Cantly Increased Research Articles

Effect of Hydrogen Peroxide and High Glucose on the Glucose Metabolism of Lymphoma-derived U937 Cells

Our study aimed to clarify speci c oxidative stress and glucose metabolic disorders in hemodialysis patients, by examining hydrogen peroxide (H2O2)and high glucose-induced oxidative stress, glucose transport and the failure of glycolysis. As an in vitro blood cell model of end-stage renal disease (ESRD) in patients with diabetes, human monocytic U937 cells of malignant lymphoma origin were exposed to high glucose (28.9 mM) for 6 days, with 5 mM H2O2 added on the last day. The generation of intracellular reactive oxygen species (ROS), glucose levels, lactate levels, AMP-activated protein kinase (AMPK) activity and Glut4 levels were examined. Exposure of U937 cells to H2O2 resulted in a signi cant increase in intracellular ROS generation and glucose levels. Under high glucose conditions, treatment with H2O2 signi cantly promoted these actions. In H2O2-induced U937 cells, AMPK activity and Glut4 levels were signi cantly increased, but lactate and pyruvate levels were signi cantly decreased. Thus, exposure of U937 cells to H2O2 and a high glucose load promoted an increase in intracellular ROS, and exposure to H2O2 induced increased glucose transport and high intracellular glucose due to reduced glycolytic metabolism. This suggests that reduced glycolytic metabolism might be induced in states of high oxidative stress in hemodialysis patients with diabetes.

Effects of Liraglutide, a Human Glucagon-Like Peptide-1 Analog, on Glucose/Lipid Metabolism, and Adipocytokines in Patients With Type 2 Diabetes

The glucagon-like peptide 1 (GLP-1), one of gastrointestinal hormones, stimulates insulin secretion from pancreatic s-cells in a glucose-dependent manner. Recently, liraglutide, a human GLP-1 analog, has been introduced as therapeutic strategies for type 2 diabetes mellitus. Clinical studies have demonstrated reduction in blood glucose and body weight, improvements in pancreatic s-cell function and a low risk for hypoglycemia with liraglutide [1, 2]. Since diabetes is signifi cantly associated with cardiovascular events, it is very important to understand effects of anti-diabetic drugs on other cardiovascular risk biomarkers. Therefore, we studied effects of liraglutide on glucose/lipid metabolism and adipocytokines in patients with type 2 diabetes. Five patients (4 females and one male) with type 2 diabetes participated in this study. The mean ± SD of age, body height, body weight, body mass index and hemoglobin A1c were 60.2 ± 8.9 years old, 156.1 ± 5.4 cm, 71.6 ± 15.6 kg, 29.5 ± 7.0 kg/m2 and 9.1 ± 2.1%, respectively. We measured high-sensitivity C-reactive protein (hs-CRP), adiponectin, interleukin-6, and small dense low-density lipoprotein (sdLDL), oxidized LDL (ox-LDL) and cholesterol level in each lipoprotein fraction using the high-performance liquid chromatography (HPLC) method before and after the two weeks treatment using liraglutide (0.3 mg for one week and 0.6 mg for one week) [3]. The data are presented in Figure 1. A statistical signifi cant increase in serum fasting C-peptide levels was observed following two week treatment with liraglutide. However, fasting plasma glucose levels were elevated. Although statistical signifi cances were not obtained compared with baseline, serum levels of total cholesterol (TC) and triglyceride (TG) tended to decrease. Liraglutide also tended to reduce TG-rich lipoproteins such as chylomicron, intermediate density-lipoprotein (IDL), very low density-lipoprotein (VLDL) and sd-LDL. Although statistical signifi cances were not also obtained compared with baseline, serum adiponectin levels decreased, and interleukin-6 and hs-CRP levels increased. Further, serum ox-LDL increased following liraglutide treatment. In the LEAD (Liraglutide Effect and Action in Diabetes) 4 study, serum C-peptide levels signifi cantly increased, and serum levels of TC, TG, LDL-cholesterol (LDL-C), free fatty acids (FFA) signifi cantly decreased following 26-week treatment with liraglutide [4]. Seino Y et al performed the 24-week, multicenter, double blind, randomized parallelgroup trial compared the effi cacy and safety of liraglutide and glibenclamide monotherapy in Japanese subjects with type 2 diabetes [5]. Liraglutide signifi cantly reduced serum FFA levels compared with glibenclamide, however, there were no signifi cant differences in serum levels of TC, LDLC, VLDL-C, HDL-C and TG between the two groups. In our study, liraglutide signifi cantly increased serum C-peptide levels compared with baseline, which supports the results of LEAD 4 study and our previous study and also suggests that two weeks is suffi cient to increase serum C-peptide [4, 6]. To our knowledge, our report is the fi rst to study serum levels of IDLC, CM-C, sd-LDL following liraglutide treatment. Although statistical signifi cant differences were not obtained compared with baseline, liraglutide tended to reduce TG, TG-rich lipoprotein, and sd-LDL. In the LEAD 4 and study by Seino Y et al, liraglutide signifi cantly decreased serum FFA levels [4, 5]. Liraglutide has been reported to reduce postprandial glucagon levels by 20% [7]. Glucagon stimulates lipolysis in adipocytes and increase plasma FFA levels [8]. Reduction of glucagon-mediated increase in serum FFA Manuscript accepted for publication August 22, 2011

