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Project oth septic shock and sodium selenite (Na2SeO3) lead to multiple organ failure through oxidation. Na2SeO3has direct oxidant effects above the nutritional level and indirect anti-oxidant properties. In a lipopolysaccharide (LPS) rat model we assessed margin of safety, toxicity and beneficial effect of pentahydrate Na2SeO3 (5H2O·Na2SeO3) at oxidant doses. Procedure In a three-step study on 204 rats we: (i) observed toxic effects of Na2SeO3 injected intraperitoneously (IP) and determined its Minimum Dose Without Toxic effect (MDWT) 0.25-0.35 mg/kg selenium (Se) content; (ii) injected IP LPS at 70% lethal dose (LD) followed, or not, one hour later by IP Na2SeO3 at MDWT and (iii) by doses > MDWT. At 48 h, in survivors, we measured plasma creatinine, lactate, aspartate and alanine aminotransferase (AST, ALT), nitric oxide (NO) and Se concentrations. Results (i) Na2SeO3 alone did not increase NO and lactate. Encephalopathy appeared at 1 mg Se/kg. Creatinine increased at 1-1.75 mg Se/kg, AST, ALT at 3-4.5 mg Se/kg, and the minimum LD was 3 mg Se/kg. (ii) Mortality after LPS was 37/50 (74%, [62-86%]) vs. 20/30 (67%, [50-84%]) when followed by Na2SeO3 at MDWT (p = 0.483) with a decreased in NO (-31%, p = 0.038) a trend for lactate decrease (-19%, p = 0.068) and an increased Se in plasma of survivals. (iii) All rats died at doses ⩾0.6 mg/kg (p < 0.001). Conclusion Mechanisms of LPS and Na2SeO3 toxicity differ (i.e. NO, lactate). In septic shock 5H2O·Na2SeO3 toxicity increased, margin of safety decrease, but IP administration of dose considered as oxidant of 5H2O·Na2SeO3showed beneficial effects. [ABSTRACT FROM AUTHOR]

The article examines the existing results of some theoretical studies on the extraction of petrophysical information from rock wide-band electromagnetic measurements. It establishes a proof of concept for the necessity to integrate electromagnetic measurements on the wide-frequency band from the KHz range to the Ghz range. It studies how wide-band electromagnetic techniques may yield petrophysical information unavailable from other in-situ measurements. A generalized pore-scale simulation framework that allows incorporating arbitrary rock morphology and multiphase fluid distribution is introduced.

Archie's empirical power laws are strictly valid only for homogeneous, water-wet (WW) rocks deprived of microporosity or substantial clay-exchange cations. When these conditions are not met, non-Archie electrical behavior arises whereby relationships among rock resistivity, porosity, and water saturation no longer exhibit power-law dependence. Currently, such an unreliable behavior of empirical laws can be quantified only through pore-scale modeling of electrical conductivity under specific sets of geometric assumptions and with substantial computation memory requirements. We introduce a new geometric concept to simulate direct-current electrical-conductivity phenomena in arbitrary rock models on the basis of 3D grain and pore objects that include explicit distributions of intragranular porosity, clay-exchange cations, nonwetting fluid blobs, thin films, and pendular rings. These objects are distributed in the pore space following simple heuristic principles of drainage/imbibition that honor capillary-pressure curves. They provide a simple way to parameterize the 3D pore space and to calculate the electrical conductivity of porous media saturated with two immiscible fluid phases by way of diffusive random walks within the brine-filled pore space. Not only is the random-walk method memory efficient but it also allows the inclusion of clay/brine cation exchange surfaces otherwise not possible with conventional pore-network models. By comparing results stemming from random-walk, pore-network, and percolation simulations, we show the importance of grain surface roughness and thin film thickness, even in water-wet rocks where those factors usually are neglected. For the case of strongly oil-wet rocks, we show that thin films, snap-offs, and pore microgeometry have a primary impact on hysteresis-dominated rock resistivity during imbibition (increasing water saturation). Our simulation method agrees well overall with percolation simulation results and is advantageously unaffected by assumptions concerning site-percolation imbibition. [ABSTRACT FROM AUTHOR]

Effective medium theories (EMTs) are invoked routinely to interpret multifrequency dispersions of dielectric permittivity and electrical conductivity of saturated rocks. However, EMTs exhibit limitations that substantially restrict their validity for petro-physical interpretation. For instance, pore connectivity is of significant interest in the study of subsurface reservoirs, but no existing EMT includes it as an explicit property in the analysis of kilohertz- to gigahertz-range dielectric measurements. We introduce a new approach to quantify the effects of pore geometry and connectivity on the kilohertz-gigahertz frequency dispersion of dielectric permittivity and electrical conductivity of clay-free porous rocks. This approach is based on the numerical solution of the internal electric fields within submicron-resolution pore maps constructed with grain and rock pixels. The discrepancy between the internal fields and electrical currents calculated for a homogeneous scatterer and those calculated for a given pore map is minimized to yield the effective electrical conductivity and dielectric constant for that pore map. This minimization is performed independently for each frequency and is verified to agree implicitly with Kramers-Kronig's causality relationships. We show that EMTs only predict an average dispersion for given microscopic geometrical parameters (e.g., porosity, pore eccentricity), whereas individual realizations honoring the same parameters are associated with dispersion about average values predicted by EMTs. Unlike any EMT prediction, we show that pore connectivity plays a major role in both the shape and amplitude of wide-band electromagnetic property dispersions. The simulation procedure introduced in this paper provides a systematic method to assess the sensitivity of a multitude of pore-scale properties on the macroscopic wide-band dielectric dispersion of saturated rocks. [ABSTRACT FROM AUTHOR]

The article talks about a study done to quantify the petrophysical limitations of two-dimensional nuclear magnetic resonance (NMR) techniques through the introduction of a pore-scale framework to accurately simulate suites of NMR measurements acquired in complex rock fluid models. It considers a general pore-scale framework based on NMR random walks for multiphase fluid diffusion and relaxations, combined with Kovscek's pore-scale model for two-phase fluid saturation and wettability alteration.

