The Romanian hamster Mesocricetus newtoni is endemic to South-Eastern Romania (Dobruja region) and North-Eastern Bulgaria, prefers steppic, arid, uncultivated habitats, but also found in alfalfa fields, less often corn cultures field-protecting vegetation belts. Previous studies provide only limited data regarding the diet of this cryptic species. one family group (one female four pups) was mon...

L IVER xenografting implies that most of the complement (C) in the recipients will be produced by the graft. It is known that membrane-bound proteins have the property of homologous restriction; ie. they inhibit MACmediated lysis only when the terminal C components are from the same species as the cells on which these proteins are expressed. I To test the hypothesis that this could be a mechani...

The cheek pouch of the Syrian hamster is an excellent model for the experimental study of oral carcinogenesis. The carcinogenic chemical 7,12-dimethylbenz[a]anthracene consistently produces epidermoid carcinomas in the cheek pouch of the Syrian hamster, giving rise to characteristic histopathological lesions in a time-dependent manner. We now present experimental evidence that c-Ki-ras mRNA can...

Endogenous retrovirus-like sequences homologous to intracisternal type-A particle (IAP) genes, which are present in the inbred mouse (Mus musculus) genome, were cloned from a Syrian hamster gene library. A typical hamster IAP gene was 7 kb long and segments homologous to long terminal repeat (IAP) sequences present in Mus musculus IAP genes were located at both ends of the gene. Contrary to the...

Upon incubation of hamster serum with bacterial endotoxin, a factor is produced which releases histamine and heparin from hamster mast cells and increases capillary permeability in guinea pig skin. The major histamine-releasing activity derived from hamster serum was characterized by gel filtration, found to have a molecular weight of approximately 60,000, and shown by electrophoresis to migrat...

Ribonucleic acids of known specific activities were separately prepared from hamster cells transformed by polyoma, simian virus 40 (SV40), and adenovirus 12. When increasing amounts of these labeled ribonucleic acids were added to nitrocellulose filters containing immobilized (14)C-hamster deoxyribonucleic acid (DNA), about 5% of the DNA sites were saturated in each case. An additive saturation...

The metabolic activation of the carcinogens N-nitrosobis(2-oxopropyl)amine (BOP) and N-nitroso(2-hydroxypropyl)(2-oxopropyl)amine (HPOP) by Fischer rat and Syrian hamster hepatocytes was investigated in order to determine the existence of species differences in the induction of cell mutation. The conversion of BOP and HPOP into forms mutagenic to V79 cells was studied by using the hepatocyte-me...

Although the increase in the rate of hamster ownership, no report of allergic sensitization to common hamster (Cricetus cricetus)-derived allergens as a consequence of domestic exposure has been published in Italy. A 64-year-old woman was referred to our Allergy Centre for the recent onset of conjunctival and severe respiratory symptoms (rhinitis, cough, wheezing and dyspnea). About three month...

The metabolism of [20-3H]-12-O-tetradecanoylphorbol-13-acetate ([3H]TPA) was studied in human and hamster cell cultures. Within 2 to 3 days after its addition to growing or confluent cultures of hamster embryo fibroblasts, no unchanged [3H]TPA remained in the medium as determined by thin-layer chromatography of the chloroform phase obtained by extraction of the medium with chloroform:methanol:H...