bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the polyphenolic composition of the organic extracts of Mauritian black teas: A potential contributor to their antioxidant functions
Authors: Luximon‐Ramma Amitabye , Neergheen Vidushi S. , Bahorun Theeshan , Crozier Alan , Zbarsky Virginia , Datla Krishna P. , Dexter David T. , Aruoma Okezie I.
Published: December 2008

There is increasing interest in the emerging view that tea improves the antioxidant status in vivo and thereby helps to lower risk of certain types of cancer, coronary heart disease and stroke and its component biofactors could provide prophylactic potential for these diseases. The polyphenolic composition and the antioxidant properties of organic extracts (acetone/methanol) of Mauritian commercial black teas were evaluated. HPLC data of the individual compounds revealed remarkably high levels (+)‐Catechin ((+)‐C), (−)‐epicatechin ((−)‐EC), (−)‐epicatechin 3‐gallate ((−)‐ECG), (−)‐epigallocatechin ((−)‐EGC), (−)‐epigallocatechin 3‐gallate ((−)‐EGCG) and gallic acid. Analysis of hydrolysed extracts indicated that quercetin was the dominant flavonol aglycone with traces of myricetin and kaempferol. Based on the Ferric Reducing Antioxidant Power (FRAP) and the Trolox Equivalent Antioxidant Capacity (TEAC) assays Extra tea from Bois Chéri exhibited the highest antioxidant potential. Linear regression analyses showed that the antioxidant capacities of the organic extracts are strongly influenced by total phenols (TEAC: r=0.95 and FRAP: r=0.96) and to a lesser extent by total proanthocyanidin and total flavonoid contents. Catechins and gallic acid seem to add up to the overall antioxidant capacity of black tea extracts. The fresh tea leaves had high levels of total phenols, total flavonoids, total proanthocyanidin and exhibited greater antioxidant potential when compared with black teas. Organic extracts of endemic teas represent useful source of phenolic antioxidants supplements for prophylactic use.
The thiol‐based redox networks of pathogens: Unexploited targets in the search for new drugs
Authors: Jaeger Timo , Flohé Leopold
Published: December 2008

Hydroperoxide metabolism in diverse pathogens is reviewed under consideration of involved enzymes as potential drug targets. The common denominator of the peroxidase systems of Trypanosoma, Leishmania, Plasmodium, and Mycobacterium species is the use of NAD(P)H to reduce hydroperoxides including peroxynitrite via a flavin‐containing disulfide reductase, a thioredoxin (Trx)‐related protein and a peroxidase that operates with thiol catalysis. In Plasmodium falciparum, thioredoxin‐ and glutathione dependent systems appear to be linked via glutaredoxin and plasmoredoxin to terminal thioredoxin peroxidases belonging to both, the peroxiredoxin (Prx) and glutathione peroxidase (GPx) family. In Mycobacterium tuberculosis, a catalase‐type peroxidase is complemented by the typical 2‐C‐Prx AhpC that, in contrast to most bacteria, is reduced by TrxC, and an atypical 2‐C‐Prx reduced by TrxB or C. A most complex variation of the scheme is found in trypanosomatids, where the unique redox metabolite trypanothione reduces the thioredoxin‐related tryparedoxin, which fuels Prx‐ and GPx‐type peroxidases as well as ribonucleotide reductase. In Trypanosoma brucei and Leishmania donovani the system has been shown to be essential for viability and virulence by inversed genetics. It is concluded that optimum efficacy can be expected from inhibitors of the most upstream components of the redox cascades. For trypanosomatids attractive validated drug targets are trypanothione reductase and trypanothione synthetase; for mycobacteria thioredoxin reductase appears most appealing, while in Plasmodium simultaneous inhibition of both the thioredoxin and the glutathione pathway appears advisable to avoid mutual substitution in co‐substrate supply to the peroxidases. Financial and organisational needs to translate the scientific progress into applicable drugs are discussed under consideration of the socio‐economic impact of the addressed diseases.
Exercise, oxidative stress and risk of cardiovascular disease in the elderly. Protective role of antioxidant functional foods
Authors: Galán Ana I. , Palacios Encarna , Ruiz Francisco , Díez Arancha , Arji Mohamed , Almar Mar , Moreno Carlos , Calvo José I. , Muñoz María E. , Delgado Marco A. , Jiménez Rafael
Published: December 2008

Free radicals and oxidative stress are involved in the pathogenic mechanisms of cardiovascular disease (CVD), diabetes and cancer. Exercise is a useful strategy for preventing CVD but in elderly persons it can enhance oxidative stress, which is why some studies recommend antioxidant supplementation for exercising elderly subjects. This intervention study was performed on 320 elderly subjects following a Geriatric Revitalization Program (GEREPRO) to maintain physical health and reduce CVD risk. GEREPRO was based on regular exercise concurrent with a nutritional antioxidant treatment based on daily intake of a functional antioxidant food, Biofrutas™. Sustained exercise (10 months, 3 sessions/week) significantly increased cardiorespiratory fitness and plasma HDL‐cholesterol; it reduced some predictors of cardiovascular risk (arterial pressure, LDL‐cholesterol, total cholesterol/LDL‐C, LDL‐C/HDL‐C), but significantly enhanced some biomarkers of oxidative stress. Concurrent antioxidant supplementation did not produce any ergogenic effects but, meaningfully, enhanced some positive effects of exercise on physical health and the CDV risk index, and it totally prevented the exercise‐induced oxidative stress. Our results show that regular and moderate exercise improves cardiorespiratory function and reduces CVD risk in elderly people, while concurrent antioxidant supplementation modulates oxidative insult during exercise in the elderly and enhances the beneficial effects of exercise.
The effect of plant cytokinin hormones on the production of ethylene, nitric oxide, and protein nitrotyrosine in ageing tobacco leaves
Authors: Wilhelmová N. , Fuksová H. , Srbová M. , Miková D. , Mýtinová Z. , Procházková D. , Vytášek R. , Wilhelm J.
Published: December 2008

