Changes In Plasma Composition Research Articles

CELL REDOX HOMEOSTASIS

Dear Editor-in-Chief: One of the intriguing questions in the field of redox biology of exercise is whether blood regulates tissue redox homeostasis. At present, the idea prevailing in the field is that blood plasma is largely considered an inert body fluid, a kind of “sink” that passively accepts reactive species and oxidative products produced mainly from exercising skeletal muscles (3). In our opinion, however, this frequently adopted cell- and muscle-centric point of view has not been put into a rigorous test whatsoever. Recent evidence by Conti et al. (1) is now challenging this notion. Using a novel approach, the researchers conditioned endothelial cells with sera from triathletes (“aerobic” activity), sprint runners (“anaerobic” activity), and soccer players (mixed “aerobic–anaerobic” activity) and examined the effects of these sera on several parameters related to redox homeostasis in endothelial cells. Although apparently, it was not one of the aims of these researchers, we believe that their innovative cell culture setup provides promising evidence to support the possible regulatory role of blood plasma on cell and tissue redox homeostasis. Conti et al. (1) reported that both primary and cell line endothelial cells incubated with blood serum (instead of fetal bovine serum as it is usually the case) and exposed or not to oxidative stress induced by hydrogen peroxide have provoked several changes in redox homeostasis in endothelial cells. Indeed, messenger RNA levels and activity of catalase in endothelial cells varied in most cases among the cells treated with sera from athletes participating in different types of sports. In addition, induction of oxidative stress in the cell culture medium increased catalase activity only in cells treated with sera from soccer players and triathletes but not from sprint runners. Likewise, incubation of endothelial cells with human sera from sprint runners but not from soccer players and triathletes increased the NAD+/NADH ratio (one of the master redox potential regulators of the cell [2]). Moreover, induction of oxidative stress increased the NAD+/NADH ratio only in cells treated with sera from soccer players. On the basis of this evidence, it is inferred that these changes in redox homeostasis are strongly dependent on the type of sport practiced by the volunteers who provided the sera. Application of this original in vitro–in vivo technique (i.e., cultured cells incubated with fresh human serum) provided probably for the first time direct evidence that human serum strongly affects redox homeostasis of endothelial cells and that these effects are, to a great extent, dependent on the exercise training stimulus. The choice of endothelial cells is critical, considering the direct contact of blood plasma with endothelial cells, increasing the physiological implications of this in vitro model. The role of blood in reactive species biology has perhaps not received the attention it deserves. Importantly, this study lends support to the hypothesis that at least some of the effects of exercise on tissue redox homeostasis are partially due to changes in the molecular composition of blood plasma. Undoubtedly, the search for the circulating factors responsible for these effects on cell redox homeostasis and the need for techniques more applicable to the in vivo state would be a fruitful area of research. Michalis G. Nikolaidis, PhD Antonios Kyparos, PhD Ioannis S. Vrabas, PhD Laboratory of Exercise Physiology and Biochemistry Department of Physical Education and Sport Sciences at Serres Aristotle University of Thessaloniki Serres, Greece The authors declare no conflicts of interest.

Deposition of nanostructured fluorocarbon plasma polymer films by RF magnetron sputtering of polytetrafluoroethylene

The RF magnetron sputtering of polytetrafluoroethylene target is studied with the aim to find out conditions leading to the deposition of super-hydrophobic thin films. It is shown that such coatings can be prepared at elevated pressures and a longer distance between the sputtered target and the substrate. This is explained by an increase in the density of longer C xF y molecules that reach the substrate and a lower flux of ions and CF 2 radicals on the surface of growing film under such deposition conditions, as observed by optical emission spectroscopy and mass spectrometry. Such changes in plasma composition result in a deposition of rough films having F/ C ratio close to 2 as observed by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. These findings clearly distinguish our results from the previous investigations of polytetrafluoroethylene sputtering performed at shorter distances from the target, where either low F/ C ratio or low roughness of the deposited films did not allow reaching super-hydrophobic character of the coatings.

