bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic characterization of polygenic type 2 diabetes in TALLYHO/JngJ mice
Authors: Kim Jung Han , Stewart Taryn P , Soltani-Bejnood Morvarid , Wang Luan , Fortuna Jennifer M , Mostafa Ola A , Moustaid-Moussa Naima , Shoieb Ahmed M , McEntee Michael F , Wang Yun , Bechtel Lawrence , Naggert Jürgen K
Published: November 2006

The TALLYHO/JngJ (TH) strain is a newly established, polygenic mouse model for type 2 diabetes (T2D) and obesity, and we have previously reported some key physiological features of this model after the overt onset of diabetes. In the present work, we conducted a comprehensive phenotypic characterization of TH in order to completely characterize this new and relevant model for human T2D and obesity. We monitored the development of obesity and diabetes starting at 4 weeks of age by measuring body weight, glucose tolerance, and plasma levels of insulin, glucose, and triglyceride. Additionally, histological alterations in the pancreas and glucose uptake and glucose transporter 4 (GLUT4) content in soleus muscle were also examined. Compared with age- and sex-matched C57BL/6J (B6) mice, both male and female TH mice were significantly heavier, hyperleptinemic, and hyperinsulinemic at 4 weeks of age, without glucose intolerance or hyperglycemia. TH mice maintained higher body weights throughout the study period of 16 weeks. The hyperinsulinemia in TH mice worsened with age, but to a lesser degree in females than in males. Both the male and the female TH mice had enlarged pancreatic islets. Male TH mice showed impaired glucose tolerance at 8 weeks that became more prominent at 16 weeks. Plasma glucose levels continuously increased with age in male TH mice resulting in frank diabetes, while female TH mice remained normoglycemic throughout the study. Impaired glucose tolerance and hyperglycemia in male TH mice were accompanied by impaired 2-deoxyglucose uptake in the soleus muscle at basal and insulin-stimulated states, but without any reduction in GLUT4 content. Interestingly, male TH mice exhibited a drastic elevation in plasma triglyceride levels in the pre-diabetic stage that was maintained throughout the study. These findings suggest that obesity and insulin resistance are an inherent part of the TH phenotype and glucose intolerance is evident preceding progression to overt diabetes in male TH mice.
Intestinal inflammation modulates expression of 11β-hydroxysteroid dehydrogenase in murine gut
Authors: Vagnerová K , Kverka M , Klusoňová P , Ergang P , Mikšík I , Tlaskalová-Hogenová H , Pácha J
Published: November 2006

The effect of glucocorticoids is controlled at the pre-receptor level by the activity of 11β-hydroxysteroid dehydrogenase (11HSD). The isoform 11HSD1 is an NADP+-dependent oxidoreductase, usually reductase, that amplifies the action of glucocorticoids due to reduction of the biologically inactive 11-oxo derivatives cortisone and 11-dehydrocorticosterone to cortisol and corticosterone. The NAD+-dependent isoform (11HSD2) is an oxidase that restrains the effect of hormones due to 11β-oxidation of cortisol and corticosterone to their 11-oxo derivatives. Although the immunosuppressive and anti-inflammatory effects of glucocorticoids are well known, the relationship between inflammation and local metabolism of glucocorticoids is not well understood. In this study, we demonstrated that colitis induced by dextran sulfate sodium modulates colonic 11HSD1. Experimentally induced intestinal inflammation stimulated colonic NADP+-dependent but not NAD+-dependent 11HSD activity. Colonic 11HSD1 mRNA was increased, whereas 11HSD2 mRNA was not changed. Additional parallel studies revealed a similar pattern of 11HSD1 mRNA induction in mesenteric lymph nodes and intestinal intraepithelial lymphocytes, but not in spleen and peritoneal macrophages. These data suggest that inflammation modulates local metabolism of glucocorticoid and support the notion that pre-receptor regulation of endogenous corticosteroids might play a role in inflammatory processes.
Angiotensin II regulates migration in mouse cultured mesangial cells: evidence for the presence of receptor subtype-specific regulation
Authors: Takeuchi Yuichiro , Yamauchi Keishi , Nakamura Junko , Shigematsu Satoshi , Hashizume Kiyoshi
Published: November 2006

The biological effects of angiotensin II (AngII) are mediated by two major subtypes of AngII receptors, type 1 (AT1R) and type 2 (AT2R). In this study, we attempted to elucidate the role of AngII subtype receptor-specific regulation in migration and proliferation of mouse cultured mesangial (MSG) cells. We found that 100 nM AngII stimulated weak migration of MSG cells. Cell motility increased more in the presence of AT2R than in the presence of AT1R, and it was suppressed by guanylate cyclase inhibitors. On the other hand, the activation of AT1R resulted in increased cell numbers, while AT2R activation inhibited cell proliferation. Moreover, high concentrations of glucose (25 mM) stimulated the expression of AT2R but not AT1R. These results indicate that there are receptor subtype-specific roles in MSG cells, and it is therefore possible that the activation of AT2R stimulates repair of glomerular tissue defect, by regulation of migration and proliferation of MSG cells. Taken together, these results suggest that the relative concentrations of AT1R and AT2R are important factors in the regulation of AngII function in glomerular tissue, and alterations in the concentrations of these receptors may contribute to progression of or protection from diabetic nephropathy.
Prolactin affects leptin action in the bovine mammary gland via the mammary fat pad
Authors: Feuermann Y , Mabjeesh S J , Niv-Spector L , Levin D , Shamay A
Published: November 2006

