Nicotinamide starvation/ 3-aminobenzamide/Dual effect/Pre-treatment/DNA repair The effects of nicotinamide (NA) deficiency and added NA and 3-aminobenzamide (3AB) on the cytotoxicity and the induction of mutations in Chinese hamster V79-14 cells were investigated. In NA de ficiency the addition of NA (up to 4 mM) and 3AB (up to 7.5 mM) was not cytotoxic. The presence of NA prior to exposure to ...

RESISTANCE to a guanine analogue, 8-azaguanine (AG) in mammalian cell lines has been the subject of a good deal of investigation in recent years. Resistant lines have been isolated, found to be stable in the absence of analogue, and a reverse selective system has been developed ( SZYBALSKI and SZYBALSKA 1962). In established mouse cell lines, several discrete levels of resistance have been desc...

Evidence for assigning the locus determining the structure of adenine phosphoribosyltransferase (APRT) to human chromosome No. 16 is presented. Hybrids of APRT-deficient mouse cells and of human fibroblasts having normal APRT were isolated by fusing the parental cells with Sendai virus, blocking de nouo purine nucleotide synthesis with azaserine and selecting for hybrids that could use exogenou...

Pretreatment of sodium arsenite reduces hypoxanthine-guanine phosphoribosyltransferase mutagenicity and overcomes the inhibition of mi tosis and cell proliferation but has no apparent effect on the cytotoxicity and clastogenicity in methyl methanesulfonate (MMS)-lreaU'd Chinese hamster ovary cells. Posttreatment of sodium arsenite drastically in creases the cytotoxicity, clastogenicity, hypoxan...

Objective-To study the possible association of purine enzyme activities with response to azathioprine (AZA) treatment in rheumatoid arthritis (RA) and their correlation with parameters of disease activity. Patients and methods--Lymphocyte activities of hypoxanthine-guanine phosphoribosyl-transferase (HGPRT), adenine phosphoribosyltransferase (APRT), purine nucleoside phosphorylase (PNP) and 5'-...

The clinical features of gout have been well-recognised since ancient times. Knowledge of its underlying metabolic causes began towards the end of the eighteenth century with the discovery of uric acid in urinary calculi and gouty tophi, and during the nineteenth century Sir Alfred Garrod showed that the blood of gouty subjects contained an excess of uric acid which became deposited in crystall...

Perfluorooctanoate (PFOA) is a fully fluorinated eight-carbon fatty acid analog with exceptional stability toward degradation that has been used as an industrial surfactant and has been detected in environmental and biological matrices. Exposures to PFOA in the workplace and in the environment have continuously stimulated investigations into its potential human health hazards. In this article, ...

how to cite this article: boroujerdi r, shariati m, naddafnia h, rezaei h. small duplication of hprt 1 gene may be causative for lesh- nyhan disease in iranian patients. iran j child neurol. 2015 winter;9(1):103-106. abstract deficiency of hypoxanthine-guanine phosphoribosyltransferase (hgprt) is a rare inborn error of purine metabolism and is characterized by uric acid overproduction along wit...

Complementation of the repair defect in xeroderma pigmentosum cells of complementation group A was achieved by the transfer of human chromosome 9. A set of mouse-human hybrid cell lines, each containing a single Ecogpt-marked human chromosome, was used as a source ofdonor chromosomes. Chromosome transfer to XPTG-1 cells, a hypoxanthine/guanine phosphoribosyltransferase-deficient mutant of simia...