Heme oxygenase-1 plays a pro-life role in experimental brain stem death via nitric oxide synthase I/protein kinase G signaling at rostral ventrolateral medulla

<p>Abstract</p> <p>Background</p> <p>Despite its clinical importance, a dearth of information exists on the cellular and molecular mechanisms that underpin brain stem death. A suitable neural substrate for mechanistic delineation on brain stem death resides in the rostral ventrolateral medulla (RVLM) because it is the origin of a life-and-death signal that sequentially increases (pro-life) and decreases (pro-death) to reflect the advancing central cardiovascular regulatory dysfunction during the progression towards brain stem death in critically ill patients. The present study evaluated the hypothesis that heme oxygnase-1 (HO-1) may play a pro-life role as an interposing signal between hypoxia-inducible factor-1 (HIF-1) and nitric oxide synthase I (NOS I)/protein kinase G (PKG) cascade in RVLM, which sustains central cardiovascular regulatory functions during brain stem death.</p> <p>Methods</p> <p>We performed cardiovascular, pharmacological, biochemical and confocal microscopy experiments in conjunction with an experimental model of brain stem death that employed microinjection of the organophosphate insecticide mevinphos (Mev; 10 nmol) bilaterally into RVLM of adult male Sprague-Dawley rats.</p> <p>Results</p> <p>Western blot analysis coupled with laser scanning confocal microscopy revealed that augmented HO-1 expression that was confined to the cytoplasm of RVLM neurons occurred preferentially during the pro-life phase of experimental brain stem death and was antagonized by immunoneutralization of HIF-1α or HIF-1β in RVLM. On the other hand, the cytoplasmic presence of HO-2 in RVLM neurons manifested insignificant changes during both phases. Furthermore, immunoneutralization of HO-1 or knockdown of <it>ho-1 </it>gene in RVLM blunted the augmented life-and-death signals exhibited during the pro-life phase. Those pretreatments also blocked the upregulated pro-life NOS I/PKG signaling without affecting the pro-death NOS II/peroxynitrite cascade in RVLM.</p> <p>Conclusions</p> <p>We conclude that transcriptional upregulation of HO-1 on activation by HIF-1 in RVLM plays a preferential pro-life role by sustaining central cardiovascular regulatory functions during brain stem death via upregulation of NOS I/PKG signaling pathway. Our results further showed that the pro-dead NOS II/peroxynitrite cascade in RVLM is not included in this repertoire of cellular events.</p

Dynamic membrane bioreactor performance enhancement by powdered activated carbon addition: Evaluation of sludge morphological, aggregative and microbial properties

© 2018 The effects of powdered activated carbon (PAC) addition on sludge morphological, aggregative and microbial properties in a dynamic membrane bioreactor (DMBR) were investigated to explore the enhancement mechanism of pollutants removal and filtration performance. Sludge properties were analyzed through various analytical measurements. The results showed that the improved sludge aggregation ability and the evolution of microbial communities affected sludge morphology in PAC-DMBR, as evidenced by the formation of large, regularly shaped and strengthened sludge flocs. The modifications of sludge characteristics promoted the formation process and filtration flux of the dynamic membrane (DM) layer. Additionally, PAC addition did not exert very significant influence on the propagation of eukaryotes (protists and metazoans) and microbial metabolic activity. High-throughput pyrosequencing results indicated that adding PAC improved the bacterial diversity in activated sludge, as PAC addition brought about additional microenvironment in the form of biological PAC (BPAC), which promoted the enrichment of Acinetobacter (13.9%), Comamonas (2.9%), Flavobacterium (0.31%) and Pseudomonas (0.62%), all contributing to sludge flocs formation and several (such as Acinetobacter) capable of biodegrading relatively complex organics. Therefore, PAC addition could favorably modify sludge properties from various aspects and thus enhance the DMBR performance

Characterization of a hybrid powdered activated carbon-dynamic membrane bioreactor (PAC-DMBR) process with high flux by gravity flow: Operational performance and sludge properties

