[The incidence and primary multiplicity of colon cancer].

Analysis of Moscow cancer register demonstrates a steady growth of colon cancer (CC) incidence and mortality in Moscow, also noted in all large industrial cities of economically developed countries. In Moscow between 1996 and 2001, the incidence of CC had grown 1.5 times (from 19.6 up to 30% per 100,000), and the CC-related mortality had grown twice (from 9.1 up to 19.5% per 100,000). The incidence of CC among women is 1.5 to 2 times higher than that among men. The burst of CC incidence is noted after age 55, and the peak incidence is noted at age 65. Not rare (2.9% of cases) are tumors that develop simultaneously in different divisions of the colon, which are diagnosed during the surgery or are omitted even then. Such synchronous large bowel tumors are found mostly in patients over 60. The analysis show that metachronous tumors (3.4% of cases) usually develop in the colon 8 to 10 years after the first surgery for CC, or some other cancer, and are found mostly in patients over 70. Unlike foreign statistics on multicentric CC cancer, according to which primary-multiple (synchronous and metachronous) cancers occur in 1.24 to 14% of cases, Moscow statistics demonstrate a lower likelihood of such a pathology in Muscovites. To sum up, patients who underwent treatment for CC or any other cancer should keep being under an oncologist's observation due to the likelihood of the development of a metachronous colon tumor 8 to 10 years later.

The role of chelators in the catalysis of glutathione-gamma-glutamyl transpeptidase-dependent lipid peroxidation by transition metals.

A gamma-glutamyl transpeptidase-glutathione (GGT-GSH) system induces transition metal-dependent lipid peroxidation (LPO). The role of the transition metals iron and copper in this system was studied by determination of LPO rates, the rates of Fe3+ reduction, and the steady state concentration of Fe2+ as function of concentration of o-phenanthroline or citrate. Optimum curves were obtained, compatible with the idea that Fe2+ chelated by an entity other than o-phenanthroline or citrate is important in thiol-driven LPO. Cu enhanced LPO at low concentrations, inhibited LPO at high ones, and catalytically elevated the steady state concentration of Fe2+. Relating the steady states of Fe2+ at various chelator concentrations with those of LPO rates, indicate that a Fe(2+)-O-O-Fe3+ complex may not be the principal oxidizing entity. The above, and the resistance of LPO to catalase, superoxide dismutase and mannitol are compatible with the notion that the Fe which participates in redox cycles is chelated to an entity that may be refractory to the action of these antioxidants.