bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, complete 1H and 13C NMR assignment and crystal structure of novel epoxide derivatives of cytochalasin B
Authors: Steyn Pieter S. , Breytenbach Jaco C. , Botha Jeanne H. , Fernandes Manuel A. , Wessels Philippus L. 
Published: April 2008

AbstractFive novel epoxide derivatives of cytochalasin B were synthesized. Reaction of cytochalasin B with t‐BHP and BuLi led to selective epoxidation of the C‐21/22 double bond to give a single monoepoxide, while reaction with m‐CPBA yielded two diepoxides. Reaction of the monoepoxide with m‐CPBA yielded two triepoxides. The relative configurations of the epoxides were elucidated by analogy with the natural product by means of spectroscopic methods; full assignment of NMR signals was achieved, and the absolute configuration was confirmed by X‐ray crystallography. Copyright © 2008 John Wiley & Sons, Ltd.
In vivo MRS markers of response to CHOP chemotherapy in the WSU‐DLCL2 human diffuse large B‐cell lymphoma xenograft
Authors: Lee Seung‐Cheol , Huang Ming Q. , Nelson David S. , Pickup Stephen , Wehrli Suzanne , Adegbola Onikepe , Poptani Harish , Delikatny Edward J. , Glickson Jerry D. 
Published: April 2008

AbstractTo identify 1H‐MRS molecular biomarkers of early clinical therapeutic response in non‐Hodgkin's lymphoma, an in vivo longitudinal study was performed on human non‐Hodgkin's diffuse large B‐cell lymphoma xenografts (WSU‐DLCL2) grown in the flanks of female SCID mice. 31P‐MRS measurements, which have been demonstrated to be prognostic clinical indices of response (Arias‐Mendoza et al. Acad. Radiol. 2004; 11: 368–376) but which provide lower spatial resolution, were included for comparison. The animals received CHOP (cyclophosphamide, hydroxydoxorubicin, oncovin and prednisone) chemotherapy for three 1‐week cycles, resulting in stable disease based on tumor volume. Localization of total choline and phosphorus metabolites in vivo was achieved with stimulated echo acquisition mode and image selected in vivo spectroscopy sequences, respectively. Significant decreases in lactate were detected by the selective multiple quantum coherence spectral editing technique after the first cycle of CHOP, whereas total choline and the phosphomonoester/nucleoside triphosphate ratio did not change until the third cycle. Ex vivo extract MRS of tumors corroborated the in vivo results. Histological staining with antibodies to Ki67 revealed a decrease in proliferation rate in CHOP‐treated tumors that coincided with the decrease in lactate. This study demonstrates the utility of lactate as an early proliferation‐sensitive indicator of therapeutic response in a mouse model of non‐Hodgkin's lymphoma and serves as a basis for future clinical implementation of these methods. Copyright © 2008 John Wiley & Sons, Ltd.
Role of reading engagement in mediating effects of reading comprehension instruction on reading outcomes
Authors: Wigfield Allan , Guthrie John T. , Perencevich Kathleen C. , Taboada Ana , Klauda Susan Lutz , McRae Angela , Barbosa Pedro 
Published: April 2008

AbstractThe engagement model of reading development suggests that instruction improves students' reading comprehension to the extent that it increases students' engagement processes in reading. We compared how Concept‐Oriented Reading Instruction (CORI) (support for cognitive and motivational processes in reading), strategy instruction (support for cognitive strategies in reading), and traditional instruction in fourth‐grade classrooms differentially influenced students' reading comprehension, strategy use, and engagement in reading. Students experiencing CORI were significantly higher than both comparison groups on reading comprehension, reading strategies, and reading engagement. When students' level of reading engagement was statistically controlled, the differences between the treatment groups were not significant. We infer that the level of students' reading engagement during classroom work mediated the instructional effects on reading outcomes. © 2008 Wiley Periodicals, Inc.
Competing Inactivation Agents for Bacterial Spores in Radio‐Frequency Oxygen Plasmas
Authors: Vicoveanu Dragos , Popescu Sebastian , Ohtsu Yasunori , Fujita Hiroharu 
Published: April 2008

