Toxicological effects of ambient fine (PM2.5-0.18) and ultrafine (PM0.18) particles in healthy and diseased 3D organo-typic mucocilary-phenotype models.

The knowledge of the underlying mechanisms by which particulate matter (PM) exerts its health effects is still incomplete since it may trigger various symptoms as some persons may be more susceptible than others. Detailed studies realized in more relevant in vitro models are highly needed. Healthy normal human bronchial epithelial (NHBE), asthma-diseased human bronchial epithelial (DHBE), and COPD-DHBE cells, differentiated at the air-liquid interface, were acutely or repeatedly exposed to fine (i.e., PM2.5-0.18, also called FP) and quasi-ultrafine (i.e., PM0.18, also called UFP) particles. Immunofluorescence labelling of pan-cytokeratin, MUC5AC, and ZO-1 confirmed their specific cell-types. Baselines of the inflammatory mediators secreted by all the cells were quite similar. Slight changes of TNFα, IL-1ß, IL-6, IL-8, GM-CSF, MCP-1, and/or TGFα, and of H3K9 histone acetylation supported a higher inflammatory response of asthma- and especially COPD-DHBE cells, after exposure to FP and especially UFP. At baseline, 35 differentially expressed genes (DEG) in asthma-DHBE, and 23 DEG in COPD-DHBE, compared to NHBE cells, were reported. They were involved in biological processes implicated in the development of asthma and COPD diseases, such as cellular process (e.g., PLA2G4C, NLRP1, S100A5, MUC1), biological regulation (e.g., CCNE1), developmental process (e.g., WNT10B), and cell component organization and synthesis (e.g., KRT34, COL6A1, COL6A2). In all the FP or UFP-exposed cell models, DEG were also functionally annotated to the chemical metabolic process (e.g., CYP1A1, CYP1B1, CYP1A2) and inflammatory response (e.g., EREG). Another DEG, FGF-1, was only down-regulated in asthma and specially COPD-DHBE cells repeatedly exposed. While RAB37 could help to counteract the down-regulation of FGF-1 in asthma-DHBE cells, the deregulation of FGR, WNT7B, VIPR1, and PPARGC1A could dramatically contribute to make it worse in COPD-DHBE cells. Taken together, these data contributed to support the highest effects of UFP versus FP and highest sensitivity of asthma- and notably COPD-DHBE versus NHBE cells.

Effects of engineered iron nanoparticles on the bryophyte, Physcomitrella patens (Hedw.) Bruch & Schimp, after foliar exposure.

The effects of iron nanoparticles on bryophytes (Physcomitrella patens) were studied following foliar exposure. We used iron nanoparticles (Fe-NP) representative of industrial emissions from the metallurgical industries. After a characterization of iron nanoparticles and the validation of nanoparticle internalization in cells, the effects (cytotoxicity, oxidative stress, lipid peroxidation of membrane) of iron nanoparticles were determined through the axenic culturing of Physcomitrella patens exposed at five different concentrations (5 ng, 50 ng, 500 ng, 5 µg and 50 µg per plant). Following exposure, the plant health, measured as ATP concentrations, was not impacted. Moreover, we studied oxidative stress in three ways: through the measure of reactive oxygen species (ROS) production, through malondialdehyde (MDA) production and also through glutathione regulation. At concentrations tested over a short period, the level of ROS, MDA and glutathione were not significantly disturbed.

Effects of nanorod structure and conformation of fatty acid self-assembled layers on superhydrophobicity of zinc oxide surface.

Superhydrophobic surfaces have been prepared from nanostructured zinc oxide layers by a treatment with fatty acid molecules. The layers are electrochemically deposited from an oxygenated aqueous zinc chloride solution. The effects of the layer's structure, from a dense film to that of a nanorod array, as well as that of the properties of the fatty acid molecules based on C18 chains are described. A contact angle (CA) as high as 167 degrees is obtained with the nanorod structure and the linear saturated molecule (stearic acid). Lower values are found with molecules having an unsaturated bond on C9, in particular with a cis conformation (140 degrees ). These results, supplemented by infrared spectroscopy, indicate an enhancement of the sensitivity to the properties of the fatty acid molecules (conformation, flexibility, saturated or not) when moving from the flat surface to the nanostructured surface. This is attributed to a specific influence of the structure of the tops of the rods and lateral wall properties on the adsorption and organization of the molecules. CA measurements show a very good stability of the surface in time if stored in an environment protected from UV radiations.

Imidazolium-based titanium substrates against bacterial colonization.

