BACKGROUND The Lesch-Nyhan syndrome (LNS) is a rare x-linked excessive disorder of purine metabolism, caused by the congenital absence of hypoxanthine guanine phosphoribosyl transferase (HGPRT). CASE REPORT In January 2000 a 2 year old boy was referred to a paediatric dental office in Landshut, Germany, because of severe and repeated lip chewing and aggressive tongue biting. A medical history...

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 de novo purine biosynthetic pathway relies on six enzymes to catalyze the conversion of phosphoribosylpyrophosphate to inosine 5'-monophosphate. Under purine-depleted conditions, these enzymes form a multienzyme complex known as the purinosome. Previous studies have revealed the spatial organization and importance of the purinosome within mammalian cancer cells. In this study, time-lapse fl...

In the process of sequencing the region of Vibrio harveyi DNA containing the luxR gene (1), which encodes an activator of luminescence gene transcription, another large open reading frame was also sequenced. This coding region is 528 base pairs in length, is located immediately upstream from the luxR gene and is transcribed in the opposite direction (fig. 1). The deduced 176 amino acid sequence...

S elf-injurious behavior (SIB) is defined as deliberate harm to one's own body without suicidal intent. It usually occurs as head banging or hitting, body hitting, skin cutting, or finger biting' and includes ocular, genital, and oral self mutilation. SIB can occur with mental retardation, coma, psychotic problems, poisoning, or character disorders. In pediatric patients, SIB usually is related...

B lymphocytes from a patient with systemic lupus erythematosus (SLE) and several circulating autoantibodies (including antinucleolar antibodies) were immortalized by fusion with a hypoxanthine/guanine phosphoribosyl transferase (HGPRT)-deficient human B cell line. Multiple human monoclonal antibodies (mAb) were obtained which, in solid-phase enzyme immunoassay, were reactive with DNA. One mAb w...

The mutagenicity, metabolism, DNA adduction and induction of unscheduled DNA synthesis (UDS) of 1-nitropyrene and 1,8-dinitropyrene were investigated in the human hepatoma cell line HepG2. Previous results had demonstrated that 1-nitropyrene was both mutagenic at the hgprt locus and induced UDS in these cells. In the present study, we find that the dinitropyrenes, although highly mutagenic in S...

Beta-amyloid precursor protein (APP) is a membrane-spanning protein with a large extracellular domain and a much smaller intracellular domain. APP plays a central role in Alzheimer's disease (AD) pathogenesis: APP processing generates β-amyloid (Aβ) peptides, which are deposited as amyloid plaques in the brains of AD individuals; point mutations and duplications of APP are causal for a subset o...

The Lesch-Nyhan syndrome is characterized clinically by choreoathetosis, spasticity, selfmutilation, and mental and growth retardation. Biochemically, there is a striking reduction of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity in affected individuals. We have examined erythrocytes from 14 patients with the Lesch-Nyhan syndrome for the presence of hypoxanthine-guanine phosph...