Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P00492 (hypoxanthine-guanine phosphoribosyltransferase)
 2,385 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several vitamins have been demonstrated to interfere with the pathogenesis of some metabolic diseases, mainly by three different mechanisms: 1) vitamin malabsorption, 2) errors in vitamin metabolism, 3) vitamin dependent syndromes. The latter is due to a deficiency of the apoenzyme whose coenzyme is the vitamin itself. In this case pharmacological, instead of nutritional doses of the vitamin may be needed. The vitamins which interfere with inborn metabolic errors are reviewed; for each vitamin the corresponding diseases which may be treated are indicated. The vitamins are: 1) thiamine (leucinosis); b) nicotinic acid (hyperlipoproteinemia); c) biotin (beta-methyl-crotonyl-glycinuria, propionic aciduria); d) pyridoxine (infantile convulsions, familial pyridoxine responsive anemia, homocystinuria, cystathioninuria, xanthurenicaciduria); e) cobalamins (congenital intrinsic factor deficiency, cobalamin malabsorption, transcobalamin deficiency, methylmalonic aciduria) f) folic acid (congenital folic acid malabsorption, formimino-transferase deficiency, methylenetetrahydrofolic reductase deficiency, Lesch-Nyhan syndrome); g) vitamin D (phosphatic diabetes, Prader's type rickets, Albright's syndrome; essential hereditary hypophosphatemia, etc). It is noteworthy that the vitamin therapy of these diseases, not only corrects the metabolic errors, but can also promote the healing or the amelioration of the psycho-physical growth, of central nervous system alterations and of other lesions.
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PMID:[Vitamins in metabolic diseases]. 702 68

The mutagenic activity of the pUC19 bacterial plasmid DNA and the pAins recombinant plasmid DNA carrying human insulin gene has been investigated. Both pUC19 and pAins plasmid DNAs have been shown to induce the gene mutations in hprt locus of Chinese hamster cell line. The high level of the gene mutations (similar to the indices of the gene mutations induced by the chemical mutagens) has been in the focus of attention. The conclusion has been made concerning impossibility to use pAins plasmid DNA in the diabetes mellitus gene therapy. It is necessary to test the mutagenic properties of the DNA molecules produced for gene therapy of human inherited diseases.
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PMID:[The induction of mutations in 6-mercaptopurine resistance in Chinese hamster cells under the action of the recombinant plasmid pAins containing the human insulin gene]. 815 50

T cells with somatically acquired mutations in the hypoxanthine-guanine phosphoribosyltransferase (hprt) gene were isolated from patients with insulin-dependent diabetes mellitus (IDDM) as representatives of populations potentially enriched for in vivo activated T cells. TCRB gene V region usage among mutant isolates from individual IDDM patients, but not from normal controls, showed a pronounced preference for BV14 and, to a lesser extent, BV6. Wild-type (nonmutant) isolates did not show such preferences. Extensive in vivo clonal expansions of the BV14 expressing mutant T cells from IDDM patients were revealed by sequence identity of TCRB chain junctional regions. These data support restricted TCRB gene usage in T cell populations enriched for in vivo activated clones in patients with IDDM.
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PMID:Selection of hprt mutant T cells as surrogates for dividing cells reveals a restricted T cell receptor BV repertoire in insulin-dependent diabetes mellitus. 1007 63

The human population is exposed to both the ultraviolet A (UVA) and B (UVB) regions of the solar spectrum. UVB induces mainly dipyrimidine photoproducts in DNA by a direct photochemical mechanism, whereas UVA is absorbed by other cellular constituents and induces mainly oxidative damage indirectly. The proportions of the different dipyrimidine photoproducts, and the ratio of dipyrimidine to oxidative damage depend on the exact spectral output of a UV source. Irradiation of human epidermal keratinocytes induces release of cytokines, with cyclobutane pyrimidine dimers playing a significant role in the process. These cytokines may then modulate the activity of cells of the immune system. Freshly isolated human lymphocytes are exquisitely sensitive to UVB irradiation, because of their low deoxyribonucleotide pools. They also have a separate defect in removal of cyclobutane pyrimidine dimers from their DNA. We have observed that frequencies of mutations at the hprt locus in human T-lymphocytes and translocations involving the bcl2 locus in B-lymphocytes appear to be associated with sunlight levels over the period before the blood sample was taken. This may be an indirect cytokine-mediated effect, and may be relevant to the possible link between non-Hodgkin's lymphoma and sunlight. On the other hand, sunlight can have beneficial effects, and may protect against autoimmune diseases including type I diabetes and multiple sclerosis.
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PMID:Possible effects of sunlight on human lymphocytes. 1070 50

