The cyclic GMP-dependent protein kinase EGL-4 regulates olfactory adaptation in C. elegans

Prolonged odor exposure causes a specific, reversible adaptation of olfactory responses. A genetic screen for negative regulators of olfaction uncovered mutations in the cGMP-dependent protein kinase EGL-4 that disrupt olfactory adaptation in C. elegans. G protein-coupled olfactory receptors within the AWC olfactory neuron signal through cGMP and a cGMP-gated channel. The cGMP-dependent kinase functions in AWC neurons during odor exposure to direct adaptation to AWC-sensed odors, suggesting that adaptation is a cell intrinsic process initiated by cGMP. A predicted phosphorylation site on the beta subunit of the cGMP-gated channel is required for adaptation after short odor exposure, suggesting that phosphorylation of signaling molecules generates adaptation at early time points. A predicted nuclear localization signal within EGL-4 is required for adaptation after longer odor exposure, suggesting that nuclear translocation of EGL-4 triggers late forms of adaptation.     

Experimental Subarachnoid Hemorrhage in Rats: Comparison of Two Endovascular Perforation Techniques with Respect to Success Rate,Confounding Pathologies and Early Hippocampal Tissue Lesion Pattern

Recently aside from the “classic” endovascular monofilament perforation technique to induce experimental subarachnoid hemorrhage (SAH) a modification using a tungsten wire advanced through a guide tube has been described. We aim to assess both techniques for their success rate (induction of SAH without confounding pathologies) as primary endpoint. Further, the early tissue lesion pattern as evidence for early brain injury will be analyzed as secondary endpoint. Sprague Dawley rats (n=39) were randomly assigned to receive either Sham surgery (n=4), SAH using the “classic” technique (n=18) or using a modified technique (n=17). Course of intracranial pressure (ICP) and regional cerebral blood flow (rCBF) was analyzed; subsequent pathologies were documented either 6 or 24 h after SAH. Hippocampal tissue samples were analyzed via immunohistochemistry and western blotting. SAH-induction, regardless of confounding pathologies, was independent from type of technique (p=0.679). There was no significant difference concerning case fatality rate (classic: 40%; modified: 20%; p=0.213). Successful induction of SAH without collateral ICH or SDH was possible in 40% with the classic and in 86.7% with the modified technique (p=0.008). Peak ICP levels differed significantly between the two groups (classic: 94 +/- 23 mmHg; modified: 68 +/- 19 mmHg; p=0.003). Evidence of early cellular stress response and activation of apoptotic pathways 6 h after SAH was demonstrated. The extent of stress response is not dependent on type of technique. Both tested techniques successfully produce SAH including activation of an early stress response and apoptotic pathways in the hippocampal tissue. However, the induction of SAH with less confounding pathologies was more frequently achieved with the modified tungsten wire technique.     

CONSORT Item Reporting Quality in the Top Ten Ranked Journals of Critical Care Medicine in 2011: A Retrospective Analysis

IntroductionReporting randomised controlled trials is a key element in order to disseminate research findings. The CONSORT statement was introduced to improve the reporting quality. We assessed the adherence to the CONSORT statement of randomised controlled trials published 2011 in the top ten ranked journals of critical care medicine (ISI Web of Knowledge 2011, Thomson Reuters, London UK).MethodsDesign. We performed a retrospective cross sectional data analysis. Setting. This study was executed at the University Hospital of RWTH, Aachen. Participants. We selected the following top ten listed journals according to ISI Web of Knowledge (Thomson Reuters, London, UK) critical care medicine ranking in the year 2011: American Journal of Respiratory and Critical Care Medicine, Critical Care Medicine, Intensive Care Medicine, CHEST, Critical Care, Journal of Neurotrauma, Resuscitation, Pediatric Critical Care Medicine, Shock and Minerva Anestesiologica. Main outcome measures. We screened the online table of contents of each included journal, to identify the randomised controlled trials. The adherence to the items of the CONSORT Checklist in each trial was evaluated. Additionally we correlated the citation frequency of the articles and the impact factor of the respective journal with the amount of reported items per trial.ResultsWe analysed 119 randomised controlled trials and found, 15 years after the implementation of the CONSORT statement, that a median of 61,1% of the checklist-items were reported. Only 55.5% of the articles were identified as randomised trials in their titles. The citation frequency of the trials correlated significantly (rs = 0,433; p<0,001 and r = 0,331; p<0,001) to the CONSORT statement adherence. The impact factor showed also a significant correlation to the CONSORT adherence (r = 0,386; p<0,001).ConclusionThe reporting quality of randomised controlled trials in the field of critical care medicine remains poor and needs considerable improvement.     

Arabidopsis ATG4 cysteine proteases specificity toward ATG8 substrates

Macroautophagy (hereafter autophagy) is a regulated intracellular process during which cytoplasmic cargo engulfed by double-membrane autophagosomes is delivered to the vacuole or lysosome for degradation and recycling. Atg8 that is conjugated to phosphatidylethanolamine (PE) during autophagy plays an important role not only in autophagosome biogenesis but also in cargo recruitment. Conjugation of PE to Atg8 requires processing of the C-terminal conserved glycine residue in Atg8 by the Atg4 cysteine protease. The Arabidopsis plant genome contains 9 Atg8 (AtATG8a to AtATG8i) and 2 Atg4 (AtATG4a and AtATG4b) family members. To understand AtATG4’s specificity toward different AtATG8 substrates, we generated a unique synthetic substrate C-AtATG8-ShR (citrine-AtATG8-Renilla luciferase SuperhRLUC). In vitro analyses indicated that AtATG4a is catalytically more active and has broad AtATG8 substrate specificity compared with AtATG4b. Arabidopsis transgenic plants expressing the synthetic substrate C-AtAtg8a-ShR is efficiently processed by endogenous AtATG4s and targeted to the vacuole during nitrogen starvation. These results indicate that the synthetic substrate mimics endogenous AtATG8, and its processing can be monitored in vivo by a bioluminescence resonance energy transfer (BRET) assay. The synthetic Atg8 substrates provide an easy and versatile method to study plant autophagy during different biological processes.     