© 2016 Elsevier Ltd Three PAC-DMBRs were developed for wastewater treatment under different PAC dosages with biomass concentrations averaged at 2.5, 3.5 and 5.0 g/L. The DMBRs could be continuously operated at 40–100 L/m2 h, while higher fluxes were obtained within the PAC-DMBRs with hydraulic retention times varying in 4–10 h. A dose of 1 g/L PAC brought about obvious improvement in the sludge particle size distribution, settling, flocculating and dewatering properties due to the formation of biological PAC, and the sludge properties were further improved at a higher PAC dose (3 g/L). The addition of PAC notably shortened the DM formation time after air backwashing and enhanced pollutant removal. Moreover, under a long solid retention time (approximately 150 d), the concentrations of both soluble and bound extracellular polymeric substances (EPS) decreased substantially because of the adsorption and biodegradation effects of the biological PAC. No obvious impact on biomass activity was observed with PAC addition

Ocean temperature and salinity components of the Madden-Julian oscillation observed by Argo floats

New diagnostics of the Madden-Julian Oscillation (MJO) cycle in ocean temperature and, for the first time, salinity are presented. The MJO composites are based on 4 years of gridded Argo float data from 2003 to 2006, and extend from the surface to 1,400 m depth in the tropical Indian and Pacific Oceans. The MJO surface salinity anomalies are consistent with precipitation minus evaporation fluxes in the Indian Ocean, and with anomalous zonal advection in the Pacific. The Argo sea surface temperature and thermocline depth anomalies are consistent with previous studies using other data sets. The near-surface density changes due to salinity are comparable to, and partially offset, those due to temperature, emphasising the importance of including salinity as well as temperature changes in mixed-layer modelling of tropical intraseasonal processes. The MJO-forced equatorial Kelvin wave that propagates along the thermocline in the Pacific extends down into the deep ocean, to at least 1,400 m. Coherent, statistically significant, MJO temperature and salinity anomalies are also present in the deep Indian Ocean

A Simple and Effective Method for Construction of Escherichia coli Strains Proficient for Genome Engineering

Multiplex genome engineering is a standalone recombineering tool for large-scale programming and accelerated evolution of cells. However, this advanced genome engineering technique has been limited to use in selected bacterial strains. We developed a simple and effective strain-independent method for effective genome engineering in Escherichia coli. The method involves introducing a suicide plasmid carrying the l Red recombination system into the mutS gene. The suicide plasmid can be excised from the chromosome via selection in the absence of antibiotics, thus allowing transient inactivation of the mismatch repair system during genome engineering. In addition, we developed another suicide plasmid that enables integration of large DNA fragments into the lacZ genomic locus. These features enable this system to be applied in the exploitation of the benefits of genome engineering in synthetic biology, as well as the metabolic engineering of different strains of E. coli.open7

Assimilable organic carbon (AOC) variation in reclaimed water: Insight on biological stability evaluation and control for sustainable water reuse

© 2018 Elsevier Ltd This review highlights the importance of conducting biological stability evaluation due to water reuse progression. Specifically, assimilable organic carbon (AOC) has been identified as a practical indicator for microbial occurrence and regrowth which ultimately influence biological stability. Newly modified AOC bioassays aimed for reclaimed water are introduced. Since elevated AOC levels are often detected after tertiary treatment, the review emphasizes that actions can be taken to either limit AOC levels prior to disinfection or conduct post-treatment (e.g. biological filtration) as a supplement to chemical oxidation based approaches (e.g. ozonation and chlorine disinfection). During subsequent distribution and storage, microbial community and possible microbial regrowth caused by complex interactions are discussed. It is suggested that microbial surveillance, AOC threshold values, real-time field applications and surrogate parameters could provide additional information. This review can be used to formulate regulatory plans and strategies, and to aid in deriving relevant control, management and operational guidance

Whole-brain metallomic analysis of the common marmoset (: Callithrix jacchus)

© 2017 The Royal Society of Chemistry. Despite the importance of transition metals for normal brain function, relatively little is known about the distribution of these elemental species across the different tissue compartments of the primate brain. In this study, we employed laser ablation-inductively coupled plasma-mass spectrometry on PFA-fixed brain sections obtained from two adult common marmosets. Concurrent cytoarchitectonic, myeloarchitectonic, and chemoarchitectonic measurements allowed for identification of the major neocortical, archaecortical, and subcortical divisions of the brain, and precise localisation of iron, manganese, and zinc concentrations within each division. Major findings across tissue compartments included: (1) differentiation of white matter tracts from grey matter based on manganese and zinc distribution; (2) high iron concentrations in the basal ganglia, cortex, and substantia nigra; (3) co-localization of high concentrations of iron and manganese in the primary sensory areas of the cerebral cortex; and (4) high manganese in the hippocampus. The marmoset has become a model species of choice for connectomic, aging, and transgenic studies in primates, and the application of metallomics to these disciplines has the potential to yield high translational and basic science value

