction of apoptosis without changes in cell proliferation. In vitro, TGF‐β1 did not induce apoptosis directly in these cells but sensitized cells to cisplatin, but not Fas, ‐induced cell death. The data suggest that TGF‐β1 induces tumour regression in vivo by Smad4‐independent pathways that sensitize keratinocytes to mitochondrial‐mediated apoptosis. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Capability Testing Based on Cpm with Multiple Samples
Authors: Wu Chien‐Wei , Pearn W. L.
Published: November 2004

Numerous process capability indices have been proposed in the manufacturing industry to provide unitless measures on process performance, which are effective tools for quality improvement and assurance. Most existing methods for capability testing are based on the distribution frequency approaches. Recently, Bayesian approaches have been proposed for testing capability indices Cp and Cpm but restricted to cases with one single sample. In this paper, we consider estimating and testing capability index Cpm based on multiple samples. We propose accordingly a Bayesian procedure for testing Cpm. Based on the Bayesian procedure, we develop a simple but practical procedure for practitioners to use in determining whether their manufacturing processes are capable of reproducing products satisfying the preset capability requirement. A process is capable if all the points in the credible interval are greater than the pre‐specified capability level. To make the proposed Bayesian approach practical for in‐plant applications, we tabulate the minimum values of $C^{\ast} (p)$ for which the posterior probability p reaches various desirable confidence levels. Copyright © 2004 John Wiley & Sons, Ltd.
Prediction of the Solubility, Activity Coefficient and Liquid/Liquid Partition Coefficient of Organic Compounds
Authors: Hilal S. H. , Karickhoff S. W. , Carreira L. A.
Published: November 2004

Solvation models, based on fundamental chemical structure theory, were developed in the SPARC mechanistic tool box to predict a large array of physical properties of organic compounds in water and in non‐aqueous solvents strictly from molecular structure. The SPARC self‐interaction solvation models that describe the intermolecular interaction between like molecules (solute‐solute or solvent‐solvent) were extended to quantify solute‐solvent interaction energy in order to estimate the activity coefficient in almost any solvent. Solvation models that include dispersion, induction, dipole‐dipole and hydrogen bonding interactions are used to describe the intermolecular interaction upon placing an organic solute molecule in any single or mixed solvent system. In addition to estimation of the activity coefficient for 2674 organic compounds, these solvation models were validated on solubility and liquid/liquid distribution coefficient in more than 163 solvents including water. The RMS deviations of the calculated versus observed activity coefficients, solubilities and liquid/liquid distribution coefficients were 0.272 log mole fraction, 0.487 log mole fraction and 0.44 log units, respectively.
Highly Correlating Distance‐Connectivity‐Based Topological Indices. 2: Prediction of 15 Properties of a Large Set of Alkanes Using a Stepwise Factor Selection‐Based PCR Analysis
Authors: Shamsipur Mojtaba , Ghavami Raoof , Hemmateenejad Bahram , Sharghi Hashem
Published: November 2004

The potential usefulness of some newly proposed topological indices (Sh indices) has been examined by their application to the prediction of 15 different properties of a large number of alkanes (C2 through C10, a total of 149 molecules). Ten different indices (Sh1 through Sh10) and a novel one (Sh index) were calculated for each molecule by different combination of the connectivity and distance sum vectors. The alkanes' properties studied included boiling point (BP), density (D), molar refraction (MR), refraction index (RI), critical temperature (CT), critical pressure (CP), surface tension (ST), molar volume (MV), heat capacity (HC), enthalpy (E), heat of vaporization (HV), heat of atomization (HA), standard heat of formation (HF), heat of formation in liquid (HFL), and heat of formation in gas (HFG). First, the novel Sh index and the Randic connectivity index were used to simply correlate them to the properties of alkane molecules. Except with D, ST and RI, in all other cases, the Sh index produced high correlation coefficients. Besides, in almost all cases, the Sh index resulted in higher correlations than the Randic index. In order to predict the properties of alkanes more accurately, the PCR analysis was employed to drive multiparametric equations between the Sh indices and alkane properties. It was found that the stepwise procedure for factor selection, which was in accordance with the correlation ranking procedure, produced more convenient models in comparison with the eigen‐value ranking procedure. The advantages of the resulting QSPR models obtained by the use of Sh indices, over some other proposed models, were lower number of variables and higher prediction power.
Using Artificial Neural Networks to Boost High‐throughput Discovery in Heterogeneous Catalysis
Authors: Baumes L. , Farrusseng D. , Lengliz M. , Mirodatos C.
Published: November 2004