Effect of remote field electromagnetic boundary conditions on microwave-induced plasma torches

A flexible versatile electromagnetic model constructed with the PLASIMO platform is employed to explore electromagnetic features of microwave-induced plasma torches. The bases, formed by a full-vector formulation of the Maxwell equations, provide the possibility to formulate the boundary conditions in a natural way. Together with the use of a direct matrix solver this gives a convergence speed-up of more than a factor of 100 when compared with a scalar formulation on an azimuthal magnetic field that uses an iterative solver. As a result, this electromagnetic model is ready to act in future studies as part of the self-consistent description of plasma–electromagnetic coupling. With the electromagnetic model three types of configuration were studied: the closed, semi-open and open configurations, all three based on the same simplified model plasmas. It is found that the closed configuration, acting as a cavity for which (de)tuning is extremely sensitive for the plasma conditions, is less suitable for applications in which changes in plasma compositions can be expected. The semi-open configuration can be seen as a model for the practice often used in laboratories to place microwave-induced plasma torches in a grid that aims at protecting the environment against microwave electromagnetic radiation. Calculations show that this is good practice provided the radius of this cylindrical grid is in the order of 90 mm. For the most often used configuration, the open version, we found that the power balance as expressed by the coefficients of absorption, transmission and reflection depends on the electron density of the plasma. The reason is that the plasma acts as an antenna, which converts the electromagnetic waves from the coaxial structure to that of the expansion region, and that this antenna function depends on the electron density. The influence of various other antenna elements is investigated as well.

Vaccenic and Elaidic Acid Modify Plasma and Splenocyte Membrane Phospholipids and Mitogen-Stimulated Cytokine Production in Obese Insulin Resistant JCR: LA-cp Rats

This study assessed the long-term effects of dietary vaccenic acid (VA) and elaidic acid (EA) on plasma and splenocyte phospholipid (PL) composition and related changes in inflammation and splenocyte phenotypes and cytokine responses in obese/insulin resistant JCR:LA-cp rats. Relative to lean control (Ctl), obese Ctl rats had higher serum haptoglobin and impaired T-cell-stimulated cytokine responses. VA and EA diets improved T-cell-stimulated cytokine production; but, only VA normalized serum haptoglobin. However, EA- and VA-fed rats had enhanced LPS-stimulated cytokine responses. The changes elicited by VA were likely due changes in essential fatty acid composition in PL; whereas EA-induced changes may due to direct incorporation into membrane PL.

Serum profile in preeclampsia and intra-uterine growth restriction revealed by iTRAQ technology

In order to identify new protein markers modified in placental diseases, high-throughput analysis of proteins in the plasma of pregnant women was carried out for normal and pathological pregnancies (Preeclampsia and/or Intra-Uterine Growth Restriction) using iTRAQ technology. We could identify 166 proteins that were modified (p<0.05) and the technique used allowed the detection of previously undetected factors, such as various members of the SERPINA clade. The modifications of two proteins (C reactive protein and antichymotrypsin, SERPINA3) were validated on individual samples. Complement and coagulation cascades proteins were significantly enriched among modified protein clusters in the case of intra-uterine growth restriction (p<2.6.10(-11)). Several proteins were specifically enriched in isolated preeclampsia and depleted when preeclampsia was complicated by intra-uterine growth restriction. These findings suggest that the growth restricted foeto-placental unit is able to moderate some changes in maternal plasma composition. Overall, the use of iTRAQ technology, for the first time on this subject, enabled us to provide a new list of proteins modified in placental diseases, among which proteins expressed at a low level that were not accessible by other methods.