Transgenic plants with genetically increased or decreased levels of cytokinins were used to investigate the effect of cytokinin level on the production of ethylene, a plant hormone with suggested role in senescence, and the production of nitric oxide, potentially important signalling and regulatory molecule. The production of these gases was followed during the course of leaf development and senescence. The production of ethylene and nitric oxide is under genetic control of genes other than those involved in regulation of senescence. The difference in basic ethylene and NO levels in different tobacco cultivars was higher than their changes in senescence. The results of this study did not indicate a direct link between ethylene production and cytokinin levels. However, there was a decreased production of NO in senescent leaves. Low cytokinins level was associated with increased NO production during leaf development. Protein nitrotyrosine proved to be a better indicator of the reactive nitrogen species than measuring of the NO production. Higher nitrotyrosine concentrations were found in insoluble proteins than in the soluble ones, pointing to membrane proteins as the primary targets of the reactive nitrogen species. In plants with elevated cytokinin levels the content of nitrated proteins decreased both in soluble and insoluble fractions. This finding indicates an antioxidative function of cytokinins against reactive nitrogen species.
Low molecular proanthocyanidin dietary biofactor Oligonol: Its modulation of oxidative stress, bioefficacy, neuroprotection, food application and chemoprevention potentials
Authors: Aruoma Okezie I. , Sun Buxiang , Fujii Hajime , Neergheen Vidushi S. , Bahorun Theeshan , Kang Kyung‐Sun , Sung Mi‐Kyung
Published: December 2008

Interdisciplinary research endeavors are directed at understanding the molecular mechanisms of neurodegenerative and chronic diseases that affect human lifestyle. Hence the potential for developing medicinal herb‐derived and food plant‐derived prophylactic agents directed at neurological, metabolic, cardiovascular and psychiatric disorders abounds. Oligonol is a novel technology product emanating from the oligomerization of polyphenols, typically proanthocyanidin from a variety of fruits (grapes, apples, persimmons etc.) that has optimized bioavailability. It is an optimized phenolic product containing catechin‐type monomers and oligomeric proanthocyanidins, the easily absorbed forms. Typically the constituents of Oligonol are 15–20% monomers, 8–12% dimers and 5–10% trimers. Supplementation of mice with Oligonol prior to the administration of ferric‐nitrilotriacetic complex (a Fenton chemistry model) significantly reduced the extent of lipid peroxidation in the kidney, brain and liver. Oligonol triggers apoptosis in the MCF‐7 and MDA‐MB‐231 breast cancer cells through modulation of the pro‐apoptotic Bcl‐2 family of proteins and the MEK/ERK signaling pathway, an observation suggesting its important chemopreventive effects. The senescence‐accelerated strain of mice (SAM) are models of senescence acceleration and geriatric disorders which exhibit learning and memory deficits and enhanced production or defective control of oxidative stress leading to neuronal damage. Oligonol has been suggested to modulate behavioral deficits, decrease the extent of inflamma‐tion scores in the SAMP8 mice as well as prolonging their life‐span. Oligonol modulates the Aβ induced oxidative insult and dysfunction in mitochondrial membrane integrity in PC12 cells indicating potential neuroprotection functions. Safety studies indicate no adverse effects in mice with an LD50 of 5 g/kg which equates to a dose of approximately 300 g for an average human with a 60 kg body weight. The application of Oligonol in pharmaceutical preparations, cosmetics, dairy, processed meat and food products, supplements and in functional beverages can be envisaged.
Salivary isoprostanes indicate increased oxidation injury in periodontitis with additional tobacco abuse
Authors: Wolfram Roswitha M. , Budinsky Alexandra C. , Eder Andreas , Presenhuber Christiane , Nell Andrea , Sperr Wolfgang , Sinzinger Helmut
Published: December 2008

Isoprostanes (IPs) are indicators of in‐vivo oxidative stress, and have been successfully used as markers for chronic inflammatory processes. The presence of chronic periodontal disease and cigarette smoking has been individually linked to the development of atherosclerosis, yet data regarding oxidative stress in this context are not available yet. The aim of this study was to evaluate levels of the salivary prostaglandins (PGs) 8‐epi‐PGF2α, 6‐oxo‐PGF1α, thromboxane B2 (TXB2) and PGF2α in association with periodontal disease status with and without additional cigarette smoking.

We analyzed saliva samples from 121 adults, (aged 21–73 years, 90 non‐smokers, 31 smokers) for levels of 8‐epi‐PGF2α, 6‐oxo‐PGF1α, TXB2 and PGF2α. On the basis of periodontal disease indices the periodontal status of each subject was assessed and outcomes were then correlated with smoking status and laboratory findings.

Salivary 8‐epi‐PGF2α levels increased with deteriorating plaque index, and were significantly higher (115.5 ± 23.5 pg/ml) in smoking individuals, when compared to non‐smokers (70.2 ± 20.4 pg/ml, p<0.0001). In addition, smokers showed higher TXB2 and PGF2α s and lower 6‐oxo‐PGF1α levels p<0.0001). Oxidative stress, as reflected by elevated salivary 8‐epi‐PGF2α levels, is associated with the extent of periodontal disease and is significantly aggravated by concomitant tobacco abuse. Chronic inflammation and smoking have been individually associated with the development of atherosclerosis. The results of this study indicate that: 1) salivary IPs can reliably assess the degree of oxidative stress, and: 2) smoking and periodontal disease are two modifiable cardiovascular risk factors, able to potentiate each other.
Coenzyme Q10 concentration in plasma and blood cells: What about diurnal changes?
Authors: Niklowitz Petra , Andler Werner , Menke Thomas
Published: December 2008

Coenzyme Q10 (CoQ10) is used by the body as an endogenous antioxidant and performs essential functions in mitochondrial energy production. The value of CoQ10 as a biomarker for oxidative stress will be severely restricted if there are huge individual daily variations in its concentration.