One of the roles of the endocrine system is to synchronize mammary function. Hormones, such as estrogen, progesterone, and prolactin act directly on the mammary gland. Metabolic hormones, such as GH, glucocorticoids, insulin, and leptin are responsible for coordinating the body’s response to metabolic homeostasis. Leptin has been shown to be an important factor in regulating the metabolic adaptation of nutrient partitioning during the energy-consuming processes of lactation. In the present study, we show that leptin is secreted from the mammary fat, and is regulated by prolactin. The expression of α-casein in a co-culture of epithelial cells and fat explants was enhanced by prolactin compared with that in epithelial cells cultured alone. Leptin antagonist abolished the effect of leptin on α-casein expression in mammary gland explants when exogenous leptin was not present in the medium. This finding supports our hypothesis that the antagonist abolishes the action of endogenous leptin secreted by the mammary adipocytes. These results lead us to the hypothesis that prolactin and leptin act in the bovine mammary gland, via mammary fat pad/adipocytes.
Valproic acid, a histone deacetylase inhibitor, enhances sensitivity to doxorubicin in anaplastic thyroid cancer cells
Authors: Catalano Maria G , Fortunati Nicoletta , Pugliese Mariateresa , Poli Roberta , Bosco Ornella , Mastrocola Raffaella , Aragno Manuela , Boccuzzi Giuseppe
Published: November 2006

Multimodality treatments (i.e. surgery, chemotherapy, and radiotherapy) are recommended for anaplastic thyroid carcinoma (ATC), an extremely lethal human cancer, but to date there is little evidence that such approaches improve survival rates. It is thus necessary to seek new therapeutic tools. Histone deacetylase (HDAC) inhibitors are a promising class of anti-neoplastic agents that induce differentiation and apoptosis. Moreover, they may enhance the cytotoxicity of drugs targeting DNA through acetylation of histones. Using two ATC cell lines (CAL-62 and ARO), we show here that valproic acid (VPA), a clinically available HDAC inhibitor, enhances the activity of doxorubicin, whose anti-tumor properties involve binding to DNA and inhibiting topoisomerase II. A meager 0.7 mM VPA, which corresponds to serum concentrations in patients treated for epilepsy, is able to increase the cytotoxicity of doxorubicin about threefold in CAL-62 cells and twofold in ARO cells. The sensitizing effect, which is through histone acetylation, involves increased apoptosis, which is also shown by the increased caspase 3 activation and the enhancement of doxorubicin-induced G2 cell cycle arrest. These results might offer a rationale for clinical studies of a new combined therapy in an effort to improve the outcome of patients with anaplastic thyroid cancer.
Anti-apoptotic effects of 3,5,3′-tri-iodothyronine in mouse hepatocytes
Authors: Sukocheva O A , Carpenter D O
Published: November 2006

The present study demonstrates that 3,5,3′-tri-iodothyronine (T3) in physiological dose range inhibits tumor necrosis factor α(TNFα)/Fas-induced apoptosis in mouse hepatocytes. T3 pretreatment prevented Fas-induced early stage of apoptosis signs assessed by flow cytometry analysis of the annexin V positive cell population. T3 attenuated TNFα/Fas-induced cleavage of caspase-8 and DNA fragmentation. We found that T3 exerted its anti-apoptotic effects by mobilization of several non-genomic mechanisms independent of transcriptional activity. Inhibition of protein kinase A (PKA), extracellular signal-regulated kinase (ERK), and Na+/H+ exchanger blocked T3-dependent anti-apoptotic effects indicating an involvement of these intracellular targets into T3-induced signaling cascade. Furthermore, physiological concentrations of T3, but not reverse T3, caused increases in intracellular cAMP content and activated PKA. T3 markedly induced phosphorylation of ERK. We also detected T3-dependent intracellular alkalinization that abolished TNFα-induced acidification. PKA inhibitor KT-5720 blocked T3-induced activation of ERK and intracellular alkalinization confirming the upstream position of PKA signaling. We further detected that hepatocytes from hypothyroid mice are more sensitive to TNFα/Fas-induced apoptosis than euthyroid animals in vivo. Together, these findings imply that T3 triggers PKA- and ERK-regulated intracellular pathways capable of driving and ensuring hepatocytes survival in the presence of death receptor ligand-induced damage under chronic inflammatory conditions.
Explorative Kinetic Study on the Thermal Degradation of Five Wood Species for Applications in the Archaeological Field
Authors: Vecchio Stefano , Luciano Giorgio , Franceschi Enrico
Published: November 2006

Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) were performed on wood samples of different essences (fir, chestnut, poplar, linden and oak) before consolidation. A kinetic analysis was applied on the two‐steps decomposition processes occurring in all wood samples using either the multi‐heating rates Kissinger equation and the isoconversional Ozawa‐Flynn‐Wall method that enables the variation of activation energy to be determined as a function of the degree of reaction. Taking into account both decomposition temperature and activation energy for the first degradation step oak seems to be the less stable sample. The comparison of DSC curves performed in air with those in oxygen enables to consider the role of the partial pressure of oxygen in the mechanisms of both decompositions.
Heavy Metals in Marine Sediments from the Mar Piccolo of Taranto (Ionian Sea, Southern Italy)
Authors: Cardellicchio Nicola , Buccolieri Alessandro , di Leo Antonella , Spada Lucia
Published: November 2006

