Feasibility of exercise treadmill N-ammonia positron emission tomography myocardial perfusion imaging using an off-site cyclotron.

Background: Myocardial perfusion imaging with treadmill exercise nitrogen-13 (N)-ammonia positron emission tomography (PET) presents a logistical challenge. We investigated the feasibility of exercise treadmill (GXT) N-ammonia PET MPI using an off-site cyclotron for production of N-ammonia.

Methods: Thirty-three patients underwent GXT N-ammonia PET MPI over 23 months.

Comparison of fetotoxic effects of a dermally applied complex organic mixture in rats and mice.

A high-boiling (288-454 degrees C), coal-derived complex organic mixture (COM) has been shown to be teratogenic in rats following inhalation and oral routes of exposure. To determine whether similar changes also occur after dermal exposure to this COM, pregnant rats and mice were exposed during periods of organogenesis (Days 11 to 15 of gestation). Shaved backs were painted with 0, 500, or 1500 mg/kg of the COM (control, low, or high dose, respectively); the exposed area was not occluded.

Elevated blood pressure and heart rate in rats exposed to a coal-derived complex organic mixture.

The susceptibility of the cardiovascular system to exposure to a high-boiling coal liquid (heavy distillate, HD) was studied in the rat using an isoproterenol (ISO) myocardial infarction model. Male Fischer rats were exposed to HD by inhalation (0.7 mg/l), 6 h/day, 5 days/week, for 6 weeks.

Influences of complex organic mixtures on tumor-initiating activity, DNA binding and adducts of benzo[a]pyrene.

Co-incubation of benzo[a]pyrene (BaP) and coal-derived complex organic mixtures has been shown to decrease the metabolism and mutagenic activity of BaP. Because of these influences, five mixtures were co-administered dermally to mice to initiate tumor development. Results from these studies demonstrated that BaP tumor-initiating activity was decreased substantially by four of the five mixtures.

Cardiovascular effects in rats following exposure to a high-boiling coal liquid.

In previous work, increased blood pressure was observed in anesthetized rats following a subchronic aerosol exposure to solvent-refined coal heavy distillate (HD). To determine if this increase is a permanent, dose-related response, 11-week-old male rats were exposed by inhalation to 0, 0.24, or 0.

Phenotypically selective promotion of diethylnitrosamine-initiated altered hepatocyte foci by dietary phenobarbital or a topically applied coal-derived organic mixture in male and female rats.

Relative frequencies of diethylnitrosamine (DEN)-initiated foci of altered hepatocytes appearing in response to promotion by either dietary phenobarbital or a topically applied coal-derived organic mixture (CDM) were investigated in male and female rats. The focus population was examined for two histochemical markers, elevated gamma-glutamyl transpeptidase [GG(+)] and iron exclusion [FE(-)], giving rise to 3 detectable focus phenotypes, i.e.

Effects of subchronic inhalation exposure of mice to a high-boiling coal liquid.

Mice (CD-1) were exposed to aerosol concentrations of 0.0, 0.03, 0.

Influence of pregnancy and lactation on maternal deposition and perinatal uptake of 241Am in the rat.

To investigate the metabolism of 241Am as affected by pregnancy and lactation, female rats were injected with 5 muCi of 241Am intravenously while nulliparous, pregnant or lactating. The females and subsequent litters were killed at various times after injection to determine 241Am distribution and retention. The temporal relationship between injection and pregnancy influenced the tissue retention of 241Am in both dams and progeny.

Effects of inhalation exposure to a high-boiling (288 to 454 degrees C) coal liquid.

Coal liquids have been evaluated in a variety of short-term toxicological assays; however, few studies have been conducted to determine the systemic effects after inhalation exposure to these materials. To extend the data base on potential health effects from coal liquefaction materials, we performed a study with solvent refined coal (SRC)-II heavy distillate (HD). Fischer-344 rats were exposed for 6 hr/day, 5 days/week for 5 or 13 weeks to an aerosol of HD (boiling range, 288 to 454 degrees C) at concentrations of 0.

Promotion of preneoplastic changes in liver by coal-derived organic mixtures applied to skin.

The promotion of preneoplastic hepatocyte foci was observed in rats neonatally initiated by a single intraperitoneal injection of benzo[a]pyrene (BP) or diethylnitrosamine (DEN) and exposed, from weaning, to repeated topical applications of coal-derived complex organic mixtures that are carcinogenic for mouse skin. Topical application of these mixtures in the absence of prior initiation did not cause significant induction of hepatocyte foci. These observations indicate the advantage of the neonatal rat hepatocarcinogenesis system for detecting promoting activity in carcinogenic mixtures and identify the existence of systemic tumorigenic risk from cutaneous contact with promoting agents.

Comparative chemical and biological analysis of coal tar-based therapeutic agents to other coal-derived materials.

