bluuebunny/crossref_metadata_2025 huggingface dataset:
A Heteroditopic Fluoroionophoric Platform for Constructing Fluorescent Probes with Large Dynamic Ranges for Zinc Ions
Authors: Zhang Lu , Clark Ronald J. , Zhu Lei
Published: January 2008

A heteroditopic fluoroionophoric platform has been designed for constructing fluorescent probes for zinc ions over large concentration ranges. The responses of the prototype probes3 aand3 bto zinc ions were shown to be consistent with our hypothesis, according to which the modulation of photoinduced electron transfer followed by conformation rigidification or enhanced internal charge transfer of a ditopic ligand upon successive zinc coordination affords a sensitive fluorescence enhancement in one wavelength channel followed by an emission band shift to another wavelength channel. The heteroditopic arylvinyl‐bipy platform established in this study provides a lead structure for constructing fluorescent probes for real‐time live cell imaging of zinc ions over broad dynamic ranges.
Selective Mono‐ and 1,2‐Difunctionalisation of Cyclopentene Derivatives via Mg and Cu Intermediates
Authors: Despotopoulou Christina , Bauer Richard C. , Krasovskiy Arkady , Mayer Peter , Stryker Jeffrey M. , Knochel Paul
Published: January 2008

A single Br/Mg exchange of 1,2‐dibromocyclopentene with iPrMgCl⋅ LiCl provides the corresponding β‐bromocyclopentenylmagnesium reagent, which can then be reacted with various electrophiles (yields: 65–82 %). In the presence of a secondary alkylmagnesium halide and Li2CuCl4 (2 mol %), these 2‐bromoalkenylmagnesium compounds undergo bromine substitution and can then further react with electrophiles to give 1,2‐difunctionalised cyclopentenes (63–79 %). The mechanism of this process is discussed.
Modellierungsansätze für die Design‐Optimierung von reaktiven Rektifikationskolonnen
Authors: Barkmann S. , Sand G. , Engell S.
Published: January 2008

Dieser Beitrag beschäftigt sich mit der Auslegung von komplexen integrierten Prozessen am Beispiel der Reaktivrektifikation. Zur Ermittlung des aus ökonomischer Sicht optimalen Apparatedesigns und Betriebspunkts können Methoden der mathematischen Optimierung eingesetzt werden. Dies führt auf große, gemischt‐ganzzahlige nichtlineare Optimierungsprobleme, die mit verfügbaren kommerziellen Algorithmen auch ohne Vorinformation über die optimale Konfiguration des Apparats oder der Apparateverschaltung gelöst werden können. Der Rechenaufwand hängt dabei stark von der Anzahl der diskreten Variablen ab. Hier werden die allgemeine Methodik vorgestellt und verschiedene Modellierungsansätze für die diskreten Entscheidungsvariablen hinsichtlich des Rechenzeitbedarfs und der Lösungsqualität der Optimierung verglichen.
Filtration zur Partikelabtrennung bei der Wasserreinigung
Authors: Gimbel R. , Nahrstedt A. , Panglisch S.
Published: January 2008

Sowohl im industriellen als auch kommunalen Bereich ist die Entfernung partikulärer Stoffe aus Wasser eine zentrale Aufgabe. Speziell zur Behandlung stark verdünnter Suspensionen und großer Volumenströme bieten sich hierfür die Tiefenfiltration sowie die Oberflächenfiltration in Form der Membranfiltration an. Die Tiefenfiltration ist seit vielen Jahrzehnten in der Wasserreinigung etabliert und wurde ständig weiterentwickelt. Dagegen ist die Membranfiltration unter Verwendung von Ultra‐ und Mikrofiltrationsmembranen, die i. d. R. als Kapillaren zum Einsatz kommen, ein Verfahren, das erst seit etwa 15 Jahren großtechnisch relevant ist, in dieser Zeitspanne aber ein geradezu exponentielles Wachstum aufweist.
Changes of the Properties in the Upper Layers of Human Skin on Treatment with Models of Different Pharmaceutical Formulations—An Ex vivo ESR Imaging Study
Authors: Moll Klaus‐Peter , Herrmann Werner , Stößer Reinhard , Borchert Hans‐Hubert
Published: January 2008

The noninvasive method of spectral‐spatial electron spin resonance imaging (ESRI) was used to obtain a polarity map of human skin. The spin probes TEMPO, TEMPOL, and CAT‐1, which are considered to act as drug representatives, were applied as reporter molecules. The polarity in skin layers was described by means of the changes of the hyperfine splitting constant Aiso, which itself is a reflection of interactions at a molecular level, and the effect of polarity on the spatial distribution of spin probes in skin samples was studied. Analyses of ESR tomograms of two‐phase systems finalized in a simplified description for the empiric interpretation of values of the isotropic hyperfine coupling constants Aiso of spin probes in different layers of human skin. The simplified statement provides values for the probability of interactions of water molecules with the NO group of spin probes. This allows conclusions concerning the state of hydration of the spin probes in different layers of the skin and introduces the spatial polarity function as additional and valuable information for existing skin models.
Role of the cytokine environment and cytokine receptor expression on the generation of functionally distinct dendritic cells from human monocytes
Authors: Conti Lucia , Cardone Marco , Varano Barbara , Puddu Patrizia , Belardelli Filippo , Gessani Sandra
Published: January 2008

