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Biomedical subjects

R W Watts

Publications and source records attributed to R W Watts.

At least 199 records · Page 11Linked to original sources
PubMed1969

The conversion of 4-hydroxypyrazolo[3,4-d]pyrimidine (allopurinol) into 4,6-dihroxypyrazolo[3,4-d]pyrimidine (Oxipurinol) in vivo in the absence of xanthine-oxen oxidoreductase.

1. A patient with congenital deficiency of xanthine oxidase (EC 1.2.3.2) (xanthinuria) excreted the xanthine isomer 4,6-dihydroxypyrazolo[3,4-d]pyrimidine (oxipurinol) in his urine when the hypoxanthine isomer 4-hydroxypyrazolo[3,4-d]pyrimidine (allopurinol) was given by mouth. 2. The identity of the oxipurinol that the patient excreted was established by mass spectrometry. 3. The mass spectra and infrared spectra of allopurinol, oxipurinol, hypoxanthine and xanthine are compared. 4. A mechanism for the fragmentation of these compounds that occurs during their mass-spectrometric investigation is proposed. 5. A possible metabolic pathway for the oxidation of allopurinol to oxipurinol in the absence of xanthine oxidase is discussed.

Adult↗
PubMed1969

The mass-spectrometirc identification of hypoxanthine and xanthine ('oxypurines') in skeletal musce from two patients with congenital xanthine oxidase deficiency (xanthinuria).

1. The presence of hypoxanthine and xanthine in the skeletal muscle of two patients with congenital xanthine oxidase deficiency (xanthinuria) was demonstrated by high-resolution mass spectrometry. 2. Evidence was obtained for the presence of a trace of hypoxanthine only in normal muscle. 3. Dry pulverized tissue was introduced directly into the mass spectrometer and preliminary chemical processing of the tissue was therefore unnecessary. 4. The criteria for the mass-spectrometric identification of hypoxanthine and xanthine in the tissue and the significance of the observations are discussed.

Adult↗
PubMed1968

Cystinuria.

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Adolescent↗
PubMed1968

Suppression of glycine-15N incorporation into urinary uric acid by adenine-8-13C in normal and gouty subjects.

Adenine inhibited the de novo synthesis of purines in both normal and gouty man as shown by inhibition of the incorporation of glycine-(15)N into urinary uric acid without altering the incorporation of glycine-(15)N into urinary creatinine. The diminished purine synthesis did not result in a diminution in the 24 hr excretion of uric acid. This observation was explainable in part by the prompt conversion of adenine to uric acid. In addition to this direct conversion, adenine-8-(13)C provided a slow and prolonged contribution to urinary uric acid.A feedback inhibition of purine synthesis by nucleotides derived from adenine provides the best interpretation of these results.

Adenine Nucleotides↗