The aim of the present study is to establish a highly sensitive method for the determination of uric acid (UA) in human saliva. The monitoring of UA levels in less invasive biological samples such as saliva is suggested for the diagnosis and therapy of gout, hyperuricemia, and the Lesch-Nyhan syndrome, and for detecting such conditions as alcohol dependence, obesity, diabetes, high cholesterol, high blood pressure, kidney disease, and heart disease. Reversed-phase high-performance liquid chromatography with electrochemical detection (HPLC-ED) was employed for the determination of UA obtained by solid-phase extraction from saliva. To quantify UA, we compared the ED efficiencies of an amperometric ED (Ampero-ED) with a single electrode and a coulometric ED (Coulo-ED) with a multiple electrode array. The results showed that the detection limits (S/N=3) were 3 nM for Ampero-ED and 6 nM for Coulo-ED, and the linearity of the calibration curves of 60-6000 nM had correlation coefficients exceeding 0.999. In addition, the total analytical time was 10 min. In the sample preparation of UA in saliva, an Oasis MAX solid-phase cartridge was used. The recoveries of UA spiked at 0.6 and 3 microM in saliva were above 95% with a relative standard deviation (RSD) of less than 15%. Therefore, the present method may be used in the routine and diagnostic determination of UA in human saliva.
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PMID:Determination of uric acid in human saliva by high-performance liquid chromatography with amperometric electrochemical detection. 1253 38

The prevalence of urolithiasis has been increasing for the past few decades in industrialized nations. Uric acid calculi account for a significant percentage of urinary stones. Certain risk factors may be involved in the pathogenesis of uric acid nephrolithiasis, including hyperuricosuria, low urinary volume, and persistently low urinary pH. Patients with medical conditions that promote profound hyperuricosuria are at high risk of developing uric acid calculi. These conditions include chronic diarrheal states; myeloproliferative disorders; insulin resistance, including diabetes mellitus; and monogenic metabolic disorders, such as Lesch-Nyhan syndrome. Computed tomography can provide a definitive diagnosis. Except in cases in which there is severe obstruction, progressive azotemia, serious infection, or unremitting pain, the initial treatment of patients with uric acid nephrolithiasis should be medical dissolution therapy because this approach is successful in the majority of cases. A thorough review of the epidemiology and pathophysiology of uric acid nephrolithiasis is crucial for the diagnosis, treatment, and prevention of stones in patients with this condition.
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PMID:Uric Acid nephrolithiasis: recent progress and future directions. 1739 68

Epidemiological data have suggested an increased cancer rates in diabetic patients, for which the underlying mechanism is poorly understood. We studied whether high level of glucose (HG) treatment that mimic the hyperglycemic condition in diabetes mellitus is mutagenic. Mutagenesis studies were carried out at both hypoxanthine phosphoribosyltransferase (hprt) and thymidine kinase (tk) loci. Role of p53 in HG-induced mutagenesis was also investigated by using human lymphoblastoid cell lines derived from same donor but differs in p53 statuses; TK6 has wild-type p53, NH32 has null p53, and WTK1 has mutant p53 (ile237). In addition, we studied the influence of antioxidant treatment on HG-induced mutagenesis. Mutation fractions at both loci increased significantly in all three lines at 21 and 28 days after HG treatments. At tk locus, the increase of a class of mutants with normal growth rate is mainly responsible for the overall increased mutant fraction. Compared to TK6 cells, both NH32 and WTK1 cells showed an early onset of mutagenesis. Treatment of cells with antioxidant N-acetyl-L-cysteine partially reduced HG induced mutagenesis. This study is the first to indicate that HG is able to induce gene mutation which may be one of the important mechanisms of diabetes-associated carcinogenesis.
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PMID:High level glucose increases mutagenesis in human lymphoblastoid cells. 1784 82