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At least 19 recordsLinked to original sources

Inhalation carcinogenicity of alpha halo ethers. I. The acute inhalation toxicity of chloromethyl methyl ether and bis(chloromethyl)ether.

A range of acute studies were performed with chloromethyl methyl either (CMME) and bis(chloromethyl)ether (BCME), including 14-day LC50's following single seven-hour inhalation exposures. The LC50's for CMME were 55 ppm for rats and 65 ppm for hamsters. The LC50's for BCME were 7 ppm for both species. All animals showed characteristic changes of acute irritation of the respiratory tract manifested by congestion, edema, and hemorrhage. Severe shortening of life span was seen in 30-day exposures of rats to CMME and in all studies with BCME. Incidences of mucosal changes, including atypia, were generally increased in a dose-related manner in both species. The carcinogenicity of BCME in these range finding experiments was demonstrated by a skin cancer in a rat after three exposures and a nasal tumor in a hamster after one exposure to 1 ppm BCME.

Animals

Stereochemical specificity of the biosynthesis of the alkyl ether bond in alkyl ether lipids.

The stereochemical course of the formation of the alkyl ether bond in alkyl ether lipids was investigated through the synthesis of stereospecifically labeled acyl R- or S-[1-3H]dihydroxyacetone 3-phosphate (DHAP) starting from L-glyceraldehyde. It was demonstrated directly that the formation of the alkyl ether bond results in the stereospecific exchange of the pro-R C-1 hydrogen of DHAP with a proton of water. The configuration of the hydrogen that is retained on C-1 after formation of the alkyl ether bond was also investigated. The alkyl ether lipid was degraded, and the DHAP backbone isolated as glycerol, converted to DHAP via glycerol 3-phosphate and treated with either aldolase or triose phosphate isomerase. The results demonstrated that the retained hydrogen on C-1, which was pro-S in the starting substrate, was pro-S in the product alkyl ether.

Carbon Radioisotopes

Ethyl acetate as a substitute for diethyl ether in the formalin-ether sedimentation technique.

Ethyl acetate appears to be a satisfactory subsitute solvent for diethyl ether in the Formalin-ether sedimentation technique. In comparative studies, concentration of organisms with ethyl acetate was equal to or greater than that with diethyl ether. No distortion or alteration of morphology was observed with eigher solvent, and preparations were comparable in appearance and ease of examination. In addition, ethyl acetate is less flammable and less hazardous to use than diethyl ether.

Acetates

Identification of hydroxylated chlorodibenzo-p-dioxins, chlorodibenzofurans, chlorodiphenyl ethers and chloronaphthalenes as their methyl ethers by gas chromatography mass spectrometry.

The methyl ethers of a number of hydroxylated (poly)chlorodibenzo-p-dioxins, chlorodibenzofurans, chlorodiphenyl ethers and chloronaphthalenes, representing all different hydroxy substitutions, were synthesized and their mass spectra investigated. With the exception of the methoxy derivatives of the chlorodibenzofurans, it appeared that the mass fragmentation patterns of the structural isomers of each class of compounds were very specific and allowed unambiguous assignment of the position of the methoxy group in the molecule. The different fragmentation patterns can be explained in terms of plausible mechanisms resulting in stable charge delocalized (oxonium) ions. Because of its diagnostic value, this method is useful in the structure elucidation of hydroxylated metabolites of pure isomers of chlorodibenzo-p-dioxins, chlorodiphenyl ethers and chloronaphthalenes.

Benzofurans

Chain substituted polymerizable ether lipids: synthesis of sorbyl and diacetylenic ether glycerophosphocholine.

Three novel polymerizable ether lipids, 1,2-O-bis[10(2',4'-hexadienoyloxy)decyl]-rac, 1,2-O-bis(10,12-tricosadiynyl)-rac, and (-)-2,3-O-bis(10,12-tricosadiynyl)-sn-glycero-1-phosphocholine, were synthesized from 3-O-benzyl-rac, 3-O-trityl-rac and (-)-1-O-trityl-sn-glycerol as starting materials, respectively. All the reactions employed in these multi-step syntheses are straightforward giving an overall yield of 21% for the sorbyl, 42% for the racemic diacetylenic and 44% for the chiral diacetylenic lipid. All the lipids form bilayer assemblies on hydration and show transitions from gel to liquid-crystalline phases at 11.4 degrees, 27.6 degrees and 30.0 degrees C, respectively. Bilayer assemblies of each are photoreactive and are readily polymerized by irradiation with 254 nm light. Tubules of the chiral diacetylenic ether lipid were observed.

