bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructural analysis of the cristae ampullares in the squirrel monkey (Saimiri sciureus)
Authors: Lysakowski Anna , Goldberg Jay M.
Published: August 2008

Type I hair cells outnumber type II hair cells (HCs) in squirrel monkey (Saimiri sciureus) cristae by a nearly 3:1 ratio. Associated with this type I HC preponderance, calyx fibers make up a much larger fraction of the afferent innervation than in rodents (Fernández et al. [1995] J. Neurophysiol. 73:1253–1269). To study how this affects synaptic architecture, we used disector methods to estimate various features associated with type I and type II HCs in central (CZ) and peripheral (PZ) zones of monkey cristae. Each type I HC makes, on average, 5‐10 ribbon synapses with the inner face of a calyx ending. Inner‐face synapses outnumber those on calyx outer faces by a 40:1 ratio. Expressed per afferent, there are, on average, 15 inner‐face ribbon synapses, 0.38 outer‐face ribbons, and 2.6 efferent boutons on calyx‐bearing endings. Calyceal invaginations per type I HC range from 19 in CZ to 3 in PZ. For type II HCs, there are many more ribbons and afferent boutons in PZ than in CZ, whereas efferent innervation is relatively uniform throughout the neuroepithelium. Despite outer‐face ribbons being more numerous in chinchilla than in squirrel monkey, afferent discharge properties are similar (Lysakowski et al. [1995] J. Neurophysiol. 73:1270–1281), reinforcing the importance of inner‐face ribbons in synaptic transmission. Comparisons across mammalian species suggest that the prevalence of type I HCs is a primate characteristic, rather than an arboreal life‐style adaptation. Unlike cristae, type II HCs predominate in monkey maculae. Differences in hair‐cell counts may reflect the stimulus magnitudes handled by semicircular canals and otolith organs. J. Comp. Neurol. 511:47–64, 2008. © 2008 Wiley‐Liss, Inc.
Kinetics of Helix‐Handedness Inversion: Folding and Unfolding in Aromatic Amide Oligomers
Authors: Delsuc Nicolas , Kawanami Takahiro , Lefeuvre Julien , Shundo Atsuomi , Ihara Hirotaka , Takafuji Makoto , Huc Ivan
Published: August 2008

A series of helically folded oligoamides of 8‐amino‐2‐quinoline carboxylic acid possessing 6, 7, 8, 9, 10 or 16 units are prepared following convergent synthetic schemes. The right‐handed (P) and the left‐handed (M) helical conformers of these oligomers undergo an exchange slow enough to allow their chromatographic separation on a chiral stationary phase. Thus, the M conformer is isolated for each of these oligomers and its slow racemization in hexane/CHCl3 solutions is monitored at various temperatures using chiral HPLC. The kinetics of racemization at different temperatures in hexane/CHCl3 (75:25 vol/vol) are fitted to a first order kinetic model to yield the kinetic constant and the Gibbs energy of activation for oligomers having 6, 7, 8, 9, 10 or 16 quinoline units. This energy gives the first quantitative measure of the exceptional stability of the helical conformers of an aromatic amide foldamer with respect to its partly unfolded conformations that occur between an M helix and a P helix. The trend of the Gibbs energy as a function of oligomer length suggests that helix‐handedness inversion does not require a complete unfolding of a helical strand and may instead occur through the propagation of a local unfolding separating two segments of opposite handedness.
Internal structure of silver crystallites: going beyond nanostructure using novel processing technique
Authors: El‐Daly A. A. , Tolba M.
Published: August 2008

Using novel processing of TEM image to investigate nanoparticles of metallic solutions is exemplified in the case of silver nano‐crystals. The results show for the first time that the real internal structure of silver crystallites consists of nuclei and multi‐layers. The multi‐layers of the crystals are arranged symmetrically around their nuclei. The dimensions of nuclei lie in the range of atomic‐scale. The shape of nuclei determined the final shape of the crystals. The mechanisms of formation and growth for both silver crystallites and silver nanoparticles are demonstrated. This technique will give birth to the ongoing revolution in nano‐technology. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diamagnetic and photoabsorption characterisation of gel‐grown cadmium oxalate single crystals
Authors: Chauhan K. M. , Arora S. K.
Published: August 2008

Perfect single crystals of cadmium oxalate trihydrate have been grown using the slow and controlled reaction between Cd+2 and (C2O4)‐2 ions in agar‐agar gel, resulting in the formation of insoluble product Cd(COO)2.3H2O. The optimum growth parameters have been determined. The variation of magnetic moment of the grown crystals under an applied static magnetic field is studied and the material is found to be diamagnetic. The polarizability is found sensitive to optical band gap. An empirical relation between magnetic susceptibility and electronic polarizability has been established. Optical absorption spectra of the sample recorded in the range 200‐2500 nm reveal transitions involving absorption and emission of phonons. The detailed study supports the existence of allowed direct and indirect allowed gaps in the material. The direct allowed transition prevails in the region of relatively higher photon energy. Some feeble disorder in the crystal is conceived to be present. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Laser‐induced crystal growth of nonlinear optical Ba3Ti3O6(BO3)2 on glass surface
Authors: Oikawa T. , Honma T. , Komatsu T.
Published: August 2008

