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Biomedical subjects

A Korhonen

Publications and source records attributed to A Korhonen.

29 records · Page 2Linked to original sources
PubMed1984

Embryotoxic effects of eight organic peroxides and hydrogen peroxide on three-day chicken embryos.

Nine peroxides were tested for embryotoxicity in 3-day chicken embryos using the air-chamber method. The potencies were expressed by the ED50 for the total embryotoxic effect of the chemicals, including deaths and malformations, up to Day 14 of the incubation. The range of the ED50's was from 0.13 to 2.7 mumoles per egg and the order of the potencies was as follows: cyclohexanoneperoxide greater than cumolhydroperoxide greater than ethylmethylketoneperoxide greater than dibenzoylperoxide greater than acetylacetoneperoxide greater than perbenzoic acid-tert-butylester greater than dicumylperoxide greater than dilauroylperoxide greater than hydrogen peroxide. All nine peroxides caused malformations at a moderate frequency. The maximum percentage of malformed embryos of the treated varied from the 16% of perbenzoic acid-tert-butylester to the 56% of dicumylperoxide. The high percentage caused by the latter could, however, result from slow diffusion of high lethal doses from the air chamber to the embryo.

Abnormalities, Drug-Induced↗
PubMed1983

Embryotoxicity of industrial chemicals on the chicken embryo: dithiocarbamates.

Seven dithiocarbamates and three acetates were tested for teratogenicity and lethality in three-day chicken embryos. These included: cadmium diethyldithiocarbamate (CdDE), zinc diethyldithiocarbamate (ZnDE), zinc ethylphenyldithiocarbamate (ZnEP), zinc dibutyldithiocarbamate (ZnDB), copper dimethyldithiocarbamate (CuDM), tellurium diethyldithiocarbamate (TeDE), and piperidine pentamethylenedithiocarbamate (PPM), cadmium acetate (CdAC), copper-(II)acetate (CuAC), and zinc acetate (ZnAC). The parameters measured were early deaths, recorded within two days of injection, late deaths of malformed embryos, late deaths of nonmalformed embryos, and malformed survivors. The order of embryotoxicity decreased as follows: CdAC greater than CdDE greater than ZnDE greater than or equal to ZnEP greater than or equal to ZnDB greater than CuDM greater than TeDE greater than CuAC greater than PPM greater than ZnAC. The only exception to this order was the relatively weak teratogenicity of the metal acetates as compared to dithiocarbamates. Cadmium and zinc dithiocarbamates were potent embryotoxic agents eliciting lethality and malformations at doses of 1 to 10 nmole per egg. Most embryonic deaths occurred at stages 29 to 31, and most of the dead embryos were malformed.

Acetates↗
PubMed1983

Embryotoxicity of sixteen industrial amines to the chicken embryo.

Sixteen amine compounds that are used in the rubber industry, and sodium nitrite, were tested on three-day chicken embryos for embryotoxicity. The parameters measured were: early deaths recorded within two days of injection, late deaths of malformed embryos, late deaths of non-malformed embryos and malformed survivors. The most embryotoxic chemicals were N-phenyl-N'-isopropyl-p-phenylenediamine, N,N,N-triethylethylenediamine, N,N'-dicyclohexyl-p-phenyleneamine and triethylamine, with total effect ED50 values, including deaths and malformations, between 0.11 and 0.90 mumol per egg. The ED50 values for triethylenetetramine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, triethanolamine, N-phenyl-2-naphtylamine, aniline and N-nitrosodiphenylamine ranged from 1.1 to 7.0 mumol per egg. Sodium nitrite was the least potent, with an ED50 of 22 mumol per egg. Six chemicals produced no effects. They probably did not reach the embryo. The four most potent chemicals, together with aniline, caused the highest frequencies of malformations.

Amines↗
PubMed1983

Embryotoxic effects of acrolein, methacrylates, guanidines and resorcinol on three day chicken embryos.

Acrolein, four methacrylates, two guanidine compounds and resorcinol were tested for embryotoxicity on three day chicken embryos. The most potent chemical was acrolein, with the ED50 0.05 mumol per egg for the total effect, including deaths and malformations. The substances next in potency were N,N'-di-o-tolyl-guanidine and N,N-diphenylguanidine, with ED50 values 0.17 and 0.20 mumol per egg, respectively. Resorcinol and the methacrylates had ED50 values ranging from 2.4 to 22.0 mumol per egg. Acrolein, diphenylguanidine, tetrahydrofururylmethacrylate and trimethylolpropanetrimethacrylate caused the largest amounts of malformed embryos.

Acrolein↗
PubMed1983

Embryotoxic effects of phtalic acid derivatives, phosphates and aromatic oils used in the manufacturing of rubber on three day chicken embryos.