Myeloid dendritic cells (DC) and macrophages evolve from a common precursor. However, factors controlling monocyte differentiation toward DC or macrophages are poorly defined. We report that the surface density of the GM‐CSF receptor (GM‐CSFR) α subunit in human peripheral blood monocytes varies among donors. Although no correlation was found between the extent of GM‐CSFR and monocyte differentiation into DC driven by GM‐CSF and IL‐4, GM‐CSFR expression strongly influenced the generation of CD1a+ dendritic‐like cells in the absence of IL‐4. CD1a+ cells generated in the presence of GM‐CSF express CD40, CD80, MHC class I and II, DC‐SIGN, MR, CCR5, and partially retain CD14 expression. Interestingly, they spontaneously induce the expansion of CD4+ and CD8+ allogeneic T lymphocytes producing IFN‐γ, and migrate toward CCL4 and CCL19. Upon stimulation with TLR ligands, they acquire the phenotypic features of mature DC. In contrast, the allostimulatory capacity is not further increased upon LPS activation. However, by blocking LPS‐induced IL‐10, a higher T cell proliferative response and IL‐12 production were observed. Interestingly, IL‐23 secretion was not affected by endogenous IL‐10. These results highlight the importance of GM‐CSFR expression in monocytes for cytokine‐induced DC generation and point to GM‐CSF as a direct player in the generation of functionally distinct DC.
SWAP‐70 regulates mast cell FcϵRI‐mediated signaling and anaphylaxis
Authors: Sivalenka Raja R. , Sinha Manoj , Jessberger Rolf
Published: January 2008

Mast cells, perhaps best known by their ability to trigger allergic reactions after stimulation through the FcϵRI, express the unusual phosphatidylinositol 3‐kinase (PI3K)‐dependent, Rac‐binding protein SWAP‐70. Here, we show that the IgE‐mediated passive cutaneous and the systemic anaphylactic responses are strongly reduced in SWAP‐70–/– mice. Cultured SWAP‐70–/– immature bone marrow mast cells (BMMC) are also impaired in FcϵRI‐mediated degranulation, which can be restored by expression of exogenous wild‐type SWAP‐70, but less so if a phosphatidylinositol trisphosphate (PIP3) binding mutant is expressed. SWAP‐70 itself supports inositol‐3‐phosphate and PIP3 production, the latter indicating a potential feedback from SWAP‐70 towards PI3K. FcϵRI‐stimulated transcription and release of cytokines is controlled by SWAP‐70. Key FcϵRI signal transduction events like activation of LAT by phosphorylation, activation of Akt/PKB and of p38 MAP kinase are reduced in SWAP‐70–/– BMMC, but ERK is strongly hyperactivated. Some requirements for SWAP‐70 were apparent only under limited‐strength signaling conditions. We suggest that SWAP‐70 defines a new element of efficient mast cell activation upon FcϵRI signaling, important for the control of mast cell‐dependent anaphylaxis.
Synthesis of para‐Amino Benzoic Acid–TiO2 Hybrid Nanostructures of Controlled Functionality by an Aqueous One‐Step Process
Authors: Rahal Raed , Daniele Stéphane , Hubert‐Pfalzgraf Liliane G. , Guyot‐Ferréol Véronique , Tranchant Jean‐François
Published: January 2008

In situ amino acid surface‐modified TiO2 nanoparticle syntheses were performed by a simple one‐pot hydrolysis of heteroleptic titanium alkoxide [Ti(OiPr)3(O2CC6H4NH2)]m in water with NnBu4Br. This process allowed precise control of the surface grafting rate by varying the amount of precursors and provided highly functionalized nanomaterials. Their compositions and microstructures were determined by C, H and N elemental analyses, TGA‐MS, 13C CP‐MAS NMR, XRD, TEM, BET, Raleigh diffusion, FTIR, Raman, XPS and UV/Vis experiments. The results indicated that (i) the aggregation rate increased with an increase in the loading of the organic substrate and (ii) the amino acid is chemisorbed as a carboxylate group onto the TiO2 nanoparticles, which leads to a strong interaction between the amino acid and the TiO2 nanoparticle and good stability of these hybrids. Applications of low‐aggregated nanomaterials were demonstrated as efficient protection additive against UVA + UVB radiations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Sc3AlN – A New Perovskite
Authors: Höglund Carina , Birch Jens , Beckers Manfred , Alling Björn , Czigány Zsolt , Mücklich Arndt , Hultman Lars
Published: January 2008

Sc3AlN with perovskite structure has been synthesized as the first ternary phase in the Sc–Al–N system. Magnetron sputter epitaxy at 650 °C was used to grow single‐crystal, stoichiometric Sc3AlN(111) thin films onto MgO(111) substrates with ScN(111) seed layers as shown by elastic recoil detection analysis, X‐ray diffraction, and transmission electron microscopy. The Sc3AlN phase has a lattice parameter of 4.40 Å, which is in good agreement with the theoretically predicted 4.42 Å. Comparisons of total formation energies show that Sc3AlN is thermodynamically stable with respect to all known binary compounds. Sc3AlN(111) films of 1.75 µm thickness exhibit a nanoindentation hardness of 14.2 GPa, an elastic modulus of 249 GPa, and a room‐temperature electrical resistivity of 41.2 µΩ cm. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Tilting of active folds and drainage asymmetry on the Manawatu anticlines, New Zealand: a preliminary investigation
Authors: Clement Alastair J. H. , Brook Martin S.
Published: January 2008

The apparent southward tilting of five anticlines in the Manawatu, North Island, New Zealand, is investigated using two drainage basin analysis techniques: the transverse topographic symmetry factor (T) and the asymmetry factor (AF). The techniques are used to determine whether westward‐flowing trunk streams on the gentle western limbs of five anticlines are migrating southwards across their drainage basins, concomitant with down‐tilting of the fold axes. While results show potential for the techniques to be applied in such a tectonic setting, our findings are inconclusive. This could be due to the incipient nature of the folds (c. 0·5 Ma in age), and it would seem more appropriate to apply the techniques in concert with detailed field analyses of river migration patterns. Copyright © 2008 John Wiley & Sons, Ltd.
The attitudes and practices of general practitioners regarding dementia diagnosis in Ireland
Authors: Cahill S. , Clark M. , O'Connell H. , Lawlor B. , Coen R. F. , Walsh C.
Published: January 2008

Background

The diagnosis of dementia poses difficulties for general practitioners (GPs) particularly when access to specialist diagnostic services is delayed. Ireland is soon to witness an increase in numbers of people presenting with dementia, yet little is known about the service needs of GPs when attempting to diagnose dementia.

