Agreement of Computerized QT and QTc Interval Measurements Between Both Bedside and Expert Nurses Using Electronic Calipers.

BACKGROUND: In hospitalized patients, QT/QTc (heart rate corrected) prolongation on the electrocardiogram (ECG) increases the risk of torsade de pointes. Manual measurements are time-consuming and often inaccurate. Some bedside monitors automatically and continuously measure QT/QTc; however, the agreement between computerized versus nurse-measured values has not been evaluated. OBJECTIVE: The aim of this study was to examine the agreement between computerized QT/QTc and bedside and expert nurses who used electronic calipers. METHODS: This was a prospective observational study in 3 intensive care units. Up to 2 QT/QTc measurements (milliseconds) per patient were collected. Bland-Altman test was used to analyze measurement agreement. RESULTS: A total of 54 QT/QTc measurements from 34 patients admitted to the ICU were included. The mean difference (bias) for QT comparisons was as follows: computerized versus expert nurses, -11.04 ± 4.45 milliseconds (95% confidence interval [CI], -2.3 to -19.8; P = .016), and computerized versus bedside nurses, -13.72 ± 6.70 (95% CI, -0.70 to -26.8; P = .044). The mean bias for QTc comparisons was as follows: computerized versus expert nurses, -12.46 ± 5.80 (95% CI, -1.1 to -23.8; P = .035), and computerized versus bedside nurses, -18.49 ± 7.90 (95% CI, -3.0 to -33.9; P = .022). CONCLUSION: Computerized QT/QTc measurements calculated by bedside monitor software and measurements performed by nurses were in close agreement; statistically significant differences were found, but differences were less than 20 milliseconds (on-half of a small box), indicating no clinical significance. Computerized measurements may be a suitable alternative to nurse-measured QT/QTc. This could reduce inaccuracies and nurse burden while increasing adherence to practice recommendations. Further research comparing computerized QT/QTc from bedside monitoring to standard 12-lead electrocardiogram in a larger sample, including non-ICU patients, is needed.

Divergent shifts in lipid mediator profile following supplementation with n-3 docosapentaenoic acid and eicosapentaenoic acid.

In contrast to the well-characterized effects of specialized proresolving lipid mediators (SPMs) derived from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), little is known about the metabolic fate of the intermediary long-chain (LC) n-3 polyunsaturated fatty acid (PUFA) docosapentaenoic acid (DPA). In this double blind crossover study, shifts in circulating levels of n-3 and n-6 PUFA-derived bioactive lipid mediators were quantified by an unbiased liquid chromatography-tandem mass spectrometry lipidomic approach. Plasma was obtained from human subjects before and after 7 d of supplementation with pure n-3 DPA, n-3 EPA or placebo (olive oil). DPA supplementation increased the SPM resolvin D5n-3DPA (RvD5n-3DPA) and maresin (MaR)-1, the DHA vicinal diol 19,20-dihydroxy-DPA and n-6 PUFA derived 15-keto-PG E2 (15-keto-PGE2). EPA supplementation had no effect on any plasma DPA or DHA derived mediators, but markedly elevated monohydroxy-eicosapentaenoic acids (HEPEs), including the e-series resolvin (RvE) precursor 18-HEPE; effects not observed with DPA supplementation. These data show that dietary n-3 DPA and EPA have highly divergent effects on human lipid mediator profile, with no overlap in PUFA metabolites formed. The recently uncovered biologic activity of n-3 DPA docosanoids and their marked modulation by dietary DPA intake reveals a unique and specific role of n-3 DPA in human physiology.-Markworth, J. F., Kaur, G., Miller, E. G., Larsen, A. E., Sinclair, A. J., Maddipati, K. R., Cameron-Smith, D. Divergent shifts in lipid mediator profile following supplementation with n-3 docosapentaenoic acid and eicosapentaenoic acid.

Postprandial Plasma Phospholipids in Men Are Influenced by the Source of Dietary Fat.

