The acute effect of 30 min of moderate exercise on high density lipoprotein cholesterol in untrained middle-aged men

Fifteen middle-aged, untrained (defined as no regular exercise) men (mean age 49.9 years, range 42-67) cycled on a cycle ergometer at 50 rpm for 30 min at an intensity producing 60% predicted maximum heart rate [(fc,max), where fc,max = 220 - age]. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (Tg) concentrations were measured from fasting fingertip capillary blood samples collected at rest, after 15 and 30 min of exercise, and at 15 min post-exercise. The mean HDL-C level increased significantly from the resting level of 0.85 mmol.l-1 to 0.97 mmol.l-1 (P < 0.05) after 15 min of exercise, increased further to 1.08 mmol.l-1 (P < 0.01) after 30 min of exercise and remained elevated at 1.07 mmol.l-1 (P < 0.01) at 15 min post-exercise. These increases represented changes above the mean resting level of 14.1%, 27.1% and 25.9% respectively. The HDL-C/LDL-C ratio increased significantly from a resting ratio of 0.20 to 0.26 after 30 min of exercise (P < 0.01) and to 0.24 at 15 min post-exercise (P < 0.05). The mean Tg level increased significantly from a resting level of 0.88 mmol.l-1 to 1.05 mmol.l-1 after 15 min, and to 1.06 mmol.l-1 after 30 min of exercise (P < 0.05 at each time). The TC/HDL-C ratio decreased significantly (P = 0.05) after 30 min of exercise and at 15 min post-exercise by 18.8% and 14%, respectively. No significant changes were observed in the levels of TC or LDL-C over time.(ABSTRACT TRUNCATED AT 250 WORDS)     

Inhibition of cholesteryl ester transfer protein by anacetrapib does not impair the anti-inflammatory properties of high density lipoprotein

Cholesteryl ester transfer protein (CETP) is a target of therapeutic intervention for coronary heart disease. Anacetrapib, a potent inhibitor of CETP, has been shown to reduce LDL-cholesterol by 40% and increase HDL-cholesterol by 140% in patients, and is currently being evaluated in a phase III cardiovascular outcomes trial. HDL is known to possess anti-inflammatory properties, however with such large increases in HDL-cholesterol, it is unclear whether CETP inhibition perturbs HDL functionality such as anti-inflammatory effects on endothelial cells. The purpose of the present study was to determine whether CETP inhibition by anacetrapib affects the anti-inflammatory properties of HDL. HDL was isolated from either hamsters treated with vehicle or anacetrapib for 2 weeks, or from normal human subjects treated either placebo, 20 mg, or 150 mg anacetrapib daily for 2 weeks. Anacetrapib treatment increased plasma HDL cholesterol levels by 65% and between 48 and 82% in hamsters and humans, respectively. Pre-incubation of human aortic endothelial cells with HDL isolated from both control and anacetrapib treated hamsters suppressed TNFα induced expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin. Similar results were obtained with human HDL samples pre and post treatment with placebo or anacetrapib. Further, HDL inhibited TNFα-induced MCP-1 secretion, monocyte adhesion and NF-κB activation in endothelial cells, and the inhibition was similar between control and anacetrapib treated groups. These studies demonstrate that anacetrapib treatment does not impair the ability of HDL to suppress an inflammatory response in endothelial cells.     

Human C-reactive protein gene polymorphism and metabolic syndrome are associated with premature coronary artery disease

The aim of this study was to investigate the association between C-reactive protein (CRP) gene polymorphism and metabolic syndrome (MetS) with premature coronary artery disease (PCAD). 116 patients with PCAD (58 with MetS and 58 without MetS) and 119 controls were included in the study. CRP gene + 1059 G>C polymorphism was analyzed by polymerase chain reaction. Serum hs-CRP was measured using high-sensitivity enzyme-linked immunosorbent assay. Carriers of C allele of the CRP + 1059 G>C polymorphism had 3.37 fold increased risk to develop MetS in patients with PCAD. In addition CRP gene and hs-CRP levels were independent risk factors for PCAD and MetS. The present study provides new evidence that the presence of CRP + 1059 G>C polymorphism and hs-CRP levels are independent determinants of PCAD and MetS in Egyptians. The results of our study suggest a synergistic effect of CRP C allele with classical risk factors such as hypertension, obesity, dyslipidemia and MetS.     