Nonlinear optical Ba3Ti3O6(BO3)2 crystals were patterned on the surface of CuO (1 mol%)‐doped 40BaO‐40TiO2‐20B2O3 glass by irradiations of continuous‐wave Nd:YAG (wavelength: λ=1064 nm) and Yb:YVO4 (λ=1080 nm) lasers. Laser energies absorbed by Cu2+ ions were transferred to the lattice system through a nonradiative relaxation process, consequently heating the glass and inducing local crystallizations. For the lines patterned by Yb:YVO4 laser irradiations with a power of 1 W and a scanning speed of 20 μm/s, a c‐axis orientation of Ba3Ti3O6(BO3)2 crystals along the laser scanning direction is proposed from measurements of X‐ray diffraction analyses, polarized optical photographs, polarized micro‐Raman scattering spectra, and azimuthal dependence of second harmonic generations. The laser‐induced crystallization technique is found to be applied successfully for the spatially selective patterning of nonlinear optical Ba3Ti3O6(BO3)2 crystals in glass. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and characterization of nano ZnS doped with Mn
Authors: Lakshmi P. Vinotha Boorana , Raj K. Sakthi , Ramachandran K.
Published: August 2008

Nanocrystalline samples of Zn1‐xMnxS (x = 0.0, 0.02, 0.04) were synthesized by chemical precipitation method and characterized for magnetism. EPR studies showed an evidence of ferromagnetism around room temperature. Hysterisis from vibrating sample magnetometer supports the observation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A novel porous network with interpenetrating topology
Authors: Wu Jian
Published: August 2008

A new CoII coordination polymer with complicated topology, namely [Co(bpp)2Cl2]n (1) (bpp=1,3‐bis(4‐pyridyl)propane), has been designed and synthesized based on flexible ligand under basic condition. The complex was characterized by single‐crystal X‐ray analysis and infrared spectroscopy. The CoII ions are linked into a 3D structure via bpp molecules. Four independent frameworks are related by translation along the c tetragonal axis in the usual interpenetration topology for diamondoid frames. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Utility of CD26 in flow cytometric immunophenotyping of T‐cell lymphomas in tissue and body fluid specimens
Authors: Pierson Diane M. , Jones Dan , Muzzafar Tariq , Kersh Marian J. , Challagundla Pramoda , Medeiros L. Jeffrey , Jorgensen Jeffrey L.
Published: August 2008

Background

CD26 is expressed by most CD4+ T cells in normal peripheral blood specimens. Neoplastic T cells are frequently CD26− in mycosis fungoides/Sezary syndrome involving the peripheral blood. However, CD26 expression by reactive and neoplastic T cells in solid tissues and body fluids has not been fully characterized by flow cytometry (FC).

Methods

Solid tissue and body fluid specimens were assayed for CD26 expression using four‐color FC immunophenotyping, by qualitative assessment of population clusters, and by quantitation with comparison with isotype controls. Benign T cells were studied in reactive tissues and in the background of other malignancies.

Results

Many T‐cell lymphomas were dim or negative for CD26, whereas a few were brightly positive. In the majority of T‐cell lymphomas, CD26 expression could potentially help identify aberrant population clusters. T cells in reactive tissue specimens and tumor‐infiltrating T cells were commonly dim to negative for CD26.

Conclusions

Both T‐cell lymphomas and reactive T cells in tissue and body fluid specimens often show low levels of CD26 expression. Therefore, quantitative methods may not reliably distinguish benign from neoplastic T cells in these specimens. However, CD26, in combination with other T‐cell markers, can be helpful for identifying aberrant population clusters in T‐cell lymphomas. © 2008 Clinical Cytometry Society
Simultaneous flow cytometric detection of basophil activation marker CD63 and intracellular phosphorylated p38 mitogen‐activated protein kinase in birch pollen allergy
Authors: Aerts Nicolaas E. , Dombrecht Evelyne J. , Bridts Chris H. , Hagendorens Margo M. , de Clerck Luc S. , Stevens Wim J. , Ebo Didier G.
Published: August 2008

Background:

Phosphorylation of p38 MAPK is a crucial step in IgE‐receptor signaling in basophils. The relation of p38 MAPK to the well‐validated diagnostic cell surface marker CD63 has not been evaluated in a clinical allergy model.

Methods:

Expression of CD63 and phosphorylation of p38 MAPK were analyzed flow cytometrically in anti‐IgE‐gated basophils from 18 birch pollen allergic patients, five grass pollen allergic patients, and five healthy individuals, after 3 and 20 min of stimulation with recombinant major birch pollen allergen (rBet v 1). Additional time points and the influence of p38 MAPK inhibitor SB203580 were studied in birch pollen allergic patients.

Results:

Phospho‐p38 MAPK and CD63 were expressed dose‐dependently in birch pollen allergic patient basophils within 1 minute of rBet v 1 stimulation. P38 MAPK phosphorylation was fastest and subsided gradually while CD63 expression remained elevated for at least 20 min. Inhibition of p38 MAPK significantly inhibited CD63 upregulation. With optimal stimulation of the cells (1 μg/mL), sensitivity and specificity for the discrimination between patients and a group of control individuals (grass pollen allergic patients and healthy controls) were 94% and 100% for CD63 at 3 and 20 min and for phospho‐p38 MAPK at 3 min.

Conclusion:

Antigen‐induced p38 MAPK phosphorylation in human basophils essentially contributes to CD63 upregulation. It is a sensitive and specific intracellular marker for allergy diagnosis and offers new insight into the mechanisms of basophil activation. © 2008 Clinical Cytometry Society
Flow cytometric detection of erythrocyte osmotic fragility
Authors: Won Dong Il , Suh Jang Soo
Published: August 2008

Background

Hereditary spherocytosis (HS) is the most common cause of inherited chronic hemolysis. The various tests developed for HS screening have many shortcomings. The purpose of this study was to develop a new, simple, reliable test using flow cytometry.

Methods

In this new test, deionized water, a hemolysis‐inducing agent, is spiked to a red cell suspension during acquisition, and the count of red cells is measured sequentially in real‐time using flow cytometry. In this study, the optimal parameters for this test were established, and the discriminatory power of the adopted protocol was verified among several groups with various degrees of osmotic fragility (OF).