Heavy metals concentrations (Cd, Cu, Hg, Pb, Sn and Zn) have been determined monthly in surface sediments from the Mar Piccolo in Taranto (Ionian Sea, Southern Italy. a semi‐enclosed marine basin very important from a mussel‐culture point of view. In sediments, sulphides, percentage of organic carbon and redox potential were also determined to show possible correlations between metals levels and redox characteristics of marine sediments. Analytical results, elaborated by multivariate statistical techniques, confirm that sediments collected in the first inlet of Mar Piccolo, where shipbuilding activities are present, have a contamination level greater than those collected in the second inlet. For each metal, the geoaccumulation index (Igeo) has been calculated as criterion to evaluate both pollution levels and metals enrichment in examined sediments: Igeo values confirm that the first inlet is an moderately polluted area from Hg and Pb. In any case, high sulphide concentrations and negative values of redox potentials bring to a conclusion that metals are present in sediments, mainly as insoluble sulphides and then as not bioavailable compounds for filter feeders organisms such as mussels.
Simultaneous Determination of Arsenic, Selenium and Mercury in Foodstuffs by Chemical Vapour Generation Inductively Coupled Plasma Optical Emission Spectroscopy
Authors: Grotti Marco , Lagomarsino Cristina , Magi Emanuele
Published: November 2006

A procedure for the simultaneous determination of arsenic, selenium and mercury in foodstuffs has been developed. After a two‐step microwave‐assisted wet digestion in closed vessels, using concentrated nitric acid and hydrogen peroxide, the solution was analysed by inductively coupled plasma multichannel‐based emission spectrometry using chemical vapour generation as the sample introduction system. All steps of the procedure, such as solid sample dissolution, pre‐reduction to the suitable oxidation state, vapor generation, transport and atomization have been designed and optimised taking into account the concomitant presence of all the analytes considered. Temporal variation of analytical signals as well as interfering effects due to transition elements were also studied. Under the optimised operating conditions, the achieved detection limits for the simultaneous determination of arsenic, selenium and mercury in foodstuffs were 0.006, 0.023 and 0.018 μg g−1, respectively, allowing their determination in real samples. Precision of the analytical procedure was 6.8% for arsenic, 5.2% for selenium and 7.7% for mercury (n=7). The accuracy and reliability of the method was verified by the analysis of both standard reference materials (rice flour and spinach leaves) and real samples (natural and Se‐enriched rice).
Inhibitory and enhancing effects of piroxicam on whole blood chemiluminescence
Authors: Alexandrova Margarita L. , Bochev Petyo G. , Markova Vanya I.
Published: November 2006

The effects of piroxicam on the production of reactive oxygen species by stimulated phagocytes was studied in whole blood by a chemiluminescence (CL) technique in relation to maximum activity, localization and kinetics of radical generation. We found that piroxicam dose‐dependently inhibited total (intra‐ and extracellular) zymosan‐stimulated luminol CL (LCL) at a high stimulant concentration (p = 0.0001). Piroxicam additionally decreased cytochalasin B‐reduced LCL, which shows that the effect of the drug should be sought in the extracellular component of the response. Piroxicam inhibited the first phase of extracellular LCL in a dose‐dependent manner (p = 0.0001) and revealed itself as an enhancing agent of CL in later time intervals after the start of respiratory burst, in a model system containing horseradish peroxidase (HRP) and sodium azide. It enhanced LCL of a cell‐free system, i.e. influenced the CL due to HRP‐catalysed decomposition of hydrogen peroxide. It also dose‐dependently inhibited the early extracellular superoxide production, evaluated by lucigenin CL (p = 0.022). Piroxicam inhibited the total fMLP‐stimulated LCL by 70% approximately and, only by about 30%, the first phase of fMLP‐stimulated extracellular LCL, which presupposes an effect on myeloperoxidase‐catalysed formation of hypochloric acid. Piroxicam slightly increased the intracellular LCL by phagocytes (p = 0.02), an effect that is probably connected with its ability to induce the release of secondary messengers in signal transduction. In conclusion, the anti‐inflammatory effect of piroxicam is probably related to the inhibition of the extracellular generation of superoxide and hypochloric acid in the early stages of phagocyte activation. Copyright © 2006 John Wiley & Sons, Ltd.
Studies on PVP hydrogel‐supported luminol chemiluminescence: 2. Luminometer calibration and potential analytical applications
Authors: Bastos Erick Leite , Ciscato Luiz Francisco Monteiro Leite , Bartoloni Fernando Heering , Catalani Luiz Henrique , Romoff Paulete , Baader Wilhelm Josef
Published: November 2006

The use of poly(N‐vinyl‐2‐pyrrolidone) (PVP) hydrogel‐supported luminol chemiluminescence (CL) for the automatic determination of hydrogen peroxide and the quantification of the antiradical capacity of Trolox is described. The hydrogel containing luminol and hemin is prepared directly on a 96‐well microplate and can be stored for up to 3 months without significant decrease in CL quantum yields. Furthermore, this system can also be used as a secondary light standard for the calibration of microplate luminometers. Copyright © 2006 John Wiley & Sons, Ltd.
Generation of a new red fluorescent condensed hetero‐aromatic compound: 7,20‐dimethyl‐7,20‐dihydro‐7,20‐diaza‐naphto[a]dibenzo[j,q]perylene
Authors: Fukai Takeshi , Kimura Masaru
Published: November 2006

A coupling reaction of 5‐methylbenz[b]acridin‐12(5H)‐one (MBA) with Zn and TiCl4 provided a red fluorescent (FL) compound, as opposed to 5,5′‐dimethyl‐12,12′‐bibenzo[b]acridylidene (DMBBA), probably through photochemical cyclization and aromatization by dehydrogenation of the overcrowded intermediate DMBBA. The structure of the red FL compound was assigned to 7,20‐dimethyl‐7,20‐dihydro‐7,20‐diaza‐naphto[a]dibenzo[j,q]perylene (DANDBP) and the fluorescence efficiency for DANDBP was determined to be 0.23 ± 0.01. Copyright © 2006 John Wiley & Sons, Ltd.
Fermentation process tracking through enhanced spectral calibration modeling
Authors: Triadaphillou Sophia , Martin Elaine , Montague Gary , Norden Alison , Jeffkins Paul , Stimpson Sarah
Published: November 2006