For analysis of diurnal changes in CoQ10 plasma and blood cell concentrations, blood was collected from nine healthy adults (at two‐ or three‐hour intervals for plasma, and three times a day for blood cells). CoQ10 was analysed by HPLC using electrochemical detection and internal standardisation.

Daytime variations in CoQ10 concentration in plasma are maintained within narrow limits and show no statistically significant difference (Kruskal‐Wallis). However, a drop at night‐time (0300 h) is accompanied by a drop in total cholesterol concentration. Remarkable inter‐individual differences in blood cell (erythrocytes, platelets, white blood cells) content of CoQ10 occur with only slight intra‐individual daily variations.

A correlation (Spearman) is found for cholesterol and CoQ10 content in circulation which may be explained by the carrier capacity of blood for this highly lipophilic substance. Moreover, a diurnal change in hepatic HMG‐CoA reductase activity may suggest a common diurnal regulation of synthesis of both CoQ10 and cholesterol.
Oral administration of Antioxidant Biofactor (AOB™) ameliorates ischemia/reperfusioninduced neuronal death in the gerbil
Authors: Yasui Hironobu , Asanuma Taketoshi , Watanabe Yasuko , Waki Kenji , Inanami Osamu , Kuwabara Mikinori
Published: December 2008

Oxidative damage due to ischemia/reperfusion has been implicated as one of the leading causes for delayed neuronal cell death in a number of neurodegenerative diseases, including stroke. The purpose of this research was to investigate whether oral administration of a fermented grain food mixture (AOB ) might offer protective effects against ischemia/reperfusioninduced neuronal damage in Mongolian gerbils, a model known for delayed neuronal death in the hippocampal CA1 region. Histological analysis revealed that AOB administration ad libitum for 3 weeks (preoperative administration) and 1 week (postoperative administration) dose‐dependently suppressed the induction of transient ischemia/reperfusion‐induced neuronal cell death. TUNEL assay also revealed that AOB suppressed it by inhibiting the induction of apoptosis. A significant increase of superoxide dismutase‐like (SOD‐like) activity was observed in the hippocampal CA1 region of the AOB‐treated gerbil. Furthermore, immunoblot analysis showed that AOB administration down‐regulated the expression of heat shock proteins HSP27 and HSP70 in the same region. These results indicated that oral administration of AOB protected against ischemia/reperfusion‐induced brain injury by minimizing oxidative damage via its SOD‐like activity and inhibiting apoptosis.
Protective effects of a red orange extract on UVB‐induced damage in human keratinocytes
Authors: Cimino Francesco , Cristani Mariateresa , Saija Antonina , Bonina Franco Paolo , Virgili Fabio
Published: December 2008

UV light is considered one of the major etiological factor in skin aging, cancer and also to systemic impairment such as immunosuppression. Increased production of reactive oxygen species (ROS) and oxidative stress condition are known to play a central role in initiating and driving the signalling events that lead to cellular response following UV irradiation. In the present study we have investigated the photoprotective activity of a standardized extract from red orange (ROE), obtained from three red orange varieties and containing as main active principles phenolic compounds (anthocyanins, flavanones and hydroxycinnamic acids) and ascorbic acid.

The aim of this study was to evaluate the efficacy of ROE in modulating cellular responses to UVB in human keratinocytes (HaCaT).

Our data indicate that ROE is potentially able to efficiently counteract UVB‐induced response, and in particular some events associated to inflammation and apoptosis, such as NF‐kB and AP‐1 translocation and procaspase‐3 cleavage. This activity is probably due to a block of cellular oxidative stress‐related events. Thus we can propose ROE as a useful natural standardised extract in skin photoprotection with promising applications in the field of dermatology.
Brazilin and the extract from Caesalpinia sappan L. protect oxidative injury through the expression of heme oxygenase‐1
Authors: Choi Byung‐Min , Lee Ju‐A. , Gao Shang Shang , Eun Sang Yong , Kim Young‐Sup , Ryu Shi‐Yong , Choi Yeon‐Hee , Park Raekil , Kwon Dae Young , Kim Bok‐Ryang
Published: December 2008

In this study, we examined the protective effects of Caesalpinia sappan L. and its major component, brazilin, against tert‐butylhydroperoxide (t‐BHP)‐induced cell death in House Ear Institute‐Organ of Corti 1 (HEI‐OC1) cells. We found that the extract of C. sappan L. and brazilin induced antioxidant response element (ARE)‐luciferase activity and heme oxygenase‐1 (HO‐1) expression in a concentration‐dependent manner. The inductive effect of brazilin was more potent than the extract of C. sappan L. and the expression of HO‐1 reached a peak at 12 h after brazilin treatment. The extract and brazilin protected the cells against t‐BHP‐induced cell death. Their protective effects were abrogated by zinc protoporphyrin IX (ZnPP IX), a HO inhibitor. These results demonstrate that the extract of C. sappan L. and brazilin induce the expression of HO‐1 and the enzyme diminishes t‐BHP‐induced cell death in HEI‐OC1 cells.
Inhibition of protein glycation by skins and seeds of the muscadine grape
Authors: Farrar Johnetta L. , Hartle Diane K. , Hargrove James L. , Greenspan Phillip
Published: December 2008