Results

The established protocol successfully discriminated between blood analyzed immediately and blood stored for 24 h (P< 0.00001). With healthy individuals as a reference, the OF measured by this protocol was significantly decreased in patients with iron deficiency anemia (P= 0.030) and was significantly increased in HS patients (P= 1.1 × 10−9). This new test found all 11 HS patients to have increased OF.

Conclusions

This new test was verified to be simple, quantitative, objective, and cost‐effective for the measurement of OF. We suggest this test as another effective approach for HS screening, although its assay performance will require further verification through more clinical trials. © 2008 Clinical Cytometry Society
Flow cytometric assessment of monocyte activation markers and circulating endothelial cells in patients with localized or metastatic breast cancer
Authors: Goodale David , Phay Carolina , Brown Wendy , Gray‐Statchuk Leslie , Furlong Patricia , Lock Michael , Chin‐Yee Ian , Keeney Michael , Allan Alison L.
Published: August 2008

Background

Monocyte activation in cancer patients may be reflective of anticancer activity. However, studies indicate that recruitment of macrophages can actually promote tumor growth and angiogenesis. Assessment of other microenvironmental cells such as circulating endothelial cells (CECs) may provide additional information regarding disease progression. The objective of this study was to assess monocyte activation and CECs in breast cancer patients and determine the potential clinical relevance during disease progression.

Methods

Patients (n = 41) with localized or metastatic breast cancer who were not currently receiving treatment were eligible for study inclusion. Peripheral blood was collected and analyzed by flow cytometry for monocyte activation (Leuko64™ assay kit), and for CECs (CD146+CD45− phenotype).

Results

Metastatic breast cancer patients demonstrated a higher monocyte CD64 index relative to normal donors and localized breast cancer patients (P < 0.05). Furthermore, breast cancer patients had a lower monocyte CD163 index relative to normal donors (P = 0.008). Localized breast cancer patients demonstrated higher levels of CD146+CD45− cells CECs relative to metastatic breast cancer patients and normal donors. Within the localized breast cancer population, levels of CD146+CD45− cells increased with disease stage (P < 0.05).

Conclusions

These results suggest that monocyte activation and CECs may play a role in breast cancer progression. We speculate that monocyte activation may reflect a reaction to metastatic cells and/or response to tissue damage caused by metastatic growth in distant organs. Furthermore, the observation that CECs increase with disease stage in localized breast cancer suggests that CECs could be a useful surrogate marker for disease progression in this patient population. © 2008 Clinical Cytometry Society
Kinetics of H2AX phosphorylation after exposure to cisplatin
Authors: Olive Peggy L. , Banáth Judit P.
Published: August 2008

Background

Cisplatin is a widely used cancer chemotherapeutic drug that causes DNA crosslinking and stimulates H2AX phosphorylation. Our goal was to assess the potential of γH2AX to help predict tumor response to cisplatin treatment.

Methods

The kinetics of cisplatin‐induced DNA interstrand crosslinks was measured using the alkaline comet assay and compared with γH2AX formation and clonogenic cell survival in several DNA repair proficient or deficient human and rodent cell lines.

Results

The comet assay was effective in ranking cell lines according to their relative sensitivity to cisplatin based on reduced crosslink formation measured 6 h after drug exposure or by the failure of irs3 and UV41 cell lines to subsequently remove crosslinks. In comparison, the initial rate of phosphorylation of H2AX measured over the first 6 h after cisplatin treatment was unrelated to drug sensitivity or crosslinking proficiency. However, for proliferating cell cultures, the fraction of cells that retained γH2AX foci 24 h after cisplatin treatment was correlated with the fraction of cells that lost clonogenic potential (slope = 1.1, r2 = 0.85).

Conclusions

H2AX phosphorylation occurs in response to replication fork damage caused by cisplatin induced DNA lesions, probably interstrand crosslinks. Although early kinetics of γH2AX formation was uninformative, retention of γH2AX foci 24 h after treatment was shown to be a useful indicator of cell response to killing by cisplatin. However, for γH2AX to serve as an indicator of cell viability after cisplatin treatment, cells must have the opportunity to transit S phase during the recovery period. © 2008 Clinical Cytometry Society
Dynamische Versuche an zweigeschossigen Mauerwerkprüfkörpern auf dem Rütteltisch der Nationalen Technischen Universität Athen
Authors: González Antonio Caballero , Meyer Udo
Published: August 2008

Im Rahmen des Arbeitspakets 7 “Statische und dynamische Schubversuche an Bauteilen” des EU‐Projekts ESECMASE wurde ab Mitte 2006 am Labor für Erdbebeningenieurwesen der Nationalen Technischen Universität (NTU) Athen eine Reihe von Bauteilversuchen auf dem dortigen Rütteltisch durchgeführt. Für diese Bauteilversuche wurden zweigeschossige Prüfkörper verwendet, die einen auf die Maße des Rütteltischs angepassten Ausschnitt eines Reihenhauses darstellten.

