Obesity is typically associated with increased tumor susceptibility, whereas caloric restriction, a regimen resulting in leanness, inhibits carcinogenesis. The link between adiposity and malignancies suggests that adipose tissue may influence carcinogenesis. An adipose tissue hormone, leptin, could be procarcinogenic because it stimulates proliferation in various tissues and tumor cell lines. L...

Esophageal cancer is the sixth leading cause of cancer death and remains one of the least survivable cancers. Esophageal cancers show wide variations in incidence in different population, suggesting that environmental or lifestyle risk factors could be controlled to reduce risk of these diseases. There are two major histopathologic types (squamous cell carcinoma and adenocarcinoma) of esophagea...

With the use of 2.1 M sucrose solution, nuclei were isolated from normal, control, and azo preneoplastic livers, and from azo dye-inducedliver tumors of rats. Four consecu tive extractions of nuclear sap in isotonic saline-phosphate buffer solubiized 49 and 37 per cent of the nitrogen of liver and tumor nuclei, respectively. Velocity sedimentation analyses revealed that the soluble nuclear macr...

This communication is an attempt to clarify and extend the concepts dealing with certain extrinsic or intrinsic factors that augment or retard .darcinogenesis. Before discussing carcinogenesis it may be helpful to differentiate again between carcinogenesis and the subsequent growth of a tumor. 1 Carcinogenesis implies the initiation of a neoplasm by a tumor-producing agent acting on normal tiss...

The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. E...

Recent epidemiological studies suggest that high meat intake is associated with promotion of colon cancer linked with haem-iron intake. We previously reported that dietary haem, in the form of either haemoglobin or meat, promotes precancerous lesions in the colon of rats given a low-calcium diet. The mechanism of promotion by haem is not known, but is associated with increased lipid peroxidatio...

56 (3). Another recent report concerned with the incidence of respiratory cancer in nickel workers refers to a total cancer mortality excess of over 3 times that in the population as a whole during the 9-year period 19@9—38, this excess occurring entirely in the two sites referred to above (11). The latter report also points out that in the Clydach Works, “Nodeaths from nasal cancer have be...

Viral carcinogenesis presents many problems which are the object of very active investigation; to condense in a lecture the present status of all these problems and to do justice to them would be impossible; I shall therefore limit the discussion to a few of them, which concern mainly the mechanism of carcinogenesis by viruses. In this discussion the at tent ion will be focused on experimental ...