Search PubMed⌕ Search

Biomedical subjects

P Ball

Publications and source records attributed to P Ball.

170 records · Page 10Linked to original sources
PubMedDate not supplied

Long-term use of quinolones and their safety.

Although short courses of 4-quinolones are effective in routine infections, longer courses are necessary for chronic, deep-seated sepsis. Oral 4-quinolones exhibit efficacy equal to that of traditional parenteral regimens against osteomyelitis caused by gram-negative pathogens and have proved successful against chronic prostatitis and suppurative otorhinologic infections. The efficacy of these agents in the prophylaxis of urinary tract infection, travelers' diarrhea, and infections in neutropenic patients suggests other indications for potential widespread, long-term use. It is therefore important that the tolerability of regimens extending from 3-6 weeks to greater than or equal to 12 months has proved excellent. Potentially serious adverse reactions (including arthritis, cataract formation, and mutagenesis) noted in chronic animal toxicity or in vitro studies have no apparent human counterparts. However, experience is limited, and restrictions on use of the quinolones in children--except where real benefit outweighs theoretical risk--should not yet be abandoned.

4-Quinolones↗
PubMedDate not supplied

Isolation and characterization of a Rhizobium loti gene required for effective nodulation of Lotus pedunculatus.

A Rhizobium loti gene required for effective invasion of the host Lotus pedunculatus has been identified by transposon Tn5 mutagenesis. Cosmids that complemented a previously isolated mutation (239) at this invasion (inv) locus were identified by in planta complementation and used to construct a physical map of the gene region. The insertion site of Tn5 in PN239 was mapped to a 7.5-kb EcoRI fragment, which complemented the mutation when subcloned into pLAFR1. Further Tn5 mutagenesis of the 7.5-kb fragment was carried out in Escherichia coli using bacteriophage lambda 467, and the mutations homogenotized into R. loti NZP2037. Three additional Fix- mutations were isolated, and these were found to map adjacent to the position of the original mutation in strain PN239. All the other Tn5 insertions isolated in the 7.5-kb fragment gave a Fix+ phenotype on L. pedunculatus. Electron microscopic examination of the L. pedunculatus nodules induced by the isolated Fix- mutants showed that bacteria were either blocked in release from the infection threads or were unable to undergo normal bacteroid development. The inv locus as defined by the Tn5 insertions was sequenced, and a single open-reading frame (ORF) of 576 bp, corresponding to a polypeptide of 21.3 kDa, was identified. The position and orientation of this ORF were consistent with those of the isolated Tn5 Fix- insertions.

Amino Acid Sequence↗