Interleukin-8 activates microtubule-associated protein 2 kinase (ERK1) in human neutrophils

The signal transduction initiated by the human cytokine interleukin-8 (IL-8), the main chemotactic cytokine for neutrophils, was investigated and found to encompass the stimulation of protein kinases. More specifically, IL-8 caused a transient, dose and time dependent activation of a Ser/Thr kinase activity towards myelin basic protein (MBP) and the MBP-derived peptide APRTPGGRR patterned after the specific concensus sequence in MBP for ERK enzymes. The activated MBP kinase was furthermore identified as an extracellular signal regulated kinase (ERK1) based on several criteria such as substrate specificity, molecular weight, activation-dependent mobility shift, and recognition by anti-ERK antibodies. For comparison, the chemotactic response of neutrophils to a stimulus of bacterial origin (fMet-Leu-Phe or fMLP) was also examined and found to involve the activation of a similar ERK enzyme. The present data clearly indicate that in terminally differentiated, non-proliferating human cells, the MBP kinase/ERK activity can serve other purposes than mitogenic signaling, and that processes such as chemotaxis, induced by bacterial peptides as well as by human cytokines like IL-8, involve the regulation of ERK enzyme.Abbreviations IL-8 interleukin-8 - fMLP fMet-Leu-Phe - MBP myelin basic protein - ERK extracellular signal regulated kinase - MAP2 microtubule-associated protein 2 - PK-A cAMP dependent protein kinase - PKI protein kinase inhibitor - PMSF phenyl-methanesulfonyl fluoride - PVDF poly-vinylidene difluoride - HBSF Hank's buffered salt solution - DAB 3,3-diaminobenzidine tetrahydrochloride - PNPP p-nitrophenyl-phosphate - HSA human serum albumin - EGTA [ethylenebis (oxyethylenenitrilo)]tetraacetic acid - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis     

The effects of intensity of exercise on excess postexercise oxygen consumption and energy expenditure in moderately trained men and women

This experiment investigated the effects of intensity of exercise on excess postexercise oxygen consumption (EPOC) in eight trained men and eight women. Three exercise intensities were employed 40%, 50%, and 70% of the predetermined maximal oxygen consumption (VO_2max). All ventilation measured was undertaken with a standard, calibrated, open circuit spirometry system. No differences in the 40%, 50% and 70% VO_2max trials were observed among resting levels of oxygen consumption (V0₂) for either the men or the women. The men had significantly higher resting VO₂ values being 0.31 (SEM 0.01) 1·min^–1 than did the women, 0.26 (SEM 0.01) 1·min^–1 (P < 0.05). The results indicated that there were highly significant EPOC for both the men and the women during the 3-h postexercise period when compared with resting levels and that these were dependent upon the exercise intensity employed. The duration of EPOC differed between the men and the women but increased with exercise intensity: for the men 40% – 31.2 min; 50% – 42.1 min; and 70% – 47.6 min and for the women, 40% – 26.9 min; 50% – 35.6 min; and 70% – 39.1 min. The highest EPOC, in terms of both time and energy utilised was at 70% VO_2max. The regression equation for the men, where y=O₂ in litres, and x=exercise intensity as a percentage of maximum was y=0.380x + 1.9 (r ²=0.968) and for the women is y=0.374x–0.857 (r ²=0.825). These findings would indicate that the men and the women had to exercise at the same percentage of their VO_2max to achieve the maximal benefits in terms of energy expenditure and hence body mass loss. However, it was shown that a significant EPOC can be achieved at moderate to low exercise intensities but without the same body mass loss and energy expenditure.     