AbstractThe inactivation of Bacillus subtilis spores in a low pressure RF oxygen plasma was studied. The experiments were especially designed to discriminate the relative importance of the competing spore inactivation agents. The decimal reduction values, characteristic for the action on the spores of heat, optical radiation and plasma particles, respectively, were estimated for different injected RF powers. These results indicated that during the initial stage of sample treatment, the most important inactivation agent is the optical radiation, whereas during the second stage of treatment, the leading role is assumed by the plasma particles. The dependence of spore inactivation kinetics on the injected RF power was also studied, by using the Z‐value.magnified image
Consequences of dichotomization
Authors: Fedorov Valerii , Mannino Frank , Zhang Rongmei 
Published: April 2008

AbstractDichotomization is the transformation of a continuous outcome (response) to a binary outcome. This approach, while somewhat common, is harmful from the viewpoint of statistical estimation and hypothesis testing. We show that this leads to loss of information, which can be large. For normally distributed data, this loss in terms of Fisher's information is at least 1 − 2/π (or 36%). In other words, 100 continuous observations are statistically equivalent to 158 dichotomized observations. The amount of information lost depends greatly on the prior choice of cut points, with the optimal cut point depending upon the unknown parameters. The loss of information leads to loss of power or conversely a sample size increase to maintain power. Only in certain cases, for instance, in estimating a value of the cumulative distribution function and when the assumed model is very different from the true model, can the use of dichotomized outcomes be considered a reasonable approach. Copyright © 2008 John Wiley & Sons, Ltd.
Pharmacological and immunological effects of individual herbs in the Food Allergy Herbal Formula‐2 (FAHF‐2) on peanut allergy
Authors: Kattan Jacob D. , Srivastava Kamal D. , Zou Zhong Mei , Goldfarb Joseph , Sampson Hugh A. , Li Xiu‐Min 
Published: April 2008

AbstractIt was previously shown that a Chinese herbal formula, Food Allergy Herbal Formula 2 (FAHF‐2) composed of nine herbs, blocked peanut‐induced anaphylaxis in a murine model. The current study was designed to investigate the pharmacological actions of individual herbs comprising FAHF‐2 on peanut‐induced anaphylactic reactions in a murine model of peanut allergy and to determine if all nine herbs are necessary to prevent an anaphylactic reaction, or if a simplified formula containing fewer herbs would be equally effective. Some individual herbs reduced peanut‐induced anaphylactic symptoms but no single herb offered full protection from anaphylactic symptoms equivalent to FAHF‐2. The herbs had highly variable effects on histamine release, as well as peanut‐specific serum IgE and IgG2a levels. The herbs also had variable effects on IL‐4, IL‐5 and IFN‐γ levels. A simplified formula comprising the most efficacious tested individual herbs showed only partial efficacy and was not able to reproduce comparably the effects of FAHF‐2, suggesting that component herbs of FAHF‐2 may work synergistically to produce the curative therapeutic effects produced by the whole formula, which appears to be the best option for future clinical trials. Copyright © 2008 John Wiley & Sons, Ltd.
Starch Retrogradation in Cassava Flour From Cooked Parenchyma
Authors: Rodríguez‐Sandoval Eduardo , Fernández‐Quintero Alejandro , Cuvelier Gerard , Relkin Perla , Bello‐Pérez Luis Arturo 
Published: April 2008

AbstractStarch changes in cassava flours made from parenchyma (peeled root) cooked either in steam or in boiling water and stored at 5ºC or −20ºC for 24 h were studied using differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction and iodine binding capacity. The storage temperature of cooked parenchyma did not have a significant effect on starch retrogradation. For storage at 5ºC, flour from steam‐cooked parenchyma presented a slightly higher melting enthalpy of retrograded starch and crystallinity compared to that of parenchyma cooked in boiling water. When stored at −20ºC, the cooking procedure had no significant effect on the melting enthalpy of retrograded starch, crystallinity and blue value index (BVI). The water content in cooked parenchyma stored at 5ºC influenced the extent of retrogradation. The cooking method and the storage temperature are important parameters that might influence the physicochemical and functional properties of cassava flours.
Preparation and Physical Properties of Starch Mixed Esters
Authors: Yang Byung Y. , Montgomery Rex 
Published: April 2008