The work presents for the first time a detailed methodology which enable to scrutinize and identify solids that are relevant to be tested in a high throughput program. In the present case study, Artificial Neural Networks (ANN) are used to predict performances of catalysts for the Water Gas Shift reaction. In contrast to previous studies, it is shown that the quantitative prediction by ANN of performances is not adapted to a primary screening stage. On the contrary, ANN used as classifier tool within the course of an Evolutionary Strategy are well performing and well suited for high throughput heterogeneous catalysis. The virtual screening enables to pre‐select candidates to be screened experimentally with a very high rate of relevance at an early stage of a high throughput experimentation program, thus reducing significantly the number of trials.
Determination of pharmaceutical compounds in skin by imaging matrix‐assisted laser desorption/ionisation mass spectrometry
Authors: Bunch Josephine , Clench Malcolm R. , Richards Don S.
Published: November 2004

Matrix‐assisted laser desorption/ionisation (MALDI) quadrupole time‐of‐flight mass spectrometry (Q‐TOFMS) has been used to detect and image the distribution of a xenobiotic substance in skin. Porcine epidermal tissue was treated with ‘Nizoral’, a medicated shampoo containing ketoconazole ((±)‐1‐acetyl‐4‐[p‐[[(2R,4S)‐2‐(2,4‐dichlorophenyl)‐2‐(imidazol‐1‐ylmethyl)‐1,3‐dioxolan‐4‐yl]methoxy]phenyl]piperazine) as active ingredient. Following incubation for 1 h at 37°C all excess formulation was washed from the surface. A cross‐section of the drug‐treated tissue was then blotted onto a cellulose membrane, precoated in matrix (α‐cyano‐4‐hydroxycinnamic acid (CHCA)), by airspray deposition. In separate experiments the tissue surface was treated with Nizoral within a triangular former, and subsequently blotted onto a matrix‐coated membrane. Sample membranes were then mounted into the recess of specialised MALDI targets with adhesive tape. All samples were analysed by MALDI‐TOFMS using an Applied Biosystem ‘Q‐star Pulsar i’ hybrid Q‐TOF mass spectrometer fitted with an orthagonal MALDI ion source and imaging software. Detection of the protonated molecule was readily achievable by this technique. Treatment of the tissue within a template gave rise to images depicting the expected distribution of the drug, demonstrating that this technique is capable of producing spatially useful data. Ion images demonstrating the permeation of the applied compound into the skin were achieved by imaging a cross‐sectional imprint of treated tissue. A calibration graph for the determination of ketoconazole was prepared using the sodium adduct of the matrix ion as an internal standard. This enabled construction of a quantitative profile of drug in skin. Conventional haematoxylin and eosin staining and microscopy methods were employed to obtain a histological image of the porcine epidermal tissue. Superimposing the mass spectrometric and histological images appeared to indicate drug permeation into the dermal tissue layer. Copyright © 2004 John Wiley & Sons, Ltd.
Improved precision and accuracy for high‐performance liquid chromatography/Fourier transform ion cyclotron resonance mass spectrometric exact mass measurement of small molecules from the simultaneous and controlled introduction of internal calibrants via a second electrospray nebuliser
Authors: Herniman Julie M. , Bristow Tony W. T. , O'Connor Gavin , Jarvis Jackie , Langley G. John
Published: November 2004

The use of a second electrospray nebuliser has proved to be highly successful for exact mass measurement during high‐performance liquid chromatography/Fourier transform ion cyclotron resonance mass spectrometry (HPLC/FTICRMS). Much improved accuracy and precision of mass measurement were afforded by the introduction of the internal calibration solution, thus overcoming space charge issues due to the lack of control over relative ion abundances of the species eluting from the HPLC column. Further, issues of suppression of ionisation, observed when using a T‐piece method, are addressed and this simple system has significant benefits over other more elaborate approaches providing data that compares very favourably with these other approaches. The technique is robust, flexible and transferable and can be used in conjunction with HPLC, infusion or flow injection analysis (FIA) to provide constant internal calibration signals to allow routine, accurate and precise mass measurements to be recorded. Copyright © 2004 John Wiley & Sons, Ltd.
Mass spectral study of alkali‐cationized Boc‐carbo‐β3‐peptides by electrospray tandem mass spectrometry
Authors: Srikanth R. , Reddy P. Nagi , Srinivas R. , Sharma G.V.M. , Reddy K. Ravinder , Radha Krishna Palakodety
Published: November 2004