Influence of food on bioanalytical results

Event Abstract Back to Event Influence of food on bioanalytical results Constantin Mircioiu1* and V Anuta1 1 Carol Davila University of Medicine & Pharmacy, Romania Introduction. An essential characteristic of bioanalytical determinations in bioequivalence studies is the fact plasma samples are collected in a fasting period as well as post- prandial . Following changes in the plasma composition after ingestion of food , analytical results have to be more or less affected . Methods. Ex vivo measurements concerned determination of extraction yield of active substances ketoconazole and carbamazepine from plasma in presence of surfactant tween 80 in concentrations before and after critical micellar concentration. Clinical experiment was a bioequivalence study comparing two omeprazole formulations. Omeprazole was determined by a HPLC method using lansoprazole as internal standard. Results. Dependence of recovery of ketoconazole and carbamazepine from plasma was strongly dependent on surfactant concentrations, the extraction yield becoming double at higher concentration. On other hand, dependence was not linear, at small concentrations probably “local micellar concentrations” a decrease of recovery being observed. The phenomenon appeared at all three drug concentrations: 1, 5 and 10 µg/ml. Statistical evaluation of food effect compared the found concentrations of internal standard – lansoprazole in some 1500 pre and post prandial plasma samples. As marker and metric of food effects it was defined a “Post Prandial Matrix Effect - PPME” as the ratio of area of analytic peaks of internal standard of corresponding samples. It was found that PPME is less than 1. In fact, examination of entire time domain put in evidence a continuous increase of recovery of is maybe connected with some evolution in plasma composition connected with fasting, interrupted by the changes associated with food absorption. In the neighborhood of time of food intake appears a parabolic evolution rather than a sudden decrease. Conclusion. Food effects on results of bioanalytical determination based on liquid/liquid extractions are a resultant of surfactants effects on rate and extent of transfer of analytes, but also of some physiological changes in plasma composition and properties before and after food intake. Keywords: Food, bioanalytic results, Omeprazole Conference: 8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010, Thessaloniki, Greece, 1 Oct - 5 Oct, 2010. Presentation Type: Invited speaker Topic: Food, drugs and environmental xenobiotics Citation: Mircioiu C and Anuta V (2010). Influence of food on bioanalytical results. Front. Pharmacol. Conference Abstract: 8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010. doi: 10.3389/conf.fphar.2010.60.00167 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 Mar 2011; Published Online: 04 Nov 2010. * Correspondence: Dr. Constantin Mircioiu, Carol Davila University of Medicine & Pharmacy, Bucharest, Romania, constantin.mircioiu@yahoo.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Constantin Mircioiu V Anuta Google Constantin Mircioiu V Anuta Google Scholar Constantin Mircioiu V Anuta PubMed Constantin Mircioiu V Anuta Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Changes in the higher fatty acid composition of blood plasma and erythrocyte membranes during long exposure of a human to hyperbaric gas medium

The gas chromatographic method was used to study the changes in the fatty acid composition of the sum of the blood serum and erythrocyte membrane lipids in healthy male volunteers under the conditions of simulation in the ground-based hyperbaric set of long dives at depths of up to 350 m in the oxygen-helium and oxygen-neon media and in the readaptation period. At a depth of 100 m, a decrease in the serum content of the sum of saturated acids (palmitic (16:0)n and stearic (18:0) acids) and a 1.5-fold increase in the linoleic acid content compared to the background was found. A comparison of the individual changes in the blood serum and erythrocyte membrane fatty acids, as well as the unsaturation index (UI, the ratio of the sum of the unsaturated fatty acid concentrations multiplied by the number of double bonds in the molecule to the sum of the saturated fatty acid concentrations) and the R index (the erythrocyte to the serum fatty acid content ratio), showed that, under the experimental conditions and in the period of readaptation, the main changes occurred in the erythrocyte membranes, in which the unsaturated fatty acid content increased, and the linoleic and, especially, the arachidonic acid contents changed in different directions, depending on the depth of the dive. In the readaptation period, the linoleic and arachidonic acid contents decreased twofold on the first day and exceeded even the background level on the fourth day. The data obtained give evidence for the adaptive role of the erythrocyte membrane lipids upon exposure of humans to a hyperbaric medium with a changed gas composition.

Administration of dietary fish oil capsules in healthy middle-aged Japanese men with a high level of fish consumption

The nutritional effects of fish oil, which is rich in the n-3 polyunsaturated fatty acids, have been reported. In this randomized, placebo-controlled, double-blind, crossover study, we evaluated the effects of dietary fish oil capsules on the hematological parameters of healthy middle-aged Japanese men with a high level of fish oil consumption. Over a 4-week period, subjects were administered five fish oil or olive oil (placebo) capsules with every meal (1,260 mg eicosapentaenoic acid and 540 mg docosahexaenoic acid/day). There was a 4-week washout period between the treatment phases. The results did not demonstrate a decrease in plasma triacylglycerol, cholesterol, low-density lipoprotein cholesterol, and whole-blood viscosity. Further, no changes in the fatty acid composition of plasma and erythrocyte phospholipids were noted. These results suggested that the supplementation of fish oil might be effective only for those subjects who have a lower level of fish oil consumption.