Effects of large enemies on success of exotic species in marine fouling communities of Washington, USA

The enemy release hypothesis, which posits that exotic species are less regulated by enemies than native species, has been well-supported in terrestrial systems but rarely tested in marine systems. Here, the enemy release hypothesis was tested in a marine system by excluding large enemies (>1.3 cm) in dock fouling communities in Washington, USA. After documenting the distribution and abundance of potential enemies such as chitons, gastropods and flatworms at 4 study sites, exclusion experiments were conducted to test the hypotheses that large grazing ene- mies (1) reduced recruitment rates in the exotic ascidian Botrylloides violaceus and native species, (2) reduced B. violaceus and native species abundance, and (3) altered fouling community struc- ture. Experiments demonstrated that, as predicted by the enemy release hypothesis, exclusion of large enemies did not significantly alter B. violaceus recruitment or abundance and it did signifi- cantly increase abundance or recruitment of 2 common native species. However, large enemy exclusion had no significant effects on most native species or on overall fouling community struc- ture. Furthermore, neither B. violaceus nor total exotic species abundance correlated positively with abundance of large enemies across sites. I therefore conclude that release from large ene- mies is likely not an important mechanism for the success of exotic species in Washington fouling communities.

Assessment of running safety of railway vehicles using multibody dynamics

An analysis model for multibody systems was developed to assess the running safety of the Saemaeul train passing through curves. Sensitivity analyses based on the variation of parameters related to derailments were conducted using this model and the ADAMS/Rail software package. These analyses showed that the derailment coefficient and the unload ratio of the right wheel were higher than that of the left wheel at low speed, but lower at high speed. The derailment coefficient and the unload ratio increased as the curve radius decreased. The derailment coefficient increased but there was no change in the unload ratio as the length of transition curves increased. The derailment coefficient and the unload rate increased in proportion to the increase in track cant.

Contrasting growth effects of prey capture in two aquatic carnivorous plant species

A detailed 11-day growth analysis was performed under greenhouse conditions on two aquatic, carnivo- rous plants in order to determine growth effects caused by supplemental feeding on zooplankton. The two species surveyed were the rare, stenotypic Aldrovanda vesiculosa and the more common, eurytopic Utricularia australis. While a highly signifi cant increase in shoot biomass (by 60 %) was found for Aldrovanda plants supplemented with prey, no signifi cant effect of prey addition occurred in Utricularia. However, main shoots of fed plants of both spe- cies were signifi cantly longer, had more mature leaf nodes, and their mean apical growth rate was higher than in unfed plants. Branching was markedly supported by prey in Aldrovanda only. Feeding signifi cantly increased the structural investment in carnivory in Utricularia but had no effect on Aldrovanda, although signifi cantly increas- ing maximum trap length in both species. Measurements of total nutrient concentrations in fed Aldrovanda plants revealed much more total N, P, K, and Mg at the end of the experiment, compared with unfed plants. In Utricularia, however, fed plants contained only more N than unfed plants but the opposite was true for the total amount of P, K and Mg. In Aldrovanda, a large proportion of N, P, K, and Mg consumption could be covered from prey. The differ- ent growth effect of prey addition in the two species could be explained by the operation of a complex food web in Utricularia traps, which possibly substitute for prey capture in barren waters.