Die Untersuchungen wurden an je drei Prüfkörpern aus Kalksandsteinmauerwerk und Ziegelmauerwerk sowie einem Prüfkörper aus Betonsteinmauerwerk durchgeführt. Alle unbewehrten Prüfkörper blieben bei dem Bemessungsbeben für die höchste deutsche Erdbebenzone 3 rissfrei. Die Versuche wurden erst bei sehr viel höhreren Bodenbeschleunigungen abgebrochen. Aus den Versuchen wurden Verhaltensfaktoren für die Strukturen abgeleitet, die am oberen Rand des Wertebereichs der EN 1998‐1 liegen.
EnEV aus Sicht der Bundesarchitektenkammer
Authors: Schlesinger Barbara Chr.
Published: August 2008

Die jüngste Änderung der Energieeinspar‐Verordnung (EnEV) ist erst am 1. Oktober 2007 in Kraft getreten. Doch die Entwicklung ist dynamisch: Schon plant die Bundesregierung die nächste Novelle – die EnEV 2009. Die Bundesarchitektenkammer (BAK) hat dazu eine Stellungnahme erarbeitet, aus der hier einige wesentliche Punkte dargestellt sind.
Novellierung der Energie‐Einsparverordnung – Fallstudie zu den Konsequenzen für den Wohnungsbau
Authors: Seim Werner
Published: August 2008

Die im Rahmen des “Integrierten Energie‐ und Klimaprogramms” der Bundesregierung formulierten Ziele zur Verringerung der Treibhausgasemissionen erfordern eine erhebliche Verbesserung des energetischen Standards von Gebäuden. In einer von der Deutschen Gesellschaft für Mauerwerksbau (DGfM) beauftragten Fallstudie wurden für zehn nach der EnEV 2007 realisierte Objekte die zusätzlichen Herstellungskosten ermittelt und bewertet, mit denen zu rechnen ist, wenn der zulässige Primärenergieverbrauch in zwei Schritten um jeweils 30% gegenüber der vorhergehenden Stufe abgesenkt wird.
Konsequenzen der geplanten EnEV 2009 für die Mauerwerkindustrie
Authors: Jachmich Wolfgang
Published: August 2008

Ende des nächsten Jahrzehnts soll Deutschland 40% weniger Treibhausgase ausstoßen als im Vergleich zu 1990. Um dieses Ziel zu erreichen, einigte sich das Kabinett Ende August 2007 auf Schloss Meseberg bei Berlin auf ein 29‐Punkte‐Papier für ein integriertes Energie‐ und Klimaprogramm.

Damit dieses Ziel schnellstmöglich umgesetzt wird, folgten die ersten 14 Gesetz‐ und Verordnungsentwürfe Anfang Dezember 2007. Bei den stetig steigenden Energiepreisen eine sinnvolle Maßnahme für den Verbraucher. Diese Maßnahme wird seitens der deutschen Wirtschaft getragen, denn seit Einführung der Energieeinsparverordnung hat Deutschland seine Emission um rd. 20% verringert und will im nächsten Jahrzehnt noch einmal so viel einsparen. Das bedeutet, dass rd. 254 Millionen Tonnen Treibhausgase eingespart werden und somit die gestiegenen Emissionen der meisten Mitgliedsstaaten kompensiert werden. Damit trägt Deutschland den Löwenanteil von 75% in der EU. Doch bei ungebremsten steigenden globalen Emissionen hat die Vorreiterrolle zu nichts geführt! Konkret haben nur Deutschland, Frankreich, England und Schweden ihre Emissionen gegenüber 1990 gesenkt. Innerhalb der EU stellt das eine einseitige Lastverteilung dar, die zu weiteren negativen Konsequenzen für Wirtschaft und Beschäftigung in Deutschland führen wird.
Steroid Withdrawal After Kidney Transplantation with Daclizumab Induction
Authors: Burhan Umber , Guilfoyle Gregg , Superdock Keith R. , Badosa Francisco
Published: August 2008

OBJECTIVE

The goal of this study was to demonstrate the non‐inferiority of early steroid withdrawal after kidney transplantation.

METHODS

A retrospective analysis of 100 transplants was performed. All patients received tacrolimus and mycophenolate mofetil maintenance immunosuppression. The first 51 patients (group S) received antithymocyte globulin (deceased donor) or daclizumab (living donor) for induction and long‐term steroids. The next 49 (group NS) received daclizumab and steroids on days 0 and 1 only.

RESULTS

There were no statistical differences between the S and NS groups in demographics, delayed graft function, acute cellular rejection (ACR), and 1‐year patient and graft survival (96% vs. 98% and 96% vs. 96%). The incidence of ACR in the NS group did not differ between African Americans (7%) and non‐African Americans (12%) or between living donors (10%) and deceased donors (11%). We concluded that rapid steroid withdrawal under daclizumab induction provides excellent results.

DISCUSSION

This study evaluated a representative US patient population receiving a contemporary immunosuppressive regimen and showed that withdrawal of steroids after 2 doses is a safe and effective strategy as measured by patient and graft survival and incidence of rejection. Longer follow‐up will be required to ensure that there are no long‐term consequences of steroid avoidance.
Recurrent Peritonitis in Peritoneal Dialysis Patients During Antibiotic Therapy: Is Catheter Removal Always Reasonable?
Authors: Fasianos E. , Angelini P. , Artesano L. , Payota G. , Berloco P. , Colagiacomo R. , Tucci R. , Sacchetti A. , Cataldi G.
Published: August 2008

International Society of Peritoneal Dialysis (ISPD) guidelines suggest that in case of bacterial peritonitis in peritoneal dialysis patients, antibiotic therapy failure, and/or the absence of clinical improvement after 4‐7 days should induce catheter removal. We present an atypical case of recurrent bacterial peritonitis, 2 episodes, during a 35‐day treatment. The second episode occurred after therapy modifi cation. In addition to having constant abnormal laboratory (increased C‐reactive protein values, leukocyte cell count, serum ferritin, etc.) and clinical (fever) findings, patients' subjective well‐being and fulfi lled dialysis effi ciency remained unchanged during the treatment period; these data induced further therapy modifi cation without catheter removal. One month later laboratory parameters returned to normal, whereas echotomography control revealed the absence of the previously observed infl ammatory signs. In conclusion, our case provides evidence that patients' clinical conditions may be more predictive than laboratory findings of outcome following bacterial peritonitis.
Template Synthesis of Platinum Complexes with Benzoxazolin‐2‐ylidene Ligands
Authors: Hahn F. Ekkehardt , Klusmann Daniel , Pape Tania
Published: August 2008

