To elucidate the mechanism of DNA strand scission by bleomycin, a d(C-G-C-G-C-G) duplex was treated with the bleomycin-iron ion complex in the presence of H2O2 and degradation products (1, 2, cytosine and deoxyguanosine 5'-phosphate) were identified. 1 and 2 contain a carboxymethyl group attached to the 3'-terminal phosphoryl group of d(C-Gp) and d(C-G-C-Gp), respectively. These compounds were identified by UV, 1H and 31P NMR spectroscopy and paper electrophoresis. 1 was synthesized from the protected dinucleotide and glycolic acid and the proton NMR spectrum was identical to that of 1 obtained as a degradation product. Thus the oligonucleotide fragments produced by the action of bleomycin on DNA were directly identified and cleavage of the C3'-C4' bond of the sugar residues was proved.

Bleomycin↗

PubMed1984

An attempt to produce an antibody of histamine and histamine derivatives.

Three conjugates of different histamine derivatives to bovine serum albumin were prepared, and an attempt was made to determine whether antibody against histamine and histamine derivatives could be produced in rabbits by immunization with these conjugates. Antibody produced by immunization with bovine serum albumin-succinylhistamine conjugate could not recognize the hapten moiety of the immunogen. Immunization of rabbits with conjugate of bovine serum albumin and p-[2-(N alpha-trifluoroacetylhistamine)azo]benzoic acid resulted in the production of antibody to N alpha-trifluoroacetylhistamine. The antibody had a specificity for histamine metabolites and their derivatives. However, the antibody also showed a small but not negligible affinity for trifluoroacetylated serotonin, norepinephrine and aniline, indicating that the antibody specificity was directed mainly to the trifluoroacetamide group. After immunization of rabbits with bovine serum albumin and p-[2-(N alpha-propionylhistamine)azo]benzoic acid conjugate, antibody against N alpha-propionylhistamine could be produced. However, the antibody had a very low affinity even for N alpha-propionylhistamine. Specific antibody to histamine and histamine derivatives could thus not be produced by immunization with the present hapten-carrier conjugates.

Animals↗

PubMed1984

Inhibition of slow-reacting substance release by calmodulin blocker.

It was examined whether a calmodulin blocker could inhibit release of slow-reacting substance from human leukocytes. W-7, a specific calmodulin blocker, completely inhibited slow-reacting substance release induced by calcium ionophore or mite allergen at 5 X 10(-5) M, while W-12, which had a lower affinity to calmodulin, failed to inhibit the release even at 10(-4) M. It was suggested that calmodulin was involved in mechanisms of slow-reacting substance release. Release of PGE2 and PGF2 alpha by calcium ionophore was partially inhibited by 5 X 10(-5) M of W-7. The inhibitory effects of W-7 on slow-reacting substance release could be considered responsible for the suppression of phospholipase A2.

Autacoids↗

PubMed1984

[Immunopharmacological actions of neurotropin (4). Effect of neurotropin on mouse peritoneal macrophages].

It was reported that neurotropin (NSP), an extract isolated from the inflamed skins of rabbits inoculated with vaccinia virus, activates murine T cell functions participating in cell-mediated immunity. The present study was undertaken to examine the effect of NSP on plastic dish-adherent macrophages (M phi) from ddY mice in vitro. Total activities of beta-glucuronidase and N-acetyl-beta-D-glucosaminidase in resident peritoneal M phi was slightly enhanced when the M phi were cultured with NSP (10-1000 micrograms/ml) for 48 and 96 hr, but no enhancement was noted in 24 hr culture. Intracellular activity of lactate dehydrogenase (LDH) was also strongly enhanced in a dose-dependent manner by culturing with NSP for 48 and 96 hr. The enhanced LDH activity in the M phi cultured with NSP for 96 hr was completely inhibited by cycloheximide, an inhibitor of protein synthesis. In addition, consumption of glucose in the culture media by the M phi was also enhanced by culturing with NSP for 96 hr. Intracellular activity of LDH and glucose consumption of plastic dish-nonadherent cells from normal mouse peritoneal cells, however, was not enhanced by NSP in 96 hr culture. In regard to allogeneic M phi-mediated cytostatic activity to P815-X2 mastocytoma, NSP had no effect on cytostatic activities of the resident and thioglycollate-induced M phi, although NSP by itself dose-dependently inhibited the growth of P815-X2 mastocytoma without affecting cell viability. These results suggest that NSP biochemically activates mouse peritoneal M phi in vitro, but the M phi activated by NSP can not inhibit the growth of P815-X2 mastocytoma.

Adjuvants, Immunologic↗

PubMed1984

[Release of slow-reacting substance of anaphylaxis (SRS-A) from human lung and inhibitory effect by beta-stimulants].

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Adrenergic beta-Agonists↗