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Systemic Concentrations (systemic + concentration)

Distribution by Scientific Domains

Medical Sciences	75%
Life Sciences	25%

Selected Abstracts

Endurance exercise is associated with increased plasma cardiac troponin I in horses

EQUINE VETERINARY JOURNAL, Issue S36 2006
T. C. HOLBROOK
Summary Reason for performing study: Information is lacking regarding the influence of long distance exercise on the systemic concentration of cardiac troponin I (cTnl) in horses. Objectives: To determine if the concentration of cTnl in horses competing in 80 and 160 km endurance races increases with exercise duration and if cTnl concentrations can be correlated with performance data. Methods: Blood samples for the measurement of cTnl and 3 min electrocardiogram recordings were obtained from horses prior to, during and after completion of 80 and 160 km endurance races at 3 ride sites during the 2004 and 2005 American Endurance Ride Conference competition seasons. Results: Full data sets were obtained from 100 of the 118 horses. Endurance exercise was associated with a significant increase in cTnl over baseline in both distance groups. Failure to finish competition (poor performance) was also associated with an increased cTnl concentration over baseline at the time of elimination when data from both distances were combined. Other than one horse that developed paroxysmal atrial fibrillation, no arrhythmias were noted on the 3 minute ECG recordings that were obtained after endurance exercise in either distance group. Conclusions: Systemic concentrations of cTnl increase in endurance horses competing in both 80 and 160 km distances. Although final cTnl concentrations were significantly increased over their baseline values in horses that failed to finish competition, the degree of increase was not greater than the increase over baseline seen in the horses that successfully completed competition. The clinical significance of increased cTnl in exercising horses could not be ascertained from the results of this study. Potential relevance: These data indicate that cardiac stress may occur in horses associated with endurance exercise. Future studies utilising echocardiograpy to assess cardiac function in horses with increased cTnl are warranted. [source]

Systemic concentrations of antioxidants and biomarkers of macromolecular oxidative damage in horses with grass sickness

EQUINE VETERINARY JOURNAL, Issue 2 2003
B. C. McGORUM
Summary Reasons for performing study: The aetiopathogenesis of equine grass sickness (EGS) is unknown. The role of free radical-mediated neuronal damage has not previously been investigated in this condition. Objectives: To investigate the potential contribution of oxidative damage and antioxidant status to neurodegeneration in EGS. Methods: Systemic levels of surrogate biomarkers were determined in 10 horses with acute EGS and in 2 control populations; 10 healthy horses co-grazing with the 10 EGS horses at the onset of clinical disease, and 10 healthy mares grazing where EGS has not been reported. Results: EGS horses had alterations in levels of several antioxidants, consistent with oxidative stress, the acute phase response and/or the secondary metabolic complications of EGS. EGS horses had elevated plasma dihydroxyphenylalanine (DOPA) levels. Conclusions: The elevated DOPA levels probably reflected a generalised disturbance of catecholamine metabolism rather than increased DOPA production via free radical-mediated oxidation of tyrosine. However, there was no evidence of systemic macromolecular oxidative damage. Potential clinical relevance: Further work is required to determine whether macromolecular oxidative damage occurring at the neuronal level contributes to EGS. [source]

Comparison of the Systemic Levels of Inflammatory Markers after Percutaneous Coronary Intervention with Bare Metal versus Sirolimus-Eluting Stents

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2 2009
ABDALLAH G. REBEIZ M.D., F.A.C.C.
Background: Percutaneous coronary intervention (PCI) with bare metal stent (BMS) deployment causes plaque disruption and a rise in systemic levels of C-reactive protein (CRP), interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1. Our aim is to study whether PCI with sirolimus-eluting stent (SES) use attenuates this response. Methods: Patients with stable angina undergoing single-vessel PCI were enrolled in a randomized, open-label fashion into a BMS group or an SES group. Blood samples were drawn pre-PCI, 24 hours post-PCI, and 30 days post-PCI. Systemic concentrations of CRP, IL-6, and MCP-1 were measured at all time points. Results: In total, 41 patients were enrolled (21 in the BMS group and 20 in the SES group). The baseline plasma concentrations of all markers were comparable between groups. At 24 hours, the mean plasma CRP concentration in the SES group was 20.21 mg/dL versus 8.95 mg/dL in the BMS group (P = 0.15). The mean plasma IL-6 concentration at 24 hours was 25.41 pg/mL in the SES group versus 17.44 pg/mL in the BMS group (P = 0.17). The mean plasma MCP-1 concentration at 24 hours was 382.38 pg/mL in the SES group versus 329.04 pg/mL in the BMS group (P = 0.2). At 30 days, plasma concentrations of all three markers decreased to similar values between groups. Conclusions: The use of SES did not inhibit the rise in systemic concentrations of CRP, IL-6, and MCP-1 at 24 hours or 30 days post-PCI, compared with BMS. Moreover, at 24 hours, there was a trend for higher systemic levels of all proinflammatory markers in the SES group compared with the BMS cohort. [source]

Endurance exercise is associated with increased plasma cardiac troponin I in horses

Resistance exercise-induced increases in putative anabolic hormones do not enhance muscle protein synthesis or intracellular signalling in young men