BACKGROUND: Postprandial lipemia represents a risk factor for chronic diseases, including type 2 diabetes. Little is known about the effect of dietary fat on the plasma lipidome in the postprandial period. OBJECTIVE: The objective of this study was to assess the effect of dairy fat and soy oil on circulating postprandial lipids in men. METHODS: Men (40-60 y old, nonsmokers; n = 16) were randomly assigned in a crossover design to consume 2 breakfast meals of dairy-based or soy oil-based foods. The changes in the plasma lipidome during the 4-h postprandial period were analyzed with electrospray ionization tandem mass spectrometry and included 316 lipid species in 23 classes and subclasses, representing sphingolipids, phospholipids, glycerolipids, and sterols. RESULTS: Nonparametric Friedman tests showed significant changes in multiple plasma lipid classes, subclasses, and species in the postprandial period after both dairy and soy meals. No difference was found in triglyceridemia after each meal. However, 6 endogenous lipid classes increased after dairy but decreased after soy (P < 0.05), including ether-linked phospholipids and plasmalogens and sphingomyelin (not present in soy), dihexosylceramide, and GM3 ganglioside. Phosphatidylcholine and phosphatidylinositol were not affected by the soy meal but were significantly elevated after the dairy meal (8.3% and 16%, respectively; P < 0.05). CONCLUSIONS: The changes in postprandial plasma phospholipids in men relate to the diet composition and the relative size of the endogenous phospholipid pools. Despite similar lipemic responses as measured by changes in triglyceride concentrations, the differential responses to dairy and soy meals derived through lipidomic analysis of phospholipids suggest differences in the metabolism of soybean oil and dairy fat. The increased concentrations of plasmalogens, with potential antioxidant capacity, in the postprandial period after dairy but not soy meals may represent a further important difference in the response to these sources of fat. The trial was registered at www.anzctr.org.au as ACTRN12610000562077.

A short-term n-3 DPA supplementation study in humans.

PURPOSE: Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids and red blood cells (RBC) in humans, very little is known about docosapentaenoic acid (DPA, 22:5 n-3). The aim of this study was to investigate the uptake and incorporation of pure DPA and EPA into human plasma and RBC lipids. METHODS: Ten female participants received 8 g of pure DPA or pure EPA in randomized crossover double-blinded manner over a 7-day period. The placebo treatment was olive oil. Blood samples were collected at days zero, four and seven, following which the plasma and RBC were separated and used for the analysis of fatty acids. RESULTS: Supplementation with DPA significantly increased the proportions of DPA in the plasma phospholipids (PL) (by twofold) and triacylglycerol (TAG) fractions (by 2.3-fold, day 4). DPA supplementation also significantly increased the proportions of EPA in TAG (by 3.1-fold, day 4) and cholesterol ester (CE) fractions (by 2.0-fold, day 7) and of DHA in TAG fraction (by 3.1-fold, day 4). DPA proportions in RBC PL did not change following supplementation. Supplementation with EPA significantly increased the proportion of EPA in the plasma CE and PL fractions, (both by 2.7-fold, day 4 and day 7) and in the RBC PL (by 1.9-fold, day 4 and day 7). EPA supplementation did not alter the proportions of DPA or DHA in any lipid fraction. These results showed that within day 4 of supplementation, DPA and EPA demonstrated different and specific incorporation patterns. CONCLUSION: The results of this short-term study suggest that DPA may act as a reservoir of the major long-chain n-3 fatty acids (LC n-3 PUFA) in humans.

Correlative chemical and elemental nano-imaging of morphology and disorder at the nacre-prismatic region interface in Pinctada margaritifera.

Understanding biomineralization relies on imaging chemically heterogeneous organic-inorganic interfaces across a hierarchy of spatial scales. Further, organic minority phases are often responsible for emergent inorganic structures from the atomic arrangement of different polymorphs, to nano- and micrometer crystal dimensions, up to meter size mollusk shells. The desired simultaneous chemical and elemental imaging to identify sparse organic moieties across a large field-of-view with nanometer spatial resolution has not yet been achieved. Here, we combine nanoscale secondary ion mass spectroscopy (NanoSIMS) with spectroscopic IR s-SNOM imaging for simultaneous chemical, molecular, and elemental nanoimaging. At the example of Pinctada margaritifera mollusk shells we identify and resolve ~ 50 nm interlamellar protein sheets periodically arranged in regular ~ 600 nm intervals. The striations typically appear ~ 15 µm from the nacre-prism boundary at the interface between disordered neonacre to mature nacre. Using the polymorph distinctive IR-vibrational carbonate resonance, the nacre and prismatic regions are consistently identified as aragonite ([Formula: see text] cm-1) and calcite ([Formula: see text] cm-1), respectively. We observe previously unreported morphological features including aragonite subdomains encapsulated in extensions of the prism-covering organic membrane and regions of irregular nacre tablet formation coincident with dispersed organics. We also identify a ~ 200 nm region in the incipient nacre region with less well-defined crystal structure and integrated organics. These results show with the identification of the interlamellar protein layer how correlative nano-IR chemical and NanoSIMS elemental imaging can help distinguish different models proposed for shell growth in particular, and how organic function may relate to inorganic structure in other biomineralized systems in general.