Electrospray tandem mass spectrometry was used to study the dissociation reactions of [M+Cat]+ (Cat = Na+ and Li+) of Boc‐carbo‐β3‐peptides. The collision‐induced dissociation (CID) spectra of [M+Cat‐Boc]+ of these peptides are found to be significantly different from those of [M+H‐Boc]+ ions. The spectra are more informative and display both C‐ and N‐terminus metallated ions in addition to characteristic fragment ions of the carbohydrate moiety. Based on the fragmentations observed in the CID spectra of the [M+Cat‐Boc]+ ions, it is suggested that the dissociation involves complexes in which the metal ion is coordinated in a multidentate arrangement involving the carbonyl oxygen atoms. The CID spectra of [M+Cat‐Boc]+ ions of the peptide acids show an abundant N‐terminal rearrangement ion [bn+17+Cat]+ which is absent for esters. Further, two pairs of positionally isomeric Boc‐carbo‐β3‐peptide acids, Boc‐NH‐Caa(S)‐β‐hGly‐OH (11) and Boc‐NH‐β‐hGly‐Caa(S)‐OH (12), and [Boc‐NH‐Caa(S)‐β‐hGly‐Caa(S)‐β‐hGly‐OH] (13) and [Boc‐NH‐β‐hGly‐Caa(S)‐β‐hGly‐Caa(S)‐OH] (14), were differentiated by the CID of [M+Cat‐Boc]+ ions. The CID spectra of compounds 11 and 13 are significantly different from those of 12 and 14, respectively. The abundance of [bn+17+Cat]+ ions is higher for peptide acids 12 and 14 with a sugar group at the C‐terminus when compared to 11 and 13 which contain a sugar moiety at the N‐terminus. The observed differences between the CID spectra of these isomeric peptides are attributed to the difference in the preferential site of metal ion binding and also on the structure of the cyclic intermediate involved in the formation of the rearrangement ion. Copyright © 2004 John Wiley & Sons, Ltd.
False diagnosis of renal agenesis on fetal MRI
Authors: Sgro M. , Shah V. , Barozzino T. , Ibach K. , Allen L. , Chitayat D.
Published: November 2004

We report a twin pregnancy in which prenatal ultrasound revealed anhydramnios and bilateral absence of the kidneys in both fetuses. To overcome the difficulties faced in obtaining accurate information on fetal ultrasound in cases with oligohydramnios, an attempt was made to use fetal magnetic resonance imaging (MRI) to confirm the renal status. However, while the fetal MRI showed renal agenesis in both twins, postnatal follow‐up revealed that one twin, which survived, had a small unilateral kidney not seen antenatally on fetal ultrasound or MRI. The second twin had bilateral renal agenesis and died of pulmonary hypoplasia. Care should be taken when using fetal MRI to replace fetal ultrasound in cases with poor visibility. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Assessment of variability of renal blood flow Doppler parameters during the menstrual cycle in women
Authors: Krejza J. , Ustymowicz A. , Szylak A. , Tomaszewski M. , Hryniewicz A. , Jawad A.
Published: November 2004

Objective

To estimate variability of renal flow Doppler parameters during the menstrual cycle in young women, and to explore whether the parameters oscillate substantially throughout the cycle.

Methods

The peak systolic, mean, and end‐diastolic velocities, pulsatility (PI) and resistance (RI) indices, acceleration time (AT) and index (AI) of the right renal artery were measured nine times during the cycle with duplex sonography in 14 healthy women (age range, 23–25 years), and correlated with plasma concentrations of 17β‐estradiol and progesterone. Coefficient of variation (CV), interclass correlation (ρ), and repeatability coefficients (RC) were used to measure the variability.

Results

The measures of the variability for AI and AT were: CV = 45.4% and 37.3%; ρ = 0.25 and 0.15; RC = 10.1 and 99.5, respectively. The CV for flow velocities varied from 24.1% to 25.5%, ρ from 0.49 to 0.50, RC from 22.7 for end‐diastolic to 63.3 for peak systolic velocity. The respective figures for PI and RI were: CV = 17% and 8.3%; ρ = 0.21 and 0.29; RC = 0.53 and 0.15. Fluctuations of the flow parameters, hematocrit, hemoglobin, heart rate, and systolic blood pressure during the menstrual cycle were insignificant, while the diastolic blood pressure decreased by about 7 mmHg (P < 0.01) in the luteal phase.