Consensus for experimental design in electromyography (CEDE) project: High-density surface electromyography matrix

High-density surface electromyography (HDsEMG) can be used to measure the spatial distribution of electrical muscle activity over the skin. As this distribution is associated with the generation and propagation of muscle fiber action potentials, HDsEMG is processed to extract information on regional muscle activation, muscle fiber characteristics and behaviour of individual motor units. This matrix, developed by the Consensus for Experimental Design in Electromyography (CEDE) project, summarizes recommendations on the use of HDsEMG in experimental studies. For each application, recommendations are included regarding electrode montage, electrode type and configuration, electrode location and orientation, data analysis, and interpretation. Cautions and reporting standards are also included. The steps of the Delphi process to reach consensus are contained in an appendix. This matrix is intended to help researchers when collecting, reporting, and interpreting HDsEMG data. It is hoped that this document will be used to generate new empirical evidence to improve how HDsEMG is used in research and in clinical applications.     

Use of phage display and high-density screening for the isolation of an antibody against the 51-kDa subunit of complex I

Monoclonal antibodies play an increasingly important role in structural biology. In this report, we develop the use of phage display technology for the isolation of an antibody that binds to a specific subunit of a macromolecular assembly. Antibodies that bind to the intact complex are selected from a phage display library and screened with a high-density Western blot to identify a subunit-specific binder. Conventional Western blotting and competition ELISA are then used to confirm the identity of the target subunit and that the antibody binds to the native protein complex and not to an epitope that is only revealed when the antibody is immobilized for phage selection. Using this technique, monoclonal scFv and Fab fragments have been produced that bind to the 51-kDa subunit of bovine complex I, a large integral membrane protein complex from mitochondria.     

Cathepsins F and S block HDL3-induced cholesterol efflux from macrophage foam cells

In atherosclerosis, accumulation of cholesterol in macrophages may partially depend on its defective removal by high-density lipoproteins (HDL). We studied the proteolytic effect of cathepsins F, S, and K on HDL(3) and on lipid-free apoA-I, and its consequence on their function as inductors of cholesterol efflux from cholesterol-filled mouse peritoneal macrophages in vitro. Incubation of HDL(3) with cathepsin F or S, but not with cathepsin K, led to rapid loss of prebeta-HDL, and reduced cholesterol efflux by 50% in only 1min. Cathepsins F or K partially degraded lipid-free apoA-I and reduced its ability to induce cholesterol efflux, whereas cathepsin S totally degraded apoA-I, leading to complete loss of apoA-I cholesterol acceptor function. These results suggest that cathepsin-secreting cells induce rapid depletion of lipid-poor (prebeta-HDL) and lipid-free apoA-I and inhibit cellular cholesterol efflux, so tending to promote the formation and maintenance of foam cells in atherosclerotic lesions.     

Novel Large Apolipoprotein E-Containing Lipoproteins of Density 1.006–1.060 g/ml in Human Cerebrospinal Fluid

Abstract: Although the critical role of apolipoprotein E (apoE) allelic variation in Alzheimer's disease and in the outcome of CNS injury is now recognized, the functions of apoE in the CNS remain obscure, particularly with regard to lipid metabolism. We used density gradient ultracentrifugation to identify apoE-containing lipoproteins in human CSF. CSF apoE lipoproteins, previously identified only in the 1.063–1.21 g/ml density range, were also demonstrated in the 1.006–1.060 g/ml density range. Plasma lipoproteins in this density range include low-density lipoprotein and high-density lipoprotein (HDL) subfraction 1 (HDL₁). The novel CSF apoE lipoproteins are designated HDL₁. No immunoreactive apolipoprotein A-I (apo A-I) or B could be identified in the CSF HDL₁ fractions. Large lipoproteins 18.3 ± 6.6 nm in diameter (mean ± SD) in the HDL₁ density range were demonstrated by electron microscopy. Following fast protein liquid chromatography of CSF at physiologic ionic strength, apoE was demonstrated in particles of average size greater than particles containing apoA-I. The largest lipoproteins separated by this technique contained apoE without apoA-I. Thus, the presence of large apoE-containing lipoproteins was confirmed without ultracentrifugation. Interconversion between the more abundant smaller apoE-HDL subfractions 2 and 3 and the novel larger apoE-HDL₁ is postulated to mediate a role in cholesterol redistribution in brain.     

