Synthesis, anti-ferroptosis, anti-quorum sensing, antibacterial and DNA interaction studies of chromene-hydrazone derivatives.

Nineteen chromene-hydrazone derivatives containing a variety of structural modifications on the hydrazone moiety were synthesized. Structure-activity correlations were investigated to determine the influence of structural variations on anti-ferroptosis, anti-quorum sensing, antibacterial, DNA cleavage and DNA binding properties. Ferroptosis inhibitory activity was determined by measuring the ability of the derivatives to reverse erastin-induced ferroptosis.

Chronic inhalation of short asbestos: lung fiber burdens and histopathology for monkeys maintained for 11.5 years after exposure.

In an earlier report, Platek et al. (1985) presented the results of an 18-month inhalation exposure of rats and monkeys to short chrysotile asbestos. The mean chamber exposure level was 1.

Fibrogenic potentials of coal slags used as abrasive blasting substitutes.

This study was designed to examine the fibrogenic potentials of four coal slags that are being used as substitutes for silica sand in abrasive blasting. Six groups of 100 male Sprague-Dawley rats, including four coal slag groups, a vehicle control, and a positive control for fibrosis (Minusil quartz), were used. Each dust treatment group was given a single 40-mg dose of test agent via intratracheal instillation.

Biological monitoring for occupational exposures to o-toluidine and aniline.

Epidemiological evidence that occupational exposure to o-toluidine and aniline is associated with an increased risk of bladder cancer led to efforts to identify biomarkers of workplace exposures to these aromatic amines. For the determination of o-toluidine and aniline in worker urine specimens, a method using high performance liquid chromatography (HPLC) followed by electrochemical detection was developed. The limits of detection were 0.

Lung particulate burdens of subjects from the Cincinnati, Ohio urban area.

Because of the relatively small data base existing for lung particulate burdens of subjects with no overt pneumoconioses, the total exogenous lung particulate concentrations of 91 subjects from the Cincinnati, Ohio urban area were determined using an automated scanning electron microscope-energy dispersive x-ray analysis-image analysis system. Four of these subjects were foundry workers and had the highest exogenous particle concentrations seen in the 91 lungs, ranging from 1860 to 2990 x 10(6) particles per gram of dry lung (ppg). The average exogenous particle concentration for the remaining 87 subjects was 476 +/- 380 x 10(6) ppg with a range of 71 to 1860 x 10(6) ppg.

Quantitative analysis of particulate burden in lung tissue.

Numerous methods have been used in the preparation and analysis of the particulate matter deposited in human lungs. Preparation techniques include those for particle isolation and for in situ analysis. Analytical techniques include bulk and particle-by-particle analysis.

Fibrogenicity and carcinogenic potential of smelter slags used as abrasive blasting substitutes.

This study was designed to examine the fibrogenic and carcinogenic potentials of three smelter slags (primary copper slag, secondary copper slag, and nickel slag) that have been used for a number of years as substitutes for sand in abrasive blasting operations. Seven groups of 85 male Fischer 344 rats (approximately 180 g) were used. Each group was given a single 20-mg dose of one of the following test materials via intratracheal instillation: primary copper slag, secondary copper slag, nickel slag, feldspar, Min-U-Sil, novaculite, or vehicle control.

Carcinogenic effects of antimony trioxide and antimony ore concentrate in rats.

This study was initiated because of a suspected increase in incidence of lung cancer in antimony smelter workers in England. Three groups of 8-mo-old Wistar-derived rats (90 males and 90 females per group) were exposed by inhalation to either Sb2O3 [time-weighted average (TWA) 45 mg/m3], Sb ore concentrate (TWA 36 + 40 mg/m3), or filtered air (controls) for 7 h/d, 5 d/wk, for up to 52 wk and sacrificed 20 wk after terminating exposures. Serial sacrifices (5 rats/sex/group) were performed at 6, 9, and 12 mo.

Chronic inhalation of short asbestos fibers.