AbstractThe use of trifluoroacetic anhydride as a promoter for the preparation of mixed esters of granular starch is reported. Efficient esterification results in complete dissolution of the starch granules, which is attained without the use of an external heat source when trifluoroacetic anhydride was added incrementally to a starch slurry in the mixed carboxylic acids. Starch mixed esters are co‐acetate/butyrate, co‐acetate/hexanoate, co‐acetate/octanoate, co‐acetate/palmitate and co‐acetate/butyrate/hexanoate/octanoate/palmitate, each from a solution of the corresponding mixed acids. The products comprise a total degree of substitution > 2.5, as analyzed by gas‐liquid or high‐pressure liquid chromatographies. In each product the extent of acid substitution is the same as or close to the composition of the corresponding acid distribution in the reaction mixture. Films cast of the resulting mixed esters, together with the corresponding single acid esters, are analyzed for glass transition and tensile properties, as measured by a dynamic mechanical analyzer. Glass transition temperature and tensile modulus increase proportionally with the increased mole fraction of acetate within the starch mixed acids. Film elongation increases with increases of acyl chain length in all of the starch esters. The dependency of those properties on the relative distribution of acyl group is discussed.
Increased Postprandial Triglyceride‐Rich Lipoprotein Levels in Elderly Survivors of Myocardial Infarction
Authors: Lekhal Samira , Børvik Trond , Nordøy Arne , Hansen John‐Bjarne 
Published: April 2008

AbstractPostprandial triglyceride‐rich lipoproteins (TRL) levels are a predictor for coronary atherosclerosis. The aim of the study was to compare fasting high density lipoprotein (HDL) cholesterol, plasma lipoprotein lipase (LPL) activity, and postprandial TRL between elderly survivors of myocardial infarction (MI) and healthy controls. A case‐control study was performed in 44 elderly patients 65–85 years of age with a previous history of MI and 43 age‐ and sex‐matched healthy controls. Each participant underwent physical examination and was given a standard oral fat load with subsequent blood sampling over the next 8 h. Total and chylomicron triglycerides were assessed by area under the curve (AUC), incremental are under the curve (AUCi) and triglyceride response (TGR). Elderly MI patients had significantly lower postheparin LPL activity (87.4 ± 36.9 mU/ml) (mean ± 1 SD) than healthy controls (106.0 ± 29.0 mU/ml) (P = 0.014). Decreased postheparin LPL activity was accompanied by significant increased and delayed clearance of postprandial TRL. Fasting HDL cholesterol was significantly lower in elderly MI patients than controls (1.45 ± 0.32 and 1.66 ± 0.47 mmol/l, respectively, P = 0.048). Multiple regression analysis revealed postheparin LPL activity as an independent predictor for postprandial TRL and fasting HDL cholesterol. Logistic regressions analysis revealed HDL cholesterol, triglycerides measured 2 h after the oral fat load, and postheparin LPL activity as independent predictors for MI. Our findings indicate that decreased fasting HDL cholesterol is associated with increased postprandial triglyceridemia which could be a target for life‐style and therapeutic interventions in patients at risk for cardiovascular disease.
Adaptive actuator failure compensation for redundant manipulators
Authors: Kececi E. Faruk , Tang Xidong , Tao Gang 
Published: April 2008

SUMMARYThis paper presents an adaptive actuator failure compensation method, which compensates for uncertainties due to unknown actuator failures for redundant manipulator systems. The method is first developed for manipulators whose joints are concurrently actuated. While physical realization of concurrently actuated manipulators and the advantages of their use have been understood before, in this paper failure modeling, controller structure, and adaptive update rules for handling uncertainties from the actuator failures are studied. The adaptive actuator failure compensation method is then expanded for a cooperating multiple manipulator system with uncertain actuator failures. Dynamic equations of such a multiple manipulator system in the task space are derived and the adaptive actuator failure compensation problem is formulated in the task space, for which a compensation controller structure is proposed with stable adaptive parameter update laws. The adaptive control scheme is able to compensate for the uncertainties of system parameters and actuator failures in a more general sense. For both cases, closed-loop system stability and asymptotic tracking are proved, despite uncertain system failures.
Eating Meals Irregularly: A Novel Environmental Risk Factor for the Metabolic Syndrome
Authors: Sierra‐Johnson Justo , Undén Anna‐Lena , Linestrand Madeleine , Rosell Magdalena , Sjogren Per , Kolak Maria , De Faire Ulf , Fisher Rachel M. , Hellénius Mai‐Lis 
Published: April 2008

