Silicone passive sampling used to identify novel dermal chemical exposures of firefighters and assess PPE innovations.

A plethora of chemicals are released into the air during combustion events, including a class of compounds called polycyclic aromatic hydrocarbons (PAHs). PAHs have been implicated in increased risk of cancer and cardiovascular disease, both of which are disease endpoints of concern in structural firefighters. Current commercially available personal protective equipment (PPE) typically worn by structural firefighters during fire responses have gaps in interfaces between the ensemble elements (e.g., hood and jacket) that allow for ingress of contaminants and dermal exposure. This pilot study aims to use silicone passive sampling to assess improvements in dermal protection afforded by a novel configuration of PPE, which incorporates a one-piece liner to eliminate gaps in two critical interfaces between pieces of gear. The study compared protection against parent and alkylated PAHs between the one-piece liner PPE and the standard configuration of PPE with traditional firefighting jacket and pants. Mannequins (n = 16) dressed in the PPE ensembles were placed in a Fireground Exposure Simulator for 10 min, and exposed to smoke from a combusting couch. Silicone passive samplers were placed underneath PPE at vulnerable locations near interfaces in standard PPE, and in the chamber air, to measure PAHs and calculate the dermal protection provided by both types of PPE. Silicone passive sampling methodology and analyses using gas chromatography with mass-spectrometry proved to be well-suited for this intervention study, allowing for the calculation and comparison of worker protection factors for 51 detected PAHs. Paired comparisons of the two PPE configurations found greater sum 2-3 ring PAH exposure underneath the standard PPE than the intervention PPE at the neck and chest, and at the chest for 4-7 ring PAHs (respective p-values: 0.00113, 0.0145, and 0.0196). Mean worker protection factors of the intervention PPE were also greater than the standard PPE for 98% of PAHs at the neck and chest. Notably, the intervention PPE showed more than 30 times the protection compared to the standard PPE against two highly carcinogenic PAHs, dibenzo[a,l]pyrene and benzo[c]fluorene. Nine of the detected PAHs in this study have not been previously reported in fireground exposure studies, and 26 other chemicals (not PAHs) were detected using a large chemical screening method on a subset of the silicone samplers. Silicone passive sampling appears to be an effective means for measuring dermal exposure reduction to fireground smoke, providing evidence in this study that reducing gaps in PPE interfaces could be further pursued as an intervention to reduce dermal exposure to PAHs, among other chemicals.

T1-Weighted Dynamic Contrast-Enhanced MRI as a Noninvasive Biomarker of Epidermal Growth Factor Receptor vIII Status.

BACKGROUND AND PURPOSE: Epidermal growth factor receptor variant III is a common mutation in glioblastoma, found in approximately 25% of tumors. Epidermal growth factor receptor variant III may accelerate angiogenesis in malignant gliomas. We correlated T1-weighted dynamic contrast-enhanced MR imaging perfusion parameters with epidermal growth factor receptor variant III status. MATERIALS AND METHODS: Eighty-two consecutive patients with glioblastoma and known epidermal growth factor receptor variant III status who had dynamic contrast-enhanced MR imaging before surgery were evaluated. Volumes of interest were drawn around the entire enhancing tumor on contrast T1-weighted images and then were transferred onto coregistered dynamic contrast-enhanced MR imaging perfusion maps. Histogram analysis with normalization was performed to determine the relative mean, 75th percentile, and 90th percentile values for plasma volume and contrast transfer coefficient. A Wilcoxon rank sum test was applied to assess the relationship between baseline perfusion parameters and positive epidermal growth factor receptor variant III status. The receiver operating characteristic method was used to select the cutoffs of the dynamic contrast-enhanced MR imaging perfusion parameters. RESULTS: Increased relative plasma volume and increased relative contrast transfer coefficient parameters were both significantly associated with positive epidermal growth factor receptor variant III status. For epidermal growth factor receptor variant III-positive tumors, relative plasma volume mean was 9.3 and relative contrast transfer coefficient mean was 6.5; for epidermal growth factor receptor variant III-negative tumors, relative plasma volume mean was 3.6 and relative contrast transfer coefficient mean was 3.7 (relative plasma volume mean, P < .001, and relative contrast transfer coefficient mean, P = .008). The predictive powers of relative plasma volume histogram metrics outperformed those of the relative contrast transfer coefficient histogram metrics (P < = .004). CONCLUSIONS: Dynamic contrast-enhanced MR imaging shows greater perfusion and leakiness in epidermal growth factor receptor variant III-positive glioblastomas than in epidermal growth factor receptor variant III-negative glioblastomas, consistent with the known effect of epidermal growth factor receptor variant III on angiogenesis. Quantitative evaluation of dynamic contrast-enhanced MR imaging may be useful as a noninvasive tool for correlating epidermal growth factor receptor variant III expression and related tumor neoangiogenesis. This potential may have implications for monitoring response to epidermal growth factor receptor variant III-targeted therapies.

Drug usage evaluation: clarithromycin as sequential therapy.

A drug usage evaluation (DUE) of the new macrolide antibiotic clarithromycin was conducted at Christ Hospital and Medical Center, an 824-bed community teaching hospital in Oak Lawn, Illinois. The purpose of this DUE was to determine whether clarithromycin was being used as early sequential therapy following other parenteral antimicrobials as recommended by the Pharmacy and Therapeutics Committee.