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P J Kirby

Publications and source records attributed to P J Kirby.

13 recordsLinked to original sources
PubMed2002

Cloning and mapping of platypus SOX2 and SOX14: insights into SOX group B evolution.

Group B SOX genes, the closest relatives to the sex-determining gene SRY, are thought to have evolved from a single ancestral SOX B by a series of duplications and translocations. The two SOX B genes SOX2 and SOX14 co-localize to chromosome 3q in humans. SOX2 and SOX14 homologues were cloned and characterized in the platypus, a monotreme mammal distantly related to man. The two genes were found to co-localize to chromosome 1q in this species. Proximity of the two related genes has therefore been conserved for 170 Myr, since humans and platypus diverged. The sequence similarity and conserved synteny of these group B genes provide clues to their origin. A simple model of SOX group B gene evolution is proposed.

Amino Acid Sequence↗
PubMed2000

Nosocomial Escherichia coli O157 infection.

Nosocomial transmission of Shiga toxin-producing Escherichia coli O157 to two patients and three nurses is described. The index case presented with rectal bleeding rather than diarrhoea, and additional infection control measures were therefore only instituted after detection of the organism. Of the nurses, two were asymptomatic and detected on a screening programme of all staff in contact with the affected patients. Two patients died, one from Clostridium perfringens bacteraemia. The use by staff of full protective gowns for handling patients from their first onset of diarrhoea is recommended, rather than plastic aprons. Interest from the media was intense, despite the small number of patients and staff affected, and early preparations for media enquiries should be made in such episodes.

Aged↗
PubMed1979

Inhibition of human lymphocyte transformation as an in vitro parallel line bioassay for anti-human lymphocyte globulin.

Horse anti-human lymphocyte globulin (HALG) is now widely clinically, but the variable immunosuppressive potency of different preparations of HALG has necessitated development of an accurate, reproducible in vitro assay of HALG potency. Currently available tests have several disadvantages, as well as showing little correlation with in vivo activity of the preparations tested. Incorporation of tritiated thymidine into lymphocytes, stimulated with mitogen (PHA) or antigen (PPD) and the inhibition of this process by HALG is described. ID50S and potency ratios have been determined for four HALG preparations. The ID50S obtained with these preparations were reproducible and the potency ratios obtained using 3 + 3 parallel line bioassay were similarly reproducible, a change in rank order being observed only once in ten assays. These in vitro results correlate with in vivo skin graft data. It is suggested that this technique could be used for evaluation of HALG preparations on peripheral blood from potential recipients.

Animals↗
PubMed1979

Relation between catecholamine-induced cyclic AMP changes and hyperpolarization in isolated rat sympathetic ganglia.

1. The effect of catecholamines on cyclic adenosine 3'5'-monophosphate (cyclic AMP) production in isolated rat superior cervical ganglia has been measured under experimental conditions in which they also produce ganglion hyperpolarization.2. (+/-)Isoprenaline (1 muM) increased cyclic AMP levels by 8-100 times after 15 min incubation at 25 degrees C. Half-maximal stimulation occurred at about 0.03 muM. This was due to stimulation of beta-receptors, since it was prevented by 1 muM-propranolol but not by 1 muM-phentolamine.3. The alpha-agonists phenylephrine (100 muM), dopamine (100 muM) and clonidine (1 muM) did not produce a detectable increase in ganglionic cyclic AMP. Dopamine (100 muM) was also ineffective at 37 degrees C in the presence of 10 mM-theophylline.4. Exogenous cyclic AMP (0.01-1 mM) hyperpolarized the ganglion. This effect was replicated by other adenosine compounds, most effectively by adenosine and by adenosine 5'-monophosphate, and was antagonized by theophylline. Dibutyryl cyclic AMP was weaker than cyclic AMP.5. Neither theophylline nor the non-xanthine phosphodiesterase inhibitor, Ro 20-1724, enhanced the hyperpolarizing actions of noradrenaline or dopamine.6. Since catecholamine-induced hyperpolarization of the isolated rat ganglion is induced via alpha-receptors, whereas cyclic AMP-production is induced via beta-receptors, it is concluded that cyclic AMP is unlikely to mediate the hyperpolarization. The effect of exogenous cyclic AMP may be due to an action on external adenosine-receptors.

Animals↗
PubMed1976

Defective PGE reactivity in leucocytes of multiple sclerosis patients.

Leucocyte migration inhibition in vitro, in response to antigen or mitogen, is suppressed by PGE2 (0.01-1.0 mug/ml). The susceptibility of leucocytes to such inhibition by PGE2 has been compared using cell preparations obtained from normal individuals, multiple sclerosis patients and from patients with other neurological diseases. The results indicate defective reactivity of leucocytes from multiple sclerosis patients.

Adult↗