The formation of advanced glycation end products (AGEs) leading to protein glycation and cross‐linking is associated with the pathogenesis of diabetic complications. The inhibition of protein glycation by phenolic and flavonoid antioxidants demonstrates that the process is mediated, in part, by oxidative processes. In this study, the effects of seed and skin extracts of the muscadine grape on AGEs formation were examined. Seeds and skins were extracted (10% w/v) with 50% ethanol and incubated at 37°C with a solution containing 250 mM fructose and 10 mg/ml albumin. After 72 h, fluorescence was measured at the wavelength pair of 370 and 440 nm as an index of the formation of AGEs. Both seed and skin extracts were found to be efficacious inhibitors of AGE formation. A 1:300 dilution of the seed extract decreased fluorescence by approximately 65%, whereas muscadine grape skin extract produced a 40% lowering. This difference correlates with the greater antioxidant activity found in muscadine seeds in comparison to skins, however, on a mass basis, the inhibitory activities of the seeds and skins were found to be nearly equivalent. Gallic acid, catechin and epicatechin, the three major polyphenols in the seeds, all significantly decreased the AGE product related fluorescence at a concentration of 50 μM. Neither muscadine seed extract nor skin extract inhibited the methylglyoxal‐mediated glycation of albumin. These results suggest that consumption of the muscadine grape may have some benefit in altering the progression of diabetic complications.
Investigation of the bioactivity and biocompatibility of different glass interfaces with hydroxyapatite, fluorohydroxyapatite and 58S bioactive glass
Authors: Han Yuling Jamie , Loo Say Chye Joachim , Lee Joel , Ma Jan
Published: December 2008

The current review investigates the bioactivity of different glass interfaces created on thin glass cover slips as substrates. The interfaces studied are plain glass, functionalized glass using 0.5 M and 5 M of sodium hydroxide (NaOH) for 24 hrs, and glass coated with bioactive 58S Bioglass (58S). A biomimetic method, involving the exposure of the three interfaces to 1.5 times simulated body fluid (SBF) tests the bioactivity of the interfaces via creation of layer of Hydroxyapatite (HA). Fluorinated SBF will precipitate fluorine doped HA (FHA) on a bioactive interface. Higher concentration of 1.5 times of SBF used in this study intended to accelerate the formation of HA and FHA layer over the substrate. HA and FHA is found to be precipitated on the thinly coated 58S. This paper, study also the thin film coatings of three forms of bioceramics — bioactive 58S, HA and FHA. The study, also proposes to draw a relation between the morphology of HA particles with duration of exposure to SBF, the effects of fluorine on the morphology and the cell interaction with bioactive 58S, HA and FHA interfaces using pre‐differentiated osteoblastic MC3T3 cells. The analysis of cells in this study is confined to three parameters that include the attachment, proliferation and viability of cells. Tests employed for the analysis of the thin film coating of HA and FHA is restricted to qualitative X‐Ray Diffraction and quantitative Field Emission Scanning Electron Microscope. Other mechanical tests such as shear test are not used to test the mechanical properties of this thin layer, due to the fact that the thin film is too thin for such analysis.
Effects of Coenzyme Q10 on TNF‐α secretion in human and murine monocytic cell lines
Authors: Schmelzer Constance , Lorenz Gerti , Lindner Inka , Rimbach Gerald , Niklowitz Petra , Menke Thomas , Döring Frank
Published: December 2008

Studies in humans and cell culture as well as bioinformatics suggested that Coenzyme Q10 (CoQ10 ) functions as an anti‐inflammatory molecule. Here we studied the influence of CoQ10 (Kaneka QTM ) on secretion of the pro‐inflammatory 10 cytokine tumor necrosis factor‐alpha (TNF‐α) by using the human and murine monocytic cell lines TH P‐1 and RAW264.7 expressing human apolipoprotein E3 (apoE3) or pro‐inflammatory apoE4. Incubation of cells with physiological (0.1–10 μM) and supra‐physiological (> 10 to ≤ 100 μM) concentrations of CoQ10 led to an intracellular accumulation of its reduced form without any cytotoxic effects. Stimulation of cell models with lipopolysaccharide (LPS) resulted in a substantially release of TNF‐α. When THP‐1 cells were pre‐incubated with 10 μM CoQ10, the LPS‐induced TNF‐α release was significantly decreased to 72 ± 32%. This effect is similar to those obtained by 10 μM N‐Acetyl‐Cysteine, a well known reference antioxidant. In RAW264.7‐apoE3 and ‐apoE4 cells, significant reductions of LPS‐induced TNF‐α secretion to 73.3 ± 2.8% and 74.7 ± 8.9% were found with 2.5 μM and 75 μM CoQ10, respectively. In conclusion, CoQ10 has moderate anti‐inflammatory effects in two monocytic cell lines which could be mediated by its antioxidant activity.
Suppressive effects of demethylated metabolites of nobiletin on phorbol ester‐induced expression of scavenger receptor genes in THP‐1 human monocytic cells
Authors: Eguchi Ai , Murakami Akira , Li Shiming , Ho Chi‐Tang , Ohigashi Hajime
Published: December 2008