Several chemicals that are used for manufacturing of rubber were tested for embryotoxicity on three day chicken embryos. Cyclohexylthiophtalimide was the most potent of the chemicals, with an ED50 value for the total embryotoxic effect 0.04 mumol (10 micrograms) per egg. Phtalic anhydride was about ten times less potent, having the total ED50 for total embryotoxicity 0.38 mumol (56 micrograms) per egg. Two esters of phtalic acid, dibutylphtalate and butylbenzylphtalate, instead, were relatively impotent, with ED50 values of about 33 mumoles and 27 mumoles per egg, respectively. Two phosphates, tricresylphosphate and synthetic arylphosphate, were not potent embryotoxic agents in the chick embryos. They had ED50 values of 7.0 mumoles (2.6 mg) per egg and 9.5 mg per egg, respectively. Sodium phosphate (NaH2PO4) had the ED50 11 mumoles per egg. Three types of oils were tested, too. A mixture known as "highly aromatic oils" was the most potent, with the ED50 31 micrograms per egg. "Low aromatic, paraffin base oils" was the next potent, with the ED50 87 micrograms per egg, while "naphtenic oils" had the ED50 480 micrograms per egg. Cyclohexylthiophtalimide and phtalic anhydride caused malformations at high frequency. The oils and tricresylphosphate appeared to be efficient teratogens under the experimental conditions used.

Abnormalities, Drug-Induced↗
PubMed1983

Toxicity of rubber chemicals towards three-day chicken embryos.

Three-day chicken embryos were exposed to 80 different rubber chemicals dissolved in either acetone or water. The following classes of chemicals were studied: thiurams, dithiocarbamates, thioureas, benzothiazoles, benzenesulfohydrazide, dithiodimorpholine, amines, acrylates, guanidines, resorcinol, phthalates, adipates, phosphates, oils, peroxides, heavy metal salts, and sodium nitrite. Dose-response curves and median lethal doses (LD50) or median effective doses (ED50) were calculated for mortality in 2 d after the treatment, for total mortality in 11 d after the treatment, and for the total effect, including deaths and malformations 11 d after the treatment, when the test was finished. Sixteen of the chemicals had no effect on the embryos when injected into the air chamber. Incomplete and irregular dose-response curves for the total effect were obtained with 13 of the chemicals. For them, the ED50 could be calculated. Among the remaining 51 chemicals, the most potent were the dithiocarbamates and cadmium and copper acetates, with the total effect ED50 from 2.4 to 160 nmol/egg. Other chemicals that had an ED50 smaller than 100 nmol/egg were thiurams, cyclohexylthiophthalimide, acrolein, and dithiodimorpholine. The majority of the chemicals had an ED50 between 100 nmol/egg and 10 mumol/egg. The least potent were sodium nitrite and methylmethacrylate with an ED50 of 22 mumol/egg. All the 64 embryotoxic chemicals caused malformations with only one exception (dibutylthiourea). The maximum observed frequencies of malformed embryos varied from 3 to 100% of the treated embryos.

Abnormalities, Drug-Induced↗
PubMed1982

Embryotoxicity of industrial chemicals on the chicken embryo: thiourea derivatives.

Six thioureas: 1,3-diphenylthiourea (DPTU), 1,3-dibutylthiourea (DBTU), tetramethylthiourea (TEMTU), trimethylthiourea (TRIMTU), 1,3-diethylthiourea (DETU), and 1,3-ethylenethiourea (ETU), were tested, in addition to carbon disulfide, on three day chicken embryos for embryotoxicity. The parameters measured were early deaths, recorded within two days of injection, late deaths of malformed embryos, late deaths of non-malformed embryos, and malformed survivors. The order of total embryotoxicity decreased as follows DBTU greater than DPTU greater than TEMTU greater than TRIMTU greater than DETU greater than ETU. The range for ED50 values for total embryotoxicity was from 0.28 (DBTU) to 4.5 (ETU) mumol/egg. DBTU caused early deaths but no malformations. TEMTU and DPTU were the most potent teratogens.

Abnormalities, Drug-Induced↗
PubMed1982

Application of the chicken embryo in testing for embryotoxicity: thiurams.

A test protocol was developed for the testing of chemicals for toxicity on the chicken embryo. The protocol called for a continuous monitoring of the developing embryo for those that died before maceration. The eggs were injected on day 3, and the test was continued up to day 14 of incubation. The following parameters of embryotoxicity were used: early deaths (spanning the first 2 d after injection), late deaths with malformed embryos, late deaths with nonmalformed embryos, and malformed survivors. The order of embryotoxic potency, in descending order, among the thiurams was tetramethylthiuramdisulfide, tetramethylthiurammonosulfide, tetraethylthiuramdisulfide. It was found that late deaths were seen in 70% of the cases with malformations. The most common types of malformations were eye defects and open coeloms. Dead embryos frequently had multiple malformations. In lethal cases, embryonic development terminated at stages 25/26 and 29 on the Hamburger-Hamilton scale.

Abnormalities, Drug-Induced↗