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Featured researches published by John W. Soper.


Journal of Forensic Sciences | 2004

DISTRIBUTION AND OPTICAL PURITY OF METHAMPHETAMINE FOUND IN TOXIC CONCENTRATION IN A CIVIL AVIATION ACCIDENT PILOT FATALITY

Arvind K. Chaturvedi; Patrick S. Cardona; John W. Soper; Dennis V. Canfield

Toxicological evaluation of postmortem samples collected from a pilot involved in a unique fatal civil aircraft accident is described in this paper. A one-occupant airplane was substantially damaged upon colliding with terrain in poor visibility. Remains of the pilot were found outside the aircraft. Pathological examination revealed multiple blunt force injuries and vascular congestion. The fluorescence polarization immunoassay disclosed 8.0 microg/mL amphetamines in urine. Gas chromatographic/mass spectrometric analyses determined the presence of methamphetamine (1.13 microg/mL in blood and 59.2 microg/mL in urine) and amphetamine (0.022 microg/mL in blood and 1.50 microg/mL in urine). Methamphetamine was distributed throughout the body, including the brain. The amount of methamphetamine in gastric contents was 575-fold higher than that of amphetamine. The (+)- and (-)-forms of methamphetamine were present in equal proportions in gastric contents. The methamphetamine concentration found in blood was in the range sufficient to produce toxic effects, causing performance impairment.


Journal of Analytical Toxicology | 2013

Effects of fluid load on human urine characteristics related to workplace drug testing.

Arvind K. Chaturvedi; Jim L. Sershon; Kristi J. Craft; Patrick S. Cardona; John W. Soper; Dennis V. Canfield; Kurt M. Dubowski; James E. Whinnery; Misti J. Leyva; Christopher E. Aston; Steve M. Blevins; Jonelle E. Wright; Albert D. Fraser; David J. Kuntz

During workplace drug testing, urine is tested for dilution, substitution and adulteration. Donors argue that these findings are due to medical, health or working conditions or diet and genetic differences. There is a paucity of data correlating changes in urine characteristics after a fluid load to various body parameters. Therefore, five urine specimens (one in the morning, one prior to drinking 800 mL of a beverage, and three time intervals thereafter) from 12 males and 12 females were tested for four different beverages on separate occasions. Of the 480 samples, 376 were in sufficient amounts. Of these 376, 36 (10%) had creatinine <20 mg/dL but ≥2 mg/dL; 27 (75%) of 36 had specific gravity <1.0030 but >1.0010. Thus, these 27 samples can be considered to be dilute; 20 (74%) of 27 were from females. For males with at least one dilute sample, body fat was 11% less and resting metabolic rate (RMR) was 29% more than males with no dilute samples (p > 0.05); for females with at least one dilute sample, height was 8% less and weight 20% less than females with no dilute samples (p > 0.05). Individuals with a higher RMR appear to have a greater potential for producing dilute urine specimens than those with a lower RMR. Thus, a dilute sample does not necessarily indicate that it was intentionally diluted. Such samples must be carefully evaluated in consideration with recent consumption of liquid by donors to avoid false accusations.


Aviation, Space, and Environmental Medicine | 2013

Toxicological findings in fatally injured pilots of 979 amateur-built aircraft accidents.

Arvind K. Chaturvedi; Kristi J. Craft; Jeffery S. Hickerson; Paul B. Rogers; John W. Soper

