WorldCat Identities

Arfsten, Darryl P.

Works: 7 works in 7 publications in 1 language and 7 library holdings
Publication Timeline
Most widely held works by Darryl P Arfsten
Impact of 30-Day Oral Dosing With N-Acetyl-L-Cysteine on Sprague-Dawley Rat Physiology( )

1 edition published in 2004 in English and held by 0 WorldCat member libraries worldwide

A number of studies have demonstrated a protective effect associated with N-acetyl-L-cysteine (NAC) against toxic chemical exposure. However, the impact of long-term oral dosing on tssue pathology has not been determined. In this study, we assessed the impact of long-term oral NAC administration on organ histopathology and tissue glutathione (GSH) and total glutathione-S-transferase (GST) activity levels in Sprague-Dawley (SD) rats. Groups of 20 SD rats (10 male, 10 female), 8 weeks of age, were dosed daily by oral gavage with deionized H2O (negative controls) or NAC solution at a rate of 600 or 1,200 mglkgld for 30 days. Animals were euthanized 6 hours after treatment on study Day 30. There were no significant differences in final body weights or weekly average weight gain between treatment groups. Serum alanine aminotransferase (ALT) activities were significantly elevated (p less than or equal to 0.05) in NAC-treated animals compared to controls when measured on study Day 30. Histopathologic evaluation of the liver, stomach, small intestine, liver, kidneys, spleen, thymus, and lungs revealed no lesions associated with NAC administration. When measured on study Day 30, total GST acUvity for kidney and skin from NAC-treated animals were increased 39-131% as compared to controls. Tissue GSH concentrations from NAC-treated animals were increased 24-81% as compared with negative controls. Further studies are needed to determine if the observed increase in tissue GSH concentraion and GST activity provide a degree of chemoprotection against dermal and systemic chemical toxicants
Derivation of Exposure Duration-Specific Occupational Exposure Limits (OELS) for 4,6-Dimethyl-2-Heptanone (CAS 19549-80-5)( )

1 edition published in 2002 in English and held by 0 WorldCat member libraries worldwide

Occupational Exposure Limits (OELs) were calculated for 4,6-dimethyl-2-heptanone (CAS4 19549-80-5) using procedures established by the National Research Council (2001) for calculating Acute Exposure Guideline Levels. There were no appropriate toxicity data available for 4,6-dimethyl-2-heptanone to use in calculating OELs. 4,6-Dimethyl-2-heptanone is similar in chemical structure to 2-6-dimethyl-4-heptanone. The NOEL for 2-6-dimethyl-4-heptanone toxicity in rats of 125 ppm was used as a point of departure for estimating OELs for 4,6- dimethyl-2-heptanone. An total uncertainty factor of 300 was applied to the estimated NOEL to account for lack of toxicity information for 4,6-dimethyl-2-heptanone (UF1 = 10), uncertainty associated with extrapolating to humans from animal study data (UF2 = 10), and uncertainty of the existence of individuals within the population that may be very reactive to 4,6-dimethyl-2- heptanone exposure (UF3 = 3). The calculated OELs for 4,6-dimethyl-2-heptanone ranged from 1.8 ppm for a 5-minute exposure to 0.36 ppm for a 480-minute exposure
Derivation of Navy Occupational Exposure Limits (OELS) for Two Solvent Compounds: Vertrel MCA and HFE-71DE( )

1 edition published in 2003 in English and held by 0 WorldCat member libraries worldwide

Currently the US Navy uses the solvent HFC-141b to clean hydraulic gauges in a semi-closed system prior to gauge calibration. The US Navy will not be able to use the solvent HFC-141b after 31 December 2002 because of a ban on its manufacture. The Navy is considering both Vertrel MCA and HFE-71DE as replacements for HFC-141b. Both solvents are azeotropic mixtures consisting of trans 1,2-DCE and either fluorocarbons or ethers Both Vertrel MCA and HFE-71DE have high vapor pressures therefore they are expected to volatilize at room temperature. The potential routes of exposure to solvent during the gauge cleaning process are inhalation of vapors and dermal contact with liquid when pouring new and spent solvents into flasks and containers
Toxicological Risk Assessment of a Nickel Compound Found on the Surfaces of Replacement Hyperstretch Neoprene (CWU-83P) Neck and Wrist Seals for a Cold water Submersion Survival Suit( )

