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J Misfeld

Publications and source records attributed to J Misfeld.

5 recordsLinked to original sources
PubMed1977

Tumours in mice after subcutaneous injection of automobile exhaust condensates.

Automobile exhaust condensate (AEC), either mixed with benzo[a]pyrene (BaP) or suspended or dissolved in tricaprylin, was injected subcutaneously into NMRI mice in a series of experiments. The addition of AEC decreased the incidence of tumours which developed with 30, 90 and 270 microgram BaP. Reduction of tumour incidence was proportional to the amount of AEC added. With an injection of 10 microgram BaP, the latent period was greatly increased when AEC was added, but the occurrence of tumours was the same. Components of AEC appear to inactivate BaP, at least temporarily. In further experiments AEC and nine fractions thereof were injected subcutaneously into mice. The fraction comprising only polycyclic aromatic hydrocarbons (PAH) induced the highest incidence of tumours. In contrast, when it was administered in combination with other fractions the PAH fraction was less active. Application of the products of further fractionation of PAH showed that polycyclic compounds with seven or more rings can also induce tumours in this model.

Animals↗
PubMed1976

[Experimental studies into syncarcinogenesis. 7th communication: Syncarcinogenic effects of polycylic aromatic hydrocarbons (PAH) in epicutaneous tests in mice].

A mixture of 11 carcinogenic and noncarcinogenic hydrocarbons was applied to the shorn skin of the back of 3400 female NMRI-mice. The proportion of the hydrocarbons in the mixture corresponded to the analytical findings in condensates of cigarette smoke, automobil exhaust gas, and preservation curing smoke and tar. Antagonistic effects by the individual hydrocarbons in the mixture were not observed, on the contrary the substances in the mixture showed additive effects. There were no differences in the mode of action of the different mixtures.

Animals↗
PubMed1976

Investigations on the carcinogenic burden by air pollution in man. XIV. Effects of automobile exhaust condensate on the Syrian golden hamster lung.

Syrian golden hamsters were intratracheally instilled with 5 or 2.5 mg/animal of automobile exhaust condensate at two weekly intervals. Moribund animals were fixed by intravascular perfusion. Samples of lobar and segmental bronchi, as well as of peripheral lung tissue, were taken for electron microscopical examination. In addition, all organs were examined histologically. After a survival time of 30 to 60 weeks all animals developed multiple pulmonary adenomas, thus indicating a marked carcinogenic effect of automobile exhaust condensate.

Adenoma↗
PubMedDate not supplied

The tumor-producing effect of automobile exhaust condensate and fractions thereof. Part III: mathematical-statistical evaluation of the test results.

This paper deals with the mathematical-statistical evaluation of experiments devoted to the following problems: 1. To what extent is the carcinogenic potency of automobile exhaust gas condensate dependent on the dose? 2. What fractions (groups of substances) of the automobile exhaust gas condensate are mainly responsible for the carcinogenic potency? 3. To what extent can the potency be explained by fractions (or single substances)? In order to answer the above questions, the working group planned animal experiments (cf. Misfeld and Timm, 1973) and obtained, prepared, and fractionalized automobile exhaust gas condensate (Grimmer, 1978). The exhaust gas condensate and its fractions were dropped onto the skin of female CFLP mice (Brune et al., 1978). In view of the problems posed above, the aim of the mathematical-statistical evaluation was to establish the dose-response relations, to assess the combined effect, and to estimate the relative potency and the assumed potency. In particular, the hypothesis (basis for the separation process) that the potency of the entire exhaust gas condensate is mainly attributable to the fraction which contains the polycyclic aromatic hydrocarbons (nitromethane phase) was examined.

Animals↗