Objectives

To detail the service needs of GPs, especially their training needs, access to diagnostic resources such as CT and MRI brain scans and access to specialist services such as Old Age Psychiatry (OAP), Geriatric Medicine (GM) and Neuropsychology (NP).

Methods

The paper is based on survey data collected from a sample of GPs (<$>n<$> = 300) registered with the Irish College of General Practitioners (ICGP) and on qualitative data collected from a Focus Group (<$>n<$> = 7).

Results

GPs were more likely to blame themselves than either the health care system, their patients or family members for the late presentation of dementia in primary care. Stigma was a major obstacle preventing GPs from being more proactive in this area. Rural GPs felt geographically disadvantaged accessing diagnostic services and both rural and urban GPs experienced considerable time delays accessing specialist diagnostic services.

Conclusions

Findings provide compelling evidence that training and access to diagnostic services are only two of several different structural and ideological obstacles that GPs encounter when attempting to diagnose dementia. Future educational supports for GPs need to be developed which concentrate on these areas.Copyright © 2008 John Wiley & Sons, Ltd.
Measuring primary care patients' attitudes about dementia screening
Authors: Boustani Malaz , Perkins Anthony J. , Monahan Patrick , Fox Chris , Watson Lea , Hopkins John , Fultz Bridget , Hui Siu , Unverzagt Frederick W. , Callahan Christopher M. , Hendrie Hugh C.
Published: January 2008

Objectives

To develop a questionnaire that will capture patients' attitudes about dementia screening in primary care.

Methods

Cross‐sectional study of 315 patients aged 65 and older attending urban and rural primary care clinics in Indianapolis and North Carolina. The Perceptions Regarding Investigational Screening for Memory in Primary Care (PRISM‐PC) questionnaire was administered via face‐to‐face or telephone interview.

Results

The PRISM‐PC questionnaire consists of two separate scales: the patient's acceptance of dementia screening scale and the patient's perceived harms and benefits of dementia screening scale. The face validity of the PRISM‐PC questionnaire was based on a systematic literature review and the opinions of 16 clinician‐investigators with experience in screening for dementia. Exploratory factor analyses for the acceptance scale revealed the presence of two dimensions: knowledge about dementia risk and testing for dementia. For the benefits and harms scale, exploratory factor analyses identified four dimensions: perceived benefits of screening, stigma of screening, suffering from screening, and impact of screening on patients' independence. The internal consistency of each of the above subscales was good with Cronbach's alpha ranging from 0.58–0.85.

Conclusion

The PRISM‐PC questionnaire captures primary care patients' acceptance, perceived harms, and perceived benefits of dementia screening. Copyright © 2008 John Wiley & Sons, Ltd.
Promotion and prevention within a decentralized framework: changing health care in Brazil and Chile
Authors: Atkinson Sarah , Cohn Amélia , Ducci Maria E. , Fernándes Lucília , Smyth Fiona
Published: January 2008

The study aims to define configurations of factors from local, regional and national levels that, within a context of decentralized health systems, enable or hinder change towards a health care model of promotion and disease prevention as advocated in current Latin American public health discourse. The project made in‐depth case studies of prevention and promotion activities in eight local health systems in rural and urban Brazil and Chile allowing three levels of comparison: national, regional and local. The data are based on interviews, secondary sources, policy documentation and observations.

The results are summarized as pathways through configurations of factors leading to what are termed active and basic degrees of activity related to disease prevention and health promotion at the local level. The results raise considerations for policy‐makers at each of the three levels of health systems regarding vertical and horizontal system structures, relationships to local government, management options and human resource incentives. The findings from this study can serve as a guide or menu of issues to consider in the implementation of new models of health care provision, not only in Brazil and Chile, but also elsewhere in Latin America and more widely in the world. Copyright © 2008 John Wiley & Sons, Ltd.
Phenotypic effects of thermal mean and fluctuations on embryonic development and hatchling traits in a lacertid lizard, Takydromus septentrionalis
Authors: Du Wei‐Guo , Feng Jia‐Hua
Published: January 2008

