Induction of lymphomas by urethane in combination with diethylstilboestrol in CFLP mice.

The combination of urethane and the non-steroidal oestrogen diethylstilboestrol induced lymphomas in CFLP mice.     

Induction of developmental anomalies in mice by maternal stress

Summary The short-time restraint of pregnant mice on day 8 of gestation led to a significant increase of the anomaly rate in fetuses. This effect may be due to stress factors of endocrine origin.The technical assistance of Mrs E. Frei is gratefully acknowledged. Supported by the Swiss National Foundation for Scientific Research.     

Induction of developmental anomalies in mice by maternal stress

The short-time restraint of pregnant mice on day 8 of gestation led to a significant increase of the anomaly rate in fetuses. This effect may be due to stress factors of endocrine origin.     

Induction of immunological memory in mice by RNA extract

Summary RNA extract isolated from spleens of mice immunized with lipopolysaccharide fromE. coli induced an immunological memory in normal mice. Application of small amounts of corresponding antigen provoked a specific secondary immune response in RNA primed mice.     

Induction of active immune state by multinucleate tumour cells in mice

Résumé Une immunité active au sarcome, produit par le cholanthrène de méthyle, a été obtenue en utilisant des cellules tumorales multinucléées, associées au virus de Sendai; les réactions ont été spécifiques à la tumeur. A la suite de ces injections, plus de 70% des souris furent résistantes aux trois inoculations, avec 10⁵ cellules vivantes tumorales.     

Induction of malignant skin tumors in mice by topical application of ethylnitrosourea

Summary A high percentage of squamous cell carcinomas were induced in the skin of Swiss-Webster mice by repeated topical application of ethylnitrosourea, indicating that this nitrosamide possesses a potent carcinogenic action when topically applied.Acknowledgments. This work was supported by PHS contract NOI CP33 278 from the National Cancer Institute.The author is grateful to Miss M. Kuhse for expert technical assistance and to Dr S. S. Mirvish for providing the ENU.     

Induction of epidermal cell proliferation by a tumour promoter in vitamin B6-deficient mice

Summary Topical application of the tumour promoter 12-0-tetradecanoyl-phorbol-13-acetate to skin caused a marked enhancement of mitotic acitivity both in mice maintained on a complete diet or on a vitamin B₆-deficient diet.Acknowledgment. The author thanks Mr P. Daenke for excellent technical assistance.This investigation was supported by the Australian Research Grants Committee and the Australian Tobacco Research Foundation.     

Influence of presensitization with allogeneic lymphoma cells on the growth and response to therapy of radiation-induced lymphomas in mice

Summary Congenic mice were sensitized with viableH-2-incompatible radiation-induced lymphomas (RIL), challenged with syngeneic RIL and treated with bis-chloroethyl-nitrosourea. Either enhancement or inhibition of RIL was found in presensitized mice, depending on the tumor-host system used.This work was supported by Progetto Finalizzato Virus, CNR (Rome, Italy), Contract No. 770025284/1152505.Acknowledgments. I wish to thank Dr J. Mayo and Mr C.R. Reeder of the Mammalian Genetics and Animal Production Section, Division of Cancer Treatment (DCT), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda (Maryland, 20014, USA) for providing the mice used in this study. I also thank Dr H.B. Wood of the Drug Synthesis and Chemistry Branch, DCT, NCI, NIH, for furnishing the BCNU used.     

Induction of obesity in obese-hyperglycaemic mice on normal food intake

Zusammenfassung Nachweis, dass bei einem Mäusestamm, welcher eine genetisch bedingte Fettsucht aufweist, die Fettsucht auch bei Nahrungseinschränkung auftritt, wenn diese Tiere homozygot sind, dies im Gegensatz zu heterozygoten Tieren. Daraus wird der Schluss gezogen, dass diese Fettsucht nicht primär alimentär, sondern durch einen genetischen, metabolischen Defekt bedingt ist.     

Influence of presensitization with allogeneic lymphoma cells on the growth and response to therapy of radiation-induced lymphomas in mice.

Congenic mice were sensitized with viable H-2-incompatible radiation-induced lymphomas (RIL), challenged with syngeneic RIL and treated with bis-chloroethyl-nitrosourea. Either enhancement or inhibition of RIL was found in presensitized mice, depending on the tumor-host system used.     

Induction of alloxan diabetes in obese-hyperglycemic mice (genotype obob)

Zusammenfassung Nachweis, dass fettsüchtige, hyperglykämische Mäuse nach Alloxan-Injektion einen erhöhten Blutzuckerspiegel und herabgesetzte Insulinkonzentrationen im Vergleich mit den unbehandelten Kontrolltieren zeigen. B-Zellen der Langerhansschen Inseln zeigen nach Alloxan nekrotische Veränderungen.

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This work was supported by the Swedish Medical Research Council, the Swedish Diabetes Association and the Nordic Insulin Foundation.     

Induction of neovascularization in vivo by glycerol

Glycerol, injected into a site between the femoral vessels of the rat, induced neovascularization, both from the preexisting microcirculation and from the side of the femoral vein facing the artery-vein interstitium where the glycerol was administered. The use of glycerol together with a known angiogenic substance (PGE₂) did not modify the neocapillary density (NCD) obtained with glycerol alone. In contrast, the lower level of NCD achieved with an acylglycerol (triacetylglycerol) was increased when the latter was associated with PGE₂. Values reached were similar to, but never higher than, those for glycerol alone, or combined with PGE₂. The results suggest that glycerol and some substances containing glycerol, amongst which 1-butyrylglycerol has been previously considered¹, may stimulate angiogenesis by a direct or indirect mechanism of action.     

Induction of sister chromatid exchanges in vivo in bone marrow cells of AKR mice]

Induction of sister chromatid exchanges (SCEs) in bone-marrow cells of AKR Mice receiving in vivo four drugs well-known for their mutagenesis activity has been tested. A decreasing activity in SCE was shown by the drugs tested in the order cyclophosphamide, procarbazine, methylmethane sulfonate and diethylnitrosamine. This technique presents an encouraging method for testing the effect of chemical agents in vivo.     

Induction of aryl hydrocarbon hydroxylase in the lungs of mice in response to cigarette smoke

Résumé L'absorption, par inhalation, de la fumée de cigarette, produit une accélération rapide de l'activité de l'aryl hydrocarbure hydroxylase dans les poumons de la souris. Après une exposition de 4 semaines, ces niveaux sont 3–4 fois plus élevés que ceux du contrôle. Dans le foie, ces actions se manifestent d'une facon beaucoup plus faible et lente.

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Supported by a grant from the Australian Tobacco Research Foundation. The authors thank L. Roberts andM. B. Hart for technical assistance.