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Biomedical subjects

P Barrow

Publications and source records attributed to P Barrow.

10 recordsLinked to original sources
PubMed1998

Use of lytic bacteriophage for control of experimental Escherichia coli septicemia and meningitis in chickens and calves.

A lytic bacteriophage, which was previously isolated from sewage and which attaches to the K1 capsular antigen, has been used to prevent septicemia and a meningitis-like infection in chickens caused by a K1+ bacteremic strain of Escherichia coli. Protection was obtained even when administration of the phage was delayed until signs of disease appeared. The phage was able to multiply in the blood. In newly borne colostrum-deprived calves given the E. coli orally, intramuscular inoculation of phage delayed appearance of the bacterium in the blood and lengthened life span. With some provisos there is considerable potential for this approach to bacterial-disease therapy.

Animals↗
PubMed1997

Resistance to salmonellosis in the chicken is linked to NRAMP1 and TNC.

Natural resistance to infection with Salmonella typhimurium in mice is controlled by two major loci, Bcg and Lps, located on mouse chromosomes 1 and 4, respectively. Both Bcg and Lps exert pleiotropic effects and contribute to cytostatic/cytocidal activities of the macrophage. Bcg encodes for a membrane phosphoglycoprotein designated Nrampl (natural resistance-associated macrophage protein 1), which belongs to an ancient family of membrane proteins, Lps has not been cloned yet, but its location on mouse chromosome 4 has been refined for positional cloning. As in mice, chicken inbred lines differ in their susceptibility to infection with Salmonella typhimurium. We have tested the candidacy of the chicken homologs of Nrampl and Tnc (a locus closely linked to Lps), in the differential resistance of chicken inbred lines to infection with S. typhimurium. We have first analyzed six inbred chicken lines of Salmonella-resistant or Salmonella-susceptible phenotypes for the presence of nucleotide sequence variations within the coding portion of NRAMP1. We have identified 11 sequence variations within NRAMP1 in the chicken inbred lines tested: 10 of these represented either silent mutations or conservative changes. However, one G-->A substitution at nucleotide 696 resulted in the nonconservative replacement of Arg223 to Gln223 within the predicted TM5-6 region. This allelic variant was specific to the susceptible line C and not observed in any of the resistant strains. To investigate the effect of NRAMP1 and TNC on resistance to infection with S. typhimurium, 425 (W1 x C)F1 x C chicken progeny were examined during a period of 15 days postinfection. Together, NRAMP1 and TNC explain 33% of the early differential resistance to infection with S. typhimurium of parental lines C and W1. Our data established that resistance to infection with S. typhimurium in chickens is inherited as a complex trait and that comparative mapping has proven to be useful to identify Salmonella-resistance genes in the chicken.

Amino Acid Sequence↗
PubMed1996

Widespread ectopic neuropeptide-Y immunoreactivity in contralateral mossy fibres after a unilateral intrahippocampal kainic acid injection in the rat.

Granule cells of the dentate gyrus can express neuropeptide-Y (NPY) in several models of epilepsy involving limbic seizures, however, the nature of this ectopic expression is not well understood at present. We have studied the expression of NPY-immunoreactivity in mossy fibres contralateral to a unilateral intrahippocampal injection of kainic acid and report that ectopic mossy fibre NPY-immunoreactivity is observed throughout the contralateral hippocampus.

Animals↗
PubMed1996

The influence of body weight on open field and swimming maze performance during the post-weaning period in the rat.

The open field and swimming maze tests are frequently used as part of a behavioural assessment battery in reproduction or developmental toxicology studies in the rat. Interpretation of the results of these tests is very difficult when the body weight of the rats is not similar in the various treatment groups. In order to better understand this problem, data from approximately 500 untreated rats tested under identical conditions were analysed with respect to body weight. No correlation was found in water maze performance or open field motor activity. A very slight but significant correlation was identified, however, in the time spent by female rats in various regions of the open field, with the smaller rats spending more time in the corners of the testing arena.

Analysis of Variance↗
PubMedDate not supplied

Resistance to Salmonella gallinarum, S. pullorum, and S. enteritidis in inbred lines of chickens.

Chickens of six inbred lines were inoculated intramuscularly with a range of doses of either Salmonella gallinarum, S. pullorum, or S. enteritidis, and levels of mortality were compared. For each serotype, large differences in mean lethal doses were observed for the different lines: Lines that had previously been shown to be resistant to S. typhimurium were also found to be resistant to S. gallinarum, S. pullorum, and S. enteritidis, and lines susceptible to S. typhimurium were also more susceptible to the other serotypes. These results suggest that there may be a general mechanism of resistance that may apply to all serotypes of Salmonella in chickens.

Animals↗