Unregulated uptake of oxidized low‐density lipoproteins (ox‐LDL) via macrophage scavenger receptors (SRs) is a key event in atherosclerosis. We previously reported that nobiletin (NOB), a citrus polymethoxylated flavone, markedly reduced 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced SRs and adhesion molecules mRNA expression and blockade of DiI‐acLDL uptake in THP‐1 human monocyte‐like cells. In this study, we examined the effects of NOB metabolites, 3 hydroxy‐5,6,7,8,4′ ‐pentamethoxyflavone (3 ‐demethyl‐NOB), 4′ ‐hydroxy‐5,6,7,8,3′ ‐pentamethoxyflavone (4′ ‐demethyl‐NOB) and 3, 4′ ‐dihydroxy‐5,6,7,8,‐tetramethoxyflavone (3, 4′ ‐didemethyl‐NOB) and NOB analog, tangeretin, on SRs and adhesion molecules mRNA expression. 3′ ‐Demethyl‐NOB significantly suppressed CD36 expression, moreover, 4′ ‐demethyl‐ and 3, 4′ ‐didemethyl‐NOB significantly suppressed TPA‐induced expression of SR‐A and LOX‐1. Further, the suppressive effects of 4′ ‐demethyl‐ and 3, 4′ ‐didemethyl‐NOB on the expression of CD36 mRNA were greater extent than parent NOB. The inhibitory effects of the metabolites toward TPA‐induced SR mRNA expression are partly associated with the suppression of AP‐1 and NF‐κB transcriptional activities. Together, our results suggest that metabolites of NOB, such as 4′ ‐demethyl‐ and 3, 4′ ‐didemethyl‐NOB, have comparable or higher potentials to attenuate SR expression than NOB.
Attenuation of mitochondrial injury by L‐arginine preconditioning of the liver
Authors: Chattopadhyay Pronobesh , Shukla Gunjan , Verma Anurag , Wahi A. K.
Published: December 2008

The present study was aimed to evaluate the efficacy of L‐arginine on mitochondrial function in ischemic and reperfusion (I/R) induced hepatic injury. Adult Wistar rat were subjected to 1 h of partial liver ischemia followed by 3 hour reperfusion. Eighteen wistar rats were divided into three groups viz. sham‐operated control group (I) (n= 6), ischemia and reperfusion (I/R) group (II) (n= 6), L‐arginine treated group (100 mg/kg body weight/daily by oral route for 7 days before induced ischemia reperfusion maneuver) (III) (n= 6). Mitochondrial injury was assessed in terms of decreased (P < 0.05) activities of mitochondrial antioxidant enzymes (GSH, SOD, CAT), respiratory marker enzymes (NADH dehydrogenase, cytochrome c oxidases) and hepatocytes nitric oxide production. Pre‐treatment with L‐arginine (10 mg/kg/p.o.for 7 days) significantly counteracted the alternations of hepatic enzymes and mitochondrial respiratory and antioxidant enzymes. In addition, electron microscopy and histopathology study showed the restoration of cellular normalcy and accredits the cytoprotective role of L‐arginine against I/R induced hepatocellular injury. On the basis of these findings it may be concluded that L‐arginine protects mitochondrial function in hepatic ischemic and reperfused liver.
Rapid determination of rifaximin in rat serum and urine by direct injection on to a shielded hydrophobic stationary phase by HPLC
Authors: Rao R. Nageswara , Shinde Dhananjay D. , Agawane Sachin B.
Published: December 2008

A simple and rapid reversed‐phase HPLC method for determination of rifaximin in rat serum and urine was developed. Separation of rifaximin from biological matrix was achieved by direct injection of rat serum and urine onto a restricted‐access medium, Supelco LC‐Hisep, a shielded hydrophobic stationary phase, using acetonitrile:water:acetic acid (18:82:0.1 v/v/v) as a mobile phase. The linear range was 0.10–20 µg/mL (r2 > 0.999, n = 6), intraday and interday variation was <6.10%. The limits of detection and quantification were 0.03 (signal‐to‐noise ratio >3) and 0.10 µg/mL (signal‐to‐noise ratio >10), respectively. The method was successfully applied to pharmacokinetic studies of rifaximin after an oral administration to rats. Copyright © 2008 John Wiley & Sons, Ltd.
Intergroup relations in action: Questions asked about lesbian, gay and bisexual issues in diversity training
Authors: Peel Elizabeth
Published: December 2008

This paper focuses on the questions which heterosexual trainees ask about lesbian, gay and bisexual (LGB) experience within diversity training about LGB issues. Drawing on a data corpus of 162 questions asked by trainees in 13 tape‐recorded training sessions, questions were coded into six categories: (1) general ‘understanding’ questions; (2) questions about the trainer's life, experience and practices; (3) professional practice questions; (4) questions about lesbian and gay related legislation, policies and procedures; (5) questions about specific people and projects and (6) questions about the meanings, derivations and correct use of terms and symbols. ‘Real’ questions are compared with the decontexualized questions (and answers to them) that are provided in training manuals and it is demonstrated that these questions differ markedly from how questionsactuallyget asked and how theyactuallyget answered. Recommendations are provided for improving training and the argument made for turning towards analyses of the real world in action, especially when considering intergroup relations. Copyright © 2008 John Wiley & Sons, Ltd.
Macrocyclic Cyclooctene‐Supported AlCl–Salen Catalysts for Conjugated Addition Reactions: Effect of Linker and Support Structure on Catalysis
Authors: Madhavan Nandita , Takatani Tait , Sherrill C. David , Weck Marcus
Published: December 2008

AlCl–salen (salen=N,N′‐bis(salicylidene)ethylenediamine dianion) catalysts supported onto macrocyclic oligomeric cyclooctene through linkers of varying length and flexibility have been developed to demonstrate the importance of support architecture on catalyst activity. The role played by the support and the linkers in dictating catalyst activity was found to vary for reactions with contrasting mechanisms, such as the bimetallic cyanide and the monometallic indole addition reactions. While the flexible support significantly enhanced the cyanide addition reaction, most likely by improving salen–salen interactions in the transition state, it lowered the reaction rate for the monometallic indole reaction. For both reactions, significant increase in catalytic activity was observed for catalysts with the longest linkers. The effect of the flexible macrocyclic support on catalysis was further exemplified by the enhanced activity of the supported catalyst in comparison with its unsupported analogue for the conjugate addition of tetrazoles, which is known to be catalyzed by dimeric μ‐oxo–salen catalysts. Our studies with the cyclooctene supported AlCl–salen catalysts provides significant insights for rationally designing highly efficient AlCl–salen catalysts for a diverse set of reactions.
Pincer Thioamide and Pincer Thioimide Palladium Complexes Catalyze Highly Efficient Negishi Coupling of Primary and Secondary Alkyl Zinc Reagents at Room Temperature
Authors: Wang Haibo , Liu Jing , Deng Yi , Min Tianyin , Yu Ganxiang , Wu Xiaojun , Yang Zhen , Lei Aiwen
Published: December 2008

