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Biomedical subjects

J Von Berger

Publications and source records attributed to J Von Berger.

5 recordsLinked to original sources
PubMed1985

Interaction of papaverine with covalently closed DNA.

Cyclic nucleotides influence viral replication and papaverine, as an inhibitor of phosphodiesterase, also affects the replication of both DNA and RNA viruses through an increase in cAMP levels. Moreover in vitro papaverine affects neither protein synthesis nor several polymerases, while it inhibits DNA synthesis. Static fluorescence studies on the interaction of the drug with ColE1 plasmid covalently closed DNA indicate that the drug binds to the nucleic acid, probably by intercalation. A comparison between the binding characteristics of Papaverine and Actinomycin D is also reported.

Bacteriocin Plasmids↗
PubMed1984

Different ability of novobiocin and coumermycin A1 to interact with nucleic acids.

The possibility of two structurally related antibiotics, Coumermycin A1 and Novobiocin, to interact with nucleic acids was investigated. Only Coumermycin A1 was able to form complexes with DNA showing an apparent affinity constant comparable to that of the interaction with ribosomal RNA. A binding specificity for A + T complementary and repeating sequences was also exhibited by Coumermycin A1. In view of the different behaviour of the two compounds some considerations are made on their mode of action; although they are acting on the same target enzymes in Escherichia coli, they may affect the functions of eukaryotic cells through a different mechanism not equally specific and probably distinct for each of the two antibiotics.

Aminocoumarins↗
PubMed1981

[Intermolecular interactions between fluorescent probes bound to linear DNA].

Intermolecular interactions of fluorescent probes bound to linear DNA. Several fluorescent probes can be widely used in determining the base content, the geometry and the possible conformational transitions of linear and circular DNAs in solution. Data are presented showing that Tb3+ and DAPI bind independently to DNA and can therefore be used to monitor the G+C and A+T content of the nucleic acid respectively.

Amidines↗
PubMed1978

[Experimental study on hepatic encephalopathy: EEG and blood amino acid findings].

The AA. describe a method of gradual occlusion of the portal vein in the rat to induce a hepatic encephalopaty. This method allows to realise a condition of hepatic ischemia and a portal hypertensive state accompanied by spontaneous portal-systemic shunts. These two factors produce a hepatic encephalopaty like in cirrhotic state or in patients after portal systemic anastomosis. A part from similar behavior at the beginning of the encephalopaty it is possible to define two classes of animals: one showing a slow recovery and one showing a transient and slight improvement followed at the end by the death of the animal. The AA. found a definite correlation amoung the clinica, EEG's, serum aminoacids and biochemical data. Probably the different anatomical and phisiological aspects of the induced portal systemic shunts and the different ways of hepatic rivascularization may determine the two different evolutions of the animals.

Amino Acids↗