Hildegard Reznik-Schüller

Proliferation of endocrine (APUD-type) cells during early N-diethylnitrosamine-induced lung carcinogenesis in hamsters.

Pronounced proliferation of amine precursor uptake and decarboxylase activity (APUD-type) cells was found in the segmental bronchi and bronchioles of Syrian golden hamsters during N-diethylnitrosamine (DEN)-induced lung carcinogenesis. Since similar epithelial alterations did not occur in previous experiments after benzo(a)pyrene (B(a)P) treatment, it is concluded that the initial stages of lung carcinogenesis differ with respect to the carcinogen administered.

Ciliary alterations in hamster respiratory tract epithelium after exposure to carcinogens and cigarette smoke

Alterations in the ultrastructure of cilia were found to be one of the initial stages in the development of benzo(a)pyrene induced cancers in the trachea and bronchi of Syrian golden hamsters, as well as in the bronchi from which pulmonary adenocarcinomata originated after European hamsters were treated with N-dibutylnitrosamine. Similar abnormalities of cilia occurred in the respiratory epithelia of Syrian golden hamsters after one year of daily exposure to cigarette smoke.

Atrophy induced in the tubules of the testes of syrian hamsters by two retinoids

This paper describes toxic lesions induced in the hamster testes by 3 different retinoids. Groups of 13 Syrian Golden hamsters were fed diets containing 120 mg/kg 13-cis-retinoic acid (CRA), 327 mg/kg ethyl retinamide (ER), or 343 mg/kg 2-hydroxyethyl retinamide (HER) for 6 months. The germinal epithelium of the testicular tubules was completely atrophic in the groups fed ER and HER. Mean testicular weights were 0.8 g and 0.7 g respectively as compared to 3.3 g in the control group. No alterations in testicular weights or morphological characteristics, at the light microscopic level, were found in the group fed CRA. At the ultrastructural level, however, asymmetrical head caps and deformed acrosomes were observed in the spermatids.

Labeling in cells of the nasal cavity of hamsters treated with tritiated N-nitrosodiethylamine☆

Syrian golden hamsters were given a single dose of N-[3H]nitrosodiethylamine ([3H]DEN) by gavage. One hour later the animals were killed and their nasal cavities processed for high resolution light microscopic autoradiography for detection of bound radioactivity. The atrioturbinals, which are lined by squamous epithelium, were unlabeled. In the respiratory portion of the nose (nasal septum, naso- and maxilloturbinals) most bound radioactivity was concentrated in the mucous cells of the respiratory epithelium and the secretory cells of submucous glands). In the olfactory region (ecto and endoturbinals) most bound radioactivity was restricted to the secretory cells of submucous glands, while in the olfactory epithelium only the sustentacular cells were slightly labeled.

Differences in blood values depending on age in laboratory-bred european hamsters (Cricetus cricetus L.):

No significant differences in blood parameters were found between males and females aged 13-900 days. A comparison of the various age groups showed significant differences in the number of erythrocytes, leucocytes, thrombocytes and in the diameter of red blood cells. The number of erythrocytes and leucocytes was lowest, and the erythrocytes had the largest diameters in young animals. The number of thrombocytes was lowest in older animals.

Pulmonary tumorigenesis in Syrian golden hamsters after intratracheal instillations with automobile exhaust condensate.

Syrian golden hamsters were intratracheally instilled once every two weeks for life with automobile exhaust condensate (AEC) at two dose levels. The condensate was prepared from the most common German passenger car driven in the Europa‐Test cycle (simulated city driving) and contained 340 μg/g benzo(a)pyrene (B(a)P). Despite the very low total dose of B(a)P received, all animals of both dosage groups developed multiple pulmonary adenomas. Electron microscopy revealed these tumors to resemble B(a)P induced pulmonary adenomas in their ultrastructure. Numerous condensate‐laden macrophages in tumor and peripheral lung tissues indicated that little of the instilled condensate had been removed from the airways through mucociliary action. Cancer 40:203–210, 1977.

