Embryonic vaccines against cancer: an early history.

Almost 100 years have passed since the seminal observations of Schöne showing that vaccination of animals with fetal tissue would prevent the growth of transplantable tumors. Many subsequent reports have affirmed the general idea that immunologic rejection of transplantable tumors, as well as prevention of carcinogenesis, may be affected by vaccination with embryonic/fetal material. Following a decade of intense research on this phenomenon during approximately 1964-1974, interest appears to have waned.

Short-term distribution of nicotine in the rat lung.

Nicotine is a dibasic amine with a pK(a) of 8.0. At physiological pH roughly 1/4 of the compound is nonionized and able to cross membranes, most notably the alveolar membranes of the lung.