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D J Fairley

Publications and source records attributed to D J Fairley.

6 recordsLinked to original sources

Expression of gentisate 1,2-dioxygenase (gdoA) genes involved in aromatic degradation in two haloarchaeal genera.

Gentisate-1,2-dioxygenase genes (gdoA), with homology to a number of bacterial dioxygenases, and genes encoding a putative coenzyme A (CoA)-synthetase subunit (acdB) and a CoA-thioesterase (tieA) were identified in two haloarchaeal isolates. In Haloarcula sp. D1, gdoA was expressed during growth on 4-hydroxybenzoate but not benzoate, and acdB and tieA were not expressed during growth on any of the aromatic substrates tested. In contrast, gdoA was expressed in Haloferax sp. D1227 during growth on benzoate, 3-hydroxybenzoate, cinnamate and phenylpropionate, and both acdB and tieA were expressed during growth on benzoate, cinnamate and phenylpropionate, but not on 3-hydroxybenzoate. This pattern of induction is consistent with these genes encoding steps in a CoA-mediated benzoate pathway in this strain.

Benzoates↗

Aerobic metabolism of 4-hydroxybenzoic acid in Archaea via an unusual pathway involving an intramolecular migration (NIH shift).

A novel haloarchaeal strain, Haloarcula sp. strain D1, grew aerobically on 4-hydroxybenzoic acid (4HBA) as a sole carbon and energy source and is the first member of the domain Archaea reported to do so. Unusually, D1 metabolized 4HBA via gentisic acid rather than via protocatechuic acid, hydroquinone, or catechol. Gentisate was detected in 4HBA-grown cultures, and gentisate 1,2-dioxygenase activity was induced in 4HBA-grown cells. Stoichiometric accumulation of gentisate from 4HBA was demonstrated in 4HBA-grown cell suspensions containing 2,2'-dipyridyl (which strongly inhibits gentisate 1,2-dioxygenase). To establish whether initial 1-hydroxylation of 4HBA with concomitant 1,2-carboxyl group migration to yield gentisate occurred, 2,6-dideutero-4HBA was synthesized and used as a substrate. Deuterated gentisate was recovered from cell suspensions and identified as 3-deutero-gentisate, using gas chromatography-mass spectrometry and proton nuclear magnetic resonance spectroscopy. This structural isomer would be expected only if a 1,2-carboxyl group migration had taken place, and it provides compelling evidence that the 4HBA pathway in Haloarcula sp. strain D1 involves a hydroxylation-induced intramolecular migration. To our knowledge, this is the first report of a pathway which involves such a transformation (called an NIH shift) in the domain Archaea.

2,2'-Dipyridyl↗

Using fixed financial triggers for incentive plans.

Of course, some organizations are making no changes at all, because they don't believe that financial performance will justify paying even small awards. Healthcare organizations with executive incentive compensation plans need to review existing plans with their compensation committees. Merely leaving in place incentive plans developed prior to BBA may be doing a dis-service to the executive teams, the hospital, and the board. Using the incentive plan to focus management's attention on a few key areas is still relevant, maybe more so than ever. A complete review of incentive plans--participation, opportunity levels, financial triggers, performance measures, and other factors--is an important element of total executive compensation, probably now more than ever.

Budgets↗

Human malignant melanoma. Melanosomal polymorphism and the ultrastructural dopa reaction.

An ultrastructural dopa reaction, with glutaraldehyde--formaldehyde prefixation, was carried out on ten specimens of malignant melanoma showing a wide variation in melanosomal morphology. All tumours, but only a minority of tumour cells, contained reaction product. In all tumours the reaction product was distributed similarly in the Golgi apparatus and Golgi associated endoplasmic reticulum (GERL). However, differences were noted in its deposition in melanosomes. Whereas vacuolar and lamellar profiles sometimes contained reaction product, it was not seen in normal, granular and abortive melanosomes. Tumour cells without melanosomes were also seen to contain reaction product.

Dihydroxyphenylalanine↗

Langerhans cells in the epidermis of athymic mice.

Langerhans cells were identified with the electron microscope in the epidermis of six athymic nu/nu mice. Their origin in the thymus is ruled out and their functional dependence on either the thymus or T lymphocytes seems improbable.

Animals↗