The mechanism of the riboflavin sensitized photodestruction of mitomycin C.

A detailed in vitro study was made of the riboflavin sensitized photodestruction of mitomycin C. The dependences of the quantum yield in the system were examined on the introduction of various amounts of quenchers, such as halogen ion, paramagnetic ion, 1,4-diazabicyclo[2,2,2]octane, 2,6-di-tert-butyl-p-cresol, and p-hydroquinone. The results are consistent with a mechanism involving oxygen molecule in the excited singlet state as the photochemically reactive species. The rate constant of the reaction between the excited singlet oxygen and mitomycin C was calculated to be 8.9 x 10(9) M-1.S-1.     

A new synthesis of 5''-deoxy-8,5''-cyclo-adenosine and -inosine: conformationally-fixed purine nucleosides (nucleosides and nucleotides. XVI).

A versatile method for the synthesis of 5'-deoxy-8,5'-cycloadenosine, a conformationally-fixed "anti" type of adenosine, was presented. Irradiation of 2', 3'-O-isopropylidene-5'-deoxy-5'-phenylthioadenosine with 60W Hg vapor lamp afforded 2',3'-O-isopropylidene-5'-deoxy-8,5'-cycloadenosine in high yield. The use of other 5'-alkylthio derivatives also gave the cycloadenosine, though the yields were rather poor. Deacetonation of the cyclocompound with 0.1N HCl gave 5'-deoxy-8,5'-cycloadenosine. The cycloinosine derivative was similarly prepared. The nmr, mass and CD spectra of 5'-deoxy-8,5'-cycloadenosine were given and discussed with the previously reported results.     

Effects of CB-154 (2-Br-alpha-ergocryptine) on prolactin and growth hormone release in an acromegalic patient with galactorrhea.

An acromegalic patient with galactorrhea was treated with an ergot alkaloid, 2-Br-alpha-ergocryptine (CB-154). Serum prolactin decreased rapidly to normal level by CB-154 and the complete cessation of galactorrhea was noted. The inhibitory effect of CB-154 On growth hormone (GH) release was also noted, but slight. The mechanism of inhibitory action of CB-154 on both prolactin and GH secretion was discussed in connection with the experimental model of pituitary tumors, in which both hormones were produced by a single type of tumor cells. The discontinuation of CB-154 treatment was associated with the return of both prolactin and GH levels to the initial high values with resumption of galactorrhea.     

Studies on live rubella vaccine. VI. Seroepidemiological surveillance and immunization of adolescents in high school.

The rubella seroimmunity status of a total of 1,204 students aged 12 to 19 in a junior and a senior high school in Osaka district was surveyed. Among these, 487 students (40.5%) were found to be seronegative (less than 1 : 8) by the hemagglutination inhibition (HI) test. A total of 287 students were immunized with live rubella vaccine, Biken lot No.7233. This caused an increased titer in all except one of the 262 seronegative students, while among 25 students with an initial HI antibody titer of 1 : 8 it caused more than 4-fold increase in 20 and 2-fold increase in 5. The vaccine caused no clinical manifestations, such as fever, rash or arthralgia.     

The physiological significance of the xanthurenic acid-insulin comples.

The xanthurenic acid-insulin complex was found to have similar immunological properties to native Zn-insulin. This complex showed less hormonal activity on glucose metabolism in adipose tissue than native An-insulin, but its activity was increased by addition of Zn2+ ions.