Resistance exercise increases NF-κB activity in human skeletal muscle.

Intense resistance exercise causes a significant inflammatory response. NF-κB has been identified as a prospective key transcription factor mediating the postexercise inflammatory response. The purpose of this study was to determine whether a single bout of intense resistance exercise regulates NF-κB signaling in human skeletal muscle. Muscle biopsy samples were obtained from the vastus lateralis of five recreationally active, but not strength-trained, males (21.9 ± 1.3 yr) prior to, and at 2 and 4 h following, a single bout of intense resistance exercise. A further five subjects (4 males, 1 female) (23 ± 0.89 yr) were recruited as a nonexercise control group to examine the effect of the muscle biopsy protocol on key markers of skeletal muscle inflammation. Protein levels of IκBα and phosphorylated NF-κB (p65), as well as the mRNA expression of inflammatory myokines monocyte chemoattractant protein 1 (MCP-1), IL-6, and IL-8 were measured. Additionally, NF-κB (p65) DNA binding to the promoter regions of MCP-1, IL-6, and IL-8 was investigated. IκBα protein levels decreased, while p-NF-κB (p65) protein levels increased 2 h postexercise and returned to near-baseline levels by 4-h postexercise. Immunohistochemical data verified these findings, illustrating an increase in p-NF-κB (p65) protein levels, and nuclear localization at 2 h postexercise. Furthermore, NF-κB DNA binding to MCP-1, IL-6, and IL-8 promoter regions increased significantly 2 h postexercise as did mRNA levels of these myokines. No significant change was observed in the nonexercise control group. These novel data provide evidence that intense resistance exercise transiently activates NF-κB signaling in human skeletal muscle during the first few hours postexercise. These findings implicate NF-κB in the transcriptional control of myokines known to be central to the postexercise inflammatory response.

The role and regulation of MAFbx/atrogin-1 and MuRF1 in skeletal muscle atrophy.

Skeletal muscle atrophy occurs in many chronic diseases and disuse conditions. Its severity reduces patient recovery, independence and quality of life. The discovery of two muscle-specific E3 ubiquitin ligases, MAFbx/atrogin-1 and Muscle RING Finger-1 (MuRF1), promoted an expectation of these molecules as targets for therapeutic development. While numerous studies have determined the conditions in which MAFbx/atrogin-1 and MuRF1 mRNA levels are regulated, few studies have investigated their functional role in skeletal muscle. Recently, studies identifying new target substrates for MAFbx/atrogin-1 and MuRF1, outside of their response to the initiation of muscle atrophy, suggest that there is more to these proteins than previously appreciated. This review will highlight our present knowledge of MAFbx/atrogin-1 and MuRF1 in skeletal muscle atrophy, the impact of potential therapeutics and their known regulators and substrates. Finally, we will comment on new approaches that may expand our knowledge of these two molecules in their control of skeletal muscle function.

Impact of resistance exercise training on interleukin-6 and JAK/STAT in young men.

The JAK/STAT signaling pathway is essential for myogenic regeneration and is regulated by a diverse range of ligands, including interleukin-6 (IL-6) and platelet-derived growth factor-BB (PDGF-BB). Our aim was to evaluate the responsiveness of IL-6 and PDGF-BB to intense exercise, along with STAT3 activation, before and after 12 weeks of resistance training. In young men, IL-6 and PDGF-BB protein concentrations were quantified in biopsied muscle and increased at 3 h post-exercise (17.5-fold and 3-fold, respectively). The response was unaltered by 12 weeks of training. Similarly, STAT3 phosphorylation was elevated post-exercise (12.5-fold), irrespective of training status, as was the expression of downstream targets c-MYC (8-fold), c-FOS (4.5-fold), and SOCS3 (2.3-fold). Thus, intense exercise transiently increases IL-6 and PDGF-BB proteins, and STAT3 phosphorylation is increased. These responses are preserved after intense exercise. This suggests they are not modified by training and may be an essential component of the adaptive responses to intense exercise.

