Hypothermia Alleviates Reductive Stress,a Root Cause of Ischemia Reperfusion Injury

Ischemia reperfusion injury is common in transplantation. Previous studies have shown that cooling can protect against hypoxic injury. To date, the protective effects of hypothermia have been largely associated with metabolic suppression. Since kidney transplantation is one of the most common organ transplant surgeries, we used human-derived renal proximal tubular cells (HKC8 cell line) as a model of normal renal cells. We performed a temperature titration curve from 37 °C to 22 °C and evaluated cellular respiration and molecular mechanisms that can counteract the build-up of reducing equivalents in hypoxic conditions. We show that the protective effects of hypothermia are likely to stem both from metabolic suppression (inhibitory component) and augmentation of stress tolerance (activating component), with the highest overlap between activating and suppressing mechanisms emerging in the window of mild hypothermia (32 °C). Hypothermia decreased hypoxia-induced rise in the extracellular lactate:pyruvate ratio, increased ATP/ADP ratio and mitochondrial content, normalized lipid content, and improved the recovery of respiration after anoxia. Importantly, it was observed that in contrast to mild hypothermia, moderate and deep hypothermia interfere with HIF1 (hypoxia inducible factor 1)-dependent HRE (hypoxia response element) induction in hypoxia. This work also demonstrates that hypothermia alleviates reductive stress, a conceptually novel and largely overlooked phenomenon at the root of ischemia reperfusion injury.     

Guest Editor's Foreword: Engineering of Recon Figurable Systems

The Journal of Supercomputing -     

Engineering of Reconfigurable Hardware/Software Objects

The Journal of Supercomputing -     

Photochemical ECE and DISP processes. The self-inhibiting disproportionation (SID) mechanisms. Theory and experiment

Channel electrodes are used to characterize the photochemical DISP2 mechanism in respect of the photoelectro-reductions of

1. (i) 9,10-diphenylanthracene,

2. (ii) benzophenone and

3. (iii) 4-fluorobenzophenone.

Quantitative measurements show that the simple DISP2 mechanism requires extension to allow for the possibilities of first a conproportionation step acting as a back-reaction to the disproportionation, and of second quenching of the excited state which leads to reaction. Both these steps, if present, serve to inhibit the overall DISP2 process. Accordingly a general scheme of Self-Inhibiting Disproportionation (SID) Mechanisms is introduced and characterized in the channel electrode geometry by computer simulations. A general protocol is established for identifying the various possible sub-cases of the general SID mechanism and illustrated with reference to the three experimental systems of interest, in all of which both conproportionation and quenching are shown to be mechanistically significant.     

Predictors and correlates of taste preferences in European children: The IDEFICS study

The present study investigated taste preferences in a sample of 1705 children aged 6 to 9 years from survey centres in Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary, and Spain and aimed to identify factors correlated with taste preference. Children’s preferences for varying levels of sucrose (sweet) in apple juice and fat, sodium chloride (salt) and monosodium glutamate (umami) in crackers were assessed using paired-comparison tests. Socio-demographics (age, sex, parental education), early feeding practises (breastfeeding, introduction of fruits), parenting behaviour (TV viewing, using food as a reward) and taste threshold sensitivity for sucrose (sweet), sodium chloride (salt), caffeine (bitter) and monosodium glutamate (umami) were investigated as possible correlates of taste preferences. Parents reported on socio-demographics, early feeding and parenting behaviour. Taste thresholds were determined via a paired-comparison staircase method. Country of residence was the strongest factor related to preferences for all four tastes. Taste preferences also differed by age. Preference for sugar and salt increased between 6 and 9 years of age while preference for monosodium glutamate decreased. The age differences remained significant even after adjustment for sex, country of residence, parental education and early feeding habits. Sex, parental education, early feeding habits, TV viewing, using food as a reward and taste thresholds were not consistently related to taste preferences among the survey centres. In summary, the results highlight the importance of culture and age in taste preferences in children younger than 10 years of age.     