The FDA process analytical technology (PAT) initiative will materialize in a significant increase in the number of installations of spectroscopic instrumentation. However, to attain the greatest benefit from the data generated, there is a need for calibration procedures that extract the maximum information content. For example, in fermentation processes, the interpretation of the resulting spectra is challenging as a consequence of the large number of wavelengths recorded, the underlying correlation structure that is evident between the wavelengths and the impact of the measurement environment. Approaches to the development of calibration models have been based on the application of partial least squares (PLS) either to the full spectral signature or to a subset of wavelengths. This paper presents a new approach to calibration modeling that combines a wavelength selection procedure, spectral window selection (SWS), where windows of wavelengths are automatically selected which are subsequently used as the basis of the calibration model. However, due to the non‐uniqueness of the windows selected when the algorithm is executed repeatedly, multiple models are constructed and these are then combined using stacking thereby increasing the robustness of the final calibration model. The methodology is applied to data generated during the monitoring of broth concentrations in an industrial fermentation process from on‐line near‐infrared (NIR) and mid‐infrared (MIR) spectrometers. It is shown that the proposed calibration modeling procedure outperforms traditional calibration procedures, as well as enabling the identification of the critical regions of the spectra with regard to the fermentation process. Biotechnol. Bioeng. 2007;97: 554–567. © 2006 Wiley Periodicals, Inc.
Thoracic aorta endografts: Variations in practice among medical specialists
Authors: Eggebrecht Holger , Pamler Reinhard , Zipfel Burkhart , Herold Ulf , Chavan Ajay , Rehders Tim C. , Nienaber Christoph A. , Hetzer Roland , Jakob Heinz G. , Mehta Rajendra H. , Erbel Raimund
Published: November 2006

Background:

Endovascular stent‐graft placement is emerging as a novel treatment option for patients with diseases of the descending thoracic aorta. However, currently no consensus guidelines exist to direct uniformity in stent‐graft procedures as well as for pre‐ and postprocedural patient management, unlike that for the management of other cardiovascular disorder. Accordingly, the aim of the present survey was to assess variations in thoracic aortic stent‐graft practice among different subspecialties in Germany.

Methods:

An interdisciplinary questionnaire survey was conducted among 206 departments of vascular surgery, radiology, cardiology, and cardiothoracic surgery in Germany that actively performed aortic stent‐graft placement. Data on preoperative procedure planning, logistics, practical/technical issues of stent‐graft placement, and postoperative patient management were evaluated using a standardized, self‐administered questionnaire comprising 29 items. Responses were tabulated for analysis.

Results:

Of a total of 206 questionnaires, 184 (89.3%) were returned with 71 (38.5%) centers reporting to have performed thoracic aortic stent‐graft placement (total number of procedures 2,267) through 1997 and 2003. The average number of stent‐graft procedures per year was 7.4 (25–75% percentile, 2.05–10.75) at participating sites, with 49% of the respondents reporting <5 procedures per year. Treatment of thoracic aortic aneurysms was the predominant indication for stent‐graft placement, followed by type B‐dissection. As anticipated, marked variability existed among the different medical specialties performing stent‐graft procedures with respect to all aspects of the procedures including indication for treatment, choice of preoperative and intraoperative imaging modalities, technical equipment and perioperative management. The only consistent agreement was on the need for lifelong follow‐up after stent‐graft placement, with CT being the preferred imaging technique (90% of centers).

Conclusion:

The present survey documents an increasing adoption of endovascular stent‐graft placement for patients with diseases of the descending thoracic aorta in Germany. Despite this, there is a lack of consensus among the different medical specialties performing stent‐graft placement with respect to indications and technical execution of stent‐grafting. Our data supports the need for consensus practice guidelines endorsed by medical professional societies for stent‐graft procedure to standardize the growing number of thoracic stent graft procedures. © 2006 Wiley‐Liss, Inc.
Manipulation of the Morphology of Semiconductor‐Based Nanostructures from Core–Shell Nanoparticles to Nanocables: The Case of CdSe/SiO2
Authors: Wang Zhenyang , Lu Qifei , Kong Mingguang , Zhang Lide
Published: November 2006

The morphology of CdSe/SiO2 was manipulated from core–shell‐structured nanoparticles to nanocables by using a chemical vapor deposition (CVD) process. The growth of nanocables, with cores no more than 20 nm in diameter, is initiated by the formation of core–shell nanoparticles with SiO2 as matrix and CdSe clusters dispersed inside. After the subsequent vaporization of the SiO2 matrix, the follow‐up CdSe vapor crystallizes with the remaining CdSe clusters as nuclei to form CdSe nanowires as the furnace was cooled to 1200 °C. During the controlled cooling of the furnace, the SiO vapor re‐deposits to sheathe the nanowires. The thickness of the shell and the diameter of core were successfully controlled. The photoluminescence measurements show that the CdSe/SiO2 nanocables have strong visible‐light emission bands located at 590 and 688 nm, which are attributed to the defects induced by SiO2 sheaths nanowires and the quantum confinement effect of the CdSe, respectively. The UV/Vis absorption spectra of the naked CdSe nanowires further validate the above‐mentioned quantum confinement effect. The deterministic growth of these nanocables is very important for the design of the nanodevices based on them.
Structural, Solid‐State NMR and Theoretical Studies of the Inverse‐Coordination of Lithium Chloride Using Group 13 Phosphide Hosts
Authors: Duer Melinda J. , García Felipe , Goodman Jonathan M. , Hehn Jörg P. , Kowenicki Richard A. , Naseri Vesal , McPartlin Mary , Stead Matthew L. , Stein Robin , Wright Dominic S.
Published: November 2006