1 edition published in 2001 in English and held by 0 WorldCat member libraries worldwide

Naval Health Research Center/Toxicology was requested to provide comment and endorse an action plan developed by Naval Air Warfare Center Aeronautics Division (NAWCAD) to remove surface nickel from hyperstretch neoprene (CWU-83/P) neck and wrist seals used in cold water submersion survival suits. The nickel compound present on the surface of the seals is most likely nickeldialkyldithiocarbamate which is a common chemical additive used to prevent photoxidation and breakdown of rubber materials. There is no data on the chronic toxicity or carcinogenicity of nickeldialkyldithiocarbamates. The conservative approach for estimating the toxicological risk of nickeldialkyldithiocarbamate exposure to humans is to assume that these compounds have the same toxic properties as soluble nickel compounds. Lifetime average daily dose (LADD) estimates for persons wearing cold water survival suits were calculated using conservative exposure assumptions
Characterization of the Reproductive Toxicity of Depleted Uranium( )

1 edition published in 2005 in English and held by 0 WorldCat member libraries worldwide

The purpose of the proposed work is to determine the reproductive and developmental toxicity of depleted uranium (DU) ore in Sprague-Dawly rats. DU-tipped munitions have become common-place on the modern battlefield and recent experience has shown that minor injuries associated with DU munitions are becoming more common. Four hundred ninety-eight adult (P1) SD rats were implanted with up to 20, 1x2mm DU pellets and mated at 30 and 120 days post-implantation. Preliminary findings indicate no adverse effect associated with DU implantation on P1 reproductive success, or F1 and F2 offspring survival and development
Acute Toxicity Assessment of Break-Free CLP: A Weapons Cleaning and Maintenance Compound( )

1 edition published in 2003 in English and held by 0 WorldCat member libraries worldwide

Break-Free CLP(R) ("Break-Free CLP") is a commercial cleaning, lubricating, and preserving compound used in both the military and civilian sectors for maintenance of small and large caliber weapons. Break-Free CLP is a complex mixture made up of polyalphaolefin oil (65%), synthetic oils, esters and other synthetic proprietary ingredients (27%), isoparaffinic hydrocarbons (5%), and dibasic ester (3%). Like many commercial mixtures, there is very little information available on the toxicity of Break-Free CLP. Studies were conducted to characterize the biological effects of single or repeat dermal application of Break-Free CLP to the clipped backs of CD-1 mice
Characterization of the Ecotoxicity of Five Biodegredable Polymers Under Consideration by NAVAIR for Use in Chaff-Dispensing Systems( )

1 edition published in 2001 in English and held by 0 WorldCat member libraries worldwide

The accumulation of discarded chaff dispenser styrene piston and endcaps in the environment is a concern of the Department of Defense. Five biodegradable materials are being considered for use in the manufacture of degradable chaff cartridges pistons and endcaps. Relative degradability of the materials is being evaluated by measuring total organic carbon (TOC) released by the materials overtime in water. Environmental toxicity testing of the dissolution products from the materials is being conducted in 2 terrestrial plant species and 7 species of aquatic organisms. Dissolution products from 4 of the biopolymers were found to be toxic to aquatic organisms with LC50s and LOELs ranging between 1.24 - 731.30 mg TOC/1. The dissolution products did not inhibit seed germination of Brassica rappa or Lepidium sativum. Average shoot length of B. rappa seedlings treated with BAK2195/CP1000 (90:10) and BIPOL D411GN were 25-40% shorter as compared with negative controls (p < 0.05). Average shoot length of L. sativum seedings treated with BAK2195/CP1000 (90:10) were 10-20% shorter than controls (p < 0.05)). Information gained from these studies will be used making decisions on which (if any) of the polymers will be suitable for the construction of biodegradable chaff cartridges, pistons, and endcaps