2‐(Trimethylsiloxy)phenyl isocyanide (1) reacted with cis‐[PtCl2(PPh3)2] (2), and subsequent hydrolysis of the O–SiMe3 bond yielded trans‐[Pt(benzoxazolin‐2‐ylidene)Cl(PPh3)2]Cl (3). Reaction of dinuclear complex [Pt(μ‐Cl)(dppe)]2(CF3SO3)2 (4) [dppe = 1,2‐bis(diphenylphosphanyl)ethane] with two equivalents of 1 did not yield the expected monocarbene complex but the dicarbene complex [Pt(benzoxazolinato‐2‐ylidene)(benzoxazolin‐2‐ylidene)(dppe)](CF3SO3) (5). A single‐crystal X‐ray diffraction study showed that complex 5 contains one deprotonated and one protonated heterocarbene ligand. The two carbene ligands are linked by aN–H···N hydrogen bond which forces them in a sterically unfavored coplanar arrangement.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Non‐Tethered Organometallic Phosphonate Inhibitors for Lipase Inhibition: Positioning of the Metal Center in the Active Site of Cutinase
Authors: Kruithof Cornelis A. , Dijkstra Harmen P. , Lutz Martin , Spek Anthony L. , Egmond Maarten R. , Klein Gebbink Robertus J. M. , van Koten Gerard
Published: August 2008

Organometallic NCN‐pincer complexes, bearing either a p‐nitrophenyl phosphonate ester or a phosphonic acid group directly attached to the aromatic ring of the pincer complex, were synthesized. These compounds were tested as covalent inhibitors for the lipase cutinase. In a stoichiometric reaction of the NCN‐pincer platinum phosphonate p‐nitrophenyl ester 2 with cutinase, a 94 % conversion to the protein–pincer metal complex hybrid was obtained in 48 h. The NCN‐pincer metal phosphonic acid derivatives (3, 4) appeared to be inactive as cutinase inhibitors. In contrast to our previous work which entails propyl tethered phosphonate esters connected to pincer metal complexes, the presented strategy allows positioning of metal complexes inside the active site of lipases. This opens up the possibility for fine‐tuning the chemical environment (second coordination sphere) around a synthetic metal center inside the pocket of an enzyme for diagnostic and catalytic purposes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Evaluation of chlorogenic acid and its metabolites as potential antioxidants for fish oils
Authors: De Leonardis Antonella , Pizzella Luciano , Macciola Vincenzo
Published: August 2008

The antioxidant effects on cod liver oil (CLO) of chlorogenic acid (CGA) and its metabolites, caffeic acid (CA) and quinic acid (QA), were investigated. All three chemicals were separately added to CLO at a concentration range of 0.001–0.080 wt‐% and tested by Rancimat. CA was the best antioxidant; its antioxidant effect was directly proportional to the dose added, but only within the concentration range of 0.005–0.050 wt‐%. QA did not show any effect on CLO oxidation, while CGA revealed itself as a weak antioxidant. Cytotoxicity was also evaluated by using murine 3T6 fibroblasts treated for 24 h with CGA, CA and QA at a concentration range of 0.1–5.0 mM. QA did not have an influence on cell proliferation, while CGA and CA showed a significant anti‐proliferative activity already at a concentration of 0.1 mM. Finally, compounds similar to the standard 8‐iso prostaglandin F2α, called CLO‐“isoprostanes”‐like compounds, were isolated. At high temperature (100 and 110 °C) CLO‐“isoprostanes‐like” compounds did not show a relevant pro‐oxidant action on the refined olive oil to which they were added in variable amounts. On the contrary, the CLO‐“isoprostanes”‐like compounds significantly decreased the antioxidant effectiveness of CA. Indeed, at a CLO‐“isoprostanes‐like” compound dose of 300 µg, the antioxidant effectiveness of CA was halved.
First Example of Organocatalysis by Polystyrene‐Supported PAMAM Dendrimers: Highly Efficient and Reusable Catalyst for Knoevenagel Condensations
Authors: Krishnan G. Rajesh , Sreekumar Krishnapillai
Published: August 2008

This paper describes the first use of polystyrene‐supported poly(amidoamine) (PAMAM) dendrimers as heterogeneous basic organocatalysts for carbon–carbon bond formation. Polystyrene‐supported PAMAM dendrimers of first, second and third generations have been used as reusable base catalysts in Knoevenagel condensations of carbonyl compounds with active methylene compounds. The reactions proceed in short periods of time and with 100 % selectivity. This novel catalyst eliminates the use of aromatic and halogenated solvents, as well as complex purification processes. The catalysts can be recycled ten times.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthetic Strategies TowardN‐Functionalized Cyclens
Authors: Suchý Mojmír , Hudson Robert H. E.
Published: August 2008

Cyclen (1,4,7,10‐tetraazadodecane) is a widely used building block in the synthesis of many important molecules with applications spanning MRI contrast agents, fluorescent probes and heavy metals sensors. This review describes the various synthetic methodologies employed for the preparation ofN‐functionalized cyclens such as: synthesis from acyclic precursors; alkylation or acylation of cyclen; and protecting group manipulations. Emphasis is given to synthetic strategies allowing for the selective, differentialN‐functionalization of cyclen which is particularly useful for many modern applications.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Reaction of Carboxylic Acids with Isocyanides: A Mechanistic DFT Study
Authors: Marcelli Tommaso , Himo Fahmi
Published: August 2008