Background: Skipping meals is a common practice in our current society; however, it is not clear whether eating meals regularly is associated with the metabolic syndrome.Objective: Our aim was to assess the association of eating meals regularly with parameters of the metabolic syndrome and insulin resistance in a representative population‐based cohort of 60‐year‐old men and women.Methods and Procedures: A population‐based cross‐sectional study of 3,607 individuals (1,686 men and 1,921 women), aged 60 years, was conducted in Stockholm County, Sweden. Medical history, socioeconomic factors, and lifestyle data were collected by a questionnaire and a medical examination, which included laboratory tests.Results: Of the subjects who were regular eaters, 20% fulfilled the criteria for the metabolic syndrome vs. 27% of subjects who were irregular eaters (P < 0.0001). The adjusted odds ratio (OR) for having the greatest number of components of the metabolic syndrome in subjects who were regular eaters was 0.27 (95% confidence interval (CI), 0.13–0.54) using subjects who did not fulfill any criteria for the metabolic syndrome as a reference group. Eating meals regularly was also inversely related to insulin resistance (OR, 0.68 (95% CI, 0.48–0.97)) and to γ‐glutamyl transferase (OR, 0.52 (95% CI, 0.33–83)) after full adjustment.Discussion: Eating meals regularly is inversely associated to the metabolic syndrome, insulin resistance and (high) serum concentrations of γ‐glutamyl transferase. These findings suggest that eating meals irregularly may be part of several potential environmental risk factors that are associated with the metabolic syndrome and may have future implications in giving dietary advice to prevent and/or treat the syndrome.
Depot‐specific Regulation of the Conversion of Cortisone to Cortisol in Human Adipose Tissue
Authors: Lee Mi‐Jeong , Fried Susan K. , Mundt Steven S. , Wang Yanxin , Sullivan Sean , Stefanni Alice , Daugherty Bruce L. , Hermanowski‐Vosatka Anne 
Published: April 2008

Objective: Our main objective was to compare the regulation of cortisol production within omental (Om) and abdominal subcutaneous (Abd sc) human adipose tissue.Methods and Procedures: Om and Abd sc adipose tissue were obtained at surgery from subjects with a wide range of BMI. Hydroxysteroid dehydrogenase (HSD) activity (3H‐cortisone and 3H‐cortisol interconversion) and expression were measured before and after organ culture with insulin and/or dexamethasone.Results: Type 1 HSD (HSD1) mRNA and reductase activity were mainly expressed within adipocytes and tightly correlated with adipocyte size within both depots. There was no depot difference in HSD1 expression or reductase activity, while cortisol inactivation and HSD2 mRNA expression (expressed in stromal cells) were higher in Om suggesting higher cortisol turnover in this depot. Culture with insulin decreased HSD reductase activity in both depots. Culture with dexamethasone plus insulin compared to insulin alone increased HSD reductase activity only in the Om depot. This depot‐specific increase in reductase activity could not be explained by an alteration in HSD1 mRNA or protein, which was paradoxically decreased. However, in Om only, hexose‐6‐phosphate dehydrogenase (H6PDH) mRNA levels were increased by culture with dexamethasone plus insulin compared to insulin alone, suggesting that higher nicotinamide adenine dinucleotide phosphate‐oxidase (NADPH) production within the endoplasmic reticulum (ER) contributed to the higher HSD reductase activity.Discussion: We conclude that in the presence of insulin, glucocorticoids cause a depot‐specific increase in the activation of cortisone within Om adipose tissue, and that this mechanism may contribute to adipocyte hypertrophy and visceral obesity.
High‐fat Diet Alters PP2A, TC10, and CIP4 Expression in Visceral Adipose Tissue of Rats
Authors: Jun Hye‐Seung , Hwang Kyujung , Kim Yunjung , Park Taesun 
Published: April 2008