Pincer thioamide PdII complex 2 was prepared, and its reaction with cyclohexylzinc chloride yielded novel pincer thioimide PdII complex 3 besides Pd0 species. The structures of complexes 2 and 3 were confirmed by X‐ray analysis. Both complexes are efficient catalysts for Negishi couplings involving primary and secondary alkyl zinc reagents bearing β‐hydrogen atoms. At a concentration of 0.1–0.5 mol % both catalysts readily promoted reactions at room temperature or even at 0 °C. The operational simplicity of these processes, in conjunction with the easy accessibility of both catalysts and substrates, promises synthetic utility of this new methodology. An experiment on a scale of 19.35 g carried out at very low catalyst loading of 2 (turnover number: 6 100 000) highlighted the potential application of the catalytic system. Monoalkyl and dialkyl zinc reagents displayed different reactivities and selectivities in reactions with aryl iodides catalyzed by complexes 2 or 3, and isomerization in reactions involving acyclic secondary alkyl zinc derivatives was suppressed by using appropriate amounts of dialkyl zinc reagents. Based on preliminary kinetic profiles and reaction evidence, three possible pathways are proposed for the reactions involving acyclic secondary alkyl zinc reagents to rationalize the difference between mono‐alkyl and dialkyl zinc derivatives.
Disparities in survival among women with invasive cervical cancer
Authors: Brookfield Kathleen F. , Cheung Michael C. , Lucci Joseph , Fleming Lora E. , Koniaris Leonidas G.
Published: December 2008

BACKGROUND:

In this study, the authors sought to understand the effects of patient race, ethnicity, and socioeconomic status (SES) on outcomes for cervical cancer.

METHOD:

The Florida Cancer Data System and the Agency for Health Care Administration data sets (1998‐2003) were merged and queried. Survival outcomes for patients with invasive cervical cancer were compared between different races, ethnicities, and community poverty levels.

RESULTS:

In total, 5367 patients with cervical cancers were identified. The overall median survival was 43 months. Significantly longer survival was observed for Caucasians (47.1 months vs 28.8 months for African Americans [AA]; P < .001), Hispanics (52.8 months vs 41.6 months for non‐Hispanics; P < .001), the insured (63 months vs 41.2 months for uninsured; P < .001), and patients from more affluent communities (53.3 months where <5% lived in poverty vs 36.9 months where >15% lived in poverty; P < .001). Surgery was associated with dramatically improved survival. AA women who were diagnosed with cervical cancer were significantly less likely to undergo surgical treatment with curative intent compared with Caucasian women (P < .001). However, on multivariate analysis, independent predictors of poorer outcomes were insurance status, tumor stage, tumor grade, and treatment. Neither race, nor ethnicity, nor SES was an independent predictor of poorer outcome.

CONCLUSIONS:

Race, ethnic, and SES disparities in cervical cancer survival were explained by late‐stage presentation and under‐treatment. Earlier diagnosis and greater access to surgery and other treatments would significantly improve the survival of women with cervical cancer. Cancer 2009. © 2008 American Cancer Society.
Defect structure and spectroscopic characteristics of codoped Hf: Er: LiNbO3 crystals
Authors: Sun Liang , Yang Chun‐Hui , Xu Yu‐Heng , Zhao Lian‐Cheng
Published: December 2008

Codoped Hf: Er: LiNbO3 crystals have been grown by the Czochralski technique. Defect structures of the crystals were analyzed by IR absorption spectra, and the compositions of the crystals were measured by X‐ray fluorescent spectrograph. A new OH–‐associated vibrational peak at 3492 cm–1 was revealed in 6 mol % Hf: 1 mol % Er: LiNbO3 crystal. It was attributed to (HfNb)–‐OH–‐(ErNb)2– defect centers. The Er3+ concentrations in crystals gradually decreased with the increase of the codoped Hf4+ concentrations in the melts. The emission characteristics of the crystals were investigated by the fluorescence spectrum. It was found that the luminescent intensity in codoped 6 mol % Hf: 1 mol % Er: LiNbO3 crystal was 3.5 times stronger than that in single doped 1 mol % Er: LiNbO3 crystal. The luminescent enhancement effect was successfully explained on the basis of defect structure of the crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Powder study of propanthioamide dervative C8H6N2S2
Authors: Dinnebier R. E. , Moustafa A. M.
Published: December 2008

The crystal structure of 2‐cyano‐3‐(2‐thienyl)prop‐2‐enethioamide (C8H6N2S2), a propanethioamide derivative was solved from high resolution laboratory X‐ray powder diffraction data collected at ambient conditions. Structure determination was performed by means of the global optimization method of simulated annealing at a resolution of 1.5 Å. Rietveld refinement yielded an RWP value of 4.02% (P21/a, a = 15.8174(2) Å, b = 5.6502(1) Å, c = 11.0952(1) Å, β = 116.9923(7)°, V = 883.6(5) Å3, Z = 4). The molecules are stacked in parallel layers and are stabilized by hydrogen bonds. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Practical Approach for Ambient‐Pressure Hydrogenations Using Pd on Porous Glass
Authors: Schmöger Christine , Stolle Achim , Bonrath Werner , Ondruschka Bernd , Keller Thomas , Jandt Klaus D.
Published: December 2008