New insight into fouling behavior and foulants accumulation property of cake sludge in a full-scale membrane bioreactor

© 2016 Elsevier B.V.. Cake sludge attached on membrane surfaces was collected and characterized in a full scale membrane bioreactor (MBR) compared with bulk sludge. The morphological, chemical and microbial properties were examined through microscopic observations, particle size distribution (PSD) analysis, chemical analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy-diffusive X-ray (EDX) analysis, specific oxygen utilization rate (SOUR) measurements and Biolog assay. The results showed that fiber-like substances might have served as the skeleton of larger size aggregates in cake sludge. Moreover, much more polysaccharides and inorganic elements such as multivalent cations were accumulated in cake sludge than proteins and humics. Cake sludge showed lower microbial activity for aerobic degradation than bulk sludge, but higher metabolic activity for the degradation of refractory substances (aromatic proteins and humics) other than polysaccharides. Based on batch filtration experiments, it was found that cake sludge had much higher cake layer fouling potential but lower membrane pore blocking resistance, probably due to the heterogeneous structure of cake sludge resulting from accumulation and interaction of various inorganic and organic foulants. This investigation could assist in obtaining a better understanding of the fouling behavior and foulants accumulation properties of cake sludge in the full-scale MBRs

No excess of mitochondrial DNA deletions within muscle in progressive multiple sclerosis

BACKGROUND: Mitochondrial dysfunction is an established feature of multiple sclerosis (MS). We recently described high levels of mitochondrial DNA (mtDNA) deletions within respiratory enzyme-deficient (lacking mitochondrial respiratory chain complex IV with intact complex II) neurons and choroid plexus epithelial cells in progressive MS. OBJECTIVES: The objective of this paper is to determine whether respiratory enzyme deficiency and mtDNA deletions in MS were in excess of age-related changes within muscle, which, like neurons, are post-mitotic cells that frequently harbour mtDNA deletions with ageing and in disease. METHODS: In progressive MS cases (n=17), known to harbour an excess of mtDNA deletions in the central nervous system (CNS), and controls (n=15), we studied muscle (paraspinal) and explored mitochondria in single fibres. Histochemistry, immunohistochemistry, laser microdissection, real-time polymerase chain reaction (PCR), long-range PCR and sequencing were used to resolve the single muscle fibres. RESULTS: The percentage of respiratory enzyme-deficient muscle fibres, mtDNA deletion level and percentage of muscle fibres harbouring high levels of mtDNA deletions were not significantly different in MS compared with controls. CONCLUSION: Our findings do not provide support to the existence of a diffuse mitochondrial abnormality involving multiple systems in MS. Understanding the cause(s) of the CNS mitochondrial dysfunction in progressive MS remains a research priority

Electrical behaviour, characteristics and properties of anodic aluminium oxide films coloured by nickel electrodeposition

Porous anodic films on 1050 aluminium substrate were coloured by AC electrodeposition of nickel. Several experiments were performed at different deposition voltages and nickel concentrations in the electrolyte in order to correlate the applied electrical power to the electrical behaviour, as well as the characteristics and properties of the coatings. The content of nickel inside the coatings reached 1.67 g/m2, depending on the experimental conditions. According to the applied AC voltage in comparison with the threshold voltage Ut, the coating either acted only as a capacitor when U\Ut and, when U[Ut, the behaviour during the anodic and cathodic parts of the power sine wave was different. In particular, due to the semi-conducting characteristics of the barrier layer, additional oxidation of the aluminium substrate occurred during the anodic part of the electrical signal, whilst metal deposition (and solvent reduction) occurred during the cathodic part; these mechanisms correspond to the blocked and pass directions of the barrier layer/electrolyte junction, respectively