Objective: Previous studies have related poor glycemic control and/or some diabetes complications to low socioeconomic status. Some aspects of socioeconomic status have not been assessed in these studies. In the present study, we used an individual index of deprivation, the Evaluation de la Précarité et des Inégalités de santé dans les Centres d'Examens de Santé (Evaluation of Precarity and Inequalities in Health Examination Centers [EPICES]) score, to determine the relationship among glycemic control, diabetes complications, and individual conditions of deprivation.Research Design and Methods: We conducted a cross-sectional prevalence study in 135 consecutive diabetic patients (age 59.41 +/- 13.2 years [mean +/- SD]) admitted in the hospitalization unit of a French endocrine department. Individual deprivation was assessed by the EPICES score, calculated from 11 socioeconomic questions. Glycemic control, lipid levels, blood pressure, retinopathy, neuropathy, and nephropathy were assessed.Results: HbA(1c) level was significantly correlated with the EPICES score (r = 0.366, P < 0.001). The more deprived patients were more likely than the less deprived patients to have poor glycemic control (beta = 1.984 [SE 0.477], P < 0.001), neuropathy (odds ratio 2.39 [95% CI 1.05-5.43], P = 0.037), retinopathy (3.66 [1.39-9.64], P = 0.009), and being less often admitted for 1-day hospitalization (0.32 [0.14-0.74], P = 0.008). No significant relationship was observed with either nephropathy or cardiovascular risk factors.Conclusions: Deprivation status is associated with poor metabolic control and more frequent microvascular complications, i.e., retinopathy and neuropathy. The medical and economic burden of deprived patients is high. [ABSTRACT FROM AUTHOR]

Background: Resting pulmonary diffusing capacity of the lung for carbon monoxide (DLCO) is known to be the best predictor of arterial desaturation during exercise in patients with sarcoidosis. However, the relative contribution of each of the two components of DLCO-alveolar membrane diffusing capacity (Dm) and pulmonary capillary blood volume (Vc)-remains unclear.Study Objectives: To evaluate which component is responsible for the decrease of resting DLCO in patients with sarcoidosis, and to determine which resting pulmonary function test, including Dm and Vc, is the best predictor of gas exchange abnormalities during submaximal exercise.Design: Prospective analysis of patients referred to our department of respiratory medicine.Patients: Twenty four patients with pulmonary sarcoidosis were separated into two groups according to chest radiographic findings: group 1, stages 2 and 3 (n = 15); group 2, stage 4 (n = 9). All the patients completed pulmonary function tests (flows, volumes, single-breath DLCO, transfer coefficient [Ka], Dm, Vc) and submaximal exercise (two steady-state levels of mild and moderate exercise corresponding respectively to a target oxygen consumption of approximately 10 to 15 mL/min/kg).Results: DLCO was reduced in the two groups (group 1, 63 +/- 16% of predicted; group 2, 64 +/- 16% of predicted). Dm was severely decreased (group 1, 58 +/- 24% of predicted; group 2, 51 +/- 15% of predicted), whereas Vc was unchanged or only mildly decreased (group 1, 81 +/- 18% of predicted; group 2, 85 +/- 28% of predicted). Whatever the group of patients and the exercise level, Dm and DLCO were the strongest predictors (p < 0.001) of gas exchange abnormalities. Ka or volumes were weak predictors, and Vc or flows were not related with exercise gas exchange.Conclusions: This study demonstrates that a decrease in Dm mostly accounts for resting DLCO reduction, and that Dm as well as DLCO are highly predictive of gas exchange abnormalities at exercise in patients with sarcoidosis. [ABSTRACT FROM AUTHOR]

Presents a numerical algorithm to simulate nuclear magnetic resonance (NMR) measurements in the presence of constant magnetic field gradients. Effect of surface relaxivity on diffusion pore coupling in the absence of a magnetic field gradient; Effect of dual field saturation on the NMR response of coupled pore modes; Application of the simulation algorithm to fluid discrimination.

Background. The association between interstitial lung disease (ILD) and an increased risk of developing lung cancer has been reported. The goal of this retrospective study was to determine the outcome of lung cancer resection among patients with ILD.Methods. Between January 1979 and March 1999, 27 patients with both lung cancer and ILD were identified. Seven patients with poor pulmonary function tests or distant metastases underwent medical treatment and were excluded from this study. Twenty patients treated by surgical resection were analyzed.Results. Various types of ILD such as sarcoidosis (n = 7), idiopathic interstitial pneumonia (n = 4), histiocytosis X (n = 4), pneumoconiosis (n = 4), and amiodarone-induced ILD (n = 1) were observed. Tumors were located in the peripheral part of the lung in 16 cases. The most frequent tumor cell types were squamous and adenocarcinoma. The resections consisted of lobectomy (n = 16), bilobectomy (n = 1), and pneumonectomy (n = 3). Most cancers were stage I (n = 10) or II (n = 6). There was no postoperative death. The postoperative course was uneventful in 16 cases. The majority of patients (70%) did not experience respiratory insufficiency during the follow-up period. The actuarial 2-year and 5-year survival rates were, respectively, 83.5% and 66.4%.Conclusions. In this series, the long-term survival of patients who had lung cancer resection appeared to be not affected by the association with ILD. This could be explained by an adequate preoperative selection based on pulmonary function tests and a preferential choice for lobectomies. Thus, surgical resection should be offered to properly selected patients with lung cancer and underlying ILD. [Copyright &y& Elsevier]