Changes in Plasma Composition of Japanese Black Steers During Grazing and Fattening Periods

Nakamura, Y.-N., Orito, H., Tsuneishi, E., Hirano, K., Kato, N., Shoji, A., Kamiya, M. and Nakanishi, Y. 2008. Changes in plasma composition of Japanese black steers during grazing and fattening periods. J. Appl. Anim. Res., 34: 157–161. The plasma compositions of five Japanese black steers during about 23 months of grazing and fattening period of about 6 months were investigated. Plasma A/G, LDH, Glu, tCho and Ins concentrations increased (P<0.05), whereas TG, UNandNEFA concentrations decreased (P<0.05) during the fattening period. Plasma Na concentration increased (P<0.05) during the fattening period. Plasma Bβ-carotene and tocopherol concentrations decreased (P<0.05) during the fattening period. Changes in plasma chemical composition during grazing and fattening were related to the chemical composition of the feed consumed and lack of exercise during housing.

Aerobic exercise training improves the role of high‐density lipoprotein antioxidant and reduces plasma lipid peroxidation in type 2 diabetes mellitus

In this study, we analyzed the effect of aerobic exercise training (AET) and of a single bout of exercise on plasma oxidative stress and on antioxidant defenses in type 2 diabetes mellitus (DM) and in healthy control subjects (C). DM and C did not differ regarding triglycerides, high-density lipoprotein cholesterol (HDL-c), insulin, and HOMA index at baseline and after AET. To measure the lag time for low-density lipoprotein (LDL) oxidation (LAG) and the maximal rate of conjugated diene formation (MCD), participants' plasma HDL(2) and HDL(3) were incubated with LDL from pooled healthy donors' plasma. In the presence of HDL(3), both LAG and MCD were similar in C and DM, but only in DM did AET improve LAG and reduce MCD. In the presence of HDL(2), the lower baseline LAG in DM equaled C after AET. MCD was unchanged in DM after AET, but was lower than C only after AET. Furthermore, after AET plasma thiobarbituric acid-reactive substances were reduced only in DM subjects. Despite not modifying the total plasma antioxidant status and serum paraoxonase-1 activity in both groups, AET lowered the plasma lipid peroxides, corrected the HDL(2), and improved the HDL(3) antioxidant efficiency in DM independent of the changes in blood glucose, insulin, and plasma HDL concentration and composition.

Seminal Plasma Composition from Ejaculates Collected by Artificial Vagina and Electroejaculation in Guirra Ram

This study was conducted to evaluate changes in ram seminal plasma composition from ejaculates obtained using artificial vagina (AV) and electroejaculation (EE). To address this question, we assessed the effect of semen collection method on volume, sperm concentration, sodium concentration, potassium concentration, sodium/potassium ratio, total protein content and protein profile using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and 2-D polyacrylamide gel electrophoresis. The main findings from this study were: (i) similar volume was obtained, while sperm concentration was significantly lower for EE method; (ii) potassium and sodium/potassium concentration ratio were not influenced by recovery method, while sodium concentration increased significantly when semen was recovered using EE; (iii) approximately 80% of the total relative seminal plasma protein is represented by four protein fractions of molecular weights around 15, 21, 24 and 50 kDa and there were not differences and (iv) focussing the two-dimensional SDS-PAGE gel on the 10-25 kDa rank, the IMAGE ANALYSIS software detected around 22 spots with isoelectric points ranging from 5.1 to 6.1. Two protein spots (15 kDa and 5.5 and 22 kDa and 5.2 for molecular weight and isoelectric point respectively) increased significantly when semen was recovered using EE. One spot protein with molecular weight around 25 kDa and isoelectric point of 5.2 were only found in the seminal plasma from the semen recovery by AV. As it was demonstrated, ejaculates obtained with EE modify the sodium concentration, alter two proteins concentration and induced the loss of one protein in seminal plasma.

Seasonal changes in semen quality and freezability in Lusitano stallions: A flow cytometric study