Nosocomial infections are often induced by the presence of pathogenic organisms on the surface of medical devices or hospital equipment. Chemical modifications of the surface are recognized as efficient strategies to prevent bacterial adhesion but they may have a negative impact on the material's interaction with living tissues. Here we have developed a photoactivated method for the modification of titanium substrates. A photoinduced technique employing a grafting-onto process has been successfully performed to covalently anchor an imidazolium-derivative siloxane onto titanium surfaces. Imidazolium surfaces showed higher bacteria-repellency performances than native titanium substrates, achieving more than 98% anti-adhesion efficiency against Escherichia coli after 24 h of incubation. In addition, these surfaces allowed for the adhesion and viability of osteoblasts cells without evidence of cytotoxicity.

213 elderly uremic patients over 75 years of age treated with long-term peritoneal dialysis: a French multicenter study.

UNLABELLED: We report our experience in 213 elderly patients over 75 years treated by peritoneal dialysis (PD) as first and exclusive dialysis therapy. The mean age at start of PD was 79.4 +/- 3.6 years, and the cumulative time on PD was 4551 months (mean time: 21.4 +/- 19.8 months). Twenty-six patients lived in institutions and 187 lived at home. Thirty patients had an effective autonomy with the ability to carry on normal activities. One hundred and two patients were cared for by a private nurse at home, and 46 patients were cared for in a family environment. Most cases were treated by three exchanges per day (152 cases) and used a nondisconnect system (175 cases) on account of absence of autonomy. The rate of peritonitis per patient-month was one episode per 16.8 patient-months. Patient survival (Kaplan-Meier curves) was 74%, 59%, 45%, and 19% at one, two, three, and five years, respectively. The causes of death were various with a higher frequency of cardiovascular causes (48.3% of the 116 deaths). Thirty-three patients died in less than six months including 18 patients in less than three months. IN CONCLUSION: elderly uremic patients can be treated with long-term PD with relatively good results. Mortality is high but essentially due to age and poor general status-the dedication of private home nursing is very important in treating elderly PD patients. This fact often is a necessary condition in maintaining these elderly patients at home.

Recurrent myalgias associated with cimetidine.

A chronically hemodialyzed patient experienced recurrent episodes of myalgia while on cimetidine treatment (400 mg/day). After two uneventful courses of cimetidine, the pain appeared at the end of a third fourteen-weeks long course. Severe myalgia occurred at the sixth week of a fourth exposure to cimetidine. Pain was predominant in the hip area, disappeared within a few days after withdrawal and recurred three weeks after resuming therapy. There was no sign of neurological involvement and CPK remained consistently normal. Ranitidine was subsequently administered for four months whereby the patient showed no symptoms of myalgia. This observation suggests that, in susceptible individuals, a progressive decrease in tolerance to cimetidine might occur with repeated courses.

Must erythropoietin be injected by the subcutaneous route for every hemodialyzed patient?

A multicenter, prospective, and controlled trial was performed to evaluate the efficacy and tolerance of intravenous (i.v.) and subcutaneous (s.c.) recombinant erythropoietin (rH-EPO) administration routes in 49 long-term hemodialyzed patients on maintenance phase of treatment, to determine the usefulness of replacing i.v. route by SC route in all of them. Each of these patients had already been treated with rH-EPO by the i.v. route for at least 6 months and included in the protocol on stabilized consumption phase. We arbitrarily chose three strata according to previous needs: Stratum A (> 150 U/kg/week) for eight patients, Stratum B (100 to 150 U/kg/week) for 12 patients, and Stratum C (< 100 U/kg/week) for 29 patients. In each stratum, the further treatment route (i.v. or s.c.) was randomized. Finally, 25 patients continued with i.v. route, and the other 24 changed to the s.c. route. The objective was to maintain a stable hemoglobin level, ranging from 9 to 10 g/dL. Tolerance and consumption in each group (i.v. and s.c.) were compared 4 months later. Globally, for an identical efficacy, rH-EPO needs were lesser using s.c. route (84 U/kg/week) than i.v. route (112 U/kg/week) (P = 0.02). However, when the strata were studied, it transpires that this benefit existed only for consumers having the highest needs (Stratum A) and not for the others. With regard to tolerance, only thrombotic events might be less frequent by using s.c. route, but the significance threshold is not reached (P = 0.09). Thus, replacing i.v. route by SC route, especially in high consumers, reduces the cost of treatment by rH-EPO. This benefit might be dependent on previous needs.