Computer aided examination of I2L structures

A structure-oriented physico-topological; model of the I²L gate is described. The mode parameters (saturation currents, base resistance, current gains) have been calculated from doping levels, geometrical and electronic parameters. The turn-over level of the transfer characteristic and the propagation delay time dependence on main technological parameters, temperature and neutron irradiation have been investigated. The temperature and neutron irradiation dependence of the transfer surface and of the dynamic behaviour of the 1²L flip-flop has also been examined. The calculations have been done with the non-linear circuit analysis program TRANZ-TBAN.     

Study of Cheese Associated Lactic Acid Bacteria Under Carbohydrate-Limited Conditions Using D-Stat Cultivation

The metabolic pathways alternative to glycolytic energy (ATP) during growth of starter and nonstarter lactic acid bacteria were studied simulating the depletion of carbohydrates during cheese ripening. D-stat cultivation strategy with the gradual decrease of galactose concentration in tryptone-arginine feeding medium was used. With the decrease of galactose feeding, the biomass yield calculated on carbohydrate consumption (Y_X/HEX) and acetate/lactate production ratio of all strains increased. We assume that ATP and biomass yields improved by directing the pyruvate flow from lactate to acetate and that metabolic energy could be obtained either by producing acetate from carbohydrates or from arginine metabolism in ADI-positive strains. Four LAB strains out of eight produced ornithine from arginine indicating active arginine-deiminase (ADI) pathway. These ADI-positive strains achieved 3-10 times higher Y_X/HEX than ADI-negative strains in tryptone-arginine medium. Lactobacillus plantarum also used serine as an energy source. Starters and NSLAB strains using the amino acids arginine and serine or limited amounts of carbohydrates therefore have the potential to influence flavor production in cheese more efficiently.     

How light conditions influence theoretical pelagic to benthic primary production ratios in small lakes

Theoretical pelagic primary production of phytoplankton and benthic primary production of periphyton were modelled for two small lakes in Estonia (Northeast Europe). Although located only 500 m apart, the water colour and light attenuation of these two lakes differed markedly. The Secchi depth (SD) in the clear‐water lake was 4.5 m and only 0.47 m in the dark‐water lake. The total phosphorus (TP) concentrations were, respectively, 15 μg/l and 28 μg/l. An empirical model whose inputs were morphometric, light conditions and dissolved organic carbon parameters obtained from in situ measurements was employed for the present study. The model calculated primary production with a time‐step of 10 min, and a spatial resolution of 10 cm, from sunrise to sunset and from lake surface to lake bottom. The primary production of periphyton and phytoplankton was almost equal in the clear lake, whereas only phytoplankton contributed to whole‐lake primary production in the dark lake because of the stronger light attenuation in the water column. The results of the present study indicated the depth‐distribution profiles differed dramatically between the two lakes. The clear lake had a deep, U‐shaped curve, with the productive layer reaching considerable depth soon after sunrise and maintaining a similar profile throughout the light hours. In contrast, the dark lake production declined rapidly with increasing depth, whereas the profile changed over the day reaching the greatest depth at noon.     

Simultaneous utilization of ammonia,free amino acids and peptides during fermentative growth of Saccharomyces cerevisiae

The efficiency of nitrogen use by yeast is one of the key determinants of the successful completion of alcoholic fermentations. In this work the growth of Saccharomyces cerevisiae S288c in a synthetic medium containing ammonia and free amino acids, supplemented with yeast hydrolysate, was studied. Experiments with ¹⁵NH₄Cl and ¹⁵N‐labelled yeast hydrolysate were carried out to gain insight into which of these three classes of assimilable nitrogen sources yeast cells prefer. Co‐consumption of all three sources was observed; approximately 40% of the total nitrogen in the yeast protein fraction originated from yeast hydrolysate, while free amino acids and ammonia contributed 40 and 20%, respectively. The results indicate that several amino acids are more readily obtained from peptides, most likely when the uptake of their free forms is competitively inhibited and/or repressed. During the second half of each fermentation, a decrease in the incorporation of yeast hydrolysate‐derived nitrogen was observed. These results highlight the nutritional role of peptides in various yeast fermentations. Copyright © 2016 The Institute of Brewing & Distilling