High level expression of human endostatin in Pichia pastoris using a synthetic gene construct

Endostatin, a 20-kDa C-terminal fragment derived from type XVIII collagen, is a potent angiogenesis inhibitor and an antitumor factor. To improve the production of recombinant human endostatin on increasing demand in clinical practice, we constructed an artificial gene encoding its mature peptide sequence in human collagen XVIII. The synthetic gene consisted of 20 codons in preference in methylotropic yeast—Pichia pastoris and was cloned into expression vector pPICZαA; and the recombinant protein was expressed in P. pastoris strain SMD1168 and purified to near homogeneity using heparin affinity chromatography. The amount of expressed recombinant protein in cultural media using described strategy was 80 mg/l in shake flask cultivation and 435 mg/l in high-density bioreactor fermentation. Methylthiazolium assay demonstrated that human endostatin expressed in P. pastoris using artificial synthetic gene of preference in P. pastoris was able to inhibit the acidic fibroblast growth factor-induced proliferation of endothelial cells in vitro.     

Constitutive expression of human angiostatin in <Emphasis Type="Italic">Pichia pastoris</Emphasis> by high-density cell culture

A high-density cell culture method to produce human angiostatin has been successfully established by constitutive expression of the protein in Pichia pastoris. The fermentation was carried out in a 20 l bioreactor with a 10 l working volume, using a high-density cell culture method by continuously feeding with 50% glycerol−0.8% PTM4 to the growing culture for 60 h at 30°C. Dissolved oxygen level was maintained at 25–30% and pH was controlled at 5 by the addition of 7 M NH₄OH. Angiostatin was constitutively expressed during the fermentation by linking its expression to the P. pastoris constitutive GAP promoter (pGAP). But after 36 h of fermentation, the peak biomass growth was 305 as measured by absorption of 600 nm, while the peak angiostatin expression was 176 mg/l. Similar to the product expressed from inducible system [24], angiostatin produced from constitutive system also inhibited the angiogenesis on the CAM and suppressed the growth of B16 melanoma in C57BL/6J mouse. The above results suggest that GAP promoter is more efficient than AOX1 promoter for the expression of angiostatin in P. pastoris by shake flask culture or high-density cell fermentation and is likely to be an alternative to AOX1 promoter in large-scale expression of angiostatin and other heterologous proteins. Supported by the Natural Science Foundation of China (39670013) and “225” Science and Technology Program of Guangzhou Municipal Government of China (99-Z-004-001).     

Establishing the impact of temporary tissue expanders on electron and photon beam dose distributions

PurposeThis study investigates the effects of temporary tissue expanders (TTEs) on the dose distributions in breast cancer radiotherapy treatments under a variety of conditions.MethodsUsing EBT2 radiochromic film, both electron and photon beam dose distribution measurements were made for different phantoms, and beam geometries. This was done to establish a more comprehensive understanding of the implant's perturbation effects under a wider variety of conditions.ResultsThe magnetic disk present in a tissue expander causes a dose reduction of approximately 20% in a photon tangent treatment and 56% in electron boost fields immediately downstream of the implant. The effects of the silicon elastomer are also much more apparent in an electron beam than a photon beam.ConclusionsEvidently, each component of the TTE attenuates the radiation beam to different degrees. This study has demonstrated that the accuracy of photon and electron treatments of post-mastectomy patients is influenced by the presence of a tissue expander for various beam orientations. The impact of TTEs on dose distributions establishes the importance of an accurately modelled high-density implant in the treatment planning system for post-mastectomy patients.