In the present study, seasonal changes in semen quality of Lusitano stallions were evaluated to establish the best time for semen cryopreservation. Seasonal changes on testicular size, seminal characteristics and semen freezability were therefore evaluated by optical microscopy and flow cytometry. Five Lusitano stallions belonging to National Stud Farm, “Coudelaria Nacional” were used in the study. Semen was collected in four periods defined as spring (March/April), summer (June/July), autumn (September/October) and winter (December/February). Ejaculates were collected once a week for 4 weeks, and cryopreserved in 0.5-ml plastic straws. Before and after each period of semen collection, testicles of all stallions were measured. For evaluation, one straw per ejaculate, per stallion, and per season was thawed at 37 �C for 30 s and microscopic evaluation (motility) was performed. A flow cytometer (Becton Dickinson, San Jose, CA, USA) was used to evaluate sperm viability and acrosomal integrity by using the combination of fluorescent probes propidium iodide (PI) and SYBR-14 (LIVE/DEAD Sperm viability Kit (L-7011), Molecular Probes, Eugene, Oregon) for sperm viability. In addition, acrosome integrity was evaluated using the fluorescein labelled lectin from the peanut plant, Arachis hypogea (FITC-PNA, Sigma Chemical, St. Louis, MO) and propidium iodide (PI) probe. Results were evaluated by the Cell-Quest software (Becton Dickinson, San Jose, CA, USA) and statistical differences by a one-way ANOVA, followed by post hoc comparison tests. The results indicated significant seasonal differences in testicular size and sperm production (p�0.05). Ultrasonographic testicular volume was maximal in March (234.03±15.8 cm3), decreased to a minimum in October and June (203.5±17.0 cm3, 168.6±10.0 cm3, respectively) and started to increase again in January (190.8±8.8 cm3). A significant positive correlation between testicular volume and sperm production (r = 0.66; P� 0.01) was demonstrated, although minimum testicular volume was reached in October while minimum sperm production was registered in January. Viability in frozen-thawed semen from ejaculates collected in autumn was 37.73±2.20% and in summer 40.99±4.08%; the results differ significantly from other seasons: winter 54.26±2.10% and spring 46.71±2.32% (p�0.05). The high number of dead spermatozoa after the freezing‐thawing process in autumn/winter most likely indicates that seasonally related changes in seminal plasma composition may affect semen preservation. Nevertheless, no significant differences were observed for acrosome integrity in different periods of the experiment. An inter-stallion variation was observed for testicular size and sperm production, but testicular size, besides sperm production, was positively correlated in all individual stallions. At the time of semen collection, sperm concentrations determined by photometry showed that both testis size and sperm production of housed Lusitano stallions were affected by season. Testicular size and function were maximal in the spring, but testicular volume was smallest in October, while sperm production continued to decrease till January. The results indicate that in our climatic/latitude conditions, it is preferable to freeze semen during winter/spring period.

Incorporation and removal of cholesterol from stallion sperm membranes during semen cryopreservation

combination of fluorescent probes propidium iodide (PI) and SYBR-14 (LIVE/DEAD Sperm viability Kit (L-7011), Molecular Probes, Eugene, Oregon) for sperm viability. In addition, acrosome integrity was evaluated using the fluorescein labelled lectin from the peanut plant, Arachis hypogea (FITC-PNA, Sigma Chemical, St. Louis, MO) and propidium iodide (PI) probe. Results were evaluated by the Cell-Quest software (Becton Dickinson, San Jose, CA, USA) and statistical differences by a one-way ANOVA, followed by post hoc comparison tests. The results indicated significant seasonal differences in testicular size and sperm production (p≤ 0.05). Ultrasonographic testicular volume was maximal in March (234.03± 15.8 cm3), decreased to a minimum in October and June (203.5± 17.0 cm3, 168.6± 10.0 cm3, respectively) and started to increase again in January (190.8± 8.8 cm3). A significant positive correlation between testicular volume and sperm production (r= 0.66; P≤ 0.01) was demonstrated, although minimum testicular volume was reached in October while minimum sperm production was registered in January. Viability in frozen-thawed semen from ejaculates collected in autumn was 37.73± 2.20% and in summer 40.99± 4.08%; the results differ significantly from other seasons: winter 54.26± 2.10% and spring 46.71± 2.32% (p≤ 0.05). The high number of dead spermatozoa after the freezing–thawing process in autumn/winter most likely indicates that seasonally related changes in seminal plasma composition may affect semen preservation. Nevertheless, no significant differences were observed for acrosome integrity in different periods of the experiment. An inter-stallion variation was observed for testicular size and sperm production, but testicular size, besides sperm production, was positively correlated in all individual stallions. At the time of semen collection, sperm concentrations determined by photometry showed that both testis size and sperm production of housed Lusitano stallions were affected by season. Testicular size and function were maximal in the spring, but testicular volume was smallest in October, while sperm production continued to decrease till January. The results indicate that in our climatic/latitude conditions, it is preferable to freeze semen during winter/spring period.

