Reduction of the number of mice used for potency testing of human and animal rabies vaccines

Summary Eight different rabies vaccines were tested for their potency in the standard mouse potency test using 3-, 5- and 7-week-old mice. 5-week-old mice seem to be best suited for this purpose, variability from test to test could be reduced considerably. An ELISA was used in parallel for the evaluation of the rabies glycoprotein content of rabies vaccines. Results of the mouse potency test correlated well with those of the ELISA if highly purified human vaccines were tested. Unspecific reactions in the ELISA caused by adjuvanted veterinary vaccines could not be blocked. Further experiments will be needed in order to evaluate the potency of inactivated veterinary rabies vaccines by a in vitro test.     

Ebola virus: the search for vaccines and treatments

Ebola viruses belong to the family Filoviridae, which are among the most virulent infectious agents known. These viruses cause acute, and frequently fatal, hemorrhagic fever in humans and nonhuman primates. Currently, no vaccines or treatments are available for human use. This review describes Ebola viruses, with a particular focus on the status of research efforts to develop vaccines and therapeutics and to identify the immune mechanisms of protection.     

Postimplantation embryo culture for the assessment of the teratogenic potential and potency of compounds

Whole rat embryos cultured during the early stages of organogenesis were subjected to a panel of selected chemicals. Of seventeen known in vivo teratogens, seventeen also induced specific malformations in embryos grown in culture. Of ten chemicals which were reported to be negative in in vivo rat teratogenicity studies, eight also did not provoke dysmorphogenic effects in vitro. Of five additionally tested retinoids, all induced multiple malformations. However, concentrations used to induce these effects varied considerably, isotretinoin inducing malformations at 10(-5) M and arotinoid at 10(-11) M. The results indicate qualitatively as well as quantitatively a high predictability of this in vitro system and suggest that the postimplantation embryo culture system may also be useful in the prospective testing of new drugs and environmental chemicals.     

Postimplantation embryo culture for the assessment of the teratogenic potential and potency of compounds

Summary Whole rat embryos cultured during the early stages of organogenesis were subjected to a panel of selected chemicals. Of seventeen known in vivo teratogens, seventeen also induced specific malformations in embryos grown in culture. Of ten chemicals which were reported to be negative in in vivo rat teratogenicity studies, eight also did not provoke dysmorphogenic effects in vitro. Of five additionally tested retinoids, all induced multiple malformations. However, concentrations used to induce these effects varied considerably, isotretinoin inducing malformations at 10^–5M and arotinoid at 10^–11M. The results indicate qualitatively as well as quantitatively a high predictability of this in vitro system and suggest that the postimplantation embryo culture system may also be useful in the prospective testing of new drugs and environmental chemicals.     

Time dependence of the number of histocompatibility loci in skin graft rejection of mice

Riassunto I dati esposti indicano che l'incremento del numero dei loci dell'istocompatibilità ai quali differiscono i due ceppi di topi «inbred» DBA/2 e C57BL/6 è inversamente proporzionale al tempo trascorso dal trapianto, ed è maggiore nelle femmine.

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This investigation was supported by a grant of the Consiglio Nazionale delle Ricerche.     

Studies on the thyroid in transgenic mice expressing the genes for human and bovine growth hormone

Summary The thyroid glands of transgenic mice (TM) expressing the genes for human (h) and bovine (b) growth hormone (GH) were studied. The percentages of larger follicles inhGH TM of either sex were significantly greater than in the corresponding normal littermates, and follicles ranging up to 350 m in diameter were present in malehGH TM. In contrast, thyroid follicles were only slightly enlarged in malebGH TM, and were unchanged in femalebGH TM. The serum concentrations of T4 were significantly decreased in malebGH TM and not altered in the other groups. Serum concentrations of T3 were slightly, but significantly increased in femalehGH TM and femalebGH TM, but were unaffected in male TM of either type. Since the principal difference between these foreign GHs in rodents is the additional lactogenic activity of human GH, these results may indicate that the effects of prolactin can influence the development of the thyroid.     

Studies on the thyroid in transgenic mice expressing the genes for human and bovine growth hormone

The thyroid glands of transgenic mice (TM) expressing the genes for human (h) and bovine (b) growth hormone (GH) were studied. The percentages of larger follicles in hGH TM of either sex were significantly greater than in the corresponding normal littermates, and follicles ranging up to 350 microns in diameter were present in male hGH TM. In contrast, thyroid follicles were only slightly enlarged in male bGH TM, and were unchanged in female bGH TM. The serum concentrations of T4 were significantly decreased in male bGH TM and not altered in the other groups. Serum concentrations of T3 were slightly, but significantly increased in female hGH TM and female bGH TM, but were unaffected in male TM of either type. Since the principal difference between these foreign GHs in rodents is the additional lactogenic activity of human GH, these results may indicate that the effects of prolactin can influence the development of the thyroid.     

Effects of increased ambient CO2 levels on human and animal health

This is the last work to have been completed by Karl Ernst Schaefer, who died on December 26th 1981, in Old Lyme, Connecticut. The physiological changes and problems brought on by an excess of carbon dioxide was, for many years, one of the prime research interests of this eminent respiratory physiologist. In the present work, Schaefer explored the physiological limits of diving with varying N₂–O₂ mixtures. The paper contains a wealth of information relevant to the many still unanswered questions in the field and invaluable suggestions with respect to the course of future research. This work yielded, moreover, some interesting disease models for such disturbances as arrhythmia and bradycardia.     

Heterotransplantation of human glioblastoma in the brain of newborn mice]

7 human multiform glioblastoma have been transplanted into the brain of 100 new born Mice. Electron microscopy and chromosome analysis confirm the growth of a human tumor showing malignant features of glioblastoma.