Calixarene‐Entrapped Nanoemulsion for Uranium Extraction from Contaminated Solutions

Accidental cutaneous contamination by actinides such as uranium occurring to nuclear power plant workers can lead to their dissemination in other tissues and induce severe damages. Until now, no specific emergency treatment for such contamination has been developed. The aim of the present work was to formulate a tricarboxylic calix[6]arene molecule, known to exhibit good affinity and selectivity for complexing uranium, within a topical delivery system for the treatment of skin contamination. Since calixarene was shown to reduce oil/water interfacial tension, we have designed an oil‐in‐water nanoemulsion, taking advantage of the small droplet size offering a high contact surface with the contaminated aqueous medium. Characterization of the calixarene nanoemulsion was performed by determination of the oily droplet size, zeta potential and pH, measured as a function of the calixarene concentration. The obtained results have confirmed the surface localization of calixarene molecules being potentially available to extract uranyl ions from an aqueous contaminated solution. In a preliminary experiments, the calixarene nanoemulsion was used for the removal of free uranium from an aqueous contaminated solution. Results showed that the calixarene nanoemulsion extracted up to 80 ± 5% of uranium, which demonstrates the potential interest of this delivery system for uranium skin decontamination. © 2009 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 1375–1383, 2010     

Cocaine-mediated supersensitivity of 5-HT2A receptors in hypothalamic paraventricular nucleus is a withdrawal-induced phenomenon

We previously reported that treatment and withdrawal from cocaine increases: (1) 5-HT2A receptor-mediated neuroendocrine responses, and (2) Galphaq and Galpha11 G-protein levels in the hypothalamic paraventricular nucleus (PVN) at 48 h post-treatment. This study investigates changes in the initial 24 h of withdrawal to discern whether 5-HT2A receptor supersensitivity is due to cocaine treatment or is induced during the withdrawal period. We report here increases in 5-HT2A receptor-mediated neuroendocrine responses only 12 or 24 h post-treatment, but not during the initial 4 h withdrawal period. Levels of membrane- or cytosol-associated Galphaq or Galpha11 proteins in PVN are not altered during the first 24 h of withdrawal. However, the density of 125I-(-)-1-(2,5 dimethoxy-4-iodophenyl)-2-amino-propane HCl (DOI)-labeled high-affinity 5-HT2A receptors in PVN increased 35% in rats withdrawn from cocaine for 24 h. These findings demonstrate that cocaine-induced increases in 5-HT2A receptor function in PVN represents a withdrawal-induced phenomena that: (1) is likely attributed to increased G-protein coupled/high-affinity conformational state of the 5-HT2A receptor, and (2) occurs in the absence of changes in the levels of associated G proteins during the first 24 h.     

Antigens and granularity of blood monocytes in relation to inflammatory markers and lipids in postmenopausal women

OBJECTIVES: The menopause is associated with an increase of inflammatory markers (C-reactive protein, fibrinogen), cytokines (INFgamma, TNF, etc.) and blood lipoproteins. In vitro, CRP, LDL and fibrinogen can modulate or potentiate interleukines production by monocytes. The aim of this work was to study, the relationships in vivo between hs-CRP, fibrinogen, lipoproteins and the phenotype of circulating monocytes. METHODS: The monocytes phenotype, in postmenopausal women (n=26) without history of cardiovascular disease, was determined, by flow cytometry, measuring granularity and CD14, HLA-DR and CD62-L antigens expression. Blood monocytes were divided in CD14+dim monocytes (low CD14 expression) and CD14+bright monocytes (high CD14 expression). RESULTS: HLA-DR was negatively correlated with hs-CRP and fibrinogen. The relationships between ApoB, LDL/ApoB ratio and CD14 expression was restricted to the CD14+bright monocytes. Blood lipids, i.e. total cholesterol, LDL-c and ApoB were correlated with the granularity of both subsets. CD14+dim monocytes were characterized by a low granularity and CD62-L expression. CONCLUSIONS: Our data show that fibrinogen and hs-CRP are correlated with a reduced antigen-presenting capacity. Expression of CD14 on CD14+bright monocytes is negatively associated to atherogenic LDL. Blood monocytes granularity was positively correlated with serum lipids indicating that monocytes could uptake modified LDL in circulation and not restricted to subendothelial space.     

