A carcinogenicity study of instant coffee in Swiss mice.

Commercially available regular instant coffee was given in the diet to barrier-maintained, specified pathogen-free Swiss mice for 2 yr. Groups of 150 males and 150 females were fed diets containing 10, 25 or 50 g instant coffee powder/kg. The animals had already been exposed to coffee in utero. Coffee increased the energy expenditure of the animals as shown by increased daily calorific intake and depressed growth. The overall tumour incidence was inversely correlated to the coffee intake, and no unusual tumour or site of origin was found. The most frequent neoplasms were lymphosarcomas, bronchiolo-alveolar adenomas and adenocarcinomas, as well as hepatocellular adenomas. The incidence of total neoplasms (benign and malignant) decreased from 70.6 and 56.8% in control males and females, respectively, to 34.8 and 36.2%, respectively, in the high-dose group. This decrease, which was essentially due to a reduction in the number of lymphosarcomas and hepatocellular adenomas, was associated with a slower growth rate. The number of leiomyomas in the uterus was slightly increased due to coffee intake as shown by the analysis of positive trend (P less than or equal to 0.05). However, the incidence of this benign tumour was very low; 2.72% of mice affected in the high-dose group, 1.37% in the low-dose group and 0% in the control and medium-dose groups. From this study it is concluded that instant coffee did not increase the incidence of malignant neoplasms in mice when fed at dietary levels of up to 5% for 2 yr.

The woolly monkey (Lagothrix lagothricha): a possible model for human hypertension research.

The anatomical-pathological findings of 15 woolly monkeys were comparable with those described in man with essential benign or malignant hypertension. Kidneys revealed arterio- and arteriolosclerosis or an onion peel-like proliferation, in some cases necrotizing endarteritis. Obesity due to restricted physical activity, unnatural feeding, and psychical and physical stress could have contributed to the development of this condition. Further, high vulnerability of the genus woolly monkey is postulated. Thus, essential hypertension of woolly monkeys appears to be a multifactorial disease.

Immunocytochemical studies in canine neuroectodermal brain tumors.

Seventy-four canine neuroectodermal tumors were examined immunocytochemically for the presence of glial fibrillary acidic protein (GFAP). Eleven oligodendrogliomas were examined for the presence of myelin basic protein (MBP) and myelin-associated glycoprotein (MAG). Twenty-three tumors, including ten astrocytomas, one ependymoma, two glioblastomas, one case of gliomatosis, and nine poorly differentiated gliomas were positive for GFAP. Two astrocytomas, eleven oligodendrogliomas, eight ependymomas, four choroid plexus papillomas, two medulloblastomas, one glioblastoma, nine poorly differentiated gliomas, six cases of gliomatosis, and three unclassified tumors were GFAP-negative. In six tumors (including four that were classified as astrocytoma) GFAP staining was equivocal. All oligodendrogliomas were MBP-negative but three expressed MAG. It was concluded that many canine gliomas are not only morphologically but also immunocytochemically similar to human gliomas, but that a larger proportion of canine neuroectodermal growths are undifferentiated tumors.

Tumours of the nervous system.

Tumours of the nervous system of animals are not as rare as has been commonly believed. In dogs, especially the brachycephalic breeds, these tumours occur as frequently as in man. The tumours are grouped according to tissue of origin as follows: nerve cells, neuroepithelium, glia, peripheral nerves and nerve sheaths, meninges and vessels, the pineal and pituitary glands, and the craniopharyngeal duct. Tumours of the glia are relatively common and are divided into the following types: astrocytoma, oligodendroglioma, glioblastoma, spongioblastoma, medulloblastoma, and unclassified gliomas.