The reaction of MeAlCl2 with ′PhPLi2′ in THF gives [{MeAl(PPh)3Li4⋅3 THF}4(μ4‐Cl)]−Li+ (1). The GaIII and InIII analogues, [{MeE(PPh)3Li4⋅3 THF}4(μ4‐Cl)]−Li+⋅(THF)3 (E=Ga (2), In (3)), are obtained by the in situ reactions of MeECl2 with PhPLi2 in THF. For all of the complexes, the cage anions have an unusual cubic arrangement that is similar to a zeolite, and contain large voids (ca. 17 Å). The location of the Li+ counterions in 1–3 and their coordination environment appears to subtly reflect variations in packing and lattice energy. Whereas in 1 highly mobile, loosely coordinated Li+ counterions are present, 2 and 3 contain less mobile THF‐solvated counterions within the cavities. X‐ray crystallographic and solid‐state NMR studies are reported on 1–3, together with model DFT calculations on the selectivity of halide coordination.
Polystyrene‐supported N‐sulfonylated amino alcohols and their applications to titanium(IV) complexes catalyzed enantioselective diethylzinc additions to aldehydes
Authors: Hui Xin‐Ping , Chen Chien‐An , Wu Kuo‐Hui , Gau Han‐Mou
Published: November 2006

Crosslinked polystyrene‐supported resins 4, 7a, and 7b containing N‐sulfonylated β‐amino alcohol in 98, 20, and 40% loadings are prepared. Asymmetric diethylzinc additions to benzaldehyde employing titanium complexes of 10 mol % resins 4, 7a, or 7b are examined and the best performed 7a/Ti(O‐i‐Pr)4 catalytic system applies to various aldehydes to afford desired secondary alcohols in excellent enantioselectivities up to 95% ee. The resin 7a is reused five times, giving the product with enantioselectivities ≥86% ee and an 81% ee is obtained when the resin is used the sixth time. The used resin 7a is refreshed with 1 M HCl and the asymmetric reaction employing the regenerated resin 7a gives the product in 88% ee. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Combining regio‐ and enantioselectivity of lipases for the preparation of (R)‐4‐chloro‐2‐butanol
Authors: Méndez Jonh J. , Oromi Mireia , Cervero Maria , Balcells Mercè , Torres Mercè , Canela Ramon
Published: November 2006

Preparation of 98% ee (R)‐4‐chloro‐2‐butanol was carried out by the enzymatic hydrolysis of chlorohydrin esters, using fungal resting cells and commercial enzymes. Hydrolyzes were carried out using lipases from Candida antarctica (Novozym 435®), C. rugosa, Rhizomucor miehei (Lipozyme® IM), Burkolia cepacia, and resting cells of Rhizopus oryzae and Aspergillus flavus. The influence of the enzyme, the solvent, the temperature, and the alkyl chain length on the selectivity of hydrolyzes of isomeric mixtures of chlorohydrin esters is described. Regioselectivity was higher than 95% for some of the tested lipases. Novozym 435 allowed preparation of the (R)‐4‐chloro‐2‐butanol after 15 min of reaction at 30–40°C. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Defining and Measuring Optical Frequencies: The Optical Clock Opportunity— And More (Nobel Lecture)
Authors: Hall John L.
Published: November 2006

Four long‐running currents in laser technology met and merged in 1999–2000. Two of these were the quest toward a stable repetitive sequence of ever‐shorter optical pulses and, on the other hand, the quest for the most time‐stable, unvarying optical frequency possible. The marriage of ultrafast‐ and ultrastable lasers was brokered mainly by two international teams and became exciting when a special “designer” microstructure optical fiber was shown to be nonlinear enough to produce “white light” from the femtosecond laser pulses, such that the output spectrum embraced a full optical octave. Then, for the first time, one could realize an optical frequency interval equal to the comb’s lowest frequency, and count out this interval as a multiple of the repetition rate of the femtosecond pulse laser. This “gear‐box” connection between the radiofrequency standard and any/all optical frequency standards came just as sensitivity‐enhancing ideas were maturing. The four‐way union empowered an explosion of accurate frequency measurement results in the standards field and prepared the way for refined tests of some of our cherished physical principles, such as the time‐stability of some of the basic numbers in physics (e.g. the “fine‐structure” constant, the speed of light, certain atomic mass ratios), and the equivalence of time‐keeping by clocks based on different physics. The stable laser technology also allows time‐synchronization between two independent femtosecond lasers so exact they can be made to appear as if the source were a single laser. By improving pump–probe experiments, one important application will be in bond‐specific spatial scanning of biological samples. This next decade in optical physics should be a blast!
Synthesis of the Chiral Side Chain of Statins – Lactone versus Lactol Pathway
Authors: Tararov Vitali I. , Andrushko Natalia , Andrushko Vasyl , König Gerd , Spannenberg Anke , Börner Armin
Published: November 2006