How fluctuating temperatures influence reptilian embryos and hatchlings has attracted increasing scientific attention, but is poorly known. We conducted an incubation experiment with a factorial design of two mean temperatures (24 vs. 28°C) and three diel thermal fluctuations (0, ±3, ±6°C) to determine the effects of diel thermal fluctuations and mean temperature on incubation duration and hatchling phenotypes. Both diel thermal fluctuations and mean temperature significantly affected incubation duration, but not hatching success. Incubation duration increased with increasing temperature fluctuations at a mean temperature of 24°C, but not at a mean temperature of 28°C. The significant interaction between diel thermal fluctuations and mean temperature on hatchling morphology indicated that the effect of thermal fluctuations depended on the mean temperature. Hatchling mass differed significantly between 24±6 and 28±6°C, but not between the two constant temperatures or the temperatures with ±3°C fluctuations. At a mean temperature of 24°C, the effect of thermal fluctuations on hatchling size was marginally significant, with relatively large hatchlings at the constant temperature; at a mean temperature of 28°C, thermal fluctuations had no impact on hatchling size. The locomotor performances were significantly affected by mean temperature rather than diel thermal fluctuations. Therefore, diel thermal fluctuations around a given mean temperature do not affect hatchling phenotypes in a relatively large magnitude, but the influence of diel thermal fluctuations may differ with changing mean temperatures. J. Exp. Zool. 309A:138–146, 2008. © 2008 Wiley‐Liss, Inc.
Potential immunological advantage of intravenous mycophenolate mofetil with tacrolimus and steroids in primary deceased donor liver transplantation and live donor liver transplantation without antibody induction
Authors: Jain Ashokkumar , Sharma Rajeev , Ryan Charlotte , Tsoulfas Georgious , Orloff Mark , Abt Peter , Kashyap Randeep , Batzold Pam , Sauberman Lisa , Safadjou Saman , Graham Maureen , Bozorgzadeh Adel
Published: January 2008

With the current immunosuppressive regimens, graft loss secondary to immunological reasons after successful liver transplantation is a rarity; acute rejections, however, do occur, with the majority of them being steroid-responsive. The aim of the present study is to examine the rate of acute rejection with tacrolimus, intravenous (IV) mycophenolate mofetil (MMF), and steroids in primary deceased donor liver transplant (DDLT) and live donor liver transplant (LDLT) recipients. During the year 2005, 130 patients (mean age: 54.9 ± 10.8, males: 84, females: 46, 112 DDLT and 18 LDLT) received primary liver transplantation. They were followed up for the incidence of acute rejection in the first 12 months. Liver biopsies were performed as clinically indicated; protocol liver biopsies were never performed. A total of 127 liver biopsies were performed. Thirty-two had a rejection activity index (RAI) score of ≥3, of which 24 biopsies in 20 patients were not treated with a steroid bolus. Eight (6.1%) patients (mean RAI score: 5.1 ± 1.4) received 750 to 1500 mg of methylprednisolone over 3 days. Out of these, 2 were noncompliant, 4 were off MMF, and 1 was on cyclosporine. All patients responded to steroid therapy. None of the patients required any antibody preparation. In conclusion, IV MMF with tacrolimus and steroids is useful and required antirejection therapy in 6.1% of liver transplant recipients. Liver Transpl 14:202–209. 2008. © 2008 AASLD.
Critical use of extended criteria donor liver grafts in adult-to-adult whole liver transplantation: A single-center experience
Authors: Gruttadauria Salvatore , Vizzini Giovanni , Biondo Domenico , Mandalà Lucio , Volpes Riccardo , Palazzo Ugo , Gridelli Bruno
Published: January 2008

This study presents our experience with the use of extended criteria donor (ECD) liver grafts. One hundred fifteen liver transplants were divided into 2 groups: standard (S) and nonstandard (NS). Fifty-eight patients in group S received a liver procured from an ideal donor, whereas 57 patients in group NS received an organ from an ECD. On the basis of the number of risk factors, patients were divided into 3 subgroups: the S group with 58 receiving a standard graft, the NS1 group with 44 receiving a graft with 1 or 2 risk factors, and the NS2 group with 13 receiving a graft with 3 to 4 risk factors. Patient survival was not different at 6, 12, and 24 months (P > 0.05), whereas graft survival was different (P = 0.0079). Both patient survival and graft survival were influenced by the cumulative number of risk factors. The univariate analysis of the donor risk factors detected hemodynamic factors as predictive of graft failure (P = 0.024) and death (P = 0.018). In the multivariate analysis, which was adjusted for recipient age and donor and recipient gender, hemodynamic risk factors and Model for End-Stage Liver. Disease score in the recipient were the only variables independently associated with graft failure (P = 0.006, P = 0.012, negatively). Finally, we observed a reduction of dropout from the list to 9% from 14.1% (P = 0.04) and of mortality on the list to 32.55% from 41.01% (P = 0.11). Critical use of ECD liver grafts allowed recipients in the waiting list to have a greater chance of being transplanted. Liver Transpl 14:220–227, 2008. © 2008 AASLD.
Self‐Assembled PEO‐Peptide Nanotapes as Ink for Plotting Nonwoven Silica Nanocomposites and Mesoporous Silica Fiber Networks
Authors: Kessel Stefanie , Börner Hans G.
Published: January 2008

Macroscopic networks of oriented polymer‐silica composite fibers can be accessed via a convenient 2D‐plotting process. By using self‐assembled PEO‐peptide nanotapes as an ink to draw the composite fibers, the macroscopic form of the fiber networks, the line width, and both network orientation as well as network anisotropy can be defined. The plotting process relies on a biomimetic silicification route, which combines self‐assembly and peptide‐directed silicification in a cooperative manner. The local injection of PEO‐peptide nanotapes into a thin layer of a dilute solution of pre‐hydrolyzed TMOS leads to the rapid formation of the composite fibers, which exhibit several levels of hierarchical order. It was shown, that the rate of plotting is a parameter, enabling one to control the line width and the orientation of the nano‐ and sub‐micrometer structure elements in the network. Moreover, the plotted composite fibers can be used as precursors for networks of oriented, mesoporous silica‐fibers. After calcination procedures, nonwoven silica fabrics can be obtained with high surface areas and cylindrical pores aligned in plot direction.

