Shiro Tsukada

Determination of metal content in three types of human gallstone

In general, human gallstones formed in the bile cyst and/or bile duct are classified into three major groups such as cholesterol stone, pigment stone and rare stone. Each group can further be divided into subgroups. It is well known that metals are minor components in the body but play very important roles for the biological functions. Metal content in human renal calculi was reported previously, but no paper have dealt with metal contents in relation to formation mechanism of gallstone. In this study, the authors have determined the metal content of gallstones. They discussed the differences of metal contents in the various components, and the age and sex differences in the metal contents of the gallstones. They also discussed the relationship between metals and formation mechanism of gallstone as well as the environmental contamination. They focused on calcium, magnesium, manganese, iron, copper, zinc, cadmium and lead.

Mutagenic activity of pyrolysates of cyanocobalamin and some other water-soluble vitamins in the model system with the Salmonella/mammalian microsomes

Pyrolysates of cyanocobalamin, thiamine hydrochloride, riboflavin, pyridoxine hydrochloride, and ascorbic acid were tested for mutagenicity in the histidine-requiring mutants Salmonella typhimurium TA98 and TA100. Each vitamin was sealed in a glass tube and heated at 100-600 degrees C in a muffle furnace. Methanol-chloroform extracts of the pyrolysate of each vitamin tested did not show any mutagenicity in either TA98 or TA100 without rat liver 9000 x g supernatant fraction (S9) added. In the presence of S9, the B-group vitamins (cyanocobalamin, thiamine hydrochloride, riboflavin, and pyridoxine hydrochloride) were all mutagenic in TA98 and TA100, with the highest activity among the vitamins tested found in the pyrolysate of cyanocobalamin. The pyrolysate of 0.25 mumole cyanocobalamin produced 3200 revertants, while the pyrolysates of 0.25 mumole thiamine hydrochloride and riboflavin produced only 910 revertants, and the pyrolysate of pyridoxine hydrochloride did not show any mutagenicity at that amount. The mutagenicity was generally more active to TA98 than to TA100, indicating that frameshift-type mutagens were contained in the pyrolysates. The pyrolysate of ascorbic acid did not show any mutagenic activity in either TA98 or TA100 under the present experimental conditions.

Determination of cadmium, copper, zinc, and lead in human renal calculi in both cadmium polluted and non-polluted areas

A number of investigators have reported about heavy metal contents in food, blood, urine, and animal tissues, including bone, hair, feather, and tooth. However, few data concerning calculi are reported as yet. Heavy metal contents in the calculi might reflect the level of metals absorbed from respiratory tract, skin and intestine. When absorbed metals from respiration are distributed in blood, a part of cadmium is accumulated in liver and kidney, and of lead is in bone, annular vessel and kidney. The remainder is excreted in the urine through the urinary tracts. From intestine, they are distributed by the blood to the liver, and excreted in the urine in the same manner of respiration. It is well known that renal calculi are produced in the urinary tract. The present study is focused on the contents of cadmium, copper, zinc and lead in human renal calculi, samples collected from Hokuriku which is one of the most cadmium polluted areas and from Chugoku which is recognized as a non-polluted one in Japan.