4‐O‐Protected (4R,6S)‐4‐hydroxy‐6‐(hydroxymethyl)tetrahydropyran‐2‐ones (3) derived from enantiomerically pure (3R,5S)‐3‐hydroxy‐5,6‐(isopropylidenedioxy)hexanoates (2) are frequently considered as pivotal intermediates for the synthesis of pharmacologically important statins. Remarkably, up to now no proof for this assumption can be derived from the literature. Our study revealed that only silyl‐type protecting groups can be successfully employed for 3‐O‐protection of initial ethyl (3R,5S)‐3‐hydroxy‐5,6‐(isopropylidenedioxy)hexanoate (1). After cyclization, hydroxy lactone 3b was transformed into tosylate 5b and successively into iodide 6b. The latter was converted into phosphonate 9b. All stereochemical assignments and the diastereomerical purity of the intermediates were confirmed by an X‐ray structural analysis of tosylate 5b. Surprisingly, neither tosylate 5b nor iodide 6b could be converted into corresponding nitrile 7b which is the key intermediate on the way to atorvastatin. Phosphonate 9b and aldehyde 4b are nearest intermediates to fluvastatin and rosuvastatin lactones. Unfortunately, Wittig–Horner‐reaction of phosphonate 9b under basic conditions was unsuccessful. Finally, it was not possible to oxidize hydroxy tetrahydropyranone 3b to related aldehyde 4b. Apparently the main reason for this unexpected behaviour of these compounds consists in the acidity of the hydrogen atoms in the 3‐position of the tetrahydropyranone‐2‐one ring which facilitates the fast elimination of tBuPh2SiOH and further decomposition of the pyranone core. In contrast, the desired transformations could be performed with related lactol 13 in hand. Thus, a successful alternative for the preparation of the side chain of statins was discovered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Palm oil mill effluent pretreatment using Moringa oleifera seeds as an environmentally friendly coagulant: laboratory and pilot plant studies
Authors: Bhatia Subhash , Othman Zalina , Ahmad Abdul L
Published: November 2006

This research paper covers the suitability of the coagulation–flocculation process using Moringa oleifera seeds after oil extraction as a natural and environmentally friendly coagulant for palm oil mill effluent treatment. The performance of M. oleifera coagulant was studied along with the flocculant KP 9650 in removal of suspended solids, organic components and in increasing the floc size. The optimum values of the operating parameters obtained from the laboratory jar test were applied in a pilot‐scale treatment plant comprised of coagulation–flocculation and filtration processes. Pilot‐scale pretreatment resulted in 99.7% suspended solids removal, 71.5% COD reduction, 68.2% BOD reduction, 100% oil and grease removal and 91% TKN removal. In pilot plant pretreatment, the percentage recovery of water was 83.3%, and 99.7% sludge was recovered after dewatering in a filter press. Copyright © 2006 Society of Chemical Industry
Addition of bisphosphonate to antibiotic and anti‐inflammatory treatment reduces bone resorption in experimental Staphylococcus aureus‐induced arthritis
Authors: Verdrengh Margareta , Carlsten Hans , Ohlsson Claes , Tarkowski Andrej
Published: November 2006

Bacterial arthritis is a disease with high morbidity leading to rapidly progressive bone resorption. We have shown earlier that treatment with antibiotics in combination with corticosteroids decreases joint inflammation and mortality but does not significantly affect bone/cartilage destruction of the joints. This study was performed to assess the effect of treatment with bisphosphonate [zoledronic acid (ZA)] in combination with antibiotics and corticosteroids, on the course and outcome of Staphlococcus aureus‐induced arthritis. Three days after intravenous inoculation with S. aureus, mice were treated with antibiotics alone, ZA alone, ZA and antibiotics, or ZA combined with antibiotics and corticosteroids, respectively. One group served as controls and received PBS. Clinical assessment of arthritis was performed as well as histological analysis of bone and cartilage destruction in the joints. One femur from each mouse was collected for bone mineral density (BMD) analysis. In addition, serum levels of type I collagen fragments (RatLaps), and osteocalcin, markers for osteoclastic and osteoblastic activity, respectively, were analyzed. Mice treated with ZA and antibiotics or with ZA in combination with antibiotics and corticosteroids lost significantly less in trabecular bone density compared to infected control mice. Furthermore, the addition of corticosteroids to animals treated with ZA and antibiotics, significantly decreased serum levels of RatLaps and osteocalcin, compared to animals treated with ZA and antibiotics or ZA alone. Treatment with bisphosphonates in combination with antimicrobial agents and corticosteroids significantly decreases the activity of osteoclasts in septic arthritis, thereby reducing the risk of skeletal destruction. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Striatal delta opioid receptor binding in experimental models of Parkinson's disease and dyskinesia
Authors: Hallett Penelope J. , Brotchie J.M.
Published: November 2006

Enhanced delta opioid receptor transmission may represent an endogenous compensatory mechanism in parkinsonism to reduce the activity of the indirect striatopallidal pathway following dopamine depletion. Furthermore, increased delta opioid receptor transmission may be causative in the production of dyskinesia following repeated dopaminergic treatment in Parkinson's disease. The present study employed radioligand receptor autoradiography, using [3H]naltrindole, a ligand selective for the delta opioid receptor, to assess delta opioid receptor binding sites in forebrain regions of reserpine‐treated rats, and in parkinsonian nondyskinetic, and dyskinetic MPTP‐lesioned macaques. In reserpine‐treated animals, specific delta opioid binding was increased in premotor cortex (+30%), sensorimotor striatum (+20%), and associative striatum (+17%) rostrally, but was not changed in caudal forebrain. In contrast, delta opioid receptor binding was not significantly altered at any region analyzed, in either nondyskinetic or dyskinetic, MPTP‐lesioned macaques, compared to normal. These results suggest that transient changes in delta opioid receptor binding may occur in motor circuits following acute dopamine depletion. However, in the more chronic MPTP‐lesioned macaque model, simple changes in delta opioid receptor number or affinity are unlikely to contribute to mechanisms for abnormal opioid transmission in Parkinson's disease and dyskinesia. © 2006 Movement Disorder Society
Gadolinium mixed‐micelles: Effect of the amphiphile on in vitro and in vivo efficacy in apolipoprotein E knockout mouse models of atherosclerosis
Authors: Briley‐Saebo Karen C. , Amirbekian Vardan , Mani Venkatesh , Aguinaldo Juan Gilberto S. , Vucic Esad , Carpenter David , Amirbekian Smbat , Fayad Zahi A.
Published: November 2006