BACKGROUND Specimens from aviation accident pilot fatalities are submitted to the Civil Aerospace Medical Institute (CAMI) for toxicological analyses. Trends of fatal amateur-built aircraft accidents and toxicological findings in the associated pilot fatalities have not been examined. METHODS Fatal amateur-built aircraft accidents that occurred during 1990-2009 were evaluated by retrieving information from the CAMI toxicology database. Probable cause/factor in the amateur-built aircraft mishaps were obtained from the National Transportation Safety Boards (NTSBs) aviation accident database. RESULTS Of 6309 fatal aviation accidents from which CAMI received postmortem samples, 979 (16%) were related to amateur-built aircraft. There was a decreasing trend in non-amateur-built aircraft accidents, but an increasing trend in amateur-built aircraft accidents. In the 979 accidents, 392 pilots (40%) were positive for ethanol and/or drugs. In these 392 accidents also, the review showed a decreasing trend with non-amateur-built aircraft and an increasing trend with amateur-built aircraft. Percentages of pilots with prescription drugs were 26% for amateur-built aircraft, 16% for non-amateur-built aircraft, and 18% for all aircraft. Ethanol/drug use and medical condition were determined to be a cause/factor in 42 (11%) of the 385 ethanol/ drug-positive amateur-built aircraft accidents investigated by the NTSB. DISCUSSION Drugs found in the pilots were consistent with commonly used medications in the general population. The contributory role of mechanical malfunction of home-built aircraft cannot be ruled out in the observed increasing trends in their accidents, with or without ethanol and/or drugs. Regardless, the increasing trends of such accidents are of significant concern.


Forensic Science International | 2006

Simultaneous analyses of cocaine, cocaethylene, and their possible metabolic and pyrolytic products.

Patrick S. Cardona; Arvind K. Chaturvedi; John W. Soper; Dennis V. Canfield


Aviation, Space, and Environmental Medicine | 2002

Characteristics and toxicological processing of postmortem pilot specimens* from fatal civil aviation accidents.

Arvind K. Chaturvedi; Dudley R. Smith; John W. Soper; Dennis V. Canfield; James E. Whinnery


Aviation, Space, and Environmental Medicine | 1999

Prevalence of Chlorpheniramine in Aviation Accident Pilot Fatalities, 1991-1996.

John W. Soper; Arvind K. Chaturvedi; Dennis V. Canfield


Archive | 2000

DNA-BASED DETECTION OF ETHANOL-PRODUCING MICROORGANISMS IN POSTMORTEM BLOOD AND TISSUES BY POLYMERASE CHAIN REACTION

Nicole T. Vu; Arvind K. Chaturvedi; Dennis V. Canfield; John W. Soper; Doris M. Kupfer; Bruce A. Roe


Archive | 2013

1 Urine Drug Testing of Chronic Pain Patients. V. Prevalence of Propoxyphene Following its Withdrawal from

Brandi Puet; Anne Z. DePriest; Julie Knight; Rebecca Heltsley; David L. Black; Yale H. Caplan; Edward J. Cone; Arvind K. Chaturvedi; Jim L. Sershon; Kristi J. Craft; Patrick S. Cardona; John W. Soper; Dennis V. Canfield; Kurt M. Dubowski; James E. Whinnery; Misti J. Leyva; Christopher E. Aston; Steve M. Blevins; Jonelle E. Wright; Albert D. Fraser; David J. Kuntz; David A. Gorelick; Robert S. Goodwin; Eugene W. Schwilke; David M. Schwope; William D. Darwin; Deanna L. Kelly; Robert P. McMahon; Fang Liu; Catherine Ortemann-Renon


Archive | 2003

SIMULTANEOUS DETERMINATION OF COCAINE, COCAETHYLENE, AND THEIR POSSIBLE PENTAFLUOROPROPYLATED METABOLITES AND PYROLYSIS PRODUCTS BY GAS CHROMATOGRAPHY/MASS SPECTROMETRY

Patrick S. Cardona; Arvind K. Chaturvedi; John W. Soper; Dennis V. Canfield


Archive | 1996

Aviation accident forensic assessment : comprehensive single-extraction urine screening procedure : final report.

Dennis V. Canfield; Vicky White; John W. Soper; Thomas C. Kupiec

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Arvind K. Chaturvedi

United States Department of Transportation

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Dennis V. Canfield

United States Department of Transportation

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Patrick S. Cardona

United States Department of Transportation

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Kristi J. Craft

United States Department of Transportation

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David J. Kuntz

North Dakota State University

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Jim L. Sershon

United States Department of Transportation

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Kurt M. Dubowski

University of Oklahoma Health Sciences Center

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Misti J. Leyva

University of Oklahoma Health Sciences Center

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