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T R Sharp

Publications and source records attributed to T R Sharp.

24 records · Page 2Linked to original sources
PubMed1977

Mandelate racemase from Pseudomonas putida. Absence of detectable intermolecular proton transfer accompanying racemization.

An equimolar mixture of DL-[alpha-2H]- and DL-[alpha-13C]mandelate, when incubated with mandelate racemase (EC 5.1.2.2), shows conversion of singly labeled mandelate to unlabeled mandelate, due to solvent exchange of the alpha proton, while the level of doubly labeled mandelate remains at a constant low level. Similarly, an equimolar mixture of unlabeled and DL-[alpha-2H,alpha-13C]mandelate, when incubated with the enzyme, shows conversion of doubly labeled mandelate to singly labeled mandelate, due to solvent exchange, while the level of unlabeled mandelate remains constant at 50%. Incubation of an equimolar mixture of DL-[alpha-3H]mandelate and DL-rho-chloromandelate. These results indicate that mandelate racemase does not catalyze an intermolecular proton transfer to achieve racemization. These data are necessary, but not sufficient, results to indicate that mandelate racemase operates via a one-acceptor mechanism, in which the proton abstracted from one stereochemical face of a substrate molecule is returned to the opposite face of the same carbon of the substrate molecule.

Carbon Isotopes↗
PubMedDate not supplied

Identification of major lipids from the scent gland secretions of Dumeril's ground boa (Acrantophis dumerili Jan) by gas chromatography-mass spectrometry.

The scent gland secretions of Dumeril's ground boa (Acrantophis dumerili), pooled from two adult males and a female, were analyzed by gas chromatography-mass spectrometry. 2-Hydroxy-propanoic acid, hexadecanoic acid, cis-9-octadecenoic acid, octadecanoic acid, cholesterol, and 5-cholesten-3-one were indicated. These results are compared with those obtained in analyses of the scent gland secretions of other snakes.

Animals↗
PubMedDate not supplied

Serum concentrations of 5-FU, ftorafur, and a major serum metabolite following ftorafur chemotherapy.

Daily 24-hour serum levels of ftorafur (FT), 5-FU, and a major FT metabolite, dehydroftorafur (DFT), were monitored by high-performance liquid chromatography as part of a phase I study designed to evaluate FT as a radiosensitizing 5-FU pro-drug in patients with advanced gastrointestinal cancers. At a daily iv bolus FT dose of 1.0 g/m2, 5-FU was not detected in serum concentrations above the reliable assay limits of approximately 25 ng/ml; FT did not generate the extracellular (serum) 5-FU concentrations required for sensitization by 5-FU per se. DFT was present in every patient serum tested and was confirmed to be a metabolite of FT by in vitro conversion to 5-FU. Chemical ionization solid-probe mass spectrometry of the DFT metabolite indicates the dehydro FT structure proposed by other researchers. In six of eight patients monitored, a consistent relationship was noted between serum levels of FT and DFT.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Conservative management without alkylating agents of squamous cell anal cancer using cyclical 5-FU alone and x-ray therapy.

We have treated 11 patients with squamous cell anal carcinoma using a regimen of repeated cycles of 120-hour infused 5-FU (25 mg/kg/24 hours) and x-rays. Total radiation doses were between 3000 (palliative) and 4750 (curative) rads. Unlike all other equivalent combined-modality studies, no alkylating agent or drug other than 5-FU was used. With follow-up between 1 and 4 years, there has been only one local recurrence (coincident with terminal disseminated disease in a stage III patient treated palliatively). All other patients have maintained local control. Inclusion of alkylating agents (eg, mitomycin) in this approach can be questioned if the patient is willing to accept somewhat greater acute but reversible toxic effects.

Alkylating Agents↗