Conclusion

The variability of renal flow Doppler parameters during the menstrual cycle in young healthy women is substantial. However, fluctuations of the values of the parameters throughout the cycle were non‐significant. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Mild detergent treatment of Candida tropicalis reveals a NADPH‐dependent reductase in the crude membrane fraction, which enables the production of pure bicyclic exo‐alcohol
Authors: Katz Michael , Johanson Ted , Gorwa‐Grauslund Marie‐F.
Published: November 2004

This study demonstrated the occurrence of a NADPH‐dependent exo‐alcohol reductase in the crude membrane fraction of Candida tropicalis. Cytosolic endo‐alcohol reductase activity could be separated from the membrane‐bound exo‐alcohol activity by means of detergent treatment, enabling the preparation of pure exo‐alcohol via the enzymatic conversion of the bicyclic diketone, bicyclo[2.2.2]octane‐2,6‐dione. The exo‐alcohol reductase is, to our knowledge, the first membrane‐bound NADPH‐dependent reductase accepting a xenobiotic carbonyl substrate that was not a steroid. When C. tropicalis was grown on D‐sorbitol, a two‐fold increase in the exo‐reductase activity was observed as compared to when grown on glucose. An in silico comparison at the protein level between putative xenobiotic carbonyl reductases in Candida albicans, C. tropicalis and Saccharomyces cerevisiae was performed to explain why Candida species are often encountered when screening yeasts for novel stereoselective reduction properties. C. albicans contained more reductases with the potential to reduce xenobiotic carbonyl compounds than did S. cerevisiae. C. tropicalis had many membrane‐bound reductases (predicted with the bioinformatics program, TMHMM), some of which had no counterpart in the two other organisms. The exo‐reductase is suspected to be either a β‐hydroxysteroid dehydrogenase or a polyol dehydrogenase from either the short chain dehydrogenase family or the dihydroflavonol reductase family. Copyright © 2004 John Wiley & Sons, Ltd.
Allelic isoforms of the H+/nucleoside co‐transporter (CaCNT) from Candida albicans reveal separate high‐ and low‐affinity transport systems for nucleosides
Authors: Slugoski Melissa D. , Loewen Shaun K. , Ng Amy M. L. , Baldwin Stephen A. , Cass Carol E. , Young James D.
Published: November 2004

Contigs 19–10196 and 19‐20196 of the Stanford Candida albicans genome sequence databank encode two putative allelic isoforms of C. albicans CaCNT, a recently characterized 608 amino acid residue H+‐coupled fungal member of the CNT family of concentrative nucleoside transport proteins. The single Ser/Gly difference between CaCNT/19‐20196 and CaCNT occurs at position 328 in putative TM 7, and corresponds to a Ser/Gly substitution previously shown to contribute to the contrasting pyrimidine and purine nucleoside selectivities of human (h) and rat (r) Na+‐dependent CNT1 and CNT2. CaCNT/19‐10196 differs from CaCNT by four amino acids, but has Gly at position 328. These new proteins were recreated by site‐directed mutagenesis of CaCNT and characterized functionally by heterologous expression in Xenopus laevis oocytes. In marked contrast to h/rCNT1/2, both CaCNT/19‐10196 and CaCNT/19‐20196 exhibited permeant selectivities for purine nucleosides (adenosine, guanosine and inosine) and uridine similar to that of CaCNT. However, although H+‐coupled, CaCNT/19‐20196 exhibited a ∼10‐fold higher apparent Km for uridine than either CaCNT or CaCNT/19‐10196. CaCNT/19‐20196 also exhibited a low apparent affinity for inosine. We conclude that the three proteins correspond to high‐affinity (CaCNT, CaCNT/19‐10196) and low‐affinity (CaCNT/19‐20196) allelic isoforms of the C. albicans CNT nucleoside transporter. This is the first example of a single amino acid residue substitution altering a CNT protein's overall apparent affinity for nucleosides. Copyright © 2004 John Wiley & Sons, Ltd.
High pressure thermal denaturation kinetics of whey proteins
Authors: Hinrichs Jörg , Rademacher Britta
Published: November 2004