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3‐Oxo‐1,3‐oxathiolanes—synthesis and stereochemistry
Authors: Pihlaja Kalevi , Sinkkonen Jari , Stájer Géza
Published: January 2008

The compound 3‐oxo‐1,3‐oxathiolane (6) and its cis ‐ and trans ‐ 2‐methyl (7,8), 4‐methyl (9,10), 5‐methyl (11,12) and 2‐p‐nitrophenyl (13,14) derivatives were prepared by oxidizing the corresponding 1,3‐oxathiolanes (1–5) with NaIO4 in water. The oxides were purified and their isomers separated using thin layer chromatography. The structural characterization was carried out with 1H NMR spectroscopy and molecular modeling. Compounds 8–10, 12, and 14 attain the half‐chair type conformation with O(1) above and C(5) below the plane (HC1), but 6, 7, 11, and 13 are, for steric reasons, the mixtures with the alternative half‐chair (HC2), where O(1) is below and C(5) above this plane. Accordingly, 6 appears based on the values of experimental coupling constants as an 81:19, 7 as a 37:63, 11 as a 33:67 and 13 as a 54:46 mixture of HC1 and HC2, respectively. The relative energies of these conformations, the values of the vicinal H,H‐coupling constants and 1H chemical shifts were estimated for compounds 6–12 also by computational methods and they support nicely the conclusions based on experimental data. Copyright © 2008 John Wiley & Sons, Ltd.
Assignment of the 1H and 13C NMR of tocotrienols
Authors: Ohnmacht Stephan , West Ryan , Simionescu Razvan , Atkinson Jeffrey
Published: January 2008

Vitamin E is a family of chromanols that vary by the degree of methylation of the chroman ring as well as the nature of the hydrophobic side chain at C2 that serves to anchor these lipids in biological membranes. The tocopherols contain saturated side chains, whereas the tocotrienols contain three sites of unsaturation and are derived from geranylgeranyl diphosphate. A growing interest in the unique biological activities of the tocotrienols has led us to begin syntheses of isotopically substituted forms and other derivatives that will be useful for probing the metabolism and membrane behavior of the tocotrienols. In order to be certain of our ability to selectively modify sites on the parent molecules it was necessary to make as complete an assignment of the 1H and 13C NMR as possible. Herein we report multidimensional NMR data (HSQC, COSY, ADEQUATE(1,1), CH HMBC, and NOESY) that have allowed us to assign the identity of almost all the resonances for α‐, β‐, γ‐, and δ‐tocotrienol. Copyright © 2008 John Wiley & Sons, Ltd.
Unexpected shielding of methyl group protons in some piperidines
Authors: Manimekalai A. , Maruthavanan T. , Selvaraju K.
Published: January 2008

High resolution 1H and 13C NMR spectra of four 3‐ethyl‐4‐hydroxy‐ 4‐phenylpiperidines 1–4 have been recorded in CDCl3 and analysed. The conformations of phenyl and hydroxyl groups at C(4) and ethyl group at C(3) were analysed in detail. The chemical shift of the methyl protons in the ethyl group are quite surprising; they are close to TMS in CDCl3 and even negative in DMSO–d6. These results are interpreted in terms of the magnetic anisotropy of the phenyl rings at C(2) and C(4) which, in turn, depend on the conformations of the ethyl group at C(3) and the hydroxyl group at C(4). Favoured conformations of ethyl group at C(3) and hydroxyl group at C(4) were calculated by AM1 methods. Copyright © 2008 John Wiley & Sons, Ltd.
Skeletal muscle telomere length is not impaired in healthy physically active old women and men
Authors: Ponsot Elodie , Lexell Jan , Kadi Fawzi
Published: January 2008

We have previously shown that the number of satellite cells is lower in old than young men and women. The aim of this study was to further explore the effects of aging on the regenerative potential of skeletal muscle in 16 young and 26 old men and women with comparable physical activity level (young, 25 ± 4 years; old, 75 ± 4 years). Mean and minimum telomere lengths were determined using Southern blot analyses on biopsies obtained from the tibialis anterior muscle. There were no significant age or gender effects on mean and minimal telomeric lengths, suggesting that the replicative potential in the remaining satellite cells in the tibialis anterior muscle is not impaired with increasing age and the existence of in vivo regulatory mechanisms allowing the maintenance of telomere length. These results imply that moderate physical activity regularly performed by old subjects is not associated with accelerated telomere loss. Muscle Nerve, 2008
Age‐related muscle fatigue after a low‐force fatiguing contraction is explained by central fatigue
Authors: Yoon Tejin , De‐Lap Bonnie Schlinder , Griffith Erin E. , Hunter Sandra K.
Published: January 2008

The contribution of central fatigue during and after low‐ and high‐force isometric contractions sustained until failure with age is not established. We compared the time to failure and changes in voluntary activation measured using motor point stimulation of 15 young and 15 old adults for an isometric contraction sustained with the elbow flexor muscles at 20% and 80% of maximal voluntary contraction (MVC) force. Young adults had a briefer time to task failure than old adults for the 20% MVC fatiguing contraction, but a similar duration for the 80% task. Voluntary activation was reduced at the end of the 20% MVC task, but by greater magnitudes for old than young adults. The reduction in MVC torque after the low‐force task was associated with the reduction in voluntary activation. After the 80% task, voluntary activation declined to similar levels for the young and old adults. Electromyographic activity levels (% MVC) of the biceps brachii and brachioradialis muscles during the fatiguing contraction were greater for the old than young for the 20% MVC task, but similar with age for the 80% MVC task. Our findings indicate that intensity and duration of contraction can be manipulated in young and old adults to induce varying magnitudes of fatigue within the central nervous system. Aging increases: (1) fatigue within the central nervous system immediately after a low‐force fatiguing contraction, and (2) the potential for large neural adaptations during neuromuscular rehabilitation in old adults. Muscle Nerve, 2008
Potential role of fetal cardiac evaluation with magnetic resonance imaging: preliminary experience
Authors: Manganaro Lucia , Savelli Sara , Di Maurizio Marco , Perrone Anna , Tesei Jacopo , Francioso Antonella , Angeletti Marco , Coratella Fabio , Irimia Daniela , Fierro Francesca , Ventriglia Flavia , Ballesio Laura
Published: January 2008

Objective

To report our experience with magnetic resonance imaging (MRI) in fetal heart evaluation.