Comparative inflammatory properties of staphylococcal superantigenic enterotoxins SEA and SEG: implications for septic shock

The severity of Staphylococcus aureus sepsis is positively associated with staphylococcal enterotoxin A (SEA) and negatively associated with the enterotoxin gene cluster (egc), which encodes five staphylococcal enterotoxins. We postulated that the variable, clinical severity of S. aureus sepsis might be a result of differences in the inflammatory properties of staphylococcal superantigens. We therefore compared the inflammatory properties of SEA with those of staphylococcal entérotoxin G (SEG), a member of the five egc superantigens. We found that SEA and SEG had similar superantigenic properties, as they induced CD69 expression on T lymphocytes and selective expansion of Vbeta subpopulations. Contrary to SEG, however, SEA induced a strong proinflammatory/Th1 response, including TNF-alpha and MIP-1alpha production. These results suggest that the association of SEA with the severity of S. aureus septic shock, characterized by a deleterious, inflammatory cascade, may be explained partly by the specific proinflammatory properties of this superantigen.     

Cell cycle features of primate embryonic stem cells

Using flow cytometry measurements combined with quantitative analysis of cell cycle kinetics, we show that rhesus monkey embryonic stem cells (ESCs) are characterized by an extremely rapid transit through the G1 phase, which accounts for 15% of the total cell cycle duration. Monkey ESCs exhibit a non-phasic expression of cyclin E, which is detected during all phases of the cell cycle, and do not growth-arrest in G1 after gamma-irradiation, reflecting the absence of a G1 checkpoint. Serum deprivation or pharmacological inhibition of mitogen-activated protein kinase kinase (MEK) did not result in any alteration in the cell cycle distribution, indicating that ESC growth does not rely on mitogenic signals transduced by the Ras/Raf/MEK pathway. Taken together, these data indicate that rhesus monkey ESCs, like their murine counterparts, exhibit unusual cell cycle features in which cell cycle control mechanisms operating during the G1 phase are reduced or absent.     

Potentiation of the bactericidal activity of Harungana madagascariensis Lam. ex Poir. (Hypericaceae) leaf extract against oral bacteria using poly (D, L-lactide-co-glycolide) nanoparticles: in vitro study

Harungana madagascariensis Lam. ex Poir. (Hypericaceae) is known to have biological properties with mainly antibacterial, antifungal, and antiviral effects. The objective of this study was to investigate the in vitro bactericidal activity of the ethyl acetate H. madagascariensis leaf extract (HLE) on the main oral bacterial strains largely implicated in dental caries and gingivitis infections, and the possibility of potentialization of HLE antibacterial effects using the poly (D,L-lactide-co-glycolide) nanoparticles (PLG-NP). The microdilution technique and the interfacial polymer deposition following the solvent diffusion method were used to investigate the in vitro bactericidal activity of ethyl acetate HLE and to prepare nanoparticles, respectively. HLE showed significant bactericidal effects against the bacterial strains tested, with minimal bactericidal concentration (MBC) to 5 x 10(2) mg/l or less, except for Lactobacillus casei with 7.5 x 10(2) mg/l. With the HLE incorporated into PLG nanoparticles (HLE-PLG-NP), we observed diminution of the bactericidal concentration compared to HLE, the upper MBC being of 1.875 x 10(2) mg/l. Incorporation of the HLE into a colloidal carrier optimized its antibacterial performance.     

Combination fixed and removable prostheses using a CoCr alloy: a clinical report

It is now possible to provide combination fixed/removable prosthetic restorations using only 1 dental alloy, such as CoCr, a nonprecious alloy. This alloy offers clinical performance and demonstrated corrosion resistance. This clinical report demonstrates use of a single CoCr alloy for metal-ceramic fixed partial dentures in conjunction with a mandibular removable partial denture.