Phosphonated mesoporous silica nanoparticles bearing ruthenium complexes used as molecular probes for tracking oxygen levels in cells and tissues

Molecular oxygen plays an important role in living organisms. Its concentration and fluctuation in cells or tissues are related to many diseases. Therefore, there is a need for molecular systems that can be used to detect and quantify oxygen levels in vitro and in vivo. In this study, we synthesized phosphonated mesoporous silica nanoparticles bearing ruthenium complexes in their pores (pM-Rus) and evaluated their photophysical and biological properties. The pM-Rus were highly soluble in water and showed robust phosphorescence under hypoxic conditions, while the addition of oxygen suppressed this emission. Cellular experiments revealed that pM-Rus with a size of 100 nm showed efficient cellular uptake to emit phosphorescence in hypoxic cells. In addition, pM-Rus have negligible toxicity to cells due to the blockage of direct contact between ruthenium complexes and intracellular biomolecules and the deactivation of singlet oxygen (¹O₂) generated by photoexcitation of ruthenium complexes before leaking out of the pores. Animal experiments confirmed that pM-Rus showed robust emission at hypoxic regions in mice. Thus, pM-Rus are promising oxygen probes for living systems

Preparation of superparamagnetic magnetite nanoparticles by reverse precipitation method: Contribution of sonochemically generated oxidants.

Magnetic iron oxide nanoparticles were successfully prepared by a novel reverse precipitation method with the irradiation of ultrasound. TEM, XRD and SQUID analyses showed that the formed particles were magnetite (Fe(3)O(4)) with about 10nm in their diameter. The magnetite nanoparticles exhibited superparamagnetism above 200K, and the saturation magnetization was 32.8emu/g at 300K. The sizes and size distributions could be controlled by the feeding conditions of FeSO(4).7H(2)O aqueous solution, and slower feeding rate and lower concentration lead to smaller and more uniform magnetite nanoparticles. The mechanisms of sonochemical oxidation were also discussed. The analyses of sonochemically produced oxidants in the presence of various gases suggested that besides sonochemically formed hydrogen peroxide, nitrite and nitrate ions contributed to Fe(II) ion oxidation

Mirtazapine has a therapeutic potency in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice model of Parkinson’s disease

Background: Mirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA), shows multiple pharmacological actions such as inhibiting presynaptic α2 noradrenaline receptor (NAR) and selectively activating 5-hydroxytriptamine (5-HT) 1A receptor (5-HT1AR). Mirtazapine was also reported to increase dopamine release in the cortical neurons with 5-HT dependent manner. To examine whether mirtazapine has a therapeutic potency in Parkinson’s disease (PD), we examined this compound in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice model of PD. Results: Male C57BL/6 mice were subjected to MPTP treatment to establish a PD model. Mirtazapine was administered once a day for 3 days after MPTP treatment. MPTP-induced motor dysfunction, assessed by beam-walking and rota-rod tests, was significantly improved by administration of mirtazapine. Biochemical examinations by high performance liquid chromatography and western blot analysis suggested mirtazapine facilitated utilization of dopamine by increasing turnover and protein expression of transporters, without affecting on neurodegenerative process by MPTP. These therapeutic effects of mirtazapine were reduced by administration of WAY100635, an inhibitor for 5HT1AR, or of clonidine, a selective agonist for α2-NAR, or of prazosin, an inhibitor for α1-NAR, respectively. Conclusion: Our results showed mirtazapine had a therapeutic potency against PD in a mouse model. Because PD patients sometimes show depression together, it will be a useful drug for a future PD treatment

Early Spectroscopy of the 2010 Outburst of U Scorpii

We present early spectroscopy of the recurrent nova U~Sco during the outburst in 2010. We successfully obtained time-series spectra at $t_{\rm d}=$0.37--0.44~d, where $t_{\rm d}$ denotes the time from the discovery of the present outburst. This is the first time-resolved spectroscopy on the first night of U Sco outbursts. At $t_{\rm d}\sim 0.4$~d the H$\alpha$ line consists of a blue-shifted ($-5000$ km s$^{-1}$) narrow absorption component and a wide emission component having triple peaks, a blue ($\sim -3000$ km s$^{-1}$), a central ($\sim 0$ km s$^{-1}$) and a red ($\sim +3000$ km s$^{-1}$) ones. The blue and red peaks developed more rapidly than the central one during the first night. This rapid variation would be caused by the growth of aspherical wind produced during the earliest stage of the outburst. At $t_{\rm d}=1.4$~d the H$\alpha$ line has a nearly flat-topped profile with weak blue and red peaks at $\sim \pm 3000$ km s$^{-1}$. This profile can be attributed to a nearly spherical shell, while the asphericity growing on the first night still remains. The wind asphericity is less significant after $t_{\rm d}=9$ d.Comment: 5 pages, 3 figures, Accepted for publication of PASJ Letter