Method

Two radiologists examined 31 MRI of fetuses with no ultrasound (US) evidence of cardio‐thoracic anomalies. T2‐weighted half‐Fourier single‐shot turbo spin–echo sequences were acquired for anatomic evaluation; fast imaging with steady‐state free precession (TrueFISP) and cine‐MR sequences with real‐time steady‐state free precession oriented like standard fetal echocardiographic projections were acquired for the characterization of cardiovascular morphology and function.

Results

In every case, MRI assessed the viscero‐atrial situs. The four‐chamber view and the short‐axis view of the left ventricle were obtained in all fetuses, the long‐axis view of the aortic arch in 28, the long‐axis view of the ductus arteriosus in 17, the five‐chamber view in 12, the long‐axis of the left ventricle in 9, the three‐vessel view in 7, the tricuspid‐aortic view in 3, and the transverse view of the aortic arch and the angulated view of the arch and the ductus arteriosus simultaneously in 2 fetuses.

Conclusion

Our preliminary experience demonstrates the feasibility to visualize the fetal heart with routine fetal MRI protocols in particular, by means of acquisition of TrueFISP imaging (morphological study) and real‐time cine‐MRI (dynamic study), potentially making MRI a second‐level tool to add to fetal echocardiography in the prenatal study of congenital cardiac malformations. Copyright © 2008 John Wiley & Sons, Ltd.
Differential expression of cardiac mitochondrial proteins
Authors: Smith Julia R. , Matus Isaac R. , Beard Daniel A. , Greene Andrew S.
Published: January 2008

Mitochondria were isolated from whole hearts of Dahl salt sensitive (SS) and chromosome 13 consomic control (SS.13BN/Mcwi) rats using a mechanical homogenization process followed by density centrifugation. The proteins present in the two mitochondria preparations were quantified; equal amounts of protein from each sample were taken and trypsinized in the presence of either 16O or 18O before pooling. Incorporation of one or two 18O atoms at the C‐terminus of the peptide cleaved by trypsin allows the distinction between the two samples. The proteins were identified by automated MS/MS sequencing and relative amounts of each protein assessed by comparison of the intensities of the constituent peptides. Relative quantification was performed using the ZoomQuant (v1.24) software. Nine proteins were found to be differentially expressed. Electron transfer flavoprotein alpha (P13803, ETFA) protein expression was two‐fold lower in the SS compared to the SS.13BN. This was confirmed by Western blot and 2‐DE gel quantification. Potential functional implications of this differential expression include an impaired capacity of the heart to oxidize fatty acids in the SS strain compared to the control. Mathematical modeling of mitochondrial electron transport predicted that the observed change in ETFA expression may result in decreased activity of the electron transport chain.
Host perception and signal transduction studies in wild‐type Blumeria graminis f. sp. hordei and a quinoxyfen‐resistant mutant implicate quinoxyfen in the inhibition of serine esterase activity
Authors: Lee Susannah , Gustafson Gary , Skamnioti Pari , Baloch Roobina , Gurr Sarah
Published: January 2008

BACKGROUND: Quinoxyfen is a potent and effective fungicide, hitherto considered to control powdery mildew disease by perturbing signal transduction during early germling differentiation. The aim of this paper is to understand the mode of action of quinoxyfen by comparing the perception of host‐derived signals and signal relay in a wild‐type Blumeria graminis f. sp. hordei EM Marchal (Bgh) (WT/IM82) and a quinoxyfen‐resistant field isolate (QR/2B11).

RESULTS: QR/2B11 germinates more promiscuously on host‐like and artificial surfaces than the quinoxyfen‐sensitive WT/IM82. The pivotal role of host cuticle deprivation in the formation of hooked appressorial germ tubes (hAGTs) in WT/IM82 and a dramatic drop in germling differentiation in the presence of the mildewicide are demonstrated. QR/2B11 strain shows a dependence on host cuticle‐like features for hAGT formation but no significant difference between germling differentiation in the presence or absence of quinoxyfen. PKC‐inhibitor Ro 318220 induces morphological changes similar to those seen in quinoxyfen‐treated germlings. PKC1 transcript accumulation is equivalently upregulated by quinoxyfen in QR/2B11 and WT/IM82 strains, but Bgh cutinase CUT1 transcript is 8 times more abundant in QR/2B11 conidia than in WT/IM82 conidia. Quinoxyfen inhibits serine esterase activity in WT/IM82, but not in QR/2B11.