Pressure processing of foodstuff has been applied to produce or modify proteinaceous gel structures. In real pressure processing the treatment is non-isothermal, due to the adiabatic nature of the process and the heat loss from the product to the vessel. In order to estimate the effect of pressurization on milk constituents pressure and temperature dependent kinetics were determined separately from each other. In a detailed kinetic study whey protein isolate was treated under isobaric (200 to 800 MPa) and isothermal conditions (−2 to 70 °C), and the resulting degree of denaturation of β-lactoglobulin A and B and α-lactalbumin was analysed. Kinetic parameters of denaturation were estimated using a one step non-linear regression method which allowed a global fit of the whole data set. The isobaric isothermal denaturation of β-lactoglobulin and α-lactalbumin was found to follow third and second order kinetics, respectively. Isothermal pressure denaturation of both β-lactoglobulin fractions do not differ significantly and were characterized by an activation volume decreasing with increasing temperature from −10 to about −30 ml mol−1, which demonstrates that the denaturation rate is accelerated with increasing temperature. The activation energy of about 70 to 100 kJ mol−1 obtained for β-lactoglobulin A and B is not dependent to a great extent on the pressure which indicates that above 200 MPa denaturation rate is limited by the aggregation rate while pressure forces unfolding of the molecule.
Quality of milk and of Canestrato Pugliese cheese from ewes exposed to different ventilation regimens
Authors: Albenzio Marzia , Marino Rosaria , Caroprese Mariangela , Santillo Antonella , Annicchiarico Giovanni , Sevi Agostino
Published: November 2004

Effects of ventilation regimen on the quality of ewes' milk and on proteolysis in Canestrato Pugliese cheese during ripening were studied. Cheeses were manufactured from the bulk milk of Comisana ewes subjected to three different ventilation regimens, which were designated low (LOV, 23 m3/h per ewe), moderate (MOV, 47 m3/h per ewe) and programmed ventilation regimen (PROV, 73 m3/h per ewe; fan set to maintain 70% relative humidity). Bulk milk was analysed for chemical and microbial composition, renneting parameters and plasmin-plasminogen activities. At 1, 15, 30 and 45 d of ripening, the cheeses were analysed for gross chemical composition, nitrogen fractions, and plasmin and plasminogen activities. The pH 4·6-insoluble nitrogen fractions were analysed by urea-PAGE. Free amino acid content was determined at the end of ripening. Lower concentrations of bulk milk somatic cell count (BMSCC) and of mesophilic bacteria were found in the MOV group than in the LOV and the PROV groups. A lower plasminogen (PG) to plasmin (PL) ratio (PG/PL) was observed in the MOV and PROV than in the LOV cheeses. Irrespective of treatment, PL activity in cheeses was higher at 15 d of ripening, while a sudden decrease of PL and PG activities was observed at 30 d, which was associated with a marked increase in non-protein nitrogen. The peptide profile characterized in the urea-PAGE showed a greater intensity of α- and β-CN hydrolysis in the MOV than in the PROV and LOV cheeses. The results provide evidence that a proper ventilation regimen is critical for optimizing the hygienic quality of milk and the proteolysis of Canestrato Pugliese cheese during ripening.
Comparative depletion of ivermectin and moxidectin milk residues in dairy sheep after oral and subcutaneous administration
Authors: Imperiale Fernanda , Lifschitz Adrian , Sallovitz Juan , Virkel Guillermo , Lanusse Carlos
Published: November 2004

Ivermectin (IVM) and moxidectin (MXD) are broad-spectrum endectocides belonging to the avermectin/milbemycin class of antiparasitic drugs not approved for use in dairy sheep. However, these compounds are widely used extra-label to control endo- and ecto-parasites in lactating dairy sheep. Effects of the route of administration on the pattern of IVM and MXD excretion in milk were comparatively characterized in lactating dairy sheep. The relationship between the milk and plasma disposition kinetics after subcutaneous (s.c.) and oral administration at 200 μg/kg body weight was also evaluated. IVM and MXD concentration profiles were measured in milk and plasma using a specific HPLC-based methodology. IVM and MXD were extensively distributed from the bloodstream to the mammary gland and large quantities, particularly for MXD, were excreted in milk. Residual concentrations of IVM were recovered in milk up to 11 d (oral treatment) or 25 d (s.c. treatment) post treatment. However, high MXD concentrations were detected in milk between 1 h and 35 d after its oral and subcutaneous administration. MXD concentrations as high as 3·77 ng/ml (oral) and 30·3 ng/ml (s.c.) were measured in milk at day 35 post administration. A higher MXD excretion in milk, compared with that of IVM, was obtained for both administration routes. An extensive plasma to milk distribution pattern was observed, being the area under the concentration-time curve of MXD obtained in milk up to 14-fold higher than that measured in the bloodstream. The total fraction of the administered dose excreted in milk for MXD was significantly higher than that for IVM, which agrees with the well known higher MXD lipophilicity. The long persistence of milk residual concentrations of MXD and IVM in lactating dairy sheep should be seriously considered before their extra-label use is recommended.