Gadolinium (Gd) micelles are nanoparticles that incorporate phospholipids, surfactants, and lipophilic Gd complexes. Preliminary studies have shown that lipid‐based nanoparticles may penetrate atherosclerotic plaque. The aim of the current study was to prepare, characterize, and evaluate in vivo the efficacy of two Gd micelle formulations using apolipoprotein E knockout (ApoE−/−) mouse models of atherosclerosis. Gd micelles were prepared using two different amphiphiles but similar GdDTPA lipids, surfactants, and fluorescent labels. The results indicate that the choice of amphiphile may affect the particle size, relaxivity, and blood clearance in wild‐type mice (WT). However, the in vivo MR efficacy, with respect to uptake in the vessel wall of ApoE−/− mice, was not affected by the amphiphile used. Significant wall enhancement of ApoE−/− mice was observed following administration of 0.015 and 0.038 mmol Gd/kg of both micelle formulations. No significant enhancement of the vessel wall of WT mice was observed for any of the dosages or formulations tested. Additionally, liver uptake 24 hr post‐injection (p.i.) was not influenced by the choice of amphiphile. The results of this study strongly suggest that liver uptake and wall enhancement may be regulated by the surface properties of the micelle and not by other factors, such as micelle size. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
The role of neutrophil elastase in elastin metabolism of pelvic tissues from women with stress urinary incontinence
Authors: Chen Bertha , Wen Yan , Yu Xiaoyun , Polan Mary Lake
Published: November 2006

Objective

Altered elastin metabolism is implicated in pelvic floor disorders. We studied neutrophil elastase (NE) and matrix metalloproteinase (MMP) activities in vaginal tissues from premenopausal women with stress urinary incontinence (SUI).

Methods

Elastase and NE activities in vaginal tissues were assessed. Protein and mRNA expressions were determined by RT‐PCR and Western blot. Total elastin and collagen contents were evaluated. To compare the relative elastolytic effect of NE and MMP‐2, we used their respective antibodies to immunoprecipitate these proteins from vaginal fibroblast extracts prior to assessing elastase activity.

Results

Elastase activity in vaginal wall tissues was significantly higher in the secretory compared to the proliferative phase. NE mRNA and protein expressions were similar between control and SUI tissues from the secretory phase. However, NE activity in the SUI tissues was higher compared to control tissues. The mRNA expression of alpha‐1 antitrypsin (ATT) was higher in control tissues from the proliferative phase compared to those from the secretory phase, while no difference was observed in SUI tissues between either phase. Protein expression of the active form of ATT was decreased in SUI tissues compared to controls during the secretory phase. Anti‐NE antibody reduced total elastase activity by 60–70%, compared to less than 20% reduction with anti‐MMP‐2 antibody.

Conclusion

During the secretory phase, elastolytic activity is increased in pelvic tissues from women with SUI, through an increase in NE activity and a concurrent decrease in ATT expression. The serine protease, NE, appears to be a more significant modulator of elastase activity compared to MMP‐2. Neurourol. Urodynam. 26:274–279, 2007. © 2006 Wiley‐Liss, Inc.
On the effectiveness of top‐down strategy for forecasting autoregressive demands
Authors: Widiarta Handik , Viswanathan S. , Piplani Rajesh
Published: November 2006

We investigate the relative effectiveness of top‐down versus bottom‐up strategies for forecasting the demand of an item that belongs to a product family. The demand for each item in the family is assumed to follow a first‐order univariate autoregressive process. Under the top‐down strategy, the aggregate demand is forecasted by using the historical data of the family demand. The demand forecast for the items is then derived by proportional allocation of the aggregate forecast. Under the bottom‐up strategy, the demand forecast for each item is directly obtained by using the historical demand data of the particular item. In both strategies, the forecasting technique used is exponential smoothing. We analytically evaluate the condition under which one forecasting strategy is preferred over the other when the lag‐1 autocorrelation of the demand time series for all the items is identical. We show that when the lag‐1 autocorrelation is smaller than or equal to 1/3, the maximum difference in the performance of the two forecasting strategies is only 1%. However, if the lag‐1 autocorrelation of the demand for at least one of the items is greater than 1/3, then the bottom‐up strategy consistently outperforms the top‐down strategy, irrespective of the items' proportion in the family and the coefficient of correlation between the item demands. A simulation study reveals that the analytical findings hold even when the lag‐1 autocorrelation of the demand processes is not identical. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007.
Fragmentation reactions of radical cations
Authors: Baciocchi Enrico , Bietti Massimo , Lanzalunga Osvaldo
Published: November 2006

