Animal vital statistics are shown in Table 1. An N of 17 sham and 13 PMMTM-exposed animals were used for the intravital preparation, and an N of 11 sham and 8 PMMTM-exposed animals were used for the isolated arteriole preparation (Table 1). All animal procedures were approved by the WVU Institutional Animal Care and Use Committee. Air was sampled at two sites within 1 mile of an active see more MTM site (Sundial, WV, USA). PM was collected on 35 mm 5 μm pore

size PTFE fiber-backed filters (Whatman, Springfield Mill, UK, Figure 1A) for 2–4 weeks. Air flow rate across the filters averaged 12 L/min. Following collection, the filters were stored at room temperature (20–25°C) and ambient humidity (10–30%) in the dark for 0.5–1 year prior to extraction. PM (Figure 1B) was removed from the filters by gentle agitation in 15 mL of ultrapure water (Cayman Chemical, Ann Arbor, MI, USA) in a glass jar for 96 hours. Storage and extraction of the particles from the filters are consistent with previously reported methods [14]. Aliquots of the particle suspension were dried down in 2 mL cryovials for 18 hours in a Speedvac (Savant, Midland, MI, USA). Total particle weight was determined by a microbalance (Metler-Toledo, Columbus,

OH, USA). Elemental concentration in atomic weight (ppm) was obtained from individual particles with a SEM (JEOL LTD., Tokyo, Japan) coupled with EDX technology (Oxford Instruments, Oxfordshire, UK). A filter sample (˜2 cm2) was obtained from a PTFE filter and mounted with double-sided DAPT mouse adhesive copper tape on a brass (Cu and Zn) specimen stub. Approximately four to five samples per selleck inhibitor filter and 20–25 individual particles per sample were randomly chosen for a total analysis of 100 particles per filter using the Spot & ID EDX Analysis Mode. An accelerating voltage of 20 kV was used and the working distance was set to 15 mm with a 120 seconds live time for X-ray acquisition. Particles 0.5–20 μm were analyzed and a quant optimization was performed on Cu. Analyses were performed on the PMMTM by a commercial laboratory (RTI International,

RTP, NC, USA). Briefly, pre-weighed PMMTM was resuspended into 5 mL of methanol and vortexed. The sample was then split into two equal volume aliquots for ICP-AES and IC analysis. ICP-AES analysis was performed via EPA method 3060C on material extracted using EPA method 3052. Sulfate IC analysis was performed by EPA method 300.0 with modifications for use on the Dionex ICS-3000 (Thermo Scientific, Sunnyvale, CA, USA) with eluent generation [44]. Standard reference material 1648a (St. Louis, MO, US Urban PM; NIST, Gaithersburg, MD, USA) was used as a quality control. The following metals and compounds were determined: Al, Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, Sn, Ti, V, Zn, and SO4. Elements not appearing in Table 2 were below detectable limits.