Nitric oxide generation by endothelial cells exposed to shear stress in glass tubes perfused with red blood cell suspensions: role of aggregation

Endothelial function is modulated by wall shear stress acting on the vessel wall, which is determined by fluid velocity and the local viscosity near the vessel wall. Red blood cell (RBC) aggregation may affect the local viscosity by favoring axial migration. The aim of this study was to investigate the role of RBC aggregation, with or without altered plasma viscosity, in the mechanically induced nitric oxide (NO)-related mechanisms of endothelial cells. Human umbilical vein endothelial cells (HUVEC) were cultured on the inner surface of cylindrical glass capillaries that were perfused with RBC suspensions having normal and increased aggregation at a nominal shear stress of 15 dyn/cm(2). RBC aggregation was enhanced by two different approaches: 1) poloxamer-coated RBC suspended in normal, autologous plasma, resulting in enhanced aggregation but unchanged plasma viscosity and 2) normal RBC suspended in autologous plasma containing 0.5% dextran (mol mass 500 kDa), with a similar level of RBC aggregation but higher plasma viscosity. Compared with normal cells in unmodified plasma, perfusion with suspensions of poloxamer-coated RBC in normal plasma resulted in decreased levels of NO metabolites and serine 1177 phosphorylation of endothelial nitric oxide synthase (eNOS). Perfusion with normal RBC in plasma containing dextran resulted in a NO level that remained elevated, whereas only a modest decrease of phosphorylated eNOS level was observed. The results of this study suggest that increases of RBC aggregation tendency affect endothelial cell functions by altering local blood composition, especially if the alterations of RBC aggregation are due to modified cellular properties and not to plasma composition changes.

Functional LCAT deficiency in human apolipoprotein A-I transgenic, SR-BI knockout mice

Reduction of plasma LCAT activity has been observed in several conditions in which the size of HDL particles is increased; however, the mechanism of this reduction remains elusive. We investigated the plasma activity, mass, and in vivo catabolism of LCAT and its association with HDL particles in human apolipoprotein A-I transgenic, scavenger receptor class B type I knockout (hA-ITg SR-BI-/-) mice. Compared with hA-ITg mice, hA-ITg SR-BI-/- mice had a 4-fold higher total plasma cholesterol concentration, which occurred predominantly in 13-18 nm diameter HDL particles, a significant reduction in plasma esterified cholesterol-total cholesterol (EC/TC) ratio, and significantly lower plasma LCAT activity, suggesting a decrease in LCAT protein. However, LCAT protein in plasma, hepatic mRNA for LCAT, and in vivo turnover of 35S-radiolabeled LCAT were similar in both genotypes of mice. HDL from hA-ITg SR-BI-/- mice was enriched in sphingomyelin (SM), relative to phosphatidylcholine, and had less associated [35S]LCAT radiolabel and endogenous LCAT activity compared with HDL from hA-ITg mice. We conclude that the decreased EC/TC ratio in the plasma of hA-ITg SR-BI-/- mice is attributed to a reduction in LCAT reactivity with SM-enriched HDL particles.

Oxidative burden in prediabetic and diabetic individuals: evidence from plasma coenzyme Q10

Individuals with diabetes and prediabetes are at risk of vascular injury. However, the exact mechanisms are unclear. The mitochondria mobile electron carrier coenzyme Q(10) (CoQ(10)) is a potent lipophilic antioxidant. We hypothesize that oxidative stress, detectable as changes in plasma CoQ(10) concentrations and composition, plays an important role in vascular disease in diabetes. We measured plasma CoQ(10) concentrations (including reduced ubiquinol and oxidized ubiquinone subfractions) in 60 subjects with normal glucose tolerance [NGT; fasting plasma glucose (FPG) < 5.5 mmol/l], 63 with impaired fasting glucose (IFG; FPG 5.6-6.9 mmol/l) and 69 with Type 2 diabetes (DM; FPG > 6.9 mmol/l). In men and women, the total CoQ(10)/total cholesterol ratio was reduced in DM (mean +/-sd) [male (M) 0.09 +/- 0.04; female (F) 0.07 +/- 0.04] compared with NGT (0.29 +/- 0.08; 0.21 +/- 0.07) and IFG (0.27 +/- 0.07; 0.23 +/- 0.07) (DM vs. NGT and IFG P = 0.001). A stepwise reduction in the plasma ubiquinol fraction (ubiquinol/total CoQ10) was observed from NGT (M 0.93 +/- 0.06; F 0.95 +/- 0.06) compared with IFG (0.43 +/- 0.25; 0.41 +/- 0.15) and DM (0.24 +/- 0.11; F 0.29 +/- 0.16) (DM vs. IFG vs. NGT P = 0.001). In contrast, the plasma ubiquinone/ubiquinol ratio increased from NGT (M 0.08 +/- 0.07, F 0.06 +/- 0.08) to IFG (2.14 +/- 1.84, 1.75 +/- 1.04) to DM (4.77 +/- 4.88, 3.81 +/- 3.71) (DM vs. IFG vs. NGT P = 0.001). These differences remained after adjusting for age, body mass index and FPG. The change in CoQ(10) with increasing FPG concentration suggests an increase in oxidative burden, already evident in the prediabetic IFG individuals. This increase in oxidative stress might contribute to the increased risk of vascular disease.