THE JOURNAL OF PHYSIOLOGY, Issue 21 2009
Daniel W. D. West
We aimed to determine whether exercise-induced elevations in systemic concentration of testosterone, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) enhanced post-exercise myofibrillar protein synthesis (MPS) and phosphorylation of signalling proteins important in regulating mRNA translation. Eight young men (20 ± 1.1 years, BMI = 26 ± 3.5 kg m,2) completed two exercise protocols designed to maintain basal hormone concentrations (low hormone, LH) or elicit increases in endogenous hormones (high hormone, HH). In the LH protocol, participants performed a bout of unilateral resistance exercise with the elbow flexors. The HH protocol consisted of the same elbow flexor exercise with the contralateral arm followed immediately by high-volume leg resistance exercise. Participants consumed 25 g of protein after arm exercise to maximize MPS. Muscle biopsies and blood samples were taken as appropriate. There were no changes in serum testosterone, GH or IGF-1 after the LH protocol, whereas there were marked elevations after HH (testosterone, P < 0.001; GH, P < 0.001; IGF-1, P < 0.05). Exercise stimulated a rise in MPS in the biceps brachii (rest = 0.040 ± 0.007, LH = 0.071 ± 0.008, HH = 0.064 ± 0.014% h,1; P < 0.05) with no effect of elevated hormones (P= 0.72). Phosphorylation of the 70 kDa S6 protein kinase (p70S6K) also increased post-exercise (P < 0.05) with no differences between conditions. We conclude that the transient increases in endogenous purportedly anabolic hormones do not enhance fed-state anabolic signalling or MPS following resistance exercise. Local mechanisms are likely to be of predominant importance for the post-exercise increase in MPS. [source]

Ex vivo TCR-induced leukocyte gene expression of inflammatory mediators is increased in type 1 diabetic patients but not in overweight children

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 1 2010
Jaime S. Rosa
Abstract Background Abnormal systemic concentrations of proinflammatory cytokines/chemokines have been implicated in the development of long-term cardiovascular complications in type 1 diabetes (T1DM) and obesity. Whether leukocyte white blood cell (WBC) gene expression of these proinflammatory mediators contributes to their increased systemic levels, however, remains unclear, especially in the pediatric patient populations. This study examines mRNA changes of 9 cytokines and chemokines in WBCs following ex vivo immunostimulation from 9 T1DM (13.4 ± 0.5 year, 4F/5 M), 23 overweight (OW, 12.3 ± 0.5 year, 10F/13M, BMI% 97.1 ± 0.5 and > 90.0), and 21 healthy (CL, 13.8 ± 0.7 year, 9F/12 M, BMI% 59.6 ± 4.6 and < 85.0) children. Methods All subjects had been maintained in euglycemic conditions for at least 90 min before blood draws. Whole blood was then sampled and incubated with anti-T-cell receptor (TCR) antibody or heat-aggregated IgG (HAG) to stimulate T-cell and Fc receptors (FcR), respectively. After lysis of leukocytes, mRNA levels of six tumor necrosis factor superfamily cytokines (TNFSF2, 5, 6, 7, 9, 14) and three chemokines (CCL8, 20, and CXCL10) were measured using RT-PCR. Results Following TCR stimulation, T1DM displayed significantly greater mRNA responses than CL for TNFSF5, 7, 9, and CCL8, and CXCL10; TNFSF9, CCL8, and CXCL10 were also significantly higher in T1DM than OW; no difference was observed between OW and CL. FcR stimulation induced similar responses across groups. Conclusions Leukocytes of T1DM children displayed exaggerated gene expression in response to ex vivo TCR induction of five key proinflammatory cytokines/chemokines. This elevated leukocyte gene expression may be one of the pathophysiological contributors to the development of vascular complications in T1DM. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Liposomes for entrapping local anesthetics: A liposome electrokinetic chromatographic study

ELECTROPHORESIS, Issue 9 2010
Jana Lokajová
Abstract Bupivacaine is a lipophilic, long-acting, amide class local anesthetic commonly used in clinical practice to provide local anesthesia during surgical procedures. Several cases of accidental overdose with cardiac arrest and death have been reported since bupivacaine was introduced to human use. Recent case reports have suggested that Intralipid (Fresenius Kabi) is an effective therapy for cardiac toxicity from high systemic concentrations of, e.g. bupivacaine, even though the mechanism behind the interaction is not fully clear yet. Our long-term aim is to develop a sensitive, efficient, and non-harmful lipid-based formulation to specifically trap harmful substances in vivo. In this study, the in vitro interaction of local anesthetics (bupivacaine, prilocaine, and lidocaine) with Intralipid or lipid vesicles containing phosphatidylglycerol, phosphatidylcholine, cardiolipin, cholesterol, and N -palmitoyl- D - erythro -sphingosine (ceramide) was determined by liposome electrokinetic chromatography. The interactions were evaluated by calculating the retention factors and distribution constants. Atomic force microscopy measurements were carried out to confirm that the interaction mechanism was solely due to interactions between the analytes and the moving pseudostationary phase and not by interactions with a stationary lipid phase adsorbed to the fused-silica wall. The heterogeneity of the liposomes was also studied by atomic force microscopy. The liposome electrokinetic chromatography results demonstrate that there is higher interaction between the drugs and negatively charged liposome dispersion than with the commercial Intralipid dispersion. [source]