Effect of 7 mT static magnetic field and iron ions on rat lymphocytes: apoptosis, necrosis and free radical processes.

Simultaneous exposure of rat lymphocytes to 7 mT static magnetic field (SMF) and iron ions caused an increase in the number of cells with DNA damage. The mechanism by which MF induces DNA damage and the possible cytotoxic consequences are not known. However, we suppose that free radicals are involved.

Evaluation of patient exposure in computerised tomogram in Poland.

The increasing number of computerised tomography (CT) procedures performed in Poland in recent years has resulted in a growing contribution of these examinations to the whole exposure of the population to ionising radiation from medical sources. (The number of CT examinations in Poland was 170,000 in 1995 and 460,000 in 1999.) An evaluation is presented of doses to patients in CT examinations performed with different types of CT unit.

Eotaxin but not MCP-3 induces eosinophil influx into nasal fluid in allergic patients.

Background: Eotaxin and MCP-3 (CC chemokines), owing to their preferential action on eosinophils, seem to be the very importance in the patophysiology of allergic rhinitis and asthma. The purpose of this study was to examine the effect of intranasally administered eotaxin and MCP-3 after specific allergen priming on the influx of inflammatory cells and their soluble mediators into the nasal mucosa.

Methods: Eotaxin and MCP-3 have been applied intranasally at the increasing doses of 1, 5 and 10 microg to allergic patients after allergen priming.

Embryolethal and teratogenic effects of carbendazim in rats.

This study was performed to evaluate the effects of prenatal development of rats. Females were exposed to carbendazim by gavage every day on days 6-15 of gestation at doses 8, 35, 160 mg/kg b.w.

Smell impairment in workers occupationally exposed to cadmium.

ENT and olfactometric examinations were carried out on 73 workers at an electrochemical plant involved in the production of cadmium-nickel batteries, where cadmium fumes were emitted into the workplace. Exposure levels exceeded the maximum allowable concentrations by about 1-2 times. The controls included 43 non-exposed, age- and cigarette-smoking-matched people.

Protective effect of melatonin against in vitro iron ions and 7 mT 50 Hz magnetic field-induced DNA damage in rat lymphocytes.

We have previously shown that simultaneous exposure of rat lymphocytes to iron ions and 50Hz magnetic field (MF) caused an increase in the number of cells with DNA strand breaks. Although the mechanism of MF-induced DNA damage is not known, we suppose that it involves free radicals. In the present study, to confirm our hypothesis, we have examined the effect of melatonin, an established free radicals scavenger, on DNA damage in rat peripheral blood lymphocytes exposed in vitro to iron ions and 50Hz MF.

Nested case-control study of lung cancer among pulp and paper workers in relation to exposure to dusts.

Background: Numerous studies have indicated an increased risk of lung cancer in pulp and paper industry workers. In a 1990 survey, standardized mortality ratio (SMR) was found to be 122 (95% CI:96-153) for lung cancer in Polish male workers in the pulp and paper industry, and 166 (95% CI:95-270) among workers engaged in paper production.

Methods: A nested case-control design within a cohort of pulp and paper workers was applied.

Hair cell regeneration in the chick basilar papilla after exposure to wide-band noise: evidence for ganglion cell involvement.

It has been demonstrated that the auditory epithelium in the chick basilar papilla may regenerate after acoustic or ototoxic damage. Both types of damage may elicit the appearance of new cells that may develop in to the sensory cells. Factors inducing this process and the role of ganglion cells, the first neuron cells in the auditory pathway, are still unknown.

H-RAS, K-RAS, and N-RAS gene activation in human bladder cancers.

Bladder cancer is one of the leading causes of cancer death in most developed countries. In this work, 19 bladder cancer specimens, along with their infiltrations of the urinary bladder wall from the same patients, were examined for the presence of H-RAS, K-RAS, and N-RAS activation using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The H-RAS activation was found in 15 (about 84%) of the 19 bladder cancers studied.

Metabolic genotype in relation to individual susceptibility to environmental carcinogens.

Earlier research indicates that within the human population there are considerable differences in the response to the carcinogenic activity of environmental carcinogens. Genetic polymorphism associated with several variants of the gene products participating in the biotransformation of various xenobiotics (including carcinogens) found in human populations constitutes a major cause of those differences. Enzymes coded by different variants of the same gene can differ in their catalytic activities.

Assessment of aniline derivatives-induced DNA damage in the liver cells of B6C3F1 mice using the alkaline single cell gel electrophoresis ('comet') assay.

The alkaline single cell gel electrophoresis (SCGE) or 'comet' assay under alkaline conditions was used to measure DNA damage in the liver cells of B6C3F1 male mice exposed to 2,4-dimethylaniline and 2,4,6-trimethylaniline. Cells embedded in agarose were lysed, subjected briefly to an electric field, stained with a fluorescent DNA-binding stain, and viewed using a fluorescence microscope. The effect of 2,4-dimethylaniline and 2,4,6-trimethylaniline was studied after single intraperitoneal injections at doses equal to 100, 200 mg/kg and 150, 300 mg/kg body wt.

Behavioral effects of occupational exposure to organophosphorous pesticides in female greenhouse planting workers.

51 women employed in gardening enterprises were studied. Of these, 26 performed planting jobs in greenhouses and were occupationally exposed to several organophosphates. The comparison group consisted of 25 women not exposed to neurotoxic chemicals.

Maternal and fetal toxicity of N-methylmorpholine by oral administration in rats.

