Assessment of the sources of suspended particulate matter aerosol using US EPA PMF 3.0.

The main purpose of this paper was to carry out a source apportionment of suspended particulate matter (SPM) samples using positive matrix factorization procedure. The central and local Government of Japan introduced strict emission regulations in 2002/10 and 2003/10, respectively, in curbing SPM pollution from major metropolitans. This paper also highlighted the impact of the measures taken by the central and local Government of Japan on the reduction of SPM and the contributions of sources. SPM samples were collected for 6 years starting from 1999 to 2005 at two sites, i.e., site A (urban) and site B (suburban) of Yokohama, Japan. Microwave digestion and inductively coupled plasma-mass spectroscopy (ICP-MS) were employed to measure Mg, Al, Ca, V, Cr, Mn, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Pb and Bi, while water soluble ions (Na(+), NH4⁺, K(+), Ca(2+), Mg(2+), Cl(-), NO3⁻ and SO4²â» as well as carbonaceous mass (EC and OC) were analyzed using ion chromatograph and CHN analyzer, respectively. The sources identified at two sites were automobile, soil dust, marine aerosol, mixed sources, and secondarily formed aerosol. Also, source quantification was performed. Automobile and soil dust were striking contributors at site A. Automobile and soil dust of SPM aerosol might be produced from local origin at current study areas. Besides, Asian dust had an impact on high concentrations of SPM aerosol in some certain period of the year due to the outflows of East Asian emission. In contrast, secondary aerosol in the form of sulfate and ammonium as well as mixed sources (coal, long-transported Cs, and other unknown sources) were remarkable at site B. Stationary/industrial combustion has apparently more impact on the release of SPM components at site B than A. Automobile regulations in 2002 and 2003, respectively, resulted in reduction of SPM by 28% for site A and 16% for site B. There was also net reduction of automobile contribution at both sites due to the above measures being implemented.

Urban and suburban aerosol in Yokohama, Japan: a comprehensive chemical characterization.

This article analyses elemental composition of suspended particulate matter (SPM) samples collected monthly from 1999 to 2005 at two locations in Yokohama, Japan. Microwave digestion and inductively coupled plasma mass spectroscopy was employed to measure Mg, Al, Ca, V, Cr, Mn, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Pb, and Bi. Water-soluble ions (Na(+), NH(4+), K(+), Ca(2+), Cl(-), NO(3-), and SO(4)2-) and carbonaceous mass (elemental and organic carbon) were detected using ion chromatograph and CHN analyzer, respectively. The results indicate that the composition of SPM on one of the sites is determined by automobile emissions and on the other by industrial combustions. The impact of the emission regulations for automobiles in large Japanese cities, which were enacted during 2002 and 2003, on the SPM composition of the samples is also studied.

A significant enhancement of therapeutic effect against hepatic metastases of M5076 in mice by a liposomal interleukin-2 (mixture).

Recombinant interleukin-2 (IL-2) was strongly and almost completely adsorbed onto small hydrophobic liposomes under optimal conditions (liposome: DSPC-DSPG; molar ratio, 10:1; 30-50 nm in size, ratio of IL-2 to liposome: 4.0 JRU/nmol lipid). This liposomal IL-2 improved the distribution of IL-2 after intravenous administration as reported, previously. Liposomal IL-2 (300-10000 JRU/mouse per day) was significantly more effective than free IL-2 alone for inhibiting against the experimental metastases of M5076 in mice. The inhibitory effect of liposomal IL-2 was greatest in the liver. The ED(50) of liposomal IL-2 and that of free IL-2 in the liver were 1640 and 12500 JRU/mouse per day, respectively. This simple preparation (mixture) using IL-2 and liposome suspension is expected to have potential for increasing therapeutic efficacy against hepatic metastases.

Oral-antigen delivery via a water-in-oil emulsion system modulates the balance of the Th1/Th2 type response in oral tolerance.

