Biomedical subjects
Publications and source records attributed to B L Carr.
Neonatal endophthalmitis is a rare entity that may be exogenous or endogenous. Pseudomonas aeruginosa is a ubiquitous gram-negative rod that may appear as a nosocomial source of infection in the neonatal intensive care unit. A case of bilateral Pseudomonas-induced endophthalmitis is presented, and a discussion of the case and of the relevant literature follows.
The pituitary of goitrogen-treated White Leghorn cockerels is smaller in size than control birds and the pituitaries of castrated cockerels is nearly twice the size of control birds. The pituitary cells generated by these treatments may not be functional thyrotrophs or gonadotrophs and may not be able to respond to their usual stimuli. Low ambient temperature is a well-known stimulus to the thyroid gland acting through pituitary TSH. Cyclic-AMP-dependent protein kinase activity levels are used here as an index of cellular activity in the pituitary and thyroid glands. Castrated cockerels with or without methimazole treatment do not have an increased pituitary cAMP-dependent protein kinase activity in cold. Methimazole-treated birds have an exaggerated pituitary protein kinase response to cold stress when compared with controls. Pituitary cAMP-dependent protein kinase activity is paralleled by a similar activity increase in the thyroid gland of methimazole-treated cockerels and no increase in the thyroid of castrated birds. Castrated birds at all temperatures have an elevated thyroid cAMP-dependent protein kinase activity ratio which is interpreted as the result of removal of testosterone inhibition.
Pituitary cyclic adenosine monophosphate-dependent protein kinase (cAMP-PK) activity ratios of castrated cockerels on a short photoperiod are highest 2 weeks after testosterone removal in castrated birds and remain high through a 3rd week. Castrated cockerels on long photoperiods have a decline in cAMP-PK activity ratios after an elevation at 1 week following testosterone removal. This is interpreted to mean that the pituitaries of cockerels on short photoperiods are sensitive to testosterone inhibition but that this sensitivity disappears in long photoperiod-stimulated birds. Long daylengths also appear to enhance thyroid activity in castrated cockerels, although thyroid cAMP-PK activity ratios increase in the thyroid of all cockerels following the removal of testosterone (castration). These results suggest that testosterone has an inhibitory effect on both the pituitary and thyroid glands.
Pituitary cyclic AMP-dependent protein kinase (cAMP-PK) activity ratios are not increased in response to thyrotropin-releasing hormone (TRH) in old chickens (retired White Leghorn breeders). This reduced responsiveness may be due to reduced hypothalamic function, reduced thyrotrope function, or to a reduction in TRH membrane receptors. The thyroid cAMP-PK activity ratio of old males does not respond to TRH treatment but the thyroid of old females does have an increased activity ratio ater TRH injection. Both males and females have a much higher basal cAMP-PK activity ratio than young birds. This higher basal level is thought to be due to an increased thyroid-stimulating hormone (TSH) stimulation, and the failure of old males to increase activity after TRH injections may be due to a loss of the thyroid's ability to respond to direct TRH stimulation.
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