Response of oxidative stress enzymes in charophyte <i>Nitellopsis obtusa</i> exposed to allochthonous leaf extracts from beech <i>Fagus sylvatica</i>

* Corresponding author. E-mail: reda_grigutyte@yahoo.com Leaf litter is one of the allochthonous sources of dissolved organic carbon (DOC) in freshwater ecosystems. Th roughout the degradation of leaves, a lot of chemical compounds are set free into water, which may promote oxidative stress via generation of reactive oxygen species and / or by disturbance of the intracellular oxidative balance in aquatic organisms. We investigated concentrationand time-dependent relationships for the activities of oxidative stress enzymes in macrophytic algae cells of Nitellopsis obtusa, induced by beech Fagus sylvatica leaf extracts, respectively, 0.11–55.0 mg L–1 DOC (aft er 24 h) and 1.1 mg L–1 DOC aft er (15 min – 24 h). Th e oxidative stress enzymes included catalase (CAT – E. C. 1.11.1.6), glutathione reductase (GR – E. C. 1.6.4.2), cytosolic and microsomal glutathione S-transferase (GST – E. C. 2.5.1.18). A signifi cant increase in sGST and mGST activities aft er a 24-h exposure to 1.1–11.0 mg L–1 and to 5.5 mg L–1 DOC of beech leaf extracts was detected. sGST activity signifi cantly increased in the whole period of exposure, while mGST activity decreased below control levels when exposed for 1–4 h. Glutathione reductase activity increased signifi cantly at all DOC concentrations of beech leaf extracts aft er 24 h of exposure. Th e highest elevation of GR activity was observed in extracts containing 5.5 mg L–1 DOC and the lowest activity increment at 0.11 mg L–1 DOC. A statistically signifi cant increase in GR activity started aft er 1 h (at 1.1 mg L–1 DOC) and was evident until the end of the 24-h exposure. Th e activity of catalase increased signifi cantly only at the lowest (1.1 mg L–1) DOC concentration aft er 24 h of exposure. Beech leaf extracts induced a statistically signifi cant time-dependent elevation of CAT activity during the whole period of exposure. In general, an increase of antioxidative enzyme activities in charophyte Nitellopsis obtusa indicated that the defence mechanisms against oxidative stress were induced when cells had been exposed to beech leaf extracts.

Effects of water regimes on ®ve pickling and double aptitude olive cultivars (Olea europaea L.)

SummaryTree development, yield and quality characteristics of fresh fruit and oil were evaluated under different water regimes for ®ve years. The olive cultivars Ascolana Tenera, Kalamata, Nocellara del Belice, Maiatica and Itrana were tested in a factorial combination of four irrigation regimes: a rainfed control (T0) and three treatments (T1, T2, and T3) irrigated daily with a restitution of 33, 66, and 66% of crop evapotranspiration (ETc). In all years the lowest values of soil water content and xylem potential were detected in September and early October in T0, during the phenological phase of rapid enlargement of fruit cells, while values were near ®eld capacity during the irrigation season in treatment T3. Growth parameters such as canopy, trunk cross section area and pruned wood showed little differences between the rain-fed control and the lowest irrigation level and between treatment T2 and T3 while differences were evident between the control and treatment T2. Yield, fruit size, pulp-stone ratio and dry-matter content of fruit peaked at an irrigation depth of 66% of ETc, while higher volumes did not signi®cantly increase yield, suggesting that complete replacement of water loss by the crop is not recommended. Only `Kalamata' showed a higher yield of T3 over T2. Irrigation regimes did not affect the oil content calculated on dry-weight basis and the increase in oil per hectare was explained according to the increase in fruit dry matter content and number of fruit for `Kalamata'. The fatty acid composition, sugar and acid content of the oil were not affected by irrigation, while the total polyphenol decreased up to treatment T2. In the most irrigated treatment bitterness and pungency of the oil slightly decreased as compared with the rainfed control, while fruiting was unaffected by irrigation.