This paper summarizes most of the recent work by our group on the kinetic aspects of a variety of fragmentation reactions of radical cations involving the cleavage of CH, OH, CC, and CS bonds. In particular, the problems that have been addressed concern: (a) the carbon acidity/oxygen acidity dichotomy in the fragmentation of aryl‐ and thioarylalkanol radical cations; (b) the decarboxylation of aryl and thioarylacetic acid radical cations; (c) the structural factors influencing the rate of CS bond cleavage in the radical cations of phenyl alkyl sulfides. The results presented and discussed have allowed us to recognize the important role played by the electron reorganization energy, associated with the intramolecular electron transfer from the scissile bond to the SOMO, with respect to the dynamics and mechanism of the fragmentation process in the radical cation. Copyright © 2006 John Wiley & Sons, Ltd.
Efficient synthesis of an aldehyde‐capped polythiophene containing fluorinated electron‐withdrawing groups
Authors: Zhang Cheng , Sun Sam‐Shajing
Published: November 2006

To incorporate an acceptor type polythiophene segment onto a supramolecular block copolymer for potential light harvesting applications, effective synthetic routes for the end‐functionalized and acceptor‐substituted polythiophenes are critical. The Ullmann coupling reaction can be utilized to obtain electron‐deficient polythiophenes and to attach terminal thiophene units that carry functional groups. In this article, the reactions involving a 2,5‐dibromothiophene monomer containing an electron‐withdrawing fluorinated ester and 5‐bromo‐2‐thiophenecarboxaldehyde (the end‐capper) were studied in detail. It was found that the Ullmann coupling reaction of the dibromide is very fast (completed in a few minutes) and the terminal bromine group does not survive long under the reaction condition. These findings lead to the development of an effective procedure for aldehyde end‐capping of electron‐deficient polythiophenes. Polymers with molecular weights around 4000 Da are routinely obtained. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 41–47, 2007
Thermally stable, light‐emitting, triphenylamine‐containing poly(amine hydrazide)s and poly(amine‐1,3,4‐oxadiazole)s bearing pendent carbazolyl groups
Authors: Liou Guey‐Sheng , Huang Nan‐Kun , Yang Yi‐Lung
Published: November 2006

A series of new organosoluble poly(amine hydrazide)s were synthesized via the Yamazaki phosphorylation reaction and were solution‐cast into transparent films. Differential scanning calorimetry indicated that the hydrazide polymers could be thermally cyclodehydrated into the corresponding oxadiazole polymers in the range of 300–400 °C. The resulting poly(amine‐1,3,4‐oxadiazole)s exhibited glass‐transition temperatures in the range of 276–297 °C, 10% weight loss temperatures in excess of 520 °C, and char yields at 800 °C in nitrogen higher than 67%. The hole‐transporting and electrochromic properties were examined with electrochemical and spectroelectrochemical methods. Cyclic voltammograms of these polymers prepared by the casting of polymer solutions onto an indium tin oxide coated glass substrate exhibited two reversible oxidative redox couples at 1.10–1.19 and 1.35–1.60 V versus Ag/AgCl in an acetonitrile solution, respectively. The poly(amine hydrazide)s revealed excellent stability of the electrochromic characteristics, changing color from the original pale yellow to green and then to blue. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 48–58, 2007
Influence of the initiating mechanism on the cationic photopolymerization of a cycloaliphatic epoxy resin with arylsulfonium salts
Authors: Fernández‐Francos Xavier , Salla Josep M. , Cadenato Ana , Morancho Josep M. , Mantecón Ana , Serra Angels , Ramis Xavier
Published: November 2006

The photocuring process of widely used 3,4‐epoxycyclohexylmethyl 3′,4′‐epoxycyclohexane carboxylate has been investigated with differential scanning photocalorimetry and attenuated total reflection/Fourier transform infrared. Mixed salts of triarylsulfonium hexafluoroantimonate have been employed as the photoinitiator. The photocuring of the biscycloaliphatic resins exhibits a complex behavior: the overall heat of reaction (including dynamic thermal postcuring) depends on the photocuring temperature, surprisingly high reaction rates are observed at lower photocuring temperatures, and the range of the glass transition of the fully cured material broadens and shifts to higher temperatures as the photocuring temperature increases. It is assumed that the balance between the initiation step and the propagation step is responsible for the changes in the reaction mechanism that produce the observed experimental results. This balance may depend on the amount of the photoinitiator, the irradiation intensity, and the photocuring temperature. The structure and final properties of the material may therefore depend on the adjustment of these parameters. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 16–25, 2007
An in vitro feeding assay to test acaricides for control of hard ticks
Authors: Kröber Thomas , Guerin Patrick M
Published: November 2006

Animal husbandry could not be practised over large areas of the planet without acaricides. The prevention of tick bite and the transmission of diseases requires the use of pesticides, but this contributes to the development of tick resistance against acaricides. This drives the quest for new molecules that target physiological processes crucial to tick survival. In vivo trials involve multiple repetitions because of inherent variations between host animals, requiring large amounts of test products and ticks. An in vitro alternative should permit the testing of the ability of a product to restrict attachment and feeding by ticks at precise doses. In this paper an in vitro feeding system is described where the European tick Ixodes ricinus L. feeds on blood through a cellulose rayon‐reinforced silicone membrane. The membrane Shore hardness is modified to imitate the elastic retraction forces of skin that ensure the closing of tick penetration sites on the membrane to prevent bleeding. Tick attachment (75–100%) is achieved by adding chemical and mechanical stimuli to the membrane. Survival curves for different doses of fipronil and ivermectin tested with the method showed highly reproducible acaricide effects within 5–7 days. Significant effects are recorded down to ppb levels in blood. Standardised tests can be made with blood from the same donor animal or culture medium under the membrane. Copyright © 2006 Society of Chemical Industry