Blunted nutrient-response pathways in adipose tissue following high fat meals in men with metabolic syndrome: A randomized postprandial transcriptomic study.

BACKGROUND: Excessive adipose tissue is central to disease burden posed by the Metabolic Syndrome (MetS). Whilst much is known of the altered transcriptomic regulation of adipose tissue under fasting conditions, little is known of the responses to high-fat meals. METHODS: Nineteen middle-aged males (mean ± SD 52.0 ± 4.6 years), consumed two isocaloric high-fat, predominately dairy-based or soy-based, breakfast meals. Abdominal subcutaneous adipose biopsies were collected after overnight fast (0 h) and 4 h following each meal. Global gene expression profiling was performed by microarray (Illumina Human WG-6 v3). RESULTS: In the fasted state, 13 genes were differently expressed between control and MetS adipose tissue (≥1.2 fold-difference, p < 0.05). In response to the meals, the control participants had widespread increases in genes related to cellular nutrient responses (≥1.2 fold-change, p < 0.05; 2444 & 2367 genes; dairy & soy, respectively). There was blunted response in the MetS group (≥1.2 fold-change, p < 0.05; 332 & 336 genes; dairy & soy, respectively). CONCLUSIONS: In middle-aged males with MetS, a widespread suppression of the subcutaneous adipose tissue nutrient responsive gene expression suggests an inflexibility in the transcriptomic responsiveness to both high-fat meals.

Actionable Ventricular Tachycardia During In-Hospital ECG Monitoring and Its Impact on Alarm Fatigue.

BACKGROUND: Ventricular tachycardia (V-tach) is the most common lethal arrhythmia, yet 90% of alarms are false and contribute to alarm fatigue. We hypothesize that some true V-tach also causes alarm fatigue because current criteria are too sensitive (i.e., ≥6 beats ≥100 beats/min [bpm]). PURPOSE: This study was designed to determine (1) the proportion of clinically actionable true V-tach events; (2) whether true actionable versus nonactionable V-tach differs in terms of heart rate and/or duration (seconds); and (3) if actionable V-tach is associated with adverse outcomes. METHODS: This was a secondary analysis in 460 intensive care unit (ICU) patients. Electronic health records were examined to determine if a V-tach event was actionable or nonactionable. Actionable V-tach was defined if a clinical action(s) was taken within 15 minutes of its occurrence (i.e., new and/or change of medication, defibrillation, and/or laboratory test). Maximal heart rate and duration for each V-tach event were measured from bedside monitor electrocardiography. Adverse patient outcomes included a code blue event and/or death. RESULTS: In 460 ICU patients, 50 (11%) had 151 true V-tach events (range 1-20). Of the 50 patients, 40 (80%) had only nonactionable V-tach (97 events); 3 (6%) had both actionable and nonactionable V-tach (32 events); and 7 patients (14%) had only actionable V-tach (23 events). There were differences in duration comparing actionable versus nonactionable V-tach (mean 56.19 ± 116.87 seconds vs. 4.28 ± 4.09 seconds; P = 0.001) and maximal heart rate (188.81 ± 116.83 bpm vs. 150.79 ± 28.26 bpm; P = 0.001). Of the 50 patients, 3 (6%) had a code blue, 2 died, and all were in the actionable V-tach group. CONCLUSIONS: In our sample, <1% experienced a code blue following true V-tach. Heart rate and duration for actionable V-tach were much faster and longer than that for nonactionable V-tach. Current default settings typically used for electrocardiographic monitoring (i.e., ≥6 beats ≥100 bpm) appear to be too conservative and can lead to crisis/red level nuisance alarms that contribute to alarm fatigue. A prospective study designed to test whether adjusting default settings to these higher levels is safe for patients is needed.

Effects of conjugated linoleic acid on myogenic and inflammatory responses in a human primary muscle and tumor coculture model.

