Photosensitizing furocoumarins: Interaction with DNA and photo-inactivation of DNA containing viruses

Riassunto Le furocumarine possono legarsi in vitro al DNA ed, in misura molto minore, all'RNA. Per irradizione UV (3655 Å) in presenza di psoralene, tre virus a DNA sono stati inattivati, mentre nessun effetto è stato notato su altri tre virus ad RNA.     

Evidences of a photoreaction of the photosensitizing furocoumarins with DNA and with pyrimidine nucleosides and nucleotides

Riassunto Modificazioni negli spettri di fluorescenza si hanno irradiando (3655 Å) soluzioni di DNA o di nucleosidi e nucleotidi pirimidinici in presenza di furocumarine fotosensibilizzatrici. La formazione di nuovi composti nelle fotoreazioni tra psoralene e nucleosidi pirimidinici è stata confermata per cromatografia su carta.

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This study was presented at the IV International Photobiology Congress, Oxford, 26–30 July 1964.     

A comparison between the photoreactivity of some furocoumarins with native DNA and their skin-photosensitizing activity

Riassunto È stata determinata la fotoreattività con DNA nativo di un gruppo di furocumarine per irradiazione a 365 nm. I valori ottenuti sono risultati in accordo con quelli di attività fotosensibilizzatrice cutanea posseduti dalle stesse sostanze.     

The photoreaction between DNA and the skin-photosensitizing furocoumarins studied using labelled bergapten

Riassunto Ricerche eseguite con bergaptene-O¹⁴CH₃ confermano che tra questa sostanza ed il DNA avviene una fotoreazione in seguito ad irradiazione a 3655 å, che porta alla formazione di una stabile combinazione tra la furocumarina e lo stesso DNA.     

Interaction of platinum compounds with bacterial DNA

Summary The cis and trans isomer of PtCl₂(NH₃)₂, cis-Pt(cpa)₂Cl₂ and 2 platinum pyrimidine blues have been used in a number of bacterial tests indicative of their interaction with bacterial DNA.This investigation was supported by a grant from C.N.R., Rome. We thank Mrs S. Saincich for skilful technical assistance.     

Photoinactivation of ehrlich ascites tumor cells in vitro obtained with skin-photosensitizing furocoumarins

Riassunto Il liquido ascitico del tumore di Ehrlich, irradiato a 3655 Å in presenza di furocumarine «fotosensibilizzatrici cutanee» e cioè di psoralene o xantotoxina o bergaptene, perde la capacità di trasmettere il tumore nel topo.     

Interaction of benznidazole reactive metabolites with nuclear and kinetoplastic DNA,proteins and lipids fromTrypanosoma cruzi

Summary Epimastigotes ofTrypanosoma cruzi (Tulahuen strain Tul 0 stock) biotransform benznidazole (N-benzyl-2-nitro-1-imidazone acetamide) to reactive metabolites that bind covalently to DNA, proteins and lipids of the parasite. These effects might be related to the trypanocidal action of benznidazole, a chemotherapeutic agent against Chagas' disease.     

Dietary immunostimulation: Interaction with BCG and LPS

Summary The action of BCG and LPS mR595 used in conjunction with a formula-defined diet is dependent on the administration timing and resembles that of interacting adjuvants affecting different elements of the immune system.Acknowledgments. This work was made possible through a grant from the Medical Research Council of Canada. The authors are grateful to Bristol Myers Co. for providing the FDD, to Drs G. Bounous and G. Fisher for their interest and helpful comments, to Mrs S. Bachand for her technical assistance and to Mr P. Charland for taking care of the animals.     

Superinfection of tumors with viruses

Zusammenfassung Neoplastische Gewebskulturen, infiziert mit einem Mäuseleukämievirus, wurden entweder mit «Newcastle Disease Virus» oder mit «Vesiculare Stomatitis Virus» superinfiziert; die Zellen zeigten beschleunigte oder verlängerte Wachstumsraten, wenn sie in den ursprünglichen Mäusestamm injiziert wurden.     

Interaction of benznidazole reactive metabolites with nuclear and kinetoplastic DNA, proteins and lipids from Trypanosoma cruzi

Epimastigotes of Trypanosoma cruzi (Tulahuen strain Tul 0 stock) biotransform benznidazole (N-benzyl-2-nitro-1-imidazole acetamide) to reactive metabolites that bind covalently to DNA, proteins and lipids of the parasite. These effects might be related to the trypanocidal action of benznidazole, a chemotherapeutic agent against Chagas' disease.     

Platelets and viruses: an ambivalent relationship

Thrombocytopenia is a frequent complication of viral infections providing evidence that interaction of platelets with viruses is an important pathophysiological phenomenon. Multiple mechanisms are involved depending on the nature of the viruses involved. These include immunological platelet destruction, inappropriate platelet activation and consumption, and impaired megakaryopoiesis. Viruses bind platelets through specific receptors and identified ligands, which lead to mutual alterations of both the platelet host and the viral aggressor. We have shown that HIV-1 viruses are internalized specifically in platelets and megakaryocytes, where they can be either sheltered, unaltered (with potential transfer of the viruses into target organs), or come in contact with platelet secretory products leading to virus destruction and facilitated platelet clearance. In this issue, we have reviewed the various pathways that platelets use in order to interact with viruses, HIV and others. This review also shows that more work is still needed to precisely identify platelet roles in viral infections, and to answer the challenge of viral safety in platelet transfusion.     

Interaction of pepsin with lysozyme

Riassunto L'autore ha studiato il complesso che si forma dall'interazione della pepsina con il lisozima.Vengono riferiti i risultati ottenuti studiando le caratteristiche torbidimetriche, elettroforetiche e di sedimentazione all'ultracentrifuga del complesso pepsinalisozima.Il complesso ha il punto isoelettrico a pH 7.3, ed ha una costante di sedimentazioneS ₂₀=4.9×10^–13.     

Interaction of lead with erythrocytes

Zusammenfassung Untersuchungen mit²⁰³Pb in vitro ergeben, dass Blei in den Erythrozyten vorwiegend an Hämoglobin gebunden wird, während Stromasubstanzen kein Blei aufnehmen.