CONCLUSION: Collectively, these data suggest that quinoxyfen interferes with the perception of host‐derived signals required for full germling differentiation, and that QR/2B11 bypasses the need for such signals. Moreover, quinoxyfen appears to target serine esterase activity, with a downstream perturbation in signal transduction; this represents the first demonstrable biochemical difference between the quinoxyfen‐resistant and ‐sensitive isolates. Copyright © 2008 Society of Chemical Industry
Study of the dissociation of a charge‐reduced phosphopeptide formed by electron transfer from an alkali metal target
Authors: Hayakawa Shigeo , Hashimoto Mami , Nagao Hirofumi , Awazu Kunio , Toyoda Michisato , Ichihara Toshio , Shigeri Yasushi
Published: January 2008

Doubly protonated phosphopeptide (YGGMHRQET(p)VDC) ions obtained by electrospray ionization were collided with Xe and Cs targets to give singly and doubly charged positive ions via collision‐induced dissociation (CID). The resulting ions were analyzed and detected by using an electrostatic analyzer (ESA). Whereas doubly charged fragment ions resulting from collisionally activated dissociation (CAD) were dominant in the CID spectrum with the Xe target, singly charged fragment ions resulting from electron transfer dissociation (ETD) were dominant in the CID spectrum with the Cs target. The most intense peak resulting from ETD was estimated to be associated with the charge‐reduced ion with H2 lost from the precursor. Five c‐type fragment ions with amino acid residues detached consecutively from the C‐terminal were clearly observed without a loss of the phosphate group. These ions must be formed by NCα bond cleavage, in a manner similar to the cases of electron capture dissociation (ECD) and ETD from negative ions. Although the accuracy in m/z of the CID spectra was about ±1 Th because of the mass analysis using the ESA, it is supposed from the m/z values of the c‐type ions that these ions were accompanied by the loss of a hydrogen atom. Four z‐type (or yNH3, or yH2O) ions analogously detached consecutively from the N‐terminal were also observed. The fragmentation processes took place within the time scale of 4.5 µs in the high‐energy collision. The present results demonstrated that high‐energy ETD with the alkali metal target allowed determination of the position of phosphorylation and the amino acid sequence of post‐translational peptides. Copyright © 2008 John Wiley & Sons, Ltd.
In Vivo MRI Detection of Gliomas by Chlorotoxin‐Conjugated Superparamagnetic Nanoprobes
Authors: Sun Conroy , Veiseh Omid , Gunn Jonathan , Fang Chen , Hansen Stacey , Lee Donghoon , Sze Raymond , Ellenbogen Richard G. , Olson Jim , Zhang Miqin
Published: January 2008

Converging advances in the development of nanoparticle‐based imaging probes and improved understanding of the molecular biology of brain tumors offer the potential to provide physicians with new tools for the diagnosis and treatment of these deadly diseases. However, the effectiveness of promising nanoparticle technologies is currently limited by insufficient accumulation of these contrast agents within tumors. Here a biocompatible nanoprobe composed of a poly(ethylene glycol) (PEG) coated iron oxide nanoparticle that is capable of specifically targeting glioma tumors via the surface‐bound targeting peptide, chlorotoxin (CTX), is presented. The preferential accumulation of the nanoprobe within gliomas and subsequent magnetic resonance imaging (MRI) contrast enhancement are demonstrated in vitro in 9L cells and in vivo in tumors of a xenograft mouse model. TEM imaging reveals that the nanoprobes are internalized into the cytoplasm of 9L cells and histological analysis of selected tissues indicates that there are no acute toxic effects of these nanoprobes. High targeting specificity and benign biological response establish this nanoprobe as a potential platform to aid in the diagnosis and treatment of gliomas and other tumors of neuroectodermal origin.
Cocaine‐induced dopamine overflow within the nucleus accumbens measured by in vivo microdialysis: A meta‐analysis
Authors: Frank Stefanie TH. , Krumm Bertram , Spanagel Rainer
Published: January 2008

A meta‐analysis was conducted on data obtained from published articles which used in vivo microdialysis to assess dose‐response curves of cocaine on dopamine (DA) overflow within the nucleus accumbens (NAC). Different experimental and biological parameters such as route of administration (ip, sc, iv, local), rat and mouse strains, gender, age aspects, and regions cannulated (NAC core and shell) were considered. Data from 116 experiments involving 833 animals (out of 266 publications) fulfilled our selection criteria and were analyzed in relation to absolute basal DA levels, the maximum peak of DA overflow (peak [%] baseline) and the time when this peak (peak time) occurred. Our meta‐analysis revealed that absolute basal DA levels lie at 2.39 nM (median of all experiments) and that cocaine‐induced DA overflow in the NAC is significantly enhanced in a linear dose‐response fashion within the applied dose range as the regression function increases following either iv or ip administration. Peak time was reached fastest in iv experiments and slowest following local application. Furthermore, it was shown in ip experiments that the higher the dose, the longer it took to reach the zenith. Results from the NAC shell region displayed greater DA overflow as compared with the NAC core. DA overflow properties following cocaine treatment in mice did not differ from that in rats. Thus, neither species differences nor other biological factors such as, age, gender, and rat/mouse strain have a pronounced impact on cocaine‐induced DA overflow. Technical parameters of the microdialysis procedure such as calcium concentration of the perfusion medium and collected sample amount have also no significant effect in terms of DA overflow properties (peak [%] baseline and peak time) following cocaine treatment. In conclusion, these data may be deemed useful for textbook knowledge and a better comparability of data given by the generalization of already existing data as well as for investigators in maximizing the effect of cocaine‐induced DA overflow. Finally, this study examplifies how meta‐analyses may be applied to a wide range of data within the field of neurochemistry. Synapse 62:243–252, 2008. © 2008 Wiley‐Liss, Inc.
Disparities in Surgery: Access to Outcomes
Authors: Rogers Selwyn O.
Published: January 2008

Surgery is an important intervention to sustain human life through its ability to cure disease, heal fractures, avert maternal death, and provide comfort for those suffering. However, surgical care is unevenly delivered throughout the world. More surprisingly, we have little knowledge about the adequacy and quality of surgical resources globally.