A Pd on porous glass catalyst system was used in the liquid‐phase hydrogenation of terpenoid substrates with dihydrogen at room temperature and atmospheric pressure. A multitude of substances were hydrogenated selectively with yields of 90–100 %. In all experiments, only CC, CN, and NN double bonds were hydrogenated. Studies revealed that carbonyl and aromatic double bonds are inert towards catalytic reduction with dihydrogen under the conditions employed. In some cases, hydrogenation was accompanied by isomerization, so that treatment of β‐pinene, for example, afforded isomeric α‐pinene, which was subsequently hydrogenated to pinane.
An efficient paradigm for wavelet‐based image processing using cellular neural networks
Authors: Yu Sung‐Nien , Lin Chien‐Nan
Published: December 2008

We propose a novel paradigm for cellular neural networks (CNNs), which enables the user to simultaneously calculate up to four subband images and to implement the integrated wavelet decomposition and a subsequent function into a single CNN. Two sets of experiments were designated to test the performance of the paradigm. In the first set of experiments, the effects of seven different wavelet filters and five feature extractors were studied in the extraction of critical features from the down‐sampled low‐low subband image using the paradigm. Among them, the combination of DB53 wavelet filter and ther=2 halftoning processor was determined to be most appropriate for low‐resolution applications. The second set of experiments demonstrated the capacity of the paradigm in the extraction of features from multi‐subband images. CNN edge detectors were embedded in a two‐subband digital wavelet transformation processor to extract the horizontal and vertical line features from the LH and HL subband images, respectively. A CNN logic OR operator proceeds to combine the results from the two subband line‐edge detectors. The proposed edge detector is capable of delineating more subtle details than using typical CNN edge detector alone, and is more robust in dealing with low‐contrast images than traditional edge detectors. The results demonstrate the proposed paradigm as a powerful and efficient scheme for image processing using CNN. Copyright © 2008 John Wiley & Sons, Ltd.
Muscle degeneration and leukocyte infiltration caused by mutation of zebrafish fad24
Authors: Walters Kevin B. , Dodd M. Ernest , Mathias Jonathan R. , Gallagher Andrea J. , Bennin David A. , Rhodes Jennifer , Kanki John P. , Look A. Thomas , Grinblat Yevgenya , Huttenlocher Anna
Published: December 2008

Factor for adipocyte differentiation 24(fad24) is a novel gene that has been implicated in adipocyte differentiation and DNA replication. In a screen for zebrafish mutants that have an abnormal tissue distribution of neutrophils, we identified an insertional allele offad24, fad24hi1019. Homozygous fad24hi1019larvae exhibit muscle degeneration accompanied by leukocyte infiltration. Muscle degeneration was extensive and included tissue apoptosis and disorganized, poorly striated muscle fibers. Blocking apoptosis using pan‐caspase inhibitors resulted in decreased neutrophil recruitment into the body of the larva, suggesting a causative link between apoptosis and leukocyte infiltration. These findings suggest that zebrafish is a powerful genetic model system to address the interplay between muscle degeneration and leukocyte infiltration, and indicate that tissue apoptosis may contribute to neutrophil recruitment in some inflammatory states. Developmental Dynamics 238:86–99, 2009. © 2008 Wiley‐Liss, Inc.
Normal developmental stages of the Madagascar ground gecko Paroedura pictus with special reference to limb morphogenesis
Authors: Noro Miyuki , Uejima Asaka , Abe Gembu , Manabe Makoto , Tamura Koji
Published: December 2008

A table of developmental stages of the target species is useful for studying the development of any animal. Although tables of developmental stages have been established for several squamates, none has been published for gekkonid lizards. We have established a table of developmental stages for the Madagascar ground gecko Paroedura pictus. The table includes 27 embryonic stages from oviposition to hatching based on chronology and external morphology. The interval from oviposition to hatching is 60 days. Eleven to sixteen somites were observed at oviposition, and 5 to 6 somites were formed each day. Limb bud swellings were recognized by the third day after oviposition. After 2 weeks of incubation, the presumptive autopod was detected by carpal/tarsal cartilage formation. Cartilages in all digits were seen by 3 weeks after oviposition. Skin pigment was visible after 4 weeks incubation, and the skin color pattern was apparent 40 days after oviposition. Developmental Dynamics 238:100–109, 2009. © 2008 Wiley‐Liss, Inc.
Bmp2 is required for cephalic neural tube closure in the mouse
Authors: Castranio Trisha , Mishina Yuji
Published: December 2008

BMPs have been shown to play a role in neural tube development particularly as dorsalizing factors. To explore the possibility that BMP2 could play a role in the developing neural tube (NT) beyond the lethality of Bmp2 null embryos, we created Bmp2 chimeras from Bmp2 null ES cells and WT blastocysts. Analysis of Bmp2 chimeras reveals NT defects at day 9.5 (E9.5). We found that exclusion of Bmp2 null ES cells from the dorsal NT did not always prevent defects. For further comparison, we used a Bmp2 mutant line in a mixed background. Phenotypes observed were similar to chimeras including open NT defects, postneurulation defects, and abnormal neural ectoderm in heterozygous and homozygous null embryos demonstrating a pattern of dose‐dependent signaling. Our data exposes BMP2 as a unique player in the developing NT for dorsal patterning and identity, and normal cephalic neural tube closure in a dose‐dependent manner. Developmental Dynamics 238:110–122, 2009. Published 2008 Wiley‐Liss, Inc.
Analysis of human muscle stem cells reveals a differentiation‐resistant progenitor cell population expressing Pax7 capable of self‐renewal
Authors: Pawlikowski Bradley , Lee Laimeng , Zuo Jianhong , Kramer Randall H.
Published: December 2008