Diversity and ecology of algae from the Nahal Qishon river,northern Israel

In 59 samples of periphyton and phytoplankton collected in 2002 - 2003 from the Nahal Qishon (Qishon River), northern Israel, we found 178 species from seven divisions of algae and cyanoprocaryotes. Diatoms, clorophytes, and cyanoprocaryotes prevail. Nitzschia and Navicula (Bacillariophyta) are the most abundant. Most of the species are cosmopolitan or widespread, except Lagynion janei (Chrysophyta), which is endemic for the Mediterranean Realm. About 17% of species (26) are new for Israel and five of them represent the first recorded genera: Crinalium endophyticum Crow, Actinocyclus normanii (Gregory) Hustedt, Rhizoclonium hieroglyphicum (Agardh) Kütz (Chlorophyta), Lagynion janei Bourelly, and Stylococcus aureus Chodat. Most of them come from a rare riverine assemblage with red alga Audouinella pygmea, as well as from the estuarine assemblage. Alkaliphiles predominate among the indicators of acidity, with few acidophiles confined to the communities under the impact of industrial wastes. Among the indicators of salinity, most numerous are the oligohalobien-indifferents and species adapted to a moderate salinity level. The relative species richness of ecological groups and the indices of saprobity are correlated with changes in conductivity, pH, and N-nitrate concentration. Indicators of organic pollution fall in the range of betameso- to alfamesosaprobic self-purification grades. Our studies show ecological significance of the Nahal Qishon as a model for a strongly disturbed aquatic ecosystem in the coastal zone of eastern Mediterranean.     

Optimal elastic cord assistance for sprinting in collegiate women soccer players

Overspeed exercises are commonly integrated into a training program to help athletes perform at a speed greater than what they are accustomed to when unassisted. However, the optimal assistance for maximal sprinting has not been determined. The purpose of this study was to determine the optimal elastic cord assistance for sprinting performance. Eighteen collegiate women soccer players completed 3 testing sessions, which consisted of a 5-minute warm-up, followed by 5 randomized experimental conditions of 0, 10, 20, 30, and 40% body weight assistance (BWA). In all BWA sessions, subjects wore a belt while attached to 2 elastic cords and performed 2 maximal sprints under each condition. Five minutes of rest was given between each sprint attempt and between conditions. Split times (0-5, 5-10, 10-15, 15-20, and 0-20 yd) for each condition were used for analysis. Results for 0-20 yd demonstrated a significant main effect for condition. Post hoc comparisons revealed that as BWA increased, sprint times decreased up to 30% BWA (0%: 3.20 ± 0.12 seconds; 10%: 3.07 ± 0.09 seconds; 20%: 2.96 ± 0.07 seconds; 30%: 2.81 ± 0.08 seconds; 40%: 2.77 ± 0.10 seconds); there was no difference between 30 and 40% BWA. There was also a main effect for condition when examining split times. Post hoc comparisons revealed that as BWA increased, sprint times decreased up to 30% BWA for distances up to 15 yd. These results demonstrate that 30% of BWA with elastic cords appears optimal in decreasing sprint times in collegiate women soccer players for distances up to 15 yd.     

Mechanomyographic amplitude and mean power frequency versus torque relationships during isokinetic and isometric muscle actions of the biceps brachii.

The purpose of this investigation was to determine the mechanomyographic (MMG) amplitude and mean power frequency (MPF) versus torque (or force) relationships during isokinetic and isometric muscle actions of the biceps brachii. Ten adults (mean +/- SD age = 21.6 +/- 1.7 years) performed submaximal to maximal isokinetic and isometric muscle actions of the dominant forearm flexors. Following determination of isokinetic peak torque (PT) and the isometric maximum voluntary contraction (MVC), the subjects randomly performed submaximal step muscle actions in 10% increments from 10% to 90% PT and MVC. Polynomial regression analyses indicated that MMG amplitude increased linearly with torque during both the isokinetic (r2 = 0.982) and isometric (r2 = 0.956) muscle actions. From 80% to 100% of isometric MVC, however, MMG amplitude appeared to plateau. Cubic models provided the best fit for the MMG MPF versus isokinetic (R2 = 0.786) and isometric (R2 = 0.940) torque relationships, although no significant increase in MMG MPF was found from 10% to 100% of isokinetic PT. For the isometric muscle actions, however, MMG MPF remained relatively stable from 10% to 50% MVC, increased from 50% to 80% MVC, and decreased from 80% to 100% MVC. The results demonstrated differences in the MMG amplitude and MPF versus torque relationships between the isokinetic and isometric muscle actions. These findings suggested that the time and frequency domains of the MMG signal may be useful for describing the unique motor control strategies that modulate dynamic versus isometric torque production.