[Permeability of 5 methemoglobin formers through red cell membrane]

By measuring the methemoglobin formation, the permeabilities of some cyanide antidotes passing through mouse erythrocyte membrane were studied. K3Fe(CN)6(0.1 mol/L) did not permeate the red cell and no methemoglobin formed. To the red cell suspension, adding PAPP 0.07 mmol/L, an useful cyanide antidote, no methemoglobin was found. On the contrary, PHAPP, the metabolite of PAPP, transported into the cell readily and reacted with hemoglobin to form methemoglobin quickly. DMAP and NaNO2 passed through the red cell membrane easily. With comparable amount of methemoglobin formation, the concentration of NaNO2 was about 200 times as much as that of DMAP. A comparison of the anticyanide potency of DMAP and NaNO2, the permeability rate constant, the half time and activation energy were measured as: 0.217 and 0.0506/min; 3.2 and 13.7 min; 17.1 and 50.2 kJ/mol, respectively. Owing to its ready permeability and formation of methemoglobin, DMAP is a better antidote than NaNO2 against cyanide poisoning.

The diagnostic value of a hepatoma-specific band of serum gamma-glutamyl transferase

Using a vertical slab electrophoretic apparatus loaded with polyacrylamide stage gel plate, we observed a total of II bands of gamma-glutamyl transferase (EC 2.3.2.2,GGT) on a gel plate and designated these GGT I-XI by order of distance beginning at the positive pole. Positive GGT II was found in 81 (90%) of 90 cases of primary hepatic carcinoma (PHC), in 9(90%) of 10 cases of secondary hepatic carcinoma (SHC), and in only 4 (3.1%) of a total of 128 cases of acute and chronic liver disease. There was one case with positive GGT II among 45 cases of cancer of ampulla of Vater, but the possibility of hepatic metastasis could not be excluded. No GGT II was found in a total of 250 healthy persons and 21 pregnant women. PHC patients with negative alpha-fetoprotein (AFP) had a positive GGT II rate of 84.6%, whereas in those with negative GGT II the positive rate for AFP was only 44.4%.