Analysis of parameters about useful life extension in 70 tools and methods related to eco-design and circular economy

One of the approaches followed by the circular economy (CE) to achieve sustainability through design is product life extension. Extending the life of products to make them useful for as long as possible is a means to reduce waste production and materials consumption, as well as the related impacts. For designers, conceptualizing products in a way that allows them to be used for longer is a challenge, and assessing how well they extend their lifespan can be helpful when it comes to choosing the best proposal. In this paper, 70 tools and methods related to eco-design and circular economy are studied to determine how many of them consider parameters related to life extension and which can be applied in the early stages of design. The results of the analysis show that most of the existing tools and methods are applicable to developed products, and only a few of them take into account parameters related to extending the useful life. Of the 70 tools and methods, only 14 include some parameter related to life extension and are applicable to concepts. CE toolkit, Eco-design PILOT, CE Designer, Circularity Assessment tool, Circularity Potential Indicator and Circular Design Tools take into consideration eight or more parameters to assess life extension in concepts. This will help designers select the most appropriate and will indicate the need for more complete tools to consider useful life extension in the early stages of design and thus enhance the selection of more sustainable products.     

Molecular mechanisms of oxidative stress-related neonatal jaundice

Oxidative stress is a pathological condition characterized by an overload of oxidant products, named free radicals, which are not well counteracted by antioxidant systems. Free radicals induce oxidative damage to many body organs and systems. In neonatal red blood cells, free-radical mediated-oxidative stress leads to eryptosis, a suicidal death process of erythrocytes consequent to alteration of cell integrity. Neonatal red blood cells are targets and at the same time generators of free radicals through the Fenton and Haber-Weiss reactions. Enhanced eryptosis in case of oxidative stress damage may cause anemia if the increased loss of erythrocytes is not enough compensated by enhanced new erythrocytes synthesis. The oxidative disruption of the red cells may cause unconjugated idiopathic hyperbilirubinemia in neonates. High levels of bilirubin are recognized to be dangerous for the central nervous system in newborns, however, many studies have highlighted the antioxidant function of bilirubin. Recently, it has been suggested that physiologic concentration of bilirubin correlates with higher antioxidant status while high pathological bilirubin levels are associated with pro-oxidants effects. The aim of this educational review is to provide an updated understanding of the molecular mechanisms underlying erythrocyte oxidant injury and its reversal in neonatal idiopathic hyperbilirubinemia.     

Proportional processing of a visual mate choice signal in the green swordtail,Xiphophorus hellerii

During mate choice, receivers often assess the magnitude (duration, size, etc.) of signals that vary along a continuum and reflect variation in signaller quality. It is generally assumed that receivers assess this variation linearly, meaning each difference in signalling trait between signallers results in a commensurate change in receiver response. However, increasing evidence shows receivers can respond to signals non-linearly, for example through Weber's Law of proportional processing, where discrimination between stimuli is based on proportional, rather than absolute, differences in magnitude. We quantified mate preferences of female green swordtail fish, Xiphophorus hellerii, for pairs of males differing in body size. Preferences for larger males were better predicted by the proportional difference between males (proportional processing) than the absolute difference (linear processing). This demonstration of proportional processing of a visual signal implies that receiver perception may be an important mechanism selecting against the evolution of ever-larger signalling traits.     

The genome of the non-cultured,bacterial-like organism associated with citrus greening disease contains thenusG-rplKAJL-rpoBC gene cluster and the gene for a bacteriophage type DNA polymerase

We have recently cloned three DNA fragments (In-2.6, In-1.0, and In-0.6) of the noncultured, bacterial-like organism (BLO) associated with citrus greening disease. Nucleotide sequence determination has shown that fragment In-2.6 is part of therplKAJL-rpoBC gene cluster, a well-known operon in eubacteria. The DNA fragment upstream of and partially overlapping with In-2.6 could be isolated and was shown to be thenusG gene. InEscherichia coli, nusG is also immediately upstream ofrplKAJL-rpoBC. Fragment In-1.0 carries the gene for a bacteriophage type DNA polymerase. Fragment In-0.6 could not be identified.When In-2.6 was used, at high stringency, as a probe to detect greening BLO strains in infected plants, hybridization was obtained with all Asian strains tested, but not with the African strain examined. At lower stringencies, In-2.6 was able to detect also the African strain. The implications of these reults in the taxonomical position of the greening BLO are discussed.