The Enterococcus hirae paradigm of copper homeostasis: Copper chaperone turnover, interactions, and transactions

The cop operon is a key element of copper homeostasis in Enterococcus hirae. It encodes two copper ATPases, CopA and CopB, the CopY repressor, and the CopZ metallochaperone. The cop operon is induced by copper, which allows uncompromised growth in up to 5mM ambient copper. Copper uptake appears to be accomplished by the CopA ATPase, a member of the heavy metal CPx-type ATPases and closely related to the human Menkes and Wilson ATPases. The related CopB ATPase extrudes copper when it reaches toxic levels. Intracellular copper routing is accomplished by the CopZ copper chaperone. Using surface plasmon resonance analysis, it was demonstrated that CopZ interacts with the CopA ATPase where it probably becomes copper loaded. CopZ in turn can donate copper to the copper responsive repressor CopY, thereby releasing it from DNA. In high copper, CopZ is proteolyzed. Cell extracts were found to contain a copper activated proteolytic activity that degrades CopZ in vitro. This post-translational control of CopZ expression presumably serves to avoid the accumulation of detrimental Cu-CopZ level

Adaptive computation of multiscale entropy and its application in EEG signals for monitoring depth of anesthesia during surgery

Entropy as an estimate of complexity of the electroencephalogram is an effective parameter for monitoring the depth of anesthesia (DOA) during surgery. Multiscale entropy (MSE) is useful to evaluate the complexity of signals over different time scales. However, the limitation of the length of processed signal is a problem due to observing the variation of sample entropy (SE) on different scales. In this study, the adaptive resampling procedure is employed to replace the process of coarse-graining in MSE. According to the analysis of various signals and practical EEG signals, it is feasible to calculate the SE from the adaptive resampled signals, and it has the highly similar results with the original MSE at small scales. The distribution of the MSE of EEG during the whole surgery based on adaptive resampling process is able to show the detailed variation of SE in small scales and complexity of EEG, which could help anesthesiologists evaluate the status of patients.The Center for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan which is sponsored by National Science Council (Grant Number: NSC 100-2911-I-008-001). Also, it was supported by Chung-Shan Institute of Science & Technology in Taiwan (Grant Numbers: CSIST-095-V101 and CSIST-095-V102). Furthermore, it was supported by the National Science Foundation of China (No.50935005)

The stress response protein Gls24 is induced by copper and interacts with the CopZ copper chaperone of Enterococcus hirae

Intracellular copper routing in Enterococcus hirae is accomplished by the CopZ copper chaperone. Under copper stress, CopZ donates Cu+ to the CopY repressor, thereby releasing its bound zinc and abolishing repressor-DNA interaction. This in turn induces the expression of the cop operon, which encodes CopY and CopZ, in addition to two copper ATPases, CopA and CopB. To gain further insight into the function of CopZ, the yeast two-hybrid system was used to screen for proteins interacting with the copper chaperone. This led to the identification of Gls24, a member of a family of stress response proteins. Gls24 is part of an operon containing eight genes. The operon was induced by a range of stress conditions, but most notably by copper. Gls24 was overexpressed and purified, and was shown by surface plasmon resonance analysis to also interact with CopZ in vitro. Circular dichroism measurements revealed that Gls24 is partially unstructured. The current findings establish a novel link between Gls24 and copper homeostasi

Focal Stenosis in Right Upper Lobe Bronchus in a Recurrently Wheezing Child Sequentially Studied by Multidetector-row Spiral Computed Tomography and Scintigraphy

Lower respiratory tract infections associated with wheezing are not uncommon in infants and young children. Among the wheezing-associated disorders, allergic etiologies are more commonly encountered than anatomic anomalies. We present a 3-year-old girl with a sudden attack of asthmatic symptoms including dyspnea, cyanosis and diffuse wheezing. Based on a history of choking, and atelectasis in the right upper lobe detected by chest films, flexible tracheobronchoscopy was arranged and incidentally detected a stenotic orifice in the right upper lobe bronchus. Multidetector-row spiral computed tomography and pulmonary scintigraphy subsequently also disclosed the focal stenosis. She suffered from recurrent wheezing, pneumonia and lung atelectasis during 1 year of follow-up. We emphasize the diagnosis, clinical course and management of focal stenosis in the right upper lobe bronchus

Transport and Elastic Properties of Fractal Media

We investigate the influence of fractal structure on material properties. We calculate the statistical correlation functions of fractal media defined by level-cut Gaussian random fields. This allows the modeling of both surface fractal and mass fractal materials. Variational bounds on the conductivity, diffusivity and elastic moduli of the materials are evaluated. We find that a fractally rough interface has a relatively strong influence on the properties of composites. In contrast a fractal volume (mass) has little effect on material properties.Comment: 10 pages, 6 figure

Carbon fibre composites: integrated electrochemical sensors for wound management

The applicability of employing a carbon fibre mesh as an electrochemical sensing substructure for assessing urate transformations within wound exudates is evaluated. Prototype sensor assemblies have been designed and their response characteristics towards uric acid and other common physiological components are detailed. Modification of the carbon fibre sensor through surface anodisation and the application of cellulose acetate permselective barriers have been shown to lead to optimized responses and much greater sensitivity (1440% increase) and specificity. These could enable the accurate periodic monitoring of uric acid in wound fluid. The performance characteristics of the composite sensors in whole blood, serum and blister fluid have been investigated

Lack of a robust unfoldase activity confers a unique level of substrate specificity to the universal AAA protease FtsH

In the present study, we have investigated the mechaases, a class that includes the eukaryotic 26S proteanism of degradation by FtsH. We previously showed that some and its structurally related prokaryotic counterFtsH recognized and degraded proteins with nonpolar parts. In the bacterium E. coli, five such ATP-dependent carboxy-terminal tails in vivo (Herman et al., 1998). Two proteases have thus far been identified: ClpAP, ClpXP, classes of nonpolar tails were identified: those recogHslUV, Lon, and FtsH (HflB). Among these, FtsH is the nized solely by FtsH in vivo (e.g., 108; to their overall thermodynamic stability. This was also FtsH is a membrane-anchored metallo-protease with true for the degradation of a membrane protein and its its active site facing the cytoplasm. It contains a wellvariants studied in vivo. Thus, unlike other well-studied conserved 200 amino acid motif called the "AAA" motif ATP-dependent proteases, FtsH appears to lack robust (so named because the diverse functions of its member unfoldase activity. Instead, our experiments are consisproteins are ATPase associated with activity [reviewed tent with the idea that ATP hydrolysis by FtsH is mainly in Ogura and Wilkinson, 2001]). FtsH degrades both inteused to translocate unfolded substrates sequentially gral membrane and cytoplasmic proteins. FtsH performs from the recognition signal to the active site. We propose that lack of a robust unfoldase enables FtsH to discriminate among proteins based on their thermodynamic sta

Complete Genome Sequence of a Pathogenic Genotype 1 Subtype 3 Porcine Reproductive and Respiratory Syndrome Virus (Strain SU1-Bel) from Pig Primary Tissue

We report here the complete genome of the pathogenic eastern European subtype 3 porcine reproductive and respiratory syndrome virus (PRRSV) strain SU1-Bel, sequenced directly from a pig lymph node. While sharing substantial sequence similarity with other subtype 3 strains, SU1-Bel is found to harbor unique indels and contain putative novel subgenomic RNAs