We present a computational investigation of the reaction between isocyanides and carboxylic acids. Our results indicate that this reaction begins with a stereoselective concerted α‐addition of the acid to the isocyanide, leading exclusively to a Z‐acyl imidate. Isomerization to the E isomer and successive rate‐limiting 1,3 O→N acyl migration yields an N‐formyl imide. The calculated barriers are in good agreement with the experimental reaction conditions. Our results might provide an explanation for the peculiar reactivity observed when this reaction is carried out in a self‐assembled capsule. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A novel covalent coupling method for coating of capillaries with liposomes in capillary electrophoresis
Authors: Mei Jie , Xu Jian‐Rong , Xiao Yu‐Xiu , Liao Xiao‐Yan , Qiu Guo‐Fu , Feng Yu‐Qi
Published: August 2008

A novel covalent coupling method for coating of capillaries with liposomes has been developed, which includes three steps: (i) epoxy‐diol coating, (ii) activation with 2,2,2‐trifluoroethanesulfonyl chloride, and (iii) liposome coupling. The coating conditions, such as the reaction time and temperature of liposome coupling, the content of dimyristoylphosphatidylethanolamine in liposomes, were optimized. Vesicles were visualized on the inner silica wall as confirmed by atomic force microscopy. The effectiveness of the coating was demonstrated by investigating the effect of pH of BGE on EOF and separating neutral compounds. The intra‐ and inter‐capillary variations in EOF are 4.02% RSD (n=30) and 6.72% RSD (n=4) respectively, and the coated capillaries can be used to perform analysis at least for one month without any performance deterioration when stored at 4°C. A set of drugs with diverse structures was applied into the developed liposome‐coated CE. The normalized capacity factor (K) was introduced to quantitatively evaluate drug–membrane interactions. The relationship between log K and the fraction dose absorbed in humans (Fa%) shows that the liposome‐coated CE can be utilized for in vitro prediction of Fa% of drugs that follow the transcellular passive transport route.
Enzymatic assay of marine bacterial phosphatases by capillary electrophoresis with laser‐induced fluorescence detection
Authors: Chichester Kimberly D. , Sebastian Marta , Ammerman James W. , Colyer Christa L.
Published: August 2008

Microbial ectoenzyme activities in aquatic environments are important determinants of polymer hydrolysis and indicators of the state of microbial carbon, nitrogen, and phosphorus nutrition. Marine ectoenzymes are found on the cell surface or in the periplasmic space of gram‐negative heterotrophic bacteria. Phosphatases, which remove phosphate groups from substrates, are one example of an ectoenzyme. Enzyme assays based on‐capillary electrophoresis (CE) take advantage of CE's high‐efficiency separation, extremely low sample volume requirements, and its ability to electrophoretically mix and separate zones of enzymes, substrates, and products all in one experimental run. CE has better resolving power and, when utilized with laser‐induced fluorescence (LIF) detection, it is more sensitive than chromatography. CE‐LIF is a promising tool for determining different phosphatases within a single microbial strain as well as the functional diversity between strains. In this study, four bacterial strains were studied (Shewanella sp., TW7, BB2AT2, and Vibrio alginolyticus) with each yielding at least one phosphatase that was kinetically characterized. Km values were calculated and found to be in the range of 0.0725–3.35 µM, whereas Vmax values ranged from 1.02×10−3 to 1.05×10−2 µM/min. The large range of values demonstrates differences among the phosphatases, suggesting different roles for each phosphatase not only between the species but also within a single bacterial species. This can have the important implications for organic matter processing in the sea.
Social influences on foraging behavior in young nonhuman primates: Learning what, where, and how to eat
Authors: Rapaport Lisa G. , Brown Gillian R.
Published: August 2008

Human infants rely on social interactions to acquire food‐related information.1, 2 Adults actively teach children about food through culturally diverse feeding practices. Characteristics we share with the other primates, such as complex diets, highly social lives, and extended juvenile periods, suggest that social learning may be important during ontogeny throughout the order. Although all young primates typically pay attention to feeding adults, great apes and callitrichids, in particular, acquire new foraging techniques through abilities unknown in other nonhuman primates; that is, they learn by imitation. However, ape social learning is almost exclusively infant‐initiated, while adult callitrichids actively teach their young. It is unlikely that the same selective forces have acted to favor sophisticated social‐learning mechanisms in both taxa.3, 4 Equipped with an ape brain, complex foraging methods, and a cooperative infant‐care system, early hominins were uniquely poised to take social learning about food and foraging techniques to a new level.
Effects of pre or posttraining dorsal hippocampus D‐AP5 injection on fear conditioning to tone, background, and foreground context
Authors: Schenberg Eduardo Ekman , Oliveira Maria Gabriela Menezes
Published: August 2008

NMDA receptor antagonist D‐AP5 was injected into the dorsal hippocampus of Wistar rats before or immediately after the training session in fear conditioning. Training was conducted both with signaled (background context) or unsignaled (foreground context) footshocks. Contextual fear conditioning was assessed 24 h later and tone fear conditioning 48 h after training (only in the signaled footshock condition). Pretraining injections impaired conditioned fear to contextual features, both in background and foreground configurations, whereas tone fear conditioning was left intact. Posttraining injections were ineffective in all cases. We conclude that dorsal hippocampal NMDA receptors are required for contextual fear acquisition independently of context saliency and that they are not required to early consolidation processes. © 2008 Wiley‐Liss, Inc.
Hippocampal levels of phosphorylated protein kinase a (phosphor‐S96) are linked to spatial memory enhancement by SGS742
Authors: Sunyer Berta , Shim Ki‐Shuk , An Gunyong , Höger Harald , Lubec Gert
Published: August 2008