In this study, methodologies developed for the analysis of synthetic fuel products were applied to the coal tar fractions isolated from coal tar-based pharmaceutical products. A pharmaceutical stock solution of 20% coal tar in alcohol, a 50% coal tar bath emulsion and a 4.3% coal tar shampoo were studied.

Variation of composition with particle size in coal liquid aerosols generated for inhalation toxicology studies.

The chemical composition and microbial mutagenicity of aerosols generated by nebulizing two coal oils (solvent refined coal [SRC]-I process solvent [PS] and SRC-II heavy distillate) were found to vary with particle size. Significant quantities of the most volatile components of PS were also present as vapors. Evaporation and condensation processes in oil deposited on surfaces as well as in the aerosol are believed to be important in determining the observed composition changes.

Fractionation of skin tumor-initiating activity in coal liquids.

Narrow temperature range distillates from biologically active solvent refined coal-I and -II heavy-end coal liquids were fractionated according to chemical class and assayed for initiation of skin carcinogenesis in CD-1 mice. In addition, instrumental chemical analyses were performed on the distillates and their chemical fractions. Results showed that initiation activity in these complex fuel mixtures could be segregated both by boiling point and chemical class.

Mutagenic and carcinogenic activity of a hydrotreated coal liquid.

A fuel-oil blend (FOB) and its hydrotreated product from the solvent-refined coal (SRC) II process were evaluated for their mutagenic and carcinogenic potential. The FOB was highly active in both cellular assays, as well as in animal (skin-painting) studies. Cell-transforming and mutagenic activities of hydrotreated FOB were consistently found to be lower than for untreated FOB.

Skin-tumor initiation activity of coal liquids with different boiling-point ranges.

High-boiling coal liquids from the solvent-refined coal-I and -II (SRC-I, -II) processes, respectively, were fractionally distilled. In the case of SRC-I process solvent (PS), 50 degrees F distillation cuts were obtained between 550 and 850 degrees F, while for the SRC-II material, the 50 degrees F cuts were only obtained between 700 and 850 degrees F. These cuts, as well as the parent material, were tested for their ability to initiate skin tumors by applying a single dose (25 mg) to the shaved backs of Charles River female CD-1 mice.

239Pu metabolism in newborn and weanling pigs.

Newborn (1-2 days old) and weanling (6 wk old) miniature pigs were injected intravenously with 239Pu citrate. Animals from each age group were killed at intervals over a 28-day period to obtain distribution and retention data. The most notable difference between the two age groups was in hepatic deposition and retention.

Pulmonary toxicity of inhaled coal liquid aerosols (boiling range 230-450 degrees C).

The biological activity of materials produced in the direct liquefaction of coal is being assessed by a variety of test systems. In this study, the pulmonary toxicity of process solvent (PS) from the solvent refined coal-I (SRC-I) process was determined by histamine aerosol challenge tests and pulmonary function and morphologic evaluations. Guinea pigs inhaled aerosols of PS (boiling range, 230 to 450 degrees C) for 6 hr/day, 5 day/week, for up to 12 days in three different experiments.

Initiation/promotion studies with coal-derived liquids.

Fractions derived from solvent-refined coal-II (SRC-II) heavy distillate (HD) were tested for their skin tumor initiating activity. Basic (BF), basic tar (BTF), neutral tar (NTF) and polynuclear aromatic (PNA) fractions were prepared from HD by solvent extraction. These fractions were tested for their initiating activities by applying a single dose to the shaved back of male, CD-1 mice (Charles River, Portage, MI).

Ornithine decarboxylase induction by chemically complex liquids from two solvent refined coal processes.

Studies with a variety of chemically purified substances have suggested that induction of the enzyme ornithine decarboxylase (ODC) in mouse epidermal cells may be a reliable indicator of neoplastic transformation. In an effort to extend these observations on ODC to chemically complex materials, we examined ODC induction by carcinogenic and non-carcinogenic mixtures and compared these results with tumorigenicity data for these materials. For these studies several boiling range fractions and several solvent-derived subfractions from two solvent-refined coal processes (SRC-I and SRC-II) were evaluated for their ability to induce ODC.

Teratogenicity following inhalation exposure of rats to a high-boiling coal liquid.

On days 12-16 of gestation pregnant rats were exposed to heavy distillate (HD), the highest-boiling material derived from the solvent refined coal-II (SRC-II) process, and the litters were examined at day 21. Adverse biological effects were observed in the group of animals exposed to an aerosol concentration of 0.66 mg 1-1 [1.

Biomagnetic effects: a consideration in fusion reactor development.

Fusion reactors will utilize powerful magnetic fields for the confinement and heating of plasma and for the diversion of impurities. Large dipole fields generated by the plasma current and the divertor and transformer coils will radiate outward for several hundred meters, resulting in magnetic fields up to 450 gauss in working areas. Since occupational personnel could be exposed to substantial magnetic fields in a fusion power plant, an attempt has been made to assess the possible biological and health consequences of such exposure, using the existing literature.