Fluorometric Assay of Thioguanine

Finkel, Joe M.

doi:10.1002/jps.2600640126

Cited by 19 publications

(3 citation statements)

References 6 publications

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“…S1). Its absorbance and fluorescence spectra and acid lability were identical to G-6-SO 3 prepared by alkaline permanganate treatment of 6-TG (9-11) and authenticated by 1 H nuclear magnetic resonance and mass spectroscopy [see supporting online material (SOM)]. This authentic G-6-SO 3 also coeluted with the fluorescent 6-TG photoproduct on HPLC.…”

mentioning

confidence: 73%

Azathioprine and UVA Light Generate Mutagenic Oxidative DNA Damage

O′Donovan

Perrett

Zhang

et al. 2005

Science

578

513

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Oxidative stress and mutagenic DNA lesions formed by reactive oxygen species (ROS) are linked to human malignancy. Clinical treatments inducing chronic oxidative stress may therefore carry a risk of therapy-related cancer. We suggest that immunosuppression by azathioprine (Aza) may be one such treatment. Aza causes the accumulation of 6-thioguanine (6-TG) in patients' DNA. Here we demonstrate that biologically relevant doses of ultraviolet A (UVA) generate ROS in cultured cells with 6-TG-substituted DNA and that 6-TG and UVA are synergistically mutagenic. A replication-blocking DNA 6-TG photoproduct, guanine sulfonate, was bypassed by error-prone, Y-family DNA polymerases in vitro. A preliminary analysis revealed that in five of five cases, Aza treatment was associated with a selective UVA photosensitivity. These findings may partly explain the prevalence of skin cancer in long-term survivors of organ transplantation.

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mentioning

confidence: 73%

Azathioprine and UVA Light Generate Mutagenic Oxidative DNA Damage

O′Donovan

Perrett

Zhang

et al. 2005

Science

578

513

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“…Principle of the assay 6-thioguanine has little native fluorescence but on oxidation to guanine 6-sulphonate it is highly fluorescent and in aqueous solution 1 ng/ml is detectable (Finkel, 1975). This sensitivity cannot be achieved directly in plasma because of very high background fluorescence, which also makes the assay non-specific.…”

Section: Methodsmentioning

confidence: 99%

“…Fluorimetric methods for determining plasma concentrations of 6-thioguanine devised by Finkel (1975) and Thomas (1976) lacked sensitivity and specificity due to interfering plasma constituents. Recently Tidd & Dedhar (1978) have solved both these problems using HPLC-flow fluorimetry.…”

Section: Clinical Applicationmentioning

confidence: 99%

Assay of 6‐thioguanine in human plasma.

Dooley¹,

Maddocks²

1980

Brit J Clinical Pharma

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1. A fluorimetric method has been developed for measuring therapeutic concentrations of 6‐thioguanine in human plasma. The drug was measured as an oxidized derivative, guanine 6‐sulphonate. 2. 6‐thioguanine was extracted from plasma by a novel procedure which isolated the drug from an interfering plasma components. This method involved the formation of the thioguanine phenyl mercury derivative in alkaline plasma and its extraction into toluene. The free drug was released by back‐extraction into hydrochloric acid. 3. The assay is specific and shows a limit of sensitivity of 5 ng/ml. This was shown to be adequate for measuring plasma concentrations of 6‐thioguanine after the administration of a 160 mg dose in a patient with leukaemia.

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6-Thioguanine fromErwinia amylovora

Feistner

Staub

1986

Current Microbiology

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Fluorometric Assay of Thioguanine

Cited by 19 publications

References 6 publications

Azathioprine and UVA Light Generate Mutagenic Oxidative DNA Damage

Azathioprine and UVA Light Generate Mutagenic Oxidative DNA Damage

Assay of 6‐thioguanine in human plasma.

6-Thioguanine fromErwinia amylovora

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