Changes in plasma composition during the expansion into the first vacuum stage of an inductively coupled plasma mass spectrometer

The effects of collisions on the composition of the plasma passing through the first vacuum stage of an inductively coupled plasma mass spectrometer were monitored in three sets of experiments. Rates of collisional quenching of an excited state in the neutral calcium atom were estimated from changes in experimental fluorescence lifetimes. Intensities from collisionally-assisted fluorescence provided evidence of energy transfer between excited states. Changes in analyte number density along the axis of the supersonic expansion in the first vacuum stage provided evidence that ion-electron recombination occurs to a significant extent during the expansion. Together, the experiments create a picture of the first vacuum stage in which collisions play an important role in shaping the composition of the plasma that is ultimately delivered to the mass analyzer.

Modeling of Surface Roughness and the Role of Debris in Micro-EDM

Surface roughness is one of the important quality characteristic of a micromachined component. This paper presents a model to predict surface roughness of micro-EDmachined surfaces. The model is based on the configuration of a single-spark cavity formed as a function of process parameters. Assuming the normal distribution of surface heights, the μ and σ(Rq) of the surface profile are evaluated after every spark. The model was further extended to capture the role of debris in micro-EDM in changing electric potential at the micropeaks on the cathode surfaces. The chemical kinetics approach was used to evaluate the change in plasma enthalpy and composition as a result of debris inclusion in the dielectric. The corresponding energy distribution between the electrodes was used to predict configuration of the single-spark cavity and the consequent surface roughness using the earlier surface roughness model. The modeling results were found to agree well with the micro-EDM validation experiments performed without and with the inclusion of artificial debris (iron particles) in the dielectric.

Changes in the lipid composition of blood plasma and liver in rats induced by severe psychic trauma

The concentration of high-density lipoprotein cholesterol and triglycerides in rat serum sharply decreased after psychic trauma caused by life hazard. The content of these substances remained unchanged for not less than 1 week after trauma. The concentration of high-density lipoprotein cholesterol was low, while serum content of triglycerides increased 6 weeks after trauma. The concentration of high-density lipoprotein cholesterol significantly decreased after repeated psychic trauma. These changes were accompanied by a sharp increase in the concentration of triglycerides in the serum. Total cholesterol concentration in the liver decreased under these conditions.

Dietary-Induced Changes in Fatty Acid Composition of Human Plasma, Platelet, and Erythrocyte Lipids Follow a Similar Time Course

The dietary-induced changes in the fatty acid composition of plasma, platelet, and erythrocyte lipids were measured as a function of time. Healthy adults consumed a diet rich in saturated fat (18% total energy, TE) for 19 d and then crossed over, without washout, to a diet rich in (n-6) polyunsaturated fat (10% TE) for a further 19 d. The fatty acid composition of plasma and blood cell lipids was measured in blood samples collected from fasting subjects on d 0, 1, 2, 5, 8, 12, and 19 of consuming the diet rich in (n-6) polyunsaturated fats. The linoleic acid composition of all plasma, platelet, and erythrocyte lipids increased to a plateau within 19 d, reaching at least 70% of maximum within 5 d. The maximum increase in linoleic acid composition of erythrocyte phosphatidylcholine was 3.8 mol% at d 12; the increase at d 1 was 2 mol% and at d 5 was 3.2 mol%. The decrease in pentadecanoic acid composition followed a similar time course in all lipids with the exception of plasma phospholipids. Our results show that the time course of dietary-induced changes in erythrocyte fatty acid composition is similar to that in plasma and platelet lipids. These results provide convincing, albeit indirect evidence that the exchange of fatty acids from plasma to erythrocytes and platelets is a major determinant of their membrane fatty acid composition.