Studies using mouse models have established a critical role for resident satellite stem cells in skeletal muscle development and regeneration, but little is known about this paradigm in human muscle. Here, using human muscle stem cells, we address their lineage progression, differentiation, migration, and self‐renewal. Isolated human satellite cells expressed α7‐integrin and other definitive muscle markers, were highly motile on laminin substrates and could undergo efficient myotube differentiation and myofibrillogenesis. However, only a subpopulation of the myoblasts expressed Pax7 and displayed a variable lineage progression as measured by desmin and MyoD expression. Analysis identified a differentiation‐resistant progenitor cell population that was Pax7+/desmin− and capable of self‐renewal. This study extends our understanding of the role of Pax7 in regulating human satellite stem cell differentiation and self‐renewal. Developmental Dynamics 238:138–149, 2009. © 2008 Wiley‐Liss, Inc.
Indenylidene Complexes of Ruthenium Bearing NHC Ligands – Structure Elucidation and Performance as Catalysts for Olefin Metathesis
Authors: Monsaert Stijn , De Canck Els , Drozdzak Renata , Van Der Voort Pascal , Verpoort Francis , Martins José C. , Hendrickx Pieter M. S.
Published: December 2008

Second‐generation catalysts of the general formula Cl2Ru(SIMes)(L)(3‐phenylinden‐1‐ylidene), 3a (L = PCy3), 3b (L = PPh3), 3c (L = py), and Cl2Ru(SIMe)(L)(3‐phenylinden‐1‐ylidene), 4a (L = PCy3), 4b (L = PPh3), 4c (L = py) were found to be of interest in various metathesis transformations. The catalysts containing SIMe ligands showed improved initiation compared to the more robust SIMes substituted catalysts. A strong temperature effect was noted on all of the reactions tested. Interestingly, complex 3a, showing the lowest initiation rate at room temperature, emerged as the most productive of all systems examined at elevated temperature. It is shown that complexes containing the SIMe ligand display higher initiation efficiency than their corresponding SIMes analogues. Since the higher initiation is related to the ease of phosphane dissociation while phosphane dissociation also promotes catalyst decomposition, complexes bearing the SIMe ligand decompose faster. The complete 1H, 13C and 31P resonance assignment and the procedure applied to obtain these from a combination of 1D and 2D NMR techniques, is also reported. Combined with the ROESY technique, these enabled to investigate several conformational processes involving rotations around N–phenyl and C–Ru bonds on the millisecond to second timescale. A clear correlation is demonstrated between the bulkiness of the axial ligand (L) and the rotational freedom of the SIMe(s) ligand. A qualitative analysis also suggests that the extra para‐methyl of SIMes leads to additional steric interactions with the 3‐phenylinden‐1‐ylidene ligand. The data reported in this paper demonstrates that substitution patterns of the N‐aryl have a significant influence on the activity of the second‐generation indenylidene catalysts for a given metathesis reaction.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Photoelectrocatalytic Oxidation of NADH at a Graphite Electrode Modified with a New Polymeric Phenothiazine
Authors: Gligor Delia , Dilgin Yusuf , Popescu Ionel Catalin , Gorton Lo
Published: December 2008

A new approach for photoelectrocatalytic oxidation of NADH is described, based on a graphite electrode (G) modified with a new phenothiazine derivative, polyphenothiazine formaldehyde (PPF). Electrochemical measurements reveal that G/PPF presents a quasireversible voltammetric response, corresponding to a 2e−/2H+ transfer and that G/PPF modified electrodes show electrocatalytic activity for NADH oxidation. When the surface of the G/PPF modified electrode was irradiated with a light source (250 W Halogen lamp), a significant increase in the electrocatalytic current was observed. The second order electrocatalytic rate constant (kobs, [NADH]=0=3.9×103 M−1 s−1, pH 7.0) was calculated from rotating disk electrode experiments, performed at various NADH concentrations. From amperometric measurements, it was noticed that, in the presence of light irradiation, the sensitivity of NADH detection (calculated as Imax/KM ratio) increased ca. 3 times.
An M&A lesson: Should money always talk?
Authors: Tokic Stijepko , Beyea Genevieve
Published: December 2008

The recent economic downturn has caused a shake‐up in the private equity markets—with important implications for mergers and acquisitions (M&As). One recent merger agreement—once lauded as exemplary—has disintegrated into four separate, contentious lawsuits. What went wrong there? And what lessons does it hold to prevent similar disasters in the future? © 2009 Wiley Periodicals, Inc.
Business combinations: New accounting guidance
Authors: Ciesielski Jack T. , Weirich Thomas R.
Published: December 2008

“Sweeping” is the best word to describe the changes in acquisition accounting from Financial Accounting Standards Board Statement No. 141(R). The authors present a detailed analysis of its guidelines and impact. © 2009 Wiley Periodicals, Inc.
Merging financial and managerial accounting: Strategic cost management and enterprise risk assessment under SOX
Authors: Shank John K. , Miguel Joseph G. San
Published: December 2008

The spate of accounting and financial reporting scandals in recent years has challenged businesses, auditors, directors, and accounting regulators to take a much broader perspective in evaluating and reporting on risk. The Sarbanes‐Oxley (SOX) legislation in the United States was an attempt to address the problems by requiring enterprises to assess their risks. This article examines the eventful life of an entrepreneurial, publicly traded U.S. telecom venture, including its efforts to support the “strategic enterprise” perspective. It points out the dangers when this perspective is ignored. © 2009 Wiley Periodicals, Inc.