Neoplasms, Mucosa, Ethmoid Turbinates, Rat

Neoplasms of the ethmoid regions of the nasal cavities of rats appear, in advanced cases, as large masses exhibiting both exophytic and endophytic patterns of growth. One or both sides of the posterior nasal cavities may be completely filled by the tumor, resulting in displacement, erosion, and destruction of the septum, turbinals, and other surrounding osseous and cartilaginous structures. Extension through the cribriform plate into the olfactory lobes of the brain can frequently be visualized grossly upon longitudinal or coronal sectioning.

An improved method for rapid electron microscopic autoradiography

~ T R O D U C T I O N Electron microscopic autoradiography is a useful technique for studies into the intracellular distribution of radioactivity in tissue samples after administration of radioactively labelled chemicals. A major disadvantage of the technique is that exposure times of several months are generally necessary to yield the required density of autoradiographic grains. Since long exposure times generally increase the background of the emulsion, any modification of the technique that results in a shorter exposure time without interfering with the distribution pattern of autoradiographic grains would be of pronounced benefit to the investigator. A number of reports have been published on the use of scintillators (Durie & Salmon, 1975; Langager et al., 1982) to increase the sensitivity of photographic emulsions and hence reduce exposure times for light microscopic autoradiography. To reduce the health hazards involved in the handling of such scintillators, En3Hance (New England Nuclear, Boston, Mass.) has recently been developed as an autoradiography enhancer for use with gel fluorography (New England Technical Bulletin 1981). We have successfully used this product to increase the sensitivity of Ilford L4 emulsion on electron microscopic autoradiograms. The method is simple, yields reproducible results, and reduces exposure times from several months to only a few days and will hence be of interest to a wide spectrum of investigators. We have tested this new method with tissue blocks that we had used earlier for a conventional autoradiographic study on the covalent binding of 13H]methapyrilene hydrochloride (Reznik-Schiiller & Lijinsky, 1981). This compound binds covalently to rat liver (Lijinsky & Muschik, 1982), is a strong liver carcinogen in rats (Lijinsky et al., 1980), and causes mitochondria1 increase in hepatocytes of this species (Reznik-Schuller & Gregg, 1983).

X-ray enlargement modified for use in experimental animal science

The primary enlarged x-ray image is produced by a reduction of the focal-film-distance to 80 cm at a given focal size of 0·15 mm. The advantages of this technique as compared to conventional x-ray methods are exemplified with x-ray images from the shoulder joint of a European hamster, a pseudoarthrosis in the foreleg of a beagle, and a renovasography of a rat. The principles of the technique and its significance for investigations using small laboratory animals are discussed.

Carcinogenic effects of skin transplantation and immunosuppression in mice

C3H and B6D2 mice recieved skin transplants from an animal of the other strain. Three groups were immunosuppressed for varying periods of time, and with different doses of vinblastine, cyclophosphamide, or azathioprine. Following transplantation, control animals received daily injections of NaCl. All animals developed tumours of lymphoreticular origin, which would indicate that immunosuppression is only a secondary cause for tumour development, with antigenic stimulation being the primary factor. C3H und B6D2 Mäuse erhielten Hautstücke von Tieren des jeweils anderen Mäusestammes transplantiert. Danach wurden drei Gruppen die Immunsuppressiva Vinblastin, Cyclophosphamid oder Azathioprin in unterschiedlicher Dosis und Behandlungsdauer und den Kontrolltieren nach Transplantation täglich NaCl verabreicht. Die Mäuse entwickelten Tumoren des lymphoreticulären Systems. Entsprechend unserer Befunde sehen wir in der antigenen Stimulierung eine wesentliche Hauptursache bei der Tumorinduktion nach Transplantation, während wir der Immunosuppression nur eine Sekundärwirkung zuschreiben.