The antiproliferative and anti-inflammatory properties of conjugated linoleic acid (CLA) make it a potentially novel treatment in chronic inflammatory muscle wasting disease, particularly cancer cachexia. Human primary muscle cells were grown in coculture with MIA PaCa-2 pancreatic tumor cells and exposed to varying concentrations of c9,t11 and t10,c12 CLA. Expression of myogenic (Myf5, MyoD, myogenin, and myostatin) and inflammatory genes (CCL-2, COX-2, IL-8, and TNF-alpha) were measured by real-time PCR. The t10,c12 CLA isomer, but not the c9,t11 isomer, significantly decreased MIA PaCa-2 proliferation by between 15% and 19%. There was a marked decrease in muscle MyoD and myogenin expression (78% and 62%, respectively), but no change in either Myf5 or myostatin, in myotubes grown in coculture with MIA PaCa-2 cells. CLA had limited influence on these responses. A similar pattern of myogenic gene expression changes was observed in myotubes treated with TNF-alpha alone. Several-fold significant increases in CCL-2, COX-2, IL-8, and TNF-alpha expression in myotubes were observed with MIA PaCa-2 coculture. The c9,t11 CLA isomer significantly decreased basal expression of TNF-alpha in myotubes and could ameliorate its tumor-induced rise. The study provides insight into the anti-inflammatory and antiproliferative actions of CLA and its application as a therapeutic agent in inflammatory disease states.

Glasgow Coma Scale: Generating Clinical Standards.

BACKGROUND: The Glasgow Coma Scale (GCS) is a tool used to aid in objectively measuring the neurological status of a patient. This study aimed to evaluate the limitations and discrepancies in GCS use among nurses in an academic medical center neurological intensive care unit and compile evidence for development of a standardized GCS educational program. METHODS: Twenty nurse participants completed a survey before attending an educational intervention. Participants then attended a 90-minute educational intervention. In follow-up, participants were asked to complete a postsurvey. RESULTS: The standardized GCS educational program significantly improved nurse knowledge of the GCS as measured by presurvey and postsurvey general GCS question scores. Educational programming improved application of the GCS as measured by presurvey and postsurvey GCS verbal component, motor component, and sum scores. GCS motor score performance was the least accurate component. CONCLUSION: Participants reported that the education has informed the unit culture and emboldened clinical nurses to speak to their practice with more authority. Educational interventions should be aimed toward applied transfer of knowledge to the case-based scenarios in the clinical setting.

Putative quorum-sensing regulator BlxR of Brucella melitensis regulates virulence factors including the type IV secretion system and flagella.

Brucella melitensis is an intracellular pathogen that establishes a replicative niche within macrophages. While the intracellular lifestyle of Brucella is poorly understood and few virulence factors have been identified, components of a quorum-sensing pathway in Brucella have recently been identified. The LuxR-type regulatory protein, VjbR, and an N-acylhomoserine lactone signaling molecule are both involved in regulating expression of the virB-encoded type IV secretion system. We have identified a second LuxR-type regulatory protein (BlxR) in Brucella. Microarray analysis of a blxR mutant suggests that BlxR regulates the expression of a number of genes, including those encoding the type IV secretion system and flagella. Confirming these results, deletion of blxR in B. melitensis reduced the transcriptional activities of promoters for the virB operon, flagellar genes, and another putative virulence factor gene, bopA. Furthermore, our data suggested that both BlxR and VjbR are positively autoregulated and cross-regulate the expression of each other. The blxR deletion strain exhibited reduced growth in macrophages, similar to that observed for a vjbR deletion strain. However, unlike the vjbR deletion, the blxR deletion did not fully attenuate virulence in mice. More strikingly, bioluminescent imaging revealed that dissemination of the blxR mutant was similar to that of wild-type B. melitensis, while the vjbR mutant was defective for systemic spread in IRF-1(-/-) mice, suggesting that these regulators are not functionally redundant but that they converge in a common pathway regulating bacterial processes.

Conjugated linoleic acid suppresses myogenic gene expression in a model of human muscle cell inflammation.

