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Unique obstacle race injuries at an extreme sports event: a case series.

Michael R. Greenberg, Ph.D. - 3 hours 48 min ago

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Unique obstacle race injuries at an extreme sports event: a case series.

Ann Emerg Med. 2014 Mar;63(3):361-6

Authors: Greenberg MR, Kim PH, Duprey RT, Jayant DA, Steinweg BH, Preiss BR, Barr GC

Abstract
Obstacle course endurance events are becoming more common. Appropriate preparedness for the volume and unique types of injury patterns, as well as the effect on public health these events may cause, has yet to be reported in emergency literature. We describe 5 patients who presented with diverse injuries to illustrate the variety of injuries sustained in this competitive event. In particular, 4 of the patients had a history of contact with electrical discharge, an obstacle distinctive to the Tough Mudder experience.

PMID: 24239287 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Exposure science: a need to focus on conducting scientific studies, rather than debating its concepts.

Paul J. Lioy, Ph.D. - 3 hours 48 min ago

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Exposure science: a need to focus on conducting scientific studies, rather than debating its concepts.

J Expo Sci Environ Epidemiol. 2013 Sep-Oct;23(5):455-6

Authors: Lioy PJ

PMID: 23963520 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Interconversion of chromium species during air sampling: effects of O3, NO2, SO2, particle matrices, temperature, and humidity.

Paul J. Lioy, Ph.D. - 3 hours 48 min ago

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Interconversion of chromium species during air sampling: effects of O3, NO2, SO2, particle matrices, temperature, and humidity.

Environ Sci Technol. 2013 May 7;47(9):4408-15

Authors: Huang L, Fan ZT, Yu CH, Hopke PK, Lioy PJ, Buckley BT, Lin L, Ma Y

Abstract
The interconversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) interconversion in the basic filter medium under typical sampling conditions. In the chamber tests, isotopically enriched (53)Cr(VI) and (50)Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were precollected on a basic MCE filter. The filter samples were then exposed to clean air or the air containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 h at 16.7 LPM flow rate at designated temperature (20 and 31 °C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on (53)Cr(VI) reduction, with (53)Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced (53)Cr(VI) reduction when exposed to clean air while reactive oxygen species in SOA could promote (50)Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) interconversion during sampling. Correction of the interconversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements.

PMID: 23550818 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Structural Changes in Hair Follicles and Sebaceous Glands of Hairless Mice Following Exposure to Sulfur Mustard.

Jeffrey D. Laskin, Ph.D. - 3 hours 48 min ago

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Structural Changes in Hair Follicles and Sebaceous Glands of Hairless Mice Following Exposure to Sulfur Mustard.

Exp Mol Pathol. 2014 Mar 21;

Authors: Joseph LB, Heck DE, Cervelli JA, Composto GM, Babin MC, Casillas RP, Sinko PJ, Gerecke DR, Laskin DL, Laskin JD

Abstract
Sulfur mustard (SM) is a bifunctional alkylating agent causing skin inflammation, edema and blistering. A hallmark of SM-induced toxicity is follicular and interfollicular epithelial damage. In the present studies we determined if SM-induced structural alterations in hair follicles and sebaceous glands were correlated with cell damage, inflammation and wound healing. The dorsal skin of hairless mice was treated with saturated SM vapor. One to seven days later, epithelial cell karyolysis within the hair root sheath, infundibulum and isthmus were apparent, along with reduced numbers of sebocytes. Increased numbers of utriculi, some with connections to the skin surface, and engorged dermal cysts were also evident. This was associated with marked changes in expression of markers of DNA damage (phospho-H2A.X), apoptosis (cleaved caspase-3), and wound healing (FGFR2 and galectin-3) throughout pilosebaceous units. Conversely, fatty acid synthase and galectin-3 were down-regulated in sebocytes after SM. Decreased numbers of hair follicles and increased numbers of inflammatory cells surrounding the utriculi and follicular cysts were noted within the wound 3-7days post SM exposure. Expression of phospho-H2A.X, cleaved caspase-3, FGFR2 and galectin-3 was decreased in dysplastic follicular epidermis. Fourteen days after SM, engorged follicular cysts which expressed galectin-3 were noted within hyperplastic epidermis. Galectin-3 was also expressed in basal keratinocytes and in the first few layers of suprabasal keratinocytes in neoepidermis formed during wound healing indicating that this lectin is important in the early stages of keratinocyte differentiation. These data indicate that hair follicles and sebaceous glands are targets for SM in the skin.

PMID: 24662110 [PubMed - as supplied by publisher]

Categories: Publications from UCDPER Members

Acetaminophen Reactive Intermediates Target Hepatic Thioredoxin Reductase.

Jeffrey D. Laskin, Ph.D. - 3 hours 48 min ago

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Acetaminophen Reactive Intermediates Target Hepatic Thioredoxin Reductase.

Chem Res Toxicol. 2014 Mar 24;

Authors: Jan YH, Heck DE, Dragomir AC, Gardner CR, Laskin DL, Laskin JD

Abstract
Acetaminophen (APAP) is metabolized in the liver to N-acetyl-p-benzoquinone imine (NAPQI), an electrophilic metabolite known to bind liver proteins resulting in hepatotoxicity. Mammalian thioredoxin reductase (TrxR) is a cellular antioxidant containing selenocysteine (Sec) in its C-terminal redox center, a highly accessible target for electrophilic modification. In the present studies, we determined if NAPQI targets TrxR. Hepatotoxicity induced by APAP treatment of mice (300 mg/kg, ip) was associated with a marked inhibition of both cytosolic TrxR1 and mitochondrial TrxR2 activity. Maximal inhibition was detected at 1 h and 6 h post APAP for TrxR1 and TrxR2, respectively. In purified rat liver TrxR1, enzyme inactivation was correlated with metabolic activation of APAP by cytochrome P450, indicating that enzyme inhibition was due to APAP reactive metabolites. NAPQI was also found to inhibit TrxR1. NADPH-reduced TrxR1 was significantly more sensitive to NAPQI (IC50 = 0.023 µM) than oxidized enzyme (IC50 = 1.0 µM), or a human TrxR1 Sec498Cys mutant enzyme (IC50 = 17 µM), indicating that cysteine and selenocysteine residues in the redox motifs of TrxR are critical for enzyme inactivation. This is supported by our findings that alkylation of reduced TrxR with biotin-conjugated iodoacetamide, which selectively reacts with selenol or thiol groups on proteins, was inhibited by NAPQI. LC-MS/MS analysis confirmed that NAPQI modified cysteine 59, cysteine 497 and selenocysteine 498 residues in the redox centers of TrxR, resulting in enzyme inhibition. In addition to disulfide reduction, TrxR is also known to mediate chemical redox cycling. We found that menadione redox cycling by TrxR was markedly less sensitive to NAPQI than disulfide reduction, suggesting that TrxR mediates these reactions via distinct mechanisms. These data demonstrate that APAP reactive metabolites target TrxR, suggesting an additional mechanism by which APAP induces oxidative stress and hepatotoxicity.

PMID: 24661219 [PubMed - as supplied by publisher]

Categories: Publications from UCDPER Members

The World Health Organization (WHO) Recommends Vaccine Composition for the 2011-2012 Northern Hemisphere Influenza Season

PandemicFlu.gov - 3 hours 49 min ago

The World Health Organization (WHO) Recommends Vaccine Composition for the 2011-2012 Northern Hemisphere Influenza Season

Categories: Government Agency News