Morphine-induced conformational changes in human monocytes, granulocytes, and endothelial cells and in invertebrate immunocytes and microglia are mediated by nitric oxide

We evaluated the contribution of nitric oxide (NO) to morphine-induced rounding of spontaneously activated (mobile) ameboid human monocytes, granulocytes, or arterial endothelial cells and invertebrate immunocytes and microglia. Morphine induced significant rounding and inactivation of ameboid cells within 20 min except for arterial endothelial cells, which became rounded 24 h after morphine exposure. The effects of morphine on cell conformation were blocked in the presence of N-nitro-L-arginine, a nitric oxide synthase inhibitor. Treatment of cells with the NO donor, sodium nitroprusside, induced cell rounding similar to that observed following morphine exposure, suggesting that NO release may mediate morphine-induced changes in cell conformation. The contribution of NO release to morphine-induced cell rounding was determined by direct evaluation of NO concentration in real-time using a NO-specific amperometric probe. Significant increases in NO concentration were observed 2 min after morphine stimulation, whereas morphine-induced NO release was markedly impaired by pretreatment with N-nitro-L-arginine or the opiate alkaloid antagonist, naloxone. In contrast, opioid peptides failed to induce NO release, consistent with our previous observations that demonstrated the failure of opioid peptides to promote cell rounding. Taken together, these data suggest that morphine-induced NO release may be mediated by activation of the opiate alkaloid-selective, opioid peptide-insensitive micro3 receptor, and that functional coupling of morphine to NO production has been conserved during evolution and may modulate cellular activation.     

Hydrodynamic Loading on River Bridges

During a flood, a bridge may be partially or entirely submerged by the flow and the subsequent loading of fluid plays a major role in assessing the vulnerability of the structure. We have performed laboratory experiments to quantify the hydrodynamic loading on a bridge deck with rectangular cross section. We measured the time-varying hydrodynamic forces acting on the obstacle for various submergences and Deck Froude numbers. The experimental results have been analyzed via dimensional analysis and relationships between time-averaged force coefficients (drag, lift, and moment coefficients), the Deck Froude number and geometrical parameters of the problem are discussed and compared against relevant literature. Due to the presence of a free surface, force coefficients can be either larger (by more than a factor of 2) or lower than the corresponding values of the unbounded domain. The experimental drag coefficients are then compared with the results obtained by the momentum equation.     

Epidemiology of factor V Leiden: clinical implications

A pronounced similarity exists between liver allograft rejection and graft-versus-host disease (GVHD) in the damage and eventual destruction of small intrahepatic bile ducts. Although an immunologic reaction has an important role, precisely identifying the target antigens or reason for persistence of the immune response has been difficult. An important difference between GVHD and liver rejection is the development of obliterative arteriopathy only in rejection. The three main histopathologic features of acute rejection are a predominantly mononuclear but mixed portal inflammation, subendothelial inflammation of portal or terminal hepatic veins (or both), and bile duct inflammation and damage. In acute rejection, a controversial issue is determining when therapeutic intervention is needed. The recommended approach is to base treatment on a combination of histopathologic changes and liver injury or dysfunction. Chronic rejection, which usually does not occur before 2 months after transplantation, is characterized by two main histopathologic features: (1) damage and loss of small bile ducts and (2) obliterative arteriopathy. Acute GVHD begins within the first month after transplantation and most commonly involves the skin, gastrointestinal tract, and liver, whereas chronic GVHD usually develops more than 80 to 100 days after liver transplantation and affects 30 to 50% of long-term survivors. Recognition of the early, cellular stages of chronic GVHD is important in preventing irreversible damage.     

Selection of Thresholding Scheme for Image Noise Reduction on Wavelet Components Using Bayesian Estimation

Methods for image noise reduction based on wavelet analysis perform by first decomposing the image and then by applying non-linear compression functions on the wavelet components. The approach commonly used to reduce the noise is to threshold the absolute pixel values of the components. The thresholding functions applied are members of a family of functions defining a specific shape. This shape has a fundamental influence on the characteristics of the output image. This work presents and tests an alternative shape deduced from statistical estimation. Optimal shapes are deduced using Bayesian theory and a new shape is defined to approximate them. The derivation of thresholding shapes is optimal in LMSE and MAP senses. The noise is assumed additive Gaussian and white (AWGN) and the components are assumed to have statistical distributions consistent with the real component distributions. The optimal shapes are then approximated by a scheme utilised in the noise reduction procedure. Results demonstrating the efficiency of the image noise reduction procedure are included in the work.     

