47 research outputs found
Integrated Modeling of Fractured Low Permeability Reservoir, Shangonghe Formation, Baolang Oilfield, Northwest China
This paper integrated Flow Zone (FZ), single sandstone sequence, with the study of fracture, and gave a fine characterization and modeling of fractured low permeability reservoir. It pointed out that calculating the porosity and permeability for low permeability reservoir based on FZ and building the 3D discrete fracture network (DFN) distribution model integrated with the static fracture character and the density distribution of high angle fracture (HAF) and low angle fracture (LAF) are efficient methods for fractured low permeability reservoir. This brings forward the use of FZ and considerable sequence stratigraphy controlled modeling method, and brings forward to build fracture surface from point which controlled by the density distribution of HAF and LAF. The result shows the efficiency of a modeling approach for a fractured low permeability reservoir by integrating low permeability characterization and fracture study
SCCRO (DCUN1D1) Is an Essential Component of the E3 Complex for Neddylation*S⃞
Covalent modification of cullins by the ubiquitin-like protein NEDD8
(neddylation) regulates protein ubiquitination by promoting the assembly of
cullin-RING ligase E3 complexes. Like ubiquitination, neddylation results from
an enzymatic cascade involving the sequential activity of a dedicated E1
(APPBP1/Uba3), E2 (Ubc12), and an ill-defined E3. We show that SCCRO (also
known as DCUN1D1) binds to the components of the neddylation pathway
(Cullin-ROC1, Ubc12, and CAND1) and augments but is not required for cullin
neddylation in reactions using purified recombinant proteins. We also show
that SCCRO recruits Ubc12∼NEDD8 to the CAND1-Cul1-ROC1 complex but that
this is not sufficient to dissociate or overcome the inhibitory effects of
CAND1 on cullin neddylation in purified protein assays. In contrast to
findings in cellular systems where no binding is seen, we show that SCCRO and
CAND1 can bind to the neddylated Cul1-ROC1 complex in assays using purified
recombinant proteins. Although neddylated (not unneddylated) Cul1-ROC1 is
released from CAND1 upon incubation with testis lysate from
SCCRO+/+ mice, the addition of recombinant SCCRO is
required to achieve the same results in lysate from
SCCRO–/– mice.
Combined, these results suggest that SCCRO is an important component of the
neddylation E3 complex that functions to recruit charged E2 and is involved in
the release of inhibitory effects of CAND1 on cullin-RING ligase E3 complex
assembly and activity
Ropivacaine attenuates endotoxin plus hyperinflation-mediated acute lung injury via inhibition of early-onset Src-dependent signaling
BACKGROUND: Acute lung injury (ALI) is associated with high mortality due to the lack of effective therapeutic strategies. Mechanical ventilation itself can cause ventilator-induced lung injury. Pulmonary vascular barrier function, regulated in part by Src kinase-dependent phosphorylation of caveolin-1 and intercellular adhesion molecule-1 (ICAM-1), plays a crucial role in the development of protein-/neutrophil-rich pulmonary edema, the hallmark of ALI. Amide-linked local anesthetics, such as ropivacaine, have anti-inflammatory properties in experimental ALI. We hypothesized ropivacaine may attenuate inflammation in a "double-hit" model of ALI triggered by bacterial endotoxin plus hyperinflation via inhibition of Src-dependent signaling.
METHODS: C57BL/6 (WT) and ICAM-1 (-/-) mice were exposed to either nebulized normal saline (NS) or lipopolysaccharide (LPS, 10Â mg) for 1Â hour. An intravenous bolus of 0.33Â mg/kg ropivacaine or vehicle was followed by mechanical ventilation with normal (7Â ml/kg, NTV) or high tidal volume (28Â ml/kg, HTV) for 2Â hours. Measures of ALI (excess lung water (ELW), extravascular plasma equivalents, permeability index, myeloperoxidase activity) were assessed and lungs were homogenized for Western blot analysis of phosphorylated and total Src, ICAM-1 and caveolin-1. Additional experiments evaluated effects of ropivacaine on LPS-induced phosphorylation/expression of Src, ICAM-1 and caveolin-1 in human lung microvascular endothelial cells (HLMVEC).
RESULTS: WT mice treated with LPS alone showed a 49% increase in ELW compared to control animals (p = 0.001), which was attenuated by ropivacaine (p = 0.001). HTV ventilation alone increased measures of ALI even more than LPS, an effect which was not altered by ropivacaine. LPS plus hyperinflation ("double-hit") increased all ALI parameters (ELW, EVPE, permeability index, MPO activity) by 3-4 fold compared to control, which were again decreased by ropivacaine. Western blot analyses of lung homogenates as well as HLMVEC treated in culture with LPS alone showed a reduction in Src activation/expression, as well as ICAM-1 expression and caveolin-1 phosphorylation. In ICAM-1 (-/-) mice, neither addition of LPS to HTV ventilation alone nor ropivacaine had an effect on the development of ALI.
CONCLUSIONS: Ropivacaine may be a promising therapeutic agent for treating the cause of pulmonary edema by blocking inflammatory Src signaling, ICAM-1 expression, leukocyte infiltration, and vascular hyperpermeability