Role of Ammonium Hydrate in the Endometrium/Myometrium

1 Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine. Correspondence should be addressed to H. V. Danylovych (e-mail: kinet@biochem.kiev.ua). We studied the possibility of production of ammonium hydrate (NH 3 ) in the endometrium and its effect on the Са/Н exchange in the plasma membrane of myometrial cells. Stroma cells of the endometrium and a suspension of intact myocytes were obtained from porcine and rat utera, respectively, using standard techniques. The АМР-deaminase activity was measured according to the characteristic maximum of ІМР absorption in UV light, while the amount of NH 3 was measured by staining using TNBS with subsequent colorimetry of the product. The concentration of cytosolic Саand intracellular рН in myocytes were measured using the fluorescent probes Fura-2AM and BCECFAM, respectively. It was found that in the suspension of stroma cells the activity of the main enzyme responsible for NH 3 biosynthesis, AMP deaminase, measured in the presence of 0.2% Triton-Х100 and 1.5 М KCl, is 53 ± ± 2 μmol ІМР/mg protein per 1 h. The basal production of NH 3 released to the extracellular medium in the cell suspension was equal, on average, to 9.5 ± ± 2.5 nmol/mg protein per 25 min. This production considerably increased after stimulation of the cells with 1 μM acetylcholine and was effectively suppressed by a relatively specific inhibitor of AMP deaminase, fluoride ions. When 0.1 mM NH 3 was added to the suspension of myometrical myocytes, the рН of the myoplasm increased from 6.7 in the control to 8.1 due to alkalization of the extracellular space by NH 4 . This increase was partially inhibited by inhibitors of the Н and K channels, 4-aminopyridine and tetraetylammonium. NH 3 induced alkalization of the extracellular space resulted in a signifi cant increase of acetylcholine (0.1 mM)-stimulated Са entry into myocytes. This process was completely suppressed by 1.0 mM Cd and 1.0 nМ nifedipine, which was indicative of a channel activity-mediated increase in the membrane permeability. Introduction of 0.05% 2,4-dinitrophenole, a protonophore, provided a dramatic drop in the effect of NH 3 , while an inhibitor of the Na/Н exchanger, amyloride (0.1 mM), signifi cantly increased this effect. Our fi ndings allow us to suppose that AMP deaminase plays a role in the production of NH 3 by stroma endometrium cells upon acetylcholine stimulation. NH 3 is released into the extracellular space and, diffusing from the endometrium, can infl uence transport processes in the plasmalemma of uteral myocytes. A solution of NH 3 , when added to the suspension of myocytes, initiates a signifi cant increase in the рН value in the extracellular space and, consequently, an increase in the proton gradient on the membrane and intensifi cation of the transmembrane Н release from the myoplasm. The rates of these processes are signifi cantly higher than that of NH 3 entry into the cell because the permeability of the membrane for Н is four orders of magnitude greater that that for NH 3 . Analysis of our results shows that the liganddirected passive Са transport can be intensifi ed by dispersion of a transmembrane proton gradient, which exists on the plasma membrane of myocytes due to cytosolic oxidative processes and can increase due to the production of NH 3 in the endometrium. The role of NH 3 , which diffuses from the endometrium, in the regulation of functional activity of the uterus needs further investigation, but even now we can suppose that NH 3 molecules (or NH 4 ions) can play the role of a paracrine regulator in the endometrium-myometrium system.

A micromechanics study on strain-localization-induced fracture initiation in bending using crystal plasticity models

A crystal-plasticity-based computational micromechanics model is presented to study the localization and fracture initiation modes in bending of sheet materials. The model accounts for the orientation-dependent non-uniform deformation within each grain. Parameters evaluated include strain hardening, second-phase particle position and distribution, and crystallographic texture. Surface roughening and localized deformation are found to result naturally from orientation and slip geometry diŒerences across neighbouring grains. Shear bands initiate on or near the outer surface and from the low points of surface roughness. The maximum plastic strain may occur below the free surface, which is diŒerent from the predictions based on continuum elastic± plastic theories. Computational results also suggest that constituent particles, especially near the free surface, can signi®cantly increase the localization intensity and the surface roughening. Crystallographic textures that contain high volume fractions of rolling texture components can increase the surface roughening signi®cantly compared with a random texture. Bifurcation analysis results in further understanding of the diŒerent localization modes between the tension and the compression sides of the bending specimen. These ®ndings from the theoretical±computational study agree well with experimental observations. They give insights into improving the bendability of aluminium sheet alloys.

Structural Science enters the electronic era.

Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, England Readers will notice that the format and presentation of Section B of Acta Crystallographica have been upgraded from this ®rst issue of 2000. This continues a policy of stylistic enhancements to all sections of Acta that re ect improved technological capabilities. These changes are closely related to the ongoing electronic revolution in the preparation and publication of IUCr journals, and the launch of IUCr's Crystallography Online initiative. For Section B this means that: (a) Notes for Authors and the Transfer of Copyright Agreement can be downloaded from the Web at http://journals.iucr.org/b/services/authorservices.html. (b) Electronic submission (diskette or e-mail) of ®nal manuscripts is preferred. (c) Most papers are typeset in-house at Chester and proofs are available electronically. (d) Full-text versions of recent volumes are web-accessible to subscribers. (e) Web access to full-text versions of all Acta papers is planned. Crystallography Online offers a range of other user services and these are described at http://journals.iucr.org. These upgrades are, of course, changes of style rather than of scienti®c substance. Section B remains committed to the publication of high-quality articles across the diverse spectrum of crystallographic research that is designated as Structural Science. The thumbnail phrases now included on the cover express principal themes in this diversity. Readers should note that full discussions of sets of related crystal strucures are encouraged in Section B, and extended descriptions of individual structures are acceptable where the length of the discussion is scienti®cally warranted, and exceeds that which may be published elsewhere in IUCr journals. The types of papers published by Section B also remain unchanged. Full Research Papers remain the central feature of the journal, complemented by Short Communications, Topical Reviews, Lead Articles and Letters to the Editor. Submission details are fully described in the updated Notes for Authors. Section B is committed to the publication of high-quality review material across its sphere of interest. Topical Reviews of up to 10 journal pages provide for focused surveys of `hot topics' in current research, while Lead Articles provide for longer in-depth accounts of major developments. Review material is commissioned by the Section Editor after discussion of scope and content with potential authors. Suggestions for both Topical Reviews and Lead Articles are welcomed. We hope that the stylistic enhancements, coupled with high-quality scienti®c content, make Section B an attractive publication medium. Rapid advances in electronic production methods should signi®cantly increase the throughput of articles and make them more easily accessible worldwide. Through these changes, Section B hopes to expand its appeal to authors and readers alike. Acta Crystallographica Section B Structural Science

Social Comparison in the Setting of Goals for Own and Others' Performance

This research examines social factors implicated by social compari- son theory to be involved in the setting of task performance goals. Participants conducted an error-checking task and selected performance goals for themselves, their roommates, and unknown others. In addition, participants made judgments regarding their relative ability on the task as well as stating their confidence in attaining the goals. Consistent with predictions, participants rated themselves as above average in ability, had more confidence in their own abilities, and set lower goals for others than for themselves. In addition, individuals had more confidence in the abilities of their roommates than unknown others, and conse- quently chose goals for their roommates that were more similar to their own goals. The results and implications of this study are discussed within the context of social comparison theory and the better-than-average effect. Goal setting is a motivational technique used as part of self-manage- ment practices (Miltenberger, 1997) and to increase productivity (see Locke & Latham, 1990, for an extensive review). Locke and Latham (1990) have demonstrated that goals that are challenging and specific can signifi- cantly increase performance on a variety of tasks. Goals are also more likely to enhance performance if the person performing the task is commit- ted to the goal and has the requisite ability. Most of the literature on goal setting has focussed on the goals and performance of individuals acting alone. However, current practices suggest that goals are often established in situations in which social factors may play a role (Austin & Bobko, 1985; Zander, 1979). Some clear examples of these situations would include joint goal setting as is common in management by objectives (Carroll & Tosi,

Mass Production of Antimatter for High-Energy Propulsion

Theoretical and experimental work completed during the past decade indicates that interstellar propulsion systems based on the annihilation of antiprotons in a propellant will be feasible during the next several decades. The major technical dife culty appears to be the efe cient production of antimatter. Estimates based on the use of currently available technologies indicate that the equipment required to produce and store antimatter would be inefe cient and expensive. Hence, potentially more efe cient processes should be examined. Currently, antiprotons are produced by colliding high-energy protons with stationary heavy-element targets, such as tungsten. Other approaches, for which experimental data are available, indicate that there are production methods that are more efe cient. Several of these have been examined, and some show a signie cant improvement in efe ciency, but they may be dife cult to implement. Two methods examined will be discussed along with some technical advantages and disadvantages. In the e rst method, antiprotons and pions are collected from the collision of high-energy protons and a heavy-element target. Many more pions are produced than antiprotons. The pions are then directed toward the same target or a different target. The collision of pions and heavy nuclei have a higher probability for the production of antiprotons and would signie cantly increase the number of antiprotons produced. In the second method,a recirculatingelectron/positroncolliderwouldproducemultiplecollisionsneara resonanceforproducing antiprotons by using beam wigglers as in free-electron lasers. This technique would allow a signie cant increase in the number of interactions that would occur and would proportionally increase the antiproton production.