PERSISTENT ORGANOCHLORINE RESIDUES IN HUMAN BREAST MILK FROM VIETNAM : CONTAMINATION, ACCUMULATION KINETICS AND RISK ASSESSMENT

Joint Research on Environmental Science and Technology for the Eart

Contamination by PCDDs, PCDFs and coplanar PCBs in open dumping sites in Vietnam-levels, patterns and toxic implications

Joint Research on Environmental Science and Technology for the Eart

Experimental Studies on Protective Effects of FK506 Against Hepatic Ischemia-Reperfusion Injury

Purposes ; FK506 (strong immunosuppressive agent) was investigated experimentally whether to protect the hepatic IRI. Methods ; Warm ischemic experiment using pigs and rats were performed and examined whether FK506 is effective. Results ; The results obtained are as follows. 1. Warm ischemia allowed time of the pigs without FK506 was 150 minutes, but as for that of FK506 group, the extension of 30 minutes was got in 180 minutes. 2. Biliary excretion rate of BSP after reperfusion were better in the group of 180 minutes ischemia with FK506 than in without FK506 group. 3. Chemiluminescence intensity in the peripheral neutrophils and adhered and infiltrated leukocytes in the liver were suppressed markedly by FK506. 4. The vascular endothelium with the scanning electron microscope was relatively preserved in the FK506 group comparing to the placebo group on 30 minutes after reperfusion. 5. Stress gastric ulcer was controlled and myeloperoxidase activity in the gastric mucosa was suppressed by FK506. Conclusion ; Based on the results of theses experiments, it was suggested that FK506 has a protective effect on IRI by suppressing : the impairment of sinusoidal endothelial cells ; the activation of KCs ; the disturbance of micro-circulation ; oxidative stress ; inflammation ; and the accumulation of leukocytes

Endocrine Disrupting Chemicals in Patients with Chronic Obstructive Pulmonary Diseases

The study of indoor environmental quality as well as the development and progression of chronic respiratory diseases have received a great deal of attention in the past few years. However, most of those surveys focus on the effects of particulate matter (PM) and biological contaminants (fungi and bacteria) and evidences on the effects of endocrine disrupting chemicals (EDCs) in these pathologies are limited. Hence, RESPIRA project aims to contribute towards a better understanding of the role of multiple stressors in respiratory diseases by providing data on the levels and effects of EDCs in patients with Chronic Obstructive Pulmonary Disease (COPD) and control individuals from Estarreja region (NW Portugal). Here we will summarize the results obtained for phenolic compounds (parabens, triclosan and triclocarban) in matched human and indoor environmental samples (house dust) from COPD patients. Overall, the concentrations in dust samples are one to two orders of magnitude higher that the concentrations in human urine. Triclosan was detected in all the dust samples, triclocarban was detected in 82% of the dust samples and parabens in 90% to 100% of the samples. In urine samples, triclosan was detected in 56% of the samples, triclocarban was always bellow detection limit (0.25 ng/mL) and parabens detection frequency varied widely (23-84%). Interestingly, the highest level reported in dust for triclosan (1200 ng/g) corresponded to the house of the patient with the highest triclosan concentration in urine (140 ng/mL).publishe

PERSISTENT ORGANIC POLLUTANTS(POPs) IN VIETNAMESE ENVIRONMENT-A REVIEW OF CONTAMINATION, FATE AND TOXIC POTENTIAL

Joint Research on Environmental Science and Technology for the Eart

Personal care products in matched human and environmental samples collected under the framework of RESPIRA Project

The indoor environment is an important source of exposure to microbial communities that may deleteriously affect human respiratory health. Recent studies demonstrated that the microbial community structure can be altered by the use of household products such as antimicrobial agents. Hence, in order to understand the modulation of the indoor microbiome by household products and their joint effect in the respiratory status of COPD patients we evaluated the levels of antimicrobials agents in dust samples and matched urine samples from patients with COPD. Overall, the concentrations in dust samples are one to two orders of magnitude higher that the concentrations in human urine. Triclosan was detected in all the dust samples, triclocarban was detected in 82% of the dust samples and parabens in 90% to 100% of the samples. In urine samples, triclosan was detected in 56% of the samples, triclocarban was always bellow detection limit (0.25 ng/mL) and parabens detection frequency varied widely (23-84%). Interestingly, the highest level reported in dust for triclosan (1200 ng/g) corresponded to the house of the patient with the highest triclosan concentration in urine (140 ng/mL) and at that house high levels of antibiotic resistant bacteria were found. Such results suggest that the use of antimicrobials might be associated with the presence of resistant bacteria and thus deserve to be further studied.publishe