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Biomedical subjects

A Sanfilippo

Publications and source records attributed to A Sanfilippo.

At least 37 records · Page 2Linked to original sources
PubMed1980

Biological activity of a new class of rifamycins. Spiro-piperidyl-rifamycins.

The biological properties of spiro-piperidyl-rifamycins, a new class of rifamycin antibiotics, are described. In these derivatives the positions 3 and 4 have been incorporated into an imidazolyl ring bearing a spiro-piperidyl group N substituted with linear and branched aliphatic chains. The in vitro antibacterial activity against Staphylococcus aureus and Mycobacterium tuberculosis increases with the number of the carbon atoms in the linera side chain, whereas the inhibitory effect on Escherichia coli is lowered. The antibacterial activity is only marginally affected by branching of the side chain. In vivo (experimental infections of mice) the optimal therapeutic activity against M. tuberculosis is shown by compounds bearing 3 approximately 5 carbon atoms as a linear or branched side chain; in comparison with rifampicin, the potency of these derivatives is 2 approximately 3 times higher. The finding is in a good agreement with the exceptional tissue tropism, which seems to be a favourable property of this group of derivatives.

Animals↗
PubMed1979

[Practical meaning of the determination of the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) (author's transl)].

The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) are the parameters generally used for evaluation of the activity of antibacterial agents. Particular care must be taken for the control of experimental conditions in which the MICs and the MBCs are determined (medium, inoculum, incubation, etc.) in order to obtain informations able to help in the choice and management of the dosage regimen of an antibacterial agent. The significance of MIC and MBC is discussed in connection with blood and tissue levels attainable during therapy and with the pharmacokinetic properties of a drug.

Anti-Bacterial Agents↗
PubMed1976

The effect of distamycin A on some biochemical functions of tissue cultures infected with Herpes simplex virus.

The antibiotic distamycin A displays no inhibition of protein synthesis in HeLa cell cultures. In HSV infected HeLa cell monolayers the drug exerts a partial inhibition of virus induced thymidine kinase synthesis but is devoid of inhibitory effect on the increase of activity of DNA polymerase and on total DNA synthesis. The antiviral activity of distamycin A is based on a mechanism which appears to be different from that displayed by other drugs such as actinomycin and IUD.

Culture Techniques↗
PubMed1975

Antiviral activity of a pyrazino-pyrazine derivative.

The 2,3-dihydroxy-6-bromo-pyrazino-[2,3-beta]-pyrazine is a substance selected during the antiviral screening of pyrazino-pyrazine derivatives. The compound shows antiviral activity in vitro against measles, NDV, some influenza viruses and against herpes simplex and zoster, infectious canine hepatitis and vaccinia viruses. It had no effect on ECHO 9 virus. Therapeutic trials showed activity also on herpetic keratoconjunctivitis experimentally induced in rabbits.

Adenoviruses, Canine↗
PubMed1975

On the mechanism of inhibition of enzyme induction in Escherichia coli by distamycin A.

The mechanism of the interference of the antiviral antibiotic distamycin A with the bacterial cell has been investigated. Labelled distamycin A is firmly bound by E. coli cells and the binding process does not require metabolic energy as indicated by the use of inhibitors. The antibiotic does not induce gross alteration in the cell membrane but inhibits cyclic AMP accumulation in the cells exposed to a glucose-free medium. This inhibition is concomitant with that exerted on the synthesis of an inducible enzyme such as beta-galactosidase. By the method of pulse induction it appears that distamycin A exterts its inhibiting effect on inducible synthesis at the level of transcription. This effect is probably related to an interference with the positive control of enzyme synthesis performed via the system represented by cyclic AMP and the CRP protein.

Binding Sites↗
PubMed1973

Axenomycins, new cestocidal antibiotics.

Axenomycins are a new group of macrolide antibiotics isolated from the fermentation broth of Streptomyces lisandri n.sp. They exhibit anthelmintic activity against tapeworms (Cestoda). Three different fractions, A, B, and D, have been obtained, the most active fraction being axenomycin D. The activities of the axenomycin complex and axenomycin D against Hymenolepis nana in mice, Taenia pisiformis, Dipylidium caninum, and Diphyllobothrium sp. in dogs, and Moniezia expansa, M. benedeni, and Avitellina centripunctata in lambs were studied in experimentally and naturally infected animals. Axenomycins were effective and well tolerated by the oral route. Worm reduction rates after a single oral dose were 90 to 100% with 5 to 10 mg of axenomycin D/kg and 50 to 100% with 20 mg of axenomycin complex/kg.

Animals↗