N-methylmorpholine, which is used as a catalyst in polyurethane foams producing, in solvents, stabilizing agents, and corrosion inhibitors, was administered to female rats by gavage at 100, 200, 600, and 900 mg/kg during organogenesis. It did not exhibit selective toxicity toward the developing conceptus. This compound administered to pregnant females was fetotoxic and teratogenic in the presence of maternal toxicity.

Assessment of aniline derivatives-induced DNA damage in the liver cells of B6C3F1 mice using the alkaline single cell gel electrophoresis ("comet") assay.

The alkaline single cell gel electrophoresis (SCGE) or "comet" assay under alkaline conditions was used to measure DNA damage in the liver cells of B6C3F1 male mice exposed to 2,4-dimethylaniline and 2, 4,6-trimethylaniline. Cells embedded in agarose were lysed, subjected briefly to an electric field, stained with a fluorescent DNA-binding stain, and viewed using a fluorescence microscope. The effect of 2,4-dimethylaniline and 2,4,6-trimethylaniline was studied after a single intraperitoneal injections at doses equal to 100, 200 mg/kg and 150, 300 mg/kg b.

Can Cytotoxic Effects Induced by Industrial Chemicals be Time-dependent?

Short-term and delayed cytotoxic effects of selected water-soluble and water-insoluble industrial chemicals (dimethyl sulphoxide, ethyl alcohol, methyl alcohol, ammonium nitrate, benzalkonium chloride, butoxyethanol and propylene glycol) were tested on confluent 3T3-L1 mouse fibroblasts by using the neutral red uptake (NRU) assay and the MTT assay. The NRU and MTT assays were performed after exposure to a chemical for 10 minutes and 3 hours and then again 7 days later. The results indicate that the system of testing used permits the assessment of both early and delayed cytotoxic effects of different classes of chemicals.

Genotoxicity evaluation of tetramethylbenzenes.

The three tetramethyl isomers of benzene (prenitene, 1,2,3,4-; izodurene, 1,2,3,5-; and durene, 1,2,4,5-tetramethylben- zene) were studied using in vitro mutagenicity and in vivo genotoxicity tests. Potency of mutate induction by these solvents was evaluated in Salmonella typhimurium cells with, and without S9-mix made from Aroclor 1254-induced rat liver S9. The potency of induction of micronuclei (MN) and sister chromatid exchanges (SCEs) by solvents was evaluated in bone marrow of mice.

Genotoxicity of Farbasol and its component: 4-ethyltoluene.

A combination of assays for gene mutations in Salmonella typhimurium TA97a, TA98, TA100 and TA102 strains with and without rat liver activation, and for micronucleus and sister chromatid exchange (SCE) in bone marrow cells of Imp:Balb/c mice was used to provide data on the mutagenic and genotoxic properties of the mixture of aromatic solvents, known under the trade name of Farbasol. In addition, 4-ethyltoluene (the main ethylmethylbenzenic component of Farbasol) was also tested for muta- and genotoxicity. The results revealed that neither Farbasol nor 4-ethyltoluene induced an increased reverse mutation in bacterial cells or the formation of micronucleated polychromatic erythrocytes in bone marrow.

Genotoxicity evaluation of trimethylbenzenes.

The three trimethyl isomers of benzene (hemimellitene, 1,2,3-TMB; pseudocumene, 1,2,4-TMB and mesitylene, 1,3,5-TMB) were investigated for different genotoxicity endpoints: in vitro, in the Ames test with Salmonella typhimurium TA97a, TA98, TA100 and TA102 strains in the presence and absence of rat liver S9 metabolic activation; in vivo, in the micronucleus and sister chromatid exchange (SCE) tests with bone marrow cells of Imp:Balb/c mice. Only the isomer of benzene with the methyl-group at position 1, 2, 3 was found to have mutagenic effect on S. typhimurium cells.

Genotoxicity of industrial dyes under the inductive effect of ethanol on monooxygenase system in mice.

The genotoxic effects of triarylmethane (Acid Green 16, C.I.44025) and arylmonoazo (Basic Orange 28, developed by Boruta Pigment Plant, Poland, C.

Retardation of the age-related increase in spontaneous cortical spike-wave discharges (SWD) in rats after a 28-day inhalation (SWD) in rats after a 28-day inhalation exposure to an industrial solvent, pseudocumene (1,2,4-trimethylbenzene).

It has been hypothesized that exposure to neurotoxins may hasten the process of brain ageing. Volatile hydrocarbons are in common use as solvents and their neurotoxic properties are acknowledged. In the rat, the age-related neurodegenerative changes in the brain develop together with an increased occurrence of bursts of spontaneous spike-wave discharges (SWD) in the neocortex.

Chemical-induced changes in intracellular redox state and in apoptosis.

Necrosis and apoptosis are two ways by which cells die. A major concept of apoptosis is that it is a controlled process. From this concept it follows that cells contain a molecule or molecules which under specific, regulated circumstances mediate cell death.

Sources of poisoning exposures in children during 1990-1995. An analysis of the National Poison Information Centre files.

Information protocols on the causes of acute poisoning exposures with chemicals in children up to 14 years old collected during 1990-95 at the National Poison Information Centre have been analyzed. Approximately 96% of intoxication were accidental, 44% of patients were poisoned with drugs, 22% with household products and 14% with pesticides. Almost 25% of drug poisonings were due to sedative and to psychotropic drugs, and 17% to drug mixtures.