Objective: The aim of this study was to investigate a possible link between high‐fat diet (HFD)–induced obesity and the expression of protein phosphatase 2A (PP2A) and Cdc42‐interacting protein 4 (CIP4) proteins, potential downstream components of the IRS/PI3K/AKT and CAP/Cbl/TC10 pathway, respectively, in the visceral adipose tissue.Methods and Procedures: Twenty male Sprague‐Dawley rats were randomly divided into two groups and were given either HFD or the normal diet (ND) for 8 weeks. The HFD‐induced changes in the expression of the epididymal adipose tissue genes involved in the insulin‐signaling pathways were evaluated using real‐time reverse‐transcription PCR and western blot analysis.Results: The exposure of rats to HFD for 8 weeks resulted in a significant increase in the expression of PP2A at both the transcriptional and translational levels, along with a marked reduction in the levels of phosphorylated AKT and insulin receptor substrate‐1 (IRS‐1) in the cytosol of visceral adipocytes, compared with the ND rats. Besides, there were significant HFD‐induced decreases in the mRNA and protein levels of CIP4 and TC10 in the adipose tissue of rats.Discussion: These data suggest that HFD might have a relevance to insulin resistance by increasing the expression of PP2A, an inhibitor of AKT activity in the phosphatidylinositol 3‐kinase (PI3K)/AKT pathway, and also by suppressing the expression of TC10 and CIP4, downstream effectors of the Cbl/CAP/TC10 insulin‐signaling cascade in the visceral adipose tissue.
Weight Loss Therapy Improves Pancreatic Endocrine Function in Obese Older Adults
Authors: Villareal Dennis T. , Banks Marian R. , Patterson Bruce W. , Polonsky Kenneth S. , Klein Samuel 
Published: April 2008

Objective: Obesity and aging increase the risk of type 2 diabetes (T2D). We evaluated whether weight loss therapy improves pancreatic endocrine function and insulin sensitivity in obese older adults.Methods and Procedures: Twenty‐four obese (BMI: 38 ± 2 kg/m2) older (age: 70 ± 2 years) adults completed a 6‐month randomized, controlled trial. Participants were randomized to diet and exercise (treatment group) or no therapy (control group). β‐Cell function (assessed using the C‐peptide minimal model), α‐cell function (assessed by the glucagon response to an oral glucose load), insulin sensitivity (assessed using the glucose minimal model), and insulin clearance rate were evaluated using a 5‐h modified oral glucose tolerance test.Results: Body weight decreased in the treatment group, but did not change in the control group (−9 ± 1% vs. 0 ± 1%; P < 0.001). Insulin sensitivity doubled in the treatment group and did not change in the control group (116 ± 49% vs. −11 ± 13%; P < 0.05). Even though indices of β‐cell responsivity to glucose did not change (P > 0.05), the disposition index (DI), which adjusts β‐cell insulin response to changes in insulin sensitivity, improved in the treatment group compared with the control group (100 ± 47% vs. −22 ± 9%; P < 0.05). The glucagon response decreased in the treatment but not in the control group (−5 ± 2% vs. 4 ± 4%; P < 0.05). Insulin secretion rate did not change (P > 0.05), but insulin clearance rate increased (51 ± 25%; P < 0.05), resulting in lower plasma insulin concentrations.Discussion: Weight loss therapy concomitantly improves β‐cell function, lowers plasma glucagon concentrations, and improves insulin action in obese older adults. These metabolic effects are likely to reduce the risk of developing T2D in this population.
Age‐Related Alterations in Reactivity of Cerebral Arterioles: Role of Oxidative Stress
Authors: Mayhan William G. , Arrick Denise M. , Sharpe Glenda M. , Sun Hong 
Published: April 2008

ABSTRACTObjective: Our goal was to identify the role of oxidative stress via activation of NAD(P)H oxidase in cerebrovascular dysfunction in aged rats.Methods: We examined the reactivity of cerebral arterioles in adult and aged Fisher‐344 rats to endothelial nitric oxide synthase (eNOS)‐dependent (acetylcholine and adenosine diphosphate [ADP]) and‐independent (nitroglycerin) agonists before and during application of tempol, apocynin, and diphenyleneiodonium chloride (DPI). We used Western blot to examine subunits of NAD(P)H oxidase, eNOS, and superoxide dismutase (SOD‐1) in cerebral microvessels and parietal cortex. Finally, we measured superoxide production by cortex tissue in adult and aged rats.Results: Acetylcholine‐and ADP‐induced, but not nitroglycerin‐induced, dilatation of cerebral arterioles was impaired in aged compared to adult rats. While tempol, apocynin, and DPI did not alter responses in adults, they alleviated impaired eNOS‐dependent vasodilatation in aged rats, without influencing responses to nitroglycerin. eNOS and p67phox proteins were increased in cerebral microvessels from aged compared to adult rats. Further, p67phox and gp91phox proteins were increased, but SOD‐1 protein was decreased, in cortex tissue of aged rats. Basal and agonist‐induced production of superoxide was elevated in aged rats.Conclusions: Aging impairs eNOS‐dependent reactivity of cerebral arterioles via an increase in superoxide produced by activation of NAD(P)H oxidase.