Cognitive enhancement by the GABA (B) receptor antagonist SGS742 has been well‐documented, but mechanisms of action are not fully elucidated. Previous work has proposed involvement of somatostatin‐14 and protein kinase C in cognitive enhancement; phospho‐protein kinase A (p‐PKA), fyn, and phospho‐fyn are known signaling systems for spatial memory. It was the aim of the study to determine hippocampal levels of these proteins following SGS742‐treatment and to correlate them with the outcome from the Morris water maze (MWM), represented by the parameter “time spent in the target quadrant” during the probe trial. OF1 mice were used for the experiments and divided into four groups: intraperitoneal SGS742 and saline solution treatment, both, tested in the MWM, and two yoked controls. Six hours following the probe trial, hippocampal protein levels were determined by immunoblotting. In the MWM, time spent in the target quadrant was significantly enhanced by SGS742 treatment. p‐PKA levels were significantly increased only in the SGS742‐treated group tested in the MWM as compared to saline treatment. In yoked controls, no significant differences in p‐PKA levels between SGS742 and saline treatment were observed. Somatostatin‐14 levels were significantly increased in both SGS742‐treated groups. No statistically significant changes of other protein levels were observed. We propose that GABA (B) antagonism represented by SGS742 treatment led to cognitive enhancement involving p‐PKA, because yoked controls treated with SGS742 were comparable to yoked saline‐treated controls. The finding that somatostatin‐14 was also induced in the SGS742‐treated yoked controls points to a drug side effect, and therefore the role of somatostatin‐14 for cognitive enhancement remains open. © 2008 Wiley‐Liss, Inc.
The protein kinase C phosphorylation site on GAP‐43 differentially regulates information storage
Authors: Holahan Matthew , Routtenberg Aryeh
Published: August 2008

Protein kinase C (PKC) is known to regulate phosphorylation of substrates such as MARCKS, GAP‐43, and the NMDA receptor, all of which have been linked to synaptic plasticity underlying information storage processes. Here we report on three transgenic mice isoforms differentiated both by mutation of the PKC site on GAP‐43 as well as by their performance in three learning situations: (1) a radial arm maze task, which evaluates spatial memory and its retention, (2) fear conditioning which assesses contextual memory, and (3) the water maze which also evaluates spatial memory and its retention. The present results show, for the first time to our knowledge, that the phosphorylation state of a single site on an identified brain growth‐ and plasticity‐associated protein differentially regulates performance of three different memory‐associated tasks. © 2008 Wiley‐Liss, Inc.
The human hippocampus at 7 T—In vivo MRI
Authors: Theysohn Jens M. , Kraff O. , Maderwald S. , Schlamann M.U. , de Greiff A. , Forsting M. , Ladd S.C. , Ladd M.E. , Gizewski E.R.
Published: August 2008

The human hippocampus plays a central role in various neuropsychiatric disorders, such as temporal lobe epilepsy (TLE), Alzheimer's dementia, mild cognitive impairment, and schizophrenia. Its volume, morphology, inner structure, and function are of scientific and clinical interest. Magnetic resonance (MR) imaging is a widely employed tool in neuroradiological workup regarding changes in brain anatomy, (sub‐) volumes, and cerebral function including the hippocampus. Gain in intrinsic MR signal provided by higher field strength scanners and concomitant improvements in spatial resolution seem highly valuable. An examination protocol permitting complete, high‐resolution imaging of the human hippocampus at 7 T was implemented. Coronal proton density, T2, T2*, and fluid‐attenuated inversion recovery contrasts were acquired as well as an isotropic 3D magnetization‐prepared rapid acquisition gradient‐echo (500 μm isotropic voxel dimension, noninterpolated). Observance of energy deposition restrictions within acceptable scan times remained challenging in the acquisition of thin, spin‐echo‐based sections. At the higher resolution enabled by 7 T, demarcation of the hippocampus and some internal features including gray/white matter differentiation and depiction of the hippocampal mantle becomes much more viable when compared with 1.5 T; thus, in the future, this imaging technology might help in the diagnosis of subtle hippocampal changes. © 2008 Wiley‐Liss, Inc.
Modulation of AMPA receptor‐mediated ion current by pituitary adenylate cyclase‐activating polypeptide (PACAP) in CA1 pyramidal neurons from rat hippocampus
Authors: Costa L. , Santangelo F. , Li Volsi G. , Ciranna L.
Published: August 2008

