S84 Abstracts / Toxicology Letters 196S (2010) S37–S351 P105-014 Beclin1 is responsible for induction of autophagy through controlling radiation-induced osteopontin in human lung cancer cells S.H. Chang 1 , A. Minai-Tehrani 2 , H.T. Lim 1 , J.Y. Shin 2 , S.J. Park 2 , J.E. Kim 1 , H.J. Sung 3 , C.O. Yun 4 , K.H. Lee 5 , G.R.J. Beck 6 , M.H. Cho 7 1 Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University & Nano Systems Institute-National Core Research Center, 2 Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, 3 Institute of Fusion Technology, Hoseo University, 4 Institute for Cancer Research, Yonsei University School of Medicine, 5 Laboratory of Radiation Molecular Oncology, Korea Institute of Radiological & Medical Sciences, 6 Division of Endocrinology, Metabolism and Lipids, Emory University School of Medicine, 7 Laboratory of Toxicology, College of Veterinary Medicine & Nano Systems Institute-National Core Research Center & Graduate School of Convergence Science, Seoul National University The purpose of this study was to investigate the potential role of the secreted protein osteopontin (OPN) in gamma-radiation induced autophagy of human lung cancer cells. OPN is a metastasis gene which contributes to stress-dependent angiogenesis. We observed that gamma-ray induce OPN expression in human lung cancer cell (A549) when p53 is presence. In this study, OPN counteracts Beclin1 (BECN1) protein expression. Exogenous hTERT-BECN1 induces the tumor-specific autophagy and inhibits the cancer cell growth following radiation and suppressed OPN by BECN1 decreases angio- genesis. These results suggest that BECN1 may be a good gene for conquest tolerance after irradiation. This work was supported by grant from the (NRL #20090078641) of the Ministry of Education, Science and Technology in Korea. doi:10.1016/j.toxlet.2010.03.308 P105-015 Fatal intoxications by sudden hydrogen sulfide emission in unconfined spaces S. Nogue 1 , R. Pou 2 , J. Fernandez 3 , P. Sanz 1 1 Hospital Clinic, 2 SGS-Tecnos, 3 Laboratorio de Análisis Dr.Echevarne Hydrogen sulfide (H 2 S) is a gas that is easily produced when three conditions coincide: (a) presence of sulfates and sulfate-reducing bacteria. (b) Anaerobic conditions. (c) Temperatures >20 ◦ C. These conditions are very common during the summer in drains, latrines, septic tanks, sewers, and deposits of dung and other decomposing organic matter. The most common cases of intoxication occur when someone enters a confined space in which the gas has accumulated over time due to lack of air exchange. Severe or fatal hydrogen sulfide intoxications are very uncom- mon in locations that lack the four characteristics of confined spaces: (a) difficulties in entering and exiting the space. (b) Lack of natural ventilation. (c) Normally without human presence. (d) Pos- sibility of accumulation of toxic, inflammable or oxygen-displacing gases. We present the investigation of two fatal accidents in uncon- fined spaces. The first accident occurred when three workers were carrying out pre-inauguration checks in a wastewater pumping substation, a few days before coming on line. The three suddenly lost conscious- ness when they entered the substation. Although they were rapidly transferred to the intensive care unit of the nearest hospital, one worker died, while the other two recovered completely without sequelae one week after the accident. Hydrogen sulfide production was due to an “embolism effect” produced by the displacement of wastewater when the substation pumps were activated. The second accident caused the death of three workers who entered an unconfined room containing a silo of sludge at the same time that a truck dumped several tons of sludge from water purifi- cation stations. The hydrogen sulfide that had accumulated inside the silo spilled out into the interior of the room due to a “splashing or bubbling effect” caused by the impact of the dumped sludge. Intoxications due to hydrogen sulfide may occur in unconfined spaces. doi:10.1016/j.toxlet.2010.03.309 P105-016 The effect of chemotherapy on oxidant and antioxidant parameters in bone marrow transplantation patients S. Sabuncuoglu 1 , H. Ozgunes 2 , D. Uckan Cetinkaya 2 1 Hacettepe University, Faculty of Pharmacy, Department of Toxicology, Turkey, 2 Hacettepe University, Faculty of Medicine, Department of Pediatrics, Turkey In patients undergoing bone marrow transplantation (BMT), high dose chemotherapy results in decreased free radical formation and depletion of plasma and tissue antioxidants. In the present study, we investigated blood MDA, reduced and oxidized glutathione levels as oxidative stress parameters. We also determined the antioxidant vitamin levels (á-tocopherol, â-caroten). In this study, blood from 18 patients receiving BMT was collected before preper- ative regimen (10 days before transplantation, day -10), before transplantation (day 0) and after transplantation (days 7, 14 and 28). The samples were collected from Bone Marrow Transplan- tation Unit, Hacettepe University, Ankara, Turkey. Our findings support that high-dose chemotherapy results in oxidative stress and depletion of antioxidants. doi:10.1016/j.toxlet.2010.03.310 P105-017 Therapeutic effects of sodium bicarbonate in organophosphate poisoning in man is pH dependent: A randomized clinical trial R. Afshari, M. Mohammadi, M. Balali-Mood Mashhad University of Medical Sciences, Iran Introduction: Organophosphate (OP) pesticides are widely used across the globe. Intentional and accidental overdoses with OPs are common in this country [1]. High doses of sodium bicarbonate have shown to be effective in OP poisoning in man [2,3]. This study aimed at comparing the therapeutic effects of sodium bicarbonate with lower doses with or without adding magnesium sulphate on organophosphate poisoning. Methods: All subjects with alleged OP poisoning (excluding mild cases) were studied prospectively from May 2008 to September 2009. Ethics approval was obtained (MUMS-84386). These subjects were randomly allocated into 4 groups: 1. Low dose sodium bicar- bonate (S). 2. Low dose magnesium sulphate (M). 3. Both (B) and 4. none (N). All cases received fluids and atropine as well as diazepam if needed.