An animal inhalation study was initiated to study the chronic biological effects of inhalation of short chrysotile asbestos fibers. Rats and monkeys were exposed for 18 months, 7 hr/day, 5 days/week to a specially prepared, chrysotile asbestos aerosol. Based upon daily chamber measurements, the mean concentration of fibers in the chamber air was 1.

A striking deposition of mineral particles in the lungs of a farmer: a case report.

The object of this study was to analyze mineral particles in lung tissue from a farmer who underwent lobectomy due to a lung tumor and relate these analytical findings to occupational exposure and histopathological and clinical diagnoses. Despite no clear evidence of previous occupational dust exposure, heavy deposits of birefringent particles and slight pulmonary fibrosis were found during histopathological examination. Extracts from the lung tissue were analyzed by electron microscopy and X-ray microanalysis for mineral particles.

Comparative in vitro cytotoxicity of volcanic ashes from Mount St. Helens, El Chichon, and Galunggung.

Dry sedimented volcanic ash samples from each of three widely separated volcanoes of the "Circum Pacific" region have been subjected to mineralogic analysis and in vitro tests for cytotoxicity. The ash samples from the three different volcanoes varied in particle size, surface area, and concentration of silica. Total crystalline silica in the respirable fraction of ashes was 1.

Mount St. Helens' volcanic ash: hemolytic activity.

Volcanic ash samples from four Mount St. Helens' volcanic eruptions were subjected to mineralogical, analytical, and hemolytic studies in order to evaluate their potential for cytotoxicity and fibrogenicity. Plagioclase minerals constituted the major component of the ash with free crystalline silica concentrations ranging from 1.

Automated characterization of particles extracted from human lungs: three cases of tungsten carbide exposure.

An automated scanning electron microscope-energy dispersive x-ray analysis-image analysis system was used to characterize particles extracted from three human lung samples which had suspected occupationally-induced lung disease. The particles were isolated from the lung tissues by low temperature ashing and deposited on Nuclepore filters. Particles in randomly selected fields of view for each filter were automatically sized, analyzed for 32 elements, and classified according to their chemistry by the system.

Pneumoconiosis in animals exposed to poly(vinyl chloride) dust.

Rats, guinea pigs and monkeys were exposed by inhalation (6 hr/day, 5 days/week) for up to 22 months to a 13 mg/m3 concentration of PVC dust. Autopsies on rats and guinea pigs were performed after 12 months of exposure and on monkeys after 22 months after 22 months of exposure. Lung function tests were performed on monkeys after 9, 14 and 22 months of exposure.

Fibrogenic potential of slags used as substitutes for sand in abrasive blasting operations.

The fibrogenic potentials of coal and copper slags used as substitutes for silica sand in abrasive blasting operations were assessed in rats. The test animals were given a single pulmonary intralobar instillation of 20 mg of test material and were sacrificed 10 months after dosing. Pulmonary fibrosis was seen in the coal slag-treated rats while no fibrosis was seen in the copper slag-treated animals.

Identification of stainless steel welding fume particulates in human lung and environmental samples using electron probe microanalysis.

Open lung biopsy specimens from two welders and air samples from their workplace environments were examined with the electron probe microanalyzer. X-ray analysis showed that the majority of particles found in the lung tissue from both workers and in the air samples to be composed of varying amounts of iron, chromium, manganese and nickel, the major components of some types of stainless steel. Based upon these analyses, it was concluded that the majority of the particles in both biopsy specimens were a result of the workplace environment.

The porosity of amosite and chrysotile asbestos.

A computer program has been set up in Fortran language to calculate pore size distribution using the Cranston-Inkley method of calculation. Nitrogen adsorption isotherms were determined on amosite and chrysotile asbestos at - 195 degrees C. Size reduction had a major effect on increasing pore volumes of both asbestos materials.

The adsorption of water and benzene on amosite and chrysotile asbestos.

In previous work the authors showed that chrysoltile is more porous than amostie and consequentd benzene with a high molecular cross-section are used as adsorbates. Benzene adsorption is extremely slow on both adsorbents with each point taking from 4 to 24 hours for equilibration. Evidently, the larger benzene molecule has a more difficult ime working its way thrugh the small pores.