Carbon Monoxide Abrogates Ischemic Insult to Neuronal Cells via the Soluble Guanylate Cyclase-cGMP Pathway

Purpose Carbon monoxide (CO) is an accepted cytoprotective molecule. The extent and mechanisms of protection in neuronal systems have not been well studied. We hypothesized that delivery of CO via a novel releasing molecule (CORM) would impart neuroprotection in vivo against ischemia-reperfusion injury (IRI)-induced apoptosis of retinal ganglion cells (RGC) and in vitro of neuronal SH-SY5Y-cells via activation of soluble guanylate-cyclase (sGC). Methods: To mimic ischemic respiratory arrest, SH-SY5Y-cells were incubated with rotenone (100 nmol/L, 4 h) ± CORM ALF186 (10–100 µmol/L) or inactivated ALF186 lacking the potential of releasing CO. Apoptosis and reactive oxygen species (ROS) production were analyzed using flow-cytometry (Annexin V, mitochondrial membrane potential, CM-H2DCFDA) and Western blot (Caspase-3). The impact of ALF186± respiratory arrest on cell signaling was assessed by measuring expression of nitric oxide synthase (NOS) and soluble guanylate-cyclase (sGC) and by analyzing cellular cGMP levels. The effect of ALF186 (10 mg/kg iv) on retinal IRI in Sprague-Dawley rats was assessed by measuring densities of fluorogold-labeled RGC after IRI and by analysis of apoptosis-related genes in retinal tissue. Results: ALF186 but not inactivated ALF186 inhibited rotenone-induced apoptosis (Annexin V positive cells: 25±2% rotenone vs. 14±1% ALF186+rotenone, p<0.001; relative mitochondrial membrane potential: 17±4% rotenone vs. 55±3% ALF186+rotenone, p<0.05). ALF186 increased cellular cGMP levels (33±5 nmol/L vs. 23±3 nmol/L; p<0.05) and sGC expression. sGC-inhibition attenuated ALF186-mediated protection (relative mitochondrial membrane potential: 55±3% ALF186+rotenone vs. 20±1% ODQ+ALF186+rotenone, p<0.05). ALF186 protected RGC in vivo (IRI 1255±327 RGC/mm2 vs. ALF186+IRI 2036±83; p<0.05) while sGC inhibition abolished the protective effects of ALF186 (ALF186+IRI 2036±83 RGC/mm2 vs. NS-2028+ALF186+IRI 1263±170, p<0.05). Conclusions: The CORM ALF186 inhibits IRI-induced neuronal cell death via activation of sGC and may be a useful treatment option for acute ischemic insults to the retina and the brain

Iterative Methods for Visualization of Implicit Surfaces on GPU

The original publication is available at www.springerlink.comInternational audienceThe ray-casting of implicit surfaces on GPU has been explored in the last few years. However, until recently, they were restricted to second degree (quadrics). We present an iterative solution to ray cast cubics and quartics on GPU. Our solution targets efficient implementation, obtaining interactive rendering for thousands of surfaces per frame. We have given special attention to torus rendering since it is a useful shape for multiple CAD models. We have tested four different iterative methods, including a novel one, comparing them with classical tessellation solution

Loop Quantum Cosmology I: Kinematics

The framework of quantum symmetry reduction is applied to loop quantum gravity with respect to transitively acting symmetry groups. This allows to test loop quantum gravity in a large class of minisuperspaces and to investigate its features - e.g. the discrete volume spectrum - in certain cosmological regimes. Contrary to previous studies of quantum cosmology (minisuperspace quantizations) the symmetry reduction is carried out not at the classical level but on an auxiliary Hilbert space of the quantum theory before solving the constraints. Therefore, kinematical properties like volume quantization survive the symmetry reduction. In this first part the kinematical framework, i.e. implementation of the quantum symmetry reduction and quantization of Gauss and diffeomorphism constraints, is presented for Bianchi class A models as well as locally rotationally symmetric and spatially isotropic closed and flat models.Comment: 24 page

Piecewise Rational Manifold Surfaces with Sharp Features

We present a construction of a piecewise rational free-form surface of arbitrary topological genus which may contain sharp features: creases, corners or cusps. The surface is automatically generated from a given closed triangular mesh. Some of the edges are tagged as sharp ones, defining the features on the surface. The surface is C s smooth, for an arbitrary value of s, except for the sharp features defined by the user. Our method is based on the manifold construction and follows the blending approach

