Effect of cigarette smoking and nicotine on plasma endothelin-1 levels.

Although cigarette smoking is an established risk factor for atherosclerosis, the true mediator of vessel diseases associated with smoking is not known. Because endothelin-1 (ET-1) exhibits potent vasoconstrictor activity, it may act as a mediator in this condition. We determined venous ET-1 and nicotine levels in 12 smokers (age 21-24 years, 2-52 pack-years) before and 10 min, 4 h, and 8 h after the beginning of smoking.

Activated macrophages and antibodies against the plant lectin, GSI-B4, recognize the same tumor-associated structure (TAS).

Activated macrophages that were stabilized with either formalin or glutaraldehyde absorbed two polypeptides (Mr 100,000 and 60,000) from detergent extracts of all of the tumor cell lines tested, but not from detergent extracts of normal human peripheral blood lymphocytes. A major polypeptide (Mr 95,000) was retained from spent culture media of tumor cell lines. Polypeptides with molecular sizes of 100,000 and 60,000 daltons were also adsorbed by activated macrophages from detergent extracts of chicken embryo cell membranes, suggesting an oncofetal nature for these proteins.