Phospholipid Ethers

The effect of ethylene glycol monomethyl ether and diethylene glycol monomethyl ether on hepatic gamma-glutamyl transpeptidase.

In this paper, we determined whether ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethyl ether (diEGME) induce hepatic gamma-glutamyl transpeptidase activity. Male adult Wistar rats weighing 220 g were used as experimental animals. EGME (100, 300 mg/kg per day) and diEGME (500, 1000, 2000 mg/kg per day) were administered by gavage for 1, 2 or 5 days or 4 weeks. In the 4-week study, experimental animals were administered EGME or diEGME once a day orally, 5 days/week. EGME treatment increased the serum gamma-glutamyl transpeptidase (GGT) level significantly, however, diEGME did not. The activities of three other enzymes (SGOT, SGPT and ALP) in serum were not altered by EGME or diEGME treatment and thus there was no biochemical indices of hepatic damage by EGME or diEGME. EGME treatment increased the GGT activities in the liver and lungs. Of the organs examined, the induction of GGT was the greatest in the liver. The inducibility in the liver was 216% for the 5-day treatment and 460% for the 4-week treatment. A dose-dependent increase of hepatic microsomal GGT activity by EGME was observed. On the other hand, renal GGT activities were declined to 72% and 60% of control by the 5-day and 4-week EGME treatments, respectively. DiEGME did not affect the GGT activities in any of the tissues except those of the brain. In the histochemical study, most hepatocytes at the periportal zones were stained with GGT staining after the 4-week treatment. However, the hepatocytes at the central zones were negative.

Animals

[Occupational lung cancer after inhalation of alkylating compounds: dichlordimethyl ether, monochlordimethyl ether and dimethyl sulphate (author's transl)].

A 42-year-old chemist died from extensive pulmonary carcinoma, having inhaled for over seven years dichlordimethyl ether, monochlordimethyl ether and small amounts of dimethyl sulphate. This exposure took place in circumstances which, in animal experiments, have led to the development of cancer. A causal connection between the occupational exposure to these chemicals and carcinogenesis has to be accepted.

Adult

Inhalation carcinogenicity of alpha halo ethers. II. Chronic inhalation studies with chloromethyl methyl ether.

Rats and hamsters were exposed to 1 ppm of chloromethyl methyl ether six hours per day, five days per week, throughout their lifetime. Mortality and weight gain of the exposed animals paralleled that of the control animals. Malignant tumors of the respiratory tract were found in two rats. These were a squamous cell carcinoma of the lung with blood vessel invasion and an esthesloneuroepithelioma originating in the olfactory epithelium and invading the forebrain. One hamster was found to have an adenocarcinoma of the lung and another, a squamous papilloma of the trachea. A single exposed rat had a pituitary tumor of primitive cell type that may well have been coincidental.

Adenocarcinoma

Inhalation carcinogenicity of alpha halo ethers. III. Lifetime and limited period inhalation studies with bis(chloromethyl)ether at 0.1 ppm.

Rats and hamsters were exposed to 0.1 ppm bis(chloromethyl)ether (BCME) six hours per day, five days per week throughout their lifetime. Additional groups of rats were given 10, 20, 40, 60, 80, and 100 exposures to 0.1 ppm BCME and then held until death. Forty cancers originating in the respiratory tract were found in the 200 rats involved in these studies. These included 14 cancers of the lung and 26 cancers of the nasal cavity. They occurred in dose-related fashion. A single undifferentiated carcinoma of the lung was seen in a hamster.

Animals

Use of ethyl ethers, deuteriomethyl ethers and cyclic n-butylboronates of hydroxychlorobiphenyls in identification of metabolites of polychlorinated biphenyls.

The mass spectra and gas chromatographic properties of a number of chlorobiphenylols, chlorobiphenyldiols, chlorophenols and naphthols, as well as their methyl, deuteriomethyl and ethyl ethers and some cyclic n-butylboronates have been investigated. Metabolism experiments with 4'-chloro-4-biphenylol showed that the selective use of ethylation and methylation is most effective in both detection and structure elucidation of metabolites partly methylated by metabolic processes. The usefulness of deuteriomethylation in such studies seems to be limited. The formation of cyclic n-butylboronates provides specific information on o-dihydroxy derivatives of chlorobiphenyls.

Animals