The Brigham and Women’s Hospital Center for Surgery and Public Health, a joint program of Harvard Medical School and the Harvard School of Public Health, seeks to remedy the knowledge deficit, to provide direction for stakeholders, and direct improvement in public health related to surgical care. To the end of raising awareness of the issue of disparities in surgical care in the United States and the world, an invitational conference on Disparities in Surgical Care: Access to Outcomes was conceived.

The Symposium brought together experts from around the world to critically examine this challenging problem. Surgeons, other clinicians, administrators, and health services researchers came together to develop approaches to translate research into practice to address disparities in access and outcomes in surgical care. The synergy of population‐based research and clinical practice may allow the surgical healthcare team of the near future to implement strategies to achieve health equity, an important dimension of quality, in surgery.
Signal valence in the nucleus accumbens to pain onset and offset
Authors: Becerra Lino , Borsook David
Published: January 2008

Pain and relief are at opposite ends of the reward–aversion continuum. Studying them provides an opportunity to evaluate dynamic changes in brain activity in reward–aversion pathways as measured by functional magnetic resonance imaging (fMRI). Of particular interest is the nucleus accumbens (NAc), a brain substrate known to be involved in reward–aversion processing, whose activation valence has been observed to be opposite in response to reward or aversive stimuli. Here we have used pain onset (aversive) and pain offset (rewarding) involving a prolonged stimulus applied to the dorsum of the hand in 10 male subjects over 120s to study the NAc fMRI response. The results show a negative signal change with pain onset and a positive signal change with pain offset in the NAc contralateral to the stimulus. The study supports the idea that the NAc fMRI signal may provide a useful marker for the effects of pain and analgesia in healthy volunteers.
Patient and clinician treatment preferences do not moderate the effect of exercise treatment in chronic whiplash‐associated disorders
Authors: Stewart Mark J. , Maher Chris G. , Refshauge Kathryn M. , Herbert Rob D. , Nicholas Michael K.
Published: January 2008

An issue that arises when selecting therapy is whether patient or clinician preferences for treatment moderate the effect of treatment.

To evaluate this question we conducted a secondary analysis of the results of a randomized controlled trial of exercise treatment of chronic whiplash. Immediately prior to randomization, treatment preference ratings were collected from each patient and from the physiotherapist who assessed each patient. Patients were then randomized to receive advice alone or exercise and advice with the primary treatment outcomes of pain and function measured immediately after conclusion of treatment. Treatment effect modification was evaluated with a treatment group by preference interaction term in the regression analyses.

The analysis revealed that neither patient nor therapist treatment preferences moderated the effect of exercise treatment for chronic whiplash. The interaction effect of treatment group by patient preference was 0.1 (−0.3 to 0.5, p=0.68) on the 0–10 pain intensity scale and −0.1 (−0.5 to 0.3, p=0.64) on the 0–10 function scale. The interaction effect of treatment group by therapist preference was 0.0 (−0.3 to 0.4, p=0.786) on the 0–10 pain intensity scale and −0.2 (−0.4 to 0.1, p=0.296) on the 0–10 function scale.

Our findings do not provide evidence that patient or therapist treatment preferences moderate the effect of exercise treatment for chronic whiplash.
Interobserver agreement in intrapartum estimation of fetal head station
Authors: Buchmann Eckhart , Libhaber Elena
Published: January 2008

Objective

To determine interobserver agreement in estimation of fetal head station during labor, and the determinants of agreement.

Methods

A prospective study of fetal head station in 508 women in term labor. Vaginal examination of station was performed by a researcher at the same time as clinicians performed routine intrapartum assessments of the participants. Station 0 was considered to represent engagement.

Results

Station could be estimated by both the researcher and clinicians in 446 women (88%). The kappa statistic for agreement was 0.23 (95% confidence interval, 0.17–0.29). There was agreement in 166 cases (37%) and disagreement by 1 cm in 208 (47%) cases. Agreement was best (50%) when the researcher assessed the head at station minus 1. Multiple regression analysis showed that agreement was not influenced by level of experience of the attending clinicians, nor by obstetric factors.

Conclusion

Estimation of station as a method of determining the level of the fetal head in labor appears imprecise and poorly reproducible.
Interaction between genes and lifestyle factors on obesity
Authors: Marti Amelia , Martinez-González Miguel Angel , Martinez J. Alfredo
Published: January 2008

Obesity originates from a failure of the body-weight control systems, which may be affected by changing environmental influences. Basically, the obesity risk depends on two important mutually-interacting factors: (1) genetic variants (single-nucleotide polymorphisms, haplotypes); (2) exposure to environmental risks (diet, physical activity etc.). Common single-nucleotide polymorphisms at candidate genes for obesity may act as effect modifiers for environmental factors. More than 127 candidate genes for obesity have been reported and there is evidence to support the role of twenty-two genes in at least five different populations. Gene–environment interactions imply that the synergy between genotype and environment deviates from either the additive or multiplicative effect (the underlying model needs to be specified to appraise the nature of the interaction). Unravelling the details of these interactions is a complex task. Emphasis should be placed on the accuracy of the assessment methods for both genotype and lifestyle factors. Appropriate study design (sample size) is crucial in avoiding false positives and ensuring that studies have enough power to detect significant interactions, the ideal design being a nested case–control study within a cohort. A growing number of studies are examining the influence of gene–environmental interactions on obesity in either epidemiological observational or intervention studies. Positive evidence has been obtained for genes involved in adiposity, lipid metabolism or energy regulation such as PPARγ2 (Pro12Ala), β-adrenoceptor 2 (Gln27Glu) or uncoupling proteins 1, 2 and 3. Variants on other genes relating to appetite regulation such as melanocortin and leptin receptors have also been investigated. Examples of some recently-identified interactions are discussed.