Kinetics of endogenous leukotriene B4 and E4 production following injection of the chemotactic peptide FMLP in the rabbit

The kinetic profiles of leukotriene B4 (LTB4) and E4 (LTE4) after intravenous administration (30 nmol/kg) of the inflammatory peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) were evaluated in male rabbits. LTB4 and LTE4 reached the maximal concentration of 84.2 +/- 60.0 and 162.2 +/- 51.4 nmol/L (mean +/- s.d.), at 2 and 5 min, respectively. The first elimination phase for LTB4 and LTE4, after FMLP administration, showed an apparent half-life of 24.6 +/- 6.7 and 36.9 +/- 13.0 min, respectively. The area under the blood concentration-time curve (AUC, nmol min/L) of LTB4 and LTE4 was 2178 +/- 1591 and 7627 +/- 3052, respectively. LTE4 and N-ac-LTE4 were the major components excreted in the urine, mostly in the first time interval (0-12 h) of urinary collection after FMLP treatment; 11-trans-LTE4 was recovered in the second interval (12-24 h). Two other more polar compounds, potential metabolites, were recovered in the first interval of urine collection. Knowledge of the kinetic characteristics of endogenously produced leukotrienes may be useful in understanding the role of these eicosanoids in inflammatory and thrombotic disease, as well as in evaluating the efficacy of drugs designed to modulate their production and effect.     

A Method for Quantitative Ultrasonic Backscatter Estimates in the Presence of Phase Distortion

A method has been developed which can predict the backscatter properties of biological tissues from single amplitude spectra. Backscatter analysis from single spectra, based on the ratio of the Fourier transforms, is strongly influenced by the amplitude fluctuations, due to the inhomogeneous nature of biological tissues. The theoretical basis for the developed method is that the tissue produces an asymmetry in the reference amplitude spectrum related to the power law frequency dependence of the backscatter coefficient. Therefore, an estimation of the spectrum asymmetry has potential for estimating backscatter indexes. This method has been tested by using computer simulation and experimental measurements and it has shown a strong rejection to noise effects.     

Macrophage-derived cytokines in the follicular fluids of women with infertility due to immunological causes. Elevated levels of interleukin 6 and low levels of granulocyte-macrophage colony-stimulating factor

Myoclonus of the middle ear is a rare condition characterized by abnormal repetitive muscle contractions of the tympanic cavity. In this paper we describe what we believe is the first reported case of continuous high-frequency objective tinnitus caused by middle ear myoclonus. During exploratory tympanomastoidectomy it was hypothesized that a small dural arteriovenous malformation not identified on previous tests was the cause of the tinnitus. However, complete disappearance of the tinnitus during administration of curare for anesthesia led us to believe that the tinnitus might have been caused by myoclonus of the middle ear. Sectioning of the stapedius and tensor tympani tendons rendered the patient asymptomatic and confirmed the diagnosis of middle ear myoclonus. At follow-up of one year, the patient's quality of life had improved substantially; the tinnitus did not recur and she no longer had vertigo.     

Ultimate behavior of axially loaded RC wall-like columns confined with GFRP

The assessment of the effectiveness of the fiber reinforced polymer (FRP) confinement on rectangular reinforced concrete (RC) columns with high aspect ratio (wall-like) still represents an unresolved issue. The present paper aims at providing more experimental evidence about the behavior of such members confined with both uni-directional and quadri-directional glass FRP laminates. Particular attention is devoted to issues related to the premature failure of confining fibers experimentally observed in wall-like columns. Test results on nine axially loaded columns are herein presented; emphasis is also given to the analysis of FRP strain profiles along the sides of the cross-section. The analysis of test results highlights that glass FRP (GFRP) confinement could determine significant strength and ductility increases; the discussion of failure modes points out that the failure of GFRP confined wall-like columns is controlled by the shape of the cross-section and occurs at transverse strains in the jacket much lower than those ultimate of the fibers. Theoretical–experimental comparisons are performed using some available models for strength prediction of such members.     