Surgical treatment of prosthetic valve endocarditis

AbstractFrom 1975 through 1992, we reoperated on 146 patients for the treatment of prosthetic valve endocarditis. Prosthetic valve endocarditis was considered to be early (<1 year after operation) in 46 cases and active in 103 cases. The extent of the infection was prosthesis only in 66 patients, anulus in 46, and cardiac invasion in 34. Surgical techniques evolved in the direction of increasingly radical débridement of infected tissue and reconstruction with biologic materials. All patients were treated with prolonged postoperative antibiotic therapy. There were 19 (13%) in-hospital deaths. Univariate analyses demonstrated trends toward increasing risk for patients with active endocarditis and extension of infection beyond the prosthesis; however, the only variables with a significant (p < 0.05) association with increased in-hospital mortality confirmed with multivariate testing were impaired left ventricular function, preoperative heart block, coronary artery disease, and culture of organisms from the surgical specimen. During the study period, mortality decreased from 20% (1975 to 1984) to 10% (1984 to 1992). For hospital survivors the mean length of stay was 25 days. Follow-up (mean interval 62 months) documented a late survival of 82% at 5 postoperative years and 60% at 10 years. Older age was the only factor associated (p = 0.006) with late death. Nineteen patients needed at least one further operation; reoperation-free survival was 75% at 5 and 50% at 10 postoperative years. Fever in the immediate preoperative period was the only factor associated with decreased late reoperation-free survival (p = 0.032). Prosthetic valve endocarditis remains a serious complication of valve replacement, but the in-hospital mortality of reoperations for prosthetic valve endocarditis has declined. With extensive débridement of infected tissue and postoperative antibiotic therapy, the extent and activity of prosthetic valve endocarditis does not appear to have a major impact on late outcome, and the majority of patients with this complication survive for 10 years after the operation. (J THORAC CARDIOVASC SURG 1996;111:198-210

The complete spectrum of the area from recoupling theory in loop quantum gravity

We compute the complete spectrum of the area operator in the loop representation of quantum gravity, using recoupling theory. This result extends previous derivations, which did not include the ``degenerate'' sector, and agrees with the recently computed spectrum of the connection-representation area operator.Comment: typos corrected in eqn.(21). Latex with IOP and epsf styles, 1 figure (eps postscript file), 12 pages. To appear in Class. Quantum Gra

Sternal reentry in a patient with previous deep sternal wound infection managed with horizontal titanium plate fixation

Redo open-heart surgery and sternal reentry in patients with previous deep sternal wound infection (DSWI) and absence of sternal integrity can be a delicate and morbid task due the lack of a dissection plane between the heart and the surrounding soft tissues. Delayed sternal reconstruction and osteosynthesis with horizontal titanium plating fixation (Synthes) following vacuum assisted therapy (KCI) has recently been proposed and adopted for the treatment of DSWI. We present such a case of a patient who was successfully reoperated for valve replacement three years after coronary artery bypass grafting complicated by DSWI and initially treated with titanium plate fixation

Use of troponins in the classification of myocardial infarction from electronic health records. The Atherosclerosis Risk in Communities (ARIC) Study

Objective: Electronic health record (EHR) data are underutilized for abstracting classification criteria for heart disease. We compared extraction of EHR data on troponin I and T levels with human abstraction. Methods: Using EHR for hospitalizations identified through the Atherosclerosis Risk in Communities (ARIC) Study in four US hospitals, we compared blood levels of troponins I and T extracted from EHR structured data elements with levels obtained through data abstraction by human abstractors to 3 decimal places. Observations were divided randomly 50/50 into training and validation sets. Bayesian multilevel logistic regression models were used to estimate agreement by hospital in first and maximum troponin levels, troponin assessment date, troponin upper limit of normal (ULN), and classification of troponin levels as normal (2× ULN), or missing. Results: Estimated overall agreement in first measured troponin level in the validation data was 88.2% (95% credible interval: 65.0%-97.5%) and 95.5% (91.2-98.2%) for the maximum troponin level observed during hospitalization. The largest variation in probability of agreement was for first troponin measured, which ranged from 66.4% to 95.8% among hospitals. Conclusion: Extraction of maximum troponin values during a hospitalization from EHR structured data is feasible and accurate

An Interpolatory Subdivision Scheme for Triangular Meshes and Progressive Transmission

4 authors, including: chen ren Guangzhou cool-smart electronical inform