Pituitary adenylate cyclase‐activating polypeptide (PACAP), a neurotrophic and neuromodulatory peptide, was recently shown to enhance NMDA receptor‐mediated currents in the hippocampus (Macdonald, et al. 2005. J Neurosci 25:11374–11384). To check if PACAP might also modulate AMPA receptor function, we tested its effects on AMPA receptor‐mediated synaptic currents on CA1 pyramidal neurons, using the patch clamp technique on hippocampal slices. In the presence of the NMDA antagonist D‐AP5, PACAP (10 nM) reduced the amplitude of excitatory postsynaptic currents (EPSCs) evoked in CA1 pyramidal neurons by stimulation of Schaffer collaterals. Following a paired‐pulse stimulation protocol, the paired‐pulse ratio was unaffected in most neurons, suggesting that the AMPA‐mediated EPSC was modulated by PACAP mainly at a postsynaptic level. PACAP also modulated the currents induced on CA1 pyramidal neurons by applications of either glutamate or AMPA. The effects of PACAP were dose‐dependent: at a 0.5 nM dose, PACAP increased AMPA‐mediated current; such effect was blocked by PACAP 6–38, a selective antagonist of PAC1 receptors. The enhancement of AMPA‐mediated current by PACAP 0.5 nM was abolished when cAMPS‐Rp, a PKA inhibitor, was added to the intracellular solution. At a 10 nM concentration, PACAP reduced AMPA‐mediated current; such effect was not blocked by PACAP 6–38. The inhibitory effect of 10 nM PACAP was mimicked by Bay 55–9837 (a selective agonist of VPAC2 receptors), persisted in the presence of intracellular BAPTA and was abolished by intracellular cAMPS‐Rp. Stimulation‐evoked EPSCs in CA1 neurons were significantly reduced following application of the PAC1 antagonist PACAP 6–38; this result indicates that PAC1 receptors in the CA1 region are tonically activated by endogenous PACAP and enhance CA3‐CA1 synaptic transmission. Our results show that PACAP differentially modulates AMPA receptor‐mediated current in CA1 pyramidal neurons by activation of PAC1 and VPAC2 receptors, both involving the cAMP/PKA pathway; the functional significance will be discussed in light of the multiple effects exerted by PACAP on the CA3‐CA1 synapse at different levels. © 2008 Wiley‐Liss, Inc.
Acidosis induces multi‐drug resistance in rat prostate cancer cells (AT1) in vitro and in vivo by increasing the activity of the p‐glycoprotein via activation of p38
Authors: Sauvant Christoph , Nowak Martin , Wirth Claudia , Schneider Bettina , Riemann Anne , Gekle Michael , Thews Oliver
Published: August 2008

Because solid growing tumors often show hypoxia and pronounced extracellular acidosis, the aim of this study was to analyze the impact of an acidotic environment on the activity of the p‐glycoprotein (pGP) and on the cellular content and cytotoxicity of the chemotherapeutic drug daunorubicin in the AT1 R‐3327 Dunning prostate carcinoma cell line cultured in vitro and in vivo. In vitro, extracellular acidosis (pH 6.6) activated p38 and ERK1/2 and thereby induced daunorubicin resistance via a pronounced activation of pGP. De‐novo protein synthesis was not necessary and analysis of transport kinetics indicated a fast and persistent pGP activation at pH 6.6 (when compared with 7.4). Intracellular acidification also induced daunorubicin resistance via activation of pGP, which was mediated by activation of p38 alone. In vivo, tumors were implanted subcutaneously, and the tumor pH was artificially lowered by forcing anaerobic metabolism. In vivo, the reduced extracellular pH of 6.6 was also able to induce daunorubicin resistance, which was abolished by inhibition of p38. These results suggest that pGP activity is dependent on extracellular pH in vitro and in vivo. Moreover, there is strong indication that this effect is mediated via activation of p38 in vivo. Activation of ERK is also suitable to induce pGP activity. Therefore, inhibition of p38 (and ERK) may be used to prevent acidosis induced increase in pGP activity and thereby attenuate multidrug resistance. In addition, supportive treatments reducing tumor acidosis may improve the cytotoxic effect of chemotherapeutic drugs. © 2008 Wiley‐Liss, Inc.
Activating transcription factor 4 is critical for proliferation and survival in primary bone marrow stromal cells and calvarial osteoblasts
Authors: Zhang Xiaoyan , Yu Shibing , Galson Deborah L. , Luo Min , Fan Jie , Zhang Jian , Guan Youfei , Xiao Guozhi
Published: August 2008

Activating transcription factor 4 (ATF4) is essential for bone formation. However, the mechanism of its actions in bone is poorly understood. The present study examined the role for ATF4 in the regulation of proliferation and survival of primary mouse bone marrow stromal cells (BMSCs) and osteoblasts. Results showed that Atf4−/− cells display a severe proliferative defect as measured by multiple cell proliferation assays. Cell cycle progression of Atf4−/− BMSCs was largely delayed with significant G1 arrest. Expression of cyclin D1 was decreased both at the mRNA and protein level. A similar proliferation defect was observed in Atf4−/− calvarial periosteal osteoblasts when compared with wt control. Knocking down Atf4 mRNA by small interfering RNA in MC3T3‐E1 subclone 4 preosteoblasts markedly reduced expression of cyclin D1 and cell proliferation. In contrast, overexpression of ATF4 increased cyclin D1 expression as well as cell proliferation in Atf4−/− BMSCs. In addition, apoptosis was significantly increased in Atf4−/− BMSCs and calvarial periosteal osteoblasts relative to wt controls. Taken together, these results for the first time demonstrate that ATF4 is a critical regulator of proliferation and survival in BMSCs and osteoblasts in vitro and in vivo. J. Cell. Biochem. 105: 885–895, 2008. © 2008 Wiley‐Liss, Inc.
Gaussian basis set of double zeta quality for atoms K through Kr: Application in DFT calculations of molecular properties
Authors: Camiletti G. G. , Machado S. F. , Jorge F. E.
Published: August 2008

Contracted basis sets of double zeta (DZ) quality for the atoms from K to Kr are presented. They were determined from fully optimized basis sets of primitive Gaussian‐type functions generated in atomic Hartree‐Fock calculations. Sets of Gaussian polarization functions optimized at the Möller‐Plesset second‐order level were added to the DZ basis set. This extends earlier work on segmented contracted DZ basis set for atoms H‐Ar. From this set, using the BP86 nonhybrid and B3LYP hybrid functionals, dissociation energy, geometric parameters, harmonic vibrational frequency, and electric dipole moment of a set of molecules were calculated and compared with results obtained with other basis sets and with experimental data reported in the literature. In addition, 57Fe and 77Se nuclear magnetic resonance chemical shifts in Fe(C5H5)2, H2Se, and CSe2 were calculated using density functional theory and gauge‐including atomic orbitals and, then, compared with theoretical and experimental values previously published in the literature. Except for chemical shift, one verifies that our results give the best agreement with experimental and benchmark values. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008