Proinflammatory cytokines, such as tumor necrosis factor (TNF)-alpha, contribute to muscle wasting in inflammatory disorders, where TNFalpha acts to regulate myogenic genes. Conjugated linoleic acid (CLA) has shown promise as an antiproliferative and antiinflammatory agent, leading to its potential as a therapeutic agent in muscle-wasting disorders. To evaluate the effect of CLA on myogenesis during inflammation, human primary muscle cells were grown in culture and exposed to varying concentrations of TNFalpha and the cis-9, trans-11 and trans-10, cis-12 CLA isomers. Expression of myogenic genes (Myf5, MyoD, myogenin, and myostatin) and the functional genes creatine kinase (CK) and myosin heavy chain (MHC IIx) were measured by real-time PCR. TNFalpha significantly downregulated MyoD and myogenin expression, whereas it increased Myf5 expression. These changes corresponded with a decrease in both CK and MHC IIx expression. Both isomers of CLA mimicked the inhibitory effect of TNFalpha treatment on MyoD and myogenin expression, whereas myostatin expression was diminished in the presence of both isomers of CLA either alone or in combination with TNFalpha. Both isomers of CLA decreased CK and MHC IIx expression. These findings demonstrate that TNFalpha can have specific regulatory effects on myogenic genes in primary human muscle cells. A postulated antiinflammatory role of CLA in myogenesis appears more complex, with an indication that CLA may have a negative effect on this process.

Cardiotrophin-1 stimulation of cardiac fibroblast growth: roles for glycoprotein 130/leukemia inhibitory factor receptor and the endothelin type A receptor.

Cardiotrophin-1 (CT-1), a member of the interleukin-6 superfamily, and endothelin-1 (ET-1) are potent hypertrophic factors in cardiomyocytes. Although CT-1 and ET-1 gene expression in the heart is upregulated in experimental heart failure, their role in the activation of the cardiac fibroblast is unknown. This study was designed to identify the presence and action of CT-1 and its receptor complex, glycoprotein130 (gp130) and leukemia inhibitory factor (LIF) receptor, on cardiac fibroblast growth in cultured adult canine cardiac fibroblasts. In addition, we investigated the interaction between CT-1/gp130/LIF receptor and ET-1/endothelin type A (ET(A)) receptor axis. Immunohistochemistry was performed using the indirect immunoperoxidase method, while we assessed the cell cycle of cardiac fibroblasts by flow cytometry, DNA synthesis by [(3)H]thymidine incorporation, and collagen synthesis by [(3)H]proline incorporation, respectively. CT-1 and gp130/LIF receptor were widely present in the cytoplasm of the cardiac fibroblasts. Exogenous CT-1 markedly stimulated [(3)H]thymidine and [(3)H]proline incorporations (P<0.01), with accumulation of cells in the S phase. Blockade of gp130 or LIF receptor inhibited basal growth as well as CT-1- or ET-1-stimulated cardiac fibroblast growth. The specific ET(A) receptor antagonist, BQ123, significantly inhibited CT-1-stimulated DNA synthesis. This study demonstrates that CT-1 and its receptors are present in cardiac fibroblasts. In addition, growth of these cells stimulated by endogenous and exogenous CT-1 requires gp130/LIF receptor as well as ET(A) receptor activation. We conclude that gp130/LIF receptor and ET(A) receptor activation are essential for cardiac fibroblast growth by CT-1 and that there is synergism with ET-1/ET(A) receptor axis.

Postprandial Responses to Lipid and Carbohydrate Ingestion in Repeated Subcutaneous Adipose Tissue Biopsies in Healthy Adults.

Adipose tissue is a primary site of meta-inflammation. Diet composition influences adipose tissue metabolism and a single meal can drive an inflammatory response in postprandial period. This study aimed to examine the effect lipid and carbohydrate ingestion compared with a non-caloric placebo on adipose tissue response. Thirty-three healthy adults (age 24.5 ± 3.3 year (mean ± standard deviation (SD)); body mass index (BMI) 24.1 ± 3.2 kg/m2, were randomised into one of three parallel beverage groups; placebo (water), carbohydrate (maltodextrin) or lipid (dairy-cream). Subcutaneous, abdominal adipose tissue biopsies and serum samples were collected prior to (0 h), as well as 2 h and 4 h after consumption of the beverage. Adipose tissue gene expression levels of monocyte chemoattractant protein-1 (MCP-1), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) increased in all three groups, without an increase in circulating TNF-α. Serum leptin (0.6-fold, p = 0.03) and adipose tissue leptin gene expression levels (0.6-fold, p = 0.001) decreased in the hours following the placebo beverage, but not the nutrient beverages. Despite increased inflammatory cytokine gene expression in adipose tissue with all beverages, suggesting a confounding effect of the repeated biopsy method, differences in metabolic responses of adipose tissue and circulating adipokines to ingestion of lipid and carbohydrate beverages were observed.

