The inhibitory effect of caffeine on hormone-induced rat breast cancer.

Studies have associated coffee and/or caffeine with human fibrocystic breast disease. Two animal studies have implicated caffeine as a promoter in rat mammary cancer. The current investigation examines the effect of two caffeine doses in ACI rats with and without diethylstilbestrol (DES). Without DES, cancer did not develop in any of the rats receiving either of the two caffeine dosages. With DES, increasing caffeine dosage lengthened the time to first cancer, decreased the number of rats that developed cancers, and decreased the number of cancers overall. The presence or amount of caffeine did not cause detectable histologic differences in the breast cancers. The presence or amount of caffeine did not influence animal weight or mortality, although the rats without DES weighed more and survived better into old age. The presence or amount of caffeine did not influence pituitary weights and prolactin levels, although values of the DES groups were three times higher than the values for the group without DES (P less than 0.05). In conclusion, chronic caffeine ingestion inhibits rat breast cancer, neither by interfering with the high prolactin levels--a necessary step in murine tumor development--nor by causing hypocaloric intake.

The broadly based pericardial flap. A tissue for atrial wall replacement that grows.

The repair of many congenital heart anomalies would be facilitated by a tissue replacement for the atrial wall or pulmonary artery which would grow with the child. Such a tissue has not previously been identified. In 12 puppies a broadly based flap of pericardium was sutured over the right atrial free wall. The atrial wall was excised from beneath the flap. In four animals the flap was then cut away from its pericardial attachments superiorly, inferiorly, and along the phrenic nerve, leaving an autogenous pericardial patch. In the other eight animals the flap was left intact, allowing retention of neural and vascular supply. The animals were put to death 263 +/- 23 days later. In four animals having a pericardial patch, the area of the patch did not increase (94% of original size, NS) despite an increase in body surface area (BSA) to 169% (p less than 0.05) of original BSA. In eight animals with a pericardial flap, the area of the flap increased to 214% (p less than 0.01) of the original size with an increase in BSA to 199% (p less than 0.01) of original BSA. The flap size index (size/BSA) increased to 109% of the original index while the patch size index decreased to 54% of the original, a significant difference (p less than 0.01). The broadly based pericardial flap grew in a manner parallel to BSA increase in these puppies.

Unusual outbreak of tuberculosis due to Mycobacterium bovis in a closed colony of rhesus monkeys (Macaca mulatta).

An outbreak of tuberculosis due to Mycobacterium bovis among 46 rhesus monkeys housed in individual cages in the same large room of a closed experimental colony appeared to originate in one male that had been in the laboratory for 25 months. During this time, the animal received a total of 17 intrapalpebral tuberculin tests and two chest radiographs, all of which were negative. Of the remaining 45 animals in the room, 43 converted from tuberculin negative to positive within 7 weeks, while the animals in all other rooms remained tuberculin negative during the 1-year follow-up period.

Neurofibrillary accumulation in the zebra (Equus burchelli).

Two young zebra siblings from consecutive pregnancies suffered from neurological disease, characterized by ventral deviation of the neck and tetraparesis which progressed to tetraplegia within a few weeks. On histological examination widespread neuronal degeneration was observed in the ventral horns of the spinal cord and in the lower brain stem. Ultrastructurally the neuronal degeneration was characterized by accumulation of neurofibrillary material resembling neurofilaments. The findings are compared to other diseases with neurofibrillary accumulation in man and animals.