A non-linear dynamic modelling approach for the characterization and error compensation in sampling oscilloscopes

A mathematical modelling approach is proposed for measurement-based characterization of non-linear dynamic sources of error in the vertical channel of a sampling oscilloscope. The proposed approach has been derived from a recently proposed modified Volterra series expansion which, under particular conditions, provides fast convergence and can be truncated to the first integral term. A possible characterization procedure, based on instrument testing under sinusoidal AC input signals with different frequencies and variable DC bias components, is described and used to evaluate the performances of a commercial oscilloscope. The waveforms obtained by using the identified model are compared with the experimental ones for model validation; successively the model is used for the error compensation of the memory effects.     

Preexposure to a nonaggressive opponent prevents low-intensity, social conflict analgesia in mice.

In a first experiment, exposure of DBA/2 mice to a small number of attack bites by a C57BL/6 mouse resulted in a low-intensity analgesia as assessed by the tail-flick test. The analgesia dissipated within 10 min and was insensitive to naloxone (10 mg/kg, sc) but was antagonized by the irreversible opioid antagonist beta-chlornaltrexamine (5 mg/kg, sc). In a second experiment, preexposure to a nonaggressive C57BL/6 opponent prevented low-intensity analgesia induced by a small number of attack bites 24 hr later. The preexposure effect was abolished by naloxone (10 mg/kg, sc) given before the nonaggressive confrontation. This suggests that the release of endogenous opioids during preexposure interferes with the subsequent activation of endogenous opioid-mediated pain control mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fast magnetic field computation in fusion technology using GPU technology

One of the main issues in the simulation of Tokamaks functioning is the reliable and accurate computation of actual field maps in the plasma chamber. In this paper a tool able to accurately compute magnetic field maps produced by active coils of any 3D shape, wound with high number of conductors, is presented. Under linearity assumption, the coil winding is modeled by means of “sticks”, following each conductor's shape, and the contribution of each stick is computed using high speed Graphic Computing Units (GPU's). Relevant speed enhancements with respect to standard parallel computing environment are achieved in this way.     

Iron Chelates: Production Processes and Reaction Evolution Analysis

Nowadays, fertilization using synthetic chelates is the most common technique to address iron chlorosis, a disease that affects plant growth. Ethylenediamine-N,N'-bis(o-hydroxyphenyl) acetic acid (EDDHA) is among the most efficient iron chelating agents. To produce EDDHA, a reaction was performed using as reactants phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide. To study the reaction kinetics, samples were withdrawn from the reactor during the reaction and the kinetics was quantified, evaluating the yield evolution during the reaction phase. This study was useful to optimize the reaction time. Then, a catalyst was added to the reaction mixture to analyze its effect on the reaction evolution. Comparing the reaction evolution of the non-catalyzed and the catalyzed reaction protocols, two main results have to be highlighted: the time to reach the final yield is lower than the one proposed in the literature and the used catalyst has a minimum effect on the reaction rate.     

PGC-1s in the Spotlight with Parkinson’s Disease

Parkinson’s disease is one of the most common neurodegenerative disorders worldwide, characterized by a progressive loss of dopaminergic neurons mainly localized in the substantia nigra pars compacta. In recent years, the detailed analyses of both genetic and idiopathic forms of the disease have led to a better understanding of the molecular and cellular pathways involved in PD, pointing to the centrality of mitochondrial dysfunctions in the pathogenic process. Failure of mitochondrial quality control is now considered a hallmark of the disease. The peroxisome proliferator-activated receptor gamma coactivator 1 (PGC-1) family acts as a master regulator of mitochondrial biogenesis. Therefore, keeping PGC-1 level in a proper range is fundamental to guarantee functional neurons. Here we review the major findings that tightly bond PD and PGC-1s, raising important points that might lead to future investigations.