Low transplant mortality in allogeneic bone marrow transplantation for acute myeloid leukemia: a randomized study of low-dose cyclosporin versus low-dose cyclosporin and low-dose methotrexate

Sixty patients undergoing allogeneic bone marrow transplant for acute myeloid leukemia (AML) in first remission (CR1; n = 49) or more advanced phase (n = 11) were entered in a prospective trial of graft-versus-host disease (GvHD) prophylaxis: low-dose cyclosporin A (IdCSA; 1 mg/kg/d from day -1 to +20 day; n = 28) or IdCSA plus low-dose methotrexate (IdMTX; 10 mg/m2 for day +1, 8 mg/m2 for days +3, +6, and +11; n = 32). Primary end points were acute GvHD (aGvHD) and transplant-related mortality (TRM); secondary end points were relapse and survival. The conditioning regimen consisted of cyclophosphamide (120 mg/kg) and fractionated total body irradiation (3.3 Gy/d for 3 consecutive days). The actuarial risk of developing aGvHD grade II-III was 61% for IdCSA alone and 34% for IdCSA + IdMTX (P = .02). The actuarial risk of TRM at 1 year was 11% versus 13%, respectively, and older patients (>/= 29 years) had higher TRM than younger patients (22% v 5%, P = .01). The age effect was significant in the IdCSA group (P = .04) but not in the IdCSA + IdMTX group (P = .1). The median follow-up is 4.4 years, with an overall actuarial survival of 78% for CR1 patients and 36% for patients with advanced disease. For patients in CR1 the outcome of the two regimens was as follows: survival 77% versus 80% (P = .6), relapse 20% versus 9% (P = .1), and TRM 13% versus 17% (P = .6). This study suggests that TRM can be reduced in AML patients undergoing allogeneic marrow transplants with a mild conditioning regimen and low-dose immunosuppression, and this translates in a 78% 5-year survival for CR1 patients. Beyond CR1 the major obstacle remains leukemia relapse, which is not prevented by low-dose in vivo immunosuppression.     

Perfluoropolyether-based organic-inorganic hybrid coatings

Perfluoropolyether-based organic-inorganic hybrids were prepared by sol-gel process and applied as functional coatings onto glass substrates. Contact angle analysis and X-ray photoemission spectroscopy were carried out in order to characterize the surface of the prepared coatings. A strong hydrophobic and lipophobic character was observed for all tested compositions. The wettability behaviour was found to be dependent on both the coating technique and the reaction time of the sol-gel reaction. A strong surface segregation of perfluoropolyether segments was noted for all the prepared samples as evidenced by XPS analysis. On the basis of the obtained results, these materials could be used as functional coatings to prepare water and oil repellent glasses or other substrates.     

Tracer Dispersion in Stirred Tank Reactors: Asymptotic Properties and Mixing Characterization

This article addresses the characterization of dispersion and homogenization phenomena in stirred vessels through the analysis of dispersion curves that can be obtained experimentally by means of conductivity measurements. New insights on mixing conditions can be achieved from the analysis of the qualitative and asymptotic properties of tracer dispersion curves. The results obtained are interpreted in the context of the spectral approach to the advection‐diffusion equation. It is shown that any flow model aimed at reproducing the experimentally determined dispersion curves must be at least two‐dimensional. Convection‐enhanced dispersion associated with the spectral structure of the advection‐diffusion equation is addressed.     

Preparation and properties of poly(L‐lactic acid) scaffolds by thermally induced phase separation from a ternary polymer–solvent system

Poly(L ‐lactic acid) (PLLA) foams for tissue engineering were prepared via thermally induced phase separation of a ternary system PLLA/dioxane/tetrahydrofuran (THF) followed by double solvent exchange (water and ethyl alcohol) and drying. An extension to solidification from solution of a previously developed method for solidification from the melt was adopted. The technique is based on a continuous cooling transformation (CCT) approach, consisting in recording the thermal history experienced by rapidly cooled samples and then analyzing the resulting sample morphology. Different foams were produced by changing the relative amount of dioxane and THF in the starting solution while the amount of polymer was kept constant. Results show that the final morphology and crystallinity (measured by DSC) depend on solvent power, which in its turn was determined by the ratio dioxane/THF, and a minimum of pore size, optimum final crystallinity and crystallization rate were achieved for a system containing 70 % of dioxane. Under this condition, a higher bulk density (evaluated by Hg intrusion porosimetry) and a larger specific surface area (measured by BET N₂ sorption technique) was achieved. Copyright © 2004 Society of Chemical Industry