Leukemia inhibitory factor is augmented in the heart in experimental heart failure.

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine that induces cardiac myocyte hypertrophy through the signal transducing molecule, glycoprotein 130. To date, localization of LIF in the heart and regulation of cardiac LIF expression in congestive heart failure (CHF) remain undefined. The present study investigates the potential activation of LIF expression in the failing canine heart that was produced by progressive rapid ventricular pacing. Immunohistochemistry for LIF revealed that LIF immunoreactivity was present in the atrial and ventricular myocytes of the normal heart and was markedly increased in the failing heart as compared to the normal heart. Northern blot analysis demonstrated that cardiac LIF mRNA was increased in both atrium and ventricle in CHF as compared to the normal heart (P<0.01). Linear regression analysis revealed a positive correlation between atrial LIF mRNA and atrial pressure (r=0.87, P<0.001 in right atrium and r=0.86, P<0.001 in left atrium). Positive correlations between left ventricular LIF mRNA and left ventricular dimensions (r=0.91, P<0.0001 in end-systolic diameter; r=0.86, P<0.001 in end-diastolic diameter), and an inverse correlation between left ventricular LIF mRNA and left ventricular ejection fraction (EF) were observed (r=-0.93, P<0.0001). There was a positive correlation between left ventricular LIF mRNA and left ventricular mass index (LVMI) (r=0.85, P<0.001). The present study demonstrates that cardiac LIF immunoreactivity and its gene expression are increased in a canine model of experimental CHF and suggests a potential role for LIF in the pathophysiology of CHF.

Ventricular cardiotrophin-1 activation precedes BNP in experimental heart failure.

Both cardiotrophin-1 (CT-1) and B-type or brain natriuretic peptide (BNP) are activated by cardiomyocyte stretch, and gene expression of CT-1 and BNP are augmented in the heart in experimental and human congestive heart failure (CHF). The goal of this study was to define cardiac gene expression of CT-1 and BNP by Northern blot analysis in normal (n=5), early left ventricular dysfunction (ELVD, n=5) and overt CHF dogs (n=5), in which ventricular function is progressively decreased. CT-1 mRNA was detected in both atria and ventricles in normal dogs. Ventricular CT-1 mRNA production increased in ELVD, and it further increased in overt CHF. Ventricular BNP mRNA remained below or at the limit of detection in normal and ELVD models, and it markedly increased in overt CHF. This study reports differential regulation of gene expression of CT-1 and BNP in the heart during the progression of CHF, and demonstrates that ventricular CT-1 gene activation precedes ventricular BNP gene activation.

Cardiotrophin-1 stimulates endothelin-1 via gp130 in vascular endothelial cells.

Endothelin-1 (ET-1) is a vasoconstricting and mitogenic peptide released from vascular endothelial cells under normal and pathophysiological conditions, and synthesis and secretion of ET-1 are stimulated by cytokines. Cardiotrophin-1 (CT-1) is a new member of the interleukin-6-type cytokines that induce biological actions through the glycoprotein (gp) 130. The present study was designed to determine the presence of CT-1 and the gp130 cytokine system in vascular endothelial cells and to investigate whether CT-1 stimulates synthesis and secretion of ET-1 in the vascular endothelial cells. We first sought to determine gene expression and immunoreactivity of CT-1, gp130 and ET-1 in cultured canine aortic endothelial cells (CAECs) using Northern blot analysis and immunocytochemistry, which revealed the presence of CT-1 and gp130 together with ET-1 in CAECs. CT-1 increased ET-1 gene expression in CAECs, and stimulated ET-1 secretion from CAECs in a dose-dependent manner. Furthermore, inhibition of gp130 by monoclonal antibody attenuated ET-1 secretion from CAECs, suggesting that actions of CT-1 on the secretion of ET-1 are mediated through gp130 receptor system. The present study, therefore, reports the presence of CT-1 and gp130 in vascular endothelial cells and mechanisms of secretion of ET-1 related to this cytokine system.