PURPOSE: To evaluate the ability of a water-in-oil (W/O) emulsion containing ovalbumin (OVA), a model antigen, to induce oral tolerance and to elucidate the mechanism for the induction of oral tolerance by the emulsion system. METHODS: A W/O emulsion containing OVA was prepared and evaluated its ability to induce oral tolerance in mice. Also, the Th1/Th2 balance in the mice tolerized was investigated in terms of the ratios of anti-OVA IgG2a titer to anti-OVA IgG1 titer (IgG2a/IgG1 ratios) and cytokine profiles. RESULTS: Anti-OVA total IgG antibody titer of mice administered OVA in saline was approximately 3.5-fold higher than that of the mice administered OVA in W/O emulsion at a dose of 0.1 mg/mouse/day. Similar total IgG responses were observed between the above two at a dose of 1 mg/mouse/day. The IgG2a/IgG1 ratios decreased as the dose of OVA in W/O emulsion, but not in saline, increased at doses of 0, 0.1, and 1 mg/mouse/day. Interferon-gamma secretion of PLN cells from the mice administered OVA in W/O emulsion decreased, whereas their interleukin-4 secretion remained high. Although interferon-gamma secretion for the mice administered OVA in saline decreased, interleukin-4 secretion did not change. CONCLUSIONS: The present study suggests that oral delivery of OVA via the W/O emulsion system may more efficiently enhance the induction of Th2-dominated imbalance than that of OVA in saline.

Continuous release of interleukin-2 from liposomal IL-2 (mixture of interleukin-2 and liposomes) after subcutaneous administration to mice.

Recombinant interleukin-2 (IL-2) was strongly and almost completely adsorbed onto small and hydrophobic liposomes by simple mixing under optimal conditions (liposome: DSPC-DSPG; molar ratio, 10:1; 30-50 nm in size, ratio of IL-2 to liposome: 4.0 JRU/nmol lipid). This liposomal IL-2 displayed better distribution after intravenous administration in mice and improved therapeutic effect against experimental M5076 metastases, as reported previously. In this study, the elimination of IL-2 from the dosing area was investigated when the liposomal IL-2 was administered to mice subcutaneously. The results suggest that the release of IL-2 from this liposome was continuous and almost complete. The mean residence time (MRT) of IL-2 in the dosing area was 11.0 +/- 1.65 hr. This resulted in the 8-fold times enhancement of MRT in the systemic circulation by the presence of liposomes, and IL-2 was detected in the serum for 2 days. Using this liposomal IL-2 is expected to have the potential to decrease the number of injections and enhance the efficacy of IL-2 in immunotherapies and therapies against tumor.

Sialyl Lewis X-carboxymethylpullulan conjugate: a novel homing device to spleen and lymph nodes.

We have previously found that carboxymethylpullulan (CMPul) conjugated with sialyl Lewis X (Neu5Acalpha2-3Galbeta1-4(Fucalpha1-3)GlcNAc-, 2-3SLex) preferentially accumulates in the lymph nodes and spleen. In the present study, we investigated the structural requirements of the 2-3SLex moiety for this accumulation using rats. Radiolabeled CMPul conjugates with various degrees of substitution (d.s.) of the 2-3SLex moiety were intravenously administered to rats, and their tissue distributions were monitored by radioactivity. When the d.s. was more than 0.5, preferential accumulation in the lymph nodes as well as the spleen was observed. However, when the d.s. was 0.025, little effect of the 2-3SLex moiety was noted. Changes in the carbohydrate structure of 2-3SLex, i.e., a change to alpha2-6-linked sialic acid (Neu5Acalpha2-6Galbeta1-4(Fucalpha1-3)GlcNAc-, 2-6SLex) or an elimination of the fucose (Neu5Acalpha2-3Galbeta1-4GlcNAc-, sialyl N-acethyllactosamine (SLN)), also made the 2-3SLex moiety ineffective. Furthermore, Microautoradiography analyses revealed that 2-3SLex-CMPul was incorporated by particular subsets of macrophages in these tissues, and that CMPul and SLN-CMPul were also located in the same cells to a lesser extent. 2-3SLex-CMPul may be able to serve as a novel drug delivery carrier to target drugs to the peripheral lymphoid tissues.

Oral delivery of antigens in liposomes with some lipid compositions modulates oral tolerance to the antigens.

Several liposomes containing ovalbumin (OVA), a model antigen, with different lipid compositions were prepared in order to evaluate their ability to induce oral tolerance. Oral administration of these liposomal OVAs induced suppression of the proliferative responses of popliteal lymph node cells from the treated mice to OVA, suggesting that these treated mice were tolerized. The efficiency of the induction of oral tolerance was affected by the liposome composition. OVA entrapment in these liposomes could modulate the tolerizing dose of OVA itself. These results suggest that some liposomes can be suitable antigen-delivery systems for modulated and/or effective induction of oral tolerance.